======================================
| [ 14.462907][ C3] #3: ffffc9000007b380 (&ldata->output_lock){+.+.}-{4:4}, at: process_output_block (drivers/tty/n_tty.c:519) 
| [ 14.463297][ C3] #4: ffffffff91b774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   14.463641][    C3]
| [   14.463641][    C3] stack backtrace:
[   14.463888][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.463891][    C3] Call Trace:
[   14.463893][    C3]  <IRQ>
[ 14.463894][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.463900][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 14.463905][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 14.463909][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 14.463914][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 14.463919][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 14.463923][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 14.463926][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 14.463929][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 14.463933][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 14.463936][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 14.463940][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 14.463944][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 14.463947][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 14.463952][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 14.463955][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 14.463958][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 14.463962][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 14.463965][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 14.463971][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 14.463975][ 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) 
[ 14.463981][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.463983][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 14.463987][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 14.463989][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 14.463994][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.463998][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.464001][ C3] ? uart_write (drivers/tty/serial/serial_core.c:74 drivers/tty/serial/serial_core.c:636) 
[ 14.464006][ C3] ? process_output_block (drivers/tty/n_tty.c:561) 
[ 14.464008][ C3] ? n_tty_write (drivers/tty/n_tty.c:2378) 
[ 14.464011][ C3] ? iterate_tty_write (drivers/tty/tty_io.c:1015) 
[ 14.464014][ C3] ? file_tty_write.constprop.0 (drivers/tty/tty_io.c:1090) 
[ 14.464017][ C3] ? vfs_write (fs/read_write.c:594 fs/read_write.c:686) 
[ 14.464022][ C3] ? ksys_write (fs/read_write.c:738) 
[ 14.464027][ C3] __put_net (net/core/net_namespace.c:732) 
[ 14.464031][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 14.464035][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.464037][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.464041][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 14.464045][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 14.464048][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 14.464051][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 14.464054][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 14.464058][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 14.464062][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 14.464067][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 14.464070][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 14.464073][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   14.464077][    C3]  </IRQ>
[   14.464078][    C3]  <TASK>
[ 14.464079][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.464082][ C3] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.464086][ C3] Code: 74 24 10 e8 c1 1e 83 fd 48 89 ef e8 79 71 83 fd 81 e3 00 02 00 00 75 29 9c 58 f6 c4 02 75 35 48 85 db 74 01 fb bf 01 00 00 00 <e8> fa 6e 77 fd 65 8b 05 13 6d 97 02 85 c0 74 0e 5b 5d c3 cc cc cc
All code
========
   0:	74 24                	je     0x26
   2:	10 e8                	adc    %ch,%al
   4:	c1 1e 83             	rcrl   $0x83,(%rsi)
   7:	fd                   	std
   8:	48 89 ef             	mov    %rbp,%rdi
   b:	e8 79 71 83 fd       	call   0xfffffffffd837189
  10:	81 e3 00 02 00 00    	and    $0x200,%ebx
  16:	75 29                	jne    0x41
  18:	9c                   	pushf
  19:	58                   	pop    %rax
  1a:	f6 c4 02             	test   $0x2,%ah
  1d:	75 35                	jne    0x54
