======================================
| [ 43.358026][ C2] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
| [   43.358223][    C2]
| [   43.358302][    C2]
| [   43.358302][    C2] stack backtrace:
[   43.358827][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   43.359175][    C2] Call Trace:
[   43.359294][    C2]  <IRQ>
[ 43.359475][ C2] dump_stack_lvl (lib/dump_stack.c:117) 
[ 43.359638][ C2] print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 43.359832][ C2] ? __pfx_print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 43.360026][ C2] ? __pfx_usage_skip (kernel/locking/lockdep.c:2264) 
[ 43.360288][ C2] ? __pfx_usage_match (kernel/locking/lockdep.c:2256) 
[ 43.360441][ C2] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:26) 
[ 43.360598][ C2] mark_lock_irq (kernel/locking/lockdep.c:4244) 
[ 43.360752][ C2] ? __pfx_mark_lock_irq (kernel/locking/lockdep.c:4207) 
[ 43.360906][ C2] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 43.361066][ C2] ? add_chain_cache (kernel/locking/lockdep.c:3730) 
[ 43.361226][ C2] ? save_trace (kernel/locking/lockdep.c:586) 
[ 43.361384][ C2] mark_lock (kernel/locking/lockdep.c:4678) 
[ 43.361503][ C2] mark_usage (kernel/locking/lockdep.c:4567) 
[ 43.361720][ C2] __lock_acquire (kernel/locking/lockdep.c:5091) 
[ 43.361877][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 43.362033][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 43.362307][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 43.362561][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 43.362793][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 43.362948][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 43.363104][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 43.363434][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 43.363587][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 43.363814][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 43.363973][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 43.364205][ C2] br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) bridge
[ 43.364433][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 43.364699][ C2] call_timer_fn (kernel/time/timer.c:1793) 
[ 43.364953][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 43.365109][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 43.365264][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1770) 
[ 43.365420][ C2] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 43.365640][ C2] __run_timers (kernel/time/timer.c:1845 kernel/time/timer.c:2418) 
[ 43.365795][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) bridge
[ 43.366062][ C2] ? __pfx___run_timers (kernel/time/timer.c:2389) 
[ 43.366224][ C2] ? 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) 
[ 43.366574][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 43.366728][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 43.366881][ C2] ? run_timer_softirq (kernel/time/timer.c:2429 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 43.367037][ C2] run_timer_softirq (kernel/time/timer.c:2430 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 43.367300][ C2] __do_softirq (kernel/softirq.c:554) 
[ 43.367455][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 43.367571][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[   43.367733][    C2]  </IRQ>
[   43.367814][    C2]  <TASK>
[ 43.367893][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 43.368085][ C2] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 43.368286][ C2] Code: 10 e8 21 49 9b fd 48 89 ef e8 59 b9 9b fd 81 e3 00 02 00 00 75 1d 9c 58 f6 c4 02 75 29 48 85 db 74 01 fb 65 ff 0d 05 bf 0f 71 <74> 0e 5b 5d c3 cc cc cc cc e8 4f b3 be fd eb dc 0f 1f 44 00 00 5b
All code
========
   0:	10 e8                	adc    %ch,%al
   2:	21 49 9b             	and    %ecx,-0x65(%rcx)
   5:	fd                   	std
   6:	48 89 ef             	mov    %rbp,%rdi
