======================================
| 0
| xx__-> [   11.672856][  T220] ------------[ cut here ]------------
| [ 11.673514][ T220] WARNING: CPU: 2 PID: 220 at ./include/net/netdev_lock.h:52 __netdev_update_features (./include/net/netdev_lock.h:52 ./include/net/netdev_lock.h:49 net/core/dev.c:10566) 
| [   11.674313][  T220] Modules linked in: netdevsim
[   11.675260][  T220] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 11.675712][ T220] RIP: 0010:__netdev_update_features (./include/net/netdev_lock.h:52 ./include/net/netdev_lock.h:49 net/core/dev.c:10566) 
[ 11.676200][ T220] Code: 00 e8 a3 4a fe ff 48 8b 5c 24 58 e9 87 fb ff ff 49 8d bf 90 0c 00 00 be ff ff ff ff e8 08 e9 78 00 85 c0 0f 85 99 00 00 00 90 <0f> 0b 90 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 20 48 c1 ea 03
All code
========
   0:	00 e8                	add    %ch,%al
   2:	a3 4a fe ff 48 8b 5c 	movabs %eax,0x58245c8b48fffe4a
   9:	24 58 
   b:	e9 87 fb ff ff       	jmp    0xfffffffffffffb97
  10:	49 8d bf 90 0c 00 00 	lea    0xc90(%r15),%rdi
  17:	be ff ff ff ff       	mov    $0xffffffff,%esi
  1c:	e8 08 e9 78 00       	call   0x78e929
  21:	85 c0                	test   %eax,%eax
  23:	0f 85 99 00 00 00    	jne    0xc2
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  34:	fc ff df 
  37:	48 8b 54 24 20       	mov    0x20(%rsp),%rdx
  3c:	48 c1 ea 03          	shr    $0x3,%rdx

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   a:	fc ff df 
   d:	48 8b 54 24 20       	mov    0x20(%rsp),%rdx
  12:	48 c1 ea 03          	shr    $0x3,%rdx
[   11.677440][  T220] RSP: 0018:ffffc900009a7548 EFLAGS: 00010246
[   11.677919][  T220] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
[   11.678501][  T220] RDX: 0000000000000000 RSI: ffff888005c4ac90 RDI: ffff8880054c2e38
[   11.679070][  T220] RBP: ffffffffb6b28600 R08: 0000000000000000 R09: fffffbfff693d944
[   11.679656][  T220] R10: ffffffffb49eca27 R11: ffff8880054c2300 R12: 0000000000000000
[   11.680250][  T220] R13: ffff888005c4a128 R14: ffff888005c4a008 R15: ffff888005c4a000
[   11.681058][  T220] FS:  00007f2b1a0501c0(0000) GS:ffff888036100000(0000) knlGS:0000000000000000
[   11.681702][  T220] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   11.682185][  T220] CR2: 00007f2b0c0f0cb0 CR3: 000000000593e006 CR4: 0000000000772ef0
[   11.682722][  T220] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   11.683283][  T220] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   11.683826][  T220] PKRU: 55555554
[   11.684129][  T220] Call Trace:
[   11.684416][  T220]  <TASK>
[ 11.684648][ T220] ? __netdev_update_features (./include/net/netdev_lock.h:52 ./include/net/netdev_lock.h:49 net/core/dev.c:10566) 
[ 11.685015][ T220] ? __warn (kernel/panic.c:748) 
[ 11.685323][ T220] ? __netdev_update_features (./include/net/netdev_lock.h:52 ./include/net/netdev_lock.h:49 net/core/dev.c:10566) 
[ 11.685712][ T220] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 11.686086][ T220] ? handle_bug (arch/x86/kernel/traps.c:285) 
[ 11.686392][ T220] ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1)) 
[ 11.686792][ T220] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) 
[ 11.687237][ T220] ? __netdev_update_features (./include/net/netdev_lock.h:52 ./include/net/netdev_lock.h:49 net/core/dev.c:10566) 
[ 11.687596][ T220] ? __netdev_update_features (./include/net/netdev_lock.h:52 net/core/dev.c:10566) 
[ 11.687977][ T220] ? __pfx___netdev_update_features (net/core/dev.c:10559) 
[ 11.688460][ T220] ? _raw_spin_unlock_irq (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./include/linux/spinlock_api_smp.h:159 kernel/locking/spinlock.c:202) 
[ 11.688827][ T220] ? netdev_register_kobject (net/core/net-sysfs.c:2344) 
[ 11.689227][ T220] register_netdevice (net/core/dev.c:11003) 
[ 11.689616][ T220] ? __pfx_register_netdevice (net/core/dev.c:10881) 
[ 11.690000][ T220] nsim_create (drivers/net/netdevsim/netdev.c:958 drivers/net/netdevsim/netdev.c:1018) netdevsim 
