TTY: plug in deinitialize_tty_struct
[linux-2.6.git] / drivers / tty / pty.c
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
8  *
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.
12  */
13
14 #include <linux/module.h>
15
16 #include <linux/errno.h>
17 #include <linux/interrupt.h>
18 #include <linux/tty.h>
19 #include <linux/tty_flip.h>
20 #include <linux/fcntl.h>
21 #include <linux/sched.h>
22 #include <linux/string.h>
23 #include <linux/major.h>
24 #include <linux/mm.h>
25 #include <linux/init.h>
26 #include <linux/sysctl.h>
27 #include <linux/device.h>
28 #include <linux/uaccess.h>
29 #include <linux/bitops.h>
30 #include <linux/devpts_fs.h>
31 #include <linux/slab.h>
32
33 #include <asm/system.h>
34
35 #ifdef CONFIG_UNIX98_PTYS
36 static struct tty_driver *ptm_driver;
37 static struct tty_driver *pts_driver;
38 #endif
39
40 static void pty_close(struct tty_struct *tty, struct file *filp)
41 {
42         BUG_ON(!tty);
43         if (tty->driver->subtype == PTY_TYPE_MASTER)
44                 WARN_ON(tty->count > 1);
45         else {
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)
62                         devpts_pty_kill(tty->link);
63 #endif
64                 tty_unlock();
65                 tty_vhangup(tty->link);
66                 tty_lock();
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
74  * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
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  */
80 static void pty_unthrottle(struct tty_struct *tty)
81 {
82         tty_wakeup(tty->link);
83         set_bit(TTY_THROTTLED, &tty->flags);
84 }
85
86 /**
87  *      pty_space       -       report space left for writing
88  *      @to: tty we are writing into
89  *
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
95 static 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
108  *
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.
113  */
114
115 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
116 {
117         struct tty_struct *to = tty->link;
118
119         if (tty->stopped)
120                 return 0;
121
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 */
126                 if (c) {
127                         tty_flip_buffer_push(to);
128                         tty_wakeup(tty);
129                 }
130         }
131         return c;
132 }
133
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
142 static int pty_write_room(struct tty_struct *tty)
143 {
144         if (tty->stopped)
145                 return 0;
146         return pty_space(tty->link);
147 }
148
149 /**
150  *      pty_chars_in_buffer     -       characters currently in our tx queue
151  *      @tty: our tty
152  *
153  *      Report how much we have in the transmit queue. As everything is
154  *      instantly at the other end this is easy to implement.
155  */
156
157 static int pty_chars_in_buffer(struct tty_struct *tty)
158 {
159         return 0;
160 }
161
162 /* Set the lock flag on a pty */
163 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
164 {
165         int val;
166         if (get_user(val, arg))
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
175 /* Send a signal to the slave */
176 static 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
192 static void pty_flush_buffer(struct tty_struct *tty)
193 {
194         struct tty_struct *to = tty->link;
195         unsigned long flags;
196
197         if (!to)
198                 return;
199         /* tty_buffer_flush(to); FIXME */
200         if (to->packet) {
201                 spin_lock_irqsave(&tty->ctrl_lock, flags);
202                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
203                 wake_up_interruptible(&to->read_wait);
204                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
205         }
206 }
207
208 static int pty_open(struct tty_struct *tty, struct file *filp)
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);
225         retval = 0;
226 out:
227         return retval;
228 }
229
230 static void pty_set_termios(struct tty_struct *tty,
231                                         struct ktermios *old_termios)
232 {
233         tty->termios->c_cflag &= ~(CSIZE | PARENB);
234         tty->termios->c_cflag |= (CS8 | CREAD);
235 }
236
237 /**
238  *      pty_do_resize           -       resize event
239  *      @tty: tty being resized
240  *      @ws: window size being set.
