Commit Graph

6776 Commits

Author SHA1 Message Date
Masami Hiramatsu (Google)
927054606d tracing/kprobes: Simplify __trace_kprobe_create() by removing gotos
Simplify __trace_kprobe_create() by removing gotos.

Link: https://lore.kernel.org/all/173643301102.1514810.6149004416601259466.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10 09:01:14 +09:00
Masami Hiramatsu (Google)
7dcc352078 tracing: Use __free() for kprobe events to cleanup
Use __free() in trace_kprobe.c to cleanup code.

Link: https://lore.kernel.org/all/173643299989.1514810.2924926552980462072.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10 09:01:01 +09:00
Masami Hiramatsu (Google)
4af0532a0f tracing: Use __free() in trace_probe for cleanup
Use __free() in trace_probe to cleanup some gotos.

Link: https://lore.kernel.org/all/173643298860.1514810.7267350121047606213.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10 09:00:13 +09:00
Masami Hiramatsu (Google)
4e83017e4c tracing/eprobe: Adopt guard() and scoped_guard()
Use guard() or scoped_guard() in eprobe events for critical sections
rather than discrete lock/unlock pairs.

Link: https://lore.kernel.org/all/173289890996.73724.17421347964110362029.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-01-10 09:00:12 +09:00
Masami Hiramatsu (Google)
f8821732dc tracing/uprobe: Adopt guard() and scoped_guard()
Use guard() or scoped_guard() in uprobe events for critical sections
rather than discrete lock/unlock pairs.

Link: https://lore.kernel.org/all/173289889911.73724.12457932738419630525.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-01-10 09:00:12 +09:00
Masami Hiramatsu (Google)
2cba0070cd tracing/kprobe: Adopt guard() and scoped_guard()
Use guard() or scoped_guard() in kprobe events for critical sections
rather than discrete lock/unlock pairs.

Link: https://lore.kernel.org/all/173289888883.73724.6586200652276577583.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-01-10 09:00:12 +09:00
Masami Hiramatsu (Google)
30c8fd31c5 tracing/kprobes: Fix to free objects when failed to copy a symbol
In __trace_kprobe_create(), if something fails it must goto error block
to free objects. But when strdup() a symbol, it returns without that.
Fix it to goto the error block to free objects correctly.

Link: https://lore.kernel.org/all/173643297743.1514810.2408159540454241947.stgit@devnote2/

Fixes: 6212dd2968 ("tracing/kprobes: Use dyn_event framework for kprobe events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-10 08:57:18 +09:00
Jiri Olsa
2ebadb60cb bpf: Return error for missed kprobe multi bpf program execution
When kprobe multi bpf program can't be executed due to recursion check,
we currently return 0 (success) to fprobe layer where it's ignored for
standard kprobe multi probes.

For kprobe session the success return value will make fprobe layer to
install return probe and try to execute it as well.

But the return session probe should not get executed, because the entry
part did not run. FWIW the return probe bpf program most likely won't get
executed, because its recursion check will likely fail as well, but we
don't need to run it in the first place.. also we can make this clear
and obvious.

It also affects missed counts for kprobe session program execution, which
are now doubled (extra count for not executed return probe).

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250106175048.1443905-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-01-08 09:39:58 -08:00
Pu Lehui
ca3c4f646a bpf: Move out synchronize_rcu_tasks_trace from mutex CS
Commit ef1b808e3b ("bpf: Fix UAF via mismatching bpf_prog/attachment
RCU flavors") resolved a possible UAF issue in uprobes that attach
non-sleepable bpf prog by explicitly waiting for a tasks-trace-RCU grace
period. But, in the current implementation, synchronize_rcu_tasks_trace
is included within the mutex critical section, which increases the
length of the critical section and may affect performance. So let's move
out synchronize_rcu_tasks_trace from mutex CS.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20250104013946.1111785-1-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-01-08 09:38:41 -08:00
Masami Hiramatsu (Google)
66fc6f521a tracing/hist: Support POLLPRI event for poll on histogram
Since POLLIN will not be flushed until the hist file is read, the user
needs to repeatedly read() and poll() on the hist file for monitoring the
event continuously. But the read() is somewhat redundant when the user is
only monitoring for event updates.

Add POLLPRI poll event on the hist file so the event returns when a
histogram is updated after open(), poll() or read(). Thus it is possible
to wait for the next event without having to issue a read().

Cc: Shuah Khan <shuah@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173527248770.464571.2536902137325258133.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-07 11:46:32 -05:00
Masami Hiramatsu (Google)
1bd13edbbe tracing/hist: Add poll(POLLIN) support on hist file
Add poll syscall support on the `hist` file. The Waiter will be waken
up when the histogram is updated with POLLIN.

Currently, there is no way to wait for a specific event in userspace.
So user needs to peek the `trace` periodicaly, or wait on `trace_pipe`.
But it is not a good idea to peek at the `trace` for an event that
randomly happens. And `trace_pipe` is not coming back until a page is
filled with events.

This allows a user to wait for a specific event on the `hist` file. User
can set a histogram trigger on the event which they want to monitor
and poll() on its `hist` file. Since this poll() returns POLLIN, the next
poll() will return soon unless a read() happens on that hist file.

NOTE: To read the hist file again, you must set the file offset to 0,
but just for monitoring the event, you may not need to read the
histogram.

Cc: Shuah Khan <shuah@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173527247756.464571.14236296701625509931.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-07 11:44:49 -05:00
Steven Rostedt
22bec11a56 tracing: Fix using ret variable in tracing_set_tracer()
When the function tracing_set_tracer() switched over to using the guard()
infrastructure, it did not need to save the 'ret' variable and would just
return the value when an error arised, instead of setting ret and jumping
to an out label.

When CONFIG_TRACER_SNAPSHOT is enabled, it had code that expected the
"ret" variable to be initialized to zero and had set 'ret' while holding
an arch_spin_lock() (not used by guard), and then upon releasing the lock
it would check 'ret' and exit if set. But because ret was only set when an
error occurred while holding the locks, 'ret' would be used uninitialized
if there was no error. The code in the CONFIG_TRACER_SNAPSHOT block should
be self contain. Make sure 'ret' is also set when no error occurred.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250106111143.2f90ff65@gandalf.local.home
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202412271654.nJVBuwmF-lkp@intel.com/
Fixes: d33b10c0c7 ("tracing: Switch trace.c code over to use guard()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-01-07 11:39:46 -05:00
Linus Torvalds
e30dd219c7 Fixes for ftrace in v6.13:
- Add needed READ_ONCE() around access to the fgraph array element
 
   The updates to the fgraph array can happen when callbacks are registered
   and unregistered. The __ftrace_return_to_handler() can handle reading
   either the old value or the new value. But once it reads that value
   it must stay consistent otherwise the check that looks to see if the
   value is a stub may show false, but if the compiler decides to re-read
   after that check, it can be true which can cause the code to crash
   later on.
 
 - Make function profiler use the top level ops for filtering again
 
   When function graph became available for instances, its filter ops became
   independent from the top level set_ftrace_filter. In the process the
   function profiler received its own filter ops as well. But the function
   profiler uses the top level set_ftrace_filter file and does not have one
   of its own. In giving it its own filter ops, it lost any user interface
   it once had. Make it use the top level set_ftrace_filter file again.
   This fixes a regression.
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Merge tag 'ftrace-v6.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace fixes from Steven Rostedt:

 - Add needed READ_ONCE() around access to the fgraph array element

   The updates to the fgraph array can happen when callbacks are
   registered and unregistered. The __ftrace_return_to_handler() can
   handle reading either the old value or the new value. But once it
   reads that value it must stay consistent otherwise the check that
   looks to see if the value is a stub may show false, but if the
   compiler decides to re-read after that check, it can be true which
   can cause the code to crash later on.

 - Make function profiler use the top level ops for filtering again

   When function graph became available for instances, its filter ops
   became independent from the top level set_ftrace_filter. In the
   process the function profiler received its own filter ops as well.
   But the function profiler uses the top level set_ftrace_filter file
   and does not have one of its own. In giving it its own filter ops, it
   lost any user interface it once had. Make it use the top level
   set_ftrace_filter file again. This fixes a regression.

* tag 'ftrace-v6.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Fix function profiler's filtering functionality
  fgraph: Add READ_ONCE() when accessing fgraph_array[]
2025-01-03 10:04:43 -08:00
Kohei Enju
789a8cff8d ftrace: Fix function profiler's filtering functionality
Commit c132be2c4f ("function_graph: Have the instances use their own
ftrace_ops for filtering"), function profiler (enabled via
function_profile_enabled) has been showing statistics for all functions,
ignoring set_ftrace_filter settings.

While tracers are instantiated, the function profiler is not. Therefore, it
should use the global set_ftrace_filter for consistency.  This patch
modifies the function profiler to use the global filter, fixing the
filtering functionality.

Before (filtering not working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
  Function                               Hit    Time            Avg
     s^2
  --------                               ---    ----            ---
     ---
  schedule                               314    22290594 us     70989.15 us
     40372231 us
  x64_sys_call                          1527    8762510 us      5738.382 us
     3414354 us
  schedule_hrtimeout_range               176    8665356 us      49234.98 us
     405618876 us
  __x64_sys_ppoll                        324    5656635 us      17458.75 us
     19203976 us
  do_sys_poll                            324    5653747 us      17449.83 us
     19214945 us
  schedule_timeout                        67    5531396 us      82558.15 us
     2136740827 us
  __x64_sys_pselect6                      12    3029540 us      252461.7 us
     63296940171 us
  do_pselect.constprop.0                  12    3029532 us      252461.0 us
     63296952931 us
```

After (filtering working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
  Function                               Hit    Time            Avg
     s^2
  --------                               ---    ----            ---
     ---
  vfs_write                              462    68476.43 us     148.217 us
     25874.48 us
  vfs_read                               641    9611.356 us     14.994 us
     28868.07 us
  vfs_fstat                              890    878.094 us      0.986 us
     1.667 us
  vfs_fstatat                            227    757.176 us      3.335 us
     18.928 us
  vfs_statx                              226    610.610 us      2.701 us
     17.749 us
  vfs_getattr_nosec                     1187    460.919 us      0.388 us
     0.326 us
  vfs_statx_path                         297    343.287 us      1.155 us
     11.116 us
  vfs_rename                               6    291.575 us      48.595 us
     9889.236 us
```

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250101190820.72534-1-enjuk@amazon.com
Fixes: c132be2c4f ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-02 17:21:33 -05:00
Zilin Guan
d654740337 fgraph: Add READ_ONCE() when accessing fgraph_array[]
In __ftrace_return_to_handler(), a loop iterates over the fgraph_array[]
elements, which are fgraph_ops. The loop checks if an element is a
fgraph_stub to prevent using a fgraph_stub afterward.

However, if the compiler reloads fgraph_array[] after this check, it might
race with an update to fgraph_array[] that introduces a fgraph_stub. This
could result in the stub being processed, but the stub contains a null
"func_hash" field, leading to a NULL pointer dereference.

To ensure that the gops compared against the fgraph_stub matches the gops
processed later, add a READ_ONCE(). A similar patch appears in commit
63a8dfb ("function_graph: Add READ_ONCE() when accessing fgraph_array[]").

Cc: stable@vger.kernel.org
Fixes: 37238abe3c ("ftrace/function_graph: Pass fgraph_ops to function graph callbacks")
Link: https://lore.kernel.org/20241231113731.277668-1-zilin@seu.edu.cn
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-01-02 17:21:18 -05:00
Steven Rostedt
afc6717628 tracing: Have process_string() also allow arrays
In order to catch a common bug where a TRACE_EVENT() TP_fast_assign()
assigns an address of an allocated string to the ring buffer and then
references it in TP_printk(), which can be executed hours later when the
string is free, the function test_event_printk() runs on all events as
they are registered to make sure there's no unwanted dereferencing.

It calls process_string() to handle cases in TP_printk() format that has
"%s". It returns whether or not the string is safe. But it can have some
false positives.

For instance, xe_bo_move() has:

 TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s",
            __entry->move_lacks_source ? "yes" : "no", __entry->bo, __entry->size,
            xe_mem_type_to_name[__entry->old_placement],
            xe_mem_type_to_name[__entry->new_placement], __get_str(device_id))

Where the "%s" references into xe_mem_type_to_name[]. This is an array of
pointers that should be safe for the event to access. Instead of flagging
this as a bad reference, if a reference points to an array, where the
record field is the index, consider it safe.

Link: https://lore.kernel.org/all/9dee19b6185d325d0e6fa5f7cbba81d007d99166.camel@sapience.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241231000646.324fb5f7@gandalf.local.home
Fixes: 65a25d9f7a ("tracing: Add "%s" check in test_event_printk()")
Reported-by: Genes Lists <lists@sapience.com>
Tested-by: Gene C <arch@sapience.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-31 00:10:32 -05:00
Gabriele Monaco
de6f45c2dd verification/dot2k: Auto patch current kernel source
dot2k suggests a list of changes to the kernel tree while adding a
monitor: edit tracepoints header, Makefile, Kconfig and moving the
monitor folder. Those changes can be easily run automatically.

Add a flag to dot2k to alter the kernel source.

The kernel source directory can be either assumed from the PWD, or from
the running kernel, if installed.
This feature works best if the kernel tree is a git repository, so that
its easier to make sure there are no unintended changes.

The main RV files (e.g. Makefile) have now a comment placeholder that
can be useful for manual editing (e.g. to know where to add new
monitors) and it is used by the script to append the required lines.

We also slightly adapt the file handling functions in dot2k: __open_file
is now called __read_file and also closes the file before returning the
content; __create_file is now a more general __write_file, we no longer
return on FileExistsError (not thrown while opening), a new
__create_file simply calls __write_file specifying the monitor folder in
the path.

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20241227144752.362911-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-27 14:39:35 -05:00
Gabriele Monaco
bc3d482dcc rv: Simplify manual steps in monitor creation
While creating a new monitor in RV, besides generating code from dot2k,
there are a few manual steps which can be tedious and error prone, like
adding the tracepoints, makefile lines and kconfig.

This patch restructures the existing monitors to keep some files in the
monitor's folder itself, which can be automatically generated by future
versions of dot2k.

Monitors have now their own Kconfig and tracepoint snippets. For
simplicity, the main tracepoint definition, is moved to the RV
directory, it defines only the tracepoint classes and includes the
monitor-specific tracepoints, which reside in the monitor directory.

Tracepoints and Kconfig no longer need to be copied and adapted from
existing ones but only need to be included in the main files.
The Makefile remains untouched since there's little advantage in having
a separated Makefile for each monitor with a single line and including
it in the main RV Makefile.

Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20241227144752.362911-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-27 14:20:03 -05:00
Linus Torvalds
411a678d30 Probes fixes for v6.13-rc4:
- tracing/kprobes: Change the priority of the module callback of kprobe
   events so that it is called after the jump label list on the module is
   updated. This ensures the kprobe can check whether it is not on the
   jump label address correctly.
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Merge tag 'probes-fixes-v6.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:
 "Change the priority of the module callback of kprobe events so that it
  is called after the jump label list on the module is updated.

  This ensures the kprobe can check whether it is not on the jump label
  address correctly"

* tag 'probes-fixes-v6.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/kprobe: Make trace_kprobe's module callback called after jump_label update
2024-12-27 11:03:15 -08:00
Masami Hiramatsu (Google)
a2224559cb tracing/fprobe: Remove nr_maxactive from fprobe
Remove depercated fprobe::nr_maxactive. This involves fprobe events to
rejects the maxactive number.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173519007257.391279.946804046982289337.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:05 -05:00
Masami Hiramatsu (Google)
b5fa903b7f fprobe: Add fprobe_header encoding feature
Fprobe store its data structure address and size on the fgraph return stack
by __fprobe_header. But most 64bit architecture can combine those to
one unsigned long value because 4 MSB in the kernel address are the same.
With this encoding, fprobe can consume less space on ret_stack.

This introduces asm/fprobe.h to define arch dependent encode/decode
macros. Note that since fprobe depends on CONFIG_HAVE_FUNCTION_GRAPH_FREGS,
currently only arm64, loongarch, riscv, s390 and x86 are supported.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173519005783.391279.5307910947400277525.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:05 -05:00
Masami Hiramatsu (Google)
4346ba1604 fprobe: Rewrite fprobe on function-graph tracer
Rewrite fprobe implementation on function-graph tracer.
Major API changes are:
 -  'nr_maxactive' field is deprecated.
 -  This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or
    !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and
    CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So currently works only
    on x86_64.
 -  Currently the entry size is limited in 15 * sizeof(long).
 -  If there is too many fprobe exit handler set on the same
    function, it will fail to probe.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/173519003970.391279.14406792285453830996.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:05 -05:00
Masami Hiramatsu (Google)
a762e9267d ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
Add CONFIG_HAVE_FTRACE_GRAPH_FUNC kconfig in addition to ftrace_graph_func
macro check. This is for the other feature (e.g. FPROBE) which requires to
access ftrace_regs from fgraph_ops::entryfunc() can avoid compiling if
the fgraph can not pass the valid ftrace_regs.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173519001472.391279.1174901685282588467.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:04 -05:00
Masami Hiramatsu (Google)
8e2759da93 bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
Enable kprobe_multi feature if CONFIG_FPROBE is enabled. The pt_regs is
converted from ftrace_regs by ftrace_partial_regs(), thus some registers
may always returns 0. But it should be enough for function entry (access
arguments) and exit (access return value).

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173519000417.391279.14011193569589886419.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Florent Revest <revest@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:04 -05:00
Masami Hiramatsu (Google)
0566cefe73 tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
Allow fprobe events to be enabled with CONFIG_DYNAMIC_FTRACE_WITH_ARGS.
With this change, fprobe events mostly use ftrace_regs instead of pt_regs.
Note that if the arch doesn't enable HAVE_FTRACE_REGS_HAVING_PT_REGS,
fprobe events will not be able to be used from perf.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173518999352.391279.13332699755290175168.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:04 -05:00
Masami Hiramatsu (Google)
762abbc0d0 fprobe: Use ftrace_regs in fprobe exit handler
Change the fprobe exit handler to use ftrace_regs structure instead of
pt_regs. This also introduce HAVE_FTRACE_REGS_HAVING_PT_REGS which
means the ftrace_regs is including the pt_regs so that ftrace_regs
can provide pt_regs without memory allocation.
Fprobe introduces a new dependency with that.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Song Liu <song@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Matt Bobrowski <mattbobrowski@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Hao Luo <haoluo@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/173518995092.391279.6765116450352977627.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:03 -05:00
Masami Hiramatsu (Google)
46bc082388 fprobe: Use ftrace_regs in fprobe entry handler
This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe
on arm64.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173518994037.391279.2786805566359674586.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Florent Revest <revest@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:03 -05:00
Masami Hiramatsu (Google)
2ca8c112c9 fgraph: Pass ftrace_regs to retfunc
Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173518992972.391279.14055405490327765506.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:03 -05:00
Masami Hiramatsu (Google)
a3ed4157b7 fgraph: Replace fgraph_ret_regs with ftrace_regs
Use ftrace_regs instead of fgraph_ret_regs for tracing return value
on function_graph tracer because of simplifying the callback interface.

The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by
CONFIG_HAVE_FUNCTION_GRAPH_FREGS.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:02 -05:00
Masami Hiramatsu (Google)
41705c4262 fgraph: Pass ftrace_regs to entryfunc
Pass ftrace_regs to the fgraph_ops::entryfunc(). If ftrace_regs is not
available, it passes a NULL instead. User callback function can access
some registers (including return address) via this ftrace_regs.

Note that the ftrace_regs can be NULL when the arch does NOT define:
HAVE_DYNAMIC_FTRACE_WITH_ARGS or HAVE_DYNAMIC_FTRACE_WITH_REGS.
More specifically, if HAVE_DYNAMIC_FTRACE_WITH_REGS is defined but
not the HAVE_DYNAMIC_FTRACE_WITH_ARGS, and the ftrace ops used to
register the function callback does not set FTRACE_OPS_FL_SAVE_REGS.
In this case, ftrace_regs can be NULL in user callback.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173518990044.391279.17406984900626078579.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:50:02 -05:00
Steven Rostedt
9e49ca756d tracing/string: Create and use __free(argv_free) in trace_dynevent.c
The function dyn_event_release() uses argv_split() which must be freed via
argv_free(). It contains several error paths that do a goto out to call
argv_free() for cleanup. This makes the code complex and error prone.

Create a new __free() directive __free(argv_free) that will call
argv_free() for data allocated with argv_split(), and use it in the
dyn_event_release() function.

Cc: Kees Cook <kees@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/20241220103313.4a74ec8e@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
08b7673171 tracing: Switch trace_stat.c code over to use guard()
There are a couple functions in trace_stat.c that have "goto out" or
equivalent on error in order to release locks that were taken. This can be
error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201346.870318466@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
6c05353e4f tracing: Switch trace_stack.c code over to use guard()
The function stack_trace_sysctl() uses a goto on the error path to jump to
the mutex_unlock() code. Replace the logic to use guard() and let the
compiler worry about it.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241225222931.684913592@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
930d2b32c0 tracing: Switch trace_osnoise.c code over to use guard() and __free()
The osnoise_hotplug_workfn() grabs two mutexes and cpu_read_lock(). It has
various gotos to handle unlocking them. Switch them over to guard() and
let the compiler worry about it.

The osnoise_cpus_read() has a temporary mask_str allocated and there's
some gotos to make sure it gets freed on error paths. Switch that over to
__free() to let the compiler worry about it.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241225222931.517329690@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
a2e27e1bb1 tracing: Switch trace_events_synth.c code over to use guard()
There are a couple functions in trace_events_synth.c that have "goto out"
or equivalent on error in order to release locks that were taken. This can
be error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201346.371082515@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
076796f74e tracing: Switch trace_events_filter.c code over to use guard()
There are a couple functions in trace_events_filter.c that have "goto out"
or equivalent on error in order to release locks that were taken. This can
be error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201346.200737679@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
63c7264168 tracing: Switch trace_events_trigger.c code over to use guard()
There are a few functions in trace_events_trigger.c that have "goto out" or
equivalent on error in order to release locks that were taken. This can be
error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Also use __free() for free a temporary buffer in event_trigger_regex_write().

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241220110621.639d3bc8@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
2b36a97aee tracing: Switch trace_events_hist.c code over to use guard()
There are a couple functions in trace_events_hist.c that have "goto out" or
equivalent on error in order to release locks that were taken. This can be
error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201345.694601480@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:37 -05:00
Steven Rostedt
59980d9b0b tracing: Switch trace_events.c code over to use guard()
There are several functions in trace_events.c that have "goto out;" or
equivalent on error in order to release locks that were taken. This can be
error prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Some locations did some simple arithmetic after releasing the lock. As
this causes no real overhead for holding a mutex while processing the file
position (*ppos += cnt;) let the lock be held over this logic too.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201345.522546095@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:36 -05:00
Steven Rostedt
4b8d63e5b6 tracing: Simplify event_enable_func() goto_reg logic
Currently there's an "out_reg:" label that gets jumped to if there's no
parameters to process. Instead, make it a proper "if (param) { }" block as
there's not much to do for the parameter processing, and remove the
"out_reg:" label.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201345.354746196@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:36 -05:00
Steven Rostedt
c949dfb974 tracing: Simplify event_enable_func() goto out_free logic
The event_enable_func() function allocates the data descriptor early in
the function just to assign its data->count value via:

  kstrtoul(number, 0, &data->count);

This makes the code more complex as there are several error paths before
the data descriptor is actually used. This means there needs to be a
goto out_free; to clean it up.

Use a local variable "count" to do the update and move the data allocation
just before it is used. This removes the "out_free" label as the data can
be freed on the failure path of where it is used.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201345.190820140@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:36 -05:00
Steven Rostedt
cad1d5bd2c tracing: Have event_enable_write() just return error on error
The event_enable_write() function is inconsistent in how it returns
errors. Sometimes it updates the ppos parameter and sometimes it doesn't.
Simplify the code to just return an error or the count if there isn't an
error.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201345.025284170@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:36 -05:00
Steven Rostedt
d1e27ee9c6 tracing: Return -EINVAL if a boot tracer tries to enable the mmiotracer at boot
The mmiotracer is not set to be enabled at boot up from the kernel command
line. If the boot command line tries to enable that tracer, it will fail
to be enabled. The return code is currently zero when that happens so the
caller just thinks it was enabled. Return -EINVAL in this case.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241219201344.854254394@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:36 -05:00
Steven Rostedt
d33b10c0c7 tracing: Switch trace.c code over to use guard()
There are several functions in trace.c that have "goto out;" or
equivalent on error in order to release locks or free values that were
allocated. This can be error prone or just simply make the code more
complex.

Switch every location that ends with unlocking a mutex or freeing on error
over to using the guard(mutex)() and __free() infrastructure to let the
compiler worry about releasing locks. This makes the code easier to read
and understand.

There's one place that should probably return an error but instead return
0. This does not change the return as the only changes are to do the
conversion without changing the logic. Fixing that location will have to
come later.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/20241224221413.7b8c68c3@batman.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-26 10:38:17 -05:00
Lizhi Xu
98feccbf32 tracing: Prevent bad count for tracing_cpumask_write
If a large count is provided, it will trigger a warning in bitmap_parse_user.
Also check zero for it.

Cc: stable@vger.kernel.org
Fixes: 9e01c1b74c ("cpumask: convert kernel trace functions")
Link: https://lore.kernel.org/20241216073238.2573704-1-lizhi.xu@windriver.com
Reported-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0aecfd34fb878546f3fd
Tested-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 21:59:15 -05:00
Masami Hiramatsu (Google)
d576aec24d fgraph: Get ftrace recursion lock in function_graph_enter
Get the ftrace recursion lock in the generic function_graph_enter()
instead of each architecture code.
This changes all function_graph tracer callbacks running in
non-preemptive state. On x86 and powerpc, this is by default, but
on the other architecutres, this will be new.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173379653720.973433.18438622234884980494.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 21:02:48 -05:00
Steven Rostedt
1d95fd9d6b ftrace: Switch ftrace.c code over to use guard()
There are a few functions in ftrace.c that have "goto out" or equivalent
on error in order to release locks that were taken. This can be error
prone or just simply make the code more complex.

Switch every location that ends with unlocking a mutex on error over to
using the guard(mutex)() infrastructure to let the compiler worry about
releasing locks. This makes the code easier to read and understand.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.718001540@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 21:01:48 -05:00
Steven Rostedt
77e53cb2fc ftrace: Remove unneeded goto jumps
There are some goto jumps to exit a program to just return a value. The
code after the label doesn't free anything nor does it do any unlocks. It
simply returns the variable that was set before the jump.

Remove these unneeded goto jumps.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.544855549@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 21:01:48 -05:00
Steven Rostedt
ac8c3b02fc ftrace: Do not disable interrupts in profiler
The function profiler disables interrupts before processing. This was
there since the profiler was introduced back in 2009 when there were
recursion issues to deal with. The function tracer is much more robust
today and has its own internal recursion protection. There's no reason to
disable interrupts in the function profiler.

Instead, just disable preemption and use the guard() infrastructure while
at it.

Before this change:

~# echo 1 > /sys/kernel/tracing/function_profile_enabled
~# perf stat -r 10 ./hackbench 10
Time: 3.099
Time: 2.556
Time: 2.500
Time: 2.705
Time: 2.985
Time: 2.959
Time: 2.859
Time: 2.621
Time: 2.742
Time: 2.631

 Performance counter stats for '/work/c/hackbench 10' (10 runs):

         23,156.77 msec task-clock                       #    6.951 CPUs utilized               ( +-  2.36% )
            18,306      context-switches                 #  790.525 /sec                        ( +-  5.95% )
               495      cpu-migrations                   #   21.376 /sec                        ( +-  8.61% )
            11,522      page-faults                      #  497.565 /sec                        ( +-  1.80% )
    47,967,124,606      cycles                           #    2.071 GHz                         ( +-  0.41% )
    80,009,078,371      instructions                     #    1.67  insn per cycle              ( +-  0.34% )
    16,389,249,798      branches                         #  707.752 M/sec                       ( +-  0.36% )
       139,943,109      branch-misses                    #    0.85% of all branches             ( +-  0.61% )

             3.332 +- 0.101 seconds time elapsed  ( +-  3.04% )

After this change:

~# echo 1 > /sys/kernel/tracing/function_profile_enabled
~# perf stat -r 10 ./hackbench 10
Time: 1.869
Time: 1.428
Time: 1.575
Time: 1.569
Time: 1.685
Time: 1.511
Time: 1.611
Time: 1.672
Time: 1.724
Time: 1.715

 Performance counter stats for '/work/c/hackbench 10' (10 runs):

         13,578.21 msec task-clock                       #    6.931 CPUs utilized               ( +-  2.23% )
            12,736      context-switches                 #  937.973 /sec                        ( +-  3.86% )
               341      cpu-migrations                   #   25.114 /sec                        ( +-  5.27% )
            11,378      page-faults                      #  837.960 /sec                        ( +-  1.74% )
    27,638,039,036      cycles                           #    2.035 GHz                         ( +-  0.27% )
    45,107,762,498      instructions                     #    1.63  insn per cycle              ( +-  0.23% )
     8,623,868,018      branches                         #  635.125 M/sec                       ( +-  0.27% )
       125,738,443      branch-misses                    #    1.46% of all branches             ( +-  0.32% )

            1.9590 +- 0.0484 seconds time elapsed  ( +-  2.47% )

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.373853944@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 20:44:29 -05:00
Steven Rostedt
7d137e604a fgraph: Remove unnecessary disabling of interrupts and recursion
The function graph tracer disables interrupts as well as prevents
recursion via NMIs when recording the graph tracer code. There's no reason
to do this today. That disabling goes back to 2008 when the function graph
tracer was first introduced and recursion protection wasn't part of the
code.

Today, there's no reason to disable interrupts or prevent the code from
recursing as the infrastructure can easily handle it.

Before this change:

~# echo function_graph > /sys/kernel/tracing/current_tracer
~# perf stat -r 10 ./hackbench 10
Time: 4.240
Time: 4.236
Time: 4.106
Time: 4.014
Time: 4.314
Time: 3.830
Time: 4.063
Time: 4.323
Time: 3.763
Time: 3.727

 Performance counter stats for '/work/c/hackbench 10' (10 runs):

         33,937.20 msec task-clock                       #    7.008 CPUs utilized               ( +-  1.85% )
            18,220      context-switches                 #  536.874 /sec                        ( +-  6.41% )
               624      cpu-migrations                   #   18.387 /sec                        ( +-  9.07% )
            11,319      page-faults                      #  333.528 /sec                        ( +-  1.97% )
    76,657,643,617      cycles                           #    2.259 GHz                         ( +-  0.40% )
   141,403,302,768      instructions                     #    1.84  insn per cycle              ( +-  0.37% )
    25,518,463,888      branches                         #  751.932 M/sec                       ( +-  0.35% )
       156,151,050      branch-misses                    #    0.61% of all branches             ( +-  0.63% )

            4.8423 +- 0.0892 seconds time elapsed  ( +-  1.84% )

After this change:

~# echo function_graph > /sys/kernel/tracing/current_tracer
~# perf stat -r 10 ./hackbench 10
Time: 3.340
Time: 3.192
Time: 3.129
Time: 2.579
Time: 2.589
Time: 2.798
Time: 2.791
Time: 2.955
Time: 3.044
Time: 3.065

 Performance counter stats for './hackbench 10' (10 runs):

         24,416.30 msec task-clock                       #    6.996 CPUs utilized               ( +-  2.74% )
            16,764      context-switches                 #  686.590 /sec                        ( +-  5.85% )
               469      cpu-migrations                   #   19.208 /sec                        ( +-  6.14% )
            11,519      page-faults                      #  471.775 /sec                        ( +-  1.92% )
    53,895,628,450      cycles                           #    2.207 GHz                         ( +-  0.52% )
   105,552,664,638      instructions                     #    1.96  insn per cycle              ( +-  0.47% )
    17,808,672,667      branches                         #  729.376 M/sec                       ( +-  0.48% )
       133,075,435      branch-misses                    #    0.75% of all branches             ( +-  0.59% )

             3.490 +- 0.112 seconds time elapsed  ( +-  3.22% )

Also removed unneeded "unlikely()" around the retaddr code.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20241223184941.204074053@goodmis.org
Fixes: 9cd2992f2d ("fgraph: Have set_graph_notrace only affect function_graph tracer") # Performance only
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-23 20:43:55 -05:00
Colin Ian King
ccb9868ab7 blktrace: remove redundant return at end of function
A recent change added return 0 before an existing return statement
at the end of function blk_trace_setup. The final return is now
redundant, so remove it.

Fixes: 64d124798244 ("blktrace: move copy_[to|from]_user() out of ->debugfs_lock")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20241204150450.399005-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23 08:17:23 -07:00
Ming Lei
b769a2f409 blktrace: move copy_[to|from]_user() out of ->debugfs_lock
Move copy_[to|from]_user() out of ->debugfs_lock and cut the dependency
between mm->mmap_lock and q->debugfs_lock, then we avoids lots of
lockdep false positive warning. Obviously ->debug_lock isn't needed
for copy_[to|from]_user().

The only behavior change is to call blk_trace_remove() in case of setup
failure handling by re-grabbing ->debugfs_lock, and this way is just
fine since we do cover concurrent setup() & remove().

Reported-by: syzbot+91585b36b538053343e4@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-block/67450fd4.050a0220.1286eb.0007.GAE@google.com/
Closes: https://lore.kernel.org/linux-block/6742e584.050a0220.1cc393.0038.GAE@google.com/
Closes: https://lore.kernel.org/linux-block/6742a600.050a0220.1cc393.002e.GAE@google.com/
Closes: https://lore.kernel.org/linux-block/67420102.050a0220.1cc393.0019.GAE@google.com/
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241128125029.4152292-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23 08:17:22 -07:00
Ming Lei
fd9b0244f5 blktrace: don't centralize grabbing q->debugfs_mutex in blk_trace_ioctl
Call each handler directly and the handler do grab q->debugfs_mutex,
prepare for killing dependency between ->debug_mutex and ->mmap_lock.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241128125029.4152292-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23 08:17:22 -07:00
Masami Hiramatsu (Google)
d685d55dfc tracing/kprobe: Make trace_kprobe's module callback called after jump_label update
Make sure the trace_kprobe's module notifer callback function is called
after jump_label's callback is called. Since the trace_kprobe's callback
eventually checks jump_label address during registering new kprobe on
the loading module, jump_label must be updated before this registration
happens.

Link: https://lore.kernel.org/all/173387585556.995044.3157941002975446119.stgit@devnote2/

Fixes: 6142431810 ("tracing/kprobes: Support module init function probing")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-12-24 00:08:13 +09:00
Linus Torvalds
5b83bcdea5 ring-buffer fixes for v6.13:
- Fix possible overflow of mmapped ring buffer with bad offset
 
   If the mmap() to the ring buffer passes in a start address that
   is passed the end of the mmapped file, it is not caught and
   a slab-out-of-bounds is triggered.
 
   Add a check to make sure the start address is within the bounds
 
 - Do not use TP_printk() to boot mapped ring buffers
 
   As a boot mapped ring buffer's data may have pointers that map to
   the previous boot's memory map, it is unsafe to allow the TP_printk()
   to be used to read the boot mapped buffer's events. If a TP_printk()
   points to a static string from within the kernel it will not match
   the current kernel mapping if KASLR is active, and it can fault.
 
   Have it simply print out the raw fields.
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Merge tag 'trace-ringbuffer-v6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer fixes from Steven Rostedt:

 - Fix possible overflow of mmapped ring buffer with bad offset

   If the mmap() to the ring buffer passes in a start address that is
   passed the end of the mmapped file, it is not caught and a
   slab-out-of-bounds is triggered.

   Add a check to make sure the start address is within the bounds

 - Do not use TP_printk() to boot mapped ring buffers

   As a boot mapped ring buffer's data may have pointers that map to the
   previous boot's memory map, it is unsafe to allow the TP_printk() to
   be used to read the boot mapped buffer's events. If a TP_printk()
   points to a static string from within the kernel it will not match
   the current kernel mapping if KASLR is active, and it can fault.

   Have it simply print out the raw fields.

* tag 'trace-ringbuffer-v6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/ring-buffer: Do not use TP_printk() formatting for boot mapped buffers
  ring-buffer: Fix overflow in __rb_map_vma
2024-12-20 10:13:26 -08:00
Steven Rostedt
8cd63406d0 trace/ring-buffer: Do not use TP_printk() formatting for boot mapped buffers
The TP_printk() of a TRACE_EVENT() is a generic printf format that any
developer can create for their event. It may include pointers to strings
and such. A boot mapped buffer may contain data from a previous kernel
where the strings addresses are different.

One solution is to copy the event content and update the pointers by the
recorded delta, but a simpler solution (for now) is to just use the
print_fields() function to print these events. The print_fields() function
just iterates the fields and prints them according to what type they are,
and ignores the TP_printk() format from the event itself.

To understand the difference, when printing via TP_printk() the output
looks like this:

  4582.696626: kmem_cache_alloc: call_site=getname_flags+0x47/0x1f0 ptr=00000000e70e10e0 bytes_req=4096 bytes_alloc=4096 gfp_flags=GFP_KERNEL node=-1 accounted=false
  4582.696629: kmem_cache_alloc: call_site=alloc_empty_file+0x6b/0x110 ptr=0000000095808002 bytes_req=360 bytes_alloc=384 gfp_flags=GFP_KERNEL node=-1 accounted=false
  4582.696630: kmem_cache_alloc: call_site=security_file_alloc+0x24/0x100 ptr=00000000576339c3 bytes_req=16 bytes_alloc=16 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1 accounted=false
  4582.696653: kmem_cache_free: call_site=do_sys_openat2+0xa7/0xd0 ptr=00000000e70e10e0 name=names_cache

But when printing via print_fields() (echo 1 > /sys/kernel/tracing/options/fields)
the same event output looks like this:

  4582.696626: kmem_cache_alloc: call_site=0xffffffff92d10d97 (-1831793257) ptr=0xffff9e0e8571e000 (-107689771147264) bytes_req=0x1000 (4096) bytes_alloc=0x1000 (4096) gfp_flags=0xcc0 (3264) node=0xffffffff (-1) accounted=(0)
  4582.696629: kmem_cache_alloc: call_site=0xffffffff92d0250b (-1831852789) ptr=0xffff9e0e8577f800 (-107689770747904) bytes_req=0x168 (360) bytes_alloc=0x180 (384) gfp_flags=0xcc0 (3264) node=0xffffffff (-1) accounted=(0)
  4582.696630: kmem_cache_alloc: call_site=0xffffffff92efca74 (-1829778828) ptr=0xffff9e0e8d35d3b0 (-107689640864848) bytes_req=0x10 (16) bytes_alloc=0x10 (16) gfp_flags=0xdc0 (3520) node=0xffffffff (-1) accounted=(0)
  4582.696653: kmem_cache_free: call_site=0xffffffff92cfbea7 (-1831879001) ptr=0xffff9e0e8571e000 (-107689771147264) name=names_cache

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241218141507.28389a1d@gandalf.local.home
Fixes: 07714b4bb3 ("tracing: Handle old buffer mappings for event strings and functions")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-18 14:20:38 -05:00
Edward Adam Davis
c58a812c8e ring-buffer: Fix overflow in __rb_map_vma
An overflow occurred when performing the following calculation:

   nr_pages = ((nr_subbufs + 1) << subbuf_order) - pgoff;

Add a check before the calculation to avoid this problem.

syzbot reported this as a slab-out-of-bounds in __rb_map_vma:

BUG: KASAN: slab-out-of-bounds in __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058
Read of size 8 at addr ffff8880767dd2b8 by task syz-executor187/5836

CPU: 0 UID: 0 PID: 5836 Comm: syz-executor187 Not tainted 6.13.0-rc2-syzkaller-00159-gf932fb9b4074 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058
 ring_buffer_map+0x56e/0x9b0 kernel/trace/ring_buffer.c:7138
 tracing_buffers_mmap+0xa6/0x120 kernel/trace/trace.c:8482
 call_mmap include/linux/fs.h:2183 [inline]
 mmap_file mm/internal.h:124 [inline]
 __mmap_new_file_vma mm/vma.c:2291 [inline]
 __mmap_new_vma mm/vma.c:2355 [inline]
 __mmap_region+0x1786/0x2670 mm/vma.c:2456
 mmap_region+0x127/0x320 mm/mmap.c:1348
 do_mmap+0xc00/0xfc0 mm/mmap.c:496
 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580
 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The reproducer for this bug is:

------------------------8<-------------------------
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <asm/types.h>
 #include <sys/mman.h>

 int main(int argc, char **argv)
 {
	int page_size = getpagesize();
	int fd;
	void *meta;

	system("echo 1 > /sys/kernel/tracing/buffer_size_kb");
	fd = open("/sys/kernel/tracing/per_cpu/cpu0/trace_pipe_raw", O_RDONLY);

	meta = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, page_size * 5);
 }
------------------------>8-------------------------

Cc: stable@vger.kernel.org
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions")
Link: https://lore.kernel.org/tencent_06924B6674ED771167C23CC336C097223609@qq.com
Reported-by: syzbot+345e4443a21200874b18@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=345e4443a21200874b18
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-18 14:15:10 -05:00
Linus Torvalds
c061cf420d tracing fixes for v6.13:
- Replace trace_check_vprintf() with test_event_printk() and ignore_event()
 
   The function test_event_printk() checks on boot up if the trace event
   printf() formats dereference any pointers, and if they do, it then looks
   at the arguments to make sure that the pointers they dereference will
   exist in the event on the ring buffer. If they do not, it issues a
   WARN_ON() as it is a likely bug.
 
   But this isn't the case for the strings that can be dereferenced with
   "%s", as some trace events (notably RCU and some IPI events) save
   a pointer to a static string in the ring buffer. As the string it
   points to lives as long as the kernel is running, it is not a bug
   to reference it, as it is guaranteed to be there when the event is read.
   But it is also possible (and a common bug) to point to some allocated
   string that could be freed before the trace event is read and the
   dereference is to bad memory. This case requires a run time check.
 
   The previous way to handle this was with trace_check_vprintf() that would
   process the printf format piece by piece and send what it didn't care
   about to vsnprintf() to handle arguments that were not strings. This
   kept it from having to reimplement vsnprintf(). But it relied on va_list
   implementation and for architectures that copied the va_list and did
   not pass it by reference, it wasn't even possible to do this check and
   it would be skipped. As 64bit x86 passed va_list by reference, most
   events were tested and this kept out bugs where strings would have been
   dereferenced after being freed.
 
   Instead of relying on the implementation of va_list, extend the boot up
   test_event_printk() function to validate all the "%s" strings that
   can be validated at boot, and for the few events that point to strings
   outside the ring buffer, flag both the event and the field that is
   dereferenced as "needs_test". Then before the event is printed, a call
   to ignore_event() is made, and if the event has the flag set, it iterates
   all its fields and for every field that is to be tested, it will read
   the pointer directly from the event in the ring buffer and make sure
   that it is valid. If the pointer is not valid, it will print a WARN_ON(),
   print out to the trace that the event has unsafe memory and ignore
   the print format.
 
   With this new update, the trace_check_vprintf() can be safely removed
   and now all events can be verified regardless of architecture.
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Merge tag 'trace-v6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Replace trace_check_vprintf() with test_event_printk() and
  ignore_event()

  The function test_event_printk() checks on boot up if the trace event
  printf() formats dereference any pointers, and if they do, it then
  looks at the arguments to make sure that the pointers they dereference
  will exist in the event on the ring buffer. If they do not, it issues
  a WARN_ON() as it is a likely bug.

  But this isn't the case for the strings that can be dereferenced with
  "%s", as some trace events (notably RCU and some IPI events) save a
  pointer to a static string in the ring buffer. As the string it points
  to lives as long as the kernel is running, it is not a bug to
  reference it, as it is guaranteed to be there when the event is read.
  But it is also possible (and a common bug) to point to some allocated
  string that could be freed before the trace event is read and the
  dereference is to bad memory. This case requires a run time check.

  The previous way to handle this was with trace_check_vprintf() that
  would process the printf format piece by piece and send what it didn't
  care about to vsnprintf() to handle arguments that were not strings.
  This kept it from having to reimplement vsnprintf(). But it relied on
  va_list implementation and for architectures that copied the va_list
  and did not pass it by reference, it wasn't even possible to do this
  check and it would be skipped. As 64bit x86 passed va_list by
  reference, most events were tested and this kept out bugs where
  strings would have been dereferenced after being freed.

  Instead of relying on the implementation of va_list, extend the boot
  up test_event_printk() function to validate all the "%s" strings that
  can be validated at boot, and for the few events that point to strings
  outside the ring buffer, flag both the event and the field that is
  dereferenced as "needs_test". Then before the event is printed, a call
  to ignore_event() is made, and if the event has the flag set, it
  iterates all its fields and for every field that is to be tested, it
  will read the pointer directly from the event in the ring buffer and
  make sure that it is valid. If the pointer is not valid, it will print
  a WARN_ON(), print out to the trace that the event has unsafe memory
  and ignore the print format.

  With this new update, the trace_check_vprintf() can be safely removed
  and now all events can be verified regardless of architecture"

* tag 'trace-v6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Check "%s" dereference via the field and not the TP_printk format
  tracing: Add "%s" check in test_event_printk()
  tracing: Add missing helper functions in event pointer dereference check
  tracing: Fix test_event_printk() to process entire print argument
2024-12-18 10:03:33 -08:00
Steven Rostedt
afd2627f72 tracing: Check "%s" dereference via the field and not the TP_printk format
The TP_printk() portion of a trace event is executed at the time a event
is read from the trace. This can happen seconds, minutes, hours, days,
months, years possibly later since the event was recorded. If the print
format contains a dereference to a string via "%s", and that string was
allocated, there's a chance that string could be freed before it is read
by the trace file.

To protect against such bugs, there are two functions that verify the
event. The first one is test_event_printk(), which is called when the
event is created. It reads the TP_printk() format as well as its arguments
to make sure nothing may be dereferencing a pointer that was not copied
into the ring buffer along with the event. If it is, it will trigger a
WARN_ON().

For strings that use "%s", it is not so easy. The string may not reside in
the ring buffer but may still be valid. Strings that are static and part
of the kernel proper which will not be freed for the life of the running
system, are safe to dereference. But to know if it is a pointer to a
static string or to something on the heap can not be determined until the
event is triggered.

This brings us to the second function that tests for the bad dereferencing
of strings, trace_check_vprintf(). It would walk through the printf format
looking for "%s", and when it finds it, it would validate that the pointer
is safe to read. If not, it would produces a WARN_ON() as well and write
into the ring buffer "[UNSAFE-MEMORY]".

The problem with this is how it used va_list to have vsnprintf() handle
all the cases that it didn't need to check. Instead of re-implementing
vsnprintf(), it would make a copy of the format up to the %s part, and
call vsnprintf() with the current va_list ap variable, where the ap would
then be ready to point at the string in question.

For architectures that passed va_list by reference this was possible. For
architectures that passed it by copy it was not. A test_can_verify()
function was used to differentiate between the two, and if it wasn't
possible, it would disable it.

Even for architectures where this was feasible, it was a stretch to rely
on such a method that is undocumented, and could cause issues later on
with new optimizations of the compiler.

Instead, the first function test_event_printk() was updated to look at
"%s" as well. If the "%s" argument is a pointer outside the event in the
ring buffer, it would find the field type of the event that is the problem
and mark the structure with a new flag called "needs_test". The event
itself will be marked by TRACE_EVENT_FL_TEST_STR to let it be known that
this event has a field that needs to be verified before the event can be
printed using the printf format.

When the event fields are created from the field type structure, the
fields would copy the field type's "needs_test" value.

Finally, before being printed, a new function ignore_event() is called
which will check if the event has the TEST_STR flag set (if not, it
returns false). If the flag is set, it then iterates through the events
fields looking for the ones that have the "needs_test" flag set.

Then it uses the offset field from the field structure to find the pointer
in the ring buffer event. It runs the tests to make sure that pointer is
safe to print and if not, it triggers the WARN_ON() and also adds to the
trace output that the event in question has an unsafe memory access.

The ignore_event() makes the trace_check_vprintf() obsolete so it is
removed.

Link: https://lore.kernel.org/all/CAHk-=wh3uOnqnZPpR0PeLZZtyWbZLboZ7cHLCKRWsocvs9Y7hQ@mail.gmail.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241217024720.848621576@goodmis.org
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-17 11:40:11 -05:00
Steven Rostedt
65a25d9f7a tracing: Add "%s" check in test_event_printk()
The test_event_printk() code makes sure that when a trace event is
registered, any dereferenced pointers in from the event's TP_printk() are
pointing to content in the ring buffer. But currently it does not handle
"%s", as there's cases where the string pointer saved in the ring buffer
points to a static string in the kernel that will never be freed. As that
is a valid case, the pointer needs to be checked at runtime.

Currently the runtime check is done via trace_check_vprintf(), but to not
have to replicate everything in vsnprintf() it does some logic with the
va_list that may not be reliable across architectures. In order to get rid
of that logic, more work in the test_event_printk() needs to be done. Some
of the strings can be validated at this time when it is obvious the string
is valid because the string will be saved in the ring buffer content.

Do all the validation of strings in the ring buffer at boot in
test_event_printk(), and make sure that the field of the strings that
point into the kernel are accessible. This will allow adding checks at
runtime that will validate the fields themselves and not rely on paring
the TP_printk() format at runtime.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241217024720.685917008@goodmis.org
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-17 11:40:11 -05:00
Steven Rostedt
917110481f tracing: Add missing helper functions in event pointer dereference check
The process_pointer() helper function looks to see if various trace event
macros are used. These macros are for storing data in the event. This
makes it safe to dereference as the dereference will then point into the
event on the ring buffer where the content of the data stays with the
event itself.

A few helper functions were missing. Those were:

  __get_rel_dynamic_array()
  __get_dynamic_array_len()
  __get_rel_dynamic_array_len()
  __get_rel_sockaddr()

Also add a helper function find_print_string() to not need to use a middle
man variable to test if the string exists.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241217024720.521836792@goodmis.org
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-17 11:40:11 -05:00
Steven Rostedt
a6629626c5 tracing: Fix test_event_printk() to process entire print argument
The test_event_printk() analyzes print formats of trace events looking for
cases where it may dereference a pointer that is not in the ring buffer
which can possibly be a bug when the trace event is read from the ring
buffer and the content of that pointer no longer exists.

The function needs to accurately go from one print format argument to the
next. It handles quotes and parenthesis that may be included in an
argument. When it finds the start of the next argument, it uses a simple
"c = strstr(fmt + i, ',')" to find the end of that argument!

In order to include "%s" dereferencing, it needs to process the entire
content of the print format argument and not just the content of the first
',' it finds. As there may be content like:

 ({ const char *saved_ptr = trace_seq_buffer_ptr(p); static const char
   *access_str[] = { "---", "--x", "w--", "w-x", "-u-", "-ux", "wu-", "wux"
   }; union kvm_mmu_page_role role; role.word = REC->role;
   trace_seq_printf(p, "sp gen %u gfn %llx l%u %u-byte q%u%s %s%s" " %snxe
   %sad root %u %s%c", REC->mmu_valid_gen, REC->gfn, role.level,
   role.has_4_byte_gpte ? 4 : 8, role.quadrant, role.direct ? " direct" : "",
   access_str[role.access], role.invalid ? " invalid" : "", role.efer_nx ? ""
   : "!", role.ad_disabled ? "!" : "", REC->root_count, REC->unsync ?
   "unsync" : "sync", 0); saved_ptr; })

Which is an example of a full argument of an existing event. As the code
already handles finding the next print format argument, process the
argument at the end of it and not the start of it. This way it has both
the start of the argument as well as the end of it.

Add a helper function "process_pointer()" that will do the processing during
the loop as well as at the end. It also makes the code cleaner and easier
to read.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20241217024720.362271189@goodmis.org
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-17 11:40:11 -05:00
Steven Rostedt
166438a432 ftrace: Do not find "true_parent" if HAVE_DYNAMIC_FTRACE_WITH_ARGS is not set
When function tracing and function graph tracing are both enabled (in
different instances) the "parent" of some of the function tracing events
is "return_to_handler" which is the trampoline used by function graph
tracing. To fix this, ftrace_get_true_parent_ip() was introduced that
returns the "true" parent ip instead of the trampoline.

To do this, the ftrace_regs_get_stack_pointer() is used, which uses
kernel_stack_pointer(). The problem is that microblaze does not implement
kerenl_stack_pointer() so when function graph tracing is enabled, the
build fails. But microblaze also does not enabled HAVE_DYNAMIC_FTRACE_WITH_ARGS.
That option has to be enabled by the architecture to reliably get the
values from the fregs parameter passed in. When that config is not set,
the architecture can also pass in NULL, which is not tested for in that
function and could cause the kernel to crash.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jeff Xie <jeff.xie@linux.dev>
Link: https://lore.kernel.org/20241216164633.6df18e87@gandalf.local.home
Fixes: 60b1f578b5 ("ftrace: Get the true parent ip for function tracer")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-16 17:22:26 -05:00
Steven Rostedt
cc252bb592 fgraph: Still initialize idle shadow stacks when starting
A bug was discovered where the idle shadow stacks were not initialized
for offline CPUs when starting function graph tracer, and when they came
online they were not traced due to the missing shadow stack. To fix
this, the idle task shadow stack initialization was moved to using the
CPU hotplug callbacks. But it removed the initialization when the
function graph was enabled. The problem here is that the hotplug
callbacks are called when the CPUs come online, but the idle shadow
stack initialization only happens if function graph is currently
active. This caused the online CPUs to not get their shadow stack
initialized.

The idle shadow stack initialization still needs to be done when the
function graph is registered, as they will not be allocated if function
graph is not registered.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241211135335.094ba282@batman.local.home
Fixes: 2c02f7375e ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks")
Reported-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Closes: https://lore.kernel.org/all/CACRpkdaTBrHwRbbrphVy-=SeDz6MSsXhTKypOtLrTQ+DgGAOcQ@mail.gmail.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-16 16:03:33 -05:00
Alexei Starovoitov
06103dccbb Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:
Auto-merging include/linux/bpf.h
Auto-merging include/linux/bpf_verifier.h
Auto-merging kernel/bpf/btf.c
Auto-merging kernel/bpf/verifier.c
Auto-merging kernel/trace/bpf_trace.c
Auto-merging tools/testing/selftests/bpf/progs/test_tp_btf_nullable.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-16 08:53:59 -08:00
Linus Torvalds
35f301dd45 BPF fixes:
- Fix a bug in the BPF verifier to track changes to packet data
   property for global functions (Eduard Zingerman)
 
 - Fix a theoretical BPF prog_array use-after-free in RCU handling
   of __uprobe_perf_func (Jann Horn)
 
 - Fix BPF tracing to have an explicit list of tracepoints and
   their arguments which need to be annotated as PTR_MAYBE_NULL
   (Kumar Kartikeya Dwivedi)
 
 - Fix a logic bug in the bpf_remove_insns code where a potential
   error would have been wrongly propagated (Anton Protopopov)
 
 - Avoid deadlock scenarios caused by nested kprobe and fentry
   BPF programs (Priya Bala Govindasamy)
 
 - Fix a bug in BPF verifier which was missing a size check for
   BTF-based context access (Kumar Kartikeya Dwivedi)
 
 - Fix a crash found by syzbot through an invalid BPF prog_array
   access in perf_event_detach_bpf_prog (Jiri Olsa)
 
 - Fix several BPF sockmap bugs including a race causing a
   refcount imbalance upon element replace (Michal Luczaj)
 
 - Fix a use-after-free from mismatching BPF program/attachment
   RCU flavors (Jann Horn)
 
 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Daniel Borkmann:

 - Fix a bug in the BPF verifier to track changes to packet data
   property for global functions (Eduard Zingerman)

 - Fix a theoretical BPF prog_array use-after-free in RCU handling of
   __uprobe_perf_func (Jann Horn)

 - Fix BPF tracing to have an explicit list of tracepoints and their
   arguments which need to be annotated as PTR_MAYBE_NULL (Kumar
   Kartikeya Dwivedi)

 - Fix a logic bug in the bpf_remove_insns code where a potential error
   would have been wrongly propagated (Anton Protopopov)

 - Avoid deadlock scenarios caused by nested kprobe and fentry BPF
   programs (Priya Bala Govindasamy)

 - Fix a bug in BPF verifier which was missing a size check for
   BTF-based context access (Kumar Kartikeya Dwivedi)

 - Fix a crash found by syzbot through an invalid BPF prog_array access
   in perf_event_detach_bpf_prog (Jiri Olsa)

 - Fix several BPF sockmap bugs including a race causing a refcount
   imbalance upon element replace (Michal Luczaj)

 - Fix a use-after-free from mismatching BPF program/attachment RCU
   flavors (Jann Horn)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (23 commits)
  bpf: Avoid deadlock caused by nested kprobe and fentry bpf programs
  selftests/bpf: Add tests for raw_tp NULL args
  bpf: Augment raw_tp arguments with PTR_MAYBE_NULL
  bpf: Revert "bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"
  selftests/bpf: Add test for narrow ctx load for pointer args
  bpf: Check size for BTF-based ctx access of pointer members
  selftests/bpf: extend changes_pkt_data with cases w/o subprograms
  bpf: fix null dereference when computing changes_pkt_data of prog w/o subprogs
  bpf: Fix theoretical prog_array UAF in __uprobe_perf_func()
  bpf: fix potential error return
  selftests/bpf: validate that tail call invalidates packet pointers
  bpf: consider that tail calls invalidate packet pointers
  selftests/bpf: freplace tests for tracking of changes_packet_data
  bpf: check changes_pkt_data property for extension programs
  selftests/bpf: test for changing packet data from global functions
  bpf: track changes_pkt_data property for global functions
  bpf: refactor bpf_helper_changes_pkt_data to use helper number
  bpf: add find_containing_subprog() utility function
  bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_prog
  bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors
  ...
2024-12-14 12:58:14 -08:00
Linus Torvalds
1594c49394 Probes fixes for v6.13-rc1:
- eprobes: Fix to release eprobe when failed to add dyn_event.
   This unregisters event call and release eprobe when it fails to add
   a dynamic event. Found in cleaning up.
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Merge tag 'probes-fixes-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull eprobes fix from Masami Hiramatsu:

 - release eprobe when failing to add dyn_event.

