tty_write_unlock identifier - Linux source code next-20260811

Projects

linux

Versions

FIXME
- FIXME
  - next-20260811

Defined in 1 files as a prototype:

drivers/tty/tty.h, line 70 (as a prototype)

Defined in 1 files as a function:

drivers/tty/tty_io.c, line 931 (as a function)

Referenced in 2 files:

Smatch caller information:

drivers/tty/tty_io.c iterate_tty_write() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->atomic_write_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->list.prev->next	5159360019465732096
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->task->blocked_on	0
PARAM_VALUE	0	tty->ldisc_sem.dep_map->name	0-255
PARAM_VALUE	0	tty->ldisc_sem.read_wait.next->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->next->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->prev	4096-ptr_max
PARAM_VALUE	0	tty->ops->flush_chars	0,4096-ptr_max
PARAM_VALUE	0	tty->ops->write	4096-ptr_max
PARAM_VALUE	0	tty->ops->write_room	0,4096-ptr_max
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->handoff_set	0-1
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->type	0-1
BUF_SIZE	0	tty->write_buf	1024-65536,u64max
DATA_SOURCE	0	tty	$1
RX_PATH
TASK_NOT_RUNNING
NOCHECK_CALL
USER_DATA	0	tty->write_cnt	1025-u16max[c]
LOCK2	0	&tty->atomic_write_lock
LOCK2	0	&tty->ldisc_sem
HALF_LOCKED2		&pool->lock
TYPE_LOCK		(struct tty_struct)->atomic_write_lock
TYPE_LOCK		(struct tty_struct)->ldisc_sem

drivers/tty/tty_io.c send_break() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->atomic_write_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter	0,4096-5159360019465732095,5159360019465732097-ptr_max
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->list.prev->next	5159360019465732096
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->task->blocked_on	0
PARAM_VALUE	0	tty->atomic_write_lock.osq.tail.counter	0-s32max
PARAM_VALUE	0	tty->driver	4096-ptr_max
PARAM_VALUE	0	tty->driver_data->lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->port_lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->write_lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->ops	4096-ptr_max
PARAM_VALUE	0	tty->ops->break_ctl	4096-ptr_max
CAPPED_DATA	0	tty	1
DATA_SOURCE	0	tty	$0
BIT_INFO	0	tty->driver->flags	0x0,0xffffffffffffffdf
NOCHECK_CALL
LOCK2	0	&tty->atomic_write_lock
TYPE_LOCK		(struct tty_struct)->atomic_write_lock

drivers/tty/tty_io.c tty_send_xchar() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->atomic_write_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter	0,4096-5159360019465732095,5159360019465732097-ptr_max
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->list.prev->next	5159360019465732096
PARAM_VALUE	0	tty->atomic_write_lock.first_waiter->task->blocked_on	0
PARAM_VALUE	0	tty->atomic_write_lock.osq.tail.counter	0-s32max
PARAM_VALUE	0	tty->ldisc	1-u64max
PARAM_VALUE	0	tty->ldisc_sem.dep_map->name	0-255
PARAM_VALUE	0	tty->ldisc_sem.read_wait.next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.next->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->next->next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev->prev	4096-ptr_max
PARAM_VALUE	0	tty->ops	4096-ptr_max
PARAM_VALUE	0	tty->ops->chars_in_buffer	0,4096-ptr_max
PARAM_VALUE	0	tty->ops->compat_ioctl	0,1607379221601308672,5008286898947497984,6364353445524312064
PARAM_VALUE	0	tty->ops->ioctl	0,4096-ptr_max
PARAM_VALUE	0	tty->ops->send_xchar	0
PARAM_VALUE	0	tty->termios.c_cc	4096-ptr_max
PARAM_VALUE	0	tty->termios_rwsem.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->handoff_set	1
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.next	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.prev	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->type	0-1
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner	(-1)
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner_cpu	u32max
CAPPED_DATA	0	tty	1
CAPPED_DATA	0	&tty->termios_rwsem	1
DATA_SOURCE	0	tty	$0
NOCHECK_CALL
LOCK2	0	&tty->atomic_write_lock
LOCK2	0	&tty->ldisc_sem
TYPE_LOCK		(struct tty_struct)->atomic_write_lock
TYPE_LOCK		(struct tty_struct)->ldisc_sem

