Commit | Line | Data |
---|---|---|
e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992 Linus Torvalds |
4 | */ | |
5 | ||
6 | /* | |
7 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
8 | * or rs-channels. It also implements echoing, cooked mode etc. | |
9 | * | |
10 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
11 | * | |
12 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
13 | * tty_struct and tty_queue structures. Previously there was an array | |
14 | * of 256 tty_struct's which was statically allocated, and the | |
15 | * tty_queue structures were allocated at boot time. Both are now | |
16 | * dynamically allocated only when the tty is open. | |
17 | * | |
18 | * Also restructured routines so that there is more of a separation | |
19 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
20 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 21 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
22 | * |
23 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
24 | * which can be dynamically activated and de-activated by the line | |
25 | * discipline handling modules (like SLIP). | |
26 | * | |
27 | * NOTE: pay no attention to the line discipline code (yet); its | |
28 | * interface is still subject to change in this version... | |
29 | * -- TYT, 1/31/92 | |
30 | * | |
31 | * Added functionality to the OPOST tty handling. No delays, but all | |
32 | * other bits should be there. | |
33 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
34 | * | |
35 | * Rewrote canonical mode and added more termios flags. | |
395e7833 | 36 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 |
1da177e4 LT |
37 | * |
38 | * Reorganized FASYNC support so mouse code can share it. | |
39 | * -- ctm@ardi.com, 9Sep95 | |
40 | * | |
41 | * New TIOCLINUX variants added. | |
42 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 43 | * |
1da177e4 LT |
44 | * Restrict vt switching via ioctl() |
45 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
46 | * | |
47 | * Move console and virtual terminal code to more appropriate files, | |
48 | * implement CONFIG_VT and generalize console device interface. | |
49 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
50 | * | |
d81ed103 | 51 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
52 | * -- Bill Hawes <whawes@star.net>, June 97 |
53 | * | |
54 | * Added devfs support. | |
55 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
56 | * | |
57 | * Added support for a Unix98-style ptmx device. | |
58 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
59 | * | |
60 | * Reduced memory usage for older ARM systems | |
61 | * -- Russell King <rmk@arm.linux.org.uk> | |
62 | * | |
63 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
64 | * alloc_tty_struct() always uses kmalloc() |
65 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
66 | */ |
67 | ||
1da177e4 LT |
68 | #include <linux/types.h> |
69 | #include <linux/major.h> | |
70 | #include <linux/errno.h> | |
71 | #include <linux/signal.h> | |
72 | #include <linux/fcntl.h> | |
3f07c014 | 73 | #include <linux/sched/signal.h> |
29930025 | 74 | #include <linux/sched/task.h> |
1da177e4 LT |
75 | #include <linux/interrupt.h> |
76 | #include <linux/tty.h> | |
77 | #include <linux/tty_driver.h> | |
78 | #include <linux/tty_flip.h> | |
79 | #include <linux/devpts_fs.h> | |
80 | #include <linux/file.h> | |
9f3acc31 | 81 | #include <linux/fdtable.h> |
1da177e4 LT |
82 | #include <linux/console.h> |
83 | #include <linux/timer.h> | |
84 | #include <linux/ctype.h> | |
85 | #include <linux/kd.h> | |
86 | #include <linux/mm.h> | |
87 | #include <linux/string.h> | |
88 | #include <linux/slab.h> | |
89 | #include <linux/poll.h> | |
b7aff093 | 90 | #include <linux/ppp-ioctl.h> |
1da177e4 LT |
91 | #include <linux/proc_fs.h> |
92 | #include <linux/init.h> | |
93 | #include <linux/module.h> | |
1da177e4 | 94 | #include <linux/device.h> |
1da177e4 LT |
95 | #include <linux/wait.h> |
96 | #include <linux/bitops.h> | |
b20f3ae5 | 97 | #include <linux/delay.h> |
a352def2 | 98 | #include <linux/seq_file.h> |
d281da7f | 99 | #include <linux/serial.h> |
5a3c6b25 | 100 | #include <linux/ratelimit.h> |
e2112038 | 101 | #include <linux/compat.h> |
1da177e4 | 102 | |
a352def2 | 103 | #include <linux/uaccess.h> |
1da177e4 LT |
104 | |
105 | #include <linux/kbd_kern.h> | |
106 | #include <linux/vt_kern.h> | |
107 | #include <linux/selection.h> | |
1da177e4 LT |
108 | |
109 | #include <linux/kmod.h> | |
b488893a | 110 | #include <linux/nsproxy.h> |
98602c01 | 111 | #include "tty.h" |
1da177e4 LT |
112 | |
113 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
114 | #ifdef TTY_DEBUG_HANGUP |
115 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
116 | #else | |
117 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
118 | #endif | |
1da177e4 LT |
119 | |
120 | #define TTY_PARANOIA_CHECK 1 | |
121 | #define CHECK_TTY_COUNT 1 | |
122 | ||
edc6afc5 | 123 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
124 | .c_iflag = ICRNL | IXON, |
125 | .c_oflag = OPOST | ONLCR, | |
126 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
127 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
128 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
129 | .c_cc = INIT_C_CC, |
130 | .c_ispeed = 38400, | |
133b1306 PH |
131 | .c_ospeed = 38400, |
132 | /* .c_line = N_TTY, */ | |
1da177e4 | 133 | }; |
1da177e4 LT |
134 | EXPORT_SYMBOL(tty_std_termios); |
135 | ||
136 | /* This list gets poked at by procfs and various bits of boot up code. This | |
b426a5b8 XT |
137 | * could do with some rationalisation such as pulling the tty proc function |
138 | * into this file. | |
139 | */ | |
37bdfb07 | 140 | |
1da177e4 LT |
141 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
142 | ||
d1d027ef | 143 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 144 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 145 | |
dd78b0c4 | 146 | static ssize_t tty_read(struct kiocb *, struct iov_iter *); |
9bb48c82 | 147 | static ssize_t tty_write(struct kiocb *, struct iov_iter *); |
afc9a42b | 148 | static __poll_t tty_poll(struct file *, poll_table *); |
1da177e4 | 149 | static int tty_open(struct inode *, struct file *); |
e10cc1df | 150 | #ifdef CONFIG_COMPAT |
37bdfb07 | 151 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
152 | unsigned long arg); |
153 | #else | |
154 | #define tty_compat_ioctl NULL | |
155 | #endif | |
ec79d605 | 156 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 157 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 158 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 159 | |
af9b897e | 160 | /** |
796a75a9 JS |
161 | * free_tty_struct - free a disused tty |
162 | * @tty: tty struct to free | |
af9b897e | 163 | * |
796a75a9 | 164 | * Free the write buffers, tty queue and tty memory itself. |
af9b897e | 165 | * |
796a75a9 | 166 | * Locking: none. Must be called after tty is definitely unused |
af9b897e | 167 | */ |
a3123fd0 | 168 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 169 | { |
c8b710b3 | 170 | tty_ldisc_deinit(tty); |
a211b1af | 171 | put_device(tty->dev); |
d6d9d17a | 172 | kvfree(tty->write_buf); |
89c8d91e | 173 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
174 | kfree(tty); |
175 | } | |
176 | ||
d996b62a NP |
177 | static inline struct tty_struct *file_tty(struct file *file) |
178 | { | |
179 | return ((struct tty_file_private *)file->private_data)->tty; | |
180 | } | |
181 | ||
fa90e1c9 | 182 | int tty_alloc_file(struct file *file) |
d996b62a NP |
183 | { |
184 | struct tty_file_private *priv; | |
185 | ||
f573bd17 PE |
186 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
187 | if (!priv) | |
188 | return -ENOMEM; | |
d996b62a | 189 | |
fa90e1c9 JS |
190 | file->private_data = priv; |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* Associate a new file with the tty structure */ | |
196 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
197 | { | |
198 | struct tty_file_private *priv = file->private_data; | |
199 | ||
d996b62a NP |
200 | priv->tty = tty; |
201 | priv->file = file; | |
