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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Copyright (C) 1991, 1992 Linus Torvalds
3 *
4 * Added support for a Unix98-style ptmx device.
5 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 */
8
Alan Coxfe9cd962008-10-13 10:43:38 +01009#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
11#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/interrupt.h>
13#include <linux/tty.h>
14#include <linux/tty_flip.h>
15#include <linux/fcntl.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040016#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/string.h>
18#include <linux/major.h>
19#include <linux/mm.h>
20#include <linux/init.h>
Alan Coxd81ed102008-10-13 10:41:42 +010021#include <linux/device.h>
Alan Coxfe9cd962008-10-13 10:43:38 +010022#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/bitops.h>
24#include <linux/devpts_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090025#include <linux/slab.h>
Alan Coxd739e652012-05-03 22:22:09 +010026#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Alan Coxfe9cd962008-10-13 10:43:38 +010028
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#ifdef CONFIG_UNIX98_PTYS
Roel Kluinda2bdf92009-01-07 18:09:15 -080030static struct tty_driver *ptm_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070031static struct tty_driver *pts_driver;
Alan Coxd739e652012-05-03 22:22:09 +010032static DEFINE_MUTEX(devpts_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#endif
34
Alan Coxfe9cd962008-10-13 10:43:38 +010035static void pty_close(struct tty_struct *tty, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036{
Alan Coxfe9cd962008-10-13 10:43:38 +010037 BUG_ON(!tty);
38 if (tty->driver->subtype == PTY_TYPE_MASTER)
39 WARN_ON(tty->count > 1);
40 else {
Peter Hurley69939032013-01-30 12:43:50 -050041 if (test_bit(TTY_IO_ERROR, &tty->flags))
42 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 if (tty->count > 2)
44 return;
45 }
Peter Hurley69939032013-01-30 12:43:50 -050046 set_bit(TTY_IO_ERROR, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 wake_up_interruptible(&tty->read_wait);
48 wake_up_interruptible(&tty->write_wait);
49 tty->packet = 0;
Alan Cox89c8d912012-08-08 16:30:13 +010050 /* Review - krefs on tty_link ?? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 if (!tty->link)
52 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
54 wake_up_interruptible(&tty->link->read_wait);
55 wake_up_interruptible(&tty->link->write_wait);
56 if (tty->driver->subtype == PTY_TYPE_MASTER) {
57 set_bit(TTY_OTHER_CLOSED, &tty->flags);
Greg Kroah-Hartmance1000d2012-02-24 13:56:36 -080058#ifdef CONFIG_UNIX98_PTYS
Alan Coxd739e652012-05-03 22:22:09 +010059 if (tty->driver == ptm_driver) {
Cong Dingb9f80332013-01-12 05:01:22 +010060 mutex_lock(&devpts_mutex);
Peter Hurley7acf6cd2013-01-30 12:43:49 -050061 if (tty->link->driver_data)
62 devpts_pty_kill(tty->link->driver_data);
Cong Dingb9f80332013-01-12 05:01:22 +010063 mutex_unlock(&devpts_mutex);
Alan Coxd739e652012-05-03 22:22:09 +010064 }
Greg Kroah-Hartmance1000d2012-02-24 13:56:36 -080065#endif
Alan Cox89c8d912012-08-08 16:30:13 +010066 tty_unlock(tty);
Arnd Bergmann11dbf202010-06-18 14:58:07 +020067 tty_vhangup(tty->link);
Alan Cox89c8d912012-08-08 16:30:13 +010068 tty_lock(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 }
70}
71
72/*
73 * The unthrottle routine is called by the line discipline to signal
74 * that it can receive more characters. For PTY's, the TTY_THROTTLED
75 * flag is always set, to force the line discipline to always call the
Alan Coxfe9cd962008-10-13 10:43:38 +010076 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 * characters in the queue. This is necessary since each time this
78 * happens, we need to wake up any sleeping processes that could be
79 * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
80 * for the pty buffer to be drained.
81 */
Alan Coxfe9cd962008-10-13 10:43:38 +010082static void pty_unthrottle(struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Alan Coxd945cb92009-07-07 16:39:41 +010084 tty_wakeup(tty->link);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 set_bit(TTY_THROTTLED, &tty->flags);
86}
87
Alan Coxd945cb92009-07-07 16:39:41 +010088/**
89 * pty_space - report space left for writing
90 * @to: tty we are writing into
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 *
Peter Hurley7bfe0b72013-06-15 09:36:08 -040092 * Limit the buffer space used by ptys to 8k.