drivers/tty/tty_ioctl.c set_termios() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->driver	4096-ptr_max
PARAM_VALUE	0	tty->ldisc	1-u64max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.next	4096-ptr_max
PARAM_VALUE	0	tty->ldisc_sem.read_wait.prev	4096-ptr_max
PARAM_VALUE	0	tty->ops	4096-ptr_max
PARAM_VALUE	0	tty->ops->chars_in_buffer	1-u64max
PARAM_VALUE	0	tty->termios_rwsem.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->handoff_set	1
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.next	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.prev	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->type	0-1
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner	(-1)
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner_cpu	u32max
CAPPED_DATA	0	&tty->termios_rwsem	1
DATA_SOURCE	0	tty	$0
NOCHECK_CALL
LOCK2		&tty->ldisc_sem
LOCK2	0	&tty->atomic_write_lock
TYPE_LOCK		(struct tty_struct)->atomic_write_lock
TYPE_LOCK		(struct tty_struct)->ldisc_sem

drivers/tty/tty_ioctl.c set_termios() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->driver	4096-ptr_max
PARAM_VALUE	0	tty->ldisc	1-u64max
PARAM_VALUE	0	tty->ldisc_sem.dep_map->name	0-255
PARAM_VALUE	0	tty->ops	4096-ptr_max
PARAM_VALUE	0	tty->ops->wait_until_sent	2578158375326154752,2614800216018440192,6874988682411192320,7074827580452507648,7916194843820081152
PARAM_VALUE	0	tty->termios_rwsem.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->handoff_set	1
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.next	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.prev	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->type	0-1
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner	(-1)
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.owner_cpu	u32max
CAPPED_DATA	0	&tty->termios_rwsem	1
DATA_SOURCE	0	tty	$0
NOCHECK_CALL
LOCK2		&tty->ldisc_sem
LOCK2	0	&tty->atomic_write_lock
HALF_LOCKED2	0	&tty->ldisc_sem
TYPE_LOCK		(struct tty_struct)->atomic_write_lock

drivers/tty/tty_ioctl.c set_termios() -> tty_write_unlock()