d996b62a | 202 | |
4a510969 | 203 | spin_lock(&tty->files_lock); |
d996b62a | 204 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 205 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 206 | } |
f573bd17 | 207 | |
796a75a9 | 208 | /** |
fa90e1c9 | 209 | * tty_free_file - free file->private_data |
796a75a9 | 210 | * @file: to free private_data of |
fa90e1c9 JS |
211 | * |
212 | * This shall be used only for fail path handling when tty_add_file was not | |
213 | * called yet. | |
214 | */ | |
215 | void tty_free_file(struct file *file) | |
216 | { | |
217 | struct tty_file_private *priv = file->private_data; | |
218 | ||
219 | file->private_data = NULL; | |
220 | kfree(priv); | |
d996b62a NP |
221 | } |
222 | ||
223 | /* Delete file from its tty */ | |
2520e274 | 224 | static void tty_del_file(struct file *file) |
d996b62a NP |
225 | { |
226 | struct tty_file_private *priv = file->private_data; | |
4a510969 | 227 | struct tty_struct *tty = priv->tty; |
d996b62a | 228 | |
4a510969 | 229 | spin_lock(&tty->files_lock); |
d996b62a | 230 | list_del(&priv->list); |
4a510969 | 231 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 232 | tty_free_file(file); |
d996b62a NP |
233 | } |
234 | ||
af9b897e | 235 | /** |
796a75a9 JS |
236 | * tty_name - return tty naming |
237 | * @tty: tty structure | |
af9b897e | 238 | * |
796a75a9 JS |
239 | * Convert a tty structure into a name. The name reflects the kernel naming |
240 | * policy and if udev is in use may not reflect user space | |
af9b897e | 241 | * |
796a75a9 | 242 | * Locking: none |
af9b897e | 243 | */ |
429b4749 | 244 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
245 | { |
246 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
247 | return "NULL tty"; |
248 | return tty->name; | |
1da177e4 | 249 | } |
1da177e4 LT |
250 | EXPORT_SYMBOL(tty_name); |
251 | ||
0a083edd PH |
252 | const char *tty_driver_name(const struct tty_struct *tty) |
253 | { | |
254 | if (!tty || !tty->driver) | |
255 | return ""; | |
256 | return tty->driver->name; | |
257 | } | |
258 | ||
82b8f888 | 259 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
260 | const char *routine) |
261 | { | |
262 | #ifdef TTY_PARANOIA_CHECK | |
263 | if (!tty) { | |
89222e62 | 264 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
265 | imajor(inode), iminor(inode), routine); |
266 | return 1; | |
267 | } | |
268 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 269 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
270 | imajor(inode), iminor(inode), routine); |
271 | return 1; | |
272 | } | |
273 | #endif | |
274 | return 0; | |
275 | } | |
276 | ||
deb287e7 | 277 | /* Caller must hold tty_lock */ |
1da177e4 LT |
278 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
279 | { | |
280 | #ifdef CHECK_TTY_COUNT | |
281 | struct list_head *p; | |
a09ac397 | 282 | int count = 0, kopen_count = 0; |
37bdfb07 | 283 | |
4a510969 | 284 | spin_lock(&tty->files_lock); |
1da177e4 LT |
285 | list_for_each(p, &tty->tty_files) { |
286 | count++; | |
287 | } | |
4a510969 | 288 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
289 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
290 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
291 | tty->link && tty->link->count) | |
292 | count++; | |
a09ac397 OK |
293 | if (tty_port_kopened(tty->port)) |
294 | kopen_count++; | |
295 | if (tty->count != (count + kopen_count)) { | |
296 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", | |
297 | routine, tty->count, count, kopen_count); | |
298 | return (count + kopen_count); | |
24ec839c | 299 | } |
1da177e4 LT |
300 | #endif |
301 | return 0; | |
302 | } | |
303 | ||
af9b897e | 304 | /** |
796a75a9 JS |
305 | * get_tty_driver - find device of a tty |
306 | * @device: device identifier | |
307 | * @index: returns the index of the tty | |
af9b897e | 308 | * |
796a75a9 JS |
309 | * This routine returns a tty driver structure, given a device number and also |
310 | * passes back the index number. | |
af9b897e | 311 | * |
796a75a9 | 312 | * Locking: caller must hold tty_mutex |
1da177e4 LT |
313 | */ |
314 | static struct tty_driver *get_tty_driver(dev_t device, int *index) | |
315 | { | |
316 | struct tty_driver *p; | |
317 | ||
318 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
319 | dev_t base = MKDEV(p->major, p->minor_start); | |
e73b2407 | 320 | |
1da177e4 LT |
321 | if (device < base || device >= base + p->num) |
322 | continue; | |
323 | *index = device - base; | |
7d7b93c1 | 324 | return tty_driver_kref_get(p); |
1da177e4 LT |
325 | } |
326 | return NULL; | |
327 | } | |
328 | ||
fc61ed51 | 329 | /** |
796a75a9 JS |
330 | * tty_dev_name_to_number - return dev_t for device name |
331 | * @name: user space name of device under /dev | |
332 | * @number: pointer to dev_t that this function will populate | |
fc61ed51 | 333 | * |
796a75a9 JS |
334 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t like |
335 | * (4, 64) or (188, 1). If no corresponding driver is registered then the | |
336 | * function returns -%ENODEV. | |
fc61ed51 | 337 | * |
796a75a9 JS |
338 | * Locking: this acquires tty_mutex to protect the tty_drivers list from |
339 | * being modified while we are traversing it, and makes sure to | |
340 | * release it before exiting. | |
fc61ed51 OK |
341 | */ |
342 | int tty_dev_name_to_number(const char *name, dev_t *number) | |
343 | { | |
344 | struct tty_driver *p; | |
345 | int ret; | |
346 | int index, prefix_length = 0; | |
347 | const char *str; | |
348 | ||
349 | for (str = name; *str && !isdigit(*str); str++) | |
350 | ; | |
351 | ||
352 | if (!*str) | |
353 | return -EINVAL; | |
354 | ||
355 | ret = kstrtoint(str, 10, &index); | |
356 | if (ret) | |
357 | return ret; | |
358 | ||
359 | prefix_length = str - name; | |
360 | mutex_lock(&tty_mutex); | |
361 | ||
362 | list_for_each_entry(p, &tty_drivers, tty_drivers) | |
363 | if (prefix_length == strlen(p->name) && strncmp(name, | |
364 | p->name, prefix_length) == 0) { | |
365 | if (index < p->num) { | |
366 | *number = MKDEV(p->major, p->minor_start + index); | |
367 | goto out; | |
368 | } | |
369 | } | |
370 | ||
371 | /* if here then driver wasn't found */ | |
372 | ret = -ENODEV; | |
373 | out: | |
374 | mutex_unlock(&tty_mutex); | |
375 | return ret; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number); | |
378 | ||
f2d937f3 JW |
379 | #ifdef CONFIG_CONSOLE_POLL |
380 | ||
381 | /** | |
796a75a9 JS |
382 | * tty_find_polling_driver - find device of a polled tty |
383 | * @name: name string to match | |
384 | * @line: pointer to resulting tty line nr | |
f2d937f3 | 385 | * |
796a75a9 JS |
386 | * This routine returns a tty driver structure, given a name and the condition |
387 | * that the tty driver is capable of polled operation. | |
f2d937f3 JW |
388 | */ |
389 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
390 | { | |
391 | struct tty_driver *p, *res = NULL; | |
392 | int tty_line = 0; | |
0dca0fd2 | 393 | int len; |
5f0878ac | 394 | char *str, *stp; |
f2d937f3 | 395 | |
0dca0fd2 JW |
396 | for (str = name; *str; str++) |
397 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
398 | break; | |
399 | if (!*str) | |
400 | return NULL; | |
401 | ||
402 | len = str - name; | |
403 | tty_line = simple_strtoul(str, &str, 10); | |
404 | ||
f2d937f3 JW |
405 | mutex_lock(&tty_mutex); |
406 | /* Search through the tty devices to look for a match */ | |
407 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
33a1a7be | 408 | if (!len || strncmp(name, p->name, len) != 0) |
0dca0fd2 | 409 | continue; |
5f0878ac AC |
410 | stp = str; |
411 | if (*stp == ',') | |
412 | stp++; | |
413 | if (*stp == '\0') | |
414 | stp = NULL; | |
f2d937f3 | 415 | |
6eb68d6f | 416 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 417 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 418 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
419 | *line = tty_line; |
420 | break; | |
421 | } | |
422 | } | |
423 | mutex_unlock(&tty_mutex); | |
424 | ||
425 | return res; | |
426 | } | |
427 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
