Revert "TTY: pty, remove superfluous ptm test"
[linux-2.6.git] / drivers / tty / pty.c
1 /*
2  *  Copyright (C) 1991, 1992  Linus Torvalds
3  *
4  *  Added support for a Unix98-style ptmx device.
5  *    -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
6  *
7  *  When reading this code see also fs/devpts. In particular note that the
8  *  driver_data field is used by the devpts side as a binding to the devpts
9  *  inode.
10  */
11
12 #include <linux/module.h>
13
14 #include <linux/errno.h>
15 #include <linux/interrupt.h>
16 #include <linux/tty.h>
17 #include <linux/tty_flip.h>
18 #include <linux/fcntl.h>
19 #include <linux/sched.h>
20 #include <linux/string.h>
21 #include <linux/major.h>
22 #include <linux/mm.h>
23 #include <linux/init.h>
24 #include <linux/device.h>
25 #include <linux/uaccess.h>
26 #include <linux/bitops.h>
27 #include <linux/devpts_fs.h>
28 #include <linux/slab.h>
29
30 #include <asm/system.h>
31
32 #ifdef CONFIG_UNIX98_PTYS
33 static struct tty_driver *ptm_driver;
34 static struct tty_driver *pts_driver;
35 #endif
36
37 static void pty_close(struct tty_struct *tty, struct file *filp)
38 {
39         BUG_ON(!tty);
40         if (tty->driver->subtype == PTY_TYPE_MASTER)
41                 WARN_ON(tty->count > 1);
42         else {
43                 if (tty->count > 2)
44                         return;
45         }
46         wake_up_interruptible(&tty->read_wait);
47         wake_up_interruptible(&tty->write_wait);
48         tty->packet = 0;
49         if (!tty->link)
50                 return;
51         tty->link->packet = 0;
52         set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
53         wake_up_interruptible(&tty->link->read_wait);
54         wake_up_interruptible(&tty->link->write_wait);
55         if (tty->driver->subtype == PTY_TYPE_MASTER) {
56                 set_bit(TTY_OTHER_CLOSED, &tty->flags);
57 #ifdef CONFIG_UNIX98_PTYS
58                 if (tty->driver == ptm_driver)
59                         devpts_pty_kill(tty->link);
60 #endif
61                 tty_unlock();
62                 tty_vhangup(tty->link);
63                 tty_lock();
64         }
65 }
66
67 /*
68  * The unthrottle routine is called by the line discipline to signal
69  * that it can receive more characters.  For PTY's, the TTY_THROTTLED
70  * flag is always set, to force the line discipline to always call the
71  * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
72  * characters in the queue.  This is necessary since each time this
73  * happens, we need to wake up any sleeping processes that could be
74  * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
75  * for the pty buffer to be drained.
76  */
77 static void pty_unthrottle(struct tty_struct *tty)
78 {
79         tty_wakeup(tty->link);
80         set_bit(TTY_THROTTLED, &tty->flags);
81 }
82
83 /**
84  *      pty_space       -       report space left for writing
85  *      @to: tty we are writing into
86  *
87  *      The tty buffers allow 64K but we sneak a peak and clip at 8K this
88  *      allows a lot of overspill room for echo and other fun messes to
89  *      be handled properly
90  */
91
92 static int pty_space(struct tty_struct *to)
93 {
94         int n = 8192 - to->buf.memory_used;
95         if (n < 0)
96                 return 0;
97         return n;
98 }
99
100 /**
101  *      pty_write               -       write to a pty
102  *      @tty: the tty we write from
103  *      @buf: kernel buffer of data
104  *      @count: bytes to write
105  *
106  *      Our "hardware" write method. Data is coming from the ldisc which
107  *      may be in a non sleeping state. We simply throw this at the other
108  *      end of the link as if we were an IRQ handler receiving stuff for
109  *      the other side of the pty/tty pair.
