TTY: unify tty_init_dev fail path handling
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / tty / pty.c
CommitLineData
1da177e4
LT
1/*
2 * linux/drivers/char/pty.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * Added support for a Unix98-style ptmx device.
7 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
1da177e4 8 *
fe9cd962
AC
9 * When reading this code see also fs/devpts. In particular note that the
10 * driver_data field is used by the devpts side as a binding to the devpts
11 * inode.
1da177e4
LT
12 */
13
fe9cd962 14#include <linux/module.h>
1da177e4
LT
15
16#include <linux/errno.h>
1da177e4
LT
17#include <linux/interrupt.h>
18#include <linux/tty.h>
19#include <linux/tty_flip.h>
20#include <linux/fcntl.h>
d43c36dc 21#include <linux/sched.h>
1da177e4
LT
22#include <linux/string.h>
23#include <linux/major.h>
24#include <linux/mm.h>
25#include <linux/init.h>
1da177e4 26#include <linux/sysctl.h>
d81ed103 27#include <linux/device.h>
fe9cd962 28#include <linux/uaccess.h>
1da177e4
LT
29#include <linux/bitops.h>
30#include <linux/devpts_fs.h>
5a0e3ad6 31#include <linux/slab.h>
1da177e4 32
fe9cd962
AC
33#include <asm/system.h>
34
1da177e4 35#ifdef CONFIG_UNIX98_PTYS
da2bdf9a 36static struct tty_driver *ptm_driver;
1da177e4
LT
37static struct tty_driver *pts_driver;
38#endif
39
fe9cd962 40static void pty_close(struct tty_struct *tty, struct file *filp)
1da177e4 41{
fe9cd962
AC
42 BUG_ON(!tty);
43 if (tty->driver->subtype == PTY_TYPE_MASTER)
44 WARN_ON(tty->count > 1);
45 else {
1da177e4
LT
46 if (tty->count > 2)
47 return;
48 }
49 wake_up_interruptible(&tty->read_wait);
50 wake_up_interruptible(&tty->write_wait);
51 tty->packet = 0;
52 if (!tty->link)
53 return;
54 tty->link->packet = 0;
55 set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
56 wake_up_interruptible(&tty->link->read_wait);
57 wake_up_interruptible(&tty->link->write_wait);
58 if (tty->driver->subtype == PTY_TYPE_MASTER) {
59 set_bit(TTY_OTHER_CLOSED, &tty->flags);
60#ifdef CONFIG_UNIX98_PTYS
61 if (tty->driver == ptm_driver)
15f1a633 62 devpts_pty_kill(tty->link);
1da177e4 63#endif
11dbf203
AB
64 tty_unlock();
65 tty_vhangup(tty->link);
66 tty_lock();
1da177e4
LT
67 }
68}
69
70/*
71 * The unthrottle routine is called by the line discipline to signal
72 * that it can receive more characters. For PTY's, the TTY_THROTTLED
73 * flag is always set, to force the line discipline to always call the
fe9cd962 74 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
1da177e4
LT
75 * characters in the queue. This is necessary since each time this
76 * happens, we need to wake up any sleeping processes that could be
77 * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
78 * for the pty buffer to be drained.
79 */
fe9cd962 80static void pty_unthrottle(struct tty_struct *tty)
1da177e4 81{
d945cb9c 82 tty_wakeup(tty->link);
1da177e4
LT
83 set_bit(TTY_THROTTLED, &tty->flags);
84}
85
d945cb9c
AC
86/**
87 * pty_space - report space left for writing
88 * @to: tty we are writing into
1da177e4 89 *
d945cb9c
AC
90 * The tty buffers allow 64K but we sneak a peak and clip at 8K this
91 * allows a lot of overspill room for echo and other fun messes to
92 * be handled properly
93 */
94
95static int pty_space(struct tty_struct *to)
96{
97 int n = 8192 - to->buf.memory_used;
98 if (n < 0)
99 return 0;
100 return n;
101}
102
103/**
104 * pty_write - write to a pty
105 * @tty: the tty we write from
106 * @buf: kernel buffer of data
107 * @count: bytes to write
762faaed 108 *
d945cb9c
AC
109 * Our "hardware" write method. Data is coming from the ldisc which
110 * may be in a non sleeping state. We simply throw this at the other
111 * end of the link as if we were an IRQ handler receiving stuff for
112 * the other side of the pty/tty pair.
