1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
5 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
6 * which can be dynamically activated and de-activated by the line
7 * discipline handling modules (like SLIP).
10 #include <linux/bits.h>
11 #include <linux/types.h>
12 #include <linux/termios.h>
13 #include <linux/errno.h>
14 #include <linux/sched/signal.h>
15 #include <linux/kernel.h>
16 #include <linux/major.h>
17 #include <linux/tty.h>
18 #include <linux/fcntl.h>
19 #include <linux/string.h>
21 #include <linux/module.h>
22 #include <linux/bitops.h>
23 #include <linux/mutex.h>
24 #include <linux/compat.h>
25 #include <linux/termios_internal.h>
29 #include <linux/uaccess.h>
34 * Internal flag options for termios setting behavior
36 #define TERMIOS_FLUSH BIT(0)
37 #define TERMIOS_WAIT BIT(1)
38 #define TERMIOS_TERMIO BIT(2)
39 #define TERMIOS_OLD BIT(3)
42 * tty_chars_in_buffer - characters pending
45 * Returns: the number of bytes of data in the device private output queue. If
46 * no private method is supplied there is assumed to be no queue on the device.
48 unsigned int tty_chars_in_buffer(struct tty_struct *tty)
50 if (tty->ops->chars_in_buffer)
51 return tty->ops->chars_in_buffer(tty);
54 EXPORT_SYMBOL(tty_chars_in_buffer);
57 * tty_write_room - write queue space
60 * Returns: the number of bytes that can be queued to this device at the present
61 * time. The result should be treated as a guarantee and the driver cannot
62 * offer a value it later shrinks by more than the number of bytes written. If
63 * no method is provided, 2K is always returned and data may be lost as there
64 * will be no flow control.
66 unsigned int tty_write_room(struct tty_struct *tty)
68 if (tty->ops->write_room)
69 return tty->ops->write_room(tty);
72 EXPORT_SYMBOL(tty_write_room);
75 * tty_driver_flush_buffer - discard internal buffer
78 * Discard the internal output buffer for this device. If no method is provided,
79 * then either the buffer cannot be hardware flushed or there is no buffer
82 void tty_driver_flush_buffer(struct tty_struct *tty)
84 if (tty->ops->flush_buffer)
85 tty->ops->flush_buffer(tty);
87 EXPORT_SYMBOL(tty_driver_flush_buffer);
90 * tty_unthrottle - flow control
93 * Indicate that a @tty may continue transmitting data down the stack. Takes
94 * the &tty_struct->termios_rwsem to protect against parallel
95 * throttle/unthrottle and also to ensure the driver can consistently reference
96 * its own termios data at this point when implementing software flow control.
98 * Drivers should however remember that the stack can issue a throttle, then
99 * change flow control method, then unthrottle.
101 void tty_unthrottle(struct tty_struct *tty)
103 down_write(&tty->termios_rwsem);
104 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
105 tty->ops->unthrottle)
106 tty->ops->unthrottle(tty);
107 tty->flow_change = TTY_FLOW_NO_CHANGE;
108 up_write(&tty->termios_rwsem);
110 EXPORT_SYMBOL(tty_unthrottle);
113 * tty_throttle_safe - flow control
116 * Indicate that a @tty should stop transmitting data down the stack.
117 * tty_throttle_safe() will only attempt throttle if @tty->flow_change is
118 * %TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race conditions
119 * when throttling is conditional on factors evaluated prior to throttling.
121 * Returns: %true if @tty is throttled (or was already throttled)
123 bool tty_throttle_safe(struct tty_struct *tty)
127 mutex_lock(&tty->throttle_mutex);
128 if (!tty_throttled(tty)) {
129 if (tty->flow_change != TTY_THROTTLE_SAFE)
132 set_bit(TTY_THROTTLED, &tty->flags);
133 if (tty->ops->throttle)
134 tty->ops->throttle(tty);
137 mutex_unlock(&tty->throttle_mutex);
143 * tty_unthrottle_safe - flow control
146 * Similar to tty_unthrottle() but will only attempt unthrottle if
147 * @tty->flow_change is %TTY_UNTHROTTLE_SAFE. Prevents an accidental unthrottle
148 * due to race conditions when unthrottling is conditional on factors evaluated
149 * prior to unthrottling.
