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
..
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 proc: mark /proc/cmdline as permanent 2023-02-02 22:50:02 -08:00
consoles.c proc: consoles: use console_list_lock for list iteration 2022-12-02 11:25:02 +01:00
cpuinfo.c x86/aperfmperf: Replace aperfmperf_get_khz() 2022-04-27 20:22:19 +02:00
devices.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
fd.c file: convert to SLAB_TYPESAFE_BY_RCU 2023-10-19 11:02:48 +02:00
fd.h fs: port ->permission() to pass mnt_idmap 2023-01-19 09:24:28 +01:00
generic.c fs: pass the request_mask to generic_fillattr 2023-08-09 08:56:36 +02:00
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
Kconfig proc: make config PROC_CHILDREN depend on PROC_FS 2022-10-03 14:21:43 -07:00
kcore.c proc/kcore: do not try to access unaccepted memory 2023-10-04 10:32:22 -07:00
kmsg.c printk changes for 6.1 2022-10-10 11:24:19 -07:00
loadavg.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
Makefile
meminfo.c mm: memtest: convert to memtest_report_meminfo() 2023-08-21 13:37:47 -07:00
namespaces.c
nommu.c fs: create helper file_user_path() for user displayed mapped file path 2023-10-19 11:03:15 +02:00
page.c mm, pagemap: remove SLOB and SLQB from comments and documentation 2023-03-29 10:32:11 +02:00
proc_net.c v6.6-fs.proc.uapi 2023-08-28 11:43:19 -07:00
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 proc: delete unused <linux/uaccess.h> includes 2022-07-17 17:31:39 -07:00
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 proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
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 vfs-6.7.misc 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 proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
util.c
version.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
vmcore.c proc/vmcore: fix signedness bug in read_from_oldmem() 2023-07-27 13:07:05 -07:00