INFO: task hung in perf_event_free

Date	Name	Commit	Repro	Result
2023/11/02	upstream (ToT)	90d624af2e5a	C	Didn't crash

Date

Name

Commit

Repro

Result

2023/11/02

upstream (ToT)

90d624af2e5a

Didn't crash

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	INFO: task hung in perf_event_free_task (3)				3	934d	1080d	0/1	auto-obsoleted due to no activity on 2022/08/31 14:29
linux-4.19	INFO: task hung in perf_event_free_task (2)				2	1291d	1363d	0/1	auto-closed as invalid on 2021/09/09 09:13
linux-4.19	INFO: task hung in perf_event_free_task (4)				4	633d	802d	0/1	upstream: reported on 2022/09/12 12:14
upstream	INFO: task hung in perf_event_free_task perf	C	done	error	40	439d	1948d	0/28	auto-obsoleted due to no activity on 2023/12/19 10:14
linux-5.15	INFO: task hung in perf_event_free_task (2)				1	274d	274d	0/3	auto-obsoleted due to no activity on 2024/06/02 07:34
linux-6.1	INFO: task hung in perf_event_free_task origin:upstream missing-backport	C		unreliable	3	333d	438d	0/3	upstream: reported C repro on 2023/09/12 07:14
linux-4.19	INFO: task hung in perf_event_free_task				5	1505d	1900d	0/1	auto-closed as invalid on 2021/02/06 21:15
upstream	INFO: task can't die in perf_event_free_task perf	syz	unreliable		6	765d	1464d	0/28	auto-obsoleted due to no activity on 2023/04/21 23:56

INFO: task syz-executor926:5913 blocked for more than 143 seconds. Not tainted 5.15.137-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor926 state:D stack:26624 pid: 5913 ppid: 3532 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 perf_event_free_task+0x555/0x680 kernel/events/core.c:13084 copy_process+0x303a/0x3ef0 kernel/fork.c:2485 kernel_clone+0x210/0x960 kernel/fork.c:2604 __do_sys_clone kernel/fork.c:2721 [inline] __se_sys_clone kernel/fork.c:2705 [inline] __x64_sys_clone+0x23f/0x290 kernel/fork.c:2705 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fca9a2dacf9 RSP: 002b:00007fca99a98228 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007fca9a2dacf9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000d816e480 RBP: 00007fca9a3653c8 R08: 0000000000000000 R09: 00007fca99a986c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca9a3653c0 R13: 00000000d816e480 R14: 00000000d816e480 R15: 00007fffb2782428 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91f020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by klogd/2951: #0: ffff8880b9b39718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 2 locks held by getty/3263: #0: ffff8880250ea098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570