151 * Returns: %true if @tty is unthrottled (or was already unthrottled)
153 bool tty_unthrottle_safe(struct tty_struct *tty)
157 mutex_lock(&tty->throttle_mutex);
158 if (tty_throttled(tty)) {
159 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
162 clear_bit(TTY_THROTTLED, &tty->flags);
163 if (tty->ops->unthrottle)
164 tty->ops->unthrottle(tty);
167 mutex_unlock(&tty->throttle_mutex);
173 * tty_wait_until_sent - wait for I/O to finish
174 * @tty: tty we are waiting for
175 * @timeout: how long we will wait
177 * Wait for characters pending in a tty driver to hit the wire, or for a
178 * timeout to occur (eg due to flow control).
183 void tty_wait_until_sent(struct tty_struct *tty, long timeout)
186 timeout = MAX_SCHEDULE_TIMEOUT;
188 timeout = wait_event_interruptible_timeout(tty->write_wait,
189 !tty_chars_in_buffer(tty), timeout);
193 if (timeout == MAX_SCHEDULE_TIMEOUT)
196 if (tty->ops->wait_until_sent)
197 tty->ops->wait_until_sent(tty, timeout);
199 EXPORT_SYMBOL(tty_wait_until_sent);
203 * Termios Helper Methods
206 static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old)
208 struct ktermios *termios = &tty->termios;
209 struct ktermios *locked = &tty->termios_locked;
212 #define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
214 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
215 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
216 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
217 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
218 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
219 for (i = 0; i < NCCS; i++)
220 termios->c_cc[i] = locked->c_cc[i] ?
221 old->c_cc[i] : termios->c_cc[i];
222 /* FIXME: What should we do for i/ospeed */
226 * tty_termios_copy_hw - copy hardware settings
230 * Propagate the hardware specific terminal setting bits from the @old termios
231 * structure to the @new one. This is used in cases where the hardware does not
232 * support reconfiguration or as a helper in some cases where only minimal
233 * reconfiguration is supported.
235 void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
237 /* The bits a dumb device handles in software. Smart devices need
238 to always provide a set_termios method */
239 new->c_cflag &= HUPCL | CREAD | CLOCAL;
240 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
241 new->c_ispeed = old->c_ispeed;
242 new->c_ospeed = old->c_ospeed;
244 EXPORT_SYMBOL(tty_termios_copy_hw);
247 * tty_termios_hw_change - check for setting change
249 * @b: termios to compare
251 * Check if any of the bits that affect a dumb device have changed between the
252 * two termios structures, or a speed change is needed.
254 * Returns: %true if change is needed
256 bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
258 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
260 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
264 EXPORT_SYMBOL(tty_termios_hw_change);
267 * tty_get_char_size - get size of a character
268 * @cflag: termios cflag value
270 * Returns: size (in bits) of a character depending on @cflag's %CSIZE setting
272 unsigned char tty_get_char_size(unsigned int cflag)
274 switch (cflag & CSIZE) {
286 EXPORT_SYMBOL_GPL(tty_get_char_size);
289 * tty_get_frame_size - get size of a frame
290 * @cflag: termios cflag value
292 * Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB, and
293 * %PARENB setting. The result is a sum of character size, start and stop bits
294 * -- one bit each -- second stop bit (if set), and parity bit (if set).
296 * Returns: size (in bits) of a frame depending on @cflag's setting.
298 unsigned char tty_get_frame_size(unsigned int cflag)
300 unsigned char bits = 2 + tty_get_char_size(cflag);
311 EXPORT_SYMBOL_GPL(tty_get_frame_size);
314 * tty_set_termios - update termios values
315 * @tty: tty to update
316 * @new_termios: desired new value
318 * Perform updates to the termios values set on this @tty. A master pty's
319 * termios should never be set.
321 * Locking: &tty_struct->termios_rwsem
323 int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
325 struct ktermios old_termios;
326 struct tty_ldisc *ld;
328 WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
329 tty->driver->subtype == PTY_TYPE_MASTER);
331 * Perform the actual termios internal changes under lock.
335 /* FIXME: we need to decide on some locking/ordering semantics
336 for the set_termios notification eventually */
337 down_write(&tty->termios_rwsem);
338 old_termios = tty->termios;
339 tty->termios = *new_termios;
340 unset_locked_termios(tty, &old_termios);
341 /* Reset any ADDRB changes, ADDRB is changed through ->rs485_config() */
342 tty->termios.c_cflag ^= (tty->termios.c_cflag ^ old_termios.c_cflag) & ADDRB;
344 if (tty->ops->set_termios)
345 tty->ops->set_termios(tty, &old_termios);
347 tty_termios_copy_hw(&tty->termios, &old_termios);
349 ld = tty_ldisc_ref(tty);
351 if (ld->ops->set_termios)
352 ld->ops->set_termios(tty, &old_termios);
355 up_write(&tty->termios_rwsem);
358 EXPORT_SYMBOL_GPL(tty_set_termios);
362 * Translate a "termio" structure into a "termios". Ugh.
