======================================
| [ 43.864205][ C2] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
| [   43.864410][    C2]
| [   43.864492][    C2]
| [   43.864492][    C2] stack backtrace:
[   43.865026][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   43.865489][    C2] Call Trace:
[   43.865625][    C2]  <IRQ>
[ 43.865710][ C2] dump_stack_lvl (lib/dump_stack.c:117) 
[ 43.865880][ C2] print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 43.866086][ C2] ? __pfx_print_irq_inversion_bug.part.0 (kernel/locking/lockdep.c:4024) 
[ 43.866386][ C2] ? __pfx_usage_skip (kernel/locking/lockdep.c:2264) 
[ 43.866547][ C2] ? __pfx_usage_match (kernel/locking/lockdep.c:2256) 
[ 43.866712][ C2] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:26) 
[ 43.866879][ C2] mark_lock_irq (kernel/locking/lockdep.c:4244) 
[ 43.867138][ C2] ? __pfx_mark_lock_irq (kernel/locking/lockdep.c:4207) 
[ 43.867304][ C2] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 43.867468][ C2] ? add_chain_cache (kernel/locking/lockdep.c:3730) 
[ 43.867635][ C2] ? save_trace (kernel/locking/lockdep.c:586) 
[ 43.867895][ C2] mark_lock (kernel/locking/lockdep.c:4678) 
[ 43.868018][ C2] mark_usage (kernel/locking/lockdep.c:4567) 
[ 43.868143][ C2] __lock_acquire (kernel/locking/lockdep.c:5091) 
[ 43.868308][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 43.868475][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) 
[ 43.868773][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 43.868937][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) 
[ 43.869150][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 43.869316][ C2] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 43.869579][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) 
[ 43.869782][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 43.869948][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) 
[ 43.870154][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 43.870412][ C2] ? br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) 
[ 43.870616][ C2] br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:87) 
[ 43.870822][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) 
[ 43.871121][ C2] call_timer_fn (kernel/time/timer.c:1793) 
[ 43.871286][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 43.871450][ C2] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1783) 
[ 43.871616][ C2] ? __pfx_call_timer_fn (kernel/time/timer.c:1770) 
[ 43.871874][ C2] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 43.872004][ C2] __run_timers (kernel/time/timer.c:1845 kernel/time/timer.c:2418) 
[ 43.872167][ C2] ? __pfx_br_forward_delay_timer_expired (net/bridge/br_stp_timer.c:80) 
[ 43.872372][ C2] ? __pfx___run_timers (kernel/time/timer.c:2389) 
[ 43.872537][ 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) 
[ 43.872791][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 43.872955][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 43.873120][ C2] ? run_timer_softirq (kernel/time/timer.c:2429 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 43.873286][ C2] run_timer_softirq (kernel/time/timer.c:2430 kernel/time/timer.c:2422 kernel/time/timer.c:2438 kernel/time/timer.c:2448) 
[ 43.873545][ C2] __do_softirq (kernel/softirq.c:554) 
[ 43.873709][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 43.873833][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[   43.873998][    C2]  </IRQ>
[   43.874082][    C2]  <TASK>
[ 43.874256][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 43.874456][ C2] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 43.874667][ C2] Code: 10 e8 81 21 79 fd 48 89 ef e8 b9 91 79 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 f5 7b 6d 68 <74> 0e 5b 5d c3 cc cc cc cc e8 0f f0 9c fd eb dc 0f 1f 44 00 00 5b
All code
========
   0:	10 e8                	adc    %ch,%al
   2:	81 21 79 fd 48 89    	andl   $0x8948fd79,(%rcx)
   8:	ef                   	out    %eax,(%dx)
   9:	e8 b9 91 79 fd       	call   0xfffffffffd7991c7
   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 f5 7b 6d 68 	decl   %gs:0x686d7bf5(%rip)        # 0x686d7c1f
  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 0f f0 9c fd       	call   0xfffffffffd9cf047
  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 0f f0 9c fd       	call   0xfffffffffd9cf01d
   e:	eb dc                	jmp    0xffffffffffffffec
  10:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  15:	5b                   	pop    %rbx
[   43.875345][    C2] RSP: 0018:ffffc90000adf330 EFLAGS: 00000282
[   43.875558][    C2] RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff32b22d9
[   43.875906][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff97964de1