1da177e4 113 */
d945cb9c 114
ac89a917 115static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
1da177e4
LT
116{
117 struct tty_struct *to = tty->link;
1da177e4 118
d945cb9c 119 if (tty->stopped)
1da177e4 120 return 0;
d945cb9c 121
d945cb9c
AC
122 if (c > 0) {
123 /* Stuff the data into the input queue of the other end */
124 c = tty_insert_flip_string(to, buf, c);
125 /* And shovel */
202c4675
LT
126 if (c) {
127 tty_flip_buffer_push(to);
128 tty_wakeup(tty);
129 }
762faaed 130 }
1da177e4
LT
131 return c;
132}
133
d945cb9c
AC
134/**
135 * pty_write_room - write space
136 * @tty: tty we are writing from
137 *
138 * Report how many bytes the ldisc can send into the queue for
139 * the other device.
140 */
141
1da177e4
LT
142static int pty_write_room(struct tty_struct *tty)
143{
85dfd81d
LT
144 if (tty->stopped)
145 return 0;
d945cb9c 146 return pty_space(tty->link);
1da177e4
LT
147}
148
d945cb9c
AC
149/**
150 * pty_chars_in_buffer - characters currently in our tx queue
151 * @tty: our tty
fe9cd962 152 *
d945cb9c
AC
153 * Report how much we have in the transmit queue. As everything is
154 * instantly at the other end this is easy to implement.
1da177e4 155 */
d945cb9c 156
1da177e4
LT
157static int pty_chars_in_buffer(struct tty_struct *tty)
158{
d945cb9c 159 return 0;
1da177e4
LT
160}
161
162/* Set the lock flag on a pty */
fe9cd962 163static int pty_set_lock(struct tty_struct *tty, int __user *arg)
1da177e4
LT
164{
165 int val;
fe9cd962 166 if (get_user(val, arg))
1da177e4
LT
167 return -EFAULT;
168 if (val)
169 set_bit(TTY_PTY_LOCK, &tty->flags);
170 else
171 clear_bit(TTY_PTY_LOCK, &tty->flags);
172 return 0;
173}
174
26df6d13 175/* Send a signal to the slave */
176static int pty_signal(struct tty_struct *tty, int sig)
177{
178 unsigned long flags;
179 struct pid *pgrp;
180
181 if (tty->link) {
182 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
183 pgrp = get_pid(tty->link->pgrp);
184 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
185
186 kill_pgrp(pgrp, sig, 1);
187 put_pid(pgrp);
188 }
189 return 0;
190}
191
1da177e4
LT
192static void pty_flush_buffer(struct tty_struct *tty)
193{
194 struct tty_struct *to = tty->link;
04f378b1 195 unsigned long flags;
fe9cd962 196
1da177e4
LT
197 if (!to)
198 return;
d945cb9c 199 /* tty_buffer_flush(to); FIXME */
1da177e4 200 if (to->packet) {
04f378b1 201 spin_lock_irqsave(&tty->ctrl_lock, flags);
1da177e4
LT
202 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
203 wake_up_interruptible(&to->read_wait);
04f378b1 204 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
1da177e4
LT
205 }
206}
207
fe9cd962 208static int pty_open(struct tty_struct *tty, struct file *filp)
1da177e4
LT
209{
210 int retval = -ENODEV;
211
212 if (!tty || !tty->link)
213 goto out;
214
215 retval = -EIO;
216 if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
217 goto out;
218 if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
219 goto out;
220 if (tty->link->count != 1)
221 goto out;
222
223 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
224 set_bit(TTY_THROTTLED, &tty->flags);
1da177e4
LT
225 retval = 0;
226out:
227 return retval;
228}
229
fe9cd962
AC
230static void pty_set_termios(struct tty_struct *tty,
231 struct ktermios *old_termios)
1da177e4 232{
fe9cd962
AC
233 tty->termios->c_cflag &= ~(CSIZE | PARENB);
234 tty->termios->c_cflag |= (CS8 | CREAD);
1da177e4
LT
235}
236
fc6f6238
AC
237/**
238 * pty_do_resize - resize event
239 * @tty: tty being resized
c774bda2 240 * @ws: window size being set.