   9:	e8 59 b9 9b fd       	call   0xfffffffffd9bb967
   e:	81 e3 00 02 00 00    	and    $0x200,%ebx
  14:	75 1d                	jne    0x33
  16:	9c                   	pushf
  17:	58                   	pop    %rax
  18:	f6 c4 02             	test   $0x2,%ah
  1b:	75 29                	jne    0x46
  1d:	48 85 db             	test   %rbx,%rbx
  20:	74 01                	je     0x23
  22:	fb                   	sti
  23:	65 ff 0d 05 bf 0f 71 	decl   %gs:0x710fbf05(%rip)        # 0x710fbf2f
  2a:*	74 0e                	je     0x3a		<-- trapping instruction
  2c:	5b                   	pop    %rbx
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	e8 4f b3 be fd       	call   0xfffffffffdbeb387
  38:	eb dc                	jmp    0x16
  3a:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  3f:	5b                   	pop    %rbx

Code starting with the faulting instruction
===========================================
   0:	74 0e                	je     0x10
   2:	5b                   	pop    %rbx
   3:	5d                   	pop    %rbp
   4:	c3                   	ret
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	e8 4f b3 be fd       	call   0xfffffffffdbeb35d
   e:	eb dc                	jmp    0xffffffffffffffec
  10:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  15:	5b                   	pop    %rbx
[   43.368937][    C2] RSP: 0018:ffffc900005cf3e0 EFLAGS: 00000282
[   43.369137][    C2] RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff2164179
[   43.369475][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ef40911
[   43.369708][    C2] RBP: ffff888001041080 R08: 0000000000000001 R09: fffffbfff21649fa
[   43.369940][    C2] R10: ffffffff90b24fd7 R11: 0000000000001000 R12: ffff888001041080
[   43.370289][    C2] R13: ffffea00001b8400 R14: ffff8880010433c0 R15: ffff888006e11000
[ 43.370521][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 43.370715][ C2] get_partial_node.part.0 (mm/slub.c:2623) 
[ 43.370872][ C2] ___slab_alloc (mm/slub.c:2583 mm/slub.c:2701 mm/slub.c:3505) 
[ 43.371026][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3715 mm/page_alloc.c:3706) 
[ 43.371191][ C2] ? p9_fcall_init (net/9p/client.c:232) 
[ 43.371344][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 43.371501][ C2] ? p9_fcall_init (net/9p/client.c:232) 
[ 43.371755][ C2] ? __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 43.371908][ C2] __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 43.372025][ C2] p9_fcall_init (net/9p/client.c:232) 
[ 43.372181][ C2] p9_tag_alloc (net/9p/client.c:295) 
[ 43.372434][ C2] ? __pfx_p9_tag_alloc (net/9p/client.c:277) 
[ 43.372592][ C2] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 43.372747][ C2] ? 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) 
[ 43.372902][ C2] p9_client_prepare_req (net/9p/client.c:641) 
[ 43.373055][ C2] ? 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) 
[ 43.373312][ C2] ? __pfx_p9_client_prepare_req (net/9p/client.c:625) 
[ 43.373504][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 43.373662][ C2] p9_client_rpc (net/9p/client.c:688 (discriminator 4)) 
[ 43.373818][ C2] ? __pfx_p9_client_rpc (net/9p/client.c:672) 
[ 43.373972][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 43.374132][ C2] ? list_lru_add (mm/list_lru.c:106) 
[ 43.374289][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 43.374443][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 43.374699][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 43.374855][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 43.375010][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 43.375172][ C2] p9_client_clunk (net/9p/client.c:1438 (discriminator 3)) 
[ 43.375428][ C2] v9fs_dentry_release (fs/9p/vfs_dentry.c:54) 
[ 43.375587][ C2] __dentry_kill (fs/dcache.c:608) 
[ 43.375743][ C2] ? __pfx_kfree_link (fs/libfs.c:1573) 
[ 43.375900][ C2] dput.part.0 (fs/dcache.c:845) 
