======================================
| [   14.338980][    C3] 1 lock held by swapper/3/0:
| [ 14.339197][ C3] #0: ffffffffb93749c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   14.339651][    C3]
| [   14.339651][    C3] stack backtrace:
[   14.340028][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.340030][    C3] Call Trace:
[   14.340032][    C3]  <IRQ>
[ 14.340036][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.340045][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 14.340051][ C3] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 14.340056][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 14.340061][ C3] ? save_trace (kernel/locking/lockdep.c:594) 
[ 14.340067][ C3] mark_lock (kernel/locking/lockdep.c:4754) 
[ 14.340070][ C3] mark_usage (kernel/locking/lockdep.c:4643) 
[ 14.340073][ C3] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 14.340078][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 14.340081][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.340086][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.340089][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 14.340092][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.340095][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 14.340099][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.340102][ C3] simple_pin_fs (fs/libfs.c:1066) 
[ 14.340105][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 14.340110][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 14.340115][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 14.340119][ C3] ? __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:2366) 
[ 14.340123][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.340129][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 14.340132][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 14.340135][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 14.340139][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.340143][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 14.340146][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 14.340149][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 14.340151][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 14.340154][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 14.340156][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 14.340159][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 14.340162][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 14.340169][ C3] __put_net (net/core/net_namespace.c:732) 
[ 14.340173][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 14.340177][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 14.340180][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.340185][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 14.340189][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 14.340193][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 14.340197][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 14.340200][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.340205][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 14.340208][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 14.340213][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 14.340216][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 14.340219][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   14.340222][    C3]  </IRQ>
[   14.340223][    C3]  <TASK>
[ 14.340225][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.340227][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 14.340232][ C3] Code: 50 b7 00 e9 c3 57 02 00 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 c3 45 12 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:	50                   	push   %rax
   1:	b7 00                	mov    $0x0,%bh
   3:	e9 c3 57 02 00       	jmp    0x257cb
   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 c3 45 12 00 	verw   0x1245c3(%rip)        # 0x1245eb
  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
[   14.340235][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   14.340238][    C3] RAX: 0000000000035a2d RBX: 1ffff9200002afc1 RCX: ffffffffb836ea19
[   14.340240][    C3] RDX: 0000000000000000 RSI: ffffffffb8e89a45 RDI: ffffffffb86513a0
[   14.340242][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   14.340244][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   14.340245][    C3] R13: ffff888001bf4640 R14: dffffc0000000000 R15: 0000000000000000
[ 14.340249][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 14.340255][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 14.340257][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 14.340259][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 14.340262][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 14.340266][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 14.340270][ C3] do_idle (kernel/sched/idle.c:325) 
[ 14.340274][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 14.340277][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 14.340279][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 14.340284][ C3] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   14.358394][    C3] RCU nest depth: 0, expected: 0
| [   14.358607][    C3] INFO: lockdep is turned off.
| [   14.359019][    C3] Preemption disabled at:
| [ 14.359022][ C3] 0x0 
[   14.359441][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.359443][    C3] Call Trace:
[   14.359445][    C3]  <IRQ>
[ 14.359448][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.359457][ C3] __might_resched (kernel/sched/core.c:8819) 
[ 14.359464][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 14.359468][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 14.359471][ C3] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 14.359476][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.359480][ C3] ? 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) 
[ 14.359485][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 14.359488][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 14.359493][ C3] ? 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) 
[ 14.359498][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 14.359501][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 14.359507][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 14.359510][ C3] ? __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:2366) 
[ 14.359515][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.359520][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 14.359524][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 14.359528][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 14.359532][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.359536][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 14.359539][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 14.359541][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 14.359544][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 14.359547][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 14.359549][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 14.359551][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 14.359555][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 14.359561][ C3] __put_net (net/core/net_namespace.c:732) 
[ 14.359565][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 14.359569][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 14.359572][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.359576][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 14.359582][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 14.359586][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 14.359591][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 14.359594][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.359599][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 14.359603][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 14.359608][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 14.359611][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 14.359614][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   14.359617][    C3]  </IRQ>
[   14.359618][    C3]  <TASK>
[ 14.359620][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.359623][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 14.359627][ C3] Code: 50 b7 00 e9 c3 57 02 00 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 c3 45 12 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:	50                   	push   %rax
   1:	b7 00                	mov    $0x0,%bh
   3:	e9 c3 57 02 00       	jmp    0x257cb
   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 c3 45 12 00 	verw   0x1245c3(%rip)        # 0x1245eb
  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
[   14.359630][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   14.359634][    C3] RAX: 0000000000035a2d RBX: 1ffff9200002afc1 RCX: ffffffffb836ea19
[   14.359636][    C3] RDX: 0000000000000000 RSI: ffffffffb8e89a45 RDI: ffffffffb86513a0
[   14.359638][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   14.359640][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   14.359641][    C3] R13: ffff888001bf4640 R14: dffffc0000000000 R15: 0000000000000000
[ 14.359645][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 14.359651][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 14.359653][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 14.359656][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 14.359658][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 14.359662][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 14.359667][ C3] do_idle (kernel/sched/idle.c:325) 
[ 14.359670][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 14.359673][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 14.359675][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 


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