======================================
| [ 746.212600][ T4750] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
| [  746.212820][ T4750]
| [  746.212999][ T4750]
| [  746.212999][ T4750] stack backtrace:
[  746.213492][ T4750] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  746.213987][ T4750] Call Trace:
[  746.214129][ T4750]  <TASK>
[ 746.214219][ T4750] dump_stack_lvl (lib/dump_stack.c:117) 
[ 746.214400][ T4750] print_bad_irq_dependency (kernel/locking/lockdep.c:2626) 
[ 746.214687][ T4750] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 746.214872][ T4750] ? __pfx_print_bad_irq_dependency (kernel/locking/lockdep.c:2569) 
[ 746.215088][ T4750] ? __pfx_usage_skip (kernel/locking/lockdep.c:2264) 
[ 746.215268][ T4750] ? __bfs (kernel/locking/lockdep.c:1787) 
[ 746.215401][ T4750] ? __pfx_usage_match (kernel/locking/lockdep.c:2256) 
[ 746.215575][ T4750] check_irq_usage (kernel/locking/lockdep.c:2871) 
[ 746.215755][ T4750] ? __pfx_check_irq_usage (kernel/locking/lockdep.c:2790) 
[ 746.215928][ T4750] ? __bfs (kernel/locking/lockdep.c:1787) 
[ 746.216063][ T4750] ? __pfx_hlock_conflict (kernel/locking/lockdep.c:2016) 
[ 746.216238][ T4750] ? check_path.constprop.0 (kernel/locking/lockdep.c:2145) 
[ 746.216412][ T4750] ? check_noncircular (kernel/locking/lockdep.c:2172) 
[ 746.216593][ T4750] ? __pfx_check_noncircular (kernel/locking/lockdep.c:2163) 
[ 746.216776][ T4750] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 746.217041][ T4750] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 746.217175][ T4750] ? check_prev_add (kernel/locking/lockdep.c:3138) 
[ 746.217348][ T4750] check_prev_add (kernel/locking/lockdep.c:3138) 
[ 746.217521][ T4750] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 746.217694][ T4750] validate_chain (kernel/locking/lockdep.c:3254 kernel/locking/lockdep.c:3869) 
[ 746.217967][ T4750] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 746.218100][ T4750] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825) 
[ 746.218279][ T4750] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 746.218452][ T4750] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 746.218584][ T4750] __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 746.218857][ T4750] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 746.219032][ T4750] ? __get_task_comm (fs/exec.c:1234) 
[ 746.219207][ T4750] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 746.219339][ T4750] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 746.219599][ T4750] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 746.219791][ T4750] ? __get_task_comm (fs/exec.c:1234) 
[ 746.219967][ T4750] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 746.220139][ T4750] ? __get_task_comm (fs/exec.c:1234) 
[ 746.220406][ T4750] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 746.220591][ T4750] ? __get_task_comm (fs/exec.c:1234) 
[ 746.220768][ T4750] __get_task_comm (fs/exec.c:1234) 
[ 746.220942][ T4750] ref_tracker_alloc (lib/ref_tracker.c:217) 
[ 746.221119][ T4750] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 746.221397][ T4750] ? __pfx_ref_tracker_alloc (lib/ref_tracker.c:193) 
[ 746.221578][ T4750] ? rt_flush_dev (./include/linux/netdevice.h:4036 ./include/linux/netdevice.h:4114 net/ipv4/route.c:1555) 
[ 746.221755][ T4750] ? fib_netdev_event (net/ipv4/fib_frontend.c:1520) 
[ 746.221929][ T4750] ? notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[ 746.222201][ T4750] ? unregister_netdevice_many_notify (net/core/dev.c:11171) 
[ 746.222418][ T4750] ? unregister_netdevice_queue (net/core/dev.c:11108) 
[ 746.222646][ T4750] ? nsim_destroy (drivers/net/netdevsim/netdev.c:502 (discriminator 2)) netdevsim
[ 746.222837][ T4750] ? __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
[ 746.223163][ T4750] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:1729) netdevsim
[ 746.223391][ T4750] ? del_port_store (drivers/net/netdevsim/bus.c:100) netdevsim
[ 746.223627][ T4750] ? kernfs_fop_write_iter (fs/kernfs/file.c:334) 
[ 746.223894][ T4750] ? vfs_write (./include/linux/fs.h:2108 fs/read_write.c:497 fs/read_write.c:590) 
[ 746.224072][ T4750] ? ksys_write (fs/read_write.c:643) 
[ 746.224247][ T4750] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 746.224423][ T4750] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[ 746.224756][ T4750] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 746.224939][ T4750] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 746.225111][ T4750] ? rt_flush_dev (net/ipv4/route.c:1551) 
