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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 *
Alan Coxd945cb92009-07-07 16:39:41 +010092 * The tty buffers allow 64K but we sneak a peak and clip at 8K this
93 * allows a lot of overspill room for echo and other fun messes to
94 * be handled properly
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 */
Alan Coxd945cb92009-07-07 16:39:41 +010096
97static int pty_space(struct tty_struct *to)
98{
Jiri Slabyecbbfd42012-10-18 22:26:47 +020099 int n = 8192 - to->port->buf.memory_used;
Alan Coxd945cb92009-07-07 16:39:41 +0100100 if (n < 0)
101 return 0;
102 return n;
103}
104
105/**
106 * pty_write - write to a pty
107 * @tty: the tty we write from
108 * @buf: kernel buffer of data
109 * @count: bytes to write
110 *
111 * Our "hardware" write method. Data is coming from the ldisc which
112 * may be in a non sleeping state. We simply throw this at the other
113 * end of the link as if we were an IRQ handler receiving stuff for
114 * the other side of the pty/tty pair.
115 */
116
Linus Torvaldsac89a912009-09-05 13:27:10 -0700117static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
119 struct tty_struct *to = tty->link;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Alan Coxd945cb92009-07-07 16:39:41 +0100121 if (tty->stopped)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return 0;
123
Alan Coxd945cb92009-07-07 16:39:41 +0100124 if (c > 0) {
125 /* Stuff the data into the input queue of the other end */
Jiri Slaby05c7cd32013-01-03 15:53:04 +0100126 c = tty_insert_flip_string(to->port, buf, c);
Alan Coxd945cb92009-07-07 16:39:41 +0100127 /* And shovel */
Linus Torvalds202c4672009-09-18 07:05:58 -0700128 if (c) {
Jiri Slaby2e124b42013-01-03 15:53:06 +0100129 tty_flip_buffer_push(to->port);
Linus Torvalds202c4672009-09-18 07:05:58 -0700130 tty_wakeup(tty);
131 }
Alan Cox762faae2009-06-16 17:01:13 +0100132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 return c;
134}
135
Alan Coxd945cb92009-07-07 16:39:41 +0100136/**
137 * pty_write_room - write space
138 * @tty: tty we are writing from
139 *
140 * Report how many bytes the ldisc can send into the queue for
141 * the other device.
142 */
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144static int pty_write_room(struct tty_struct *tty)
145{
Linus Torvalds85dfd812009-08-10 13:21:19 -0700146 if (tty->stopped)
147 return 0;
Alan Coxd945cb92009-07-07 16:39:41 +0100148 return pty_space(tty->link);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149}
150
Alan Coxd945cb92009-07-07 16:39:41 +0100151/**
152 * pty_chars_in_buffer - characters currently in our tx queue
153 * @tty: our tty
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 *
Alan Coxd945cb92009-07-07 16:39:41 +0100155 * Report how much we have in the transmit queue. As everything is
156 * instantly at the other end this is easy to implement.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
Alan Coxd945cb92009-07-07 16:39:41 +0100158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159static int pty_chars_in_buffer(struct tty_struct *tty)
160{
Alan Coxd945cb92009-07-07 16:39:41 +0100161 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162}
163
164/* Set the lock flag on a pty */
Alan Coxfe9cd962008-10-13 10:43:38 +0100165static int pty_set_lock(struct tty_struct *tty, int __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
167 int val;
Alan Coxfe9cd962008-10-13 10:43:38 +0100168 if (get_user(val, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 return -EFAULT;
170 if (val)
171 set_bit(TTY_PTY_LOCK, &tty->flags);
172 else
173 clear_bit(TTY_PTY_LOCK, &tty->flags);
174 return 0;
175}
176
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400177static int pty_get_lock(struct tty_struct *tty, int __user *arg)
178{
179 int locked = test_bit(TTY_PTY_LOCK, &tty->flags);
180 return put_user(locked, arg);
181}
182
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400183/* Set the packet mode on a pty */
184static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
185{
