os_timer_one_shot() gets passed a value "unsigned long delta",
so must not have an "int ticks" as that actually ends up being
-1, and thus triggering a timer over and over again.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
While the affected code is run in user-mode, the build still warns
about it. Convert all uses of VLA to dynamic allocations.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reverts commit b6024b21fe and
adjusts default stack sizing to cope with larger size of
floating point save registers on the newer Intel CPUs.
b6024b21fe replaced storing the
register state on the stack with kmalloc-ed storage. That has
a number of issues and a panic if that fails.
1. kmalloc/ATOMIC can fail. There was a latent hard crash
in all interrupt and fault handling as a result.
2. kmalloc in the interrupt path introduces a considerable
performance penalty for networking ~ 14% on iperf.
This commit restores uml to a stable state until a better
solution is found.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Support for DISCARD and WRITE_ZEROES in the ubd driver using
fallocate.
DISCARD is enabled by default and can be disabled using a new
UBD command line flag.
If the underlying fs on which the UBD image is stored does not
support DISCARD the support for both DISCARD and WRITE_ZEROES
is turned off.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Fixes:
arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of
non-void function [-Wreturn-type]
longjmp() never returns but gcc still warns that the end of the function
can be reached.
Add a return code and debug aid to detect this impossible case.
Signed-off-by: Richard Weinberger <richard@nod.at>
__uml_initcall() is not used and .uml.initcall.init section is empty:
$ grep -r '__uml_initcall('
arch/um/include/shared/init.h:#define __uml_initcall(fn) \
$ readelf -s ../umobj/linux | grep __uml_initcall
23214: 00000000603b75d8 0 NOTYPE GLOBAL DEFAULT 32 __uml_initcall_start
25337: 00000000603b75d8 0 NOTYPE GLOBAL DEFAULT 32 __uml_initcall_end
So it is unnecessary.
Signed-off-by: Alexander Pateenok <pateenoc@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Recent libcs have gotten a bit more strict, so we actually need to
include the right headers and use the right types. This enables UML to
compile again.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
1. Removes the need to walk the IRQ/Device list to determine
who triggered the IRQ.
2. Improves scalability (up to several times performance
improvement for cases with 10s of devices).
3. Improves UML baseline IO performance for one disk + one NIC
use case by up to 10%.
4. Introduces write poll triggered IRQs.
5. Prerequisite for introducing high performance mmesg family
of functions in network IO.
6. Fixes RNG shutdown which was leaking a file descriptor
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
glibc 2.26 removed the 'struct ucontext' to "improve" POSIX compliance
and break programs, including User Mode Linux. Fix User Mode Linux
by using POSIX ucontext_t.
This fixes:
arch/um/os-Linux/signal.c: In function 'hard_handler':
arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to incomplete type 'struct ucontext'
mcontext_t *mc = &uc->uc_mcontext;
arch/x86/um/stub_segv.c: In function 'stub_segv_handler':
arch/x86/um/stub_segv.c:16:13: error: dereferencing pointer to incomplete type 'struct ucontext'
&uc->uc_mcontext);
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The intention is to return negative error codes. "pid" is already
negative but we accidentally negate it again back to positive.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Also use correct function name spelling (stub_segv_handler) for better grepping
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
When ptrace fails to set GP/FP regs for the target process,
log the error before crashing the UML kernel.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Use os_warn() instead of printf/fprintf to print out
pre-boot warning/error messages to stderr.
Note that the help message and version message are
kept to print out to stdout, because user explicitly
specifies those options to get such information.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Add os_warn() for printing out pre-boot warning/error
messages in stderr. The messages via os_warn() are not
suppressed by quiet option.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Use os_info() for printing out the messages on the
normal execution path.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Add os_info() for printing out pre-boot information
level messages in stderr. The messages via os_info()
are suppressed by "quiet" kernel command line.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Since this function will be called after printk buffer
initialized, use printk as other functions do.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Define NR_CPUS required by the timer subsystem.
Fixes this make warning:
scripts/kconfig/conf --oldconfig arch/x86/um/Kconfig
kernel/time/Kconfig:155:warning: range is invalid
Signed-off-by: Nikola Kotur <kotnick@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This adds support for kcov to UML.
There is a small problem where UML will randomly segfault during boot;
this is because current_thread_info() occasionally returns an invalid
(non-NULL) pointer and we try to dereference it in
__sanitizer_cov_trace_pc(). I consider this a bug in UML itself and this
patch merely exposes it.
[v2: disable instrumentation in UML-specific code]
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: user-mode-linux-devel <user-mode-linux-devel@lists.sourceforge.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
We are in atomic context and must not sleep.
Sleeping here is possible since malloc() maps
to kmalloc() with GFP_KERNEL.
Cc: stable@vger.kernel.org
Fixes: b6024b21 ("um: extend fpstate to _xstate to support YMM registers")
Signed-off-by: Richard Weinberger <richard@nod.at>
Extends fpstate to _xstate, in order to hold AVX/YMM registers.
To avoid oversized stack frame, the following functions have been
refactored by using malloc.
- sig_handler_common
- timer_real_alarm_handler
Signed-off-by: Eli Cooper <elicooper@gmx.com>
Open the memory mapped file with the O_TMPFILE flag when available.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Acked-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Remove the insecure 0777 mode for temporary file to prohibit other users
to change the executable mapped code.
An attacker could gain access to the mapped file descriptor from the
temporary file (before it is unlinked) in a read-only mode but it should
not be accessible in write mode to avoid arbitrary code execution.
To not change the hostfs behavior, the temporary file creation
permission now depends on the current umask(2) and the implementation of
mkstemp(3).
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Acked-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This fix two related bugs:
* PTRACE_GETREGS doesn't get the right orig_ax (syscall) value
* PTRACE_SETREGS can't set the orig_ax value (erased by initial value)
Get rid of the now useless and error-prone get_syscall().
Fix inconsistent behavior in the ptrace implementation for i386 when
updating orig_eax automatically update the syscall number as well. This
is now updated in handle_syscall().
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Anton Ivanov <aivanov@brocade.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: David Drysdale <drysdale@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Kees Cook <keescook@chromium.org>
This decreases the number of syscalls per read/write by half.
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The existing IRQ handler design in UML does not prevent reentrancy
This is mitigated by fd-enable/fd-disable semantics for the IO
portion of the UML subsystem. The timer, however, can and is
re-entered resulting in very deep stack usage and occasional
stack exhaustion.
This patch prevents this by checking if there is a timer
interrupt in-flight before processing any pending timer interrupts.
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
I was seeing some really weird behaviour where piping UML's output
somewhere would cause output to get duplicated:
$ ./vmlinux | head -n 40
Checking that ptrace can change system call numbers...Core dump limits :
soft - 0
hard - NONE
OK
Checking syscall emulation patch for ptrace...Core dump limits :
soft - 0
hard - NONE
OK
Checking advanced syscall emulation patch for ptrace...Core dump limits :
soft - 0
hard - NONE
OK
Core dump limits :
soft - 0
hard - NONE
This is because these tests do a fork() which duplicates the non-empty
stdout buffer, then glibc flushes the duplicated buffer as each child
exits.