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 */
Alan Coxd945cb92009-07-07 16:39:41 +010094
95static int pty_space(struct tty_struct *to)
96{
Peter Hurley7bfe0b72013-06-15 09:36:08 -040097 int n = tty_buffer_space_avail(to->port);
98 return min(n, 8192);
Alan Coxd945cb92009-07-07 16:39:41 +010099}
100
101/**
102 * pty_write - write to a pty
103 * @tty: the tty we write from
104 * @buf: kernel buffer of data
105 * @count: bytes to write
106 *
107 * Our "hardware" write method. Data is coming from the ldisc which
108 * may be in a non sleeping state. We simply throw this at the other
109 * end of the link as if we were an IRQ handler receiving stuff for
110 * the other side of the pty/tty pair.
111 */
112
Linus Torvaldsac89a912009-09-05 13:27:10 -0700113static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114{
115 struct tty_struct *to = tty->link;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Alan Coxd945cb92009-07-07 16:39:41 +0100117 if (tty->stopped)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 return 0;
119
Alan Coxd945cb92009-07-07 16:39:41 +0100120 if (c > 0) {
121 /* Stuff the data into the input queue of the other end */
Jiri Slaby05c7cd32013-01-03 15:53:04 +0100122 c = tty_insert_flip_string(to->port, buf, c);
Alan Coxd945cb92009-07-07 16:39:41 +0100123 /* And shovel */
Peter Hurley5ede5252013-07-24 08:29:57 -0400124 if (c)
Jiri Slaby2e124b42013-01-03 15:53:06 +0100125 tty_flip_buffer_push(to->port);
Alan Cox762faae2009-06-16 17:01:13 +0100126 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 return c;
128}
129
Alan Coxd945cb92009-07-07 16:39:41 +0100130/**
131 * pty_write_room - write space
132 * @tty: tty we are writing from
133 *
134 * Report how many bytes the ldisc can send into the queue for
135 * the other device.
136 */
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138static int pty_write_room(struct tty_struct *tty)
139{
Linus Torvalds85dfd812009-08-10 13:21:19 -0700140 if (tty->stopped)
141 return 0;
Alan Coxd945cb92009-07-07 16:39:41 +0100142 return pty_space(tty->link);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
144
Alan Coxd945cb92009-07-07 16:39:41 +0100145/**
146 * pty_chars_in_buffer - characters currently in our tx queue
147 * @tty: our tty
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 *
Alan Coxd945cb92009-07-07 16:39:41 +0100149 * Report how much we have in the transmit queue. As everything is
150 * instantly at the other end this is easy to implement.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 */
Alan Coxd945cb92009-07-07 16:39:41 +0100152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153static int pty_chars_in_buffer(struct tty_struct *tty)
154{
Alan Coxd945cb92009-07-07 16:39:41 +0100155 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156}
157
158/* Set the lock flag on a pty */
Alan Coxfe9cd962008-10-13 10:43:38 +0100159static int pty_set_lock(struct tty_struct *tty, int __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
161 int val;
Alan Coxfe9cd962008-10-13 10:43:38 +0100162 if (get_user(val, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 return -EFAULT;
164 if (val)
165 set_bit(TTY_PTY_LOCK, &tty->flags);
166 else
167 clear_bit(TTY_PTY_LOCK, &tty->flags);
168 return 0;
169}
170
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400171static int pty_get_lock(struct tty_struct *tty, int __user *arg)
172{
173 int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
174 return put_user(locked, arg);
175}
176
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400177/* Set the packet mode on a pty */
178static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
179{
180 unsigned long flags;
181 int pktmode;
182
183 if (get_user(pktmode, arg))
184 return -EFAULT;
185
186 spin_lock_irqsave(&tty->ctrl_lock, flags);
187 if (pktmode) {
188 if (!tty->packet) {
189 tty->packet = 1;
190 tty->link->ctrl_status = 0;
191 }
192 } else
193 tty->packet = 0;
194 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
195
196 return 0;
197}
198
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400199/* Get the packet mode of a pty */
200static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
201{
202 int pktmode = tty->packet;
203 return put_user(pktmode, arg);
204}
205
hyc@symas.com26df6d12010-06-22 10:14:49 -0700206/* Send a signal to the slave */
207static int pty_signal(struct tty_struct *tty, int sig)
208{
209 unsigned long flags;
