======================================
| [ 49.506145][ C0] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
| [   49.506346][    C0]
| [   49.506427][    C0]
| [   49.506427][    C0] stack backtrace:
[   49.507050][    C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   49.507395][    C0] Call Trace:
[   49.507632][    C0]  <IRQ>
[ 49.507713][ C0] dump_stack_lvl (lib/dump_stack.c:117) 
[ 49.507871][ C0] print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 49.508070][ C0] ? __pfx_print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 49.508271][ C0] ? __pfx_usage_skip (kernel/locking/lockdep.c:2264) 
[ 49.508426][ C0] ? __pfx_usage_match (kernel/locking/lockdep.c:2256) 
[ 49.508581][ C0] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:26) 
[ 49.508739][ C0] mark_lock_irq (kernel/locking/lockdep.c:4244) 
[ 49.508900][ C0] ? __pfx_mark_lock_irq (kernel/locking/lockdep.c:4207) 
[ 49.509055][ C0] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 49.509213][ C0] ? add_chain_cache (kernel/locking/lockdep.c:3730) 
[ 49.509375][ C0] ? save_trace (kernel/locking/lockdep.c:586) 
[ 49.509533][ C0] mark_lock (kernel/locking/lockdep.c:4678) 
[ 49.509652][ C0] mark_usage (kernel/locking/lockdep.c:4567) 
[ 49.509770][ C0] __lock_acquire (kernel/locking/lockdep.c:5091) 
[ 49.509927][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 49.510084][ C0] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 49.510455][ C0] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 49.510612][ C0] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 49.510846][ C0] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 49.511003][ C0] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 49.511261][ C0] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 49.511490][ C0] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 49.511645][ C0] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 49.511875][ C0] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 49.512131][ C0] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 49.512365][ C0] br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 49.512597][ C0] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 49.513092][ C0] call_timer_fn (kernel/time/timer.c:1793) 
[ 49.513262][ C0] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 49.513418][ C0] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 49.513574][ C0] ? __pfx_call_timer_fn (kernel/time/timer.c:1770) 
[ 49.513841][ C0] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 49.514003][ C0] __run_timers (kernel/time/timer.c:1845 kernel/time/timer.c:2418) 
[ 49.514159][ C0] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 49.514428][ C0] ? __pfx___run_timers (kernel/time/timer.c:2389) 
[ 49.514687][ C0] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:115 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 49.514844][ C0] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 49.514998][ C0] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 49.515155][ C0] ? run_timer_softirq (kernel/time/timer.c:2429 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 49.515412][ C0] run_timer_softirq (kernel/time/timer.c:2430 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 49.515573][ C0] __do_softirq (kernel/softirq.c:554) 
[ 49.515731][ C0] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 49.515849][ C0] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[   49.516006][    C0]  </IRQ>
[   49.516187][    C0]  <TASK>
[ 49.516267][ C0] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 49.516475][ C0] RIP: 0010:kasan_report (mm/kasan/report.c:586) 
[ 49.516654][ C0] Code: 0f b6 d3 48 89 ee 48 8d 7c 24 08 e8 e3 fc ff ff ff 34 24 9d 48 83 c4 70 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc <45> 31 e4 eb e1 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90
All code
========