fc6f6238 241 *
3ad2f3fb 242 * Update the termios variables and send the necessary signals to
fc6f6238
AC
243 * peform a terminal resize correctly
244 */
245
246int pty_resize(struct tty_struct *tty, struct winsize *ws)
247{
248 struct pid *pgrp, *rpgrp;
249 unsigned long flags;
250 struct tty_struct *pty = tty->link;
251
252 /* For a PTY we need to lock the tty side */
253 mutex_lock(&tty->termios_mutex);
254 if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
255 goto done;
256
257 /* Get the PID values and reference them so we can
258 avoid holding the tty ctrl lock while sending signals.
259 We need to lock these individually however. */
260
261 spin_lock_irqsave(&tty->ctrl_lock, flags);
262 pgrp = get_pid(tty->pgrp);
263 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
264
265 spin_lock_irqsave(&pty->ctrl_lock, flags);
266 rpgrp = get_pid(pty->pgrp);
267 spin_unlock_irqrestore(&pty->ctrl_lock, flags);
268
269 if (pgrp)
270 kill_pgrp(pgrp, SIGWINCH, 1);
271 if (rpgrp != pgrp && rpgrp)
272 kill_pgrp(rpgrp, SIGWINCH, 1);
273
274 put_pid(pgrp);
275 put_pid(rpgrp);
276
277 tty->winsize = *ws;
278 pty->winsize = *ws; /* Never used so will go away soon */
279done:
280 mutex_unlock(&tty->termios_mutex);
281 return 0;
282}
283
342a5971
LT
284/* Traditional BSD devices */
285#ifdef CONFIG_LEGACY_PTYS
286
bf970ee4
AC
287static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
288{
289 struct tty_struct *o_tty;
290 int idx = tty->index;
291 int retval;
292
293 o_tty = alloc_tty_struct();
294 if (!o_tty)
295 return -ENOMEM;
296 if (!try_module_get(driver->other->owner)) {
297 /* This cannot in fact currently happen */
298 free_tty_struct(o_tty);
299 return -ENOMEM;
300 }
301 initialize_tty_struct(o_tty, driver->other, idx);
302
303 /* We always use new tty termios data so we can do this
304 the easy way .. */
305 retval = tty_init_termios(tty);
306 if (retval)
307 goto free_mem_out;
308
309 retval = tty_init_termios(o_tty);
310 if (retval) {
311 tty_free_termios(tty);
312 goto free_mem_out;
313 }
fe9cd962 314
bf970ee4
AC
315 /*
316 * Everything allocated ... set up the o_tty structure.
317 */
318 driver->other->ttys[idx] = o_tty;
319 tty_driver_kref_get(driver->other);
320 if (driver->subtype == PTY_TYPE_MASTER)
321 o_tty->count++;
322 /* Establish the links in both directions */
323 tty->link = o_tty;
324 o_tty->link = tty;
325
326 tty_driver_kref_get(driver);
327 tty->count++;
328 driver->ttys[idx] = tty;
329 return 0;
330free_mem_out:
331 module_put(o_tty->driver->owner);
332 free_tty_struct(o_tty);
333 return -ENOMEM;
334}
335
6caa76b7 336static int pty_bsd_ioctl(struct tty_struct *tty,
1da177e4
LT
337 unsigned int cmd, unsigned long arg)
338{
339 switch (cmd) {
340 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
341 return pty_set_lock(tty, (int __user *) arg);
26df6d13 342 case TIOCSIG: /* Send signal to other side of pty */
343 return pty_signal(tty, (int) arg);
1da177e4
LT
344 }
345 return -ENOIOCTLCMD;
346}
347
dc8c8587
KS
348static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
349module_param(legacy_count, int, 0);
350
342a5971
LT
351/*
352 * The master side of a pty can do TIOCSPTLCK and thus
353 * has pty_bsd_ioctl.