  1f:	48 85 db             	test   %rbx,%rbx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
  2a:*	e8 fa 6e 77 fd       	call   0xfffffffffd776f29		<-- trapping instruction
  2f:	65 8b 05 13 6d 97 02 	mov    %gs:0x2976d13(%rip),%eax        # 0x2976d49
  36:	85 c0                	test   %eax,%eax
  38:	74 0e                	je     0x48
  3a:	5b                   	pop    %rbx
  3b:	5d                   	pop    %rbp
  3c:	c3                   	ret
  3d:	cc                   	int3
  3e:	cc                   	int3
  3f:	cc                   	int3

Code starting with the faulting instruction
===========================================
   0:	e8 fa 6e 77 fd       	call   0xfffffffffd776eff
   5:	65 8b 05 13 6d 97 02 	mov    %gs:0x2976d13(%rip),%eax        # 0x2976d1f
   c:	85 c0                	test   %eax,%eax
   e:	74 0e                	je     0x1e
  10:	5b                   	pop    %rbx
  11:	5d                   	pop    %rbp
  12:	c3                   	ret
  13:	cc                   	int3
  14:	cc                   	int3
  15:	cc                   	int3
[   14.464089][    C3] RSP: 0018:ffffc90000a37aa0 EFLAGS: 00000206
[   14.464092][    C3] RAX: 0000000000000006 RBX: 0000000000000200 RCX: 0000000000000040
[   14.464094][    C3] RDX: 0000000000000000 RSI: ffffffff9168f4e4 RDI: 0000000000000001
[   14.464096][    C3] RBP: ffffffff9457bf00 R08: 0000000000000001 R09: 0000000000000001
[   14.464097][    C3] R10: ffffffff925e68d7 R11: ffff888006248970 R12: 00000000ffffffff
[   14.464099][    C3] R13: 0000000000000001 R14: ffffffff9457c008 R15: 00000000ffffffff
[ 14.464105][ C3] uart_write (drivers/tty/serial/serial_core.c:74 drivers/tty/serial/serial_core.c:636) 
[ 14.464110][ C3] process_output_block (drivers/tty/n_tty.c:561) 
[ 14.464114][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 14.464119][ C3] n_tty_write (drivers/tty/n_tty.c:2378) 
[ 14.464124][ C3] ? __pfx_n_tty_write (drivers/tty/n_tty.c:2348) 
[ 14.464127][ C3] ? __pfx_woken_wake_function (kernel/sched/wait.c:439) 
[ 14.464132][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 14.464135][ C3] ? iterate_tty_write (drivers/tty/tty_io.c:948 drivers/tty/tty_io.c:967) 
[ 14.464140][ C3] iterate_tty_write (drivers/tty/tty_io.c:1015) 
[ 14.464145][ C3] ? tty_ldisc_ref_wait (drivers/tty/tty_ldisc.c:244) 
[ 14.464149][ C3] file_tty_write.constprop.0 (drivers/tty/tty_io.c:1090) 
[ 14.464154][ C3] vfs_write (fs/read_write.c:594 fs/read_write.c:686) 
[ 14.464159][ C3] ? __pfx_vfs_write (fs/read_write.c:667) 
[ 14.464164][ C3] ? __pfx_lock_vma_under_rcu (mm/memory.c:6547) 
[ 14.464170][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 14.464175][ C3] ksys_write (fs/read_write.c:738) 
[ 14.464178][ C3] ? __pfx_ksys_write (fs/read_write.c:728) 
[ 14.464181][ C3] ? do_user_addr_fault (./arch/x86/include/asm/atomic.h:93 ./include/linux/atomic/atomic-arch-fallback.h:949 ./include/linux/atomic/atomic-instrumented.h:401 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/mm.h:704 ./include/linux/mm.h:799 arch/x86/mm/fault.c:1338) 
[ 14.464186][ C3] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) 
[ 14.464190][ C3] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   14.464193][    C3] RIP: 0033:0x7fe92875fb77
[ 14.464197][ C3] Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
All code
========
   0:	0b 00                	or     (%rax),%eax
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b7                	jmp    0xffffffffffffffc7
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  3c:	48                   	rex.W
  3d:	89                   	.byte 0x89
  3e:	74 24                	je     0x64

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	48 89 54 24 18       	mov    %rdx,0x18(%rsp)
  12:	48                   	rex.W
  13:	89                   	.byte 0x89
  14:	74 24                	je     0x3a
[   14.464199][    C3] RSP: 002b:00007ffdbb252b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   14.464201][    C3] RAX: ffffffffffffffda RBX: 0000562013239250 RCX: 00007fe92875fb77
[   14.464203][    C3] RDX: 0000000000000001 RSI: 0000562013239250 RDI: 0000000000000001
[   14.464205][    C3] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000002000
[   14.464206][    C3] R10: 0000000000000001 R11: 0000000000000246 R12: 0000562013225600
[   14.464208][    C3] R13: 00005620132062a0 R14: 0000000000000001 R15: 0000562013225600
| [   14.484888][    C3] RCU nest depth: 0, expected: 0
| [   14.485066][    C3] INFO: lockdep is turned off.