   This unregisters event call and release eprobe when it fails to add a
   dynamic event. Found in cleaning up.

* tag 'probes-fixes-v6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/eprobe: Fix to release eprobe when failed to add dyn_event
2024-12-10 18:15:25 -08:00
Jann Horn
7d0d673627 bpf: Fix theoretical prog_array UAF in __uprobe_perf_func()
Currently, the pointer stored in call->prog_array is loaded in
__uprobe_perf_func(), with no RCU annotation and no immediately visible
RCU protection, so it looks as if the loaded pointer can immediately be
dangling.
Later, bpf_prog_run_array_uprobe() starts a RCU-trace read-side critical
section, but this is too late. It then uses rcu_dereference_check(), but
this use of rcu_dereference_check() does not actually dereference anything.

Fix it by aligning the semantics to bpf_prog_run_array(): Let the caller
provide rcu_read_lock_trace() protection and then load call->prog_array
with rcu_dereference_check().

This issue seems to be theoretical: I don't know of any way to reach this
code without having handle_swbp() further up the stack, which is already
holding a rcu_read_lock_trace() lock, so where we take
rcu_read_lock_trace() in __uprobe_perf_func()/bpf_prog_run_array_uprobe()
doesn't actually have any effect.

Fixes: 8c7dcb84e3 ("bpf: implement sleepable uprobes by chaining gps")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241210-bpf-fix-uprobe-uaf-v4-1-5fc8959b2b74@google.com
2024-12-10 13:06:51 -08:00
Jiri Olsa
978c4486cc bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_prog
Syzbot reported [1] crash that happens for following tracing scenario:

  - create tracepoint perf event with attr.inherit=1, attach it to the
    process and set bpf program to it
  - attached process forks -> chid creates inherited event

    the new child event shares the parent's bpf program and tp_event
    (hence prog_array) which is global for tracepoint

  - exit both process and its child -> release both events
  - first perf_event_detach_bpf_prog call will release tp_event->prog_array
    and second perf_event_detach_bpf_prog will crash, because
    tp_event->prog_array is NULL

The fix makes sure the perf_event_detach_bpf_prog checks prog_array
is valid before it tries to remove the bpf program from it.

[1] https://lore.kernel.org/bpf/Z1MR6dCIKajNS6nU@krava/T/#m91dbf0688221ec7a7fc95e896a7ef9ff93b0b8ad

Fixes: 0ee288e69d ("bpf,perf: Fix perf_event_detach_bpf_prog error handling")
Reported-by: syzbot+2e0d2840414ce817aaac@syzkaller.appspotmail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241208142507.1207698-1-jolsa@kernel.org
2024-12-10 10:16:28 -08:00
Jann Horn
ef1b808e3b bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors
Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU
protection. But it is possible to attach a non-sleepable BPF program to a
uprobe, and non-sleepable BPF programs are freed via normal RCU (see
__bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal
RCU grace period does not imply a tasks-trace-RCU grace period.

Fix it by explicitly waiting for a tasks-trace-RCU grace period after
removing the attachment of a bpf_prog to a perf_event.

Fixes: 8c7dcb84e3 ("bpf: implement sleepable uprobes by chaining gps")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20241210-bpf-fix-actual-uprobe-uaf-v1-1-19439849dd44@google.com
2024-12-10 10:14:02 -08:00
Alexei Starovoitov
442bc81bd3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

Trivial conflict:
tools/testing/selftests/bpf/prog_tests/verifier.c

Adjacent changes in:
Auto-merging kernel/bpf/verifier.c
Auto-merging samples/bpf/Makefile
Auto-merging tools/testing/selftests/bpf/.gitignore
Auto-merging tools/testing/selftests/bpf/Makefile
Auto-merging tools/testing/selftests/bpf/prog_tests/verifier.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-08 17:01:51 -08:00
Masami Hiramatsu (Google)
494b332064 tracing/eprobe: Fix to release eprobe when failed to add dyn_event
Fix eprobe event to unregister event call and release eprobe when it fails
to add dynamic event correctly.

Link: https://lore.kernel.org/all/173289886698.73724.1959899350183686006.stgit@devnote2/

Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-12-08 23:25:09 +09:00
Steven Rostedt
dc1b157b82 tracing: Fix archs that still call tracepoints without RCU watching
Tracepoints require having RCU "watching" as it uses RCU to do updates to
the tracepoints. There are some cases that would call a tracepoint when
RCU was not "watching". This was usually in the idle path where RCU has
"shutdown". For the few locations that had tracepoints without RCU
watching, there was an trace_*_rcuidle() variant that could be used. This
used SRCU for protection.

There are tracepoints that trace when interrupts and preemption are
enabled and disabled. In some architectures, these tracepoints are called
in a path where RCU is not watching. When x86 and arm64 removed these
locations, it was incorrectly assumed that it would be safe to remove the
trace_*_rcuidle() variant and also remove the SRCU logic, as it made the
code more complex and harder to implement new tracepoint features (like
faultable tracepoints and tracepoints in rust).

Instead of bringing back the trace_*_rcuidle(), as it will not be trivial
to do as new code has already been added depending on its removal, add a
workaround to the one file that still requires it (trace_preemptirq.c). If
the architecture does not define CONFIG_ARCH_WANTS_NO_INSTR, then check if
the code is in the idle path, and if so, call ct_irq_enter/exit() which
will enable RCU around the tracepoint.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20241204100414.4d3e06d0@gandalf.local.home
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 48bcda6848 ("tracing: Remove definition of trace_*_rcuidle()")
Closes: https://lore.kernel.org/all/bddb02de-957a-4df5-8e77-829f55728ea2@roeck-us.net/
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-05 09:28:58 -05:00
Kuan-Wei Chiu
e63fbd5f68 tracing: Fix cmp_entries_dup() to respect sort() comparison rules
The cmp_entries_dup() function used as the comparator for sort()
violated the symmetry and transitivity properties required by the
sorting algorithm. Specifically, it returned 1 whenever memcmp() was
non-zero, which broke the following expectations:

* Symmetry: If x < y, then y > x.
* Transitivity: If x < y and y < z, then x < z.

These violations could lead to incorrect sorting and failure to
correctly identify duplicate elements.

Fix the issue by directly returning the result of memcmp(), which
adheres to the required comparison properties.

Cc: stable@vger.kernel.org
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Link: https://lore.kernel.org/20241203202228.1274403-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-12-04 10:38:24 -05:00
Marco Elver
3bfb49d73f bpf: Refactor bpf_tracing_func_proto() and remove bpf_get_probe_write_proto()
With bpf_get_probe_write_proto() no longer printing a message, we can
avoid it being a special case with its own permission check.

Refactor bpf_tracing_func_proto() similar to bpf_base_func_proto() to
have a section conditional on bpf_token_capable(CAP_SYS_ADMIN), where
the proto for bpf_probe_write_user() is returned. Finally, remove the
unnecessary bpf_get_probe_write_proto().

This simplifies the code, and adding additional CAP_SYS_ADMIN-only
helpers in future avoids duplicating the same CAP_SYS_ADMIN check.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20241129090040.2690691-2-elver@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-02 08:42:02 -08:00
Marco Elver
b28573ebfa bpf: Remove bpf_probe_write_user() warning message
The warning message for bpf_probe_write_user() was introduced in
96ae522795 ("bpf: Add bpf_probe_write_user BPF helper to be called in
tracers"), with the following in the commit message:

    Given this feature is meant for experiments, and it has a risk of
    crashing the system, and running programs, we print a warning on
    when a proglet that attempts to use this helper is installed,
    along with the pid and process name.

After 8 years since 96ae522795, bpf_probe_write_user() has found
successful applications beyond experiments [1, 2], with no other good
alternatives. Despite its intended purpose for "experiments", that
doesn't stop Hyrum's law, and there are likely many more users depending
on this helper: "[..] it does not matter what you promise [..] all
observable behaviors of your system will be depended on by somebody."

The ominous "helper that may corrupt user memory!" has offered no real
benefit, and has been found to lead to confusion where the system
administrator is loading programs with valid use cases.

As such, remove the warning message.

Link: https://lore.kernel.org/lkml/20240404190146.1898103-1-elver@google.com/ [1]
Link: https://lore.kernel.org/r/lkml/CAAn3qOUMD81-vxLLfep0H6rRd74ho2VaekdL4HjKq+Y1t9KdXQ@mail.gmail.com/ [2]
Link: https://lore.kernel.org/all/CAEf4Bzb4D_=zuJrg3PawMOW3KqF8JvJm9SwF81_XHR2+u5hkUg@mail.gmail.com/
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20241129090040.2690691-1-elver@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-02 08:42:02 -08:00
Ingo Molnar
bcfd5f644c Linux 6.13-rc1
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Merge tag 'v6.13-rc1' into perf/core, to refresh the branch

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-12-02 11:52:59 +01:00
Christian Brauner
7863dcc72d
pid: allow pid_max to be set per pid namespace
The pid_max sysctl is a global value. For a long time the default value
has been 65535 and during the pidfd dicussions Linus proposed to bump
pid_max by default (cf. [1]). Based on this discussion systemd started
bumping pid_max to 2^22. So all new systems now run with a very high
pid_max limit with some distros having also backported that change.
The decision to bump pid_max is obviously correct. It just doesn't make
a lot of sense nowadays to enforce such a low pid number. There's
sufficient tooling to make selecting specific processes without typing
really large pid numbers available.

In any case, there are workloads that have expections about how large
pid numbers they accept. Either for historical reasons or architectural
reasons. One concreate example is the 32-bit version of Android's bionic
libc which requires pid numbers less than 65536. There are workloads
where it is run in a 32-bit container on a 64-bit kernel. If the host
has a pid_max value greater than 65535 the libc will abort thread
creation because of size assumptions of pthread_mutex_t.

That's a fairly specific use-case however, in general specific workloads
that are moved into containers running on a host with a new kernel and a
new systemd can run into issues with large pid_max values. Obviously
making assumptions about the size of the allocated pid is suboptimal but
we have userspace that does it.

Of course, giving containers the ability to restrict the number of
processes in their respective pid namespace indepent of the global limit
through pid_max is something desirable in itself and comes in handy in
general.

Independent of motivating use-cases the existence of pid namespaces
makes this also a good semantical extension and there have been prior
proposals pushing in a similar direction.
The trick here is to minimize the risk of regressions which I think is
doable. The fact that pid namespaces are hierarchical will help us here.

What we mostly care about is that when the host sets a low pid_max
limit, say (crazy number) 100 that no descendant pid namespace can
allocate a higher pid number in its namespace. Since pid allocation is
hierarchial this can be ensured by checking each pid allocation against
the pid namespace's pid_max limit. This means if the allocation in the
descendant pid namespace succeeds, the ancestor pid namespace can reject
it. If the ancestor pid namespace has a higher limit than the descendant
pid namespace the descendant pid namespace will reject the pid
allocation. The ancestor pid namespace will obviously not care about
this.
All in all this means pid_max continues to enforce a system wide limit
on the number of processes but allows pid namespaces sufficient leeway
in handling workloads with assumptions about pid values and allows
containers to restrict the number of processes in a pid namespace
through the pid_max interface.

[1]: https://lore.kernel.org/linux-api/CAHk-=wiZ40LVjnXSi9iHLE_-ZBsWFGCgdmNiYZUXn1-V5YBg2g@mail.gmail.com
- rebased from 5.14-rc1
- a few fixes (missing ns_free_inum on error path, missing initialization, etc)
- permission check changes in pid_table_root_permissions
- unsigned int pid_max -> int pid_max (keep pid_max type as it was)
- add READ_ONCE in alloc_pid() as suggested by Christian
- rebased from 6.7 and take into account:
 * sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
 * sysctl: treewide: constify ctl_table_header::ctl_table_arg
 * pidfd: add pidfs
 * tracing: Move saved_cmdline code into trace_sched_switch.c

Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Link: https://lore.kernel.org/r/20241122132459.135120-2-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-12-02 11:25:25 +01:00
Thomas Gleixner
0172afefbf tracing: Record task flag NEED_RESCHED_LAZY.
The scheduler added NEED_RESCHED_LAZY scheduling. Record this state as
part of trace flags and expose it in the need_resched field.

Record and expose NEED_RESCHED_LAZY.

[bigeasy: Commit description, documentation bits.]

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241122202849.7DfYpJR0@linutronix.de
Reviewed-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-22 17:49:39 -05:00
Linus Torvalds
06afb0f361 tracing updates for v6.13:
- Addition of faultable tracepoints
 
   There's a tracepoint attached to both a system call entry and exit. This
   location is known to allow page faults. The tracepoints are called under
   an rcu_read_lock() which does not allow faults that can sleep. This limits
   the ability of tracepoint handlers to page fault in user space system call
   parameters. Now these tracepoints have been made "faultable", allowing the
   callbacks to fault in user space parameters and record them.
 
   Note, only the infrastructure has been implemented. The consumers (perf,
   ftrace, BPF) now need to have their code modified to allow faults.
 
 - Fix up of BPF code for the tracepoint faultable logic
 
 - Update tracepoints to use the new static branch API
 
 - Remove trace_*_rcuidle() variants and the SRCU protection they used
 
 - Remove unused TRACE_EVENT_FL_FILTERED logic
 
 - Replace strncpy() with strscpy() and memcpy()
 
 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()
 
 - Fix perf events to not duplicate samples when tracing is enabled
 
 - Replace atomic64_add_return(1, counter) with atomic64_inc_return(counter)
 
 - Make stack trace buffer 4K instead of PAGE_SIZE
 
 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used
 
 - Get the true return address for function tracer when function graph tracer
   is also running.
 
   When function_graph trace is running along with function tracer,
   the parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.
 
 - Remove (un)regfunc pointers out of tracepoint structure
 
 - Added last minute bug fix for setting pending modules in stack function
   filter.
 
   echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
 
   Would cause a kernel NULL dereference.
 
 - Minor clean ups
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Merge tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of faultable tracepoints

   There's a tracepoint attached to both a system call entry and exit.
   This location is known to allow page faults. The tracepoints are
   called under an rcu_read_lock() which does not allow faults that can
   sleep. This limits the ability of tracepoint handlers to page fault
   in user space system call parameters. Now these tracepoints have been
   made "faultable", allowing the callbacks to fault in user space
   parameters and record them.

   Note, only the infrastructure has been implemented. The consumers
   (perf, ftrace, BPF) now need to have their code modified to allow
   faults.

 - Fix up of BPF code for the tracepoint faultable logic

 - Update tracepoints to use the new static branch API

 - Remove trace_*_rcuidle() variants and the SRCU protection they used

 - Remove unused TRACE_EVENT_FL_FILTERED logic

 - Replace strncpy() with strscpy() and memcpy()

 - Use replace per_cpu_ptr(smp_processor_id()) with this_cpu_ptr()

 - Fix perf events to not duplicate samples when tracing is enabled

 - Replace atomic64_add_return(1, counter) with
   atomic64_inc_return(counter)

 - Make stack trace buffer 4K instead of PAGE_SIZE

 - Remove TRACE_FLAG_IRQS_NOSUPPORT flag as it was never used

 - Get the true return address for function tracer when function graph
   tracer is also running.

   When function_graph trace is running along with function tracer, the
   parent function of the function tracer sometimes is
   "return_to_handler", which is the function graph trampoline to record
   the exit of the function. Use existing logic that calls into the
   fgraph infrastructure to find the real return address.

 - Remove (un)regfunc pointers out of tracepoint structure

 - Added last minute bug fix for setting pending modules in stack
   function filter.

     echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter

   Would cause a kernel NULL dereference.

 - Minor clean ups

* tag 'trace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  ftrace: Fix regression with module command in stack_trace_filter
  tracing: Fix function name for trampoline
  ftrace: Get the true parent ip for function tracer
  tracing: Remove redundant check on field->field in histograms
  bpf: ensure RCU Tasks Trace GP for sleepable raw tracepoint BPF links
  bpf: decouple BPF link/attach hook and BPF program sleepable semantics
  bpf: put bpf_link's program when link is safe to be deallocated
  tracing: Replace strncpy() with strscpy() when copying comm
  tracing: Add might_fault() check in __DECLARE_TRACE_SYSCALL
  tracing: Fix syscall tracepoint use-after-free
  tracing: Introduce tracepoint_is_faultable()
  tracing: Introduce tracepoint extended structure
  tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
  tracing: Replace multiple deprecated strncpy with memcpy
  tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
  tracing: Use atomic64_inc_return() in trace_clock_counter()
  trace/trace_event_perf: remove duplicate samples on the first tracepoint event
  tracing/bpf: Add might_fault check to syscall probes
  tracing/perf: Add might_fault check to syscall probes
  tracing/ftrace: Add might_fault check to syscall probes
  ...
2024-11-22 13:27:01 -08:00
Linus Torvalds
4b01712311 tracing/tools: Updates for 6.13
- Add ':' to getopt option 'trace-buffer-size' in timerlat_hist for
   consistency
 
 - Remove unused sched_getattr define
 
 - Rename sched_setattr() helper to syscall_sched_setattr() to avoid
   conflicts
 
 - Update counters to long from int to avoid overflow
 
 - Add libcpupower dependency detection
 
 - Add --deepest-idle-state to timerlat to limit deep idle sleeps
 
 - Other minor clean ups and documentation changes
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Merge tag 'trace-tools-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing tools updates from Steven Rostedt:

 - Add ':' to getopt option 'trace-buffer-size' in timerlat_hist for
   consistency

 - Remove unused sched_getattr define

 - Rename sched_setattr() helper to syscall_sched_setattr() to avoid
   conflicts

 - Update counters to long from int to avoid overflow

 - Add libcpupower dependency detection

 - Add --deepest-idle-state to timerlat to limit deep idle sleeps

 - Other minor clean ups and documentation changes

* tag 'trace-tools-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  verification/dot2: Improve dot parser robustness
  tools/rtla: Improve exception handling in timerlat_load.py
  tools/rtla: Enhance argument parsing in timerlat_load.py
  tools/rtla: Improve code readability in timerlat_load.py
  rtla/timerlat: Do not set params->user_workload with -U
  rtla: Documentation: Mention --deepest-idle-state
  rtla/timerlat: Add --deepest-idle-state for hist
  rtla/timerlat: Add --deepest-idle-state for top
  rtla/utils: Add idle state disabling via libcpupower
  rtla: Add optional dependency on libcpupower
  tools/build: Add libcpupower dependency detection
  rtla/timerlat: Make timerlat_hist_cpu->*_count unsigned long long
  rtla/timerlat: Make timerlat_top_cpu->*_count unsigned long long
  tools/rtla: fix collision with glibc sched_attr/sched_set_attr
  tools/rtla: drop __NR_sched_getattr
  rtla: Fix consistency in getopt_long for timerlat_hist
  rv: Fix a typo
  tools/rv: Correct the grammatical errors in the comments
  tools/rv: Correct the grammatical errors in the comments
  rtla: use the definition for stdout fd when calling isatty()
2024-11-22 13:24:22 -08:00
Linus Torvalds
f1db825805 trace ring-buffer updates for v6.13
- Limit time interrupts are disabled in rb_check_pages()
 
   The rb_check_pages() is called after the ring buffer size is updated to
   make sure that the ring buffer has not been corrupted. Commit
   c2274b908d ("ring-buffer: Fix a race between readers and resize
   checks") fixed a race with the check pages and simultaneous resizes to the
   ring buffer by adding a raw_spin_lock_irqsave() around the check
   operation. Although this was a simple fix, it would hold interrupts
   disabled for non determinative amount of time. This could harm PREEMPT_RT
   operations.
 
   Instead, modify the logic by adding a counter when the buffer is modified
   and to release the raw_spin_lock() at each iteration. It checks the
   counter under the lock to see if a modification happened during the loop,
   and if it did, it would restart the loop up to 3 times. After 3 times, it
   will simply exit the check, as it is unlikely that would ever happen as
   buffer resizes are rare occurrences.
 
 - Replace some open coded str_low_high() with the helper
 
 - Fix some documentation/comments
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Merge tag 'trace-ring-buffer-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull trace ring-buffer updates from Steven Rostedt:

 - Limit time interrupts are disabled in rb_check_pages()

   rb_check_pages() is called after the ring buffer size is updated to
   make sure that the ring buffer has not been corrupted. Commit
   c2274b908d ("ring-buffer: Fix a race between readers and resize
   checks") fixed a race with the check pages and simultaneous resizes
   to the ring buffer by adding a raw_spin_lock_irqsave() around the
   check operation. Although this was a simple fix, it would hold
   interrupts disabled for non determinative amount of time. This could
   harm PREEMPT_RT operations.

   Instead, modify the logic by adding a counter when the buffer is
   modified and to release the raw_spin_lock() at each iteration. It
   checks the counter under the lock to see if a modification happened
   during the loop, and if it did, it would restart the loop up to 3
   times. After 3 times, it will simply exit the check, as it is
   unlikely that would ever happen as buffer resizes are rare
   occurrences.

 - Replace some open coded str_low_high() with the helper

 - Fix some documentation/comments

* tag 'trace-ring-buffer-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Correct a grammatical error in a comment
  ring-buffer: Use str_low_high() helper in ring_buffer_producer()
  ring-buffer: Reorganize kerneldoc parameter names
  ring-buffer: Limit time with disabled interrupts in rb_check_pages()
2024-11-22 13:11:17 -08:00
Linus Torvalds
6e95ef0258 bpf-next-bpf-next-6.13
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Merge tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Add BPF uprobe session support (Jiri Olsa)

 - Optimize uprobe performance (Andrii Nakryiko)

 - Add bpf_fastcall support to helpers and kfuncs (Eduard Zingerman)

 - Avoid calling free_htab_elem() under hash map bucket lock (Hou Tao)

 - Prevent tailcall infinite loop caused by freplace (Leon Hwang)

 - Mark raw_tracepoint arguments as nullable (Kumar Kartikeya Dwivedi)

 - Introduce uptr support in the task local storage map (Martin KaFai
   Lau)

 - Stringify errno log messages in libbpf (Mykyta Yatsenko)

 - Add kmem_cache BPF iterator for perf's lock profiling (Namhyung Kim)

 - Support BPF objects of either endianness in libbpf (Tony Ambardar)

 - Add ksym to struct_ops trampoline to fix stack trace (Xu Kuohai)

 - Introduce private stack for eligible BPF programs (Yonghong Song)

 - Migrate samples/bpf tests to selftests/bpf test_progs (Daniel T. Lee)

 - Migrate test_sock to selftests/bpf test_progs (Jordan Rife)

* tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (152 commits)
  libbpf: Change hash_combine parameters from long to unsigned long
  selftests/bpf: Fix build error with llvm 19
  libbpf: Fix memory leak in bpf_program__attach_uprobe_multi
  bpf: use common instruction history across all states
  bpf: Add necessary migrate_disable to range_tree.
  bpf: Do not alloc arena on unsupported arches
  selftests/bpf: Set test path for token/obj_priv_implicit_token_envvar
  selftests/bpf: Add a test for arena range tree algorithm
  bpf: Introduce range_tree data structure and use it in bpf arena
  samples/bpf: Remove unused variable in xdp2skb_meta_kern.c
  samples/bpf: Remove unused variables in tc_l2_redirect_kern.c
  bpftool: Cast variable `var` to long long
  bpf, x86: Propagate tailcall info only for subprogs
  bpf: Add kernel symbol for struct_ops trampoline
  bpf: Use function pointers count as struct_ops links count
  bpf: Remove unused member rcu from bpf_struct_ops_map
  selftests/bpf: Add struct_ops prog private stack tests
  bpf: Support private stack for struct_ops progs
  selftests/bpf: Add tracing prog private stack tests
  bpf, x86: Support private stack in jit
  ...
2024-11-21 08:11:04 -08:00
Linus Torvalds
f89a687aae kgdb patches for 6.13
A relatively modest collection of changes:
 
 * Adopt kstrtoint() and kstrtol() instead of the simple_strtoXX family
   for better error checking of user input.
 * Align the print behavour when breakpoints are enabled and disabled by
   adopting the current behaviour of breakpoint disable for both.
 * Remove some of the (rather odd and user hostile) hex fallbacks and
   require kdb users to prefix with 0x instead.
 * Tidy up (and fix) control code handling in kdb's keyboard code. This
   makes the control code handling at the keyboard behave the same way
   as it does via the UART.
 * Switch my own entry in MAINTAINERS to my @kernel.org address.
 
 Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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Merge tag 'kgdb-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

Pull kgdb updates from Daniel Thompson:
 "A relatively modest collection of changes:

   - Adopt kstrtoint() and kstrtol() instead of the simple_strtoXX
     family for better error checking of user input.

   - Align the print behavour when breakpoints are enabled and disabled
     by adopting the current behaviour of breakpoint disable for both.

   - Remove some of the (rather odd and user hostile) hex fallbacks and
     require kdb users to prefix with 0x instead.

   - Tidy up (and fix) control code handling in kdb's keyboard code.
     This makes the control code handling at the keyboard behave the
     same way as it does via the UART.

   - Switch my own entry in MAINTAINERS to my @kernel.org address"

* tag 'kgdb-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard mode
  MAINTAINERS: Use Daniel Thompson's korg address for kgdb work
  kdb: Fix breakpoint enable to be silent if already enabled
  kdb: Remove fallback interpretation of arbitrary numbers as hex
  trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump
  kdb: Replace the use of simple_strto with safer kstrto in kdb_main
2024-11-20 11:47:43 -08:00
Linus Torvalds
aad3a0d084 ftrace updates for v6.13:
- Merged tag ftrace-v6.12-rc4
 
   There was a fix to locking in register_ftrace_graph() for shadow stacks
   that was sent upstream. But this code was also being rewritten, and the
   locking fix was needed. Merging this fix was required to continue the
   work.
 
 - Restructure the function graph shadow stack to prepare it for use with
   kretprobes
 
   With the goal of merging the shadow stack logic of function graph and
   kretprobes, some more restructuring of the function shadow stack is
   required.
 
   Move out function graph specific fields from the fgraph infrastructure and
   store it on the new stack variables that can pass data from the entry
   callback to the exit callback.
 
   Hopefully, with this change, the merge of kretprobes to use fgraph shadow
   stacks will be ready by the next merge window.
 
 - Make shadow stack 4k instead of using PAGE_SIZE.
 
   Some architectures have very large PAGE_SIZE values which make its use for
   shadow stacks waste a lot of memory.
 
 - Give shadow stacks its own kmem cache.
 
   When function graph is started, every task on the system gets a shadow
   stack. In the future, shadow stacks may not be 4K in size. Have it have
   its own kmem cache so that whatever size it becomes will still be
   efficient in allocations.
 
 - Initialize profiler graph ops as it will be needed for new updates to fgraph
 
 - Convert to use guard(mutex) for several ftrace and fgraph functions
 
 - Add more comments and documentation
 
 - Show function return address in function graph tracer
 
   Add an option to show the caller of a function at each entry of the
   function graph tracer, similar to what the function tracer does.
 
 - Abstract out ftrace_regs from being used directly like pt_regs
 
   ftrace_regs was created to store a partial pt_regs. It holds only the
   registers and stack information to get to the function arguments and
   return values. On several archs, it is simply a wrapper around pt_regs.
   But some users would access ftrace_regs directly to get the pt_regs which
   will not work on all archs. Make ftrace_regs an abstract structure that
   requires all access to its fields be through accessor functions.
 
 - Show how long it takes to do function code modifications
 
   When code modification for function hooks happen, it always had the time
   recorded in how long it took to do the conversion. But this value was
   never exported. Recently the code was touched due to new ROX modification
   handling that caused a large slow down in doing the modifications and
   had a significant impact on boot times.
 
   Expose the timings in the dyn_ftrace_total_info file. This file was
   created a while ago to show information about memory usage and such to
   implement dynamic function tracing. It's also an appropriate file to store
   the timings of this modification as well. This will make it easier to see
   the impact of changes to code modification on boot up timings.
 
 - Other clean ups and small fixes
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Merge tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:

 - Restructure the function graph shadow stack to prepare it for use
   with kretprobes

   With the goal of merging the shadow stack logic of function graph and
   kretprobes, some more restructuring of the function shadow stack is
   required.

   Move out function graph specific fields from the fgraph
   infrastructure and store it on the new stack variables that can pass
   data from the entry callback to the exit callback.

   Hopefully, with this change, the merge of kretprobes to use fgraph
   shadow stacks will be ready by the next merge window.

 - Make shadow stack 4k instead of using PAGE_SIZE.

   Some architectures have very large PAGE_SIZE values which make its
   use for shadow stacks waste a lot of memory.

 - Give shadow stacks its own kmem cache.

   When function graph is started, every task on the system gets a
   shadow stack. In the future, shadow stacks may not be 4K in size.
   Have it have its own kmem cache so that whatever size it becomes will
   still be efficient in allocations.

 - Initialize profiler graph ops as it will be needed for new updates to
   fgraph

 - Convert to use guard(mutex) for several ftrace and fgraph functions

 - Add more comments and documentation

 - Show function return address in function graph tracer

   Add an option to show the caller of a function at each entry of the
   function graph tracer, similar to what the function tracer does.

 - Abstract out ftrace_regs from being used directly like pt_regs

   ftrace_regs was created to store a partial pt_regs. It holds only the
   registers and stack information to get to the function arguments and
   return values. On several archs, it is simply a wrapper around
   pt_regs. But some users would access ftrace_regs directly to get the
   pt_regs which will not work on all archs. Make ftrace_regs an
   abstract structure that requires all access to its fields be through
   accessor functions.

 - Show how long it takes to do function code modifications

   When code modification for function hooks happen, it always had the
   time recorded in how long it took to do the conversion. But this
   value was never exported. Recently the code was touched due to new
   ROX modification handling that caused a large slow down in doing the
   modifications and had a significant impact on boot times.

   Expose the timings in the dyn_ftrace_total_info file. This file was
   created a while ago to show information about memory usage and such
   to implement dynamic function tracing. It's also an appropriate file
   to store the timings of this modification as well. This will make it
   easier to see the impact of changes to code modification on boot up
   timings.

 - Other clean ups and small fixes

* tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (22 commits)
  ftrace: Show timings of how long nop patching took
  ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()
  ftrace: Use guard to take the ftrace_lock in release_probe()
  ftrace: Use guard to lock ftrace_lock in cache_mod()
  ftrace: Use guard for match_records()
  fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()
  fgraph: Give ret_stack its own kmem cache
  fgraph: Separate size of ret_stack from PAGE_SIZE
  ftrace: Rename ftrace_regs_return_value to ftrace_regs_get_return_value
  selftests/ftrace: Fix check of return value in fgraph-retval.tc test
  ftrace: Use arch_ftrace_regs() for ftrace_regs_*() macros
  ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs
  ftrace: Make ftrace_regs abstract from direct use
  fgragh: No need to invoke the function call_filter_check_discard()
  fgraph: Simplify return address printing in function graph tracer
  function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()
  function_graph: Support recording and printing the function return address
  ftrace: Have calltime be saved in the fgraph storage
  ftrace: Use a running sleeptime instead of saving on shadow stack
  fgraph: Use fgraph data to store subtime for profiler
  ...
2024-11-20 11:34:10 -08:00
guoweikang
45af52e7d3 ftrace: Fix regression with module command in stack_trace_filter
When executing the following command:

    # echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter

The current mod command causes a null pointer dereference. While commit
0f17976568 ("ftrace: Fix regression with module command in stack_trace_filter")
has addressed part of the issue, it left a corner case unhandled, which still
results in a kernel crash.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241120052750.275463-1-guoweikang.kernel@gmail.com
Fixes: 04ec7bb642 ("tracing: Have the trace_array hold the list of registered func probes");
Signed-off-by: guoweikang <guoweikang.kernel@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-20 11:15:29 -05:00
Linus Torvalds
f41dac3efb Performance events changes for v6.13:
- Uprobes:
     - Add BPF session support (Jiri Olsa)
     - Switch to RCU Tasks Trace flavor for better performance (Andrii Nakryiko)
     - Massively increase uretprobe SMP scalability by SRCU-protecting
       the uretprobe lifetime (Andrii Nakryiko)
     - Kill xol_area->slot_count (Oleg Nesterov)
 
  - Core facilities:
     - Implement targeted high-frequency profiling by adding the ability
       for an event to "pause" or "resume" AUX area tracing (Adrian Hunter)
 
  - VM profiling/sampling:
     - Correct perf sampling with guest VMs (Colton Lewis)
 
  - New hardware support:
     - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)
 
  - Misc fixes and enhancements:
     - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
     - x86/amd: Warn only on new bits set (Breno Leitao)
     - x86/amd/uncore: Avoid a false positive warning about snprintf
                       truncation in amd_uncore_umc_ctx_init (Jean Delvare)
     - uprobes: Re-order struct uprobe_task to save some space (Christophe JAILLET)
     - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
     - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
     - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg Nesterov)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Uprobes:
    - Add BPF session support (Jiri Olsa)
    - Switch to RCU Tasks Trace flavor for better performance (Andrii
      Nakryiko)
    - Massively increase uretprobe SMP scalability by SRCU-protecting
      the uretprobe lifetime (Andrii Nakryiko)
    - Kill xol_area->slot_count (Oleg Nesterov)

  Core facilities:
    - Implement targeted high-frequency profiling by adding the ability
      for an event to "pause" or "resume" AUX area tracing (Adrian
      Hunter)

  VM profiling/sampling:
    - Correct perf sampling with guest VMs (Colton Lewis)

  New hardware support:
    - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi)

  Misc fixes and enhancements:
    - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter)
    - x86/amd: Warn only on new bits set (Breno Leitao)
    - x86/amd/uncore: Avoid a false positive warning about snprintf
      truncation in amd_uncore_umc_ctx_init (Jean Delvare)
    - uprobes: Re-order struct uprobe_task to save some space
      (Christophe JAILLET)
    - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang)
    - x86/rapl: Clean up cpumask and hotplug (Kan Liang)
    - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg
      Nesterov)"

* tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/core: Correct perf sampling with guest VMs
  perf/x86: Refactor misc flag assignments
  perf/powerpc: Use perf_arch_instruction_pointer()
  perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()
  perf/arm: Drop unused functions
  uprobes: Re-order struct uprobe_task to save some space
  perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init
  perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling
  perf/x86/intel/pt: Add support for pause / resume
  perf/core: Add aux_pause, aux_resume, aux_start_paused
  perf/x86/intel/pt: Fix buffer full but size is 0 case
  uprobes: SRCU-protect uretprobe lifetime (with timeout)
  uprobes: allow put_uprobe() from non-sleepable softirq context
  perf/x86/rapl: Clean up cpumask and hotplug
  perf/x86/rapl: Move the pmu allocation out of CPU hotplug
  uprobe: Add support for session consumer
  uprobe: Add data pointer to consumer handlers
  perf/x86/amd: Warn only on new bits set
  uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
  uprobes: kill xol_area->slot_count
  ...
2024-11-19 13:34:06 -08:00
Yabin Cui
b9c44b9147 perf/core: Save raw sample data conditionally based on sample type
Currently, space for raw sample data is always allocated within sample
records for both BPF output and tracepoint events. This leads to unused
space in sample records when raw sample data is not requested.

This patch enforces checking sample type of an event in
perf_sample_save_raw_data(). So raw sample data will only be saved if
explicitly requested, reducing overhead when it is not needed.

Fixes: 0a9081cf0a ("perf/core: Add perf_sample_save_raw_data() helper")
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-2-yabinc@google.com
2024-11-19 09:23:42 +01:00
Tatsuya S
6ce5a6f0a0 tracing: Fix function name for trampoline
The issue that unrelated function name is shown on stack trace like
following even though it should be trampoline code address is caused by
the creation of trampoline code in the area where .init.text section
of module was freed after module is loaded.

bash-1344    [002] .....    43.644608: <stack trace>
=> (MODULE INIT FUNCTION)
=> vfs_write
=> ksys_write
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe

To resolve this, when function address of stack trace entry is in
trampoline, output without looking up symbol name.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241021071454.34610-2-tatsuya.s2862@gmail.com
Signed-off-by: Tatsuya S <tatsuya.s2862@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-18 15:08:10 -05:00
Jeff Xie
60b1f578b5 ftrace: Get the true parent ip for function tracer
When using both function tracer and function graph simultaneously,
it is found that function tracer sometimes captures a fake parent ip
(return_to_handler) instead of the true parent ip.

This issue is easy to reproduce. Below are my reproduction steps:

jeff-labs:~/bin # ./trace-net.sh

jeff-labs:~/bin # cat /sys/kernel/debug/tracing/instances/foo/trace | grep return_to_handler
    trace-net.sh-405     [001] ...2.    31.859501: avc_has_perm+0x4/0x190 <-return_to_handler+0x0/0x40
    trace-net.sh-405     [001] ...2.    31.859503: simple_setattr+0x4/0x70 <-return_to_handler+0x0/0x40
    trace-net.sh-405     [001] ...2.    31.859503: truncate_pagecache+0x4/0x60 <-return_to_handler+0x0/0x40
    trace-net.sh-405     [001] ...2.    31.859505: unmap_mapping_range+0x4/0x140 <-return_to_handler+0x0/0x40
    trace-net.sh-405     [001] ...3.    31.859508: _raw_spin_unlock+0x4/0x30 <-return_to_handler+0x0/0x40
    [...]

The following is my simple trace script:

<snip>
jeff-labs:~/bin # cat ./trace-net.sh
TRACE_PATH="/sys/kernel/tracing"

set_events() {
        echo 1 > $1/events/net/enable
        echo 1 > $1/events/tcp/enable
        echo 1 > $1/events/sock/enable
        echo 1 > $1/events/napi/enable
        echo 1 > $1/events/fib/enable
        echo 1 > $1/events/neigh/enable
}

set_events ${TRACE_PATH}
echo 1 > ${TRACE_PATH}/options/sym-offset
echo 1 > ${TRACE_PATH}/options/funcgraph-tail
echo 1 > ${TRACE_PATH}/options/funcgraph-proc
echo 1 > ${TRACE_PATH}/options/funcgraph-abstime

echo 'tcp_orphan*' > ${TRACE_PATH}/set_ftrace_notrace
echo function_graph > ${TRACE_PATH}/current_tracer

INSTANCE_FOO=${TRACE_PATH}/instances/foo
if [ ! -e $INSTANCE_FOO ]; then
        mkdir ${INSTANCE_FOO}
fi
set_events ${INSTANCE_FOO}
echo 1 > ${INSTANCE_FOO}/options/sym-offset
echo 'tcp_orphan*' > ${INSTANCE_FOO}/set_ftrace_notrace
echo function > ${INSTANCE_FOO}/current_tracer

echo 1 > ${TRACE_PATH}/tracing_on
echo 1 > ${INSTANCE_FOO}/tracing_on

echo > ${TRACE_PATH}/trace
echo > ${INSTANCE_FOO}/trace
</snip>

Link: https://lore.kernel.org/20241008033159.22459-1-jeff.xie@linux.dev
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jeff Xie <jeff.xie@linux.dev>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-18 12:02:43 -05:00
liujing
537affea16 ring-buffer: Correct a grammatical error in a comment
The word "trace" begins with a consonant sound,
so "a" should be used instead of "an".

Link: https://lore.kernel.org/20241107095327.6390-1-liujing@cmss.chinamobile.com
Signed-off-by: liujing <liujing@cmss.chinamobile.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-18 09:40:17 -05:00
Linus Torvalds
b5a24181e4 Ring buffer fixes for 6.12:
- Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
 
   A crash that happened on cpu hotplug was actually caused by the incorrect
   ref counting that was fixed by commit 2cf9733891 ("ring-buffer: Fix
   refcount setting of boot mapped buffers"). The removal of calling cpu
   hotplug callbacks on memory mapped buffers was not an issue even though
   the tests at the time pointed toward it. But in fact, there's a check in
   that code that tests to see if the buffers are already allocated or not,
   and will not allocate them again if they are. Not calling the cpu hotplug
   callbacks ended up not initializing the non boot CPU buffers.
 
   Simply remove that change.
 
 - Clear all CPU buffers when starting tracing in a boot mapped buffer
 
   To properly process events from a previous boot, the address space needs to
   be accounted for due to KASLR and the events in the buffer are updated
   accordingly when read. This also requires that when the buffer has tracing
   enabled again in the current boot that the buffers are reset so that events
   from the previous boot do not interact with the events of the current boot
   and cause confusing due to not having the proper meta data.
 
   It was found that if a CPU is taken offline, that its per CPU buffer is not
   reset when tracing starts. This allows for events to be from both the
   previous boot and the current boot to be in the buffer at the same time.
   Clear all CPU buffers when tracing is started in a boot mapped buffer.
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Merge tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring buffer fixes from Steven Rostedt:

 - Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU
   hotplug"

   A crash that happened on cpu hotplug was actually caused by the
   incorrect ref counting that was fixed by commit 2cf9733891
   ("ring-buffer: Fix refcount setting of boot mapped buffers"). The
   removal of calling cpu hotplug callbacks on memory mapped buffers was
   not an issue even though the tests at the time pointed toward it. But
   in fact, there's a check in that code that tests to see if the
   buffers are already allocated or not, and will not allocate them
   again if they are. Not calling the cpu hotplug callbacks ended up not
   initializing the non boot CPU buffers.

   Simply remove that change.

 - Clear all CPU buffers when starting tracing in a boot mapped buffer

   To properly process events from a previous boot, the address space
   needs to be accounted for due to KASLR and the events in the buffer
   are updated accordingly when read. This also requires that when the
   buffer has tracing enabled again in the current boot that the buffers
   are reset so that events from the previous boot do not interact with
   the events of the current boot and cause confusing due to not having
   the proper meta data.

   It was found that if a CPU is taken offline, that its per CPU buffer
   is not reset when tracing starts. This allows for events to be from
   both the previous boot and the current boot to be in the buffer at
   the same time. Clear all CPU buffers when tracing is started in a
   boot mapped buffer.

* tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording
  Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
2024-11-16 08:12:43 -08:00
Steven Rostedt
09663753bb tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording
The events of a memory mapped ring buffer from the previous boot should
not be mixed in with events from the current boot. There's meta data that
is used to handle KASLR so that function names can be shown properly.

Also, since the timestamps of the previous boot have no meaning to the
timestamps of the current boot, having them intermingled in a buffer can
also cause confusion because there could possibly be events in the future.

When a trace is activated the meta data is reset so that the pointers of
are now processed for the new address space. The trace buffers are reset
when tracing starts for the first time. The problem here is that the reset
only happens on online CPUs. If a CPU is offline, it does not get reset.

To demonstrate the issue, a previous boot had tracing enabled in the boot
mapped ring buffer on reboot. On the following boot, tracing has not been
started yet so the function trace from the previous boot is still visible.

 # trace-cmd show -B boot_mapped -c 3 | tail
          <idle>-0       [003] d.h2.   156.462395: __rcu_read_lock <-cpu_emergency_disable_virtualization
          <idle>-0       [003] d.h2.   156.462396: vmx_emergency_disable_virtualization_cpu <-cpu_emergency_disable_virtualization
          <idle>-0       [003] d.h2.   156.462396: __rcu_read_unlock <-__sysvec_reboot
          <idle>-0       [003] d.h2.   156.462397: stop_this_cpu <-__sysvec_reboot
          <idle>-0       [003] d.h2.   156.462397: set_cpu_online <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462397: disable_local_APIC <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462398: clear_local_APIC <-disable_local_APIC
          <idle>-0       [003] d.h2.   156.462574: mcheck_cpu_clear <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462575: mce_intel_feature_clear <-stop_this_cpu
          <idle>-0       [003] d.h2.   156.462575: lmce_supported <-mce_intel_feature_clear

Now, if CPU 3 is taken offline, and tracing is started on the memory
mapped ring buffer, the events from the previous boot in the CPU 3 ring
buffer is not reset. Now those events are using the meta data from the
current boot and produces just hex values.

 # echo 0 > /sys/devices/system/cpu/cpu3/online
 # trace-cmd start -B boot_mapped -p function
 # trace-cmd show -B boot_mapped -c 3 | tail
          <idle>-0       [003] d.h2.   156.462395: 0xffffffff9a1e3194 <-0xffffffff9a0f655e
          <idle>-0       [003] d.h2.   156.462396: 0xffffffff9a0a1d24 <-0xffffffff9a0f656f
          <idle>-0       [003] d.h2.   156.462396: 0xffffffff9a1e6bc4 <-0xffffffff9a0f7323
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a0d12b4 <-0xffffffff9a0f732a
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a1458d4 <-0xffffffff9a0d12e2
          <idle>-0       [003] d.h2.   156.462397: 0xffffffff9a0faed4 <-0xffffffff9a0d12e7
          <idle>-0       [003] d.h2.   156.462398: 0xffffffff9a0faaf4 <-0xffffffff9a0faef2
          <idle>-0       [003] d.h2.   156.462574: 0xffffffff9a0e3444 <-0xffffffff9a0d12ef
          <idle>-0       [003] d.h2.   156.462575: 0xffffffff9a0e4964 <-0xffffffff9a0d12ef
          <idle>-0       [003] d.h2.   156.462575: 0xffffffff9a0e3fb0 <-0xffffffff9a0e496f

Reset all CPUs when starting a boot mapped ring buffer for the first time,
and not just the online CPUs.

Fixes: 7a1d1e4b96 ("tracing/ring-buffer: Add last_boot_info file to boot instance")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14 11:54:34 -05:00
Steven Rostedt
580bb355bc Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
A crash happened when testing cpu hotplug with respect to the memory
mapped ring buffers. It was assumed that the hot plug code was adding a
per CPU buffer that was already created that caused the crash. The real
problem was due to ref counting and was fixed by commit 2cf9733891
("ring-buffer: Fix refcount setting of boot mapped buffers").

When a per CPU buffer is created, it will not be created again even with
CPU hotplug, so the fix to not use CPU hotplug was a red herring. In fact,
it caused only the boot CPU buffer to be created, leaving the other CPU
per CPU buffers disabled.

Revert that change as it was not the culprit of the fix it was intended to
be.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241113230839.6c03640f@gandalf.local.home
Fixes: 912da2c384 ("ring-buffer: Do not have boot mapped buffers hook to CPU hotplug")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14 10:01:00 -05:00
Alexei Starovoitov
8714381703 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

In particular to bring the fix in
commit aa30eb3260 ("bpf: Force checkpoint when jmp history is too long").
The follow up verifier work depends on it.
And the fix in
commit 6801cf7890 ("selftests/bpf: Use -4095 as the bad address for bits iterator").
It's fixing instability of BPF CI on s390 arch.

No conflicts.

Adjacent changes in:
Auto-merging arch/Kconfig
Auto-merging kernel/bpf/helpers.c
Auto-merging kernel/bpf/memalloc.c
Auto-merging kernel/bpf/verifier.c
Auto-merging mm/slab_common.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-13 12:52:51 -08:00
Colin Ian King
6371b4bc17 tracing: Remove redundant check on field->field in histograms
The check on field->field being true is handled as the first check
on the cascaded if statement, so the later checks on field->field
are redundant because this clause has already been handled. Since
this later check is redundant, just remove it.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241107120530.18728-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-12 11:36:57 -05:00
Jiri Olsa
99b403d206 bpf: Add support for uprobe multi session context
Placing bpf_session_run_ctx layer in between bpf_run_ctx and
bpf_uprobe_multi_run_ctx, so the session data can be retrieved
from uprobe_multi link.

Plus granting session kfuncs access to uprobe session programs.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-5-jolsa@kernel.org
2024-11-11 08:18:04 -08:00
Jiri Olsa
d920179b3d bpf: Add support for uprobe multi session attach
Adding support to attach BPF program for entry and return probe
of the same function. This is common use case which at the moment
requires to create two uprobe multi links.

Adding new BPF_TRACE_UPROBE_SESSION attach type that instructs
kernel to attach single link program to both entry and exit probe.

It's possible to control execution of the BPF program on return
probe simply by returning zero or non zero from the entry BPF
program execution to execute or not the BPF program on return
probe respectively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-4-jolsa@kernel.org
2024-11-11 08:18:03 -08:00
Jiri Olsa
f505005bc7 bpf: Force uprobe bpf program to always return 0
As suggested by Andrii make uprobe multi bpf programs to always return 0,
so they can't force uprobe removal.

Keeping the int return type for uprobe_prog_run, because it will be used
in following session changes.

Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-3-jolsa@kernel.org
2024-11-11 08:18:00 -08:00
Andrii Nakryiko
5f67329cb2 Stable tag for bpf-next's uprobe work.
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Merge tag 'perf-core-for-bpf-next' from tip tree

Stable tag for bpf-next's uprobe work.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2024-11-06 08:13:03 -08:00
Yuran Pereira
0c10cc2435 trace: kdb: Replace simple_strtoul with kstrtoul in kdb_ftdump
The function simple_strtoul performs no error checking in scenarios
where the input value overflows the intended output variable.
This results in this function successfully returning, even when the
output does not match the input string (aka the function returns
successfully even when the result is wrong).

Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(),
simple_strtoul(), and simple_strtoull() functions explicitly ignore
overflows, which may lead to unexpected results in callers."
Hence, the use of those functions is discouraged.

This patch replaces all uses of the simple_strtoul with the safer
alternatives kstrtoint and kstrtol.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull

Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[nir: style fixes]
Signed-off-by: Nir Lichtman <nir@lichtman.org>
Link: https://lore.kernel.org/r/20241028192100.GB918454@lichtman.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2024-11-02 08:33:13 +00:00
Jinjie Ruan
242b32d807 tracing: Replace strncpy() with strscpy() when copying comm
Replace the depreciated[1] strncpy() calls with strscpy()
when copying comm.

Link: https://github.com/KSPP/linux/issues/90 [1]

Cc: <mhiramat@kernel.org>
Cc: <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241031120139.1343025-1-ruanjinjie@huawei.com
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-01 14:37:31 -04:00
Sebastian Andrzej Siewior
e9f0a36347 tracing: Remove TRACE_FLAG_IRQS_NOSUPPORT
It was possible to enable tracing with no IRQ tracing support. The
tracing infrastructure would then record TRACE_FLAG_IRQS_NOSUPPORT as
the only tracing flag and show an 'X' in the output.

The last user of this feature was PPC32 which managed to implement it
during PowerPC merge in 2009. Since then, it was unused and the PPC32
dependency was finally removed in commit 0ea5ee0351 ("tracing: Remove
PPC32 wart from config TRACING_SUPPORT").
Since the PowerPC merge the code behind !CONFIG_TRACE_IRQFLAGS_SUPPORT
with TRACING enabled can no longer be selected used and the 'X' is not
displayed or recorded.

Remove the CONFIG_TRACE_IRQFLAGS_SUPPORT from the tracing code. Remove
TRACE_FLAG_IRQS_NOSUPPORT.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241022110112.XJI8I9T2@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-01 14:37:30 -04:00
Kalesh Singh
fa17cb4b3b tracing: Document tracefs gid mount option
Commit ee7f366699 ("tracefs: Have new files inherit the ownership of
their parent") and commit 48b27b6b51 ("tracefs: Set all files to the
same group ownership as the mount option") introduced a new gid mount
option that allows specifying a group to apply to all entries in tracefs.

Document this in the tracing readme.

Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ali Zahraee <ahzahraee@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/20241030171928.4168869-3-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-01 08:57:17 -04:00
Justin Stitt
77a1326f64 tracing: Replace multiple deprecated strncpy with memcpy
strncpy() is deprecated for use on NUL-terminated destination strings [1] and
as such we should prefer more robust and less ambiguous string interfaces.

String copy operations involving manual pointer offset and length
calculations followed by explicit NUL-byte assignments are best changed
to either strscpy or memcpy.

strscpy is not a drop-in replacement as @len would need a one subtracted
from it to avoid truncating the source string.

To not sabotage readability of the current code, use memcpy (retaining
the manual NUL assignment) as this unambiguously describes the desired
behavior.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90 [2]

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/20241014-strncpy-kernel-trace-trace_events_filter-c-v2-1-d821e81e371e@google.com
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-30 19:41:08 -04:00
Ryan Roberts
2c33155ef6 tracing: Make percpu stack trace buffer invariant to PAGE_SIZE
Previously the size of "struct ftrace_stacks" depended upon PAGE_SIZE.
For the common 4K page size, on a 64-bit system, sizeof(struct
ftrace_stacks) was 32K. But for a 64K page size, sizeof(struct
ftrace_stacks) was 512K.

But ftrace stack usage requirements should be invariant to page size. So
let's redefine FTRACE_KSTACK_ENTRIES so that "struct ftrace_stacks" is
always sized at 32K for 64-bit and 16K for 32-bit.

As a side effect, it removes the PAGE_SIZE compile-time constant
assumption from this code, which is required to reach the goal of
boot-time page size selection.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241021141832.3668264-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-30 19:41:07 -04:00
Steven Rostedt
36a367b891 ftrace: Show timings of how long nop patching took
Since the beginning of ftrace, the code that did the patching had its
timings saved on how long it took to complete. But this information was
never exposed. It was used for debugging and exposing it was always
something that was on the TODO list. Now it's time to expose it. There's
even a file that is where it should go!

Also include how long patching modules took as a separate value.

 # cat /sys/kernel/tracing/dyn_ftrace_total_info
 57680 pages:231 groups: 9
 ftrace boot update time = 14024666 (ns)
 ftrace module total update time = 126070 (ns)

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241017113105.1edfa943@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-30 19:20:53 -04:00
Steven Rostedt
8b0cb3a4c5 ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()
The ftrace_lock is taken for most of the ftrace_graph_set_hash() function
throughout the end. Use guard to take the ftrace_lock to simplify the exit
paths.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.406073025@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
9687bbf219 ftrace: Use guard to take the ftrace_lock in release_probe()
The ftrace_lock is held throughout the entire release_probe() function.
Use guard to simplify any exit paths.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.250787901@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
1432afb50d ftrace: Use guard to lock ftrace_lock in cache_mod()
The ftrace_lock is held throughout cache_mod(), use guard to simplify the
error paths.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071308.088458856@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
06294cf045 ftrace: Use guard for match_records()
The ftrace_lock is held for most of match_records() until the end of the
function. Use guard to make error paths simpler.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071307.927146604@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
6348a3fa72 fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()
The ftrace_lock is held throughout unregister_ftrace_graph(), use a guard
to simplify the error paths.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071307.770550792@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
434098485b fgraph: Give ret_stack its own kmem cache
The ret_stack (shadow stack used by function graph infrastructure) is
created for every task on the system when function graph is enabled. Give
it its own kmem_cache. This will make it easier to see how much memory is
being used specifically for function graph shadow stacks.

In the future, this size may change and may not be a power of two. Having
its own cache can also keep it from fragmenting memory.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/20241026063210.7d4910a7@rorschach.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:02 -04:00
Steven Rostedt
6ea8b69da6 fgraph: Separate size of ret_stack from PAGE_SIZE
The ret_stack (shadow stack used by function graph infrastructure) is
currently defined as PAGE_SIZE. But some architectures which have 64K
PAGE_SIZE, this is way overkill. Also there's an effort to allow the
PAGE_SIZE to be defined at boot up.

Hard code it for now to 4096. In the future, this size may change and even
be dependent on specific architectures.

Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241019152951.053f9646@rorschach.local.home
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:43:01 -04:00
Steven Rostedt
81ec38ee9d Fixes for function graph:
- Fix missing mutex unlock in error path of register_ftrace_graph()
 
   A previous fix added a return on an error path and forgot to unlock the
   mutex. Instead of dealing with error paths, use guard(mutex) as the mutex
   is just released at the exit of the function anyway. Other functions
   in this file should be updated with this, but that's a cleanup and not
   a fix.
 
 - Change cpuhp setup name to be consistent with other cpuhp states
 
   The same fix that the above patch fixes added a cpuhp_setup_state() call
   with the name of "fgraph_idle_init". I was informed that it should instead
   be something like: "fgraph:online". Update that too.
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Merge tag 'ftrace-v6.12-rc4' into trace/ftrace/core

In order to modify the code that allocates the shadow stacks, merge the
changes that fixed the CPU hotplug shadow stack allocations and build on
top of that.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-29 07:31:50 -04:00
Linus Torvalds
f69a1accfe Fixes for function graph:
- Fix missing mutex unlock in error path of register_ftrace_graph()
 
   A previous fix added a return on an error path and forgot to unlock the
   mutex. Instead of dealing with error paths, use guard(mutex) as the mutex
   is just released at the exit of the function anyway. Other functions
   in this file should be updated with this, but that's a cleanup and not
   a fix.
 
 - Change cpuhp setup name to be consistent with other cpuhp states
 
   The same fix that the above patch fixes added a cpuhp_setup_state() call
   with the name of "fgraph_idle_init". I was informed that it should instead
   be something like: "fgraph:online". Update that too.
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Merge tag 'ftrace-v6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace fixes from Steven Rostedt:

 - Fix missing mutex unlock in error path of register_ftrace_graph()

   A previous fix added a return on an error path and forgot to unlock
   the mutex. Instead of dealing with error paths, use guard(mutex) as
   the mutex is just released at the exit of the function anyway. Other
   functions in this file should be updated with this, but that's a
   cleanup and not a fix.

