tty: cleanup prohibition of direct opening for unix98 pty master
[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/sysctl.h>
25 #include <linux/device.h>
26 #include <linux/uaccess.h>
27 #include <linux/bitops.h>
28 #include <linux/devpts_fs.h>
29 #include <linux/slab.h>
30
31 #include <asm/system.h>
32
33 #ifdef CONFIG_UNIX98_PTYS
34 static struct tty_driver *ptm_driver;
35 static struct tty_driver *pts_driver;
36 #endif
37
38 static void pty_close(struct tty_struct *tty, struct file *filp)
39 {
40         BUG_ON(!tty);
41         if (tty->driver->subtype == PTY_TYPE_MASTER)
42                 WARN_ON(tty->count > 1);
43         else {
44                 if (tty->count > 2)
45                         return;
46         }
47         wake_up_interruptible(&tty->read_wait);
48         wake_up_interruptible(&tty->write_wait);
49         tty->packet = 0;
50         if (!tty->link)
51                 return;
52         tty->link->packet = 0;
53         set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
54         wake_up_interruptible(&tty->link->read_wait);
55         wake_up_interruptible(&tty->link->write_wait);
56         if (tty->driver->subtype == PTY_TYPE_MASTER) {
57                 set_bit(TTY_OTHER_CLOSED, &tty->flags);
58 #ifdef CONFIG_UNIX98_PTYS
59                 if (tty->driver == ptm_driver)
60                         devpts_pty_kill(tty->link);
61 #endif
62                 tty_unlock();
63                 tty_vhangup(tty->link);
64                 tty_lock();
65         }
66 }
67
68 /*
69  * The unthrottle routine is called by the line discipline to signal
70  * that it can receive more characters.  For PTY's, the TTY_THROTTLED
71  * flag is always set, to force the line discipline to always call the
72  * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
73  * characters in the queue.  This is necessary since each time this
74  * happens, we need to wake up any sleeping processes that could be
75  * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
76  * for the pty buffer to be drained.
77  */
78 static void pty_unthrottle(struct tty_struct *tty)
79 {
80         tty_wakeup(tty->link);
81         set_bit(TTY_THROTTLED, &tty->flags);
82 }
83
84 /**
85  *      pty_space       -       report space left for writing
86  *      @to: tty we are writing into
87  *
88  *      The tty buffers allow 64K but we sneak a peak and clip at 8K this
89  *      allows a lot of overspill room for echo and other fun messes to
90  *      be handled properly
91  */
92
93 static int pty_space(struct tty_struct *to)
94 {
95         int n = 8192 - to->buf.memory_used;
96         if (n < 0)
97                 return 0;
98         return n;
99 }
100
101 /**
102  *      pty_write               -       write to a pty
103  *      @tty: the tty we write from
104  *      @buf: kernel buffer of data
105  *      @count: bytes to write
106  *
107  *      Our "hardware" write method. Data is coming from the ldisc which
108  *      may be in a non sleeping state. We simply throw this at the other
109  *      end of the link as if we were an IRQ handler receiving stuff for
110  *      the other side of the pty/tty pair.
111  */
112
113 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
114 {
115         struct tty_struct *to = tty->link;
116
117         if (tty->stopped)
118                 return 0;
119
120         if (c > 0) {
121                 /* Stuff the data into the input queue of the other end */
122                 c = tty_insert_flip_string(to, buf, c);
123                 /* And shovel */
124                 if (c) {
125                         tty_flip_buffer_push(to);
126                         tty_wakeup(tty);
127                 }
128         }
129         return c;
130 }
131
132 /**
133  *      pty_write_room  -       write space
134  *      @tty: tty we are writing from
135  *
136  *      Report how many bytes the ldisc can send into the queue for
137  *      the other device.
138  */
139
140 static int pty_write_room(struct tty_struct *tty)
141 {
142         if (tty->stopped)
143                 return 0;
144         return pty_space(tty->link);
145 }
146
147 /**
148  *      pty_chars_in_buffer     -       characters currently in our tx queue
149  *      @tty: our tty
150  *
151  *      Report how much we have in the transmit queue. As everything is
152  *      instantly at the other end this is easy to implement.
