rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=807/1/0x4000000000000000 softirq=111709/111716 fqs=5172 (t=10500 jiffies g=170589 q=3369) NMI backtrace for cpu 0 CPU: 0 PID: 1233 Comm: aoe_tx0 Not tainted 5.17.0-rc1-next-20220128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:639 [inline] check_cpu_stall kernel/rcu/tree_stall.h:723 [inline] rcu_pending kernel/rcu/tree.c:3924 [inline] rcu_sched_clock_irq.cold+0xa1/0x8d6 kernel/rcu/tree.c:2626 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 6a 0a fd f7 48 89 ef e8 12 80 fd f7 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 f3 2e f0 f7 65 8b 05 6c 1e a2 76 85 c0 74 0a 5b 5d c3 e8 d0 93 RSP: 0018:ffffc90005397a90 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff204e97e RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000001 RBP: ffffffff90a1db58 R08: 0000000000000001 R09: ffffffff90201a77 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000020 R13: ffff888019da18b0 R14: ffff88801a820fe0 R15: 0000000000000001 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] uart_write+0x423/0x570 drivers/tty/serial/serial_core.c:570 handle_tx+0x204/0x610 drivers/net/caif/caif_serial.c:236 __netdev_start_xmit include/linux/netdevice.h:4683 [inline] netdev_start_xmit include/linux/netdevice.h:4697 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2a24/0x3760 net/core/dev.c:4116 tx+0x68/0xb0 drivers/block/aoe/aoenet.c:63 kthread+0x1e7/0x3b0 drivers/block/aoe/aoecmd.c:1229 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 74 24 je 0x26 2: 10 e8 adc %ch,%al 4: 6a 0a pushq $0xa 6: fd std 7: f7 48 89 ef e8 12 80 testl $0x8012e8ef,-0x77(%rax) e: fd std f: f7 81 e3 00 02 00 00 testl $0x9c257500,0x200e3(%rcx) 16: 75 25 9c 19: 58 pop %rax 1a: f6 c4 02 test $0x2,%ah 1d: 75 2d jne 0x4c 1f: 48 85 db test %rbx,%rbx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 f3 2e f0 f7 callq 0xf7f02f22 <-- trapping instruction 2f: 65 8b 05 6c 1e a2 76 mov %gs:0x76a21e6c(%rip),%eax # 0x76a21ea2 36: 85 c0 test %eax,%eax 38: 74 0a je 0x44 3a: 5b pop %rbx 3b: 5d pop %rbp 3c: c3 retq 3d: e8 .byte 0xe8 3e: d0 .byte 0xd0 3f: 93 xchg %eax,%ebx