354 */
355static const struct tty_operations master_pty_ops_bsd = {
356 .install = pty_install,
3e8e88ca
AC
357 .open = pty_open,
358 .close = pty_close,
359 .write = pty_write,
360 .write_room = pty_write_room,
361 .flush_buffer = pty_flush_buffer,
362 .chars_in_buffer = pty_chars_in_buffer,
363 .unthrottle = pty_unthrottle,
364 .set_termios = pty_set_termios,
365 .ioctl = pty_bsd_ioctl,
fc6f6238 366 .resize = pty_resize
3e8e88ca
AC
367};
368
342a5971
LT
369static const struct tty_operations slave_pty_ops_bsd = {
370 .install = pty_install,
371 .open = pty_open,
372 .close = pty_close,
373 .write = pty_write,
374 .write_room = pty_write_room,
375 .flush_buffer = pty_flush_buffer,
376 .chars_in_buffer = pty_chars_in_buffer,
377 .unthrottle = pty_unthrottle,
378 .set_termios = pty_set_termios,
379 .resize = pty_resize
380};
381
1da177e4
LT
382static void __init legacy_pty_init(void)
383{
342a5971
LT
384 struct tty_driver *pty_driver, *pty_slave_driver;
385
dc8c8587
KS
386 if (legacy_count <= 0)
387 return;
1da177e4 388
dc8c8587 389 pty_driver = alloc_tty_driver(legacy_count);
1da177e4
LT
390 if (!pty_driver)
391 panic("Couldn't allocate pty driver");
392
dc8c8587 393 pty_slave_driver = alloc_tty_driver(legacy_count);
1da177e4
LT
394 if (!pty_slave_driver)
395 panic("Couldn't allocate pty slave driver");
396
397 pty_driver->owner = THIS_MODULE;
398 pty_driver->driver_name = "pty_master";
399 pty_driver->name = "pty";
1da177e4
LT
400 pty_driver->major = PTY_MASTER_MAJOR;
401 pty_driver->minor_start = 0;
402 pty_driver->type = TTY_DRIVER_TYPE_PTY;
403 pty_driver->subtype = PTY_TYPE_MASTER;
404 pty_driver->init_termios = tty_std_termios;
405 pty_driver->init_termios.c_iflag = 0;
406 pty_driver->init_termios.c_oflag = 0;
407 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
408 pty_driver->init_termios.c_lflag = 0;
606d099c
AC
409 pty_driver->init_termios.c_ispeed = 38400;
410 pty_driver->init_termios.c_ospeed = 38400;
1da177e4
LT
411 pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
412 pty_driver->other = pty_slave_driver;
342a5971 413 tty_set_operations(pty_driver, &master_pty_ops_bsd);
1da177e4
LT
414
415 pty_slave_driver->owner = THIS_MODULE;
416 pty_slave_driver->driver_name = "pty_slave";
417 pty_slave_driver->name = "ttyp";
1da177e4
LT
418 pty_slave_driver->major = PTY_SLAVE_MAJOR;
419 pty_slave_driver->minor_start = 0;
420 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
421 pty_slave_driver->subtype = PTY_TYPE_SLAVE;
422 pty_slave_driver->init_termios = tty_std_termios;
423 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
606d099c
AC
424 pty_slave_driver->init_termios.c_ispeed = 38400;
425 pty_slave_driver->init_termios.c_ospeed = 38400;
1da177e4
LT
426 pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
427 TTY_DRIVER_REAL_RAW;
428 pty_slave_driver->other = pty_driver;
342a5971 429 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
1da177e4
LT
430
431 if (tty_register_driver(pty_driver))
432 panic("Couldn't register pty driver");
433 if (tty_register_driver(pty_slave_driver))
434 panic("Couldn't register pty slave driver");
435}
436#else
437static inline void legacy_pty_init(void) { }
438#endif
439
440/* Unix98 devices */
441#ifdef CONFIG_UNIX98_PTYS
442/*
443 * sysctl support for setting limits on the number of Unix98 ptys allocated.