186 unsigned long flags;
187 int pktmode;
188
189 if (get_user(pktmode, arg))
190 return -EFAULT;
191
192 spin_lock_irqsave(&tty->ctrl_lock, flags);
193 if (pktmode) {
194 if (!tty->packet) {
195 tty->packet = 1;
196 tty->link->ctrl_status = 0;
197 }
198 } else
199 tty->packet = 0;
200 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
201
202 return 0;
203}
204
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400205/* Get the packet mode of a pty */
206static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
207{
208 int pktmode = tty->packet;
209 return put_user(pktmode, arg);
210}
211
hyc@symas.com26df6d12010-06-22 10:14:49 -0700212/* Send a signal to the slave */
213static int pty_signal(struct tty_struct *tty, int sig)
214{
215 unsigned long flags;
216 struct pid *pgrp;
217
218 if (tty->link) {
219 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
220 pgrp = get_pid(tty->link->pgrp);
221 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
222
223 kill_pgrp(pgrp, sig, 1);
224 put_pid(pgrp);
225 }
226 return 0;
227}
228
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229static void pty_flush_buffer(struct tty_struct *tty)
230{
231 struct tty_struct *to = tty->link;
Alan Cox04f378b2008-04-30 00:53:29 -0700232 unsigned long flags;
Alan Coxfe9cd962008-10-13 10:43:38 +0100233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (!to)
235 return;
Alan Coxd945cb92009-07-07 16:39:41 +0100236 /* tty_buffer_flush(to); FIXME */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 if (to->packet) {
Alan Cox04f378b2008-04-30 00:53:29 -0700238 spin_lock_irqsave(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
240 wake_up_interruptible(&to->read_wait);
Alan Cox04f378b2008-04-30 00:53:29 -0700241 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 }
243}
244
Alan Coxfe9cd962008-10-13 10:43:38 +0100245static int pty_open(struct tty_struct *tty, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 if (!tty || !tty->link)
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400248 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
251 goto out;
252 if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
253 goto out;
Peter Hurley80cace72013-01-30 12:43:52 -0500254 if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 goto out;
256
Peter Hurley69939032013-01-30 12:43:50 -0500257 clear_bit(TTY_IO_ERROR, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
259 set_bit(TTY_THROTTLED, &tty->flags);
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400260 return 0;
261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262out:
Peter Hurley7c61c3d2013-06-13 15:56:37 -0400263 set_bit(TTY_IO_ERROR, &tty->flags);
264 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Alan Coxfe9cd962008-10-13 10:43:38 +0100267static void pty_set_termios(struct tty_struct *tty,
268 struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269{
Alan Coxadc8d742012-07-14 15:31:47 +0100270 tty->termios.c_cflag &= ~(CSIZE | PARENB);
271 tty->termios.c_cflag |= (CS8 | CREAD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272}
273
Alan Coxfc6f6232009-01-02 13:43:17 +0000274/**
275 * pty_do_resize - resize event
276 * @tty: tty being resized
Alan Coxc774bda2009-01-11 19:46:49 +0000277 * @ws: window size being set.
Alan Coxfc6f6232009-01-02 13:43:17 +0000278 *
Daniel Mack3ad2f3f2010-02-03 08:01:28 +0800279 * Update the termios variables and send the necessary signals to
Alan Coxfc6f6232009-01-02 13:43:17 +0000280 * peform a terminal resize correctly
281 */
282
Josh Triplett159a8e92012-11-18 21:27:40 -0800283static int pty_resize(struct tty_struct *tty, struct winsize *ws)
Alan Coxfc6f6232009-01-02 13:43:17 +0000284{
285 struct pid *pgrp, *rpgrp;
286 unsigned long flags;
287 struct tty_struct *pty = tty->link;
288
289 /* For a PTY we need to lock the tty side */
290 mutex_lock(&tty->termios_mutex);
291 if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
292 goto done;
293
294 /* Get the PID values and reference them so we can
295 avoid holding the tty ctrl lock while sending signals.