A simple workaround is to flush before forking.
Cc: stable@vger.kernel.org
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.
This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.
Fixes:
- crashes when hosts suspends/resumes
- broken userspace timers - effecive ~40Hz instead
of what they should be. Note - this modifies skas behavior
by no longer setting an itimer per clone(). Timer events
are relayed instead.
- kernel network packet scheduling disciplines
- tcp behaviour especially under load
- various timer related corner cases
Finally, overall responsiveness of userspace is better.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
[rw: massaged commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
If UML is executing a helper program it is using
waitpid() with the __WCLONE flag to wait for the program
as the helper is executed from a clone()'ed thread.
While using __WCLONE is perfectly fine for clone()'ed
childs it won't detect terminated childs if the helper
has issued an execve().
We have to use __WALL to wait for both clone()'ed and
regular childs to detect the termination before and
after an execve().
Reported-and-tested-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull UML updates from Richard Weinberger:
- remove hppfs ("HonePot ProcFS")
- initial support for musl libc
- uaccess cleanup
- random cleanups and bug fixes all over the place
* 'for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (21 commits)
um: Don't pollute kernel namespace with uapi
um: Include sys/types.h for makedev(), major(), minor()
um: Do not use stdin and stdout identifiers for struct members
um: Do not use __ptr_t type for stack_t's .ss pointer
um: Fix mconsole dependency
um: Handle tracehook_report_syscall_entry() result
um: Remove copy&paste code from init.h
um: Stop abusing __KERNEL__
um: Catch unprotected user memory access
um: Fix warning in setup_signal_stack_si()
um: Rework uaccess code
um: Add uaccess.h to ldt.c
um: Add uaccess.h to syscalls_64.c
um: Add asm/elf.h to vma.c
um: Cleanup mem_32/64.c headers
um: Remove hppfs
um: Move syscall() declaration into os.h
um: kernel: ksyms: Export symbol syscall() for fixing modpost issue
um/os-Linux: Use char[] for syscall_stub declarations
um: Use char[] for linker script address declarations
...
The functions in question are not part of the POSIX standard,
documentation however hints that the corresponding header shall
be sys/types.h. C libraries other than glibc, namely musl, did
not include that header via other ways and complained.
Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
stdin, stdout and stderr are macros according to C89/C99.
Thus do not use them as struct member identifiers to avoid
bad results from macro expansion.
Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
__ptr_t type is a glibc-specific type, while the generally
documented type is a void*. That's what other C libraries use,
too.
Signed-off-by: Hans-Werner Hilse <hwhilse@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
When declaring __syscall_stub_start, use the same type in UML userspace
code as in arch/um/include/asm/sections.h.
While at it, also declare batch_syscall_stub as char[].
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
[um maintainers appear to be vanished]
I can't prove the case pointed out in
https://bugzilla.kernel.org/show_bug.cgi?id=82341
is correct so let us play safe.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atomic_notifier_chain_register() and uml_postsetup() do call kernel code
that rely on the "current" kernel macro and a valid task_struct resp.
thread_info struct. Give those functions a valid stack by moving
uml_postsetup() in the init_thread stack. This moves enables a panic()
call in this early code to generate a valid stacktrace, instead of
crashing.
E.g. when an UML kernel is started with an initrd but too few physical
memory the panic() call get's actually processed.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Before we had SKAS0 UML had two modes of operation
TT (tracing thread) and SKAS3/4 (separated kernel address space).
TT was known to be insecure and got removed a long time ago.
SKAS3/4 required a few (3 or 4) patches on the host side which never went
mainline. The last host patch is 10 years old.
With SKAS0 mode (separated kernel address space using 0 host patches),
default since 2005, SKAS3/4 is obsolete and can be removed.
Signed-off-by: Richard Weinberger <richard@nod.at>
This reverts commit 0974a9cadc.
The real for for that issue is to release current->mm->mmap_sem in
fix_range_common().
Signed-off-by: Richard Weinberger <richard@nod.at>
The reverse case of this race (you must msync before read) is
well known. This is the not so common one.
It can be triggered only on systems which do a lot of task
switching and only at UML startup. If you are starting 200+ UMLs
~ 0.5% will always die without this fix.
Signed-off-by: Anton Ivanov <antivano@cisco.com>
[rw: minor whitespace fixes]
Signed-off-by: Richard Weinberger <richard@nod.at>
UML does not handle sigpipe. As a result when running it under
expect or redirecting the IO from the console to an external program
it will crash if the program stops or exits.
Signed-off-by: Anton Ivanov <antivano@cisco.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Inferring the mount hierarchy correctly from /proc/mounts is hard when MS_MOVE
may have been used, and the previous code did it wrongly. This change simplifies
the logic to only require that /dev/shm be _on_ tmpfs (which can be checked
trivially with statfs) rather than that it be a _mountpoint_ of tmpfs, since
there isn't a compelling reason to be that strict. We also now check for tmpfs
on whatever directory we ultimately use so that the user is better informed.
This change also moves the more standard TMPDIR environment variable check ahead
of the others.
Applies to 3.12.
Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
As UML uses an alternative signal stack we cannot use
the current stack pointer for stack dumping if UML itself
dies by SIGSEGV. To bypass this issue we save regs taken
from mcontext in our segv handler into thread_struct and
use these regs to obtain the stack pointer in show_stack().
Signed-off-by: Richard Weinberger <richard@nod.at>
If UML is not run by a shell it can happen that UML
will kill unrelated proceses upon a fatal exit because
it issues a kill(0, ...).
To prevent such oddities we create a new session in main().
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
UML's block device driver does not support write barriers,
to support this this patch adds REQ_FLUSH suppport.
Every time the block layer sends a REQ_FLUSH we fsync() now
our backing file to guarantee data consistency.
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
UML needs it's own probe_kernel_read() to handle kernel
mode faults correctly.
The implementation uses mincore() on the host side to detect
whether a page is owned by the UML kernel process.
This fixes also a possible crash when sysrq-t is used.
Starting with 3.10 sysrq-t calls probe_kernel_read() to
read details from the kernel workers. As kernel worker are
completely async pointers may turn NULL while reading them.
Cc: <stian@nixia.no>
Cc: <tj@kernel.org>
Cc: <stable@vger.kernel.org> # 3.10.x
Signed-off-by: Richard Weinberger <richard@nod.at>
Currently we use both struct siginfo and siginfo_t.
Let's use struct siginfo internally to avoid ongoing
compiler warning. We are allowed to do so because
struct siginfo and siginfo_t are equivalent.
Signed-off-by: Richard Weinberger <richard@nod.at>
which_tmpdir did the wrong thing if /dev/shm was a symlink (e.g., to /run/shm),
if there were multiple mounts on top of each other, if the mount(s) were
obscured by a later mount, or if /dev/shm was a prefix of another mount point.
This fixes these cases. Applies to 3.9.6.
Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If we die within a stub handler we only way to reliable
kill the (obviously) dying uml guest process is killing
it's host twin on the host side.
Signed-off-by: Richard Weinberger <richard@nod.at>
The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.
Merge a common upstream merge point that has these
updates.
Conflicts:
include/linux/perf_event.h
kernel/rcutree.h
kernel/rcutree_plugin.h
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.
