Commit Graph

516355 Commits

Author SHA1 Message Date
Davidlohr Bueso
fd89a65f15 powerpc/oprofile: reduce mmap_sem hold for exe_file
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>
2015-04-17 09:04:11 -04:00
Davidlohr Bueso
11163348a2 oprofile: reduce mmap_sem hold for mm->exe_file
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>
2015-04-17 09:04:11 -04:00
Joshua Kinard
15beb694c6 mips: ip32: add platform data hooks to use DS1685 driver
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>
2015-04-17 09:04:11 -04:00
Andrew Morton
9e522c0d28 lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
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>
2015-04-17 09:04:10 -04:00
Kees Cook
8eb68bf75e x86: switch to using asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
d0f138b085 sparc: switch to using asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
1a3aff9ec3 powerpc: switch to using asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
cf7a71b602 parisc: switch to using asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
97247fd99d mips: switch to using asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
cc2d316fe7 microblaze: use asm-generic for seccomp.h
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>
2015-04-17 09:04:10 -04:00
Kees Cook
6bcf4e9aab arm: use asm-generic for seccomp.h
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>
2015-04-17 09:04:09 -04:00
Kees Cook
ddaa27ee62 seccomp: allow COMPAT sigreturn overrides
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>
2015-04-17 09:04:09 -04:00
Davidlohr Bueso
be2a7fce39 arc: do not export symbols in troubleshoot.c
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>
2015-04-17 09:04:09 -04:00
Michal Simek
02d699f1f4 include/linux/kconfig.h: ese macros which are already defined
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>
2015-04-17 09:04:09 -04:00
Dan Carpenter
13f6b191aa memstick: mspro_block: add missing curly braces
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>
2015-04-17 09:04:09 -04:00
Sanidhya Kashyap
c3fe5872eb bfs: correct return values
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>
2015-04-17 09:04:09 -04:00
Jiri Slaby
8f7d3f0f1e bfs: bfad_worker cleanup
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>
2015-04-17 09:04:09 -04:00
Sanidhya Kashyap
c8f33d0bec affs: kstrdup() memory handling
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>
2015-04-17 09:04:09 -04:00
Fabian Frederick
79bda4d510 fs/affs: use affs_test_opt()
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>
2015-04-17 09:04:08 -04:00
Fabian Frederick
34f2483538 fs/affs/super.c: use affs_set_opt()
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>
2015-04-17 09:04:08 -04:00
Fabian Frederick
6bf445ce35 fs/affs/affs.h: add mount option manipulation macros
Add clear/set/test affs mount option macros.

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>
2015-04-17 09:04:08 -04:00
Fabian Frederick
a0016ff286 fs/affs: use AFFS_MOUNT prefix for mount options
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>
2015-04-17 09:04:08 -04:00
Sanidhya Kashyap
b796410630 adfs: return correct return values
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>
2015-04-17 09:04:08 -04:00
Andrey Ryabinin
9d796e6623 gcov: fix softlockups
gcov profiling if enabled with other heavy compile-time instrumentation
like KASan could trigger following softlockups:

  NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]
  Modules linked in:
  irq event stamp: 22823276
  hardirqs last  enabled at (22823275): [<ffffffff86e8d10d>] mutex_lock_nested+0x7d9/0x930
  hardirqs last disabled at (22823276): [<ffffffff86e9521d>] apic_timer_interrupt+0x6d/0x80
  softirqs last  enabled at (22823172): [<ffffffff811ed969>] __do_softirq+0x4db/0x729
  softirqs last disabled at (22823167): [<ffffffff811edfcf>] irq_exit+0x7d/0x15b
  CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W       3.19.0-05245-gbb33326-dirty #3
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
  task: ffff88006cba8000 ti: ffff88006cbb0000 task.ti: ffff88006cbb0000
  RIP: kasan_mem_to_shadow+0x1e/0x1f
  Call Trace:
    strcmp+0x28/0x70
    get_node_by_name+0x66/0x99
    gcov_event+0x4f/0x69e
    gcov_enable_events+0x54/0x7b
    gcov_fs_init+0xf8/0x134
    do_one_initcall+0x1b2/0x288
    kernel_init_freeable+0x467/0x580
    kernel_init+0x15/0x18b
    ret_from_fork+0x7c/0xb0
  Kernel panic - not syncing: softlockup: hung tasks

Fix this by sticking cond_resched() in gcov_enable_events().

