pty: reconnect the BSD TIOCSPTLCK handling to legacy ptys
[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                 if (c) {
124                         tty_flip_buffer_push(to);
125                         tty_wakeup(tty);
126                 }
127         }
128         return c;
129 }
130
131 /**
132  *      pty_write_room  -       write space
133  *      @tty: tty we are writing from
134  *
135  *      Report how many bytes the ldisc can send into the queue for
136  *      the other device.
137  */
138
139 static int pty_write_room(struct tty_struct *tty)
140 {
141         if (tty->stopped)
142                 return 0;
143         return pty_space(tty->link);
144 }
145
146 /**
147  *      pty_chars_in_buffer     -       characters currently in our tx queue
148  *      @tty: our tty
149  *
150  *      Report how much we have in the transmit queue. As everything is
151  *      instantly at the other end this is easy to implement.
152  */
153
154 static int pty_chars_in_buffer(struct tty_struct *tty)
155 {
156         return 0;
157 }
158
159 /* Set the lock flag on a pty */
160 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
161 {
162         int val;
163         if (get_user(val, arg))
164                 return -EFAULT;
165         if (val)
166                 set_bit(TTY_PTY_LOCK, &tty->flags);
167         else
168                 clear_bit(TTY_PTY_LOCK, &tty->flags);
169         return 0;
170 }
171
172 static void pty_flush_buffer(struct tty_struct *tty)
173 {
174         struct tty_struct *to = tty->link;
175         unsigned long flags;
176
177         if (!to)
178                 return;
179         /* tty_buffer_flush(to); FIXME */
180         if (to->packet) {
181                 spin_lock_irqsave(&tty->ctrl_lock, flags);
182                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
183                 wake_up_interruptible(&to->read_wait);
184                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
185         }
186 }
187
188 static int pty_open(struct tty_struct *tty, struct file *filp)
189 {
190         int     retval = -ENODEV;
191
192         if (!tty || !tty->link)
193                 goto out;
194
195         retval = -EIO;
196         if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
197                 goto out;
198         if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
199                 goto out;
200         if (tty->link->count != 1)
201                 goto out;
202
203         clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
204         set_bit(TTY_THROTTLED, &tty->flags);
205         retval = 0;
206 out:
207         return retval;
208 }
209
210 static void pty_set_termios(struct tty_struct *tty,
211                                         struct ktermios *old_termios)
212 {
213         tty->termios->c_cflag &= ~(CSIZE | PARENB);
214         tty->termios->c_cflag |= (CS8 | CREAD);
215 }
216
217 /**
218  *      pty_do_resize           -       resize event
219  *      @tty: tty being resized
220  *      @ws: window size being set.
221  *
222  *      Update the termios variables and send the neccessary signals to
223  *      peform a terminal resize correctly
224  */
225
226 int pty_resize(struct tty_struct *tty,  struct winsize *ws)
227 {
228         struct pid *pgrp, *rpgrp;
229         unsigned long flags;
230         struct tty_struct *pty = tty->link;
231
232         /* For a PTY we need to lock the tty side */
233         mutex_lock(&tty->termios_mutex);
234         if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
235                 goto done;
236
237         /* Get the PID values and reference them so we can
238            avoid holding the tty ctrl lock while sending signals.