296 We need to lock these individually however. */
297
298 spin_lock_irqsave(&tty->ctrl_lock, flags);
299 pgrp = get_pid(tty->pgrp);
300 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
301
302 spin_lock_irqsave(&pty->ctrl_lock, flags);
303 rpgrp = get_pid(pty->pgrp);
304 spin_unlock_irqrestore(&pty->ctrl_lock, flags);
305
306 if (pgrp)
307 kill_pgrp(pgrp, SIGWINCH, 1);
308 if (rpgrp != pgrp && rpgrp)
309 kill_pgrp(rpgrp, SIGWINCH, 1);
310
311 put_pid(pgrp);
312 put_pid(rpgrp);
313
314 tty->winsize = *ws;
315 pty->winsize = *ws; /* Never used so will go away soon */
316done:
317 mutex_unlock(&tty->termios_mutex);
318 return 0;
319}
320
Alan Coxd1552552012-07-27 18:02:54 +0100321/**
322 * pty_common_install - set up the pty pair
323 * @driver: the pty driver
324 * @tty: the tty being instantiated
325 * @bool: legacy, true if this is BSD style
326 *
327 * Perform the initial set up for the tty/pty pair. Called from the
328 * tty layer when the port is first opened.
329 *
330 * Locking: the caller must hold the tty_mutex
331 */
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200332static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
333 bool legacy)
Alan Coxbf970ee2008-10-13 10:42:39 +0100334{
335 struct tty_struct *o_tty;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200336 struct tty_port *ports[2];
Alan Coxbf970ee2008-10-13 10:42:39 +0100337 int idx = tty->index;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200338 int retval = -ENOMEM;
Alan Coxbf970ee2008-10-13 10:42:39 +0100339
340 o_tty = alloc_tty_struct();
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200341 if (!o_tty)
342 goto err;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200343 ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
344 ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200345 if (!ports[0] || !ports[1])
Jiri Slabyd03702a2012-06-04 13:35:30 +0200346 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100347 if (!try_module_get(driver->other->owner)) {
348 /* This cannot in fact currently happen */
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100349 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100350 }
351 initialize_tty_struct(o_tty, driver->other, idx);
352
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200353 if (legacy) {
354 /* We always use new tty termios data so we can do this
355 the easy way .. */
356 retval = tty_init_termios(tty);
357 if (retval)
358 goto err_deinit_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100359
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200360 retval = tty_init_termios(o_tty);
361 if (retval)
362 goto err_free_termios;
363
364 driver->other->ttys[idx] = o_tty;
365 driver->ttys[idx] = tty;
366 } else {
Alan Coxadc8d742012-07-14 15:31:47 +0100367 memset(&tty->termios_locked, 0, sizeof(tty->termios_locked));
368 tty->termios = driver->init_termios;
369 memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked));
370 o_tty->termios = driver->other->init_termios;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200371 }
Alan Coxfe9cd962008-10-13 10:43:38 +0100372
Alan Coxbf970ee2008-10-13 10:42:39 +0100373 /*
374 * Everything allocated ... set up the o_tty structure.