| [   14.485246][    C3] Preemption disabled at:
| [ 14.485248][ C3] 0x0 
[   14.485693][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.485695][    C3] Call Trace:
[   14.485697][    C3]  <IRQ>
[ 14.485698][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.485705][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 14.485712][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 14.485716][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 14.485719][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 14.485723][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 14.485727][ 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) 
[ 14.485733][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 14.485736][ 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) 
[ 14.485739][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 14.485744][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 14.485747][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 14.485752][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 14.485756][ 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) 
[ 14.485760][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.485764][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 14.485767][ C3] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 14.485771][ C3] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 14.485775][ C3] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.485779][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.485783][ C3] ? uart_write (drivers/tty/serial/serial_core.c:74 drivers/tty/serial/serial_core.c:636) 
[ 14.485787][ C3] ? process_output_block (drivers/tty/n_tty.c:561) 
[ 14.485791][ C3] ? n_tty_write (drivers/tty/n_tty.c:2378) 
[ 14.485793][ C3] ? iterate_tty_write (drivers/tty/tty_io.c:1015) 
[ 14.485798][ C3] ? file_tty_write.constprop.0 (drivers/tty/tty_io.c:1090) 
[ 14.485801][ C3] ? vfs_write (fs/read_write.c:594 fs/read_write.c:686) 
[ 14.485805][ C3] ? ksys_write (fs/read_write.c:738) 
[ 14.485810][ C3] __put_net (net/core/net_namespace.c:732) 
[ 14.485813][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 14.485817][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.485820][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 14.485823][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 14.485828][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 14.485832][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 14.485835][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 14.485838][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 14.485842][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 14.485845][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 14.485851][ C3] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 14.485853][ C3] irq_exit_rcu (kernel/softirq.c:698) 
[ 14.485856][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   14.485860][    C3]  </IRQ>
[   14.485861][    C3]  <TASK>
[ 14.485862][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 14.485865][ C3] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 14.485869][ C3] Code: 74 24 10 e8 c1 1e 83 fd 48 89 ef e8 79 71 83 fd 81 e3 00 02 00 00 75 29 9c 58 f6 c4 02 75 35 48 85 db 74 01 fb bf 01 00 00 00 <e8> fa 6e 77 fd 65 8b 05 13 6d 97 02 85 c0 74 0e 5b 5d c3 cc cc cc
All code
========
   0:	74 24                	je     0x26
   2:	10 e8                	adc    %ch,%al
   4:	c1 1e 83             	rcrl   $0x83,(%rsi)
   7:	fd                   	std
   8:	48 89 ef             	mov    %rbp,%rdi
   b:	e8 79 71 83 fd       	call   0xfffffffffd837189
  10:	81 e3 00 02 00 00    	and    $0x200,%ebx
  16:	75 29                	jne    0x41
  18:	9c                   	pushf
  19:	58                   	pop    %rax
  1a:	f6 c4 02             	test   $0x2,%ah
  1d:	75 35                	jne    0x54
  1f:	48 85 db             	test   %rbx,%rbx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