110  */
111
112 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
113 {
114         struct tty_struct *to = tty->link;
115
116         if (tty->stopped)
117                 return 0;
118
119         if (c > 0) {
120                 /* Stuff the data into the input queue of the other end */
121                 c = tty_insert_flip_string(to, buf, c);
122                 /* And shovel */
123                 if (c) {
124                         tty_flip_buffer_push(to);
125                         tty_wakeup(tty);
126                 }
127         }
128         return c;
129 }
130
131 /**
132  *      pty_write_room  -       write space
133  *      @tty: tty we are writing from
134  *
135  *      Report how many bytes the ldisc can send into the queue for
136  *      the other device.
137  */
138
139 static int pty_write_room(struct tty_struct *tty)
140 {
141         if (tty->stopped)
142                 return 0;
143         return pty_space(tty->link);
144 }
145
146 /**
147  *      pty_chars_in_buffer     -       characters currently in our tx queue
148  *      @tty: our tty
149  *
150  *      Report how much we have in the transmit queue. As everything is
151  *      instantly at the other end this is easy to implement.
152  */
153
154 static int pty_chars_in_buffer(struct tty_struct *tty)
155 {
156         return 0;
157 }
158
159 /* Set the lock flag on a pty */
160 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
161 {
162         int val;
163         if (get_user(val, arg))
164                 return -EFAULT;
165         if (val)
166                 set_bit(TTY_PTY_LOCK, &tty->flags);
167         else
168                 clear_bit(TTY_PTY_LOCK, &tty->flags);
169         return 0;
170 }
171
172 /* Send a signal to the slave */
173 static int pty_signal(struct tty_struct *tty, int sig)
174 {
175         unsigned long flags;
176         struct pid *pgrp;
177
178         if (tty->link) {
179                 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
180                 pgrp = get_pid(tty->link->pgrp);
181                 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
182
183                 kill_pgrp(pgrp, sig, 1);
184                 put_pid(pgrp);
185         }
186         return 0;
187 }
188
189 static void pty_flush_buffer(struct tty_struct *tty)
190 {
191         struct tty_struct *to = tty->link;
192         unsigned long flags;
193
194         if (!to)
195                 return;
196         /* tty_buffer_flush(to); FIXME */
197         if (to->packet) {
198                 spin_lock_irqsave(&tty->ctrl_lock, flags);
199                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
200                 wake_up_interruptible(&to->read_wait);
201                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
202         }
203 }
204
205 static int pty_open(struct tty_struct *tty, struct file *filp)
206 {
207         int     retval = -ENODEV;
208
209         if (!tty || !tty->link)
210                 goto out;
211
212         retval = -EIO;
213         if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
214                 goto out;
215         if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
216                 goto out;
217         if (tty->link->count != 1)
218                 goto out;
219
220         clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
221         set_bit(TTY_THROTTLED, &tty->flags);
222         retval = 0;
223 out:
224         return retval;
225 }
226
227 static void pty_set_termios(struct tty_struct *tty,
228                                         struct ktermios *old_termios)
229 {
230         tty->termios->c_cflag &= ~(CSIZE | PARENB);
231         tty->termios->c_cflag |= (CS8 | CREAD);
232 }
233
234 /**
235  *      pty_do_resize           -       resize event
236  *      @tty: tty being resized
237  *      @ws: window size being set.
238  *
239  *      Update the termios variables and send the necessary signals to
240  *      peform a terminal resize correctly
241  */
242
243 int pty_resize(struct tty_struct *tty,  struct winsize *ws)
244 {
245         struct pid *pgrp, *rpgrp;
246         unsigned long flags;
247         struct tty_struct *pty = tty->link;
248
249         /* For a PTY we need to lock the tty side */
250         mutex_lock(&tty->termios_mutex);
251         if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
252                 goto done;
253
254         /* Get the PID values and reference them so we can
255            avoid holding the tty ctrl lock while sending signals.