   0:	0f b6 d3             	movzbl %bl,%edx
   3:	48 89 ee             	mov    %rbp,%rsi
   6:	48 8d 7c 24 08       	lea    0x8(%rsp),%rdi
   b:	e8 e3 fc ff ff       	call   0xfffffffffffffcf3
  10:	ff 34 24             	push   (%rsp)
  13:	9d                   	popf
  14:	48 83 c4 70          	add    $0x70,%rsp
  18:	44 89 e0             	mov    %r12d,%eax
  1b:	5b                   	pop    %rbx
  1c:	5d                   	pop    %rbp
  1d:	41 5c                	pop    %r12
  1f:	41 5d                	pop    %r13
  21:	41 5e                	pop    %r14
  23:	41 5f                	pop    %r15
  25:	c3                   	ret
  26:	cc                   	int3
  27:	cc                   	int3
  28:	cc                   	int3
  29:	cc                   	int3
  2a:*	45 31 e4             	xor    %r12d,%r12d		<-- trapping instruction
  2d:	eb e1                	jmp    0x10
  2f:	0f 1f 40 00          	nopl   0x0(%rax)
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	45 31 e4             	xor    %r12d,%r12d
   3:	eb e1                	jmp    0xffffffffffffffe6
   5:	0f 1f 40 00          	nopl   0x0(%rax)
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[   49.517328][    C0] RSP: 0018:ffffc900005cf228 EFLAGS: 00000286
[   49.517531][    C0] RAX: 00000000ffffffff RBX: ffff8880035b7ce8 RCX: ffffffff9e83b764
[   49.517872][    C0] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880035b7ce8
[   49.518109][    C0] RBP: 0000000000002000 R08: 0000000000000004 R09: 0000000000000004
[   49.518347][    C0] R10: ffff8880035b4054 R11: ffff88803ffdb700 R12: 5a5a5a5a5a5a5a5a
[   49.518691][    C0] R13: 000000000000005a R14: dffffc0000000000 R15: ffff888006668040
[ 49.518928][ C0] ? memchr_inv (lib/string.c:856) 
[ 49.519088][ C0] ? __alloc_pages (mm/page_alloc.c:4541) 
[ 49.519248][ C0] ? __pfx___alloc_pages (mm/page_alloc.c:4541) 
[ 49.519404][ C0] ? p9_client_readlink (net/9p/client.c:2238) 
[ 49.519565][ C0] memchr_inv (lib/string.c:856) 
[ 49.519685][ C0] slab_pad_check.part.0 (mm/slub.c:1281) 
[ 49.519843][ C0] check_slab (mm/slub.c:1397 mm/slub.c:1395 mm/slub.c:1374) 
[ 49.519962][ C0] alloc_debug_processing (mm/slub.c:1536 mm/slub.c:1554) 
[ 49.520119][ C0] ___slab_alloc (mm/slub.c:2537 mm/slub.c:3536) 
[ 49.520275][ C0] ? fs_reclaim_acquire (mm/page_alloc.c:3715 mm/page_alloc.c:3706) 
[ 49.520436][ C0] ? p9_fcall_init (net/9p/client.c:232) 
[ 49.520698][ C0] ? p9_fcall_init (net/9p/client.c:232) 
[ 49.520862][ C0] ? __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 49.521020][ C0] __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 49.521139][ C0] p9_fcall_init (net/9p/client.c:232) 
[ 49.521297][ C0] p9_tag_alloc (net/9p/client.c:297) 
[ 49.521557][ C0] ? __pfx_p9_tag_alloc (net/9p/client.c:277) 
[ 49.521716][ C0] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 49.521835][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 49.521997][ C0] p9_client_prepare_req (net/9p/client.c:641) 
[ 49.522254][ C0] ? __pfx_p9_client_prepare_req (net/9p/client.c:625) 
[ 49.522459][ C0] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 49.522622][ C0] p9_client_rpc (net/9p/client.c:688 (discriminator 4)) 
[ 49.522778][ C0] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:115 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 49.523038][ C0] ? __pfx_p9_client_rpc (net/9p/client.c:672) 
[ 49.523197][ C0] ? v9fs_fid_find (fs/9p/fid.c:114) 
[ 49.523355][ C0] ? 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) 
[ 49.523511][ C0] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 49.523669][ C0] ? __pfx_v9fs_fid_find (fs/9p/fid.c:114) 
[ 49.524038][ C0] ? __pfx_make_vfsgid (fs/mnt_idmapping.c:110) 
[ 49.524197][ C0] ? v9fs_fid_add (fs/9p/fid.c:41) 
[ 49.524355][ C0] p9_client_readlink (net/9p/client.c:2238) 
[ 49.524513][ C0] v9fs_vfs_get_link_dotl (fs/9p/vfs_inode_dotl.c:822 fs/9p/vfs_inode_dotl.c:806) 
