TTY: unify pty_install fail path handling
[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_module_put;
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_module_put:
331         module_put(o_tty->driver->owner);
332 err_free_tty:
333         free_tty_struct(o_tty);
334         return retval;
335 }
336
337 static int pty_bsd_ioctl(struct tty_struct *tty,
338                          unsigned int cmd, unsigned long arg)
339 {
340         switch (cmd) {
341         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
342                 return pty_set_lock(tty, (int __user *) arg);
343         case TIOCSIG:    /* Send signal to other side of pty */
344                 return pty_signal(tty, (int) arg);
345         }
346         return -ENOIOCTLCMD;
347 }
348
349 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
350 module_param(legacy_count, int, 0);
351
352 /*
353  * The master side of a pty can do TIOCSPTLCK and thus
354  * has pty_bsd_ioctl.
355  */
356 static const struct tty_operations master_pty_ops_bsd = {
357         .install = pty_install,
358         .open = pty_open,
359         .close = pty_close,
360         .write = pty_write,
361         .write_room = pty_write_room,
362         .flush_buffer = pty_flush_buffer,
363         .chars_in_buffer = pty_chars_in_buffer,
364         .unthrottle = pty_unthrottle,
365         .set_termios = pty_set_termios,
366         .ioctl = pty_bsd_ioctl,
367         .resize = pty_resize
368 };
369
370 static const struct tty_operations slave_pty_ops_bsd = {
371         .install = pty_install,
372         .open = pty_open,
373         .close = pty_close,
374         .write = pty_write,
375         .write_room = pty_write_room,
376         .flush_buffer = pty_flush_buffer,
377         .chars_in_buffer = pty_chars_in_buffer,
378         .unthrottle = pty_unthrottle,
379         .set_termios = pty_set_termios,
380         .resize = pty_resize
381 };
382
383 static void __init legacy_pty_init(void)
384 {
385         struct tty_driver *pty_driver, *pty_slave_driver;
386
387         if (legacy_count <= 0)
388                 return;
389
390         pty_driver = alloc_tty_driver(legacy_count);
391         if (!pty_driver)
392                 panic("Couldn't allocate pty driver");
393
394         pty_slave_driver = alloc_tty_driver(legacy_count);
395         if (!pty_slave_driver)
396                 panic("Couldn't allocate pty slave driver");
397
398         pty_driver->owner = THIS_MODULE;
399         pty_driver->driver_name = "pty_master";
400         pty_driver->name = "pty";
401         pty_driver->major = PTY_MASTER_MAJOR;
402         pty_driver->minor_start = 0;
403         pty_driver->type = TTY_DRIVER_TYPE_PTY;
404         pty_driver->subtype = PTY_TYPE_MASTER;
405         pty_driver->init_termios = tty_std_termios;
406         pty_driver->init_termios.c_iflag = 0;
407         pty_driver->init_termios.c_oflag = 0;
408         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
409         pty_driver->init_termios.c_lflag = 0;
410         pty_driver->init_termios.c_ispeed = 38400;
411         pty_driver->init_termios.c_ospeed = 38400;
412         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
413         pty_driver->other = pty_slave_driver;
414         tty_set_operations(pty_driver, &master_pty_ops_bsd);
415
416         pty_slave_driver->owner = THIS_MODULE;
417         pty_slave_driver->driver_name = "pty_slave";
418         pty_slave_driver->name = "ttyp";
419         pty_slave_driver->major = PTY_SLAVE_MAJOR;
420         pty_slave_driver->minor_start = 0;
421         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
422         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
423         pty_slave_driver->init_termios = tty_std_termios;
424         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
425         pty_slave_driver->init_termios.c_ispeed = 38400;
426         pty_slave_driver->init_termios.c_ospeed = 38400;
427         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
428                                         TTY_DRIVER_REAL_RAW;
429         pty_slave_driver->other = pty_driver;
430         tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
431
432         if (tty_register_driver(pty_driver))
433                 panic("Couldn't register pty driver");
434         if (tty_register_driver(pty_slave_driver))
435                 panic("Couldn't register pty slave driver");
436 }
437 #else
438 static inline void legacy_pty_init(void) { }
439 #endif
440
441 /* Unix98 devices */
442 #ifdef CONFIG_UNIX98_PTYS
443 /*
444  * sysctl support for setting limits on the number of Unix98 ptys allocated.
