======================================
| [   10.364506][  T179] softirqs last disabled at (31905): __irq_exit_rcu (kernel/softirq.c:679 kernel/softirq.c:519 kernel/softirq.c:767)
| [   10.364509][  T179] Preemption disabled at:
| [   10.364510][  T179] vprintk_emit (kernel/printk/printk.c:2471)
| [   10.364519][  T179] Tainted: [W]=WARN
[   10.364520][  T179] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   10.364521][  T179] Call Trace:
[   10.364523][  T179]  <TASK>
[   10.364525][  T179]  dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
[   10.364530][  T179]  ? vprintk_emit (kernel/printk/printk.c:2471)
[   10.364532][  T179]  __might_resched.cold (kernel/sched/core.c:9234)
[   10.364536][  T179]  ? perf_trace_sched_switch (./include/linux/list.h:1037 (discriminator 3))
[   10.364540][  T179]  ? __kmalloc_noprof (./include/linux/sched/mm.h:317 mm/slub.c:4636 mm/slub.c:4974 mm/slub.c:5413 mm/slub.c:5439)
[   10.364546][  T179]  __kmalloc_noprof (./include/linux/sched/mm.h:322 (discriminator 2) mm/slub.c:4636 (discriminator 2) mm/slub.c:4974 (discriminator 2) mm/slub.c:5413 (discriminator 2) mm/slub.c:5439 (discriminator 2))
[   10.364548][  T179]  ? alloc_buf.isra.0 (./include/linux/slab.h:995 drivers/char/virtio_console.c:429)
[   10.364555][  T179]  ? do_raw_spin_unlock (./include/linux/instrumented.h:82 ./include/linux/atomic/atomic-instrumented.h:32 ./include/asm-generic/qspinlock.h:58 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141)
[   10.364557][  T179]  alloc_buf.isra.0 (./include/linux/slab.h:995 drivers/char/virtio_console.c:429)
[   10.364561][  T179]  put_chars (drivers/char/virtio_console.c:1176)
[   10.364564][  T179]  ? __send_to_port (drivers/char/virtio_console.c:654)
[   10.364567][  T179]  ? validate_chain (kernel/locking/lockdep.c:3817 (discriminator 2) kernel/locking/lockdep.c:3837 (discriminator 2) kernel/locking/lockdep.c:3892 (discriminator 2))
[   10.364573][  T179]  hvc_console_print (drivers/tty/hvc/hvc_console.c:177 (discriminator 2))
[   10.364581][  T179]  ? hvc_write (drivers/tty/hvc/hvc_console.c:501)
[   10.364583][  T179]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   10.364587][  T179]  ? lock_acquire (./include/trace/events/lock.h:23 (discriminator 22) kernel/locking/lockdep.c:5871 (discriminator 22))
[   10.364591][  T179]  console_emit_next_record (kernel/printk/printk.c:3183)
[   10.364595][  T179]  ? devkmsg_read (./arch/x86/include/asm/atomic64_64.h:20)
[   10.364599][  T179]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   10.364601][  T179]  ? lock_acquire (./include/trace/events/lock.h:23 (discriminator 22) kernel/locking/lockdep.c:5871 (discriminator 22))
[   10.364605][  T179]  console_flush_one_record (kernel/printk/printk.c:3268)
[   10.364609][  T179]  ? console_emit_next_record (kernel/printk/printk.c:3150)
[   10.364610][  T179]  ? __lock_acquire (kernel/locking/lockdep.c:5254)
[   10.364620][  T179]  console_unlock (kernel/printk/printk.c:3350 kernel/printk/printk.c:3380 kernel/printk/printk.c:3420)
[   10.364623][  T179]  ? console_flush_one_record (kernel/printk/printk.c:3316)
[   10.364624][  T179]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   10.364626][  T179]  ? lock_acquire (kernel/locking/lockdep.c:5913)
[   10.364630][  T179]  ? __down_trylock_console_sem (kernel/printk/printk.c:334)
[   10.364632][  T179]  ? vprintk_emit (kernel/printk/printk.c:2478)
[   10.364635][  T179]  vprintk_emit (kernel/printk/printk.c:2479)
[   10.364639][  T179]  ? wake_up_klogd_work_func (kernel/printk/printk.c:4603 (discriminator 126))
[   10.364640][  T179]  ? find_held_lock (kernel/locking/lockdep.c:5367)
[   10.364643][  T179]  ? __lock_release.isra.0 (kernel/locking/lockdep.c:5554)
[   10.364645][  T179]  ? fast_dput (./include/linux/rcupdate.h:319 (discriminator 2) ./include/linux/rcupdate.h:880 (discriminator 2) fs/dcache.c:948 (discriminator 2))
[   10.364650][  T179]  ? cleanup_netconsole (./include/linux/list.h:99 (discriminator 2) ./include/linux/list.h:169 (discriminator 2) ./include/linux/list.h:206 (discriminator 2) ./include/linux/configfs.h:112 (discriminator 2) drivers/net/netconsole.c:1718 (discriminator 2)) netconsole
[   10.364654][  T179]  _printk (kernel/printk/printk.c:2504)
[   10.364657][  T179]  ? snapshot_read.cold (user.c:?)