 - Change cpuhp setup name to be consistent with other cpuhp states

   The same fix that the above patch fixes added a cpuhp_setup_state()
   call with the name of "fgraph_idle_init". I was informed that it
   should instead be something like: "fgraph:online". Update that too.

* tag 'ftrace-v6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fgraph: Change the name of cpuhp state to "fgraph:online"
  fgraph: Fix missing unlock in register_ftrace_graph()
2024-10-27 08:56:22 -10:00
Steven Rostedt
a574e7f80e fgraph: Change the name of cpuhp state to "fgraph:online"
The cpuhp state name given to cpuhp_setup_state() is "fgraph_idle_init"
which doesn't really conform to the names that are used for cpu hotplug
setups. Instead rename it to "fgraph:online" to be in line with other
states.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241024222944.473d88c5@rorschach.local.home
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 2c02f7375e ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-24 23:41:14 -04:00
Li Huafei
bd3734db86 fgraph: Fix missing unlock in register_ftrace_graph()
Use guard(mutex)() to acquire and automatically release ftrace_lock,
fixing the issue of not unlocking when calling cpuhp_setup_state()
fails.

Fixes smatch warning:

kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'.

Link: https://lore.kernel.org/20241024155917.1019580-1-lihuafei1@huawei.com
Fixes: 2c02f7375e ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202410220121.wxg0olfd-lkp@intel.com/
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-24 22:26:06 -04:00
Alexei Starovoitov
bfa7b5c98b Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:

include/linux/bpf.h
include/uapi/linux/bpf.h
kernel/bpf/btf.c
kernel/bpf/helpers.c
kernel/bpf/syscall.c
kernel/bpf/verifier.c
kernel/trace/bpf_trace.c
mm/slab_common.c
tools/include/uapi/linux/bpf.h
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/all/20241024215724.60017-1-daniel@iogearbox.net/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 18:47:28 -07:00
Linus Torvalds
ae90f6a617 BPF fixes:
- Fix an out-of-bounds read in bpf_link_show_fdinfo for BPF
   sockmap link file descriptors (Hou Tao)
 
 - Fix BPF arm64 JIT's address emission with tag-based KASAN
   enabled reserving not enough size (Peter Collingbourne)
 
 - Fix BPF verifier do_misc_fixups patching for inlining of the
   bpf_get_branch_snapshot BPF helper (Andrii Nakryiko)
 
 - Fix a BPF verifier bug and reject BPF program write attempts
   into read-only marked BPF maps (Daniel Borkmann)
 
 - Fix perf_event_detach_bpf_prog error handling by removing an
   invalid check which would skip BPF program release (Jiri Olsa)
 
 - Fix memory leak when parsing mount options for the BPF
   filesystem (Hou Tao)
 
 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Daniel Borkmann:

 - Fix an out-of-bounds read in bpf_link_show_fdinfo for BPF sockmap
   link file descriptors (Hou Tao)

 - Fix BPF arm64 JIT's address emission with tag-based KASAN enabled
   reserving not enough size (Peter Collingbourne)

 - Fix BPF verifier do_misc_fixups patching for inlining of the
   bpf_get_branch_snapshot BPF helper (Andrii Nakryiko)

 - Fix a BPF verifier bug and reject BPF program write attempts into
   read-only marked BPF maps (Daniel Borkmann)

 - Fix perf_event_detach_bpf_prog error handling by removing an invalid
   check which would skip BPF program release (Jiri Olsa)

 - Fix memory leak when parsing mount options for the BPF filesystem
   (Hou Tao)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Check validity of link->type in bpf_link_show_fdinfo()
  bpf: Add the missing BPF_LINK_TYPE invocation for sockmap
  bpf: fix do_misc_fixups() for bpf_get_branch_snapshot()
  bpf,perf: Fix perf_event_detach_bpf_prog error handling
  selftests/bpf: Add test for passing in uninit mtu_len
  selftests/bpf: Add test for writes to .rodata
  bpf: Remove MEM_UNINIT from skb/xdp MTU helpers
  bpf: Fix overloading of MEM_UNINIT's meaning
  bpf: Add MEM_WRITE attribute
  bpf: Preserve param->string when parsing mount options
  bpf, arm64: Fix address emission with tag-based KASAN enabled
2024-10-24 16:53:20 -07:00
Jiri Olsa
0ee288e69d bpf,perf: Fix perf_event_detach_bpf_prog error handling
Peter reported that perf_event_detach_bpf_prog might skip to release
the bpf program for -ENOENT error from bpf_prog_array_copy.

This can't happen because bpf program is stored in perf event and is
detached and released only when perf event is freed.

Let's drop the -ENOENT check and make sure the bpf program is released
in any case.

Fixes: 170a7e3ea0 ("bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found")
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241023200352.3488610-1-jolsa@kernel.org

Closes: https://lore.kernel.org/lkml/20241022111638.GC16066@noisy.programming.kicks-ass.net/
2024-10-23 14:33:02 -07:00
Jiri Olsa
da09a9e0c3 uprobe: Add data pointer to consumer handlers
Adding data pointer to both entry and exit consumer handlers and all
its users. The functionality itself is coming in following change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241018202252.693462-2-jolsa@kernel.org
2024-10-23 20:52:27 +02:00
Leo Yan
0b6e2e22cb tracing: Consider the NULL character when validating the event length
strlen() returns a string length excluding the null byte. If the string
length equals to the maximum buffer length, the buffer will have no
space for the NULL terminating character.

This commit checks this condition and returns failure for it.

Link: https://lore.kernel.org/all/20241007144724.920954-1-leo.yan@arm.com/

Fixes: dec65d79fd ("tracing/probe: Check event name length correctly")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-23 17:24:47 +09:00
Mikel Rychliski
73f3508047 tracing/probes: Fix MAX_TRACE_ARGS limit handling
When creating a trace_probe we would set nr_args prior to truncating the
arguments to MAX_TRACE_ARGS. However, we would only initialize arguments
up to the limit.

This caused invalid memory access when attempting to set up probes with
more than 128 fetchargs.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
  RIP: 0010:__set_print_fmt+0x134/0x330

Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return
an error when there are too many arguments instead of silently
truncating.

Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/

Fixes: 035ba76014 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init")
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-23 17:24:44 +09:00
Daniel Borkmann
6fad274f06 bpf: Add MEM_WRITE attribute
Add a MEM_WRITE attribute for BPF helper functions which can be used in
bpf_func_proto to annotate an argument type in order to let the verifier
know that the helper writes into the memory passed as an argument. In
the past MEM_UNINIT has been (ab)used for this function, but the latter
merely tells the verifier that the passed memory can be uninitialized.

There have been bugs with overloading the latter but aside from that
there are also cases where the passed memory is read + written which
currently cannot be expressed, see also 4b3786a6c5 ("bpf: Zero former
ARG_PTR_TO_{LONG,INT} args in case of error").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241021152809.33343-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-22 15:42:56 -07:00
Puranjay Mohan
6280cf718d bpf: Implement bpf_send_signal_task() kfunc
Implement bpf_send_signal_task kfunc that is similar to
bpf_send_signal_thread and bpf_send_signal helpers  but can be used to
send signals to other threads and processes. It also supports sending a
cookie with the signal similar to sigqueue().

If the receiving process establishes a handler for the signal using the
SA_SIGINFO flag to sigaction(), then it can obtain this cookie via the
si_value field of the siginfo_t structure passed as the second argument
to the handler.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241016084136.10305-2-puranjay@kernel.org
2024-10-21 15:02:49 -07:00
Qiao Ma
373b9338c9 uprobe: avoid out-of-bounds memory access of fetching args
Uprobe needs to fetch args into a percpu buffer, and then copy to ring
buffer to avoid non-atomic context problem.

Sometimes user-space strings, arrays can be very large, but the size of
percpu buffer is only page size. And store_trace_args() won't check
whether these data exceeds a single page or not, caused out-of-bounds
memory access.

It could be reproduced by following steps:
1. build kernel with CONFIG_KASAN enabled
2. save follow program as test.c

```
\#include <stdio.h>
\#include <stdlib.h>
\#include <string.h>

// If string length large than MAX_STRING_SIZE, the fetch_store_strlen()
// will return 0, cause __get_data_size() return shorter size, and
// store_trace_args() will not trigger out-of-bounds access.
// So make string length less than 4096.
\#define STRLEN 4093

void generate_string(char *str, int n)
{
    int i;
    for (i = 0; i < n; ++i)
    {
        char c = i % 26 + 'a';
        str[i] = c;
    }
    str[n-1] = '\0';
}

void print_string(char *str)
{
    printf("%s\n", str);
}

int main()
{
    char tmp[STRLEN];

    generate_string(tmp, STRLEN);
    print_string(tmp);

    return 0;
}
```
3. compile program
`gcc -o test test.c`

4. get the offset of `print_string()`
```
objdump -t test | grep -w print_string
0000000000401199 g     F .text  000000000000001b              print_string
```

5. configure uprobe with offset 0x1199
```
off=0x1199

cd /sys/kernel/debug/tracing/
echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring"
 > uprobe_events
echo 1 > events/uprobes/enable
echo 1 > tracing_on
```

6. run `test`, and kasan will report error.
==================================================================
BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0
Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18
Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x55/0x70
 print_address_description.constprop.0+0x27/0x310
 kasan_report+0x10f/0x120
 ? strncpy_from_user+0x1d6/0x1f0
 strncpy_from_user+0x1d6/0x1f0
 ? rmqueue.constprop.0+0x70d/0x2ad0
 process_fetch_insn+0xb26/0x1470
 ? __pfx_process_fetch_insn+0x10/0x10
 ? _raw_spin_lock+0x85/0xe0
 ? __pfx__raw_spin_lock+0x10/0x10
 ? __pte_offset_map+0x1f/0x2d0
 ? unwind_next_frame+0xc5f/0x1f80
 ? arch_stack_walk+0x68/0xf0
 ? is_bpf_text_address+0x23/0x30
 ? kernel_text_address.part.0+0xbb/0xd0
 ? __kernel_text_address+0x66/0xb0
 ? unwind_get_return_address+0x5e/0xa0
 ? __pfx_stack_trace_consume_entry+0x10/0x10
 ? arch_stack_walk+0xa2/0xf0
 ? _raw_spin_lock_irqsave+0x8b/0xf0
 ? __pfx__raw_spin_lock_irqsave+0x10/0x10
 ? depot_alloc_stack+0x4c/0x1f0
 ? _raw_spin_unlock_irqrestore+0xe/0x30
 ? stack_depot_save_flags+0x35d/0x4f0
 ? kasan_save_stack+0x34/0x50
 ? kasan_save_stack+0x24/0x50
 ? mutex_lock+0x91/0xe0
 ? __pfx_mutex_lock+0x10/0x10
 prepare_uprobe_buffer.part.0+0x2cd/0x500
 uprobe_dispatcher+0x2c3/0x6a0
 ? __pfx_uprobe_dispatcher+0x10/0x10
 ? __kasan_slab_alloc+0x4d/0x90
 handler_chain+0xdd/0x3e0
 handle_swbp+0x26e/0x3d0
 ? __pfx_handle_swbp+0x10/0x10
 ? uprobe_pre_sstep_notifier+0x151/0x1b0
 irqentry_exit_to_user_mode+0xe2/0x1b0
 asm_exc_int3+0x39/0x40
RIP: 0033:0x401199
Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce
RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206
RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2
RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0
RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20
R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040
R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

This commit enforces the buffer's maxlen less than a page-size to avoid
store_trace_args() out-of-memory access.

Link: https://lore.kernel.org/all/20241015060148.1108331-1-mqaio@linux.alibaba.com/

Fixes: dcad1a204f ("tracing/uprobes: Fetch args before reserving a ring buffer")
Signed-off-by: Qiao Ma <mqaio@linux.alibaba.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-10-21 13:15:28 +09:00
Linus Torvalds
2b4d25010d - Add PREEMPT_RT maintainers
- Fix another aspect of delayed dequeued tasks wrt determining their state,
   i.e., whether they're runnable or blocked
 
 - Handle delayed dequeued tasks and their migration wrt PSI properly
 
 - Fix the situation where a delayed dequeue task gets enqueued into a new
   class, which should not happen
 
 - Fix a case where memory allocation would happen while the runqueue lock is
   held, which is a no-no
 
 - Do not over-schedule when tasks with shorter slices preempt the currently
   running task
 
 - Make sure delayed to deque entities are properly handled before unthrottling
 
 - Other smaller cleanups and improvements
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Merge tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduling fixes from Borislav Petkov:

 - Add PREEMPT_RT maintainers

 - Fix another aspect of delayed dequeued tasks wrt determining their
   state, i.e., whether they're runnable or blocked

 - Handle delayed dequeued tasks and their migration wrt PSI properly

 - Fix the situation where a delayed dequeue task gets enqueued into a
   new class, which should not happen

 - Fix a case where memory allocation would happen while the runqueue
   lock is held, which is a no-no

 - Do not over-schedule when tasks with shorter slices preempt the
   currently running task

 - Make sure delayed to deque entities are properly handled before
   unthrottling

 - Other smaller cleanups and improvements

* tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Add an entry for PREEMPT_RT.
  sched/fair: Fix external p->on_rq users
  sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug
  sched/core: Dequeue PSI signals for blocked tasks that are delayed
  sched: Fix delayed_dequeue vs switched_from_fair()
  sched/core: Disable page allocation in task_tick_mm_cid()
  sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl()
  sched/eevdf: Fix wakeup-preempt by checking cfs_rq->nr_running
  sched: Fix sched_delayed vs cfs_bandwidth
2024-10-20 11:30:56 -07:00
Linus Torvalds
06526daaff ftrace: A couple of fixes to function graph infrastructure
- Fix allocation of idle shadow stack allocation during hotplug
 
   If function graph tracing is started when a CPU is offline, if it were
   come online during the trace then the idle task that represents the CPU
   will not get a shadow stack allocated for it. This means all function
   graph hooks that happen while that idle task is running (including in
   interrupt mode) will have all its events dropped.
 
   Switch over to the CPU hotplug mechanism that will have any newly
   brought on line CPU get a callback that can allocate the shadow stack
   for its idle task.
 
 - Fix allocation size of the ret_stack_list array
 
   When function graph tracing converted over to allowing more than one
   user at a time, it had to convert its shadow stack from an array of
   ret_stack structures to an array of unsigned longs. The shadow stacks
   are allocated in batches of 32 at a time and assigned to every running
   task. The batch is held by the ret_stack_list array. But when the
   conversion happened, instead of allocating an array of 32 pointers, it
   was allocated as a ret_stack itself (PAGE_SIZE). This ret_stack_list
   gets passed to a function that iterates over what it believes is its
   size defined by the FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32).
 
   Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise this
   would have been an array overflow. This still should be fixed and the
   ret_stack_list should be allocated to the size it is expected to be as
   someday it may end up being bigger than SHADOW_STACK_SIZE.
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Merge tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace fixes from Steven Rostedt:
 "A couple of fixes to function graph infrastructure:

   - Fix allocation of idle shadow stack allocation during hotplug

     If function graph tracing is started when a CPU is offline, if it
     were come online during the trace then the idle task that
     represents the CPU will not get a shadow stack allocated for it.
     This means all function graph hooks that happen while that idle
     task is running (including in interrupt mode) will have all its
     events dropped.

     Switch over to the CPU hotplug mechanism that will have any newly
     brought on line CPU get a callback that can allocate the shadow
     stack for its idle task.

   - Fix allocation size of the ret_stack_list array

     When function graph tracing converted over to allowing more than
     one user at a time, it had to convert its shadow stack from an
     array of ret_stack structures to an array of unsigned longs. The
     shadow stacks are allocated in batches of 32 at a time and assigned
     to every running task. The batch is held by the ret_stack_list
     array.

     But when the conversion happened, instead of allocating an array of
     32 pointers, it was allocated as a ret_stack itself (PAGE_SIZE).
     This ret_stack_list gets passed to a function that iterates over
     what it believes is its size defined by the
     FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32).

     Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise
     this would have been an array overflow. This still should be fixed
     and the ret_stack_list should be allocated to the size it is
     expected to be as someday it may end up being bigger than
     SHADOW_STACK_SIZE"

* tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fgraph: Allocate ret_stack_list with proper size
  fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
2024-10-19 12:42:14 -07:00
Thorsten Blum
514da6924e ring-buffer: Use str_low_high() helper in ring_buffer_producer()
Remove hard-coded strings by using the helper function str_low_high().

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018110709.111707-2-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-19 11:12:25 -04:00
Julia Lawall
0b60a7fb60 ring-buffer: Reorganize kerneldoc parameter names
Reorganize kerneldoc parameter names to match the parameter
order in the function header.

Problems identified using Coccinelle.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240930112121.95324-22-Julia.Lawall@inria.fr
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-19 11:12:25 -04:00
Petr Pavlu
b237e1f7d2 ring-buffer: Limit time with disabled interrupts in rb_check_pages()
The function rb_check_pages() validates the integrity of a specified
per-CPU tracing ring buffer. It does so by traversing the underlying
linked list and checking its next and prev links.

To guarantee that the list isn't modified during the check, a caller
typically needs to take cpu_buffer->reader_lock. This prevents the check
from running concurrently, for example, with a potential reader which
can make the list temporarily inconsistent when swapping its old reader
page into the buffer.

A problem with this approach is that the time when interrupts are
disabled is non-deterministic, dependent on the ring buffer size. This
particularly affects PREEMPT_RT because the reader_lock is a raw
spinlock which doesn't become sleepable on PREEMPT_RT kernels.

Modify the check so it still attempts to traverse the entire list, but
gives up the reader_lock between checking individual pages. Introduce
for this purpose a new variable ring_buffer_per_cpu.cnt which is bumped
any time the list is modified. The value is used by rb_check_pages() to
detect such a change and restart the check.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112810.27203-1-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-19 11:12:01 -04:00
Steven Rostedt
fae4078c28 fgraph: Allocate ret_stack_list with proper size
The ret_stack_list is an array of ret_stack shadow stacks for the function
graph usage. When the first function graph is enabled, all tasks in the
system get a shadow stack. The ret_stack_list is a 32 element array of
pointers to these shadow stacks. It allocates the shadow stack in batches
(32 stacks at a time), assigns them to running tasks, and continues until
all tasks are covered.

When the function graph shadow stack changed from an array of
ftrace_ret_stack structures to an array of longs, the allocation of
ret_stack_list went from allocating an array of 32 elements to just a
block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE
and is much more than enough to hold 32 pointers. But it is way overkill
for the amount needed to allocate.

Change the allocation of ret_stack_list back to a kcalloc() of
FTRACE_RETSTACK_ALLOC_SIZE pointers.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach
Fixes: 42675b723b ("function_graph: Convert ret_stack to a series of longs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18 21:57:20 -04:00
Steven Rostedt
2c02f7375e fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
The function graph infrastructure allocates a shadow stack for every task
when enabled. This includes the idle tasks. The first time the function
graph is invoked, the shadow stacks are created and never freed until the
task exits. This includes the idle tasks.

Only the idle tasks that were for online CPUs had their shadow stacks
created when function graph tracing started. If function graph tracing is
enabled and a CPU comes online, the idle task representing that CPU will
not have its shadow stack created, and all function graph tracing for that
idle task will be silently dropped.

Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks.
This will include idle tasks for CPUs that come online during tracing.

This issue can be reproduced by:

 # cd /sys/kernel/tracing
 # echo 0 > /sys/devices/system/cpu/cpu1/online
 # echo 0 > set_ftrace_pid
 # echo function_graph > current_tracer
 # echo 1 > options/funcgraph-proc
 # echo 1 > /sys/devices/system/cpu/cpu1
 # grep '<idle>' per_cpu/cpu1/trace | head

Before, nothing would show up.

After:
 1)    <idle>-0    |   0.811 us    |                        __enqueue_entity();
 1)    <idle>-0    |   5.626 us    |                      } /* enqueue_entity */
 1)    <idle>-0    |               |                      dl_server_update_idle_time() {
 1)    <idle>-0    |               |                        dl_scaled_delta_exec() {
 1)    <idle>-0    |   0.450 us    |                          arch_scale_cpu_capacity();
 1)    <idle>-0    |   1.242 us    |                        }
 1)    <idle>-0    |   1.908 us    |                      }
 1)    <idle>-0    |               |                      dl_server_start() {
 1)    <idle>-0    |               |                        enqueue_dl_entity() {
 1)    <idle>-0    |               |                          task_contending() {

Note, if tracing stops and restarts, the old way would then initialize
the onlined CPUs.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241018214300.6df82178@rorschach
Fixes: 868baf07b1 ("ftrace: Fix memory leak with function graph and cpu hotplug")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18 21:56:56 -04:00
Linus Torvalds
3d5ad2d4ec BPF fixes:
- Fix BPF verifier to not affect subreg_def marks in its range
   propagation, from Eduard Zingerman.
 
 - Fix a truncation bug in the BPF verifier's handling of
   coerce_reg_to_size_sx, from Dimitar Kanaliev.
 
 - Fix the BPF verifier's delta propagation between linked
   registers under 32-bit addition, from Daniel Borkmann.
 
 - Fix a NULL pointer dereference in BPF devmap due to missing
   rxq information, from Florian Kauer.
 
 - Fix a memory leak in bpf_core_apply, from Jiri Olsa.
 
 - Fix an UBSAN-reported array-index-out-of-bounds in BTF
   parsing for arrays of nested structs, from Hou Tao.
 
 - Fix build ID fetching where memory areas backing the file
   were created with memfd_secret, from Andrii Nakryiko.
 
 - Fix BPF task iterator tid filtering which was incorrectly
   using pid instead of tid, from Jordan Rome.
 
 - Several fixes for BPF sockmap and BPF sockhash redirection
   in combination with vsocks, from Michal Luczaj.
 
 - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered,
   from Andrea Parri.
 
 - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the
   possibility of an infinite BPF tailcall, from Pu Lehui.
 
 - Fix a build warning from resolve_btfids that bpf_lsm_key_free
   cannot be resolved, from Thomas Weißschuh.
 
 - Fix a bug in kfunc BTF caching for modules where the wrong
   BTF object was returned, from Toke Høiland-Jørgensen.
 
 - Fix a BPF selftest compilation error in cgroup-related tests
   with musl libc, from Tony Ambardar.
 
 - Several fixes to BPF link info dumps to fill missing fields,
   from Tyrone Wu.
 
 - Add BPF selftests for kfuncs from multiple modules, checking
   that the correct kfuncs are called, from Simon Sundberg.
 
 - Ensure that internal and user-facing bpf_redirect flags
   don't overlap, also from Toke Høiland-Jørgensen.
 
 - Switch to use kvzmalloc to allocate BPF verifier environment,
   from Rik van Riel.
 
 - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic
   splat under RT, from Wander Lairson Costa.
 
 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Daniel Borkmann:

 - Fix BPF verifier to not affect subreg_def marks in its range
   propagation (Eduard Zingerman)

 - Fix a truncation bug in the BPF verifier's handling of
   coerce_reg_to_size_sx (Dimitar Kanaliev)

 - Fix the BPF verifier's delta propagation between linked registers
   under 32-bit addition (Daniel Borkmann)

 - Fix a NULL pointer dereference in BPF devmap due to missing rxq
   information (Florian Kauer)

 - Fix a memory leak in bpf_core_apply (Jiri Olsa)

 - Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for
   arrays of nested structs (Hou Tao)

 - Fix build ID fetching where memory areas backing the file were
   created with memfd_secret (Andrii Nakryiko)

 - Fix BPF task iterator tid filtering which was incorrectly using pid
   instead of tid (Jordan Rome)

 - Several fixes for BPF sockmap and BPF sockhash redirection in
   combination with vsocks (Michal Luczaj)

 - Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri)

 - Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility
   of an infinite BPF tailcall (Pu Lehui)

 - Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot
   be resolved (Thomas Weißschuh)

 - Fix a bug in kfunc BTF caching for modules where the wrong BTF object
   was returned (Toke Høiland-Jørgensen)

 - Fix a BPF selftest compilation error in cgroup-related tests with
   musl libc (Tony Ambardar)

 - Several fixes to BPF link info dumps to fill missing fields (Tyrone
   Wu)

 - Add BPF selftests for kfuncs from multiple modules, checking that the
   correct kfuncs are called (Simon Sundberg)

 - Ensure that internal and user-facing bpf_redirect flags don't overlap
   (Toke Høiland-Jørgensen)

 - Switch to use kvzmalloc to allocate BPF verifier environment (Rik van
   Riel)

 - Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat
   under RT (Wander Lairson Costa)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits)
  lib/buildid: Handle memfd_secret() files in build_id_parse()
  selftests/bpf: Add test case for delta propagation
  bpf: Fix print_reg_state's constant scalar dump
  bpf: Fix incorrect delta propagation between linked registers
  bpf: Properly test iter/task tid filtering
  bpf: Fix iter/task tid filtering
  riscv, bpf: Make BPF_CMPXCHG fully ordered
  bpf, vsock: Drop static vsock_bpf_prot initialization
  vsock: Update msg_count on read_skb()
  vsock: Update rx_bytes on read_skb()
  bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock
  selftests/bpf: Add asserts for netfilter link info
  bpf: Fix link info netfilter flags to populate defrag flag
  selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx()
  selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx()
  bpf: Fix truncation bug in coerce_reg_to_size_sx()
  selftests/bpf: Assert link info uprobe_multi count & path_size if unset
  bpf: Fix unpopulated path_size when uprobe_multi fields unset
  selftests/bpf: Fix cross-compiling urandom_read
  selftests/bpf: Add test for kfunc module order
  ...
2024-10-18 16:27:14 -07:00
Ingo Molnar
be602cde65 Merge branch 'linus' into sched/urgent, to resolve conflict
Conflicts:
	kernel/sched/ext.c

There's a context conflict between this upstream commit:

  3fdb9ebcec sched_ext: Start schedulers with consistent p->scx.slice values

... and this fix in sched/urgent:

  98442f0ccd sched: Fix delayed_dequeue vs switched_from_fair()

Resolve it.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-10-17 09:58:07 +02:00
Petr Pavlu
09661f75e7 ring-buffer: Fix reader locking when changing the sub buffer order
The function ring_buffer_subbuf_order_set() updates each
ring_buffer_per_cpu and installs new sub buffers that match the requested
page order. This operation may be invoked concurrently with readers that
rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or
the ring_buffer_per_cpu.pages and reader_page pointers. However, no
exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying
the mentioned data while a reader also operates on them can then result in
incorrect memory access and various crashes.

Fix the problem by taking the reader_lock when updating a specific
ring_buffer_per_cpu in ring_buffer_subbuf_order_set().

Link: https://lore.kernel.org/linux-trace-kernel/20240715145141.5528-1-petr.pavlu@suse.com/
Link: https://lore.kernel.org/linux-trace-kernel/20241010195849.2f77cc3f@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20241011112850.17212b25@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112440.26987-1-petr.pavlu@suse.com
Fixes: 8e7b58c27b ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-15 11:18:51 -04:00
Steven Rostedt
2cf9733891 ring-buffer: Fix refcount setting of boot mapped buffers
A ring buffer which has its buffered mapped at boot up to fixed memory
should not be freed. Other buffers can be. The ref counting setup was
wrong for both. It made the not mapped buffers ref count have zero, and the
boot mapped buffer a ref count of 1. But an normally allocated buffer
should be 1, where it can be removed.

Keep the ref count of a normal boot buffer with its setup ref count (do
not decrement it), and increment the fixed memory boot mapped buffer's ref
count.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241011165224.33dd2624@gandalf.local.home
Fixes: e645535a95 ("tracing: Add option to use memmapped memory for trace boot instance")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-14 14:30:59 -04:00
Peter Zijlstra
cd9626e9eb sched/fair: Fix external p->on_rq users
Sean noted that ever since commit 152e11f6df ("sched/fair: Implement
delayed dequeue") KVM's preemption notifiers have started
mis-classifying preemption vs blocking.

Notably p->on_rq is no longer sufficient to determine if a task is
runnable or blocked -- the aforementioned commit introduces tasks that
remain on the runqueue even through they will not run again, and
should be considered blocked for many cases.

Add the task_is_runnable() helper to classify things and audit all
external users of the p->on_rq state. Also add a few comments.

Fixes: 152e11f6df ("sched/fair: Implement delayed dequeue")
Reported-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net
2024-10-14 09:14:35 +02:00
Tyrone Wu
ad6b5b6ea9 bpf: Fix unpopulated path_size when uprobe_multi fields unset
Previously when retrieving `bpf_link_info.uprobe_multi` with `path` and
`path_size` fields unset, the `path_size` field is not populated
(remains 0). This behavior was inconsistent with how other input/output
string buffer fields work, as the field should be populated in cases
when:
- both buffer and length are set (currently works as expected)
- both buffer and length are unset (not working as expected)

This patch now fills the `path_size` field when `path` and `path_size`
are unset.

Fixes: e56fdbfb06 ("bpf: Add link_info support for uprobe multi link")
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241011000803.681190-1-wudevelops@gmail.com
2024-10-10 19:11:28 -07:00
Steven Rostedt
7888af4166 ftrace: Make ftrace_regs abstract from direct use
ftrace_regs was created to hold registers that store information to save
function parameters, return value and stack. Since it is a subset of
pt_regs, it should only be used by its accessor functions. But because
pt_regs can easily be taken from ftrace_regs (on most archs), it is
tempting to use it directly. But when running on other architectures, it
may fail to build or worse, build but crash the kernel!

Instead, make struct ftrace_regs an empty structure and have the
architectures define __arch_ftrace_regs and all the accessor functions
will typecast to it to get to the actual fields. This will help avoid
usage of ftrace_regs directly.

Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/

Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "x86@kernel.org" <x86@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul  Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas  Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav  Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10 20:18:01 -04:00
Steven Rostedt
c73eb02a47 fgragh: No need to invoke the function call_filter_check_discard()
The function call_filter_check_discard() has been removed in the
commit 49e4154f4b ("tracing: Remove TRACE_EVENT_FL_FILTERED logic"),
from another topic branch. But when merged together with commit
21e92806d3 ("function_graph: Support recording and printing the
function return address") which added another call to
call_filter_check_discard(), it caused the build to fail. Since the
function call_filter_check_discard() is useless, it can simply be removed
regardless of being merged with commit 49e4154f4b or not.

Link: https://lore.kernel.org/all/20241010134649.43ed357c@canb.auug.org.au/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Link: https://lore.kernel.org/20241010194020.46192b21@gandalf.local.home
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 21e92806d3 ("function_graph: Support recording and printing the function return address")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10 19:49:41 -04:00
Masami Hiramatsu (Google)
0a6c61bc9c fgraph: Simplify return address printing in function graph tracer
Simplify return address printing in the function graph tracer by removing
fgraph_extras. Since this feature is only used by the function graph
tracer and the feature flags can directly accessible from the function
graph tracer, fgraph_extras can be removed from the fgraph callback.

Cc: Donglin Peng <dolinux.peng@gmail.com>
Link: https://lore.kernel.org/172857234900.270774.15378354017601069781.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-10 14:06:26 -04:00
Uros Bizjak
eb887c4567 tracing: Use atomic64_inc_return() in trace_clock_counter()
Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
to use optimized implementation and ease register pressure around
the primitive for targets that implement optimized variant.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241007085651.48544-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 19:59:49 -04:00
Levi Yun
afe5960dc2 trace/trace_event_perf: remove duplicate samples on the first tracepoint event
When a tracepoint event is created with attr.freq = 1,
'hwc->period_left' is not initialized correctly. As a result,
in the perf_swevent_overflow() function, when the first time the event occurs,
it calculates the event overflow and the perf_swevent_set_period() returns 3,
this leads to the event are recorded for three duplicate times.

Step to reproduce:
    1. Enable the tracepoint event & starting tracing
         $ echo 1 > /sys/kernel/tracing/events/module/module_free
         $ echo 1 > /sys/kernel/tracing/tracing_on

    2. Record with perf
         $ perf record -a --strict-freq -F 1 -e "module:module_free"

    3. Trigger module_free event.
         $ modprobe -i sunrpc
         $ modprobe -r sunrpc

Result:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe-174509  [003] .....  6504.868896: module_free: sunrpc

     - perf sample:
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc
         modprobe  174509 [003]  6504.868980: module:module_free: sunrpc

By setting period_left via perf_swevent_set_period() as other sw_event did,
This problem could be solved.

After patch:
     - Trace pipe result:
         $ cat trace_pipe
         modprobe 1153096 [068] 613468.867774: module:module_free: xfs

     - perf sample
         modprobe 1153096 [068] 613468.867794: module:module_free: xfs

Link: https://lore.kernel.org/20240913021347.595330-1-yeoreum.yun@arm.com
Fixes: bd2b5b1284 ("perf_counter: More aggressive frequency adjustment")
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 19:44:54 -04:00
Mathieu Desnoyers
cdb537ac41 tracing/perf: Add might_fault check to syscall probes
Add a might_fault() check to validate that the perf sys_enter/sys_exit
probe callbacks are indeed called from a context where page faults can
be handled.

Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241009010718.2050182-8-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 17:09:46 -04:00
Mathieu Desnoyers
a3204c740a tracing/ftrace: Add might_fault check to syscall probes
Add a might_fault() check to validate that the ftrace sys_enter/sys_exit
probe callbacks are indeed called from a context where page faults can
be handled.

Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241009010718.2050182-7-mathieu.desnoyers@efficios.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 17:09:36 -04:00
Mathieu Desnoyers
65e7462a16 tracing/perf: disable preemption in syscall probe
In preparation for allowing system call enter/exit instrumentation to
handle page faults, make sure that perf can handle this change by
explicitly disabling preemption within the perf system call tracepoint
probes to respect the current expectations within perf ring buffer code.

This change does not yet allow perf to take page faults per se within
its probe, but allows its existing probes to adapt to the upcoming
change.

Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241009010718.2050182-4-mathieu.desnoyers@efficios.com
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 17:07:25 -04:00
Mathieu Desnoyers
13d750c2c0 tracing/ftrace: disable preemption in syscall probe
In preparation for allowing system call enter/exit instrumentation to
handle page faults, make sure that ftrace can handle this change by
explicitly disabling preemption within the ftrace system call tracepoint
probes to respect the current expectations within ftrace ring buffer
code.

This change does not yet allow ftrace to take page faults per se within
its probe, but allows its existing probes to adapt to the upcoming
change.

Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241009010718.2050182-3-mathieu.desnoyers@efficios.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 17:07:00 -04:00
Steven Rostedt
912da2c384 ring-buffer: Do not have boot mapped buffers hook to CPU hotplug
The boot mapped ring buffer has its buffer mapped at a fixed location
found at boot up. It is not dynamic. It cannot grow or be expanded when
new CPUs come online.

Do not hook fixed memory mapped ring buffers to the CPU hotplug callback,
otherwise it can cause a crash when it tries to add the buffer to the
memory that is already fully occupied.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241008143242.25e20801@gandalf.local.home
Fixes: be68d63a13 ("ring-buffer: Add ring_buffer_alloc_range()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-09 09:24:35 -04:00
Steven Rostedt
48bcda6848 tracing: Remove definition of trace_*_rcuidle()
The trace_*_rcuidle() variant of a tracepoint was to handle places where a
tracepoint was located but RCU was not "watching". All those locations
have been removed, and RCU should be watching where all tracepoints are
located. We can now remove the trace_*_rcuidle() variant.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241003181629.36209057@gandalf.local.home
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-08 21:17:39 -04:00
Josh Poimboeuf
4a8840af5f tracepoints: Use new static branch API
The old static key API is deprecated.  Switch to the new one.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/7a08dae3c5eddb14b13864923c1b58ac1f4af83c.1728414936.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-08 21:17:39 -04:00
Zheng Yejian
49e4154f4b tracing: Remove TRACE_EVENT_FL_FILTERED logic
After commit dcb0b5575d ("tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER
 logic"), no one's going to set the TRACE_EVENT_FL_FILTERED or change the
call->filter, so remove related logic.

Link: https://lore.kernel.org/20240911010026.2302849-1-zhengyejian@huaweicloud.com
Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-08 15:24:49 -04:00
Justin Stitt
2aa746ec02 tracing/branch-profiler: Replace deprecated strncpy with strscpy
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

Both of these fields want to be NUL-terminated as per their use in
printk:

    F_printk("%u:%s:%s (%u)%s",
      __entry->line,
      __entry->func, __entry->file, __entry->correct,
      __entry->constant ? " CONSTANT" : "")

Use strscpy() as it NUL-terminates the destination buffer, so it doesn't
have to be done manually.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/20240826-strncpy-kernel-trace-trace_branch-c-v1-1-b2c14f2e9e84@google.com
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-08 15:24:38 -04:00
Li Chen
e32540b1e4 ftrace: Use this_cpu_ptr() instead of per_cpu_ptr(smp_processor_id())
Use this_cpu_ptr() instead of open coding the equivalent in various
ftrace functions.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/87y14t6ofi.wl-me@linux.beauty
Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-08 15:24:22 -04:00
Oleg Nesterov
474ec3e849 function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()
After the commit 29c1c24a27 ("function_graph: Fix up ftrace_graph_ret_addr()")
ftrace_graph_ret_addr() doesn't need to initialize "int i" at the start.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/20240916175818.GA28944@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-05 10:14:04 -04:00
Donglin Peng
21e92806d3 function_graph: Support recording and printing the function return address
When using function_graph tracer to analyze the flow of kernel function
execution, it is often necessary to quickly locate the exact line of code
where the call occurs. While this may be easy at times, it can be more
time-consuming when some functions are inlined or the flow is too long.

This feature aims to simplify the process by recording the return address
of traced funcions and printing it when outputing trace logs.

To enhance human readability, the prefix 'ret=' is used for the kernel return
value, while '<-' serves as the prefix for the return address in trace logs to
make it look more like the function tracer.

A new trace option named 'funcgraph-retaddr' has been introduced, and the
existing option 'sym-addr' can be used to control the format of the return
address.

See below logs with both funcgraph-retval and funcgraph-retaddr enabled.

0)             | load_elf_binary() { /* <-bprm_execve+0x249/0x600 */
0)             |   load_elf_phdrs() { /* <-load_elf_binary+0x84/0x1730 */
0)             |     __kmalloc_noprof() { /* <-load_elf_phdrs+0x4a/0xb0 */
0)   3.657 us  |       __cond_resched(); /* <-__kmalloc_noprof+0x28c/0x390 ret=0x0 */
0) + 24.335 us |     } /* __kmalloc_noprof ret=0xffff8882007f3000 */
0)             |     kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0)             |       rw_verify_area() { /* <-kernel_read+0x2b/0x50 */
0)             |         security_file_permission() { /* <-kernel_read+0x2b/0x50 */
0)             |           selinux_file_permission() { /* <-security_file_permission+0x26/0x40 */
0)             |             __inode_security_revalidate() { /* <-selinux_file_permission+0x6d/0x140 */
0)   2.034 us  |               __cond_resched(); /* <-__inode_security_revalidate+0x5f/0x80 ret=0x0 */
0)   6.602 us  |             } /* __inode_security_revalidate ret=0x0 */
0)   2.214 us  |             avc_policy_seqno(); /* <-selinux_file_permission+0x107/0x140 ret=0x0 */
0) + 16.670 us |           } /* selinux_file_permission ret=0x0 */
0) + 20.809 us |         } /* security_file_permission ret=0x0 */
0) + 25.217 us |       } /* rw_verify_area ret=0x0 */
0)             |       __kernel_read() { /* <-load_elf_phdrs+0x6c/0xb0 */
0)             |         ext4_file_read_iter() { /* <-__kernel_read+0x160/0x2e0 */

Then, we can use the faddr2line to locate the source code, for example:

$ ./scripts/faddr2line ./vmlinux load_elf_phdrs+0x6c/0xb0
load_elf_phdrs+0x6c/0xb0:
elf_read at fs/binfmt_elf.c:471
(inlined by) load_elf_phdrs at fs/binfmt_elf.c:531

Link: https://lore.kernel.org/20240915032912.1118397-1-dolinux.peng@gmail.com
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409150605.HgUmU8ea-lkp@intel.com/
Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
[ Rebased to handle text_delta offsets ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-05 10:14:04 -04:00
Andrew Kreimer
ac1987f8f5 rv: Fix a typo
Fix a typo in comments.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240911114349.20449-1-algonell@gmail.com
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-04 19:09:23 -04:00
Wei Li
2a13ca2e8a tracing/hwlat: Fix a race during cpuhp processing
The cpuhp online/offline processing race also exists in percpu-mode hwlat
tracer in theory, apply the fix too. That is:

    T1                       | T2
    [CPUHP_ONLINE]           | cpu_device_down()
     hwlat_hotplug_workfn()  |
                             |     cpus_write_lock()
                             |     takedown_cpu(1)
                             |     cpus_write_unlock()
    [CPUHP_OFFLINE]          |
        cpus_read_lock()     |
        start_kthread(1)     |
        cpus_read_unlock()   |

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-5-liwei391@huawei.com
Fixes: ba998f7d95 ("trace/hwlat: Support hotplug operations")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-03 16:43:23 -04:00
Wei Li
829e0c9f08 tracing/timerlat: Fix a race during cpuhp processing
There is another found exception that the "timerlat/1" thread was
scheduled on CPU0, and lead to timer corruption finally:

```
ODEBUG: init active (active state 0) object: ffff888237c2e108 object type: hrtimer hint: timerlat_irq+0x0/0x220
WARNING: CPU: 0 PID: 426 at lib/debugobjects.c:518 debug_print_object+0x7d/0xb0
Modules linked in:
CPU: 0 UID: 0 PID: 426 Comm: timerlat/1 Not tainted 6.11.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:debug_print_object+0x7d/0xb0
...
Call Trace:
 <TASK>
 ? __warn+0x7c/0x110
 ? debug_print_object+0x7d/0xb0
 ? report_bug+0xf1/0x1d0
 ? prb_read_valid+0x17/0x20
 ? handle_bug+0x3f/0x70
 ? exc_invalid_op+0x13/0x60
 ? asm_exc_invalid_op+0x16/0x20
 ? debug_print_object+0x7d/0xb0
 ? debug_print_object+0x7d/0xb0
 ? __pfx_timerlat_irq+0x10/0x10
 __debug_object_init+0x110/0x150
 hrtimer_init+0x1d/0x60
 timerlat_main+0xab/0x2d0
 ? __pfx_timerlat_main+0x10/0x10
 kthread+0xb7/0xe0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2d/0x40
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>
```

After tracing the scheduling event, it was discovered that the migration
of the "timerlat/1" thread was performed during thread creation. Further
analysis confirmed that it is because the CPU online processing for
osnoise is implemented through workers, which is asynchronous with the
offline processing. When the worker was scheduled to create a thread, the
CPU may has already been removed from the cpu_online_mask during the offline
process, resulting in the inability to select the right CPU:

T1                       | T2
[CPUHP_ONLINE]           | cpu_device_down()
osnoise_hotplug_workfn() |
                         |     cpus_write_lock()
                         |     takedown_cpu(1)
                         |     cpus_write_unlock()
[CPUHP_OFFLINE]          |
    cpus_read_lock()     |
    start_kthread(1)     |
    cpus_read_unlock()   |

To fix this, skip online processing if the CPU is already offline.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-4-liwei391@huawei.com
Fixes: c8895e271f ("trace/osnoise: Support hotplug operations")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-03 16:43:22 -04:00
Wei Li
b484a02c9c tracing/timerlat: Drop interface_lock in stop_kthread()
stop_kthread() is the offline callback for "trace/osnoise:online", since
commit 5bfbcd1ee5 ("tracing/timerlat: Add interface_lock around clearing
of kthread in stop_kthread()"), the following ABBA deadlock scenario is
introduced:

T1                            | T2 [BP]               | T3 [AP]
osnoise_hotplug_workfn()      | work_for_cpu_fn()     | cpuhp_thread_fun()
                              |   _cpu_down()         |   osnoise_cpu_die()
  mutex_lock(&interface_lock) |                       |     stop_kthread()
                              |     cpus_write_lock() |       mutex_lock(&interface_lock)
  cpus_read_lock()            |     cpuhp_kick_ap()   |

As the interface_lock here in just for protecting the "kthread" field of
the osn_var, use xchg() instead to fix this issue. Also use
for_each_online_cpu() back in stop_per_cpu_kthreads() as it can take
cpu_read_lock() again.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-3-liwei391@huawei.com
Fixes: 5bfbcd1ee5 ("tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-03 16:43:22 -04:00
Wei Li
0bb0a5c12e tracing/timerlat: Fix duplicated kthread creation due to CPU online/offline
osnoise_hotplug_workfn() is the asynchronous online callback for
"trace/osnoise:online". It may be congested when a CPU goes online and
offline repeatedly and is invoked for multiple times after a certain
online.

This will lead to kthread leak and timer corruption. Add a check
in start_kthread() to prevent this situation.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240924094515.3561410-2-liwei391@huawei.com
Fixes: c8895e271f ("trace/osnoise: Support hotplug operations")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-03 16:43:22 -04:00
Steven Rostedt
50a3242d84 tracing: Fix trace_check_vprintf() when tp_printk is used
When the tp_printk kernel command line is used, the trace events go
directly to printk(). It is still checked via the trace_check_vprintf()
function to make sure the pointers of the trace event are legit.

The addition of reading buffers from previous boots required adding a
delta between the addresses of the previous boot and the current boot so
that the pointers in the old buffer can still be used. But this required
adding a trace_array pointer to acquire the delta offsets.

The tp_printk code does not provide a trace_array (tr) pointer, so when
the offsets were examined, a NULL pointer dereference happened and the
kernel crashed.

If the trace_array does not exist, just default the delta offsets to zero,
as that also means the trace event is not being read from a previous boot.

Link: https://lore.kernel.org/all/Zv3z5UsG_jsO9_Tb@aschofie-mobl2.lan/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241003104925.4e1b1fd9@gandalf.local.home
Fixes: 07714b4bb3 ("tracing: Handle old buffer mappings for event strings and functions")
Reported-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-03 16:43:22 -04:00
Steven Rostedt
f1f36e22be ftrace: Have calltime be saved in the fgraph storage
The calltime field in the shadow stack frame is only used by the function
graph tracer and profiler. But now that there's other users of the function
graph infrastructure, this adds overhead and wastes space on the shadow
stack. Move the calltime to the fgraph data storage, where the function
graph and profiler entry functions will save it in its own graph storage and
retrieve it in its exit functions.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214827.096968730@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-30 11:12:46 -04:00
Steven Rostedt
3c9880f3ab ftrace: Use a running sleeptime instead of saving on shadow stack
The fgraph "sleep-time" option tells the function graph tracer and the
profiler whether to include the time a function "sleeps" (is scheduled off
the CPU) in its duration for the function. By default it is true, which
means the duration of a function is calculated by the timestamp of when the
function was entered to the timestamp of when it exits.

If the "sleep-time" option is disabled, it needs to remove the time that the
task was not running on the CPU during the function. Currently it is done in
a sched_switch tracepoint probe where it moves the "calltime" (time of entry
of the function) forward by the sleep time calculated. It updates all the
calltime in the shadow stack.

This is time consuming for those users of the function graph tracer that
does not care about the sleep time. Instead, add a "ftrace_sleeptime" to the
task_struct that gets the sleep time added each time the task wakes up. Then
have the function entry save the current "ftrace_sleeptime" and on function
exit, move the calltime forward by the difference of the current
"ftrace_sleeptime" from the saved sleeptime.

This removes one dependency of "calltime" needed to be on the shadow stack.
It also simplifies the code that removes the sleep time of functions.

TODO: Only enable the sched_switch tracepoint when this is needed.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214826.938908568@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-30 11:12:46 -04:00
Steven Rostedt
a312a0f783 fgraph: Use fgraph data to store subtime for profiler
Instead of having the "subtime" for the function profiler in the
infrastructure ftrace_ret_stack structure, have it use the fgraph data
reserve and retrieve functions.

This will keep the limited shadow stack from wasting 8 bytes for something
that is seldom used.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Link: https://lore.kernel.org/20240914214826.780323141@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-30 11:12:46 -04:00
Masami Hiramatsu (Google)
c54a1a06da tracing: Fix function timing profiler to initialize hashtable
Since the new fgraph requires to initialize fgraph_ops.ops.func_hash before
calling register_ftrace_graph(), initialize it with default (tracing all
functions) parameter.

Cc: stable@vger.kernel.org
Fixes: 5fccc7552c ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-30 11:12:46 -04:00
Al Viro
cb787f4ac0 [tree-wide] finally take no_llseek out
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\<no_llseek\>/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-27 08:18:43 -07:00
Linus Torvalds
5159938e10 Probes updates for v6.12:
- uprobes: make trace_uprobe->nhit counter a per-CPU one
    This makes uprobe event's hit counter per-CPU for improving
    scalability on multi-core environment.
 
 - kprobes: Remove obsoleted declaration for init_test_probes
    Remove unused init_test_probes() from header.
 
 - Raw tracepoint probe supports raw tracepoint events on modules.
    The tracepoint events using fprobe were introduced in v6.5, but
    tracepoints can be compiled in modules. This supports such a case.
    This includes the following improvements.
   . tracepoint: add a function for iterating over all tracepoints in
     all modules.
   . tracepoint: Add a function for iterating over tracepoints in a
     module.
   . tracing/fprobe: Support raw tracepoint events on modules.
   . tracing/fprobe: Support raw tracepoints on future loaded modules.
      This allows user to add tracepoint events on modules which is
      not loaded yet.
   . selftests/tracing: Add a test for tracepoint events on modules.
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Merge tag 'probes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:

 - uprobes: make trace_uprobe->nhit counter a per-CPU one

   This makes uprobe event's hit counter per-CPU for improving
   scalability on multi-core environment

 - kprobes: Remove obsoleted declaration for init_test_probes

   Remove unused init_test_probes() from header

 - Raw tracepoint probe supports raw tracepoint events on modules:
     - add a function for iterating over all tracepoints in all modules
     - add a function for iterating over tracepoints in a module
     - support raw tracepoint events on modules
     - support raw tracepoints on future loaded modules
     - add a test for tracepoint events on modules"

* tag 'probes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  sefltests/tracing: Add a test for tracepoint events on modules
  tracing/fprobe: Support raw tracepoints on future loaded modules
  tracing/fprobe: Support raw tracepoint events on modules
  tracepoint: Support iterating tracepoints in a loading module
  tracepoint: Support iterating over tracepoints on modules
  kprobes: Remove obsoleted declaration for init_test_probes
  uprobes: turn trace_uprobe's nhit counter to be per-CPU one
2024-09-26 08:55:36 -07:00
Masami Hiramatsu (Google)
57a7e6de9e tracing/fprobe: Support raw tracepoints on future loaded modules
Support raw tracepoint events on future loaded (unloaded) modules.
This allows user to create raw tracepoint events which can be used from
module's __init functions.

Note: since the kernel does not have any information about the tracepoints
in the unloaded modules, fprobe events can not check whether the tracepoint
exists nor extend the BTF based arguments.

Link: https://lore.kernel.org/all/172397780593.286558.18360375226968537828.stgit@devnote2/

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-09-25 23:23:44 +09:00
Masami Hiramatsu (Google)
67e9a9ee47 tracing/fprobe: Support raw tracepoint events on modules
Support raw tracepoint event on module by fprobe events.
Since it only uses for_each_kernel_tracepoint() to find a tracepoint,
the tracepoints on modules are not handled. Thus if user specified a
tracepoint on a module, it shows an error.
This adds new for_each_module_tracepoint() API to tracepoint subsystem,
and uses it to find tracepoints on modules.

Link: https://lore.kernel.org/all/172397779651.286558.15903703620679186867.stgit@devnote2/

Reported-by: don <zds100@gmail.com>
Closes: https://lore.kernel.org/all/20240530215718.aeec973a1d0bf058d39cb1e3@kernel.org/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-09-25 23:23:44 +09:00
Andrii Nakryiko
10cdb82aa7 uprobes: turn trace_uprobe's nhit counter to be per-CPU one
trace_uprobe->nhit counter is not incremented atomically, so its value
is questionable in when uprobe is hit on multiple CPUs simultaneously.

Also, doing this shared counter increment across many CPUs causes heavy
cache line bouncing, limiting uprobe/uretprobe performance scaling with
number of CPUs.

Solve both problems by making this a per-CPU counter.

Link: https://lore.kernel.org/all/20240813203409.3985398-1-andrii@kernel.org/

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-09-25 20:10:38 +09:00
Linus Torvalds
af9c191ac2 ring-buffer: Updates for v6.12:
- Merged v6.11-rc3 into trace/ring-buffer/core
 
   The v6.10 ring buffer pull request was not made due to Mathieu Desnoyers
   making a comment to the pull request. Mathieu and I resolved it on IRC,
   but we did not let Linus know that it was resolved. Linus did not do the
   pull thinking it still had some unresolved issues.
 
   The ring buffer work for 6.12 was dependent on both this pull request as
   well as the reserve_mem kernel command line option that was going upstream
   through the memory management tree. The ring buffer repo was being used by
   others so it could not be rebased. In order to continue the work, the
   v6.11-rc3 branch was pulled in to get access to the reserve_mem work.
 
 This has the 6.11 pull request that did not make it into 6.11, which was:
 
   tracing/ring-buffer: Have persistent buffer across reboots
 
   This allows for the tracing instance ring buffer to stay persistent across
   reboots. The way this is done is by adding to the kernel command line:
 
     trace_instance=boot_map@0x285400000:12M
 
   This will reserve 12 megabytes at the address 0x285400000, and then map
   the tracing instance "boot_map" ring buffer to that memory. This will
   appear as a normal instance in the tracefs system:
 
     /sys/kernel/tracing/instances/boot_map
 
   A user could enable tracing in that instance, and on reboot or kernel
   crash, if the memory is not wiped by the firmware, it will recreate the
   trace in that instance. For example, if one was debugging a shutdown of a
   kernel reboot:
 
    # cd /sys/kernel/tracing
    # echo function > instances/boot_map/current_tracer
    # reboot
   [..]
    # cd /sys/kernel/tracing
    # tail instances/boot_map/trace
          swapper/0-1       [000] d..1.   164.549800: restore_boot_irq_mode <-native_machine_shutdown
          swapper/0-1       [000] d..1.   164.549801: native_restore_boot_irq_mode <-native_machine_shutdown
          swapper/0-1       [000] d..1.   164.549802: disconnect_bsp_APIC <-native_machine_shutdown
          swapper/0-1       [000] d..1.   164.549811: hpet_disable <-native_machine_shutdown
          swapper/0-1       [000] d..1.   164.549812: iommu_shutdown_noop <-native_machine_restart
          swapper/0-1       [000] d..1.   164.549813: native_machine_emergency_restart <-__do_sys_reboot
          swapper/0-1       [000] d..1.   164.549813: tboot_shutdown <-native_machine_emergency_restart
          swapper/0-1       [000] d..1.   164.549820: acpi_reboot <-native_machine_emergency_restart
          swapper/0-1       [000] d..1.   164.549821: acpi_reset <-acpi_reboot
          swapper/0-1       [000] d..1.   164.549822: acpi_os_write_port <-acpi_reboot
 
   On reboot, the buffer is examined to make sure it is valid. The validation
   check even steps through every event to make sure the meta data of the
   event is correct. If any test fails, it will simply reset the buffer, and
   the buffer will be empty on boot.
 
 The new changes for 6.12 are:
 
 - Allow the tracing persistent boot buffer to use the "reserve_mem" option
 
   Instead of having the admin find a physical address to store the persistent
   buffer, which can be very tedious if they have to administrate several
   different machines, allow them to use the "reserve_mem" option that will
   find a location for them. It is not as reliable because of KASLR, as the
   loading of the kernel in different locations can cause the memory
   allocated to be inconsistent. Booting with "nokaslr" can make reserve_mem
   more reliable.
 
 - Have function graph tracer handle offsets from a previous boot.
 
   The ring buffer output from a previous boot may have different addresses
   due to kaslr. Have the function graph tracer handle these by using the
   delta from the previous boot to the new boot address space.
 
 - Only reset the saved meta offset when the buffer is started or reset
 
   In the persistent memory meta data, it holds the previous address space
   information, so that it can calculate the delta to have function tracing
   work. But this gets updated after being read to hold the new address
   space. But if the buffer isn't used for that boot, on reboot, the delta is
   now calculated from the previous boot and not the boot that holds the data
   in the ring buffer. This causes the functions not to be shown. Do not save
   the address space information of the current kernel until it is being
   recorded.
 
 - Add a magic variable to test the valid meta data
 
   Add a magic variable in the meta data that can also be used for
   validation. The validator of the previous buffer doesn't need this magic
   data, but it can be used if the meta data is changed by a new kernel, which
   may have the same format that passes the validator but is used
   differently. This magic number can also be used as a "versioning" of the
   meta data.
 
 - Align user space mapped ring buffer sub buffers to improve TLB entries
 
   Linus mentioned that the mapped ring buffer sub buffers were misaligned
   between the meta page and the sub-buffers, so that if the sub-buffers were
   bigger than PAGE_SIZE, it wouldn't allow the TLB to use bigger entries.
 
 - Add new kernel command line "traceoff" to disable tracing on boot for instances
 
   If tracing is enabled for a boot instance, there needs a way to be able to
   disable it on boot so that new events do not get entered into the ring
   buffer and be mixed with events from a previous boot, as that can be
   confusing.
 
 - Allow trace_printk() to go to other instances
 
   Currently, trace_printk() can only go to the top level instance. When
   debugging with a persistent buffer, it is really useful to be able to add
   trace_printk() to go to that buffer, so that you have access to them after
   a crash.
 