  2a:*	e8 fa 6e 77 fd       	call   0xfffffffffd776f29		<-- trapping instruction
  2f:	65 8b 05 13 6d 97 02 	mov    %gs:0x2976d13(%rip),%eax        # 0x2976d49
  36:	85 c0                	test   %eax,%eax
  38:	74 0e                	je     0x48
  3a:	5b                   	pop    %rbx
  3b:	5d                   	pop    %rbp
  3c:	c3                   	ret
  3d:	cc                   	int3
  3e:	cc                   	int3
  3f:	cc                   	int3

Code starting with the faulting instruction
===========================================
   0:	e8 fa 6e 77 fd       	call   0xfffffffffd776eff
   5:	65 8b 05 13 6d 97 02 	mov    %gs:0x2976d13(%rip),%eax        # 0x2976d1f
   c:	85 c0                	test   %eax,%eax
   e:	74 0e                	je     0x1e
  10:	5b                   	pop    %rbx
  11:	5d                   	pop    %rbp
  12:	c3                   	ret
  13:	cc                   	int3
  14:	cc                   	int3
  15:	cc                   	int3
[   14.485872][    C3] RSP: 0018:ffffc90000a37aa0 EFLAGS: 00000206
[   14.485874][    C3] RAX: 0000000000000006 RBX: 0000000000000200 RCX: 0000000000000040
[   14.485877][    C3] RDX: 0000000000000000 RSI: ffffffff9168f4e4 RDI: 0000000000000001
[   14.485878][    C3] RBP: ffffffff9457bf00 R08: 0000000000000001 R09: 0000000000000001
[   14.485880][    C3] R10: ffffffff925e68d7 R11: ffff888006248970 R12: 00000000ffffffff
[   14.485882][    C3] R13: 0000000000000001 R14: ffffffff9457c008 R15: 00000000ffffffff
[ 14.485888][ C3] uart_write (drivers/tty/serial/serial_core.c:74 drivers/tty/serial/serial_core.c:636) 
[ 14.485893][ C3] process_output_block (drivers/tty/n_tty.c:561) 
[ 14.485896][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 14.485901][ C3] n_tty_write (drivers/tty/n_tty.c:2378) 
[ 14.485906][ C3] ? __pfx_n_tty_write (drivers/tty/n_tty.c:2348) 
[ 14.485910][ C3] ? __pfx_woken_wake_function (kernel/sched/wait.c:439) 
[ 14.485915][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 14.485918][ C3] ? iterate_tty_write (drivers/tty/tty_io.c:948 drivers/tty/tty_io.c:967) 
[ 14.485923][ C3] iterate_tty_write (drivers/tty/tty_io.c:1015) 
[ 14.485928][ C3] ? tty_ldisc_ref_wait (drivers/tty/tty_ldisc.c:244) 
[ 14.485933][ C3] file_tty_write.constprop.0 (drivers/tty/tty_io.c:1090) 
[ 14.485938][ C3] vfs_write (fs/read_write.c:594 fs/read_write.c:686) 
[ 14.485942][ C3] ? __pfx_vfs_write (fs/read_write.c:667) 
[ 14.485947][ C3] ? __pfx_lock_vma_under_rcu (mm/memory.c:6547) 
[ 14.485953][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 14.485958][ C3] ksys_write (fs/read_write.c:738) 
[ 14.485961][ C3] ? __pfx_ksys_write (fs/read_write.c:728) 
[ 14.485964][ C3] ? do_user_addr_fault (./arch/x86/include/asm/atomic.h:93 ./include/linux/atomic/atomic-arch-fallback.h:949 ./include/linux/atomic/atomic-instrumented.h:401 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/mm.h:704 ./include/linux/mm.h:799 arch/x86/mm/fault.c:1338) 
[ 14.485969][ C3] do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) 
[ 14.485973][ C3] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   14.485975][    C3] RIP: 0033:0x7fe92875fb77
[ 14.485981][ C3] Code: Unable to access opcode bytes at 0x7fe92875fb4d.

Code starting with the faulting instruction
===========================================
[   14.485982][    C3] RSP: 002b:00007ffdbb252b78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   14.485985][    C3] RAX: ffffffffffffffda RBX: 0000562013239250 RCX: 00007fe92875fb77
[   14.485987][    C3] RDX: 0000000000000001 RSI: 0000562013239250 RDI: 0000000000000001
[   14.485988][    C3] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000002000
[   14.485990][    C3] R10: 0000000000000001 R11: 0000000000000246 R12: 0000562013225600
[   14.485991][    C3] R13: 00005620132062a0 R14: 0000000000000001 R15: 0000562013225600
| [   16.075145][    C1] INFO: lockdep is turned off.
