======================================
| [   12.687329][    C2] 1 lock held by swapper/2/0:
| [ 12.687517][ C2] #0: ffffffff98b774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.687857][    C2]
| [   12.687857][    C2] stack backtrace:
[   12.688097][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.688099][    C2] Call Trace:
[   12.688104][    C2]  <IRQ>
[ 12.688106][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.688115][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.688120][ C2] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.688124][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.688131][ C2] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.688135][ C2] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.688139][ C2] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.688144][ C2] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.688147][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.688152][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.688155][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.688159][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.688165][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.688168][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.688171][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.688175][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.688177][ C2] simple_pin_fs (fs/libfs.c:1067) 
[ 12.688182][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.688185][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.688192][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.688195][ 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:2376) 
[ 12.688204][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.688207][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.688210][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.688213][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 12.688219][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.688224][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.688227][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.688230][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.688232][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.688239][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 12.688241][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.688244][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.688249][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.688257][ C2] __put_net (net/core/net_namespace.c:732) 
[ 12.688265][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.688269][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.688272][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.688275][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 12.688279][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.688283][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.688287][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.688290][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 12.688295][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.688301][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 12.688307][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.688310][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.688313][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   12.688317][    C2]  </IRQ>
[   12.688318][    C2]  <TASK>
[ 12.688320][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.688322][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.688327][ C2] Code: 92 b4 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 83 07 0f 00 fb f4 <e9> fc 54 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
All code
========
   0:	92                   	xchg   %eax,%edx
   1:	b4 00                	mov    $0x0,%ah
   3:	c3                   	ret
   4:	cc                   	int3
   5:	cc                   	int3
   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 83 07 0f 00 	verw   0xf0783(%rip)        # 0xf07ab
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	e9 fc 54 02 00       	jmp    0x2552b		<-- trapping instruction
  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:	e9 fc 54 02 00       	jmp    0x25501
   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
[   12.688329][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   12.688335][    C2] RAX: 000000000003629f RBX: 1ffff92000028fc1 RCX: ffffffff97ba35d9
[   12.688337][    C2] RDX: 0000000000000000 RSI: ffffffff9869175c RDI: ffffffff97e53ca0
[   12.688339][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c266fa
[   12.688340][    C2] R10: ffff8880361337d3 R11: ffffffff98811288 R12: 0000000000000000
[   12.688342][    C2] R13: ffff888001bf2300 R14: dffffc0000000000 R15: 0000000000000000
[ 12.688346][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.688351][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.688353][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.688356][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.688361][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.688365][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 12.688371][ C2] do_idle (kernel/sched/idle.c:325) 
[ 12.688375][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.688379][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.688382][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 12.688387][ C2] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   12.704262][    C2] RCU nest depth: 0, expected: 0
| [   12.704461][    C2] INFO: lockdep is turned off.
| [   12.704647][    C2] Preemption disabled at:
| [ 12.704649][ C2] 0x0 
[   12.704998][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.705000][    C2] Call Trace:
[   12.705002][    C2]  <IRQ>
[ 12.705004][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.705011][ C2] __might_resched (kernel/sched/core.c:8796) 
[ 12.705024][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.705029][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.705032][ C2] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.705036][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.705042][ 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) 
[ 12.705046][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.705049][ 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) 
[ 12.705051][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.705059][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.705062][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.705066][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.705069][ 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:2376) 
[ 12.705073][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.705077][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.705080][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.705085][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 12.705089][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.705093][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.705096][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.705098][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.705101][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.705105][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 12.705108][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.705110][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.705114][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.705120][ C2] __put_net (net/core/net_namespace.c:732) 
[ 12.705126][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.705130][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.705133][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.705136][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 12.705141][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.705144][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.705149][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.705152][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 12.705157][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.705162][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 12.705167][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.705171][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.705174][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   12.705178][    C2]  </IRQ>
[   12.705179][    C2]  <TASK>
[ 12.705180][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.705183][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.705187][ C2] Code: 92 b4 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 83 07 0f 00 fb f4 <e9> fc 54 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
All code
========
   0:	92                   	xchg   %eax,%edx
   1:	b4 00                	mov    $0x0,%ah
   3:	c3                   	ret
   4:	cc                   	int3
   5:	cc                   	int3
   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 83 07 0f 00 	verw   0xf0783(%rip)        # 0xf07ab
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	e9 fc 54 02 00       	jmp    0x2552b		<-- trapping instruction
  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:	e9 fc 54 02 00       	jmp    0x25501
   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
[   12.705189][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   12.705192][    C2] RAX: 000000000003629f RBX: 1ffff92000028fc1 RCX: ffffffff97ba35d9
[   12.705194][    C2] RDX: 0000000000000000 RSI: ffffffff9869175c RDI: ffffffff97e53ca0
[   12.705196][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c266fa
[   12.705197][    C2] R10: ffff8880361337d3 R11: ffffffff98811288 R12: 0000000000000000
[   12.705199][    C2] R13: ffff888001bf2300 R14: dffffc0000000000 R15: 0000000000000000
[ 12.705203][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.705208][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.705210][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.705212][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.705217][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.705221][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 12.705226][ C2] do_idle (kernel/sched/idle.c:325) 
[ 12.705230][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.705233][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.705236][ C2] ? __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