 - Do not use "bin_printk()" for traces to a boot instance
 
   The bin_printk() saves only a pointer to the printk format in the ring
   buffer, as the reader of the buffer can still have access to it. But this
   is not the case if the buffer is from a previous boot. If the
   trace_printk() is going to a "persistent" buffer, it will use the slower
   version that writes the printk format into the buffer.
 
 - Add command line option to allow trace_printk() to go to an instance
 
   Allow the kernel command line to define which instance the trace_printk()
   goes to, instead of forcing the admin to set it for every boot via the
   tracefs options.
 
 - Start a document that explains how to use tracefs to debug the kernel
 
 - Add some more kernel selftests to test user mapped ring buffer
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Merge tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer updates from Steven Rostedt:

 - tracing/ring-buffer: persistent buffer across reboots

   This allows for the tracing instance ring buffer to stay persistent
   across reboots. The way this is done is by adding to the kernel
   command line:

     trace_instance=boot_map@0x285400000:12M

   This will reserve 12 megabytes at the address 0x285400000, and then
   map the tracing instance "boot_map" ring buffer to that memory. This
   will appear as a normal instance in the tracefs system:

     /sys/kernel/tracing/instances/boot_map

   A user could enable tracing in that instance, and on reboot or kernel
   crash, if the memory is not wiped by the firmware, it will recreate
   the trace in that instance. For example, if one was debugging a
   shutdown of a kernel reboot:

     # cd /sys/kernel/tracing
     # echo function > instances/boot_map/current_tracer
     # reboot
     [..]
     # cd /sys/kernel/tracing
     # tail instances/boot_map/trace
           swapper/0-1       [000] d..1.   164.549800: restore_boot_irq_mode <-native_machine_shutdown
           swapper/0-1       [000] d..1.   164.549801: native_restore_boot_irq_mode <-native_machine_shutdown
           swapper/0-1       [000] d..1.   164.549802: disconnect_bsp_APIC <-native_machine_shutdown
           swapper/0-1       [000] d..1.   164.549811: hpet_disable <-native_machine_shutdown
           swapper/0-1       [000] d..1.   164.549812: iommu_shutdown_noop <-native_machine_restart
           swapper/0-1       [000] d..1.   164.549813: native_machine_emergency_restart <-__do_sys_reboot
           swapper/0-1       [000] d..1.   164.549813: tboot_shutdown <-native_machine_emergency_restart
           swapper/0-1       [000] d..1.   164.549820: acpi_reboot <-native_machine_emergency_restart
           swapper/0-1       [000] d..1.   164.549821: acpi_reset <-acpi_reboot
           swapper/0-1       [000] d..1.   164.549822: acpi_os_write_port <-acpi_reboot

   On reboot, the buffer is examined to make sure it is valid. The
   validation check even steps through every event to make sure the meta
   data of the event is correct. If any test fails, it will simply reset
   the buffer, and the buffer will be empty on boot.

 - Allow the tracing persistent boot buffer to use the "reserve_mem"
   option

   Instead of having the admin find a physical address to store the
   persistent buffer, which can be very tedious if they have to
   administrate several different machines, allow them to use the
   "reserve_mem" option that will find a location for them. It is not as
   reliable because of KASLR, as the loading of the kernel in different
   locations can cause the memory allocated to be inconsistent. Booting
   with "nokaslr" can make reserve_mem more reliable.

 - Have function graph tracer handle offsets from a previous boot.

   The ring buffer output from a previous boot may have different
   addresses due to kaslr. Have the function graph tracer handle these
   by using the delta from the previous boot to the new boot address
   space.

 - Only reset the saved meta offset when the buffer is started or reset

   In the persistent memory meta data, it holds the previous address
   space information, so that it can calculate the delta to have
   function tracing work. But this gets updated after being read to hold
   the new address space. But if the buffer isn't used for that boot, on
   reboot, the delta is now calculated from the previous boot and not
   the boot that holds the data in the ring buffer. This causes the
   functions not to be shown. Do not save the address space information
   of the current kernel until it is being recorded.

 - Add a magic variable to test the valid meta data

   Add a magic variable in the meta data that can also be used for
   validation. The validator of the previous buffer doesn't need this
   magic data, but it can be used if the meta data is changed by a new
   kernel, which may have the same format that passes the validator but
   is used differently. This magic number can also be used as a
   "versioning" of the meta data.

 - Align user space mapped ring buffer sub buffers to improve TLB
   entries

   Linus mentioned that the mapped ring buffer sub buffers were
   misaligned between the meta page and the sub-buffers, so that if the
   sub-buffers were bigger than PAGE_SIZE, it wouldn't allow the TLB to
   use bigger entries.

 - Add new kernel command line "traceoff" to disable tracing on boot for
   instances

   If tracing is enabled for a boot instance, there needs a way to be
   able to disable it on boot so that new events do not get entered into
   the ring buffer and be mixed with events from a previous boot, as
   that can be confusing.

 - Allow trace_printk() to go to other instances

   Currently, trace_printk() can only go to the top level instance. When
   debugging with a persistent buffer, it is really useful to be able to
   add trace_printk() to go to that buffer, so that you have access to
   them after a crash.

 - Do not use "bin_printk()" for traces to a boot instance

   The bin_printk() saves only a pointer to the printk format in the
   ring buffer, as the reader of the buffer can still have access to it.
   But this is not the case if the buffer is from a previous boot. If
   the trace_printk() is going to a "persistent" buffer, it will use the
   slower version that writes the printk format into the buffer.

 - Add command line option to allow trace_printk() to go to an instance

   Allow the kernel command line to define which instance the
   trace_printk() goes to, instead of forcing the admin to set it for
   every boot via the tracefs options.

 - Start a document that explains how to use tracefs to debug the kernel

 - Add some more kernel selftests to test user mapped ring buffer

* tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (28 commits)
  selftests/ring-buffer: Handle meta-page bigger than the system
  selftests/ring-buffer: Verify the entire meta-page padding
  tracing/Documentation: Start a document on how to debug with tracing
  tracing: Add option to set an instance to be the trace_printk destination
  tracing: Have trace_printk not use binary prints if boot buffer
  tracing: Allow trace_printk() to go to other instance buffers
  tracing: Add "traceoff" flag to boot time tracing instances
  ring-buffer: Align meta-page to sub-buffers for improved TLB usage
  ring-buffer: Add magic and struct size to boot up meta data
  ring-buffer: Don't reset persistent ring-buffer meta saved addresses
  tracing/fgraph: Have fgraph handle previous boot function addresses
  tracing: Allow boot instances to use reserve_mem boot memory
  tracing: Fix ifdef of snapshots to not prevent last_boot_info file
  ring-buffer: Use vma_pages() helper function
  tracing: Fix NULL vs IS_ERR() check in enable_instances()
  tracing: Add last boot delta offset for stack traces
  tracing: Update function tracing output for previous boot buffer
  tracing: Handle old buffer mappings for event strings and functions
  tracing/ring-buffer: Add last_boot_info file to boot instance
  ring-buffer: Save text and data locations in mapped meta data
  ...
2024-09-22 09:47:16 -07:00
Linus Torvalds
440b652328 bpf-next-6.12
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Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with
   corresponding support in LLVM.

   It is similar to existing 'no_caller_saved_registers' attribute in
   GCC/LLVM with a provision for backward compatibility. It allows
   compilers generate more efficient BPF code assuming the verifier or
   JITs will inline or partially inline a helper/kfunc with such
   attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast,
   bpf_get_smp_processor_id are the first set of such helpers.

 - Harden and extend ELF build ID parsing logic.

   When called from sleepable context the relevants parts of ELF file
   will be read to find and fetch .note.gnu.build-id information. Also
   harden the logic to avoid TOCTOU, overflow, out-of-bounds problems.

 - Improvements and fixes for sched-ext:
    - Allow passing BPF iterators as kfunc arguments
    - Make the pointer returned from iter_next method trusted
    - Fix x86 JIT convergence issue due to growing/shrinking conditional
      jumps in variable length encoding

 - BPF_LSM related:
    - Introduce few VFS kfuncs and consolidate them in
      fs/bpf_fs_kfuncs.c
    - Enforce correct range of return values from certain LSM hooks
    - Disallow attaching to other LSM hooks

 - Prerequisite work for upcoming Qdisc in BPF:
    - Allow kptrs in program provided structs
    - Support for gen_epilogue in verifier_ops

 - Important fixes:
    - Fix uprobe multi pid filter check
    - Fix bpf_strtol and bpf_strtoul helpers
    - Track equal scalars history on per-instruction level
    - Fix tailcall hierarchy on x86 and arm64
    - Fix signed division overflow to prevent INT_MIN/-1 trap on x86
    - Fix get kernel stack in BPF progs attached to tracepoint:syscall

 - Selftests:
    - Add uprobe bench/stress tool
    - Generate file dependencies to drastically improve re-build time
    - Match JIT-ed and BPF asm with __xlated/__jited keywords
    - Convert older tests to test_progs framework
    - Add support for RISC-V
    - Few fixes when BPF programs are compiled with GCC-BPF backend
      (support for GCC-BPF in BPF CI is ongoing in parallel)
    - Add traffic monitor
    - Enable cross compile and musl libc

* tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits)
  btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version
  btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug
  btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh
  bpf: Call the missed kfree() when there is no special field in btf
  bpf: Call the missed btf_record_free() when map creation fails
  selftests/bpf: Add a test case to write mtu result into .rodata
  selftests/bpf: Add a test case to write strtol result into .rodata
  selftests/bpf: Rename ARG_PTR_TO_LONG test description
  selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test
  bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
  bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types
  bpf: Fix helper writes to read-only maps
  bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers
  bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit
  selftests/bpf: Add tests for sdiv/smod overflow cases
  bpf: Fix a sdiv overflow issue
  libbpf: Add bpf_object__token_fd accessor
  docs/bpf: Add missing BPF program types to docs
  docs/bpf: Add constant values for linkages
  bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
  ...
2024-09-21 09:27:50 -07:00
Linus Torvalds
2004cef11e In the v6.12 scheduler development cycle we had 63 commits from 18 contributors:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot de Oliveira's
    last major contribution to the kernel:
 
      "SCHED_DEADLINE servers can help fixing starvation issues of low priority
      tasks (e.g., SCHED_OTHER) when higher priority tasks monopolize CPU
      cycles. Today we have RT Throttling; DEADLINE servers should be able to
      replace and improve that."
 
      (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes,
       Youssef Esmat, Huang Shijie)
 
  - Preparatory changes for sched_ext integration:
 
      - Use set_next_task(.first) where required
      - Fix up set_next_task() implementations
      - Clean up DL server vs. core sched
      - Split up put_prev_task_balance()
      - Rework pick_next_task()
      - Combine the last put_prev_task() and the first set_next_task()
      - Rework dl_server
      - Add put_prev_task(.next)
 
       (Peter Zijlstra, with a fix by Tejun Heo)
 
  - Complete the EEVDF transition and refine EEVDF scheduling:
 
      - Implement delayed dequeue
      - Allow shorter slices to wakeup-preempt
      - Use sched_attr::sched_runtime to set request/slice suggestion
      - Document the new feature flags
      - Remove unused and duplicate-functionality fields
      - Simplify & unify pick_next_task_fair()
      - Misc debuggability enhancements
 
       (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann,
        Valentin Schneider and Chuyi Zhou)
 
  - Initialize the vruntime of a new task when it is first enqueued,
    resulting in significant decrease in latency of newly woken tasks.
    (Zhang Qiao)
 
  - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
    (K Prateek Nayak, Peter Zijlstra)
 
  - Clean up and clarify the usage of Clean up usage of rt_task()
    (Qais Yousef)
 
  - Preempt SCHED_IDLE entities in strict cgroup hierarchies
    (Tianchen Ding)
 
  - Clarify the documentation of time units for deadline scheduler
    parameters. (Christian Loehle)
 
  - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
    the original change seems to be working fine.
    (Phil Auld)
 
  - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
    Peilin He, Qais Yousefm and Vincent Guittot)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

 - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
   de Oliveira's last major contribution to the kernel:

     "SCHED_DEADLINE servers can help fixing starvation issues of low
      priority tasks (e.g., SCHED_OTHER) when higher priority tasks
      monopolize CPU cycles. Today we have RT Throttling; DEADLINE
      servers should be able to replace and improve that."

   (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
   Esmat, Huang Shijie)

 - Preparatory changes for sched_ext integration:
     - Use set_next_task(.first) where required
     - Fix up set_next_task() implementations
     - Clean up DL server vs. core sched
     - Split up put_prev_task_balance()
     - Rework pick_next_task()
     - Combine the last put_prev_task() and the first set_next_task()
     - Rework dl_server
     - Add put_prev_task(.next)

   (Peter Zijlstra, with a fix by Tejun Heo)

 - Complete the EEVDF transition and refine EEVDF scheduling:
     - Implement delayed dequeue
     - Allow shorter slices to wakeup-preempt
     - Use sched_attr::sched_runtime to set request/slice suggestion
     - Document the new feature flags
     - Remove unused and duplicate-functionality fields
     - Simplify & unify pick_next_task_fair()
     - Misc debuggability enhancements

   (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
   Schneider and Chuyi Zhou)

 - Initialize the vruntime of a new task when it is first enqueued,
   resulting in significant decrease in latency of newly woken tasks
   (Zhang Qiao)

 - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
   (K Prateek Nayak, Peter Zijlstra)

 - Clean up and clarify the usage of Clean up usage of rt_task()
   (Qais Yousef)

 - Preempt SCHED_IDLE entities in strict cgroup hierarchies
   (Tianchen Ding)

 - Clarify the documentation of time units for deadline scheduler
   parameters (Christian Loehle)

 - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
   the original change seems to be working fine (Phil Auld)

 - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
   Peilin He, Qais Yousefm and Vincent Guittot)

* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  sched/cpufreq: Use NSEC_PER_MSEC for deadline task
  cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
  sched/deadline: Clarify nanoseconds in uapi
  sched/deadline: Convert schedtool example to chrt
  sched/debug: Fix the runnable tasks output
  sched: Fix sched_delayed vs sched_core
  kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
  kthread: Fix task state in kthread worker if being frozen
  sched/pelt: Use rq_clock_task() for hw_pressure
  sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
  sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
  sched: Add put_prev_task(.next)
  sched: Rework dl_server
  sched: Combine the last put_prev_task() and the first set_next_task()
  sched: Rework pick_next_task()
  sched: Split up put_prev_task_balance()
  sched: Clean up DL server vs core sched
  sched: Fixup set_next_task() implementations
  sched: Use set_next_task(.first) where required
  sched/fair: Properly deactivate sched_delayed task upon class change
  ...
2024-09-19 15:55:58 +02:00
Linus Torvalds
9f0c253ddd Performance events changes for v6.12:
- Implement per-PMU context rescheduling to significantly improve single-PMU
    performance, and related cleanups/fixes. (by Peter Zijlstra and Namhyung Kim)
 
  - Fix ancient bug resulting in a lot of events being dropped erroneously
    at higher sampling frequencies. (by Luo Gengkun)
 
  - uprobes enhancements:
 
      - Implement RCU-protected hot path optimizations for better performance:
 
          "For baseline vs SRCU, peak througput increased from 3.7 M/s (million uprobe
           triggerings per second) up to about 8 M/s. For uretprobes it's a bit more
           modest with bump from 2.4 M/s to 5 M/s.
 
           For SRCU vs RCU Tasks Trace, peak throughput for uprobes increases further from
           8 M/s to 10.3 M/s (+28%!), and for uretprobes from 5.3 M/s to 5.8 M/s (+11%),
           as we have more work to do on uretprobes side.
 
           Even single-thread (no contention) performance is slightly better: 3.276 M/s to
           3.396 M/s (+3.5%) for uprobes, and 2.055 M/s to 2.174 M/s (+5.8%)
           for uretprobes."
 
           (by Andrii Nakryiko et al)
 
      - Document mmap_lock, don't abuse get_user_pages_remote(). (by Oleg Nesterov)
 
      - Cleanups & fixes to prepare for future work:
 
         - Remove uprobe_register_refctr()
 	- Simplify error handling for alloc_uprobe()
         - Make uprobe_register() return struct uprobe *
         - Fold __uprobe_unregister() into uprobe_unregister()
         - Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
         - BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
 
           (by Oleg Nesterov)
 
  - New feature & ABI extension: allow events to use PERF_SAMPLE READ with
    inheritance, enabling sample based profiling of a group of counters over
    a hierarchy of processes or threads.  (by Ben Gainey)
 
  - Intel uncore & power events updates:
 
       - Add Arrow Lake and Lunar Lake support
       - Add PERF_EV_CAP_READ_SCOPE
       - Clean up and enhance cpumask and hotplug support
 
         (by Kan Liang)
 
       - Add LNL uncore iMC freerunning support
       - Use D0:F0 as a default device
 
         (by Zhenyu Wang)
 
  - Intel PT: fix AUX snapshot handling race. (by Adrian Hunter)
 
  - Misc fixes and cleanups. (by James Clark, Jiri Olsa, Oleg Nesterov and Peter Zijlstra)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events updates from Ingo Molnar:

 - Implement per-PMU context rescheduling to significantly improve
   single-PMU performance, and related cleanups/fixes (Peter Zijlstra
   and Namhyung Kim)

 - Fix ancient bug resulting in a lot of events being dropped
   erroneously at higher sampling frequencies (Luo Gengkun)

 - uprobes enhancements:

     - Implement RCU-protected hot path optimizations for better
       performance:

         "For baseline vs SRCU, peak througput increased from 3.7 M/s
          (million uprobe triggerings per second) up to about 8 M/s. For
          uretprobes it's a bit more modest with bump from 2.4 M/s to
          5 M/s.

          For SRCU vs RCU Tasks Trace, peak throughput for uprobes
          increases further from 8 M/s to 10.3 M/s (+28%!), and for
          uretprobes from 5.3 M/s to 5.8 M/s (+11%), as we have more
          work to do on uretprobes side.

          Even single-thread (no contention) performance is slightly
          better: 3.276 M/s to 3.396 M/s (+3.5%) for uprobes, and 2.055
          M/s to 2.174 M/s (+5.8%) for uretprobes."

          (Andrii Nakryiko et al)

     - Document mmap_lock, don't abuse get_user_pages_remote() (Oleg
       Nesterov)

     - Cleanups & fixes to prepare for future work:
        - Remove uprobe_register_refctr()
	- Simplify error handling for alloc_uprobe()
        - Make uprobe_register() return struct uprobe *
        - Fold __uprobe_unregister() into uprobe_unregister()
        - Shift put_uprobe() from delete_uprobe() to uprobe_unregister()
        - BPF: Fix use-after-free in bpf_uprobe_multi_link_attach()
          (Oleg Nesterov)

 - New feature & ABI extension: allow events to use PERF_SAMPLE READ
   with inheritance, enabling sample based profiling of a group of
   counters over a hierarchy of processes or threads (Ben Gainey)

 - Intel uncore & power events updates:

      - Add Arrow Lake and Lunar Lake support
      - Add PERF_EV_CAP_READ_SCOPE
      - Clean up and enhance cpumask and hotplug support
        (Kan Liang)

      - Add LNL uncore iMC freerunning support
      - Use D0:F0 as a default device
        (Zhenyu Wang)

 - Intel PT: fix AUX snapshot handling race (Adrian Hunter)

 - Misc fixes and cleanups (James Clark, Jiri Olsa, Oleg Nesterov and
   Peter Zijlstra)

* tag 'perf-core-2024-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  dmaengine: idxd: Clean up cpumask and hotplug for perfmon
  iommu/vt-d: Clean up cpumask and hotplug for perfmon
  perf/x86/intel/cstate: Clean up cpumask and hotplug
  perf: Add PERF_EV_CAP_READ_SCOPE
  perf: Generic hotplug support for a PMU with a scope
  uprobes: perform lockless SRCU-protected uprobes_tree lookup
  rbtree: provide rb_find_rcu() / rb_find_add_rcu()
  perf/uprobe: split uprobe_unregister()
  uprobes: travers uprobe's consumer list locklessly under SRCU protection
  uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
  uprobes: protected uprobe lifetime with SRCU
  uprobes: revamp uprobe refcounting and lifetime management
  bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
  perf/core: Fix small negative period being ignored
  perf: Really fix event_function_call() locking
  perf: Optimize __pmu_ctx_sched_out()
  perf: Add context time freeze
  perf: Fix event_function_call() locking
  perf: Extract a few helpers
  perf: Optimize context reschedule for single PMU cases
  ...
2024-09-18 15:03:58 +02:00
Linus Torvalds
067610ebaa RCU pull request for v6.12
This pull request contains the following branches:
 
 context_tracking.15.08.24a: Rename context tracking state related
         symbols and remove references to "dynticks" in various context
         tracking state variables and related helpers; force
         context_tracking_enabled_this_cpu() to be inlined to avoid
         leaving a noinstr section.
 
 csd.lock.15.08.24a: Enhance CSD-lock diagnostic reports; add an API
         to provide an indication of ongoing CSD-lock stall.
 
 nocb.09.09.24a: Update and simplify RCU nocb code to handle
         (de-)offloading of callbacks only for offline CPUs; fix RT
         throttling hrtimer being armed from offline CPU.
 
 rcutorture.14.08.24a: Remove redundant rcu_torture_ops get_gp_completed
         fields; add SRCU ->same_gp_state and ->get_comp_state
         functions; add generic test for NUM_ACTIVE_*RCU_POLL* for
         testing RCU and SRCU polled grace periods; add CFcommon.arch
         for arch-specific Kconfig options; print number of update types
         in rcu_torture_write_types();
         add rcutree.nohz_full_patience_delay testing to the TREE07
         scenario; add a stall_cpu_repeat module parameter to test
         repeated CPU stalls; add argument to limit number of CPUs a
         guest OS can use in torture.sh;
 
 rcustall.09.09.24a: Abbreviate RCU CPU stall warnings during CSD-lock
         stalls; Allow dump_cpu_task() to be called without disabling
         preemption; defer printing stall-warning backtrace when holding
         rcu_node lock.
 
 srcu.12.08.24a: Make SRCU gp seq wrap-around faster; add KCSAN checks
         for concurrent updates to ->srcu_n_exp_nodelay and
         ->reschedule_count which are used in heuristics governing
         auto-expediting of normal SRCU grace periods and
         grace-period-state-machine delays; mark idle SRCU-barrier
         callbacks to help identify stuck SRCU-barrier callback.
 
 rcu.tasks.14.08.24a: Remove RCU Tasks Rude asynchronous APIs as they
         are no longer used; stop testing RCU Tasks Rude asynchronous
         APIs; fix access to non-existent percpu regions; check
         processor-ID assumptions during chosen CPU calculation for
         callback enqueuing; update description of rtp->tasks_gp_seq
         grace-period sequence number; add rcu_barrier_cb_is_done()
         to identify whether a given rcu_barrier callback is stuck;
         mark idle Tasks-RCU-barrier callbacks; add
         *torture_stats_print() functions to print detailed
         diagnostics for Tasks-RCU variants; capture start time of
         rcu_barrier_tasks*() operation to help distinguish a hung
         barrier operation from a long series of barrier operations.
 
 rcu_scaling_tests.15.08.24a:
         refscale: Add a TINY scenario to support tests of Tiny RCU
         and Tiny SRCU; Optimize process_durations() operation;
 
         rcuscale: Dump stacks of stalled rcu_scale_writer() instances;
         dump grace-period statistics when rcu_scale_writer() stalls;
         mark idle RCU-barrier callbacks to identify stuck RCU-barrier
         callbacks; print detailed grace-period and barrier diagnostics
         on rcu_scale_writer() hangs for Tasks-RCU variants; warn if
         async module parameter is specified for RCU implementations
         that do not have async primitives such as RCU Tasks Rude;
         make all writer tasks report upon hang; tolerate repeated
         GFP_KERNEL failure in rcu_scale_writer(); use special allocator
         for rcu_scale_writer(); NULL out top-level pointers to heap
         memory to avoid double-free bugs on modprobe failures; maintain
         per-task instead of per-CPU callbacks count to avoid any issues
         with migration of either tasks or callbacks; constify struct
         ref_scale_ops.
 
 fixes.12.08.24a: Use system_unbound_wq for kfree_rcu work to avoid
         disturbing isolated CPUs.
 
 misc.11.08.24a: Warn on unexpected rcu_state.srs_done_tail state;
         Better define "atomic" for list_replace_rcu() and
         hlist_replace_rcu() routines; annotate struct
         kvfree_rcu_bulk_data with __counted_by().
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Merge tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

Pull RCU updates from Neeraj Upadhyay:
 "Context tracking:
   - rename context tracking state related symbols and remove references
     to "dynticks" in various context tracking state variables and
     related helpers
   - force context_tracking_enabled_this_cpu() to be inlined to avoid
     leaving a noinstr section

  CSD lock:
   - enhance CSD-lock diagnostic reports
   - add an API to provide an indication of ongoing CSD-lock stall

  nocb:
   - update and simplify RCU nocb code to handle (de-)offloading of
     callbacks only for offline CPUs
   - fix RT throttling hrtimer being armed from offline CPU

  rcutorture:
   - remove redundant rcu_torture_ops get_gp_completed fields
   - add SRCU ->same_gp_state and ->get_comp_state functions
   - add generic test for NUM_ACTIVE_*RCU_POLL* for testing RCU and SRCU
     polled grace periods
   - add CFcommon.arch for arch-specific Kconfig options
   - print number of update types in rcu_torture_write_types()
   - add rcutree.nohz_full_patience_delay testing to the TREE07 scenario
   - add a stall_cpu_repeat module parameter to test repeated CPU stalls
   - add argument to limit number of CPUs a guest OS can use in
     torture.sh

  rcustall:
   - abbreviate RCU CPU stall warnings during CSD-lock stalls
   - Allow dump_cpu_task() to be called without disabling preemption
   - defer printing stall-warning backtrace when holding rcu_node lock

  srcu:
   - make SRCU gp seq wrap-around faster
   - add KCSAN checks for concurrent updates to ->srcu_n_exp_nodelay and
     ->reschedule_count which are used in heuristics governing
     auto-expediting of normal SRCU grace periods and
     grace-period-state-machine delays
   - mark idle SRCU-barrier callbacks to help identify stuck
     SRCU-barrier callback

  rcu tasks:
   - remove RCU Tasks Rude asynchronous APIs as they are no longer used
   - stop testing RCU Tasks Rude asynchronous APIs
   - fix access to non-existent percpu regions
   - check processor-ID assumptions during chosen CPU calculation for
     callback enqueuing
   - update description of rtp->tasks_gp_seq grace-period sequence
     number
   - add rcu_barrier_cb_is_done() to identify whether a given
     rcu_barrier callback is stuck
   - mark idle Tasks-RCU-barrier callbacks
   - add *torture_stats_print() functions to print detailed diagnostics
     for Tasks-RCU variants
   - capture start time of rcu_barrier_tasks*() operation to help
     distinguish a hung barrier operation from a long series of barrier
     operations

  refscale:
   - add a TINY scenario to support tests of Tiny RCU and Tiny
     SRCU
   - optimize process_durations() operation

  rcuscale:
   - dump stacks of stalled rcu_scale_writer() instances and
     grace-period statistics when rcu_scale_writer() stalls
   - mark idle RCU-barrier callbacks to identify stuck RCU-barrier
     callbacks
   - print detailed grace-period and barrier diagnostics on
     rcu_scale_writer() hangs for Tasks-RCU variants
   - warn if async module parameter is specified for RCU implementations
     that do not have async primitives such as RCU Tasks Rude
   - make all writer tasks report upon hang
   - tolerate repeated GFP_KERNEL failure in rcu_scale_writer()
   - use special allocator for rcu_scale_writer()
   - NULL out top-level pointers to heap memory to avoid double-free
     bugs on modprobe failures
   - maintain per-task instead of per-CPU callbacks count to avoid any
     issues with migration of either tasks or callbacks
   - constify struct ref_scale_ops

  Fixes:
   - use system_unbound_wq for kfree_rcu work to avoid disturbing
     isolated CPUs

  Misc:
   - warn on unexpected rcu_state.srs_done_tail state
   - better define "atomic" for list_replace_rcu() and
     hlist_replace_rcu() routines
   - annotate struct kvfree_rcu_bulk_data with __counted_by()"

* tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (90 commits)
  rcu: Defer printing stall-warning backtrace when holding rcu_node lock
  rcu/nocb: Remove superfluous memory barrier after bypass enqueue
  rcu/nocb: Conditionally wake up rcuo if not already waiting on GP
  rcu/nocb: Fix RT throttling hrtimer armed from offline CPU
  rcu/nocb: Simplify (de-)offloading state machine
  context_tracking: Tag context_tracking_enabled_this_cpu() __always_inline
  context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching
  rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()
  rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
  rcu: Rename rcu_implicit_dynticks_qs() into rcu_watching_snap_recheck()
  rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()
  rcu: Rename struct rcu_data .exp_dynticks_snap into .exp_watching_snap
  rcu: Rename struct rcu_data .dynticks_snap into .watching_snap
  rcu: Rename rcu_dynticks_zero_in_eqs() into rcu_watching_zero_in_eqs()
  rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_snap_stopped_since()
  rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()
  rcu: Rename rcu_dynticks_eqs_online() into rcu_watching_online()
  context_tracking, rcu: Rename rcu_dynticks_curr_cpu_in_eqs() into rcu_is_watching_curr_cpu()
  context_tracking, rcu: Rename rcu_dynticks_task*() into rcu_task*()
  refscale: Constify struct ref_scale_ops
  ...
2024-09-18 07:52:24 +02:00
Daniel Borkmann
32556ce93b bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.

In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.

The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.

However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).

MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val.

Fixes: 57c3bb725a ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types")
Reported-by: Lonial Con <kongln9170@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240913191754.13290-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-13 13:17:55 -07:00
Yonghong Song
376bd59e2a bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing
Salvatore Benedetto reported an issue that when doing syscall tracepoint
tracing the kernel stack is empty. For example, using the following
command line
  bpftrace -e 'tracepoint:syscalls:sys_enter_read { print("Kernel Stack\n"); print(kstack()); }'
  bpftrace -e 'tracepoint:syscalls:sys_exit_read { print("Kernel Stack\n"); print(kstack()); }'
the output for both commands is
===
  Kernel Stack
===

Further analysis shows that pt_regs used for bpf syscall tracepoint
tracing is from the one constructed during user->kernel transition.
The call stack looks like
  perf_syscall_enter+0x88/0x7c0
  trace_sys_enter+0x41/0x80
  syscall_trace_enter+0x100/0x160
  do_syscall_64+0x38/0xf0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The ip address stored in pt_regs is from user space hence no kernel
stack is printed.

To fix the issue, kernel address from pt_regs is required.
In kernel repo, there are already a few cases like this. For example,
in kernel/trace/bpf_trace.c, several perf_fetch_caller_regs(fake_regs_ptr)
instances are used to supply ip address or use ip address to construct
call stack.

Instead of allocate fake_regs in the stack which may consume
a lot of bytes, the function perf_trace_buf_alloc() in
perf_syscall_{enter, exit}() is leveraged to create fake_regs,
which will be passed to perf_call_bpf_{enter,exit}().

For the above bpftrace script, I got the following output with this patch:
for tracepoint:syscalls:sys_enter_read
===
  Kernel Stack

        syscall_trace_enter+407
        syscall_trace_enter+407
        do_syscall_64+74
        entry_SYSCALL_64_after_hwframe+75
===
and for tracepoint:syscalls:sys_exit_read
===
Kernel Stack

        syscall_exit_work+185
        syscall_exit_work+185
        syscall_exit_to_user_mode+305
        do_syscall_64+118
        entry_SYSCALL_64_after_hwframe+75
===

Reported-by: Salvatore Benedetto <salvabenedetto@meta.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240910214037.3663272-1-yonghong.song@linux.dev
2024-09-11 13:27:27 -07:00
Andrii Nakryiko
d4dd9775ec bpf: wire up sleepable bpf_get_stack() and bpf_get_task_stack() helpers
Add sleepable implementations of bpf_get_stack() and
bpf_get_task_stack() helpers and allow them to be used from sleepable
BPF program (e.g., sleepable uprobes).

Note, the stack trace IPs capturing itself is not sleepable (that would
need to be a separate project), only build ID fetching is sleepable and
thus more reliable, as it will wait for data to be paged in, if
necessary. For that we make use of sleepable build_id_parse()
implementation.

Now that build ID related internals in kernel/bpf/stackmap.c can be used
both in sleepable and non-sleepable contexts, we need to add additional
rcu_read_lock()/rcu_read_unlock() protection around fetching
perf_callchain_entry, but with the refactoring in previous commit it's
now pretty straightforward. We make sure to do rcu_read_unlock (in
sleepable mode only) right before stack_map_get_build_id_offset() call
which can sleep. By that time we don't have any more use of
perf_callchain_entry.

Note, bpf_get_task_stack() will fail for user mode if task != current.
And for kernel mode build ID are irrelevant. So in that sense adding
sleepable bpf_get_task_stack() implementation is a no-op. It feel right
to wire this up for symmetry and completeness, but I'm open to just
dropping it until we support `user && crosstask` condition.

Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240829174232.3133883-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-11 09:58:31 -07:00
Andy Shevchenko
4e378158e5 tracing: Drop unused helper function to fix the build
A helper function defined but not used. This, in particular,
prevents kernel builds with clang, `make W=1` and CONFIG_WERROR=y:

kernel/trace/trace.c:2229:19: error: unused function 'run_tracer_selftest' [-Werror,-Wunused-function]
 2229 | static inline int run_tracer_selftest(struct tracer *type)
      |                   ^~~~~~~~~~~~~~~~~~~

Fix this by dropping unused functions.

See also commit 6863f5643d ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/20240909105314.928302-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-09 16:04:25 -04:00
Steven Rostedt
af17814334 tracing/osnoise: Fix build when timerlat is not enabled
To fix some critical section races, the interface_lock was added to a few
locations. One of those locations was above where the interface_lock was
declared, so the declaration was moved up before that usage.
Unfortunately, where it was placed was inside a CONFIG_TIMERLAT_TRACER
ifdef block. As the interface_lock is used outside that config, this broke
the build when CONFIG_OSNOISE_TRACER was enabled but
CONFIG_TIMERLAT_TRACER was not.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Helena Anna" <helena.anna.dubel@intel.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Link: https://lore.kernel.org/20240909103231.23a289e2@gandalf.local.home
Fixes: e6a53481da ("tracing/timerlat: Only clear timer if a kthread exists")
Reported-by: "Bityutskiy, Artem" <artem.bityutskiy@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-09 16:03:57 -04:00
Jiri Olsa
900f362e20 bpf: Fix uprobe multi pid filter check
Uprobe multi link does its own process (thread leader) filtering before
running the bpf program by comparing task's vm pointers.

But as Oleg pointed out there can be processes sharing the vm (CLONE_VM),
so we can't just compare task->vm pointers, but instead we need to use
same_thread_group call.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/bpf/20240905115124.1503998-2-jolsa@kernel.org
2024-09-05 12:43:22 -07:00
Steven Rostedt
5bfbcd1ee5 tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()
The timerlat interface will get and put the task that is part of the
"kthread" field of the osn_var to keep it around until all references are
released. But here's a race in the "stop_kthread()" code that will call
put_task_struct() on the kthread if it is not a kernel thread. This can
race with the releasing of the references to that task struct and the
put_task_struct() can be called twice when it should have been called just
once.

Take the interface_lock() in stop_kthread() to synchronize this change.
But to do so, the function stop_per_cpu_kthreads() needs to change the
loop from for_each_online_cpu() to for_each_possible_cpu() and remove the
cpu_read_lock(), as the interface_lock can not be taken while the cpu
locks are held. The only side effect of this change is that it may do some
extra work, as the per_cpu variables of the offline CPUs would not be set
anyway, and would simply be skipped in the loop.

Remove unneeded "return;" in stop_kthread().

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905113359.2b934242@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 12:01:37 -04:00
Steven Rostedt
e6a53481da tracing/timerlat: Only clear timer if a kthread exists
The timerlat tracer can use user space threads to check for osnoise and
timer latency. If the program using this is killed via a SIGTERM, the
threads are shutdown one at a time and another tracing instance can start
up resetting the threads before they are fully closed. That causes the
hrtimer assigned to the kthread to be shutdown and freed twice when the
dying thread finally closes the file descriptors, causing a use-after-free
bug.

Only cancel the hrtimer if the associated thread is still around. Also add
the interface_lock around the resetting of the tlat_var->kthread.

Note, this is just a quick fix that can be backported to stable. A real
fix is to have a better synchronization between the shutdown of old
threads and the starting of new ones.

Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240905085330.45985730@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Reported-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 11:30:23 -04:00
Steven Rostedt
177e1cc2f4 tracing/osnoise: Use a cpumask to know what threads are kthreads
The start_kthread() and stop_thread() code was not always called with the
interface_lock held. This means that the kthread variable could be
unexpectedly changed causing the kthread_stop() to be called on it when it
should not have been, leading to:

 while true; do
   rtla timerlat top -u -q & PID=$!;
   sleep 5;
   kill -INT $PID;
   sleep 0.001;
   kill -TERM $PID;
   wait $PID;
  done

Causing the following OOPS:

 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI
 KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
 CPU: 5 UID: 0 PID: 885 Comm: timerlatu/5 Not tainted 6.11.0-rc4-test-00002-gbc754cc76d1b-dirty #125 a533010b71dab205ad2f507188ce8c82203b0254
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
 RIP: 0010:hrtimer_active+0x58/0x300
 Code: 48 c1 ee 03 41 54 48 01 d1 48 01 d6 55 53 48 83 ec 20 80 39 00 0f 85 30 02 00 00 49 8b 6f 30 4c 8d 75 10 4c 89 f0 48 c1 e8 03 <0f> b6 3c 10 4c 89 f0 83 e0 07 83 c0 03 40 38 f8 7c 09 40 84 ff 0f
 RSP: 0018:ffff88811d97f940 EFLAGS: 00010202
 RAX: 0000000000000002 RBX: ffff88823c6b5b28 RCX: ffffed10478d6b6b
 RDX: dffffc0000000000 RSI: ffffed10478d6b6c RDI: ffff88823c6b5b28
 RBP: 0000000000000000 R08: ffff88823c6b5b58 R09: ffff88823c6b5b60
 R10: ffff88811d97f957 R11: 0000000000000010 R12: 00000000000a801d
 R13: ffff88810d8b35d8 R14: 0000000000000010 R15: ffff88823c6b5b28
 FS:  0000000000000000(0000) GS:ffff88823c680000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000561858ad7258 CR3: 000000007729e001 CR4: 0000000000170ef0
 Call Trace:
  <TASK>
  ? die_addr+0x40/0xa0
  ? exc_general_protection+0x154/0x230
  ? asm_exc_general_protection+0x26/0x30
  ? hrtimer_active+0x58/0x300
  ? __pfx_mutex_lock+0x10/0x10
  ? __pfx_locks_remove_file+0x10/0x10
  hrtimer_cancel+0x15/0x40
  timerlat_fd_release+0x8e/0x1f0
  ? security_file_release+0x43/0x80
  __fput+0x372/0xb10
  task_work_run+0x11e/0x1f0
  ? _raw_spin_lock+0x85/0xe0
  ? __pfx_task_work_run+0x10/0x10
  ? poison_slab_object+0x109/0x170
  ? do_exit+0x7a0/0x24b0
  do_exit+0x7bd/0x24b0
  ? __pfx_migrate_enable+0x10/0x10
  ? __pfx_do_exit+0x10/0x10
  ? __pfx_read_tsc+0x10/0x10
  ? ktime_get+0x64/0x140
  ? _raw_spin_lock_irq+0x86/0xe0
  do_group_exit+0xb0/0x220
  get_signal+0x17ba/0x1b50
  ? vfs_read+0x179/0xa40
  ? timerlat_fd_read+0x30b/0x9d0
  ? __pfx_get_signal+0x10/0x10
  ? __pfx_timerlat_fd_read+0x10/0x10
  arch_do_signal_or_restart+0x8c/0x570
  ? __pfx_arch_do_signal_or_restart+0x10/0x10
  ? vfs_read+0x179/0xa40
  ? ksys_read+0xfe/0x1d0
  ? __pfx_ksys_read+0x10/0x10
  syscall_exit_to_user_mode+0xbc/0x130
  do_syscall_64+0x74/0x110
  ? __pfx___rseq_handle_notify_resume+0x10/0x10
  ? __pfx_ksys_read+0x10/0x10
  ? fpregs_restore_userregs+0xdb/0x1e0
  ? fpregs_restore_userregs+0xdb/0x1e0
  ? syscall_exit_to_user_mode+0x116/0x130
  ? do_syscall_64+0x74/0x110
  ? do_syscall_64+0x74/0x110
  ? do_syscall_64+0x74/0x110
  entry_SYSCALL_64_after_hwframe+0x71/0x79
 RIP: 0033:0x7ff0070eca9c
 Code: Unable to access opcode bytes at 0x7ff0070eca72.
 RSP: 002b:00007ff006dff8c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007ff0070eca9c
 RDX: 0000000000000400 RSI: 00007ff006dff9a0 RDI: 0000000000000003
 RBP: 00007ff006dffde0 R08: 0000000000000000 R09: 00007ff000000ba0
 R10: 00007ff007004b08 R11: 0000000000000246 R12: 0000000000000003
 R13: 00007ff006dff9a0 R14: 0000000000000007 R15: 0000000000000008
  </TASK>
 Modules linked in: snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hwdep snd_hda_core
 ---[ end trace 0000000000000000 ]---

This is because it would mistakenly call kthread_stop() on a user space
thread making it "exit" before it actually exits.

Since kthreads are created based on global behavior, use a cpumask to know
when kthreads are running and that they need to be shutdown before
proceeding to do new work.

Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/

This was debugged by using the persistent ring buffer:

Link: https://lore.kernel.org/all/20240823013902.135036960@goodmis.org/

Note, locking was originally used to fix this, but that proved to cause too
many deadlocks to work around:

  https://lore.kernel.org/linux-trace-kernel/20240823102816.5e55753b@gandalf.local.home/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20240904103428.08efdf4c@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Reported-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 11:30:22 -04:00
Peter Zijlstra
04b01625da perf/uprobe: split uprobe_unregister()
With uprobe_unregister() having grown a synchronize_srcu(), it becomes
fairly slow to call. Esp. since both users of this API call it in a
loop.

Peel off the sync_srcu() and do it once, after the loop.

We also need to add uprobe_unregister_sync() into uprobe_register()'s
error handling path, as we need to be careful about returning to the
caller before we have a guarantee that partially attached consumer won't
be called anymore. This is an unlikely slow path and this should be
totally fine to be slow in the case of a failed attach.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20240903174603.3554182-6-andrii@kernel.org
2024-09-05 16:56:14 +02:00
Andrii Nakryiko
59da880afe uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks
It serves no purpose beyond adding unnecessray argument passed to the
filter callback. Just get rid of it, no one is actually using it.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20240903174603.3554182-4-andrii@kernel.org
2024-09-05 16:56:14 +02:00
Oleg Nesterov
5fe6e308ab bpf: Fix use-after-free in bpf_uprobe_multi_link_attach()
If bpf_link_prime() fails, bpf_uprobe_multi_link_attach() goes to the
error_free label and frees the array of bpf_uprobe's without calling
bpf_uprobe_unregister().

This leaks bpf_uprobe->uprobe and worse, this frees bpf_uprobe->consumer
without removing it from the uprobe->consumers list.

Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Closes: https://lore.kernel.org/all/000000000000382d39061f59f2dd@google.com/
Reported-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: syzbot+f7a1c2c2711e4a780f19@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240813152524.GA7292@redhat.com
2024-09-05 16:56:13 +02:00
Zheng Yejian
49aa8a1f4d tracing: Avoid possible softlockup in tracing_iter_reset()
In __tracing_open(), when max latency tracers took place on the cpu,
the time start of its buffer would be updated, then event entries with
timestamps being earlier than start of the buffer would be skipped
(see tracing_iter_reset()).

Softlockup will occur if the kernel is non-preemptible and too many
entries were skipped in the loop that reset every cpu buffer, so add
cond_resched() to avoid it.

Cc: stable@vger.kernel.org
Fixes: 2f26ebd549 ("tracing: use timestamp to determine start of latency traces")
Link: https://lore.kernel.org/20240827124654.3817443-1-zhengyejian@huaweicloud.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-09-05 10:18:48 -04:00
Ingo Molnar
95c13662b6 Merge branch 'perf/urgent' into perf/core, to pick up fixes
This also refreshes the -rc1 based branch to -rc5.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-09-05 11:17:43 +02:00
Steven Rostedt
ef2bd81d0c tracing: Add option to set an instance to be the trace_printk destination
Add a option "trace_printk_dest" that will make the tracing instance the
location that trace_printk() will go to. This is useful if the
trace_printk or one of the top level tracers is too noisy and there's a
need to separate the two. Then an instance can be created, the
trace_printk can be set to go there instead, where it will not be lost in
the noise of the top level tracer.

Note, only one instance can be the destination of trace_printk at a time.
If an instance sets this flag, the instance that had it set will have it
cleared. There is always one instance that has this set. By default, that
is the top instance. This flag cannot be cleared from the top instance.
Doing so will result in an -EINVAL. The only way this flag can be cleared
from the top instance is by another instance setting it.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Aring <aahringo@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Link: https://lore.kernel.org/20240823014019.545459018@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:54:08 -04:00
Steven Rostedt
9b7bdf6f6e tracing: Have trace_printk not use binary prints if boot buffer
If the persistent boot mapped ring buffer is used for trace_printk(),
force it to not use the binary versions. trace_printk() by default uses
bin_printf() that only saves the pointer to the format and not the format
itself inside the ring buffer. But for a persistent buffer that is read
after reboot, the pointers to the format strings may not be the same, or
worse, not even exist! Instead, just force the more robust, but slower,
version that does the formatting before saving into the ring buffer.

The boot mapped buffer can now be used for trace_printk and friends!

Using the trace_printk() and the persistent buffer was used to debug the
issue with the osnoise tracer:

Link: https://lore.kernel.org/all/20240822103443.6a6ae051@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Aring <aahringo@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Link: https://lore.kernel.org/20240823014019.386925800@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:54:08 -04:00
Steven Rostedt
ddb8ea9e5a tracing: Allow trace_printk() to go to other instance buffers
Currently, trace_printk() just goes to the top level ring buffer. But
there may be times that it should go to one of the instances created by
the kernel command line.

Add a new trace_instance flag: traceprintk (also can use "printk" or
"trace_printk" as people tend to forget the actual flag name).

  trace_instance=foo^traceprintk

Will assign the trace_printk to this buffer at boot up.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Aring <aahringo@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Link: https://lore.kernel.org/20240823014019.226694946@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:54:08 -04:00
Steven Rostedt
b6fc31b687 tracing: Add "traceoff" flag to boot time tracing instances
Add a "flags" delimiter (^) to the "trace_instance" kernel command line
parameter, and add the "traceoff" flag. The format is:

   trace_instance=<name>[^<flag1>[^<flag2>]][@<memory>][,<events>]

The code allows for more than one flag to be added, but currently only
"traceoff" is done so.

The motivation for this change came from debugging with the persistent
ring buffer and having trace_printk() writing to it. The trace_printk
calls are always enabled, and the boot after the crash was having the
unwanted trace_printks from the current boot inject into the ring buffer
with the trace_printks of the crash kernel, making the output very
confusing.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Aring <aahringo@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Link: https://lore.kernel.org/20240823014019.053229958@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:54:08 -04:00
Vincent Donnefort
eb2dcde9f9 ring-buffer: Align meta-page to sub-buffers for improved TLB usage
Previously, the mapped ring-buffer layout caused misalignment between
the meta-page and sub-buffers when the sub-buffer size was not a
multiple of PAGE_SIZE. This prevented hardware with larger TLB entries
from utilizing them effectively.

Add a padding with the zero-page between the meta-page and sub-buffers.
Also update the ring-buffer map_test to verify that padding.

Link: https://lore.kernel.org/20240628104611.1443542-1-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:42:23 -04:00
Steven Rostedt
d0f2d6e951 ring-buffer: Add magic and struct size to boot up meta data
Add a magic number as well as save the struct size of the ring_buffer_meta
structure in the meta data to also use as validation. Updating the magic
number could be used to force a invalidation between kernel versions, and
saving the structure size is also a good method to make sure the content
is what is expected.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20240815115032.0c197b32@rorschach.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:34:22 -04:00
Steven Rostedt
bca704f62d ring-buffer: Don't reset persistent ring-buffer meta saved addresses
The text and data address is saved in the meta data so that it can be used
to know the delta of the text and data addresses of the last boot compared
to the text and data addresses of the current boot. The delta is used to
convert function pointer entries in the ring buffer to something that can
be used by kallsyms (note this only works for built-in functions).

But the saved addresses get reset on boot up. If the buffer is not used
and there's another reboot, then the saved text and data addresses will be
of the last boot and not that of the boot that created the content in the
ring buffer.

To get an idea of the issue:

 # trace-cmd start -B boot_mapped -p function
 # reboot
 # trace-cmd show -B boot_mapped | tail
           <...>-1       [000] d..1.   461.983243: native_apic_msr_write <-native_kick_ap
           <...>-1       [000] d..1.   461.983244: __pfx_native_apic_msr_eoi <-native_kick_ap
           <...>-1       [000] d..1.   461.983244: reserve_irq_vector_locked <-native_kick_ap
           <...>-1       [000] d..1.   461.983262: branch_emulate_op <-native_kick_ap
           <...>-1       [000] d..1.   461.983262: __ia32_sys_ia32_pread64 <-native_kick_ap
           <...>-1       [000] d..1.   461.983263: native_kick_ap <-__smpboot_create_thread
           <...>-1       [000] d..1.   461.983263: store_cache_disable <-native_kick_ap
           <...>-1       [000] d..1.   461.983279: acpi_power_off_prepare <-native_kick_ap
           <...>-1       [000] d..1.   461.983280: __pfx_acpi_ns_delete_node <-acpi_suspend_enter
           <...>-1       [000] d..1.   461.983280: __pfx_acpi_os_release_lock <-acpi_suspend_enter
 # reboot
 # trace-cmd show -B boot_mapped  |tail
           <...>-1       [000] d..1.   461.983243: 0xffffffffa9669220 <-0xffffffffa965f3db
           <...>-1       [000] d..1.   461.983244: 0xffffffffa96690f0 <-0xffffffffa965f3db
           <...>-1       [000] d..1.   461.983244: 0xffffffffa9663fa0 <-0xffffffffa965f3db
           <...>-1       [000] d..1.   461.983262: 0xffffffffa9672e80 <-0xffffffffa965f3e0
           <...>-1       [000] d..1.   461.983262: 0xffffffffa962b940 <-0xffffffffa965f3ec
           <...>-1       [000] d..1.   461.983263: 0xffffffffa965f540 <-0xffffffffa96e1362
           <...>-1       [000] d..1.   461.983263: 0xffffffffa963c940 <-0xffffffffa965f55b
           <...>-1       [000] d..1.   461.983279: 0xffffffffa9ee30c0 <-0xffffffffa965f59b
           <...>-1       [000] d..1.   461.983280: 0xffffffffa9f16c10 <-0xffffffffa9ee3157
           <...>-1       [000] d..1.   461.983280: 0xffffffffa9ee02e0 <-0xffffffffa9ee3157

By not updating the saved text and data addresses in the meta data at
every boot up and only updating them when the buffer is reset, it
allows multiple boots to see the same data.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20240815113629.0dc90af8@rorschach.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-26 13:33:53 -04:00
Alexei Starovoitov
50c374c6d1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR including
important fixes (from bpf-next point of view):
commit 41c24102af ("selftests/bpf: Filter out _GNU_SOURCE when compiling test_cpp")
commit fdad456cbc ("bpf: Fix updating attached freplace prog in prog_array map")

No conflicts.

Adjacent changes in:
include/linux/bpf_verifier.h
kernel/bpf/verifier.c
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/bpf/20240813234307.82773-1-alexei.starovoitov@gmail.com/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-22 09:48:44 -07:00
Masami Hiramatsu (Google)
bc754cc76d tracing: Fix memory leak in fgraph storage selftest
With ftrace boot-time selftest, kmemleak reported some memory leaks in
the new test case for function graph storage for multiple tracers.

unreferenced object 0xffff888005060080 (size 32):
  comm "swapper/0", pid 1, jiffies 4294676440
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 20 10 06 05 80 88 ff ff  ........ .......
    54 0c 1e 81 ff ff ff ff 00 00 00 00 00 00 00 00  T...............
  backtrace (crc 7c93416c):
    [<000000000238ee6f>] __kmalloc_cache_noprof+0x11f/0x2a0
    [<0000000033d2b6c5>] enter_record+0xe8/0x150
    [<0000000054c38424>] match_records+0x1cd/0x230
    [<00000000c775b63d>] ftrace_set_hash+0xff/0x380
    [<000000007bf7208c>] ftrace_set_filter+0x70/0x90
    [<00000000a5c08dda>] test_graph_storage_multi+0x2e/0xf0
    [<000000006ba028ca>] trace_selftest_startup_function_graph+0x1e8/0x260
    [<00000000a715d3eb>] run_tracer_selftest+0x111/0x190
    [<00000000395cbf90>] register_tracer+0xdf/0x1f0
    [<0000000093e67f7b>] do_one_initcall+0x141/0x3b0
    [<00000000c591b682>] do_initcall_level+0x82/0xa0
    [<000000004e4c6600>] do_initcalls+0x43/0x70
    [<0000000034f3c4e4>] kernel_init_freeable+0x170/0x1f0
    [<00000000c7a5dab2>] kernel_init+0x1a/0x1a0
    [<00000000ea105947>] ret_from_fork+0x3a/0x50
    [<00000000a1932e84>] ret_from_fork_asm+0x1a/0x30
...

This means filter hash allocated for the fixtures are not correctly
released after the test.

Free those hash lists after tests are done and split the loop for
initialize fixture and register fixture for rollback.

Fixes: dd120af2d5 ("ftrace: Add multiple fgraph storage selftest")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/172411539857.28895.13119957560263401102.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-21 15:10:33 -04:00
Masami Hiramatsu (Google)
a069a22f39 tracing: fgraph: Fix to add new fgraph_ops to array after ftrace_startup_subops()
Since the register_ftrace_graph() assigns a new fgraph_ops to
fgraph_array before registring it by ftrace_startup_subops(), the new
fgraph_ops can be used in function_graph_enter().

In most cases, it is still OK because those fgraph_ops's hashtable is
already initialized by ftrace_set_filter*() etc.

But if a user registers a new fgraph_ops which does not initialize the
hash list, ftrace_ops_test() in function_graph_enter() causes a NULL
pointer dereference BUG because fgraph_ops->ops.func_hash is NULL.

This can be reproduced by the below commands because function profiler's
fgraph_ops does not initialize the hash list;

 # cd /sys/kernel/tracing
 # echo function_graph > current_tracer
 # echo 1 > function_profile_enabled

To fix this problem, add a new fgraph_ops to fgraph_array after
ftrace_startup_subops(). Thus, until the new fgraph_ops is initialized,
we will see fgraph_stub on the corresponding fgraph_array entry.

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2
Fixes: c132be2c4f ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-21 13:49:59 -04:00
Matteo Croce
7f6287417b bpf: Allow bpf_current_task_under_cgroup() with BPF_CGROUP_*
The helper bpf_current_task_under_cgroup() currently is only allowed for
tracing programs, allow its usage also in the BPF_CGROUP_* program types.

Move the code from kernel/trace/bpf_trace.c to kernel/bpf/helpers.c,
so it compiles also without CONFIG_BPF_EVENTS.

This will be used in systemd-networkd to monitor the sysctl writes,
and filter it's own writes from others:
https://github.com/systemd/systemd/pull/32212

Signed-off-by: Matteo Croce <teknoraver@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240819162805.78235-3-technoboy85@gmail.com
2024-08-19 15:25:30 -07:00
Valentin Schneider
32a9f26e5e rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
The context_tracking.state RCU_DYNTICKS subvariable has been renamed to
RCU_WATCHING, replace "dyntick_idle" into "eqs" to drop the dyntick
reference.

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
2024-08-15 21:30:42 +05:30
Steven Rostedt
4c57d0be52 tracing/fgraph: Have fgraph handle previous boot function addresses
Update the function graph code to modify the function addresses for a
previous boot buffer so that it matches the current kallsyms (note this
does not handle module addresses, yet).

