kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 22525 Comm: syz-executor4 Not tainted 4.16.0+ #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
RSP: 0018:ffff8801dae06aa0 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8801ac01c4f8
RDX: 0000000000000007 RSI: ffffffff81783421 RDI: 0000000000000038
RBP: ffff8801dae06ab8 R08: ffffed003b5c46c3 R09: 0000000000000001
R10: ffff8801dae06b48 R11: ffff8801dae23613 R12: ffff8801d7bc26c0
R13: ffff8801ac01c4c0 R14: ffff8801ac01c4fc R15: 0000000000000002
FS: 00007ff20a666700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000021ad7d0 CR3: 0000000008c6a000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 00000000200003c0 DR2: 0000000020000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
delayacct_blkio_end include/linux/delayacct.h:128 [inline]
try_to_wake_up+0xa89/0x1190 kernel/sched/core.c:2034
default_wake_function+0x30/0x50 kernel/sched/core.c:3743
autoremove_wake_function+0x7a/0x350 kernel/sched/wait.c:373
wake_bit_function+0xcb/0x160 kernel/sched/wait_bit.c:30
__wake_up_common+0x189/0x730 kernel/sched/wait.c:90
__wake_up_common_lock+0x1b4/0x300 kernel/sched/wait.c:119
__wake_up+0xe/0x10 kernel/sched/wait.c:143
__wake_up_bit+0x1a6/0x270 kernel/sched/wait_bit.c:125
wake_up_bit+0x3d/0x40 kernel/sched/wait_bit.c:148
journal_end_buffer_io_sync+0xa4/0xe0 fs/jbd2/commit.c:44
end_bio_bh_io_sync+0xf3/0x140 fs/buffer.c:2992
bio_endio+0x4b8/0x920 block/bio.c:1775
req_bio_endio block/blk-core.c:280 [inline]
blk_update_request+0x3a3/0xcb0 block/blk-core.c:3076
scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:672
scsi_io_completion+0xca9/0x1d10 drivers/scsi/scsi_lib.c:891
scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1676
__blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:551
blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:636
scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1987
virtscsi_complete_cmd+0x573/0x740 drivers/scsi/virtio_scsi.c:207
virtscsi_vq_done+0xc3/0x170 drivers/scsi/virtio_scsi.c:223
virtscsi_req_done+0xa7/0xd0 drivers/scsi/virtio_scsi.c:238
vring_interrupt+0x128/0x170 drivers/virtio/virtio_ring.c:950
__handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:641
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
RIP: 0010:lock_acquire+0x257/0x520 kernel/locking/lockdep.c:3923
RSP: 0018:ffff8801b2ab7100 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda
RAX: dffffc0000000000 RBX: 1ffff10036556e25 RCX: 0000000000000000
RDX: 1ffffffff11a30ed RSI: ffff8801d7bc2ef8 RDI: 0000000000000282
RBP: ffff8801b2ab71f0 R08: 00000000000043b1 R09: 0000000000000001
R10: ffff8801d7bc2f20 R11: ffff8801d7bc26c0 R12: ffff8801d7bc26c0
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:310 [inline]
fast_dput fs/dcache.c:730 [inline]
dput.part.27+0x5a1/0x7b0 fs/dcache.c:837
dput+0x1f/0x30 fs/dcache.c:830
path_put+0x31/0x70 fs/namei.c:484
free_fs_struct+0x22/0x60 fs/fs_struct.c:90
exit_fs+0xf3/0x130 fs/fs_struct.c:107
do_exit+0xf58/0x2730 kernel/exit.c:861
do_group_exit+0x16f/0x430 kernel/exit.c:968
get_signal+0x886/0x1960 kernel/signal.c:2469
do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455389
RSP: 002b:00007ff20a665ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000072bec8 RCX: 0000000000455389
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bec8
RBP: 000000000072bec8 R08: 0000000000000000 R09: 000000000072bea0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0fcd0c3f R14: 00007ff20a6669c0 R15: 0000000000000000
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 80 00 00 00 48 8b 9b 30 12 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 51 44 8b 63 38 31 ff 41 83 e4
RIP: __delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82 RSP: ffff8801dae06aa0
======================================================
WARNING: possible circular locking dependency detected
4.16.0+ #8 Not tainted
------------------------------------------------------
syz-executor4/22525 is trying to acquire lock:
00000000c0ec3b83 (console_owner){-...}, at: log_next kernel/printk/printk.c:496 [inline]
00000000c0ec3b83 (console_owner){-...}, at: console_unlock+0x583/0x1100 kernel/printk/printk.c:2382
but task is already holding lock:
0000000020fed98b (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&p->pi_lock){-.-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963
default_wake_function+0x30/0x50 kernel/sched/core.c:3743
woken_wake_function+0x31/0x60 kernel/sched/wait.c:443
