linux/fs/proc
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
..
Kconfig
Makefile
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
cmdline.c
consoles.c
cpuinfo.c
devices.c
fd.c
fd.h
generic.c
inode.c As usual, lots of singleton and doubleton patches all over the tree and 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
kcore.c
kmsg.c
loadavg.c
meminfo.c
namespaces.c
nommu.c
page.c
proc_net.c
proc_sysctl.c misc cleanups (the part that hadn't been picked by individual fs trees) 2024-01-11 20:23:50 -08:00
proc_tty.c
root.c
self.c
softirqs.c
stat.c
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
thread_self.c
uptime.c
util.c
version.c
vmcore.c