[   10.364660][  T179]  ? __up_write (kernel/locking/rwsem.c:1422 (discriminator 1))
[   10.364663][  T179]  ? cleanup_netconsole (./include/linux/list.h:99 (discriminator 2) ./include/linux/list.h:169 (discriminator 2) ./include/linux/list.h:206 (discriminator 2) ./include/linux/configfs.h:112 (discriminator 2) drivers/net/netconsole.c:1718 (discriminator 2)) netconsole
[   10.364667][  T179]  ? configfs_register_subsystem (./include/linux/instrumented.h:112 ./include/linux/atomic/atomic-instrumented.h:1383 fs/configfs/dir.c:173 fs/configfs/dir.c:171 fs/configfs/dir.c:1929)
[   10.364672][  T179] init_netconsole (drivers/net/netconsole.c:1286) netconsole
[   10.364675][  T179]  ? cleanup_netconsole (./include/linux/list.h:99 (discriminator 2) ./include/linux/list.h:169 (discriminator 2) ./include/linux/list.h:206 (discriminator 2) ./include/linux/configfs.h:112 (discriminator 2) drivers/net/netconsole.c:1718 (discriminator 2)) netconsole
[   10.364682][  T179]  ? cleanup_netconsole (./include/linux/list.h:99 (discriminator 2) ./include/linux/list.h:169 (discriminator 2) ./include/linux/list.h:206 (discriminator 2) ./include/linux/configfs.h:112 (discriminator 2) drivers/net/netconsole.c:1718 (discriminator 2)) netconsole
[   10.364684][  T179]  do_one_initcall (init/main.c:1357)
[   10.364687][  T179]  ? trace_event_raw_event_initcall_level (./include/trace/events/initcall.h:10)
[   10.364692][  T179]  ? do_init_module (./include/linux/slab.h:991 (discriminator 1) kernel/module/main.c:3105 (discriminator 1))
[   10.364695][  T179]  ? kasan_unpoison (mm/kasan/shadow.c:146 mm/kasan/shadow.c:178)
[   10.364700][  T179]  do_init_module (kernel/module/main.c:3117)
[   10.364703][  T179]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4488)
[   10.364707][  T179]  ? free_module (./include/trace/events/module.h:50 (discriminator 19))
[   10.364710][  T179]  ? kfree (./include/linux/kasan.h:235 mm/slub.c:2748 mm/slub.c:6499 mm/slub.c:6792)
[   10.364715][  T179]  load_module (kernel/module/main.c:3593)
[   10.364721][  T179]  ? layout_and_allocate.isra.0 (kernel/module/main.c:3016)
[   10.364725][  T179]  ? __ia32_sys_fsconfig (??:?)
