rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=ab2/1/0x4000000000000004 softirq=106351/106351 fqs=4 (t=10500 jiffies g=177965 q=485) rcu: rcu_preempt kthread starved for 10491 jiffies! g177965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28952 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x7b7/0xc30 kernel/sched/core.c:4078 schedule+0x131/0x1e0 kernel/sched/core.c:4145 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1639 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1799 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 19808 Comm: syz-executor.5 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2795 [inline] rcu_sched_clock_irq+0xe22/0x1ae0 kernel/rcu/tree.c:2244 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1299 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xad/0xe0 kernel/locking/spinlock.c:191 Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 f0 8f 8a 88 e8 d2 88 31 fa 48 83 3d 3a 5f 0f 01 00 74 2d 4c 89 f7 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 14 ff d4 f9 65 8b 05 f9 cc 86 78 RSP: 0018:ffff8880aeb09be0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11151fe RBX: ffff8880aeb24a80 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff8880aeb09bf0 R08: ffff88809a3c8f18 R09: fffffbfff12bc2ae R10: fffffbfff12bc2ae R11: 0000000000000000 R12: ffff8880aeb24a80 R13: ffff8880367cbc10 R14: 0000000000000286 R15: 0000000000000000 __mod_timer+0xf01/0x1590 kernel/time/timer.c:1057 mod_timer+0x1f/0x30 kernel/time/timer.c:1100 can_stat_update+0xb51/0xbf0 net/can/proc.c:181 call_timer_fn+0x95/0x170 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers+0x7b6/0x990 kernel/time/timer.c:1773 run_timer_softirq+0x4a/0x90 kernel/time/timer.c:1786 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:766 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x227/0x230 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x113/0x280 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:check_preemption_disabled+0x4f/0x2a0 lib/smp_processor_id.c:52 Code: 8b 1d 61 61 b9 7c 89 de 81 e6 ff ff ff 7f 31 ff e8 f6 dd 2a fe 81 e3 ff ff ff 7f 74 17 e8 49 da 2a fe 44 89 e8 48 83 c4 10 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c0 e8 8f 8a 88 48 c1 e8 03 48 RSP: 0018:ffff88801d72f538 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffea00025d5378 RCX: ffff88809a3c86c0 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffff88801d72f558 R08: ffffffff83489c7a R09: fffff940004baa69 R10: fffff940004baa69 R11: 0000000000000000 R12: 01fffc0000000002 R13: 0000000000000001 R14: ffffffff884f4c70 R15: ffffffff883940dd debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:299 [inline] rcu_is_watching+0x20/0xa0 kernel/rcu/tree.c:901 rcu_read_unlock include/linux/rcupdate.h:649 [inline] __unlock_page_memcg+0xf2/0x140 mm/memcontrol.c:2136 unlock_page_memcg+0x33/0x40 mm/memcontrol.c:2145 page_remove_file_rmap+0x5a4/0x700 mm/rmap.c:1254 page_remove_rmap+0xb0/0x690 mm/rmap.c:1305 zap_pte_range mm/memory.c:1062 [inline] zap_pmd_range mm/memory.c:1166 [inline] zap_pud_range mm/memory.c:1195 [inline] zap_p4d_range mm/memory.c:1216 [inline] unmap_page_range+0x1784/0x2540 mm/memory.c:1237 unmap_single_vma+0x1d4/0x2e0 mm/memory.c:1282 unmap_vmas+0x163/0x2a0 mm/memory.c:1314 exit_mmap+0x27b/0x530 mm/mmap.c:3161 __mmput+0x120/0x3a0 kernel/fork.c:1079 mmput+0x5d/0x70 kernel/fork.c:1100 exit_mm+0x50a/0x590 kernel/exit.c:485 do_exit+0x565/0x2190 kernel/exit.c:804 do_group_exit+0x15c/0x2b0 kernel/exit.c:921 get_signal+0x4ac/0x1d60 kernel/signal.c:2734 do_signal+0x37/0x640 arch/x86/kernel/signal.c:815 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline] prepare_exit_to_usermode+0x303/0x580 arch/x86/entry/common.c:194 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: 03 00 00 48 29 f0 48 3d f8 12 00 00 76 7d 48 81 ec 08 10 00 00 48 89 ac 24 00 10 00 00 48 8d ac 24 00 10 00 00 48 8b 59 20 48 <85> db 75 67 48 8b b4 24 20 10 00 00 8b 8c 24 28 10 00 00 48 89 e7 RSP: 002b:00007f0622dbbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffa2 RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000a RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0622dbc6d4 R13: 00000000004c99cc R14: 00000000004e13a0 R15: 00000000ffffffff