[ 746.225297][ T4750] rt_flush_dev (./include/linux/netdevice.h:4036 ./include/linux/netdevice.h:4114 net/ipv4/route.c:1555) 
[ 746.225479][ T4750] ? __timer_delete_sync (kernel/time/timer.c:1648 (discriminator 1)) 
[ 746.225656][ T4750] ? __timer_delete_sync (kernel/time/timer.c:1668 (discriminator 34)) 
[ 746.225835][ T4750] fib_netdev_event (net/ipv4/fib_frontend.c:1520) 
[ 746.226019][ T4750] notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[ 746.226197][ T4750] unregister_netdevice_many_notify (net/core/dev.c:11171) 
[ 746.226421][ T4750] ? nsim_destroy (drivers/net/netdevsim/netdev.c:497) netdevsim
[ 746.226622][ T4750] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 746.226800][ T4750] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 52)) 
[ 746.226979][ T4750] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11113) 
[ 746.227289][ T4750] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:618 kernel/locking/mutex.c:752) 
[ 746.227462][ T4750] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:43 drivers/net/netdevsim/dev.c:1694 drivers/net/netdevsim/dev.c:1724) netdevsim
[ 746.227700][ T4750] ? nsim_destroy (drivers/net/netdevsim/netdev.c:497) netdevsim
[ 746.227976][ T4750] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 746.228156][ T4750] unregister_netdevice_queue (net/core/dev.c:11108) 
[ 746.228329][ T4750] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:43 drivers/net/netdevsim/dev.c:1694 drivers/net/netdevsim/dev.c:1724) netdevsim
[ 746.228566][ T4750] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11097) 
[ 746.228872][ T4750] ? __pfx___mutex_lock (kernel/locking/mutex.c:751) 
[ 746.229050][ T4750] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 746.229220][ T4750] nsim_destroy (drivers/net/netdevsim/netdev.c:502 (discriminator 2)) netdevsim
[ 746.229409][ T4750] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
[ 746.229753][ T4750] nsim_drv_port_del (drivers/net/netdevsim/dev.c:1729) netdevsim
[ 746.229990][ T4750] del_port_store (drivers/net/netdevsim/bus.c:100) netdevsim
[ 746.230178][ T4750] ? __pfx_del_port_store (drivers/net/netdevsim/bus.c:88) netdevsim
[ 746.230406][ T4750] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 746.230579][ T4750] ? sysfs_file_ops (fs/sysfs/file.c:31 (discriminator 1)) 
[ 746.230754][ T4750] ? sysfs_kf_write (fs/sysfs/file.c:130) 
[ 746.230930][ T4750] kernfs_fop_write_iter (fs/kernfs/file.c:334) 
[ 746.231111][ T4750] vfs_write (./include/linux/fs.h:2108 fs/read_write.c:497 fs/read_write.c:590) 
[ 746.231244][ T4750] ? __pfx_locks_remove_posix (fs/locks.c:2608) 
[ 746.231433][ T4750] ? __pfx_vfs_write (fs/read_write.c:571) 
[ 746.231608][ T4750] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 746.231784][ T4750] ? __fget_light (./include/linux/atomic/atomic-arch-fallback.h:479 ./include/linux/atomic/atomic-instrumented.h:50 fs/file.c:1145) 
[ 746.231967][ T4750] ksys_write (fs/read_write.c:643) 
[ 746.232187][ T4750] ? __pfx_ksys_write (fs/read_write.c:633) 
[ 746.232365][ T4750] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 746.232543][ T4750] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[  746.232764][ T4750] RIP: 0033:0x7f64b0361957
[ 746.233143][ T4750] Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
All code
========
   0:	0b 00                	or     (%rax),%eax
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b7                	jmp    0xffffffffffffffc7
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	74 24                	je     0x64

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  12:	48                   	rex.W
  13:	89                   	.byte 0x89
  14:	74 24                	je     0x3a
[  746.233761][ T4750] RSP: 002b:00007ffc83367168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  746.234124][ T4750] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f64b0361957
[  746.234392][ T4750] RDX: 0000000000000002 RSI: 000055e436a79510 RDI: 0000000000000001
[  746.234746][ T4750] RBP: 000055e436a79510 R08: 0000000000000000 R09: 00007f64b03d44e0
[  746.235015][ T4750] R10: 00007f64b03d43e0 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
dump_stack_lvl:print_bad_irq_dependency:check_irq_usage:check_prev_add