[   10.364727][  T179]  ? ovl_real_file (fs/overlayfs/file.c:195)
[   10.364731][  T179]  ? backing_file_read_iter (fs/backing-file.c:211)
[   10.364735][  T179]  ? rcu_lockdep_current_cpu_online (kernel/rcu/tree.c:4116 (discriminator 3) kernel/rcu/tree.c:4108 (discriminator 3))
[   10.364738][  T179]  init_module_from_file (kernel/module/main.c:3790)
[   10.364741][  T179]  ? __do_sys_init_module (kernel/module/main.c:3664)
[   10.364748][  T179]  ? __rwlock_init (kernel/locking/spinlock_debug.c:48)
[   10.364751][  T179]  ? do_raw_spin_unlock (./include/linux/instrumented.h:82 ./include/linux/atomic/atomic-instrumented.h:32 ./include/asm-generic/qspinlock.h:58 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141)
[   10.364754][  T179]  idempotent_init_module (kernel/module/main.c:3802)
[   10.364757][  T179]  ? init_module_from_file (kernel/module/main.c:3791)
[   10.364763][  T179]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   10.364765][  T179]  ? cap_capable (./include/trace/events/capability.h:26 (discriminator 22) security/commoncap.c:130 (discriminator 22))
[   10.364770][  T179]  __x64_sys_finit_module (kernel/module/main.c:3828 kernel/module/main.c:3812 kernel/module/main.c:3812)
[   10.364772][  T179]  ? trace_irq_enable.constprop.0 (./include/trace/events/preemptirq.h:40 (discriminator 22))
[   10.364776][  T179]  do_syscall_64 (arch/x86/entry/syscall_64.c:61 arch/x86/entry/syscall_64.c:84)
[   10.364777][  T179]  ? exc_page_fault (arch/x86/mm/fault.c:1489 (discriminator 3) arch/x86/mm/fault.c:1536 (discriminator 3))
[   10.364780][  T179]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[   10.364782][  T179] RIP: 0033:0x7f1dafd9737d
[   10.364785][  T179] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 4b aa 0f 00 f7 d8 64 89 01 48
All code
========
   0:	ff c3                	inc    %ebx
   2:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   9:	00 00 00 
   c:	90                   	nop
   d:	f3 0f 1e fa          	endbr64
  11:	48 89 f8             	mov    %rdi,%rax
  14:	48 89 f7             	mov    %rsi,%rdi
  17:	48 89 d6             	mov    %rdx,%rsi
  1a:	48 89 ca             	mov    %rcx,%rdx
  1d:	4d 89 c2             	mov    %r8,%r10
  20:	4d 89 c8             	mov    %r9,%r8
  23:	4c 8b 4c 24 08       	mov    0x8(%rsp),%r9
  28:	0f 05                	syscall
  2a:*	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax		<-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	ret
  33:	48 8b 0d 4b aa 0f 00 	mov    0xfaa4b(%rip),%rcx        # 0xfaa85
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W

Code starting with the faulting instruction
===========================================
   0:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax
   6:	73 01                	jae    0x9
   8:	c3                   	ret
   9:	48 8b 0d 4b aa 0f 00 	mov    0xfaa4b(%rip),%rcx        # 0xfaa5b
  10:	f7 d8                	neg    %eax
  12:	64 89 01             	mov    %eax,%fs:(%rcx)
  15:	48                   	rex.W
[   10.364787][  T179] RSP: 002b:00007fff97755148 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   10.364790][  T179] RAX: ffffffffffffffda RBX: 0000564d4a879700 RCX: 00007f1dafd9737d
[   10.364791][  T179] RDX: 0000000000000000 RSI: 0000564d31770ffd RDI: 0000000000000005
[   10.364792][  T179] RBP: 00007fff977551e0 R08: 0000000000000000 R09: 0000000000000000
[   10.364793][  T179] R10: 0000000000000000 R11: 0000000000000246 R12: 0000564d31770ffd
[   10.364793][  T179] R13: 0000564d4a879810 R14: 0000000000040000 R15: 0000000000000000
| [   14.711590][  T167] softirqs last disabled at (146914): restore_fpregs_from_user (./include/linux/bottom_half.h:20 (discriminator 2) ./arch/x86/include/asm/fpu/api.h:69 (discriminator 2) arch/x86/kernel/fpu/signal.c:277 (discriminator 2))
| [   14.711593][  T167] Preemption disabled at:
| [   14.711594][  T167] vprintk_emit (kernel/printk/printk.c:2471)
| [   14.711603][  T167] Tainted: [W]=WARN