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:08 -04:00
Heinrich Schuchardt
230633d109 kernel/sysctl.c: detect overflows when converting to int
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>
2015-04-17 09:04:08 -04:00
Sergey Senozhatsky
534b483a86 cpumask: don't perform while loop in cpumask_next_and()
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>
2015-04-17 09:04:08 -04:00
Kirill Tkhai
dfcce791fb fs/exec.c:de_thread: move notify_count write under lock
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>
2015-04-17 09:04:07 -04:00
Davidlohr Bueso
6e399cd144 prctl: avoid using mmap_sem for exe_file serialization
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>
2015-04-17 09:04:07 -04:00
Konstantin Khlebnikov
90f31d0ea8 mm: rcu-protected get_mm_exe_file()
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>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt
0ec62afeb1 Doc/sysctl/kernel.txt: document threads-max
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>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt
16db3d3f11 kernel/sysctl.c: threads-max observe limits
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>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt
ac1b398de1 kernel/fork.c: avoid division by zero
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>
2015-04-17 09:04:07 -04:00
Heinrich Schuchardt
ff691f6e03 kernel/fork.c: new function for max_threads
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>
2015-04-17 09:04:06 -04:00
Jean Delvare
3ea7f5e25e fork_init: update max_threads comment
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>
2015-04-17 09:04:06 -04:00
Michal Hocko
35f71bc0a0 fork: report pid reservation failure properly
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>
2015-04-17 09:04:06 -04:00
Vladimir Davydov
69828dce7a signal: remove warning about using SI_TKILL in rt_[tg]sigqueueinfo
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>
2015-04-17 09:04:06 -04:00
Oleg Nesterov
64a4096c5c ptrace: ptrace_detach() can no longer race with SIGKILL
ptrace_detach() re-checks ->ptrace under tasklist lock and calls
release_task() if __ptrace_detach() returns true.  This was needed because
the __TASK_TRACED tracee could be killed/untraced, and it could even pass
exit_notify() before we take tasklist_lock.

But this is no longer possible after 9899d11f65 "ptrace: ensure
arch_ptrace/ptrace_request can never race with SIGKILL".  We can turn
these checks into WARN_ON() and remove release_task().

While at it, document the setting of child->exit_code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Labath <labath@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Oleg Nesterov
b72c186999 ptrace: fix race between ptrace_resume() and wait_task_stopped()
ptrace_resume() is called when the tracee is still __TASK_TRACED.  We set
tracee->exit_code and then wake_up_state() changes tracee->state.  If the
tracer's sub-thread does wait() in between, task_stopped_code(ptrace => T)
wrongly looks like another report from tracee.

This confuses debugger, and since wait_task_stopped() clears ->exit_code
the tracee can miss a signal.

Test-case:

	#include <stdio.h>
	#include <unistd.h>
	#include <sys/wait.h>
	#include <sys/ptrace.h>
	#include <pthread.h>
	#include <assert.h>

	int pid;

	void *waiter(void *arg)
	{
		int stat;

		for (;;) {
			assert(pid == wait(&stat));
			assert(WIFSTOPPED(stat));
			if (WSTOPSIG(stat) == SIGHUP)
				continue;

			assert(WSTOPSIG(stat) == SIGCONT);
			printf("ERR! extra/wrong report:%x\n", stat);
		}
	}

	int main(void)
	{
		pthread_t thread;

		pid = fork();
		if (!pid) {
			assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
			for (;;)
				kill(getpid(), SIGHUP);
		}

		assert(pthread_create(&thread, NULL, waiter, NULL) == 0);

		for (;;)
			ptrace(PTRACE_CONT, pid, 0, SIGCONT);

		return 0;
	}

Note for stable: the bug is very old, but without 9899d11f65 "ptrace:
ensure arch_ptrace/ptrace_request can never race with SIGKILL" the fix
should use lock_task_sighand(child).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Pavel Labath <labath@google.com>
Tested-by: Pavel Labath <labath@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Alexander Kuleshov
8de560def7 fs/fat: comment fix, fat_bits can be also 32
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Alexander Kuleshov
58932ef7f2 fs/fat: remove unnecessary includes
'fat.h' includes <linux/buffer_head.h> which includes <linux/fs.h> which
includes all the header files required for all *.c files fat filesystem.

[akpm@linux-foundation.org: fs/fat/iode.c needs seq_file.h]
[sfr@canb.auug.org.au: put one actually necessary include file back]
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:06 -04:00
Alexander Kuleshov
a40a7d9d07 fs/fat: remove unnecessary defintion
'*sb' never used, so let's remote it and pass inode->i_sb directly to the
MSDOS_SB.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:05 -04:00
Thomas Hebb
db579e76f0 hfsplus: don't store special "osx" xattr prefix on-disk
On Mac OS X, HFS+ extended attributes are not namespaced.  Since we want
to be compatible with OS X filesystems and yet still support the Linux
namespacing system, the hfsplus driver implements a special "osx"
namespace that is reported for any attribute that is not namespaced
on-disk.  However, the current code for getting and setting these
unprefixed attributes is broken.

hfsplus_osx_setattr() and hfsplus_osx_getattr() are passed names that have
already had their "osx." prefixes stripped by the generic functions.  The
functions first, quite correctly, check those names to make sure that they
aren't prefixed with a known namespace, which would allow namespace access
restrictions to be bypassed.  However, the functions then prepend "osx."
to the name they're given before passing it on to hfsplus_getattr() and
hfsplus_setattr().  Not only does this cause the "osx." prefix to be
stored on-disk, defeating its purpose, it also breaks the check for the
special "com.apple.FinderInfo" attribute, which is reported for all files,
and as a consequence makes some userspace applications (e.g.  GNU patch)
fail even when extended attributes are not otherwise in use.