239            We need to lock these individually however. */
240
241         spin_lock_irqsave(&tty->ctrl_lock, flags);
242         pgrp = get_pid(tty->pgrp);
243         spin_unlock_irqrestore(&tty->ctrl_lock, flags);
244
245         spin_lock_irqsave(&pty->ctrl_lock, flags);
246         rpgrp = get_pid(pty->pgrp);
247         spin_unlock_irqrestore(&pty->ctrl_lock, flags);
248
249         if (pgrp)
250                 kill_pgrp(pgrp, SIGWINCH, 1);
251         if (rpgrp != pgrp && rpgrp)
252                 kill_pgrp(rpgrp, SIGWINCH, 1);
253
254         put_pid(pgrp);
255         put_pid(rpgrp);
256
257         tty->winsize = *ws;
258         pty->winsize = *ws;     /* Never used so will go away soon */
259 done:
260         mutex_unlock(&tty->termios_mutex);
261         return 0;
262 }
263
264 /* Traditional BSD devices */
265 #ifdef CONFIG_LEGACY_PTYS
266
267 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
268 {
269         struct tty_struct *o_tty;
270         int idx = tty->index;
271         int retval;
272
273         o_tty = alloc_tty_struct();
274         if (!o_tty)
275                 return -ENOMEM;
276         if (!try_module_get(driver->other->owner)) {
277                 /* This cannot in fact currently happen */
278                 free_tty_struct(o_tty);
279                 return -ENOMEM;
280         }
281         initialize_tty_struct(o_tty, driver->other, idx);
282
283         /* We always use new tty termios data so we can do this
284            the easy way .. */
285         retval = tty_init_termios(tty);
286         if (retval)
287                 goto free_mem_out;
288
289         retval = tty_init_termios(o_tty);
290         if (retval) {
291                 tty_free_termios(tty);
292                 goto free_mem_out;
293         }
294
295         /*
296          * Everything allocated ... set up the o_tty structure.
297          */
298         driver->other->ttys[idx] = o_tty;
299         tty_driver_kref_get(driver->other);
300         if (driver->subtype == PTY_TYPE_MASTER)
301                 o_tty->count++;
302         /* Establish the links in both directions */
303         tty->link   = o_tty;
304         o_tty->link = tty;
305
306         tty_driver_kref_get(driver);
307         tty->count++;
308         driver->ttys[idx] = tty;
309         return 0;
310 free_mem_out:
311         module_put(o_tty->driver->owner);
312         free_tty_struct(o_tty);
313         return -ENOMEM;
314 }
315
316 static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
317                          unsigned int cmd, unsigned long arg)
318 {
319         switch (cmd) {
320         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
321                 return pty_set_lock(tty, (int __user *) arg);
322         }
323         return -ENOIOCTLCMD;
324 }
325
326 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
327 module_param(legacy_count, int, 0);
328
329 /*
330  * The master side of a pty can do TIOCSPTLCK and thus
331  * has pty_bsd_ioctl.
332  */
333 static const struct tty_operations master_pty_ops_bsd = {
334         .install = pty_install,
335         .open = pty_open,
336         .close = pty_close,
337         .write = pty_write,
338         .write_room = pty_write_room,
339         .flush_buffer = pty_flush_buffer,
340         .chars_in_buffer = pty_chars_in_buffer,
341         .unthrottle = pty_unthrottle,
342         .set_termios = pty_set_termios,
343         .ioctl = pty_bsd_ioctl,
344         .resize = pty_resize
345 };
346
347 static const struct tty_operations slave_pty_ops_bsd = {
348         .install = pty_install,
349         .open = pty_open,
350         .close = pty_close,
351         .write = pty_write,
352         .write_room = pty_write_room,
353         .flush_buffer = pty_flush_buffer,
354         .chars_in_buffer = pty_chars_in_buffer,
355         .unthrottle = pty_unthrottle,
356         .set_termios = pty_set_termios,
357         .resize = pty_resize
358 };
359
360 static void __init legacy_pty_init(void)
361 {
362         struct tty_driver *pty_driver, *pty_slave_driver;
363
364         if (legacy_count <= 0)
365                 return;
366
367         pty_driver = alloc_tty_driver(legacy_count);
368         if (!pty_driver)
369                 panic("Couldn't allocate pty driver");
370
371         pty_slave_driver = alloc_tty_driver(legacy_count);
372         if (!pty_slave_driver)
373                 panic("Couldn't allocate pty slave driver");
374
375         pty_driver->owner = THIS_MODULE;
376         pty_driver->driver_name = "pty_master";
377         pty_driver->name = "pty";