444 * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
445 */
446int pty_limit = NR_UNIX98_PTY_DEFAULT;
fe9cd962 447static int pty_limit_min;
1da177e4 448static int pty_limit_max = NR_UNIX98_PTY_MAX;
fe9cd962 449static int pty_count;
1da177e4 450
d81ed103
AC
451static struct cdev ptmx_cdev;
452
35834ca1 453static struct ctl_table pty_table[] = {
1da177e4 454 {
1da177e4
LT
455 .procname = "max",
456 .maxlen = sizeof(int),
457 .mode = 0644,
458 .data = &pty_limit,
6d456111 459 .proc_handler = proc_dointvec_minmax,
1da177e4
LT
460 .extra1 = &pty_limit_min,
461 .extra2 = &pty_limit_max,
462 }, {
1da177e4
LT
463 .procname = "nr",
464 .maxlen = sizeof(int),
465 .mode = 0444,
bf970ee4 466 .data = &pty_count,
6d456111 467 .proc_handler = proc_dointvec,
894d2491
EB
468 },
469 {}
1da177e4
LT
470};
471
35834ca1
EB
472static struct ctl_table pty_kern_table[] = {
473 {
35834ca1
EB
474 .procname = "pty",
475 .mode = 0555,
476 .child = pty_table,
477 },
478 {}
479};
480
481static struct ctl_table pty_root_table[] = {
482 {
35834ca1
EB
483 .procname = "kernel",
484 .mode = 0555,
485 .child = pty_kern_table,
486 },
487 {}
488};
489
490
6caa76b7 491static int pty_unix98_ioctl(struct tty_struct *tty,
1da177e4
LT
492 unsigned int cmd, unsigned long arg)
493{
494 switch (cmd) {
495 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
496 return pty_set_lock(tty, (int __user *)arg);
497 case TIOCGPTN: /* Get PT Number */
498 return put_user(tty->index, (unsigned int __user *)arg);
26df6d13 499 case TIOCSIG: /* Send signal to other side of pty */
500 return pty_signal(tty, (int) arg);
1da177e4
LT
501 }
502
503 return -ENOIOCTLCMD;
504}
505
99f1fe18
AC
506/**
507 * ptm_unix98_lookup - find a pty master
508 * @driver: ptm driver
509 * @idx: tty index
510 *
511 * Look up a pty master device. Called under the tty_mutex for now.
512 * This provides our locking.
513 */
514
15f1a633
SB
515static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
516 struct inode *ptm_inode, int idx)
99f1fe18 517{
15f1a633 518 struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
99f1fe18
AC
519 if (tty)
520 tty = tty->link;
521 return tty;
522}
523
524/**
525 * pts_unix98_lookup - find a pty slave
526 * @driver: pts driver
527 * @idx: tty index
528 *
529 * Look up a pty master device. Called under the tty_mutex for now.
530 * This provides our locking.
531 */
532
15f1a633
SB
533static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
534 struct inode *pts_inode, int idx)
99f1fe18 535{
15f1a633 536 struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
99f1fe18
AC
537 /* Master must be open before slave */
538 if (!tty)
539 return ERR_PTR(-EIO);
540 return tty;
541}
542
bf970ee4 543static void pty_unix98_shutdown(struct tty_struct *tty)
feebed65
AC
544{
545 /* We have our own method as we don't use the tty index */
546 kfree(tty->termios);
feebed65
AC
547}
548
8b0a88d5
AC
549/* We have no need to install and remove our tty objects as devpts does all
550 the work for us */
551
bf970ee4 552static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
8b0a88d5 553{
bf970ee4
AC
554 struct tty_struct *o_tty;
555 int idx = tty->index;
556
557 o_tty = alloc_tty_struct();
558 if (!o_tty)
559 return -ENOMEM;
560 if (!try_module_get(driver->other->owner)) {
561 /* This cannot in fact currently happen */
562 free_tty_struct(o_tty);
563 return -ENOMEM;
564 }
565 initialize_tty_struct(o_tty, driver->other, idx);
566
8dff04ea 567 tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
bf970ee4
AC
568 if (tty->termios == NULL)
569 goto free_mem_out;
570 *tty->termios = driver->init_termios;
8dff04ea
AC
571 tty->termios_locked = tty->termios + 1;
572
573 o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
bf970ee4
AC
574 if (o_tty->termios == NULL)
575 goto free_mem_out;
576 *o_tty->termios = driver->other->init_termios;
8dff04ea 577 o_tty->termios_locked = o_tty->termios + 1;
bf970ee4
AC
578
579 tty_driver_kref_get(driver->other);
580 if (driver->subtype == PTY_TYPE_MASTER)
581 o_tty->count++;
582 /* Establish the links in both directions */
583 tty->link = o_tty;
584 o_tty->link = tty;
585 /*
586 * All structures have been allocated, so now we install them.
