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pty: fix data loss when stopped (^S/^Q)
[~shefty/rdma-dev.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,
113                                                                 int count)
114 {
115         struct tty_struct *to = tty->link;
116         int c;
117
118         if (tty->stopped)
119                 return 0;
120
121         /* This isn't locked but our 8K is quite sloppy so no
122            big deal */
123
124         c = pty_space(to);
125         if (c > count)
126                 c = count;
127         if (c > 0) {
128                 /* Stuff the data into the input queue of the other end */
129                 c = tty_insert_flip_string(to, buf, c);
130                 /* And shovel */
131                 tty_flip_buffer_push(to);
132                 tty_wakeup(tty);
133         }
134         return c;
135 }
136
137 /**
138  *      pty_write_room  -       write space
139  *      @tty: tty we are writing from
140  *
141  *      Report how many bytes the ldisc can send into the queue for
142  *      the other device.
143  */
144
145 static int pty_write_room(struct tty_struct *tty)
146 {
147         if (tty->stopped)
148                 return 0;
149         return pty_space(tty->link);
150 }
151
152 /**
153  *      pty_chars_in_buffer     -       characters currently in our tx queue
154  *      @tty: our tty
155  *
156  *      Report how much we have in the transmit queue. As everything is
157  *      instantly at the other end this is easy to implement.
158  */
159
160 static int pty_chars_in_buffer(struct tty_struct *tty)
161 {
162         return 0;
163 }
164
165 /* Set the lock flag on a pty */
166 static int pty_set_lock(struct tty_struct *tty, int __user *arg)
167 {
168         int val;
169         if (get_user(val, arg))
170                 return -EFAULT;
171         if (val)
172                 set_bit(TTY_PTY_LOCK, &tty->flags);
173         else
174                 clear_bit(TTY_PTY_LOCK, &tty->flags);
175         return 0;
176 }
177
178 static void pty_flush_buffer(struct tty_struct *tty)
179 {
180         struct tty_struct *to = tty->link;
181         unsigned long flags;
182
183         if (!to)
184                 return;
185         /* tty_buffer_flush(to); FIXME */
186         if (to->packet) {
187                 spin_lock_irqsave(&tty->ctrl_lock, flags);
188                 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
189                 wake_up_interruptible(&to->read_wait);
190                 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
191         }
192 }
193
194 static int pty_open(struct tty_struct *tty, struct file *filp)
195 {
196         int     retval = -ENODEV;
197
198         if (!tty || !tty->link)
199                 goto out;
200
201         retval = -EIO;
202         if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
203                 goto out;
204         if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
205                 goto out;
206         if (tty->link->count != 1)
207                 goto out;
208
209         clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
210         set_bit(TTY_THROTTLED, &tty->flags);
211         retval = 0;
212 out:
213         return retval;
214 }
215
216 static void pty_set_termios(struct tty_struct *tty,
217                                         struct ktermios *old_termios)
218 {
219         tty->termios->c_cflag &= ~(CSIZE | PARENB);
220         tty->termios->c_cflag |= (CS8 | CREAD);
221 }
222
223 /**
224  *      pty_do_resize           -       resize event
225  *      @tty: tty being resized
226  *      @ws: window size being set.
227  *
228  *      Update the termios variables and send the neccessary signals to
229  *      peform a terminal resize correctly
230  */
231
232 int pty_resize(struct tty_struct *tty,  struct winsize *ws)
233 {
234         struct pid *pgrp, *rpgrp;
235         unsigned long flags;
236         struct tty_struct *pty = tty->link;
237
238         /* For a PTY we need to lock the tty side */
239         mutex_lock(&tty->termios_mutex);
240         if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
241                 goto done;
242
243         /* Get the PID values and reference them so we can
244            avoid holding the tty ctrl lock while sending signals.