378         pty_driver->major = PTY_MASTER_MAJOR;
379         pty_driver->minor_start = 0;
380         pty_driver->type = TTY_DRIVER_TYPE_PTY;
381         pty_driver->subtype = PTY_TYPE_MASTER;
382         pty_driver->init_termios = tty_std_termios;
383         pty_driver->init_termios.c_iflag = 0;
384         pty_driver->init_termios.c_oflag = 0;
385         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
386         pty_driver->init_termios.c_lflag = 0;
387         pty_driver->init_termios.c_ispeed = 38400;
388         pty_driver->init_termios.c_ospeed = 38400;
389         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
390         pty_driver->other = pty_slave_driver;
391         tty_set_operations(pty_driver, &master_pty_ops_bsd);
392
393         pty_slave_driver->owner = THIS_MODULE;
394         pty_slave_driver->driver_name = "pty_slave";
395         pty_slave_driver->name = "ttyp";
396         pty_slave_driver->major = PTY_SLAVE_MAJOR;
397         pty_slave_driver->minor_start = 0;
398         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
399         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
400         pty_slave_driver->init_termios = tty_std_termios;
401         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
402         pty_slave_driver->init_termios.c_ispeed = 38400;
403         pty_slave_driver->init_termios.c_ospeed = 38400;
404         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
405                                         TTY_DRIVER_REAL_RAW;
406         pty_slave_driver->other = pty_driver;
407         tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
408
409         if (tty_register_driver(pty_driver))
410                 panic("Couldn't register pty driver");
411         if (tty_register_driver(pty_slave_driver))
412                 panic("Couldn't register pty slave driver");
413 }
414 #else
415 static inline void legacy_pty_init(void) { }
416 #endif
417
418 /* Unix98 devices */
419 #ifdef CONFIG_UNIX98_PTYS
420 /*
421  * sysctl support for setting limits on the number of Unix98 ptys allocated.
422  * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
423  */
424 int pty_limit = NR_UNIX98_PTY_DEFAULT;
425 static int pty_limit_min;
426 static int pty_limit_max = NR_UNIX98_PTY_MAX;
427 static int pty_count;
428
429 static struct cdev ptmx_cdev;
430
431 static struct ctl_table pty_table[] = {
432         {
433                 .ctl_name       = PTY_MAX,
434                 .procname       = "max",
435                 .maxlen         = sizeof(int),
436                 .mode           = 0644,
437                 .data           = &pty_limit,
438                 .proc_handler   = &proc_dointvec_minmax,
439                 .strategy       = &sysctl_intvec,
440                 .extra1         = &pty_limit_min,
441                 .extra2         = &pty_limit_max,
442         }, {
443                 .ctl_name       = PTY_NR,
444                 .procname       = "nr",
445                 .maxlen         = sizeof(int),
446                 .mode           = 0444,
447                 .data           = &pty_count,
448                 .proc_handler   = &proc_dointvec,
449         }, {
450                 .ctl_name       = 0
451         }
452 };
453
454 static struct ctl_table pty_kern_table[] = {
455         {
456                 .ctl_name       = KERN_PTY,
457                 .procname       = "pty",
458                 .mode           = 0555,
459                 .child          = pty_table,
460         },
461         {}
462 };
463
464 static struct ctl_table pty_root_table[] = {
465         {
466                 .ctl_name       = CTL_KERN,
467                 .procname       = "kernel",
468                 .mode           = 0555,
469                 .child          = pty_kern_table,
470         },
471         {}
472 };
473
474
475 static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
476                             unsigned int cmd, unsigned long arg)
477 {
478         switch (cmd) {
479         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
480                 return pty_set_lock(tty, (int __user *)arg);
481         case TIOCGPTN: /* Get PT Number */
482                 return put_user(tty->index, (unsigned int __user *)arg);
483         }
484
485         return -ENOIOCTLCMD;
486 }
487
488 /**
489  *      ptm_unix98_lookup       -       find a pty master
490  *      @driver: ptm driver
491  *      @idx: tty index
492  *
493  *      Look up a pty master device. Called under the tty_mutex for now.
494  *      This provides our locking.
