]> nv-tegra.nvidia Code Review - linux-2.6.git/blob - drivers/char/pty.c
pty: don't limit the writes to 'pty_space()' inside 'pty_write()'
[linux-2.6.git] / drivers / char / 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/string.h>
22 #include <linux/major.h>
23 #include <linux/mm.h>
24 #include <linux/init.h>
25 #include <linux/smp_lock.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
32 #include <asm/system.h>
33
34 #ifdef CONFIG_UNIX98_PTYS
35 static struct tty_driver *ptm_driver;
36 static struct tty_driver *pts_driver;
37 #endif
38
39 static void pty_close(struct tty_struct *tty, struct file *filp)
40 {
41         BUG_ON(!tty);
42         if (tty->driver->subtype == PTY_TYPE_MASTER)
43                 WARN_ON(tty->count > 1);
44         else {
45                 if (tty->count > 2)
46                         return;
47         }
48         wake_up_interruptible(&tty->read_wait);
49         wake_up_interruptible(&tty->write_wait);
50         tty->packet = 0;
51         if (!tty->link)
52                 return;
53         tty->link->packet = 0;
54         set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
55         wake_up_interruptible(&tty->link->read_wait);
56         wake_up_interruptible(&tty->link->write_wait);
57         if (tty->driver->subtype == PTY_TYPE_MASTER) {
58                 set_bit(TTY_OTHER_CLOSED, &tty->flags);
59 #ifdef CONFIG_UNIX98_PTYS
60                 if (tty->driver == ptm_driver)
61                         devpts_pty_kill(tty->link);
62 #endif
63                 tty_vhangup(tty->link);
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                 tty_flip_buffer_push(to);
124                 tty_wakeup(tty);
125         }
126         return c;
127 }
128
129 /**
130  *      pty_write_room  -       write space
131  *      @tty: tty we are writing from
132  *
133  *      Report how many bytes the ldisc can send into the queue for
134  *      the other device.
135  */
136
137 static int pty_write_room(struct tty_struct *tty)
138 {
139         if (tty->stopped)
140                 return 0;
141         return pty_space(tty->link);
142 }
143
144 /**
145  *      pty_chars_in_buffer     -       characters currently in our tx queue
146  *      @tty: our tty
147  *
148  *      Report how much we have in the transmit queue. As everything is
149  *      instantly at the other end this is easy to implement.
150  */
151
152 static int pty_chars_in_buffer(struct tty_struct *tty)
153 {
154         return 0;
155 }
156
157 /* Set the lock flag on a pty */
158 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
159 {
160         int val;
161         if (get_user(val, arg))
162                 return -EFAULT;
163         if (val)
164                 set_bit(TTY_PTY_LOCK, &tty->flags);
165         else
166                 clear_bit(TTY_PTY_LOCK, &tty->flags);
167         return 0;
168 }
169
170 static void pty_flush_buffer(struct tty_struct *tty)
171 {
172         struct tty_struct *to = tty->link;
173         unsigned long flags;
174
175         if (!to)
176                 return;
177         /* tty_buffer_flush(to); FIXME */
178         if (to->packet) {
179                 spin_lock_irqsave(&tty->ctrl_lock, flags);
180                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
181                 wake_up_interruptible(&to->read_wait);
182                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
183         }
184 }
185
186 static int pty_open(struct tty_struct *tty, struct file *filp)
187 {
188         int     retval = -ENODEV;
189
190         if (!tty || !tty->link)
191                 goto out;
192
193         retval = -EIO;
194         if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
195                 goto out;
196         if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
197                 goto out;
198         if (tty->link->count != 1)
199                 goto out;
200
201         clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
202         set_bit(TTY_THROTTLED, &tty->flags);
203         retval = 0;
204 out:
205         return retval;
206 }
207
208 static void pty_set_termios(struct tty_struct *tty,
209                                         struct ktermios *old_termios)
210 {
211         tty->termios->c_cflag &= ~(CSIZE | PARENB);
212         tty->termios->c_cflag |= (CS8 | CREAD);
213 }
214
215 /**
216  *      pty_do_resize           -       resize event
217  *      @tty: tty being resized
218  *      @ws: window size being set.