As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.
It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.
On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.
But we can't afford both at the same time or we run into
a circular dependency:
1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE
We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.
So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.
Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
arch/um/os-Linux/signal.c:18:8: error: conflicting types for 'sig_info'
In file included from /home/slyfox/linux-2.6/arch/um/os-Linux/signal.c:12:0:
arch/um/include/shared/as-layout.h:64:15: note: previous declaration of 'sig_info' was here
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
CC: Jeff Dike <jdike@addtoit.com>
CC: Richard Weinberger <richard@nod.at>
CC: "Martin Pärtel" <martin.partel@gmail.com>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: user-mode-linux-devel@lists.sourceforge.net
CC: user-mode-linux-user@lists.sourceforge.net
CC: linux-kernel@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
arch/um/os-Linux/start_up.c: In function 'check_coredump_limit':
arch/um/os-Linux/start_up.c:338:16: error: storage size of 'lim' isn't known
arch/um/os-Linux/start_up.c:339:2: error: implicit declaration of function 'getrlimit' [-Werror=implicit-function-declaration]
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
CC: Jeff Dike <jdike@addtoit.com>
CC: Richard Weinberger <richard@nod.at>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: user-mode-linux-devel@lists.sourceforge.net
CC: user-mode-linux-user@lists.sourceforge.net
CC: linux-kernel@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull third pile of kernel_execve() patches from Al Viro:
"The last bits of infrastructure for kernel_thread() et.al., with
alpha/arm/x86 use of those. Plus sanitizing the asm glue and
do_notify_resume() on alpha, fixing the "disabled irq while running
task_work stuff" breakage there.
At that point the rest of kernel_thread/kernel_execve/sys_execve work
can be done independently for different architectures. The only
pending bits that do depend on having all architectures converted are
restrictred to fs/* and kernel/* - that'll obviously have to wait for
the next cycle.
I thought we'd have to wait for all of them done before we start
eliminating the longjump-style insanity in kernel_execve(), but it
turned out there's a very simple way to do that without flagday-style
changes."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to saner kernel_execve() semantics
arm: switch to saner kernel_execve() semantics
x86, um: convert to saner kernel_execve() semantics
infrastructure for saner ret_from_kernel_thread semantics
make sure that kernel_thread() callbacks call do_exit() themselves
make sure that we always have a return path from kernel_execve()
ppc: eeh_event should just use kthread_run()
don't bother with kernel_thread/kernel_execve for launching linuxrc
alpha: get rid of switch_stack argument of do_work_pending()
alpha: don't bother passing switch_stack separately from regs
alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
alpha: simplify TIF_NEED_RESCHED handling
Fix the following compile error on UML.
arch/um/os-Linux/time.c: In function 'deliver_alarm':
arch/um/os-Linux/time.c:117:3: error: too few arguments to function 'alarm_handler'
arch/um/os-Linux/internal.h:1:6: note: declared here
The error was introduced by commit d3c1cfcd ("um: pass siginfo to guest
process") in 3.6-rc1.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Martin Pärtel <martin.partel@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE,
SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct
where previously they were si_addr = NULL and si_code = 128.
Signed-off-by: Martin Pärtel <martin.partel@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
... the same one that controls whether elf_aux.o is included into the
build, bringing the vsyscall_e... into it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
it's i386-specific; moreover, analogs on other targets have
incompatible interface - PTRACE_GET_THREAD_AREA does exist
elsewhere, but struct user_desc does *not*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
now we don't mix host and guest signal frame layouts anymore; moreover,
we don't need host's struct sigcontext at all.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
For one thing, we always block the same signals (IRQ ones - IO, WINCH, VTALRM),
so there's no need to pass sa_mask elements in arguments. For another, the
flags depend only on whether it's an IRQ signal or not (we add SA_RESTART
for them).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
We used to generate those, but we hadn't done that for a long
time. No need to bother blocking them for signal handlers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Some time ago Jeff prepared 42daba3165 ("uml: stop saving process FP
state") for UML to stop saving the process FP state between task
switches. The assumption was that since with SKAS0 every guest process
runs inside a host process context the host OS will take care of keeping
the proper FP state.
Unfortunately this is not true for multi-threaded applications, where
all guest threads share a single host process context yet all may use
the FPU on their own. Although I haven't verified it I suspect things
to be even worse in SKAS3 mode where all guest processes run inside a
single host process.
The patch reintroduces the saving and restoring of the FP context
between task switches.
[richard@nod.at: Ingo posted this patch in 2009, sadly it was never applied
and got lost. Now in 2011 the problem was reported by Gunnar.]
Signed-off-by: Ingo van Lil <inguin@gmx.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: <gunnarlindroth@hotmail.com>
Tested-by: <gunnarlindroth@hotmail.com>
Cc: Stanislav Meduna <stano@meduna.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reusing the host's vDSO makes only sense on x86_32.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When creating the temp file there's a memory and file descriptor leak upon
error.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix this warning:
arch/um/os-Linux/helper.c: In function `helper_child':
arch/um/os-Linux/helper.c:38:7: warning: ignoring return value of `write', declared with attribute warn_unused_result
[richard@nod.at: happens only with -D_FORTIFY_SOURCE=2]
Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When UML is compiled with _FORTIFY_SOURCE we have to export all _chk()
functions which are used in modules. For now it's only the case for
__sprintf_chk().
Tested-by: Florian Fainelli <florian@openwrt.org>
Reported-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_dump_core() emits SIGTERM to terminate all UML processes. Kernel
threads have to exit on SIGTERM instead of calling last_ditch_exit().
Multiple calls to last_ditch_exit() can cause a crash.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
User Mode Linux can also benefit from earlyprintk. UML's earlyprintk
writes kernel messages directly to stdout.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The UML kernel ignores SIGHUP anyway. This handler is in vain.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UML_LIB_PATH is hardcoded to /usr/lib/uml/, on 64bit systems UML_LIB_PATH
needs to be /usr/lib64/uml/.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
os_dump_core() uses abort() to terminate UML in case of an fatal error.
glibc's abort() calls raise(SIGABRT) which makes use of tgkill().
tgkill() has no effect within UML's kernel threads because they are not
pthreads. As fallback abort() executes an invalid instruction to
terminate the process. Therefore UML gets killed by SIGSEGV and leaves a
ugly log entry in the host's kernel ring buffer.
To get rid of this we use our own abort routine.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a issue which was introduced by fe2cc53e ("uml: track and make
up lost ticks").
timeval_to_ns() returns long long and not int. Due to that UML's timer
did not work properlt and caused timer freezes.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The os-linux/mem.c file calls fchmod function, which is declared in sys/stat.h
header file, so include it. Fixes build breakage under FC13.
Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We now have to to include linux/slab.h explicitly for kmalloc &
friends. Files that build against host headers already get their
prototypes via um_malloc.h, linux/slab.h may even be unavailable.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
fix the following 'make includecheck' warning:
arch/um/os-Linux/helper.c: linux/limits.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: jdike@addtoit.com
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1247064950.4382.45.camel@ht.satnam>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
These error messages are from check_sysemu(), not check_ptrace().
