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master
909 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Steven Rostedt
|
bfb336cf97 |
ftrace: Also allocate and copy hash for reading of filter files
Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds
the pointer to the global tracer hash to its iterator. Unlike the writer
that allocates a copy of the hash, the reader keeps the pointer to the
filter hashes. This is problematic because this pointer is static across
function calls that release the locks that can update the global tracer
hashes. This can cause UAF and similar bugs.
Allocate and copy the hash for reading the filter files like it is done
for the writers. This not only fixes UAF bugs, but also makes the code a
bit simpler as it doesn't have to differentiate when to free the
iterator's hash between writers and readers.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250822183606.12962cc3@batman.local.home
Fixes:
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Steven Rostedt
|
4d6d0a6263 |
tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
Ftrace is tightly coupled with architecture specific code because it requires the use of trampolines written in assembly. This means that when a new feature or optimization is made, it must be done for all architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are added to denote which architecture has the new enhancement so that other architectures can still function until they too have been updated. The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the DYNAMIC_FTRACE work, but now every architecture that implements DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant with the HAVE_DYNAMIC_FTRACE. Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where applicable. Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Linus Torvalds
|
119b1e61a7 |
RISC-V Patches for the 6.16 Merge Window, Part 1
* Support for the FWFT SBI extension, which is part of SBI 3.0 and a dependency for many new SBI and ISA extensions. * Support for getrandom() in the VDSO. * Support for mseal. * Optimized routines for raid6 syndrome and recovery calculations. * kexec_file() supports loading Image-formatted kernel binaries. * Improvements to the instruction patching framework to allow for atomic instruction patching, along with rules as to how systems need to behave in order to function correctly. * Support for a handful of new ISA extensions: Svinval, Zicbop, Zabha, some SiFive vendor extensions. * Various fixes and cleanups, including: misaligned access handling, perf symbol mangling, module loading, PUD THPs, and improved uaccess routines. -----BEGIN PGP SIGNATURE----- iQJNBAABCAA3FiEEKzw3R0RoQ7JKlDp6LhMZ81+7GIkFAmhDLP8ZHHBhbG1lcmRh YmJlbHRAZ29vZ2xlLmNvbQAKCRAuExnzX7sYiZhFD/4+Zikkld812VjFb9dTF+Wj n/x9h86zDwAEFgf2BMIpUQhHru6vtdkO2l/Ky6mQblTPMWLafF4eK85yCsf84sQ0 +RX4sOMLZ0+qvqxKX+aOFe9JXOWB0QIQuPvgBfDDOV4UTm60sglIxwqOpKcsBEHs 2nplXXjiv0ckaMFLos8xlwu1uy4A/jMfT3Y9FDcABxYCqBoKOZ1frcL9ezJZbHbv BoOKLDH8ZypFxIG/eQ511lIXXtrnLas0l4jHWjrfsWu6pmXTgJasKtbGuH3LoLnM G/4qvHufR6lpVUOIL5L0V6PpsmYwDi/ciFIFlc8NH2oOZil3qiVaGSEbJIkWGFu9 8lWTXQWnbinZbfg2oYbWp8GlwI70vKomtDyYNyB9q9Cq9jyiTChMklRNODr4764j ZiEnzc/l4KyvaxUg8RLKCT595lKECiUDnMytbIbunJu05HBqRCoGpBtMVzlQsyUd ybkRt3BA7eOR8/xFA7ZZQeJofmiu2yxkBs5ggMo8UnSragw27hmv/OA0mWMXEuaD aaWc4ZKpKqf7qLchLHOvEl5ORUhsisyIJgZwOqdme5rQoWorVtr51faA4AKwFAN4 vcKgc5qJjK8vnpW+rl3LNJF9LtH+h4TgmUI853vUlukPoH2oqRkeKVGSkxG0iAze eQy2VjP1fJz6ciRtJZn9aw== =cZGy -----END PGP SIGNATURE----- Merge tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the FWFT SBI extension, which is part of SBI 3.0 and a dependency for many new SBI and ISA extensions - Support for getrandom() in the VDSO - Support for mseal - Optimized routines for raid6 syndrome and recovery calculations - kexec_file() supports loading Image-formatted kernel binaries - Improvements to the instruction patching framework to allow for atomic instruction patching, along with rules as to how systems need to behave in order to function correctly - Support for a handful of new ISA extensions: Svinval, Zicbop, Zabha, some SiFive vendor extensions - Various fixes and cleanups, including: misaligned access handling, perf symbol mangling, module loading, PUD THPs, and improved uaccess routines * tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (69 commits) riscv: uaccess: Only restore the CSR_STATUS SUM bit RISC-V: vDSO: Wire up getrandom() vDSO implementation riscv: enable mseal sysmap for RV64 raid6: Add RISC-V SIMD syndrome and recovery calculations riscv: mm: Add support for Svinval extension RISC-V: Documentation: Add enough title underlines