219  *
220  *      Update the termios variables and send the neccessary signals to
221  *      peform a terminal resize correctly
222  */
223
224 int pty_resize(struct tty_struct *tty,  struct winsize *ws)
225 {
226         struct pid *pgrp, *rpgrp;
227         unsigned long flags;
228         struct tty_struct *pty = tty->link;
229
230         /* For a PTY we need to lock the tty side */
231         mutex_lock(&tty->termios_mutex);
232         if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
233                 goto done;
234
235         /* Get the PID values and reference them so we can
236            avoid holding the tty ctrl lock while sending signals.
237            We need to lock these individually however. */
238
239         spin_lock_irqsave(&tty->ctrl_lock, flags);
240         pgrp = get_pid(tty->pgrp);
241         spin_unlock_irqrestore(&tty->ctrl_lock, flags);
242
243         spin_lock_irqsave(&pty->ctrl_lock, flags);
244         rpgrp = get_pid(pty->pgrp);
245         spin_unlock_irqrestore(&pty->ctrl_lock, flags);
246
247         if (pgrp)
248                 kill_pgrp(pgrp, SIGWINCH, 1);
249         if (rpgrp != pgrp && rpgrp)
250                 kill_pgrp(rpgrp, SIGWINCH, 1);
251
252         put_pid(pgrp);
253         put_pid(rpgrp);
254
255         tty->winsize = *ws;
256         pty->winsize = *ws;     /* Never used so will go away soon */
257 done:
258         mutex_unlock(&tty->termios_mutex);
259         return 0;
260 }
261
262 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
263 {
264         struct tty_struct *o_tty;
265         int idx = tty->index;
266         int retval;
267
268         o_tty = alloc_tty_struct();
269         if (!o_tty)
270                 return -ENOMEM;
271         if (!try_module_get(driver->other->owner)) {
272                 /* This cannot in fact currently happen */
273                 free_tty_struct(o_tty);
274                 return -ENOMEM;
275         }
276         initialize_tty_struct(o_tty, driver->other, idx);
277
278         /* We always use new tty termios data so we can do this
279            the easy way .. */
280         retval = tty_init_termios(tty);
281         if (retval)
282                 goto free_mem_out;
283
284         retval = tty_init_termios(o_tty);
285         if (retval) {
286                 tty_free_termios(tty);
287                 goto free_mem_out;
288         }
289
290         /*
291          * Everything allocated ... set up the o_tty structure.
292          */
293         driver->other->ttys[idx] = o_tty;
294         tty_driver_kref_get(driver->other);
295         if (driver->subtype == PTY_TYPE_MASTER)
296                 o_tty->count++;
297         /* Establish the links in both directions */
298         tty->link   = o_tty;
299         o_tty->link = tty;
300
301         tty_driver_kref_get(driver);
302         tty->count++;
303         driver->ttys[idx] = tty;
304         return 0;
305 free_mem_out:
306         module_put(o_tty->driver->owner);
307         free_tty_struct(o_tty);
308         return -ENOMEM;
309 }
310
311
312 static const struct tty_operations pty_ops = {
313         .install = pty_install,
314         .open = pty_open,
315         .close = pty_close,
316         .write = pty_write,
317         .write_room = pty_write_room,
318         .flush_buffer = pty_flush_buffer,
319         .chars_in_buffer = pty_chars_in_buffer,
320         .unthrottle = pty_unthrottle,
321         .set_termios = pty_set_termios,
322         .resize = pty_resize
323 };
324
325 /* Traditional BSD devices */
326 #ifdef CONFIG_LEGACY_PTYS
327 static struct tty_driver *pty_driver, *pty_slave_driver;
328
329 static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
330                          unsigned int cmd, unsigned long arg)
331 {
332         switch (cmd) {
333         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
334                 return pty_set_lock(tty, (int __user *) arg);
335         }
336         return -ENOIOCTLCMD;
337 }
338
339 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
340 module_param(legacy_count, int, 0);
341
342 static const struct tty_operations pty_ops_bsd = {
343         .open = pty_open,
344         .close = pty_close,
345         .write = pty_write,
346         .write_room = pty_write_room,
347         .flush_buffer = pty_flush_buffer,
348         .chars_in_buffer = pty_chars_in_buffer,
349         .unthrottle = pty_unthrottle,
350         .set_termios = pty_set_termios,
351         .ioctl = pty_bsd_ioctl,
352         .resize = pty_resize
353 };
354
355 static void __init legacy_pty_init(void)
356 {
357         if (legacy_count <= 0)
358                 return;
359
360         pty_driver = alloc_tty_driver(legacy_count);
361         if (!pty_driver)
362                 panic("Couldn't allocate pty driver");
363