245            We need to lock these individually however. */
246
247         spin_lock_irqsave(&tty->ctrl_lock, flags);
248         pgrp = get_pid(tty->pgrp);
249         spin_unlock_irqrestore(&tty->ctrl_lock, flags);
250
251         spin_lock_irqsave(&pty->ctrl_lock, flags);
252         rpgrp = get_pid(pty->pgrp);
253         spin_unlock_irqrestore(&pty->ctrl_lock, flags);
254
255         if (pgrp)
256                 kill_pgrp(pgrp, SIGWINCH, 1);
257         if (rpgrp != pgrp && rpgrp)
258                 kill_pgrp(rpgrp, SIGWINCH, 1);
259
260         put_pid(pgrp);
261         put_pid(rpgrp);
262
263         tty->winsize = *ws;
264         pty->winsize = *ws;     /* Never used so will go away soon */
265 done:
266         mutex_unlock(&tty->termios_mutex);
267         return 0;
268 }
269
270 static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
271 {
272         struct tty_struct *o_tty;
273         int idx = tty->index;
274         int retval;
275
276         o_tty = alloc_tty_struct();
277         if (!o_tty)
278                 return -ENOMEM;
279         if (!try_module_get(driver->other->owner)) {
280                 /* This cannot in fact currently happen */
281                 free_tty_struct(o_tty);
282                 return -ENOMEM;
283         }
284         initialize_tty_struct(o_tty, driver->other, idx);
285
286         /* We always use new tty termios data so we can do this
287            the easy way .. */
288         retval = tty_init_termios(tty);
289         if (retval)
290                 goto free_mem_out;
291
292         retval = tty_init_termios(o_tty);
293         if (retval) {
294                 tty_free_termios(tty);
295                 goto free_mem_out;
296         }
297
298         /*
299          * Everything allocated ... set up the o_tty structure.
300          */
301         driver->other->ttys[idx] = o_tty;
302         tty_driver_kref_get(driver->other);
303         if (driver->subtype == PTY_TYPE_MASTER)
304                 o_tty->count++;
305         /* Establish the links in both directions */
306         tty->link   = o_tty;
307         o_tty->link = tty;
308
309         tty_driver_kref_get(driver);
310         tty->count++;
311         driver->ttys[idx] = tty;
312         return 0;
313 free_mem_out:
314         module_put(o_tty->driver->owner);
315         free_tty_struct(o_tty);
316         return -ENOMEM;
317 }
318
319
320 static const struct tty_operations pty_ops = {
321         .install = pty_install,
322         .open = pty_open,
323         .close = pty_close,
324         .write = pty_write,
325         .write_room = pty_write_room,
326         .flush_buffer = pty_flush_buffer,
327         .chars_in_buffer = pty_chars_in_buffer,
328         .unthrottle = pty_unthrottle,
329         .set_termios = pty_set_termios,
330         .resize = pty_resize
331 };
332
333 /* Traditional BSD devices */
334 #ifdef CONFIG_LEGACY_PTYS
335 static struct tty_driver *pty_driver, *pty_slave_driver;
336
337 static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
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         }
344         return -ENOIOCTLCMD;
345 }
346
347 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
348 module_param(legacy_count, int, 0);
349
350 static const struct tty_operations pty_ops_bsd = {
351         .open = pty_open,
352         .close = pty_close,
353         .write = pty_write,
354         .write_room = pty_write_room,
355         .flush_buffer = pty_flush_buffer,
356         .chars_in_buffer = pty_chars_in_buffer,
357         .unthrottle = pty_unthrottle,
358         .set_termios = pty_set_termios,
359         .ioctl = pty_bsd_ioctl,
360         .resize = pty_resize
361 };
362
363 static void __init legacy_pty_init(void)
364 {
365         if (legacy_count <= 0)
366                 return;
367
368         pty_driver = alloc_tty_driver(legacy_count);
369         if (!pty_driver)
370                 panic("Couldn't allocate pty driver");
371
372         pty_slave_driver = alloc_tty_driver(legacy_count);
373         if (!pty_slave_driver)
374                 panic("Couldn't allocate pty slave driver");
375
376         pty_driver->owner = THIS_MODULE;
377         pty_driver->driver_name = "pty_master";
378         pty_driver->name = "pty";
379         pty_driver->major = PTY_MASTER_MAJOR;
380         pty_driver->minor_start = 0;
381         pty_driver->type = TTY_DRIVER_TYPE_PTY;
