======================================
| [ 749.905632][ T4746] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
| [  749.905811][ T4746]
| [  749.905887][ T4746]
| [  749.905887][ T4746] stack backtrace:
[  749.906406][ T4746] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  749.906729][ T4746] Call Trace:
[  749.906934][ T4746]  <TASK>
[ 749.907011][ T4746] dump_stack_lvl (lib/dump_stack.c:117) 
[ 749.907176][ T4746] print_bad_irq_dependency (kernel/locking/lockdep.c:2626) 
[ 749.907324][ T4746] ? 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) 
[ 749.907475][ T4746] ? __pfx_print_bad_irq_dependency (kernel/locking/lockdep.c:2569) 
[ 749.907757][ T4746] ? __pfx_usage_skip (kernel/locking/lockdep.c:2264) 
[ 749.907904][ T4746] ? __bfs (kernel/locking/lockdep.c:1787) 
[ 749.908014][ T4746] ? __pfx_usage_match (kernel/locking/lockdep.c:2256) 
[ 749.908161][ T4746] check_irq_usage (kernel/locking/lockdep.c:2871) 
[ 749.908399][ T4746] ? __pfx_check_irq_usage (kernel/locking/lockdep.c:2790) 
[ 749.908548][ T4746] ? __bfs (kernel/locking/lockdep.c:1787) 
[ 749.908659][ T4746] ? __pfx_hlock_conflict (kernel/locking/lockdep.c:2016) 
[ 749.908807][ T4746] ? check_path.constprop.0 (kernel/locking/lockdep.c:2145) 
[ 749.908958][ T4746] ? check_noncircular (kernel/locking/lockdep.c:2172) 
[ 749.909200][ T4746] ? __pfx_check_noncircular (kernel/locking/lockdep.c:2163) 
[ 749.909349][ T4746] ? 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) 
[ 749.909494][ T4746] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 749.909606][ T4746] ? check_prev_add (kernel/locking/lockdep.c:3138) 
[ 749.909753][ T4746] check_prev_add (kernel/locking/lockdep.c:3138) 
[ 749.909898][ T4746] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 749.910047][ T4746] validate_chain (kernel/locking/lockdep.c:3254 kernel/locking/lockdep.c:3869) 
[ 749.910192][ T4746] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 749.910307][ T4746] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825) 
[ 749.910548][ T4746] ? 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) 
[ 749.910692][ T4746] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 749.910804][ T4746] __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 749.910953][ T4746] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 749.911203][ T4746] ? __get_task_comm (fs/exec.c:1234) 
[ 749.911351][ T4746] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 749.911465][ T4746] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 749.911618][ T4746] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 749.911765][ T4746] ? __get_task_comm (fs/exec.c:1234) 
[ 749.912003][ T4746] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 749.912147][ T4746] ? __get_task_comm (fs/exec.c:1234) 
[ 749.912294][ T4746] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 749.912440][ T4746] ? __get_task_comm (fs/exec.c:1234) 
[ 749.912675][ T4746] __get_task_comm (fs/exec.c:1234) 
[ 749.912819][ T4746] ref_tracker_alloc (lib/ref_tracker.c:217) 
[ 749.912971][ T4746] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 749.913124][ T4746] ? __pfx_ref_tracker_alloc (lib/ref_tracker.c:193) 
[ 749.913363][ T4746] ? rt_flush_dev (./include/linux/netdevice.h:4036 ./include/linux/netdevice.h:4114 net/ipv4/route.c:1555) 
[ 749.913512][ T4746] ? fib_netdev_event (net/ipv4/fib_frontend.c:1520) 
[ 749.913661][ T4746] ? notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[ 749.913808][ T4746] ? unregister_netdevice_many_notify (net/core/dev.c:11171) 
[ 749.914099][ T4746] ? unregister_netdevice_queue (net/core/dev.c:11108) 
[ 749.914281][ T4746] ? nsim_destroy (drivers/net/netdevsim/netdev.c:502 (discriminator 2)) netdevsim
[ 749.914444][ T4746] ? __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
[ 749.914635][ T4746] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:1729) netdevsim
[ 749.914829][ T4746] ? del_port_store (drivers/net/netdevsim/bus.c:100) netdevsim
[ 749.915023][ T4746] ? kernfs_fop_write_iter (fs/kernfs/file.c:334) 
[ 749.915175][ T4746] ? vfs_write (./include/linux/fs.h:2108 fs/read_write.c:497 fs/read_write.c:590) 
[ 749.915323][ T4746] ? ksys_write (fs/read_write.c:643) 
