======================================
| [   12.863179][    C2] 1 lock held by swapper/2/0:
| [ 12.863362][ C2] #0: ffffffff9fb74480 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   12.863688][    C2]
| [   12.863688][    C2] stack backtrace:
[   12.863936][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.863938][    C2] Call Trace:
[   12.863939][    C2]  <IRQ>
[ 12.863942][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.863948][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 12.863952][ C2] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 12.863956][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.863960][ C2] ? save_trace (kernel/locking/lockdep.c:594) 
[ 12.863965][ C2] mark_lock (kernel/locking/lockdep.c:4754) 
[ 12.863968][ C2] mark_usage (kernel/locking/lockdep.c:4643) 
[ 12.863971][ C2] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 12.863976][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 12.863978][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 12.863981][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 12.863984][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 12.863987][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 12.863990][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.863993][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 12.863995][ C2] simple_pin_fs (fs/libfs.c:1066) 
[ 12.863998][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.864002][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 12.864008][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.864011][ 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:2333) 
[ 12.864016][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.864020][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.864023][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.864026][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 12.864029][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.864033][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 12.864036][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 12.864039][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.864041][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.864045][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 12.864047][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.864049][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.864061][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.864067][ C2] __put_net (net/core/net_namespace.c:732) 
[ 12.864071][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 12.864075][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.864078][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.864083][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 12.864087][ C2] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 12.864090][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 12.864093][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.864097][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 12.864101][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 12.864106][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.864108][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.864111][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   12.864114][    C2]  </IRQ>
[   12.864115][    C2]  <TASK>
[ 12.864116][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.864119][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 12.864123][ C2] Code: a0 b7 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 a0 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:	a0 b7 00 c3 cc cc cc 	movabs 0xfccccccccc300b7,%al
   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 a3 a0 12 00 	verw   0x12a0a3(%rip)        # 0x12a0cb
  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
[   12.864126][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   12.864130][    C2] RAX: 00000000000354c9 RBX: 1ffff92000028fc1 RCX: ffffffff9eb68a19
[   12.864132][    C2] RDX: 0000000000000000 RSI: ffffffff9f6881e1 RDI: ffffffff9ee50e20
[   12.864134][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2667a
[   12.864135][    C2] R10: ffff8880361333d3 R11: 0000000000000000 R12: 0000000000000000
[   12.864137][    C2] R13: ffff888001bb2340 R14: dffffc0000000000 R15: 0000000000000000
[ 12.864141][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.864146][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 12.864150][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.864152][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.864154][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.864158][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 12.864162][ C2] do_idle (kernel/sched/idle.c:325) 
[ 12.864165][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.864168][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.864170][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 
[ 12.864174][ C2] common_startup_64 (arch/x86/kernel/head_64.S:419) 
| [   12.881636][    C2] RCU nest depth: 0, expected: 0
| [   12.881836][    C2] INFO: lockdep is turned off.
| [   12.882045][    C2] Preemption disabled at:
| [ 12.882047][ C2] 0x0 
[   12.882423][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.882425][    C2] Call Trace:
[   12.882427][    C2]  <IRQ>
[ 12.882429][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.882437][ C2] __might_resched (kernel/sched/core.c:8819) 
[ 12.882445][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.882448][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.882451][ C2] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 12.882456][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 12.882461][ 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) 
[ 12.882466][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 12.882469][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.882474][ 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) 
[ 12.882478][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.882481][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 12.882487][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.882490][ 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:2333) 
[ 12.882495][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.882500][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.882503][ C2] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 12.882507][ C2] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[ 12.882512][ C2] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.882515][ C2] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 12.882518][ C2] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 12.882522][ C2] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.882524][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.882527][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 12.882529][ C2] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.882531][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.882534][ C2] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 12.882540][ C2] __put_net (net/core/net_namespace.c:732) 
[ 12.882544][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 12.882548][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.882552][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 12.882557][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 12.882561][ C2] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 12.882564][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 12.882566][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.882572][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 12.882575][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 12.882580][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 12.882583][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 12.882585][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049) 
[   12.882588][    C2]  </IRQ>
[   12.882589][    C2]  <TASK>
[ 12.882591][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 12.882593][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:81) 
[ 12.882597][ C2] Code: a0 b7 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 a0 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:	a0 b7 00 c3 cc cc cc 	movabs 0xfccccccccc300b7,%al
   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 a3 a0 12 00 	verw   0x12a0a3(%rip)        # 0x12a0cb
  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
[   12.882600][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   12.882603][    C2] RAX: 00000000000354c9 RBX: 1ffff92000028fc1 RCX: ffffffff9eb68a19
[   12.882605][    C2] RDX: 0000000000000000 RSI: ffffffff9f6881e1 RDI: ffffffff9ee50e20
[   12.882607][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2667a
[   12.882608][    C2] R10: ffff8880361333d3 R11: 0000000000000000 R12: 0000000000000000
[   12.882610][    C2] R13: ffff888001bb2340 R14: dffffc0000000000 R15: 0000000000000000
[ 12.882614][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 12.882619][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:748) 
[ 12.882623][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 12.882625][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 12.882628][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 12.882631][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 12.882635][ C2] do_idle (kernel/sched/idle.c:325) 
[ 12.882638][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 12.882641][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 12.882643][ C2] ? __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