syzbot


BUG: soft lockup in watchdog_timer_fn

Status: auto-closed as invalid on 2021/12/24 06:54
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+a1e39aba1e637346be87@syzkaller.appspotmail.com
First crash: 943d, last: 943d

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 368s! [migration/1:17]
Modules linked in:
irq event stamp: 77860
hardirqs last  enabled at (77859): [<80200ad8>] __irq_svc+0x78/0x94 arch/arm/kernel/entry-armv.S:216
hardirqs last disabled at (77860): [<80200aac>] __irq_svc+0x4c/0x94 arch/arm/kernel/entry-armv.S:204
softirqs last  enabled at (2448): [<8020167c>] __do_softirq+0x584/0x7ac kernel/softirq.c:372
softirqs last disabled at (2423): [<8024dff4>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (2423): [<8024dff4>] invoke_softirq kernel/softirq.c:228 [inline]
softirqs last disabled at (2423): [<8024dff4>] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422
CPU: 1 PID: 17 Comm: migration/1 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Stopper: multi_cpu_stop+0x0/0x1bc kernel/stop_machine.c:200 <- 0x0
PC is at atomic_add_return include/linux/atomic-fallback.h:215 [inline]
PC is at rcu_momentary_dyntick_idle+0x5c/0xe4 kernel/rcu/tree.c:430
LR is at debug_smp_processor_id+0x20/0x24 lib/smp_processor_id.c:64
pc : [<802ef90c>]    lr : [<8181daac>]    psr: 60000013
sp : 83535eb0  ip : 83535ea0  fp : 83535ec4
r10: 00000001  r9 : 00000000  r8 : 00000000
r7 : 82a22498  r6 : 86d8fad4  r5 : 00000001  r4 : 828afa40
r3 : ddfe3a40  r2 : ddfe3ae8  r1 : d8ea0726  r0 : 00000000
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 86c19880  DAC: 00000000
CPU: 1 PID: 17 Comm: migration/1 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Stopper: multi_cpu_stop+0x0/0x1bc kernel/stop_machine.c:200 <- 0x0
Backtrace: 
[<81802550>] (dump_backtrace) from [<818027c4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252)
 r7:00000080 r6:60000193 r5:00000000 r4:82b58344
[<818027ac>] (show_stack) from [<81809e98>] (__dump_stack lib/dump_stack.c:79 [inline])
[<818027ac>] (show_stack) from [<81809e98>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120)
[<81809de0>] (dump_stack) from [<802096bc>] (show_regs+0x14/0x18 arch/arm/kernel/process.c:191)
 r7:00000170 r6:828a7ac9 r5:82a225f8 r4:83534000
[<802096a8>] (show_regs) from [<80366760>] (watchdog_timer_fn+0x2b8/0x33c kernel/watchdog.c:418)
[<803664a8>] (watchdog_timer_fn) from [<8030807c>] (__run_hrtimer kernel/time/hrtimer.c:1537 [inline])
[<803664a8>] (watchdog_timer_fn) from [<8030807c>] (__hrtimer_run_queues+0x294/0x690 kernel/time/hrtimer.c:1601)
 r10:803664a8 r9:83534000 r8:ddfdb3e0 r7:ddfdb380 r6:82a22498 r5:83534000
 r4:ddfdbad0
[<80307de8>] (__hrtimer_run_queues) from [<80308da0>] (hrtimer_interrupt+0x14c/0x2e0 kernel/time/hrtimer.c:1663)
 r10:ddfdb4d8 r9:ddfdb498 r8:ddfdb458 r7:ddfdb4a0 r6:ddfdb4e0 r5:20000193
 r4:ddfdb380
[<80308c54>] (hrtimer_interrupt) from [<8114c308>] (timer_handler drivers/clocksource/arm_arch_timer.c:647 [inline])
[<80308c54>] (hrtimer_interrupt) from [<8114c308>] (arch_timer_handler_virt+0x30/0x38 drivers/clocksource/arm_arch_timer.c:658)
 r10:83535df8 r9:83535e60 r8:83535dc8 r7:8348d940 r6:82a22c34 r5:0000001c
 r4:8348b000
[<8114c2d8>] (arch_timer_handler_virt) from [<802df904>] (handle_percpu_devid_irq+0xa4/0x19c kernel/irq/chip.c:930)
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (generic_handle_irq_desc include/linux/irqdesc.h:158 [inline])
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (generic_handle_irq kernel/irq/irqdesc.c:652 [inline])
[<802df860>] (handle_percpu_devid_irq) from [<802d8730>] (__handle_domain_irq+0xb0/0x120 kernel/irq/irqdesc.c:689)
 r10:83535df8 r9:83535e60 r8:00000001 r7:00000000 r6:828ad498 r5:00000000
 r4:828ad498 r3:00010001
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (handle_domain_irq include/linux/irqdesc.h:176 [inline])
[<802d8680>] (__handle_domain_irq) from [<8088af70>] (gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370)
 r10:00000001 r9:83534000 r8:e000200c r7:828ad4bc r6:e0002000 r5:83535e60
 r4:82a22c34
[<8088aeec>] (gic_handle_irq) from [<80200abc>] (__irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205)
Exception stack(0x83535e60 to 0x83535ea8)
5e60: 00000000 d8ea0726 ddfe3ae8 ddfe3a40 828afa40 00000001 86d8fad4 82a22498
5e80: 00000000 00000000 00000001 83535ec4 83535ea0 83535eb0 8181daac 802ef90c
5ea0: 60000013 ffffffff
 r9:83534000 r8:00000000 r7:83535e94 r6:ffffffff r5:60000013 r4:802ef90c
[<802ef8b0>] (rcu_momentary_dyntick_idle) from [<803549e4>] (multi_cpu_stop+0x104/0x1bc kernel/stop_machine.c:254)
 r5:00000001 r4:86d8fae8
[<803548e0>] (multi_cpu_stop) from [<803544b0>] (cpu_stopper_thread+0xb0/0x148 kernel/stop_machine.c:510)
 r10:86d8faec r9:ddfdba50 r8:83534000 r7:86d8fad4 r6:ddfdba28 r5:803548e0
 r4:ddfdba24
[<80354400>] (cpu_stopper_thread) from [<80279970>] (smpboot_thread_fn+0x1d4/0x334 kernel/smpboot.c:165)
 r10:00000001 r9:802797cc r8:82b12448 r7:834b6c80 r6:00000000 r5:00000001
 r4:83534000
[<8027979c>] (smpboot_thread_fn) from [<80271d20>] (kthread+0x184/0x1a4 kernel/kthread.c:292)
 r10:834dfd5c r9:834b6c80 r8:8027979c r7:00000000 r6:83534000 r5:834b6d40
 r4:8348ee00
[<80271b9c>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x83535fb0 to 0x83535ff8)
5fa0:                                     00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80271b9c
 r4:834b6d40
Sending NMI from CPU 1 to CPUs 0:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/09/25 06:54 upstream bf152b0b41dc 8cac236e .config console log report info ci-qemu2-arm32 BUG: soft lockup in watchdog_timer_fn
* Struck through repros no longer work on HEAD.