Oleg Nesterov fd63fb84ed fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand() ... [ Upstream commit 60f92acb60 ] Patch series "fs/proc: do_task_stat: use sig->stats_". do_task_stat() has the same problem as getrusage() had before "getrusage: use sig->stats_lock rather than lock_task_sighand()": a hard lockup. If NR_CPUS threads call lock_task_sighand() at the same time and the process has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS * NR_THREADS) time. This patch (of 3): thread_group_cputime() does its own locking, we can safely shift thread_group_cputime_adjusted() which does another for_each_thread loop outside of ->siglock protected section. Not only this removes for_each_thread() from the critical section with irqs disabled, this removes another case when stats_lock is taken with siglock held. We want to remove this dependency, then we can change the users of stats_lock to not disable irqs. Link: https://lkml.kernel.org/r/20240123153313.GA21832@redhat.com Link: https://lkml.kernel.org/r/20240123153355.GA21854@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> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-03-15 10:48:22 -04:00
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Kconfig	…
Makefile	…
array.c	fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()	2024-03-15 10:48:22 -04:00
base.c	procfs: block chmod on /proc/thread-self/comm	2023-09-19 12:22:52 +02:00
bootconfig.c	proc: bootconfig: Add null pointer check	2022-04-08 14:24:12 +02:00
cmdline.c	…
consoles.c	…
cpuinfo.c	…
devices.c	…
fd.c	procfs: prevent unprivileged processes accessing fdinfo dir	2022-05-18 10:26:50 +02:00
fd.h	…
generic.c	proc: fix dentry/inode overinstantiating under /proc/${pid}/net	2022-06-09 10:23:10 +02:00
inode.c	…
internal.h	…
interrupts.c	…
kcore.c	…
kmsg.c	…
loadavg.c	…
meminfo.c	…
namespaces.c	…
nommu.c	…
page.c	…
proc_net.c	proc: fix dentry/inode overinstantiating under /proc/${pid}/net	2022-06-09 10:23:10 +02:00
proc_sysctl.c	proc: sysctl: prevent aliased sysctls from getting passed to init	2023-12-03 07:31:24 +01:00
proc_tty.c	…
root.c	…
self.c	…
softirqs.c	…
stat.c	…
task_mmu.c	mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps	2023-02-09 11:26:44 +01:00
task_nommu.c	proc: nommu: /proc/<pid>/maps: release mmap read lock	2023-10-06 13:18:22 +02:00
thread_self.c	…
uptime.c	…
util.c	…
version.c	…
vmcore.c	…