[   14.711604][  T167] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.711606][  T167] Call Trace:
[   14.711608][  T167]  <TASK>
[   14.711609][  T167]  dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
[   14.711614][  T167]  ? vprintk_emit (kernel/printk/printk.c:2471)
[   14.711616][  T167]  __might_resched.cold (kernel/sched/core.c:9234)
[   14.711621][  T167]  ? perf_trace_sched_switch (./include/linux/list.h:1037 (discriminator 3))
[   14.711624][  T167]  ? __kmalloc_noprof (./include/linux/sched/mm.h:317 mm/slub.c:4636 mm/slub.c:4974 mm/slub.c:5413 mm/slub.c:5439)
[   14.711639][  T167]  __kmalloc_noprof (./include/linux/sched/mm.h:322 (discriminator 2) mm/slub.c:4636 (discriminator 2) mm/slub.c:4974 (discriminator 2) mm/slub.c:5413 (discriminator 2) mm/slub.c:5439 (discriminator 2))
[   14.711641][  T167]  ? alloc_buf.isra.0 (./include/linux/slab.h:995 drivers/char/virtio_console.c:429)
[   14.711648][  T167]  ? do_raw_spin_unlock (./include/linux/instrumented.h:82 ./include/linux/atomic/atomic-instrumented.h:32 ./include/asm-generic/qspinlock.h:58 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141)
[   14.711650][  T167]  alloc_buf.isra.0 (./include/linux/slab.h:995 drivers/char/virtio_console.c:429)
[   14.711653][  T167]  put_chars (drivers/char/virtio_console.c:1176)
[   14.711657][  T167]  ? __send_to_port (drivers/char/virtio_console.c:654)
[   14.711659][  T167]  ? printk_get_next_message (kernel/printk/printk.c:3072)
[   14.711662][  T167]  ? rcu_read_lock_any_held (./include/linux/lockdep.h:249 kernel/rcu/update.c:386 kernel/rcu/update.c:380)
[   14.711666][  T167]  ? validate_chain (kernel/locking/lockdep.c:3817 (discriminator 2) kernel/locking/lockdep.c:3837 (discriminator 2) kernel/locking/lockdep.c:3892 (discriminator 2))
[   14.711670][  T167]  hvc_console_print (drivers/tty/hvc/hvc_console.c:177 (discriminator 2))
[   14.711674][  T167]  ? __lock_acquire (kernel/locking/lockdep.c:5254)
[   14.711676][  T167]  ? __lock_acquire (kernel/locking/lockdep.c:5254)
[   14.711681][  T167]  ? hvc_write (drivers/tty/hvc/hvc_console.c:501)
[   14.711685][  T167]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   14.711687][  T167]  ? lock_acquire (./include/trace/events/lock.h:23 (discriminator 22) kernel/locking/lockdep.c:5871 (discriminator 22))
[   14.711691][  T167]  console_emit_next_record (kernel/printk/printk.c:3183)
[   14.711695][  T167]  ? devkmsg_read (./arch/x86/include/asm/atomic64_64.h:20)
[   14.711699][  T167]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   14.711701][  T167]  ? lock_acquire (./include/trace/events/lock.h:23 (discriminator 22) kernel/locking/lockdep.c:5871 (discriminator 22))
[   14.711705][  T167]  console_flush_one_record (kernel/printk/printk.c:3268)
[   14.711708][  T167]  ? console_emit_next_record (kernel/printk/printk.c:3150)
[   14.711710][  T167]  ? __lock_acquire (kernel/locking/lockdep.c:5254)
[   14.711715][  T167]  console_unlock (kernel/printk/printk.c:3350 kernel/printk/printk.c:3380 kernel/printk/printk.c:3420)
[   14.711718][  T167]  ? console_flush_one_record (kernel/printk/printk.c:3316)
[   14.711719][  T167]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   14.711721][  T167]  ? lock_acquire (kernel/locking/lockdep.c:5913)
[   14.711725][  T167]  ? __down_trylock_console_sem (kernel/printk/printk.c:334)
[   14.711727][  T167]  ? vprintk_emit (kernel/printk/printk.c:2478)
[   14.711730][  T167]  vprintk_emit (kernel/printk/printk.c:2479)
[   14.711733][  T167]  ? wake_up_klogd_work_func (kernel/printk/printk.c:4603 (discriminator 126))
[   14.711736][  T167]  ? _copy_from_iter (./include/linux/instrumented.h:146 lib/iov_iter.c:66 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:261 lib/iov_iter.c:272)
[   14.711741][  T167]  devkmsg_emit.constprop.0 (kernel/printk/printk.c:733)
[   14.711745][  T167]  ? vprintk_emit.cold (kernel/printk/printk.c:2449)
[   14.711749][  T167]  ? __kmalloc_noprof (mm/slub.c:5415 mm/slub.c:5439)
[   14.711751][  T167]  ? idr_get_free (??:?)