382         pty_driver->subtype = PTY_TYPE_MASTER;
383         pty_driver->init_termios = tty_std_termios;
384         pty_driver->init_termios.c_iflag = 0;
385         pty_driver->init_termios.c_oflag = 0;
386         pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
387         pty_driver->init_termios.c_lflag = 0;
388         pty_driver->init_termios.c_ispeed = 38400;
389         pty_driver->init_termios.c_ospeed = 38400;
390         pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
391         pty_driver->other = pty_slave_driver;
392         tty_set_operations(pty_driver, &pty_ops);
393
394         pty_slave_driver->owner = THIS_MODULE;
395         pty_slave_driver->driver_name = "pty_slave";
396         pty_slave_driver->name = "ttyp";
397         pty_slave_driver->major = PTY_SLAVE_MAJOR;
398         pty_slave_driver->minor_start = 0;
399         pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
400         pty_slave_driver->subtype = PTY_TYPE_SLAVE;
401         pty_slave_driver->init_termios = tty_std_termios;
402         pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
403         pty_slave_driver->init_termios.c_ispeed = 38400;
404         pty_slave_driver->init_termios.c_ospeed = 38400;
405         pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
406                                         TTY_DRIVER_REAL_RAW;
407         pty_slave_driver->other = pty_driver;
408         tty_set_operations(pty_slave_driver, &pty_ops);
409
410         if (tty_register_driver(pty_driver))
411                 panic("Couldn't register pty driver");
412         if (tty_register_driver(pty_slave_driver))
413                 panic("Couldn't register pty slave driver");
414 }
415 #else
416 static inline void legacy_pty_init(void) { }
417 #endif
418
419 /* Unix98 devices */
420 #ifdef CONFIG_UNIX98_PTYS
421 /*
422  * sysctl support for setting limits on the number of Unix98 ptys allocated.
423  * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
424  */
425 int pty_limit = NR_UNIX98_PTY_DEFAULT;
426 static int pty_limit_min;
427 static int pty_limit_max = NR_UNIX98_PTY_MAX;
428 static int pty_count;
429
430 static struct cdev ptmx_cdev;
431
432 static struct ctl_table pty_table[] = {
433         {
434                 .ctl_name       = PTY_MAX,
435                 .procname       = "max",
436                 .maxlen         = sizeof(int),
437                 .mode           = 0644,
438                 .data           = &pty_limit,
439                 .proc_handler   = &proc_dointvec_minmax,
440                 .strategy       = &sysctl_intvec,
441                 .extra1         = &pty_limit_min,
442                 .extra2         = &pty_limit_max,
443         }, {
444                 .ctl_name       = PTY_NR,
445                 .procname       = "nr",
446                 .maxlen         = sizeof(int),
447                 .mode           = 0444,
448                 .data           = &pty_count,
449                 .proc_handler   = &proc_dointvec,
450         }, {
451                 .ctl_name       = 0
452         }
453 };
454
455 static struct ctl_table pty_kern_table[] = {
456         {
457                 .ctl_name       = KERN_PTY,
458                 .procname       = "pty",
459                 .mode           = 0555,
460                 .child          = pty_table,
461         },
462         {}
463 };
464
465 static struct ctl_table pty_root_table[] = {
466         {
467                 .ctl_name       = CTL_KERN,
468                 .procname       = "kernel",
469                 .mode           = 0555,
470                 .child          = pty_kern_table,
471         },
472         {}
473 };
474
475
476 static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
477                             unsigned int cmd, unsigned long arg)
478 {
479         switch (cmd) {
480         case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
481                 return pty_set_lock(tty, (int __user *)arg);
482         case TIOCGPTN: /* Get PT Number */
483                 return put_user(tty->index, (unsigned int __user *)arg);
484         }
485
486         return -ENOIOCTLCMD;
487 }
488
489 /**
490  *      ptm_unix98_lookup       -       find a pty master
491  *      @driver: ptm driver
492  *      @idx: tty index
493  *
494  *      Look up a pty master device. Called under the tty_mutex for now.
495  *      This provides our locking.