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following warning on x86_64:
LD vmlinux.o
MODPOST vmlinux.o
WARNING: vmlinux: 'memcpy' exported twice. Previous export was in vmlinux
For x86_64, this symbol is already exported from arch/um/sys-x86_64/ksyms.c.
Reported-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Tested-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simply replace netdev->priv with netdev_priv().
Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
we can get DEV_NULL defined for arch/um/drivers/null.c in less
convoluted ways, TYVM...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Remove the dead CONFIG_TTY_LOG (no kconfig option).
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Make some variables and functions static, since they don't need to be
global.
- Remove an unused function - arch/um/kernel/time.c::sched_clock().
- Clean the style a bit as complained by checkpatch.pl.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fedora broke PTRACE_SYSEMU again, and UML crashes as a result when it
doesn't need to. This patch makes the PTRACE_SYSEMU check fail gracefully
and makes UML fall back to PTRACE_SYSCALL.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I allowed an include of asm/user.h to sneak back in. This patch replaces
it with sys/user.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Include limits.h to get a definition of PATH_MAX.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We lost the marking of SIGWINCH as being OK to receive during stub
execution, causing a panic should that happen.
Cc: Benedict Verheyen <benedict.verheyen@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes os_get_task_size locate the bottom of the address space,
as well as the top. This is for systems which put a lower limit on mmap
addresses. It works by manually scanning pages from zero onwards until a
valid page is found.
Because the bottom of the address space may not be zero, it's not
sufficient to assume the top of the address space is the size of the
address space. The size is the difference between the top address and
bottom address.
[jdike@addtoit.com: changed the name to reflect that this function is
supposed to return the top of the process address space, not its size and
changed the return value to reflect that. Also some minor formatting
changes]
Signed-off-by: Tom Spink <tspink@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Protection against the host's time going backwards (eg, ntp activity on
the host) by keeping track of the time at the last tick and if it's
greater than the current time, keep time stopped until the host catches
up.
Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want sys/ptrace.h before any includes of linux/ptrace.h and
asm/user.h pulls the latter.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alarm delivery could be noticably late in the !CONFIG_NOHZ case because lost
ticks weren't being taken into account. This is now treated more carefully,
with the time between ticks being calculated and the appropriate number of
ticks delivered to the timekeeping system.
Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The random driver would essentially hang if the host's /dev/random returned
-EAGAIN. There was a test of need_resched followed by a schedule inside the
loop, but that didn't help and it's the wrong way to work anyway.
The right way is to ask for an interrupt when there is input available from
the host and handle it then rather than polling.
Now, when the host's /dev/random returns -EAGAIN, the driver asks for a wakeup
when there's randomness available again and sleeps. The interrupt routine
just wakes up whatever processes are sleeping on host_read_wait.
There is an atomic_t, host_sleep_count, which counts the number of processes
waiting for randomness. When this reaches zero, the interrupt is disabled.
An added complication is that async I/O notification was only recently added
to /dev/random (by me), so essentially all hosts will lack it. So, we use the
sigio workaround here, which is to have a separate thread poll on the
descriptor and send an interrupt when there is input on it. This mechanism is
activated when a process gets -EAGAIN (activating this multiple times is
harmless, if a bit wasteful) and deactivated by the last process still
waiting.
The module name was changed from "random" to "hw_random" in order for udev to
recognize it.
The sigio workaround needed some changes. sigio_broken was added for cases
when we know that async notification doesn't work. This is now called from
maybe_sigio_broken, which deals with pts devices.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reintroduce uml_kmalloc for the benefit of UML libc code. The
previous tactic of declaring __kmalloc so it could be called directly
from the libc side of the house turned out to be getting too intimate
with slab, and it doesn't work with slob.
So, the uml_kmalloc wrapper is back. It calls kmalloc or whatever
that translates into, and libc code calls it.
kfree is left alone since that still works, leaving a somewhat
inconsistent API.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tidy the ptrace interface code. Removed a bunch of unused macros.
Started converting register sets from arrays of longs to structures.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A few random style fixes.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Redo how host capabilities are recorded at startup and disabled on the
command line.
There are now explicit variables saying what's been disabled by the
command line rather than the implicitness of the have_* variable being
zero. The capability variables now start at zero and are set to one
as their capabilities are found to be present on the host.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve this code a bit: check sigaction's return value and remove a useless
fflush().
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- lets ptrace_child become void
- adds checking for the return value of change_sig
- moves errors info into stderr instead of stdout.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fix:
arch/um/os-Linux/helper.c: In function 'run_helper':
arch/um/os-Linux/helper.c:73: error: 'PATH_MAX' undeclared (first use in this function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit ee3d9bd4de ("uml: simplify SIGSEGV
handling"), while greatly simplifying the kernel SIGSEGV handler that
runs in the process address space, introduced a bug which corrupts FP
state in the process.
Previously, the SIGSEGV handler called the sigreturn system call by hand - it
couldn't return through the restorer provided to it because that could try to
call the libc restorer which likely wouldn't exist in the process address
space. So, it blocked off some signals, including SIGUSR1, on entry to the
SIGSEGV handler, queued a SIGUSR1 to itself, and invoked sigreturn. The
SIGUSR1 was delivered, and was visible to the UML kernel after sigreturn
finished.
The commit eliminated the signal masking and the call to sigreturn. The
handler simply hits itself with a SIGTRAP to let the UML kernel know that it
is finished. UML then restores the process registers, which effectively
longjmps the process out of the signal handler, skipping sigreturn's restoring
of register state and the signal mask.
The bug is that the host apparently sets used_fp to 0 when it saves the
process FP state in the sigcontext on the process signal stack. Thus, when
the process is longjmped out of the handler, its FP state is corrupt because
it wasn't saved on the context switch to the UML kernel.
This manifested itself as sleep hanging. For some reason, sleep uses floating
point in order to calculate the sleep interval. When a page fault corrupts
its FP state, it is faked into essentially sleeping forever.
This patch saves the FP state before entering the SIGSEGV handler and restores
it afterwards.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Style changes under arch/um/os-Linux:
include trimming
CodingStyle fixes
some printks needed severity indicators
make_tempfile turns out not to be used outside of mem.c, so it is now static.
Its declaration in tempfile.h is no longer needed, and tempfile.h itself is no
longer needed.
create_tmp_file was also made static.
checkpatch moans about an EXPORT_SYMBOL in user_syms.c which is part of a
macro definition - this is copying a bit of kernel infrastructure into the
libc side of UML because the kernel headers can't be included there.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is
needed on i386 if UML is to run on hosts with varying VMSPLITs without
recompilation.
TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of
an include of pgtable.h from processor.h, which can cause include loops.
On i386, task_size is calculated early in boot by probing the address space in
a binary search to figure out where the boundary between usable and non-usable
memory is. This tries to make sure that a page that is considered to be in
userspace is, or can be made, read-write. I'm concerned about a system-global
VDSO page in kernel memory being hit and considered to be a userspace page.
On x86_64, task_size is just the old value of CONFIG_TOP_ADDR.
A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced
by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it
irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in
arch/um/Makefile are also gone.
I noticed and fixed a missing extern in os.h when adding os_get_task_size.
