In the future mm->exe_file will be done without mmap_sem
serialization, thus isolate and reorganize the tile elf
code to make the transition easier. Good users will, make
use of the more standard get_mm_exe_file(), requiring only
holding the mmap_sem to read the value, and relying on reference
counting to make sure that the exe file won't dissappear
underneath us.
The visible effects of this patch are:
o We now take and drop the mmap_sem more often. Instead of
just in arch_setup_additional_pages(), we also do it in:
1) get_mm_exe_file()
2) to get the mm->vm_file and notify the simulator.
[Note that 1) will disappear once we change the locking
rules for exe_file.]
o We avoid getting a free page and doing d_path() while
holding the mmap_sem. This requires reordering the checks.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
To be compatible with the generic get_compat_sigevent(), the
copy_siginfo_to_user32() and thus copy_siginfo_from_user32()
have to use si_int instead of si_ptr. Using si_ptr means that
for the case of ILP32 compat code running in big-endian mode,
we would end up copying the high 32 bits of the pointer value
into si_int instead of the desired low 32 bits.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
The code that replaces the enum names with the enum values in the
tracepoints' format files could possible miss the end of string nul
character. This was caused by processing things like backslashes, quotes
and other tokens. After processing the tokens, a check for the nul
character needed to be done before continuing the loop, because the loop
incremented the pointer before doing the check, which could bypass the nul
character.
Link: http://lkml.kernel.org/r/552E661D.5060502@oracle.com
Reported-by: Sasha Levin <sasha.levin@oracle.com> # via KASan
Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Fixes: 0c564a538a "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit 889fa31f00 was a bit too eager in reducing the loop count,
so we ended up missing queues in some configurations. Ensure that
our division rounds up, so that's not the case.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 889fa31f00 ("blk-mq: reduce unnecessary software queue looping")
Signed-off-by: Jens Axboe <axboe@fb.com>
This function is a bit unusual because it accepts negative values as
"conn_len". It's theoretically possible for both "cache_len" and
"conn_len" to be -ENOSPC and in that case we would oops trying to run
memcmp() on the uninitialized "list" pointer.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Merge third patchbomb from Andrew Morton:
- various misc things
- a couple of lib/ optimisations
- provide DIV_ROUND_CLOSEST_ULL()
- checkpatch updates
- rtc tree
- befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs
- ptrace fixes
- fork() fixes
- seccomp cleanups
- more mmap_sem hold time reductions from Davidlohr
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (138 commits)
proc: show locks in /proc/pid/fdinfo/X
docs: add missing and new /proc/PID/status file entries, fix typos
drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic
Documentation/spi/spidev_test.c: fix warning
drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type
.gitignore: ignore *.tar
MAINTAINERS: add Mediatek SoC mailing list
tomoyo: reduce mmap_sem hold for mm->exe_file
powerpc/oprofile: reduce mmap_sem hold for exe_file
oprofile: reduce mmap_sem hold for mm->exe_file
mips: ip32: add platform data hooks to use DS1685 driver
lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
x86: switch to using asm-generic for seccomp.h
sparc: switch to using asm-generic for seccomp.h
powerpc: switch to using asm-generic for seccomp.h
parisc: switch to using asm-generic for seccomp.h
mips: switch to using asm-generic for seccomp.h
microblaze: use asm-generic for seccomp.h
arm: use asm-generic for seccomp.h
seccomp: allow COMPAT sigreturn overrides
...
Let's show locks which are associated with a file descriptor in
its fdinfo file.
Currently we don't have a reliable way to determine who holds a lock. We
can find some information in /proc/locks, but PID which is reported there
can be wrong. For example, a process takes a lock, then forks a child and
dies. In this case /proc/locks contains the parent pid, which can be
reused by another process.
$ cat /proc/locks
...
6: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF
...
