kvm: vcpu 0: requested 34187 ns lapic timer period limited to 500000 ns ------------[ cut here ]------------ ODEBUG: free active (active state 0) object type: work_struct hint: process_one_req+0x0/0x6c0 include/net/dst.h:165 WARNING: CPU: 0 PID: 8596 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 lib/debugobjects.c:288 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8596 Comm: kworker/u4:8 Not tainted 4.16.0-rc7+ #368 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ib_addr process_one_req Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 panic+0x1e4/0x41c kernel/panic.c:183 __warn+0x1dc/0x200 kernel/panic.c:547 report_bug+0x1f4/0x2b0 lib/bug.c:186 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 fixup_bug arch/x86/kernel/traps.c:247 [inline] do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 RIP: 0010:debug_print_object+0x166/0x220 lib/debugobjects.c:288 RSP: 0018:ffff8801b4cf7210 EFLAGS: 00010086 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff815b7bde RDX: 0000000000000000 RSI: 1ffff1003699edf2 RDI: 1ffff1003699edc7 RBP: ffff8801b4cf7250 R08: ffffffff87b3b658 R09: 1ffff1003699ed99 R10: ffffed003699ee71 R11: ffffffff87b3b658 R12: 0000000000000001 R13: ffffffff87b16640 R14: ffffffff86e59240 R15: ffffffff8147fea0 __debug_check_no_obj_freed lib/debugobjects.c:745 [inline] debug_check_no_obj_freed+0x662/0xf1f lib/debugobjects.c:774 kfree+0xc7/0x260 mm/slab.c:3799 process_one_req+0x2e7/0x6c0 drivers/infiniband/core/addr.c:592 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 ====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc7+ #368 Not tainted ------------------------------------------------------ kworker/u4:8/8596 is trying to acquire lock: ((console_sem).lock){..-.}, at: [<0000000059164d61>] down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: (&obj_hash[i].lock){-.-.}, at: [<000000002c89d701>] __debug_check_no_obj_freed lib/debugobjects.c:736 [inline] (&obj_hash[i].lock){-.-.}, at: [<000000002c89d701>] debug_check_no_obj_freed+0x1e9/0xf1f lib/debugobjects.c:774 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+0x96/0xc0 kernel/locking/spinlock.c:152 __debug_object_init+0x109/0x1040 lib/debugobjects.c:343 debug_object_init+0x17/0x20 lib/debugobjects.c:391 debug_hrtimer_init kernel/time/hrtimer.c:410 [inline] debug_init kernel/time/hrtimer.c:458 [inline] hrtimer_init+0x8c/0x410 kernel/time/hrtimer.c:1259 init_dl_task_timer+0x1b/0x50 kernel/sched/deadline.c:1060 __sched_fork+0x2bb/0xb60 kernel/sched/core.c:2189 init_idle+0x75/0x820 kernel/sched/core.c:5352 sched_init+0xb19/0xc43 kernel/sched/core.c:6049 start_kernel+0x452/0x819 init/main.c:586 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1760 [inline] task_fork_fair+0x7a/0x690 kernel/sched/fair.c:9471 sched_fork+0x450/0xc10 kernel/sched/core.c:2405 copy_process.part.38+0x17c9/0x4bd0 kernel/fork.c:1763 copy_process kernel/fork.c:1606 [inline] _do_fork+0x1f7/0xf70 kernel/fork.c:2087 kernel_thread+0x34/0x40 kernel/fork.c:2146 rest_init+0x22/0xf0 init/main.c:403 start_kernel+0x7f1/0x819 init/main.c:717 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 try_to_wake_up+0xbc/0x15f0 kernel/sched/core.c:1989 wake_up_process+0x10/0x20 kernel/sched/core.c:2152 __up.isra.0+0x1cc/0x2c0 kernel/locking/semaphore.c:262 up+0x13b/0x1d0 kernel/locking/semaphore.c:187 __up_console_sem+0xb2/0x1a0 kernel/printk/printk.c:242 console_unlock+0x5af/0xfb0 kernel/printk/printk.c:2417 do_con_write+0x106e/0x1f70 drivers/tty/vt/vt.c:2433 con_write+0x25/0xb0 drivers/tty/vt/vt.c:2782 process_output_block drivers/tty/n_tty.c:579 [inline] n_tty_write+0x5ef/0xec0 drivers/tty/n_tty.c:2308 do_tty_write drivers/tty/tty_io.c:958 [inline] tty_write+0x3fa/0x840 drivers/tty/tty_io.c:1042 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 ((console_sem).lock){..-.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 __warn_printk+0x90/0xf0 kernel/panic.c:599 debug_print_object+0x166/0x220 lib/debugobjects.c:288 __debug_check_no_obj_freed lib/debugobjects.c:745 [inline] debug_check_no_obj_freed+0x662/0xf1f lib/debugobjects.c:774 kfree+0xc7/0x260 mm/slab.c:3799 process_one_req+0x2e7/0x6c0 drivers/infiniband/core/addr.c:592 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 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 *** 3 locks held by kworker/u4:8/8596: #0: ((wq_completion)"ib_addr"){+.+.}, at: [<0000000036b91b71>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"ib_addr"){+.+.}, at: [<0000000036b91b71>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"ib_addr"){+.+.}, at: [<0000000036b91b71>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"ib_addr"){+.+.}, at: [<0000000036b91b71>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&req->work)->work)){+.+.}, at: [<00000000acb330ba>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&obj_hash[i].lock){-.-.}, at: [<000000002c89d701>] __debug_check_no_obj_freed lib/debugobjects.c:736 [inline] #2: (&obj_hash[i].lock){-.-.}, at: [<000000002c89d701>] debug_check_no_obj_freed+0x1e9/0xf1f lib/debugobjects.c:774 stack backtrace: CPU: 0 PID: 8596 Comm: kworker/u4:8 Not tainted 4.16.0-rc7+ #368 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ib_addr process_one_req Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xa2/0x1e0 kernel/printk/printk.c:225 console_trylock+0x15/0x70 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x5b5/0xb90 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379 printk+0xaa/0xca kernel/printk/printk.c:1980 __warn_printk+0x90/0xf0 kernel/panic.c:599 debug_print_object+0x166/0x220 lib/debugobjects.c:288 __debug_check_no_obj_freed lib/debugobjects.c:745 [inline] debug_check_no_obj_freed+0x662/0xf1f lib/debugobjects.c:774 kfree+0xc7/0x260 mm/slab.c:3799 process_one_req+0x2e7/0x6c0 drivers/infiniband/core/addr.c:592 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..