256            We need to lock these individually however. */
257
258         spin_lock_irqsave(&tty->ctrl_lock, flags);
259         pgrp = get_pid(tty->pgrp);
260         spin_unlock_irqrestore(&tty->ctrl_lock, flags);
261
262         spin_lock_irqsave(&pty->ctrl_lock, flags);
263         rpgrp = get_pid(pty->pgrp);
264         spin_unlock_irqrestore(&pty->ctrl_lock, flags);
265
266         if (pgrp)
267                 kill_pgrp(pgrp, SIGWINCH, 1);
268         if (rpgrp != pgrp && rpgrp)
269                 kill_pgrp(rpgrp, SIGWINCH, 1);
270
271         put_pid(pgrp);
272         put_pid(rpgrp);
273
274         tty->winsize = *ws;
275         pty->winsize = *ws;     /* Never used so will go away soon */
276 done:
277         mutex_unlock(&tty->termios_mutex);
278         return 0;
279 }
280
281 /* Traditional BSD devices */
282 #ifdef CONFIG_LEGACY_PTYS
283
284 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
285 {
286         struct tty_struct *o_tty;
287         int idx = tty->index;
288         int retval;
289
290         o_tty = alloc_tty_struct();
291         if (!o_tty)
292                 return -ENOMEM;
293         if (!try_module_get(driver->other->owner)) {
294                 /* This cannot in fact currently happen */
295                 retval = -ENOMEM;
296                 goto err_free_tty;
297         }
298         initialize_tty_struct(o_tty, driver->other, idx);
299
300         /* We always use new tty termios data so we can do this
301            the easy way .. */
302         retval = tty_init_termios(tty);
303         if (retval)
304                 goto err_deinit_tty;
305
306         retval = tty_init_termios(o_tty);
307         if (retval)
308                 goto err_free_termios;
309
310         /*
311          * Everything allocated ... set up the o_tty structure.
312          */
313         driver->other->ttys[idx] = o_tty;
314         tty_driver_kref_get(driver->other);
315         if (driver->subtype == PTY_TYPE_MASTER)
316                 o_tty->count++;
317         /* Establish the links in both directions */
318         tty->link   = o_tty;
319         o_tty->link = tty;
320
321         tty_driver_kref_get(driver);
322         tty->count++;
323         driver->ttys[idx] = tty;
324         return 0;
325 err_free_termios:
326         tty_free_termios(tty);
327 err_deinit_tty:
328         deinitialize_tty_struct(o_tty);
329         module_put(o_tty->driver->owner);
330 err_free_tty:
331         free_tty_struct(o_tty);
332         return retval;
333 }
334
335 static int pty_bsd_ioctl(struct tty_struct *tty,
336                          unsigned int cmd, unsigned long arg)
337 {
338         switch (cmd) {
339         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
340                 return pty_set_lock(tty, (int __user *) arg);
341         case TIOCSIG:    /* Send signal to other side of pty */
342                 return pty_signal(tty, (int) arg);
343         }
344         return -ENOIOCTLCMD;
345 }
346
347 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
348 module_param(legacy_count, int, 0);
349
350 /*
351  * The master side of a pty can do TIOCSPTLCK and thus
352  * has pty_bsd_ioctl.