153  */
154
155 static int pty_chars_in_buffer(struct tty_struct *tty)
156 {
157         return 0;
158 }
159
160 /* Set the lock flag on a pty */
161 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
162 {
163         int val;
164         if (get_user(val, arg))
165                 return -EFAULT;
166         if (val)
167                 set_bit(TTY_PTY_LOCK, &tty->flags);
168         else
169                 clear_bit(TTY_PTY_LOCK, &tty->flags);
170         return 0;
171 }
172
173 /* Send a signal to the slave */
174 static int pty_signal(struct tty_struct *tty, int sig)
175 {
176         unsigned long flags;
177         struct pid *pgrp;
178
179         if (tty->link) {
180                 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
181                 pgrp = get_pid(tty->link->pgrp);
182                 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
183
184                 kill_pgrp(pgrp, sig, 1);
185                 put_pid(pgrp);
186         }
187         return 0;
188 }
189
190 static void pty_flush_buffer(struct tty_struct *tty)
191 {
192         struct tty_struct *to = tty->link;
193         unsigned long flags;
194
195         if (!to)
196                 return;
197         /* tty_buffer_flush(to); FIXME */
198         if (to->packet) {
199                 spin_lock_irqsave(&tty->ctrl_lock, flags);
200                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
201                 wake_up_interruptible(&to->read_wait);
202                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
203         }
204 }
205
206 static int pty_open(struct tty_struct *tty, struct file *filp)
207 {
208         int     retval = -ENODEV;
209
210         if (!tty || !tty->link)
211                 goto out;
212
213         retval = -EIO;
214         if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
215                 goto out;
216         if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
217                 goto out;
218         if (tty->link->count != 1)
219                 goto out;
220
221         clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
222         set_bit(TTY_THROTTLED, &tty->flags);
223         retval = 0;
224 out:
225         return retval;
226 }
227
228 static void pty_set_termios(struct tty_struct *tty,
229                                         struct ktermios *old_termios)
230 {
231         tty->termios->c_cflag &= ~(CSIZE | PARENB);
232         tty->termios->c_cflag |= (CS8 | CREAD);
233 }
234
235 /**
236  *      pty_do_resize           -       resize event
237  *      @tty: tty being resized
238  *      @ws: window size being set.
239  *
240  *      Update the termios variables and send the necessary signals to
241  *      peform a terminal resize correctly
242  */
243
244 int pty_resize(struct tty_struct *tty,  struct winsize *ws)
245 {
246         struct pid *pgrp, *rpgrp;
247         unsigned long flags;
248         struct tty_struct *pty = tty->link;
249
250         /* For a PTY we need to lock the tty side */
251         mutex_lock(&tty->termios_mutex);
252         if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
253                 goto done;
254
255         /* Get the PID values and reference them so we can
256            avoid holding the tty ctrl lock while sending signals.
257            We need to lock these individually however. */
258
259         spin_lock_irqsave(&tty->ctrl_lock, flags);
260         pgrp = get_pid(tty->pgrp);
261         spin_unlock_irqrestore(&tty->ctrl_lock, flags);
262
263         spin_lock_irqsave(&pty->ctrl_lock, flags);
264         rpgrp = get_pid(pty->pgrp);
265         spin_unlock_irqrestore(&pty->ctrl_lock, flags);
266
267         if (pgrp)
268                 kill_pgrp(pgrp, SIGWINCH, 1);
269         if (rpgrp != pgrp && rpgrp)
270                 kill_pgrp(rpgrp, SIGWINCH, 1);
271
272         put_pid(pgrp);
273         put_pid(rpgrp);
274
275         tty->winsize = *ws;
276         pty->winsize = *ws;     /* Never used so will go away soon */
277 done:
278         mutex_unlock(&tty->termios_mutex);
279         return 0;
280 }
281
282 /* Traditional BSD devices */
283 #ifdef CONFIG_LEGACY_PTYS
284
285 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
286 {
287         struct tty_struct *o_tty;
288         int idx = tty->index;
289         int retval;
290
291         o_tty = alloc_tty_struct();
292         if (!o_tty)
293                 return -ENOMEM;
294         if (!try_module_get(driver->other->owner)) {
295                 /* This cannot in fact currently happen */
296                 retval = -ENOMEM;
297                 goto err_free_tty;
298         }
299         initialize_tty_struct(o_tty, driver->other, idx);
300
301         /* We always use new tty termios data so we can do this
302            the easy way .. */
303         retval = tty_init_termios(tty);
304         if (retval)
305                 goto err_deinit_tty;
306
307         retval = tty_init_termios(o_tty);
308         if (retval)
309                 goto err_free_termios;
310
311         /*
312          * Everything allocated ... set up the o_tty structure.