428 | #endif | |
429 | ||
ddc5fda7 | 430 | static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 LT |
431 | { |
432 | return 0; | |
433 | } | |
434 | ||
17749851 | 435 | static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) |
1da177e4 LT |
436 | { |
437 | return -EIO; | |
438 | } | |
439 | ||
440 | /* No kernel lock held - none needed ;) */ | |
afc9a42b | 441 | static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 442 | { |
a9a08845 | 443 | return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; |
1da177e4 LT |
444 | } |
445 | ||
04f378b1 AC |
446 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
447 | unsigned long arg) | |
38ad2ed0 PF |
448 | { |
449 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
450 | } | |
451 | ||
37bdfb07 | 452 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 453 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
454 | { |
455 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
456 | } | |
457 | ||
f557474c PH |
458 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
459 | { | |
460 | return -ENOTTY; | |
461 | } | |
462 | ||
d01c3289 MY |
463 | static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
464 | { | |
465 | struct tty_struct *tty = file_tty(file); | |
466 | ||
467 | if (tty && tty->ops && tty->ops->show_fdinfo) | |
468 | tty->ops->show_fdinfo(tty, m); | |
469 | } | |
470 | ||
62322d25 | 471 | static const struct file_operations tty_fops = { |
1da177e4 | 472 | .llseek = no_llseek, |
dd78b0c4 | 473 | .read_iter = tty_read, |
9bb48c82 | 474 | .write_iter = tty_write, |
dd78b0c4 | 475 | .splice_read = generic_file_splice_read, |
9bb48c82 | 476 | .splice_write = iter_file_splice_write, |
1da177e4 | 477 | .poll = tty_poll, |
04f378b1 | 478 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 479 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
480 | .open = tty_open, |
481 | .release = tty_release, | |
482 | .fasync = tty_fasync, | |
d01c3289 | 483 | .show_fdinfo = tty_show_fdinfo, |
1da177e4 LT |
484 | }; |
485 | ||
62322d25 | 486 | static const struct file_operations console_fops = { |
1da177e4 | 487 | .llseek = no_llseek, |
dd78b0c4 | 488 | .read_iter = tty_read, |
9bb48c82 | 489 | .write_iter = redirected_tty_write, |
dd78b0c4 | 490 | .splice_read = generic_file_splice_read, |
9bb48c82 | 491 | .splice_write = iter_file_splice_write, |
1da177e4 | 492 | .poll = tty_poll, |
04f378b1 | 493 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 494 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
495 | .open = tty_open, |
496 | .release = tty_release, | |
497 | .fasync = tty_fasync, | |
498 | }; | |
499 | ||
62322d25 | 500 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 | 501 | .llseek = no_llseek, |
ddc5fda7 | 502 | .read_iter = hung_up_tty_read, |
17749851 | 503 | .write_iter = hung_up_tty_write, |
1da177e4 | 504 | .poll = hung_up_tty_poll, |
04f378b1 | 505 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 506 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 507 | .release = tty_release, |
f557474c | 508 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
509 | }; |
510 | ||
511 | static DEFINE_SPINLOCK(redirect_lock); | |
512 | static struct file *redirect; | |
513 | ||
514 | /** | |
796a75a9 JS |
515 | * tty_wakeup - request more data |
516 | * @tty: terminal | |
1da177e4 | 517 | * |
796a75a9 JS |
518 | * Internal and external helper for wakeups of tty. This function informs the |
519 | * line discipline if present that the driver is ready to receive more output | |
520 | * data. | |
1da177e4 | 521 | */ |
1da177e4 LT |
522 | void tty_wakeup(struct tty_struct *tty) |
523 | { | |
524 | struct tty_ldisc *ld; | |
37bdfb07 | 525 | |
1da177e4 LT |
526 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
527 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 528 | if (ld) { |
a352def2 AC |
529 | if (ld->ops->write_wakeup) |
530 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
531 | tty_ldisc_deref(ld); |
532 | } | |
533 | } | |
a9a08845 | 534 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 | 535 | } |
1da177e4 LT |
536 | EXPORT_SYMBOL_GPL(tty_wakeup); |
537 | ||
f446776e | 538 | /** |
796a75a9 JS |
539 | * tty_release_redirect - Release a redirect on a pty if present |
540 | * @tty: tty device | |
f446776e | 541 | * |
796a75a9 JS |
542 | * This is available to the pty code so if the master closes, if the slave is a |
543 | * redirect it can release the redirect. | |
f446776e | 544 | */ |
dd9f6114 | 545 | static struct file *tty_release_redirect(struct tty_struct *tty) |
f446776e CM |
546 | { |
547 | struct file *f = NULL; | |
548 | ||
549 | spin_lock(&redirect_lock); | |
550 | if (redirect && file_tty(redirect) == tty) { | |
551 | f = redirect; | |
552 | redirect = NULL; | |
553 | } | |
554 | spin_unlock(&redirect_lock); | |
555 | ||
556 | return f; | |
557 | } | |
f446776e | 558 | |
af9b897e | 559 | /** |
796a75a9 JS |
560 | * __tty_hangup - actual handler for hangup events |
561 | * @tty: tty device | |
562 | * @exit_session: if non-zero, signal all foreground group processes | |
563 | * | |
564 | * This can be called by a "kworker" kernel thread. That is process synchronous | |
565 | * but doesn't hold any locks, so we need to make sure we have the appropriate | |
566 | * locks for what we're doing. | |
567 | * | |
568 | * The hangup event clears any pending redirections onto the hung up device. It | |
569 | * ensures future writes will error and it does the needed line discipline | |
570 | * hangup and signal delivery. The tty object itself remains intact. | |
571 | * | |
572 | * Locking: | |
573 | * * BTM | |
574 | * | |
575 | * * redirect lock for undoing redirection | |
576 | * * file list lock for manipulating list of ttys | |
577 | * * tty_ldiscs_lock from called functions | |
578 | * * termios_rwsem resetting termios data | |
579 | * * tasklist_lock to walk task list for hangup event | |
580 | * | |
581 | * * ->siglock to protect ->signal/->sighand | |
582 | * | |
1da177e4 | 583 | */ |
f91e2590 | 584 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 585 | { |
37bdfb07 | 586 | struct file *cons_filp = NULL; |
f446776e | 587 | struct file *filp, *f; |
d996b62a | 588 | struct tty_file_private *priv; |
1da177e4 | 589 | int closecount = 0, n; |
ea648a47 | 590 | int refs; |
1da177e4 LT |
591 | |
592 | if (!tty) | |
593 | return; | |
594 | ||
f446776e | 595 | f = tty_release_redirect(tty); |
37bdfb07 | 596 | |
89c8d91e | 597 | tty_lock(tty); |
11dbf203 | 598 | |
cb50e523 PH |
599 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
600 | tty_unlock(tty); | |
601 | return; | |
602 | } | |
603 | ||
28b0f8a6 TH |
604 | /* |
605 | * Some console devices aren't actually hung up for technical and | |
606 | * historical reasons, which can lead to indefinite interruptible | |
607 | * sleep in n_tty_read(). The following explicitly tells | |
608 | * n_tty_read() to abort readers. | |
609 | */ | |
610 | set_bit(TTY_HUPPING, &tty->flags); | |
611 | ||
ec79d605 | 612 | /* inuse_filps is protected by the single tty lock, |
b426a5b8 XT |
613 | * this really needs to change if we want to flush the |
614 | * workqueue with the lock held. | |
615 | */ | |
11dbf203 | 616 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 617 | |
4a510969 | 618 | spin_lock(&tty->files_lock); |
1da177e4 | 619 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
620 | list_for_each_entry(priv, &tty->tty_files, list) { |
621 | filp = priv->file; | |
9bb48c82 | 622 | if (filp->f_op->write_iter == redirected_tty_write) |
1da177e4 | 623 | cons_filp = filp; |
9bb48c82 | 624 | if (filp->f_op->write_iter != tty_write) |
1da177e4 LT |
625 | continue; |
626 | closecount++; | |
ec79d605 | 627 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
628 | filp->f_op = &hung_up_tty_fops; |
629 | } | |
4a510969 | 630 | spin_unlock(&tty->files_lock); |
37bdfb07 | 631 | |
25fdf243 PH |
632 | refs = tty_signal_session_leader(tty, exit_session); |
633 | /* Account for the p->signal references we killed */ | |
634 | while (refs--) | |
635 | tty_kref_put(tty); | |
636 | ||