to CMODX riscv: Improve Kconfig help for RISCV_ISA_V_PREEMPTIVE MAINTAINERS: Update Atish's email address riscv: uaccess: do not do misaligned accesses in get/put_user() riscv: process: use unsigned int instead of unsigned long for put_user() riscv: make unsafe user copy routines use existing assembly routines riscv: hwprobe: export Zabha extension riscv: Make regs_irqs_disabled() more clear perf symbols: Ignore mapping symbols on riscv RISC-V: Kconfig: Fix help text of CMDLINE_EXTEND riscv: module: Optimize PLT/GOT entry counting riscv: Add support for PUD THP riscv: xchg: Prefetch the destination word for sc.w riscv: Add ARCH_HAS_PREFETCH[W] support with Zicbop riscv: Add support for Zicbop ... |
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Palmer Dabbelt
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2670a39b1e
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Merge tag 'riscv-mw2-6.16-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux into for-next
riscv patches for 6.16-rc1, part 2 * Performance improvements - Add support for vdso getrandom - Implement raid6 calculations using vectors - Introduce svinval tlb invalidation * Cleanup - A bunch of deduplication of the macros we use for manipulating instructions * Misc - Introduce a kunit test for kprobes - Add support for mseal as riscv fits the requirements (thanks to Lorenzo for making sure of that :)) [Palmer: There was a rebase between part 1 and part 2, so I've had to do some more git surgery here... at least two rounds of surgery...] * alex-pr-2: (866 commits) RISC-V: vDSO: Wire up getrandom() vDSO implementation riscv: enable mseal sysmap for RV64 raid6: Add RISC-V SIMD syndrome and recovery calculations riscv: mm: Add support for Svinval extension riscv: Add kprobes KUnit test riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_UTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RD_REG riscv: kprobes: Remove duplication of RVC_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RVC_EXTRACT_C2_RS1_REG riscv: kproves: Remove duplication of RVC_EXTRACT_JTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_BTYPE_IMM riscv: kprobes: Remove duplication of RV_EXTRACT_RS1_REG riscv: kprobes: Remove duplication of RV_EXTRACT_JTYPE_IMM riscv: kprobes: Move branch_funct3 to insn.h riscv: kprobes: Move branch_rs2_idx to insn.h Linux 6.15-rc6 Input: xpad - fix xpad_device sorting Input: xpad - add support for several more controllers Input: xpad - fix Share button on Xbox One controllers ... |
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Andy Chiu
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500e626c4a
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kernel: ftrace: export ftrace_sync_ipi
The following ftrace patch for riscv uses a data store to update ftrace function. Therefore, a romote fence is required to order it against function_trace_op updates. The mechanism is similar to the fence between function_trace_op and update_ftrace_func in the generic ftrace, so we leverage the same ftrace_sync_ipi function. [ alex: Fix build warning when !CONFIG_DYNAMIC_FTRACE ] Signed-off-by: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/r/20250407180838.42877-4-andybnac@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com> |
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Ye Bin
|
5834a59738 |
ftrace: Don't allocate ftrace module map if ftrace is disabled
If ftrace is disabled, it is meaningless to allocate a module map. Add a check in allocate_ftrace_mod_map() to not allocate if ftrace is disabled. Link: https://lore.kernel.org/20250529111955.2349189-3-yebin@huaweicloud.com Signed-off-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Ye Bin
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f914b52c37 |
ftrace: Fix UAF when lookup kallsym after ftrace disabled
The following issue happens with a buggy module:
BUG: unable to handle page fault for address: ffffffffc05d0218
PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
RIP: 0010:sized_strscpy+0x81/0x2f0
RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
FS: 00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ftrace_mod_get_kallsym+0x1ac/0x590
update_iter_mod+0x239/0x5b0
s_next+0x5b/0xa0
seq_read_iter+0x8c9/0x1070
seq_read+0x249/0x3b0
proc_reg_read+0x1b0/0x280
vfs_read+0x17f/0x920
ksys_read+0xf3/0x1c0
do_syscall_64+0x5f/0x2e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The above issue may happen as follows:
(1) Add kprobe tracepoint;
(2) insmod test.ko;
(3) Module triggers ftrace disabled;
(4) rmmod test.ko;
(5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
ftrace_mod_get_kallsym()
...