After a reboot, instead of seeing:

 # trace-cmd show -B boot_mapped | tail -n30
       swapper/0-1       [000] d..2.    56.286470:  0)   0.481 us    |                    0xffffffff925da5c4();
       swapper/0-1       [000] d....    56.286471:  0)   4.065 us    |                  }
       swapper/0-1       [000] d....    56.286471:  0)   4.920 us    |                }
       swapper/0-1       [000] d..1.    56.286472:  0)               |                0xffffffff92536254() {
       swapper/0-1       [000] d..1.    56.286472:  0) + 28.974 us   |                  0xffffffff92534e30();
       swapper/0-1       [000] d....    56.286516:  0) + 43.881 us   |                }
       swapper/0-1       [000] d..1.    56.286517:  0)               |                0xffffffff925136c4() {
       swapper/0-1       [000] d..1.    56.286518:  0)               |                  0xffffffff92514a14() {
       swapper/0-1       [000] d..1.    56.286518:  0)   6.003 us    |                    0xffffffff92514200();
       swapper/0-1       [000] d....    56.286529:  0) + 11.510 us   |                  }
       swapper/0-1       [000] d....    56.286529:  0) + 12.895 us   |                }
       swapper/0-1       [000] d....    56.286530:  0) ! 382.884 us  |              }
       swapper/0-1       [000] d..1.    56.286530:  0)               |              0xffffffff92536444() {
       swapper/0-1       [000] d..1.    56.286531:  0)               |                0xffffffff92536254() {
       swapper/0-1       [000] d..1.    56.286531:  0) + 26.335 us   |                  0xffffffff92534e30();
       swapper/0-1       [000] d....    56.286560:  0) + 29.511 us   |                }
       swapper/0-1       [000] d....    56.286561:  0) + 30.452 us   |              }
       swapper/0-1       [000] d..1.    56.286562:  0)               |              0xffffffff9253c014() {
       swapper/0-1       [000] d..1.    56.286562:  0)               |                0xffffffff9253bed4() {
       swapper/0-1       [000] d..1.    56.286563:  0) + 13.465 us   |                  0xffffffff92536684();
       swapper/0-1       [000] d....    56.286577:  0) + 14.651 us   |                }
       swapper/0-1       [000] d....    56.286577:  0) + 15.821 us   |              }
       swapper/0-1       [000] d..1.    56.286578:  0)   0.667 us    |              0xffffffff92547074();
       swapper/0-1       [000] d..1.    56.286579:  0)   0.453 us    |              0xffffffff924f35c4();
       swapper/0-1       [000] d....    56.286580:  0) # 3906.348 us |            }
       swapper/0-1       [000] d..1.    56.286581:  0)               |            0xffffffff92531a14() {
       swapper/0-1       [000] d..1.    56.286581:  0)   0.518 us    |              0xffffffff92505cb4();
       swapper/0-1       [000] d..1.    56.286595:  0)               |              0xffffffff92db83c4() {
       swapper/0-1       [000] d..1.    56.286596:  0)               |                0xffffffff92dec2e4() {
       swapper/0-1       [000] d..1.    56.286597:  0)               |                  0xffffffff92db5304() {

It now shows:

 # trace-cmd show -B boot_mapped | tail -n30
       swapper/0-1       [000] d..2.   363.079099:  0)   0.483 us    |                    preempt_count_sub();
       swapper/0-1       [000] d....   363.079100:  0)   4.112 us    |                  }
       swapper/0-1       [000] d....   363.079101:  0)   4.979 us    |                }
       swapper/0-1       [000] d..1.   363.079101:  0)               |                disable_local_APIC() {
       swapper/0-1       [000] d..1.   363.079102:  0) + 29.153 us   |                  clear_local_APIC.part.0();
       swapper/0-1       [000] d....   363.079148:  0) + 46.517 us   |                }
       swapper/0-1       [000] d..1.   363.079149:  0)               |                mcheck_cpu_clear() {
       swapper/0-1       [000] d..1.   363.079149:  0)               |                  mce_intel_feature_clear() {
       swapper/0-1       [000] d..1.   363.079150:  0)   5.871 us    |                    lmce_supported();
       swapper/0-1       [000] d....   363.079161:  0) + 11.340 us   |                  }
       swapper/0-1       [000] d....   363.079161:  0) + 12.638 us   |                }
       swapper/0-1       [000] d....   363.079162:  0) ! 383.518 us  |              }
       swapper/0-1       [000] d..1.   363.079162:  0)               |              lapic_shutdown() {
       swapper/0-1       [000] d..1.   363.079163:  0)               |                disable_local_APIC() {
       swapper/0-1       [000] d..1.   363.079163:  0) + 26.144 us   |                  clear_local_APIC.part.0();
       swapper/0-1       [000] d....   363.079192:  0) + 29.424 us   |                }
       swapper/0-1       [000] d....   363.079192:  0) + 30.376 us   |              }
       swapper/0-1       [000] d..1.   363.079193:  0)               |              restore_boot_irq_mode() {
       swapper/0-1       [000] d..1.   363.079194:  0)               |                native_restore_boot_irq_mode() {
       swapper/0-1       [000] d..1.   363.079194:  0) + 13.863 us   |                  disconnect_bsp_APIC();
       swapper/0-1       [000] d....   363.079209:  0) + 14.933 us   |                }
       swapper/0-1       [000] d....   363.079209:  0) + 16.009 us   |              }
       swapper/0-1       [000] d..1.   363.079210:  0)   0.694 us    |              hpet_disable();
       swapper/0-1       [000] d..1.   363.079211:  0)   0.511 us    |              iommu_shutdown_noop();
       swapper/0-1       [000] d....   363.079212:  0) # 3980.260 us |            }
       swapper/0-1       [000] d..1.   363.079212:  0)               |            native_machine_emergency_restart() {
       swapper/0-1       [000] d..1.   363.079213:  0)   0.495 us    |              tboot_shutdown();
       swapper/0-1       [000] d..1.   363.079230:  0)               |              acpi_reboot() {
       swapper/0-1       [000] d..1.   363.079231:  0)               |                acpi_reset() {
       swapper/0-1       [000] d..1.   363.079232:  0)               |                  acpi_os_write_port() {

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20240813171257.478901820@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-15 08:35:48 -04:00
Steven Rostedt (Google)
29a02ec665 tracing: Allow boot instances to use reserve_mem boot memory
Allow boot instances to use memory reserved by the reserve_mem boot
option.

  reserve_mem=12M:4096:trace  trace_instance=boot_mapped@trace

The above will allocate 12 megs with 4096 alignment and label it "trace".
The second parameter will create a "boot_mapped" instance and use the
memory reserved and labeled as "trace" as the memory for the ring buffer.

That will create an instance called "boot_mapped":

  /sys/kernel/tracing/instances/boot_mapped

Note, because the ring buffer is using a defined memory ranged, it will
act just like a memory mapped ring buffer. It will not have a snapshot
buffer, as it can't swap out the buffer. The snapshot files as well as any
tracers that uses a snapshot will not be present in the boot_mapped
instance.

Also note that reserve_mem is not reliable in acquiring the same physical
memory at each soft reboot. It is possible that KALSR could map the kernel
at the previous boot memory location forcing the reserve_mem to return a
different memory location. In this case, the previous ring buffer will be
lost.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20240815082811.669f7d8c@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-15 08:34:48 -04:00
Steven Rostedt
6d02eefecc tracing: Fix ifdef of snapshots to not prevent last_boot_info file
The mapping of the ring buffer to memory allocated at boot up will also
expose a "last_boot_info" to help tooling to read the raw data from the
last boot. As instances that have their ring buffer mapped to fixed
memory cannot perform snapshots, they can either have the "snapshot" file
or the "last_boot_info" file, but not both.

The code that added the "last_boot_info" file failed to notice that the
"snapshot" creation was inside a "#ifdef CONFIG_TRACER_SNAPSHOT" and
incorrectly placed the creation of the "last_boot_info" file within the
ifdef block. Not only does it cause a warning when CONFIG_TRACER_SNAPSHOT
is not enabled, it also incorrectly prevents the file from appearing.

Link: https://lore.kernel.org/all/20240719102640.718554-1-arnd@kernel.org/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Arnd Bergmann <arnd@kernel.org>
Link: https://lore.kernel.org/20240719101312.3d4ac707@rorschach.local.home
Fixes: 7a1d1e4b96 ("tracing/ring-buffer: Add last_boot_info file to boot instance")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-14 17:01:03 -04:00
Steven Rostedt
ee057c8c19 Linux 6.11-rc3
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 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGwUAIAJNwbkdgTIqEsyBU
 wsFcXGaFSsGJNbTulINJb34jl2gD2yr4pmnnrA0NePW1TUKOnx169hNMF8NWbr/A
 0cHIREV9cyfnm/kzAcnHn7cWLSmsKd+x3TnCbCyodDZQDJzdLmw3LQG+4dTNJbw1
 WtJO/EoaU4qaydW2VxtApw54sirq5bopZz7rpcRapA1afzbA2TUDbnnuEWjm9KCF
 5K+RZTJZA/xI9gqEwJB+/p5FglW4n/T3xcDwaQp5uFsDskgV5e1AUrRLM+icTsem
 0Egrs8Ca2Vp4oBM+r9miCSwjRu04jLKyuu20p7AN8zXLyN7WGAjduS15Dv+aHRZ/
 9XABZs0=
 =/T17
 -----END PGP SIGNATURE-----

Merge tag 'v6.11-rc3' into trace/ring-buffer/core

The "reserve_mem" kernel command line parameter has been pulled into
v6.11. Merge the latest -rc3 to allow the persistent ring buffer memory to
be able to be mapped at the address specified by the "reserve_mem" command
line parameter.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-14 16:59:28 -04:00
Steven Rostedt
d0949cd44a tracing: Return from tracing_buffers_read() if the file has been closed
When running the following:

 # cd /sys/kernel/tracing/
 # echo 1 > events/sched/sched_waking/enable
 # echo 1 > events/sched/sched_switch/enable
 # echo 0 > tracing_on
 # dd if=per_cpu/cpu0/trace_pipe_raw of=/tmp/raw0.dat

The dd task would get stuck in an infinite loop in the kernel. What would
happen is the following:

When ring_buffer_read_page() returns -1 (no data) then a check is made to
see if the buffer is empty (as happens when the page is not full), it will
call wait_on_pipe() to wait until the ring buffer has data. When it is it
will try again to read data (unless O_NONBLOCK is set).

The issue happens when there's a reader and the file descriptor is closed.
The wait_on_pipe() will return when that is the case. But this loop will
continue to try again and wait_on_pipe() will again return immediately and
the loop will continue and never stop.

Simply check if the file was closed before looping and exit out if it is.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240808235730.78bf63e5@rorschach.local.home
Fixes: 2aa043a55b ("tracing/ring-buffer: Fix wait_on_pipe() race")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-09 12:59:35 -04:00
Jianhui Zhou
58f7e4d7ba ring-buffer: Remove unused function ring_buffer_nr_pages()
Because ring_buffer_nr_pages() is not an inline function and user accesses
buffer->buffers[cpu]->nr_pages directly, the function ring_buffer_nr_pages
is removed.

Signed-off-by: Jianhui Zhou <912460177@qq.com>
Link: https://lore.kernel.org/tencent_F4A7E9AB337F44E0F4B858D07D19EF460708@qq.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:26:44 -04:00
Tze-nan Wu
bcf86c01ca tracing: Fix overflow in get_free_elt()
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.

Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.

Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 08d43a5fa0 ("tracing: Add lock-free tracing_map")
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Link: https://lore.kernel.org/20240805055922.6277-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:23:12 -04:00
Petr Pavlu
604b72b325 function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()
When ftrace_graph_ret_addr() is invoked to convert a found stack return
address to its original value, the function can end up producing the
following crash:

[   95.442712] BUG: kernel NULL pointer dereference, address: 0000000000000028
[   95.442720] #PF: supervisor read access in kernel mode
[   95.442724] #PF: error_code(0x0000) - not-present page
[   95.442727] PGD 0 P4D 0-
[   95.442731] Oops: Oops: 0000 [#1] PREEMPT SMP PTI
[   95.442736] CPU: 1 UID: 0 PID: 2214 Comm: insmod Kdump: loaded Tainted: G           OE K    6.11.0-rc1-default #1 67c62a3b3720562f7e7db5f11c1fdb40b7a2857c
[   95.442747] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE, [K]=LIVEPATCH
[   95.442750] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
[   95.442754] RIP: 0010:ftrace_graph_ret_addr+0x42/0xc0
[   95.442766] Code: [...]
[   95.442773] RSP: 0018:ffff979b80ff7718 EFLAGS: 00010006
[   95.442776] RAX: ffffffff8ca99b10 RBX: ffff979b80ff7760 RCX: ffff979b80167dc0
[   95.442780] RDX: ffffffff8ca99b10 RSI: ffff979b80ff7790 RDI: 0000000000000005
[   95.442783] RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
[   95.442786] R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff8e9491e0
[   95.442790] R13: ffffffff8d6f70f0 R14: ffff979b80167da8 R15: ffff979b80167dc8
[   95.442793] FS:  00007fbf83895740(0000) GS:ffff8a0afdd00000(0000) knlGS:0000000000000000
[   95.442797] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   95.442800] CR2: 0000000000000028 CR3: 0000000005070002 CR4: 0000000000370ef0
[   95.442806] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   95.442809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   95.442816] Call Trace:
[   95.442823]  <TASK>
[   95.442896]  unwind_next_frame+0x20d/0x830
[   95.442905]  arch_stack_walk_reliable+0x94/0xe0
[   95.442917]  stack_trace_save_tsk_reliable+0x7d/0xe0
[   95.442922]  klp_check_and_switch_task+0x55/0x1a0
[   95.442931]  task_call_func+0xd3/0xe0
[   95.442938]  klp_try_switch_task.part.5+0x37/0x150
[   95.442942]  klp_try_complete_transition+0x79/0x2d0
[   95.442947]  klp_enable_patch+0x4db/0x890
[   95.442960]  do_one_initcall+0x41/0x2e0
[   95.442968]  do_init_module+0x60/0x220
[   95.442975]  load_module+0x1ebf/0x1fb0
[   95.443004]  init_module_from_file+0x88/0xc0
[   95.443010]  idempotent_init_module+0x190/0x240
[   95.443015]  __x64_sys_finit_module+0x5b/0xc0
[   95.443019]  do_syscall_64+0x74/0x160
[   95.443232]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   95.443236] RIP: 0033:0x7fbf82f2c709
[   95.443241] Code: [...]
[   95.443247] RSP: 002b:00007fffd5ea3b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   95.443253] RAX: ffffffffffffffda RBX: 000056359c48e750 RCX: 00007fbf82f2c709
[   95.443257] RDX: 0000000000000000 RSI: 000056356ed4efc5 RDI: 0000000000000003
[   95.443260] RBP: 000056356ed4efc5 R08: 0000000000000000 R09: 00007fffd5ea3c10
[   95.443263] R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
[   95.443267] R13: 000056359c48e6f0 R14: 0000000000000000 R15: 0000000000000000
[   95.443272]  </TASK>
[   95.443274] Modules linked in: [...]
[   95.443385] Unloaded tainted modules: intel_uncore_frequency(E):1 isst_if_common(E):1 skx_edac(E):1
[   95.443414] CR2: 0000000000000028

The bug can be reproduced with kselftests:

 cd linux/tools/testing/selftests
 make TARGETS='ftrace livepatch'
 (cd ftrace; ./ftracetest test.d/ftrace/fgraph-filter.tc)
 (cd livepatch; ./test-livepatch.sh)

The problem is that ftrace_graph_ret_addr() is supposed to operate on the
ret_stack of a selected task but wrongly accesses the ret_stack of the
current task. Specifically, the above NULL dereference occurs when
task->curr_ret_stack is non-zero, but current->ret_stack is NULL.

Correct ftrace_graph_ret_addr() to work with the right ret_stack.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/20240803131211.17255-1-petr.pavlu@suse.com
Fixes: 7aa1eaef9f ("function_graph: Allow multiple users to attach to function graph")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 20:20:30 -04:00
Steven Rostedt
6e2fdceffd tracing: Use refcount for trace_event_file reference counter
Instead of using an atomic counter for the trace_event_file reference
counter, use the refcount interface. It has various checks to make sure
the reference counting is correct, and will warn if it detects an error
(like refcount_inc() on '0').

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240726144208.687cce24@rorschach.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Steven Rostedt
b156040869 tracing: Have format file honor EVENT_FILE_FL_FREED
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).

All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.

A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them.  The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.

This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:

In one console run:

 # cd tools/testing/selftests/user_events
 # while true; do ./ftrace_test; done

And in another console run:

 # cd /sys/kernel/tracing/
 # while true; do cat events/user_events/__test_event/format; done 2>/dev/null

With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.

After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.

Link: https://lore.kernel.org/all/20240719204701.1605950-1-minipli@grsecurity.net/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers   <mathieu.desnoyers@efficios.com>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Cc: Ilkka Naulapää    <digirigawa@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al   Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter   <dan.carpenter@linaro.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Florian Fainelli  <florian.fainelli@broadcom.com>
Cc: Alexey Makhalov    <alexey.makhalov@broadcom.com>
Cc: Vasavi Sirnapalli    <vasavi.sirnapalli@broadcom.com>
Link: https://lore.kernel.org/20240730110657.3b69d3c1@gandalf.local.home
Fixes: b63db58e2f ("eventfs/tracing: Add callback for release of an eventfs_inode")
Reported-by: Mathias Krause <minipli@grsecurity.net>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07 18:12:46 -04:00
Song Liu
fa4e5afa97 bpf: Move bpf_get_file_xattr to fs/bpf_fs_kfuncs.c
We are putting all fs kfuncs in fs/bpf_fs_kfuncs.c. Move existing
bpf_get_file_xattr to it.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240806230904.71194-2-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-07 11:26:53 -07:00
Qais Yousef
ae04f69de0 sched/rt: Rename realtime_{prio, task}() to rt_or_dl_{prio, task}()
Some find the name realtime overloaded. Use rt_or_dl() as an
alternative, hopefully better, name.

Suggested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Qais Yousef <qyousef@layalina.io>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240610192018.1567075-4-qyousef@layalina.io
2024-08-07 18:32:38 +02:00
Qais Yousef
130fd056dd sched/rt: Clean up usage of rt_task()
rt_task() checks if a task has RT priority. But depends on your
dictionary, this could mean it belongs to RT class, or is a 'realtime'
task, which includes RT and DL classes.

Since this has caused some confusion already on discussion [1], it
seemed a clean up is due.

I define the usage of rt_task() to be tasks that belong to RT class.
Make sure that it returns true only for RT class and audit the users and
replace the ones required the old behavior with the new realtime_task()
which returns true for RT and DL classes. Introduce similar
realtime_prio() to create similar distinction to rt_prio() and update
the users that required the old behavior to use the new function.

Move MAX_DL_PRIO to prio.h so it can be used in the new definitions.

Document the functions to make it more obvious what is the difference
between them. PI-boosted tasks is a factor that must be taken into
account when choosing which function to use.

Rename task_is_realtime() to realtime_task_policy() as the old name is
confusing against the new realtime_task().

No functional changes were intended.

[1] https://lore.kernel.org/lkml/20240506100509.GL40213@noisy.programming.kicks-ass.net/

Signed-off-by: Qais Yousef <qyousef@layalina.io>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240610192018.1567075-2-qyousef@layalina.io
2024-08-07 18:32:37 +02:00
Oleg Nesterov
3c83a9ad02 uprobes: make uprobe_register() return struct uprobe *
This way uprobe_unregister() and uprobe_apply() can use "struct uprobe *"
rather than inode + offset. This simplifies the code and allows to avoid
the unnecessary find_uprobe() + put_uprobe() in these functions.

TODO: uprobe_unregister() still needs get_uprobe/put_uprobe to ensure that
this uprobe can't be freed before up_write(&uprobe->register_rwsem).

Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240801132734.GA8803@redhat.com
2024-08-02 11:30:31 +02:00
Oleg Nesterov
e04332ebc8 uprobes: kill uprobe_register_refctr()
It doesn't make any sense to have 2 versions of _register(). Note that
trace_uprobe_enable(), the only user of uprobe_register(), doesn't need
to check tu->ref_ctr_offset to decide which one should be used, it could
safely pass ref_ctr_offset == 0 to uprobe_register_refctr().

Add this argument to uprobe_register(), update the callers, and kill
uprobe_register_refctr().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240801132728.GA8800@redhat.com
2024-08-02 11:30:31 +02:00
Linus Torvalds
1a251f52cf minmax: make generic MIN() and MAX() macros available everywhere
This just standardizes the use of MIN() and MAX() macros, with the very
traditional semantics.  The goal is to use these for C constant
expressions and for top-level / static initializers, and so be able to
simplify the min()/max() macros.

These macro names were used by various kernel code - they are very
traditional, after all - and all such users have been fixed up, with a
few different approaches:

 - trivial duplicated macro definitions have been removed

   Note that 'trivial' here means that it's obviously kernel code that
   already included all the major kernel headers, and thus gets the new
   generic MIN/MAX macros automatically.

 - non-trivial duplicated macro definitions are guarded with #ifndef

   This is the "yes, they define their own versions, but no, the include
   situation is not entirely obvious, and maybe they don't get the
   generic version automatically" case.

 - strange use case #1

   A couple of drivers decided that the way they want to describe their
   versioning is with

	#define MAJ 1
	#define MIN 2
	#define DRV_VERSION __stringify(MAJ) "." __stringify(MIN)

   which adds zero value and I just did my Alexander the Great
   impersonation, and rewrote that pointless Gordian knot as

	#define DRV_VERSION "1.2"

   instead.

 - strange use case #2

   A couple of drivers thought that it's a good idea to have a random
   'MIN' or 'MAX' define for a value or index into a table, rather than
   the traditional macro that takes arguments.

   These values were re-written as C enum's instead. The new
   function-line macros only expand when followed by an open
   parenthesis, and thus don't clash with enum use.

Happily, there weren't really all that many of these cases, and a lot of
users already had the pattern of using '#ifndef' guarding (or in one
case just using '#undef MIN') before defining their own private version
that does the same thing. I left such cases alone.

Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-28 15:49:18 -07:00
Joel Granados
78eb4ea25c sysctl: treewide: constify the ctl_table argument of proc_handlers
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-24 20:59:29 +02:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Linus Torvalds
70045bfc4c ftrace: Rewrite of function graph tracer
Up until now, the function graph tracer could only have a single user
 attached to it. If another user tried to attach to the function graph
 tracer while one was already attached, it would fail. Allowing function
 graph tracer to have more than one user has been asked for since 2009, but
 it required a rewrite to the logic to pull it off so it never happened.
 Until now!
 
 There's three systems that trace the return of a function. That is
 kretprobes, function graph tracer, and BPF. kretprobes and function graph
 tracing both do it similarly. The difference is that kretprobes uses a
 shadow stack per callback and function graph tracer creates a shadow stack
 for all tasks. The function graph tracer method makes it possible to trace
 the return of all functions. As kretprobes now needs that feature too,
 allowing it to use function graph tracer was needed. BPF also wants to
 trace the return of many probes and its method doesn't scale either.
 Having it use function graph tracer would improve that.
 
 By allowing function graph tracer to have multiple users allows both
 kretprobes and BPF to use function graph tracer in these cases. This will
 allow kretprobes code to be removed in the future as it's version will no
 longer be needed. Note, function graph tracer is only limited to 16
 simultaneous users, due to shadow stack size and allocated slots.
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Merge tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace updates from Steven Rostedt:
 "Rewrite of function graph tracer to allow multiple users

  Up until now, the function graph tracer could only have a single user
  attached to it. If another user tried to attach to the function graph
  tracer while one was already attached, it would fail. Allowing
  function graph tracer to have more than one user has been asked for
  since 2009, but it required a rewrite to the logic to pull it off so
  it never happened. Until now!

  There's three systems that trace the return of a function. That is
  kretprobes, function graph tracer, and BPF. kretprobes and function
  graph tracing both do it similarly. The difference is that kretprobes
  uses a shadow stack per callback and function graph tracer creates a
  shadow stack for all tasks. The function graph tracer method makes it
  possible to trace the return of all functions. As kretprobes now needs
  that feature too, allowing it to use function graph tracer was needed.
  BPF also wants to trace the return of many probes and its method
  doesn't scale either. Having it use function graph tracer would
  improve that.

  By allowing function graph tracer to have multiple users allows both
  kretprobes and BPF to use function graph tracer in these cases. This
  will allow kretprobes code to be removed in the future as it's version
  will no longer be needed.

  Note, function graph tracer is only limited to 16 simultaneous users,
  due to shadow stack size and allocated slots"

* tag 'ftrace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (49 commits)
  fgraph: Use str_plural() in test_graph_storage_single()
  function_graph: Add READ_ONCE() when accessing fgraph_array[]
  ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct()
  function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it
  function_graph: Fix up ftrace_graph_ret_addr()
  function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE
  function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests
  fgraph: Remove some unused functions
  ftrace: Hide one more entry in stack trace when ftrace_pid is enabled
  function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled
  function_graph: Make fgraph_do_direct static key static
  ftrace: Fix prototypes for ftrace_startup/shutdown_subops()
  ftrace: Assign RCU list variable with rcu_assign_ptr()
  ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU
  ftrace: Declare function_trace_op in header to quiet sparse warning
  ftrace: Add comments to ftrace_hash_move() and friends
  ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()
  ftrace: Add comments to ftrace_hash_rec_disable/enable()
  ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update()
  ftrace: Rename dup_hash() and comment it
  ...
2024-07-18 13:36:33 -07:00
Linus Torvalds
2fd4130e53 tracing: Trivial updates for 6.11
- Set rtla/osnoise default threshold to 1us from 5us
   The 5us default was missing noise that people cared about.
   Changing it to 1us makes it work as expected.
 
 - Restructure how sched_switch prev_comm and next_comm was being saved.
   The prev_comm was being saved along with the other next fields, and the
   next_comm was being saved along with the other prev fields. This is just
   a cosmetic change.
 
 - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL.
   The allocation can happen in irq_work context, but luckily, the size
   was by default so large, it was never triggered. But in case it ever is,
   use the NOWAIT allocation in the interrupt context.
 
 - Fix some kernel doc errors.
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Merge tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:
 "Trivial updates for 6.11:

   - Set rtla/osnoise default threshold to 1us from 5us

     The 5us default was missing noise that people cared about. Changing
     it to 1us makes it work as expected.

   - Restructure how sched_switch prev_comm and next_comm was being saved

     The prev_comm was being saved along with the other next fields, and
     the next_comm was being saved along with the other prev fields.
     This is just a cosmetic change.

   - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL

     The allocation can happen in irq_work context, but luckily, the
     size was by default so large, it was never triggered. But in case
     it ever is, use the NOWAIT allocation in the interrupt context.

   - Fix some kernel doc errors"

* tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/pid_list: Change gfp flags in pid_list_fill_irq()
  tracing/sched: sched_switch: place prev_comm and next_comm in right order
  rtla/osnoise: set the default threshold to 1us
  tracing: Fix trace_pid_list_free() kernel-doc
2024-07-18 13:29:25 -07:00
Linus Torvalds
91bd008d4e Probes updates for v6.11:
Uprobes:
 - x86/shstk: Make return uprobe work with shadow stack.
 - Add uretprobe syscall which speeds up the uretprobe 10-30% faster. This
   syscall is automatically used from user-space trampolines which are
   generated by the uretprobe. If this syscall is used by normal
   user program, it will cause SIGILL. Note that this is currently only
   implemented on x86_64.
   (This also has 2 fixes for adjusting the syscall number to avoid conflict
    with new *attrat syscalls.)
 - uprobes/perf: fix user stack traces in the presence of pending uretprobe.
   This corrects the uretprobe's trampoline address in the stacktrace with
   correct return address.
 - selftests/x86: Add a return uprobe with shadow stack test.
 - selftests/bpf: Add uretprobe syscall related tests.
   . test case for register integrity check.
   . test case with register changing case.
   . test case for uretprobe syscall without uprobes (expected to be failed).
   . test case for uretprobe with shadow stack.
 - selftests/bpf: add test validating uprobe/uretprobe stack traces
 - MAINTAINERS: Add uprobes entry. This does not specify the tree but to
   clarify who maintains and reviews the uprobes.
 
 Kprobes:
 - tracing/kprobes: Test case cleanups. Replace redundant WARN_ON_ONCE() +
   pr_warn() with WARN_ONCE() and remove unnecessary code from selftest.
 - tracing/kprobes: Add symbol counting check when module loads. This
   checks the uniqueness of the probed symbol on modules. The same check
   has already done for kernel symbols.
   (This also has a fix for build error with CONFIG_MODULES=n)
 
 Cleanup:
 - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples.
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Merge tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "Uprobes:

   - x86/shstk: Make return uprobe work with shadow stack

   - Add uretprobe syscall which speeds up the uretprobe 10-30% faster.
     This syscall is automatically used from user-space trampolines
     which are generated by the uretprobe. If this syscall is used by
     normal user program, it will cause SIGILL. Note that this is
     currently only implemented on x86_64.

     (This also has two fixes for adjusting the syscall number to avoid
     conflict with new *attrat syscalls.)

   - uprobes/perf: fix user stack traces in the presence of pending
     uretprobe. This corrects the uretprobe's trampoline address in the
     stacktrace with correct return address

   - selftests/x86: Add a return uprobe with shadow stack test

   - selftests/bpf: Add uretprobe syscall related tests.
      - test case for register integrity check
      - test case with register changing case
      - test case for uretprobe syscall without uprobes (expected to fail)
      - test case for uretprobe with shadow stack

   - selftests/bpf: add test validating uprobe/uretprobe stack traces

   - MAINTAINERS: Add uprobes entry. This does not specify the tree but
     to clarify who maintains and reviews the uprobes

  Kprobes:

   - tracing/kprobes: Test case cleanups.

     Replace redundant WARN_ON_ONCE() + pr_warn() with WARN_ONCE() and
     remove unnecessary code from selftest

   - tracing/kprobes: Add symbol counting check when module loads.

     This checks the uniqueness of the probed symbol on modules. The
     same check has already done for kernel symbols

     (This also has a fix for build error with CONFIG_MODULES=n)

  Cleanup:

   - Add MODULE_DESCRIPTION() macros for fprobe and kprobe examples"

* tag 'probes-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  MAINTAINERS: Add uprobes entry
  selftests/bpf: Change uretprobe syscall number in uprobe_syscall test
  uprobe: Change uretprobe syscall scope and number
  tracing/kprobes: Fix build error when find_module() is not available
  tracing/kprobes: Add symbol counting check when module loads
  selftests/bpf: add test validating uprobe/uretprobe stack traces
  perf,uprobes: fix user stack traces in the presence of pending uretprobes
  tracing/kprobe: Remove cleanup code unrelated to selftest
  tracing/kprobe: Integrate test warnings into WARN_ONCE
  selftests/bpf: Add uretprobe shadow stack test
  selftests/bpf: Add uretprobe syscall call from user space test
  selftests/bpf: Add uretprobe syscall test for regs changes
  selftests/bpf: Add uretprobe syscall test for regs integrity
  selftests/x86: Add return uprobe shadow stack test
  uprobe: Add uretprobe syscall to speed up return probe
  uprobe: Wire up uretprobe system call
  x86/shstk: Make return uprobe work with shadow stack
  samples: kprobes: add missing MODULE_DESCRIPTION() macros
  fprobe: add missing MODULE_DESCRIPTION() macro
2024-07-18 12:19:20 -07:00
Thorsten Blum
b96c312551 ring-buffer: Use vma_pages() helper function
Use the vma_pages() helper function and fix the following
Coccinelle/coccicheck warning reported by vma_pages.cocci:

  WARNING: Consider using vma_pages helper on vma

Rename the local variable vma_pages accordingly.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Link: https://lore.kernel.org/20240709215657.322071-2-thorsten.blum@toblux.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-15 15:09:06 -04:00
levi.yun
7dc836187f trace/pid_list: Change gfp flags in pid_list_fill_irq()
pid_list_fill_irq() runs via irq_work.
When CONFIG_PREEMPT_RT is disabled, it would run in irq_context.
so it shouldn't sleep while memory allocation.

Change gfp flags from GFP_KERNEL to GFP_NOWAIT to prevent sleep in
irq_work.

This change wouldn't impact functionality in practice because the worst-size
is 2K.

Cc: stable@goodmis.org
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Link: https://lore.kernel.org/20240704150226.1359936-1-yeoreum.yun@arm.com
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: levi.yun <yeoreum.yun@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-15 15:07:14 -04:00
Dan Carpenter
94dfa500e7 tracing: Fix NULL vs IS_ERR() check in enable_instances()
The trace_array_create_systems() function returns error pointers, not
NULL.  Fix the check to match.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: e645535a95 ("tracing: Add option to use memmapped memory for trace boot instance")
Link: https://lore.kernel.org/9b23ea03-d709-435f-a309-461c3d747457@moroto.mountain
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-15 14:55:02 -04:00
Masami Hiramatsu (Google)
b10545b6b8 tracing/kprobes: Fix build error when find_module() is not available
The kernel test robot reported that the find_module() is not available
if CONFIG_MODULES=n.
Fix this error by hiding find_modules() in #ifdef CONFIG_MODULES with
related rcu locks as try_module_get_by_name().

Link: https://lore.kernel.org/all/172056819167.201571.250053007194508038.stgit@devnote2/

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407070744.RcLkn8sq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202407070917.VVUCBlaS-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-07-10 09:47:00 +09:00
Paolo Abeni
7b769adc26 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-08

The following pull-request contains BPF updates for your *net-next* tree.

We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).

The main changes are:

1) Support resilient split BTF which cuts down on duplication and makes BTF
   as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.

2) Add support for dumping kfunc prototypes from BTF which enables both detecting
   as well as dumping compilable prototypes for kfuncs, from Daniel Xu.

3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
   support for BPF exceptions, from Ilya Leoshkevich.

4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
   for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.

5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
   for skbs and add coverage along with it, from Vadim Fedorenko.

6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
   a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.

7) Extend the BPF verifier to track the delta between linked registers in order
   to better deal with recent LLVM code optimizations, from Alexei Starovoitov.

8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
   have been a pointer to the map value, from Benjamin Tissoires.

9) Extend BPF selftests to add regular expression support for test output matching
   and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.

10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
    iterates exactly once anyway, from Dan Carpenter.

11) Add the capability to offload the netfilter flowtable in XDP layer through
    kfuncs, from Florian Westphal & Lorenzo Bianconi.

12) Various cleanups in networking helpers in BPF selftests to shave off a few
    lines of open-coded functions on client/server handling, from Geliang Tang.

13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
    that x86 JIT does not need to implement detection, from Leon Hwang.

14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
    out-of-bounds memory access for dynpointers, from Matt Bobrowski.

15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
    it might lead to problems on 32-bit archs, from Jiri Olsa.

16) Enhance traffic validation and dynamic batch size support in xsk selftests,
    from Tushar Vyavahare.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
  selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
  selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
  bpf: helpers: fix bpf_wq_set_callback_impl signature
  libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
  selftests/bpf: Remove exceptions tests from DENYLIST.s390x
  s390/bpf: Implement exceptions
  s390/bpf: Change seen_reg to a mask
  bpf: Remove unnecessary loop in task_file_seq_get_next()
  riscv, bpf: Optimize stack usage of trampoline
  bpf, devmap: Add .map_alloc_check
  selftests/bpf: Remove arena tests from DENYLIST.s390x
  selftests/bpf: Add UAF tests for arena atomics
  selftests/bpf: Introduce __arena_global
  s390/bpf: Support arena atomics
  s390/bpf: Enable arena
  s390/bpf: Support address space cast instruction
  s390/bpf: Support BPF_PROBE_MEM32
  s390/bpf: Land on the next JITed instruction after exception
  s390/bpf: Introduce pre- and post- probe functions
  s390/bpf: Get rid of get_probe_mem_regno()
  ...
====================

Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-07-09 17:01:46 +02:00
Masami Hiramatsu (Google)
9d8616034f tracing/kprobes: Add symbol counting check when module loads
Currently, kprobe event checks whether the target symbol name is unique
or not, so that it does not put a probe on an unexpected place. But this
skips the check if the target is on a module because the module may not
be loaded.

To fix this issue, this patch checks the number of probe target symbols
in a target module when the module is loaded. If the probe is not on the
unique name symbols in the module, it will be rejected at that point.

Note that the symbol which has a unique name in the target module,
it will be accepted even if there are same-name symbols in the
kernel or other modules,

Link: https://lore.kernel.org/all/172016348553.99543.2834679315611882137.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-06 09:27:47 +09:00
Ilya Leoshkevich
c02525a339 ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
Patch series "kmsan: Enable on s390", v7.


Architectures use assembly code to initialize ftrace_regs and call
ftrace_ops_list_func().  Therefore, from the KMSAN's point of view,
ftrace_regs is poisoned on ftrace_ops_list_func entry().  This causes
KMSAN warnings when running the ftrace testsuite.

Fix by trusting the architecture-specific assembly code and always
unpoisoning ftrace_regs in ftrace_ops_list_func.

The issue was not encountered on x86_64 so far only by accident:
assembly-allocated ftrace_regs was overlapping a stale partially
unpoisoned stack frame.  Poisoning stack frames before returns [1] makes
the issue appear on x86_64 as well.

[1] https://github.com/iii-i/llvm-project/commits/msan-poison-allocas-before-returning-2024-06-12/

Link: https://lkml.kernel.org/r/20240621113706.315500-1-iii@linux.ibm.com
Link: https://lkml.kernel.org/r/20240621113706.315500-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:21 -07:00
Jiapeng Chong
b576d375b5 fgraph: Use str_plural() in test_graph_storage_single()
Use existing str_plural() function rather than duplicating its
implementation.

./kernel/trace/trace_selftest.c:880:56-60: opportunity for str_plural(size).

Link: https://lore.kernel.org/linux-trace-kernel/20240618072014.20855-1-jiapeng.chong@linux.alibaba.com

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9349
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-01 19:57:51 -04:00
Luis Claudio R. Goncalves
c40583e19e rtla/osnoise: set the default threshold to 1us
Change the default threshold for osnoise to 1us, so that any noise
equal or above this value is recorded. Let the user set a higher
threshold if necessary.

Link: https://lore.kernel.org/linux-trace-kernel/Zmb-QhiiiI6jM9To@uudg.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Suggested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Clark Williams <williams@redhat.com>
Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-07-01 18:54:31 -04:00
Arnd Bergmann
7e1f4eb9a6 kallsyms: rework symbol lookup return codes
Building with W=1 in some configurations produces a false positive
warning for kallsyms:

kernel/kallsyms.c: In function '__sprint_symbol.isra':
kernel/kallsyms.c:503:17: error: 'strcpy' source argument is the same as destination [-Werror=restrict]
  503 |                 strcpy(buffer, name);
      |                 ^~~~~~~~~~~~~~~~~~~~

This originally showed up while building with -O3, but later started
happening in other configurations as well, depending on inlining
decisions. The underlying issue is that the local 'name' variable is
always initialized to the be the same as 'buffer' in the called functions
that fill the buffer, which gcc notices while inlining, though it could
see that the address check always skips the copy.

The calling conventions here are rather unusual, as all of the internal
lookup functions (bpf_address_lookup, ftrace_mod_address_lookup,
ftrace_func_address_lookup, module_address_lookup and
kallsyms_lookup_buildid) already use the provided buffer and either return
the address of that buffer to indicate success, or NULL for failure,
but the callers are written to also expect an arbitrary other buffer
to be returned.

Rework the calling conventions to return the length of the filled buffer
instead of its address, which is simpler and easier to follow as well
as avoiding the warning. Leave only the kallsyms_lookup() calling conventions
unchanged, since that is called from 16 different functions and
adapting this would be a much bigger change.

Link: https://lore.kernel.org/lkml/20200107214042.855757-1-arnd@arndb.de/
Link: https://lore.kernel.org/lkml/20240326130647.7bfb1d92@gandalf.local.home/
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-27 17:43:40 +02:00
Jiri Olsa
717d6313bb bpf: Change bpf_session_cookie return value to __u64 *
This reverts [1] and changes return value for bpf_session_cookie
in bpf selftests. Having long * might lead to problems on 32-bit
architectures.

Fixes: 2b8dd87332 ("bpf: Make bpf_session_cookie() kfunc return long *")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240619081624.1620152-1-jolsa@kernel.org
2024-06-21 19:32:36 +02:00
Steven Rostedt (Google)
63a8dfb889 function_graph: Add READ_ONCE() when accessing fgraph_array[]
In function_graph_enter() there's a loop that looks at fgraph_array[]
elements which are fgraph_ops. It first tests if it is a fgraph_stub op,
and if so skips it, as that's just there as a place holder. Then it checks
the fgraph_ops filters to see if the ops wants to trace the current
function.

But if the compiler reloads the fgraph_array[] after the check against
fgraph_stub, it could race with the fgraph_array[] being updated with the
fgraph_stub. That would cause the stub to be processed. But the stub has a
null "func_hash" field which will cause a NULL pointer dereference.

Add a READ_ONCE() so that the gops that is compared against the
fgraph_stub is also the gops that is processed later.

Link: https://lore.kernel.org/all/CA+G9fYsSVJQZH=nM=1cjTc94PgSnMF9y65BnOv6XSoCG_b6wmw@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240613095223.1f07e3a4@rorschach.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-06-14 12:37:08 -04:00
Steven Rostedt (Google)
a62b4f6fbd tracing: Add last boot delta offset for stack traces
The addresses of a stack trace event are relative to the kallsyms. As that
can change between boots, when printing the stack trace from a buffer that
was from the last boot, it needs all the addresses to be added to the
"text_delta" that gives the delta between the addresses of the functions
for the current boot compared to the address of the last boot. Then it can
be passed to kallsyms to find the function name, otherwise it just shows a
useless list of addresses.

Link: https://lkml.kernel.org/r/20240612232027.145807384@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:22 -04:00
Steven Rostedt (Google)
7cfeb9033d tracing: Update function tracing output for previous boot buffer
For a persistent ring buffer that is saved across boots, if function
tracing was performed in the previous boot, it only saves the address of
the functions and uses "%pS" to print their names. But the current boot,
those functions may be in different locations. The persistent meta-data
saves the text delta between the two boots and can be used to find the
address of the saved function of where it is located in the current boot.

Link: https://lkml.kernel.org/r/20240612232026.988226055@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:22 -04:00
Steven Rostedt (Google)
07714b4bb3 tracing: Handle old buffer mappings for event strings and functions
Use the saved text_delta and data_delta of a persistent memory mapped ring
buffer that was saved from a previous boot, and use the delta in the trace
event print output so that strings and functions show up normally.

That is, for an event like trace_kmalloc() that prints the callsite via
"%pS", if it used the address saved in the ring buffer it will not match
the function that was saved in the previous boot if the kernel remaps
itself between boots.

For RCU events that point to saved static strings where only the address
of the string is saved in the ring buffer, it too will be adjusted to
point to where the string is on the current boot.

Link: https://lkml.kernel.org/r/20240612232026.821020753@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:22 -04:00
Steven Rostedt (Google)
7a1d1e4b96 tracing/ring-buffer: Add last_boot_info file to boot instance
If an instance is mapped to memory on boot up, create a new file called
"last_boot_info" that will hold information that can be used to properly
parse the raw data in the ring buffer.

It will export the delta of the addresses for text and data from what it
was from the last boot. It does not expose actually addresses (unless you
knew what the actual address was from the last boot).

The output will look like:

 # cat last_boot_info
 text delta:	-268435456
 data delta:	-268435456

The text and data are kept separate in case they are ever made different.

Link: https://lkml.kernel.org/r/20240612232026.658680738@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:22 -04:00
Steven Rostedt (Google)
8f3e665965 ring-buffer: Save text and data locations in mapped meta data
When a ring buffer is mapped to a specific address, save the address of a
text function and some data. This will be used to determine the delta
between the last boot and the current boot for pointers to functions as
well as to data.

Link: https://lkml.kernel.org/r/20240612232026.496176678@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
e645535a95 tracing: Add option to use memmapped memory for trace boot instance
Add an option to the trace_instance kernel command line parameter that
allows it to use the reserved memory from memmap boot parameter.

  memmap=12M$0x284500000 trace_instance=boot_mapped@0x284500000:12M

The above will reserves 12 megs at the physical address 0x284500000.
The second parameter will create a "boot_mapped" instance and use the
memory reserved as the memory for the ring buffer.

That will create an instance called "boot_mapped":

  /sys/kernel/tracing/instances/boot_mapped

Note, because the ring buffer is using a defined memory ranged, it will
act just like a memory mapped ring buffer. It will not have a snapshot
buffer, as it can't swap out the buffer. The snapshot files as well as any
tracers that uses a snapshot will not be present in the boot_mapped
instance.

Link: https://lkml.kernel.org/r/20240612232026.329660169@goodmis.org

Cc: linux-mm@kvack.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
5f3b6e839f ring-buffer: Validate boot range memory events
Make sure all the events in each of the sub-buffers that were mapped in a
memory region are valid. This moves the code that walks the buffers for
time-stamp validation out of the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS
ifdef block and is used to validate the content. Only the ring buffer
event meta data and time stamps are checked and not the data load.

This also has a second purpose. The buffer_page structure that points to
the data sub-buffers has accounting that keeps track of the number of
events that are on the sub-buffer. This updates that counter as well. That
counter is used in reading the buffer and knowing if the ring buffer is
empty or not.

Link: https://lkml.kernel.org/r/20240612232026.172503570@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
c76883f18e ring-buffer: Add test if range of boot buffer is valid
Add a test against the ring buffer memory range to see if it has valid
data. The ring_buffer_meta structure is given a new field called
"first_buffer" which holds the address of the first sub-buffer. This is
used to both determine if the other fields are valid as well as finding
the offset between the old addresses of the sub-buffer from the previous
boot to the new addresses of the current boot.

Since the values for nr_subbufs and subbuf_size is to be the same, check
if the values in the meta page match the values calculated.

Take the range of the first_buffer and the total size of all the buffers
and make sure the saved head_buffer and commit_buffer fall in the range.

Iterate through all the sub-buffers to make sure that the values in the
sub-buffer "commit" field (the field that holds the amount of data on the
sub-buffer) is within the end of the sub-buffer. Also check the index
array to make sure that all the indexes are within nr_subbufs.

Link: https://lkml.kernel.org/r/20240612232026.013843655@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
950032ffce ring-buffer: Add output of ring buffer meta page
Add a buffer_meta per-cpu file for the trace instance that is mapped to
boot memory. This shows the current meta-data and can be used by user
space tools to record off the current mappings to help reconstruct the
ring buffer after a reboot.

It does not expose any virtual addresses, just indexes into the sub-buffer
pages.

Link: https://lkml.kernel.org/r/20240612232025.854471446@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
2124de79ad tracing: Implement creating an instance based on a given memory region
Allow for creating a new instance by passing in an address and size to map
the ring buffer for the instance to.

This will allow features like a pstore memory mapped region to be used for
an tracing instance ring buffer that can be retrieved from one boot to the
next.

Link: https://lkml.kernel.org/r/20240612232025.692086240@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:21 -04:00
Steven Rostedt (Google)
b14d032973 ring-buffer: Add ring_buffer_meta data
Populate the ring_buffer_meta array. It holds the pointer to the
head_buffer (next to read), the commit_buffer (next to write) the size of
the sub-buffers, number of sub-buffers and an array that keeps track of
the order of the sub-buffers.

This information will be stored in the persistent memory to help on reboot
to reconstruct the ring buffer.

Link: https://lkml.kernel.org/r/20240612232025.530733577@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:20 -04:00
Steven Rostedt (Google)
be68d63a13 ring-buffer: Add ring_buffer_alloc_range()
In preparation to allowing the trace ring buffer to be allocated in a
range of memory that is persistent across reboots, add
ring_buffer_alloc_range(). It takes a contiguous range of memory and will
split it up evenly for the per CPU ring buffers.

If there's not enough memory to handle all CPUs with the minimum size, it
will fail to allocate the ring buffer.

Link: https://lkml.kernel.org/r/20240612232025.363998725@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:20 -04:00
Steven Rostedt (Google)
dd4900d94f ring-buffer: Allow mapped field to be set without mapping
In preparation for having the ring buffer mapped to a dedicated location,
which will have the same restrictions as user space memory mapped buffers,
allow it to use the "mapped" field of the ring_buffer_per_cpu structure
without having the user space meta page mapping.

When this starts using the mapped field, it will need to handle adding a
user space mapping (and removing it) from a ring buffer that is using a
dedicated memory range.

Link: https://lkml.kernel.org/r/20240612232025.190908567@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14 12:28:20 -04:00
Daniel Xu
cce4c40b96 bpf: treewide: Align kfunc signatures to prog point-of-view
Previously, kfunc declarations in bpf_kfuncs.h (and others) used "user
facing" types for kfuncs prototypes while the actual kfunc definitions
used "kernel facing" types. More specifically: bpf_dynptr vs
bpf_dynptr_kern, __sk_buff vs sk_buff, and xdp_md vs xdp_buff.

It wasn't an issue before, as the verifier allows aliased types.
However, since we are now generating kfunc prototypes in vmlinux.h (in
addition to keeping bpf_kfuncs.h around), this conflict creates
compilation errors.

Fix this conflict by using "user facing" types in kfunc definitions.
This results in more casts, but otherwise has no additional runtime
cost.

Note, similar to 5b268d1ebc ("bpf: Have bpf_rdonly_cast() take a const
pointer"), we also make kfuncs take const arguments where appropriate in
order to make the kfunc more permissive.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/b58346a63a0e66bc9b7504da751b526b0b189a67.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:31 -07:00
Daniel Xu
2b8dd87332 bpf: Make bpf_session_cookie() kfunc return long *
We will soon be generating kfunc prototypes from BTF. As part of that,
we need to align the manual signatures in bpf_kfuncs.h with the actual
kfunc definitions. There is currently a conflicting signature for
bpf_session_cookie() w.r.t. return type.

The original intent was to return long * and not __u64 *. You can see
evidence of that intent in a3a5113393 ("selftests/bpf: Add kprobe
session cookie test").

Fix conflict by changing kfunc definition.

Fixes: 5c919acef8 ("bpf: Add support for kprobe session cookie")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/7043e1c251ab33151d6e3830f8ea1902ed2604ac.1718207789.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-06-12 11:01:31 -07:00
Masami Hiramatsu (Google)
3eddb03196 tracing/kprobe: Remove cleanup code unrelated to selftest
This cleanup all kprobe events code is not related to the selftest
itself, and it can fail by the reason unrelated to this test.
If the test is successful, the generated events are cleaned up.
And if not, we cannot guarantee that the kprobe events will work
correctly. So, anyway, there is no need to clean it up.

Link: https://lore.kernel.org/all/171811265627.85078.16897867213512435822.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:46:00 +09:00
Masami Hiramatsu (Google)
41051daa38 tracing/kprobe: Integrate test warnings into WARN_ONCE
Cleanup the redundant WARN_ON_ONCE(cond) + pr_warn(msg) into
WARN_ONCE(cond, msg). Also add some WARN_ONCE() for hitcount check.
These WARN_ONCE() errors makes it easy to handle errors from ktest.

Link: https://lore.kernel.org/all/171811264685.85078.8068819097047430463.stgit@devnote2/

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:44:44 +09:00
Masami Hiramatsu (Google)
3572bd5689 tracing: Build event generation tests only as modules
The kprobes and synth event generation test modules add events and lock
(get a reference) those event file reference in module init function,
and unlock and delete it in module exit function. This is because those
are designed for playing as modules.

If we make those modules as built-in, those events are left locked in the
kernel, and never be removed. This causes kprobe event self-test failure
as below.

[   97.349708] ------------[ cut here ]------------
[   97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480
[   97.357106] Modules linked in:
[   97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14
[   97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480
[   97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90
[   97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286
[   97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000
[   97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68
[   97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[   97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000
[   97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000
[   97.381536] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   97.383813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0
[   97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   97.391196] Call Trace:
[   97.391967]  <TASK>
[   97.392647]  ? __warn+0xcc/0x180
[   97.393640]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.395181]  ? report_bug+0xbd/0x150
[   97.396234]  ? handle_bug+0x3e/0x60
[   97.397311]  ? exc_invalid_op+0x1a/0x50
[   97.398434]  ? asm_exc_invalid_op+0x1a/0x20
[   97.399652]  ? trace_kprobe_is_busy+0x20/0x20
[   97.400904]  ? tracing_reset_all_online_cpus+0x15/0x90
[   97.402304]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.403773]  ? init_kprobe_trace+0x50/0x50
[   97.404972]  do_one_initcall+0x112/0x240
[   97.406113]  do_initcall_level+0x95/0xb0
[   97.407286]  ? kernel_init+0x1a/0x1a0
[   97.408401]  do_initcalls+0x3f/0x70
[   97.409452]  kernel_init_freeable+0x16f/0x1e0
[   97.410662]  ? rest_init+0x1f0/0x1f0
[   97.411738]  kernel_init+0x1a/0x1a0
[   97.412788]  ret_from_fork+0x39/0x50
[   97.413817]  ? rest_init+0x1f0/0x1f0
[   97.414844]  ret_from_fork_asm+0x11/0x20
[   97.416285]  </TASK>
[   97.417134] irq event stamp: 13437323
[   97.418376] hardirqs last  enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150
[   97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150
[   97.423838] softirqs last  enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0
[   97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0
[   97.428850] ---[ end trace 0000000000000000 ]---

And also, since we can not cleanup dynamic_event file, ftracetest are
failed too.

To avoid these issues, build these tests only as modules.

Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/

Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-12 08:43:12 +09:00
Marilene A Garcia
9b5a45eb63 ftrace: Add missing kerneldoc parameters to unregister_ftrace_direct()
Add the description to the parameters addr and free_filters
of the function unregister_ftrace_direct().

Link: https://lore.kernel.org/linux-trace-kernel/20240606132520.1397567-1-marilene.agarcia@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Signed-off-by: Marilene A Garcia <marilene.agarcia@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
5f7fb89a11 function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove it
All architectures that implement function graph also implements
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no longer a
differentiator.

Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.982047614@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
29c1c24a27 function_graph: Fix up ftrace_graph_ret_addr()
Yang Li sent a patch to fix the kerneldoc of ftrace_graph_ret_addr().
While reviewing it, I realized that the comments in the entire function
header needed a rewrite. When doing that, I realized that @idx parameter
was being ignored. Every time this was called by the unwinder, it would
start the loop at the top of the shadow stack and look for the matching
stack pointer. When it found it, it would return it. When the unwinder
asked for the next function, it would search from the beginning again.

In reality, it should start from where it left off. That was the reason
for the @idx parameter in the first place. The first time the unwinder
calls this function, the @idx pointer would contain zero. That would mean
to start from the top of the stack. The function was supposed to update
the @idx with the index where it found the return address, so that the
next time the unwinder calls this function it doesn't have to search
through the previous addresses it found (making it O(n^2)!).

This speeds up the unwinder's use of ftrace_graph_ret_addr() by an order
of magnitude.

Link: https://lore.kernel.org/linux-trace-kernel/20240610181746.656e3759@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.821995106@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Reported-by: Yang Li <yang.lee@linux.alibaba.com>
Fixes: 7aa1eaef9f ("function_graph: Allow multiple users to attach to function graph")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11 11:18:24 -04:00
Steven Rostedt (Google)
4267fda4af function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE
When CONFIG_DYNAMIC_FTRACE is not set, the function
fgraph_update_pid_func() doesn't do anything. Currently, most of its logic
is within a "#ifdef CONFIG_DYNAMIC_FTRACE" block, but its variables were
declared outside that, and when DYNAMIC_FTRACE is not set, it produces
unused variable warnings.

Instead, just place it (and the helper function fgraph_pid_func()) within
the #ifdef block and have the header file use a empty stub function for
when DYNAMIC_FTRACE is not defined.

Link: https://lore.kernel.org/linux-trace-kernel/20240607094833.6a787d73@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406071806.BRjaC5FF-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-10 18:08:23 -04:00
Steven Rostedt (Google)
2f6b884dfc function_graph: Rename BYTE_NUMBER to CHAR_NUMBER in selftests
The function_graph selftests checks various size variables to pass from
the entry of the function to the exit. It tests 1, 2, 4 and 8 byte words.
The 1 byte macro was called BYTE_NUMBER but that is used in the sh
architecture: arch/sh/include/asm/bitops-op32.h

Just rename the macro to CHAR_NUMBER.

Link: https://lore.kernel.org/linux-trace-kernel/20240606081846.4cb82dc4@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 47c3c70aa3 ("function_graph: Add selftest for passing local variables")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406061744.rZDXfRrG-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:19 -04:00
Jiapeng Chong
9a2a3aab73 fgraph: Remove some unused functions
These functions are defined in the fgraph.c file, but not
called elsewhere, so delete these unused functions.

kernel/trace/fgraph.c:273:1: warning: unused function 'set_bitmap_bits'.
kernel/trace/fgraph.c:259:19: warning: unused function 'get_fgraph_type'.

Link: https://lore.kernel.org/linux-trace-kernel/20240606021053.27783-1-jiapeng.chong@linux.alibaba.com

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9289
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:19 -04:00
Tatsuya S
6c1f7f0aca ftrace: Hide one more entry in stack trace when ftrace_pid is enabled
On setting set_ftrace_pid, a extra entry generated by ftrace_pid_func()
is shown on stack trace(CONFIG_UNWINDER_FRAME_POINTER=y).

        [004] .....    68.459382: <stack trace>
 => 0xffffffffa00090af
 => ksys_read
 => __x64_sys_read
 => x64_sys_call
 => do_syscall_64
 => entry_SYSCALL_64_after_hwframe

To resolve this issue, increment skip count
in function_stack_trace_call() if pids are set.

Link: https://lore.kernel.org/linux-trace-kernel/20240528032604.6813-3-tatsuya.s2862@gmail.com

Signed-off-by: Tatsuya S <tatsuya.s2862@gmail.com>
[ Rebased to current tree ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
4057fd2cdd function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabled
The ftrace subops is only defined if CONFIG_DYNAMIC_FTRACE is enabled. If
it is not, function tracing is extremely limited, and the subops in the
ftrace_ops structure is not defined (and will fail to compile). If
DYNAMIC_FTRACE is not enabled, then function graph filtering will not
work (as it shouldn't).

Link: https://lore.kernel.org/linux-trace-kernel/20240605202709.096020676@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: df3ec5da6a ("function_graph: Add pid tracing back to function graph tracer")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051855.9VIYXbTB-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
0c4d8cbb2c function_graph: Make fgraph_do_direct static key static
The static branch key "fgraph_do_direct" was not declared static but is
only used in one file. Change it to a static variable.

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.936515302@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051711.dS1sQZ9n-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
86b49970e0 ftrace: Fix prototypes for ftrace_startup/shutdown_subops()
The ftrace_startup_subops() was in the wrong header, and both functions
were not defined on !CONFIG_DYNAMIC_FTRACE.