210 struct pid *pgrp;
211
212 if (tty->link) {
213 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
214 pgrp = get_pid(tty->link->pgrp);
215 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
216
217 kill_pgrp(pgrp, sig, 1);
218 put_pid(pgrp);
219 }
220 return 0;
221}
222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223static void pty_flush_buffer(struct tty_struct *tty)
224{
225 struct tty_struct *to = tty->link;
Alan Cox04f378b2008-04-30 00:53:29 -0700226 unsigned long flags;
Alan Coxfe9cd962008-10-13 10:43:38 +0100227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if (!to)
229 return;
Alan Coxd945cb92009-07-07 16:39:41 +0100230 /* tty_buffer_flush(to); FIXME */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 if (to->packet) {
Alan Cox04f378b2008-04-30 00:53:29 -0700232 spin_lock_irqsave(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
234 wake_up_interruptible(&to->read_wait);
Alan Cox04f378b2008-04-30 00:53:29 -0700235 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 }
237}
238
Alan Coxfe9cd962008-10-13 10:43:38 +0100239static int pty_open(struct tty_struct *tty, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 if (!tty || !tty->link)
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400242 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
245 goto out;
246 if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
247 goto out;
Peter Hurley80cace72013-01-30 12:43:52 -0500248 if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 goto out;
250
Peter Hurley69939032013-01-30 12:43:50 -0500251 clear_bit(TTY_IO_ERROR, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
253 set_bit(TTY_THROTTLED, &tty->flags);
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400254 return 0;
255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256out:
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400257 set_bit(TTY_IO_ERROR, &tty->flags);
258 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
Alan Coxfe9cd962008-10-13 10:43:38 +0100261static void pty_set_termios(struct tty_struct *tty,
262 struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263{
Alan Coxadc8d742012-07-14 15:31:47 +0100264 tty->termios.c_cflag &= ~(CSIZE | PARENB);
265 tty->termios.c_cflag |= (CS8 | CREAD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266}
267
Alan Coxfc6f6232009-01-02 13:43:17 +0000268/**
269 * pty_do_resize - resize event
270 * @tty: tty being resized
Alan Coxc774bda2009-01-11 19:46:49 +0000271 * @ws: window size being set.
Alan Coxfc6f6232009-01-02 13:43:17 +0000272 *
Daniel Mack3ad2f3f2010-02-03 08:01:28 +0800273 * Update the termios variables and send the necessary signals to
Alan Coxfc6f6232009-01-02 13:43:17 +0000274 * peform a terminal resize correctly
275 */
276
Josh Triplett159a8e92012-11-18 21:27:40 -0800277static int pty_resize(struct tty_struct *tty, struct winsize *ws)
Alan Coxfc6f6232009-01-02 13:43:17 +0000278{
279 struct pid *pgrp, *rpgrp;
280 unsigned long flags;
281 struct tty_struct *pty = tty->link;
282
283 /* For a PTY we need to lock the tty side */
Peter Hurleydee4a0b2013-07-24 16:43:51 -0400284 mutex_lock(&tty->winsize_mutex);
Alan Coxfc6f6232009-01-02 13:43:17 +0000285 if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
286 goto done;
287
288 /* Get the PID values and reference them so we can
289 avoid holding the tty ctrl lock while sending signals.
290 We need to lock these individually however. */
291
292 spin_lock_irqsave(&tty->ctrl_lock, flags);
293 pgrp = get_pid(tty->pgrp);
294 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
295
296 spin_lock_irqsave(&pty->ctrl_lock, flags);
297 rpgrp = get_pid(pty->pgrp);
298 spin_unlock_irqrestore(&pty->ctrl_lock, flags);
299
300 if (pgrp)
301 kill_pgrp(pgrp, SIGWINCH, 1);
302 if (rpgrp != pgrp && rpgrp)
303 kill_pgrp(rpgrp, SIGWINCH, 1);
304
305 put_pid(pgrp);
306 put_pid(rpgrp);
307
308 tty->winsize = *ws;
309 pty->winsize = *ws; /* Never used so will go away soon */
310done:
Peter Hurleydee4a0b2013-07-24 16:43:51 -0400311 mutex_unlock(&tty->winsize_mutex);
Alan Coxfc6f6232009-01-02 13:43:17 +0000312 return 0;
313}
314
Alan Coxd1552552012-07-27 18:02:54 +0100315/**
316 * pty_common_install - set up the pty pair
317 * @driver: the pty driver
318 * @tty: the tty being instantiated
319 * @bool: legacy, true if this is BSD style
320 *
321 * Perform the initial set up for the tty/pty pair. Called from the
322 * tty layer when the port is first opened.