364         pty_slave_driver = alloc_tty_driver(legacy_count);
365         if (!pty_slave_driver)
366                 panic("Couldn't allocate pty slave driver");
367
368         pty_driver->owner = THIS_MODULE;
369         pty_driver->driver_name = "pty_master";
370         pty_driver->name = "pty";
371         pty_driver->major = PTY_MASTER_MAJOR;
372         pty_driver->minor_start = 0;
373         pty_driver->type = TTY_DRIVER_TYPE_PTY;
374         pty_driver->subtype = PTY_TYPE_MASTER;
375         pty_driver->init_termios = tty_std_termios;
376         pty_driver->init_termios.c_iflag = 0;
377         pty_driver->init_termios.c_oflag = 0;
378         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
379         pty_driver->init_termios.c_lflag = 0;
380         pty_driver->init_termios.c_ispeed = 38400;
381         pty_driver->init_termios.c_ospeed = 38400;
382         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
383         pty_driver->other = pty_slave_driver;
384         tty_set_operations(pty_driver, &pty_ops);
385
386         pty_slave_driver->owner = THIS_MODULE;
387         pty_slave_driver->driver_name = "pty_slave";
388         pty_slave_driver->name = "ttyp";
389         pty_slave_driver->major = PTY_SLAVE_MAJOR;
390         pty_slave_driver->minor_start = 0;
391         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
392         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
393         pty_slave_driver->init_termios = tty_std_termios;
394         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
395         pty_slave_driver->init_termios.c_ispeed = 38400;
396         pty_slave_driver->init_termios.c_ospeed = 38400;
397         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
398                                         TTY_DRIVER_REAL_RAW;
399         pty_slave_driver->other = pty_driver;
400         tty_set_operations(pty_slave_driver, &pty_ops);
401
402         if (tty_register_driver(pty_driver))
403                 panic("Couldn't register pty driver");
404         if (tty_register_driver(pty_slave_driver))
405                 panic("Couldn't register pty slave driver");
406 }
407 #else
408 static inline void legacy_pty_init(void) { }
409 #endif
410
411 /* Unix98 devices */
412 #ifdef CONFIG_UNIX98_PTYS
413 /*
414  * sysctl support for setting limits on the number of Unix98 ptys allocated.
415  * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
416  */
417 int pty_limit = NR_UNIX98_PTY_DEFAULT;
418 static int pty_limit_min;
419 static int pty_limit_max = NR_UNIX98_PTY_MAX;
420 static int pty_count;
421
422 static struct cdev ptmx_cdev;
423
424 static struct ctl_table pty_table[] = {
425         {
426                 .ctl_name       = PTY_MAX,
427                 .procname       = "max",
428                 .maxlen         = sizeof(int),
429                 .mode           = 0644,
430                 .data           = &pty_limit,
431                 .proc_handler   = &proc_dointvec_minmax,
432                 .strategy       = &sysctl_intvec,
433                 .extra1         = &pty_limit_min,
434                 .extra2         = &pty_limit_max,
435         }, {
436                 .ctl_name       = PTY_NR,
437                 .procname       = "nr",
438                 .maxlen         = sizeof(int),
439                 .mode           = 0444,
440                 .data           = &pty_count,
441                 .proc_handler   = &proc_dointvec,
442         }, {
443                 .ctl_name       = 0
444         }
445 };
446
447 static struct ctl_table pty_kern_table[] = {
448         {
449                 .ctl_name       = KERN_PTY,
450                 .procname       = "pty",
451                 .mode           = 0555,
452                 .child          = pty_table,
453         },
454         {}
455 };
456
457 static struct ctl_table pty_root_table[] = {
458         {
459                 .ctl_name       = CTL_KERN,
460                 .procname       = "kernel",
461                 .mode           = 0555,
462                 .child          = pty_kern_table,
463         },
464         {}
465 };
466
467
468 static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
469                             unsigned int cmd, unsigned long arg)
470 {
471         switch (cmd) {
472         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
473                 return pty_set_lock(tty, (int __user *)arg);
474         case TIOCGPTN: /* Get PT Number */
475                 return put_user(tty->index, (unsigned int __user *)arg);
476         }
477
478         return -ENOIOCTLCMD;
479 }
480
481 /**
482  *      ptm_unix98_lookup       -       find a pty master
483  *      @driver: ptm driver
484  *      @idx: tty index
485  *
486  *      Look up a pty master device. Called under the tty_mutex for now.
