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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
4 | * | |
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). | |
8 | */ | |
9 | ||
0b05223b | 10 | #include <linux/bits.h> |
1da177e4 LT |
11 | #include <linux/types.h> |
12 | #include <linux/termios.h> | |
13 | #include <linux/errno.h> | |
174cd4b1 | 14 | #include <linux/sched/signal.h> |
1da177e4 LT |
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> | |
20 | #include <linux/mm.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/bitops.h> | |
5785c95b | 23 | #include <linux/mutex.h> |
8193c429 | 24 | #include <linux/compat.h> |
c9874d3f | 25 | #include <linux/termios_internal.h> |
9f72cab1 | 26 | #include "tty.h" |
1da177e4 LT |
27 | |
28 | #include <asm/io.h> | |
7c0f6ba6 | 29 | #include <linux/uaccess.h> |
1da177e4 | 30 | |
1da177e4 LT |
31 | #undef DEBUG |
32 | ||
33 | /* | |
34 | * Internal flag options for termios setting behavior | |
35 | */ | |
0b05223b IJ |
36 | #define TERMIOS_FLUSH BIT(0) |
37 | #define TERMIOS_WAIT BIT(1) | |
38 | #define TERMIOS_TERMIO BIT(2) | |
39 | #define TERMIOS_OLD BIT(3) | |
1da177e4 | 40 | |
d81ed103 | 41 | /** |
3b1a696b JSS |
42 | * tty_chars_in_buffer - characters pending |
43 | * @tty: terminal | |
d81ed103 | 44 | * |
3b1a696b JSS |
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. | |
d81ed103 | 47 | */ |
fff4ef17 | 48 | unsigned int tty_chars_in_buffer(struct tty_struct *tty) |
f34d7a5b AC |
49 | { |
50 | if (tty->ops->chars_in_buffer) | |
51 | return tty->ops->chars_in_buffer(tty); | |
ab78b0c9 | 52 | return 0; |
f34d7a5b | 53 | } |
f34d7a5b AC |
54 | EXPORT_SYMBOL(tty_chars_in_buffer); |
55 | ||
d81ed103 | 56 | /** |
3b1a696b JSS |
57 | * tty_write_room - write queue space |
58 | * @tty: terminal | |
d81ed103 | 59 | * |
3b1a696b JSS |
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. | |
d81ed103 | 65 | */ |
03b3b1a2 | 66 | unsigned int tty_write_room(struct tty_struct *tty) |
f34d7a5b AC |
67 | { |
68 | if (tty->ops->write_room) | |
69 | return tty->ops->write_room(tty); | |
70 | return 2048; | |
71 | } | |
f34d7a5b AC |
72 | EXPORT_SYMBOL(tty_write_room); |
73 | ||
d81ed103 | 74 | /** |
3b1a696b JSS |
75 | * tty_driver_flush_buffer - discard internal buffer |
76 | * @tty: terminal | |
d81ed103 | 77 | * |
3b1a696b JSS |
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 | |
80 | * driver side. | |
d81ed103 | 81 | */ |
f34d7a5b AC |
82 | void tty_driver_flush_buffer(struct tty_struct *tty) |
83 | { | |
84 | if (tty->ops->flush_buffer) | |
85 | tty->ops->flush_buffer(tty); | |
86 | } | |
f34d7a5b AC |
87 | EXPORT_SYMBOL(tty_driver_flush_buffer); |
88 | ||
d81ed103 | 89 | /** |
3b1a696b JSS |
90 | * tty_unthrottle - flow control |
91 | * @tty: terminal | |
d81ed103 | 92 | * |
3b1a696b JSS |
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. | |
38db8979 | 97 | * |
3b1a696b JSS |
98 | * Drivers should however remember that the stack can issue a throttle, then |
99 | * change flow control method, then unthrottle. | |
d81ed103 | 100 | */ |
39c2e60f AC |
101 | void tty_unthrottle(struct tty_struct *tty) |
102 | { | |
6a1c0680 | 103 | down_write(&tty->termios_rwsem); |
39c2e60f AC |
104 | if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) && |
105 | tty->ops->unthrottle) | |
106 | tty->ops->unthrottle(tty); | |
e5d0424a | 107 | tty->flow_change = TTY_FLOW_NO_CHANGE; |
6a1c0680 | 108 | up_write(&tty->termios_rwsem); |
39c2e60f AC |
109 | } |
110 | EXPORT_SYMBOL(tty_unthrottle); | |
f34d7a5b | 111 | |
70bc1264 | 112 | /** |
3b1a696b JSS |
113 | * tty_throttle_safe - flow control |
114 | * @tty: terminal | |
70bc1264 | 115 | * |
3b1a696b JSS |
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. | |
70bc1264 | 120 | * |
3b1a696b | 121 | * Returns: %true if @tty is throttled (or was already throttled) |
70bc1264 | 122 | */ |
c2a36609 | 123 | bool tty_throttle_safe(struct tty_struct *tty) |
70bc1264 | 124 | { |
5b4f9cf3 | 125 | bool ret = true; |
70bc1264 | 126 | |
d8c1f929 | 127 | mutex_lock(&tty->throttle_mutex); |
97ef38b8 | 128 | if (!tty_throttled(tty)) { |
70bc1264 | 129 | if (tty->flow_change != TTY_THROTTLE_SAFE) |
5b4f9cf3 | 130 | ret = false; |
70bc1264 | 131 | else { |
579a00a5 | 132 | set_bit(TTY_THROTTLED, &tty->flags); |
70bc1264 PH |
133 | if (tty->ops->throttle) |
134 | tty->ops->throttle(tty); | |
135 | } | |
136 | } | |
d8c1f929 | 137 | mutex_unlock(&tty->throttle_mutex); |
70bc1264 PH |
138 | |
139 | return ret; | |
140 | } | |
141 | ||
142 | /** | |
3b1a696b JSS |
143 | * tty_unthrottle_safe - flow control |
144 | * @tty: terminal | |
70bc1264 | 145 | * |
3b1a696b JSS |
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. | |
70bc1264 | 150 | * |
3b1a696b | 151 | * Returns: %true if @tty is unthrottled (or was already unthrottled) |
70bc1264 | 152 | */ |
c2a36609 | 153 | bool tty_unthrottle_safe(struct tty_struct *tty) |
70bc1264 | 154 | { |
5b4f9cf3 | 155 | bool ret = true; |
70bc1264 | 156 | |
d8c1f929 | 157 | mutex_lock(&tty->throttle_mutex); |
97ef38b8 | 158 | if (tty_throttled(tty)) { |
70bc1264 | 159 | if (tty->flow_change != TTY_UNTHROTTLE_SAFE) |
5b4f9cf3 | 160 | ret = false; |
70bc1264 | 161 | else { |
579a00a5 | 162 | clear_bit(TTY_THROTTLED, &tty->flags); |
70bc1264 PH |
163 | if (tty->ops->unthrottle) |
164 | tty->ops->unthrottle(tty); | |
165 | } | |
166 | } | |
d8c1f929 | 167 | mutex_unlock(&tty->throttle_mutex); |
70bc1264 PH |
168 | |
169 | return ret; | |
170 | } | |
171 | ||
af9b897e | 172 | /** |
3b1a696b JSS |
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 | |
af9b897e | 176 | * |
3b1a696b JSS |
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). | |
af9b897e | 179 | * |
3b1a696b | 180 | * Locking: none |
af9b897e AC |
181 | */ |
182 | ||
355d95a1 | 183 | void tty_wait_until_sent(struct tty_struct *tty, long timeout) |
1da177e4 | 184 | { |
1da177e4 LT |
185 | if (!timeout) |
186 | timeout = MAX_SCHEDULE_TIMEOUT; | |
79fbf4a5 | 187 | |
c37bc682 JH |
188 | timeout = wait_event_interruptible_timeout(tty->write_wait, |
189 | !tty_chars_in_buffer(tty), timeout); | |
190 | if (timeout <= 0) | |
79fbf4a5 | 191 | return; |
79fbf4a5 JH |
192 | |
193 | if (timeout == MAX_SCHEDULE_TIMEOUT) | |
194 | timeout = 0; | |
195 | ||
196 | if (tty->ops->wait_until_sent) | |
197 | tty->ops->wait_until_sent(tty, timeout); | |
1da177e4 | 198 | } |
1da177e4 LT |
199 | EXPORT_SYMBOL(tty_wait_until_sent); |
200 | ||
d81ed103 AC |
201 | |
202 | /* | |
203 | * Termios Helper Methods | |
204 | */ | |
205 | ||
bec5b814 | 206 | static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old) |
1da177e4 | 207 | { |
d97ba9cd PH |
208 | struct ktermios *termios = &tty->termios; |
209 | struct ktermios *locked = &tty->termios_locked; | |
1da177e4 | 210 | int i; |
355d95a1 AC |
211 | |
212 | #define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z))) | |
1da177e4 | 213 | |
1da177e4 LT |
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; | |
355d95a1 | 219 | for (i = 0; i < NCCS; i++) |
1da177e4 LT |
220 | termios->c_cc[i] = locked->c_cc[i] ? |
221 | old->c_cc[i] : termios->c_cc[i]; | |
edc6afc5 | 222 | /* FIXME: What should we do for i/ospeed */ |
1da177e4 LT |
223 | } |
224 | ||
5f519d72 | 225 | /** |
3b1a696b JSS |
226 | * tty_termios_copy_hw - copy hardware settings |
227 | * @new: new termios | |
228 | * @old: old termios | |
5f519d72 | 229 | * |
3b1a696b JSS |
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. | |
5f519d72 | 234 | */ |
d15f89d9 | 235 | void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old) |
5f519d72 AC |
236 | { |
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; | |
243 | } | |
5f519d72 AC |
244 | EXPORT_SYMBOL(tty_termios_copy_hw); |
245 | ||
bf5e5834 | 246 | /** |
3b1a696b JSS |
247 | * tty_termios_hw_change - check for setting change |
248 | * @a: termios | |
249 | * @b: termios to compare | |
bf5e5834 | 250 | * |
3b1a696b JSS |
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. | |
253 | * | |
254 | * Returns: %true if change is needed | |
bf5e5834 | 255 | */ |
87f22db4 | 256 | bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b) |
bf5e5834 AC |
257 | { |
258 | if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed) | |
87f22db4 | 259 | return true; |
bf5e5834 | 260 | if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL)) |
87f22db4 IJ |
261 | return true; |
262 | return false; | |
bf5e5834 AC |
263 | } |
264 | EXPORT_SYMBOL(tty_termios_hw_change); | |
265 | ||
654ee49b | 266 | /** |
3b1a696b JSS |
267 | * tty_get_char_size - get size of a character |
268 | * @cflag: termios cflag value | |
654ee49b | 269 | * |
3b1a696b | 270 | * Returns: size (in bits) of a character depending on @cflag's %CSIZE setting |
654ee49b JS |
271 | */ |
272 | unsigned char tty_get_char_size(unsigned int cflag) | |
273 | { | |
274 | switch (cflag & CSIZE) { | |
275 | case CS5: | |
276 | return 5; | |
277 | case CS6: | |
278 | return 6; | |
279 | case CS7: | |
280 | return 7; | |
281 | case CS8: | |
282 | default: | |
283 | return 8; | |
284 | } | |
285 | } | |
286 | EXPORT_SYMBOL_GPL(tty_get_char_size); | |
287 | ||
288 | /** | |
3b1a696b JSS |
289 | * tty_get_frame_size - get size of a frame |
290 | * @cflag: termios cflag value | |
654ee49b | 291 | * |
3b1a696b JSS |
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). | |
295 | * | |
296 | * Returns: size (in bits) of a frame depending on @cflag's setting. | |
654ee49b JS |
297 | */ |
298 | unsigned char tty_get_frame_size(unsigned int cflag) | |
299 | { | |
300 | unsigned char bits = 2 + tty_get_char_size(cflag); | |
301 | ||
302 | if (cflag & CSTOPB) | |
303 | bits++; | |
304 | if (cflag & PARENB) | |
305 | bits++; | |
4f768e94 IJ |
306 | if (cflag & ADDRB) |
307 | bits++; | |
654ee49b JS |
308 | |
309 | return bits; | |
310 | } | |
311 | EXPORT_SYMBOL_GPL(tty_get_frame_size); | |
312 | ||
af9b897e | 313 | /** |
3b1a696b JSS |
314 | * tty_set_termios - update termios values |
315 | * @tty: tty to update | |
316 | * @new_termios: desired new value | |
af9b897e | 317 | * |
3b1a696b JSS |
318 | * Perform updates to the termios values set on this @tty. A master pty's |
319 | * termios should never be set. | |
6460fbbf | 320 | * |
3b1a696b | 321 | * Locking: &tty_struct->termios_rwsem |
af9b897e | 322 | */ |
b00f5c2d | 323 | int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) |
1da177e4 | 324 | { |
978e595f | 325 | struct ktermios old_termios; |
1da177e4 | 326 | struct tty_ldisc *ld; |
355d95a1 | 327 | |
6460fbbf PH |
328 | WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && |
329 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1da177e4 LT |
330 | /* |
331 | * Perform the actual termios internal changes under lock. | |
332 | */ | |
355d95a1 | 333 | |
1da177e4 LT |
334 | |
335 | /* FIXME: we need to decide on some locking/ordering semantics | |
336 | for the set_termios notification eventually */ | |
6a1c0680 | 337 | down_write(&tty->termios_rwsem); |
adc8d746 AC |
338 | old_termios = tty->termios; |
339 | tty->termios = *new_termios; | |
d97ba9cd | 340 | unset_locked_termios(tty, &old_termios); |
4f768e94 IJ |
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; | |
1da177e4 | 343 | |
f34d7a5b | 344 | if (tty->ops->set_termios) |
c961bfb1 | 345 | tty->ops->set_termios(tty, &old_termios); |
5f519d72 | 346 | else |
adc8d746 | 347 | tty_termios_copy_hw(&tty->termios, &old_termios); |
1da177e4 LT |
348 | |
349 | ld = tty_ldisc_ref(tty); | |
350 | if (ld != NULL) { | |
a352def2 | 351 | if (ld->ops->set_termios) |
c961bfb1 | 352 | ld->ops->set_termios(tty, &old_termios); |
1da177e4 LT |
353 | tty_ldisc_deref(ld); |
354 | } | |
6a1c0680 | 355 | up_write(&tty->termios_rwsem); |
8d075b19 | 356 | return 0; |
1da177e4 | 357 | } |
b00f5c2d | 358 | EXPORT_SYMBOL_GPL(tty_set_termios); |
1da177e4 | 359 | |
1d5d6682 AV |
360 | |
361 | /* | |
362 | * Translate a "termio" structure into a "termios". Ugh. | |
363 | */ | |
364 | __weak int user_termio_to_kernel_termios(struct ktermios *termios, | |
365 | struct termio __user *termio) | |
366 | { | |
367 | struct termio v; | |
368 | ||
369 | if (copy_from_user(&v, termio, sizeof(struct termio))) | |
370 | return -EFAULT; | |
371 | ||
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); | |
378 | return 0; | |
379 | } | |
380 | ||
381 | /* | |
382 | * Translate a "termios" structure into a "termio". Ugh. | |
383 | */ | |
384 | __weak int kernel_termios_to_user_termio(struct termio __user *termio, | |
385 | struct ktermios *termios) | |
386 | { | |
387 | struct termio v; | |
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)); | |
396 | } | |
397 | ||
398 | #ifdef TCGETS2 | |
399 | __weak int user_termios_to_kernel_termios(struct ktermios *k, | |
400 | struct termios2 __user *u) | |
401 | { | |
402 | return copy_from_user(k, u, sizeof(struct termios2)); | |
403 | } | |
404 | __weak int kernel_termios_to_user_termios(struct termios2 __user *u, | |
405 | struct ktermios *k) | |
406 | { | |
407 | return copy_to_user(u, k, sizeof(struct termios2)); | |
408 | } | |
409 | __weak int user_termios_to_kernel_termios_1(struct ktermios *k, | |
410 | struct termios __user *u) | |
411 | { | |
412 | return copy_from_user(k, u, sizeof(struct termios)); | |
413 | } | |
414 | __weak int kernel_termios_to_user_termios_1(struct termios __user *u, | |
415 | struct ktermios *k) | |
416 | { | |
417 | return copy_to_user(u, k, sizeof(struct termios)); | |
418 | } | |
419 | ||
420 | #else | |
421 | ||
422 | __weak int user_termios_to_kernel_termios(struct ktermios *k, | |
423 | struct termios __user *u) | |
424 | { | |
425 | return copy_from_user(k, u, sizeof(struct termios)); | |
426 | } | |
427 | __weak int kernel_termios_to_user_termios(struct termios __user *u, | |
428 | struct ktermios *k) | |
429 | { | |
430 | return copy_to_user(u, k, sizeof(struct termios)); | |
431 | } | |
432 | #endif /* TCGETS2 */ | |
433 | ||
af9b897e | 434 | /** |
3b1a696b JSS |
435 | * set_termios - set termios values for a tty |
436 | * @tty: terminal device | |
437 | * @arg: user data | |
438 | * @opt: option information | |
af9b897e | 439 | * |
3b1a696b JSS |
440 | * Helper function to prepare termios data and run necessary other functions |
441 | * before using tty_set_termios() to do the actual changes. | |
af9b897e | 442 | * |
3b1a696b JSS |
443 | * Locking: called functions take &tty_struct->ldisc_sem and |
444 | * &tty_struct->termios_rwsem locks | |
445 | * | |
446 | * Returns: 0 on success, an error otherwise | |
af9b897e | 447 | */ |
355d95a1 | 448 | static int set_termios(struct tty_struct *tty, void __user *arg, int opt) |
1da177e4 | 449 | { |
edc6afc5 | 450 | struct ktermios tmp_termios; |
1da177e4 LT |
451 | struct tty_ldisc *ld; |
452 | int retval = tty_check_change(tty); | |
453 | ||
454 | if (retval) | |
455 | return retval; | |
456 | ||
6a1c0680 | 457 | down_read(&tty->termios_rwsem); |
adc8d746 | 458 | tmp_termios = tty->termios; |
6a1c0680 | 459 | up_read(&tty->termios_rwsem); |
64bb6c5e | 460 | |
1da177e4 | 461 | if (opt & TERMIOS_TERMIO) { |
1da177e4 LT |
462 | if (user_termio_to_kernel_termios(&tmp_termios, |
463 | (struct termio __user *)arg)) | |
464 | return -EFAULT; | |
edc6afc5 AC |
465 | #ifdef TCGETS2 |
466 | } else if (opt & TERMIOS_OLD) { | |
edc6afc5 | 467 | if (user_termios_to_kernel_termios_1(&tmp_termios, |
64bb6c5e | 468 | (struct termios __user *)arg)) |
edc6afc5 | 469 | return -EFAULT; |
1da177e4 LT |
470 | } else { |
471 | if (user_termios_to_kernel_termios(&tmp_termios, | |
64bb6c5e | 472 | (struct termios2 __user *)arg)) |
1da177e4 LT |
473 | return -EFAULT; |
474 | } | |
64bb6c5e AC |
475 | #else |
476 | } else if (user_termios_to_kernel_termios(&tmp_termios, | |
477 | (struct termios __user *)arg)) | |
478 | return -EFAULT; | |
479 | #endif | |
1da177e4 | 480 | |
355d95a1 AC |
481 | /* If old style Bfoo values are used then load c_ispeed/c_ospeed |
482 | * with the real speed so its unconditionally usable */ | |
edc6afc5 AC |
483 | tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios); |
484 | tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios); | |
485 | ||
094fb49a IJ |
486 | if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) { |
487 | retry_write_wait: | |
488 | retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty)); | |
489 | if (retval < 0) | |
490 | return retval; | |
491 | ||
af815336 | 492 | if (tty_write_lock(tty, false) < 0) |
094fb49a IJ |
493 | goto retry_write_wait; |
494 | ||
495 | /* Racing writer? */ | |
496 | if (tty_chars_in_buffer(tty)) { | |
497 | tty_write_unlock(tty); | |
498 | goto retry_write_wait; | |
499 | } | |
355d95a1 | 500 | |
094fb49a IJ |
501 | ld = tty_ldisc_ref(tty); |
502 | if (ld != NULL) { | |
503 | if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer) | |
504 | ld->ops->flush_buffer(tty); | |
505 | tty_ldisc_deref(ld); | |
506 | } | |
355d95a1 | 507 | |
094fb49a IJ |
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); | |
512 | return -ERESTARTSYS; | |
513 | } | |
514 | } | |
515 | ||
516 | tty_set_termios(tty, &tmp_termios); | |
1da177e4 | 517 | |
094fb49a IJ |
518 | tty_write_unlock(tty); |
519 | } else { | |
520 | tty_set_termios(tty, &tmp_termios); | |
521 | } | |
5f519d72 AC |
522 | |
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 | |
526 | succeeded */ | |
1da177e4 LT |
527 | return 0; |
528 | } | |
529 | ||
26a2e20f AC |
530 | static void copy_termios(struct tty_struct *tty, struct ktermios *kterm) |
531 | { | |
6a1c0680 | 532 | down_read(&tty->termios_rwsem); |
adc8d746 | 533 | *kterm = tty->termios; |
6a1c0680 | 534 | up_read(&tty->termios_rwsem); |
26a2e20f AC |
535 | } |
536 | ||
537 | static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm) | |
538 | { | |
6a1c0680 | 539 | down_read(&tty->termios_rwsem); |
adc8d746 | 540 | *kterm = tty->termios_locked; |
6a1c0680 | 541 | up_read(&tty->termios_rwsem); |
26a2e20f AC |
542 | } |
543 | ||
355d95a1 | 544 | static int get_termio(struct tty_struct *tty, struct termio __user *termio) |
1da177e4 | 545 | { |
26a2e20f AC |
546 | struct ktermios kterm; |
547 | copy_termios(tty, &kterm); | |
548 | if (kernel_termios_to_user_termio(termio, &kterm)) | |
1da177e4 LT |
549 | return -EFAULT; |
550 | return 0; | |
551 | } | |
552 | ||
1da177e4 LT |
553 | #ifdef TIOCGETP |
554 | /* | |
555 | * These are deprecated, but there is limited support.. | |
556 | * | |
557 | * The "sg_flags" translation is a joke.. | |
558 | */ | |
355d95a1 | 559 | static int get_sgflags(struct tty_struct *tty) |
1da177e4 LT |
560 | { |
561 | int flags = 0; | |
562 | ||
9db276f8 PH |
563 | if (!L_ICANON(tty)) { |
564 | if (L_ISIG(tty)) | |
1da177e4 LT |
565 | flags |= 0x02; /* cbreak */ |
566 | else | |
567 | flags |= 0x20; /* raw */ | |
568 | } | |
9db276f8 | 569 | if (L_ECHO(tty)) |
1da177e4 | 570 | flags |= 0x08; /* echo */ |
9db276f8 PH |
571 | if (O_OPOST(tty)) |
572 | if (O_ONLCR(tty)) | |
1da177e4 LT |
573 | flags |= 0x10; /* crmod */ |
574 | return flags; | |
575 | } | |
576 | ||
355d95a1 | 577 | static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) |
1da177e4 LT |
578 | { |
579 | struct sgttyb tmp; | |
580 | ||
6a1c0680 | 581 | down_read(&tty->termios_rwsem); |
adc8d746 AC |
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]; | |
1da177e4 | 586 | tmp.sg_flags = get_sgflags(tty); |
6a1c0680 | 587 | up_read(&tty->termios_rwsem); |
355d95a1 | 588 | |
1da177e4 LT |
589 | return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0; |
590 | } | |
591 | ||
355d95a1 | 592 | static void set_sgflags(struct ktermios *termios, int flags) |
1da177e4 | 593 | { |
9833facf AC |
594 | termios->c_iflag = ICRNL | IXON; |
595 | termios->c_oflag = 0; | |
596 | termios->c_lflag = ISIG | ICANON; | |
1da177e4 | 597 | if (flags & 0x02) { /* cbreak */ |
9833facf AC |
598 | termios->c_iflag = 0; |
599 | termios->c_lflag &= ~ICANON; | |
1da177e4 LT |
600 | } |
601 | if (flags & 0x08) { /* echo */ | |
9833facf | 602 | termios->c_lflag |= ECHO | ECHOE | ECHOK | |
1da177e4 LT |
603 | ECHOCTL | ECHOKE | IEXTEN; |
604 | } | |
605 | if (flags & 0x10) { /* crmod */ | |
9833facf | 606 | termios->c_oflag |= OPOST | ONLCR; |
1da177e4 LT |
607 | } |
608 | if (flags & 0x20) { /* raw */ | |
9833facf AC |
609 | termios->c_iflag = 0; |
610 | termios->c_lflag &= ~(ISIG | ICANON); | |
1da177e4 | 611 | } |
9833facf AC |
612 | if (!(termios->c_lflag & ICANON)) { |
613 | termios->c_cc[VMIN] = 1; | |
614 | termios->c_cc[VTIME] = 0; | |
1da177e4 LT |
615 | } |
616 | } | |
617 | ||
af9b897e | 618 | /** |
3b1a696b JSS |
619 | * set_sgttyb - set legacy terminal values |
620 | * @tty: tty structure | |
621 | * @sgttyb: pointer to old style terminal structure | |
af9b897e | 622 | * |
3b1a696b | 623 | * Updates a terminal from the legacy BSD style terminal information structure. |
af9b897e | 624 | * |
3b1a696b JSS |
625 | * Locking: &tty_struct->termios_rwsem |
626 | * | |
627 | * Returns: 0 on success, an error otherwise | |
af9b897e | 628 | */ |
355d95a1 | 629 | static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb) |
1da177e4 LT |
630 | { |
631 | int retval; | |
632 | struct sgttyb tmp; | |
edc6afc5 | 633 | struct ktermios termios; |
1da177e4 LT |
634 | |
635 | retval = tty_check_change(tty); | |
636 | if (retval) | |
637 | return retval; | |
355d95a1 | 638 | |
1da177e4 LT |
639 | if (copy_from_user(&tmp, sgttyb, sizeof(tmp))) |
640 | return -EFAULT; | |
641 | ||
6a1c0680 | 642 | down_write(&tty->termios_rwsem); |
adc8d746 | 643 | termios = tty->termios; |
1da177e4 LT |
644 | termios.c_cc[VERASE] = tmp.sg_erase; |
645 | termios.c_cc[VKILL] = tmp.sg_kill; | |
646 | set_sgflags(&termios, tmp.sg_flags); | |
edc6afc5 | 647 | /* Try and encode into Bfoo format */ |
355d95a1 AC |
648 | tty_termios_encode_baud_rate(&termios, termios.c_ispeed, |
649 | termios.c_ospeed); | |
6a1c0680 | 650 | up_write(&tty->termios_rwsem); |
8d075b19 | 651 | tty_set_termios(tty, &termios); |
1da177e4 LT |
652 | return 0; |
653 | } | |
654 | #endif | |
655 | ||
656 | #ifdef TIOCGETC | |
355d95a1 | 657 | static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars) |
1da177e4 LT |
658 | { |
659 | struct tchars tmp; | |
660 | ||
6a1c0680 | 661 | down_read(&tty->termios_rwsem); |
adc8d746 AC |
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? */ | |
6a1c0680 | 668 | up_read(&tty->termios_rwsem); |
1da177e4 LT |
669 | return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0; |
670 | } | |
671 | ||
355d95a1 | 672 | static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars) |
1da177e4 LT |
673 | { |
674 | struct tchars tmp; | |
675 | ||
676 | if (copy_from_user(&tmp, tchars, sizeof(tmp))) | |
677 | return -EFAULT; | |
6a1c0680 | 678 | down_write(&tty->termios_rwsem); |
adc8d746 AC |
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? */ | |
6a1c0680 | 685 | up_write(&tty->termios_rwsem); |
1da177e4 LT |
686 | return 0; |
687 | } | |
688 | #endif | |
689 | ||
690 | #ifdef TIOCGLTC | |
355d95a1 | 691 | static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) |
1da177e4 LT |
692 | { |
693 | struct ltchars tmp; | |
694 | ||
6a1c0680 | 695 | down_read(&tty->termios_rwsem); |
adc8d746 | 696 | tmp.t_suspc = tty->termios.c_cc[VSUSP]; |
355d95a1 | 697 | /* what is dsuspc anyway? */ |
adc8d746 AC |
698 | tmp.t_dsuspc = tty->termios.c_cc[VSUSP]; |
699 | tmp.t_rprntc = tty->termios.c_cc[VREPRINT]; | |
355d95a1 | 700 | /* what is flushc anyway? */ |
adc8d746 AC |
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]; | |
6a1c0680 | 704 | up_read(&tty->termios_rwsem); |
1da177e4 LT |
705 | return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0; |
706 | } | |
707 | ||
355d95a1 | 708 | static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars) |
1da177e4 LT |
709 | { |
710 | struct ltchars tmp; | |
711 | ||
712 | if (copy_from_user(&tmp, ltchars, sizeof(tmp))) | |
713 | return -EFAULT; | |
714 | ||
6a1c0680 | 715 | down_write(&tty->termios_rwsem); |
adc8d746 | 716 | tty->termios.c_cc[VSUSP] = tmp.t_suspc; |
355d95a1 | 717 | /* what is dsuspc anyway? */ |
adc8d746 AC |
718 | tty->termios.c_cc[VEOL2] = tmp.t_dsuspc; |
719 | tty->termios.c_cc[VREPRINT] = tmp.t_rprntc; | |
355d95a1 | 720 | /* what is flushc anyway? */ |
adc8d746 AC |
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; | |
6a1c0680 | 724 | up_write(&tty->termios_rwsem); |
1da177e4 LT |
725 | return 0; |
726 | } | |
727 | #endif | |
728 | ||
1c2630cc | 729 | /** |
3b1a696b JSS |
730 | * tty_change_softcar - carrier change ioctl helper |
731 | * @tty: tty to update | |
732 | * @enable: enable/disable %CLOCAL | |
1c2630cc | 733 | * |
3b1a696b JSS |
734 | * Perform a change to the %CLOCAL state and call into the driver layer to make |
735 | * it visible. | |
736 | * | |
737 | * Locking: &tty_struct->termios_rwsem. | |
738 | * | |
739 | * Returns: 0 on success, an error otherwise | |
1c2630cc | 740 | */ |
77b425e4 | 741 | static int tty_change_softcar(struct tty_struct *tty, bool enable) |
1c2630cc AC |
742 | { |
743 | int ret = 0; | |
f34d7a5b | 744 | struct ktermios old; |
77b425e4 | 745 | tcflag_t bit = enable ? CLOCAL : 0; |
1c2630cc | 746 | |
6a1c0680 | 747 | down_write(&tty->termios_rwsem); |
adc8d746 AC |
748 | old = tty->termios; |
749 | tty->termios.c_cflag &= ~CLOCAL; | |
750 | tty->termios.c_cflag |= bit; | |
f34d7a5b AC |
751 | if (tty->ops->set_termios) |
752 | tty->ops->set_termios(tty, &old); | |
9db276f8 | 753 | if (C_CLOCAL(tty) != bit) |
1c2630cc | 754 | ret = -EINVAL; |
6a1c0680 | 755 | up_write(&tty->termios_rwsem); |
1c2630cc AC |
756 | return ret; |
757 | } | |
758 | ||
0fc00e24 | 759 | /** |
3b1a696b JSS |
760 | * tty_mode_ioctl - mode related ioctls |
761 | * @tty: tty for the ioctl | |
762 | * @cmd: command | |
763 | * @arg: ioctl argument | |
0fc00e24 | 764 | * |
3b1a696b JSS |
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 | |
767 | * setting. | |
0fc00e24 | 768 | */ |
dcc223e8 | 769 | int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) |
1da177e4 | 770 | { |
355d95a1 | 771 | struct tty_struct *real_tty; |
1da177e4 | 772 | void __user *p = (void __user *)arg; |
8f520021 | 773 | int ret = 0; |
26a2e20f | 774 | struct ktermios kterm; |
1da177e4 LT |
775 | |
776 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
777 | tty->driver->subtype == PTY_TYPE_MASTER) | |
778 | real_tty = tty->link; | |
779 | else | |
780 | real_tty = tty; | |
781 | ||
782 | switch (cmd) { | |
783 | #ifdef TIOCGETP | |
355d95a1 AC |
784 | case TIOCGETP: |
785 | return get_sgttyb(real_tty, (struct sgttyb __user *) arg); | |
786 | case TIOCSETP: | |
787 | case TIOCSETN: | |
788 | return set_sgttyb(real_tty, (struct sgttyb __user *) arg); | |
1da177e4 LT |
789 | #endif |
790 | #ifdef TIOCGETC | |
355d95a1 AC |
791 | case TIOCGETC: |
792 | return get_tchars(real_tty, p); | |
793 | case TIOCSETC: | |
794 | return set_tchars(real_tty, p); | |
1da177e4 LT |
795 | #endif |
796 | #ifdef TIOCGLTC | |
355d95a1 AC |
797 | case TIOCGLTC: |
798 | return get_ltchars(real_tty, p); | |
799 | case TIOCSLTC: | |
800 | return set_ltchars(real_tty, p); | |
1da177e4 | 801 | #endif |
355d95a1 AC |
802 | case TCSETSF: |
803 | return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD); | |
804 | case TCSETSW: | |
805 | return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD); | |
806 | case TCSETS: | |
807 | return set_termios(real_tty, p, TERMIOS_OLD); | |
edc6afc5 | 808 | #ifndef TCGETS2 |
355d95a1 | 809 | case TCGETS: |
26a2e20f AC |
810 | copy_termios(real_tty, &kterm); |
811 | if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm)) | |
8f520021 | 812 | ret = -EFAULT; |
8f520021 | 813 | return ret; |
edc6afc5 | 814 | #else |
355d95a1 | 815 | case TCGETS: |
26a2e20f AC |
816 | copy_termios(real_tty, &kterm); |
817 | if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm)) | |
8f520021 | 818 | ret = -EFAULT; |
8f520021 | 819 | return ret; |
355d95a1 | 820 | case TCGETS2: |
26a2e20f AC |
821 | copy_termios(real_tty, &kterm); |
822 | if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm)) | |
8f520021 | 823 | ret = -EFAULT; |
8f520021 | 824 | return ret; |
355d95a1 AC |
825 | case TCSETSF2: |
826 | return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT); | |
827 | case TCSETSW2: | |
828 | return set_termios(real_tty, p, TERMIOS_WAIT); | |
829 | case TCSETS2: | |
830 | return set_termios(real_tty, p, 0); | |
edc6afc5 | 831 | #endif |
355d95a1 AC |
832 | case TCGETA: |
833 | return get_termio(real_tty, p); | |
834 | case TCSETAF: | |
835 | return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO); | |
836 | case TCSETAW: | |
837 | return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO); | |
838 | case TCSETA: | |
839 | return set_termios(real_tty, p, TERMIOS_TERMIO); | |
0fc00e24 | 840 | #ifndef TCGETS2 |
355d95a1 | 841 | case TIOCGLCKTRMIOS: |
26a2e20f AC |
842 | copy_termios_locked(real_tty, &kterm); |
843 | if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm)) | |
8f520021 | 844 | ret = -EFAULT; |
8f520021 | 845 | return ret; |
355d95a1 | 846 | case TIOCSLCKTRMIOS: |
e0f25b89 | 847 | if (!checkpoint_restore_ns_capable(&init_user_ns)) |
355d95a1 | 848 | return -EPERM; |
26a2e20f AC |
849 | copy_termios_locked(real_tty, &kterm); |
850 | if (user_termios_to_kernel_termios(&kterm, | |
355d95a1 | 851 | (struct termios __user *) arg)) |
26a2e20f | 852 | return -EFAULT; |
6a1c0680 | 853 | down_write(&real_tty->termios_rwsem); |
adc8d746 | 854 | real_tty->termios_locked = kterm; |
6a1c0680 | 855 | up_write(&real_tty->termios_rwsem); |
26a2e20f | 856 | return 0; |
0fc00e24 | 857 | #else |
355d95a1 | 858 | case TIOCGLCKTRMIOS: |
26a2e20f AC |
859 | copy_termios_locked(real_tty, &kterm); |
860 | if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm)) | |
8f520021 | 861 | ret = -EFAULT; |
8f520021 | 862 | return ret; |
355d95a1 | 863 | case TIOCSLCKTRMIOS: |
e0f25b89 | 864 | if (!checkpoint_restore_ns_capable(&init_user_ns)) |
26a2e20f AC |
865 | return -EPERM; |
866 | copy_termios_locked(real_tty, &kterm); | |
867 | if (user_termios_to_kernel_termios_1(&kterm, | |
355d95a1 | 868 | (struct termios __user *) arg)) |
26a2e20f | 869 | return -EFAULT; |
6a1c0680 | 870 | down_write(&real_tty->termios_rwsem); |
adc8d746 | 871 | real_tty->termios_locked = kterm; |
6a1c0680 | 872 | up_write(&real_tty->termios_rwsem); |
8f520021 | 873 | return ret; |
0fc00e24 | 874 | #endif |
1d65b4a0 | 875 | #ifdef TCGETX |
e0efb316 | 876 | case TCGETX: |
1d65b4a0 | 877 | case TCSETX: |
1d65b4a0 | 878 | case TCSETXW: |
1d65b4a0 | 879 | case TCSETXF: |
8871de06 JH |
880 | return -ENOTTY; |
881 | #endif | |
355d95a1 | 882 | case TIOCGSOFTCAR: |
26a2e20f AC |
883 | copy_termios(real_tty, &kterm); |
884 | ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0, | |
355d95a1 | 885 | (int __user *)arg); |
8f520021 | 886 | return ret; |
355d95a1 AC |
887 | case TIOCSSOFTCAR: |
888 | if (get_user(arg, (unsigned int __user *) arg)) | |
889 | return -EFAULT; | |
f753f327 | 890 | return tty_change_softcar(real_tty, arg); |
355d95a1 AC |
891 | default: |
892 | return -ENOIOCTLCMD; | |
0fc00e24 AC |
893 | } |
894 | } | |
0fc00e24 AC |
895 | EXPORT_SYMBOL_GPL(tty_mode_ioctl); |
896 | ||
e7f3880c PH |
897 | |
898 | /* Caller guarantees ldisc reference is held */ | |
899 | static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg) | |
0fc00e24 | 900 | { |
e7f3880c | 901 | struct tty_ldisc *ld = tty->ldisc; |
0fc00e24 | 902 | |
0fc00e24 AC |
903 | switch (arg) { |
904 | case TCIFLUSH: | |
a1bf9584 | 905 | if (ld && ld->ops->flush_buffer) { |
a352def2 | 906 | ld->ops->flush_buffer(tty); |
a1bf9584 IZ |
907 | tty_unthrottle(tty); |
908 | } | |
0fc00e24 AC |
909 | break; |
910 | case TCIOFLUSH: | |
a1bf9584 | 911 | if (ld && ld->ops->flush_buffer) { |
a352def2 | 912 | ld->ops->flush_buffer(tty); |
a1bf9584 IZ |
913 | tty_unthrottle(tty); |
914 | } | |
df561f66 | 915 | fallthrough; |
0fc00e24 | 916 | case TCOFLUSH: |
f34d7a5b | 917 | tty_driver_flush_buffer(tty); |
0fc00e24 AC |
918 | break; |
919 | default: | |
0fc00e24 AC |
920 | return -EINVAL; |
921 | } | |
0fc00e24 AC |
922 | return 0; |
923 | } | |
e7f3880c PH |
924 | |
925 | int tty_perform_flush(struct tty_struct *tty, unsigned long arg) | |
926 | { | |
927 | struct tty_ldisc *ld; | |
928 | int retval = tty_check_change(tty); | |
929 | if (retval) | |
930 | return retval; | |
931 | ||
932 | ld = tty_ldisc_ref_wait(tty); | |
933 | retval = __tty_perform_flush(tty, arg); | |
934 | if (ld) | |
935 | tty_ldisc_deref(ld); | |
936 | return retval; | |
937 | } | |
0fc00e24 AC |
938 | EXPORT_SYMBOL_GPL(tty_perform_flush); |
939 | ||
7c783601 JS |
940 | int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd, |
941 | unsigned long arg) | |
0fc00e24 | 942 | { |
0fc00e24 AC |
943 | int retval; |
944 | ||
0fc00e24 | 945 | switch (cmd) { |
355d95a1 AC |
946 | case TCXONC: |
947 | retval = tty_check_change(tty); | |
948 | if (retval) | |
949 | return retval; | |
950 | switch (arg) { | |
951 | case TCOOFF: | |
6e94dbc7 JS |
952 | spin_lock_irq(&tty->flow.lock); |
953 | if (!tty->flow.tco_stopped) { | |
954 | tty->flow.tco_stopped = true; | |
c545b66c | 955 | __stop_tty(tty); |
1da177e4 | 956 | } |
6e94dbc7 | 957 | spin_unlock_irq(&tty->flow.lock); |
355d95a1 AC |
958 | break; |
959 | case TCOON: | |
6e94dbc7 JS |
960 | spin_lock_irq(&tty->flow.lock); |
961 | if (tty->flow.tco_stopped) { | |
962 | tty->flow.tco_stopped = false; | |
c545b66c | 963 | __start_tty(tty); |
355d95a1 | 964 | } |
6e94dbc7 | 965 | spin_unlock_irq(&tty->flow.lock); |
355d95a1 AC |
966 | break; |
967 | case TCIOFF: | |
968 | if (STOP_CHAR(tty) != __DISABLED_CHAR) | |
c274f6ef | 969 | retval = tty_send_xchar(tty, STOP_CHAR(tty)); |
355d95a1 AC |
970 | break; |
971 | case TCION: | |
972 | if (START_CHAR(tty) != __DISABLED_CHAR) | |
c274f6ef | 973 | retval = tty_send_xchar(tty, START_CHAR(tty)); |
355d95a1 | 974 | break; |
1da177e4 | 975 | default: |
355d95a1 | 976 | return -EINVAL; |
1da177e4 | 977 | } |
c274f6ef | 978 | return retval; |
355d95a1 | 979 | case TCFLSH: |
5cec7bf6 PH |
980 | retval = tty_check_change(tty); |
981 | if (retval) | |
982 | return retval; | |
e7f3880c | 983 | return __tty_perform_flush(tty, arg); |
355d95a1 AC |
984 | default: |
985 | /* Try the mode commands */ | |
dcc223e8 | 986 | return tty_mode_ioctl(tty, cmd, arg); |
355d95a1 | 987 | } |
1da177e4 | 988 | } |
47afa7a5 | 989 | EXPORT_SYMBOL(n_tty_ioctl_helper); |