FS-Cache: O-cookie d=00000000febabb5a n=0000000087a4b608 ------------[ cut here ]------------ FS-Cache: O-key=[10] '0200020000807f000008' ODEBUG: free active (active state 0) object type: timer_list hint: xprt_init_autodisconnect+0x0/0x230 net/sunrpc/xprt.c:109 FS-Cache: N-cookie c=00000000bb0af7c5 [p=00000000f2b5ca98 fl=2 nc=0 na=1] WARNING: CPU: 0 PID: 9 at lib/debugobjects.c:328 debug_print_object+0x16a/0x210 lib/debugobjects.c:325 FS-Cache: N-cookie d=00000000febabb5a n=00000000e425f904 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc7+ #155 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+0x244/0x39d lib/dump_stack.c:113 FS-Cache: N-key=[10] '0200020000807f000008' panic+0x2ad/0x55c kernel/panic.c:188 __warn.cold.8+0x20/0x45 kernel/panic.c:540 report_bug+0x254/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:debug_print_object+0x16a/0x210 lib/debugobjects.c:325 Code: 60 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 92 00 00 00 48 8b 14 dd 60 e0 60 88 4c 89 fe 48 c7 c7 00 d6 60 88 e8 36 a1 b5 fd <0f> 0b 83 05 81 30 83 06 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffff8881d9aff540 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000100 RSI: ffffffff8165e495 RDI: 0000000000000005 FS-Cache: Duplicate cookie detected RBP: ffff8881d9aff580 R08: ffff8881d9aec240 R09: fffffbfff12b22d8 FS-Cache: O-cookie c=00000000d8e76b3c [p=00000000f2b5ca98 fl=222 nc=0 na=1] R10: fffffbfff12b22d8 R11: ffffffff895916c3 R12: 0000000000000001 FS-Cache: O-cookie d=00000000febabb5a n=0000000087a4b608 R13: ffffffff895a5980 R14: ffffffff816c2760 R15: ffffffff8860daa0 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:817 FS-Cache: O-key=[10] '0200020000807f000008' kfree+0xbd/0x230 mm/slab.c:3816 FS-Cache: N-cookie c=00000000b1c3a786 [p=00000000f2b5ca98 fl=2 nc=0 na=1] __rcu_reclaim kernel/rcu/rcu.h:233 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0x1140/0x1ac0 kernel/rcu/tree.c:2697 FS-Cache: N-cookie d=00000000febabb5a n=00000000ca2218d3 FS-Cache: N-key=[10] '0200020000807f000008' __do_softirq+0x308/0xb7e kernel/softirq.c:292 run_ksoftirqd+0x5e/0x100 kernel/softirq.c:654 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 ====================================================== WARNING: possible circular locking dependency detected 4.20.0-rc7+ #155 Not tainted ------------------------------------------------------ ksoftirqd/0/9 is trying to acquire lock: 00000000e3ddf4d7 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 000000004cebd29a (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:776 [inline] 000000004cebd29a (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x17a/0x58d lib/debugobjects.c:817 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&obj_hash[i].lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 __debug_object_init+0x127/0x1290 lib/debugobjects.c:383 debug_object_init+0x16/0x20 lib/debugobjects.c:431 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x97/0x490 kernel/time/hrtimer.c:1308 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1057 __sched_fork+0x2ae/0x590 kernel/sched/core.c:2166 init_idle+0x75/0x740 kernel/sched/core.c:5374 sched_init+0xb33/0xc07 kernel/sched/core.c:6063 start_kernel+0x4c1/0xa30 init/main.c:608 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1124 [inline] task_fork_fair+0xb0/0x6d0 kernel/sched/fair.c:9802 sched_fork+0x443/0xba0 kernel/sched/core.c:2359 copy_process+0x25b8/0x87a0 kernel/fork.c:1887 _do_fork+0x1cb/0x11d0 kernel/fork.c:2216 kernel_thread+0x34/0x40 kernel/fork.c:2275 rest_init+0x28/0x372 init/main.c:409 arch_call_rest_init+0xe/0x1b