892d1fa7 | 637 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 638 | |
64d608db | 639 | spin_lock_irq(&tty->ctrl.lock); |
c65c9bc3 | 640 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 641 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
64d608db JS |
642 | put_pid(tty->ctrl.session); |
643 | put_pid(tty->ctrl.pgrp); | |
644 | tty->ctrl.session = NULL; | |
645 | tty->ctrl.pgrp = NULL; | |
646 | tty->ctrl.pktstatus = 0; | |
647 | spin_unlock_irq(&tty->ctrl.lock); | |
9c9f4ded | 648 | |
1da177e4 | 649 | /* |
37bdfb07 AC |
650 | * If one of the devices matches a console pointer, we |
651 | * cannot just call hangup() because that will cause | |
652 | * tty->count and state->count to go out of sync. | |
653 | * So we just call close() the right number of times. | |
1da177e4 LT |
654 | */ |
655 | if (cons_filp) { | |
f34d7a5b | 656 | if (tty->ops->close) |
1da177e4 | 657 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
658 | tty->ops->close(tty, cons_filp); |
659 | } else if (tty->ops->hangup) | |
7c6d340f | 660 | tty->ops->hangup(tty); |
37bdfb07 | 661 | /* |
892d1fa7 PH |
662 | * We don't want to have driver/ldisc interactions beyond the ones |
663 | * we did here. The driver layer expects no calls after ->hangup() | |
664 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 665 | */ |
1da177e4 | 666 | set_bit(TTY_HUPPED, &tty->flags); |
28b0f8a6 | 667 | clear_bit(TTY_HUPPING, &tty->flags); |
89c8d91e | 668 | tty_unlock(tty); |
11dbf203 | 669 | |
1da177e4 LT |
670 | if (f) |
671 | fput(f); | |
672 | } | |
673 | ||
ddcd9fb6 AB |
674 | static void do_tty_hangup(struct work_struct *work) |
675 | { | |
676 | struct tty_struct *tty = | |
677 | container_of(work, struct tty_struct, hangup_work); | |
678 | ||
f91e2590 | 679 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
680 | } |
681 | ||
af9b897e | 682 | /** |
796a75a9 JS |
683 | * tty_hangup - trigger a hangup event |
684 | * @tty: tty to hangup | |
af9b897e | 685 | * |
796a75a9 JS |
686 | * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a |
687 | * hangup sequence to run after this event. | |
af9b897e | 688 | */ |
37bdfb07 | 689 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 690 | { |
d435cefe | 691 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
692 | schedule_work(&tty->hangup_work); |
693 | } | |
1da177e4 LT |
694 | EXPORT_SYMBOL(tty_hangup); |
695 | ||
af9b897e | 696 | /** |
796a75a9 JS |
697 | * tty_vhangup - process vhangup |
698 | * @tty: tty to hangup | |
af9b897e | 699 | * |
796a75a9 JS |
700 | * The user has asked via system call for the terminal to be hung up. We do |
701 | * this synchronously so that when the syscall returns the process is complete. | |
702 | * That guarantee is necessary for security reasons. | |
af9b897e | 703 | */ |
37bdfb07 | 704 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 705 | { |
d435cefe | 706 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 707 | __tty_hangup(tty, 0); |
1da177e4 LT |
708 | } |
709 | EXPORT_SYMBOL(tty_vhangup); | |
710 | ||
11dbf203 | 711 | |
2cb5998b | 712 | /** |
796a75a9 | 713 | * tty_vhangup_self - process vhangup for own ctty |
2cb5998b | 714 | * |
796a75a9 | 715 | * Perform a vhangup on the current controlling tty |
2cb5998b | 716 | */ |
2cb5998b AC |
717 | void tty_vhangup_self(void) |
718 | { | |
719 | struct tty_struct *tty; | |
720 | ||
2cb5998b AC |
721 | tty = get_current_tty(); |
722 | if (tty) { | |
723 | tty_vhangup(tty); | |
724 | tty_kref_put(tty); | |
725 | } | |
2cb5998b AC |
726 | } |
727 | ||
f91e2590 | 728 | /** |
796a75a9 JS |
729 | * tty_vhangup_session - hangup session leader exit |
730 | * @tty: tty to hangup | |
f91e2590 | 731 | * |
796a75a9 JS |
732 | * The session leader is exiting and hanging up its controlling terminal. |
733 | * Every process in the foreground process group is signalled %SIGHUP. | |
f91e2590 | 734 | * |
796a75a9 JS |
735 | * We do this synchronously so that when the syscall returns the process is |
736 | * complete. That guarantee is necessary for security reasons. | |
f91e2590 | 737 | */ |
a1235b3e | 738 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 739 | { |
d435cefe | 740 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
741 | __tty_hangup(tty, 1); |
742 | } | |
743 | ||
af9b897e | 744 | /** |
796a75a9 JS |
745 | * tty_hung_up_p - was tty hung up |
746 | * @filp: file pointer of tty | |
af9b897e | 747 | * |
796a75a9 | 748 | * Return: true if the tty has been subject to a vhangup or a carrier loss |
af9b897e | 749 | */ |
37bdfb07 | 750 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 751 | { |
ed3f0af8 | 752 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 | 753 | } |
1da177e4 LT |
754 | EXPORT_SYMBOL(tty_hung_up_p); |
755 | ||
d06e256f JS |
756 | void __stop_tty(struct tty_struct *tty) |
757 | { | |
758 | if (tty->flow.stopped) | |
759 | return; | |
760 | tty->flow.stopped = true; | |
761 | if (tty->ops->stop) | |
762 | tty->ops->stop(tty); | |
763 | } | |
764 | ||
af9b897e | 765 | /** |
796a75a9 JS |
766 | * stop_tty - propagate flow control |
767 | * @tty: tty to stop | |
af9b897e | 768 | * |
796a75a9 JS |
769 | * Perform flow control to the driver. May be called on an already stopped |
770 | * device and will not re-call the &tty_driver->stop() method. | |
af9b897e | 771 | * |
796a75a9 JS |
772 | * This functionality is used by both the line disciplines for halting incoming |
773 | * flow and by the driver. It may therefore be called from any context, may be | |
774 | * under the tty %atomic_write_lock but not always. | |
af9b897e | 775 | * |
796a75a9 JS |
776 | * Locking: |
777 | * flow.lock | |
af9b897e | 778 | */ |
f9e053dc PH |
779 | void stop_tty(struct tty_struct *tty) |
780 | { | |
781 | unsigned long flags; | |
782 | ||
6e94dbc7 | 783 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 784 | __stop_tty(tty); |
6e94dbc7 | 785 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 786 | } |
1da177e4 LT |
787 | EXPORT_SYMBOL(stop_tty); |
788 | ||
d06e256f JS |
789 | void __start_tty(struct tty_struct *tty) |
790 | { | |
791 | if (!tty->flow.stopped || tty->flow.tco_stopped) | |
792 | return; | |
793 | tty->flow.stopped = false; | |
794 | if (tty->ops->start) | |
795 | tty->ops->start(tty); | |
796 | tty_wakeup(tty); | |
797 | } | |
798 | ||
af9b897e | 799 | /** |
796a75a9 JS |
800 | * start_tty - propagate flow control |
801 | * @tty: tty to start | |
af9b897e | 802 | * |
796a75a9 JS |
803 | * Start a tty that has been stopped if at all possible. If @tty was previously |
804 | * stopped and is now being started, the &tty_driver->start() method is invoked | |
805 | * and the line discipline woken. | |
af9b897e | 806 | * |
796a75a9 JS |
807 | * Locking: |
808 | * flow.lock | |
af9b897e | 809 | */ |
f9e053dc PH |
810 | void start_tty(struct tty_struct *tty) |
811 | { | |
812 | unsigned long flags; | |
813 | ||
6e94dbc7 | 814 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 815 | __start_tty(tty); |
6e94dbc7 | 816 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 817 | } |
1da177e4 LT |
818 | EXPORT_SYMBOL(start_tty); |
819 | ||
c884f871 | 820 | static void tty_update_time(struct timespec64 *time) |
37b7f3c7 | 821 | { |
c884f871 | 822 | time64_t sec = ktime_get_real_seconds(); |
fbf47635 GKH |
823 | |
824 | /* | |
825 | * We only care if the two values differ in anything other than the | |
826 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
827 | * the time of the tty device, otherwise it could be construded as a | |
828 | * security leak to let userspace know the exact timing of the tty. | |
829 | */ | |
830 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
831 | time->tv_sec = sec; |
832 | } | |
833 | ||
3b830a9c LT |
834 | /* |
835 | * Iterate on the ldisc ->read() function until we've gotten all | |
836 | * the data the ldisc has for us. | |
837 | * | |
838 | * The "cookie" is something that the ldisc read function can fill | |
839 | * in to let us know that there is more data to be had. | |
840 | * | |
841 | * We promise to continue to call the ldisc until it stops returning | |