[ 43.376154][ C2] walk_component (fs/namei.c:562 fs/namei.c:1027 fs/namei.c:2009) 
[ 43.376311][ C2] link_path_walk.part.0.constprop.0 (fs/namei.c:2328) 
[ 43.376504][ C2] ? __pfx_link_path_walk.part.0.constprop.0 (fs/namei.c:2249) 
[ 43.376695][ C2] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 43.376850][ C2] ? 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) 
[ 43.377009][ C2] path_lookupat (fs/namei.c:2254 (discriminator 2) fs/namei.c:2484 (discriminator 2)) 
[ 43.377170][ C2] filename_lookup (fs/namei.c:2514) 
[ 43.377325][ C2] ? __pfx_filename_lookup (fs/namei.c:2508) 
[ 43.377580][ C2] ? __pfx_kfree_link (fs/libfs.c:1573) 
[ 43.377742][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 43.377896][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 43.378050][ C2] ? __might_fault (mm/memory.c:6216 mm/memory.c:6209) 
[ 43.378207][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 43.378559][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 43.378726][ C2] vfs_statx (fs/stat.c:244) 
[ 43.378847][ C2] ? __pfx_vfs_statx (fs/stat.c:234) 
[ 43.379002][ C2] ? getname_flags (./arch/x86/include/asm/atomic.h:28 ./include/linux/atomic/atomic-arch-fallback.h:503 ./include/linux/atomic/atomic-instrumented.h:68 fs/namei.c:190) 
[ 43.379274][ C2] vfs_fstatat (fs/stat.c:305) 
[ 43.379392][ C2] __do_sys_newfstatat (fs/stat.c:469) 
[ 43.379546][ C2] ? __pfx___do_sys_newfstatat (fs/stat.c:464) 
[ 43.379703][ C2] ? __x64_sys_openat (fs/open.c:1432) 
[ 43.379858][ C2] ? __pfx___x64_sys_openat (fs/open.c:1432) 
[ 43.380012][ C2] ? __pfx_do_faccessat (fs/open.c:465) 
[ 43.380169][ C2] ? lockdep_hardirqs_on_prepare.part.0 (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359) 
[ 43.380363][ C2] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 43.380517][ C2] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[   43.380808][    C2] RIP: 0033:0x7fc0f3504eae
[ 43.380967][ C2] Code: 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 07 00 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 0b 31 c0 c3 0f 1f 84 00 00 00 00 00 f7 d8 89 05
All code
========
   0:	48 89 f2             	mov    %rsi,%rdx
   3:	b9 00 01 00 00       	mov    $0x100,%ecx
   8:	48 89 fe             	mov    %rdi,%rsi
   b:	bf 9c ff ff ff       	mov    $0xffffff9c,%edi
  10:	e9 07 00 00 00       	jmp    0x1c
  15:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  1c:	f3 0f 1e fa          	endbr64
  20:	41 89 ca             	mov    %ecx,%r10d
  23:	b8 06 01 00 00       	mov    $0x106,%eax
  28:	0f 05                	syscall
  2a:*	3d 00 f0 ff ff       	cmp    $0xfffff000,%eax		<-- trapping instruction
  2f:	77 0b                	ja     0x3c
  31:	31 c0                	xor    %eax,%eax
  33:	c3                   	ret
  34:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  3b:	00 
  3c:	f7 d8                	neg    %eax
  3e:	89                   	.byte 0x89
  3f:	05                   	.byte 0x5

Code starting with the faulting instruction
===========================================
   0:	3d 00 f0 ff ff       	cmp    $0xfffff000,%eax
   5:	77 0b                	ja     0x12
   7:	31 c0                	xor    %eax,%eax
   9:	c3                   	ret
   a:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  11:	00 
  12:	f7 d8                	neg    %eax
  14:	89                   	.byte 0x89
  15:	05                   	.byte 0x5
[   43.381642][    C2] RSP: 002b:00007ffcdd6a1ba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[   43.381877][    C2] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc0f3504eae
[   43.382214][    C2] RDX: 00007ffcdd6a1c70 RSI: 00007ffcdd6a1bb0 RDI: 00000000ffffff9c
[   43.382446][    C2] RBP: 00007ffcdd6a1d30 R08: 00000000ffffffff R09: 00007ffcdd6a1bb0
[   43.382677][    C2] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcdd6a1bb7


Finger prints:
dump_stack_lvl:mark_lock_irq:mark_lock:mark_usage