241  *
242  *      Update the termios variables and send the necessary signals to
243  *      peform a terminal resize correctly
244  */
245
246 int 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 */
279 done:
280         mutex_unlock(&tty->termios_mutex);
281         return 0;
282 }
283
284 /* Traditional BSD devices */
285 #ifdef CONFIG_LEGACY_PTYS
286
287 static 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                 retval = -ENOMEM;
299                 goto err_free_tty;
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 err_deinit_tty;
308
309         retval = tty_init_termios(o_tty);
310         if (retval)
311                 goto err_free_termios;
312
313         /*
314          * Everything allocated ... set up the o_tty structure.
315          */
316         driver->other->ttys[idx] = o_tty;
317         tty_driver_kref_get(driver->other);
318         if (driver->subtype == PTY_TYPE_MASTER)
319                 o_tty->count++;
320         /* Establish the links in both directions */
321         tty->link   = o_tty;
322         o_tty->link = tty;
323
324         tty_driver_kref_get(driver);
325         tty->count++;
326         driver->ttys[idx] = tty;
327         return 0;
328 err_free_termios:
329         tty_free_termios(tty);
330 err_deinit_tty:
331         deinitialize_tty_struct(o_tty);
332         module_put(o_tty->driver->owner);
333 err_free_tty:
334         free_tty_struct(o_tty);
335         return retval;
336 }
337
338 static int pty_bsd_ioctl(struct tty_struct *tty,
339                          unsigned int cmd, unsigned long arg)
340 {
341         switch (cmd) {
342         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
343                 return pty_set_lock(tty, (int __user *) arg);
344         case TIOCSIG:    /* Send signal to other side of pty */
345                 return pty_signal(tty, (int) arg);
346         }
347         return -ENOIOCTLCMD;
348 }
349
350 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
351 module_param(legacy_count, int, 0);
352
353 /*
354  * The master side of a pty can do TIOCSPTLCK and thus
355  * has pty_bsd_ioctl.
356  */
357 static const struct tty_operations master_pty_ops_bsd = {
358         .install = pty_install,
359         .open = pty_open,
360         .close = pty_close,
361         .write = pty_write,
362         .write_room = pty_write_room,
363         .flush_buffer = pty_flush_buffer,
364         .chars_in_buffer = pty_chars_in_buffer,
365         .unthrottle = pty_unthrottle,
366         .set_termios = pty_set_termios,
367         .ioctl = pty_bsd_ioctl,
368         .resize = pty_resize
369 };
370
371 static const struct tty_operations slave_pty_ops_bsd = {
372         .install = pty_install,
373         .open = pty_open,
374         .close = pty_close,
375         .write = pty_write,
376         .write_room = pty_write_room,
377         .flush_buffer = pty_flush_buffer,
378         .chars_in_buffer = pty_chars_in_buffer,
379         .unthrottle = pty_unthrottle,
380         .set_termios = pty_set_termios,
381         .resize = pty_resize
382 };
383
384 static void __init legacy_pty_init(void)
385 {
386         struct tty_driver *pty_driver, *pty_slave_driver;
387
388         if (legacy_count <= 0)
389                 return;
390
391         pty_driver = alloc_tty_driver(legacy_count);
392         if (!pty_driver)
393                 panic("Couldn't allocate pty driver");
394
395         pty_slave_driver = alloc_tty_driver(legacy_count);
396         if (!pty_slave_driver)
397                 panic("Couldn't allocate pty slave driver");
398
399         pty_driver->owner = THIS_MODULE;
400         pty_driver->driver_name = "pty_master";
401         pty_driver->name = "pty";
402         pty_driver->major = PTY_MASTER_MAJOR;
403         pty_driver->minor_start = 0;
404         pty_driver->type = TTY_DRIVER_TYPE_PTY;
405         pty_driver->subtype = PTY_TYPE_MASTER;
406         pty_driver->init_termios = tty_std_termios;
407         pty_driver->init_termios.c_iflag = 0;
408         pty_driver->init_termios.c_oflag = 0;
409         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
410         pty_driver->init_termios.c_lflag = 0;
411         pty_driver->init_termios.c_ispeed = 38400;
412         pty_driver->init_termios.c_ospeed = 38400;
413         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
414         pty_driver->other = pty_slave_driver;
415         tty_set_operations(pty_driver, &master_pty_ops_bsd);
416
417         pty_slave_driver->owner = THIS_MODULE;
418         pty_slave_driver->driver_name = "pty_slave";
419         pty_slave_driver->name = "ttyp";
420         pty_slave_driver->major = PTY_SLAVE_MAJOR;
421         pty_slave_driver->minor_start = 0;
422         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
423         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
424         pty_slave_driver->init_termios = tty_std_termios;
425         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
426         pty_slave_driver->init_termios.c_ispeed = 38400;
427         pty_slave_driver->init_termios.c_ospeed = 38400;
428         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
429                                         TTY_DRIVER_REAL_RAW;
430         pty_slave_driver->other = pty_driver;
431         tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
432
433         if (tty_register_driver(pty_driver))
434                 panic("Couldn't register pty driver");
435         if (tty_register_driver(pty_slave_driver))
436                 panic("Couldn't register pty slave driver");
437 }
438 #else
439 static inline void legacy_pty_init(void) { }
440 #endif
441
442 /* Unix98 devices */
443 #ifdef CONFIG_UNIX98_PTYS
444 /*
445  * sysctl support for setting limits on the number of Unix98 ptys allocated.
446  * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
447  */
448 int pty_limit = NR_UNIX98_PTY_DEFAULT;
449 static int pty_limit_min;
450 static int pty_limit_max = NR_UNIX98_PTY_MAX;
451 static int pty_count;
452
453 static struct cdev ptmx_cdev;
454
455 static struct ctl_table pty_table[] = {
456         {
457                 .procname       = "max",
458                 .maxlen         = sizeof(int),
459                 .mode           = 0644,
460                 .data           = &pty_limit,
461                 .proc_handler   = proc_dointvec_minmax,
462                 .extra1         = &pty_limit_min,
463                 .extra2         = &pty_limit_max,
464         }, {
465                 .procname       = "nr",
466                 .maxlen         = sizeof(int),
467                 .mode           = 0444,
468                 .data           = &pty_count,
469                 .proc_handler   = proc_dointvec,
470         }, 
471         {}
472 };
473
474 static struct ctl_table pty_kern_table[] = {
475         {
476                 .procname       = "pty",
477                 .mode           = 0555,
478                 .child          = pty_table,
479         },
480         {}
481 };
482
483 static struct ctl_table pty_root_table[] = {
484         {
485                 .procname       = "kernel",
486                 .mode           = 0555,
487                 .child          = pty_kern_table,
488         },
489         {}
490 };
491
492
493 static int pty_unix98_ioctl(struct tty_struct *tty,
494                             unsigned int cmd, unsigned long arg)
495 {
496         switch (cmd) {
497         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
498                 return pty_set_lock(tty, (int __user *)arg);
499         case TIOCGPTN: /* Get PT Number */
500                 return put_user(tty->index, (unsigned int __user *)arg);
501         case TIOCSIG:    /* Send signal to other side of pty */
502                 return pty_signal(tty, (int) arg);
503         }
504
505         return -ENOIOCTLCMD;
506 }
507
508 /**
509  *      ptm_unix98_lookup       -       find a pty master
510  *      @driver: ptm driver
511  *      @idx: tty index
512  *
513  *      Look up a pty master device. Called under the tty_mutex for now.
514  *      This provides our locking.
515  */
516
517 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
518                 struct inode *ptm_inode, int idx)
519 {
520         struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
521         if (tty)
522                 tty = tty->link;
523         return tty;
524 }
525
526 /**
527  *      pts_unix98_lookup       -       find a pty slave
528  *      @driver: pts driver
529  *      @idx: tty index
530  *
531  *      Look up a pty master device. Called under the tty_mutex for now.