445  * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
446  */
447 int pty_limit = NR_UNIX98_PTY_DEFAULT;
448 static int pty_limit_min;
449 static int pty_limit_max = NR_UNIX98_PTY_MAX;
450 static int pty_count;
451
452 static struct cdev ptmx_cdev;
453
454 static struct ctl_table pty_table[] = {
455         {
456                 .procname       = "max",
457                 .maxlen         = sizeof(int),
458                 .mode           = 0644,
459                 .data           = &pty_limit,
460                 .proc_handler   = proc_dointvec_minmax,
461                 .extra1         = &pty_limit_min,
462                 .extra2         = &pty_limit_max,
463         }, {
464                 .procname       = "nr",
465                 .maxlen         = sizeof(int),
466                 .mode           = 0444,
467                 .data           = &pty_count,
468                 .proc_handler   = proc_dointvec,
469         }, 
470         {}
471 };
472
473 static struct ctl_table pty_kern_table[] = {
474         {
475                 .procname       = "pty",
476                 .mode           = 0555,
477                 .child          = pty_table,
478         },
479         {}
480 };
481
482 static struct ctl_table pty_root_table[] = {
483         {
484                 .procname       = "kernel",
485                 .mode           = 0555,
486                 .child          = pty_kern_table,
487         },
488         {}
489 };
490
491
492 static int pty_unix98_ioctl(struct tty_struct *tty,
493                             unsigned int cmd, unsigned long arg)
494 {
495         switch (cmd) {
496         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
497                 return pty_set_lock(tty, (int __user *)arg);
498         case TIOCGPTN: /* Get PT Number */
499                 return put_user(tty->index, (unsigned int __user *)arg);
500         case TIOCSIG:    /* Send signal to other side of pty */
501                 return pty_signal(tty, (int) arg);
502         }
503
504         return -ENOIOCTLCMD;
505 }
506
507 /**
508  *      ptm_unix98_lookup       -       find a pty master
509  *      @driver: ptm driver
510  *      @idx: tty index
511  *
512  *      Look up a pty master device. Called under the tty_mutex for now.
513  *      This provides our locking.
514  */
515
516 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
517                 struct inode *ptm_inode, int idx)
518 {
519         struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
520         if (tty)
521                 tty = tty->link;
522         return tty;
523 }
524
525 /**
526  *      pts_unix98_lookup       -       find a pty slave
527  *      @driver: pts driver
528  *      @idx: tty index
529  *
530  *      Look up a pty master device. Called under the tty_mutex for now.
531  *      This provides our locking.
532  */
533
534 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
535                 struct inode *pts_inode, int idx)
536 {
537         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
538         /* Master must be open before slave */
539         if (!tty)
540                 return ERR_PTR(-EIO);
541         return tty;
542 }
543
544 static void pty_unix98_shutdown(struct tty_struct *tty)
545 {
546         /* We have our own method as we don't use the tty index */
547         kfree(tty->termios);
548 }
549
550 /* We have no need to install and remove our tty objects as devpts does all
551    the work for us */
552
553 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
554 {
555         struct tty_struct *o_tty;
556         int idx = tty->index;
557
558         o_tty = alloc_tty_struct();
559         if (!o_tty)
560                 return -ENOMEM;
561         if (!try_module_get(driver->other->owner)) {
562                 /* This cannot in fact currently happen */
563                 free_tty_struct(o_tty);
564                 return -ENOMEM;
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 free_mem_out;
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 free_mem_out;
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 free_mem_out:
596         kfree(o_tty->termios);
597         module_put(o_tty->driver->owner);
598         free_tty_struct(o_tty);
599         kfree(tty->termios);
600         return -ENOMEM;
601 }
602
603 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
604 {
605         pty_count--;
606 }
607
608 static const struct tty_operations ptm_unix98_ops = {
609         .lookup = ptm_unix98_lookup,
610         .install = pty_unix98_install,
611         .remove = pty_unix98_remove,
612         .open = pty_open,
613         .close = pty_close,
614         .write = pty_write,
615         .write_room = pty_write_room,
616         .flush_buffer = pty_flush_buffer,
617         .chars_in_buffer = pty_chars_in_buffer,
618         .unthrottle = pty_unthrottle,
619         .set_termios = pty_set_termios,
620         .ioctl = pty_unix98_ioctl,
621         .shutdown = pty_unix98_shutdown,
622         .resize = pty_resize
623 };
624
625 static const struct tty_operations pty_unix98_ops = {
626         .lookup = pts_unix98_lookup,
627         .install = pty_unix98_install,
628         .remove = pty_unix98_remove,
629         .open = pty_open,
630         .close = pty_close,
631         .write = pty_write,
632         .write_room = pty_write_room,
633         .flush_buffer = pty_flush_buffer,
634         .chars_in_buffer = pty_chars_in_buffer,
635         .unthrottle = pty_unthrottle,
636         .set_termios = pty_set_termios,
637         .shutdown = pty_unix98_shutdown
638 };
639
640 /**
641  *      ptmx_open               -       open a unix 98 pty master
642  *      @inode: inode of device file
643  *      @filp: file pointer to tty
644  *
645  *      Allocate a unix98 pty master device from the ptmx driver.