[   43.876152][    C2] RBP: ffff888001041080 R08: 0000000000000001 R09: fffffbfff32b2b5a
[   43.876397][    C2] R10: ffffffff99595ad7 R11: 0000000000001000 R12: ffff888001041080
[   43.876643][    C2] R13: ffffea000023b400 R14: ffff8880010433c0 R15: ffff888008ed1000
[ 43.876890][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 43.877093][ C2] get_partial_node.part.0 (mm/slub.c:2623) 
[ 43.877263][ C2] ___slab_alloc (mm/slub.c:2583 mm/slub.c:2701 mm/slub.c:3505) 
[ 43.877425][ C2] ? fs_reclaim_acquire (mm/page_alloc.c:3715 mm/page_alloc.c:3706) 
[ 43.877588][ C2] ? p9_fcall_init (net/9p/client.c:232) 
[ 43.877752][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 43.877917][ C2] ? p9_fcall_init (net/9p/client.c:232) 
[ 43.878175][ C2] ? __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 43.878337][ C2] __kmalloc (mm/slub.c:3610 mm/slub.c:3663 mm/slub.c:3835 mm/slub.c:3965 mm/slub.c:3979) 
[ 43.878462][ C2] p9_fcall_init (net/9p/client.c:232) 
[ 43.878630][ C2] p9_tag_alloc (net/9p/client.c:295) 
[ 43.878893][ C2] ? __pfx_p9_tag_alloc (net/9p/client.c:277) 
[ 43.879059][ C2] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 3)) 
[ 43.879183][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 43.879345][ C2] p9_client_prepare_req (net/9p/client.c:641) 
[ 43.879506][ C2] ? __pfx_p9_client_prepare_req (net/9p/client.c:625) 
[ 43.879708][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 43.879871][ C2] p9_client_rpc (net/9p/client.c:688 (discriminator 4)) 
[ 43.880032][ 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) 
[ 43.880198][ C2] ? __pfx_p9_client_rpc (net/9p/client.c:672) 
[ 43.880360][ C2] ? v9fs_fid_find (fs/9p/fid.c:114) 
[ 43.880523][ C2] ? 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) 
[ 43.880684][ C2] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 43.880847][ C2] ? __pfx_v9fs_fid_find (fs/9p/fid.c:114) 
[ 43.881106][ C2] ? __pfx_make_vfsgid (fs/mnt_idmapping.c:110) 
[ 43.881269][ C2] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 43.881432][ C2] ? v9fs_fid_add (fs/9p/fid.c:41) 
[ 43.881596][ C2] p9_client_readlink (net/9p/client.c:2238) 
[ 43.881859][ C2] v9fs_vfs_get_link_dotl (fs/9p/vfs_inode_dotl.c:822 fs/9p/vfs_inode_dotl.c:806) 
[ 43.882023][ C2] ? __pfx_v9fs_vfs_get_link_dotl (fs/9p/vfs_inode_dotl.c:809) 
[ 43.882226][ C2] ? __lookup_slow (fs/namei.c:1692) 
[ 43.882388][ C2] pick_link (fs/namei.c:1808) 
[ 43.882511][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 43.882674][ C2] step_into (fs/namei.c:1874) 
[ 43.882796][ C2] ? __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) 
[ 43.882960][ C2] ? __pfx_step_into (fs/namei.c:1839) 
[ 43.883125][ C2] ? walk_component (fs/namei.c:2005) 
[ 43.883288][ C2] link_path_walk.part.0.constprop.0 (fs/namei.c:2331) 
[ 43.883490][ C2] ? __pfx_link_path_walk.part.0.constprop.0 (fs/namei.c:2249) 
[ 43.883695][ C2] path_openat (fs/namei.c:3795) 
[ 43.883857][ C2] ? __pfx_path_openat (fs/namei.c:3781) 
[ 43.884113][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 43.884275][ C2] do_filp_open (fs/namei.c:3826) 
[ 43.884436][ C2] ? __pfx_do_filp_open (fs/namei.c:3820) 
[ 43.884599][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 43.884862][ C2] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 43.885025][ C2] ? alloc_fd (fs/file.c:555 (discriminator 10)) 
[ 43.885149][ C2] ? 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) 
[ 43.885310][ C2] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 43.885472][ C2] ? alloc_fd (fs/file.c:555 (discriminator 10)) 
[ 43.885597][ C2] do_sys_openat2 (fs/open.c:1406) 
[ 43.885758][ C2] ? vfs_fstatat (fs/stat.c:308) 
[ 43.885918][ C2] ? __pfx_do_sys_openat2 (fs/open.c:1392) 
[ 43.886082][ C2] ? __pfx___do_sys_newfstatat (fs/stat.c:464) 
[ 43.886248][ C2] __x64_sys_openat (fs/open.c:1432) 
[ 43.886411][ C2] ? __pfx___x64_sys_openat (fs/open.c:1432) 
[ 43.886573][ C2] ? __pfx_do_faccessat (fs/open.c:465) 
[ 43.886738][ C2] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 43.887001][ C2] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129) 
[   43.887201][    C2] RIP: 0033:0x7f9a638f30e8
[ 43.887369][ C2] 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
[   43.888152][    C2] RSP: 002b:00007ffc4f28ca98 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
[   43.888401][    C2] RAX: ffffffffffffffda RBX: 00007ffc4f28cd2f RCX: 00007f9a638f30e8
[   43.888647][    C2] RDX: 0000000000080000 RSI: 00007ffc4f28cb10 RDI: 00000000ffffff9c
[   43.888895][    C2] RBP: 00007ffc4f28cb00 R08: 0000000000080000 R09: 00007ffc4f28cb10
[   43.889144][    C2] R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffc4f28cb17


Finger prints:
dump_stack_lvl:mark_lock_irq:mark_lock:mark_usage