$ ps -C rpcbind
PID TTY TIME CMD
332 ? 00:00:00 rpcbind
$ cat /proc/332/fdinfo/4
pos: 0
flags: 0100000
mnt_id: 22
lock: 1: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF
$ ls -l /proc/332/fd/4
lr-x------ 1 root root 64 Mar 5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock
$ ls -l /proc/324/fd/
total 0
lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0
You can see that the process with the 324 pid doesn't hold the lock.
This information is required for proper dumping and restoring file
locks.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the __raw IO calls to readl/write_relaxed which makes the driver
endian agnostic to run properly on big endian systems.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Andrew Victor <linux@maxim.org.za>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/spi/spidev_test.c:83:5: warning: no previous prototype for 'unespcape' [-Wmissing-prototypes]
fix spelling too.
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The RTC driver supports two flavors of S5M devices: S5M8767-like and
S2MPS14-like.
On S2MPS13 and S2MPS14 devices the RTC module is the same so we want to
re-use the existing support of S2MPS14. However device type was passed
from parent MFD driver in platform data structure. This way for the
S2MPS13 device the main MFD driver passed device type of 'S2MPS13X'.
Instead decouple detecting of device type between main MFD and RTC driver.
This allows adding support for other S2MPS14 variations (like S2MPS11 and
S2MPS13) easily by adding to mfd/sec-core.c:
static const struct mfd_cell s2mps13_devs[] = {
{ .name = "s2mps14-rtc", }
};
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Running make tar-pkg results in following:
# Untracked files:
# (use "git add <file>..." to include in what will be committed)
#
# linux-4.0.0-rc3-next-20150313-150225--x86.tar
This patch makes git ignore *.tar files.
Running 'git ls-files -i --exclude-standard' does not show any
tar files excluded from tracking after the change.
Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add the new list that Mediatek specific patches should also be
directed to.
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mm->exe_file is currently serialized with mmap_sem (shared) in order
to both safely (1) read the file and (2) compute the realpath by calling
tomoyo_realpath_from_path, making it an absolute overkill. Good users
will, on the other hand, make use of the more standard get_mm_exe_file(),
requiring only holding the mmap_sem to read the value, and relying on
reference
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the future mm->exe_file will be done without mmap_sem serialization,
thus isolate and reorganize the related code to make the transition
easier. Good users will, make use of the more standard get_mm_exe_file(),
requiring only holding the mmap_sem to read the value, and relying on
reference counting to make sure that the exe file won't dissappear
underneath us while getting the dcookie.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robert Richter <rric@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sync_buffer() needs the mmap_sem for two distinct operations, both only
occurring upon user context switch handling:
1) Dealing with the exe_file.
2) Adding the dcookie data as we need to lookup the vma that
backs it. This is done via add_sample() and add_data().
This patch isolates 1), for it will no longer need the mmap_sem for
serialization. However, for now, make of the more standard
get_mm_exe_file(), requiring only holding the mmap_sem to read the value,
and relying on reference counting to make sure that the exe file won't
dissappear underneath us while doing the get dcookie.
As a consequence, for 2) we move the mmap_sem locking into where we really
need it, in lookup_dcookie(). The benefits are twofold: reduce mmap_sem
hold times, and cleaner code.
[akpm@linux-foundation.org: export get_mm_exe_file for arch/x86/oprofile/oprofile.ko]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This modifies the IP32 (SGI O2) platform and reset code to utilize the new
rtc-ds1685 driver. The old mc146818rtc.h header is removed and ip32_defconfig
is updated as well.
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yalin Wang <yalin.wang@sonymobile.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. The obsolete sigreturn syscall override
is retained in 32-bit mode, and the ia32 syscall overrides are used in
the compat case. Remaining definitions were identical.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.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>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. The obsolete sigreturn in COMPAT mode
is retained as an override. Remaining definitions are identical. Also
corrected missing #define for header reinclusion protection.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. The obsolete sigreturn in COMPAT mode is
retained as an override. Remaining definitions are identical, though they
incorrectly appeared in uapi, which has been corrected.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. Definitions were identical.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. COMPAT definitions retain their
overrides and the remaining definitions were identical.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. Since microblaze is 32-bit, the COMPAT
seccomp defines are unused and can be dropped. The obsolete sigreturn
for seccomp strict mode is retained as an override. Remaining definitions
are identical.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. Definitions were identical.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures don't need to do much special for the strict-mode
seccomp syscall entries. Remove the redundant headers and reduce the
others.