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
...
The problem is when a module triggers an issue with ftrace and
sets ftrace_disable. The ftrace_disable is set when an anomaly is
discovered and to prevent any more damage, ftrace stops all text
modification. The issue that happened was that the ftrace_disable stops
more than just the text modification.
When a module is loaded, its init functions can also be traced. Because
kallsyms deletes the init functions after a module has loaded, ftrace
saves them when the module is loaded and function tracing is enabled. This
allows the output of the function trace to show the init function names
instead of just their raw memory addresses.
When a module is removed, ftrace_release_mod() is called, and if
ftrace_disable is set, it just returns without doing anything more. The
problem here is that it leaves the mod_list still around and if kallsyms
is called, it will call into this code and access the module memory that
has already been freed as it will return:
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
Where the "mod" no longer exists and triggers a UAF bug.
Link: https://lore.kernel.org/all/20250523135452.626d8dcd@gandalf.local.home/
Cc: stable@vger.kernel.org
Fixes:
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Steven Rostedt
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a54665ab7c |
ftrace: Comment that ftrace_func_mapper is freed with free_ftrace_hash()
The structure ftrace_func_mapper only contains a single field and that is a ftrace_hash. It is used to abstract it out from a normal hash to control users of how it gets modified. The freeing of a ftrace_func_mapper structure is: free_ftrace_hash(&mapper->hash); Without context, this looks like a bug. It should be commented that it is not a bug and it is freed this way. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/20250416165420.5c717420@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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88cefd99ee |
ftrace: Show subops in enabled_functions
The function graph infrastructure uses subops of the function tracer.
These are not shown in enabled_functions. Add a "subops:" section to the
enabled_functions line to show what functions are attached via subops. If
the subops is from the function_graph infrastructure, then show the entry
and return callbacks that are attached.
Here's an example of the output:
schedule_on_each_cpu (1) tramp: 0xffffffffc03ef000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:trace_graph_entry+0x0/0x20 ret:trace_graph_return+0x0/0x150}
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/20250410153830.5d97f108@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Colin Ian King
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3c1d9cfa84 |
ftrace: Fix NULL memory allocation check
The check for a failed memory location is incorrectly checking
the wrong level of pointer indirection by checking !filter_hash
rather than !*filter_hash. Fix this.
Cc: asami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250422221335.89896-1-colin.i.king@gmail.com
Fixes:
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Menglong Dong
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92f1d3b401 |
ftrace: fix incorrect hash size in register_ftrace_direct()
The maximum of the ftrace hash bits is made fls(32) in
register_ftrace_direct(), which seems illogical. So, we fix it by making
the max hash bits FTRACE_HASH_MAX_BITS instead.
Link: https://lore.kernel.org/20250413014444.36724-1-dongml2@chinatelecom.cn
Fixes:
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Steven Rostedt
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c45c585dde |
ftrace: Free ftrace hashes after they are replaced in the subops code
The subops processing creates new hashes when adding and removing subops.
There were some places that the old hashes that were replaced were not
freed and this caused some memory leaks.
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/20250417135939.245b128d@gandalf.local.home
Fixes:
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Steven Rostedt
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08275e59a7 |
ftrace: Reinitialize hash to EMPTY_HASH after freeing
There's several locations that free a ftrace hash pointer but may be
referenced again. Reset them to EMPTY_HASH so that a u-a-f bug doesn't
happen.
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/20250417110933.20ab718b@gandalf.local.home
Fixes:
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Steven Rostedt
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31d1139956 |
ftrace: Initialize variables for ftrace_startup/shutdown_subops()
The reworking to fix and simplify the ftrace_startup_subops() and the
ftrace_shutdown_subops() made it possible for the filter_hash and
notrace_hash variables to be used uninitialized in a way that the compiler
did not catch it.
Initialize both filter_hash and notrace_hash to the EMPTY_HASH as that is
what they should be if they never are used.
