======================================
| [   42.878724][    C2] 1 lock held by swapper/2/0:
| [ 42.878908][ C2] #0: ffffffffadb74c00 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   42.879237][    C2]
| [   42.879237][    C2] stack backtrace:
[   42.879488][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   42.879490][    C2] Call Trace:
[   42.879491][    C2]  <IRQ>
[ 42.879494][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 42.879500][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 42.879505][ C2] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 42.879509][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 42.879514][ C2] ? save_trace (kernel/locking/lockdep.c:594) 
[ 42.879519][ C2] mark_lock (kernel/locking/lockdep.c:4754) 
[ 42.879522][ C2] mark_usage (kernel/locking/lockdep.c:4643) 
[ 42.879525][ C2] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 42.879530][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 42.879533][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 42.879536][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 42.879540][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 42.879542][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 42.879546][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 42.879548][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 42.879551][ C2] simple_pin_fs (fs/libfs.c:1066) 
[ 42.879554][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 42.879558][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 42.879562][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 42.879566][ C2] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 42.879571][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.879573][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 42.879576][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 42.879579][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 42.879584][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 42.879587][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 42.879590][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 42.879594][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 42.879596][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 42.879600][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 42.879602][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 42.879604][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 42.879609][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 42.879615][ C2] __put_net (net/core/net_namespace.c:732) 
[ 42.879618][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 42.879622][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.879624][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.879627][ C2] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 42.879631][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 42.879635][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 42.879638][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 42.879641][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 42.879645][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 42.879650][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 42.879655][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 42.879657][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 42.879660][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   42.879663][    C2]  </IRQ>
[   42.879664][    C2]  <TASK>
[ 42.879666][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 42.879668][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 42.879672][ C2] Code: 00 b2 00 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 b0 0b 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
All code
========
   0:	00 b2 00 c3 cc cc    	add    %dh,-0x33333d00(%rdx)
   6:	cc                   	int3
   7:	cc                   	int3
   8:	0f 1f 00             	nopl   (%rax)
   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
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d a3 b0 0b 00 	verw   0xbb0a3(%rip)        # 0xbb0cb
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	c3                   	ret		<-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  36:	00 00 00 
  39:	66 90                	xchg   %ax,%ax
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	c3                   	ret
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   c:	00 00 00 
   f:	66 90                	xchg   %ax,%ax
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[   42.879675][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   42.879678][    C2] RAX: 00000000000a6e2d RBX: 1ffff92000028fc1 RCX: ffffffffacbd7a19
[   42.879680][    C2] RDX: 0000000000000000 RSI: ffffffffad69c7ba RDI: fffffffface55ce0
[   42.879682][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2667a
[   42.879684][    C2] R10: ffff8880361333d3 R11: 0000000000000000 R12: 0000000000000000
[   42.879685][    C2] R13: ffff888001bba340 R14: dffffc0000000000 R15: 0000000000000000
[ 42.879689][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 42.879694][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 42.879698][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 42.879700][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 42.879703][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 42.879706][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 42.879711][ C2] do_idle (kernel/sched/idle.c:325) 
[ 42.879714][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 42.879717][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 42.879720][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 42.879724][ C2] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   42.895671][    C2] RCU nest depth: 0, expected: 0
| [   42.895976][    C2] INFO: lockdep is turned off.
| [   42.896162][    C2] Preemption disabled at:
| [ 42.896164][ C2] 0x0 
[   42.896487][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   42.896489][    C2] Call Trace:
[   42.896491][    C2]  <IRQ>
[ 42.896493][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 42.896501][ C2] __might_resched (kernel/sched/core.c:8819) 
[ 42.896508][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 42.896511][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 42.896514][ C2] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 42.896519][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 42.896524][ 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) 
[ 42.896529][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 42.896532][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 42.896539][ 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) 
[ 42.896544][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 42.896547][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 42.896551][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 42.896554][ C2] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 42.896559][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.896562][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 42.896565][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 42.896569][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 42.896574][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 42.896578][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 42.896581][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 42.896584][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 42.896586][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 42.896590][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 42.896592][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 42.896595][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 42.896598][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 42.896605][ C2] __put_net (net/core/net_namespace.c:732) 
[ 42.896607][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 42.896611][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.896613][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 42.896616][ C2] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 42.896621][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 42.896624][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 42.896628][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 42.896632][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 42.896636][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 42.896640][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 42.896645][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 42.896648][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 42.896651][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   42.896654][    C2]  </IRQ>
[   42.896655][    C2]  <TASK>
[ 42.896657][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 42.896660][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 42.896664][ C2] Code: 00 b2 00 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 b0 0b 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
All code
========
   0:	00 b2 00 c3 cc cc    	add    %dh,-0x33333d00(%rdx)
   6:	cc                   	int3
   7:	cc                   	int3
   8:	0f 1f 00             	nopl   (%rax)
   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
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d a3 b0 0b 00 	verw   0xbb0a3(%rip)        # 0xbb0cb
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	c3                   	ret		<-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  36:	00 00 00 
  39:	66 90                	xchg   %ax,%ax
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	c3                   	ret
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   c:	00 00 00 
   f:	66 90                	xchg   %ax,%ax
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[   42.896667][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   42.896670][    C2] RAX: 00000000000a6e2d RBX: 1ffff92000028fc1 RCX: ffffffffacbd7a19
[   42.896672][    C2] RDX: 0000000000000000 RSI: ffffffffad69c7ba RDI: fffffffface55ce0
[   42.896674][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2667a
[   42.896675][    C2] R10: ffff8880361333d3 R11: 0000000000000000 R12: 0000000000000000
[   42.896677][    C2] R13: ffff888001bba340 R14: dffffc0000000000 R15: 0000000000000000
[ 42.896681][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 42.896686][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 42.896689][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 42.896691][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 42.896694][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 42.896698][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 42.896702][ C2] do_idle (kernel/sched/idle.c:325) 
[ 42.896705][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 42.896708][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 42.896711][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock
__might_resched:down_write:simple_recursive_removal:debugfs_remove:ref_tracker_dir_exit