Note: This has been revised to fix the 32-bit UML on 64-bit host bug that
Miklos ran into.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calling init_registers inside the skas3 checking causes mysterious crashes if
it doesn't happen because the skas3 checking is bypassed. This patch moves it
to os_early_checks.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some printks were missing newlines.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The .a flags in openflags never had an implementation.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init_irq_signals doesn't need to be called from the context of a new process.
It initializes handlers, which are useless in process context. With that call
gone, init_irq_signals has only one caller, so it can be inlined into
init_new_thread_signals.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch tidies the signal handling code slightly.
pending is renamed to signals_pending for symmetry with signals_enabled.
remove_sigstack was unused, so can be deleted.
The value of change_sig was never used, so it is now void and the
return value is not calculated any more.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sig_handler_common_skas needs significant modernization, starting with
its name and storage class.
There is no need to hide the true type of the sigcontext pointer, so
the void * dummy parameter can be replaced with a sigcontext *sc.
The array of uml_pt_regs structs used in the page fault case are gone,
replaced by a local variable. This is also used in the non-segfault
case instead of the copy in the task_struct. Since it's local, the
special handling of the is_user flag can go away.
There hasn't been any special treatment of SIGUSR1 in ages, so the
line that enables it can be deleted.
The special treatment of SIGSEGV similarly goes away, but to
compensate, SA_NODEFER is added to sa_mask when registering a signal
handler.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves sig_handler_common_skas from
arch/um/os-Linux/skas/trap.c to its only caller in
arch/um/os-Linux/signal.c. trap.c is now empty, so it can be removed.
This is code movement only - the significant cleanup needed here is
done in the next patch.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kill a process that tries to branch into a stub and execute a system
call. There are no security implications here - a system call in a
stub is treated the same as a system call anywhere else. But if a
process is trying to branch into a stub, either it is trying something
nasty or it has gone haywire, so it's a good idea to get rid of it in
either case.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Style fixes to arch/um/os/helper.c and tidying up the breakpoint fix a
bit.
helper.c gets all the usual style fixes -
updated copyright
all printks get severities
Also -
errval changes to err in helper_child
fixed an obsolete comment
run_helper was killing a child process which is guaranteed to
be dead or dying anyway
Removed the nohang and pname arguments from helper_wait and fixed the
declaration and callers. nohang was used only in the slirp driver and
I don't think it was needed. I think pname was a bit of overkill in
putting out an error message when something goes wrong.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
signals_enabled and pending have requirements on the order in which they are
modified. This used to be done by declaring them volatile and putting an mb()
where the ordering requirements were in effect.
After getting a better (I hope) understanding of how to do this correctly, the
volatile declarations are gone and the mb()'s replaced by barrier()'s.
One of the mb()'s was deleted because I see no problematic writes that could
be re-ordered past that point.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It turns out that if there's a panic early enough, UML will just sit there in
the LED-blinking loop because the panic notifier hadn't been installed yet.
This patch installs it earlier.
It also fixes the problem which exposed the hang, namely that if you give UML
a zero-sized initrd, it will ask alloc_bootmem for zero bytes, and that will
cause the panic.
While I was in initrd.c, I gave it a style makeover.
Prompted by checkpatch, I moved a couple extern declarations of uml_exitcode
to kern_util.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
setjmp_wrapper existed to provide setjmp to kernel code when UML used libc's
setjmp and longjmp. Now that UML has its own implementation, this isn't
needed and kernel code can invoke setjmp directly.
do_buffer_op is massively cleaned up since it is no longer a callback from
setjmp_wrapper and given a va_list from which it must extract its arguments.
The actual setjmp is moved from buffer_op to do_op_one_page because the copy
operation is inside an atomic section (kmap_atomic to kunmap_atomic) and it
shouldn't be longjmp-ed out of.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/um/os-Linux/file.c needed some style work -
updated the copyright
cleaned up the includes
CodingStyle fixes
added some missing CATCH_EINTRs
os_set_owner was unused, so it is gone
all printks now have severities
fcntl(F_GETFL) was being called without checking the return
removed an obsolete comment
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Code tidying -
the pid field of struct irq_fd isn't used, so it is removed
os_set_fd_async needed to read flags before changing them, it
doesn't need a pid passed in because it can call getpid itself, and a
block of unused code needed deleting
os_get_exec_close was unused, so it is removed
ptrace_child called _exit for historical reasons which are no
longer valid, so just calls exit instead
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Style fixes in arch/um/os-Linux/irq.c and arch/um/os-Linux/sigio.c:
Updated copyrights
trimmed includes
added severity indicators to printks
CodingStyle fixes
turned an bunch of panics into printks
call some libc functions directly instead of going through the
os_* wrappers
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UML was panicing in the case of failures of libc calls which shouldn't happen.
This is an overreaction since a failure from libc doesn't normally mean that
kernel data structures are in an unknown state. Instead, the current process
should just be killed if there is no way to recover.
The case that prompted this was a failure of PTRACE_SETREGS restoring the same
state that was read by PTRACE_GETREGS. It appears that when a process tries
to load a bogus value into a segment register, it segfaults (as expected) and
the value is actually loaded and is seen by PTRACE_GETREGS (not expected).
This case is fixed by forcing a fatal SIGSEGV on the process so that it
immediately dies. fatal_sigsegv was added for this purpose. It was declared
as noreturn, so in order to pursuade gcc that it actually does not return, I
added a call to os_dump_core (and declared it noreturn) so that I get a core
file if somehow the process survives.
All other calls in arch/um/os-Linux/skas/process.c got the same treatment,
with failures causing the process to die instead of a kernel panic, with some
exceptions.
userspace_tramp exits with status 1 if anything goes wrong there. That will
cause start_userspace to return an error. copy_context_skas0 and
map_stub_pages also now return errors instead of panicing. Callers of thes
functions were changed to check for errors and do something appropriate.
Usually that's to return an error to their callers.
check_skas3_ptrace_faultinfo just exits since that's too early to do anything
else.
save_registers, restore_registers, and init_registers now return status
instead of panicing on failure, with their callers doing something
appropriate.
There were also duplicate declarations of save_registers and restore_registers
in os.h - these are gone.
I noticed and fixed up some whitespace damage.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some register accessor cleanups -
userspace() was calling restore_registers and save_registers for no
reason, since userspace() is on the libc side of the house, and these
add no value over calling ptrace directly
init_thread_registers and get_safe_registers were the same thing,
so init_thread_registers is gone
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify the page fault stub by not masking signals while it is running. This
allows it to signal that it is done by executing an instruction which will
generate a SIGTRAP (int3 on x86) rather than running sigreturn by hand after
queueing a blocked SIGUSR1.
userspace_tramp now no longer puts anything in the SIGSEGV sa_mask, but it
does add SA_NODEFER to sa_flags so that SIGSEGV is still enabled after the
signal handler fails to run sigreturn.
SIGWINCH is just blocked so that we don't have to deal with it and the signal
masks used by wait_stub_done are updated to reflect the smaller number of
signals that it has to worry about.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch changes a few functions into returning void. The return values
were not used anyway, so I think it should not be a problem. Also removed a
little leftover bit from TT mode.