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/20250417104017.3aea66c2@gandalf.local.home
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Fixes:
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Steven Rostedt
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0ae6b8ce20 |
ftrace: Fix accounting of subop hashes
The function graph infrastructure uses ftrace to hook to functions. It has a single ftrace_ops to manage all the users of function graph. Each individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to track the functions it will have its callback called from. These ftrace_ops are "subops" to the main ftrace_ops of the function graph infrastructure. Each ftrace_ops has a filter_hash and a notrace_hash that is defined as: Only trace functions that are in the filter_hash but not in the notrace_hash. If the filter_hash is empty, it means to trace all functions. If the notrace_hash is empty, it means do not disable any function. The function graph main ftrace_ops needs to be a superset containing all the functions to be traced by all the subops it has. The algorithm to perform this merge was incorrect. When the first subops was added to the main ops, it simply made the main ops a copy of the subops (same filter_hash and notrace_hash). When a second ops was added, it joined the new subops filter_hash with the main ops filter_hash as a union of the two sets. The intersect between the new subops notrace_hash and the main ops notrace_hash was created as the new notrace_hash of the main ops. The issue here is that it would then start tracing functions than no subops were tracing. For example if you had two subops that had: subops 1: filter_hash = '*sched*' # trace all functions with "sched" in it notrace_hash = '*time*' # except do not trace functions with "time" subops 2: filter_hash = '*lock*' # trace all functions with "lock" in it notrace_hash = '*clock*' # except do not trace functions with "clock" The intersect of '*time*' functions with '*clock*' functions could be the empty set. That means the main ops will be tracing all functions with '*time*' and all "*clock*" in it! Instead, modify the algorithm to be a bit simpler and correct. First, when adding a new subops, even if it's the first one, do not add the notrace_hash if the filter_hash is not empty. Instead, just add the functions that are in the filter_hash of the subops but not in the notrace_hash of the subops into the main ops filter_hash. There's no reason to add anything to the main ops notrace_hash. The notrace_hash of the main ops should only be non empty iff all subops filter_hashes are empty (meaning to trace all functions) and all subops notrace_hashes include the same functions. That is, the main ops notrace_hash is empty if any subops filter_hash is non empty. The main ops notrace_hash only has content in it if all subops filter_hashes are empty, and the content are only functions that intersect all the subops notrace_hashes. If any subops notrace_hash is empty, then so is the main ops notrace_hash. 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: Shuah Khan <skhan@linuxfoundation.org> Cc: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Andy Chiu
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04a80a34c2 |
ftrace: Properly merge notrace hashes
The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes:
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zhoumin
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42ea22e754 |
ftrace: Add cond_resched() to ftrace_graph_set_hash()
When the kernel contains a large number of functions that can be traced,
the loop in ftrace_graph_set_hash() may take a lot of time to execute.
This may trigger the softlockup watchdog.
Add cond_resched() within the loop to allow the kernel to remain
responsive even when processing a large number of functions.
This matches the cond_resched() that is used in other locations of the
code that iterates over all functions that can be traced.
Cc: stable@vger.kernel.org
Fixes:
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Linus Torvalds
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31eb415bf6 |
ftrace changes for v6.15:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the function
graph tracer (funcgraph-args) that when set, the tracers will record the
registers that hold the arguments into each function event. On reading of
the trace, it will use BTF to print those arguments. Most archs support up
to 6 arguments (depending on the complexity of the arguments) and those
are printed. If a function has more arguments then what was recorded, the
output will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
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Merge tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the
function graph tracer (funcgraph-args) that when set, the tracers
will record the registers that hold the arguments into each function
event. On reading of the trace, it will use BTF to print those
arguments. Most archs support up to 6 arguments (depending on the
complexity of the arguments) and those are printed.
If a function has more arguments then what was recorded, the output
will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
* tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use hashtable.h for event_hash
tracing: Fix use-after-free in print_graph_function_flags during tracer switching
function_graph: Remove the unused variable func
ftrace: Add arguments to function tracer
ftrace: Have funcgraph-args take affect during tracing
ftrace: Add support for function argument to graph tracer
ftrace: Add print_function_args()
ftrace: Have ftrace_free_filter() WARN and exit if ops is active
fgraph: Correct typo in ftrace_return_to_handler comment
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Linus Torvalds
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dd161f74f8 |
tracing and sorttable updates for 6.15:
- Implement arm64 build time sorting of the mcount location table When gcc is used to build arm64, the mcount_loc section is all zeros in the vmlinux elf file. The addresses are stored in the Elf_Rela location. To sort at build time, an array is allocated and the addresses are added to it via the content of the mcount_loc section as well as he Elf_Rela data. After sorting, the information is put back into the Elf_Rela which now has the section sorted. - Make sorting of mcount location table for arm64 work with clang as well When clang is used, the mcount_loc section contains the addresses, unlike the gcc build. An array is still created and the sorting works for both methods. - Remove weak functions from the mcount_loc section Have the sorttable code pass in the data of functions defined via nm -S which shows the functions as well as their sizes. Using this information the sorttable code can determine if a function in the mcount_loc section was weak and overridden. If the function is not found, it is set to be zero. On boot, when the mcount_loc section is read and the ftrace table is created, if the address in the mcount_loc is not in the kernel core text then it is removed and not added to the ftrace_filter_functions (the functions that can be attached by ftrace callbacks). - Update and fix the reporting of how much data is used for ftrace functions On boot, a report of how many pages were used by the ftrace table as well as how they were grouped (the table holds a list of sections that are groups of pages that were able to be allocated). The removing of the weak functions required the accounting to be updated. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ+MnThQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qivsAQDhPOCaONai7rvHX9T1aOHGjdajZ7SI qoZgBOsc2ZUkoQD/U2M/m7Yof9aR4I+VFKtT5NsAwpfqPSOL/t/1j6UEOQ8= =45AV -----END PGP SIGNATURE----- Merge tag 'trace-sorttable-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing / sorttable updates from Steven Rostedt: - Implement arm64 build time sorting of the mcount location table When gcc is used to build arm64, the mcount_loc section is all zeros in the vmlinux elf file. The addresses are stored in the Elf_Rela location. To sort at build time, an array is allocated and the addresses are added to it via the content of the mcount_loc section as well as he Elf_Rela data. After sorting, the information is put back into the Elf_Rela which now has the section sorted. - Make sorting of mcount location table for arm64 work with clang as well When clang is used, the mcount_loc section contains the addresses, unlike the gcc build. An array is still created and the sorting works for both methods. - Remove weak functions from the mcount_loc section Have the sorttable code pass in the data of functions defined via 'nm -S' which shows the functions as well as their sizes. Using this information the sorttable code can determine if a function in the mcount_loc section was weak and overridden. If the function is not found, it is set to be zero. On boot, when the mcount_loc section is read and the ftrace table is created, if the address in the mcount_loc is not in the kernel core text then it is removed and not added to the ftrace_filter_functions (the functions that can be attached by ftrace callbacks). - Update and fix the reporting of how much data is used for ftrace functions On boot, a report of how many pages were used by the ftrace table as well as how they were grouped (the table holds a list of sections that are groups of pages that were able to be allocated). The removing of the weak functions required the accounting to be updated. * tag 'trace-sorttable-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: scripts/sorttable: Allow matches to functions before function entry scripts/sorttable: Use normal sort if theres no relocs in the mcount section ftrace: Check against is_kernel_text() instead of kaslr_offset() ftrace: Test mcount_loc addr before calling ftrace_call_addr() ftrace: Have ftrace pages output reflect freed pages ftrace: Update the mcount_loc check of skipped entries scripts/sorttable: Zero out weak functions in mcount_loc table scripts/sorttable: Always use an array for the mcount_loc sorting scripts/sorttable: Have mcount rela sort use direct values arm64: scripts/sorttable: Implement sorting mcount_loc at boot for arm64 |
||
|
Steven Rostedt
|
0c667775fe |
ftrace: Have ftrace_free_filter() WARN and exit if ops is active
The ftrace_free_filter() is used to reset the ops filters. But it must be done if the ops is not currently active (tracing). If it is, it will mess up the ftrace accounting of what functions are attached and what is not. WARN and exit the ftrace_free_filter() if the ops is active when it is called. Currently, it doesn't seem if anything does this, but it may in the future. Link: https://lore.kernel.org/all/20250219095330.2e9f171c@gandalf.local.home/ Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250219135040.3a9fbe00@gandalf.local.home Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Nikolay Kuratov
|
a1a7eb89ca |
ftrace: Avoid potential division by zero in function_stat_show()
Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64}
produce zero and skip stddev computation in that case.
For now don't care about rec->counter * rec->counter overflow because
rec->time * rec->time overflow will likely happen earlier.
Cc: stable@vger.kernel.org
Cc: Wen Yang <wenyang@linux.alibaba.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250206090156.1561783-1-kniv@yandex-team.ru
Fixes:
|
||
|
Steven Rostedt
|
da0f622b34 |
ftrace: Check against is_kernel_text() instead of kaslr_offset()
As kaslr_offset() is architecture dependent and also may not be defined by
all architectures, when zeroing out unused weak functions, do not check
against kaslr_offset(), but instead check if the address is within the
kernel text sections. If KASLR added a shift to the zeroed out function,
it would still not be located in the kernel text. This is a more robust
way to test if the text is valid or not.
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: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Arnd Bergmann" <arnd@arndb.de>
Link: https://lore.kernel.org/20250225182054.471759017@goodmis.org
Fixes:
|
||
|
Steven Rostedt
|
6eeca746fa |
ftrace: Test mcount_loc addr before calling ftrace_call_addr()
The addresses in the mcount_loc can be zeroed and then moved by KASLR
making them invalid addresses. ftrace_call_addr() for ARM 64 expects a
valid address to kernel text. If the addr read from the mcount_loc section
is invalid, it must not call ftrace_call_addr(). Move the addr check
before calling ftrace_call_addr() in ftrace_process_locs().