842 | * data or clears the cookie. The cookie may be something that the | |
843 | * ldisc maintains state for and needs to free. | |
844 | */ | |
dd78b0c4 LT |
845 | static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, |
846 | struct file *file, struct iov_iter *to) | |
3b830a9c LT |
847 | { |
848 | int retval = 0; | |
849 | void *cookie = NULL; | |
850 | unsigned long offset = 0; | |
851 | char kernel_buf[64]; | |
dd78b0c4 | 852 | size_t count = iov_iter_count(to); |
3b830a9c LT |
853 | |
854 | do { | |
dd78b0c4 | 855 | int size, copied; |
3b830a9c LT |
856 | |
857 | size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count; | |
858 | size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); | |
859 | if (!size) | |
860 | break; | |
861 | ||
3b830a9c | 862 | if (size < 0) { |
e71a8d5c LT |
863 | /* Did we have an earlier error (ie -EFAULT)? */ |
864 | if (retval) | |
865 | break; | |
866 | retval = size; | |
867 | ||
868 | /* | |
869 | * -EOVERFLOW means we didn't have enough space | |
870 | * for a whole packet, and we shouldn't return | |
871 | * a partial result. | |
872 | */ | |
873 | if (retval == -EOVERFLOW) | |
874 | offset = 0; | |
875 | break; | |
3b830a9c LT |
876 | } |
877 | ||
dd78b0c4 LT |
878 | copied = copy_to_iter(kernel_buf, size, to); |
879 | offset += copied; | |
880 | count -= copied; | |
3b830a9c LT |
881 | |
882 | /* | |
883 | * If the user copy failed, we still need to do another ->read() | |
884 | * call if we had a cookie to let the ldisc clear up. | |
885 | * | |
886 | * But make sure size is zeroed. | |
887 | */ | |
dd78b0c4 | 888 | if (unlikely(copied != size)) { |
3b830a9c LT |
889 | count = 0; |
890 | retval = -EFAULT; | |
891 | } | |
892 | } while (cookie); | |
893 | ||
894 | /* We always clear tty buffer in case they contained passwords */ | |
895 | memzero_explicit(kernel_buf, sizeof(kernel_buf)); | |
896 | return offset ? offset : retval; | |
897 | } | |
898 | ||
899 | ||
af9b897e | 900 | /** |
796a75a9 JS |
901 | * tty_read - read method for tty device files |
902 | * @iocb: kernel I/O control block | |
903 | * @to: destination for the data read | |
af9b897e | 904 | * |
796a75a9 JS |
905 | * Perform the read system call function on this terminal device. Checks |
906 | * for hung up devices before calling the line discipline method. | |
af9b897e | 907 | * |
796a75a9 JS |
908 | * Locking: |
909 | * Locks the line discipline internally while needed. Multiple read calls | |
910 | * may be outstanding in parallel. | |
af9b897e | 911 | */ |
dd78b0c4 | 912 | static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 LT |
913 | { |
914 | int i; | |
dd78b0c4 | 915 | struct file *file = iocb->ki_filp; |
37b7f3c7 | 916 | struct inode *inode = file_inode(file); |
d996b62a | 917 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
918 | struct tty_ldisc *ld; |
919 | ||
37b7f3c7 | 920 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 921 | return -EIO; |
18900ca6 | 922 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
923 | return -EIO; |
924 | ||
925 | /* We want to wait for the line discipline to sort out in this | |
b426a5b8 XT |
926 | * situation. |
927 | */ | |
1da177e4 | 928 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 | 929 | if (!ld) |
ddc5fda7 | 930 | return hung_up_tty_read(iocb, to); |
3b830a9c | 931 | i = -EIO; |
a352def2 | 932 | if (ld->ops->read) |
dd78b0c4 | 933 | i = iterate_tty_read(ld, tty, file, to); |
1da177e4 | 934 | tty_ldisc_deref(ld); |
b0de59b5 | 935 | |
c884f871 AB |
936 | if (i > 0) |
937 | tty_update_time(&inode->i_atime); | |
37b7f3c7 | 938 | |
1da177e4 LT |
939 | return i; |
940 | } | |
941 | ||
136d5258 | 942 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
943 | { |
944 | mutex_unlock(&tty->atomic_write_lock); | |
a9a08845 | 945 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
9c1729db AC |
946 | } |
947 | ||
136d5258 | 948 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
949 | { |
950 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
951 | if (ndelay) | |
952 | return -EAGAIN; | |
953 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
954 | return -ERESTARTSYS; | |
955 | } | |
956 | return 0; | |
957 | } | |
958 | ||
1da177e4 LT |
959 | /* |
960 | * Split writes up in sane blocksizes to avoid | |
961 | * denial-of-service type attacks | |
962 | */ | |
963 | static inline ssize_t do_tty_write( | |
964 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
965 | struct tty_struct *tty, | |
966 | struct file *file, | |
9bb48c82 | 967 | struct iov_iter *from) |
1da177e4 | 968 | { |
9bb48c82 | 969 | size_t count = iov_iter_count(from); |
9c1729db | 970 | ssize_t ret, written = 0; |
1da177e4 | 971 | unsigned int chunk; |
37bdfb07 | 972 | |
9c1729db AC |
973 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
974 | if (ret < 0) | |
975 | return ret; | |
1da177e4 LT |
976 | |
977 | /* | |
978 | * We chunk up writes into a temporary buffer. This | |
979 | * simplifies low-level drivers immensely, since they | |
980 | * don't have locking issues and user mode accesses. | |
981 | * | |
982 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
983 | * big chunk-size.. | |
984 | * | |
985 | * The default chunk-size is 2kB, because the NTTY | |
986 | * layer has problems with bigger chunks. It will | |
987 | * claim to be able to handle more characters than | |
988 | * it actually does. | |
989 | */ | |
990 | chunk = 2048; | |
991 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
992 | chunk = 65536; | |
993 | if (count < chunk) | |
994 | chunk = count; | |
995 | ||
70522e12 | 996 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 997 | if (tty->write_cnt < chunk) { |
402fda92 | 998 | unsigned char *buf_chunk; |
1da177e4 LT |
999 | |
1000 | if (chunk < 1024) | |
1001 | chunk = 1024; | |
1002 | ||
d6d9d17a | 1003 | buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL); |
402fda92 | 1004 | if (!buf_chunk) { |
9c1729db AC |
1005 | ret = -ENOMEM; |
1006 | goto out; | |
1da177e4 | 1007 | } |
d6d9d17a | 1008 | kvfree(tty->write_buf); |
1da177e4 | 1009 | tty->write_cnt = chunk; |
402fda92 | 1010 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1011 | } |
1012 | ||
1013 | /* Do the write .. */ | |
1014 | for (;;) { | |
1015 | size_t size = count; | |
e73b2407 | 1016 | |
1da177e4 LT |
1017 | if (size > chunk) |
1018 | size = chunk; | |
9bb48c82 | 1019 | |
1da177e4 | 1020 | ret = -EFAULT; |
9bb48c82 | 1021 | if (copy_from_iter(tty->write_buf, size, from) != size) |
1da177e4 | 1022 | break; |
9bb48c82 | 1023 | |
1da177e4 | 1024 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1025 | if (ret <= 0) |
1026 | break; | |
9bb48c82 | 1027 | |
3342ff26 LT |
1028 | written += ret; |
1029 | if (ret > size) | |
1030 | break; | |
1031 | ||
9bb48c82 LT |
1032 | /* FIXME! Have Al check this! */ |
1033 | if (ret != size) | |
1034 | iov_iter_revert(from, size-ret); | |
1035 | ||
1da177e4 LT |
1036 | count -= ret; |
1037 | if (!count) | |
1038 | break; | |
1039 | ret = -ERESTARTSYS; | |
1040 | if (signal_pending(current)) | |
1041 | break; | |
1042 | cond_resched(); | |
1043 | } | |
37b7f3c7 | 1044 | if (written) { |
c884f871 | 1045 | tty_update_time(&file_inode(file)->i_mtime); |
1da177e4 | 1046 | ret = written; |
37b7f3c7 | 1047 | } |
9c1729db AC |
1048 | out: |
1049 | tty_write_unlock(tty); | |
1da177e4 LT |
1050 | return ret; |
1051 | } | |
1052 | ||
95f9bfc6 AC |
1053 | /** |
1054 | * tty_write_message - write a message to a certain tty, not just the console. | |
1055 | * @tty: the destination tty_struct | |
1056 | * @msg: the message to write | |
1057 | * | |
796a75a9 JS |
1058 | * This is used for messages that need to be redirected to a specific tty. We |
1059 | * don't put it into the syslog queue right now maybe in the future if really | |
1060 | * needed. | |
95f9bfc6 | 1061 | * |
ec79d605 | 1062 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 | 1063 | */ |
95f9bfc6 AC |
1064 | void tty_write_message(struct tty_struct *tty, char *msg) |
1065 | { | |
95f9bfc6 AC |
1066 | if (tty) { |
1067 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1068 | tty_lock(tty); |