323 *
324 * Locking: the caller must hold the tty_mutex
325 */
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200326static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
327 bool legacy)
Alan Coxbf970ee2008-10-13 10:42:39 +0100328{
329 struct tty_struct *o_tty;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200330 struct tty_port *ports[2];
Alan Coxbf970ee2008-10-13 10:42:39 +0100331 int idx = tty->index;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200332 int retval = -ENOMEM;
Alan Coxbf970ee2008-10-13 10:42:39 +0100333
334 o_tty = alloc_tty_struct();
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200335 if (!o_tty)
336 goto err;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200337 ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
338 ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200339 if (!ports[0] || !ports[1])
Jiri Slabyd03702a2012-06-04 13:35:30 +0200340 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100341 if (!try_module_get(driver->other->owner)) {
342 /* This cannot in fact currently happen */
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100343 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100344 }
345 initialize_tty_struct(o_tty, driver->other, idx);
346
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200347 if (legacy) {
348 /* We always use new tty termios data so we can do this
349 the easy way .. */
350 retval = tty_init_termios(tty);
351 if (retval)
352 goto err_deinit_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100353
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200354 retval = tty_init_termios(o_tty);
355 if (retval)
356 goto err_free_termios;
357
358 driver->other->ttys[idx] = o_tty;
359 driver->ttys[idx] = tty;
360 } else {
Alan Coxadc8d742012-07-14 15:31:47 +0100361 memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
362 tty->termios = driver->init_termios;
363 memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
364 o_tty->termios = driver->other->init_termios;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200365 }
Alan Coxfe9cd962008-10-13 10:43:38 +0100366
Alan Coxbf970ee2008-10-13 10:42:39 +0100367 /*
368 * Everything allocated ... set up the o_tty structure.
369 */
Alan Coxbf970ee2008-10-13 10:42:39 +0100370 tty_driver_kref_get(driver->other);
371 if (driver->subtype == PTY_TYPE_MASTER)
372 o_tty->count++;
373 /* Establish the links in both directions */
374 tty->link = o_tty;
375 o_tty->link = tty;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200376 tty_port_init(ports[0]);
377 tty_port_init(ports[1]);
378 o_tty->port = ports[0];
379 tty->port = ports[1];
Jiri Slaby967fab62012-10-18 22:26:46 +0200380 o_tty->port->itty = o_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100381
382 tty_driver_kref_get(driver);
383 tty->count++;
Alan Coxbf970ee2008-10-13 10:42:39 +0100384 return 0;
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100385err_free_termios:
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200386 if (legacy)
387 tty_free_termios(tty);
Jiri Slabya9dccdd2011-03-23 10:48:36 +0100388err_deinit_tty:
389 deinitialize_tty_struct(o_tty);
Alan Coxbf970ee2008-10-13 10:42:39 +0100390 module_put(o_tty->driver->owner);
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100391err_free_tty:
Jiri Slabyd03702a2012-06-04 13:35:30 +0200392 kfree(ports[0]);
393 kfree(ports[1]);
Alan Coxbf970ee2008-10-13 10:42:39 +0100394 free_tty_struct(o_tty);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200395err:
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100396 return retval;
Alan Coxbf970ee2008-10-13 10:42:39 +0100397}
398
Jiri Slabyd03702a2012-06-04 13:35:30 +0200399static void pty_cleanup(struct tty_struct *tty)
400{
Jiri Slaby81c79832012-11-15 09:49:49 +0100401 tty_port_put(tty->port);
Jiri Slabyd03702a2012-06-04 13:35:30 +0200402}
403
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200404/* Traditional BSD devices */
405#ifdef CONFIG_LEGACY_PTYS
406
407static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
408{
409 return pty_common_install(driver, tty, true);
410}
411
Alan Coxd1552552012-07-27 18:02:54 +0100412static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
413{
414 struct tty_struct *pair = tty->link;
415 driver->ttys[tty->index] = NULL;
416 if (pair)
417 pair->driver->ttys[pair->index] = NULL;
418}
419
Alan Cox6caa76b2011-02-14 16:27:22 +0000420static int pty_bsd_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 unsigned int cmd, unsigned long arg)
422{
423 switch (cmd) {
424 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
425 return pty_set_lock(tty, (int __user *) arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400426 case TIOCGPTLCK: /* Get PT Lock status */
427 return pty_get_lock(tty, (int __user *)arg);
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400428 case TIOCPKT: /* Set PT packet mode */
429 return pty_set_pktmode(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400430 case TIOCGPKT: /* Get PT packet mode */
431 return pty_get_pktmode(tty, (int __user *)arg);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700432 case TIOCSIG: /* Send signal to other side of pty */
433 return pty_signal(tty, (int) arg);
Jiri Slabyded2f292013-01-11 12:06:27 +0100434 case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
435 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 }
437 return -ENOIOCTLCMD;
438}
439
Kay Sieversdc8c8582007-08-15 12:25:38 +0200440static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
441module_param(legacy_count, int, 0);
442
Linus Torvalds342a5972009-09-30 07:49:40 -0700443/*
444 * The master side of a pty can do TIOCSPTLCK and thus
445 * has pty_bsd_ioctl.