353  */
354 static const struct tty_operations master_pty_ops_bsd = {
355         .install = pty_install,
356         .open = pty_open,
357         .close = pty_close,
358         .write = pty_write,
359         .write_room = pty_write_room,
360         .flush_buffer = pty_flush_buffer,
361         .chars_in_buffer = pty_chars_in_buffer,
362         .unthrottle = pty_unthrottle,
363         .set_termios = pty_set_termios,
364         .ioctl = pty_bsd_ioctl,
365         .resize = pty_resize
366 };
367
368 static const struct tty_operations slave_pty_ops_bsd = {
369         .install = pty_install,
370         .open = pty_open,
371         .close = pty_close,
372         .write = pty_write,
373         .write_room = pty_write_room,
374         .flush_buffer = pty_flush_buffer,
375         .chars_in_buffer = pty_chars_in_buffer,
376         .unthrottle = pty_unthrottle,
377         .set_termios = pty_set_termios,
378         .resize = pty_resize
379 };
380
381 static void __init legacy_pty_init(void)
382 {
383         struct tty_driver *pty_driver, *pty_slave_driver;
384
385         if (legacy_count <= 0)
386                 return;
387
388         pty_driver = alloc_tty_driver(legacy_count);
389         if (!pty_driver)
390                 panic("Couldn't allocate pty driver");
391
392         pty_slave_driver = alloc_tty_driver(legacy_count);
393         if (!pty_slave_driver)
394                 panic("Couldn't allocate pty slave driver");
395
396         pty_driver->owner = THIS_MODULE;
397         pty_driver->driver_name = "pty_master";
398         pty_driver->name = "pty";
399         pty_driver->major = PTY_MASTER_MAJOR;
400         pty_driver->minor_start = 0;
401         pty_driver->type = TTY_DRIVER_TYPE_PTY;
402         pty_driver->subtype = PTY_TYPE_MASTER;
403         pty_driver->init_termios = tty_std_termios;
404         pty_driver->init_termios.c_iflag = 0;
405         pty_driver->init_termios.c_oflag = 0;
406         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
407         pty_driver->init_termios.c_lflag = 0;
408         pty_driver->init_termios.c_ispeed = 38400;
409         pty_driver->init_termios.c_ospeed = 38400;
410         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
411         pty_driver->other = pty_slave_driver;
412         tty_set_operations(pty_driver, &master_pty_ops_bsd);
413
414         pty_slave_driver->owner = THIS_MODULE;
415         pty_slave_driver->driver_name = "pty_slave";
416         pty_slave_driver->name = "ttyp";
417         pty_slave_driver->major = PTY_SLAVE_MAJOR;
418         pty_slave_driver->minor_start = 0;
419         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
420         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
421         pty_slave_driver->init_termios = tty_std_termios;
422         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
423         pty_slave_driver->init_termios.c_ispeed = 38400;
424         pty_slave_driver->init_termios.c_ospeed = 38400;
425         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
426                                         TTY_DRIVER_REAL_RAW;
427         pty_slave_driver->other = pty_driver;
428         tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
429
430         if (tty_register_driver(pty_driver))
431                 panic("Couldn't register pty driver");
432         if (tty_register_driver(pty_slave_driver))
433                 panic("Couldn't register pty slave driver");
434 }
435 #else
436 static inline void legacy_pty_init(void) { }
437 #endif
438
439 /* Unix98 devices */
440 #ifdef CONFIG_UNIX98_PTYS
441
442 static struct cdev ptmx_cdev;
443
444 static int pty_unix98_ioctl(struct tty_struct *tty,
445                             unsigned int cmd, unsigned long arg)
446 {
447         switch (cmd) {
448         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
449                 return pty_set_lock(tty, (int __user *)arg);
450         case TIOCGPTN: /* Get PT Number */
451                 return put_user(tty->index, (unsigned int __user *)arg);
452         case TIOCSIG:    /* Send signal to other side of pty */
453                 return pty_signal(tty, (int) arg);
454         }
455
456         return -ENOIOCTLCMD;
457 }
458
459 /**
460  *      ptm_unix98_lookup       -       find a pty master
461  *      @driver: ptm driver
462  *      @idx: tty index
463  *
464  *      Look up a pty master device. Called under the tty_mutex for now.
465  *      This provides our locking.
466  */
467
468 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
469                 struct inode *ptm_inode, int idx)
470 {
471         /* Master must be open via /dev/ptmx */
472         return ERR_PTR(-EIO);
473 }
474
475 /**
476  *      pts_unix98_lookup       -       find a pty slave
477  *      @driver: pts driver
478  *      @idx: tty index
479  *
480  *      Look up a pty master device. Called under the tty_mutex for now.
481  *      This provides our locking.