587 * Failures after this point use release_tty to clean up, so
588 * there's no need to null out the local pointers.
589 */
590 tty_driver_kref_get(driver);
591 tty->count++;
592 pty_count++;
8b0a88d5 593 return 0;
bf970ee4 594free_mem_out:
8dff04ea 595 kfree(o_tty->termios);
bf970ee4
AC
596 module_put(o_tty->driver->owner);
597 free_tty_struct(o_tty);
8dff04ea 598 kfree(tty->termios);
bf970ee4 599 return -ENOMEM;
8b0a88d5
AC
600}
601
bf970ee4 602static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
8b0a88d5 603{
bf970ee4 604 pty_count--;
8b0a88d5
AC
605}
606
feebed65 607static const struct tty_operations ptm_unix98_ops = {
99f1fe18 608 .lookup = ptm_unix98_lookup,
bf970ee4
AC
609 .install = pty_unix98_install,
610 .remove = pty_unix98_remove,
3e8e88ca
AC
611 .open = pty_open,
612 .close = pty_close,
613 .write = pty_write,
614 .write_room = pty_write_room,
615 .flush_buffer = pty_flush_buffer,
616 .chars_in_buffer = pty_chars_in_buffer,
617 .unthrottle = pty_unthrottle,
618 .set_termios = pty_set_termios,
feebed65 619 .ioctl = pty_unix98_ioctl,
fc6f6238
AC
620 .shutdown = pty_unix98_shutdown,
621 .resize = pty_resize
3e8e88ca
AC
622};
623
99f1fe18
AC
624static const struct tty_operations pty_unix98_ops = {
625 .lookup = pts_unix98_lookup,
bf970ee4
AC
626 .install = pty_unix98_install,
627 .remove = pty_unix98_remove,
99f1fe18
AC
628 .open = pty_open,
629 .close = pty_close,
630 .write = pty_write,
631 .write_room = pty_write_room,
632 .flush_buffer = pty_flush_buffer,
633 .chars_in_buffer = pty_chars_in_buffer,
634 .unthrottle = pty_unthrottle,
635 .set_termios = pty_set_termios,
bf970ee4 636 .shutdown = pty_unix98_shutdown
99f1fe18 637};
d81ed103
AC
638
639/**
640 * ptmx_open - open a unix 98 pty master
641 * @inode: inode of device file
642 * @filp: file pointer to tty
643 *
644 * Allocate a unix98 pty master device from the ptmx driver.
645 *
646 * Locking: tty_mutex protects the init_dev work. tty->count should
647 * protect the rest.