[   14.711755][  T167]  ? devkmsg_write (./include/linux/slab.h:995 kernel/printk/printk.c:762)
[   14.711757][  T167]  ? _copy_from_iter (./include/linux/instrumented.h:146 lib/iov_iter.c:66 ./include/linux/iov_iter.h:30 ./include/linux/iov_iter.h:302 ./include/linux/iov_iter.h:330 lib/iov_iter.c:261 lib/iov_iter.c:272)
[   14.711760][  T167]  devkmsg_write.cold (kernel/printk/printk.c:796)
[   14.711763][  T167]  ? vprintk_default (kernel/printk/printk.c:2494)
[   14.711764][  T167]  ? handle_pte_fault (mm/memory.c:6582)
[   14.711769][  T167]  ? do_numa_page.isra.0 (mm/memory.c:6319 (discriminator 1))
[   14.711771][  T167]  ? vprintk_default (kernel/printk/printk.c:2494)
[   14.711773][  T167]  new_sync_write (fs/read_write.c:595)
[   14.711778][  T167]  ? new_sync_read (./include/linux/ioprio.h:41)
[   14.711779][  T167]  ? lock_vma_under_rcu (./include/linux/rcupdate.h:319 (discriminator 2) ./include/linux/rcupdate.h:880 (discriminator 2) mm/mmap_lock.c:329 (discriminator 2))
[   14.711788][  T167]  vfs_write (fs/read_write.c:687)
[   14.711792][  T167]  ksys_write (fs/read_write.c:739)
[   14.711794][  T167]  ? __ia32_sys_read (fs/read_write.c:723)
[   14.711796][  T167]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   14.711798][  T167]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 3) kernel/rcu/tree.c:753 (discriminator 3))
[   14.711801][  T167]  do_syscall_64 (arch/x86/entry/syscall_64.c:61 arch/x86/entry/syscall_64.c:84)
[   14.711804][  T167]  ? exc_page_fault (arch/x86/mm/fault.c:1489 (discriminator 3) arch/x86/mm/fault.c:1536 (discriminator 3))
[   14.711807][  T167]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[   14.711809][  T167] RIP: 0033:0x7f77e196454e
[   14.711813][  T167] Code: 4d 89 d8 e8 b4 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 b4 bd 00 00       	call   0xbdbc
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 03 ff ff ff       	call   0xffffffffffffff3c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 03 ff ff ff       	call   0xffffffffffffff12
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[   14.711815][  T167] RSP: 002b:00007ffc0b4d8a40 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[   14.711818][  T167] RAX: ffffffffffffffda RBX: 00007f77e1ae5580 RCX: 00007f77e196454e
[   14.711819][  T167] RDX: 0000000000000023 RSI: 00005644c2870120 RDI: 0000000000000001
[   14.711820][  T167] RBP: 00007ffc0b4d8a50 R08: 0000000000000000 R09: 0000000000000000
[   14.711821][  T167] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000023


Finger prints:
restore_fpregs_from_user:vprintk_emit:dump_stack_lvl:__kmalloc_noprof:put_chars
__irq_exit_rcu:vprintk_emit:dump_stack_lvl:__kmalloc_noprof:put_chars