487  *      This provides our locking.
488  */
489
490 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
491                 struct inode *ptm_inode, int idx)
492 {
493         struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
494         if (tty)
495                 tty = tty->link;
496         return tty;
497 }
498
499 /**
500  *      pts_unix98_lookup       -       find a pty slave
501  *      @driver: pts driver
502  *      @idx: tty index
503  *
504  *      Look up a pty master device. Called under the tty_mutex for now.
505  *      This provides our locking.
506  */
507
508 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
509                 struct inode *pts_inode, int idx)
510 {
511         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
512         /* Master must be open before slave */
513         if (!tty)
514                 return ERR_PTR(-EIO);
515         return tty;
516 }
517
518 static void pty_unix98_shutdown(struct tty_struct *tty)
519 {
520         /* We have our own method as we don't use the tty index */
521         kfree(tty->termios);
522 }
523
524 /* We have no need to install and remove our tty objects as devpts does all
525    the work for us */
526
527 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
528 {
529         struct tty_struct *o_tty;
530         int idx = tty->index;
531
532         o_tty = alloc_tty_struct();
533         if (!o_tty)
534                 return -ENOMEM;
535         if (!try_module_get(driver->other->owner)) {
536                 /* This cannot in fact currently happen */
537                 free_tty_struct(o_tty);
538                 return -ENOMEM;
539         }
540         initialize_tty_struct(o_tty, driver->other, idx);
541
542         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
543         if (tty->termios == NULL)
544                 goto free_mem_out;
545         *tty->termios = driver->init_termios;
546         tty->termios_locked = tty->termios + 1;
547
548         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
549         if (o_tty->termios == NULL)
550                 goto free_mem_out;
551         *o_tty->termios = driver->other->init_termios;
552         o_tty->termios_locked = o_tty->termios + 1;
553
554         tty_driver_kref_get(driver->other);
555         if (driver->subtype == PTY_TYPE_MASTER)
556                 o_tty->count++;
557         /* Establish the links in both directions */
558         tty->link   = o_tty;
559         o_tty->link = tty;
560         /*
561          * All structures have been allocated, so now we install them.
562          * Failures after this point use release_tty to clean up, so
563          * there's no need to null out the local pointers.
564          */
565         tty_driver_kref_get(driver);
566         tty->count++;
567         pty_count++;
568         return 0;
569 free_mem_out:
570         kfree(o_tty->termios);
571         module_put(o_tty->driver->owner);
572         free_tty_struct(o_tty);
573         kfree(tty->termios);
574         return -ENOMEM;
575 }
576
577 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
578 {
579         pty_count--;
580 }
581
582 static const struct tty_operations ptm_unix98_ops = {
583         .lookup = ptm_unix98_lookup,
584         .install = pty_unix98_install,
585         .remove = pty_unix98_remove,
586         .open = pty_open,
587         .close = pty_close,
588         .write = pty_write,
589         .write_room = pty_write_room,
590         .flush_buffer = pty_flush_buffer,
591         .chars_in_buffer = pty_chars_in_buffer,
592         .unthrottle = pty_unthrottle,
593         .set_termios = pty_set_termios,
594         .ioctl = pty_unix98_ioctl,
595         .shutdown = pty_unix98_shutdown,
596         .resize = pty_resize
597 };
598
599 static const struct tty_operations pty_unix98_ops = {
600         .lookup = pts_unix98_lookup,
601         .install = pty_unix98_install,
602         .remove = pty_unix98_remove,
603         .open = pty_open,
604         .close = pty_close,
605         .write = pty_write,
606         .write_room = pty_write_room,
607         .flush_buffer = pty_flush_buffer,
608         .chars_in_buffer = pty_chars_in_buffer,
609         .unthrottle = pty_unthrottle,
610         .set_termios = pty_set_termios,
611         .shutdown = pty_unix98_shutdown
612 };
613
614 /**
615  *      ptmx_open               -       open a unix 98 pty master
616  *      @inode: inode of device file
617  *      @filp: file pointer to tty
618  *
619  *      Allocate a unix98 pty master device from the ptmx driver.