496  */
497
498 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
499                 struct inode *ptm_inode, int idx)
500 {
501         struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
502         if (tty)
503                 tty = tty->link;
504         return tty;
505 }
506
507 /**
508  *      pts_unix98_lookup       -       find a pty slave
509  *      @driver: pts 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 *pts_unix98_lookup(struct tty_driver *driver,
517                 struct inode *pts_inode, int idx)
518 {
519         struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
520         /* Master must be open before slave */
521         if (!tty)
522                 return ERR_PTR(-EIO);
523         return tty;
524 }
525
526 static void pty_unix98_shutdown(struct tty_struct *tty)
527 {
528         /* We have our own method as we don't use the tty index */
529         kfree(tty->termios);
530 }
531
532 /* We have no need to install and remove our tty objects as devpts does all
533    the work for us */
534
535 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
536 {
537         struct tty_struct *o_tty;
538         int idx = tty->index;
539
540         o_tty = alloc_tty_struct();
541         if (!o_tty)
542                 return -ENOMEM;
543         if (!try_module_get(driver->other->owner)) {
544                 /* This cannot in fact currently happen */
545                 free_tty_struct(o_tty);
546                 return -ENOMEM;
547         }
548         initialize_tty_struct(o_tty, driver->other, idx);
549
550         tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
551         if (tty->termios == NULL)
552                 goto free_mem_out;
553         *tty->termios = driver->init_termios;
554         tty->termios_locked = tty->termios + 1;
555
556         o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
557         if (o_tty->termios == NULL)
558                 goto free_mem_out;
559         *o_tty->termios = driver->other->init_termios;
560         o_tty->termios_locked = o_tty->termios + 1;
561
562         tty_driver_kref_get(driver->other);
563         if (driver->subtype == PTY_TYPE_MASTER)
564                 o_tty->count++;
565         /* Establish the links in both directions */
566         tty->link   = o_tty;
567         o_tty->link = tty;
568         /*
569          * All structures have been allocated, so now we install them.
570          * Failures after this point use release_tty to clean up, so
571          * there's no need to null out the local pointers.
572          */
573         tty_driver_kref_get(driver);
574         tty->count++;
575         pty_count++;
576         return 0;
577 free_mem_out:
578         kfree(o_tty->termios);
579         module_put(o_tty->driver->owner);
580         free_tty_struct(o_tty);
581         kfree(tty->termios);
582         return -ENOMEM;
583 }
584
585 static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
586 {
587         pty_count--;
588 }
589
590 static const struct tty_operations ptm_unix98_ops = {
591         .lookup = ptm_unix98_lookup,
592         .install = pty_unix98_install,
593         .remove = pty_unix98_remove,
594         .open = pty_open,
595         .close = pty_close,
596         .write = pty_write,
597         .write_room = pty_write_room,
598         .flush_buffer = pty_flush_buffer,
599         .chars_in_buffer = pty_chars_in_buffer,
600         .unthrottle = pty_unthrottle,
601         .set_termios = pty_set_termios,
602         .ioctl = pty_unix98_ioctl,
603         .shutdown = pty_unix98_shutdown,
604         .resize = pty_resize
605 };
606
607 static const struct tty_operations pty_unix98_ops = {
608         .lookup = pts_unix98_lookup,
609         .install = pty_unix98_install,
610         .remove = pty_unix98_remove,
611         .open = pty_open,
612         .close = pty_close,
613         .write = pty_write,
614         .write_room = pty_write_room,
615         .flush_buffer = pty_flush_buffer,
616         .chars_in_buffer = pty_chars_in_buffer,
617         .unthrottle = pty_unthrottle,
618         .set_termios = pty_set_termios,
619         .shutdown = pty_unix98_shutdown
620 };
621
622 /**
623  *      ptmx_open               -       open a unix 98 pty master
624  *      @inode: inode of device file
625  *      @filp: file pointer to tty
626  *
627  *      Allocate a unix98 pty master device from the ptmx driver.
628  *
629  *      Locking: tty_mutex protects the init_dev work. tty->count should
630  *              protect the rest.