446 */
447static const struct tty_operations master_pty_ops_bsd = {
448 .install = pty_install,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700449 .open = pty_open,
450 .close = pty_close,
451 .write = pty_write,
452 .write_room = pty_write_room,
453 .flush_buffer = pty_flush_buffer,
454 .chars_in_buffer = pty_chars_in_buffer,
455 .unthrottle = pty_unthrottle,
456 .set_termios = pty_set_termios,
457 .ioctl = pty_bsd_ioctl,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200458 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100459 .resize = pty_resize,
460 .remove = pty_remove
Alan Cox3e8e88c2008-04-30 00:54:10 -0700461};
462
Linus Torvalds342a5972009-09-30 07:49:40 -0700463static const struct tty_operations slave_pty_ops_bsd = {
464 .install = pty_install,
465 .open = pty_open,
466 .close = pty_close,
467 .write = pty_write,
468 .write_room = pty_write_room,
469 .flush_buffer = pty_flush_buffer,
470 .chars_in_buffer = pty_chars_in_buffer,
471 .unthrottle = pty_unthrottle,
472 .set_termios = pty_set_termios,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200473 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100474 .resize = pty_resize,
475 .remove = pty_remove
Linus Torvalds342a5972009-09-30 07:49:40 -0700476};
477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478static void __init legacy_pty_init(void)
479{
Linus Torvalds342a5972009-09-30 07:49:40 -0700480 struct tty_driver *pty_driver, *pty_slave_driver;
481
Kay Sieversdc8c8582007-08-15 12:25:38 +0200482 if (legacy_count <= 0)
483 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200485 pty_driver = tty_alloc_driver(legacy_count,
486 TTY_DRIVER_RESET_TERMIOS |
487 TTY_DRIVER_REAL_RAW |
488 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300489 if (IS_ERR(pty_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 panic("Couldn't allocate pty driver");
491
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200492 pty_slave_driver = tty_alloc_driver(legacy_count,
493 TTY_DRIVER_RESET_TERMIOS |
494 TTY_DRIVER_REAL_RAW |
495 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300496 if (IS_ERR(pty_slave_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 panic("Couldn't allocate pty slave driver");
498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 pty_driver->driver_name = "pty_master";
500 pty_driver->name = "pty";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 pty_driver->major = PTY_MASTER_MAJOR;
502 pty_driver->minor_start = 0;
503 pty_driver->type = TTY_DRIVER_TYPE_PTY;
504 pty_driver->subtype = PTY_TYPE_MASTER;
505 pty_driver->init_termios = tty_std_termios;
506 pty_driver->init_termios.c_iflag = 0;
507 pty_driver->init_termios.c_oflag = 0;
508 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
509 pty_driver->init_termios.c_lflag = 0;
Alan Cox606d0992006-12-08 02:38:45 -0800510 pty_driver->init_termios.c_ispeed = 38400;
511 pty_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 pty_driver->other = pty_slave_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700513 tty_set_operations(pty_driver, &master_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 pty_slave_driver->driver_name = "pty_slave";
516 pty_slave_driver->name = "ttyp";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 pty_slave_driver->major = PTY_SLAVE_MAJOR;
518 pty_slave_driver->minor_start = 0;
519 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
520 pty_slave_driver->subtype = PTY_TYPE_SLAVE;
521 pty_slave_driver->init_termios = tty_std_termios;
522 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
Alan Cox606d0992006-12-08 02:38:45 -0800523 pty_slave_driver->init_termios.c_ispeed = 38400;
524 pty_slave_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 pty_slave_driver->other = pty_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700526 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 if (tty_register_driver(pty_driver))
529 panic("Couldn't register pty driver");
530 if (tty_register_driver(pty_slave_driver))
531 panic("Couldn't register pty slave driver");
532}
533#else
534static inline void legacy_pty_init(void) { }
535#endif
536
537/* Unix98 devices */
538#ifdef CONFIG_UNIX98_PTYS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Alan Coxd81ed102008-10-13 10:41:42 +0100540static struct cdev ptmx_cdev;
541
Alan Cox6caa76b2011-02-14 16:27:22 +0000542static int pty_unix98_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 unsigned int cmd, unsigned long arg)
544{
545 switch (cmd) {
546 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
547 return pty_set_lock(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400548 case TIOCGPTLCK: /* Get PT Lock status */
549 return pty_get_lock(tty, (int __user *)arg);
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400550 case TIOCPKT: /* Set PT packet mode */
551 return pty_set_pktmode(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400552 case TIOCGPKT: /* Get PT packet mode */
553 return pty_get_pktmode(tty, (int __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 case TIOCGPTN: /* Get PT Number */
555 return put_user(tty->index, (unsigned int __user *)arg);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700556 case TIOCSIG: /* Send signal to other side of pty */
557 return pty_signal(tty, (int) arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 }
559
560 return -ENOIOCTLCMD;
561}
562
Alan Cox99f1fe12008-10-13 10:42:00 +0100563/**
564 * ptm_unix98_lookup - find a pty master
565 * @driver: ptm driver
566 * @idx: tty index
567 *
568 * Look up a pty master device. Called under the tty_mutex for now.