| [   16.075320][    C1] Preemption disabled at:
| [ 16.075322][ C1] 0x0 
| [   16.075647][    C1] Tainted: [W]=WARN
[   16.075648][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.075650][    C1] Call Trace:
[   16.075652][    C1]  <IRQ>
[ 16.075655][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 16.075663][ C1] __might_resched (kernel/sched/core.c:8796) 
[ 16.075671][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 16.075676][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 16.075679][ C1] ? simple_recursive_removal (fs/libfs.c:614) 
[ 16.075683][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 16.075688][ C1] ? 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) 
[ 16.075694][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 16.075697][ C1] ? 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) 
[ 16.075700][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 16.075705][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 16.075708][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 16.075714][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 16.075718][ C1] ? __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) 
[ 16.075723][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 16.075727][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 16.075730][ C1] ? irq_exit_rcu (kernel/softirq.c:698) 
[ 16.075736][ C1] ? sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[ 16.075741][ C1] ? asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 16.075745][ C1] ? pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 16.075748][ C1] ? default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 16.075751][ C1] ? default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 16.075753][ C1] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.075757][ C1] ? do_idle (kernel/sched/idle.c:325) 
[ 16.075759][ C1] ? cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 16.075762][ C1] ? start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 16.075765][ C1] ? common_startup_64 (arch/x86/kernel/head_64.S:419) 
[ 16.075772][ C1] ? bpf_sk_storage_free (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/bpf_sk_storage.c:61) 
[ 16.075775][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 16.075780][ C1] __put_net (net/core/net_namespace.c:732) 
[ 16.075784][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 16.075788][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 16.075790][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 16.075795][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 16.075798][ C1] ? trace_irq_enable.constprop.0 (./include/trace/events/preemptirq.h:40) 
[ 16.075804][ C1] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:104 ./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 16.075810][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 16.075814][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 16.075820][ C1] __irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680) 
[ 16.075823][ C1] irq_exit_rcu (kernel/softirq.c:698) 
[ 16.075825][ C1] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 arch/x86/kernel/apic/apic.c:1050) 
[   16.075829][    C1]  </IRQ>
[   16.075830][    C1]  <TASK>
[ 16.075831][ C1] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 16.075834][ C1] RIP: 0010:pv_native_safe_halt (arch/x86/kernel/paravirt.c:82) 
[ 16.075838][ C1] Code: 92 b5 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 37 10 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:	92                   	xchg   %eax,%edx
   1:	b5 00                	mov    $0x0,%ch
   3:	c3                   	ret
   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 83 37 10 00 	verw   0x103783(%rip)        # 0x1037ab
  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
[   16.075841][    C1] RSP: 0018:ffffc90000137de8 EFLAGS: 00000246
[   16.075845][    C1] RAX: 0000000000000001 RBX: 1ffff92000026fc1 RCX: ffffffff90b905d9
[   16.075847][    C1] RDX: ffffed1006c166fb RSI: ffffffff90e53b60 RDI: ffffffff8e38d18f
[   16.075849][    C1] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffed1006c166fa
[   16.075850][    C1] R10: ffff8880360b37d3 R11: ffff8880029f2818 R12: 0000000000000000
[   16.075852][    C1] R13: ffff888001bf0040 R14: dffffc0000000000 R15: 0000000000000000
[ 16.075856][ C1] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:146) 
[ 16.075859][ C1] ? cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.075863][ C1] default_idle (./arch/x86/include/asm/paravirt.h:107 arch/x86/kernel/process.c:743) 
[ 16.075866][ C1] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 16.075868][ C1] cpuidle_idle_call (kernel/sched/idle.c:186) 
[ 16.075872][ C1] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 16.075875][ C1] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:60) 
[ 16.075880][ C1] do_idle (kernel/sched/idle.c:325) 
[ 16.075883][ C1] cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) 
[ 16.075886][ C1] start_secondary (arch/x86/kernel/smpboot.c:203 arch/x86/kernel/smpboot.c:283) 
[ 16.075889][ C1] ? __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