There are five commits which have touched this particular code:

  127e5f5ae5 ("hfsplus: rework functionality of getting, setting and deleting of extended attributes")
  b168fff721 ("hfsplus: use xattr handlers for removexattr")
  bf29e886b2 ("hfsplus: correct usage of HFSPLUS_ATTR_MAX_STRLEN for non-English attributes")
  fcacbd95e121 ("fs/hfsplus: move xattr_name allocation in hfsplus_getxattr()")
  ec1bbd346f18 ("fs/hfsplus: move xattr_name allocation in hfsplus_setxattr()")

The first commit creates the functions to begin with.  The namespace is
prepended by the original code, which I believe was correct at the time,
since hfsplus_?etattr() stripped the prefix if found.  The second commit
removes this behavior from hfsplus_?etattr() and appears to have been
intended to also remove the prefixing from hfsplus_osx_?etattr().
However, what it actually does is remove a necessary strncpy() call
completely, breaking the osx namespace entirely.  The third commit re-adds
the strncpy() call as it was originally, but doesn't mention it in its
commit message.  The final two commits refactor the code and don't affect
its functionality.

This commit does what b168fff attempted to do (prevent the prefix from
being added), but does it properly, instead of passing in an empty buffer
(which is what b168fff actually did).

Fixes: b168fff721 ("hfsplus: use xattr handlers for removexattr")
Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Sergei Antonov <saproj@gmail.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:05 -04:00
Sergei Antonov
059a704c43 hfsplus: fix expand when not enough available space
Fix a bug which is reproduced as follows. Create a file:

 echo abc > test_file

Try to expand the file beyond available space:

 truncate --size=<size exceeding available space> test_file

Since HFS+ does not support file size > allocated size, truncate should
fail.  However, it ends successfully.  The driver returns success despite
having been unable to allocate the requested space for the file.  Also
filesystem check finds an error:

 Checking catalog file.
 Incorrect size for file test_file
 (It should be 469094400 instead of 1000000000)

Add a piece of code analogous to code in the fat driver.  Now a proper
error is returned and filesystem remains consistent.

Signed-off-by: Sergei Antonov <saproj@gmail.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Reviewed-by: Anton Altaparmakov <anton@tuxera.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Sougata Santra <sougata@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:05 -04:00
Chengyu Song
27a4e3884e hfsplus: incorrect return value
In case of memory allocation error, the return should be -ENOMEM, instead
of -ENOSPC.

Signed-off-by: Chengyu Song <csong84@gatech.edu>
Reviewed-by: Sergei Antonov <saproj@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:05 -04:00
Fabian Frederick
7ce844a20e fs/hfsplus: replace if/BUG by BUG_ON
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>
2015-04-17 09:04:05 -04:00
Fabian Frederick
1ad8d63d63 fs/hfsplus: use bool instead of int for is_known_namespace() return value
is_known_namespace() only returns true/false.  Also remove inline and let
compiler decide what to do with static functions.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
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>
2015-04-17 09:04:05 -04:00
Fabian Frederick
73d28d571d fs/hfsplus: atomically set inode->i_flags
According to commit 5f16f3225b ("ext4: atomically set inode->i_flags in
ext4_set_inode_flags()").

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:05 -04:00
Fabian Frederick
5e61473ea9 fs/hfsplus: move xattr_name allocation in hfsplus_setxattr()
security/trusted/user/osx setxattr did the same
xattr_name initialization. Move that operation in hfsplus_setxattr().

Tested with security/trusted/user getfattr/setfattr

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>
2015-04-17 09:04:05 -04:00
Fabian Frederick
a3cef4cd68 fs/hfsplus: move xattr_name allocation in hfsplus_getxattr()
security/trusted/user/osx getxattr did the same
xattr_name initialization. Move that operation in hfsplus_getxattr().

Tested with security/trusted/user getfattr/setfattr

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>
2015-04-17 09:04:04 -04:00
Dan Carpenter
f01fa5fb35 hfsplus: add missing curly braces in hfsplus_delete_cat()
This doesn't change how the code works, but clearly the curly braces were
intended.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Sougata Santra <sougata@tuxera.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:04 -04:00