620  *
621  *      Locking: tty_mutex protects the init_dev work. tty->count should
622  *              protect the rest.
623  *              allocated_ptys_lock handles the list of free pty numbers
624  */
625
626 static int __ptmx_open(struct inode *inode, struct file *filp)
627 {
628         struct tty_struct *tty;
629         int retval;
630         int index;
631
632         nonseekable_open(inode, filp);
633
634         /* find a device that is not in use. */
635         index = devpts_new_index(inode);
636         if (index < 0)
637                 return index;
638
639         mutex_lock(&tty_mutex);
640         tty = tty_init_dev(ptm_driver, index, 1);
641         mutex_unlock(&tty_mutex);
642
643         if (IS_ERR(tty)) {
644                 retval = PTR_ERR(tty);
645                 goto out;
646         }
647
648         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
649         filp->private_data = tty;
650         file_move(filp, &tty->tty_files);
651
652         retval = devpts_pty_new(inode, tty->link);
653         if (retval)
654                 goto out1;
655
656         retval = ptm_driver->ops->open(tty, filp);
657         if (!retval)
658                 return 0;
659 out1:
660         tty_release_dev(filp);
661         return retval;
662 out:
663         devpts_kill_index(inode, index);
664         return retval;
665 }
666
667 static int ptmx_open(struct inode *inode, struct file *filp)
668 {
669         int ret;
670
671         lock_kernel();
672         ret = __ptmx_open(inode, filp);
673         unlock_kernel();
674         return ret;
675 }
676
677 static struct file_operations ptmx_fops;
678
679 static void __init unix98_pty_init(void)
680 {
681         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
682         if (!ptm_driver)
683                 panic("Couldn't allocate Unix98 ptm driver");
684         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
685         if (!pts_driver)
686                 panic("Couldn't allocate Unix98 pts driver");
687
688         ptm_driver->owner = THIS_MODULE;
689         ptm_driver->driver_name = "pty_master";
690         ptm_driver->name = "ptm";
691         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
692         ptm_driver->minor_start = 0;
693         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
694         ptm_driver->subtype = PTY_TYPE_MASTER;
695         ptm_driver->init_termios = tty_std_termios;
696         ptm_driver->init_termios.c_iflag = 0;
697         ptm_driver->init_termios.c_oflag = 0;
698         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
699         ptm_driver->init_termios.c_lflag = 0;
700         ptm_driver->init_termios.c_ispeed = 38400;
701         ptm_driver->init_termios.c_ospeed = 38400;
702         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
703                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
704         ptm_driver->other = pts_driver;
705         tty_set_operations(ptm_driver, &ptm_unix98_ops);
706
707         pts_driver->owner = THIS_MODULE;
708         pts_driver->driver_name = "pty_slave";
709         pts_driver->name = "pts";
710         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
711         pts_driver->minor_start = 0;
712         pts_driver->type = TTY_DRIVER_TYPE_PTY;
713         pts_driver->subtype = PTY_TYPE_SLAVE;
714         pts_driver->init_termios = tty_std_termios;
715         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
716         pts_driver->init_termios.c_ispeed = 38400;
717         pts_driver->init_termios.c_ospeed = 38400;
718         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
719                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
720         pts_driver->other = ptm_driver;
721         tty_set_operations(pts_driver, &pty_unix98_ops);
722
723         if (tty_register_driver(ptm_driver))
724                 panic("Couldn't register Unix98 ptm driver");
725         if (tty_register_driver(pts_driver))
726                 panic("Couldn't register Unix98 pts driver");
727
728         register_sysctl_table(pty_root_table);
729
730         /* Now create the /dev/ptmx special device */
731         tty_default_fops(&ptmx_fops);
732         ptmx_fops.open = ptmx_open;
733
734         cdev_init(&ptmx_cdev, &ptmx_fops);
735         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
736             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
737                 panic("Couldn't register /dev/ptmx driver\n");
738         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
739 }
740
741 #else
742 static inline void unix98_pty_init(void) { }
743 #endif
744
745 static int __init pty_init(void)
746 {
747         legacy_pty_init();
748         unix98_pty_init();
749         return 0;
750 }
751 module_init(pty_init);