[ 49.524776][ C0] ? __pfx_v9fs_vfs_get_link_dotl (fs/9p/vfs_inode_dotl.c:809) 
[ 49.524974][ C0] ? __lookup_slow (fs/namei.c:1692) 
[ 49.525131][ C0] pick_link (fs/namei.c:1808) 
[ 49.525249][ C0] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 49.525616][ C0] step_into (fs/namei.c:1874) 
[ 49.525738][ C0] ? __up_read (./arch/x86/include/asm/atomic64_64.h:79 ./include/linux/atomic/atomic-arch-fallback.h:2749 ./include/linux/atomic/atomic-long.h:184 ./include/linux/atomic/atomic-instrumented.h:3317 kernel/locking/rwsem.c:1347) 
[ 49.525893][ C0] ? __pfx_step_into (fs/namei.c:1839) 
[ 49.526049][ C0] ? walk_component (fs/namei.c:2005) 
[ 49.526211][ C0] link_path_walk.part.0.constprop.0 (fs/namei.c:2331) 
[ 49.526405][ C0] ? __pfx_link_path_walk.part.0.constprop.0 (fs/namei.c:2249) 
[ 49.526600][ C0] path_openat (fs/namei.c:3795) 
[ 49.526761][ C0] ? __pfx_path_openat (fs/namei.c:3781) 
[ 49.526916][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 49.527075][ C0] do_filp_open (fs/namei.c:3826) 
[ 49.527232][ C0] ? __pfx_do_filp_open (fs/namei.c:3820) 
[ 49.527390][ C0] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 49.527548][ C0] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 49.527808][ C0] ? alloc_fd (fs/file.c:555 (discriminator 10)) 
[ 49.527929][ C0] ? 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) 
[ 49.528083][ C0] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 49.528243][ C0] ? alloc_fd (fs/file.c:555 (discriminator 10)) 
[ 49.528468][ C0] do_sys_openat2 (fs/open.c:1406) 
[ 49.528631][ C0] ? vfs_fstatat (fs/stat.c:308) 
[ 49.528788][ C0] ? __pfx_do_sys_openat2 (fs/open.c:1392) 
[ 49.528946][ C0] ? __pfx___do_sys_newfstatat (fs/stat.c:464) 
[ 49.529105][ C0] __x64_sys_openat (fs/open.c:1432) 
[ 49.529366][ C0] ? __pfx___x64_sys_openat (fs/open.c:1432) 
[ 49.529523][ C0] ? __pfx_do_faccessat (fs/open.c:465) 
[ 49.529682][ C0] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 49.529837][ C0] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[   49.530137][    C0] RIP: 0033:0x7f59ab3b30e8
[ 49.530303][ C0] Code: f9 41 89 f0 41 83 e2 40 75 30 89 f0 25 00 00 41 00 3d 00 00 41 00 74 22 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 30 c3 0f 1f 80 00 00 00 00 48 8d 44 24 08 c7
All code
========
   0:	f9                   	stc
   1:	41 89 f0             	mov    %esi,%r8d
   4:	41 83 e2 40          	and    $0x40,%r10d
   8:	75 30                	jne    0x3a
   a:	89 f0                	mov    %esi,%eax
   c:	25 00 00 41 00       	and    $0x410000,%eax
  11:	3d 00 00 41 00       	cmp    $0x410000,%eax
  16:	74 22                	je     0x3a
  18:	44 89 c2             	mov    %r8d,%edx
  1b:	4c 89 ce             	mov    %r9,%rsi
  1e:	bf 9c ff ff ff       	mov    $0xffffff9c,%edi
  23:	b8 01 01 00 00       	mov    $0x101,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 30                	ja     0x62
  32:	c3                   	ret
  33:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  3a:	48 8d 44 24 08       	lea    0x8(%rsp),%rax
  3f:	c7                   	.byte 0xc7

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 30                	ja     0x38
   8:	c3                   	ret
   9:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  10:	48 8d 44 24 08       	lea    0x8(%rsp),%rax
  15:	c7                   	.byte 0xc7
[   49.530964][    C0] RSP: 002b:00007ffe2f46f2d8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
[   49.531203][    C0] RAX: ffffffffffffffda RBX: 00007ffe2f46f56f RCX: 00007f59ab3b30e8
[   49.531439][    C0] RDX: 0000000000080000 RSI: 00007ffe2f46f350 RDI: 00000000ffffff9c
[   49.531788][    C0] RBP: 00007ffe2f46f340 R08: 0000000000080000 R09: 00007ffe2f46f350
[   49.532022][    C0] R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffe2f46f357


Finger prints:
dump_stack_lvl:mark_lock_irq:mark_lock:mark_usage