start_kernel+0x9f5/0xa30 init/main.c:745 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 try_to_wake_up+0xdc/0x1440 kernel/sched/core.c:1965 wake_up_process+0x10/0x20 kernel/sched/core.c:2129 __up.isra.1+0x1c0/0x2a0 kernel/locking/semaphore.c:262 up+0x13c/0x1c0 kernel/locking/semaphore.c:187 __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:236 console_unlock+0x811/0x1190 kernel/printk/printk.c:2432 do_con_write+0x1356/0x23b0 drivers/tty/vt/vt.c:2767 con_write+0x25/0xc0 drivers/tty/vt/vt.c:3116 do_output_char+0x653/0x880 drivers/tty/n_tty.c:445 process_output drivers/tty/n_tty.c:512 [inline] n_tty_write+0x77d/0x11a0 drivers/tty/n_tty.c:2343 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1043 __vfs_write+0x119/0x9f0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 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+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2247 console_trylock_spinning kernel/printk/printk.c:1653 [inline] vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __warn_printk+0x8c/0xe0 kernel/panic.c:594 debug_print_object+0x16a/0x210 lib/debugobjects.c:325 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:817 kfree+0xbd/0x230 mm/slab.c:3816 __rcu_reclaim kernel/rcu/rcu.h:233 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0x1140/0x1ac0 kernel/rcu/tree.c:2697 __do_softirq+0x308/0xb7e kernel/softirq.c:292 run_ksoftirqd+0x5e/0x100 kernel/softirq.c:654 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 other info that might help us debug this: Chain exists of: (console_sem).lock --> &rq->lock --> &obj_hash[i].lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&obj_hash[i].lock); lock(&rq->lock); lock(&obj_hash[i].lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by ksoftirqd/0/9: #0: 00000000d5bb14e1 (rcu_callback){....}, at: __rcu_reclaim kernel/rcu/rcu.h:228 [inline] #0: 00000000d5bb14e1 (rcu_callback){....}, at: rcu_do_batch kernel/rcu/tree.c:2437 [inline] #0: 00000000d5bb14e1 (rcu_callback){....}, at: invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] #0: 00000000d5bb14e1 (rcu_callback){....}, at: rcu_process_callbacks+0x1103/0x1ac0 kernel/rcu/tree.c:2697 #1: 000000004cebd29a (&obj_hash[i].lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:776 [inline] #1: 000000004cebd29a (&obj_hash[i].lock){-.-.}, at: debug_check_no_obj_freed+0x17a/0x58d lib/debugobjects.c:817 stack backtrace: CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc7+ #155 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+0x244/0x39d lib/dump_stack.c:113 print_circular_bug.isra.35.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2347 [inline] __lock_acquire+0x3399/0x4c20 kernel/locking/lockdep.c:3341 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x1f0 kernel/printk/printk.c:219 console_trylock+0x15/0xa0 kernel/printk/printk.c:2247 console_trylock_spinning kernel/printk/printk.c:1653 [inline] vprintk_emit+0x372/0x990 kernel/printk/printk.c:1921 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __warn_printk+0x8c/0xe0 kernel/panic.c:594 debug_print_object+0x16a/0x210 lib/debugobjects.c:325 __debug_check_no_obj_freed lib/debugobjects.c:785 [inline] debug_check_no_obj_freed+0x3ae/0x58d lib/debugobjects.c:817 kfree+0xbd/0x230 mm/slab.c:3816 __rcu_reclaim kernel/rcu/rcu.h:233 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0x1140/0x1ac0 kernel/rcu/tree.c:2697 __do_softirq+0x308/0xb7e kernel/softirq.c:292 run_ksoftirqd+0x5e/0x100 kernel/softirq.c:654 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Kernel Offset: disabled Rebooting in 86400 seconds..