======================================
| [   18.456014][    C3] 1 lock held by swapper/3/0:
| [ 18.456192][ C3] #0: ffffffff8e574480 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   18.456518][    C3]
| [   18.456518][    C3] stack backtrace:
[   18.456742][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   18.456744][    C3] Call Trace:
[   18.456746][    C3]  <IRQ>
[ 18.456749][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 18.456756][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 18.456761][ C3] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 18.456766][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 18.456772][ C3] ? save_trace (kernel/locking/lockdep.c:594) 
[ 18.456777][ C3] mark_lock (kernel/locking/lockdep.c:4754) 
[ 18.456781][ C3] mark_usage (kernel/locking/lockdep.c:4643) 
[ 18.456784][ C3] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 18.456789][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 18.456793][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 18.456797][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 18.456804][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 18.456807][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 18.456812][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 18.456814][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 18.456818][ C3] simple_pin_fs (fs/libfs.c:1066) 
[ 18.456822][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 18.456825][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 18.456831][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 18.456834][ 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:2333) 
[ 18.456842][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.456845][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 18.456848][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 18.456850][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 18.456854][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 18.456858][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 18.456861][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 18.456863][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 18.456866][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 18.456872][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 18.456875][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 18.456878][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 18.456884][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 18.456892][ C3] __put_net (net/core/net_namespace.c:732) 
[ 18.456897][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 18.456900][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.456904][ C3] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.456907][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 18.456911][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 18.456915][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 18.456918][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 18.456922][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 18.456926][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 18.456930][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 18.456934][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 18.456937][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 18.456939][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   18.456942][    C3]  </IRQ>
[   18.456943][    C3]  <TASK>
[ 18.456945][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 18.456947][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 18.456951][ C3] Code: b0 b8 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 d0 13 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:	b0 b8                	mov    $0xb8,%al
   2:	00 c3                	add    %al,%bl
   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 a3 d0 13 00 	verw   0x13d0a3(%rip)        # 0x13d0cb
  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
[   18.456954][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   18.456958][    C3] RAX: 000000000005192b RBX: 1ffff9200002afc1 RCX: ffffffff8d555a19
[   18.456960][    C3] RDX: 0000000000000000 RSI: ffffffff8e085f31 RDI: ffffffff8d850ce0
[   18.456962][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   18.456963][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   18.456965][    C3] R13: ffff888001bb4640 R14: dffffc0000000000 R15: 0000000000000000
[ 18.456969][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 18.456974][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 18.456976][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 18.456979][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 18.456982][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 18.456986][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 18.456991][ C3] do_idle (kernel/sched/idle.c:325) 
[ 18.456995][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 18.456999][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 18.457002][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 18.457007][ C3] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   18.472895][    C3] RCU nest depth: 0, expected: 0
| [   18.473173][    C3] INFO: lockdep is turned off.
| [   18.473339][    C3] Preemption disabled at:
| [ 18.473340][ C3] 0x0 
[   18.473647][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   18.473648][    C3] Call Trace:
[   18.473650][    C3]  <IRQ>
[ 18.473652][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 18.473658][ C3] __might_resched (kernel/sched/core.c:8819) 
[ 18.473664][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 18.473668][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 18.473670][ C3] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 18.473674][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 18.473679][ 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) 
[ 18.473684][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 18.473687][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 18.473691][ 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) 
[ 18.473695][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 18.473698][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 18.473702][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 18.473705][ 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:2333) 
[ 18.473710][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.473714][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 18.473716][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 18.473720][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 18.473724][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 18.473727][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 18.473730][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 18.473732][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 18.473734][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 18.473738][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 18.473741][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 18.473744][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 18.473748][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 18.473754][ C3] __put_net (net/core/net_namespace.c:732) 
[ 18.473757][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 18.473761][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.473764][ C3] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 18.473767][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 18.473772][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 18.473775][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 18.473779][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 18.473783][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 18.473788][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 18.473791][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 18.473795][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 18.473798][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 18.473800][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   18.473803][    C3]  </IRQ>
[   18.473804][    C3]  <TASK>
[ 18.473806][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 18.473808][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 18.473812][ C3] Code: b0 b8 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 d0 13 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:	b0 b8                	mov    $0xb8,%al
   2:	00 c3                	add    %al,%bl
   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 a3 d0 13 00 	verw   0x13d0a3(%rip)        # 0x13d0cb
  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
[   18.473815][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   18.473818][    C3] RAX: 000000000005192b RBX: 1ffff9200002afc1 RCX: ffffffff8d555a19
[   18.473820][    C3] RDX: 0000000000000000 RSI: ffffffff8e085f31 RDI: ffffffff8d850ce0
[   18.473822][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   18.473823][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   18.473825][    C3] R13: ffff888001bb4640 R14: dffffc0000000000 R15: 0000000000000000
[ 18.473829][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 18.473834][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 18.473836][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 18.473839][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 18.473842][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 18.473846][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 18.473851][ C3] do_idle (kernel/sched/idle.c:325) 
[ 18.473855][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 18.473859][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 18.473862][ C3] ? __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