__wake_up_common+0x189/0x730 kernel/sched/wait.c:90
__wake_up_common_lock+0x1b4/0x300 kernel/sched/wait.c:119
__wake_up+0xe/0x10 kernel/sched/wait.c:143
tty_wakeup+0x73/0x110 drivers/tty/tty_io.c:536
tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:50
tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:390
uart_write_wakeup+0x44/0x60 drivers/tty/serial/serial_core.c:103
serial8250_tx_chars+0x4be/0xb60 drivers/tty/serial/8250/8250_port.c:1804
serial8250_handle_irq.part.25+0x1ee/0x280 drivers/tty/serial/8250/8250_port.c:1877
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1863 [inline]
serial8250_default_handle_irq+0xc8/0x150 drivers/tty/serial/8250/8250_port.c:1893
serial8250_interrupt+0xfa/0x1d0 drivers/tty/serial/8250/8250_core.c:125
__handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
ret_from_intr+0x0/0x1e
arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
spin_unlock_irqrestore include/linux/spinlock.h:365 [inline]
uart_write+0x3df/0x620 drivers/tty/serial/serial_core.c:591
process_output_block drivers/tty/n_tty.c:579 [inline]
n_tty_write+0x6b9/0x1180 drivers/tty/n_tty.c:2308
do_tty_write drivers/tty/tty_io.c:958 [inline]
tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042
redirected_tty_write+0xaf/0xc0 drivers/tty/tty_io.c:1063
__vfs_write+0x10b/0x960 fs/read_write.c:485
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0xf9/0x250 fs/read_write.c:598
SYSC_write fs/read_write.c:610 [inline]
SyS_write+0x24/0x30 fs/read_write.c:607
do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #2 (&tty->write_wait){-.-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
__wake_up_common_lock+0x190/0x300 kernel/sched/wait.c:118
__wake_up+0xe/0x10 kernel/sched/wait.c:143
tty_wakeup+0x73/0x110 drivers/tty/tty_io.c:536
tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:50
tty_port_tty_wakeup+0x5d/0x70 drivers/tty/tty_port.c:390
uart_write_wakeup+0x44/0x60 drivers/tty/serial/serial_core.c:103
serial8250_tx_chars+0x4be/0xb60 drivers/tty/serial/8250/8250_port.c:1804
serial8250_handle_irq.part.25+0x1ee/0x280 drivers/tty/serial/8250/8250_port.c:1877
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1863 [inline]
serial8250_default_handle_irq+0xc8/0x150 drivers/tty/serial/8250/8250_port.c:1893
serial8250_interrupt+0xfa/0x1d0 drivers/tty/serial/8250/8250_core.c:125
__handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
ret_from_intr+0x0/0x1e
arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
spin_unlock_irqrestore include/linux/spinlock.h:365 [inline]
uart_write+0x3df/0x620 drivers/tty/serial/serial_core.c:591
process_output_block drivers/tty/n_tty.c:579 [inline]
n_tty_write+0x6b9/0x1180 drivers/tty/n_tty.c:2308
do_tty_write drivers/tty/tty_io.c:958 [inline]
tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042
redirected_tty_write+0xaf/0xc0 drivers/tty/tty_io.c:1063
__vfs_write+0x10b/0x960 fs/read_write.c:485
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0xf9/0x250 fs/read_write.c:598
SYSC_write fs/read_write.c:610 [inline]
SyS_write+0x24/0x30 fs/read_write.c:607
do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #1 (&port_lock_key){-.-.}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
serial8250_console_write+0x8d5/0xb00 drivers/tty/serial/8250/8250_port.c:3226
univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590
call_console_drivers kernel/printk/printk.c:1718 [inline]
console_unlock+0xac2/0x1100 kernel/printk/printk.c:2395
vprintk_emit+0x6ad/0xdd0 kernel/printk/printk.c:1907
vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
printk+0x9e/0xba kernel/printk/printk.c:1980
register_console+0x7e7/0xc00 kernel/printk/printk.c:2714
univ8250_console_init+0x3f/0x4b drivers/tty/serial/8250/8250_core.c:685
console_init+0x6d9/0xa38 kernel/printk/printk.c:2798
start_kernel+0x608/0x92d init/main.c:660
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:443
x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:424
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242
-> #0 (console_owner){-...}:
lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
console_lock_spinning_enable kernel/printk/printk.c:1581 [inline]
console_unlock+0x5ef/0x1100 kernel/printk/printk.c:2392
vprintk_emit+0x6ad/0xdd0 kernel/printk/printk.c:1907
vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
printk+0x9e/0xba kernel/printk/printk.c:1980
kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:253
notifier_call_chain+0x178/0x380 kernel/notifier.c:93
__atomic_notifier_call_chain kernel/notifier.c:183 [inline]
atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193