532  *      This provides our locking.
533  */
534
535 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
536                 struct inode *pts_inode, int idx)
537 {
538         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
539         /* Master must be open before slave */
540         if (!tty)
541                 return ERR_PTR(-EIO);
542         return tty;
543 }
544
545 static void pty_unix98_shutdown(struct tty_struct *tty)
546 {
547         /* We have our own method as we don't use the tty index */
548         kfree(tty->termios);
549 }
550
551 /* We have no need to install and remove our tty objects as devpts does all
552    the work for us */
553
554 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
555 {
556         struct tty_struct *o_tty;
557         int idx = tty->index;
558
559         o_tty = alloc_tty_struct();
560         if (!o_tty)
561                 return -ENOMEM;
562         if (!try_module_get(driver->other->owner)) {
563                 /* This cannot in fact currently happen */
564                 goto err_free_tty;
565         }
566         initialize_tty_struct(o_tty, driver->other, idx);
567
568         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
569         if (tty->termios == NULL)
570                 goto err_free_mem;
571         *tty->termios = driver->init_termios;
572         tty->termios_locked = tty->termios + 1;
573
574         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
575         if (o_tty->termios == NULL)
576                 goto err_free_mem;
577         *o_tty->termios = driver->other->init_termios;
578         o_tty->termios_locked = o_tty->termios + 1;
579
580         tty_driver_kref_get(driver->other);
581         if (driver->subtype == PTY_TYPE_MASTER)
582                 o_tty->count++;
583         /* Establish the links in both directions */
584         tty->link   = o_tty;
585         o_tty->link = tty;
586         /*
587          * All structures have been allocated, so now we install them.
588          * Failures after this point use release_tty to clean up, so
589          * there's no need to null out the local pointers.
590          */
591         tty_driver_kref_get(driver);
592         tty->count++;
593         pty_count++;
594         return 0;
595 err_free_mem:
596         deinitialize_tty_struct(o_tty);
597         kfree(o_tty->termios);
598         kfree(tty->termios);
599         module_put(o_tty->driver->owner);
600 err_free_tty:
601         free_tty_struct(o_tty);
602         return -ENOMEM;
603 }
604
605 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
606 {
607         pty_count--;
608 }
609
610 static const struct tty_operations ptm_unix98_ops = {
611         .lookup = ptm_unix98_lookup,
612         .install = pty_unix98_install,
613         .remove = pty_unix98_remove,
614         .open = pty_open,
615         .close = pty_close,
616         .write = pty_write,
617         .write_room = pty_write_room,
618         .flush_buffer = pty_flush_buffer,
619         .chars_in_buffer = pty_chars_in_buffer,
620         .unthrottle = pty_unthrottle,
621         .set_termios = pty_set_termios,
622         .ioctl = pty_unix98_ioctl,
623         .shutdown = pty_unix98_shutdown,
624         .resize = pty_resize
625 };
626
627 static const struct tty_operations pty_unix98_ops = {
628         .lookup = pts_unix98_lookup,
629         .install = pty_unix98_install,
630         .remove = pty_unix98_remove,
631         .open = pty_open,
632         .close = pty_close,
633         .write = pty_write,
634         .write_room = pty_write_room,
635         .flush_buffer = pty_flush_buffer,
636         .chars_in_buffer = pty_chars_in_buffer,
637         .unthrottle = pty_unthrottle,
638         .set_termios = pty_set_termios,
639         .shutdown = pty_unix98_shutdown
640 };
641
642 /**
643  *      ptmx_open               -       open a unix 98 pty master
644  *      @inode: inode of device file
645  *      @filp: file pointer to tty
646  *
647  *      Allocate a unix98 pty master device from the ptmx driver.
648  *
649  *      Locking: tty_mutex protects the init_dev work. tty->count should
650  *              protect the rest.