569 * This provides our locking.
570 */
571
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100572static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
573 struct inode *ptm_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100574{
Konstantin Khlebnikov593a27c2012-01-05 13:04:21 +0400575 /* Master must be open via /dev/ptmx */
576 return ERR_PTR(-EIO);
Alan Cox99f1fe12008-10-13 10:42:00 +0100577}
578
579/**
580 * pts_unix98_lookup - find a pty slave
581 * @driver: pts driver
582 * @idx: tty index
583 *
584 * Look up a pty master device. Called under the tty_mutex for now.
Alan Coxd739e652012-05-03 22:22:09 +0100585 * This provides our locking for the tty pointer.
Alan Cox99f1fe12008-10-13 10:42:00 +0100586 */
587
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100588static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
589 struct inode *pts_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100590{
Alan Coxd739e652012-05-03 22:22:09 +0100591 struct tty_struct *tty;
592
593 mutex_lock(&devpts_mutex);
Jiri Slaby8fcbaa22012-10-18 22:26:27 +0200594 tty = devpts_get_priv(pts_inode);
Alan Coxd739e652012-05-03 22:22:09 +0100595 mutex_unlock(&devpts_mutex);
Alan Cox99f1fe12008-10-13 10:42:00 +0100596 /* Master must be open before slave */
597 if (!tty)
598 return ERR_PTR(-EIO);
599 return tty;
600}
601
Alan Cox8b0a88d2008-10-13 10:42:19 +0100602/* We have no need to install and remove our tty objects as devpts does all
603 the work for us */
604
Alan Coxbf970ee2008-10-13 10:42:39 +0100605static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
Alan Cox8b0a88d2008-10-13 10:42:19 +0100606{
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200607 return pty_common_install(driver, tty, false);
Alan Cox8b0a88d2008-10-13 10:42:19 +0100608}
609
Jiri Slaby71716042012-06-04 13:35:28 +0200610static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
Jiri Slaby484af542011-11-16 16:27:11 +0100611{
Alan Cox8b0a88d2008-10-13 10:42:19 +0100612}
613
Jiri Slabyf4b208e2013-04-15 07:52:05 +0200614/* this is called once with whichever end is closed last */
615static void pty_unix98_shutdown(struct tty_struct *tty)
616{
617 devpts_kill_index(tty->driver_data, tty->index);
618}
619
Alan Coxfeebed62008-10-13 10:41:30 +0100620static const struct tty_operations ptm_unix98_ops = {
Alan Cox99f1fe12008-10-13 10:42:00 +0100621 .lookup = ptm_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100622 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200623 .remove = pty_unix98_remove,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700624 .open = pty_open,
625 .close = pty_close,
626 .write = pty_write,
627 .write_room = pty_write_room,
628 .flush_buffer = pty_flush_buffer,
629 .chars_in_buffer = pty_chars_in_buffer,
630 .unthrottle = pty_unthrottle,
631 .set_termios = pty_set_termios,
Alan Coxfeebed62008-10-13 10:41:30 +0100632 .ioctl = pty_unix98_ioctl,
Alan Cox36b3c072012-07-17 17:06:57 +0100633 .resize = pty_resize,
Jiri Slabyfa2ecfc5a2012-10-18 22:26:31 +0200634 .shutdown = pty_unix98_shutdown,
Alan Cox36b3c072012-07-17 17:06:57 +0100635 .cleanup = pty_cleanup
Alan Cox3e8e88c2008-04-30 00:54:10 -0700636};
637
Alan Cox99f1fe12008-10-13 10:42:00 +0100638static const struct tty_operations pty_unix98_ops = {
639 .lookup = pts_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100640 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200641 .remove = pty_unix98_remove,
Alan Cox99f1fe12008-10-13 10:42:00 +0100642 .open = pty_open,
643 .close = pty_close,
644 .write = pty_write,
645 .write_room = pty_write_room,
646 .flush_buffer = pty_flush_buffer,
647 .chars_in_buffer = pty_chars_in_buffer,
648 .unthrottle = pty_unthrottle,
649 .set_termios = pty_set_termios,
Jiri Slabyfa2ecfc5a2012-10-18 22:26:31 +0200650 .shutdown = pty_unix98_shutdown,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200651 .cleanup = pty_cleanup,
Alan Cox99f1fe12008-10-13 10:42:00 +0100652};
Alan Coxd81ed102008-10-13 10:41:42 +0100653
654/**
655 * ptmx_open - open a unix 98 pty master
656 * @inode: inode of device file
657 * @filp: file pointer to tty
658 *
659 * Allocate a unix98 pty master device from the ptmx driver.