364 __weak int user_termio_to_kernel_termios(struct ktermios *termios,
365 struct termio __user *termio)
369 if (copy_from_user(&v, termio, sizeof(struct termio)))
372 termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag;
373 termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag;
374 termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag;
375 termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag;
376 termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line;
377 memcpy(termios->c_cc, v.c_cc, NCC);
382 * Translate a "termios" structure into a "termio". Ugh.
384 __weak int kernel_termios_to_user_termio(struct termio __user *termio,
385 struct ktermios *termios)
388 memset(&v, 0, sizeof(struct termio));
389 v.c_iflag = termios->c_iflag;
390 v.c_oflag = termios->c_oflag;
391 v.c_cflag = termios->c_cflag;
392 v.c_lflag = termios->c_lflag;
393 v.c_line = termios->c_line;
394 memcpy(v.c_cc, termios->c_cc, NCC);
395 return copy_to_user(termio, &v, sizeof(struct termio));
399 __weak int user_termios_to_kernel_termios(struct ktermios *k,
400 struct termios2 __user *u)
402 return copy_from_user(k, u, sizeof(struct termios2));
404 __weak int kernel_termios_to_user_termios(struct termios2 __user *u,
407 return copy_to_user(u, k, sizeof(struct termios2));
409 __weak int user_termios_to_kernel_termios_1(struct ktermios *k,
410 struct termios __user *u)
412 return copy_from_user(k, u, sizeof(struct termios));
414 __weak int kernel_termios_to_user_termios_1(struct termios __user *u,
417 return copy_to_user(u, k, sizeof(struct termios));
422 __weak int user_termios_to_kernel_termios(struct ktermios *k,
423 struct termios __user *u)
425 return copy_from_user(k, u, sizeof(struct termios));
427 __weak int kernel_termios_to_user_termios(struct termios __user *u,
430 return copy_to_user(u, k, sizeof(struct termios));
435 * set_termios - set termios values for a tty
436 * @tty: terminal device
438 * @opt: option information
440 * Helper function to prepare termios data and run necessary other functions
441 * before using tty_set_termios() to do the actual changes.
443 * Locking: called functions take &tty_struct->ldisc_sem and
444 * &tty_struct->termios_rwsem locks
446 * Returns: 0 on success, an error otherwise
448 static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
450 struct ktermios tmp_termios;
451 struct tty_ldisc *ld;
452 int retval = tty_check_change(tty);
457 down_read(&tty->termios_rwsem);
458 tmp_termios = tty->termios;
459 up_read(&tty->termios_rwsem);
461 if (opt & TERMIOS_TERMIO) {
462 if (user_termio_to_kernel_termios(&tmp_termios,
463 (struct termio __user *)arg))
466 } else if (opt & TERMIOS_OLD) {
467 if (user_termios_to_kernel_termios_1(&tmp_termios,
468 (struct termios __user *)arg))
471 if (user_termios_to_kernel_termios(&tmp_termios,
472 (struct termios2 __user *)arg))
476 } else if (user_termios_to_kernel_termios(&tmp_termios,
477 (struct termios __user *)arg))
481 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
482 * with the real speed so its unconditionally usable */
483 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
484 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
486 if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) {
488 retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty));
492 if (tty_write_lock(tty, false) < 0)
493 goto retry_write_wait;
496 if (tty_chars_in_buffer(tty)) {
497 tty_write_unlock(tty);
498 goto retry_write_wait;
501 ld = tty_ldisc_ref(tty);
503 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
504 ld->ops->flush_buffer(tty);
508 if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) {
509 tty->ops->wait_until_sent(tty, 0);
510 if (signal_pending(current)) {
511 tty_write_unlock(tty);
516 tty_set_termios(tty, &tmp_termios);
518 tty_write_unlock(tty);
520 tty_set_termios(tty, &tmp_termios);
523 /* FIXME: Arguably if tmp_termios == tty->termios AND the
524 actual requested termios was not tmp_termios then we may
525 want to return an error as no user requested change has
530 static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
532 down_read(&tty->termios_rwsem);
533 *kterm = tty->termios;
534 up_read(&tty->termios_rwsem);
537 static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
539 down_read(&tty->termios_rwsem);
540 *kterm = tty->termios_locked;
541 up_read(&tty->termios_rwsem);
544 static int get_termio(struct tty_struct *tty, struct termio __user *termio)
546 struct ktermios kterm;
547 copy_termios(tty, &kterm);
548 if (kernel_termios_to_user_termio(termio, &kterm))
555 * These are deprecated, but there is limited support..