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.773583114@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 5fccc7552c ("ftrace: Add subops logic to allow one ops to manage many")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406051524.a12JqLqx-lkp@intel.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
0ddef5d601 ftrace: Assign RCU list variable with rcu_assign_ptr()
Use rcu_assign_ptr() to assign the list pointer as it is marked as RCU,
and this quiets the sparse warning:

   kernel/trace/ftrace.c:313:23: warning: incorrect type in assignment (different address spaces)
   kernel/trace/ftrace.c:313:23:    expected struct ftrace_ops [noderef] __rcu *
   kernel/trace/ftrace.c:313:23:    got struct ftrace_ops *

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.613471310@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
1f51ba905e ftrace: Assign ftrace_list_end to ftrace_ops_list type cast to RCU
Use a type cast to convert ftrace_list_end to RCU when assigning
ftrace_ops_list. This will quiet the sparse warning:

 kernel/trace/ftrace.c:125:59: warning: incorrect type in initializer (different address spaces)
 kernel/trace/ftrace.c:125:59:    expected struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list
 kernel/trace/ftrace.c:125:59:    got struct ftrace_ops *

Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.450784356@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:18 -04:00
Steven Rostedt (Google)
d66bb33479 ftrace: Add comments to ftrace_hash_move() and friends
Describe what ftrace_hash_move() does and add some more comments to some
other functions to make it easier to understand.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.179520305@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:22:03 -04:00
Steven Rostedt (Google)
1a88c07167 ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()
The parameter "inc" in the function ftrace_hash_rec_update_modify() is
boolean. Change it to be such.

Also add documentation to what the function does.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180409.021080462@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:21:28 -04:00
Steven Rostedt (Google)
da73f6d490 ftrace: Add comments to ftrace_hash_rec_disable/enable()
Add comments to describe what the functions ftrace_hash_rec_disable() and
ftrace_hash_rec_enable() do. Also change the passing of the "inc" variable
to __ftrace_hash_rec_update() to a boolean value as that is what it is
supposed to take.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180408.857333430@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:21:25 -04:00
Steven Rostedt (Google)
07bbe0833e ftrace: Remove "filter_hash" parameter from __ftrace_hash_rec_update()
While adding comments to the function __ftrace_hash_rec_update() and
trying to describe in detail what the parameter for "filter_hash" does, I
realized that it basically does exactly the same thing (but differently)
if it is set or not!

If it is set, the idea was the ops->filter_hash was being updated, and the
code should focus on the functions that are in the ops->filter_hash and
add them. But it still had to pay attention to the functions in the
ops->notrace_hash, to ignore them.

If it was cleared, it focused on the ops->notrace_hash, and would add
functions that were not in the ops->notrace_hash but would still keep
functions in the "ops->filter_hash". Basically doing the same thing.

In reality, the __ftrace_hash_rec_update() only needs to either remove the
functions associated to the give ops (if "inc" is set) or remove them (if
"inc" is cleared). It has to pay attention to both the filter_hash and
notrace_hash regardless.

Remove the "filter_hash" parameter from __filter_hash_rec_update() and
comment the function for what it really is doing.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180408.691995506@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 15:20:27 -04:00
Steven Rostedt (Google)
3afd801f42 ftrace: Rename dup_hash() and comment it
The name "dup_hash()" is a misnomer as it does not duplicate the hash that
is passed in, but instead moves its entities from that hash to a newly
allocated one. Rename it to "__move_hash()" (using starting underscores as
it is an internal function), and add some comments about what it does.

Link: https://lore.kernel.org/linux-trace-kernel/20240605180408.537723591@goodmis.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 12:45:17 -04:00
Jeff Johnson
22b639253e tracing: Fix trace_pid_list_free() kernel-doc
make C=1 reports:

kernel/trace/pid_list.c:458: warning: Function parameter or struct member 'pid_list' not described in 'trace_pid_list_free'

Add the missing parameter to the trace_pid_list_free() kernel-doc.

Link: https://lore.kernel.org/linux-trace-kernel/20240506-trace_pid_list_free-kdoc-v1-1-c70f0ae29144@quicinc.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06 08:26:47 -04:00
Steven Rostedt (Google)
2431196248 ftrace: Add back ftrace_update_trampoline() to ftrace_update_pid_func()
The update to the ops trampoline done by the function
ftrace_update_trampoline() was accidentally removed from
ftrace_update_pid_func(). Add it back.

Link: https://lore.kernel.org/linux-trace-kernel/20240605205337.6115e9a5@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: df3ec5da6a ("function_graph: Add pid tracing back to function graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-05 20:57:48 -04:00
Steven Rostedt (Google)
fe835e3ca4 function_graph: Use static_call and branch to optimize return function
In most cases function graph is used by a single user. Instead of calling
a loop to call function graph callbacks in this case, call the function
return callback directly.

Use the static_key that is set when the function graph tracer has less
than 2 callbacks registered. It will do the direct call in that case, and
will do the loop over all callers when there are 2 or more callbacks
registered.

Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.921460797@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:38:23 -04:00
Steven Rostedt (Google)
cc60ee813b function_graph: Use static_call and branch to optimize entry function
In most cases function graph is used by a single user. Instead of calling
a loop to call function graph callbacks in this case, call the function
entry callback directly.

Add a static_key that will be used to set the function graph logic to
either do the loop (when more than one callback is registered) or to call
the callback directly if there is only one registered callback.

Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.766858241@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:38:15 -04:00
Steven Rostedt (Google)
a5b6d4da02 function_graph: Use bitmask to loop on fgraph entry
Instead of looping through all the elements of fgraph_array[] to see if
there's an gops attached to one and then calling its gops->func(). Create
a fgraph_array_bitmask that sets bits when an index in the array is
reserved (via the simple lru algorithm). Then only the bits set in this
bitmask needs to be looked at where only elements in the array that have
ops registered need to be looked at.

Note, we do not care about races. If a bit is set before the gops is
assigned, it only wastes time looking at the element and ignoring it (as
it did before this bitmask is added).

Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.604448781@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:38:10 -04:00
Steven Rostedt (Google)
420e1354bc function_graph: Use for_each_set_bit() in __ftrace_return_to_handler()
Instead of iterating through the entire fgraph_array[] and seeing if one
of the bitmap bits are set to know to call the array's retfunc() function,
use for_each_set_bit() on the bitmap itself. This will only iterate for
the number of set bits.

Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.447448026@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:38:03 -04:00
Masami Hiramatsu (Google)
dd120af2d5 ftrace: Add multiple fgraph storage selftest
Add a selftest for multiple function graph tracer with storage on a same
function. In this case, the shadow stack entry will be shared among those
fgraph with different data storage. So this will ensure the fgraph will
not mixed those storage data.

Link: https://lore.kernel.org/linux-trace-kernel/171509111465.162236.3795819216426570800.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.284049716@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:59 -04:00
Steven Rostedt (VMware)
47c3c70aa3 function_graph: Add selftest for passing local variables
Add boot up selftest that passes variables from a function entry to a
function exit, and make sure that they do get passed around.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509110271.162236.11047551496319744627.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.122952310@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:52 -04:00
Steven Rostedt (VMware)
91c46b0aa9 function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()
Added functions that can be called by a fgraph_ops entryfunc and retfunc to
store state between the entry of the function being traced to the exit of
the same function. The fgraph_ops entryfunc() may call
fgraph_reserve_data() to store up to 32 words onto the task's shadow
ret_stack and this then can be retrieved by fgraph_retrieve_data() called
by the corresponding retfunc().

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509109089.162236.11372474169781184034.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.959703050@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:48 -04:00
Steven Rostedt (VMware)
b84214890a function_graph: Move graph notrace bit to shadow stack global var
The use of the task->trace_recursion for the logic used for the function
graph no-trace was a bit of an abuse of that variable. Now that there
exists global vars that are per stack for registered graph traces, use
that instead.

Link: https://lore.kernel.org/linux-trace-kernel/171509107907.162236.6564679266777519065.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.796709456@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:44 -04:00
Steven Rostedt (VMware)
068da098eb function_graph: Move graph depth stored data to shadow stack global var
The use of the task->trace_recursion for the logic used for the function
graph depth was a bit of an abuse of that variable. Now that there
exists global vars that are per stack for registered graph traces, use that
instead.

Link: https://lore.kernel.org/linux-trace-kernel/171509106728.162236.2398372644430125344.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.634870264@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:40 -04:00
Steven Rostedt (VMware)
12117f3307 function_graph: Move set_graph_function tests to shadow stack global var
The use of the task->trace_recursion for the logic used for the
set_graph_function was a bit of an abuse of that variable. Now that there
exists global vars that are per stack for registered graph traces, use that
instead.

Link: https://lore.kernel.org/linux-trace-kernel/171509105520.162236.10339831553995971290.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.472955399@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:35 -04:00
Steven Rostedt (VMware)
4497412a1f function_graph: Add "task variables" per task for fgraph_ops
Add a "task variables" array on the tasks shadow ret_stack that is the
size of longs for each possible registered fgraph_ops. That's a total
of 16, taking up 8 * 16 = 128 bytes (out of a page size 4k).

This will allow for fgraph_ops to do specific features on a per task basis
having a way to maintain state for each task.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509104383.162236.12239656156685718550.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.308806126@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:29 -04:00
Masami Hiramatsu (Google)
6d4786592a function_graph: Use a simple LRU for fgraph_array index number
Since the fgraph_array index is used for the bitmap on the shadow
stack, it may leave some entries after a function_graph instance is
removed. Thus if another instance reuses the fgraph_array index soon
after releasing it, the fgraph may confuse to call the newer callback
for the entries which are pushed by the older instance.
To avoid reusing the fgraph_array index soon after releasing, introduce
a simple LRU table for managing the index number. This will reduce the
possibility of this confusion.

Link: https://lore.kernel.org/linux-trace-kernel/171509103267.162236.6885097397289135378.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.147421545@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:21 -04:00
Steven Rostedt (Google)
df3ec5da6a function_graph: Add pid tracing back to function graph tracer
Now that the function_graph has a main callback that handles the function
graph subops tracing, it no longer honors the pid filtering of ftrace. Add
back this logic in the function_graph code to update the gops callback for
the entry function to test if it should trace the current task or not.

Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.991720703@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:37:11 -04:00
Steven Rostedt (VMware)
c132be2c4f function_graph: Have the instances use their own ftrace_ops for filtering
Allow for instances to have their own ftrace_ops part of the fgraph_ops
that makes the funtion_graph tracer filter on the set_ftrace_filter file
of the instance and not the top instance.

This uses the new ftrace_startup_subops(), by using graph_ops as the
"manager ops" that defines the callback function and adds the functions
defined by the filters of the ops for each trace instance. The callback
defined by the manager ops will call the registered fgraph ops that were
added to the fgraph_array.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509102088.162236.15758883237657317789.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.832946261@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:52 -04:00
Steven Rostedt (Google)
d9bbfbd14f ftrace: Allow subops filtering to be modified
The subops filters use a "manager" ops to enable and disable its filters.
The manager ops can handle more than one subops, and its filter is what
controls what functions get set. Add a ftrace_hash_move_and_update_subops()
function that will update the manager ops when the subops filters change.

Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.673932251@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:44 -04:00
Steven Rostedt (Google)
5fccc7552c ftrace: Add subops logic to allow one ops to manage many
There are cases where a single system will use a single function callback
to handle multiple users. For example, to allow function_graph tracer to
have multiple users where each can trace their own set of functions, it is
useful to only have one ftrace_ops registered to ftrace that will call a
function by the function_graph tracer to handle the multiplexing with the
different registered  function_graph tracers.

Add a "subop_list" to the ftrace_ops that will hold a list of other
ftrace_ops that the top ftrace_ops will manage.

The function ftrace_startup_subops() that takes the manager ftrace_ops and
a subop ftrace_ops it will manage. If there are no subops with the
ftrace_ops yet, it will copy the ftrace_ops subop filters to the manager
ftrace_ops and register that with ftrace_startup(), and adds the subop to
its subop_list. If the manager ops already has something registered, it
will then merge the new subop filters with what it has and enable the new
functions that covers all the subops it has.

To remove a subop, ftrace_shutdown_subops() is called which will use the
subop_list of the manager ops to rebuild all the functions it needs to
trace, and update the ftrace records to only call the functions it now has
registered. If there are no more functions registered, it will then call
ftrace_shutdown() to disable itself completely.

Note, it is up to the manager ops callback to always make sure that the
subops callbacks are called if its filter matches, as there are times in
the update where the callback could be calling more functions than those
that are currently registered.

This could be updated to handle other systems other than function_graph,
for example, fprobes could use this (but will need an interface to call
ftrace_startup_subops()).

Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.508431129@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:38 -04:00
Steven Rostedt (VMware)
26dda5631d ftrace: Allow function_graph tracer to be enabled in instances
Now that function graph tracing can handle more than one user, allow it to
be enabled in the ftrace instances. Note, the filtering of the functions is
still joined by the top level set_ftrace_filter and friends, as well as the
graph and nograph files.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509099743.162236.1699959255446248163.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.190630762@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:28 -04:00
Steven Rostedt (VMware)
37238abe3c ftrace/function_graph: Pass fgraph_ops to function graph callbacks
Pass the fgraph_ops structure to the function graph callbacks. This will
allow callbacks to add a descriptor to a fgraph_ops private field that wil
be added in the future and use it for the callbacks. This will be useful
when more than one callback can be registered to the function graph tracer.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509098588.162236.4787930115997357578.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.035147698@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:22 -04:00
Steven Rostedt (VMware)
2fbb549983 function_graph: Remove logic around ftrace_graph_entry and return
The function pointers ftrace_graph_entry and ftrace_graph_return are no
longer called via the function_graph tracer. Instead, an array structure is
now used that will allow for multiple users of the function_graph
infrastructure. The variables are still used by the architecture code for
non dynamic ftrace configs, where a test is made against them to see if
they point to the default stub function or not. This is how the static
function tracing knows to call into the function graph tracer
infrastructure or not.

Two new stub functions are made. entry_run() and return_run(). The
ftrace_graph_entry and ftrace_graph_return are set to them respectively
when the function graph tracer is enabled, and this will trigger the
architecture specific function graph code to be executed.

This also requires checking the global_ops hash for all calls into the
function_graph tracer.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509097408.162236.17387844142114638932.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.872127216@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:11 -04:00
Masami Hiramatsu (Google)
375bb57292 function_graph: Handle tail calls for stack unwinding
For the tail-call, there would be 2 or more ftrace_ret_stacks on the
ret_stack, which records "return_to_handler" as the return address except
for the last one.  But on the real stack, there should be 1 entry because
tail-call reuses the return address on the stack and jump to the next
function.

In ftrace_graph_ret_addr() that is used for stack unwinding, skip tail
calls as a real stack unwinder would do.

Link: https://lore.kernel.org/linux-trace-kernel/171509096221.162236.8806372072523195752.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.717065217@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:36:05 -04:00
Steven Rostedt (VMware)
7aa1eaef9f function_graph: Allow multiple users to attach to function graph
Allow for multiple users to attach to function graph tracer at the same
time. Only 16 simultaneous users can attach to the tracer. This is because
there's an array that stores the pointers to the attached fgraph_ops. When
a function being traced is entered, each of the ftrace_ops entryfunc is
called and if it returns non zero, its index into the array will be added
to the shadow stack.

On exit of the function being traced, the shadow stack will contain the
indexes of the ftrace_ops on the array that want their retfunc to be
called.

Because a function may sleep for a long time (if a task sleeps itself),
the return of the function may be literally days later. If the ftrace_ops
is removed, its place on the array is replaced with a ftrace_ops that
contains the stub functions and that will be called when the function
finally returns.

If another ftrace_ops is added that happens to get the same index into the
array, its return function may be called. But that's actually the way
things current work with the old function graph tracer. If one tracer is
removed and another is added, the new one will get the return calls of the
function traced by the previous one, thus this is not a regression. This
can be fixed by adding a counter to each time the array item is updated and
save that on the shadow stack as well, such that it won't be called if the
index saved does not match the index on the array.

Note, being able to filter functions when both are called is not completely
handled yet, but that shouldn't be too hard to manage.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509096221.162236.8806372072523195752.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.555493396@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:35:58 -04:00
Steven Rostedt (VMware)
518d6804a8 function_graph: Add an array structure that will allow multiple callbacks
Add an array structure that will eventually allow the function graph tracer
to have up to 16 simultaneous callbacks attached. It's an array of 16
fgraph_ops pointers, that is assigned when one is registered. On entry of a
function the entry of the first item in the array is called, and if it
returns zero, then the callback returns non zero if it wants the return
callback to be called on exit of the function.

The array will simplify the process of having more than one callback
attached to the same function, as its index into the array can be stored on
the shadow stack. We need to only save the index, because this will allow
the fgraph_ops to be freed before the function returns (which may happen if
the function call schedule for a long time).

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509095075.162236.8272148192748284581.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.392113213@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:35:53 -04:00
Steven Rostedt (VMware)
59e5f04e41 fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long
Instead of using "ALIGN()", use BUILD_BUG_ON() as the structures should
always be divisible by sizeof(long).

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509093949.162236.14518699447151894536.stgit@devnote2
Link: http://lkml.kernel.org/r/20190524111144.GI2589@hirez.programming.kicks-ass.net
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.232168933@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:35:40 -04:00
Steven Rostedt (VMware)
42675b723b function_graph: Convert ret_stack to a series of longs
In order to make it possible to have multiple callbacks registered with the
function_graph tracer, the retstack needs to be converted from an array of
ftrace_ret_stack structures to an array of longs. This will allow to store
the list of callbacks on the stack for the return side of the functions.

Link: https://lore.kernel.org/linux-trace-kernel/171509092742.162236.4427737821399314856.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.073111754@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04 10:35:09 -04:00
Jiri Olsa
aeb8fe0283 bpf: Fix bpf_session_cookie BTF_ID in special_kfunc_set list
The bpf_session_cookie is unavailable for !CONFIG_FPROBE as reported
by Sebastian [1].

To fix that we remove CONFIG_FPROBE ifdef for session kfuncs, which
is fine, because there's filter for session programs.

Then based on bpf_trace.o dependency:
  obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o

we add bpf_session_cookie BTF_ID in special_kfunc_set list dependency
on CONFIG_BPF_EVENTS.

[1] https://lore.kernel.org/bpf/20240531071557.MvfIqkn7@linutronix.de/T/#m71c6d5ec71db2967288cb79acedc15cc5dbfeec5
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Fixes: 5c919acef8 ("bpf: Add support for kprobe session cookie")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240531194500.2967187-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-31 14:54:48 -07:00
Linus Torvalds
d8ec19857b Including fixes from bpf and netfilter.
Current release - regressions:
 
   - gro: initialize network_offset in network layer
 
   - tcp: reduce accepted window in NEW_SYN_RECV state
 
 Current release - new code bugs:
 
   - eth: mlx5e: do not use ptp structure for tx ts stats when not initialized
 
   - eth: ice: check for unregistering correct number of devlink params
 
 Previous releases - regressions:
 
   - bpf: Allow delete from sockmap/sockhash only if update is allowed
 
   - sched: taprio: extend minimum interval restriction to entire cycle too
 
   - netfilter: ipset: add list flush to cancel_gc
 
   - ipv4: fix address dump when IPv4 is disabled on an interface
 
   - sock_map: avoid race between sock_map_close and sk_psock_put
 
   - eth: mlx5: use mlx5_ipsec_rx_status_destroy to correctly delete status rules
 
 Previous releases - always broken:
 
   - core: fix __dst_negative_advice() race
 
   - bpf:
     - fix multi-uprobe PID filtering logic
     - fix pkt_type override upon netkit pass verdict
 
   - netfilter: tproxy: bail out if IP has been disabled on the device
 
   - af_unix: annotate data-race around unix_sk(sk)->addr
 
   - eth: mlx5e: fix UDP GSO for encapsulated packets
 
   - eth: idpf: don't enable NAPI and interrupts prior to allocating Rx buffers
 
   - eth: i40e: fully suspend and resume IO operations in EEH case
 
   - eth: octeontx2-pf: free send queue buffers incase of leaf to inner
 
   - eth: ipvlan: dont Use skb->sk in ipvlan_process_v{4,6}_outbound
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf and netfilter.

  Current release - regressions:

   - gro: initialize network_offset in network layer

   - tcp: reduce accepted window in NEW_SYN_RECV state

  Current release - new code bugs:

   - eth: mlx5e: do not use ptp structure for tx ts stats when not
     initialized

   - eth: ice: check for unregistering correct number of devlink params

  Previous releases - regressions:

   - bpf: Allow delete from sockmap/sockhash only if update is allowed

   - sched: taprio: extend minimum interval restriction to entire cycle
     too

   - netfilter: ipset: add list flush to cancel_gc

   - ipv4: fix address dump when IPv4 is disabled on an interface

   - sock_map: avoid race between sock_map_close and sk_psock_put

   - eth: mlx5: use mlx5_ipsec_rx_status_destroy to correctly delete
     status rules

  Previous releases - always broken:

   - core: fix __dst_negative_advice() race

   - bpf:
       - fix multi-uprobe PID filtering logic
       - fix pkt_type override upon netkit pass verdict

   - netfilter: tproxy: bail out if IP has been disabled on the device

   - af_unix: annotate data-race around unix_sk(sk)->addr

   - eth: mlx5e: fix UDP GSO for encapsulated packets

   - eth: idpf: don't enable NAPI and interrupts prior to allocating Rx
     buffers

   - eth: i40e: fully suspend and resume IO operations in EEH case

   - eth: octeontx2-pf: free send queue buffers incase of leaf to inner

   - eth: ipvlan: dont Use skb->sk in ipvlan_process_v{4,6}_outbound"

* tag 'net-6.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
  netdev: add qstat for csum complete
  ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound
  net: ena: Fix redundant device NUMA node override
  ice: check for unregistering correct number of devlink params
  ice: fix 200G PHY types to link speed mapping
  i40e: Fully suspend and resume IO operations in EEH case
  i40e: factoring out i40e_suspend/i40e_resume
  e1000e: move force SMBUS near the end of enable_ulp function
  net: dsa: microchip: fix RGMII error in KSZ DSA driver
  ipv4: correctly iterate over the target netns in inet_dump_ifaddr()
  net: fix __dst_negative_advice() race
  nfc/nci: Add the inconsistency check between the input data length and count
  MAINTAINERS: dwmac: starfive: update Maintainer
  net/sched: taprio: extend minimum interval restriction to entire cycle too
  net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()
  netfilter: nft_fib: allow from forward/input without iif selector
  netfilter: tproxy: bail out if IP has been disabled on the device
  netfilter: nft_payload: skbuff vlan metadata mangle support
  net: ti: icssg-prueth: Fix start counter for ft1 filter
  sock_map: avoid race between sock_map_close and sk_psock_put
  ...
2024-05-30 08:33:04 -07:00
Jakub Kicinski
2786ae339e bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-05-27

We've added 15 non-merge commits during the last 7 day(s) which contain
a total of 18 files changed, 583 insertions(+), 55 deletions(-).

The main changes are:

1) Fix broken BPF multi-uprobe PID filtering logic which filtered by thread
   while the promise was to filter by process, from Andrii Nakryiko.

2) Fix the recent influx of syzkaller reports to sockmap which triggered
   a locking rule violation by performing a map_delete, from Jakub Sitnicki.

3) Fixes to netkit driver in particular on skb->pkt_type override upon pass
   verdict, from Daniel Borkmann.

4) Fix an integer overflow in resolve_btfids which can wrongly trigger build
   failures, from Friedrich Vock.

5) Follow-up fixes for ARC JIT reported by static analyzers,
   from Shahab Vahedi.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Cover verifier checks for mutating sockmap/sockhash
  Revert "bpf, sockmap: Prevent lock inversion deadlock in map delete elem"
  bpf: Allow delete from sockmap/sockhash only if update is allowed
  selftests/bpf: Add netkit test for pkt_type
  selftests/bpf: Add netkit tests for mac address
  netkit: Fix pkt_type override upon netkit pass verdict
  netkit: Fix setting mac address in l2 mode
  ARC, bpf: Fix issues reported by the static analyzers
  selftests/bpf: extend multi-uprobe tests with USDTs
  selftests/bpf: extend multi-uprobe tests with child thread case
  libbpf: detect broken PID filtering logic for multi-uprobe
  bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic
  bpf: fix multi-uprobe PID filtering logic
  bpf: Fix potential integer overflow in resolve_btfids
  MAINTAINERS: Add myself as reviewer of ARM64 BPF JIT
====================

Link: https://lore.kernel.org/r/20240527203551.29712-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-27 16:26:30 -07:00
Carlos López
e569eb3497 tracing/probes: fix error check in parse_btf_field()
btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.

Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/

Fixes: c440adfbe3 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-27 21:32:35 +09:00
Andrii Nakryiko
4a8f635a60 bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic
get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), so there is no point to do this one extra time.

This is a drive-by improvement and has no correctness implications.

Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-25 10:46:02 -07:00
Andrii Nakryiko
46ba0e49b6 bpf: fix multi-uprobe PID filtering logic
Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.

Fix the check in uprobe_prog_run() to perform the same task->mm check.

While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.

Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.

We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.

Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade4 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-25 10:46:02 -07:00
Andrii Nakryiko
699646734a uprobes: prevent mutex_lock() under rcu_read_lock()
Recent changes made uprobe_cpu_buffer preparation lazy, and moved it
deeper into __uprobe_trace_func(). This is problematic because
__uprobe_trace_func() is called inside rcu_read_lock()/rcu_read_unlock()
block, which then calls prepare_uprobe_buffer() -> uprobe_buffer_get() ->
mutex_lock(&ucb->mutex), leading to a splat about using mutex under
non-sleepable RCU:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
   in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 98231, name: stress-ng-sigq
   preempt_count: 0, expected: 0
   RCU nest depth: 1, expected: 0
   ...
   Call Trace:
    <TASK>
    dump_stack_lvl+0x3d/0xe0
    __might_resched+0x24c/0x270
    ? prepare_uprobe_buffer+0xd5/0x1d0
    __mutex_lock+0x41/0x820
    ? ___perf_sw_event+0x206/0x290
    ? __perf_event_task_sched_in+0x54/0x660
    ? __perf_event_task_sched_in+0x54/0x660
    prepare_uprobe_buffer+0xd5/0x1d0
    __uprobe_trace_func+0x4a/0x140
    uprobe_dispatcher+0x135/0x280
    ? uprobe_dispatcher+0x94/0x280
    uprobe_notify_resume+0x650/0xec0
    ? atomic_notifier_call_chain+0x21/0x110
    ? atomic_notifier_call_chain+0xf8/0x110
    irqentry_exit_to_user_mode+0xe2/0x1e0
    asm_exc_int3+0x35/0x40
   RIP: 0033:0x7f7e1d4da390
   Code: 33 04 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b9 01 00 00 00 e9 b2 fc ff ff 66 90 f3 0f 1e fa 31 c9 e9 a5 fc ff ff 0f 1f 44 00 00 <cc> 0f 1e fa b8 27 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 6e
   RSP: 002b:00007ffd2abc3608 EFLAGS: 00000246
   RAX: 0000000000000000 RBX: 0000000076d325f1 RCX: 0000000000000000
   RDX: 0000000076d325f1 RSI: 000000000000000a RDI: 00007ffd2abc3690
   RBP: 000000000000000a R08: 00017fb700000000 R09: 00017fb700000000
   R10: 00017fb700000000 R11: 0000000000000246 R12: 0000000000017ff2
   R13: 00007ffd2abc3610 R14: 0000000000000000 R15: 00007ffd2abc3780
    </TASK>

Luckily, it's easy to fix by moving prepare_uprobe_buffer() to be called
slightly earlier: into uprobe_trace_func() and uretprobe_trace_func(), outside
of RCU locked section. This still keeps this buffer preparation lazy and helps
avoid the overhead when it's not needed. E.g., if there is only BPF uprobe
handler installed on a given uprobe, buffer won't be initialized.

Note, the other user of prepare_uprobe_buffer(), __uprobe_perf_func(), is not
affected, as it doesn't prepare buffer under RCU read lock.

Link: https://lore.kernel.org/all/20240521053017.3708530-1-andrii@kernel.org/

Fixes: 1b8f85defb ("uprobes: prepare uprobe args buffer lazily")
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-24 07:44:44 +09:00
Linus Torvalds
404001ddf3 tracing: Minor last minute fixes
- Fix a very tight race between the ring buffer readers and resizing
   the ring buffer.
 
 - Correct some stale comments in the ring buffer code.
 
 - Fix kernel-doc in the rv code.
 
 - Add a MODULE_DESCRIPTION to preemptirq_delay_test
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Merge tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Minor last minute fixes:

   - Fix a very tight race between the ring buffer readers and resizing
     the ring buffer

   - Correct some stale comments in the ring buffer code

   - Fix kernel-doc in the rv code

   - Add a MODULE_DESCRIPTION to preemptirq_delay_test"

* tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rv: Update rv_en(dis)able_monitor doc to match kernel-doc
  tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test
  ring-buffer: Fix a race between readers and resize checks
  ring-buffer: Correct stale comments related to non-consuming readers
2024-05-23 12:36:38 -07:00
Steven Rostedt (Google)
2c92ca849f tracing/treewide: Remove second parameter of __assign_str()
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.

This means that with:

  __string(field, mystring)

Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.

There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:

  git grep -l __assign_str | while read a ; do
      sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
      mv /tmp/test-file $a;
  done

I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.

Note, the same updates will need to be done for:

  __assign_str_len()
  __assign_rel_str()
  __assign_rel_str_len()

I tested this with both an allmodconfig and an allyesconfig (build only for both).

[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/

Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>	# xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
2024-05-22 20:14:47 -04:00
Yang Li
1e8b7b3dbb rv: Update rv_en(dis)able_monitor doc to match kernel-doc
The patch updates the function documentation comment for
rv_en(dis)able_monitor to adhere to the kernel-doc specification.

Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com

Fixes: 102227b970 ("rv: Add Runtime Verification (RV) interface")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-21 19:03:35 -04:00
Jeff Johnson
23748e3e0f tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test
Fix the 'make W=1' warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o

Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: f96e8577da ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-21 19:03:35 -04:00
Petr Pavlu
c2274b908d ring-buffer: Fix a race between readers and resize checks
The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.

The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:

[  190.271762] ------------[ cut here ]------------
[  190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[  190.271789] Modules linked in: [...]
[  190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[  190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G            E      6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[  190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[  190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[  190.272023] Code: [...]
[  190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[  190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[  190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[  190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[  190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[  190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[  190.272053] FS:  00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[  190.272057] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[  190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  190.272077] Call Trace:
[  190.272098]  <TASK>
[  190.272189]  ring_buffer_resize+0x2ab/0x460
[  190.272199]  __tracing_resize_ring_buffer.part.0+0x23/0xa0
[  190.272206]  tracing_resize_ring_buffer+0x65/0x90
[  190.272216]  tracing_entries_write+0x74/0xc0
[  190.272225]  vfs_write+0xf5/0x420
[  190.272248]  ksys_write+0x67/0xe0
[  190.272256]  do_syscall_64+0x82/0x170
[  190.272363]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  190.272373] RIP: 0033:0x7f1bd657d263
[  190.272381] Code: [...]
[  190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[  190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[  190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[  190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[  190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[  190.272412]  </TASK>
[  190.272414] ---[ end trace 0000000000000000 ]---

Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab79270
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.

The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():

 ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
 if (!ret)
 	goto spin;
 for (unsigned i = 0; i < 1U << 26; i++)  /* inserted delay loop */
 	__asm__ __volatile__ ("" : : : "memory");
 rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;

.. and then run the following commands on the target system:

 echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
 while true; do
 	echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 	echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 done &
 while true; do
 	for i in /sys/kernel/tracing/per_cpu/*; do
 		timeout 0.1 cat $i/trace_pipe; sleep 0.2
 	done
 done

To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.

Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 659f451ff2 ("ring-buffer: Add integrity check at end of iter read")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
[ Fixed whitespace ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-21 19:03:35 -04:00
Petr Pavlu
ea70a9628e ring-buffer: Correct stale comments related to non-consuming readers
Adjust the following code documentation:

* Kernel-doc comments for ring_buffer_read_prepare() and
  ring_buffer_read_finish() mention that recording to the ring buffer is
  disabled when the read is active. Remove mention of this restriction
  because it was already lifted in commit 1039221cc2 ("ring-buffer: Do
  not disable recording when there is an iterator").

* Function ring_buffer_read_finish() performs a self-check of the
  ring-buffer by locking cpu_buffer->reader_lock and then calling
  rb_check_pages(). The preceding comment explains that the lock is
  needed because rb_check_pages() clears the HEAD flag required by
  readers which might be running in parallel. Remove this explanation
  because commit 8843e06f67 ("ring-buffer: Handle race between
  rb_move_tail and rb_check_pages") simplified the function so it no
  longer resets the mentioned flag. Nonetheless, the lock is still
  needed because a reader swapping a page into the ring buffer can make
  the underlying doubly-linked list temporarily inconsistent.

This is a non-functional change.

Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-2-petr.pavlu@suse.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-21 19:03:35 -04:00
Linus Torvalds
eb6a9339ef Mainly singleton patches, documented in their respective changelogs.
Notable series include:
 
 - Some maintenance and performance work for ocfs2 in Heming Zhao's
   series "improve write IO performance when fragmentation is high".
 
 - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
   exposed by fstests".
 
 - kfifo header rework from Andy Shevchenko in the series "kfifo: Clean
   up kfifo.h".
 
 - GDB script fixes from Florian Rommel in the series "scripts/gdb: Fixes
   for $lx_current and $lx_per_cpu".
 
 - After much discussion, a coding-style update from Barry Song
   explaining one reason why inline functions are preferred over macros.
   The series is "codingstyle: avoid unused parameters for a function-like
   macro".
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Merge tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:
 "Mainly singleton patches, documented in their respective changelogs.
  Notable series include:

   - Some maintenance and performance work for ocfs2 in Heming Zhao's
     series "improve write IO performance when fragmentation is high".

   - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
     exposed by fstests".

   - kfifo header rework from Andy Shevchenko in the series "kfifo:
     Clean up kfifo.h".

   - GDB script fixes from Florian Rommel in the series "scripts/gdb:
     Fixes for $lx_current and $lx_per_cpu".

   - After much discussion, a coding-style update from Barry Song
     explaining one reason why inline functions are preferred over
     macros. The series is "codingstyle: avoid unused parameters for a
     function-like macro""

* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
  fs/proc: fix softlockup in __read_vmcore
  nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
  scripts: checkpatch: check unused parameters for function-like macro
  Documentation: coding-style: ask function-like macros to evaluate parameters
  nilfs2: use __field_struct() for a bitwise field
  selftests/kcmp: remove unused open mode
  nilfs2: remove calls to folio_set_error() and folio_clear_error()
  kernel/watchdog_perf.c: tidy up kerneldoc
  watchdog: allow nmi watchdog to use raw perf event
  watchdog: handle comma separated nmi_watchdog command line
  nilfs2: make superblock data array index computation sparse friendly
  squashfs: remove calls to set the folio error flag
  squashfs: convert squashfs_symlink_read_folio to use folio APIs
  scripts/gdb: fix detection of current CPU in KGDB
  scripts/gdb: make get_thread_info accept pointers
  scripts/gdb: fix parameter handling in $lx_per_cpu
  scripts/gdb: fix failing KGDB detection during probe
  kfifo: don't use "proxy" headers
  media: stih-cec: add missing io.h
  media: rc: add missing io.h
  ...
2024-05-19 14:02:03 -07:00
Linus Torvalds
fa3889d970 user-event updates for v6.10:
- Minor update to the user_events interface
   The ABI of creating a user event states that the fields
   are separated by semicolons, and spaces should be ignored.
   But the parsing expected at least one space to be there (which was incorrect).
   Fix the reading of the string to handle fields separated by
   semicolons but no space between them.
 
   This does extend the API sightly as now "field;field" will now be
   parsed and not cause an error. But it should not cause any regressions
   as no logic should expect it to fail.
 
   Note, that the logic that parses the event fields to create the
   trace_event works with no spaces after the semi-colon. It is
   the logic that tests against existing events that is inconsistent.
   This causes registering an event without using spaces to succeed
   if it doesn't exist, but makes the same call that tries to register
   to the same event, but doesn't use spaces, fail.
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Merge tag 'trace-user-events-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing user-event updates from Steven Rostedt:

 - Minor update to the user_events interface

  The ABI of creating a user event states that the fields are separated
  by semicolons, and spaces should be ignored.

  But the parsing expected at least one space to be there (which was
  incorrect). Fix the reading of the string to handle fields separated
  by semicolons but no space between them.

  This does extend the API sightly as now "field;field" will now be
  parsed and not cause an error. But it should not cause any regressions
  as no logic should expect it to fail.

  Note, that the logic that parses the event fields to create the
  trace_event works with no spaces after the semi-colon. It is
  the logic that tests against existing events that is inconsistent.
  This causes registering an event without using spaces to succeed
  if it doesn't exist, but makes the same call that tries to register
  to the same event, but doesn't use spaces, fail.

* tag 'trace-user-events-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/user_events: Add non-spacing separator check
  tracing/user_events: Fix non-spaced field matching
2024-05-17 18:46:30 -07:00
Linus Torvalds
53683e4080 tracing ring buffer updates for v6.10:
- Add ring_buffer memory mappings
 
   The tracing ring buffer was created based on being mostly used with the
   splice system call. It is broken up into page ordered sub-buffers and the
   reader swaps a new sub-buffer with an existing sub-buffer that's part
   of the write buffer. It then has total access to the swapped out
   sub-buffer and can do copyless movements of the memory into other mediums
   (file system, network, etc).
 
   The buffer is great for passing around the ring buffer contents in the
   kernel, but is not so good for when the consumer is the user space task
   itself.
 
   A new interface is added that allows user space to memory map the ring
   buffer. It will get all the write sub-buffers as well as reader sub-buffer
   (that is not written to). It can send an ioctl to change which sub-buffer
   is the new reader sub-buffer.
 
   The ring buffer is read only to user space. It only needs to call the
   ioctl when it is finished with a sub-buffer and needs a new sub-buffer
   that the writer will not write over.
 
   A self test program was also created for testing and can be used as
   an example for the interface to user space. The libtracefs (external
   to the kernel) also has code that interacts with this, although it is
   disabled until the interface is in a official release. It can be enabled
   by compiling the library with a special flag. This was used for testing
   applications that perform better with the buffer being mapped.
 
   Memory mapped buffers have limitations. The main one is that it can not be
   used with the snapshot logic. If the buffer is mapped, snapshots will be
   disabled. If any logic is set to trigger snapshots on a buffer, that
   buffer will not be allowed to be mapped.
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Merge tag 'trace-ringbuffer-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing ring buffer updates from Steven Rostedt:
 "Add ring_buffer memory mappings.

  The tracing ring buffer was created based on being mostly used with
  the splice system call. It is broken up into page ordered sub-buffers
  and the reader swaps a new sub-buffer with an existing sub-buffer
  that's part of the write buffer. It then has total access to the
  swapped out sub-buffer and can do copyless movements of the memory
  into other mediums (file system, network, etc).

  The buffer is great for passing around the ring buffer contents in the
  kernel, but is not so good for when the consumer is the user space
  task itself.

  A new interface is added that allows user space to memory map the ring
  buffer. It will get all the write sub-buffers as well as reader
  sub-buffer (that is not written to). It can send an ioctl to change
  which sub-buffer is the new reader sub-buffer.

  The ring buffer is read only to user space. It only needs to call the
  ioctl when it is finished with a sub-buffer and needs a new sub-buffer
  that the writer will not write over.

  A self test program was also created for testing and can be used as an
  example for the interface to user space. The libtracefs (external to
  the kernel) also has code that interacts with this, although it is
  disabled until the interface is in a official release. It can be
  enabled by compiling the library with a special flag. This was used
  for testing applications that perform better with the buffer being
  mapped.

  Memory mapped buffers have limitations. The main one is that it can
  not be used with the snapshot logic. If the buffer is mapped,
  snapshots will be disabled. If any logic is set to trigger snapshots
  on a buffer, that buffer will not be allowed to be mapped"

* tag 'trace-ringbuffer-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Add cast to unsigned long addr passed to virt_to_page()
  ring-buffer: Have mmapped ring buffer keep track of missed events
  ring-buffer/selftest: Add ring-buffer mapping test
  Documentation: tracing: Add ring-buffer mapping
  tracing: Allow user-space mapping of the ring-buffer
  ring-buffer: Introducing ring-buffer mapping functions
  ring-buffer: Allocate sub-buffers with __GFP_COMP
2024-05-17 18:40:37 -07:00
Linus Torvalds
594d28157f tracing cleanups for v6.10:
- Removed unused ftrace_direct_funcs variables
 
 - Fix a possible NULL pointer dereference race in eventfs
 
 - Update do_div() usage in trace event benchmark test
 
 - Speedup direct function registration with asynchronous RCU callback.
   The synchronization was done in the registration code and this
   caused delays when registering direct callbacks. Move the freeing
   to a call_rcu() that will prevent delaying of the registering.
 
 - Replace simple_strtoul() usage with kstrtoul()
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Merge tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Remove unused ftrace_direct_funcs variables

 - Fix a possible NULL pointer dereference race in eventfs

 - Update do_div() usage in trace event benchmark test

 - Speedup direct function registration with asynchronous RCU callback.

   The synchronization was done in the registration code and this caused
   delays when registering direct callbacks. Move the freeing to a
   call_rcu() that will prevent delaying of the registering.

 - Replace simple_strtoul() usage with kstrtoul()

* tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix a possible null pointer dereference in eventfs_find_events()
  ftrace: Fix possible use-after-free issue in ftrace_location()
  ftrace: Remove unused global 'ftrace_direct_func_count'
  ftrace: Remove unused list 'ftrace_direct_funcs'
  tracing: Improve benchmark test performance by using do_div()
  ftrace: Use asynchronous grace period for register_ftrace_direct()
  ftrace: Replaces simple_strtoul in ftrace
2024-05-17 18:34:27 -07:00
Linus Torvalds
70a663205d Probes updates for v6.10:
- tracing/probes: Adding new pseudo-types %pd and %pD support for dumping
   dentry name from 'struct dentry *' and file name from 'struct file *'.
 
 - uprobes: Some performance optimizations have been done.
  . Speed up the BPF uprobe event by delaying the fetching of the uprobe
    event arguments that are not used in BPF.
  . Avoid locking by speculatively checking whether uprobe event is valid.
  . Reduce lock contention by using read/write_lock instead of spinlock for
    uprobe list operation. This improved BPF uprobe benchmark result 43% on
    average.
 
 - rethook: Removes non-fatal warning messages when tracing stack from BPF
   and skip rcu_is_watching() validation in rethook if possible.
 
 - objpool: Optimizing objpool (which is used by kretprobes and fprobe as
   rethook backend storage) by inlining functions and avoid caching nr_cpu_ids
   because it is a const value.
 
 - fprobe: Add entry/exit callbacks types (code cleanup)
 - kprobes: Check ftrace was killed in kprobes if it uses ftrace.
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Merge tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:

 - tracing/probes: Add new pseudo-types %pd and %pD support for dumping
   dentry name from 'struct dentry *' and file name from 'struct file *'

 - uprobes performance optimizations:
    - Speed up the BPF uprobe event by delaying the fetching of the
      uprobe event arguments that are not used in BPF
    - Avoid locking by speculatively checking whether uprobe event is
      valid
    - Reduce lock contention by using read/write_lock instead of
      spinlock for uprobe list operation. This improved BPF uprobe
      benchmark result 43% on average

 - rethook: Remove non-fatal warning messages when tracing stack from
   BPF and skip rcu_is_watching() validation in rethook if possible

 - objpool: Optimize objpool (which is used by kretprobes and fprobe as
   rethook backend storage) by inlining functions and avoid caching
   nr_cpu_ids because it is a const value

 - fprobe: Add entry/exit callbacks types (code cleanup)

 - kprobes: Check ftrace was killed in kprobes if it uses ftrace

* tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobe/ftrace: bail out if ftrace was killed
  selftests/ftrace: Fix required features for VFS type test case
  objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids
  objpool: enable inlining objpool_push() and objpool_pop() operations
  rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get()
  ftrace: make extra rcu_is_watching() validation check optional
  uprobes: reduce contention on uprobes_tree access
  rethook: Remove warning messages printed for finding return address of a frame.
  fprobe: Add entry/exit callbacks types
  selftests/ftrace: add fprobe test cases for VFS type "%pd" and "%pD"
  selftests/ftrace: add kprobe test cases for VFS type "%pd" and "%pD"
  Documentation: tracing: add new type '%pd' and '%pD' for kprobe
  tracing/probes: support '%pD' type for print struct file's name
  tracing/probes: support '%pd' type for print struct dentry's name
  uprobes: add speculative lockless system-wide uprobe filter check
  uprobes: prepare uprobe args buffer lazily
  uprobes: encapsulate preparation of uprobe args buffer
2024-05-17 18:29:30 -07:00
Linus Torvalds
91b6163be4 sysctl changes for v6.10-rc1
Summary
 * Removed sentinel elements from ctl_table structs in kernel/*
 
   Removing sentinels in ctl_table arrays reduces the build time size and
   runtime memory consumed by ~64 bytes per array. Removals for net/, io_uring/,
   mm/, ipc/ and security/ are set to go into mainline through their respective
   subsystems making the next release the most likely place where the final
   series that removes the check for proc_name == NULL will land. This PR adds
   to removals already in arch/, drivers/ and fs/.
 
 * Adjusted ctl_table definitions and references to allow constification
 
   Adjustments:
     - Removing unused ctl_table function arguments
     - Moving non-const elements from ctl_table to ctl_table_header
     - Making ctl_table pointers const in ctl_table_root structure
 
   Making the static ctl_table structs const will increase safety by keeping the
   pointers to proc_handler functions in .rodata. Though no ctl_tables where
   made const in this PR, the ground work for making that possible has started
   with these changes sent by Thomas Weißschuh.
 
 Testing
 * These changes went into linux-next after v6.9-rc4; giving it a good month of
   testing.
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Merge tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove sentinel elements from ctl_table structs in kernel/*

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. Removals for
   net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline
   through their respective subsystems making the next release the most
   likely place where the final series that removes the check for
   proc_name == NULL will land.

   This adds to removals already in arch/, drivers/ and fs/.

 - Adjust ctl_table definitions and references to allow constification
     - Remove unused ctl_table function arguments
     - Move non-const elements from ctl_table to ctl_table_header
     - Make ctl_table pointers const in ctl_table_root structure

   Making the static ctl_table structs const will increase safety by
   keeping the pointers to proc_handler functions in .rodata. Though no
   ctl_tables where made const in this PR, the ground work for making
   that possible has started with these changes sent by Thomas
   Weißschuh.

* tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: drop now unnecessary out-of-bounds check
  sysctl: move sysctl type to ctl_table_header
  sysctl: drop sysctl_is_perm_empty_ctl_table
  sysctl: treewide: constify argument ctl_table_root::permissions(table)
  sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
  bpf: Remove the now superfluous sentinel elements from ctl_table array
  delayacct: Remove the now superfluous sentinel elements from ctl_table array
  kprobes: Remove the now superfluous sentinel elements from ctl_table array
  printk: Remove the now superfluous sentinel elements from ctl_table array
  scheduler: Remove the now superfluous sentinel elements from ctl_table array
  seccomp: Remove the now superfluous sentinel elements from ctl_table array
  timekeeping: Remove the now superfluous sentinel elements from ctl_table array
  ftrace: Remove the now superfluous sentinel elements from ctl_table array
  umh: Remove the now superfluous sentinel elements from ctl_table array
  kernel misc: Remove the now superfluous sentinel elements from ctl_table array
2024-05-17 17:31:24 -07:00
Stephen Brennan
1a7d0890dd kprobe/ftrace: bail out if ftrace was killed
If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.

This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:

[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer

  sudo perf probe --add commit_creds
  sudo perf trace -e probe:commit_creds
  # In another terminal
  make
  sudo insmod ftrace_killer.ko  # calls ftrace_kill(), simulating bug
  # Back to perf terminal
  # ctrl-c
  sudo perf probe --del commit_creds

After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.

Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-16 07:23:30 +09:00
Linus Torvalds
a49468240e Modules changes for v6.10-rc1
Finally something fun. Mike Rapoport does some cleanup to allow us to
 take out module_alloc() out of modules into a new paint shedded execmem_alloc()
 and execmem_free() so to make emphasis these helpers are actually used outside
 of modules. It starts with a no-functional changes API rename / placeholders
 to then allow architectures to define their requirements into a new shiny
 struct execmem_info with ranges, and requirements for those ranges. Archs
 now can intitialize this execmem_info as the last part of mm_core_init() if
 they have to diverge from the norm. Each range is a known type clearly
 articulated and spelled out in enum execmem_type.
 
 Although a lot of this is major cleanup and prep work for future enhancements an
 immediate clear gain is we get to enable KPROBES without MODULES now. That is
 ultimately what motiviated to pick this work up again, now with smaller goal as
 concrete stepping stone.
 
 This has been sitting on linux-next for a little less than a month, a few issues
 were found already and fixed, in particular an odd mips boot issue. Arch folks
 reviewed the code too. This is ready for wider exposure and testing.
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Merge tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from Luis Chamberlain:
 "Finally something fun. Mike Rapoport does some cleanup to allow us to
  take out module_alloc() out of modules into a new paint shedded
  execmem_alloc() and execmem_free() so to make emphasis these helpers
  are actually used outside of modules.

  It starts with a non-functional changes API rename / placeholders to
  then allow architectures to define their requirements into a new shiny
  struct execmem_info with ranges, and requirements for those ranges.

  Archs now can intitialize this execmem_info as the last part of
  mm_core_init() if they have to diverge from the norm. Each range is a
  known type clearly articulated and spelled out in enum execmem_type.

  Although a lot of this is major cleanup and prep work for future
  enhancements an immediate clear gain is we get to enable KPROBES
  without MODULES now. That is ultimately what motiviated to pick this
  work up again, now with smaller goal as concrete stepping stone"

* tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of
  kprobes: remove dependency on CONFIG_MODULES
  powerpc: use CONFIG_EXECMEM instead of CONFIG_MODULES where appropriate
  x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
  arch: make execmem setup available regardless of CONFIG_MODULES
  powerpc: extend execmem_params for kprobes allocations
  arm64: extend execmem_info for generated code allocations
  riscv: extend execmem_params for generated code allocations
  mm/execmem, arch: convert remaining overrides of module_alloc to execmem
  mm/execmem, arch: convert simple overrides of module_alloc to execmem
  mm: introduce execmem_alloc() and execmem_free()
  module: make module_memory_{alloc,free} more self-contained
  sparc: simplify module_alloc()
  nios2: define virtual address space for modules
  mips: module: rename MODULE_START to MODULES_VADDR
  arm64: module: remove unneeded call to kasan_alloc_module_shadow()
  kallsyms: replace deprecated strncpy with strscpy
  module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.
2024-05-15 14:05:08 -07:00
Steven Rostedt (Google)
b9c6820f02 ring-buffer: Add cast to unsigned long addr passed to virt_to_page()
The sub-buffer pages are held in an unsigned long array, and when it is
passed to virt_to_page() a cast is needed.

Link: https://lore.kernel.org/all/20240515124808.06279d04@canb.auug.org.au/
Link: https://lore.kernel.org/linux-trace-kernel/20240515010558.4abaefdd@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-15 01:28:42 -04:00
Linus Torvalds
1b294a1f35 Networking changes for 6.10.
Core & protocols
 ----------------
 
  - Complete rework of garbage collection of AF_UNIX sockets.
    AF_UNIX is prone to forming reference count cycles due to fd passing
    functionality. New method based on Tarjan's Strongly Connected Components
    algorithm should be both faster and remove a lot of workarounds
    we accumulated over the years.
 
  - Add TCP fraglist GRO support, allowing chaining multiple TCP packets
    and forwarding them together. Useful for small switches / routers which
    lack basic checksum offload in some scenarios (e.g. PPPoE).
 
  - Support using SMP threads for handling packet backlog i.e. packet
    processing from software interfaces and old drivers which don't
    use NAPI. This helps move the processing out of the softirq jumble.
 
  - Continue work of converting from rtnl lock to RCU protection.
    Don't require rtnl lock when reading: IPv6 routing FIB, IPv6 address
    labels, netdev threaded NAPI sysfs files, bonding driver's sysfs files,
    MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics, TC Qdiscs,
    neighbor entries, ARP entries via ioctl(SIOCGARP), a lot of the link
    information available via rtnetlink.
 
  - Small optimizations from Eric to UDP wake up handling, memory accounting,
    RPS/RFS implementation, TCP packet sizing etc.
 
  - Allow direct page recycling in the bulk API used by XDP, for +2% PPS.
 
  - Support peek with an offset on TCP sockets.
 
  - Add MPTCP APIs for querying last time packets were received/sent/acked,
    and whether MPTCP "upgrade" succeeded on a TCP socket.
 
  - Add intra-node communication shortcut to improve SMC performance.
 
  - Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol driver.
 
  - Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.
 
  - Add reset reasons for tracing what caused a TCP reset to be sent.
 
  - Introduce direction attribute for xfrm (IPSec) states.
    State can be used either for input or output packet processing.
 
 Things we sprinkled into general kernel code
 --------------------------------------------
 
  - Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().
    This required touch-ups and renaming of a few existing users.
 
  - Add Endian-dependent __counted_by_{le,be} annotations.
 
  - Make building selftests "quieter" by printing summaries like
    "CC object.o" rather than full commands with all the arguments.
 
 Netfilter
 ---------
 
  - Use GFP_KERNEL to clone elements, to deal better with OOM situations
    and avoid failures in the .commit step.
 
 BPF
 ---
 
  - Add eBPF JIT for ARCv2 CPUs.
 
  - Support attaching kprobe BPF programs through kprobe_multi link in
    a session mode, meaning, a BPF program is attached to both function entry
    and return, the entry program can decide if the return program gets
    executed and the entry program can share u64 cookie value with return
    program. "Session mode" is a common use-case for tetragon and bpftrace.
 
  - Add the ability to specify and retrieve BPF cookie for raw tracepoint
    programs in order to ease migration from classic to raw tracepoints.
 
  - Add an internal-only BPF per-CPU instruction for resolving per-CPU
    memory addresses and implement support in x86, ARM64 and RISC-V JITs.
    This allows inlining functions which need to access per-CPU state.
 
  - Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
    atomics in bpf_arena which can be JITed as a single x86 instruction.
    Support BPF arena on ARM64.
 
  - Add a new bpf_wq API for deferring events and refactor process-context
    bpf_timer code to keep common code where possible.
 
  - Harden the BPF verifier's and/or/xor value tracking.
 
  - Introduce crypto kfuncs to let BPF programs call kernel crypto APIs.
 
  - Support bpf_tail_call_static() helper for BPF programs with GCC 13.
 
  - Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled.
 
 Driver API
 ----------
 
  - Skip software TC processing completely if all installed rules are
    marked as HW-only, instead of checking the HW-only flag rule by rule.
 
  - Add support for configuring PoE (Power over Ethernet), similar to
    the already existing support for PoDL (Power over Data Line) config.
 
  - Initial bits of a queue control API, for now allowing a single queue
    to be reset without disturbing packet flow to other queues.
 
  - Common (ethtool) statistics for hardware timestamping.
 
 Tests and tooling
 -----------------
 
  - Remove the need to create a config file to run the net forwarding tests
    so that a naive "make run_tests" can exercise them.
 
  - Define a method of writing tests which require an external endpoint
    to communicate with (to send/receive data towards the test machine).
    Add a few such tests.
 
  - Create a shared code library for writing Python tests. Expose the YAML
    Netlink library from tools/ to the tests for easy Netlink access.
 
  - Move netfilter tests under net/, extend them, separate performance tests
    from correctness tests, and iron out issues found by running them
    "on every commit".
 
  - Refactor BPF selftests to use common network helpers.
 
  - Further work filling in YAML definitions of Netlink messages for:
    nftables, team driver, bonding interfaces, vlan interfaces, VF info,
    TC u32 mark, TC police action.
 
  - Teach Python YAML Netlink to decode attribute policies.
 
  - Extend the definition of the "indexed array" construct in the specs
    to cover arrays of scalars rather than just nests.
 
  - Add hyperlinks between definitions in generated Netlink docs.
 
 Drivers
 -------
 
  - Make sure unsupported flower control flags are rejected by drivers,
    and make more drivers report errors directly to the application rather
    than dmesg (large number of driver changes from Asbjørn Sloth Tønnesen).
 
  - Ethernet high-speed NICs:
    - Broadcom (bnxt):
      - support multiple RSS contexts and steering traffic to them
      - support XDP metadata
      - make page pool allocations more NUMA aware
    - Intel (100G, ice, idpf):
      - extract datapath code common among Intel drivers into a library
      - use fewer resources in switchdev by sharing queues with the PF
      - add PFCP filter support
      - add Ethernet filter support
      - use a spinlock instead of HW lock in PTP clock ops
      - support 5 layer Tx scheduler topology
    - nVidia/Mellanox:
      - 800G link modes and 100G SerDes speeds
      - per-queue IRQ coalescing configuration
    - Marvell Octeon:
      - support offloading TC packet mark action
 
  - Ethernet NICs consumer, embedded and virtual:
    - stop lying about skb->truesize in USB Ethernet drivers, it messes up
      TCP memory calculations
    - Google cloud vNIC:
      - support changing ring size via ethtool
      - support ring reset using the queue control API
    - VirtIO net:
      - expose flow hash from RSS to XDP
      - per-queue statistics
      - add selftests
    - Synopsys (stmmac):
      - support controllers which require an RX clock signal from the MII
        bus to perform their hardware initialization
    - TI:
      - icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
      - icssg_prueth: add SW TX / RX Coalescing based on hrtimers
      - cpsw: minimal XDP support
    - Renesas (ravb):
      - support describing the MDIO bus
    - Realtek (r8169):
      - add support for RTL8168M
    - Microchip Sparx5:
      - matchall and flower actions mirred and redirect
 
  - Ethernet switches:
    - nVidia/Mellanox:
      - improve events processing performance
    - Marvell:
      - add support for MV88E6250 family internal PHYs
    - Microchip:
      - add DCB and DSCP mapping support for KSZ switches
      - vsc73xx: convert to PHYLINK
    - Realtek:
      - rtl8226b/rtl8221b: add C45 instances and SerDes switching
 
  - Many driver changes related to PHYLIB and PHYLINK deprecated API cleanup.
 