Signed-off-by: Karol Swietlicki <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Lucas Woods <woodzy@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tidy kern_util.h. It turns out that most of the function declarations
aren't used, so they can go away. os.h no longer includes
kern_util.h, so files which got it through os.h now need to include it
directly. A number of other files never needed it, so these includes
are deleted.
The structure which was used to pass signal handlers from the kernel
side to the userspace side is gone. Instead, the handlers are
declared here, and used directly from libc code. This allows
arch/um/os-Linux/trap.c to be deleted, with its remnants being moved
to arch/um/os-Linux/skas/trap.c.
arch/um/os-Linux/tty.c had its inclusions changed, and it needed some
style attention, so it got tidied.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch also does some improvements for uml code. Improvements include
dropping unnecessary cast, killing some unnecessary code and still some
constifying for pointers etc..
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch contains varied fixes and improvements for some files under
arch/um/os-Linux/, such as a typo fix in a perror message, a missing
argument fix for a printf, some constifying for pointers and so on.
[ jdike - made sigprocmask failure return -errno instead of -1 ]
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes when UML is debugged gdb miss breakpoints.
When process traced by gdb do fork, debugger remove breakpoints from
child address space. There is possibility to trace more than one fork,
but this not work with UML, I guess (only guess) there is a deadlock -
gdb waits for UML and UML waits for gdb.
When clone() is called with SIGCHLD and CLONE_VM flags, gdb see this
as PTRACE_EVENT_FORK not as PTRACE_EVENT_CLONE and remove breakpoints
from child and at the same time from traced process, because either
have the same address space.
Maybe it is possible to do fix in gdb, but I'm not sure if there is
easy way to find out if traced and child processes share memory. So I
do fix for UML, it simply do not call clone() with both SIGCHLD and
CLONE_VM flags together. Additionally __WALL flag is used for
waitpid() to assure not miss clone and normal process events.
[ jdike - checkpatch fixes ]
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I forgot to have an int-returning function actually return something.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With NO_HZ disabled, the UML idle loop effectively becomes a busy loop, as
it will sleep for no time.
The cause was forgetting to restart the tick after waking up from sleep.
It was disabled before sleeping, and the remaining time used as the
interval to sleep. So, the tick needs to be restarted when nanosleep
finishes.
This is done by introducing after_sleep_interval, which is empty in the
NO_HZ case, but which sets the tick starting in the !NO_HZ case.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stupid bug - we need to compare the return value of recvmsg to the value of
iov_len, not its size. This caused port_helper processes not to be killed on
shutdown on x86_64 because the pids weren't being passed out properly.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In a stock 2.6.22.6 kernel, poweroff a user mode linux guest (2.6.22.6 running
in skas0 mode) will halt the host linux. I think the reason is the kernel
thread abort because of a bug. Then the sys_reboot in process of user mode
linux guest is not trapped by the user mode linux kernel and is executed by
host. I think it is better to make sure all of our children process to quit
when user mode linux kernel abort.
[ jdike - the kernel process needs to ignore SIGTERM, plus the waitpid/kill
loop is needed to make sure that all of our children are dead before the
kernel exits ]
Signed-off-by: Lepton Wu <ytht.net@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.
I'd rather not duplicate the four known host vmsplit cases for each of these
symbols. I'd also like to calculate them based on the highest userspace
address.
The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h. CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone. In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.
i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently. However, they are also used in stub.S, where C types don't work
so well. So, there are ASM_ versions of these constants for use in stub.S. I
also ifdef-ed the non-asm-friendly portion of as-layout.h.
With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.
defconfig has the old symbols deleted.
I also print these addresses out in case there is any problem mapping them on
the host.
The two stub.S files had some trailing whitespace, so that is cleaned up here.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A bunch of MTU-related cleanups in the network code.
First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers. This is used to size the skb that will receive a
packet. This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.
Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **. They just need the sk_buff * now. The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.
The MAX_PACKET definitions in most of the drivers are gone.
The set_mtu methods were all the same and did nothing, so they can be
removed.
The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it. It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Style and other non-functional changes in the UML networking code, including
include tidying
style violations
copyright updates
printks getting severities
userspace code calling libc directly rather than using the os_*
wrappers
There's also a exit path cleanup in the pcap driver.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are various uses of powers of 1000, plus the odd BILLION constant in the
time code. However, there are perfectly good definitions of *SEC_PER_*SEC in
linux/time.h which can be used instaed.
These are replaced directly in kernel code. Userspace code imports those
constants as UM_*SEC_PER_*SEC and uses these.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that ITIMER_REAL is no longer used, there is no need for any use of
SIGALRM whatsoever. This patch removes all mention of it.
In addition, real_alarm_handler took a signal argument which is now always
SIGVTALRM. So, that is gone.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Put back an implementation of timeval_to_ns in arch/um/os-Linux/time.c.
tglx pointed out in his review of tickless support that there was a
perfectly good implementation of it in linux/time.h. The problem is that
this is userspace code which can't pull in kernel headers and there doesn't
seem to be a libc version.
So, I'm copying the version from linux/time.h rather than resurrecting my
version. This causes some declaration changes as it now returns a signed
value rather than an unsigned value.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, the idle loop now longer needs SIGALRM firing - it can just sleep for the
requisite amount of time and fake a timer interrupt when it finishes.
Any use of ITIMER_REAL now goes away. disable_timer only turns off
ITIMER_VIRTUAL. switch_timers is no longer needed, so it, and all calls, goes
away.
disable_timer now returns the amount of time remaining on the timer.
default_idle uses this to tell idle_sleep how long to sleep. idle_sleep will
call alarm_handler if nanosleep returns 0, which is the case if it didn't
return early due to an interrupt. Otherwise, it just returns.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable tickless support.
CONFIG_TICK_ONESHOT and CONFIG_NO_HZ are enabled.
itimer_clockevent gets CLOCK_EVT_FEAT_ONESHOT and an implementation of
.set_next_event.
CONFIG_UML_REAL_TIME_CLOCK goes away because it only makes sense when there is
a clock ticking away all the time. timer_handler now just calls do_IRQ once
without trying to figure out how many ticks to emulate.
The idle loop now needs to turn ticking on and off.
Userspace ticks keep happening as usual. However, the userspace loop keep
track of when the next wakeup should happen and suppresses process ticks until
that happens.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable CONFIG_GENERIC_CLOCKEVENTS.
timer_irq gets its name changed to timer_handler, and becomes the recipient of
timer signals.
The clock_event_device is set up to imitate the current ticking clock, i.e.
CLOCK_EVT_FEAT_ONESHOT is not enabled yet.
disable_timer now doesn't ignore SIGALRM and SIGVTALRM because that breaks
delay calibration.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move timer signal initialization from init_irq_signals to a new function,
timer_init.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_interval took a timer type as an argument, but it always specified a
virtual timer. So, it is not needed, and it is gone, and set_interval is
simplified appropriately.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix up the switching between virtual and real timers. The idle loop sleeps,
so the timer at that point must be real time. At all other times, the timer
must be virtual. Even when userspace is running, and the kernel is asleep,
the virtual timer is correct because the process timer will be running and the
process timer will be firing.