4b41b953 | 1069 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1070 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1071 | tty_unlock(tty); |
95f9bfc6 AC |
1072 | tty_write_unlock(tty); |
1073 | } | |
95f9bfc6 AC |
1074 | } |
1075 | ||
a9cbbb80 | 1076 | static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) |
1da177e4 | 1077 | { |
d996b62a | 1078 | struct tty_struct *tty = file_tty(file); |
395e7833 | 1079 | struct tty_ldisc *ld; |
1da177e4 | 1080 | ssize_t ret; |
37bdfb07 | 1081 | |
6131ffaa | 1082 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1083 | return -EIO; |
18900ca6 | 1084 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
5e4d5ac3 | 1085 | return -EIO; |
f34d7a5b AC |
1086 | /* Short term debug to catch buggy drivers */ |
1087 | if (tty->ops->write_room == NULL) | |
339f36ba | 1088 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1089 | ld = tty_ldisc_ref_wait(tty); |
17749851 LT |
1090 | if (!ld) |
1091 | return hung_up_tty_write(iocb, from); | |
1092 | if (!ld->ops->write) | |
1da177e4 LT |
1093 | ret = -EIO; |
1094 | else | |
9bb48c82 | 1095 | ret = do_tty_write(ld->ops->write, tty, file, from); |
1da177e4 LT |
1096 | tty_ldisc_deref(ld); |
1097 | return ret; | |
1098 | } | |
1099 | ||
756a4e4a | 1100 | /** |
796a75a9 JS |
1101 | * tty_write - write method for tty device file |
1102 | * @iocb: kernel I/O control block | |
1103 | * @from: iov_iter with data to write | |
756a4e4a | 1104 | * |
796a75a9 | 1105 | * Write data to a tty device via the line discipline. |
756a4e4a | 1106 | * |
796a75a9 JS |
1107 | * Locking: |
1108 | * Locks the line discipline as required | |
1109 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1110 | * and are then processed in chunks to the device. The line | |
1111 | * discipline write method will not be invoked in parallel for | |
1112 | * each device. | |
756a4e4a | 1113 | */ |
a9cbbb80 LT |
1114 | static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) |
1115 | { | |
1116 | return file_tty_write(iocb->ki_filp, iocb, from); | |
1117 | } | |
1118 | ||
9bb48c82 | 1119 | ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 LT |
1120 | { |
1121 | struct file *p = NULL; | |
1122 | ||
1123 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1124 | if (redirect) |
1125 | p = get_file(redirect); | |
1da177e4 LT |
1126 | spin_unlock(&redirect_lock); |
1127 | ||
a9cbbb80 | 1128 | /* |
44969f85 | 1129 | * We know the redirected tty is just another tty, we can |
a9cbbb80 LT |
1130 | * call file_tty_write() directly with that file pointer. |
1131 | */ | |
1da177e4 LT |
1132 | if (p) { |
1133 | ssize_t res; | |
e73b2407 | 1134 | |
a9cbbb80 | 1135 | res = file_tty_write(p, iocb, iter); |
1da177e4 LT |
1136 | fput(p); |
1137 | return res; | |
1138 | } | |
9bb48c82 | 1139 | return tty_write(iocb, iter); |
1da177e4 LT |
1140 | } |
1141 | ||
796a75a9 JS |
1142 | /** |
1143 | * tty_send_xchar - send priority character | |
1144 | * @tty: the tty to send to | |
1145 | * @ch: xchar to send | |
136d5258 | 1146 | * |
796a75a9 | 1147 | * Send a high priority character to the tty even if stopped. |
136d5258 | 1148 | * |
796a75a9 | 1149 | * Locking: none for xchar method, write ordering for write method. |
136d5258 | 1150 | */ |
136d5258 PH |
1151 | int tty_send_xchar(struct tty_struct *tty, char ch) |
1152 | { | |
6e94dbc7 | 1153 | bool was_stopped = tty->flow.stopped; |
136d5258 PH |
1154 | |
1155 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1156 | down_read(&tty->termios_rwsem); |
136d5258 | 1157 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1158 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1159 | return 0; |
1160 | } | |
1161 | ||
1162 | if (tty_write_lock(tty, 0) < 0) | |
1163 | return -ERESTARTSYS; | |
1164 | ||
ee0c1a65 | 1165 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1166 | if (was_stopped) |
1167 | start_tty(tty); | |
1168 | tty->ops->write(tty, &ch, 1); | |
1169 | if (was_stopped) | |
1170 | stop_tty(tty); | |
ee0c1a65 | 1171 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1172 | tty_write_unlock(tty); |
1173 | return 0; | |
1174 | } | |
1175 | ||
af9b897e | 1176 | /** |
796a75a9 JS |
1177 | * pty_line_name - generate name for a pty |
1178 | * @driver: the tty driver in use | |
1179 | * @index: the minor number | |
1180 | * @p: output buffer of at least 6 bytes | |
af9b897e | 1181 | * |
796a75a9 JS |
1182 | * Generate a name from a @driver reference and write it to the output buffer |
1183 | * @p. | |
af9b897e | 1184 | * |
796a75a9 | 1185 | * Locking: None |
af9b897e AC |
1186 | */ |
1187 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 | 1188 | { |
a846dcf9 | 1189 | static const char ptychar[] = "pqrstuvwxyzabcde"; |
1da177e4 LT |
1190 | int i = index + driver->name_base; |
1191 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1192 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1193 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1194 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1195 | } |
1196 | ||
af9b897e | 1197 | /** |
796a75a9 JS |
1198 | * tty_line_name - generate name for a tty |
1199 | * @driver: the tty driver in use | |
1200 | * @index: the minor number | |
1201 | * @p: output buffer of at least 7 bytes | |
af9b897e | 1202 | * |
796a75a9 JS |
1203 | * Generate a name from a @driver reference and write it to the output buffer |
1204 | * @p. | |
af9b897e | 1205 | * |
796a75a9 | 1206 | * Locking: None |
af9b897e | 1207 | */ |
723abd87 | 1208 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1209 | { |
0019b408 | 1210 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1211 | return sprintf(p, "%s", driver->name); |
0019b408 | 1212 | else |
723abd87 HR |
1213 | return sprintf(p, "%s%d", driver->name, |
1214 | index + driver->name_base); | |
1da177e4 LT |
1215 | } |
1216 | ||
99f1fe18 | 1217 | /** |
796a75a9 JS |
1218 | * tty_driver_lookup_tty() - find an existing tty, if any |
1219 | * @driver: the driver for the tty | |
1220 | * @file: file object | |
1221 | * @idx: the minor number | |
23499705 | 1222 | * |
796a75a9 JS |
1223 | * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the |
1224 | * driver lookup() method returns an error. | |
23499705 | 1225 | * |
796a75a9 | 1226 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1227 | */ |
a47d545f | 1228 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1229 | struct file *file, int idx) |
23499705 | 1230 | { |
aa3cb814 PH |
1231 | struct tty_struct *tty; |
1232 | ||
99f1fe18 | 1233 | if (driver->ops->lookup) |
12e84c71 OK |
1234 | if (!file) |
1235 | tty = ERR_PTR(-EIO); | |
1236 | else | |
1237 | tty = driver->ops->lookup(driver, file, idx); | |
aa3cb814 PH |
1238 | else |
1239 | tty = driver->ttys[idx]; | |
23499705 | 1240 | |
aa3cb814 PH |
1241 | if (!IS_ERR(tty)) |
1242 | tty_kref_get(tty); | |
1243 | return tty; | |
23499705 SB |
1244 | } |
1245 | ||
bf970ee4 | 1246 | /** |
796a75a9 JS |
1247 | * tty_init_termios - helper for termios setup |
1248 | * @tty: the tty to set up | |
bf970ee4 | 1249 | * |
796a75a9 JS |
1250 | * Initialise the termios structure for this tty. This runs under the |
1251 | * %tty_mutex currently so we can be relaxed about ordering. | |
bf970ee4 | 1252 | */ |
a3123fd0 | 1253 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1254 | { |
fe6e29fd | 1255 | struct ktermios *tp; |
bf970ee4 AC |
1256 | int idx = tty->index; |
1257 | ||
36b3c070 AC |
1258 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1259 | tty->termios = tty->driver->init_termios; | |
1260 | else { | |
1261 | /* Check for lazy saved data */ | |
1262 | tp = tty->driver->termios[idx]; | |
ece53405 | 1263 | if (tp != NULL) { |
36b3c070 | 1264 | tty->termios = *tp; |
ece53405 PH |
1265 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1266 | } else | |
36b3c070 | 1267 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1268 | } |
bf970ee4 | 1269 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1270 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1271 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1272 | } |
fe1ae7fd | 1273 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1274 | |
