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sst-linux/kernel
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Oleg Nesterov 9793a3bb53 getrusage: use sig->stats_lock rather than lock_task_sighand() 
[ Upstream commit f7ec1cd5cc7ef3ad964b677ba82b8b77f1c93009 ]

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

Change getrusage() to use sig->stats_lock, it was specifically designed
for this type of use. This way it runs lockless in the likely case.

TODO:
	- Change do_task_stat() to use sig->stats_lock too, then we can
	  remove spin_lock_irq(siglock) in wait_task_zombie().

	- Turn sig->stats_lock into seqcount_rwlock_t, this way the
	  readers in the slow mode won't exclude each other. See
	  https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/

	- stats_lock has to disable irqs because ->siglock can be taken
	  in irq context, it would be very nice to change __exit_signal()
	  to avoid the siglock->stats_lock dependency.

Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dylan Hatch <dylanbhatch@google.com>
Tested-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
..
bpf cpumap: Zero-initialise xdp_rxq_info struct before running XDP program 2024-03-15 10:48:15 -04:00
cgroup cgroup_freezer: cgroup_freezing: Check if not frozen 2023-12-13 18:39:19 +01:00
configs Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
debug kdb: Fix a potential buffer overflow in kdb_local() 2024-01-25 15:27:51 -08:00
dma dma-mapping: clear dev->dma_mem to NULL after freeing it 2024-01-25 15:27:28 -08:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-30 12:49:13 +02:00
events perf: Fix the nr_addr_filters fix 2024-02-05 20:13:00 +00:00
futex futex: Don't include process MM in futex key on no-MMU 2023-11-20 11:51:50 +01:00
gcov gcov: add support for checksum field 2022-12-31 13:33:11 +01:00
irq genirq/affinity: Move group_cpus_evenly() into lib/ 2024-01-10 17:10:33 +01:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-07-19 16:21:37 +02:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:52:10 +01:00
locking lockdep: Fix block chain corruption 2023-12-03 07:32:09 +01:00
module kallsyms: Make module_kallsyms_on_each_symbol generally available 2024-01-05 15:18:40 +01:00
power PM: hibernate: Enforce ordering during image compression/decompression 2024-01-31 16:16:58 -08:00
printk printk: Consolidate console deferred printing 2023-09-23 11:11:07 +02:00
rcu rcu: Defer RCU kthreads wakeup when CPU is dying 2024-01-31 16:17:05 -08:00
sched sched/rt: sysctl_sched_rr_timeslice show default timeslice after reset 2024-03-01 13:26:24 +01:00
time hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range() 2024-02-23 09:12:50 +01:00
trace bpf: Remove trace_printk_lock 2024-02-23 09:12:51 +01:00
.gitignore
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:32:58 +01:00
async.c async: Introduce async_schedule_dev_nocall() 2024-01-31 16:17:00 -08:00
audit_fsnotify.c
audit_tree.c
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 17:07:08 +00:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-05 20:12:47 +00:00
audit.h
auditfilter.c
auditsc.c audit,io_uring: io_uring openat triggers audit reference count underflow 2023-10-25 12:03:04 +02:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c xfs: don't generate selinux audit messages for capability testing 2022-03-09 10:32:06 -08:00
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-06 12:10:40 +02:00
configs.c
context_tracking.c context_tracking: Fix noinstr vs KASAN 2023-03-10 09:33:45 +01:00
cpu_pm.c
cpu.c cpu/SMT: Make SMT control more robust against enumeration failures 2024-01-10 17:10:26 +01:00
crash_core.c
crash_dump.c
cred.c cred: switch to using atomic_long_t 2023-12-20 17:00:20 +01:00
delayacct.c delayacct: support re-entrance detection of thrashing accounting 2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c exit: Detect and fix irq disabled state in oops 2023-03-10 09:33:45 +01:00
extable.c
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 13:55:39 +01:00