  - Ethernet PHYs:
    - Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
    - micrel: lan8814: add support for PPS out and external timestamp trigger
 
  - WiFi:
    - Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices drivers.
      Modern devices can only be configured using nl80211.
    - mac80211/cfg80211
      - handle color change per link for WiFi 7 Multi-Link Operation
    - Intel (iwlwifi):
      - don't support puncturing in 5 GHz
      - support monitor mode on passive channels
      - BZ-W device support
      - P2P with HE/EHT support
      - re-add support for firmware API 90
      - provide channel survey information for Automatic Channel Selection
    - MediaTek (mt76):
      - mt7921 LED control
      - mt7925 EHT radiotap support
      - mt7920e PCI support
    - Qualcomm (ath11k):
      - P2P support for QCA6390, WCN6855 and QCA2066
      - support hibernation
      - ieee80211-freq-limit Device Tree property support
    - Qualcomm (ath12k):
      - refactoring in preparation of multi-link support
      - suspend and hibernation support
      - ACPI support
      - debugfs support, including dfs_simulate_radar support
    - RealTek:
      - rtw88: RTL8723CS SDIO device support
      - rtw89: RTL8922AE Wi-Fi 7 PCI device support
      - rtw89: complete features of new WiFi 7 chip 8922AE including
        BT-coexistence and Wake-on-WLAN
      - rtw89: use BIOS ACPI settings to set TX power and channels
      - rtl8xxxu: enable Management Frame Protection (MFP) support
 
  - Bluetooth:
    - support for Intel BlazarI and Filmore Peak2 (BE201)
    - support for MediaTek MT7921S SDIO
    - initial support for Intel PCIe BT driver
    - remove HCI_AMP support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Complete rework of garbage collection of AF_UNIX sockets.

     AF_UNIX is prone to forming reference count cycles due to fd
     passing functionality. New method based on Tarjan's Strongly
     Connected Components algorithm should be both faster and remove a
     lot of workarounds we accumulated over the years.

   - Add TCP fraglist GRO support, allowing chaining multiple TCP
     packets and forwarding them together. Useful for small switches /
     routers which lack basic checksum offload in some scenarios (e.g.
     PPPoE).

   - Support using SMP threads for handling packet backlog i.e. packet
     processing from software interfaces and old drivers which don't use
     NAPI. This helps move the processing out of the softirq jumble.

   - Continue work of converting from rtnl lock to RCU protection.

     Don't require rtnl lock when reading: IPv6 routing FIB, IPv6
     address labels, netdev threaded NAPI sysfs files, bonding driver's
     sysfs files, MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics,
     TC Qdiscs, neighbor entries, ARP entries via ioctl(SIOCGARP), a lot
     of the link information available via rtnetlink.

   - Small optimizations from Eric to UDP wake up handling, memory
     accounting, RPS/RFS implementation, TCP packet sizing etc.

   - Allow direct page recycling in the bulk API used by XDP, for +2%
     PPS.

   - Support peek with an offset on TCP sockets.

   - Add MPTCP APIs for querying last time packets were received/sent/acked
     and whether MPTCP "upgrade" succeeded on a TCP socket.

   - Add intra-node communication shortcut to improve SMC performance.

   - Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol
     driver.

   - Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.

   - Add reset reasons for tracing what caused a TCP reset to be sent.

   - Introduce direction attribute for xfrm (IPSec) states. State can be
     used either for input or output packet processing.

  Things we sprinkled into general kernel code:

   - Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().

     This required touch-ups and renaming of a few existing users.

   - Add Endian-dependent __counted_by_{le,be} annotations.

   - Make building selftests "quieter" by printing summaries like
     "CC object.o" rather than full commands with all the arguments.

  Netfilter:

   - Use GFP_KERNEL to clone elements, to deal better with OOM
     situations and avoid failures in the .commit step.

  BPF:

   - Add eBPF JIT for ARCv2 CPUs.

   - Support attaching kprobe BPF programs through kprobe_multi link in
     a session mode, meaning, a BPF program is attached to both function
     entry and return, the entry program can decide if the return
     program gets executed and the entry program can share u64 cookie
     value with return program. "Session mode" is a common use-case for
     tetragon and bpftrace.

   - Add the ability to specify and retrieve BPF cookie for raw
     tracepoint programs in order to ease migration from classic to raw
     tracepoints.

   - Add an internal-only BPF per-CPU instruction for resolving per-CPU
     memory addresses and implement support in x86, ARM64 and RISC-V
     JITs. This allows inlining functions which need to access per-CPU
     state.

   - Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
     atomics in bpf_arena which can be JITed as a single x86
     instruction. Support BPF arena on ARM64.

   - Add a new bpf_wq API for deferring events and refactor
     process-context bpf_timer code to keep common code where possible.

   - Harden the BPF verifier's and/or/xor value tracking.

   - Introduce crypto kfuncs to let BPF programs call kernel crypto
     APIs.

   - Support bpf_tail_call_static() helper for BPF programs with GCC 13.

   - Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
     program to have code sections where preemption is disabled.

  Driver API:

   - Skip software TC processing completely if all installed rules are
     marked as HW-only, instead of checking the HW-only flag rule by
     rule.

   - Add support for configuring PoE (Power over Ethernet), similar to
     the already existing support for PoDL (Power over Data Line)
     config.

   - Initial bits of a queue control API, for now allowing a single
     queue to be reset without disturbing packet flow to other queues.

   - Common (ethtool) statistics for hardware timestamping.

  Tests and tooling:

   - Remove the need to create a config file to run the net forwarding
     tests so that a naive "make run_tests" can exercise them.

   - Define a method of writing tests which require an external endpoint
     to communicate with (to send/receive data towards the test
     machine). Add a few such tests.

   - Create a shared code library for writing Python tests. Expose the
     YAML Netlink library from tools/ to the tests for easy Netlink
     access.

   - Move netfilter tests under net/, extend them, separate performance
     tests from correctness tests, and iron out issues found by running
     them "on every commit".

   - Refactor BPF selftests to use common network helpers.

   - Further work filling in YAML definitions of Netlink messages for:
     nftables, team driver, bonding interfaces, vlan interfaces, VF
     info, TC u32 mark, TC police action.

   - Teach Python YAML Netlink to decode attribute policies.

   - Extend the definition of the "indexed array" construct in the specs
     to cover arrays of scalars rather than just nests.

   - Add hyperlinks between definitions in generated Netlink docs.

  Drivers:

   - Make sure unsupported flower control flags are rejected by drivers,
     and make more drivers report errors directly to the application
     rather than dmesg (large number of driver changes from Asbjørn
     Sloth Tønnesen).

   - Ethernet high-speed NICs:
      - Broadcom (bnxt):
         - support multiple RSS contexts and steering traffic to them
         - support XDP metadata
         - make page pool allocations more NUMA aware
      - Intel (100G, ice, idpf):
         - extract datapath code common among Intel drivers into a library
         - use fewer resources in switchdev by sharing queues with the PF
         - add PFCP filter support
         - add Ethernet filter support
         - use a spinlock instead of HW lock in PTP clock ops
         - support 5 layer Tx scheduler topology
      - nVidia/Mellanox:
         - 800G link modes and 100G SerDes speeds
         - per-queue IRQ coalescing configuration
      - Marvell Octeon:
         - support offloading TC packet mark action

   - Ethernet NICs consumer, embedded and virtual:
      - stop lying about skb->truesize in USB Ethernet drivers, it
        messes up TCP memory calculations
      - Google cloud vNIC:
         - support changing ring size via ethtool
         - support ring reset using the queue control API
      - VirtIO net:
         - expose flow hash from RSS to XDP
         - per-queue statistics
         - add selftests
      - Synopsys (stmmac):
         - support controllers which require an RX clock signal from the
           MII bus to perform their hardware initialization
      - TI:
         - icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
         - icssg_prueth: add SW TX / RX Coalescing based on hrtimers
         - cpsw: minimal XDP support
      - Renesas (ravb):
         - support describing the MDIO bus
      - Realtek (r8169):
         - add support for RTL8168M
      - Microchip Sparx5:
         - matchall and flower actions mirred and redirect

   - Ethernet switches:
      - nVidia/Mellanox:
         - improve events processing performance
      - Marvell:
         - add support for MV88E6250 family internal PHYs
      - Microchip:
         - add DCB and DSCP mapping support for KSZ switches
         - vsc73xx: convert to PHYLINK
      - Realtek:
         - rtl8226b/rtl8221b: add C45 instances and SerDes switching

   - Many driver changes related to PHYLIB and PHYLINK deprecated API
     cleanup

   - Ethernet PHYs:
      - Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
      - micrel: lan8814: add support for PPS out and external timestamp trigger

   - WiFi:
      - Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices
        drivers. Modern devices can only be configured using nl80211.
      - mac80211/cfg80211
         - handle color change per link for WiFi 7 Multi-Link Operation
      - Intel (iwlwifi):
         - don't support puncturing in 5 GHz
         - support monitor mode on passive channels
         - BZ-W device support
         - P2P with HE/EHT support
         - re-add support for firmware API 90
         - provide channel survey information for Automatic Channel Selection
      - MediaTek (mt76):
         - mt7921 LED control
         - mt7925 EHT radiotap support
         - mt7920e PCI support
      - Qualcomm (ath11k):
         - P2P support for QCA6390, WCN6855 and QCA2066
         - support hibernation
         - ieee80211-freq-limit Device Tree property support
      - Qualcomm (ath12k):
         - refactoring in preparation of multi-link support
         - suspend and hibernation support
         - ACPI support
         - debugfs support, including dfs_simulate_radar support
      - RealTek:
         - rtw88: RTL8723CS SDIO device support
         - rtw89: RTL8922AE Wi-Fi 7 PCI device support
         - rtw89: complete features of new WiFi 7 chip 8922AE including
           BT-coexistence and Wake-on-WLAN
         - rtw89: use BIOS ACPI settings to set TX power and channels
         - rtl8xxxu: enable Management Frame Protection (MFP) support

   - Bluetooth:
      - support for Intel BlazarI and Filmore Peak2 (BE201)
      - support for MediaTek MT7921S SDIO
      - initial support for Intel PCIe BT driver
      - remove HCI_AMP support"

* tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1827 commits)
  selftests: netfilter: fix packetdrill conntrack testcase
  net: gro: fix napi_gro_cb zeroed alignment
  Bluetooth: btintel_pcie: Refactor and code cleanup
  Bluetooth: btintel_pcie: Fix warning reported by sparse
  Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1
  Bluetooth: btintel: Fix compiler warning for multi_v7_defconfig config
  Bluetooth: btintel_pcie: Fix compiler warnings
  Bluetooth: btintel_pcie: Add *setup* function to download firmware
  Bluetooth: btintel_pcie: Add support for PCIe transport
  Bluetooth: btintel: Export few static functions
  Bluetooth: HCI: Remove HCI_AMP support
  Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
  Bluetooth: qca: Fix error code in qca_read_fw_build_info()
  Bluetooth: hci_conn: Use __counted_by() and avoid -Wfamnae warning
  Bluetooth: btintel: Add support for Filmore Peak2 (BE201)
  Bluetooth: btintel: Add support for BlazarI
  LE Create Connection command timeout increased to 20 secs
  dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth
  Bluetooth: compute LE flow credits based on recvbuf space
  Bluetooth: hci_sync: Use cmd->num_cis instead of magic number
  ...
2024-05-14 19:42:24 -07:00
Zheng Yejian
e60b613df8 ftrace: Fix possible use-after-free issue in ftrace_location()
KASAN reports a bug:

  BUG: KASAN: use-after-free in ftrace_location+0x90/0x120
  Read of size 8 at addr ffff888141d40010 by task insmod/424
  CPU: 8 PID: 424 Comm: insmod Tainted: G        W          6.9.0-rc2+
  [...]
  Call Trace:
   <TASK>
   dump_stack_lvl+0x68/0xa0
   print_report+0xcf/0x610
   kasan_report+0xb5/0xe0
   ftrace_location+0x90/0x120
   register_kprobe+0x14b/0xa40
   kprobe_init+0x2d/0xff0 [kprobe_example]
   do_one_initcall+0x8f/0x2d0
   do_init_module+0x13a/0x3c0
   load_module+0x3082/0x33d0
   init_module_from_file+0xd2/0x130
   __x64_sys_finit_module+0x306/0x440
   do_syscall_64+0x68/0x140
   entry_SYSCALL_64_after_hwframe+0x71/0x79

The root cause is that, in lookup_rec(), ftrace record of some address
is being searched in ftrace pages of some module, but those ftrace pages
at the same time is being freed in ftrace_release_mod() as the
corresponding module is being deleted:

           CPU1                       |      CPU2
  register_kprobes() {                | delete_module() {
    check_kprobe_address_safe() {     |
      arch_check_ftrace_location() {  |
        ftrace_location() {           |
          lookup_rec() // USE!        |   ftrace_release_mod() // Free!

To fix this issue:
  1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();
  2. Use ftrace_location_range() instead of lookup_rec() in
     ftrace_location();
  3. Call synchronize_rcu() before freeing any ftrace pages both in
     ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().

Link: https://lore.kernel.org/linux-trace-kernel/20240509192859.1273558-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mathieu.desnoyers@efficios.com>
Fixes: ae6aa16fdc ("kprobes: introduce ftrace based optimization")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-14 11:13:27 -04:00
Mike Rapoport (IBM)
7582b7be16 kprobes: remove dependency on CONFIG_MODULES
kprobes depended on CONFIG_MODULES because it has to allocate memory for
code.

Since code allocations are now implemented with execmem, kprobes can be
enabled in non-modular kernels.

Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside
modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the
dependency of CONFIG_KPROBES on CONFIG_MODULES.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
[mcgrof: rebase in light of NEED_TASKS_RCU ]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14 00:35:06 -07:00
Dr. David Alan Gilbert
d2cc859cc8 ftrace: Remove unused global 'ftrace_direct_func_count'
Commit 8788ca164e ("ftrace: Remove the legacy _ftrace_direct API")
stopped setting the 'ftrace_direct_func_count' variable, but left
it around.  Clean it up.

Link: https://lore.kernel.org/linux-trace-kernel/20240506233305.215735-1-linux@treblig.org

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-14 02:09:40 -04:00
Dr. David Alan Gilbert
c9d5b7b826 ftrace: Remove unused list 'ftrace_direct_funcs'
Commit 8788ca164e ("ftrace: Remove the legacy _ftrace_direct API")
stopped using 'ftrace_direct_funcs' (and the associated
struct ftrace_direct_func).  Remove them.

Build tested only (on x86-64 with FTRACE and DYNAMIC_FTRACE
enabled)

Link: https://lore.kernel.org/linux-trace-kernel/20240504132303.67538-1-linux@treblig.org

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-14 02:09:00 -04:00
Thorsten Blum
347bd7f072 tracing: Improve benchmark test performance by using do_div()
Partially revert commit d6cb38e108 ("tracing: Use div64_u64() instead
of do_div()") and use do_div() again to utilize its faster 64-by-32
division compared to the 64-by-64 division done by div64_u64().

Explicitly cast the divisor bm_cnt to u32 to prevent a Coccinelle
warning reported by do_div.cocci. The warning was removed with commit
d6cb38e108 ("tracing: Use div64_u64() instead of do_div()").

Using the faster 64-by-32 division and casting bm_cnt to u32 is safe
because we return early from trace_do_benchmark() if bm_cnt > UINT_MAX.
This approach is already used twice in trace_do_benchmark() when
calculating the standard deviation:

	do_div(stddev, (u32)bm_cnt);
	do_div(stddev, (u32)bm_cnt - 1);

Link: https://lore.kernel.org/linux-trace-kernel/20240329160229.4874-2-thorsten.blum@toblux.com

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 20:00:57 -04:00
Steven Rostedt (Google)
fe832be05a ring-buffer: Have mmapped ring buffer keep track of missed events
While testing libtracefs on the mmapped ring buffer, the test that checks
if missed events are accounted for failed when using the mapped buffer.
This is because the mapped page does not update the missed events that
were dropped because the writer filled up the ring buffer before the
reader could catch it.

Add the missed events to the reader page/sub-buffer when the IOCTL is done
and a new reader page is acquired.

Note that all accesses to the reader_page via rb_page_commit() had to be
switched to rb_page_size(), and rb_page_size() which was just a copy of
rb_page_commit() but now it masks out the RB_MISSED bits. This is needed
as the mapped reader page is still active in the ring buffer code and
where it reads the commit field of the bpage for the size, it now must
mask it otherwise the missed bits that are now set will corrupt the size
returned.

Link: https://lore.kernel.org/linux-trace-kernel/20240312175405.12fb6726@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 19:55:22 -04:00
Jakub Kicinski
6e62702feb bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-05-13

We've added 119 non-merge commits during the last 14 day(s) which contain
a total of 134 files changed, 9462 insertions(+), 4742 deletions(-).

The main changes are:

1) Add BPF JIT support for 32-bit ARCv2 processors, from Shahab Vahedi.

2) Add BPF range computation improvements to the verifier in particular
   around XOR and OR operators, refactoring of checks for range computation
   and relaxing MUL range computation so that src_reg can also be an unknown
   scalar, from Cupertino Miranda.

3) Add support to attach kprobe BPF programs through kprobe_multi link in
   a session mode, meaning, a BPF program is attached to both function entry
   and return, the entry program can decide if the return program gets
   executed and the entry program can share u64 cookie value with return
   program. Session mode is a common use-case for tetragon and bpftrace,
   from Jiri Olsa.

4) Fix a potential overflow in libbpf's ring__consume_n() and improve libbpf
   as well as BPF selftest's struct_ops handling, from Andrii Nakryiko.

5) Improvements to BPF selftests in context of BPF gcc backend,
   from Jose E. Marchesi & David Faust.

6) Migrate remaining BPF selftest tests from test_sock_addr.c to prog_test-
   -style in order to retire the old test, run it in BPF CI and additionally
   expand test coverage, from Jordan Rife.

7) Big batch for BPF selftest refactoring in order to remove duplicate code
   around common network helpers, from Geliang Tang.

8) Another batch of improvements to BPF selftests to retire obsolete
   bpf_tcp_helpers.h as everything is available vmlinux.h,
   from Martin KaFai Lau.

9) Fix BPF map tear-down to not walk the map twice on free when both timer
   and wq is used, from Benjamin Tissoires.

10) Fix BPF verifier assumptions about socket->sk that it can be non-NULL,
    from Alexei Starovoitov.

11) Change BTF build scripts to using --btf_features for pahole v1.26+,
    from Alan Maguire.

12) Small improvements to BPF reusing struct_size() and krealloc_array(),
    from Andy Shevchenko.

13) Fix s390 JIT to emit a barrier for BPF_FETCH instructions,
    from Ilya Leoshkevich.

14) Extend TCP ->cong_control() callback in order to feed in ack and
    flag parameters and allow write-access to tp->snd_cwnd_stamp
    from BPF program, from Miao Xu.

15) Add support for internal-only per-CPU instructions to inline
    bpf_get_smp_processor_id() helper call for arm64 and riscv64 BPF JITs,
    from Puranjay Mohan.

16) Follow-up to remove the redundant ethtool.h from tooling infrastructure,
    from Tushar Vyavahare.

17) Extend libbpf to support "module:<function>" syntax for tracing
    programs, from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  bpf: make list_for_each_entry portable
  bpf: ignore expected GCC warning in test_global_func10.c
  bpf: disable strict aliasing in test_global_func9.c
  selftests/bpf: Free strdup memory in xdp_hw_metadata
  selftests/bpf: Fix a few tests for GCC related warnings.
  bpf: avoid gcc overflow warning in test_xdp_vlan.c
  tools: remove redundant ethtool.h from tooling infra
  selftests/bpf: Expand ATTACH_REJECT tests
  selftests/bpf: Expand getsockname and getpeername tests
  sefltests/bpf: Expand sockaddr hook deny tests
  selftests/bpf: Expand sockaddr program return value tests
  selftests/bpf: Retire test_sock_addr.(c|sh)
  selftests/bpf: Remove redundant sendmsg test cases
  selftests/bpf: Migrate ATTACH_REJECT test cases
  selftests/bpf: Migrate expected_attach_type tests
  selftests/bpf: Migrate wildcard destination rewrite test
  selftests/bpf: Migrate sendmsg6 v4 mapped address tests
  selftests/bpf: Migrate sendmsg deny test cases
  selftests/bpf: Migrate WILDCARD_IP test
  selftests/bpf: Handle SYSCALL_EPERM and SYSCALL_ENOTSUPP test cases
  ...
====================

Link: https://lore.kernel.org/r/20240513134114.17575-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-13 16:41:10 -07:00
Paul E. McKenney
33f137143e ftrace: Use asynchronous grace period for register_ftrace_direct()
When running heavy test workloads with KASAN enabled, RCU Tasks grace
periods can extend for many tens of seconds, significantly slowing
trace registration.  Therefore, make the registration-side RCU Tasks
grace period be asynchronous via call_rcu_tasks().

Link: https://lore.kernel.org/linux-trace-kernel/ac05be77-2972-475b-9b57-56bef15aa00a@paulmck-laptop

Reported-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Reported-by: Chris Mason <clm@fb.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 19:36:40 -04:00
Yuran Pereira
c5963a0990 ftrace: Replaces simple_strtoul in ftrace
The function simple_strtoul performs no error checking in scenarios
where the input value overflows the intended output variable.
This results in this function successfully returning, even when the
output does not match the input string (aka the function returns
successfully even when the result is wrong).

Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(),
simple_strtoul(), and simple_strtoull() functions explicitly ignore
overflows, which may lead to unexpected results in callers."
Hence, the use of those functions is discouraged.

This patch replaces all uses of the simple_strtoul with the safer
alternatives kstrtoul and kstruint.

Callers affected:
- add_rec_by_index
- set_graph_max_depth_function

Side effects of this patch:
- Since `fgraph_max_depth` is an `unsigned int`, this patch uses
  kstrtouint instead of kstrtoul to avoid any compiler warnings
  that could originate from calling the latter.
- This patch ensures that the callers of kstrtou* return accordingly
  when kstrtoul and kstruint fail for some reason.
  In this case, both callers this patch is addressing return 0 on error.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull

Link: https://lore.kernel.org/linux-trace-kernel/GV1PR10MB656333529A8D7B8AFB28D238E8B4A@GV1PR10MB6563.EURPRD10.PROD.OUTLOOK.COM

Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 19:36:40 -04:00
Vincent Donnefort
cf9f0f7c4c tracing: Allow user-space mapping of the ring-buffer
Currently, user-space extracts data from the ring-buffer via splice,
which is handy for storage or network sharing. However, due to splice
limitations, it is imposible to do real-time analysis without a copy.

A solution for that problem is to let the user-space map the ring-buffer
directly.

The mapping is exposed via the per-CPU file trace_pipe_raw. The first
element of the mapping is the meta-page. It is followed by each
subbuffer constituting the ring-buffer, ordered by their unique page ID:

  * Meta-page -- include/uapi/linux/trace_mmap.h for a description
  * Subbuf ID 0
  * Subbuf ID 1
     ...

It is therefore easy to translate a subbuf ID into an offset in the
mapping:

  reader_id = meta->reader->id;
  reader_offset = meta->meta_page_size + reader_id * meta->subbuf_size;

When new data is available, the mapper must call a newly introduced ioctl:
TRACE_MMAP_IOCTL_GET_READER. This will update the Meta-page reader ID to
point to the next reader containing unread data.

Mapping will prevent snapshot and buffer size modifications.

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-4-vdonnefort@google.com

CC: <linux-mm@kvack.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 18:09:56 -04:00
Vincent Donnefort
117c39200d ring-buffer: Introducing ring-buffer mapping functions
In preparation for allowing the user-space to map a ring-buffer, add
a set of mapping functions:

  ring_buffer_{map,unmap}()

And controls on the ring-buffer:

  ring_buffer_map_get_reader()  /* swap reader and head */

Mapping the ring-buffer also involves:

  A unique ID for each subbuf of the ring-buffer, currently they are
  only identified through their in-kernel VA.

  A meta-page, where are stored ring-buffer statistics and a
  description for the current reader

The linear mapping exposes the meta-page, and each subbuf of the
ring-buffer, ordered following their unique ID, assigned during the
first mapping.

Once mapped, no subbuf can get in or out of the ring-buffer: the buffer
size will remain unmodified and the splice enabling functions will in
reality simply memcpy the data instead of swapping subbufs.

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-3-vdonnefort@google.com

CC: <linux-mm@kvack.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 18:09:56 -04:00
Vincent Donnefort
c09d4167b5 ring-buffer: Allocate sub-buffers with __GFP_COMP
In preparation for the ring-buffer memory mapping, allocate compound
pages for the ring-buffer sub-buffers to enable us to map them to
user-space with vm_insert_pages().

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-2-vdonnefort@google.com

Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 18:09:55 -04:00
Linus Torvalds
c0b9620bc3 RCU pull request for v6.10
This pull request contains the following branches:
 
 fixes.2024.04.15a: Fix a lockdep complain for lazy-preemptible kernel,
 remove redundant BH disable for TINY_RCU, remove redundant READ_ONCE()
 in tree.c, fix false positives KCSAN splat and fix buffer overflow in
 the print_cpu_stall_info().
 
 misc.2024.04.12a: Misc updates related to bpf, tracing and update the
 MAINTAINERS file.
 
 rcu-sync-normal-improve.2024.04.15a: An improvement of a normal
 synchronize_rcu() call in terms of latency. It maintains a separate
 track for sync. users only. This approach bypasses per-cpu nocb-lists
 thus sync-users do not depend on nocb-list length and how fast regular
 callbacks are processed.
 
 rcu-tasks.2024.04.15a: RCU tasks, switch tasks RCU grace periods to
 sleep at TASK_IDLE priority, fix some comments, add some diagnostic
 warning to the exit_tasks_rcu_start() and fix a buffer overflow in
 the show_rcu_tasks_trace_gp_kthread().
 
 rcutorture.2024.04.15a: Increase memory to guest OS, fix a Tasks
 Rude RCU testing, some updates for TREE09, dump mode information
 to debug GP kthread state, remove redundant READ_ONCE(), fix some
 comments about RCU_TORTURE_PIPE_LEN and pipe_count, remove some
 redundant pointer initialization, fix a hung splat task by when
 the rcutorture tests start to exit, fix invalid context warning,
 add '--do-kvfree' parameter to torture test and use slow register
 unregister callbacks only for rcutype test.
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Merge tag 'rcu.next.v6.10' of https://github.com/urezki/linux

Pull RCU updates from Uladzislau Rezki:

 - Fix a lockdep complain for lazy-preemptible kernel, remove redundant
   BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix
   false positives KCSAN splat and fix buffer overflow in the
   print_cpu_stall_info().

 - Misc updates related to bpf, tracing and update the MAINTAINERS file.

 - An improvement of a normal synchronize_rcu() call in terms of
   latency. It maintains a separate track for sync. users only. This
   approach bypasses per-cpu nocb-lists thus sync-users do not depend on
   nocb-list length and how fast regular callbacks are processed.

 - RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE
   priority, fix some comments, add some diagnostic warning to the
   exit_tasks_rcu_start() and fix a buffer overflow in the
   show_rcu_tasks_trace_gp_kthread().

 - RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU
   testing, some updates for TREE09, dump mode information to debug GP
   kthread state, remove redundant READ_ONCE(), fix some comments about
   RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer
   initialization, fix a hung splat task by when the rcutorture tests
   start to exit, fix invalid context warning, add '--do-kvfree'
   parameter to torture test and use slow register unregister callbacks
   only for rcutype test.

* tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits)
  rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test
  torture: Scale --do-kvfree test time
  rcutorture: Fix invalid context warning when enable srcu barrier testing
  rcutorture: Make stall-tasks directly exit when rcutorture tests end
  rcutorture: Removing redundant function pointer initialization
  rcutorture: Make rcutorture support print rcu-tasks gp state
  rcutorture: Use the gp_kthread_dbg operation specified by cur_ops
  rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading
  rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment
  rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE()
  rcu: Allocate WQ with WQ_MEM_RECLAIM bit set
  rcu: Support direct wake-up of synchronize_rcu() users
  rcu: Add a trace event for synchronize_rcu_normal()
  rcu: Reduce synchronize_rcu() latency
  rcu: Fix buffer overflow in print_cpu_stall_info()
  rcu: Mollify sparse with RCU guard
  rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow
  rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer
  rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE()
  rcu: Remove redundant CONFIG_PROVE_RCU #if condition
  ...
2024-05-13 09:49:06 -07:00
Beau Belgrave
bd125a0840 tracing/user_events: Fix non-spaced field matching
When the ABI was updated to prevent same name w/different args, it
missed an important corner case when fields don't end with a space.
Typically, space is used for fields to help separate them, like
"u8 field1; u8 field2". If no spaces are used, like
"u8 field1;u8 field2", then the parsing works for the first time.
However, the match check fails on a subsequent register, leading to
confusion.

This is because the match check uses argv_split() and assumes that all
fields will be split upon the space. When spaces are used, we get back
{ "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }.
This causes a mismatch, and the user program gets back -EADDRINUSE.

Add a method to detect this case before calling argv_split(). If found
force a space after the field separator character ';'. This ensures all
cases work properly for matching.

With this fix, the following are all treated as matching:
u8 field1;u8 field2
u8 field1; u8 field2
u8 field1;\tu8 field2
u8 field1;\nu8 field2

Link: https://lore.kernel.org/linux-trace-kernel/20240423162338.292-2-beaub@linux.microsoft.com

Fixes: ba470eebc2 ("tracing/user_events: Prevent same name but different args event")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-13 12:15:45 -04:00
Jakub Kicinski
e7073830cc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
  35d92abfba ("net: hns3: fix kernel crash when devlink reload during initialization")
  2a1a1a7b5f ("net: hns3: add command queue trace for hns3")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-09 10:01:01 -07:00
Linus Torvalds
2c17a1cd90 Probes fixes for v6.9-rc6:
- probe-events: Fix memory leak in parsing probe argument. There is a
   memory leak (forget to free an allocated buffer) in a memory allocation
   failure path. Fixes it to jump to the correct error handling code.
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Merge tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:

 - probe-events: Fix memory leak in parsing probe argument.

   There is a memory leak (forget to free an allocated buffer) in a
   memory allocation failure path. Fix it to jump to the correct error
   handling code.

* tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()
2024-05-05 09:56:50 -07:00
Steven Rostedt (Google)
b63db58e2f eventfs/tracing: Add callback for release of an eventfs_inode
Synthetic events create and destroy tracefs files when they are created
and removed. The tracing subsystem has its own file descriptor
representing the state of the events attached to the tracefs files.
There's a race between the eventfs files and this file descriptor of the
tracing system where the following can cause an issue:

With two scripts 'A' and 'B' doing:

  Script 'A':
    echo "hello int aaa" > /sys/kernel/tracing/synthetic_events
    while :
    do
      echo 0 > /sys/kernel/tracing/events/synthetic/hello/enable
    done

  Script 'B':
    echo > /sys/kernel/tracing/synthetic_events

Script 'A' creates a synthetic event "hello" and then just writes zero
into its enable file.

Script 'B' removes all synthetic events (including the newly created
"hello" event).

What happens is that the opening of the "enable" file has:

 {
	struct trace_event_file *file = inode->i_private;
	int ret;

	ret = tracing_check_open_get_tr(file->tr);
 [..]

But deleting the events frees the "file" descriptor, and a "use after
free" happens with the dereference at "file->tr".

The file descriptor does have a reference counter, but there needs to be a
way to decrement it from the eventfs when the eventfs_inode is removed
that represents this file descriptor.

Add an optional "release" callback to the eventfs_entry array structure,
that gets called when the eventfs file is about to be removed. This allows
for the creating on the eventfs file to increment the tracing file
descriptor ref counter. When the eventfs file is deleted, it can call the
release function that will call the put function for the tracing file
descriptor.

This will protect the tracing file from being freed while a eventfs file
that references it is being opened.

Link: https://lore.kernel.org/linux-trace-kernel/20240426073410.17154-1-Tze-nan.Wu@mediatek.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240502090315.448cba46@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5790b1fb3d ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Tze-nan wu <Tze-nan.Wu@mediatek.com>
Tested-by: Tze-nan Wu (吳澤南) <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-05-04 04:25:37 -04:00
Andrii Nakryiko
e03c05ac98 rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get()
Take into account CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING when validating
that RCU is watching when trying to setup rethooko on a function entry.

One notable exception when we force rcu_is_watching() check is
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y case, in which case kretprobes will use
old-style int3-based workflow instead of relying on ftrace, making RCU
watching check important to validate.

This further (in addition to improvements in the previous patch)
improves BPF multi-kretprobe (which rely on rethook) runtime throughput
by 2.3%, according to BPF benchmarks ([0]).

  [0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/

Link: https://lore.kernel.org/all/20240418190909.704286-2-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:48 +09:00
Andrii Nakryiko
b0e28a4b5b ftrace: make extra rcu_is_watching() validation check optional
Introduce CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING config option to
control whether ftrace low-level code performs additional
rcu_is_watching()-based validation logic in an attempt to catch noinstr
violations.

This check is expected to never be true and is mostly useful for
low-level validation of ftrace subsystem invariants. For most users it
should probably be kept disabled to eliminate unnecessary runtime
overhead.

This improves BPF multi-kretprobe (relying on ftrace and rethook
infrastructure) runtime throughput by 2%, according to BPF benchmarks ([0]).

  [0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/

Link: https://lore.kernel.org/all/20240418190909.704286-1-andrii@kernel.org/

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:48 +09:00
Kui-Feng Lee
5120d167e2 rethook: Remove warning messages printed for finding return address of a frame.
The function rethook_find_ret_addr() prints a warning message and returns 0
when the target task is running and is not the "current" task in order to
prevent the incorrect return address, although it still may return an
incorrect address.

However, the warning message turns into noise when BPF profiling programs
call bpf_get_task_stack() on running tasks in a firm with a large number of
hosts.

The callers should be aware and willing to take the risk of receiving an
incorrect return address from a task that is currently running other than
the "current" one. A warning is not needed here as the callers are intent
on it.

Link: https://lore.kernel.org/all/20240408175140.60223-1-thinker.li@gmail.com/

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:47 +09:00
Ye Bin
20fe4d07bd tracing/probes: support '%pD' type for print struct file's name
As like '%pd' type, this patch supports print type '%pD' for print file's
name. For example "name=$arg1:%pD" casts the `$arg1` as (struct file*),
dereferences the "file.f_path.dentry.d_name.name" field and stores it to
"name" argument as a kernel string.
Here is an example:
[tracing]# echo 'p:testprobe vfs_read name=$arg1:%pD' > kprobe_event
[tracing]# echo 1 > events/kprobes/testprobe/enable
[tracing]# grep -q "1" events/kprobes/testprobe/enable
[tracing]# echo 0 > events/kprobes/testprobe/enable
[tracing]# grep "vfs_read" trace | grep "enable"
            grep-15108   [003] .....  5228.328609: testprobe: (vfs_read+0x4/0xbb0) name="enable"

Note that this expects the given argument (e.g. $arg1) is an address of struct
file. User must ensure it.

Link: https://lore.kernel.org/all/20240322064308.284457-3-yebin10@huawei.com/
[Masami: replaced "previous patch" with '%pd' type]

Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:47 +09:00
Ye Bin
d9b15224dd tracing/probes: support '%pd' type for print struct dentry's name
During fault locating, the file name needs to be printed based on the
dentry  address. The offset needs to be calculated each time, which
is troublesome. Similar to printk, kprobe support print type '%pd' for
print dentry's name. For example "name=$arg1:%pd" casts the `$arg1`
as (struct dentry *), dereferences the "d_name.name" field and stores
it to "name" argument as a kernel string.
Here is an example:
[tracing]# echo 'p:testprobe dput name=$arg1:%pd' > kprobe_events
[tracing]# echo 1 > events/kprobes/testprobe/enable
[tracing]# grep -q "1" events/kprobes/testprobe/enable
[tracing]# echo 0 > events/kprobes/testprobe/enable
[tracing]# cat trace | grep "enable"
	    bash-14844   [002] ..... 16912.889543: testprobe: (dput+0x4/0x30) name="enable"
            grep-15389   [003] ..... 16922.834182: testprobe: (dput+0x4/0x30) name="enable"
            grep-15389   [003] ..... 16922.836103: testprobe: (dput+0x4/0x30) name="enable"
            bash-14844   [001] ..... 16931.820909: testprobe: (dput+0x4/0x30) name="enable"

Note that this expects the given argument (e.g. $arg1) is an address of struct
dentry. User must ensure it.

Link: https://lore.kernel.org/all/20240322064308.284457-2-yebin10@huawei.com/

Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:47 +09:00
Andrii Nakryiko
cdf355cc60 uprobes: add speculative lockless system-wide uprobe filter check
It's very common with BPF-based uprobe/uretprobe use cases to have
a system-wide (not PID specific) probes used. In this case uprobe's
trace_uprobe_filter->nr_systemwide counter is bumped at registration
time, and actual filtering is short circuited at the time when
uprobe/uretprobe is triggered.

This is a great optimization, and the only issue with it is that to even
get to checking this counter uprobe subsystem is taking
read-side trace_uprobe_filter->rwlock. This is actually noticeable in
profiles and is just another point of contention when uprobe is
triggered on multiple CPUs simultaneously.

This patch moves this nr_systemwide check outside of filter list's
rwlock scope, as rwlock is meant to protect list modification, while
nr_systemwide-based check is speculative and racy already, despite the
lock (as discussed in [0]). trace_uprobe_filter_remove() and
trace_uprobe_filter_add() already check for filter->nr_systewide
explicitly outside of __uprobe_perf_filter, so no modifications are
required there.

Confirming with BPF selftests's based benchmarks.

BEFORE (based on changes in previous patch)
===========================================
uprobe-nop     :    2.732 ± 0.022M/s
uprobe-push    :    2.621 ± 0.016M/s
uprobe-ret     :    1.105 ± 0.007M/s
uretprobe-nop  :    1.396 ± 0.007M/s
uretprobe-push :    1.347 ± 0.008M/s
uretprobe-ret  :    0.800 ± 0.006M/s

AFTER
=====
uprobe-nop     :    2.878 ± 0.017M/s (+5.5%, total +8.3%)
uprobe-push    :    2.753 ± 0.013M/s (+5.3%, total +10.2%)
uprobe-ret     :    1.142 ± 0.010M/s (+3.8%, total +3.8%)
uretprobe-nop  :    1.444 ± 0.008M/s (+3.5%, total +6.5%)
uretprobe-push :    1.410 ± 0.010M/s (+4.8%, total +7.1%)
uretprobe-ret  :    0.816 ± 0.002M/s (+2.0%, total +3.9%)

In the above, first percentage value is based on top of previous patch
(lazy uprobe buffer optimization), while the "total" percentage is
based on kernel without any of the changes in this patch set.

As can be seen, we get about 4% - 10% speed up, in total, with both lazy
uprobe buffer and speculative filter check optimizations.

  [0] https://lore.kernel.org/bpf/20240313131926.GA19986@redhat.com/

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/all/20240318181728.2795838-4-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:46 +09:00
Andrii Nakryiko
1b8f85defb uprobes: prepare uprobe args buffer lazily
uprobe_cpu_buffer and corresponding logic to store uprobe args into it
are used for uprobes/uretprobes that are created through tracefs or
perf events.

BPF is yet another user of uprobe/uretprobe infrastructure, but doesn't
need uprobe_cpu_buffer and associated data. For BPF-only use cases this
buffer handling and preparation is a pure overhead. At the same time,
BPF-only uprobe/uretprobe usage is very common in practice. Also, for
a lot of cases applications are very senstivie to performance overheads,
as they might be tracing a very high frequency functions like
malloc()/free(), so every bit of performance improvement matters.

All that is to say that this uprobe_cpu_buffer preparation is an
unnecessary overhead that each BPF user of uprobes/uretprobe has to pay.
This patch is changing this by making uprobe_cpu_buffer preparation
optional. It will happen only if either tracefs-based or perf event-based
uprobe/uretprobe consumer is registered for given uprobe/uretprobe. For
BPF-only use cases this step will be skipped.

We used uprobe/uretprobe benchmark which is part of BPF selftests (see [0])
to estimate the improvements. We have 3 uprobe and 3 uretprobe
scenarios, which vary an instruction that is replaced by uprobe: nop
(fastest uprobe case), `push rbp` (typical case), and non-simulated
`ret` instruction (slowest case). Benchmark thread is constantly calling
user space function in a tight loop. User space function has attached
BPF uprobe or uretprobe program doing nothing but atomic counter
increments to count number of triggering calls. Benchmark emits
throughput in millions of executions per second.

BEFORE these changes
====================
uprobe-nop     :    2.657 ± 0.024M/s
uprobe-push    :    2.499 ± 0.018M/s
uprobe-ret     :    1.100 ± 0.006M/s
uretprobe-nop  :    1.356 ± 0.004M/s
uretprobe-push :    1.317 ± 0.019M/s
uretprobe-ret  :    0.785 ± 0.007M/s

AFTER these changes
===================
uprobe-nop     :    2.732 ± 0.022M/s (+2.8%)
uprobe-push    :    2.621 ± 0.016M/s (+4.9%)
uprobe-ret     :    1.105 ± 0.007M/s (+0.5%)
uretprobe-nop  :    1.396 ± 0.007M/s (+2.9%)
uretprobe-push :    1.347 ± 0.008M/s (+2.3%)
uretprobe-ret  :    0.800 ± 0.006M/s (+1.9)

So the improvements on this particular machine seems to be between 2% and 5%.

  [0] https://github.com/torvalds/linux/blob/master/tools/testing/selftests/bpf/benchs/bench_trigger.c

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/all/20240318181728.2795838-3-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:46 +09:00
Andrii Nakryiko
3eaea21b4d uprobes: encapsulate preparation of uprobe args buffer
Move the logic of fetching temporary per-CPU uprobe buffer and storing
uprobes args into it to a new helper function. Store data size as part
of this buffer, simplifying interfaces a bit, as now we only pass single
uprobe_cpu_buffer reference around, instead of pointer + dsize.

This logic was duplicated across uprobe_dispatcher and uretprobe_dispatcher,
and now will be centralized. All this is also in preparation to make
this uprobe_cpu_buffer handling logic optional in the next patch.

Link: https://lore.kernel.org/all/20240318181728.2795838-2-andrii@kernel.org/
[Masami: update for v6.9-rc3 kernel]

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-01 23:18:46 +09:00
Jiri Olsa
5c919acef8 bpf: Add support for kprobe session cookie
Adding support for cookie within the session of kprobe multi
entry and return program.

The session cookie is u64 value and can be retrieved be new
kfunc bpf_session_cookie, which returns pointer to the cookie
value. The bpf program can use the pointer to store (on entry)
and load (on return) the value.

The cookie value is implemented via fprobe feature that allows
to share values between entry and return ftrace fprobe callbacks.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-4-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jiri Olsa
adf46d88ae bpf: Add support for kprobe session context
Adding struct bpf_session_run_ctx object to hold session related
data, which is atm is_return bool and data pointer coming in
following changes.

Placing bpf_session_run_ctx layer in between bpf_run_ctx and
bpf_kprobe_multi_run_ctx so the session data can be retrieved
regardless of if it's kprobe_multi or uprobe_multi link, which
support is coming in future. This way both kprobe_multi and
uprobe_multi can use same kfuncs to access the session data.

Adding bpf_session_is_return kfunc that returns true if the
bpf program is executed from the exit probe of the kprobe multi
link attached in wrapper mode. It returns false otherwise.

Adding new kprobe hook for kprobe program type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-3-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jiri Olsa
535a3692ba bpf: Add support for kprobe session attach
Adding support to attach bpf program for entry and return probe
of the same function. This is common use case which at the moment
requires to create two kprobe multi links.

Adding new BPF_TRACE_KPROBE_SESSION attach type that instructs
kernel to attach single link program to both entry and exit probe.

It's possible to control execution of the bpf program on return
probe simply by returning zero or non zero from the entry bpf
program execution to execute or not the bpf program on return
probe respectively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-2-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jakub Kicinski
89de2db193 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-04-29

We've added 147 non-merge commits during the last 32 day(s) which contain
a total of 158 files changed, 9400 insertions(+), 2213 deletions(-).

The main changes are:

1) Add an internal-only BPF per-CPU instruction for resolving per-CPU
   memory addresses and implement support in x86 BPF JIT. This allows
   inlining per-CPU array and hashmap lookups
   and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko.

2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song.

3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
   atomics in bpf_arena which can be JITed as a single x86 instruction,
   from Alexei Starovoitov.

4) Add support for passing mark with bpf_fib_lookup helper,
   from Anton Protopopov.

5) Add a new bpf_wq API for deferring events and refactor sleepable
   bpf_timer code to keep common code where possible,
   from Benjamin Tissoires.

6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs
   to check when NULL is passed for non-NULLable parameters,
   from Eduard Zingerman.

7) Harden the BPF verifier's and/or/xor value tracking,
   from Harishankar Vishwanathan.

8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel
   crypto subsystem, from Vadim Fedorenko.

9) Various improvements to the BPF instruction set standardization doc,
   from Dave Thaler.

10) Extend libbpf APIs to partially consume items from the BPF ringbuffer,
    from Andrea Righi.

11) Bigger batch of BPF selftests refactoring to use common network helpers
    and to drop duplicate code, from Geliang Tang.

12) Support bpf_tail_call_static() helper for BPF programs with GCC 13,
    from Jose E. Marchesi.

13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled,
    from Kumar Kartikeya Dwivedi.

14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs,
    from David Vernet.

15) Extend the BPF verifier to allow different input maps for a given
    bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu.

16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions
    for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan.

17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison
    the stack memory, from Martin KaFai Lau.

18) Improve xsk selftest coverage with new tests on maximum and minimum
    hardware ring size configurations, from Tushar Vyavahare.

19) Various ReST man pages fixes as well as documentation and bash completion
    improvements for bpftool, from Rameez Rehman & Quentin Monnet.

20) Fix libbpf with regards to dumping subsequent char arrays,
    from Quentin Deslandes.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits)
  bpf, docs: Clarify PC use in instruction-set.rst
  bpf_helpers.h: Define bpf_tail_call_static when building with GCC
  bpf, docs: Add introduction for use in the ISA Internet Draft
  selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us
  bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args
  selftests/bpf: dummy_st_ops should reject 0 for non-nullable params
  bpf: check bpf_dummy_struct_ops program params for test runs
  selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops
  selftests/bpf: adjust dummy_st_ops_success to detect additional error
  bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
  selftests/bpf: Add ring_buffer__consume_n test.
  bpf: Add bpf_guard_preempt() convenience macro
  selftests: bpf: crypto: add benchmark for crypto functions
  selftests: bpf: crypto skcipher algo selftests
  bpf: crypto: add skcipher to bpf crypto
  bpf: make common crypto API for TC/XDP programs
  bpf: update the comment for BTF_FIELDS_MAX
  selftests/bpf: Fix wq test.
  selftests/bpf: Use make_sockaddr in test_sock_addr
  selftests/bpf: Use connect_to_addr in test_sock_addr
  ...
====================

Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-29 13:12:19 -07:00
LuMingYin
dce3696271 tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()
If traceprobe_parse_probe_arg_body() failed to allocate 'parg->fmt',
it jumps to the label 'out' instead of 'fail' by mistake.In the result,
the buffer 'tmp' is not freed in this case and leaks its memory.

Thus jump to the label 'fail' in that error case.

Link: https://lore.kernel.org/all/20240427072347.1421053-1-lumingyindetect@126.com/

Fixes: 032330abd0 ("tracing/probes: Cleanup probe argument parser")
Signed-off-by: LuMingYin <lumingyindetect@126.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-04-29 22:30:46 +09:00
Arnd Bergmann
051e750307 blktrace: convert strncpy() to strscpy_pad()
gcc-9 warns about a possibly non-terminated string copy:

kernel/trace/blktrace.c: In function 'do_blk_trace_setup':
kernel/trace/blktrace.c:527:2: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]

Newer versions are fine here because they see the following explicit
nul-termination. Using strscpy_pad() avoids the warning and
simplifies the code a little. The padding helps  give a clean
buffer to userspace.

Link: https://lkml.kernel.org/r/20240409140059.3806717-5-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Justin Stitt <justinstitt@google.com>
Cc: Alexey Starikovskiy <astarikovskiy@suse.de>
Cc: Bob Moore <robert.moore@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Len Brown <lenb@kernel.org>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Richard Russon (FlatCap)" <ldm@flatcap.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 21:07:08 -07:00
Joel Granados
66f20b11d3 ftrace: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel elements from ftrace_sysctls and user_event_sysctls

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-04-24 09:43:53 +02:00
Jakub Kicinski
41e3ddb291 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/trace/events/rpcgss.h
  386f4a7379 ("trace: events: cleanup deprecated strncpy uses")
  a4833e3aba ("SUNRPC: Fix rpcgss_context trace event acceptor field")

Adjacent changes:

drivers/net/ethernet/intel/ice/ice_tc_lib.c
  2cca35f5dd ("ice: Fix checking for unsupported keys on non-tunnel device")
  784feaa65d ("ice: Add support for PFCP hardware offload in switchdev")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-18 13:12:24 -07:00
Paul E. McKenney
64ec8b6ad6 ftrace: Choose RCU Tasks based on TASKS_RCU rather than PREEMPTION
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that
even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY
might see the occasional preemption, and that this preemption just might
happen within a trampoline.

Therefore, update ftrace_shutdown() to invoke synchronize_rcu_tasks()
based on CONFIG_TASKS_RCU instead of CONFIG_PREEMPTION.

[ paulmck: Apply Steven Rostedt feedback. ]

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <linux-trace-kernel@vger.kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-12 11:23:42 +02:00
Steven Rostedt (Google)
ffe3986fec ring-buffer: Only update pages_touched when a new page is touched
The "buffer_percent" logic that is used by the ring buffer splice code to
only wake up the tasks when there's no data after the buffer is filled to
the percentage of the "buffer_percent" file is dependent on three
variables that determine the amount of data that is in the ring buffer:

 1) pages_read - incremented whenever a new sub-buffer is consumed
 2) pages_lost - incremented every time a writer overwrites a sub-buffer
 3) pages_touched - incremented when a write goes to a new sub-buffer

The percentage is the calculation of:

  (pages_touched - (pages_lost + pages_read)) / nr_pages

Basically, the amount of data is the total number of sub-bufs that have been
touched, minus the number of sub-bufs lost and sub-bufs consumed. This is
divided by the total count to give the buffer percentage. When the
percentage is greater than the value in the "buffer_percent" file, it
wakes up splice readers waiting for that amount.

It was observed that over time, the amount read from the splice was
constantly decreasing the longer the trace was running. That is, if one
asked for 60%, it would read over 60% when it first starts tracing, but
then it would be woken up at under 60% and would slowly decrease the
amount of data read after being woken up, where the amount becomes much
less than the buffer percent.

This was due to an accounting of the pages_touched incrementation. This
value is incremented whenever a writer transfers to a new sub-buffer. But
the place where it was incremented was incorrect. If a writer overflowed
the current sub-buffer it would go to the next one. If it gets preempted
by an interrupt at that time, and the interrupt performs a trace, it too
will end up going to the next sub-buffer. But only one should increment
the counter. Unfortunately, that was not the case.

Change the cmpxchg() that does the real switch of the tail-page into a
try_cmpxchg(), and on success, perform the increment of pages_touched. This
will only increment the counter once for when the writer moves to a new
sub-buffer, and not when there's a race and is incremented for when a
writer and its preempting writer both move to the same new sub-buffer.

Link: https://lore.kernel.org/linux-trace-kernel/20240409151309.0d0e5056@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11 17:49:57 -04:00
Arnd Bergmann
5281ec8345 tracing: hide unused ftrace_event_id_fops
When CONFIG_PERF_EVENTS, a 'make W=1' build produces a warning about the
unused ftrace_event_id_fops variable:

kernel/trace/trace_events.c:2155:37: error: 'ftrace_event_id_fops' defined but not used [-Werror=unused-const-variable=]
 2155 | static const struct file_operations ftrace_event_id_fops = {

Hide this in the same #ifdef as the reference to it.

Link: https://lore.kernel.org/linux-trace-kernel/20240403080702.3509288-7-arnd@kernel.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Clément Léger <cleger@rivosinc.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Fixes: 620a30e97f ("tracing: Don't pass file_operations array to event_create_dir()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11 17:46:55 -04:00
Prasad Pandit
d96c36004e tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry
Fix FTRACE_RECORD_RECURSION_SIZE entry, replace tab with
a space character. It helps Kconfig parsers to read file
without error.

Link: https://lore.kernel.org/linux-trace-kernel/20240322121801.1803948-1-ppandit@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 773c167050 ("ftrace: Add recording of functions that caused recursion")
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11 17:45:18 -04:00
Paul E. McKenney
02b3c5fcdf tracing: Select new NEED_TASKS_RCU Kconfig option
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does
"select TASKS_RCU if PREEMPTION".  This works, but requires any change in
this enablement logic to be replicated across all such "select" clauses.
A new NEED_TASKS_RCU Kconfig option has been created to allow this
enablement logic to be in one place in kernel/rcu/Kconfig.

Therefore, select the new NEED_TASKS_RCU Kconfig option instead of the
old TASKS_RCU option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <linux-trace-kernel@vger.kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-11 18:18:47 +02:00
Jakub Kicinski
cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605b ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1 ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 18:01:07 -07:00
Andrii Nakryiko
5e6a3c1ee6 bpf: make bpf_get_branch_snapshot() architecture-agnostic
perf_snapshot_branch_stack is set up in an architecture-agnostic way, so
there is no reason for BPF subsystem to keep track of which
architectures do support LBR or not. E.g., it looks like ARM64 might soon
get support for BRBE ([0]), which (with proper integration) should be
possible to utilize using this BPF helper.

perf_snapshot_branch_stack static call will point to
__static_call_return0() by default, which just returns zero, which will
lead to -ENOENT, as expected. So no need to guard anything here.

  [0] https://lore.kernel.org/linux-arm-kernel/20240125094119.2542332-1-anshuman.khandual@arm.com/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404002640.1774210-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04 13:08:01 -07:00
Alexander Lobakin
7d8296b250 bitops: make BYTES_TO_BITS() treewide-available
Avoid open-coding that simple expression each time by moving
BYTES_TO_BITS() from the probes code to <linux/bitops.h> to export
it to the rest of the kernel.
Simplify the macro while at it. `BITS_PER_LONG / sizeof(long)` always
equals to %BITS_PER_BYTE, regardless of the target architecture.
Do the same for the tools ecosystem as well (incl. its version of
bitops.h). The previous implementation had its implicit type of long,
while the new one is int, so adjust the format literal accordingly in
the perf code.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01 10:49:27 +01:00
Andrii Nakryiko
1a80dbcb2d bpf: support deferring bpf_link dealloc to after RCU grace period
BPF link for some program types is passed as a "context" which can be
used by those BPF programs to look up additional information. E.g., for
multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values.

Because of this runtime dependency, when bpf_link refcnt drops to zero
there could still be active BPF programs running accessing link data.

This patch adds generic support to defer bpf_link dealloc callback to
after RCU GP, if requested. This is done by exposing two different
deallocation callbacks, one synchronous and one deferred. If deferred
one is provided, bpf_link_free() will schedule dealloc_deferred()
callback to happen after RCU GP.

BPF is using two flavors of RCU: "classic" non-sleepable one and RCU
tasks trace one. The latter is used when sleepable BPF programs are
used. bpf_link_free() accommodates that by checking underlying BPF
program's sleepable flag, and goes either through normal RCU GP only for
non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP
(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF
program is sleepable.

We use this for multi-kprobe and multi-uprobe links, which dereference
link during program run. We also preventively switch raw_tp link to use
deferred dealloc callback, as upcoming changes in bpf-next tree expose
raw_tp link data (specifically, cookie value) to BPF program at runtime
as well.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com
Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com
Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:47:45 -07:00
Andrii Nakryiko
e9c856cabe bpf: put uprobe link's path and task in release callback
There is no need to delay putting either path or task to deallocation
step. It can be done right after bpf_uprobe_unregister. Between release
and dealloc, there could be still some running BPF programs, but they
don't access either task or path, only data in link->uprobes, so it is
safe to do.

On the other hand, doing path_put() in dealloc callback makes this
dealloc sleepable because path_put() itself might sleep. Which is
problematic due to the need to call uprobe's dealloc through call_rcu(),
which is what is done in the next bug fix patch. So solve the problem by
releasing these resources early.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:47:45 -07:00
Jakub Kicinski
5e47fbe5ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts, or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-28 17:25:57 -07:00
Linus Torvalds
962490525c Probes fixes for v6.9-rc1:
- tracing/probes: initialize a 'val' local variable with zero. This variable
    is read by FETCH_OP_ST_EDATA in a loop, and is expected to be initialized
    by FETCH_OP_ARG in the same loop. Since this expectation is not obvious,
    thus smatch warns it. Initializing 'val' with zero fixes this warning.
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Merge tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixlet from Masami Hiramatsu:

 - tracing/probes: initialize a 'val' local variable with zero.