31bc35d3 JS |
1275 | /** |
1276 | * tty_standard_install - usual tty->ops->install | |
1277 | * @driver: the driver for the tty | |
1278 | * @tty: the tty | |
1279 | * | |
1280 | * If the @driver overrides @tty->ops->install, it still can call this function | |
1281 | * to perform the standard install operations. | |
1282 | */ | |
66d450e8 JS |
1283 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1284 | { | |
a3123fd0 | 1285 | tty_init_termios(tty); |
66d450e8 JS |
1286 | tty_driver_kref_get(driver); |
1287 | tty->count++; | |
1288 | driver->ttys[tty->index] = tty; | |
1289 | return 0; | |
1290 | } | |
1291 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1292 | ||
99f1fe18 | 1293 | /** |
796a75a9 JS |
1294 | * tty_driver_install_tty() - install a tty entry in the driver |
1295 | * @driver: the driver for the tty | |
1296 | * @tty: the tty | |
8b0a88d5 | 1297 | * |
796a75a9 JS |
1298 | * Install a tty object into the driver tables. The @tty->index field will be |
1299 | * set by the time this is called. This method is responsible for ensuring any | |
1300 | * need additional structures are allocated and configured. | |
8b0a88d5 | 1301 | * |
796a75a9 | 1302 | * Locking: tty_mutex for now |
8b0a88d5 AC |
1303 | */ |
1304 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1305 | struct tty_struct *tty) | |
1306 | { | |
66d450e8 JS |
1307 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1308 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1309 | } |
1310 | ||
1311 | /** | |
796a75a9 JS |
1312 | * tty_driver_remove_tty() - remove a tty from the driver tables |
1313 | * @driver: the driver for the tty | |
1314 | * @tty: tty to remove | |
8b0a88d5 | 1315 | * |
796a75a9 JS |
1316 | * Remove a tty object from the driver tables. The tty->index field will be set |
1317 | * by the time this is called. | |
8b0a88d5 | 1318 | * |
796a75a9 | 1319 | * Locking: tty_mutex for now |
8b0a88d5 | 1320 | */ |
05de87ed | 1321 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1322 | { |
1323 | if (driver->ops->remove) | |
1324 | driver->ops->remove(driver, tty); | |
1325 | else | |
1326 | driver->ttys[tty->index] = NULL; | |
1327 | } | |
1328 | ||
fa441954 | 1329 | /** |
796a75a9 JS |
1330 | * tty_reopen() - fast re-open of an open tty |
1331 | * @tty: the tty to open | |
23499705 | 1332 | * |
796a75a9 | 1333 | * Re-opens on master ptys are not allowed and return -%EIO. |
23499705 | 1334 | * |
796a75a9 JS |
1335 | * Locking: Caller must hold tty_lock |
1336 | * Return: 0 on success, -errno on error. | |
23499705 | 1337 | */ |
99f1fe18 | 1338 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1339 | { |
1340 | struct tty_driver *driver = tty->driver; | |
d3736d82 DS |
1341 | struct tty_ldisc *ld; |
1342 | int retval = 0; | |
23499705 | 1343 | |
23499705 | 1344 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1345 | driver->subtype == PTY_TYPE_MASTER) |
1346 | return -EIO; | |
23499705 | 1347 | |
7f22f6c9 PH |
1348 | if (!tty->count) |
1349 | return -EAGAIN; | |
1350 | ||
86f2c00f PH |
1351 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1352 | return -EBUSY; | |
1353 | ||
d3736d82 DS |
1354 | ld = tty_ldisc_ref_wait(tty); |
1355 | if (ld) { | |
1356 | tty_ldisc_deref(ld); | |
1357 | } else { | |
1358 | retval = tty_ldisc_lock(tty, 5 * HZ); | |
1359 | if (retval) | |
1360 | return retval; | |
1361 | ||
1362 | if (!tty->ldisc) | |
1363 | retval = tty_ldisc_reinit(tty, tty->termios.c_line); | |
1364 | tty_ldisc_unlock(tty); | |
1365 | } | |
23499705 | 1366 | |
cf62a1a1 DS |
1367 | if (retval == 0) |
1368 | tty->count++; | |
fe324167 DS |
1369 | |
1370 | return retval; | |
23499705 SB |
1371 | } |
1372 | ||
af9b897e | 1373 | /** |
796a75a9 JS |
1374 | * tty_init_dev - initialise a tty device |
1375 | * @driver: tty driver we are opening a device on | |
1376 | * @idx: device index | |
af9b897e | 1377 | * |
796a75a9 JS |
1378 | * Prepare a tty device. This may not be a "new" clean device but could also be |
1379 | * an active device. The pty drivers require special handling because of this. | |
af9b897e | 1380 | * |
796a75a9 JS |
1381 | * Locking: |
1382 | * The function is called under the tty_mutex, which protects us from the | |
1383 | * tty struct or driver itself going away. | |
af9b897e | 1384 | * |
796a75a9 JS |
1385 | * On exit the tty device has the line discipline attached and a reference |
1386 | * count of 1. If a pair was created for pty/tty use and the other was a pty | |
1387 | * master then it too has a reference count of 1. | |
af9b897e | 1388 | * |
796a75a9 JS |
1389 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed |
1390 | * open. The new code protects the open with a mutex, so it's really quite | |
1391 | * straightforward. The mutex locking can probably be relaxed for the (most | |
1392 | * common) case of reopening a tty. | |
fa441954 | 1393 | * |
796a75a9 | 1394 | * Return: new tty structure |
1da177e4 | 1395 | */ |
593a27c4 | 1396 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1397 | { |
bf970ee4 | 1398 | struct tty_struct *tty; |
73ec06fc | 1399 | int retval; |
1da177e4 | 1400 | |
1da177e4 LT |
1401 | /* |
1402 | * First time open is complex, especially for PTY devices. | |
1403 | * This code guarantees that either everything succeeds and the | |
1404 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1405 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1406 | * may be retained.) |
1da177e4 LT |
1407 | */ |
1408 | ||
73ec06fc AC |
1409 | if (!try_module_get(driver->owner)) |
1410 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1411 | |
2c964a2f | 1412 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1413 | if (!tty) { |
1414 | retval = -ENOMEM; | |
1415 | goto err_module_put; | |
1416 | } | |
1da177e4 | 1417 | |
89c8d91e | 1418 | tty_lock(tty); |
73ec06fc | 1419 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1420 | if (retval < 0) |
c8b710b3 | 1421 | goto err_free_tty; |
8b0a88d5 | 1422 | |
04831dc1 JS |
1423 | if (!tty->port) |
1424 | tty->port = driver->ports[idx]; | |
1425 | ||
2ae0b31e JS |
1426 | if (WARN_RATELIMIT(!tty->port, |
1427 | "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", | |
1428 | __func__, tty->driver->name)) { | |
1429 | retval = -EINVAL; | |
1430 | goto err_release_lock; | |
1431 | } | |
5d4121c0 | 1432 | |
b027e229 GK |
1433 | retval = tty_ldisc_lock(tty, 5 * HZ); |
1434 | if (retval) | |
1435 | goto err_release_lock; | |
967fab69 JS |
1436 | tty->port->itty = tty; |
1437 | ||
37bdfb07 | 1438 | /* |
1da177e4 | 1439 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1440 | * If we fail here just call release_tty to clean up. No need |
1441 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1442 | */ |
bf970ee4 | 1443 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1444 | if (retval) |
d5543503 | 1445 | goto err_release_tty; |
b027e229 | 1446 | tty_ldisc_unlock(tty); |
89c8d91e | 1447 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1448 | return tty; |
1da177e4 | 1449 | |
c8b710b3 | 1450 | err_free_tty: |
89c8d91e | 1451 | tty_unlock(tty); |
d5543503 JS |
1452 | free_tty_struct(tty); |
1453 | err_module_put: | |
1da177e4 | 1454 | module_put(driver->owner); |
d5543503 | 1455 | return ERR_PTR(retval); |
1da177e4 | 1456 | |
d5698c28 | 1457 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1458 | err_release_tty: |
b027e229 | 1459 | tty_ldisc_unlock(tty); |
339f36ba PH |
1460 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1461 | retval, idx); | |
b027e229 GK |
1462 | err_release_lock: |
1463 | tty_unlock(tty); | |
d5698c28 | 1464 | release_tty(tty, idx); |
73ec06fc | 1465 | return ERR_PTR(retval); |
1da177e4 LT |
1466 | } |
1467 | ||
f51ccf46 JH |
1468 | /** |
1469 | * tty_save_termios() - save tty termios data in driver table | |
1470 | * @tty: tty whose termios data to save | |
1471 | * | |
1472 | * Locking: Caller guarantees serialisation with tty_init_termios(). | |
1473 | */ | |
1474 | void tty_save_termios(struct tty_struct *tty) | |
feebed65 AC |
1475 | { |
1476 | struct ktermios *tp; | |
1477 | int idx = tty->index; | |