375 */
Alan Coxbf970ee2008-10-13 10:42:39 +0100376 tty_driver_kref_get(driver->other);
377 if (driver->subtype == PTY_TYPE_MASTER)
378 o_tty->count++;
379 /* Establish the links in both directions */
380 tty->link = o_tty;
381 o_tty->link = tty;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200382 tty_port_init(ports[0]);
383 tty_port_init(ports[1]);
384 o_tty->port = ports[0];
385 tty->port = ports[1];
Jiri Slaby967fab62012-10-18 22:26:46 +0200386 o_tty->port->itty = o_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100387
388 tty_driver_kref_get(driver);
389 tty->count++;
Alan Coxbf970ee2008-10-13 10:42:39 +0100390 return 0;
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100391err_free_termios:
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200392 if (legacy)
393 tty_free_termios(tty);
Jiri Slabya9dccdd2011-03-23 10:48:36 +0100394err_deinit_tty:
395 deinitialize_tty_struct(o_tty);
Alan Coxbf970ee2008-10-13 10:42:39 +0100396 module_put(o_tty->driver->owner);
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100397err_free_tty:
Jiri Slabyd03702a2012-06-04 13:35:30 +0200398 kfree(ports[0]);
399 kfree(ports[1]);
Alan Coxbf970ee2008-10-13 10:42:39 +0100400 free_tty_struct(o_tty);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200401err:
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100402 return retval;
Alan Coxbf970ee2008-10-13 10:42:39 +0100403}
404
Jiri Slabyd03702a2012-06-04 13:35:30 +0200405static void pty_cleanup(struct tty_struct *tty)
406{
Jiri Slaby81c79832012-11-15 09:49:49 +0100407 tty_port_put(tty->port);
Jiri Slabyd03702a2012-06-04 13:35:30 +0200408}
409
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200410/* Traditional BSD devices */
411#ifdef CONFIG_LEGACY_PTYS
412
413static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
414{
415 return pty_common_install(driver, tty, true);
416}
417
Alan Coxd1552552012-07-27 18:02:54 +0100418static void pty_remove(struct tty_driver *driver, struct tty_struct *tty)
419{
420 struct tty_struct *pair = tty->link;
421 driver->ttys[tty->index] = NULL;
422 if (pair)
423 pair->driver->ttys[pair->index] = NULL;
424}
425
Alan Cox6caa76b2011-02-14 16:27:22 +0000426static int pty_bsd_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 unsigned int cmd, unsigned long arg)
428{
429 switch (cmd) {
430 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
431 return pty_set_lock(tty, (int __user *) arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400432 case TIOCGPTLCK: /* Get PT Lock status */
433 return pty_get_lock(tty, (int __user *)arg);
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400434 case TIOCPKT: /* Set PT packet mode */
435 return pty_set_pktmode(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400436 case TIOCGPKT: /* Get PT packet mode */
437 return pty_get_pktmode(tty, (int __user *)arg);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700438 case TIOCSIG: /* Send signal to other side of pty */
439 return pty_signal(tty, (int) arg);
Jiri Slabyded2f292013-01-11 12:06:27 +0100440 case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */
441 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 }
443 return -ENOIOCTLCMD;
444}
445
Kay Sieversdc8c8582007-08-15 12:25:38 +0200446static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
447module_param(legacy_count, int, 0);
448
Linus Torvalds342a5972009-09-30 07:49:40 -0700449/*
450 * The master side of a pty can do TIOCSPTLCK and thus
451 * has pty_bsd_ioctl.
452 */
453static const struct tty_operations master_pty_ops_bsd = {
454 .install = pty_install,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700455 .open = pty_open,
456 .close = pty_close,
457 .write = pty_write,
458 .write_room = pty_write_room,
459 .flush_buffer = pty_flush_buffer,
460 .chars_in_buffer = pty_chars_in_buffer,
461 .unthrottle = pty_unthrottle,
462 .set_termios = pty_set_termios,
463 .ioctl = pty_bsd_ioctl,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200464 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100465 .resize = pty_resize,
466 .remove = pty_remove
Alan Cox3e8e88c2008-04-30 00:54:10 -0700467};
468
Linus Torvalds342a5972009-09-30 07:49:40 -0700469static const struct tty_operations slave_pty_ops_bsd = {
470 .install = pty_install,
471 .open = pty_open,
472 .close = pty_close,
473 .write = pty_write,
474 .write_room = pty_write_room,
475 .flush_buffer = pty_flush_buffer,
476 .chars_in_buffer = pty_chars_in_buffer,
477 .unthrottle = pty_unthrottle,