482  */
483
484 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
485                 struct inode *pts_inode, int idx)
486 {
487         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
488         /* Master must be open before slave */
489         if (!tty)
490                 return ERR_PTR(-EIO);
491         return tty;
492 }
493
494 static void pty_unix98_shutdown(struct tty_struct *tty)
495 {
496         tty_driver_remove_tty(tty->driver, tty);
497         /* We have our own method as we don't use the tty index */
498         kfree(tty->termios);
499 }
500
501 /* We have no need to install and remove our tty objects as devpts does all
502    the work for us */
503
504 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
505 {
506         struct tty_struct *o_tty;
507         int idx = tty->index;
508
509         o_tty = alloc_tty_struct();
510         if (!o_tty)
511                 return -ENOMEM;
512         if (!try_module_get(driver->other->owner)) {
513                 /* This cannot in fact currently happen */
514                 goto err_free_tty;
515         }
516         initialize_tty_struct(o_tty, driver->other, idx);
517
518         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
519         if (tty->termios == NULL)
520                 goto err_free_mem;
521         *tty->termios = driver->init_termios;
522         tty->termios_locked = tty->termios + 1;
523
524         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
525         if (o_tty->termios == NULL)
526                 goto err_free_mem;
527         *o_tty->termios = driver->other->init_termios;
528         o_tty->termios_locked = o_tty->termios + 1;
529
530         tty_driver_kref_get(driver->other);
531         if (driver->subtype == PTY_TYPE_MASTER)
532                 o_tty->count++;
533         /* Establish the links in both directions */
534         tty->link   = o_tty;
535         o_tty->link = tty;
536         /*
537          * All structures have been allocated, so now we install them.
538          * Failures after this point use release_tty to clean up, so
539          * there's no need to null out the local pointers.
540          */
541         tty_driver_kref_get(driver);
542         tty->count++;
543         return 0;
544 err_free_mem:
545         deinitialize_tty_struct(o_tty);
546         kfree(o_tty->termios);
547         kfree(tty->termios);
548         module_put(o_tty->driver->owner);
549 err_free_tty:
550         free_tty_struct(o_tty);
551         return -ENOMEM;
552 }
553
554 static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
555 {
556 }
557
558 static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
559 {
560 }
561
562 static const struct tty_operations ptm_unix98_ops = {
563         .lookup = ptm_unix98_lookup,
564         .install = pty_unix98_install,
565         .remove = ptm_unix98_remove,
566         .open = pty_open,
567         .close = pty_close,
568         .write = pty_write,
569         .write_room = pty_write_room,
570         .flush_buffer = pty_flush_buffer,
571         .chars_in_buffer = pty_chars_in_buffer,
572         .unthrottle = pty_unthrottle,
573         .set_termios = pty_set_termios,
574         .ioctl = pty_unix98_ioctl,
575         .shutdown = pty_unix98_shutdown,
576         .resize = pty_resize
577 };
578
579 static const struct tty_operations pty_unix98_ops = {
580         .lookup = pts_unix98_lookup,
581         .install = pty_unix98_install,
582         .remove = pts_unix98_remove,
583         .open = pty_open,
584         .close = pty_close,
585         .write = pty_write,
586         .write_room = pty_write_room,
587         .flush_buffer = pty_flush_buffer,
588         .chars_in_buffer = pty_chars_in_buffer,
589         .unthrottle = pty_unthrottle,
590         .set_termios = pty_set_termios,
591         .shutdown = pty_unix98_shutdown
592 };
593
594 /**
595  *      ptmx_open               -       open a unix 98 pty master
596  *      @inode: inode of device file
597  *      @filp: file pointer to tty
598  *
599  *      Allocate a unix98 pty master device from the ptmx driver.
600  *
601  *      Locking: tty_mutex protects the init_dev work. tty->count should
602  *              protect the rest.