Type	Parameter	Key	Value
PARAM_VALUE	0	tty	4096-ptr_max
PARAM_VALUE	0	tty->disc_data->icanon	0-1
PARAM_VALUE	0	tty->disc_data->lnext	0
PARAM_VALUE	0	tty->disc_data->raw	0-1
PARAM_VALUE	0	tty->disc_data->real_raw	0-1
PARAM_VALUE	0	tty->driver	4096-ptr_max
PARAM_VALUE	0	tty->driver_data->FCR	0-1,33,65,129,193
PARAM_VALUE	0	tty->driver_data->MCR	0-255
PARAM_VALUE	0	tty->driver_data->clocal	0-1
PARAM_VALUE	0	tty->driver_data->control->dev.power.deferred_resume	0-1
PARAM_VALUE	0	tty->driver_data->control->dev.power.idle_notification	0-1
PARAM_VALUE	0	tty->driver_data->control->dev.power.request	0-4294967295
PARAM_VALUE	0	tty->driver_data->control->dev.power.request_pending	0-1
PARAM_VALUE	0	tty->driver_data->control->dev.power.runtime_error	s32min-s32max
PARAM_VALUE	0	tty->driver_data->control->dev.power.runtime_status	s32min-s32max
PARAM_VALUE	0	tty->driver_data->control->dev.power.timer_autosuspends	0-1
PARAM_VALUE	0	tty->driver_data->control->dev.power.usage_count.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->control->dev.power.wakeirq->status	0-4294967295
PARAM_VALUE	0	tty->driver_data->ctrlout	0-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->claim_cnt	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->claimed	0-1
PARAM_VALUE	0	tty->driver_data->func->card->host->cqe_on	0-1
PARAM_VALUE	0	tty->driver_data->func->card->host->doing_retune	0-1
PARAM_VALUE	0	tty->driver_data->func->card->host->fail_mmc_request.ratelimit_state.flags	0-4294967295
PARAM_VALUE	0	tty->driver_data->func->card->host->fail_mmc_request.space.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->fail_mmc_request.times.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->hold_retune	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->func->card->host->need_retune	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func->card->host->ongoing_mrq->uhs2_cmd.packet_len	0,4-12
PARAM_VALUE	0	tty->driver_data->func->card->host->ongoing_mrq->uhs2_cmd.payload_len	0-8
PARAM_VALUE	0	tty->driver_data->func->card->host->ongoing_mrq->uhs2_cmd.tmode_half_duplex	0-1
PARAM_VALUE	0	tty->driver_data->func->card->host->ongoing_mrq->uhs2_cmd.uhs2_resp_len	0,4-6,8
PARAM_VALUE	0	tty->driver_data->func->card->host->retune_now	0-1
PARAM_VALUE	0	tty->driver_data->func->card->host->uhs2_app_cmd	0-1
PARAM_VALUE	0	tty->driver_data->func_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->list.prev->next	5159360019465732096
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->list.prev->prev	5159360019465732096
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->task->blocked_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->task->blocked_lock.owner	(-1)
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->task->blocked_lock.owner_cpu	4294967295
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->task->blocked_lock.raw_lock.val.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func_lock.first_waiter->task->usage.refs.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->func_lock.osq.tail.counter	0-s32max
PARAM_VALUE	0	tty->driver_data->icount.tx	0-4294967295
PARAM_VALUE	0	tty->driver_data->ier	0-255
PARAM_VALUE	0	tty->driver_data->ignore_status_mask	0-1,12-13,16-19,28-31
PARAM_VALUE	0	tty->driver_data->lcr	0-31
PARAM_VALUE	0	tty->driver_data->line.bCharFormat	0,2
PARAM_VALUE	0	tty->driver_data->line.bDataBits	5-8
PARAM_VALUE	0	tty->driver_data->line.bParityType	0-4
PARAM_VALUE	0	tty->driver_data->line.dwDTERate	0-4294967295
PARAM_VALUE	0	tty->driver_data->line_coding.data_bits	5-8
PARAM_VALUE	0	tty->driver_data->line_coding.flow_control	0-1
PARAM_VALUE	0	tty->driver_data->line_coding.format	0,2
PARAM_VALUE	0	tty->driver_data->line_coding.parity	0-4
PARAM_VALUE	0	tty->driver_data->line_coding.rate	0-4294967295
PARAM_VALUE	0	tty->driver_data->lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->mctrl	0-4294967295
PARAM_VALUE	0	tty->driver_data->port->client_data->serdev->write_comp.wait.lock.owner	(-4611686018427387904)-4611686018427387903
PARAM_VALUE	0	tty->driver_data->port.client_data->serdev->write_comp.done	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.client_data->serdev->write_comp.wait.lock.owner	(-1)
PARAM_VALUE	0	tty->driver_data->port.client_data->serdev->write_comp.wait.lock.owner_cpu	4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock->read_count	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->__state	0,512