   This variable is read by FETCH_OP_ST_EDATA in a loop, and is
   initialized by FETCH_OP_ARG in the same loop. Since this
   initialization is not obvious, smatch warns about it.

   Explicitly initializing 'val' with zero fixes this warning.

* tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: probes: Fix to zero initialize a local variable
2024-03-27 10:01:24 -07:00
Jakub Kicinski
2a702c2e57 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-03-25

We've added 38 non-merge commits during the last 13 day(s) which contain
a total of 50 files changed, 867 insertions(+), 274 deletions(-).

The main changes are:

1) Add the ability to specify and retrieve BPF cookie also for raw
   tracepoint programs in order to ease migration from classic to raw
   tracepoints, from Andrii Nakryiko.

2) Allow the use of bpf_get_{ns_,}current_pid_tgid() helper for all
   program types and add additional BPF selftests, from Yonghong Song.

3) Several improvements to bpftool and its build, for example, enabling
   libbpf logs when loading pid_iter in debug mode, from Quentin Monnet.

4) Check the return code of all BPF-related set_memory_*() functions during
   load and bail out in case they fail, from Christophe Leroy.

5) Avoid a goto in regs_refine_cond_op() such that the verifier can
   be better integrated into Agni tool which doesn't support backedges
   yet, from Harishankar Vishwanathan.

6) Add a small BPF trie perf improvement by always inlining
   longest_prefix_match, from Jesper Dangaard Brouer.

7) Small BPF selftest refactor in bpf_tcp_ca.c to utilize start_server()
   helper instead of open-coding it, from Geliang Tang.

8) Improve test_tc_tunnel.sh BPF selftest to prevent client connect
   before the server bind, from Alessandro Carminati.

9) Fix BPF selftest benchmark for older glibc and use syscall(SYS_gettid)
   instead of gettid(), from Alan Maguire.

10) Implement a backward-compatible method for struct_ops types with
    additional fields which are not present in older kernels,
    from Kui-Feng Lee.

11) Add a small helper to check if an instruction is addr_space_cast
    from as(0) to as(1) and utilize it in x86-64 JIT, from Puranjay Mohan.

12) Small cleanup to remove unnecessary error check in
    bpf_struct_ops_map_update_elem, from Martin KaFai Lau.

13) Improvements to libbpf fd validity checks for BPF map/programs,
    from Mykyta Yatsenko.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (38 commits)
  selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
  bpf: implement insn_is_cast_user() helper for JITs
  bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
  selftests/bpf: Use start_server in bpf_tcp_ca
  bpf: Sync uapi bpf.h to tools directory
  libbpf: Add new sec_def "sk_skb/verdict"
  selftests/bpf: Mark uprobe trigger functions with nocf_check attribute
  selftests/bpf: Use syscall(SYS_gettid) instead of gettid() wrapper in bench
  bpf-next: Avoid goto in regs_refine_cond_op()
  bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
  selftests/bpf: scale benchmark counting by using per-CPU counters
  bpftool: Remove unnecessary source files from bootstrap version
  bpftool: Enable libbpf logs when loading pid_iter in debug mode
  selftests/bpf: add raw_tp/tp_btf BPF cookie subtests
  libbpf: add support for BPF cookie for raw_tp/tp_btf programs
  bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
  bpf: pass whole link instead of prog when triggering raw tracepoint
  bpf: flatten bpf_probe_register call chain
  selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh
  selftests/bpf: Add a sk_msg prog bpf_get_ns_current_pid_tgid() test
  ...
====================

Link: https://lore.kernel.org/r/20240325233940.7154-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-27 07:52:34 -07:00
Andrii Nakryiko
a8497506cd bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
get_kernel_nofault() (or, rather, underlying copy_from_kernel_nofault())
is not free and it does pop up in performance profiles when
kprobes are heavily utilized with CONFIG_X86_KERNEL_IBT=y config.

Let's avoid using it if we know that fentry_ip - 4 can't cross page
boundary. We do that by masking lowest 12 bits and checking if they are

Another benefit (and actually what caused a closer look at this part of
code) is that now LBR record is (typically) not wasted on
copy_from_kernel_nofault() call and code, which helps tools like
retsnoop that grab LBR records from inside BPF code in kretprobes.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20240319212013.1046779-1-andrii@kernel.org
2024-03-25 17:05:48 +01:00
Masami Hiramatsu (Google)
0add699ad0 tracing: probes: Fix to zero initialize a local variable
Fix to initialize 'val' local variable with zero.
Dan reported that Smatch static code checker reports an error that a local
'val' variable needs to be initialized. Actually, the 'val' is expected to
be initialized by FETCH_OP_ARG in the same loop, but it is not obvious. So
initialize it with zero.

Link: https://lore.kernel.org/all/171092223833.237219.17304490075697026697.stgit@devnote2/

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/b010488e-68aa-407c-add0-3e059254aaa0@moroto.mountain/
Fixes: 25f00e40ce ("tracing/probes: Support $argN in return probe (kprobe and fprobe)")
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-03-25 16:24:31 +09:00
Andrii Nakryiko
68ca5d4eeb bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF
aware variants). This brings them up to part w.r.t. BPF cookie usage
with classic tracepoint and fentry/fexit programs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-4-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:34 -07:00
Andrii Nakryiko
d4dfc5700e bpf: pass whole link instead of prog when triggering raw tracepoint
Instead of passing prog as an argument to bpf_trace_runX() helpers, that
are called from tracepoint triggering calls, store BPF link itself
(struct bpf_raw_tp_link for raw tracepoints). This will allow to pass
extra information like BPF cookie into raw tracepoint registration.

Instead of replacing `struct bpf_prog *prog = __data;` with
corresponding `struct bpf_raw_tp_link *link = __data;` assignment in
`__bpf_trace_##call` I just passed `__data` through into underlying
bpf_trace_runX() call. This works well because we implicitly cast `void *`,
and it also avoids naming clashes with arguments coming from
tracepoint's "proto" list. We could have run into the same problem with
"prog", we just happened to not have a tracepoint that has "prog" input
argument. We are less lucky with "link", as there are tracepoints using
"link" argument name already. So instead of trying to avoid naming
conflicts, let's just remove intermediate local variable. It doesn't
hurt readibility, it's either way a bit of a maze of calls and macros,
that requires careful reading.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-3-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:33 -07:00
Andrii Nakryiko
6b9c2950c9 bpf: flatten bpf_probe_register call chain
bpf_probe_register() and __bpf_probe_register() have identical
signatures and bpf_probe_register() just redirect to
__bpf_probe_register(). So get rid of this extra function call step to
simplify following the source code.

It has no difference at runtime due to inlining, of course.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-2-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:33 -07:00
Yonghong Song
eb166e522c bpf: Allow helper bpf_get_[ns_]current_pid_tgid() for all prog types
Currently bpf_get_current_pid_tgid() is allowed in tracing, cgroup
and sk_msg progs while bpf_get_ns_current_pid_tgid() is only allowed
in tracing progs.

We have an internal use case where for an application running
in a container (with pid namespace), user wants to get
the pid associated with the pid namespace in a cgroup bpf
program. Currently, cgroup bpf progs already allow
bpf_get_current_pid_tgid(). Let us allow bpf_get_ns_current_pid_tgid()
as well.

With auditing the code, bpf_get_current_pid_tgid() is also used
by sk_msg prog. But there are no side effect to expose these two
helpers to all prog types since they do not reveal any kernel specific
data. The detailed discussion is in [1].

So with this patch, both bpf_get_current_pid_tgid() and bpf_get_ns_current_pid_tgid()
are put in bpf_base_func_proto(), making them available to all
program types.

  [1] https://lore.kernel.org/bpf/20240307232659.1115872-1-yonghong.song@linux.dev/

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240315184854.2975190-1-yonghong.song@linux.dev
2024-03-19 14:24:07 -07:00
Thorsten Blum
d6cb38e108 tracing: Use div64_u64() instead of do_div()
Fixes Coccinelle/coccicheck warnings reported by do_div.cocci.

Compared to do_div(), div64_u64() does not implicitly cast the divisor and
does not unnecessarily calculate the remainder.

Link: https://lore.kernel.org/linux-trace-kernel/20240225164507.232942-2-thorsten.blum@toblux.com

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:06 -04:00
Huang Yiwei
19f0423fd5 tracing: Support to dump instance traces by ftrace_dump_on_oops
Currently ftrace only dumps the global trace buffer on an OOPs. For
debugging a production usecase, instance trace will be helpful to
check specific problems since global trace buffer may be used for
other purposes.

This patch extend the ftrace_dump_on_oops parameter to dump a specific
or multiple trace instances:

  - ftrace_dump_on_oops=0: as before -- don't dump
  - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer
  on all CPUs
  - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global
  trace buffer on CPU that triggered the oops
  - ftrace_dump_on_oops=<instance_name>: new behavior -- dump the
  tracing instance matching <instance_name>
  - ftrace_dump_on_oops[=2/orig_cpu],<instance1_name>[=2/orig_cpu],
  <instrance2_name>[=2/orig_cpu]: new behavior -- dump the global trace
  buffer and multiple instance buffer on all CPUs, or only dump on CPU
  that triggered the oops if =2 or =orig_cpu is given

Also, the sysctl node can handle the input accordingly.

Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com

Cc: Ross Zwisler <zwisler@google.com>
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mcgrof@kernel.org>
Cc: <keescook@chromium.org>
Cc: <j.granados@samsung.com>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <corbet@lwn.net>
Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:06 -04:00
Randy Dunlap
d15304135c ftrace: Fix most kernel-doc warnings
Reduce the number of kernel-doc warnings from 52 down to 10, i.e.,
fix 42 kernel-doc warnings by (a) using the Returns: format for
function return values or (b) using "@var:" instead of "@var -"
for function parameter descriptions.

Fix one return values list so that it is formatted correctly when
rendered for output.

Spell "non-zero" with a hyphen in several places.

Link: https://lore.kernel.org/linux-trace-kernel/20240223054833.15471-1-rdunlap@infradead.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/oe-kbuild-all/202312180518.X6fRyDSN-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:05 -04:00
Steven Rostedt (Google)
2048fdc275 tracing: Decrement the snapshot if the snapshot trigger fails to register
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a snapshot trigger was added, even if that snapshot trigger
failed.

 # cd /sys/kernel/tracing
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 -bash: echo: write error: File exists

That second one that fails increments the snapshot counter but doesn't
decrement it. It needs to be decremented when the snapshot fails.

Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.729055907@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:05 -04:00
Steven Rostedt (Google)
cca990c7b5 tracing: Fix snapshot counter going between two tracers that use it
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a tracer that uses the snapshot is enabled even if the snapshot
was used by the previous tracer.

That is:

 # cd /sys/kernel/tracing
 # echo wakeup_rt > current_tracer
 # echo wakeup_dl > current_tracer
 # echo nop > current_tracer

would leave the snapshot counter at 1 and not zero. That's because the
enabling of wakeup_dl would increment the counter again but the setting
the tracer to nop would only decrement it once.

Do not arm the snapshot for a tracer if the previous tracer already had it
armed.

Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.570525723@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:05 -04:00
John Garry
ed89683763 tracing: Use init_utsname()->release
Instead of using UTS_RELEASE, use init_utsname()->release, which means that
we don't need to rebuild the code just for the git head commit changing.

Link: https://lore.kernel.org/linux-trace-kernel/20240222124639.65629-1-john.g.garry@oracle.com

Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:13:21 -04:00
Beau Belgrave
64805e4039 tracing/user_events: Introduce multi-format events
Currently user_events supports 1 event with the same name and must have
the exact same format when referenced by multiple programs. This opens
an opportunity for malicious or poorly thought through programs to
create events that others use with different formats. Another scenario
is user programs wishing to use the same event name but add more fields
later when the software updates. Various versions of a program may be
running side-by-side, which is prevented by the current single format
requirement.

Add a new register flag (USER_EVENT_REG_MULTI_FORMAT) which indicates
the user program wishes to use the same user_event name, but may have
several different formats of the event. When this flag is used, create
the underlying tracepoint backing the user_event with a unique name
per-version of the format. It's important that existing ABI users do
not get this logic automatically, even if one of the multi format
events matches the format. This ensures existing programs that create
events and assume the tracepoint name will match exactly continue to
work as expected. Add logic to only check multi-format events with
other multi-format events and single-format events to only check
single-format events during find.

Change system name of the multi-format event tracepoint to ensure that
multi-format events are isolated completely from single-format events.
This prevents single-format names from conflicting with multi-format
events if they end with the same suffix as the multi-format events.

Add a register_name (reg_name) to the user_event struct which allows for
split naming of events. We now have the name that was used to register
within user_events as well as the unique name for the tracepoint. Upon
registering events ensure matches based on first the reg_name, followed
by the fields and format of the event. This allows for multiple events
with the same registered name to have different formats. The underlying
tracepoint will have a unique name in the format of {reg_name}.{unique_id}.

For example, if both "test u32 value" and "test u64 value" are used with
the USER_EVENT_REG_MULTI_FORMAT the system would have 2 unique
tracepoints. The dynamic_events file would then show the following:
  u:test u64 count
  u:test u32 count

The actual tracepoint names look like this:
  test.0
  test.1

Both would be under the new user_events_multi system name to prevent the
older ABI from being used to squat on multi-formatted events and block
their use.

Deleting events via "!u:test u64 count" would only delete the first
tracepoint that matched that format. When the delete ABI is used all
events with the same name will be attempted to be deleted. If
per-version deletion is required, user programs should either not use
persistent events or delete them via dynamic_events.

Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-3-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:13:03 -04:00
Beau Belgrave
1e953de9e9 tracing/user_events: Prepare find/delete for same name events
The current code for finding and deleting events assumes that there will
never be cases when user_events are registered with the same name, but
different formats. Scenarios exist where programs want to use the same
name but have different formats. An example is multiple versions of a
program running side-by-side using the same event name, but with updated
formats in each version.

This change does not yet allow for multi-format events. If user_events
are registered with the same name but different arguments the programs
see the same return values as before. This change simply makes it
possible to easily accommodate for this.

Update find_user_event() to take in argument parameters and register
flags to accommodate future multi-format event scenarios. Have find
validate argument matching and return error pointers to cover when
an existing event has the same name but different format. Update
callers to handle error pointer logic.

Move delete_user_event() to use hash walking directly now that
find_user_event() has changed. Delete all events found that match the
register name, stop if an error occurs and report back to the user.

Update user_fields_match() to cover list_empty() scenarios now that
find_user_event() uses it directly. This makes the logic consistent
across several callsites.

Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-2-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:12:54 -04:00
Vincent Donnefort
180e4e3909 tracing: Add snapshot refcount
When a ring-buffer is memory mapped by user-space, no trace or
ring-buffer swap is possible. This means the snapshot feature is
mutually exclusive with the memory mapping. Having a refcount on
snapshot users will help to know if a mapping is possible or not.

Instead of relying on the global trace_types_lock, a new spinlock is
introduced to serialize accesses to trace_array->snapshot. This intends
to allow access to that variable in a context where the mmap lock is
already held.

Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-4-vdonnefort@google.com

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:12:47 -04:00
Steven Rostedt (Google)
b70f293824 ring-buffer: Make wake once of ring_buffer_wait() more robust
The default behavior of ring_buffer_wait() when passed a NULL "cond"
parameter is to exit the function the first time it is woken up. The
current implementation uses a counter that starts at zero and when it is
greater than one it exits the wait_event_interruptible().

But this relies on the internal working of wait_event_interruptible() as
that code basically has:

  if (cond)
    return;
  prepare_to_wait();
  if (!cond)
    schedule();
  finish_wait();

That is, cond is called twice before it sleeps. The default cond of
ring_buffer_wait() needs to account for that and wait for its counter to
increment twice before exiting.

Instead, use the seq/atomic_inc logic that is used by the tracing code
that calls this function. Add an atomic_t seq to rb_irq_work and when cond
is NULL, have the default callback take a descriptor as its data that
holds the rbwork and the value of the seq when it started.

The wakeups will now increment the rbwork->seq and the cond callback will
simply check if that number is different, and no longer have to rely on
the implementation of wait_event_interruptible().

Link: https://lore.kernel.org/linux-trace-kernel/20240315063115.6cb5d205@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 7af9ded0c2 ("ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:11:43 -04:00
linke li
f1e30cb636 ring-buffer: use READ_ONCE() to read cpu_buffer->commit_page in concurrent environment
In function ring_buffer_iter_empty(), cpu_buffer->commit_page is read
while other threads may change it. It may cause the time_stamp that read
in the next line come from a different page. Use READ_ONCE() to avoid
having to reason about compiler optimizations now and in future.

Link: https://lore.kernel.org/linux-trace-kernel/tencent_DFF7D3561A0686B5E8FC079150A02505180A@qq.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-17 07:58:53 -04:00
Vincent Donnefort
6b76323e5a ring-buffer: Zero ring-buffer sub-buffers
In preparation for the ring-buffer memory mapping where each subbuf will
be accessible to user-space, zero all the page allocations.

Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-2-vdonnefort@google.com

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-17 07:58:53 -04:00
Steven Rostedt (Google)
2cc621fd2e tracing: Move saved_cmdline code into trace_sched_switch.c
The code that handles saved_cmdlines is split between the trace.c file and
the trace_sched_switch.c. There's some history to this. The
trace_sched_switch.c was originally created to handle the sched_switch
tracer that was deprecated due to sched_switch trace event making it
obsolete. But that file did not get deleted as it had some code to help
with saved_cmdlines. But trace.c has grown tremendously since then. Just
move all the saved_cmdlines code into trace_sched_switch.c as that's the
only reason that file still exists, and trace.c has gotten too big.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.497966629@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-17 07:58:53 -04:00
Steven Rostedt (Google)
e85d471c2b tracing: Move open coded processing of tgid_map into helper function
In preparation of moving the saved_cmdlines logic out of trace.c and into
trace_sched_switch.c, replace the open coded manipulation of tgid_map in
set_tracer_flag() into a helper function trace_alloc_tgid_map() so that it
can be easily moved into trace_sched_switch.c without changing existing
functions in trace.c.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.338116216@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-17 07:58:52 -04:00
Steven Rostedt (Google)
0b18c852cc tracing: Have saved_cmdlines arrays all in one allocation
The saved_cmdlines have three arrays for mapping PIDs to COMMs:

 - map_pid_to_cmdline[]
 - map_cmdline_to_pid[]
 - saved_cmdlines

The map_pid_to_cmdline[] is PID_MAX_DEFAULT in size and holds the index
into the other arrays. The map_cmdline_to_pid[] is a mapping back to the
full pid as it can be larger than PID_MAX_DEFAULT. And the
saved_cmdlines[] just holds the COMMs associated to the pids.

Currently the map_pid_to_cmdline[] and saved_cmdlines[] are allocated
together (in reality the saved_cmdlines is just in the memory of the
rounding of the allocation of the structure as it is always allocated in
powers of two). The map_cmdline_to_pid[] array is allocated separately.

Since the rounding to a power of two is rather large (it allows for 8000
elements in saved_cmdlines), also include the map_cmdline_to_pid[] array.
(This drops it to 6000 by default, which is still plenty for most use
cases). This saves even more memory as the map_cmdline_to_pid[] array
doesn't need to be allocated.

Link: https://lore.kernel.org/linux-trace-kernel/20240212174011.068211d9@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.182330529@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Fixes: 44dc5c41b5 ("tracing: Fix wasted memory in saved_cmdlines logic")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-17 07:58:52 -04:00
Linus Torvalds
63bd30f249 Tracing/ring-buffer fixes for 6.8 (to be applied in 6.9-rc):
- Do not update shortest_full in rb_watermark_hit() if the watermark
   is hit. The shortest_full field was being updated regardless if
   the task was going to wait or not. If the watermark is hit, then
   the task is not going to wait, so do not update the shortest_full
   field (used by the waker).
 
 - Update shortest_full field before setting the full_waiters_pending flag
 
   In the poll logic, the full_waiters_pending flag was being set
   before the shortest_full field was set. If the full_waiters_pending
   flag is set, writers will check the shortest_full field which has
   the least percentage of data that the ring buffer needs to be
   filled before waking up. The writer will check shortest_full if
   full_waiters_pending is set, and if the ring buffer percentage filled
   is greater than shortest full, then it will call the irq_work to
   wake up the waiters.
 
   The problem was that the poll logic set the full_waiters_pending flag
   before updating shortest_full, which when zero will always trigger
   the writer to call the irq_work to wake up the waiters. The irq_work
   will reset the shortest_full field back to zero as the woken waiters
   is suppose to reset it.
 
 - There's some optimized logic in the rb_watermark_hit() that is used
   in ring_buffer_wait(). Use that helper function in the poll logic
   as well.
 
 - Restructure ring_buffer_wait() to use wait_event_interruptible()
 
   The logic to wake up pending readers when the file descriptor is
   closed is racy. Restructure ring_buffer_wait() to allow callers
   to pass in conditions besides the ring buffer having enough data
   in it by using wait_event_interruptible().
 
 - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with
   its own conditions to exit the wait loop.
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Merge tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Do not update shortest_full in rb_watermark_hit() if the watermark is
   hit. The shortest_full field was being updated regardless if the task
   was going to wait or not. If the watermark is hit, then the task is
   not going to wait, so do not update the shortest_full field (used by
   the waker).

 - Update shortest_full field before setting the full_waiters_pending
   flag

   In the poll logic, the full_waiters_pending flag was being set before
   the shortest_full field was set. If the full_waiters_pending flag is
   set, writers will check the shortest_full field which has the least
   percentage of data that the ring buffer needs to be filled before
   waking up. The writer will check shortest_full if
   full_waiters_pending is set, and if the ring buffer percentage filled
   is greater than shortest full, then it will call the irq_work to wake
   up the waiters.

   The problem was that the poll logic set the full_waiters_pending flag
   before updating shortest_full, which when zero will always trigger
   the writer to call the irq_work to wake up the waiters. The irq_work
   will reset the shortest_full field back to zero as the woken waiters
   is suppose to reset it.

 - There's some optimized logic in the rb_watermark_hit() that is used
   in ring_buffer_wait(). Use that helper function in the poll logic as
   well.

 - Restructure ring_buffer_wait() to use wait_event_interruptible()

   The logic to wake up pending readers when the file descriptor is
   closed is racy. Restructure ring_buffer_wait() to allow callers to
   pass in conditions besides the ring buffer having enough data in it
   by using wait_event_interruptible().

 - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with its
   own conditions to exit the wait loop.

* tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/ring-buffer: Fix wait_on_pipe() race
  ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()
  ring-buffer: Reuse rb_watermark_hit() for the poll logic
  ring-buffer: Fix full_waiters_pending in poll
  ring-buffer: Do not set shortest_full when full target is hit
2024-03-14 16:25:01 -07:00
Linus Torvalds
01732755ee Probes updates for v6.9:
- x96/kprobes: Use boolean for some function return instead of 0 and 1.
  - x86/kprobes: Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a special
     purpose in the kernel.
  - x86/kprobes: Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed without
     ip register fixup, allow those to be boosted (direct execution on the
     trampoline buffer with a JMP).
 
  - tracing/probes: Add function argument access from return events (kretprobe
     and fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also accepts
     function argument access by name. This also includes below patches;
   . Fix a wrong comment (using "Kretprobe" in fprobe)
   . Cleanup a big probe argument parser function into three parts, type
      parser, post-processing function, and main parser.
   . Cleanup to set nr_args field when initializing trace_probe instead of
      counting up it while parsing.
   . Cleanup a redundant #else block from tracefs/README source code.
   . Update selftests to check entry argument access from return probes.
   . Documentation update about entry argument access from return probes.
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Merge tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "x86 kprobes:

   - Use boolean for some function return instead of 0 and 1

   - Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a
     special purpose in the kernel

   - Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed
     without ip register fixup, allow those to be boosted (direct
     execution on the trampoline buffer with a JMP)

  tracing:

   - Add function argument access from return events (kretprobe and
     fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also
     accepts function argument access by name.

   - Fix a wrong comment (using "Kretprobe" in fprobe)

   - Cleanup a big probe argument parser function into three parts, type
     parser, post-processing function, and main parser

   - Cleanup to set nr_args field when initializing trace_probe instead
     of counting up it while parsing

   - Cleanup a redundant #else block from tracefs/README source code

   - Update selftests to check entry argument access from return probes

   - Documentation update about entry argument access from return
     probes"

* tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add entry argument access at function exit
  selftests/ftrace: Add test cases for entry args at function exit
  tracing/probes: Support $argN in return probe (kprobe and fprobe)
  tracing: Remove redundant #else block for BTF args from README
  tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
  tracing/probes: Cleanup probe argument parser
  tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
  x86/kprobes: Boost more instructions from grp2/3/4/5
  x86/kprobes: Prohibit kprobing on INT and UD
  x86/kprobes: Refactor can_{probe,boost} return type to bool
2024-03-14 16:16:33 -07:00
Linus Torvalds
9187210eee Networking changes for 6.9.
Core & protocols
 ----------------
 
  - Large effort by Eric to lower rtnl_lock pressure and remove locks:
 
    - Make commonly used parts of rtnetlink (address, route dumps etc.)
      lockless, protected by RCU instead of rtnl_lock.
 
    - Add a netns exit callback which already holds rtnl_lock,
      allowing netns exit to take rtnl_lock once in the core
      instead of once for each driver / callback.
 
    - Remove locks / serialization in the socket diag interface.
 
    - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.
 
    - Remove the dev_base_lock, depend on RCU where necessary.
 
  - Support busy polling on a per-epoll context basis. Poll length
    and budget parameters can be set independently of system defaults.
 
  - Introduce struct net_hotdata, to make sure read-mostly global config
    variables fit in as few cache lines as possible.
 
  - Add optional per-nexthop statistics to ease monitoring / debug
    of ECMP imbalance problems.
 
  - Support TCP_NOTSENT_LOWAT in MPTCP.
 
  - Ensure that IPv6 temporary addresses' preferred lifetimes are long
    enough, compared to other configured lifetimes, and at least 2 sec.
 
  - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.
 
  - Add support for the independent control state machine for bonding
    per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
    control state machine.
 
  - Add "network ID" to MCTP socket APIs to support hosts with multiple
    disjoint MCTP networks.
 
  - Re-use the mono_delivery_time skbuff bit for packets which user
    space wants to be sent at a specified time. Maintain the timing
    information while traversing veth links, bridge etc.
 
  - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.
 
  - Simplify many places iterating over netdevs by using an xarray
    instead of a hash table walk (hash table remains in place, for
    use on fastpaths).
 
  - Speed up scanning for expired routes by keeping a dedicated list.
 
  - Speed up "generic" XDP by trying harder to avoid large allocations.
 
  - Support attaching arbitrary metadata to netconsole messages.
 
 Things we sprinkled into general kernel code
 --------------------------------------------
 
  - Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
    VM_SPARSE kind and vm_area_[un]map_pages (used by bpf_arena).
 
  - Rework selftest harness to enable the use of the full range of
    ksft exit code (pass, fail, skip, xfail, xpass).
 
 Netfilter
 ---------
 
  - Allow userspace to define a table that is exclusively owned by a daemon
    (via netlink socket aliveness) without auto-removing this table when
    the userspace program exits. Such table gets marked as orphaned and
    a restarting management daemon can re-attach/regain ownership.
 
  - Speed up element insertions to nftables' concatenated-ranges set type.
    Compact a few related data structures.
 
 BPF
 ---
 
  - Add BPF token support for delegating a subset of BPF subsystem
    functionality from privileged system-wide daemons such as systemd
    through special mount options for userns-bound BPF fs to a trusted
    & unprivileged application.
 
  - Introduce bpf_arena which is sparse shared memory region between BPF
    program and user space where structures inside the arena can have
    pointers to other areas of the arena, and pointers work seamlessly
    for both user-space programs and BPF programs.
 
  - Introduce may_goto instruction that is a contract between the verifier
    and the program. The verifier allows the program to loop assuming it's
    behaving well, but reserves the right to terminate it.
 
  - Extend the BPF verifier to enable static subprog calls in spin lock
    critical sections.
 
  - Support registration of struct_ops types from modules which helps
    projects like fuse-bpf that seeks to implement a new struct_ops type.
 
  - Add support for retrieval of cookies for perf/kprobe multi links.
 
  - Support arbitrary TCP SYN cookie generation / validation in the TC
    layer with BPF to allow creating SYN flood handling in BPF firewalls.
 
  - Add code generation to inline the bpf_kptr_xchg() helper which
    improves performance when stashing/popping the allocated BPF objects.
 
 Wireless
 --------
 
  - Add SPP (signaling and payload protected) AMSDU support.
 
  - Support wider bandwidth OFDMA, as required for EHT operation.
 
 Driver API
 ----------
 
  - Major overhaul of the Energy Efficient Ethernet internals to support
    new link modes (2.5GE, 5GE), share more code between drivers
    (especially those using phylib), and encourage more uniform behavior.
    Convert and clean up drivers.
 
  - Define an API for querying per netdev queue statistics from drivers.
 
  - IPSec: account in global stats for fully offloaded sessions.
 
  - Create a concept of Ethernet PHY Packages at the Device Tree level,
    to allow parameterizing the existing PHY package code.
 
  - Enable Rx hashing (RSS) on GTP protocol fields.
 
 Misc
 ----
 
  - Improvements and refactoring all over networking selftests.
 
  - Create uniform module aliases for TC classifiers, actions,
    and packet schedulers to simplify creating modprobe policies.
 
  - Address all missing MODULE_DESCRIPTION() warnings in networking.
 
  - Extend the Netlink descriptions in YAML to cover message encapsulation
    or "Netlink polymorphism", where interpretation of nested attributes
    depends on link type, classifier type or some other "class type".
 
 Drivers
 -------
 
  - Ethernet high-speed NICs:
    - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
    - Intel (100G, ice, idpf):
      - support E825-C devices
    - nVidia/Mellanox:
      - support devices with one port and multiple PCIe links
    - Broadcom (bnxt):
      - support n-tuple filters
      - support configuring the RSS key
    - Wangxun (ngbe/txgbe):
      - implement irq_domain for TXGBE's sub-interrupts
    - Pensando/AMD:
      - support XDP
      - optimize queue submission and wakeup handling (+17% bps)
      - optimize struct layout, saving 28% of memory on queues
 
  - Ethernet NICs embedded and virtual:
    - Google cloud vNIC:
      - refactor driver to perform memory allocations for new queue
        config before stopping and freeing the old queue memory
    - Synopsys (stmmac):
      - obey queueMaxSDU and implement counters required by 802.1Qbv
    - Renesas (ravb):
      - support packet checksum offload
      - suspend to RAM and runtime PM support
 
  - Ethernet switches:
    - nVidia/Mellanox:
      - support for nexthop group statistics
    - Microchip:
      - ksz8: implement PHY loopback
      - add support for KSZ8567, a 7-port 10/100Mbps switch
 
  - PTP:
    - New driver for RENESAS FemtoClock3 Wireless clock generator.
    - Support OCP PTP cards designed and built by Adva.
 
  - CAN:
    - Support recvmsg() flags for own, local and remote traffic
      on CAN BCM sockets.
    - Support for esd GmbH PCIe/402 CAN device family.
    - m_can:
      - Rx/Tx submission coalescing
      - wake on frame Rx
 
  - WiFi:
    - Intel (iwlwifi):
      - enable signaling and payload protected A-MSDUs
      - support wider-bandwidth OFDMA
      - support for new devices
      - bump FW API to 89 for AX devices; 90 for BZ/SC devices
    - MediaTek (mt76):
      - mt7915: newer ADIE version support
      - mt7925: radio temperature sensor support
    - Qualcomm (ath11k):
      - support 6 GHz station power modes: Low Power Indoor (LPI),
        Standard Power) SP and Very Low Power (VLP)
      - QCA6390 & WCN6855: support 2 concurrent station interfaces
      - QCA2066 support
    - Qualcomm (ath12k):
      - refactoring in preparation for Multi-Link Operation (MLO) support
      - 1024 Block Ack window size support
      - firmware-2.bin support
      - support having multiple identical PCI devices (firmware needs to
        have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
      - QCN9274: support split-PHY devices
      - WCN7850: enable Power Save Mode in station mode
      - WCN7850: P2P support
    - RealTek:
      - rtw88: support for more rtw8811cu and rtw8821cu devices
      - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
      - rtlwifi: speed up USB firmware initialization
      - rtwl8xxxu:
        - RTL8188F: concurrent interface support
        - Channel Switch Announcement (CSA) support in AP mode
    - Broadcom (brcmfmac):
      - per-vendor feature support
      - per-vendor SAE password setup
      - DMI nvram filename quirk for ACEPC W5 Pro
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Large effort by Eric to lower rtnl_lock pressure and remove locks:

      - Make commonly used parts of rtnetlink (address, route dumps
        etc) lockless, protected by RCU instead of rtnl_lock.

      - Add a netns exit callback which already holds rtnl_lock,
        allowing netns exit to take rtnl_lock once in the core instead
        of once for each driver / callback.

      - Remove locks / serialization in the socket diag interface.

      - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

      - Remove the dev_base_lock, depend on RCU where necessary.

   - Support busy polling on a per-epoll context basis. Poll length and
     budget parameters can be set independently of system defaults.

   - Introduce struct net_hotdata, to make sure read-mostly global
     config variables fit in as few cache lines as possible.

   - Add optional per-nexthop statistics to ease monitoring / debug of
     ECMP imbalance problems.

   - Support TCP_NOTSENT_LOWAT in MPTCP.

   - Ensure that IPv6 temporary addresses' preferred lifetimes are long
     enough, compared to other configured lifetimes, and at least 2 sec.

   - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

   - Add support for the independent control state machine for bonding
     per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
     control state machine.

   - Add "network ID" to MCTP socket APIs to support hosts with multiple
     disjoint MCTP networks.

   - Re-use the mono_delivery_time skbuff bit for packets which user
     space wants to be sent at a specified time. Maintain the timing
     information while traversing veth links, bridge etc.

   - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

   - Simplify many places iterating over netdevs by using an xarray
     instead of a hash table walk (hash table remains in place, for use
     on fastpaths).

   - Speed up scanning for expired routes by keeping a dedicated list.

   - Speed up "generic" XDP by trying harder to avoid large allocations.

   - Support attaching arbitrary metadata to netconsole messages.

  Things we sprinkled into general kernel code:

   - Enforce VM_IOREMAP flag and range in ioremap_page_range and
     introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
     bpf_arena).

   - Rework selftest harness to enable the use of the full range of ksft
     exit code (pass, fail, skip, xfail, xpass).

  Netfilter:

   - Allow userspace to define a table that is exclusively owned by a
     daemon (via netlink socket aliveness) without auto-removing this
     table when the userspace program exits. Such table gets marked as
     orphaned and a restarting management daemon can re-attach/regain
     ownership.

   - Speed up element insertions to nftables' concatenated-ranges set
     type. Compact a few related data structures.

  BPF:

   - Add BPF token support for delegating a subset of BPF subsystem
     functionality from privileged system-wide daemons such as systemd
     through special mount options for userns-bound BPF fs to a trusted
     & unprivileged application.

   - Introduce bpf_arena which is sparse shared memory region between
     BPF program and user space where structures inside the arena can
     have pointers to other areas of the arena, and pointers work
     seamlessly for both user-space programs and BPF programs.

   - Introduce may_goto instruction that is a contract between the
     verifier and the program. The verifier allows the program to loop
     assuming it's behaving well, but reserves the right to terminate
     it.

   - Extend the BPF verifier to enable static subprog calls in spin lock
     critical sections.

   - Support registration of struct_ops types from modules which helps
     projects like fuse-bpf that seeks to implement a new struct_ops
     type.

   - Add support for retrieval of cookies for perf/kprobe multi links.

   - Support arbitrary TCP SYN cookie generation / validation in the TC
     layer with BPF to allow creating SYN flood handling in BPF
     firewalls.

   - Add code generation to inline the bpf_kptr_xchg() helper which
     improves performance when stashing/popping the allocated BPF
     objects.

  Wireless:

   - Add SPP (signaling and payload protected) AMSDU support.

   - Support wider bandwidth OFDMA, as required for EHT operation.

  Driver API:

   - Major overhaul of the Energy Efficient Ethernet internals to
     support new link modes (2.5GE, 5GE), share more code between
     drivers (especially those using phylib), and encourage more
     uniform behavior. Convert and clean up drivers.

   - Define an API for querying per netdev queue statistics from
     drivers.

   - IPSec: account in global stats for fully offloaded sessions.

   - Create a concept of Ethernet PHY Packages at the Device Tree level,
     to allow parameterizing the existing PHY package code.

   - Enable Rx hashing (RSS) on GTP protocol fields.

  Misc:

   - Improvements and refactoring all over networking selftests.

   - Create uniform module aliases for TC classifiers, actions, and
     packet schedulers to simplify creating modprobe policies.

   - Address all missing MODULE_DESCRIPTION() warnings in networking.

   - Extend the Netlink descriptions in YAML to cover message
     encapsulation or "Netlink polymorphism", where interpretation of
     nested attributes depends on link type, classifier type or some
     other "class type".

  Drivers:

   - Ethernet high-speed NICs:
      - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
      - Intel (100G, ice, idpf):
         - support E825-C devices
      - nVidia/Mellanox:
         - support devices with one port and multiple PCIe links
      - Broadcom (bnxt):
         - support n-tuple filters
         - support configuring the RSS key
      - Wangxun (ngbe/txgbe):
         - implement irq_domain for TXGBE's sub-interrupts
      - Pensando/AMD:
         - support XDP
         - optimize queue submission and wakeup handling (+17% bps)
         - optimize struct layout, saving 28% of memory on queues

   - Ethernet NICs embedded and virtual:
      - Google cloud vNIC:
         - refactor driver to perform memory allocations for new queue
           config before stopping and freeing the old queue memory
      - Synopsys (stmmac):
         - obey queueMaxSDU and implement counters required by 802.1Qbv
      - Renesas (ravb):
         - support packet checksum offload
         - suspend to RAM and runtime PM support

   - Ethernet switches:
      - nVidia/Mellanox:
         - support for nexthop group statistics
      - Microchip:
         - ksz8: implement PHY loopback
         - add support for KSZ8567, a 7-port 10/100Mbps switch

   - PTP:
      - New driver for RENESAS FemtoClock3 Wireless clock generator.
      - Support OCP PTP cards designed and built by Adva.

   - CAN:
      - Support recvmsg() flags for own, local and remote traffic on CAN
        BCM sockets.
      - Support for esd GmbH PCIe/402 CAN device family.
      - m_can:
         - Rx/Tx submission coalescing
         - wake on frame Rx

   - WiFi:
      - Intel (iwlwifi):
         - enable signaling and payload protected A-MSDUs
         - support wider-bandwidth OFDMA
         - support for new devices
         - bump FW API to 89 for AX devices; 90 for BZ/SC devices
      - MediaTek (mt76):
         - mt7915: newer ADIE version support
         - mt7925: radio temperature sensor support
      - Qualcomm (ath11k):
         - support 6 GHz station power modes: Low Power Indoor (LPI),
           Standard Power) SP and Very Low Power (VLP)
         - QCA6390 & WCN6855: support 2 concurrent station interfaces
         - QCA2066 support
      - Qualcomm (ath12k):
         - refactoring in preparation for Multi-Link Operation (MLO)
           support
         - 1024 Block Ack window size support
         - firmware-2.bin support
         - support having multiple identical PCI devices (firmware needs
           to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
         - QCN9274: support split-PHY devices
         - WCN7850: enable Power Save Mode in station mode
         - WCN7850: P2P support
      - RealTek:
         - rtw88: support for more rtw8811cu and rtw8821cu devices
         - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
         - rtlwifi: speed up USB firmware initialization
         - rtwl8xxxu:
             - RTL8188F: concurrent interface support
             - Channel Switch Announcement (CSA) support in AP mode
      - Broadcom (brcmfmac):
         - per-vendor feature support
         - per-vendor SAE password setup
         - DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
  nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
  nexthop: Fix out-of-bounds access during attribute validation
  nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
  nexthop: Only parse NHA_OP_FLAGS for get messages that require it
  bpf: move sleepable flag from bpf_prog_aux to bpf_prog
  bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
  selftests/bpf: Add kprobe multi triggering benchmarks
  ptp: Move from simple ida to xarray
  vxlan: Remove generic .ndo_get_stats64
  vxlan: Do not alloc tstats manually
  devlink: Add comments to use netlink gen tool
  nfp: flower: handle acti_netdevs allocation failure
  net/packet: Add getsockopt support for PACKET_COPY_THRESH
  net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
  selftests/bpf: Add bpf_arena_htab test.
  selftests/bpf: Add bpf_arena_list test.
  selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
  bpf: Add helper macro bpf_addr_space_cast()
  libbpf: Recognize __arena global variables.
  bpftool: Recognize arena map type
  ...
2024-03-12 17:44:08 -07:00
Steven Rostedt (Google)
2aa043a55b tracing/ring-buffer: Fix wait_on_pipe() race
When the trace_pipe_raw file is closed, there should be no new readers on
the file descriptor. This is mostly handled with the waking and wait_index
fields of the iterator. But there's still a slight race.

     CPU 0                              CPU 1
     -----                              -----
                                   wait_index++;
   index = wait_index;
                                   ring_buffer_wake_waiters();
   wait_on_pipe()
     ring_buffer_wait();

The ring_buffer_wait() will miss the wakeup from CPU 1. The problem is
that the ring_buffer_wait() needs the logic of:

        prepare_to_wait();
        if (!condition)
                schedule();

Where the missing condition check is the iter->wait_index update.

Have the ring_buffer_wait() take a conditional callback function and a
data parameter that can be used within the wait_event_interruptible() of
the ring_buffer_wait() function.

In wait_on_pipe(), pass a condition function that will check if the
wait_index has been updated, if it has, it will return true to break out
of the wait_event_interruptible() loop.

Create a new field "closed" in the trace_iterator and set it in the
.flush() callback before calling ring_buffer_wake_waiters().
This will keep any new readers from waiting on a closed file descriptor.

Have the wait_on_pipe() condition callback also check the closed field.

Change the wait_index field of the trace_iterator to atomic_t. There's no
reason it needs to be 'long' and making it atomic and using
atomic_read_acquire() and atomic_fetch_inc_release() will provide the
necessary memory barriers.

Add a "woken" flag to tracing_buffers_splice_read() to exit the loop after
one more try to fetch data. That is, if it waited for data and something
woke it up, it should try to collect any new data and then exit back to
user space.

Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.557950713@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-12 12:44:48 -04:00
Steven Rostedt (Google)
7af9ded0c2 ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()
Convert ring_buffer_wait() over to wait_event_interruptible(). The default
condition is to execute the wait loop inside __wait_event() just once.

This does not change the ring_buffer_wait() prototype yet, but
restructures the code so that it can take a "cond" and "data" parameter
and will call wait_event_interruptible() with a helper function as the
condition.

The helper function (rb_wait_cond) takes the cond function and data
parameters. It will first check if the buffer hit the watermark defined by
the "full" parameter and then call the passed in condition parameter. If
either are true, it returns true.

If rb_wait_cond() does not return true, it will set the appropriate
"waiters_pending" flag and returns false.

Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.399598519@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-12 12:44:35 -04:00
Steven Rostedt (Google)
e36f19a645 ring-buffer: Reuse rb_watermark_hit() for the poll logic
The check for knowing if the poll should wait or not is basically the
exact same logic as rb_watermark_hit(). The only difference is that
rb_watermark_hit() also handles the !full case. But for the full case, the
logic is the same. Just call that instead of duplicating the code in
ring_buffer_poll_wait().

Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.802267543@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-12 12:44:07 -04:00
Steven Rostedt (Google)
8145f1c35f ring-buffer: Fix full_waiters_pending in poll
If a reader of the ring buffer is doing a poll, and waiting for the ring
buffer to hit a specific watermark, there could be a case where it gets
into an infinite ping-pong loop.

The poll code has:

  rbwork->full_waiters_pending = true;
  if (!cpu_buffer->shortest_full ||
      cpu_buffer->shortest_full > full)
         cpu_buffer->shortest_full = full;

The writer will see full_waiters_pending and check if the ring buffer is
filled over the percentage of the shortest_full value. If it is, it calls
an irq_work to wake up all the waiters.

But the code could get into a circular loop:

	CPU 0					CPU 1
	-----					-----
 [ Poll ]
   [ shortest_full = 0 ]
   rbwork->full_waiters_pending = true;
					  if (rbwork->full_waiters_pending &&
					      [ buffer percent ] > shortest_full) {
					         rbwork->wakeup_full = true;
					         [ queue_irqwork ]

   cpu_buffer->shortest_full = full;

					  [ IRQ work ]
					  if (rbwork->wakeup_full) {
					        cpu_buffer->shortest_full = 0;
					        wakeup poll waiters;
  [woken]
   if ([ buffer percent ] > full)
      break;
   rbwork->full_waiters_pending = true;
					  if (rbwork->full_waiters_pending &&
					      [ buffer percent ] > shortest_full) {
					         rbwork->wakeup_full = true;
					         [ queue_irqwork ]

   cpu_buffer->shortest_full = full;

					  [ IRQ work ]
					  if (rbwork->wakeup_full) {
					        cpu_buffer->shortest_full = 0;
					        wakeup poll waiters;
  [woken]

 [ Wash, rinse, repeat! ]

In the poll, the shortest_full needs to be set before the
full_pending_waiters, as once that is set, the writer will compare the
current shortest_full (which is incorrect) to decide to call the irq_work,
which will reset the shortest_full (expecting the readers to update it).

Also move the setting of full_waiters_pending after the check if the ring
buffer has the required percentage filled. There's no reason to tell the
writer to wake up waiters if there are no waiters.

Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.630922155@goodmis.org

Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-12 12:43:30 -04:00
Steven Rostedt (Google)
761d9473e2 ring-buffer: Do not set shortest_full when full target is hit
The rb_watermark_hit() checks if the amount of data in the ring buffer is
above the percentage level passed in by the "full" variable. If it is, it
returns true.

But it also sets the "shortest_full" field of the cpu_buffer that informs
writers that it needs to call the irq_work if the amount of data on the
ring buffer is above the requested amount.

The rb_watermark_hit() always sets the shortest_full even if the amount in
the ring buffer is what it wants. As it is not going to wait, because it
has what it wants, there's no reason to set shortest_full.

Link: https://lore.kernel.org/linux-trace-kernel/20240312115641.6aa8ba08@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-12 12:40:28 -04:00
Linus Torvalds
685d982112 Core x86 changes for v6.9:
- The biggest change is the rework of the percpu code,
   to support the 'Named Address Spaces' GCC feature,
   by Uros Bizjak:
 
    - This allows C code to access GS and FS segment relative
      memory via variables declared with such attributes,
      which allows the compiler to better optimize those accesses
      than the previous inline assembly code.
 
    - The series also includes a number of micro-optimizations
      for various percpu access methods, plus a number of
      cleanups of %gs accesses in assembly code.
 
    - These changes have been exposed to linux-next testing for
      the last ~5 months, with no known regressions in this area.
 
 - Fix/clean up __switch_to()'s broken but accidentally
   working handling of FPU switching - which also generates
   better code.
 
 - Propagate more RIP-relative addressing in assembly code,
   to generate slightly better code.
 
 - Rework the CPU mitigations Kconfig space to be less idiosyncratic,
   to make it easier for distros to follow & maintain these options.
 
 - Rework the x86 idle code to cure RCU violations and
   to clean up the logic.
 
 - Clean up the vDSO Makefile logic.
 
 - Misc cleanups and fixes.
 
 [ Please note that there's a higher number of merge commits in
   this branch (three) than is usual in x86 topic trees. This happened
   due to the long testing lifecycle of the percpu changes that
   involved 3 merge windows, which generated a longer history
   and various interactions with other core x86 changes that we
   felt better about to carry in a single branch. ]
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core x86 updates from Ingo Molnar:

 - The biggest change is the rework of the percpu code, to support the
   'Named Address Spaces' GCC feature, by Uros Bizjak:

      - This allows C code to access GS and FS segment relative memory
        via variables declared with such attributes, which allows the
        compiler to better optimize those accesses than the previous
        inline assembly code.

      - The series also includes a number of micro-optimizations for
        various percpu access methods, plus a number of cleanups of %gs
        accesses in assembly code.

      - These changes have been exposed to linux-next testing for the
        last ~5 months, with no known regressions in this area.

 - Fix/clean up __switch_to()'s broken but accidentally working handling
   of FPU switching - which also generates better code

 - Propagate more RIP-relative addressing in assembly code, to generate
   slightly better code

 - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
   make it easier for distros to follow & maintain these options

 - Rework the x86 idle code to cure RCU violations and to clean up the
   logic

 - Clean up the vDSO Makefile logic

 - Misc cleanups and fixes

* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/idle: Select idle routine only once
  x86/idle: Let prefer_mwait_c1_over_halt() return bool
  x86/idle: Cleanup idle_setup()
  x86/idle: Clean up idle selection
  x86/idle: Sanitize X86_BUG_AMD_E400 handling
  sched/idle: Conditionally handle tick broadcast in default_idle_call()
  x86: Increase brk randomness entropy for 64-bit systems
  x86/vdso: Move vDSO to mmap region
  x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
  x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
  x86/retpoline: Ensure default return thunk isn't used at runtime
  x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
  x86/vdso: Use $(addprefix ) instead of $(foreach )
  x86/vdso: Simplify obj-y addition
  x86/vdso: Consolidate targets and clean-files
  x86/bugs: Rename CONFIG_RETHUNK              => CONFIG_MITIGATION_RETHUNK
  x86/bugs: Rename CONFIG_CPU_SRSO             => CONFIG_MITIGATION_SRSO
  x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY       => CONFIG_MITIGATION_IBRS_ENTRY
  x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY      => CONFIG_MITIGATION_UNRET_ENTRY
  x86/bugs: Rename CONFIG_SLS                  => CONFIG_MITIGATION_SLS
  ...
2024-03-11 19:53:15 -07:00
Jakub Kicinski
5f20e6ab1f for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2024-03-11

We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).

The main changes are:

1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
   VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
   from Alexei.

2) Introduce bpf_arena which is sparse shared memory region between bpf
   program and user space where structures inside the arena can have
   pointers to other areas of the arena, and pointers work seamlessly for
   both user-space programs and bpf programs, from Alexei and Andrii.

3) Introduce may_goto instruction that is a contract between the verifier
   and the program. The verifier allows the program to loop assuming it's
   behaving well, but reserves the right to terminate it, from Alexei.

4) Use IETF format for field definitions in the BPF standard
   document, from Dave.

5) Extend struct_ops libbpf APIs to allow specify version suffixes for
   stuct_ops map types, share the same BPF program between several map
   definitions, and other improvements, from Eduard.

6) Enable struct_ops support for more than one page in trampolines,
   from Kui-Feng.

7) Support kCFI + BPF on riscv64, from Puranjay.

8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.

9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================

Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 18:06:04 -07:00
Andrii Nakryiko
66c8473135 bpf: move sleepable flag from bpf_prog_aux to bpf_prog
prog->aux->sleepable is checked very frequently as part of (some) BPF
program run hot paths. So this extra aux indirection seems wasteful and
on busy systems might cause unnecessary memory cache misses.

Let's move sleepable flag into prog itself to eliminate unnecessary
pointer dereference.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Message-ID: <20240309004739.2961431-1-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-11 16:41:25 -07:00
Linus Torvalds
fa4b851b4a Tracing fixes for v6.8-rc7:
- Do not allow large strings (> 4096) as single write to trace_marker
 
   The size of a string written into trace_marker was determined by
   the size of the sub-buffer in the ring buffer. That size is
   dependent on the PAGE_SIZE of the architecture as it can be mapped
   into user space. But on PowerPC, where PAGE_SIZE is 64K, that made
   the limit of the string of writing into trace_marker 64K.
 
   One of the selftests looks at the size of the ring buffer sub-buffers
   and writes that plus more into the trace_marker. The write will take
   what it can and report back what it consumed so that the user space
   application (like echo) will write the rest of the string. The string
   is stored in the ring buffer and can be read via the "trace" or
   "trace_pipe" files.
 
   The reading of the ring buffer uses vsnprintf(), which uses a precision
   "%.*s" to make sure it only reads what is stored in the buffer, as
   a bug could cause the string to be non terminated.
 
   With the combination of the precision change and the PAGE_SIZE of 64K
   allowing huge strings to be added into the ring buffer, plus the test
   that would actually stress that limit, a bug was reported that
   the precision used was too big for "%.*s" as the string was close to
   64K in size and the max precision of vsnprintf is 32K.
 
   Linus suggested not to have that precision as it could hide a bug
   if the string was again stored without a nul byte.
 
   Another issue that was brought up is that the trace_seq buffer is
   also based on PAGE_SIZE even though it is not tied to the architecture
   limit like the ring buffer sub-buffer is. Having it be 64K * 2 is
   simply just too big and wasting memory on systems with 64K page sizes.
   It is now hardcoded to 8K which is what all other architectures with
   4K PAGE_SIZE has.
 
   Finally, the write to trace_marker is now limited to 4K as there is no
   reason to write larger strings into trace_marker.
 
 - ring_buffer_wait() should not loop.
   The ring_buffer_wait() does not have the full context (yet) on if it
   should loop or not. Just exit the loop as soon as its woken up and
   let the callers decide to loop or not (they already do, so it's a bit
   redundant).
 
 - Fix shortest_full field to be the smallest amount in the ring buffer that
   a waiter is waiting for. The "shortest_full" field is updated when a new
   waiter comes in and wants to wait for a smaller amount of data in the
   ring buffer than other waiters. But after all waiters are woken up, it's
   not reset, so if another waiter comes in wanting to wait for more data,
   it will be woken up when the ring buffer has a smaller amount from what
   the previous waiters were waiting for.
 
 - The wake up all waiters on close is incorrectly called frome .release()
   and not from .flush() so it will never wake up any waiters as the
   .release() will not get called until all .read() calls are finished. And the
   wakeup is for the waiters in those .read() calls.
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Merge tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Do not allow large strings (> 4096) as single write to trace_marker

   The size of a string written into trace_marker was determined by the
   size of the sub-buffer in the ring buffer. That size is dependent on
   the PAGE_SIZE of the architecture as it can be mapped into user
   space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of
   the string of writing into trace_marker 64K.

   One of the selftests looks at the size of the ring buffer sub-buffers
   and writes that plus more into the trace_marker. The write will take
   what it can and report back what it consumed so that the user space
   application (like echo) will write the rest of the string. The string
   is stored in the ring buffer and can be read via the "trace" or
   "trace_pipe" files.

   The reading of the ring buffer uses vsnprintf(), which uses a
   precision "%.*s" to make sure it only reads what is stored in the
   buffer, as a bug could cause the string to be non terminated.

   With the combination of the precision change and the PAGE_SIZE of 64K
   allowing huge strings to be added into the ring buffer, plus the test
   that would actually stress that limit, a bug was reported that the
   precision used was too big for "%.*s" as the string was close to 64K
   in size and the max precision of vsnprintf is 32K.

   Linus suggested not to have that precision as it could hide a bug if
   the string was again stored without a nul byte.

   Another issue that was brought up is that the trace_seq buffer is
   also based on PAGE_SIZE even though it is not tied to the
   architecture limit like the ring buffer sub-buffer is. Having it be
   64K * 2 is simply just too big and wasting memory on systems with 64K
   page sizes. It is now hardcoded to 8K which is what all other
   architectures with 4K PAGE_SIZE has.

   Finally, the write to trace_marker is now limited to 4K as there is
   no reason to write larger strings into trace_marker.

 - ring_buffer_wait() should not loop.

   The ring_buffer_wait() does not have the full context (yet) on if it
   should loop or not. Just exit the loop as soon as its woken up and
   let the callers decide to loop or not (they already do, so it's a bit
   redundant).

 - Fix shortest_full field to be the smallest amount in the ring buffer
   that a waiter is waiting for. The "shortest_full" field is updated
   when a new waiter comes in and wants to wait for a smaller amount of
   data in the ring buffer than other waiters. But after all waiters are
   woken up, it's not reset, so if another waiter comes in wanting to
   wait for more data, it will be woken up when the ring buffer has a
   smaller amount from what the previous waiters were waiting for.

 - The wake up all waiters on close is incorrectly called frome
   .release() and not from .flush() so it will never wake up any waiters
   as the .release() will not get called until all .read() calls are
   finished. And the wakeup is for the waiters in those .read() calls.

* tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Use .flush() call to wake up readers
  ring-buffer: Fix resetting of shortest_full
  ring-buffer: Fix waking up ring buffer readers
  tracing: Limit trace_marker writes to just 4K
  tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE
  tracing: Remove precision vsnprintf() check from print event
2024-03-10 11:53:21 -07:00
Steven Rostedt (Google)
e5d7c19165 tracing: Use .flush() call to wake up readers
The .release() function does not get called until all readers of a file
descriptor are finished.

If a thread is blocked on reading a file descriptor in ring_buffer_wait(),
and another thread closes the file descriptor, it will not wake up the
other thread as ring_buffer_wake_waiters() is called by .release(), and
that will not get called until the .read() is finished.

The issue originally showed up in trace-cmd, but the readers are actually
other processes with their own file descriptors. So calling close() would wake
up the other tasks because they are blocked on another descriptor then the
one that was closed(). But there's other wake ups that solve that issue.

When a thread is blocked on a read, it can still hang even when another
thread closed its descriptor.

This is what the .flush() callback is for. Have the .flush() wake up the
readers.

Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-10 12:27:47 -04:00