651  *              allocated_ptys_lock handles the list of free pty numbers
652  */
653
654 static int ptmx_open(struct inode *inode, struct file *filp)
655 {
656         struct tty_struct *tty;
657         int retval;
658         int index;
659
660         nonseekable_open(inode, filp);
661
662         /* find a device that is not in use. */
663         tty_lock();
664         index = devpts_new_index(inode);
665         tty_unlock();
666         if (index < 0)
667                 return index;
668
669         mutex_lock(&tty_mutex);
670         tty_lock();
671         tty = tty_init_dev(ptm_driver, index, 1);
672         mutex_unlock(&tty_mutex);
673
674         if (IS_ERR(tty)) {
675                 retval = PTR_ERR(tty);
676                 goto out;
677         }
678
679         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
680
681         retval = tty_add_file(tty, filp);
682         if (retval)
683                 goto out;
684
685         retval = devpts_pty_new(inode, tty->link);
686         if (retval)
687                 goto out1;
688
689         retval = ptm_driver->ops->open(tty, filp);
690         if (retval)
691                 goto out2;
692 out1:
693         tty_unlock();
694         return retval;
695 out2:
696         tty_unlock();
697         tty_release(inode, filp);
698         return retval;
699 out:
700         devpts_kill_index(inode, index);
701         tty_unlock();
702         return retval;
703 }
704
705 static struct file_operations ptmx_fops;
706
707 static void __init unix98_pty_init(void)
708 {
709         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
710         if (!ptm_driver)
711                 panic("Couldn't allocate Unix98 ptm driver");
712         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
713         if (!pts_driver)
714                 panic("Couldn't allocate Unix98 pts driver");
715
716         ptm_driver->owner = THIS_MODULE;
717         ptm_driver->driver_name = "pty_master";
718         ptm_driver->name = "ptm";
719         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
720         ptm_driver->minor_start = 0;
721         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
722         ptm_driver->subtype = PTY_TYPE_MASTER;
723         ptm_driver->init_termios = tty_std_termios;
724         ptm_driver->init_termios.c_iflag = 0;
725         ptm_driver->init_termios.c_oflag = 0;
726         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
727         ptm_driver->init_termios.c_lflag = 0;
728         ptm_driver->init_termios.c_ispeed = 38400;
729         ptm_driver->init_termios.c_ospeed = 38400;
730         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
731                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
732         ptm_driver->other = pts_driver;
733         tty_set_operations(ptm_driver, &ptm_unix98_ops);
734
735         pts_driver->owner = THIS_MODULE;
736         pts_driver->driver_name = "pty_slave";
737         pts_driver->name = "pts";
738         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
739         pts_driver->minor_start = 0;
740         pts_driver->type = TTY_DRIVER_TYPE_PTY;
741         pts_driver->subtype = PTY_TYPE_SLAVE;
742         pts_driver->init_termios = tty_std_termios;
743         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
744         pts_driver->init_termios.c_ispeed = 38400;
745         pts_driver->init_termios.c_ospeed = 38400;
746         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
747                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
748         pts_driver->other = ptm_driver;
749         tty_set_operations(pts_driver, &pty_unix98_ops);
750
751         if (tty_register_driver(ptm_driver))
752                 panic("Couldn't register Unix98 ptm driver");
753         if (tty_register_driver(pts_driver))
754                 panic("Couldn't register Unix98 pts driver");
755
756         register_sysctl_table(pty_root_table);
757
758         /* Now create the /dev/ptmx special device */
759         tty_default_fops(&ptmx_fops);
760         ptmx_fops.open = ptmx_open;
761
762         cdev_init(&ptmx_cdev, &ptmx_fops);
763         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
764             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
765                 panic("Couldn't register /dev/ptmx driver\n");
766         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
767 }
768
769 #else
770 static inline void unix98_pty_init(void) { }
771 #endif
772
773 static int __init pty_init(void)
774 {
775         legacy_pty_init();
776         unix98_pty_init();
777         return 0;
778 }
779 module_init(pty_init);