313          */
314         driver->other->ttys[idx] = o_tty;
315         tty_driver_kref_get(driver->other);
316         if (driver->subtype == PTY_TYPE_MASTER)
317                 o_tty->count++;
318         /* Establish the links in both directions */
319         tty->link   = o_tty;
320         o_tty->link = tty;
321
322         tty_driver_kref_get(driver);
323         tty->count++;
324         driver->ttys[idx] = tty;
325         return 0;
326 err_free_termios:
327         tty_free_termios(tty);
328 err_deinit_tty:
329         deinitialize_tty_struct(o_tty);
330         module_put(o_tty->driver->owner);
331 err_free_tty:
332         free_tty_struct(o_tty);
333         return retval;
334 }
335
336 static int pty_bsd_ioctl(struct tty_struct *tty,
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);
342         case TIOCSIG:    /* Send signal to other side of pty */
343                 return pty_signal(tty, (int) arg);
344         }
345         return -ENOIOCTLCMD;
346 }
347
348 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
349 module_param(legacy_count, int, 0);
350
351 /*
352  * The master side of a pty can do TIOCSPTLCK and thus
353  * has pty_bsd_ioctl.
354  */
355 static const struct tty_operations master_pty_ops_bsd = {
356         .install = pty_install,
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,
366         .resize = pty_resize
367 };
368
369 static 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
382 static void __init legacy_pty_init(void)
383 {
384         struct tty_driver *pty_driver, *pty_slave_driver;
385
386         if (legacy_count <= 0)
387                 return;
388
389         pty_driver = alloc_tty_driver(legacy_count);
390         if (!pty_driver)
391                 panic("Couldn't allocate pty driver");
392
393         pty_slave_driver = alloc_tty_driver(legacy_count);
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";
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;
409         pty_driver->init_termios.c_ispeed = 38400;
410         pty_driver->init_termios.c_ospeed = 38400;
411         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
412         pty_driver->other = pty_slave_driver;
413         tty_set_operations(pty_driver, &master_pty_ops_bsd);
414
415         pty_slave_driver->owner = THIS_MODULE;
416         pty_slave_driver->driver_name = "pty_slave";
417         pty_slave_driver->name = "ttyp";
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;
424         pty_slave_driver->init_termios.c_ispeed = 38400;
425         pty_slave_driver->init_termios.c_ospeed = 38400;
426         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
427                                         TTY_DRIVER_REAL_RAW;
428         pty_slave_driver->other = pty_driver;
429         tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
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
437 static 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  */
446 int pty_limit = NR_UNIX98_PTY_DEFAULT;
447 static int pty_limit_min;
448 static int pty_limit_max = NR_UNIX98_PTY_MAX;
449 static int pty_count;
450
451 static struct cdev ptmx_cdev;
452
453 static struct ctl_table pty_table[] = {
454         {
455                 .procname       = "max",
456                 .maxlen         = sizeof(int),
457                 .mode           = 0644,
458                 .data           = &pty_limit,
459                 .proc_handler   = proc_dointvec_minmax,
460                 .extra1         = &pty_limit_min,
461                 .extra2         = &pty_limit_max,
462         }, {
463                 .procname       = "nr",
464                 .maxlen         = sizeof(int),
465                 .mode           = 0444,
466                 .data           = &pty_count,
467                 .proc_handler   = proc_dointvec,
468         }, 
469         {}
470 };
471
472 static struct ctl_table pty_kern_table[] = {
473         {
474                 .procname       = "pty",
475                 .mode           = 0555,
476                 .child          = pty_table,
477         },
478         {}
479 };
480
481 static struct ctl_table pty_root_table[] = {
482         {
483                 .procname       = "kernel",
484                 .mode           = 0555,
485                 .child          = pty_kern_table,
486         },
487         {}
488 };
489
490
491 static int pty_unix98_ioctl(struct tty_struct *tty,
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);
499         case TIOCSIG:    /* Send signal to other side of pty */
500                 return pty_signal(tty, (int) arg);
501         }
502
503         return -ENOIOCTLCMD;
504 }
505
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
515 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
516                 struct inode *ptm_inode, int idx)
517 {
518         /* Master must be open via /dev/ptmx */
519         return ERR_PTR(-EIO);
520 }
521
522 /**
523  *      pts_unix98_lookup       -       find a pty slave
524  *      @driver: pts driver
525  *      @idx: tty index
526  *
527  *      Look up a pty master device. Called under the tty_mutex for now.