478 .set_termios = pty_set_termios,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200479 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100480 .resize = pty_resize,
481 .remove = pty_remove
Linus Torvalds342a5972009-09-30 07:49:40 -0700482};
483
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484static void __init legacy_pty_init(void)
485{
Linus Torvalds342a5972009-09-30 07:49:40 -0700486 struct tty_driver *pty_driver, *pty_slave_driver;
487
Kay Sieversdc8c8582007-08-15 12:25:38 +0200488 if (legacy_count <= 0)
489 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200491 pty_driver = tty_alloc_driver(legacy_count,
492 TTY_DRIVER_RESET_TERMIOS |
493 TTY_DRIVER_REAL_RAW |
494 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300495 if (IS_ERR(pty_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 panic("Couldn't allocate pty driver");
497
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200498 pty_slave_driver = tty_alloc_driver(legacy_count,
499 TTY_DRIVER_RESET_TERMIOS |
500 TTY_DRIVER_REAL_RAW |
501 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300502 if (IS_ERR(pty_slave_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 panic("Couldn't allocate pty slave driver");
504
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 pty_driver->driver_name = "pty_master";
506 pty_driver->name = "pty";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 pty_driver->major = PTY_MASTER_MAJOR;
508 pty_driver->minor_start = 0;
509 pty_driver->type = TTY_DRIVER_TYPE_PTY;
510 pty_driver->subtype = PTY_TYPE_MASTER;
511 pty_driver->init_termios = tty_std_termios;
512 pty_driver->init_termios.c_iflag = 0;
513 pty_driver->init_termios.c_oflag = 0;
514 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
515 pty_driver->init_termios.c_lflag = 0;
Alan Cox606d0992006-12-08 02:38:45 -0800516 pty_driver->init_termios.c_ispeed = 38400;
517 pty_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 pty_driver->other = pty_slave_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700519 tty_set_operations(pty_driver, &master_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 pty_slave_driver->driver_name = "pty_slave";
522 pty_slave_driver->name = "ttyp";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 pty_slave_driver->major = PTY_SLAVE_MAJOR;
524 pty_slave_driver->minor_start = 0;
525 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
526 pty_slave_driver->subtype = PTY_TYPE_SLAVE;
527 pty_slave_driver->init_termios = tty_std_termios;
528 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
Alan Cox606d0992006-12-08 02:38:45 -0800529 pty_slave_driver->init_termios.c_ispeed = 38400;
530 pty_slave_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 pty_slave_driver->other = pty_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700532 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
534 if (tty_register_driver(pty_driver))
535 panic("Couldn't register pty driver");
536 if (tty_register_driver(pty_slave_driver))
537 panic("Couldn't register pty slave driver");
538}
539#else
540static inline void legacy_pty_init(void) { }
541#endif
542
543/* Unix98 devices */
544#ifdef CONFIG_UNIX98_PTYS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
Alan Coxd81ed102008-10-13 10:41:42 +0100546static struct cdev ptmx_cdev;
547
Alan Cox6caa76b2011-02-14 16:27:22 +0000548static int pty_unix98_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 unsigned int cmd, unsigned long arg)
550{
551 switch (cmd) {
552 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
553 return pty_set_lock(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400554 case TIOCGPTLCK: /* Get PT Lock status */
555 return pty_get_lock(tty, (int __user *)arg);
Cyrill Gorcunov06026d92012-10-24 23:43:20 +0400556 case TIOCPKT: /* Set PT packet mode */
557 return pty_set_pktmode(tty, (int __user *)arg);
Cyrill Gorcunov84fd7bd2012-10-24 23:43:22 +0400558 case TIOCGPKT: /* Get PT packet mode */
559 return pty_get_pktmode(tty, (int __user *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 case TIOCGPTN: /* Get PT Number */
561 return put_user(tty->index, (unsigned int __user *)arg);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700562 case TIOCSIG: /* Send signal to other side of pty */
563 return pty_signal(tty, (int) arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 }
565
566 return -ENOIOCTLCMD;
567}
568
Alan Cox99f1fe12008-10-13 10:42:00 +0100569/**
570 * ptm_unix98_lookup - find a pty master
571 * @driver: ptm driver
572 * @idx: tty index
573 *
574 * Look up a pty master device. Called under the tty_mutex for now.
575 * This provides our locking.
