rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=6045, q=68) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294953770-4294943267), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.4 R running task 25056 8157 8156 0x0000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271 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:1310 __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:829 RIP: 0010:check_kcov_mode kernel/kcov.c:79 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:102 Code: 64 02 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 b8 81 8b 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 <83> fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 RSP: 0018:ffffc900029b7280 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff8880a2bee680 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00023eb380 RBP: ffffc900029b72a8 R08: 000000000003a768 R09: ffffed101393faf7 R10: ffffed101393faf7 R11: 0000000000000000 R12: dffffc0000000000 R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff88809c9fd7a8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 try_to_wake_up+0xe78/0x1050 kernel/sched/core.c:2650 wake_up_process kernel/sched/core.c:2668 [inline] wake_up_q+0x8c/0xe0 kernel/sched/core.c:496 __mutex_unlock_slowpath+0x586/0x5b0 kernel/locking/mutex.c:1283 mutex_unlock+0x1b/0x30 kernel/locking/mutex.c:743 __rtnl_unlock+0x2c/0xa0 net/core/rtnetlink.c:98 netdev_run_todo+0xe5/0xe10 net/core/dev.c:9545 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112 nsim_create+0x224/0x230 drivers/net/netdevsim/netdev.c:312 __nsim_dev_port_add+0x289/0x4d0 drivers/net/netdevsim/dev.c:648 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:697 [inline] nsim_dev_probe+0xb55/0xef0 drivers/net/netdevsim/dev.c:818 nsim_bus_probe+0x15/0x20 drivers/net/netdevsim/bus.c:242 really_probe+0x71c/0xf40 drivers/base/dd.c:548 driver_probe_device+0xfc/0x260 drivers/base/dd.c:721 __device_attach_driver+0x336/0x3f0 drivers/base/dd.c:828 bus_for_each_drv+0x12b/0x180 drivers/base/bus.c:430 __device_attach+0x1ea/0x390 drivers/base/dd.c:894 device_initial_probe+0x1a/0x20 drivers/base/dd.c:941 bus_probe_device+0xb9/0x1f0 drivers/base/bus.c:490 device_add+0x1710/0x1ad0 drivers/base/core.c:2487 device_register+0x1d/0x20 drivers/base/core.c:2560 nsim_bus_dev_new drivers/net/netdevsim/bus.c:288 [inline] new_device_store+0x286/0x510 drivers/net/netdevsim/bus.c:182 bus_attr_store+0x78/0x90 drivers/base/bus.c:121 sysfs_kf_write+0x281/0x2f0 fs/sysfs/file.c:138 kernfs_fop_write+0x3e4/0x4e0 fs/kernfs/file.c:315 __vfs_write+0xb8/0x740 fs/read_write.c:494 vfs_write+0x275/0x590 fs/read_write.c:558 ksys_write+0x117/0x220 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:620 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414130 Code: b0 89 c8 f7 d8 eb ed b8 6e 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 83 3d 3d 43 66 00 00 75 14 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 c4 1b 00 00 c3 48 83 ec 08 e8 ca fc ff ff RSP: 002b:00007fffdd5c8598 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000414130 RDX: 0000000000000003 RSI: 00007fffdd5c85c0 RDI: 0000000000000004 RBP: 00007fffdd5c85c0 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000000075 R11: 0000000000000246 R12: 00000000004bfc97 R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10549 jiffies! g6045 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 28992 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352