INFO: task syz.3.3679:20489 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3679 state:D stack:25464 pid:20489 tgid:20482 ppid:19195 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
blk_debugfs_lock_nomemsave block/blk.h:816 [inline]
blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:903
sg_ioctl_common drivers/scsi/sg.c:-1 [inline]
sg_ioctl+0xb0c/0x21a0 drivers/scsi/sg.c:1158
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb02839fb19
RSP: 002b:00007fb0291d7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb028626090 RCX: 00007fb02839fb19
RDX: 0000000000000000 RSI: 0000000000001274 RDI: 000000000000000d
RBP: 00007fb028437b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb028626128 R14: 00007fb028626090 R15: 00007fb02874fa48
INFO: task syz.3.3679:20497 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3679 state:D stack:28808 pid:20497 tgid:20482 ppid:19195 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
blk_debugfs_lock_nomemsave block/blk.h:816 [inline]
blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
sg_ioctl_common drivers/scsi/sg.c:1124 [inline]
sg_ioctl+0x457/0x21a0 drivers/scsi/sg.c:1158
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb02839fb19
RSP: 002b:00007fb029195028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb028626270 RCX: 00007fb02839fb19
RDX: 0000000000003800 RSI: 0000000000001276 RDI: 000000000000000d
RBP: 00007fb028437b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb028626308 R14: 00007fb028626270 R15: 00007fb02874fa48
Showing all locks held in the system:
locks held by pr/ttyS0/33: 1, last CPU#0:
#0: ffffffff90033d58 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff90033d58 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:529 [inline]
#0: ffffffff90033d58 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
locks held by khungtaskd/34: 1, last CPU#1:
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kswapd0/91: 2, last CPU#1:
#0: ffffffff90294f40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7332 [inline]
#0: ffffffff90294f40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xa53/0x3a20 mm/vmscan.c:7705
#1: ffffe8ffffd20ea8 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:869 [inline]
#1: ffffe8ffffd20ea8 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1454 [inline]
#1: ffffe8ffffd20ea8 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_store+0xbde/0x2200 mm/zswap.c:1569
locks held by klogd/4993: 1, last CPU#1:
#0: ffffffff902b1cd0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:249 [inline]
#0: ffffffff902b1cd0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:356
locks held by getty/5394: 2, on CPU#1:
#0: ffff888032ea30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/0:8/11115: 4, on CPU#0:
#0: ffff8880236b6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880236b6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880236b6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff8880236b6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc9000374fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000374fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000374fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc9000374fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff888026c131d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff888026c131d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917
#3: ffff88807b3571d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff88807b3571d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1106
locks held by kworker/u8:14/11383: 3, last CPU#1:
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90005d27c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005d27c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005d27c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90005d27c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff888035b20258 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834
locks held by kworker/u8:16/11412: 3, last CPU#1:
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90005637c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005637c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005637c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90005637c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88807ad78258 (&devlink->lock_key#19){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834
locks held by syz.3.3679/20489: 1, on CPU#1:
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:816 [inline]
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:903
locks held by syz.3.3679/20494: 3, last CPU#1:
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:816 [inline]
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:830 [inline]
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d0/0x520 kernel/trace/blktrace.c:788
#1: ffffffff901bae80 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3a4/0x900 kernel/relay.c:515
#2: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#2: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.3.3679/20497: 1, on CPU#0:
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:816 [inline]
#0: ffff88801ff91b48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561
locks held by udevd/21663: 4, on CPU#0:
#0: ffff888043a4ecf8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
#1: ffff888027f97880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#2: ffff888057fee698 (kn->active#30){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888057fee698 (kn->active#30){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#3: ffff88807b3571d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff88807b3571d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by syz.4.4112/22656: 1, last CPU#1:
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.5.4155/22815: 2, last CPU#1:
#0: ffff88807f9ac478 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0xac3/0x10c0 fs/coredump.c:1312
#1: ffff888034444ba8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1026 [inline]
#1: ffff888034444ba8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3679
locks held by syz.5.4157/22831: 3, last CPU#1:
#0: ffff88807f9ac478 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0xac3/0x10c0 fs/coredump.c:1312
#1: ffff8880692c4590 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1026 [inline]
#1: ffff8880692c4590 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3679
#2: ffff8880b823c5e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:685
locks held by syz.4.4169/22871: 1, last CPU#1:
#0: ffff888022bb8f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:548 [inline]
#0: ffff888022bb8f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d5/0xa40 mm/mmap.c:1323
locks held by syz.2.4172/22877: 2, last CPU#1:
#0: ffff88803306a478 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0xac3/0x10c0 fs/coredump.c:1312
#1: ffff888035b4f038 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1026 [inline]
#1: ffff888035b4f038 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3679
locks held by syz.9.4173/22884: 1, on CPU#0:
#0: ffff888082760f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:625
locks held by syz.9.4173/22885: 4, last CPU#1:
#0: ffffffff9023a5d0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1536 [inline]
#0: ffffffff9023a5d0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0xf6/0x640 kernel/fork.c:1602
#1: ffff888082760f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:566 [inline]
#1: ffff888082760f80 (&mm->mmap_lock){++++}-{4:4}, at: dup_mm kernel/fork.c:1537 [inline]
#1: ffff888082760f80 (&mm->mmap_lock){++++}-{4:4}, at: copy_mm+0x110/0x640 kernel/fork.c:1602
#2: ffff888082760340 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:556 [inline]
#2: ffff888082760340 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1f6/0x1c80 mm/mmap.c:1722
#3: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff9015a260 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by syz.1.4174/22886: 1, on CPU#1:
#0: ffffffff901607b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x175/0x610 kernel/rcu/tree.c:4002
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
watchdog+0x1073/0x10f0 kernel/hung_task.c:598
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425
Code: e8 2e 6a 43 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 2f f3 ba fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 9a 14 83 06 cc 44 89 f9 80 e1 07
RSP: 0000:ffffc90000a978b8 EFLAGS: 00000002
RAX: 1ffffffff3840b00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8585a440 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9c205ec0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888123409000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560ccabb2ef0 CR3: 0000000013b26000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245