======================================
| [   13.803252][    C3] 1 lock held by swapper/3/0:
| [ 13.803441][ C3] #0: ffffffffac1749c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   13.803781][    C3]
| [   13.803781][    C3] stack backtrace:
[   13.804017][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.804019][    C3] Call Trace:
[   13.804021][    C3]  <IRQ>
[ 13.804023][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.804029][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 13.804033][ C3] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 13.804038][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 13.804042][ C3] ? save_trace (kernel/locking/lockdep.c:594) 
[ 13.804048][ C3] mark_lock (kernel/locking/lockdep.c:4754) 
[ 13.804051][ C3] mark_usage (kernel/locking/lockdep.c:4643) 
[ 13.804054][ C3] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 13.804059][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 13.804062][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.804065][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.804068][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 13.804071][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.804074][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 13.804077][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.804080][ C3] simple_pin_fs (fs/libfs.c:1066) 
[ 13.804083][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 13.804086][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.804092][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.804095][ 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) 
[ 13.804101][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.804104][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.804107][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 13.804110][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 13.804114][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.804117][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 13.804121][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 13.804123][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.804125][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.804128][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 13.804130][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.804133][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.804136][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 13.804142][ C3] __put_net (net/core/net_namespace.c:732) 
[ 13.804146][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 13.804150][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.804154][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.804158][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 13.804162][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.804167][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.804170][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.804173][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 13.804178][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.804181][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 13.804186][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 13.804189][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 13.804192][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   13.804195][    C3]  </IRQ>
[   13.804196][    C3]  <TASK>
[ 13.804198][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.804200][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 13.804204][ 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
[   13.804207][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000242
[   13.804210][    C3] RAX: 0000000000038b07 RBX: 1ffff9200002afc1 RCX: ffffffffab16ea19
[   13.804212][    C3] RDX: 0000000000000000 RSI: ffffffffabc89a45 RDI: ffffffffab4513a0
[   13.804214][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   13.804216][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   13.804217][    C3] R13: ffff888001bf4640 R14: dffffc0000000000 R15: 0000000000000000
[ 13.804221][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 13.804227][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 13.804229][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.804232][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.804235][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 13.804238][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 13.804242][ C3] do_idle (kernel/sched/idle.c:325) 
[ 13.804246][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.804248][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.804251][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 13.804255][ C3] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   13.820747][    C3] RCU nest depth: 0, expected: 0
| [   13.820921][    C3] INFO: lockdep is turned off.
| [   13.821095][    C3] Preemption disabled at:
| [ 13.821096][ C3] 0x0 
[   13.821411][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.821413][    C3] Call Trace:
[   13.821414][    C3]  <IRQ>
[ 13.821416][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.821423][ C3] __might_resched (kernel/sched/core.c:8819) 
[ 13.821429][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 13.821433][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 13.821435][ C3] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 13.821440][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.821443][ 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) 
[ 13.821449][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 13.821452][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 13.821456][ 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) 
[ 13.821460][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 13.821464][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.821469][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.821472][ 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) 
[ 13.821476][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.821480][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.821484][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 13.821487][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 13.821491][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.821493][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 13.821496][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 13.821498][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.821501][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.821503][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 13.821505][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.821507][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.821510][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 13.821515][ C3] __put_net (net/core/net_namespace.c:732) 
[ 13.821518][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 13.821522][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.821525][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.821529][ C3] ? find_held_lock (kernel/locking/lockdep.c:5348) 
[ 13.821534][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.821538][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.821542][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.821545][ C3] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 13.821550][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.821553][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 13.821558][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 13.821561][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 13.821564][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   13.821567][    C3]  </IRQ>
[   13.821568][    C3]  <TASK>
[ 13.821570][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.821573][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 13.821576][ 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
[   13.821579][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000242
[   13.821582][    C3] RAX: 0000000000038b07 RBX: 1ffff9200002afc1 RCX: ffffffffab16ea19
[   13.821584][    C3] RDX: 0000000000000000 RSI: ffffffffabc89a45 RDI: ffffffffab4513a0
[   13.821586][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3667a
[   13.821588][    C3] R10: ffff8880361b33d3 R11: 0000000000000000 R12: 0000000000000000
[   13.821590][    C3] R13: ffff888001bf4640 R14: dffffc0000000000 R15: 0000000000000000
[ 13.821594][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 13.821599][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 13.821601][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.821604][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.821607][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 13.821610][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 13.821614][ C3] do_idle (kernel/sched/idle.c:325) 
[ 13.821618][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.821620][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.821623][ 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