IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 42s! Showing busy workqueues and worker pools: workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/512 in-flight: 89:flush_to_ldisc ====================================================== WARNING: possible circular locking dependency detected 4.17.0+ #96 Not tainted ------------------------------------------------------ swapper/0/0 is trying to acquire lock: (____ptrval____) (console_owner){-.-.}, at: log_next kernel/printk/printk.c:496 [inline] (____ptrval____) (console_owner){-.-.}, at: console_unlock+0x546/0x10a0 kernel/printk/printk.c:2376 but task is already holding lock: (____ptrval____) (&pool->lock/1){..-.}, at: show_workqueue_state.cold.47+0xafe/0x15cf kernel/workqueue.c:4542 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pool->lock/1){..-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:310 [inline] __queue_work+0x34a/0x13f0 kernel/workqueue.c:1417 queue_work_on+0x19a/0x1e0 kernel/workqueue.c:1486 queue_work include/linux/workqueue.h:512 [inline] tty_schedule_flip+0x145/0x1c0 drivers/tty/tty_buffer.c:408 tty_flip_buffer_push+0x15/0x20 drivers/tty/tty_buffer.c:547 pty_write+0x19d/0x1f0 drivers/tty/pty.c:124 n_tty_write+0xc41/0x1180 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:958 [inline] tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042 __vfs_write+0x10b/0x9d0 fs/read_write.c:485 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 tty_port_tty_get+0x20/0x80 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x15/0x40 drivers/tty/tty_port.c:47 tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:390 uart_write_wakeup+0x44/0x60 drivers/tty/serial/serial_core.c:103 serial8250_tx_chars+0x4be/0xb60 drivers/tty/serial/8250/8250_port.c:1808 serial8250_handle_irq.part.25+0x1ee/0x280 drivers/tty/serial/8250/8250_port.c:1881 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1867 [inline] serial8250_default_handle_irq+0xc8/0x150 drivers/tty/serial/8250/8250_port.c:1897 serial8250_interrupt+0xfa/0x1d0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149 handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77 do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245 ret_from_intr+0x0/0x1e native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc2/0x440 arch/x86/kernel/process.c:500 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x395/0x560 kernel/sched/idle.c:262 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368 start_secondary+0x42b/0x5c0 arch/x86/kernel/smpboot.c:265 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 serial8250_console_write+0x8d5/0xb00 drivers/tty/serial/8250/8250_port.c:3230 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 call_console_drivers kernel/printk/printk.c:1718 [inline] console_unlock+0xa9d/0x10a0 kernel/printk/printk.c:2389 vprintk_emit+0x6b2/0xde0 kernel/printk/printk.c:1907 vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 printk+0x9e/0xba kernel/printk/printk.c:1981 register_console+0x7e7/0xc00 kernel/printk/printk.c:2704 univ8250_console_init+0x3f/0x4b drivers/tty/serial/8250/8250_core.c:685 console_init+0x6d9/0xa38 kernel/printk/printk.c:2788 start_kernel+0x608/0x92d init/main.c:661 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 -> #0 (console_owner){-.-.}: lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924 console_lock_spinning_enable kernel/printk/printk.c:1581 [inline] console_unlock+0x5b3/0x10a0 kernel/printk/printk.c:2386 vprintk_emit+0x6b2/0xde0 kernel/printk/printk.c:1907 vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 printk+0x9e/0xba kernel/printk/printk.c:1981 show_pwq kernel/workqueue.c:4449 [inline] show_workqueue_state.cold.47+0xca0/0x15cf kernel/workqueue.c:4544 wq_watchdog_timer_fn+0x6f1/0x810 kernel/workqueue.c:5556 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x79e/0xc50 kernel/time/timer.c:1666 run_timer_softirq+0x60/0x70 kernel/time/timer.c:1694 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:404 exiting_irq arch/x86/include/asm/apic.h:527 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc2/0x440 arch/x86/kernel/process.c:500 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x395/0x560 kernel/sched/idle.c:262 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:368 rest_init+0xe1/0xe4 init/main.c:442 start_kernel+0x906/0x92d init/main.c:738 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:452 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:433 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 other info that might help us debug this: Chain exists of: console_owner --> &(&port->lock)->rlock --> &pool->lock/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pool->lock/1); lock(&(&port->lock)->rlock); lock(&pool->lock/1); lock(console_owner); *** DEADLOCK *** 4 locks held by swapper/0/0: #0: (____ptrval____) ((&wq_watchdog_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:178 [inline] #0: (____ptrval____) ((&wq_watchdog_timer)){+.-.}, at: call_timer_fn+0x1bb/0x940 kernel/time/timer.c:1316 #1: (____ptrval____) (rcu_read_lock_sched){....}, at: show_workqueue_state+0x0/0x1c0 kernel/workqueue.c:4408 #2: (____ptrval____) (&pool->lock/1){..-.}, at: show_workqueue_state.cold.47+0xafe/0x15cf kernel/workqueue.c:4542 #3: (____ptrval____) (console_lock){+.+.}, at: console_trylock_spinning kernel/printk/printk.c:1643 [inline] #3: (____ptrval____) (console_lock){+.+.}, at: vprintk_emit+0x699/0xde0 kernel/printk/printk.c:1906 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.17.0+ #96 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+0x1b9/0x294 lib/dump_stack.c:113 print_circular_bug.isra.36.cold.56+0x1bd/0x27d kernel/locking/lockdep.c:1227 check_prev_add kernel/locking/lockdep.c:1867 [inline] check_prevs_add kernel/locking/lockdep.c:1980 [inline] validate_chain kernel/locking/lockdep.c:2421 [inline] __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3435 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924 console_lock_spinning_enable kernel/printk/printk.c:1581 [inline] console_unlock+0x5b3/0x10a0 kernel/printk/printk.c:2386 vprintk_emit+0x6b2/0xde0 kernel/printk/printk.c:1907 vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 printk+0x9e/0xba kernel/printk/printk.c:1981 show_pwq kernel/workqueue.c:4449 [inline] show_workqueue_state.cold.47+0xca0/0x15cf kernel/workqueue.c:4544 wq_watchdog_timer_fn+0x6f1/0x810 kernel/workqueue.c:5556 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x79e/0xc50 kernel/time/timer.c:1666 run_timer_softirq+0x60/0x70 kernel/time/timer.c:1694 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:404 exiting_irq arch/x86/include/asm/apic.h:527 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 ? kv Lost 105 message(s)! workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 pending: gc_worker workqueue ipv6_addrconf: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 pending: addrconf_dad_work delayed: addrconf_dad_work, addrconf_dad_work pool 4: cpus=0-1 flags=0x4 nice=0 hung=3s workers=12 idle: 6456 6494 7 6464 6557 6493 34 261 6448 6523 23