fork.c kernel/fork: beware of __put_task_struct() calling context 2023-09-23 11:11:00 +02:00
freezer.c
gen_kheaders.sh kbuild: build init/built-in.a just once 2022-09-29 04:40:15 +09:00
groups.c
hung_task.c sched: Fix more TASK_state comparisons 2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kallsyms_internal.h kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[] 2023-10-25 12:03:16 +02:00
kallsyms.c kallsyms: Add helper kallsyms_on_each_match_symbol() 2023-10-25 12:03:16 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: kmsan: unpoison area->list in kcov_remote_area_put() 2022-10-03 14:03:23 -07:00
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-19 16:21:08 +02:00
kexec_elf.c
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-21 16:00:55 +02:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec.c kernel: kexec: copy user-array safely 2023-11-28 17:06:57 +00:00
kheaders.c kheaders: Use array declaration instead of char 2023-05-11 23:03:02 +09:00
kmod.c
kprobes.c kprobes: consistent rcu api usage for kretprobe holder 2023-12-13 18:39:17 +01:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2022-09-11 21:55:06 -07:00
kthread.c signal: break out of wait loops on kthread_stop() 2022-10-09 16:01:59 -07:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
Makefile cfi: Fix CFI failure with KASAN 2022-12-31 13:33:08 +01:00
module_signature.c
notifier.c
nsproxy.c Revert "fs/exec: allow to unshare a time namespace on vfork+exec" 2022-09-13 10:38:43 -07:00
padata.c crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 17:06:58 +00:00
panic.c panic: Reenable preemption in WARN slowpath 2023-09-23 11:11:09 +02:00
params.c kobject: remove kset from struct kset_uevent_ops callbacks 2021-12-28 11:26:18 +01:00
pid_namespace.c rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() 2023-03-10 09:32:52 +01:00
pid.c
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 17:07:13 +00:00
regset.c
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-11 23:03:03 +09:00
resource_kunit.c
resource.c PCI: Allow drivers to request exclusive config regions 2023-09-13 09:42:46 +02:00
rseq.c rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered 2022-11-14 09:58:32 +01:00
scftorture.c scftorture: Forgive memory-allocation failure if KASAN 2023-09-23 11:11:00 +02:00
scs.c
seccomp.c seccomp: Add wait_killable semantic to seccomp user notifier 2022-05-03 14:11:58 -07:00
signal.c mm: suppress mm fault logging if fatal signal already pending 2023-08-03 10:24:01 +02:00
smp.c smp,csd: Throw an error if a CSD lock is stuck for too long 2023-11-28 17:06:55 +00:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c uaccess: remove CONFIG_SET_FS 2022-02-25 09:36:06 +01:00
static_call_inline.c
static_call.c
stop_machine.c
sys_ni.c
sys.c getrusage: use sig->stats_lock rather than lock_task_sighand() 2024-03-15 10:48:22 -04:00
sysctl-test.c
sysctl.c proc: proc_skip_spaces() shouldn't think it is working on C strings 2022-12-05 12:09:06 -08:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c
torture.c torture: Fix hang during kthread shutdown phase 2023-03-10 09:34:07 +01:00
tracepoint.c tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming() 2022-09-26 13:01:18 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL 2023-02-22 12:59:50 +01:00
up.c
user_namespace.c ucounts: Split rlimit and ucount values and max values 2022-10-09 16:24:05 -07:00
user-return-notifier.c
user.c
usermode_driver.c
utsname_sysctl.c kernel/utsname_sysctl.c: Fix hostname polling 2022-10-23 12:01:01 -07:00
utsname.c
watch_queue.c kernel: watch_queue: copy user-array safely 2023-11-28 17:06:57 +00:00
watchdog_hld.c watchdog/perf: more properly prevent false positives with turbo modes 2023-07-19 16:21:08 +02:00
watchdog.c watchdog: move softlockup_panic back to early_param 2023-11-28 17:07:09 +00:00
workqueue_internal.h
workqueue.c workqueue: Provide one lock class key per work_on_cpu() callsite 2023-11-28 17:06:55 +00:00