notify_die+0x1a3/0x2b0 kernel/notifier.c:549
do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:558
general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1158
__delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
delayacct_blkio_end include/linux/delayacct.h:128 [inline]
try_to_wake_up+0xa89/0x1190 kernel/sched/core.c:2034
default_wake_function+0x30/0x50 kernel/sched/core.c:3743
autoremove_wake_function+0x7a/0x350 kernel/sched/wait.c:373
wake_bit_function+0xcb/0x160 kernel/sched/wait_bit.c:30
__wake_up_common+0x189/0x730 kernel/sched/wait.c:90
__wake_up_common_lock+0x1b4/0x300 kernel/sched/wait.c:119
__wake_up+0xe/0x10 kernel/sched/wait.c:143
__wake_up_bit+0x1a6/0x270 kernel/sched/wait_bit.c:125
wake_up_bit+0x3d/0x40 kernel/sched/wait_bit.c:148
journal_end_buffer_io_sync+0xa4/0xe0 fs/jbd2/commit.c:44
end_bio_bh_io_sync+0xf3/0x140 fs/buffer.c:2992
bio_endio+0x4b8/0x920 block/bio.c:1775
req_bio_endio block/blk-core.c:280 [inline]
blk_update_request+0x3a3/0xcb0 block/blk-core.c:3076
scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:672
scsi_io_completion+0xca9/0x1d10 drivers/scsi/scsi_lib.c:891
scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1676
__blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:551
blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:636
scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1987
virtscsi_complete_cmd+0x573/0x740 drivers/scsi/virtio_scsi.c:207
virtscsi_vq_done+0xc3/0x170 drivers/scsi/virtio_scsi.c:223
virtscsi_req_done+0xa7/0xd0 drivers/scsi/virtio_scsi.c:238
vring_interrupt+0x128/0x170 drivers/virtio/virtio_ring.c:950
__handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
ret_from_intr+0x0/0x1e
arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
lock_acquire+0x257/0x520 kernel/locking/lockdep.c:3923
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
spin_lock include/linux/spinlock.h:310 [inline]
fast_dput fs/dcache.c:730 [inline]
dput.part.27+0x5a1/0x7b0 fs/dcache.c:837
dput+0x1f/0x30 fs/dcache.c:830
path_put+0x31/0x70 fs/namei.c:484
free_fs_struct+0x22/0x60 fs/fs_struct.c:90
exit_fs+0xf3/0x130 fs/fs_struct.c:107
do_exit+0xf58/0x2730 kernel/exit.c:861
do_group_exit+0x16f/0x430 kernel/exit.c:968
get_signal+0x886/0x1960 kernel/signal.c:2469
do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
other info that might help us debug this:
Chain exists of:
console_owner --> &tty->write_wait --> &p->pi_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&p->pi_lock);
lock(&tty->write_wait);
lock(&p->pi_lock);
lock(console_owner);
*** DEADLOCK ***
8 locks held by syz-executor4/22525:
#0: 00000000844b4a5b (rcu_read_lock){....}, at: dput.part.27+0x6c/0x7b0 fs/dcache.c:828
#1: 000000004620fe1f (&(&dentry->d_lockref.lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline]
#1: 000000004620fe1f (&(&dentry->d_lockref.lock)->rlock){+.+.}, at: fast_dput fs/dcache.c:730 [inline]
#1: 000000004620fe1f (&(&dentry->d_lockref.lock)->rlock){+.+.}, at: dput.part.27+0x5a1/0x7b0 fs/dcache.c:837
#2: 0000000056518472 (&(&virtscsi_vq->vq_lock)->rlock){-.-.}, at: virtscsi_vq_done+0x9d/0x170 drivers/scsi/virtio_scsi.c:219
#3: 00000000844b4a5b (rcu_read_lock){....}, at: hctx_lock+0x7a/0x1d0 block/blk-mq.c:570
#4: 00000000ae312ec0 (bit_wait_table + i){-.-.}, at: __wake_up_common_lock+0x190/0x300 kernel/sched/wait.c:118
#5: 0000000020fed98b (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963
#6: 00000000844b4a5b (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 include/linux/compiler.h:188
#7: 000000007731ebb9 (console_lock){+.+.}, at: console_trylock_spinning kernel/printk/printk.c:1643 [inline]
#7: 000000007731ebb9 (console_lock){+.+.}, at: vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906
stack backtrace:
CPU: 0 PID: 22525 Comm: syz-executor4 Not tainted 4.16.0+ #8
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_circular_bug.isra.36.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1223
check_prev_add kernel/locking/lockdep.c:1863 [inline]
check_prevs_add kernel/locking/lockdep.c:1976 [inline]
validate_chain kernel/locking/lockdep.c:2417 [inline]
__lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3431
lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
console_lock_spinning_enable kernel/printk/printk.c:1581 [inline]
console_unlock+0x5ef/0x1100 kernel/printk/printk.c:2392
vprintk_emit+0x6ad/0xdd0 kernel/printk/printk.c:1907
? __lock_acqui
Lost 233 message(s)!
---[ end trace 3977e9d33bda8618 ]---