[ 11.690417][ T220] __nsim_dev_port_add (drivers/net/netdevsim/dev.c:1393) netdevsim 
[ 11.690893][ T220] ? __pfx___nsim_dev_port_add (drivers/net/netdevsim/dev.c:1357) netdevsim 
[ 11.691413][ T220] ? nsim_dev_hwstats_init (./include/linux/workqueue.h:817 drivers/net/netdevsim/hwstats.c:442) netdevsim 
[ 11.691910][ T220] nsim_drv_probe (drivers/net/netdevsim/dev.c:1450 drivers/net/netdevsim/dev.c:1607) netdevsim 
[ 11.692321][ T220] ? __pfx_nsim_drv_probe (drivers/net/netdevsim/dev.c:1528) netdevsim 
[ 11.692780][ T220] ? kernfs_create_link (fs/kernfs/symlink.c:48) 
[ 11.693174][ T220] ? kernfs_put (./arch/x86/include/asm/atomic.h:67 (discriminator 1) ./include/linux/atomic/atomic-arch-fallback.h:2278 (discriminator 1) ./include/linux/atomic/atomic-instrumented.h:1384 (discriminator 1) fs/kernfs/dir.c:557 (discriminator 1)) 
[ 11.693458][ T220] ? sysfs_do_create_link_sd (fs/sysfs/symlink.c:48) 
[ 11.693835][ T220] really_probe (drivers/base/dd.c:579 drivers/base/dd.c:658) 
[ 11.694229][ T220] __driver_probe_device (drivers/base/dd.c:800) 
[ 11.694607][ T220] driver_probe_device (drivers/base/dd.c:830) 
[ 11.694974][ T220] __device_attach_driver (drivers/base/dd.c:959) 
[ 11.695370][ T220] ? __pfx___device_attach_driver (drivers/base/dd.c:922) 
[ 11.695805][ T220] bus_for_each_drv (drivers/base/bus.c:462) 
[ 11.696201][ T220] ? __pfx_bus_for_each_drv (drivers/base/bus.c:450) 
[ 11.696549][ T220] ? bus_to_subsys (drivers/base/bus.c:85) 
[ 11.696910][ T220] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 11.697311][ T220] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 11.697686][ T220] __device_attach (drivers/base/dd.c:1030) 
[ 11.698039][ T220] ? __pfx___device_attach (drivers/base/dd.c:1001) 
[ 11.698427][ T220] ? bus_to_subsys (drivers/base/bus.c:85) 
[ 11.698787][ T220] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 11.699191][ T220] bus_probe_device (drivers/base/bus.c:537) 
[ 11.699561][ T220] device_add (drivers/base/core.c:3672) 
[ 11.699941][ T220] ? __pfx_device_add (drivers/base/core.c:3548) 
[ 11.700328][ T220] ? __init_waitqueue_head (./include/linux/list.h:37 kernel/sched/wait.c:12) 
[ 11.700717][ T220] new_device_store (drivers/net/netdevsim/bus.c:443 drivers/net/netdevsim/bus.c:173) netdevsim 
[ 11.701204][ T220] ? __pfx_new_device_store (drivers/net/netdevsim/bus.c:142) netdevsim 
[ 11.701680][ T220] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:132) 
[ 11.702089][ T220] ? sysfs_file_ops (fs/sysfs/file.c:31 (discriminator 1)) 
[ 11.702530][ T220] ? __pfx_sysfs_kf_write (fs/sysfs/file.c:132) 
[ 11.702895][ T220] kernfs_fop_write_iter (fs/kernfs/file.c:334) 
[ 11.703304][ T220] vfs_write (fs/read_write.c:586 fs/read_write.c:679) 
[ 11.703607][ T220] ? __pfx_vfs_write (fs/read_write.c:660) 
[ 11.704013][ T220] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 11.704397][ T220] ? do_user_addr_fault (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[ 11.704779][ T220] ? __pfx___up_read (kernel/locking/rwsem.c:1337) 
[ 11.705176][ T220] ksys_write (fs/read_write.c:731) 
[ 11.705469][ T220] ? __pfx_ksys_write (fs/read_write.c:721) 
[ 11.705831][ T220] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[ 11.706243][ T220] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 11.706608][ T220] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   11.707059][  T220] RIP: 0033:0x7f2b1a26ab77
[ 11.707476][ T220] 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
[   11.708772][  T220] RSP: 002b:00007ffc5f23a7d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   11.709331][  T220] RAX: ffffffffffffffda RBX: 00007f2b1a050140 RCX: 00007f2b1a26ab77
[   11.709875][  T220] RDX: 0000000000000009 RSI: 0000558ce623d5b0 RDI: 0000000000000005
[   11.710430][  T220] RBP: 0000000000000009 R08: 0000000000000000 R09: 0000000000000000
[   11.710947][  T220] R10: 0000000000000002 R11: 0000000000000246 R12: 00007f2b0bf03580


Finger prints:
__netdev_update_features:register_netdevice:nsim_create:__nsim_dev_port_add:nsim_drv_probe