[ 749.915564][ T4746] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 749.915710][ T4746] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[ 749.915900][ T4746] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 749.916048][ T4746] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 749.916299][ T4746] ? rt_flush_dev (net/ipv4/route.c:1551) 
[ 749.916448][ T4746] rt_flush_dev (./include/linux/netdevice.h:4036 ./include/linux/netdevice.h:4114 net/ipv4/route.c:1555) 
[ 749.916595][ T4746] ? __timer_delete_sync (kernel/time/timer.c:1648 (discriminator 1)) 
[ 749.916744][ T4746] ? __timer_delete_sync (kernel/time/timer.c:1668 (discriminator 34)) 
[ 749.916981][ T4746] fib_netdev_event (net/ipv4/fib_frontend.c:1520) 
[ 749.917129][ T4746] notifier_call_chain (kernel/notifier.c:93 (discriminator 2)) 
[ 749.917297][ T4746] unregister_netdevice_many_notify (net/core/dev.c:11171) 
[ 749.917496][ T4746] ? nsim_destroy (drivers/net/netdevsim/netdev.c:497) netdevsim
[ 749.917744][ T4746] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 749.917892][ T4746] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 52)) 
[ 749.918043][ T4746] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11113) 
[ 749.918224][ T4746] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:618 kernel/locking/mutex.c:752) 
[ 749.918460][ T4746] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:43 drivers/net/netdevsim/dev.c:1694 drivers/net/netdevsim/dev.c:1724) netdevsim
[ 749.918649][ T4746] ? nsim_destroy (drivers/net/netdevsim/netdev.c:497) netdevsim
[ 749.918816][ T4746] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 749.918965][ T4746] unregister_netdevice_queue (net/core/dev.c:11108) 
[ 749.919208][ T4746] ? nsim_drv_port_del (drivers/net/netdevsim/dev.c:43 drivers/net/netdevsim/dev.c:1694 drivers/net/netdevsim/dev.c:1724) netdevsim
[ 749.919402][ T4746] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11097) 
[ 749.919587][ T4746] ? __pfx___mutex_lock (kernel/locking/mutex.c:751) 
[ 749.919735][ T4746] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 749.919973][ T4746] nsim_destroy (drivers/net/netdevsim/netdev.c:502 (discriminator 2)) netdevsim
[ 749.920138][ T4746] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
[ 749.920333][ T4746] nsim_drv_port_del (drivers/net/netdevsim/dev.c:1729) netdevsim
[ 749.920526][ T4746] del_port_store (drivers/net/netdevsim/bus.c:100) netdevsim
[ 749.920778][ T4746] ? __pfx_del_port_store (drivers/net/netdevsim/bus.c:88) netdevsim
[ 749.920973][ T4746] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:129) 
[ 749.921120][ T4746] ? sysfs_file_ops (fs/sysfs/file.c:31 (discriminator 1)) 
[ 749.921267][ T4746] ? sysfs_kf_write (fs/sysfs/file.c:130) 
[ 749.921511][ T4746] kernfs_fop_write_iter (fs/kernfs/file.c:334) 
[ 749.921662][ T4746] vfs_write (./include/linux/fs.h:2108 fs/read_write.c:497 fs/read_write.c:590) 
[ 749.921774][ T4746] ? __pfx_locks_remove_posix (fs/locks.c:2608) 
[ 749.921934][ T4746] ? __pfx_vfs_write (fs/read_write.c:571) 
[ 749.922181][ T4746] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 749.922331][ T4746] ? __fget_light (./include/linux/atomic/atomic-arch-fallback.h:479 ./include/linux/atomic/atomic-instrumented.h:50 fs/file.c:1145) 
[ 749.922485][ T4746] ksys_write (fs/read_write.c:643) 
[ 749.922600][ T4746] ? __pfx_ksys_write (fs/read_write.c:633) 
[ 749.922751][ T4746] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 749.922997][ T4746] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[  749.923183][ T4746] RIP: 0033:0x7f9b9b1ed957
[ 749.923340][ T4746] 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
[  749.923961][ T4746] RSP: 002b:00007fff59946e78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  749.924199][ T4746] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f9b9b1ed957
[  749.924518][ T4746] RDX: 0000000000000002 RSI: 000055ebc5e60510 RDI: 0000000000000001
[  749.924741][ T4746] RBP: 000055ebc5e60510 R08: 0000000000000000 R09: 00007f9b9b2604e0
[  749.924964][ T4746] R10: 00007f9b9b2603e0 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
dump_stack_lvl:print_bad_irq_dependency:check_irq_usage:check_prev_add