The timer switch used to be in the context switch and timer handler code.
This is moved to the idle loop and the signal handler, making it much more
clear why it is happening.
switch_timers now returns the old timer type so that it may be restored. The
signal handler uses this in order to restore the previous timer type when it
returns.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eliminate hz() since its only purpose was to provide a kernel-space constant
to userspace code. This can be done instead by providing the constant
directly through kernel_constants.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/um/os-Linux/tt.c is no longer used.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tidy the code affected by the floating point fixes.
A bunch of unused stuff is gone, including two sigcontext.c files,
which turned out to be entirely unneeded.
There are the usual fixes -
whitespace and style cleanups
copyright updates
emacs formatting comments gone
include cleanups
adding severities to printks
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Handle floating point state in across signals correctly. UML/i386 needs to
know whether the host does PTRACE_[GS]ETFPXREGS, so an arch_init_registers
hook is added, which on x86_64 does nothing.
UML doesn't save and restore floating point registers on kernel entry and
exit, so they need to be copied between the host process and the sigcontext.
save_fpx_registers and restore_fpx_registers are added for this purpose.
save_fp_registers and restore_fp_registers already exist.
There was a bunch of floating point state conversion code in
arch/um/sys-i386/ptrace.c which isn't needed there, but is needed in signal.c,
so it is moved over.
The i386 code now distinguishes between fp and fpx state and handles them
correctly. The x86_64 code just needs to copy state as-is between the host
process and the stack. There are also some fixes there to pass the correct
address of the floating point state around.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A number of files that were changed in the recent removal of tt mode
are userspace files which call the os_* wrappers instead of calling
libc directly. A few other files were affected by this, through
This patch makes these call glibc directly.
There are also style fixes in the affected areas.
os_print_error has no remaining callers, so it is deleted.
There is a interface change to os_set_exec_close, eliminating a
parameter which was always the same. The callers are fixed as well.
os_process_pc got its error path cleaned up.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the boot-time host ptrace testing from clone to fork. They were
essentially doing fork anyway. This cleans up the code a bit, and makes
valgrind a bit happier about grinding it.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes some userspace files which were calling libc through the os_*
wrappers.
It turns out that there was only one user of os_new_tty_pgrp, so it can be
deleted.
There are also some style and whitespace fixes in here.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before the removal of tt mode, access to a register on the skas-mode side of a
pt_regs struct looked like pt_regs.regs.skas.regs.regs[FOO]. This was bad
enough, but it became pt_regs.regs.regs.regs[FOO] with the removal of the
union from the middle. To get rid of the run of three "regs", the last field
is renamed to "gp".
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_longjmp used to be needed when UML didn't have its own implementation of
setjmp and longjmp. They came from libc, and couldn't be called directly from
kernel code, as the libc jmp_buf couldn't be imported there. do_longjmp was a
userspace function which served to provide longjmp access to kernel code.
This is gone, and a number of void * pointers can now be jmp_buf *.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eliminate some uses of __u64 in the physical memory support. It's hard to get
a definition of __u64 in both kernel and userspace code on x86_64, so this
changes them to unsigned long long.
There are also a copyright update and formatting comment removal from the
affected header.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Formatting changes in the files which have been changed in the course
of folding foo_skas functions into their callers. These include:
copyright updates
header file trimming
style fixes
adding severity to printks
These changes should be entirely non-functional.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE. There were lots of functions that looked like
int foo(args){
foo_skas(args);
}
The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.
In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.
It turns out that usr2_handler was unused, so it is gone.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The next stage after removing code which depends on CONFIG_MODE_TT is removing
the CHOOSE_MODE abstraction, which provided both compile-time and run-time
branching to either tt-mode or skas-mode code.
This patch removes choose-mode.h and all inclusions of it, and replaces all
CHOOSE_MODE invocations with the skas branch. This leaves a number of trivial
functions which will be dealt with in a later patch.
There are some changes in the uaccess and tls support which go somewhat beyond
this and eliminate some of the now-redundant functions.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Formatting changes in the files which have been changed in the
tt-removal patchset so far. These include:
copyright updates
header file trimming
style fixes
adding severity to printks
indenting Kconfig help according to the predominant kernel style
These changes should be entirely non-functional.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset throws out tt mode, which has been non-functional for a while.
This is done in phases, interspersed with code cleanups on the affected files.
The removal is done as follows:
remove all code, config options, and files which depend on
CONFIG_MODE_TT
get rid of the CHOOSE_MODE macro, which decided whether to
call tt-mode or skas-mode code, and replace invocations with their
skas portions
replace all now-trivial procedures with their skas equivalents
There are now a bunch of now-redundant pieces of data structures, including
mode-specific pieces of the thread structure, pt_regs, and mm_context. These
are all replaced with their skas-specific contents.
As part of the ongoing style compliance project, I made a style pass over all
files that were changed. There are three such patches, one for each phase,
covering the files affected by that phase but no later ones.
I noticed that we weren't freeing the LDT state associated with a process when
it exited, so that's fixed in one of the later patches.
The last patch is a tidying patch which I've had for a while, but which caused
inexplicable crashes under tt mode. Since that is no longer a problem, this
can now go in.
This patch:
Start getting rid of tt mode support.
This patch throws out CONFIG_MODE_TT and all config options, code, and files
which depend on it.
CONFIG_MODE_SKAS is gone and everything that depends on it is included
unconditionally.
The few changed lines are in re-written Kconfig help, lines which needed
something skas-related removed from them, and a few more which weren't
strictly deletions.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Throw out a lot of code dealing with saving and restoring floating-point
state. In skas mode, where processes run in a restoring floating-point state
on kernel entry and exit is pointless.
This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c. Most
of what remained is now arch-indpendent, and can be moved up to
arch/um/os-Linux/registers.c. Both arches need the jmp_buf accessor
get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during
sigreturn by getting the fp state using ptrace rather than copying it out of
the process sigcontext.
After this, it turns out that arch/um/include/skas/mode-skas.h is almost
completely unneeded. The declarations in it are variables which either don't
exist or which don't have global scope. The one exception is
kill_off_processes_skas. If that's removed, this header can be deleted.
This uncovered a bug in user.h, which wasn't correctly making sure that a
size_t definition was available to both userspace and kernelspace files.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of asm/page.h from libc code. This header seems to be
disappearing, and UML doesn't make much use of it anyway.
The one use, PAGE_SHIFT in stub.h, is handled by copying the constant from the
kernel side of the house in common_offsets.h.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the generic console operations are in a userspace file, we
can do the following:
directly call into libc instead of through the os_* wrappers
eliminate os_window_size since it has only one user
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes a crash caused by an interrupt coming in when an IRQ stack
is being torn down. When this happens, handle_signal will loop, setting up
the IRQ stack again because the tearing down had finished, and handling
whatever signals had come in.
However, to_irq_stack returns a mask of pending signals to be handled, plus
bit zero is set if the IRQ stack was already active, and thus shouldn't be
torn down. This causes a problem because when handle_signal goes around
the loop, sig will be zero, and to_irq_stack will duly set bit zero in the
returned mask, faking handle_signal into believing that it shouldn't tear
down the IRQ stack and return thread_info pointers back to their original
values.