495  */
496
497 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
498                 struct inode *ptm_inode, int idx)
499 {
500         struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
501         if (tty)
502                 tty = tty->link;
503         return tty;
504 }
505
506 /**
507  *      pts_unix98_lookup       -       find a pty slave
508  *      @driver: pts 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 *pts_unix98_lookup(struct tty_driver *driver,
516                 struct inode *pts_inode, int idx)
517 {
518         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
519         /* Master must be open before slave */
520         if (!tty)
521                 return ERR_PTR(-EIO);
522         return tty;
523 }
524
525 static void pty_unix98_shutdown(struct tty_struct *tty)
526 {
527         /* We have our own method as we don't use the tty index */
528         kfree(tty->termios);
529 }
530
531 /* We have no need to install and remove our tty objects as devpts does all
532    the work for us */
533
534 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
535 {
536         struct tty_struct *o_tty;
537         int idx = tty->index;
538
539         o_tty = alloc_tty_struct();
540         if (!o_tty)
541                 return -ENOMEM;
542         if (!try_module_get(driver->other->owner)) {
543                 /* This cannot in fact currently happen */
544                 free_tty_struct(o_tty);
545                 return -ENOMEM;
546         }
547         initialize_tty_struct(o_tty, driver->other, idx);
548
549         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
550         if (tty->termios == NULL)
551                 goto free_mem_out;
552         *tty->termios = driver->init_termios;
553         tty->termios_locked = tty->termios + 1;
554
555         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
556         if (o_tty->termios == NULL)
557                 goto free_mem_out;
558         *o_tty->termios = driver->other->init_termios;
559         o_tty->termios_locked = o_tty->termios + 1;
560
561         tty_driver_kref_get(driver->other);
562         if (driver->subtype == PTY_TYPE_MASTER)
563                 o_tty->count++;
564         /* Establish the links in both directions */
565         tty->link   = o_tty;
566         o_tty->link = tty;
567         /*
568          * All structures have been allocated, so now we install them.
569          * Failures after this point use release_tty to clean up, so
570          * there's no need to null out the local pointers.
571          */
572         tty_driver_kref_get(driver);
573         tty->count++;
574         pty_count++;
575         return 0;
576 free_mem_out:
577         kfree(o_tty->termios);
578         module_put(o_tty->driver->owner);
579         free_tty_struct(o_tty);
580         kfree(tty->termios);
581         return -ENOMEM;
582 }
583
584 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
585 {
586         pty_count--;
587 }
588
589 static const struct tty_operations ptm_unix98_ops = {
590         .lookup = ptm_unix98_lookup,
591         .install = pty_unix98_install,
592         .remove = pty_unix98_remove,
593         .open = pty_open,
594         .close = pty_close,
595         .write = pty_write,
596         .write_room = pty_write_room,
597         .flush_buffer = pty_flush_buffer,
598         .chars_in_buffer = pty_chars_in_buffer,
599         .unthrottle = pty_unthrottle,
600         .set_termios = pty_set_termios,
601         .ioctl = pty_unix98_ioctl,
602         .shutdown = pty_unix98_shutdown,
603         .resize = pty_resize
604 };
605
606 static const struct tty_operations pty_unix98_ops = {
607         .lookup = pts_unix98_lookup,
608         .install = pty_unix98_install,
609         .remove = pty_unix98_remove,
610         .open = pty_open,
611         .close = pty_close,
612         .write = pty_write,
613         .write_room = pty_write_room,
614         .flush_buffer = pty_flush_buffer,
615         .chars_in_buffer = pty_chars_in_buffer,
616         .unthrottle = pty_unthrottle,
617         .set_termios = pty_set_termios,
618         .shutdown = pty_unix98_shutdown
619 };
620
621 /**
622  *      ptmx_open               -       open a unix 98 pty master
623  *      @inode: inode of device file
624  *      @filp: file pointer to tty
625  *
626  *      Allocate a unix98 pty master device from the ptmx driver.
627  *
628  *      Locking: tty_mutex protects the init_dev work. tty->count should
629  *              protect the rest.
