Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Haifeng Xu 5bbf6ad532 perf/core: Fix missing wakeup when waiting for context reference ... [ Upstream commit 74751ef5c1912ebd3e65c3b65f45587e05ce5d36 ] In our production environment, we found many hung tasks which are blocked for more than 18 hours. Their call traces are like this: [346278.191038] __schedule+0x2d8/0x890 [346278.191046] schedule+0x4e/0xb0 [346278.191049] perf_event_free_task+0x220/0x270 [346278.191056] ? init_wait_var_entry+0x50/0x50 [346278.191060] copy_process+0x663/0x18d0 [346278.191068] kernel_clone+0x9d/0x3d0 [346278.191072] __do_sys_clone+0x5d/0x80 [346278.191076] __x64_sys_clone+0x25/0x30 [346278.191079] do_syscall_64+0x5c/0xc0 [346278.191083] ? syscall_exit_to_user_mode+0x27/0x50 [346278.191086] ? do_syscall_64+0x69/0xc0 [346278.191088] ? irqentry_exit_to_user_mode+0x9/0x20 [346278.191092] ? irqentry_exit+0x19/0x30 [346278.191095] ? exc_page_fault+0x89/0x160 [346278.191097] ? asm_exc_page_fault+0x8/0x30 [346278.191102] entry_SYSCALL_64_after_hwframe+0x44/0xae The task was waiting for the refcount become to 1, but from the vmcore, we found the refcount has already been 1. It seems that the task didn't get woken up by perf_event_release_kernel() and got stuck forever. The below scenario may cause the problem. Thread A Thread B ... ... perf_event_free_task perf_event_release_kernel ... acquire event->child_mutex ... get_ctx ... release event->child_mutex acquire ctx->mutex ... perf_free_event (acquire/release event->child_mutex) ... release ctx->mutex wait_var_event acquire ctx->mutex acquire event->child_mutex # move existing events to free_list release event->child_mutex release ctx->mutex put_ctx ... ... In this case, all events of the ctx have been freed, so we couldn't find the ctx in free_list and Thread A will miss the wakeup. It's thus necessary to add a wakeup after dropping the reference. Fixes: 1cf8dfe8a6 ("perf/core: Fix race between close() and fork()") Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20240513103948.33570-1-haifeng.xu@shopee.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-07-05 09:08:25 +02:00
..
bpf	bpf: report RCU QS in cpumap kthread	2024-03-26 18:22:25 -04:00
cgroup	sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level	2024-06-16 13:28:41 +02:00
configs
debug	kdb: Use format-specifiers rather than memset() for padding in kdb_read()	2024-06-16 13:28:52 +02:00
dma	dma-mapping: clear dev->dma_mem to NULL after freeing it	2024-01-25 14:34:25 -08:00
events	perf/core: Fix missing wakeup when waiting for context reference	2024-07-05 09:08:25 +02:00
gcov	gcov: add support for GCC 14	2024-07-05 09:08:24 +02:00
irq	genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline	2024-06-16 13:28:48 +02:00
livepatch	livepatch: fix race between fork and KLP transition	2022-10-26 13:22:18 +02:00
locking	locking/ww_mutex/test: Fix potential workqueue corruption	2023-11-28 16:50:13 +00:00
power	PM: suspend: Set mem_sleep_current during kernel command line setup	2024-04-13 12:51:24 +02:00
printk	printk: Update @console_may_schedule in console_trylock_spinning()	2024-04-13 12:51:29 +02:00
rcu	rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment	2024-07-05 09:08:20 +02:00
sched	sched/fair: Allow disabling sched_balance_newidle with sched_relax_domain_level	2024-06-16 13:28:41 +02:00
time	tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device()	2024-07-05 09:08:19 +02:00
trace	tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test	2024-07-05 09:08:25 +02:00
.gitignore	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:04:16 +02:00
acct.c	acct: fix potential integer overflow in encode_comp_t()	2023-01-18 11:41:34 +01:00
async.c	treewide: Remove uninitialized_var() usage	2023-06-09 10:29:01 +02:00
audit.c	audit: Send netlink ACK before setting connection in auditd_set	2024-02-23 08:24:54 +01:00
audit.h	audit: log AUDIT_TIME_* records only from rules	2022-04-15 14:18:04 +02:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-09-05 10:27:38 +02:00
audit_tree.c	audit: move put_tree() to avoid trim_trees refcount underflow and UAF	2021-09-03 10:08:16 +02:00
audit_watch.c	audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare()	2023-11-28 16:50:18 +00:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:30:59 +02:00
auditsc.c	audit: fix possible soft lockup in __audit_inode_child()	2023-09-23 10:59:46 +02:00
backtracetest.c	treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()	2023-04-20 12:07:32 +02:00
bounds.c	bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS	2024-05-02 16:18:37 +02:00
capability.c
compat.c	sched_getaffinity: don't assume 'cpumask_size()' is fully initialized	2023-04-05 11:16:42 +02:00