660 *
661 * Locking: tty_mutex protects the init_dev work. tty->count should
Cong Dingb9f80332013-01-12 05:01:22 +0100662 * protect the rest.
Alan Coxd81ed102008-10-13 10:41:42 +0100663 * allocated_ptys_lock handles the list of free pty numbers
664 */
665
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200666static int ptmx_open(struct inode *inode, struct file *filp)
Alan Coxd81ed102008-10-13 10:41:42 +0100667{
668 struct tty_struct *tty;
Jiri Slaby162b97c2012-10-18 22:26:28 +0200669 struct inode *slave_inode;
Alan Coxd81ed102008-10-13 10:41:42 +0100670 int retval;
671 int index;
672
673 nonseekable_open(inode, filp);
674
Linus Torvaldsb0b88562013-05-01 07:32:21 -0700675 /* We refuse fsnotify events on ptmx, since it's a shared resource */
676 filp->f_mode |= FMODE_NONOTIFY;
677
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200678 retval = tty_alloc_file(filp);
679 if (retval)
680 return retval;
681
Alan Coxd81ed102008-10-13 10:41:42 +0100682 /* find a device that is not in use. */
Alan Cox89c8d912012-08-08 16:30:13 +0100683 mutex_lock(&devpts_mutex);
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100684 index = devpts_new_index(inode);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200685 if (index < 0) {
686 retval = index;
Alan Cox05fb79e2012-09-19 15:34:47 +0100687 mutex_unlock(&devpts_mutex);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200688 goto err_file;
689 }
Alan Coxd81ed102008-10-13 10:41:42 +0100690
Alan Cox6d31a882012-07-14 15:31:27 +0100691 mutex_unlock(&devpts_mutex);
Alan Cox89c8d912012-08-08 16:30:13 +0100692
693 mutex_lock(&tty_mutex);
694 tty = tty_init_dev(ptm_driver, index);
Alan Coxd81ed102008-10-13 10:41:42 +0100695
Alan Cox73ec06f2008-10-13 10:42:29 +0100696 if (IS_ERR(tty)) {
697 retval = PTR_ERR(tty);
Alan Coxd81ed102008-10-13 10:41:42 +0100698 goto out;
Alan Cox73ec06f2008-10-13 10:42:29 +0100699 }
Alan Coxd81ed102008-10-13 10:41:42 +0100700
Alan Cox89c8d912012-08-08 16:30:13 +0100701 /* The tty returned here is locked so we can safely
702 drop the mutex */
703 mutex_unlock(&tty_mutex);
704
Alan Coxd81ed102008-10-13 10:41:42 +0100705 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
Peter Hurley7acf6cd2013-01-30 12:43:49 -0500706 tty->driver_data = inode;
Nick Pigginee2ffa02010-08-18 04:37:35 +1000707
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200708 tty_add_file(tty, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100709
Jiri Slabyf11afb62012-10-18 22:26:29 +0200710 slave_inode = devpts_pty_new(inode,
711 MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
712 tty->link);
Jiri Slaby162b97c2012-10-18 22:26:28 +0200713 if (IS_ERR(slave_inode)) {
714 retval = PTR_ERR(slave_inode);
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200715 goto err_release;
Jiri Slaby162b97c2012-10-18 22:26:28 +0200716 }
Peter Hurley7acf6cd2013-01-30 12:43:49 -0500717 tty->link->driver_data = slave_inode;
Alan Coxd81ed102008-10-13 10:41:42 +0100718
719 retval = ptm_driver->ops->open(tty, filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200720 if (retval)
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200721 goto err_release;
722
Alan Cox89c8d912012-08-08 16:30:13 +0100723 tty_unlock(tty);
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200724 return 0;
725err_release:
Alan Cox89c8d912012-08-08 16:30:13 +0100726 tty_unlock(tty);
Alan Coxeeb89d92009-11-30 13:18:29 +0000727 tty_release(inode, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100728 return retval;
729out:
Alan Cox89c8d912012-08-08 16:30:13 +0100730 mutex_unlock(&tty_mutex);
Jiri Slabyd3bda522012-01-30 21:14:32 +0100731 devpts_kill_index(inode, index);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200732err_file:
733 tty_free_file(filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200734 return retval;
Alan Coxd81ed102008-10-13 10:41:42 +0100735}
736
737static struct file_operations ptmx_fops;
738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739static void __init unix98_pty_init(void)
740{
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200741 ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
742 TTY_DRIVER_RESET_TERMIOS |
743 TTY_DRIVER_REAL_RAW |
744 TTY_DRIVER_DYNAMIC_DEV |
745 TTY_DRIVER_DEVPTS_MEM |
746 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300747 if (IS_ERR(ptm_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 panic("Couldn't allocate Unix98 ptm driver");
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200749 pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
750 TTY_DRIVER_RESET_TERMIOS |
751 TTY_DRIVER_REAL_RAW |
752 TTY_DRIVER_DYNAMIC_DEV |
753 TTY_DRIVER_DEVPTS_MEM |
754 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300755 if (IS_ERR(pts_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 panic("Couldn't allocate Unix98 pts driver");
757
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 ptm_driver->driver_name = "pty_master";
759 ptm_driver->name = "ptm";
760 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
761 ptm_driver->minor_start = 0;
762 ptm_driver->type = TTY_DRIVER_TYPE_PTY;
763 ptm_driver->subtype = PTY_TYPE_MASTER;
764 ptm_driver->init_termios = tty_std_termios;
765 ptm_driver->init_termios.c_iflag = 0;
766 ptm_driver->init_termios.c_oflag = 0;
767 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
768 ptm_driver->init_termios.c_lflag = 0;
Alan Cox606d0992006-12-08 02:38:45 -0800769 ptm_driver->init_termios.c_ispeed = 38400;
770 ptm_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 ptm_driver->other = pts_driver;
Alan Coxfeebed62008-10-13 10:41:30 +0100772 tty_set_operations(ptm_driver, &ptm_unix98_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 pts_driver->driver_name = "pty_slave";
775 pts_driver->name = "pts";
776 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
777 pts_driver->minor_start = 0;
778 pts_driver->type = TTY_DRIVER_TYPE_PTY;
779 pts_driver->subtype = PTY_TYPE_SLAVE;
780 pts_driver->init_termios = tty_std_termios;
781 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
Alan Cox606d0992006-12-08 02:38:45 -0800782 pts_driver->init_termios.c_ispeed = 38400;
783 pts_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 pts_driver->other = ptm_driver;
Alan Cox99f1fe12008-10-13 10:42:00 +0100785 tty_set_operations(pts_driver, &pty_unix98_ops);
Alan Coxfe9cd962008-10-13 10:43:38 +0100786
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 if (tty_register_driver(ptm_driver))
788 panic("Couldn't register Unix98 ptm driver");
789 if (tty_register_driver(pts_driver))
790 panic("Couldn't register Unix98 pts driver");
791
Alan Coxd81ed102008-10-13 10:41:42 +0100792 /* Now create the /dev/ptmx special device */
793 tty_default_fops(&ptmx_fops);
794 ptmx_fops.open = ptmx_open;
795
796 cdev_init(&ptmx_cdev, &ptmx_fops);
797 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
798 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
Cong Ding82f8c352013-01-12 05:01:21 +0100799 panic("Couldn't register /dev/ptmx driver");
Alan Coxd81ed102008-10-13 10:41:42 +0100800 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801}
Alan Coxd81ed102008-10-13 10:41:42 +0100802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803#else
804static inline void unix98_pty_init(void) { }
805#endif
806
807static int __init pty_init(void)
808{
809 legacy_pty_init();
810 unix98_pty_init();
811 return 0;
812}
813module_init(pty_init);