Oleg Nesterov 7601df8031 fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats ...

lock_task_sighand() can trigger a hard lockup.  If NR_CPUS threads call
do_task_stat() at the same time and the process has NR_THREADS, it will
spin with irqs disabled O(NR_CPUS * NR_THREADS) time.

Change do_task_stat() to use sig->stats_lock to gather the statistics
outside of ->siglock protected section, in the likely case this code will
run lockless.

Link: https://lkml.kernel.org/r/20240123153357.GA21857@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Dylan Hatch <dylanbhatch@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2024-02-07 21:20:33 -08:00

..

array.c

fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats

2024-02-07 21:20:33 -08:00

base.c

proc: Use lsmids instead of lsm names for attrs

2023-11-12 22:54:42 -05:00

bootconfig.c

fs/proc: Add boot loader arguments as comment to /proc/bootconfig

2023-10-07 10:45:56 +09:00

cmdline.c

…

consoles.c

…

cpuinfo.c

…

devices.c

…

fd.c

file: convert to SLAB_TYPESAFE_BY_RCU

2023-10-19 11:02:48 +02:00

fd.h

…

generic.c

fs: pass the request_mask to generic_fillattr

2023-08-09 08:56:36 +02:00

inode.c

Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-11-02 20:53:31 -10:00

internal.h

proc: Use lsmids instead of lsm names for attrs

2023-11-12 22:54:42 -05:00

interrupts.c

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Kconfig

…

kcore.c

proc/kcore: do not try to access unaccepted memory

2023-10-04 10:32:22 -07:00

kmsg.c

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loadavg.c

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Makefile

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meminfo.c

mm: memtest: convert to memtest_report_meminfo()

2023-08-21 13:37:47 -07:00

namespaces.c

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nommu.c

fs: create helper file_user_path() for user displayed mapped file path

2023-10-19 11:03:15 +02:00

page.c

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proc_net.c

Merge tag 'v6.6-fs.proc.uapi' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-08-28 11:43:19 -07:00

proc_sysctl.c

Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-01-11 20:23:50 -08:00

proc_tty.c

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root.c

fs: super: dynamically allocate the s_shrink

2023-10-04 10:32:26 -07:00

self.c

proc: convert to new timestamp accessors

2023-10-18 14:08:26 +02:00

softirqs.c

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stat.c

proc/stat: remove arch_idle_time()

2023-04-18 16:39:33 -07:00

task_mmu.c

fs/proc/task_mmu: move mmu notification mechanism inside mm lock

2024-01-12 15:20:46 -08:00

task_nommu.c

Merge tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

2023-10-30 09:14:19 -10:00

thread_self.c

proc: convert to new timestamp accessors

2023-10-18 14:08:26 +02:00

uptime.c

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util.c

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version.c

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vmcore.c

proc/vmcore: fix signedness bug in read_from_oldmem()

2023-07-27 13:07:05 -07:00