557 * The "sg_flags" translation is a joke..
559 static int get_sgflags(struct tty_struct *tty)
563 if (!L_ICANON(tty)) {
565 flags |= 0x02; /* cbreak */
567 flags |= 0x20; /* raw */
570 flags |= 0x08; /* echo */
573 flags |= 0x10; /* crmod */
577 static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
581 down_read(&tty->termios_rwsem);
582 tmp.sg_ispeed = tty->termios.c_ispeed;
583 tmp.sg_ospeed = tty->termios.c_ospeed;
584 tmp.sg_erase = tty->termios.c_cc[VERASE];
585 tmp.sg_kill = tty->termios.c_cc[VKILL];
586 tmp.sg_flags = get_sgflags(tty);
587 up_read(&tty->termios_rwsem);
589 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
592 static void set_sgflags(struct ktermios *termios, int flags)
594 termios->c_iflag = ICRNL | IXON;
595 termios->c_oflag = 0;
596 termios->c_lflag = ISIG | ICANON;
597 if (flags & 0x02) { /* cbreak */
598 termios->c_iflag = 0;
599 termios->c_lflag &= ~ICANON;
601 if (flags & 0x08) { /* echo */
602 termios->c_lflag |= ECHO | ECHOE | ECHOK |
603 ECHOCTL | ECHOKE | IEXTEN;
605 if (flags & 0x10) { /* crmod */
606 termios->c_oflag |= OPOST | ONLCR;
608 if (flags & 0x20) { /* raw */
609 termios->c_iflag = 0;
610 termios->c_lflag &= ~(ISIG | ICANON);
612 if (!(termios->c_lflag & ICANON)) {
613 termios->c_cc[VMIN] = 1;
614 termios->c_cc[VTIME] = 0;
619 * set_sgttyb - set legacy terminal values
620 * @tty: tty structure
621 * @sgttyb: pointer to old style terminal structure
623 * Updates a terminal from the legacy BSD style terminal information structure.
625 * Locking: &tty_struct->termios_rwsem
627 * Returns: 0 on success, an error otherwise
629 static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
633 struct ktermios termios;
635 retval = tty_check_change(tty);
639 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
642 down_write(&tty->termios_rwsem);
643 termios = tty->termios;
644 termios.c_cc[VERASE] = tmp.sg_erase;
645 termios.c_cc[VKILL] = tmp.sg_kill;
646 set_sgflags(&termios, tmp.sg_flags);
647 /* Try and encode into Bfoo format */
648 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
650 up_write(&tty->termios_rwsem);
651 tty_set_termios(tty, &termios);
657 static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
661 down_read(&tty->termios_rwsem);
662 tmp.t_intrc = tty->termios.c_cc[VINTR];
663 tmp.t_quitc = tty->termios.c_cc[VQUIT];
664 tmp.t_startc = tty->termios.c_cc[VSTART];
665 tmp.t_stopc = tty->termios.c_cc[VSTOP];
666 tmp.t_eofc = tty->termios.c_cc[VEOF];
667 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
668 up_read(&tty->termios_rwsem);
669 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
672 static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
676 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
678 down_write(&tty->termios_rwsem);
679 tty->termios.c_cc[VINTR] = tmp.t_intrc;
680 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
681 tty->termios.c_cc[VSTART] = tmp.t_startc;
682 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
683 tty->termios.c_cc[VEOF] = tmp.t_eofc;
684 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
685 up_write(&tty->termios_rwsem);
691 static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
695 down_read(&tty->termios_rwsem);
696 tmp.t_suspc = tty->termios.c_cc[VSUSP];
697 /* what is dsuspc anyway? */
698 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
699 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
700 /* what is flushc anyway? */
701 tmp.t_flushc = tty->termios.c_cc[VEOL2];
702 tmp.t_werasc = tty->termios.c_cc[VWERASE];
703 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
704 up_read(&tty->termios_rwsem);
705 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
708 static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
712 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
715 down_write(&tty->termios_rwsem);
716 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
717 /* what is dsuspc anyway? */
718 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
719 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
720 /* what is flushc anyway? */
721 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
722 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
723 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
724 up_write(&tty->termios_rwsem);
730 * tty_change_softcar - carrier change ioctl helper
731 * @tty: tty to update
732 * @enable: enable/disable %CLOCAL
734 * Perform a change to the %CLOCAL state and call into the driver layer to make
737 * Locking: &tty_struct->termios_rwsem.
739 * Returns: 0 on success, an error otherwise
741 static int tty_change_softcar(struct tty_struct *tty, bool enable)
745 tcflag_t bit = enable ? CLOCAL : 0;
747 down_write(&tty->termios_rwsem);
749 tty->termios.c_cflag &= ~CLOCAL;
750 tty->termios.c_cflag |= bit;
751 if (tty->ops->set_termios)
752 tty->ops->set_termios(tty, &old);
753 if (C_CLOCAL(tty) != bit)
755 up_write(&tty->termios_rwsem);
760 * tty_mode_ioctl - mode related ioctls
761 * @tty: tty for the ioctl
763 * @arg: ioctl argument
765 * Perform non-line discipline specific mode control ioctls. This is designed
766 * to be called by line disciplines to ensure they provide consistent mode
769 int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
771 struct tty_struct *real_tty;
772 void __user *p = (void __user *)arg;
774 struct ktermios kterm;
776 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
777 tty->driver->subtype == PTY_TYPE_MASTER)
778 real_tty = tty->link;
785 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
788 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
792 return get_tchars(real_tty, p);
794 return set_tchars(real_tty, p);
798 return get_ltchars(real_tty, p);
800 return set_ltchars(real_tty, p);
803 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
805 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
807 return set_termios(real_tty, p, TERMIOS_OLD);
810 copy_termios(real_tty, &kterm);
811 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
816 copy_termios(real_tty, &kterm);
817 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
821 copy_termios(real_tty, &kterm);
822 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
826 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
828 return set_termios(real_tty, p, TERMIOS_WAIT);
830 return set_termios(real_tty, p, 0);
833 return get_termio(real_tty, p);
835 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
837 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
839 return set_termios(real_tty, p, TERMIOS_TERMIO);
842 copy_termios_locked(real_tty, &kterm);
843 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
847 if (!checkpoint_restore_ns_capable(&init_user_ns))
849 copy_termios_locked(real_tty, &kterm);
850 if (user_termios_to_kernel_termios(&kterm,
851 (struct termios __user *) arg))
853 down_write(&real_tty->termios_rwsem);
854 real_tty->termios_locked = kterm;
855 up_write(&real_tty->termios_rwsem);
859 copy_termios_locked(real_tty, &kterm);
860 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
864 if (!checkpoint_restore_ns_capable(&init_user_ns))
866 copy_termios_locked(real_tty, &kterm);
867 if (user_termios_to_kernel_termios_1(&kterm,
868 (struct termios __user *) arg))
870 down_write(&real_tty->termios_rwsem);
871 real_tty->termios_locked = kterm;
872 up_write(&real_tty->termios_rwsem);
883 copy_termios(real_tty, &kterm);
884 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
888 if (get_user(arg, (unsigned int __user *) arg))
890 return tty_change_softcar(real_tty, arg);
895 EXPORT_SYMBOL_GPL(tty_mode_ioctl);
898 /* Caller guarantees ldisc reference is held */
899 static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
901 struct tty_ldisc *ld = tty->ldisc;
905 if (ld && ld->ops->flush_buffer) {
906 ld->ops->flush_buffer(tty);
911 if (ld && ld->ops->flush_buffer) {
912 ld->ops->flush_buffer(tty);
917 tty_driver_flush_buffer(tty);
925 int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
927 struct tty_ldisc *ld;
928 int retval = tty_check_change(tty);
932 ld = tty_ldisc_ref_wait(tty);
933 retval = __tty_perform_flush(tty, arg);
938 EXPORT_SYMBOL_GPL(tty_perform_flush);
940 int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
947 retval = tty_check_change(tty);
952 spin_lock_irq(&tty->flow.lock);
953 if (!tty->flow.tco_stopped) {
954 tty->flow.tco_stopped = true;
957 spin_unlock_irq(&tty->flow.lock);
960 spin_lock_irq(&tty->flow.lock);
961 if (tty->flow.tco_stopped) {
962 tty->flow.tco_stopped = false;
965 spin_unlock_irq(&tty->flow.lock);
968 if (STOP_CHAR(tty) != __DISABLED_CHAR)
969 retval = tty_send_xchar(tty, STOP_CHAR(tty));
972 if (START_CHAR(tty) != __DISABLED_CHAR)
973 retval = tty_send_xchar(tty, START_CHAR(tty));
980 retval = tty_check_change(tty);
983 return __tty_perform_flush(tty, arg);
985 /* Try the mode commands */
986 return tty_mode_ioctl(tty, cmd, arg);
989 EXPORT_SYMBOL(n_tty_ioctl_helper);