This patch (of 8):
Some architectures may need to override the compat sigreturn definition,
as is already possible in the non-compat case.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
print_task_path_n_nm() is local to this file, its only user being
show_regs(). Mark the function static and avoid the EXPORT_SYMBOL.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Vineet Gupta <vgupta@synoipsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is better to use macros which are already available because then there
is just one location which needs to be change.
[akpm@linux-foundation.org: move IS_ENABLED definition to after the IS_BUILTIN and IS_MODULE definitions]
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using the indenting we can see the curly braces were obviously intended.
This is a static checker fix, but my guess is that we don't read enough
bytes, because we don't calculate "t_len" correctly.
Fixes: f1d8269802 ('memstick: use fully asynchronous request processing')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case of failed memory allocation, the return should be ENOMEM instead
of ENOSPC.
Return -EIO when sb_bread() fails.
Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This kthread is not loop at all due to break at the end of the loop. Make
that function linear, with no while loop.
And remove an unnecessary cast.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Anil Gurumurthy <anil.gurumurthy@qlogic.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a possibility of kstrdup() failure upon memory pressure.
Therefore, returning ENOMEM even for new_opts.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: Taesoo kim <taesoo@gatech.edu>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace mount option test by affs_test_opt().
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace direct mount option assignation by affs_set_opt() macro.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, affs still uses direct access on mount_options. This patch
prepares to use affs_clear/set/test_opt() like other filesystems.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the wrong values returned by various functions such as EIO and ENOMEM.
Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Cc: Taesoo kim <taesoo@gatech.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When converting unsigned long to int overflows may occur. These currently
are not detected when writing to the sysctl file system.
E.g. on a system where int has 32 bits and long has 64 bits
echo 0x800001234 > /proc/sys/kernel/threads-max
has the same effect as
echo 0x1234 > /proc/sys/kernel/threads-max
The patch adds the missing check in do_proc_dointvec_conv.
With the patch an overflow will result in an error EINVAL when writing to
the the sysctl file system.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cpumask_next_and() is looking for cpumask_next() in src1 in a loop and
tests if found cpu is also present in src2. remove that loop, perform
cpumask_and() of src1 and src2 first and use that new mask to find
cpumask_next().
Apart from removing while loop, ./bloat-o-meter on x86_64 shows
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-8 (-8)
function old new delta
cpumask_next_and 62 54 -8
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We set sig->notify_count = -1 between RELEASE and ACQUIRE operations:
spin_unlock_irq(lock);
...
if (!thread_group_leader(tsk)) {
...
for (;;) {
sig->notify_count = -1;
write_lock_irq(&tasklist_lock);
There are no restriction on it so other processors may see this STORE
mixed with other STOREs in both areas limited by the spinlocks.
Probably, it may be reordered with the above
sig->group_exit_task = tsk;
sig->notify_count = zap_other_threads(tsk);
in some way.
Set it under tasklist_lock locked to be sure nothing will be reordered.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg cleverly suggested using xchg() to set the new mm->exe_file instead
of calling set_mm_exe_file() which requires some form of serialization --
mmap_sem in this case. For archs that do not have atomic rmw instructions
we still fallback to a spinlock alternative, so this should always be
safe. As such, we only need the mmap_sem for looking up the backing
vm_file, which can be done sharing the lock. Naturally, this means we
need to manually deal with both the new and old file reference counting,
and we need not worry about the MMF_EXE_FILE_CHANGED bits, which can
probably be deleted in the future anyway.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch removes mm->mmap_sem from mm->exe_file read side.
Also it kills dup_mm_exe_file() and moves exe_file duplication into
dup_mmap() where both mmap_sems are locked.