630  *              allocated_ptys_lock handles the list of free pty numbers
631  */
632
633 static int __ptmx_open(struct inode *inode, struct file *filp)
634 {
635         struct tty_struct *tty;
636         int retval;
637         int index;
638
639         nonseekable_open(inode, filp);
640
641         /* find a device that is not in use. */
642         index = devpts_new_index(inode);
643         if (index < 0)
644                 return index;
645
646         mutex_lock(&tty_mutex);
647         tty = tty_init_dev(ptm_driver, index, 1);
648         mutex_unlock(&tty_mutex);
649
650         if (IS_ERR(tty)) {
651                 retval = PTR_ERR(tty);
652                 goto out;
653         }
654
655         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
656         filp->private_data = tty;
657         file_move(filp, &tty->tty_files);
658
659         retval = devpts_pty_new(inode, tty->link);
660         if (retval)
661                 goto out1;
662
663         retval = ptm_driver->ops->open(tty, filp);
664         if (!retval)
665                 return 0;
666 out1:
667         tty_release_dev(filp);
668         return retval;
669 out:
670         devpts_kill_index(inode, index);
671         return retval;
672 }
673
674 static int ptmx_open(struct inode *inode, struct file *filp)
675 {
676         int ret;
677
678         lock_kernel();
679         ret = __ptmx_open(inode, filp);
680         unlock_kernel();
681         return ret;
682 }
683
684 static struct file_operations ptmx_fops;
685
686 static void __init unix98_pty_init(void)
687 {
688         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
689         if (!ptm_driver)
690                 panic("Couldn't allocate Unix98 ptm driver");
691         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
692         if (!pts_driver)
693                 panic("Couldn't allocate Unix98 pts driver");
694
695         ptm_driver->owner = THIS_MODULE;
696         ptm_driver->driver_name = "pty_master";
697         ptm_driver->name = "ptm";
698         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
699         ptm_driver->minor_start = 0;
700         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
701         ptm_driver->subtype = PTY_TYPE_MASTER;
702         ptm_driver->init_termios = tty_std_termios;
703         ptm_driver->init_termios.c_iflag = 0;
704         ptm_driver->init_termios.c_oflag = 0;
705         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
706         ptm_driver->init_termios.c_lflag = 0;
707         ptm_driver->init_termios.c_ispeed = 38400;
708         ptm_driver->init_termios.c_ospeed = 38400;
709         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
710                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
711         ptm_driver->other = pts_driver;
712         tty_set_operations(ptm_driver, &ptm_unix98_ops);
713
714         pts_driver->owner = THIS_MODULE;
715         pts_driver->driver_name = "pty_slave";
716         pts_driver->name = "pts";
717         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
718         pts_driver->minor_start = 0;
719         pts_driver->type = TTY_DRIVER_TYPE_PTY;
720         pts_driver->subtype = PTY_TYPE_SLAVE;
721         pts_driver->init_termios = tty_std_termios;
722         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
723         pts_driver->init_termios.c_ispeed = 38400;
724         pts_driver->init_termios.c_ospeed = 38400;
725         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
726                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
727         pts_driver->other = ptm_driver;
728         tty_set_operations(pts_driver, &pty_unix98_ops);
729
730         if (tty_register_driver(ptm_driver))
731                 panic("Couldn't register Unix98 ptm driver");
732         if (tty_register_driver(pts_driver))
733                 panic("Couldn't register Unix98 pts driver");
734
735         register_sysctl_table(pty_root_table);
736
737         /* Now create the /dev/ptmx special device */
738         tty_default_fops(&ptmx_fops);
739         ptmx_fops.open = ptmx_open;
740
741         cdev_init(&ptmx_cdev, &ptmx_fops);
742         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
743             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
744                 panic("Couldn't register /dev/ptmx driver\n");
745         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
746 }
747
748 #else
749 static inline void unix98_pty_init(void) { }
750 #endif
751
752 static int __init pty_init(void)
753 {
754         legacy_pty_init();
755         unix98_pty_init();
756         return 0;
757 }
758 module_init(pty_init);