576 */
577
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100578static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
579 struct inode *ptm_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100580{
Konstantin Khlebnikov593a27c2012-01-05 13:04:21 +0400581 /* Master must be open via /dev/ptmx */
582 return ERR_PTR(-EIO);
Alan Cox99f1fe12008-10-13 10:42:00 +0100583}
584
585/**
586 * pts_unix98_lookup - find a pty slave
587 * @driver: pts driver
588 * @idx: tty index
589 *
590 * Look up a pty master device. Called under the tty_mutex for now.
Alan Coxd739e652012-05-03 22:22:09 +0100591 * This provides our locking for the tty pointer.
Alan Cox99f1fe12008-10-13 10:42:00 +0100592 */
593
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100594static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
595 struct inode *pts_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100596{
Alan Coxd739e652012-05-03 22:22:09 +0100597 struct tty_struct *tty;
598
599 mutex_lock(&devpts_mutex);
Jiri Slaby8fcbaa22012-10-18 22:26:27 +0200600 tty = devpts_get_priv(pts_inode);
Alan Coxd739e652012-05-03 22:22:09 +0100601 mutex_unlock(&devpts_mutex);
Alan Cox99f1fe12008-10-13 10:42:00 +0100602 /* Master must be open before slave */
603 if (!tty)
604 return ERR_PTR(-EIO);
605 return tty;
606}
607
Alan Cox8b0a88d2008-10-13 10:42:19 +0100608/* We have no need to install and remove our tty objects as devpts does all
609 the work for us */
610
Alan Coxbf970ee2008-10-13 10:42:39 +0100611static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
Alan Cox8b0a88d2008-10-13 10:42:19 +0100612{
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200613 return pty_common_install(driver, tty, false);
Alan Cox8b0a88d2008-10-13 10:42:19 +0100614}
615
Jiri Slaby71716042012-06-04 13:35:28 +0200616static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
Jiri Slaby484af542011-11-16 16:27:11 +0100617{
Alan Cox8b0a88d2008-10-13 10:42:19 +0100618}
619
Jiri Slabyf4b208e2013-04-15 07:52:05 +0200620/* this is called once with whichever end is closed last */
621static void pty_unix98_shutdown(struct tty_struct *tty)
622{
623 devpts_kill_index(tty->driver_data, tty->index);
624}
625
Alan Coxfeebed62008-10-13 10:41:30 +0100626static const struct tty_operations ptm_unix98_ops = {
Alan Cox99f1fe12008-10-13 10:42:00 +0100627 .lookup = ptm_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100628 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200629 .remove = pty_unix98_remove,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700630 .open = pty_open,
631 .close = pty_close,
632 .write = pty_write,
633 .write_room = pty_write_room,
634 .flush_buffer = pty_flush_buffer,
635 .chars_in_buffer = pty_chars_in_buffer,
636 .unthrottle = pty_unthrottle,
637 .set_termios = pty_set_termios,
Alan Coxfeebed62008-10-13 10:41:30 +0100638 .ioctl = pty_unix98_ioctl,
Alan Cox36b3c072012-07-17 17:06:57 +0100639 .resize = pty_resize,
Jiri Slabyfa2ecfc5a2012-10-18 22:26:31 +0200640 .shutdown = pty_unix98_shutdown,
Alan Cox36b3c072012-07-17 17:06:57 +0100641 .cleanup = pty_cleanup
Alan Cox3e8e88c2008-04-30 00:54:10 -0700642};
643
Alan Cox99f1fe12008-10-13 10:42:00 +0100644static const struct tty_operations pty_unix98_ops = {
645 .lookup = pts_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100646 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200647 .remove = pty_unix98_remove,
Alan Cox99f1fe12008-10-13 10:42:00 +0100648 .open = pty_open,
649 .close = pty_close,
650 .write = pty_write,
651 .write_room = pty_write_room,
652 .flush_buffer = pty_flush_buffer,
653 .chars_in_buffer = pty_chars_in_buffer,
654 .unthrottle = pty_unthrottle,
655 .set_termios = pty_set_termios,
Jiri Slabyfa2ecfc5a2012-10-18 22:26:31 +0200656 .shutdown = pty_unix98_shutdown,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200657 .cleanup = pty_cleanup,
Alan Cox99f1fe12008-10-13 10:42:00 +0100658};
Alan Coxd81ed102008-10-13 10:41:42 +0100659
660/**
661 * ptmx_open - open a unix 98 pty master
662 * @inode: inode of device file
663 * @filp: file pointer to tty
664 *
665 * Allocate a unix98 pty master device from the ptmx driver.