528  *      This provides our locking.
529  */
530
531 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
532                 struct inode *pts_inode, int idx)
533 {
534         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
535         /* Master must be open before slave */
536         if (!tty)
537                 return ERR_PTR(-EIO);
538         return tty;
539 }
540
541 static void pty_unix98_shutdown(struct tty_struct *tty)
542 {
543         tty_driver_remove_tty(tty->driver, tty);
544         /* We have our own method as we don't use the tty index */
545         kfree(tty->termios);
546 }
547
548 /* We have no need to install and remove our tty objects as devpts does all
549    the work for us */
550
551 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
552 {
553         struct tty_struct *o_tty;
554         int idx = tty->index;
555
556         o_tty = alloc_tty_struct();
557         if (!o_tty)
558                 return -ENOMEM;
559         if (!try_module_get(driver->other->owner)) {
560                 /* This cannot in fact currently happen */
561                 goto err_free_tty;
562         }
563         initialize_tty_struct(o_tty, driver->other, idx);
564
565         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
566         if (tty->termios == NULL)
567                 goto err_free_mem;
568         *tty->termios = driver->init_termios;
569         tty->termios_locked = tty->termios + 1;
570
571         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
572         if (o_tty->termios == NULL)
573                 goto err_free_mem;
574         *o_tty->termios = driver->other->init_termios;
575         o_tty->termios_locked = o_tty->termios + 1;
576
577         tty_driver_kref_get(driver->other);
578         if (driver->subtype == PTY_TYPE_MASTER)
579                 o_tty->count++;
580         /* Establish the links in both directions */
581         tty->link   = o_tty;
582         o_tty->link = tty;
583         /*
584          * All structures have been allocated, so now we install them.
585          * Failures after this point use release_tty to clean up, so
586          * there's no need to null out the local pointers.
587          */
588         tty_driver_kref_get(driver);
589         tty->count++;
590         pty_count++;
591         return 0;
592 err_free_mem:
593         deinitialize_tty_struct(o_tty);
594         kfree(o_tty->termios);
595         kfree(tty->termios);
596         module_put(o_tty->driver->owner);
597 err_free_tty:
598         free_tty_struct(o_tty);
599         return -ENOMEM;
600 }
601
602 static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
603 {
604         pty_count--;
605 }
606
607 static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
608 {
609 }
610
611 static const struct tty_operations ptm_unix98_ops = {
612         .lookup = ptm_unix98_lookup,
613         .install = pty_unix98_install,
614         .remove = ptm_unix98_remove,
615         .open = pty_open,
616         .close = pty_close,
617         .write = pty_write,
618         .write_room = pty_write_room,
619         .flush_buffer = pty_flush_buffer,
620         .chars_in_buffer = pty_chars_in_buffer,
621         .unthrottle = pty_unthrottle,
622         .set_termios = pty_set_termios,
623         .ioctl = pty_unix98_ioctl,
624         .shutdown = pty_unix98_shutdown,
625         .resize = pty_resize
626 };
627
628 static const struct tty_operations pty_unix98_ops = {
629         .lookup = pts_unix98_lookup,
630         .install = pty_unix98_install,
631         .remove = pts_unix98_remove,
632         .open = pty_open,
633         .close = pty_close,
634         .write = pty_write,
635         .write_room = pty_write_room,
636         .flush_buffer = pty_flush_buffer,
637         .chars_in_buffer = pty_chars_in_buffer,
638         .unthrottle = pty_unthrottle,
639         .set_termios = pty_set_termios,
640         .shutdown = pty_unix98_shutdown
641 };
642
643 /**
644  *      ptmx_open               -       open a unix 98 pty master
645  *      @inode: inode of device file
646  *      @filp: file pointer to tty
647  *
648  *      Allocate a unix98 pty master device from the ptmx driver.