646  *
647  *      Locking: tty_mutex protects the init_dev work. tty->count should
648  *              protect the rest.
649  *              allocated_ptys_lock handles the list of free pty numbers
650  */
651
652 static int ptmx_open(struct inode *inode, struct file *filp)
653 {
654         struct tty_struct *tty;
655         int retval;
656         int index;
657
658         nonseekable_open(inode, filp);
659
660         /* find a device that is not in use. */
661         tty_lock();
662         index = devpts_new_index(inode);
663         tty_unlock();
664         if (index < 0)
665                 return index;
666
667         mutex_lock(&tty_mutex);
668         tty_lock();
669         tty = tty_init_dev(ptm_driver, index, 1);
670         mutex_unlock(&tty_mutex);
671
672         if (IS_ERR(tty)) {
673                 retval = PTR_ERR(tty);
674                 goto out;
675         }
676
677         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
678
679         retval = tty_add_file(tty, filp);
680         if (retval)
681                 goto out;
682
683         retval = devpts_pty_new(inode, tty->link);
684         if (retval)
685                 goto out1;
686
687         retval = ptm_driver->ops->open(tty, filp);
688         if (retval)
689                 goto out2;
690 out1:
691         tty_unlock();
692         return retval;
693 out2:
694         tty_unlock();
695         tty_release(inode, filp);
696         return retval;
697 out:
698         devpts_kill_index(inode, index);
699         tty_unlock();
700         return retval;
701 }
702
703 static struct file_operations ptmx_fops;
704
705 static void __init unix98_pty_init(void)
706 {
707         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
708         if (!ptm_driver)
709                 panic("Couldn't allocate Unix98 ptm driver");
710         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
711         if (!pts_driver)
712                 panic("Couldn't allocate Unix98 pts driver");
713
714         ptm_driver->owner = THIS_MODULE;
715         ptm_driver->driver_name = "pty_master";
716         ptm_driver->name = "ptm";
717         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
718         ptm_driver->minor_start = 0;
719         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
720         ptm_driver->subtype = PTY_TYPE_MASTER;
721         ptm_driver->init_termios = tty_std_termios;
722         ptm_driver->init_termios.c_iflag = 0;
723         ptm_driver->init_termios.c_oflag = 0;
724         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
725         ptm_driver->init_termios.c_lflag = 0;
726         ptm_driver->init_termios.c_ispeed = 38400;
727         ptm_driver->init_termios.c_ospeed = 38400;
728         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
729                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
730         ptm_driver->other = pts_driver;
731         tty_set_operations(ptm_driver, &ptm_unix98_ops);
732
733         pts_driver->owner = THIS_MODULE;
734         pts_driver->driver_name = "pty_slave";
735         pts_driver->name = "pts";
736         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
737         pts_driver->minor_start = 0;
738         pts_driver->type = TTY_DRIVER_TYPE_PTY;
739         pts_driver->subtype = PTY_TYPE_SLAVE;
740         pts_driver->init_termios = tty_std_termios;
741         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
742         pts_driver->init_termios.c_ispeed = 38400;
743         pts_driver->init_termios.c_ospeed = 38400;
744         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
745                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
746         pts_driver->other = ptm_driver;
747         tty_set_operations(pts_driver, &pty_unix98_ops);
748
749         if (tty_register_driver(ptm_driver))
750                 panic("Couldn't register Unix98 ptm driver");
751         if (tty_register_driver(pts_driver))
752                 panic("Couldn't register Unix98 pts driver");
753
754         register_sysctl_table(pty_root_table);
755
756         /* Now create the /dev/ptmx special device */
757         tty_default_fops(&ptmx_fops);
758         ptmx_fops.open = ptmx_open;
759
760         cdev_init(&ptmx_cdev, &ptmx_fops);
761         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
762             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
763                 panic("Couldn't register /dev/ptmx driver\n");
764         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
765 }
766
767 #else
768 static inline void unix98_pty_init(void) { }
769 #endif
770
771 static int __init pty_init(void)
772 {
773         legacy_pty_init();
774         unix98_pty_init();
775         return 0;
776 }
777 module_init(pty_init);