======================================
| [   12.874753][    C3] 1 lock held by swapper/3/0:
| [ 12.874943][ C3] #0: ffffffff997774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.875279][    C3]
| [   12.875279][    C3] stack backtrace:
[   12.875525][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.875528][    C3] Call Trace:
[   12.875533][    C3]  <IRQ>
[ 12.875535][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.875543][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.875548][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.875552][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.875557][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.875561][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.875565][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.875568][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.875573][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.875578][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.875581][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.875585][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.875590][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.875592][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.875596][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.875599][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.875602][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 12.875605][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.875608][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.875614][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.875617][ 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:2376) 
[ 12.875622][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.875625][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.875627][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.875630][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 12.875635][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.875638][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.875642][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.875644][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.875646][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.875651][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 12.875653][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.875656][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.875660][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.875670][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.875674][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.875678][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.875681][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.875686][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.875689][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.875693][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.875696][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.875701][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.875705][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.875711][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.875715][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.875718][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   12.875721][    C3]  </IRQ>
[   12.875722][    C3]  <TASK>
[ 12.875724][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.875726][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.875730][ C3] 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
[   12.875733][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000242
[   12.875738][    C3] RAX: 000000000003628f RBX: 1ffff9200002afc1 RCX: ffffffff987a35d9
[   12.875740][    C3] RDX: 0000000000000000 RSI: ffffffff9929175c RDI: ffffffff98a53ca0
[   12.875742][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c366fa
[   12.875743][    C3] R10: ffff8880361b37d3 R11: ffffffff99411288 R12: 0000000000000000
[   12.875745][    C3] R13: ffff888001bf45c0 R14: dffffc0000000000 R15: 0000000000000000
[ 12.875749][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.875754][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.875756][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.875759][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.875762][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.875766][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 12.875771][ C3] do_idle (kernel/sched/idle.c:325) 
[ 12.875775][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.875778][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.875781][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 12.875786][ C3] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   12.891241][    C3] RCU nest depth: 0, expected: 0
| [   12.891416][    C3] INFO: lockdep is turned off.
| [   12.891590][    C3] Preemption disabled at:
| [ 12.891591][ C3] 0x0 
[   12.891943][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.891944][    C3] Call Trace:
[   12.891946][    C3]  <IRQ>
[ 12.891947][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.891953][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 12.891962][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.891966][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.891968][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.891973][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.891978][ 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) 
[ 12.891982][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.891985][ 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) 
[ 12.891987][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.891992][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.891996][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.891999][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.892004][ 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:2376) 
[ 12.892008][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892012][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.892014][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.892019][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 12.892023][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.892027][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.892030][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.892033][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.892035][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.892039][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 12.892042][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.892044][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.892048][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.892054][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.892057][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.892061][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892064][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892069][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.892072][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.892077][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.892080][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.892086][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.892091][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.892096][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.892100][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.892102][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   12.892106][    C3]  </IRQ>
[   12.892107][    C3]  <TASK>
[ 12.892109][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.892111][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 12.892115][ C3] 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
[   12.892117][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000242
[   12.892120][    C3] RAX: 000000000003628f RBX: 1ffff9200002afc1 RCX: ffffffff987a35d9
[   12.892122][    C3] RDX: 0000000000000000 RSI: ffffffff9929175c RDI: ffffffff98a53ca0
[   12.892124][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c366fa
[   12.892126][    C3] R10: ffff8880361b37d3 R11: ffffffff99411288 R12: 0000000000000000
[   12.892127][    C3] R13: ffff888001bf45c0 R14: dffffc0000000000 R15: 0000000000000000
[ 12.892131][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.892136][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 12.892138][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.892141][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.892144][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.892148][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 12.892153][ C3] do_idle (kernel/sched/idle.c:325) 
[ 12.892156][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.892160][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.892163][ 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