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: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/20250225182054.290128736@goodmis.org
Fixes:
|
||
|
Steven Rostedt
|
8eb4b09e0b |
ftrace: Do not add duplicate entries in subops manager ops
Check if a function is already in the manager ops of a subops. A manager
ops contains multiple subops, and if two or more subops are tracing the
same function, the manager ops only needs a single entry in its hash.
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>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.226762894@goodmis.org
Fixes:
|
||
|
Steven Rostedt
|
38b1406194 |
ftrace: Fix accounting of adding subops to a manager ops
Function graph uses a subops and manager ops mechanism to attach to
ftrace. The manager ops connects to ftrace and the functions it connects
to is defined by a list of subops that it manages.
The function hash that defines what the above ops attaches to limits the
functions to attach if the hash has any content. If the hash is empty, it
means to trace all functions.
The creation of the manager ops hash is done by iterating over all the
subops hashes. If any of the subops hashes is empty, it means that the
manager ops hash must trace all functions as well.
The issue is in the creation of the manager ops. When a second subops is
attached, a new hash is created by starting it as NULL and adding the
subops one at a time. But the NULL ops is mistaken as an empty hash, and
once an empty hash is found, it stops the loop of subops and just enables
all functions.
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
try_to_run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
cleanup_rapl_pmus (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_free_pcibus_map (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_types_exit (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
kvm_shutdown (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_dump_msrs (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_cleanup_l1d_flush (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
[..]
Fix this by initializing the new hash to NULL and if the hash is NULL do
not treat it as an empty hash but instead allocate by copying the content
of the first sub ops. Then on subsequent iterations, the new hash will not
be NULL, but the content of the previous subops. If that first subops
attached to all functions, then new hash may assume that the manager ops
also needs to attach to all functions.
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: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.060300046@goodmis.org
Fixes:
|
||
|
Steven Rostedt
|
264143c4e5 |
ftrace: Have ftrace pages output reflect freed pages
The amount of memory that ftrace uses to save the descriptors to manage the functions it can trace is shown at output. But if there are a lot of functions that are skipped because they were weak or the architecture added holes into the tables, then the extra pages that were allocated are freed. But these freed pages are not reflected in the numbers shown, and they can even be inconsistent with what is reported: ftrace: allocating 57482 entries in 225 pages ftrace: allocated 224 pages with 3 groups The above shows the number of original entries that are in the mcount_loc section and the pages needed to save them (225), but the second output reflects the number of pages that were actually used. The two should be consistent as: ftrace: allocating 56739 entries in 224 pages ftrace: allocated 224 pages with 3 groups The above also shows the accurate number of entires that were actually stored and does not include the entries that were removed. Cc: bpf <bpf@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: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Zheng Yejian <zhengyejian1@huawei.com> Cc: Martin Kelly <martin.kelly@crowdstrike.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/20250218200023.221100846@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
4a3efc6baf |
ftrace: Update the mcount_loc check of skipped entries
Now that weak functions turn into skipped entries, update the check to make sure the amount that was allocated would fit both the entries that were allocated as well as those that were skipped. Cc: bpf <bpf@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: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Zheng Yejian <zhengyejian1@huawei.com> Cc: Martin Kelly <martin.kelly@crowdstrike.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/20250218200023.055162048@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
ef378c3b82 |
scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit
|
||
|
Joel Granados
|
1751f872cc |
treewide: const qualify ctl_tables where applicable
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit
|
||
|
Linus Torvalds
|
e8744fbc83 |
tracing updates for v6.14:
- Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Update the Rust tracepoint code to use the C code too There was some duplication of the tracepoint code for Rust that did the same logic as the C code. Add a helper that makes it possible for both algorithms to use the same logic in one place. - Add poll to trace event hist files It is useful to know when an event is triggered, or even with some filtering. Since hist files of events get updated when active and the event is triggered, allow applications to poll the hist file and wake up when an event is triggered. This will let the application know that the event it is waiting for happened. - Add :mod: command to enable events for current or future modules The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Add the command where if ':mod:<module>' is written into set_event, then either all the modules events are enabled if it is loaded, or cache it so that the module's events are enabled when it is loaded. This also works from the kernel command line, where "trace_event=:mod:<module>", when the module is loaded at boot up, its events will be enabled then. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ5EbMxQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qkZsAP9Amgx9frSbR1pn1t0I3wVnQx7khgOu s/b8Ro+vjTx1/QD/RN2AA7f+HK4F27w3Aqfrs0nKXAPtXWsJ9Epp8raG5w8= =Pg+4 -----END PGP SIGNATURE----- Merge tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Update the Rust tracepoint code to use the C code too There was some duplication of the tracepoint code for Rust that did the same logic as the C code. Add a helper that makes it possible for both algorithms to use the same logic in one place. - Add poll to trace event hist files It is useful to know when an event is triggered, or even with some filtering. Since hist files of events get updated when active and the event is triggered, allow applications to poll the hist file and wake up when an event is triggered. This will let the application know that the event it is waiting for happened. - Add :mod: command to enable events for current or future modules The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Add the command where if ':mod:<module>' is written into set_event, then either all the modules events are enabled if it is loaded, or cache it so that the module's events are enabled when it is loaded. This also works from the kernel command line, where "trace_event=:mod:<module>", when the module is loaded at boot up, its events will be enabled then. * tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits) tracing: Fix output of set_event for some cached module events tracing: Fix allocation of printing set_event file content tracing: Rename update_cache() to update_mod_cache() tracing: Fix #if CONFIG_MODULES to #ifdef CONFIG_MODULES selftests/ftrace: Add test that tests event :mod: commands tracing: Cache ":mod:" events for modules not loaded yet tracing: Add :mod: command to enabled module events selftests/tracing: Add hist poll() support test tracing/hist: Support POLLPRI event for poll on histogram tracing/hist: Add poll(POLLIN) support on hist file tracing: Fix using ret variable in tracing_set_tracer() tracepoint: Reduce duplication of __DO_TRACE_CALL tracing/string: Create and use __free(argv_free) in trace_dynevent.c tracing: Switch trace_stat.c code over to use guard() tracing: Switch trace_stack.c code over to use guard() tracing: Switch trace_osnoise.c code over to use guard() and __free() tracing: Switch trace_events_synth.c code over to use guard() tracing: Switch trace_events_filter.c code over to use guard() tracing: Switch trace_events_trigger.c code over to use guard() tracing: Switch trace_events_hist.c code over to use guard() ... |
||
|
Linus Torvalds
|
2e04247f7c |
ftrace updates for v6.14:
- Have fprobes built on top of function graph infrastructure The fprobe logic is an optimized kprobe that uses ftrace to attach to functions when a probe is needed at the start or end of the function. The fprobe and kretprobe logic implements a similar method as the function graph tracer to trace the end of the function. That is to hijack the return address and jump to a trampoline to do the trace when the function exits. To do this, a shadow stack needs to be created to store the original return address. Fprobes and function graph do this slightly differently. Fprobes (and kretprobes) has slots per callsite that are reserved to save the return address. This is fine when just a few points are traced. But users of fprobes, such as BPF programs, are starting to add many more locations, and this method does not scale. The function graph tracer was created to trace all functions in the kernel. In order to do this, when function graph tracing is started, every task gets its own shadow stack to hold the return address that is going to be traced. The function graph tracer has been updated to allow multiple users to use its infrastructure. Now have fprobes be one of those users. This will also allow for the fprobe and kretprobe methods to trace the return address to become obsolete. With new technologies like CFI that need to know about these methods of hijacking the return address, going toward a solution that has only one method of doing this will make the kernel less complex. - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Remove disabling of interrupts in the function graph tracer When function graph tracer was first introduced, it could race with interrupts and NMIs. To prevent that race, it would disable interrupts and not trace NMIs. But the code has changed to allow NMIs and also interrupts. This change was done a long time ago, but the disabling of interrupts was never removed. Remove the disabling of interrupts in the function graph tracer is it is not needed. This greatly improves its performance. - Allow the :mod: command to enable tracing module functions on the kernel command line. The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Because enabling function tracing can be done very early at boot up (before scheduling is enabled), the commands that can be done when function tracing is started is limited. Having the ":mod:" command to trace module functions as they are loaded is very useful. Update the kernel command line function filtering to allow it. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ42E2RQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qqXSAPwOMxuhye8tb1GYG62QD9+w7e6nOmlC 2GCPj4detnEM2QD/ciivkhespVKhHpZHRewAuSnJgHPSM45NQ3EVESzjWQ4= =snbx -----END PGP SIGNATURE----- Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace updates from Steven Rostedt: - Have fprobes built on top of function graph infrastructure The fprobe logic is an optimized kprobe that uses ftrace to attach to functions when a probe is needed at the start or end of the function. The fprobe and kretprobe logic implements a similar method as the function graph tracer to trace the end of the function. That is to hijack the return address and jump to a trampoline to do the trace when the function exits. To do this, a shadow stack needs to be created to store the original return address. Fprobes and function graph do this slightly differently. Fprobes (and kretprobes) has slots per callsite that are reserved to save the return address. This is fine when just a few points are traced. But users of fprobes, such as BPF programs, are starting to add many more locations, and this method does not scale. The function graph tracer was created to trace all functions in the kernel. In order to do this, when function graph tracing is started, every task gets its own shadow stack to hold the return address that is going to be traced. The function graph tracer has been updated to allow multiple users to use its infrastructure. Now have fprobes be one of those users. This will also allow for the fprobe and kretprobe methods to trace the return address to become obsolete. With new technologies like CFI that need to know about these methods of hijacking the return address, going toward a solution that has only one method of doing this will make the kernel less complex. - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Remove disabling of interrupts in the function graph tracer When function graph tracer was first introduced, it could race with interrupts and NMIs. To prevent that race, it would disable interrupts and not trace NMIs. But the code has