[akpm@linux-foundation.org: fix comment typo]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
File /proc/sys/kernel/threads-max controls the maximum number of threads
that can be created using fork().
[akpm@linux-foundation.org: fix typo, per Guenter]
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Users can change the maximum number of threads by writing to
/proc/sys/kernel/threads-max.
With the patch the value entered is checked against the same limits that
apply when fork_init is called.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PAGE_SIZE is not guaranteed to be equal to or less than 8 times the
THREAD_SIZE.
E.g. architecture hexagon may have page size 1M and thread size 4096.
This would lead to a division by zero in the calculation of max_threads.
With 32-bit calculation there is no solution which delivers valid results
for all possible combinations of the parameters. The code is only called
once. Hence a 64-bit calculation can be used as solution.
[akpm@linux-foundation.org: use clamp_t(), per Oleg]
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PAGE_SIZE is not guaranteed to be equal to or less than 8 times the
THREAD_SIZE.
E.g. architecture hexagon may have page size 1M and thread size 4096.
This would lead to a division by zero in the calculation of max_threads.
With this patch the buggy code is moved to a separate function
set_max_threads. The error is not fixed.
After fixing the problem in a separate patch the new function can be
reused to adjust max_threads after adding or removing memory.
Argument mempages of function fork_init() is removed as totalram_pages is
an exported symbol.
The creation of separate patches for refactoring to a new function and for
fixing the logic was suggested by Ingo Molnar.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The comment explaining what value max_threads is set to is outdated. The
maximum memory consumption ratio for thread structures was 1/2 until
February 2002, then it was briefly changed to 1/16 before being set to 1/8
which we still use today. The comment was never updated to reflect that
change, it's about time.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
copy_process will report any failure in alloc_pid as ENOMEM currently
which is misleading because the pid allocation might fail not only when
the memory is short but also when the pid space is consumed already.
The current man page even mentions this case:
: EAGAIN
:
: A system-imposed limit on the number of threads was encountered.
: There are a number of limits that may trigger this error: the
: RLIMIT_NPROC soft resource limit (set via setrlimit(2)), which
: limits the number of processes and threads for a real user ID, was
: reached; the kernel's system-wide limit on the number of processes
: and threads, /proc/sys/kernel/threads-max, was reached (see
: proc(5)); or the maximum number of PIDs, /proc/sys/kernel/pid_max,
: was reached (see proc(5)).
so the current behavior is also incorrect wrt. documentation. POSIX man
page also suggest returing EAGAIN when the process count limit is reached.
This patch simply propagates error code from alloc_pid and makes sure we
return -EAGAIN due to reservation failure. This will make behavior of
fork closer to both our documentation and POSIX.
alloc_pid might alsoo fail when the reaper in the pid namespace is dead
(the namespace basically disallows all new processes) and there is no
good error code which would match documented ones. We have traditionally
returned ENOMEM for this case which is misleading as well but as per
Eric W. Biederman this behavior is documented in man pid_namespaces(7)
: If the "init" process of a PID namespace terminates, the kernel
: terminates all of the processes in the namespace via a SIGKILL signal.
: This behavior reflects the fact that the "init" process is essential for
: the correct operation of a PID namespace. In this case, a subsequent
: fork(2) into this PID namespace will fail with the error ENOMEM; it is
: not possible to create a new processes in a PID namespace whose "init"
: process has terminated.
and introducing a new error code would be too risky so let's stick to
ENOMEM for this case.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sending SI_TKILL from rt_[tg]sigqueueinfo was deprecated, so now we issue
a warning on the first attempt of doing it. We use WARN_ON_ONCE, which is
not informative and, what is worse, taints the kernel, making the trinity
syscall fuzzer complain false-positively from time to time.
It does not look like we need this warning at all, because the behaviour
changed quite a long time ago (2.6.39), and if an application relies on
the old API, it gets EPERM anyway and can issue a warning by itself.
So let us zap the warning in kernel.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
