======================================
| [ 1884.477680][    C2] 1 lock held by swapper/2/0:
| [ 1884.477876][ C2] #0: ffffffffacd8d440 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [ 1884.478243][    C2]
| [ 1884.478243][    C2] stack backtrace:
[ 1884.478515][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1884.478519][    C2] Call Trace:
[ 1884.478524][    C2]  <IRQ>
[ 1884.478529][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 1884.478543][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 1884.478551][ C2] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 1884.478558][ C2] mark_lock (kernel/locking/lockdep.c:4756) 
[ 1884.478562][ C2] mark_usage (kernel/locking/lockdep.c:4645) 
[ 1884.478566][ C2] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 1884.478569][ C2] ? unwind_next_frame (./include/linux/rcupdate.h:874 ./include/linux/rcupdate.h:1155 arch/x86/kernel/unwind_orc.c:479) 
[ 1884.478581][ C2] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 1884.478588][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 1884.478592][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 1884.478598][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 1884.478605][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 1884.478608][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 1884.478613][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 1884.478617][ C2] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 1884.478621][ C2] xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 1884.478624][ C2] ? __pfx_xa_set_mark (lib/xarray.c:2144) 
[ 1884.478628][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 1884.478633][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 1884.478637][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:54 lib/ref_tracker.c:223) 
[ 1884.478643][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 1884.478646][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:213) 
[ 1884.478649][ C2] ? ref_tracker_free (lib/ref_tracker.c:281) 
[ 1884.478652][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 1884.478655][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:281) 
[ 1884.478657][ 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) 
[ 1884.478675][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 1884.478678][ C2] ? rcu_core (kernel/rcu/tree.c:2834) 
[ 1884.478682][ C2] ? handle_softirqs (kernel/softirq.c:579) 
[ 1884.478688][ C2] __put_net (./include/linux/llist.h:238 ./include/linux/llist.h:265 net/core/net_namespace.c:732) 
[ 1884.478694][ C2] ? do_idle (kernel/sched/idle.c:325) 
[ 1884.478702][ C2] ? __pfx___put_net (net/core/net_namespace.c:729) 
[ 1884.478706][ C2] ? bpf_sk_storage_free (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/bpf_sk_storage.c:61) 
[ 1884.478717][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2368) 
[ 1884.478721][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 1884.478724][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 1884.478728][ C2] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 1884.478731][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 1884.478735][ C2] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 1884.478738][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 1884.478743][ C2] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 1884.478747][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 1884.478751][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 1884.478757][ C2] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 1884.478760][ C2] irq_exit_rcu (kernel/softirq.c:698) 
[ 1884.478763][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 1884.478767][    C2]  </IRQ>
[ 1884.478768][    C2]  <TASK>
[ 1884.478769][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 1884.478781][ C2] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 1884.478785][ C2] Code: 54 ce 00 e9 d3 58 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 33 07 1f 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:	54                   	push   %rsp
   1:	ce                   	(bad)
   2:	00 e9                	add    %ch,%cl
   4:	d3 58 02             	rcrl   %cl,0x2(%rax)
   7:	00 0f                	add    %cl,(%rdi)
   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 33 07 1f 00 	verw   0x1f0733(%rip)        # 0x1f075b
  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
[ 1884.478787][    C2] RSP: 0018:ffffc90000147de8 EFLAGS: 00000246
[ 1884.478794][    C2] RAX: 00000000012e852d RBX: 1ffff92000028fc1 RCX: ffffffffab6a43e9
[ 1884.478797][    C2] RDX: 0000000000000000 RSI: ffffffffac32ba5f RDI: ffffffffaba5cf00
[ 1884.478799][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d9e6702
[ 1884.478801][    C2] R10: ffff88806cf33813 R11: ffffffffaca11288 R12: 0000000000000000
[ 1884.478803][    C2] R13: ffff888001b62300 R14: dffffc0000000000 R15: 0000000000000000
[ 1884.478807][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 1884.478812][ C2] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 1884.478815][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 1884.478819][ C2] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 1884.478823][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 1884.478827][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 1884.478832][ C2] do_idle (kernel/sched/idle.c:325) 
[ 1884.478835][ C2] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 1884.478839][ C2] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 1884.478842][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:233) 


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