648 * allocated_ptys_lock handles the list of free pty numbers
649 */
650
64ba3dc3 651static int ptmx_open(struct inode *inode, struct file *filp)
d81ed103
AC
652{
653 struct tty_struct *tty;
654 int retval;
655 int index;
656
657 nonseekable_open(inode, filp);
658
659 /* find a device that is not in use. */
64ba3dc3 660 tty_lock();
15f1a633 661 index = devpts_new_index(inode);
64ba3dc3 662 tty_unlock();
d81ed103
AC
663 if (index < 0)
664 return index;
665
666 mutex_lock(&tty_mutex);
64ba3dc3 667 tty_lock();
73ec06fc 668 tty = tty_init_dev(ptm_driver, index, 1);
d81ed103
AC
669 mutex_unlock(&tty_mutex);
670
73ec06fc
AC
671 if (IS_ERR(tty)) {
672 retval = PTR_ERR(tty);
d81ed103 673 goto out;
73ec06fc 674 }
d81ed103
AC
675
676 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
ee2ffa0d 677
f573bd17
PE
678 retval = tty_add_file(tty, filp);
679 if (retval)
680 goto out;
d81ed103 681
15f1a633 682 retval = devpts_pty_new(inode, tty->link);
d81ed103
AC
683 if (retval)
684 goto out1;
685
686 retval = ptm_driver->ops->open(tty, filp);
64ba3dc3
AB
687 if (retval)
688 goto out2;
d81ed103 689out1:
64ba3dc3
AB
690 tty_unlock();
691 return retval;
692out2:
693 tty_unlock();
eeb89d91 694 tty_release(inode, filp);
d81ed103
AC
695 return retval;
696out:
15f1a633 697 devpts_kill_index(inode, index);
ec79d605 698 tty_unlock();
64ba3dc3 699 return retval;
d81ed103
AC
700}
701
702static struct file_operations ptmx_fops;
703
1da177e4
LT
704static void __init unix98_pty_init(void)
705{
1da177e4
LT
706 ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
707 if (!ptm_driver)
708 panic("Couldn't allocate Unix98 ptm driver");
709 pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
710 if (!pts_driver)
711 panic("Couldn't allocate Unix98 pts driver");
712
713 ptm_driver->owner = THIS_MODULE;
714 ptm_driver->driver_name = "pty_master";
715 ptm_driver->name = "ptm";
716 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
717 ptm_driver->minor_start = 0;
718 ptm_driver->type = TTY_DRIVER_TYPE_PTY;
719 ptm_driver->subtype = PTY_TYPE_MASTER;
720 ptm_driver->init_termios = tty_std_termios;
721 ptm_driver->init_termios.c_iflag = 0;
722 ptm_driver->init_termios.c_oflag = 0;
723 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
724 ptm_driver->init_termios.c_lflag = 0;
606d099c
AC
725 ptm_driver->init_termios.c_ispeed = 38400;
726 ptm_driver->init_termios.c_ospeed = 38400;
1da177e4 727 ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
331b8319 728 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
1da177e4 729 ptm_driver->other = pts_driver;
feebed65 730 tty_set_operations(ptm_driver, &ptm_unix98_ops);
1da177e4
LT
731
732 pts_driver->owner = THIS_MODULE;
733 pts_driver->driver_name = "pty_slave";
734 pts_driver->name = "pts";
735 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
736 pts_driver->minor_start = 0;
737 pts_driver->type = TTY_DRIVER_TYPE_PTY;
738 pts_driver->subtype = PTY_TYPE_SLAVE;
739 pts_driver->init_termios = tty_std_termios;
740 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
606d099c
AC
741 pts_driver->init_termios.c_ispeed = 38400;
742 pts_driver->init_termios.c_ospeed = 38400;
1da177e4 743 pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
331b8319 744 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
1da177e4 745 pts_driver->other = ptm_driver;
99f1fe18 746 tty_set_operations(pts_driver, &pty_unix98_ops);
fe9cd962 747
1da177e4
LT
748 if (tty_register_driver(ptm_driver))
749 panic("Couldn't register Unix98 ptm driver");
750 if (tty_register_driver(pts_driver))
751 panic("Couldn't register Unix98 pts driver");
752
fe9cd962 753 register_sysctl_table(pty_root_table);
d81ed103
AC
754
755 /* Now create the /dev/ptmx special device */
756 tty_default_fops(&ptmx_fops);
757 ptmx_fops.open = ptmx_open;
758
759 cdev_init(&ptmx_cdev, &ptmx_fops);
760 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
761 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
762 panic("Couldn't register /dev/ptmx driver\n");
763 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
1da177e4 764}
d81ed103 765
1da177e4
LT
766#else
767static inline void unix98_pty_init(void) { }
768#endif
769
770static int __init pty_init(void)
771{
772 legacy_pty_init();
773 unix98_pty_init();
774 return 0;
775}
776module_init(pty_init);