changed to allow NMIs and also interrupts. This change was done a long time ago, but the disabling of interrupts was never removed. Remove the disabling of interrupts in the function graph tracer is it is not needed. This greatly improves its performance. - Allow the :mod: command to enable tracing module functions on the kernel command line. The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Because enabling function tracing can be done very early at boot up (before scheduling is enabled), the commands that can be done when function tracing is started is limited. Having the ":mod:" command to trace module functions as they are loaded is very useful. Update the kernel command line function filtering to allow it. * tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits) ftrace: Implement :mod: cache filtering on kernel command line tracing: Adopt __free() and guard() for trace_fprobe.c bpf: Use ftrace_get_symaddr() for kprobe_multi probes ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr Documentation: probes: Update fprobe on function-graph tracer selftests/ftrace: Add a test case for repeating register/unregister fprobe selftests: ftrace: Remove obsolate maxactive syntax check tracing/fprobe: Remove nr_maxactive from fprobe fprobe: Add fprobe_header encoding feature fprobe: Rewrite fprobe on function-graph tracer s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS tracing: Add ftrace_fill_perf_regs() for perf event tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs fprobe: Use ftrace_regs in fprobe exit handler fprobe: Use ftrace_regs in fprobe entry handler fgraph: Pass ftrace_regs to retfunc fgraph: Replace fgraph_ret_regs with ftrace_regs ... |
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Steven Rostedt
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31f505dc70 |
ftrace: Implement :mod: cache filtering on kernel command line
Module functions can be set to set_ftrace_filter before the module is loaded. # echo :mod:snd_hda_intel > set_ftrace_filter This will enable all the functions for the module snd_hda_intel. If that module is not loaded, it is "cached" in the trace array for when the module is loaded, its functions will be traced. But this is not implemented in the kernel command line. That's because the kernel command line filtering is added very early in boot up as it is needed to be done before boot time function tracing can start, which is also available very early in boot up. The code used by the "set_ftrace_filter" file can not be used that early as it depends on some other initialization to occur first. But some of the functions can. Implement the ":mod:" feature of "set_ftrace_filter" in the kernel command line parsing. Now function tracing on just a single module that is loaded at boot up can be done. Adding: ftrace=function ftrace_filter=:mod:sna_hda_intel To the kernel command line will only enable the sna_hda_intel module functions when the module is loaded, and it will start tracing. 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/20250116175832.34e39779@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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b355247df1 |
tracing: Cache ":mod:" events for modules not loaded yet
When the :mod: command is written into /sys/kernel/tracing/set_event (or that file within an instance), if the module specified after the ":mod:" is not yet loaded, it will store that string internally. When the module is loaded, it will enable the events as if the module was loaded when the string was written into the set_event file. This can also be useful to enable events that are in the init section of the module, as the events are enabled before the init section is executed. This also works on the kernel command line: trace_event=:mod:<module> Will enable the events for <module> when it is loaded. 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/20250116143533.514730995@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Kohei Enju
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789a8cff8d |
ftrace: Fix function profiler's filtering functionality
Commit |
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Masami Hiramatsu (Google)
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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> |
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Masami Hiramatsu (Google)
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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> |
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Steven Rostedt
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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> |
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Steven Rostedt
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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> |
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Steven Rostedt
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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>
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Linus Torvalds
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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
...
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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
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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> |
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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> |
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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> |
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Steven Rostedt
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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> |
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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> |
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Steven Rostedt
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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> |
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Masami Hiramatsu (Google)
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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> |
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Donglin Peng
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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>
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Steven Rostedt
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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> |