configs.c
context_tracking.c
cpu.c	hrtimers: Push pending hrtimers away from outgoing CPU earlier	2023-12-13 18:18:09 +01:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-06-22 09:31:22 +02:00
crash_core.c
crash_dump.c
cred.c	cred: switch to using atomic_long_t	2023-12-20 15:41:18 +01:00
delayacct.c
dma.c
exec_domain.c
exit.c	treewide: Remove uninitialized_var() usage	2023-06-09 10:29:01 +02:00
extable.c	kernel/extable.c: use address-of operator on section symbols	2023-06-09 10:29:01 +02:00
fail_function.c	kernel/fail_function: fix memory leak with using debugfs_lookup()	2023-03-11 16:44:15 +01:00
fork.c	kernel/fork: beware of __put_task_struct() calling context	2023-09-23 11:00:03 +02:00
freezer.c
futex.c	treewide: Remove uninitialized_var() usage	2023-06-09 10:29:01 +02:00
gen_kheaders.sh	kheaders: explicitly define file modes for archived headers	2024-07-05 09:08:25 +02:00
groups.c
hung_task.c
iomem.c
irq_work.c
jump_label.c
kallsyms.c	kallsyms: Refactor kallsyms_show_value() to take cred	2020-07-16 08:16:44 +02:00
kcmp.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:44:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kexec.c
kexec_core.c	kexec: fix a memory leak in crash_shrink_memory()	2023-07-27 08:37:10 +02:00
kexec_elf.c
kexec_file.c	kexec: support purgatories with .text.hot sections	2023-06-21 15:44:10 +02:00
kexec_internal.h
kheaders.c	kheaders: Use array declaration instead of char	2023-05-17 11:35:33 +02:00
kmod.c	kmod: make request_module() return an error when autoloading is disabled	2020-04-17 10:50:22 +02:00
kprobes.c	kprobes: Fix possible use-after-free issue on kprobe registration	2024-05-02 16:18:30 +02:00
ksysfs.c
kthread.c	kthread: Fix PF_KTHREAD vs to_kthread() race	2021-09-12 08:56:39 +02:00
latencytop.c
Makefile	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:04:16 +02:00
module-internal.h
module.c	modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules	2023-09-23 10:59:36 +02:00
module_signature.c	module: harden ELF info handling	2021-04-07 14:47:38 +02:00
module_signing.c	module: harden ELF info handling	2021-04-07 14:47:38 +02:00
notifier.c	kernel/notifier.c: intercept duplicate registrations to avoid infinite loops	2020-10-01 13:17:23 +02:00
nsproxy.c
padata.c	crypto: pcrypt - Fix hungtask for PADATA_RESET	2023-11-28 16:50:14 +00:00
panic.c	panic: Flush kernel log buffer at the end	2024-04-13 12:51:37 +02:00
params.c	params: lift param_set_uint_minmax to common code	2024-06-16 13:28:45 +02:00
pid.c
pid_namespace.c	memcg: enable accounting for pids in nested pid namespaces	2021-09-22 12:26:37 +02:00
profile.c	profiling: fix shift too large makes kernel panic	2022-08-25 11:18:02 +02:00
ptrace.c	ptrace: Reimplement PTRACE_KILL by always sending SIGKILL	2022-06-14 18:11:24 +02:00
range.c
reboot.c	kernel/reboot: emergency_restart: Set correct system_state	2023-11-28 16:50:19 +00:00
relay.c	relayfs: fix out-of-bounds access in relay_file_read	2023-05-17 11:35:58 +02:00
resource.c	/dev/mem: Revoke mappings when a driver claims the region	2020-06-24 17:50:35 +02:00
rseq.c
seccomp.c	seccomp: Invalidate seccomp mode to catch death failures	2022-02-16 12:52:53 +01:00
signal.c	signal handling: don't use BUG_ON() for debugging	2022-07-21 20:59:27 +02:00
smp.c	smp: Fix offline cpu check in flush_smp_call_function_queue()	2022-04-20 09:19:39 +02:00
smpboot.c	kthread: Extract KTHREAD_IS_PER_CPU	2021-02-07 15:35:49 +01:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
stop_machine.c
sys.c	getrusage: use sig->stats_lock rather than lock_task_sighand()	2024-03-15 10:48:19 -04:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-09-05 10:27:38 +02:00
sysctl-test.c	kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()	2020-10-01 13:17:10 +02:00
sysctl.c	sched/rt: Disallow writing invalid values to sched_rt_period_us	2024-03-01 13:13:33 +01:00
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c	tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing	2021-07-14 16:53:08 +02:00
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-02-23 11:59:57 +01:00
ucount.c
uid16.c
uid16.h
umh.c	usermodehelper: reset umask to default before executing user process	2020-10-14 10:32:58 +02:00
up.c	smp: Fix smp_call_function_single_async prototype	2021-05-14 09:44:33 +02:00
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c	watchdog: export lockup_detector_reconfigure	2022-08-25 11:18:37 +02:00
watchdog_hld.c	watchdog/perf: more properly prevent false positives with turbo modes	2023-07-27 08:37:10 +02:00
workqueue.c	workqueue: Override implicit ordered attribute in workqueue_apply_unbound_cpumask()	2023-10-25 11:53:18 +02:00
workqueue_internal.h