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_defer	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_defer_armed	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_overrun	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_server	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_throttled	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.dl_yielded	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.flags	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->cpu	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->nr_pinned	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->nr_running	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->online	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->push_busy	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->push_cpu	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->sched_count	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->ttwu_count	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->ttwu_local	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->dl.rq->yld_count	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->nr_cpus_allowed	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->numa_scan_period	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->on_rq	0-1,3-255
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->psi_flags	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->recent_used_cpu	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->rt.on_list	0-u16max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->rt.on_rq	0-u16max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->rt.time_slice	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->sched_migrated	1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->throttled	0-1
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->proto_lock.writer.task->wake_cpu	0-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->disc_data->refcnt.refs.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->kref.refcount.refs.counter	s32min-s32max
PARAM_VALUE	0	tty->driver_data->port.tty->ldisc_sem.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->port.xmit_fifo.kfifo.esize	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.xmit_fifo.kfifo.mask	0-4294967295
PARAM_VALUE	0	tty->driver_data->port.xmit_fifo.kfifo.out	0-4294967295
PARAM_VALUE	0	tty->driver_data->port_write_buf.kfifo.esize	0-4294967295
PARAM_VALUE	0	tty->driver_data->port_write_buf.kfifo.mask	0-4294967295
PARAM_VALUE	0	tty->driver_data->port_write_buf.kfifo.out	0-4294967295
PARAM_VALUE	0	tty->driver_data->read_status_mask	35,47,51,63
PARAM_VALUE	0	tty->driver_data->rx_enable	0
PARAM_VALUE	0	tty->driver_data->timeout	0-4294967295
PARAM_VALUE	0	tty->driver_data->tx_boundary	0-4294967295
PARAM_VALUE	0	tty->driver_data->tx_running	0
PARAM_VALUE	0	tty->driver_data->uart_port->hw_stopped	0-1
PARAM_VALUE	0	tty->driver_data->uart_port->lock.rlock.dep_map->name	0-255
PARAM_VALUE	0	tty->driver_data->uart_port->mctrl	0-4294967295
PARAM_VALUE	0	tty->driver_data->uart_port->status	0-4294967295
PARAM_VALUE	0	tty->driver_data->write_busy	0
PARAM_VALUE	0	tty->driver_data->write_started	s32min-s32max
PARAM_VALUE	0	tty->ldisc	1-u64max
PARAM_VALUE	0	tty->ops	4096-ptr_max
PARAM_VALUE	0	tty->ops->set_termios	0,4096-ptr_max
PARAM_VALUE	0	tty->ops->wait_until_sent	0,2578158375326154752,2614800216018440192,6874988682411192320,7074827580452507648,7916194843820081152
PARAM_VALUE	0	tty->termios_rwsem.dep_map->name	0-255
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->handoff_set	1
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.next	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->list.prev	2212933610777083904
PARAM_VALUE	0	tty->termios_rwsem.first_waiter->type	0-1
PARAM_VALUE	0	tty->termios_rwsem.wait_lock.dep_map->name	0-255
PARAM_VALUE	0	*tty->driver_data->port.tty->disc_data->proto_lock.read_count	0-4294967295
PARAM_VALUE	0	*tty->termios->c_cc	0-255
CAPPED_DATA	0	&tty->termios_rwsem	1
DATA_SOURCE	0	tty	$0
NOCHECK_CALL
USER_DATA	0	tty->disc_data->icanon	0-1
USER_DATA	0	tty->driver_data->clocal	0-1
USER_DATA	0	tty->driver_data->line.bParityType	1-4[c]
USER_DATA	0	tty->driver_data->line.dwDTERate	0-4294967295
USER_DATA	0	tty->driver_data->line_coding.parity	1-4[c]
USER_DATA	0	tty->driver_data->line_coding.rate	0-4294967295
USER_DATA	0	tty->driver_data->timeout	5-320005[c]
USER_DATA	0	tty->driver_data->vc_pos	s64min-s64max
USER_DATA	0	tty->driver_data->vc_utf_char	s32min-s32max[c]
USER_DATA	0	tty->termios.c_cflag	0-u32max[c]
USER_DATA	0	tty->termios.c_iflag	0-u32max[c]
USER_DATA	0	tty->termios.c_ispeed	0-u32max
USER_DATA	0	tty->termios.c_lflag	0-u32max[c]
USER_DATA	0	tty->termios.c_line	0-255
USER_DATA	0	tty->termios.c_oflag	0-u32max[c]
USER_DATA	0	tty->termios.c_ospeed	0-u32max
LOCK2		&tty->ldisc_sem
LOCK2	0	&tty->atomic_write_lock
HALF_LOCKED2	0	&tty->ldisc_sem
TYPE_LOCK		(struct tty_struct)->atomic_write_lock