This will eventually cause a crash, as the IRQ stack thread_info will
continue pointing to the original task_struct and an interrupt will look
into it after it has been freed.
The fix is to stop passing a signal number into to_irq_stack. Rather, the
pending signals mask is initialized beforehand with the bit for sig already
set. References to sig in to_irq_stack can be replaced with references to
the mask.
[akpm@linux-foundation.org: use UL]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I found a type mismatch in UML that makes host block devices unusable as ubd
devices on x86_64 and other 64 bits systems (segfault of the mm subsystem):
In block/ioctl.c, the following lines show that the BLKGETSIZE ioctl expects
a pointer to a long:
case BLKGETSIZE:
if ((bdev->bd_inode->i_size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(arg, bdev->bd_inode->i_size >> 9);
In arch/um/os-Linux/file.c, os_file_size calls it with an int.
The ioctl_list man page should be fixed as well.
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stop UML crashing when trying to dump a process core on x86_64. This is the
minimal fix to stop the crash - more things are broken here, and patches are
forthcoming.
The immediate thing to do is define ELF_CORE_COPY_REGS and
ELF_CORE_COPY_FPREGS. Defining ELF_CORE_COPY_FPREGS allows dump_fpu to go
away. It is defined in terms of save_fp_registers, so that needs to be added.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.23-rc1 turned up another batch of references from non-__init code to
__init code. In most cases, these were missing __init annotations. In one
case (os_drop_memory), the annotation was present but wrong.
init_maps is __init, but for some reason was being very careful about the
mechanism by which it allocated memory, checking whether it was OK to use
kmalloc (at this point in the boot, it definitely isn't) and using either
alloc_bootmem_low_pages or kmalloc/vmalloc. So, the kmalloc/vmalloc code is
removed.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restructure do_aio thanks to commments from Ulrich and Al.
Uli started this by seeing that UML's initialization of a struct iocb
initialized fields that it shouldn't.
Al followed up by adding the following cleanups:
eliminating a variable by just using an anonymous structure in
its place.
hoisting a duplicated line out of the switch.
simplifying the error checking at the end.
I added a severity to the printk.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In 2.6.23-rc1, i386 fiddled its string support such that UML started getting
undefined references from modules. The UML asm/string.h was including the
i386 string.h, which defined __HAVE_ARCH_STR*, but the corresponding
implementations weren't being pulled in.
This is fixed by adding arch/i386/lib/string.h to the list of host
architecture files to be pulled in to UML.
A complication is that the libc exports file assumed that the generic strlen
and strstr weren't in use (i.e. __HAVE_ARCH_STR is defined), then they aren't
exported. This is untrue for strlen, which is exported in either case, so
this logic is not needed.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add some exports for hostfs that are required after Alberto Bertogli's fixes
for accessing unlinked host files.
Also did some style cleanups while I was here.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UML had two wrapper procedures for kmalloc, um_kmalloc and um_kmalloc_atomic
because the flag constants weren't available in userspace code.
kern_constants.h had made kernel constants available for a long time, so there
is no need for these wrappers any more. Rather, userspace code calls kmalloc
directly with the userspace versions of the gfp flags.
kmalloc isn't a real procedure, so I had to essentially copy the inline
wrapper around __kmalloc.
vmalloc also had its own wrapper for no good reason. This is now gone.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
run_helper and run_helper_thread had arguments which were the same in all
callers. run_helper's stack_out was always NULL and run_helper_thread's
stack_order was always 0. These are now gone, and the constants folded
into the code.
Also fixed leaks of the helper stack in the AIO and SIGIO code.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanup of the SIGWINCH support.
Some code and comment reformatting.
The stack used for SIGWINCH threads was leaked. This is now fixed by storing
it with the pid and other information, and freeing it when the thread is
killed.
If something goes wrong with a WIGWINCH thread, and this is discovered in the
interrupt handler, the winch record would leak. It is now freed, except that
the IRQ isn't freed. This is hard to do from interrupt context. This has the
side-effect that the IRQ system maintains a reference to the freed structure,
but that shouldn't cause a problem since the descriptor is disabled.
register_winch_irq is now much better about cleaning up after an
initialization failure.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Distros seem to be removing PAGE_SIZE from asm/page.h. So, the libc side of
UML should stop using it.
I replace it with UM_KERN_PAGE_SIZE, which is defined to be the same as
PAGE_SIZE on the kernel side of the house. I could also use getpagesize(),
but it's more important that UML have the same value of PAGE_SIZE everywhere.
It's conceivable that it could be built with a larger PAGE_SIZE, and use of
getpagesize() would break that badly.
PAGE_MASK got the same treatment, as it is closely tied to PAGE_SIZE.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the PTRACE_SYSEMU checking more robust. It will make sure that system
call numbers are reported correctly. If there is a problem, it will disable
PTRACE_SYSEMU use and use PTRACE_SYSCALL instead.
Thanks to Balaji G for helping reproduce this problem.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a separate IRQ stack. This differs from i386 in having the entire
interrupt run on a separate stack rather than starting on the normal kernel
stack and switching over once some preparation has been done. The underlying
mechanism, is of course, sigaltstack.
Another difference is that interrupts that happen in userspace are handled on
the normal kernel stack. These cause a wait wakeup instead of a signal
delivery so there is no point in trying to switch stacks for these. There's
no other stuff on the stack, so there is no extra stack consumption.
This quirk makes it possible to have the entire interrupt run on a separate
stack - process preemption (and calls to schedule()) happens on a normal
kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought.
The IRQ stack for CPU 0 is declared in the same way as the initial kernel
stack. IRQ stacks for other CPUs will be allocated dynamically.
An extra field was added to the thread_info structure. When the active
thread_info is copied to the IRQ stack, the real_thread field points back to
the original stack. This makes it easy to tell where to copy the thread_info
struct back to when the interrupt is finished. It also serves as a marker of
a nested interrupt. It is NULL for the first interrupt on the stack, and
non-NULL for any nested interrupts.
Care is taken to behave correctly if a second interrupt comes in when the
thread_info structure is being set up or taken down. I could just disable
interrupts here, but I don't feel like giving up any of the performance gained
by not flipping signals on and off.
If an interrupt comes in during these critical periods, the handler can't run
because it has no idea what shape the stack is in. So, it sets a bit for its
signal in a global mask and returns. The outer handler will deal with this
signal itself.
Atomicity is had with xchg. A nested interrupt that needs to bail out will
xchg its signal mask into pending_mask and repeat in case yet another
interrupt hit at the same time, until the mask stabilizes.
The outermost interrupt will set up the thread_info and xchg a zero into
pending_mask when it is done. At this point, nested interrupts will look at
->real_thread and see that no setup needs to be done. They can just continue
normally.
Similar care needs to be taken when exiting the outer handler. If another
interrupt comes in while it is copying the thread_info, it will drop a bit
into pending_mask. The outer handler will check this and if it is non-zero,
will loop, set up the stack again, and handle the interrupt.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some tidying of the irq code before introducing irq stacks. Mostly
style fixes, but the timer handler calls the timer code directly
rather than going through the generic sig_handler_common_skas.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