649  *
650  *      Locking: tty_mutex protects the init_dev work. tty->count should
651  *              protect the rest.
652  *              allocated_ptys_lock handles the list of free pty numbers
653  */
654
655 static int ptmx_open(struct inode *inode, struct file *filp)
656 {
657         struct tty_struct *tty;
658         int retval;
659         int index;
660
661         nonseekable_open(inode, filp);
662
663         retval = tty_alloc_file(filp);
664         if (retval)
665                 return retval;
666
667         /* find a device that is not in use. */
668         tty_lock();
669         index = devpts_new_index(inode);
670         tty_unlock();
671         if (index < 0) {
672                 retval = index;
673                 goto err_file;
674         }
675
676         mutex_lock(&tty_mutex);
677         tty_lock();
678         tty = tty_init_dev(ptm_driver, index);
679         mutex_unlock(&tty_mutex);
680
681         if (IS_ERR(tty)) {
682                 retval = PTR_ERR(tty);
683                 goto out;
684         }
685
686         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
687
688         tty_add_file(tty, filp);
689
690         retval = devpts_pty_new(inode, tty->link);
691         if (retval)
692                 goto err_release;
693
694         retval = ptm_driver->ops->open(tty, filp);
695         if (retval)
696                 goto err_release;
697
698         tty_unlock();
699         return 0;
700 err_release:
701         tty_unlock();
702         tty_release(inode, filp);
703         return retval;
704 out:
705         devpts_kill_index(inode, index);
706         tty_unlock();
707 err_file:
708         tty_free_file(filp);
709         return retval;
710 }
711
712 static struct file_operations ptmx_fops;
713
714 static void __init unix98_pty_init(void)
715 {
716         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
717         if (!ptm_driver)
718                 panic("Couldn't allocate Unix98 ptm driver");
719         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
720         if (!pts_driver)
721                 panic("Couldn't allocate Unix98 pts driver");
722
723         ptm_driver->owner = THIS_MODULE;
724         ptm_driver->driver_name = "pty_master";
725         ptm_driver->name = "ptm";
726         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
727         ptm_driver->minor_start = 0;
728         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
729         ptm_driver->subtype = PTY_TYPE_MASTER;
730         ptm_driver->init_termios = tty_std_termios;
731         ptm_driver->init_termios.c_iflag = 0;
732         ptm_driver->init_termios.c_oflag = 0;
733         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
734         ptm_driver->init_termios.c_lflag = 0;
735         ptm_driver->init_termios.c_ispeed = 38400;
736         ptm_driver->init_termios.c_ospeed = 38400;
737         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
738                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
739         ptm_driver->other = pts_driver;
740         tty_set_operations(ptm_driver, &ptm_unix98_ops);
741
742         pts_driver->owner = THIS_MODULE;
743         pts_driver->driver_name = "pty_slave";
744         pts_driver->name = "pts";
745         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
746         pts_driver->minor_start = 0;
747         pts_driver->type = TTY_DRIVER_TYPE_PTY;
748         pts_driver->subtype = PTY_TYPE_SLAVE;
749         pts_driver->init_termios = tty_std_termios;
750         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
751         pts_driver->init_termios.c_ispeed = 38400;
752         pts_driver->init_termios.c_ospeed = 38400;
753         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
754                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
755         pts_driver->other = ptm_driver;
756         tty_set_operations(pts_driver, &pty_unix98_ops);
757
758         if (tty_register_driver(ptm_driver))
759                 panic("Couldn't register Unix98 ptm driver");
760         if (tty_register_driver(pts_driver))
761                 panic("Couldn't register Unix98 pts driver");
762
763         register_sysctl_table(pty_root_table);
764
765         /* Now create the /dev/ptmx special device */
766         tty_default_fops(&ptmx_fops);
767         ptmx_fops.open = ptmx_open;
768
769         cdev_init(&ptmx_cdev, &ptmx_fops);
770         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
771             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
772                 panic("Couldn't register /dev/ptmx driver\n");
773         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
774 }
775
776 #else
777 static inline void unix98_pty_init(void) { }
778 #endif
779
780 static int __init pty_init(void)
781 {
782         legacy_pty_init();
783         unix98_pty_init();
784         return 0;
785 }
786 module_init(pty_init);