666 *
667 * Locking: tty_mutex protects the init_dev work. tty->count should
Cong Dingb9f80332013-01-12 05:01:22 +0100668 * protect the rest.
Alan Coxd81ed102008-10-13 10:41:42 +0100669 * allocated_ptys_lock handles the list of free pty numbers
670 */
671
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200672static int ptmx_open(struct inode *inode, struct file *filp)
Alan Coxd81ed102008-10-13 10:41:42 +0100673{
674 struct tty_struct *tty;
Jiri Slaby162b97c2012-10-18 22:26:28 +0200675 struct inode *slave_inode;
Alan Coxd81ed102008-10-13 10:41:42 +0100676 int retval;
677 int index;
678
679 nonseekable_open(inode, filp);
680
Linus Torvaldsb0b88562013-05-01 07:32:21 -0700681 /* We refuse fsnotify events on ptmx, since it's a shared resource */
682 filp->f_mode |= FMODE_NONOTIFY;
683
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200684 retval = tty_alloc_file(filp);
685 if (retval)
686 return retval;
687
Alan Coxd81ed102008-10-13 10:41:42 +0100688 /* find a device that is not in use. */
Alan Cox89c8d912012-08-08 16:30:13 +0100689 mutex_lock(&devpts_mutex);
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100690 index = devpts_new_index(inode);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200691 if (index < 0) {
692 retval = index;
Alan Cox05fb79e2012-09-19 15:34:47 +0100693 mutex_unlock(&devpts_mutex);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200694 goto err_file;
695 }
Alan Coxd81ed102008-10-13 10:41:42 +0100696
Alan Cox6d31a882012-07-14 15:31:27 +0100697 mutex_unlock(&devpts_mutex);
Alan Cox89c8d912012-08-08 16:30:13 +0100698
699 mutex_lock(&tty_mutex);
700 tty = tty_init_dev(ptm_driver, index);
Alan Coxd81ed102008-10-13 10:41:42 +0100701
Alan Cox73ec06f2008-10-13 10:42:29 +0100702 if (IS_ERR(tty)) {
703 retval = PTR_ERR(tty);
Alan Coxd81ed102008-10-13 10:41:42 +0100704 goto out;
Alan Cox73ec06f2008-10-13 10:42:29 +0100705 }
Alan Coxd81ed102008-10-13 10:41:42 +0100706
Alan Cox89c8d912012-08-08 16:30:13 +0100707 /* The tty returned here is locked so we can safely
708 drop the mutex */
709 mutex_unlock(&tty_mutex);
710
Alan Coxd81ed102008-10-13 10:41:42 +0100711 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
Peter Hurley7acf6cd2013-01-30 12:43:49 -0500712 tty->driver_data = inode;
Nick Pigginee2ffa02010-08-18 04:37:35 +1000713
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200714 tty_add_file(tty, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100715
Jiri Slabyf11afb62012-10-18 22:26:29 +0200716 slave_inode = devpts_pty_new(inode,
717 MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
718 tty->link);
Jiri Slaby162b97c2012-10-18 22:26:28 +0200719 if (IS_ERR(slave_inode)) {
720 retval = PTR_ERR(slave_inode);
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200721 goto err_release;
Jiri Slaby162b97c2012-10-18 22:26:28 +0200722 }
Peter Hurley7acf6cd2013-01-30 12:43:49 -0500723 tty->link->driver_data = slave_inode;
Alan Coxd81ed102008-10-13 10:41:42 +0100724
725 retval = ptm_driver->ops->open(tty, filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200726 if (retval)
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200727 goto err_release;
728
Alan Cox89c8d912012-08-08 16:30:13 +0100729 tty_unlock(tty);
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200730 return 0;
731err_release:
Alan Cox89c8d912012-08-08 16:30:13 +0100732 tty_unlock(tty);
Alan Coxeeb89d92009-11-30 13:18:29 +0000733 tty_release(inode, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100734 return retval;
735out:
Alan Cox89c8d912012-08-08 16:30:13 +0100736 mutex_unlock(&tty_mutex);
Jiri Slabyd3bda522012-01-30 21:14:32 +0100737 devpts_kill_index(inode, index);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200738err_file:
739 tty_free_file(filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200740 return retval;
Alan Coxd81ed102008-10-13 10:41:42 +0100741}
742
743static struct file_operations ptmx_fops;
744
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745static void __init unix98_pty_init(void)
746{
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200747 ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
748 TTY_DRIVER_RESET_TERMIOS |
749 TTY_DRIVER_REAL_RAW |
750 TTY_DRIVER_DYNAMIC_DEV |
751 TTY_DRIVER_DEVPTS_MEM |
752 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300753 if (IS_ERR(ptm_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 panic("Couldn't allocate Unix98 ptm driver");
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200755 pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
756 TTY_DRIVER_RESET_TERMIOS |
757 TTY_DRIVER_REAL_RAW |
758 TTY_DRIVER_DYNAMIC_DEV |
759 TTY_DRIVER_DEVPTS_MEM |
760 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300761 if (IS_ERR(pts_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 panic("Couldn't allocate Unix98 pts driver");
763
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 ptm_driver->driver_name = "pty_master";
765 ptm_driver->name = "ptm";
766 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
767 ptm_driver->minor_start = 0;
768 ptm_driver->type = TTY_DRIVER_TYPE_PTY;
769 ptm_driver->subtype = PTY_TYPE_MASTER;
770 ptm_driver->init_termios = tty_std_termios;
771 ptm_driver->init_termios.c_iflag = 0;
772 ptm_driver->init_termios.c_oflag = 0;
773 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
774 ptm_driver->init_termios.c_lflag = 0;
Alan Cox606d0992006-12-08 02:38:45 -0800775 ptm_driver->init_termios.c_ispeed = 38400;
776 ptm_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 ptm_driver->other = pts_driver;
Alan Coxfeebed62008-10-13 10:41:30 +0100778 tty_set_operations(ptm_driver, &ptm_unix98_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 pts_driver->driver_name = "pty_slave";
781 pts_driver->name = "pts";
782 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
783 pts_driver->minor_start = 0;
784 pts_driver->type = TTY_DRIVER_TYPE_PTY;
785 pts_driver->subtype = PTY_TYPE_SLAVE;
786 pts_driver->init_termios = tty_std_termios;
787 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
Alan Cox606d0992006-12-08 02:38:45 -0800788 pts_driver->init_termios.c_ispeed = 38400;
789 pts_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 pts_driver->other = ptm_driver;
Alan Cox99f1fe12008-10-13 10:42:00 +0100791 tty_set_operations(pts_driver, &pty_unix98_ops);
Alan Coxfe9cd962008-10-13 10:43:38 +0100792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 if (tty_register_driver(ptm_driver))
794 panic("Couldn't register Unix98 ptm driver");
795 if (tty_register_driver(pts_driver))
796 panic("Couldn't register Unix98 pts driver");
797
Alan Coxd81ed102008-10-13 10:41:42 +0100798 /* Now create the /dev/ptmx special device */
799 tty_default_fops(&ptmx_fops);
800 ptmx_fops.open = ptmx_open;
801
802 cdev_init(&ptmx_cdev, &ptmx_fops);
803 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
804 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
Cong Ding82f8c352013-01-12 05:01:21 +0100805 panic("Couldn't register /dev/ptmx driver");
Alan Coxd81ed102008-10-13 10:41:42 +0100806 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807}
Alan Coxd81ed102008-10-13 10:41:42 +0100808
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809#else
810static inline void unix98_pty_init(void) { }
811#endif
812
813static int __init pty_init(void)
814{
815 legacy_pty_init();
816 unix98_pty_init();
817 return 0;
818}
819module_init(pty_init);