631  *              allocated_ptys_lock handles the list of free pty numbers
632  */
633
634 static int __ptmx_open(struct inode *inode, struct file *filp)
635 {
636         struct tty_struct *tty;
637         int retval;
638         int index;
639
640         nonseekable_open(inode, filp);
641
642         /* find a device that is not in use. */
643         index = devpts_new_index(inode);
644         if (index < 0)
645                 return index;
646
647         mutex_lock(&tty_mutex);
648         tty = tty_init_dev(ptm_driver, index, 1);
649         mutex_unlock(&tty_mutex);
650
651         if (IS_ERR(tty)) {
652                 retval = PTR_ERR(tty);
653                 goto out;
654         }
655
656         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
657         filp->private_data = tty;
658         file_move(filp, &tty->tty_files);
659
660         retval = devpts_pty_new(inode, tty->link);
661         if (retval)
662                 goto out1;
663
664         retval = ptm_driver->ops->open(tty, filp);
665         if (!retval)
666                 return 0;
667 out1:
668         tty_release_dev(filp);
669         return retval;
670 out:
671         devpts_kill_index(inode, index);
672         return retval;
673 }
674
675 static int ptmx_open(struct inode *inode, struct file *filp)
676 {
677         int ret;
678
679         lock_kernel();
680         ret = __ptmx_open(inode, filp);
681         unlock_kernel();
682         return ret;
683 }
684
685 static struct file_operations ptmx_fops;
686
687 static void __init unix98_pty_init(void)
688 {
689         ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
690         if (!ptm_driver)
691                 panic("Couldn't allocate Unix98 ptm driver");
692         pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
693         if (!pts_driver)
694                 panic("Couldn't allocate Unix98 pts driver");
695
696         ptm_driver->owner = THIS_MODULE;
697         ptm_driver->driver_name = "pty_master";
698         ptm_driver->name = "ptm";
699         ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
700         ptm_driver->minor_start = 0;
701         ptm_driver->type = TTY_DRIVER_TYPE_PTY;
702         ptm_driver->subtype = PTY_TYPE_MASTER;
703         ptm_driver->init_termios = tty_std_termios;
704         ptm_driver->init_termios.c_iflag = 0;
705         ptm_driver->init_termios.c_oflag = 0;
706         ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
707         ptm_driver->init_termios.c_lflag = 0;
708         ptm_driver->init_termios.c_ispeed = 38400;
709         ptm_driver->init_termios.c_ospeed = 38400;
710         ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
711                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
712         ptm_driver->other = pts_driver;
713         tty_set_operations(ptm_driver, &ptm_unix98_ops);
714
715         pts_driver->owner = THIS_MODULE;
716         pts_driver->driver_name = "pty_slave";
717         pts_driver->name = "pts";
718         pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
719         pts_driver->minor_start = 0;
720         pts_driver->type = TTY_DRIVER_TYPE_PTY;
721         pts_driver->subtype = PTY_TYPE_SLAVE;
722         pts_driver->init_termios = tty_std_termios;
723         pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
724         pts_driver->init_termios.c_ispeed = 38400;
725         pts_driver->init_termios.c_ospeed = 38400;
726         pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
727                 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
728         pts_driver->other = ptm_driver;
729         tty_set_operations(pts_driver, &pty_unix98_ops);
730
731         if (tty_register_driver(ptm_driver))
732                 panic("Couldn't register Unix98 ptm driver");
733         if (tty_register_driver(pts_driver))
734                 panic("Couldn't register Unix98 pts driver");
735
736         register_sysctl_table(pty_root_table);
737
738         /* Now create the /dev/ptmx special device */
739         tty_default_fops(&ptmx_fops);
740         ptmx_fops.open = ptmx_open;
741
742         cdev_init(&ptmx_cdev, &ptmx_fops);
743         if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
744             register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
745                 panic("Couldn't register /dev/ptmx driver\n");
746         device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
747 }
748
749 #else
750 static inline void unix98_pty_init(void) { }
751 #endif
752
753 static int __init pty_init(void)
754 {
755         legacy_pty_init();
756         unix98_pty_init();
757         return 0;
758 }
759 module_init(pty_init);