603  *              allocated_ptys_lock handles the list of free pty numbers
604  */
605
606 static int ptmx_open(struct inode *inode, struct file *filp)
607 {
608         struct tty_struct *tty;
609         int retval;
610         int index;
611
612         nonseekable_open(inode, filp);
613
614         retval = tty_alloc_file(filp);
615         if (retval)
616                 return retval;
617
618         /* find a device that is not in use. */
619         tty_lock();
620         index = devpts_new_index(inode);
621         tty_unlock();
622         if (index < 0) {
623                 retval = index;
624                 goto err_file;
625         }
626
627         mutex_lock(&tty_mutex);
628         tty_lock();
629         tty = tty_init_dev(ptm_driver, index);
630         mutex_unlock(&tty_mutex);
631
632         if (IS_ERR(tty)) {
633                 retval = PTR_ERR(tty);
634                 goto out;
635         }
636
637         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
638
639         tty_add_file(tty, filp);
640
641         retval = devpts_pty_new(inode, tty->link);
642         if (retval)
643                 goto err_release;
644
645         retval = ptm_driver->ops->open(tty, filp);
646         if (retval)
647                 goto err_release;
648
649         tty_unlock();
650         return 0;
651 err_release:
652         tty_unlock();
653         tty_release(inode, filp);
654         return retval;
655 out:
656         devpts_kill_index(inode, index);
657         tty_unlock();
658 err_file:
659         tty_free_file(filp);
660         return retval;
661 }
662
663 static struct file_operations ptmx_fops;
664
665 static void __init unix98_pty_init(void)
666 {
667         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
668         if (!ptm_driver)
669                 panic("Couldn't allocate Unix98 ptm driver");
670         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
671         if (!pts_driver)
672                 panic("Couldn't allocate Unix98 pts driver");
673
674         ptm_driver->owner = THIS_MODULE;
675         ptm_driver->driver_name = "pty_master";
676         ptm_driver->name = "ptm";
677         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
678         ptm_driver->minor_start = 0;
679         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
680         ptm_driver->subtype = PTY_TYPE_MASTER;
681         ptm_driver->init_termios = tty_std_termios;
682         ptm_driver->init_termios.c_iflag = 0;
683         ptm_driver->init_termios.c_oflag = 0;
684         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
685         ptm_driver->init_termios.c_lflag = 0;
686         ptm_driver->init_termios.c_ispeed = 38400;
687         ptm_driver->init_termios.c_ospeed = 38400;
688         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
689                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
690         ptm_driver->other = pts_driver;
691         tty_set_operations(ptm_driver, &ptm_unix98_ops);
692
693         pts_driver->owner = THIS_MODULE;
694         pts_driver->driver_name = "pty_slave";
695         pts_driver->name = "pts";
696         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
697         pts_driver->minor_start = 0;
698         pts_driver->type = TTY_DRIVER_TYPE_PTY;
699         pts_driver->subtype = PTY_TYPE_SLAVE;
700         pts_driver->init_termios = tty_std_termios;
701         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
702         pts_driver->init_termios.c_ispeed = 38400;
703         pts_driver->init_termios.c_ospeed = 38400;
704         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
705                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
706         pts_driver->other = ptm_driver;
707         tty_set_operations(pts_driver, &pty_unix98_ops);
708
709         if (tty_register_driver(ptm_driver))
710                 panic("Couldn't register Unix98 ptm driver");
711         if (tty_register_driver(pts_driver))
712                 panic("Couldn't register Unix98 pts driver");
713
714         /* Now create the /dev/ptmx special device */
715         tty_default_fops(&ptmx_fops);
716         ptmx_fops.open = ptmx_open;
717
718         cdev_init(&ptmx_cdev, &ptmx_fops);
719         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
720             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
721                 panic("Couldn't register /dev/ptmx driver\n");
722         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
723 }
724
725 #else
726 static inline void unix98_pty_init(void) { }
727 #endif
728
729 static int __init pty_init(void)
730 {
731         legacy_pty_init();
732         unix98_pty_init();
733         return 0;
734 }
735 module_init(pty_init);