======================================
| [   76.344013][    C2] 1 lock held by swapper/2/0:
| [ 76.344203][ C2] #0: ffffffffb8379b40 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   76.344541][    C2]
| [   76.344541][    C2] stack backtrace:
[   76.344779][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   76.344781][    C2] Call Trace:
[   76.344785][    C2]  <IRQ>
[ 76.344787][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 76.344796][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 76.344801][ C2] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 76.344808][ C2] mark_lock (kernel/locking/lockdep.c:4756) 
[ 76.344812][ C2] mark_usage (kernel/locking/lockdep.c:4645) 
[ 76.344815][ C2] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 76.344818][ C2] ? unwind_next_frame (./include/linux/rcupdate.h:874 ./include/linux/rcupdate.h:1155 arch/x86/kernel/unwind_orc.c:479) 
[ 76.344825][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 76.344829][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 76.344832][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 76.344836][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 76.344844][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 76.344846][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 76.344850][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 76.344853][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 76.344856][ C2] xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 76.344859][ C2] ? __pfx_xa_set_mark (lib/xarray.c:2144) 
[ 76.344861][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 76.344866][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 76.344872][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:54 lib/ref_tracker.c:223) 
[ 76.344877][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 76.344881][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:213) 
[ 76.344884][ C2] ? ref_tracker_free (lib/ref_tracker.c:281) 
[ 76.344888][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 76.344891][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:281) 
[ 76.344894][ 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:2368) 
[ 76.344904][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 76.344906][ C2] ? rcu_core (kernel/rcu/tree.c:2834) 
[ 76.344913][ C2] ? handle_softirqs (kernel/softirq.c:580) 
[ 76.344917][ C2] __put_net (./include/linux/llist.h:238 ./include/linux/llist.h:265 net/core/net_namespace.c:732) 
[ 76.344928][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 76.344936][ C2] ? __pfx___put_net (net/core/net_namespace.c:729) 
[ 76.344940][ C2] ? bpf_sk_storage_free (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/bpf_sk_storage.c:61) 
[ 76.344948][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2368) 
[ 76.344952][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 76.344954][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 76.344958][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 76.344962][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 76.344965][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 76.344969][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 76.344976][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 76.344981][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 76.344985][ C2] handle_softirqs (kernel/softirq.c:580) 
[ 76.344990][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 76.344993][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 76.344996][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   76.345000][    C2]  </IRQ>
[   76.345002][    C2]  <TASK>
[ 76.345005][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 76.345012][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 76.345017][ C2] Code: b4 cc 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 53 87 24 00 fb f4 <e9> cc 58 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
All code
========
   0:	b4 cc                	mov    $0xcc,%ah
   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 53 87 24 00 	verw   0x248753(%rip)        # 0x24877b
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	e9 cc 58 02 00       	jmp    0x258fb		<-- 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 cc 58 02 00       	jmp    0x258d1
   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
[   76.345021][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[   76.345026][    C2] RAX: 0000000000125959 RBX: 1ffff92000028fc1 RCX: ffffffffb724c3c9
[   76.345028][    C2] RDX: 0000000000000000 RSI: ffffffffb7ebc1ba RDI: ffffffffb765f220
[   76.345030][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c26702
[   76.345032][    C2] R10: ffff888036133813 R11: ffffffffb8011288 R12: 0000000000000000
[   76.345034][    C2] R13: ffff888001bfa340 R14: dffffc0000000000 R15: 0000000000000000
[ 76.345038][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 76.345044][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 76.345047][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 76.345050][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 76.345053][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 76.345057][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 76.345062][ C2] do_idle (kernel/sched/idle.c:325) 
[ 76.345065][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 76.345068][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 76.345071][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock