2 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
4 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
5 * which can be dynamically activated and de-activated by the line
6 * discipline handling modules (like SLIP).
9 #include <linux/types.h>
10 #include <linux/termios.h>
11 #include <linux/errno.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/major.h>
15 #include <linux/tty.h>
16 #include <linux/fcntl.h>
17 #include <linux/string.h>
19 #include <linux/module.h>
20 #include <linux/bitops.h>
21 #include <linux/mutex.h>
22 #include <linux/compat.h>
25 #include <asm/uaccess.h>
27 #undef TTY_DEBUG_WAIT_UNTIL_SENT
32 * Internal flag options for termios setting behavior
34 #define TERMIOS_FLUSH 1
35 #define TERMIOS_WAIT 2
36 #define TERMIOS_TERMIO 4
41 * tty_chars_in_buffer - characters pending
44 * Return the number of bytes of data in the device private
45 * output queue. If no private method is supplied there is assumed
46 * to be no queue on the device.
49 int tty_chars_in_buffer(struct tty_struct *tty)
51 if (tty->ops->chars_in_buffer)
52 return tty->ops->chars_in_buffer(tty);
56 EXPORT_SYMBOL(tty_chars_in_buffer);
59 * tty_write_room - write queue space
62 * Return the number of bytes that can be queued to this device
63 * at the present time. The result should be treated as a guarantee
64 * and the driver cannot offer a value it later shrinks by more than
65 * the number of bytes written. If no method is provided 2K is always
66 * returned and data may be lost as there will be no flow control.
69 int tty_write_room(struct tty_struct *tty)
71 if (tty->ops->write_room)
72 return tty->ops->write_room(tty);
75 EXPORT_SYMBOL(tty_write_room);
78 * tty_driver_flush_buffer - discard internal buffer
81 * Discard the internal output buffer for this device. If no method
82 * is provided then either the buffer cannot be hardware flushed or
83 * there is no buffer driver side.
85 void tty_driver_flush_buffer(struct tty_struct *tty)
87 if (tty->ops->flush_buffer)
88 tty->ops->flush_buffer(tty);
90 EXPORT_SYMBOL(tty_driver_flush_buffer);
93 * tty_throttle - flow control
96 * Indicate that a tty should stop transmitting data down the stack.
97 * Takes the termios rwsem to protect against parallel throttle/unthrottle
98 * and also to ensure the driver can consistently reference its own
99 * termios data at this point when implementing software flow control.
102 void tty_throttle(struct tty_struct *tty)
104 down_write(&tty->termios_rwsem);
105 /* check TTY_THROTTLED first so it indicates our state */
106 if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
108 tty->ops->throttle(tty);
109 tty->flow_change = 0;
110 up_write(&tty->termios_rwsem);
112 EXPORT_SYMBOL(tty_throttle);
115 * tty_unthrottle - flow control
118 * Indicate that a tty may continue transmitting data down the stack.
119 * Takes the termios rwsem to protect against parallel throttle/unthrottle
120 * and also to ensure the driver can consistently reference its own
121 * termios data at this point when implementing software flow control.
123 * Drivers should however remember that the stack can issue a throttle,
124 * then change flow control method, then unthrottle.
127 void tty_unthrottle(struct tty_struct *tty)
129 down_write(&tty->termios_rwsem);
130 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
131 tty->ops->unthrottle)
132 tty->ops->unthrottle(tty);
133 tty->flow_change = 0;
134 up_write(&tty->termios_rwsem);
136 EXPORT_SYMBOL(tty_unthrottle);
139 * tty_throttle_safe - flow control
142 * Similar to tty_throttle() but will only attempt throttle
143 * if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
144 * throttle due to race conditions when throttling is conditional
145 * on factors evaluated prior to throttling.
147 * Returns 0 if tty is throttled (or was already throttled)
150 int tty_throttle_safe(struct tty_struct *tty)
154 mutex_lock(&tty->throttle_mutex);
155 if (!test_bit(TTY_THROTTLED, &tty->flags)) {
156 if (tty->flow_change != TTY_THROTTLE_SAFE)
159 set_bit(TTY_THROTTLED, &tty->flags);
160 if (tty->ops->throttle)
161 tty->ops->throttle(tty);
164 mutex_unlock(&tty->throttle_mutex);
170 * tty_unthrottle_safe - flow control
173 * Similar to tty_unthrottle() but will only attempt unthrottle
174 * if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
175 * unthrottle due to race conditions when unthrottling is conditional
176 * on factors evaluated prior to unthrottling.
178 * Returns 0 if tty is unthrottled (or was already unthrottled)
181 int tty_unthrottle_safe(struct tty_struct *tty)
185 mutex_lock(&tty->throttle_mutex);
186 if (test_bit(TTY_THROTTLED, &tty->flags)) {
187 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
190 clear_bit(TTY_THROTTLED, &tty->flags);
191 if (tty->ops->unthrottle)
192 tty->ops->unthrottle(tty);
195 mutex_unlock(&tty->throttle_mutex);
201 * tty_wait_until_sent - wait for I/O to finish
202 * @tty: tty we are waiting for
203 * @timeout: how long we will wait
205 * Wait for characters pending in a tty driver to hit the wire, or
206 * for a timeout to occur (eg due to flow control)
211 void tty_wait_until_sent(struct tty_struct *tty, long timeout)
213 #ifdef TTY_DEBUG_WAIT_UNTIL_SENT
216 printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
219 timeout = MAX_SCHEDULE_TIMEOUT;
220 if (wait_event_interruptible_timeout(tty->write_wait,
221 !tty_chars_in_buffer(tty), timeout) >= 0) {
222 if (tty->ops->wait_until_sent)
223 tty->ops->wait_until_sent(tty, timeout);
226 EXPORT_SYMBOL(tty_wait_until_sent);
230 * Termios Helper Methods
233 static void unset_locked_termios(struct ktermios *termios,
234 struct ktermios *old,
235 struct ktermios *locked)
239 #define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
242 printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
246 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
247 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
248 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
249 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
250 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
251 for (i = 0; i < NCCS; i++)
252 termios->c_cc[i] = locked->c_cc[i] ?
253 old->c_cc[i] : termios->c_cc[i];
254 /* FIXME: What should we do for i/ospeed */
258 * Routine which returns the baud rate of the tty
260 * Note that the baud_table needs to be kept in sync with the
261 * include/asm/termbits.h file.
263 static const speed_t baud_table[] = {
264 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
265 9600, 19200, 38400, 57600, 115200, 230400, 460800,
267 76800, 153600, 307200, 614400, 921600
269 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
270 2500000, 3000000, 3500000, 4000000
275 static const tcflag_t baud_bits[] = {
276 B0, B50, B75, B110, B134, B150, B200, B300, B600,
277 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
278 B57600, B115200, B230400, B460800, B500000, B576000,
279 B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
280 B3000000, B3500000, B4000000
283 static const tcflag_t baud_bits[] = {
284 B0, B50, B75, B110, B134, B150, B200, B300, B600,
285 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
286 B57600, B115200, B230400, B460800, B76800, B153600,
287 B307200, B614400, B921600
291 static int n_baud_table = ARRAY_SIZE(baud_table);
294 * tty_termios_baud_rate
295 * @termios: termios structure
297 * Convert termios baud rate data into a speed. This should be called
298 * with the termios lock held if this termios is a terminal termios
299 * structure. May change the termios data. Device drivers can call this
300 * function but should use ->c_[io]speed directly as they are updated.
305 speed_t tty_termios_baud_rate(struct ktermios *termios)
309 cbaud = termios->c_cflag & CBAUD;
312 /* Magic token for arbitrary speed via c_ispeed/c_ospeed */
314 return termios->c_ospeed;
316 if (cbaud & CBAUDEX) {
319 if (cbaud < 1 || cbaud + 15 > n_baud_table)
320 termios->c_cflag &= ~CBAUDEX;
324 return baud_table[cbaud];
326 EXPORT_SYMBOL(tty_termios_baud_rate);
329 * tty_termios_input_baud_rate
330 * @termios: termios structure
332 * Convert termios baud rate data into a speed. This should be called
333 * with the termios lock held if this termios is a terminal termios
334 * structure. May change the termios data. Device drivers can call this
335 * function but should use ->c_[io]speed directly as they are updated.
340 speed_t tty_termios_input_baud_rate(struct ktermios *termios)
343 unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
346 return tty_termios_baud_rate(termios);
348 /* Magic token for arbitrary speed via c_ispeed*/
350 return termios->c_ispeed;
352 if (cbaud & CBAUDEX) {
355 if (cbaud < 1 || cbaud + 15 > n_baud_table)
356 termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
360 return baud_table[cbaud];
362 return tty_termios_baud_rate(termios);
365 EXPORT_SYMBOL(tty_termios_input_baud_rate);
368 * tty_termios_encode_baud_rate
369 * @termios: ktermios structure holding user requested state
370 * @ispeed: input speed
371 * @ospeed: output speed
373 * Encode the speeds set into the passed termios structure. This is
374 * used as a library helper for drivers so that they can report back
375 * the actual speed selected when it differs from the speed requested
377 * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
378 * we need to carefully set the bits when the user does not get the
379 * desired speed. We allow small margins and preserve as much of possible
380 * of the input intent to keep compatibility.
382 * Locking: Caller should hold termios lock. This is already held
383 * when calling this function from the driver termios handler.
385 * The ifdefs deal with platforms whose owners have yet to update them
386 * and will all go away once this is done.
389 void tty_termios_encode_baud_rate(struct ktermios *termios,
390 speed_t ibaud, speed_t obaud)
393 int ifound = -1, ofound = -1;
394 int iclose = ibaud/50, oclose = obaud/50;
397 if (obaud == 0) /* CD dropped */
398 ibaud = 0; /* Clear ibaud to be sure */
400 termios->c_ispeed = ibaud;
401 termios->c_ospeed = obaud;
404 /* If the user asked for a precise weird speed give a precise weird
405 answer. If they asked for a Bfoo speed they may have problems
406 digesting non-exact replies so fuzz a bit */
408 if ((termios->c_cflag & CBAUD) == BOTHER)
410 if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
412 if ((termios->c_cflag >> IBSHIFT) & CBAUD)
413 ibinput = 1; /* An input speed was specified */
415 termios->c_cflag &= ~CBAUD;
418 * Our goal is to find a close match to the standard baud rate
419 * returned. Walk the baud rate table and if we get a very close
420 * match then report back the speed as a POSIX Bxxxx value by
425 if (obaud - oclose <= baud_table[i] &&
426 obaud + oclose >= baud_table[i]) {
427 termios->c_cflag |= baud_bits[i];
430 if (ibaud - iclose <= baud_table[i] &&
431 ibaud + iclose >= baud_table[i]) {
432 /* For the case input == output don't set IBAUD bits
433 if the user didn't do so */
434 if (ofound == i && !ibinput)
439 termios->c_cflag |= (baud_bits[i] << IBSHIFT);
443 } while (++i < n_baud_table);
446 * If we found no match then use BOTHER if provided or warn
447 * the user their platform maintainer needs to wake up if not.
451 termios->c_cflag |= BOTHER;
452 /* Set exact input bits only if the input and output differ or the
454 if (ifound == -1 && (ibaud != obaud || ibinput))
455 termios->c_cflag |= (BOTHER << IBSHIFT);
457 if (ifound == -1 || ofound == -1) {
458 printk_once(KERN_WARNING "tty: Unable to return correct "
459 "speed data as your architecture needs updating.\n");
463 EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
466 * tty_encode_baud_rate - set baud rate of the tty
467 * @ibaud: input baud rate
468 * @obad: output baud rate
470 * Update the current termios data for the tty with the new speed
471 * settings. The caller must hold the termios_rwsem for the tty in
475 void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
477 tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
479 EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
482 * tty_termios_copy_hw - copy hardware settings
486 * Propagate the hardware specific terminal setting bits from
487 * the old termios structure to the new one. This is used in cases
488 * where the hardware does not support reconfiguration or as a helper
489 * in some cases where only minimal reconfiguration is supported
492 void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
494 /* The bits a dumb device handles in software. Smart devices need
495 to always provide a set_termios method */
496 new->c_cflag &= HUPCL | CREAD | CLOCAL;
497 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
498 new->c_ispeed = old->c_ispeed;
499 new->c_ospeed = old->c_ospeed;
501 EXPORT_SYMBOL(tty_termios_copy_hw);
504 * tty_termios_hw_change - check for setting change
506 * @b: termios to compare
508 * Check if any of the bits that affect a dumb device have changed
509 * between the two termios structures, or a speed change is needed.
512 int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
514 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
516 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
520 EXPORT_SYMBOL(tty_termios_hw_change);
523 * tty_set_termios - update termios values
524 * @tty: tty to update
525 * @new_termios: desired new value
527 * Perform updates to the termios values set on this terminal.
528 * A master pty's termios should never be set.
530 * Locking: termios_rwsem
533 static int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
535 struct ktermios old_termios;
536 struct tty_ldisc *ld;
538 WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
539 tty->driver->subtype == PTY_TYPE_MASTER);
541 * Perform the actual termios internal changes under lock.
545 /* FIXME: we need to decide on some locking/ordering semantics
546 for the set_termios notification eventually */
547 down_write(&tty->termios_rwsem);
548 old_termios = tty->termios;
549 tty->termios = *new_termios;
550 unset_locked_termios(&tty->termios, &old_termios, &tty->termios_locked);
552 if (tty->ops->set_termios)
553 tty->ops->set_termios(tty, &old_termios);
555 tty_termios_copy_hw(&tty->termios, &old_termios);
557 ld = tty_ldisc_ref(tty);
559 if (ld->ops->set_termios)
560 ld->ops->set_termios(tty, &old_termios);
563 up_write(&tty->termios_rwsem);
568 * set_termios - set termios values for a tty
569 * @tty: terminal device
571 * @opt: option information
573 * Helper function to prepare termios data and run necessary other
574 * functions before using tty_set_termios to do the actual changes.
577 * Called functions take ldisc and termios_rwsem locks
580 static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
582 struct ktermios tmp_termios;
583 struct tty_ldisc *ld;
584 int retval = tty_check_change(tty);
589 down_read(&tty->termios_rwsem);
590 tmp_termios = tty->termios;
591 up_read(&tty->termios_rwsem);
593 if (opt & TERMIOS_TERMIO) {
594 if (user_termio_to_kernel_termios(&tmp_termios,
595 (struct termio __user *)arg))
598 } else if (opt & TERMIOS_OLD) {
599 if (user_termios_to_kernel_termios_1(&tmp_termios,
600 (struct termios __user *)arg))
603 if (user_termios_to_kernel_termios(&tmp_termios,
604 (struct termios2 __user *)arg))
608 } else if (user_termios_to_kernel_termios(&tmp_termios,
609 (struct termios __user *)arg))
613 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
614 * with the real speed so its unconditionally usable */
615 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
616 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
618 ld = tty_ldisc_ref(tty);
621 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
622 ld->ops->flush_buffer(tty);
626 if (opt & TERMIOS_WAIT) {
627 tty_wait_until_sent(tty, 0);
628 if (signal_pending(current))
632 tty_set_termios(tty, &tmp_termios);
634 /* FIXME: Arguably if tmp_termios == tty->termios AND the
635 actual requested termios was not tmp_termios then we may
636 want to return an error as no user requested change has
641 static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
643 down_read(&tty->termios_rwsem);
644 *kterm = tty->termios;
645 up_read(&tty->termios_rwsem);
648 static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
650 down_read(&tty->termios_rwsem);
651 *kterm = tty->termios_locked;
652 up_read(&tty->termios_rwsem);
655 static int get_termio(struct tty_struct *tty, struct termio __user *termio)
657 struct ktermios kterm;
658 copy_termios(tty, &kterm);
659 if (kernel_termios_to_user_termio(termio, &kterm))
668 * set_termiox - set termiox fields if possible
670 * @arg: termiox structure from user
671 * @opt: option flags for ioctl type
673 * Implement the device calling points for the SYS5 termiox ioctl
677 static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
680 struct tty_ldisc *ld;
682 if (tty->termiox == NULL)
684 if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
687 ld = tty_ldisc_ref(tty);
689 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
690 ld->ops->flush_buffer(tty);
693 if (opt & TERMIOS_WAIT) {
694 tty_wait_until_sent(tty, 0);
695 if (signal_pending(current))
699 down_write(&tty->termios_rwsem);
700 if (tty->ops->set_termiox)
701 tty->ops->set_termiox(tty, &tnew);
702 up_write(&tty->termios_rwsem);
711 * These are deprecated, but there is limited support..
713 * The "sg_flags" translation is a joke..
715 static int get_sgflags(struct tty_struct *tty)
719 if (!(tty->termios.c_lflag & ICANON)) {
720 if (tty->termios.c_lflag & ISIG)
721 flags |= 0x02; /* cbreak */
723 flags |= 0x20; /* raw */
725 if (tty->termios.c_lflag & ECHO)
726 flags |= 0x08; /* echo */
727 if (tty->termios.c_oflag & OPOST)
728 if (tty->termios.c_oflag & ONLCR)
729 flags |= 0x10; /* crmod */
733 static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
737 down_read(&tty->termios_rwsem);
738 tmp.sg_ispeed = tty->termios.c_ispeed;
739 tmp.sg_ospeed = tty->termios.c_ospeed;
740 tmp.sg_erase = tty->termios.c_cc[VERASE];
741 tmp.sg_kill = tty->termios.c_cc[VKILL];
742 tmp.sg_flags = get_sgflags(tty);
743 up_read(&tty->termios_rwsem);
745 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
748 static void set_sgflags(struct ktermios *termios, int flags)
750 termios->c_iflag = ICRNL | IXON;
751 termios->c_oflag = 0;
752 termios->c_lflag = ISIG | ICANON;
753 if (flags & 0x02) { /* cbreak */
754 termios->c_iflag = 0;
755 termios->c_lflag &= ~ICANON;
757 if (flags & 0x08) { /* echo */
758 termios->c_lflag |= ECHO | ECHOE | ECHOK |
759 ECHOCTL | ECHOKE | IEXTEN;
761 if (flags & 0x10) { /* crmod */
762 termios->c_oflag |= OPOST | ONLCR;
764 if (flags & 0x20) { /* raw */
765 termios->c_iflag = 0;
766 termios->c_lflag &= ~(ISIG | ICANON);
768 if (!(termios->c_lflag & ICANON)) {
769 termios->c_cc[VMIN] = 1;
770 termios->c_cc[VTIME] = 0;
775 * set_sgttyb - set legacy terminal values
776 * @tty: tty structure
777 * @sgttyb: pointer to old style terminal structure
779 * Updates a terminal from the legacy BSD style terminal information
782 * Locking: termios_rwsem
785 static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
789 struct ktermios termios;
791 retval = tty_check_change(tty);
795 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
798 down_write(&tty->termios_rwsem);
799 termios = tty->termios;
800 termios.c_cc[VERASE] = tmp.sg_erase;
801 termios.c_cc[VKILL] = tmp.sg_kill;
802 set_sgflags(&termios, tmp.sg_flags);
803 /* Try and encode into Bfoo format */
805 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
808 up_write(&tty->termios_rwsem);
809 tty_set_termios(tty, &termios);
815 static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
819 down_read(&tty->termios_rwsem);
820 tmp.t_intrc = tty->termios.c_cc[VINTR];
821 tmp.t_quitc = tty->termios.c_cc[VQUIT];
822 tmp.t_startc = tty->termios.c_cc[VSTART];
823 tmp.t_stopc = tty->termios.c_cc[VSTOP];
824 tmp.t_eofc = tty->termios.c_cc[VEOF];
825 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
826 up_read(&tty->termios_rwsem);
827 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
830 static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
834 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
836 down_write(&tty->termios_rwsem);
837 tty->termios.c_cc[VINTR] = tmp.t_intrc;
838 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
839 tty->termios.c_cc[VSTART] = tmp.t_startc;
840 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
841 tty->termios.c_cc[VEOF] = tmp.t_eofc;
842 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
843 up_write(&tty->termios_rwsem);
849 static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
853 down_read(&tty->termios_rwsem);
854 tmp.t_suspc = tty->termios.c_cc[VSUSP];
855 /* what is dsuspc anyway? */
856 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
857 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
858 /* what is flushc anyway? */
859 tmp.t_flushc = tty->termios.c_cc[VEOL2];
860 tmp.t_werasc = tty->termios.c_cc[VWERASE];
861 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
862 up_read(&tty->termios_rwsem);
863 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
866 static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
870 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
873 down_write(&tty->termios_rwsem);
874 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
875 /* what is dsuspc anyway? */
876 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
877 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
878 /* what is flushc anyway? */
879 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
880 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
881 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
882 up_write(&tty->termios_rwsem);
888 * tty_change_softcar - carrier change ioctl helper
889 * @tty: tty to update
890 * @arg: enable/disable CLOCAL
892 * Perform a change to the CLOCAL state and call into the driver
893 * layer to make it visible. All done with the termios rwsem
896 static int tty_change_softcar(struct tty_struct *tty, int arg)
899 int bit = arg ? CLOCAL : 0;
902 down_write(&tty->termios_rwsem);
904 tty->termios.c_cflag &= ~CLOCAL;
905 tty->termios.c_cflag |= bit;
906 if (tty->ops->set_termios)
907 tty->ops->set_termios(tty, &old);
908 if ((tty->termios.c_cflag & CLOCAL) != bit)
910 up_write(&tty->termios_rwsem);
915 * tty_mode_ioctl - mode related ioctls
916 * @tty: tty for the ioctl
917 * @file: file pointer for the tty
919 * @arg: ioctl argument
921 * Perform non line discipline specific mode control ioctls. This
922 * is designed to be called by line disciplines to ensure they provide
923 * consistent mode setting.
926 int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
927 unsigned int cmd, unsigned long arg)
929 struct tty_struct *real_tty;
930 void __user *p = (void __user *)arg;
932 struct ktermios kterm;
934 BUG_ON(file == NULL);
936 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
937 tty->driver->subtype == PTY_TYPE_MASTER)
938 real_tty = tty->link;
945 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
948 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
952 return get_tchars(real_tty, p);
954 return set_tchars(real_tty, p);
958 return get_ltchars(real_tty, p);
960 return set_ltchars(real_tty, p);
963 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
965 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
967 return set_termios(real_tty, p, TERMIOS_OLD);
970 copy_termios(real_tty, &kterm);
971 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
976 copy_termios(real_tty, &kterm);
977 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
981 copy_termios(real_tty, &kterm);
982 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
986 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
988 return set_termios(real_tty, p, TERMIOS_WAIT);
990 return set_termios(real_tty, p, 0);
993 return get_termio(real_tty, p);
995 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
997 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
999 return set_termios(real_tty, p, TERMIOS_TERMIO);
1001 case TIOCGLCKTRMIOS:
1002 copy_termios_locked(real_tty, &kterm);
1003 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
1006 case TIOCSLCKTRMIOS:
1007 if (!capable(CAP_SYS_ADMIN))
1009 copy_termios_locked(real_tty, &kterm);
1010 if (user_termios_to_kernel_termios(&kterm,
1011 (struct termios __user *) arg))
1013 down_write(&real_tty->termios_rwsem);
1014 real_tty->termios_locked = kterm;
1015 up_write(&real_tty->termios_rwsem);
1018 case TIOCGLCKTRMIOS:
1019 copy_termios_locked(real_tty, &kterm);
1020 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
1023 case TIOCSLCKTRMIOS:
1024 if (!capable(CAP_SYS_ADMIN))
1026 copy_termios_locked(real_tty, &kterm);
1027 if (user_termios_to_kernel_termios_1(&kterm,
1028 (struct termios __user *) arg))
1030 down_write(&real_tty->termios_rwsem);
1031 real_tty->termios_locked = kterm;
1032 up_write(&real_tty->termios_rwsem);
1037 struct termiox ktermx;
1038 if (real_tty->termiox == NULL)
1040 down_read(&real_tty->termios_rwsem);
1041 memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
1042 up_read(&real_tty->termios_rwsem);
1043 if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
1048 return set_termiox(real_tty, p, 0);
1050 return set_termiox(real_tty, p, TERMIOS_WAIT);
1052 return set_termiox(real_tty, p, TERMIOS_FLUSH);
1055 copy_termios(real_tty, &kterm);
1056 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
1060 if (get_user(arg, (unsigned int __user *) arg))
1062 return tty_change_softcar(real_tty, arg);
1064 return -ENOIOCTLCMD;
1067 EXPORT_SYMBOL_GPL(tty_mode_ioctl);
1070 /* Caller guarantees ldisc reference is held */
1071 static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
1073 struct tty_ldisc *ld = tty->ldisc;
1077 if (ld && ld->ops->flush_buffer) {
1078 ld->ops->flush_buffer(tty);
1079 tty_unthrottle(tty);
1083 if (ld && ld->ops->flush_buffer) {
1084 ld->ops->flush_buffer(tty);
1085 tty_unthrottle(tty);
1089 tty_driver_flush_buffer(tty);
1097 int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
1099 struct tty_ldisc *ld;
1100 int retval = tty_check_change(tty);
1104 ld = tty_ldisc_ref_wait(tty);
1105 retval = __tty_perform_flush(tty, arg);
1107 tty_ldisc_deref(ld);
1110 EXPORT_SYMBOL_GPL(tty_perform_flush);
1112 int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
1113 unsigned int cmd, unsigned long arg)
1119 retval = tty_check_change(tty);
1124 spin_lock_irq(&tty->flow_lock);
1125 if (!tty->flow_stopped) {
1126 tty->flow_stopped = 1;
1129 spin_unlock_irq(&tty->flow_lock);
1132 spin_lock_irq(&tty->flow_lock);
1133 if (tty->flow_stopped) {
1134 tty->flow_stopped = 0;
1137 spin_unlock_irq(&tty->flow_lock);
1140 down_read(&tty->termios_rwsem);
1141 if (STOP_CHAR(tty) != __DISABLED_CHAR)
1142 retval = tty_send_xchar(tty, STOP_CHAR(tty));
1143 up_read(&tty->termios_rwsem);
1146 down_read(&tty->termios_rwsem);
1147 if (START_CHAR(tty) != __DISABLED_CHAR)
1148 retval = tty_send_xchar(tty, START_CHAR(tty));
1149 up_read(&tty->termios_rwsem);
1156 retval = tty_check_change(tty);
1159 return __tty_perform_flush(tty, arg);
1161 /* Try the mode commands */
1162 return tty_mode_ioctl(tty, file, cmd, arg);
1165 EXPORT_SYMBOL(n_tty_ioctl_helper);
1167 #ifdef CONFIG_COMPAT
1168 long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
1169 unsigned int cmd, unsigned long arg)
1172 case TIOCGLCKTRMIOS:
1173 case TIOCSLCKTRMIOS:
1174 return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg));
1176 return -ENOIOCTLCMD;
1179 EXPORT_SYMBOL(n_tty_compat_ioctl_helper);