INFO: rcu detected stall in chrdev

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	INFO: rcu detected stall in chrdev_open (2)				1	1434d	1434d	0/1	auto-closed as invalid on 2020/09/12 23:19
linux-4.14	INFO: rcu detected stall in chrdev_open	C		error	4	744d	849d	0/1	upstream: reported C repro on 2021/12/21 07:54
linux-4.19	INFO: rcu detected stall in chrdev_open (3)	C		error	17	569d	1123d	0/1	upstream: reported C repro on 2021/03/22 19:09
upstream	INFO: rcu detected stall in chrdev_open (3) kernel				1	508d	508d	0/26	auto-obsoleted due to no activity on 2023/02/09 20:53
upstream	INFO: rcu detected stall in chrdev_open (5) serial				1	180d	180d	0/26	auto-obsoleted due to no activity on 2024/01/19 06:34
upstream	INFO: rcu detected stall in chrdev_open (4) media				1	283d	283d	0/26	auto-obsoleted due to no activity on 2023/10/08 11:46
upstream	INFO: rcu detected stall in chrdev_open (2) serial	C	done	inconclusive	55	821d	1589d	0/26	closed as invalid on 2022/02/08 10:45
upstream	INFO: rcu detected stall in chrdev_open kernel				4	1598d	1599d	0/26	closed as invalid on 2019/12/04 14:04

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=273229, q=31) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295085511-4295075009), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 26784 5439 7743 0x00000000 Call Trace: <IRQ> sched_show_task kernel/sched/core.c:5338 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5313 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xaa1/0xd90 kernel/rcu/tree.c:2682 update_process_times+0x32/0x80 kernel/time/timer.c:1638 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:164 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x33b/0xdc0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 </IRQ> RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x54/0x90 kernel/locking/spinlock.c:192 Code: c0 d8 5b f2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 4d ff a5 01 00 74 20 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 22 b4 fc f9 65 8b 05 2b 91 b5 78 85 c0 74 06 41 RSP: 0018:ffff88809fab7718 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11e4b7b RBX: ffff888095934b60 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff888095934dbc RBP: ffff88809fab7720 R08: ffff888095934540 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae82c240 R13: ffffffff87aa96a0 R14: ffff888095934540 R15: ffff8880ae82c240 rq_unlock_irq kernel/sched/sched.h:1842 [inline] __schedule+0x1495/0x1dc0 kernel/sched/core.c:3518 schedule+0x92/0x1c0 kernel/sched/core.c:3559 tty_open+0x765/0xb70 drivers/tty/tty_io.c:2036 chrdev_open+0x245/0x6b0 fs/char_dev.c:423 do_dentry_open+0x4c3/0x1210 fs/open.c:796 vfs_open+0xa0/0xd0 fs/open.c:905 do_last fs/namei.c:3418 [inline] path_openat+0x10d7/0x45e0 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1088 __do_sys_openat fs/open.c:1115 [inline] __se_sys_openat fs/open.c:1109 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1109 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6a76257c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a9e9 RDX: 0000000000000000 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a762586d4 R13: 00000000004c87ee R14: 00000000004e0018 R15: 00000000ffffffff rcu: rcu_preempt kthread starved for 10502 jiffies! g273229 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29104 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x4db/0xfc0 kernel/time/timer.c:1806 rcu_gp_kthread+0xd5c/0x2190 kernel/rcu/tree.c:2202 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415