======================================
| [   13.726434][    C3] 1 lock held by swapper/3/0:
| [ 13.726664][ C3] #0: ffffffff8cd774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   13.727052][    C3]
| [   13.727052][    C3] stack backtrace:
[   13.727344][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.727347][    C3] Call Trace:
[   13.727349][    C3]  <IRQ>
[ 13.727351][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.727361][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 13.727370][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 13.727378][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 13.727385][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 13.727389][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 13.727393][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 13.727396][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 13.727400][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 13.727407][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 13.727412][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 13.727419][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.727425][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 13.727428][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 13.727432][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 13.727435][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 13.727438][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 13.727441][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 13.727445][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 13.727453][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.727458][ 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) 
[ 13.727467][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.727470][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.727472][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 13.727476][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 13.727481][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.727485][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 13.727489][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 13.727493][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.727497][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.727504][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 13.727509][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.727511][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.727517][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 13.727524][ C3] __put_net (net/core/net_namespace.c:732) 
[ 13.727529][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 13.727533][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.727537][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.727546][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 13.727552][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 13.727557][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.727561][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.727565][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 13.727570][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 13.727575][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 13.727580][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 13.727585][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   13.727590][    C3]  </IRQ>
[   13.727592][    C3]  <TASK>
[ 13.727595][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.727600][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 13.727604][ C3] Code: a2 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 17 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:	a2 b4 00 c3 cc cc cc 	movabs %al,0xfccccccccc300b4
   7:	cc 0f 
   9:	1f                   	(bad)
   a:	00 90 90 90 90 90    	add    %dl,-0x6f6f6f70(%rax)
  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 17 0f 00 	verw   0xf1783(%rip)        # 0xf17ab
  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
[   13.727606][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   13.727610][    C3] RAX: 0000000000037d21 RBX: 1ffff9200002afc1 RCX: ffffffff8bda25d9
[   13.727612][    C3] RDX: 0000000000000000 RSI: ffffffff8c89175c RDI: ffffffff8c053ca0
[   13.727614][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1005eb66fa
[   13.727615][    C3] R10: ffff88802f5b37d3 R11: ffffffff8ca11288 R12: 0000000000000000
[   13.727617][    C3] R13: ffff888001bf45c0 R14: dffffc0000000000 R15: 0000000000000000
[ 13.727623][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 13.727631][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 13.727635][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.727640][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.727644][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 13.727648][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 13.727653][ C3] do_idle (kernel/sched/idle.c:325) 
[ 13.727657][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.727660][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.727665][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 13.727673][ C3] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   13.745780][    C3] RCU nest depth: 0, expected: 0
| [   13.745959][    C3] INFO: lockdep is turned off.
| [   13.746130][    C3] Preemption disabled at:
| [ 13.746132][ C3] 0x0 
[   13.746451][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.746453][    C3] Call Trace:
[   13.746455][    C3]  <IRQ>
[ 13.746457][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.746465][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 13.746475][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 13.746479][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 13.746482][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 13.746487][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.746493][ 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) 
[ 13.746497][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 13.746500][ 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) 
[ 13.746502][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 13.746508][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 13.746511][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 13.746516][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.746519][ 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) 
[ 13.746524][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.746527][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.746530][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 13.746535][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 13.746539][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.746543][ C3] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 13.746546][ C3] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 13.746549][ C3] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.746551][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.746556][ C3] ? do_idle (kernel/sched/idle.c:325) 
[ 13.746558][ C3] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.746561][ C3] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.746565][ C3] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 13.746572][ C3] __put_net (net/core/net_namespace.c:732) 
[ 13.746576][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 13.746580][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.746583][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.746588][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 13.746592][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 13.746597][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.746600][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.746606][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 13.746611][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 13.746616][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 13.746620][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 13.746623][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   13.746627][    C3]  </IRQ>
[   13.746628][    C3]  <TASK>
[ 13.746630][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 13.746632][ C3] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 13.746636][ C3] Code: a2 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 17 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:	a2 b4 00 c3 cc cc cc 	movabs %al,0xfccccccccc300b4
   7:	cc 0f 
   9:	1f                   	(bad)
   a:	00 90 90 90 90 90    	add    %dl,-0x6f6f6f70(%rax)
  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 17 0f 00 	verw   0xf1783(%rip)        # 0xf17ab
  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
[   13.746639][    C3] RSP: 0018:ffffc90000157de8 EFLAGS: 00000246
[   13.746642][    C3] RAX: 0000000000037d21 RBX: 1ffff9200002afc1 RCX: ffffffff8bda25d9
[   13.746644][    C3] RDX: 0000000000000000 RSI: ffffffff8c89175c RDI: ffffffff8c053ca0
[   13.746646][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1005eb66fa
[   13.746648][    C3] R10: ffff88802f5b37d3 R11: ffffffff8ca11288 R12: 0000000000000000
[   13.746650][    C3] R13: ffff888001bf45c0 R14: dffffc0000000000 R15: 0000000000000000
[ 13.746653][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 13.746658][ C3] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 13.746660][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 13.746663][ C3] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 13.746666][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 13.746670][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 13.746675][ C3] do_idle (kernel/sched/idle.c:325) 
[ 13.746679][ C3] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 13.746682][ C3] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 13.746685][ 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