36b3c070 AC |
1478 | |
1479 | /* If the port is going to reset then it has no termios to save */ | |
1480 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1481 | return; | |
1482 | ||
1483 | /* Stash the termios data */ | |
1484 | tp = tty->driver->termios[idx]; | |
1485 | if (tp == NULL) { | |
a3241891 | 1486 | tp = kmalloc(sizeof(*tp), GFP_KERNEL); |
25080652 | 1487 | if (tp == NULL) |
36b3c070 | 1488 | return; |
4ac5d705 | 1489 | tty->driver->termios[idx] = tp; |
feebed65 | 1490 | } |
36b3c070 | 1491 | *tp = tty->termios; |
feebed65 | 1492 | } |
f51ccf46 | 1493 | EXPORT_SYMBOL_GPL(tty_save_termios); |
feebed65 | 1494 | |
a2965b7b | 1495 | /** |
796a75a9 JS |
1496 | * tty_flush_works - flush all works of a tty/pty pair |
1497 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1498 | * |
796a75a9 | 1499 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1500 | */ |
1501 | static void tty_flush_works(struct tty_struct *tty) | |
1502 | { | |
1503 | flush_work(&tty->SAK_work); | |
1504 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1505 | if (tty->link) { |
1506 | flush_work(&tty->link->SAK_work); | |
1507 | flush_work(&tty->link->hangup_work); | |
1508 | } | |
a2965b7b | 1509 | } |
feebed65 | 1510 | |
af9b897e | 1511 | /** |
796a75a9 JS |
1512 | * release_one_tty - release tty structure memory |
1513 | * @work: work of tty we are obliterating | |
af9b897e | 1514 | * |
796a75a9 JS |
1515 | * Releases memory associated with a tty structure, and clears out the |
1516 | * driver table slots. This function is called when a device is no longer | |
1517 | * in use. It also gets called when setup of a device fails. | |
af9b897e | 1518 | * |
796a75a9 JS |
1519 | * Locking: |
1520 | * takes the file list lock internally when working on the list of ttys | |
1521 | * that the driver keeps. | |
b50989dc | 1522 | * |
796a75a9 JS |
1523 | * This method gets called from a work queue so that the driver private |
1524 | * cleanup ops can sleep (needed for USB at least) | |
1da177e4 | 1525 | */ |
b50989dc | 1526 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1527 | { |
b50989dc AC |
1528 | struct tty_struct *tty = |
1529 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1530 | struct tty_driver *driver = tty->driver; |
b216df53 | 1531 | struct module *owner = driver->owner; |
d5698c28 | 1532 | |
f278a2f7 DY |
1533 | if (tty->ops->cleanup) |
1534 | tty->ops->cleanup(tty); | |
1535 | ||
1da177e4 | 1536 | tty->magic = 0; |
7d7b93c1 | 1537 | tty_driver_kref_put(driver); |
b216df53 | 1538 | module_put(owner); |
d5698c28 | 1539 | |
4a510969 | 1540 | spin_lock(&tty->files_lock); |
1da177e4 | 1541 | list_del_init(&tty->tty_files); |
4a510969 | 1542 | spin_unlock(&tty->files_lock); |
d5698c28 | 1543 | |
64d608db JS |
1544 | put_pid(tty->ctrl.pgrp); |
1545 | put_pid(tty->ctrl.session); | |
1da177e4 LT |
1546 | free_tty_struct(tty); |
1547 | } | |
1548 | ||
b50989dc AC |
1549 | static void queue_release_one_tty(struct kref *kref) |
1550 | { | |
1551 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1552 | |
b50989dc | 1553 | /* The hangup queue is now free so we can reuse it rather than |
b426a5b8 XT |
1554 | * waste a chunk of memory for each port. |
1555 | */ | |
b50989dc AC |
1556 | INIT_WORK(&tty->hangup_work, release_one_tty); |
1557 | schedule_work(&tty->hangup_work); | |
1558 | } | |
1559 | ||
9c9f4ded | 1560 | /** |
796a75a9 JS |
1561 | * tty_kref_put - release a tty kref |
1562 | * @tty: tty device | |
9c9f4ded | 1563 | * |
796a75a9 JS |
1564 | * Release a reference to the @tty device and if need be let the kref layer |
1565 | * destruct the object for us. | |
9c9f4ded | 1566 | */ |
9c9f4ded AC |
1567 | void tty_kref_put(struct tty_struct *tty) |
1568 | { | |
1569 | if (tty) | |
b50989dc | 1570 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1571 | } |
1572 | EXPORT_SYMBOL(tty_kref_put); | |
1573 | ||
d5698c28 | 1574 | /** |
796a75a9 JS |
1575 | * release_tty - release tty structure memory |
1576 | * @tty: tty device release | |
1577 | * @idx: index of the tty device release | |
d5698c28 | 1578 | * |
796a75a9 JS |
1579 | * Release both @tty and a possible linked partner (think pty pair), |
1580 | * and decrement the refcount of the backing module. | |
9c9f4ded | 1581 | * |
796a75a9 JS |
1582 | * Locking: |
1583 | * tty_mutex | |
1584 | * takes the file list lock internally when working on the list of ttys | |
1585 | * that the driver keeps. | |
d5698c28 CH |
1586 | */ |
1587 | static void release_tty(struct tty_struct *tty, int idx) | |
1588 | { | |
9c9f4ded AC |
1589 | /* This should always be true but check for the moment */ |
1590 | WARN_ON(tty->index != idx); | |
d155255a | 1591 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1592 | if (tty->ops->shutdown) |
1593 | tty->ops->shutdown(tty); | |
f51ccf46 | 1594 | tty_save_termios(tty); |
36b3c070 | 1595 | tty_driver_remove_tty(tty->driver, tty); |
4466d6d2 MR |
1596 | if (tty->port) |
1597 | tty->port->itty = NULL; | |
64e377dc PH |
1598 | if (tty->link) |
1599 | tty->link->port->itty = NULL; | |
4466d6d2 MR |
1600 | if (tty->port) |
1601 | tty_buffer_cancel_work(tty->port); | |
2b022ab7 S |
1602 | if (tty->link) |
1603 | tty_buffer_cancel_work(tty->link->port); | |
36b3c070 | 1604 | |
a211b1af | 1605 | tty_kref_put(tty->link); |
9c9f4ded | 1606 | tty_kref_put(tty); |
d5698c28 CH |
1607 | } |
1608 | ||
955787ca | 1609 | /** |
796a75a9 JS |
1610 | * tty_release_checks - check a tty before real release |
1611 | * @tty: tty to check | |
1612 | * @idx: index of the tty | |
955787ca | 1613 | * |
796a75a9 JS |
1614 | * Performs some paranoid checking before true release of the @tty. This is a |
1615 | * no-op unless %TTY_PARANOIA_CHECK is defined. | |
955787ca | 1616 | */ |
359b9fb5 | 1617 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1618 | { |
1619 | #ifdef TTY_PARANOIA_CHECK | |
1620 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1621 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1622 | return -1; |
1623 | } | |
1624 | ||
1625 | /* not much to check for devpts */ | |
1626 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1627 | return 0; | |
1628 | ||
1629 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1630 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1631 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1632 | return -1; |
1633 | } | |
955787ca | 1634 | if (tty->driver->other) { |
359b9fb5 PH |
1635 | struct tty_struct *o_tty = tty->link; |
1636 | ||
955787ca | 1637 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1638 | tty_debug(tty, "bad other table[%d] = %p\n", |
1639 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1640 | return -1; |
1641 | } | |
955787ca | 1642 | if (o_tty->link != tty) { |
e2dfa3d3 | 1643 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1644 | return -1; |
1645 | } | |
1646 | } | |
1647 | #endif | |
1648 | return 0; | |
1649 | } | |
1650 | ||
a09ac397 | 1651 | /** |
796a75a9 JS |
1652 | * tty_kclose - closes tty opened by tty_kopen |
1653 | * @tty: tty device | |
a09ac397 | 1654 | * |
796a75a9 JS |
1655 | * Performs the final steps to release and free a tty device. It is the same as |
1656 | * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on | |
1657 | * @tty->port. | |
a09ac397 OK |
1658 | */ |
1659 | void tty_kclose(struct tty_struct *tty) | |
1660 | { | |
1661 | /* | |
1662 | * Ask the line discipline code to release its structures | |
1663 | */ | |
1664 | tty_ldisc_release(tty); | |
1665 | ||
1666 | /* Wait for pending work before tty destruction commmences */ | |
1667 | tty_flush_works(tty); | |
1668 | ||
1669 | tty_debug_hangup(tty, "freeing structure\n"); | |
1670 | /* | |
1671 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1672 | * the slots and preserving the termios structure. |
a09ac397 OK |
1673 | */ |
1674 | mutex_lock(&tty_mutex); | |
1675 | tty_port_set_kopened(tty->port, 0); | |
1676 | release_tty(tty, tty->index); | |
1677 | mutex_unlock(&tty_mutex); | |
1678 | } | |
1679 | EXPORT_SYMBOL_GPL(tty_kclose); | |
1680 | ||
9ed90d20 | 1681 | /** |
796a75a9 JS |
1682 | * tty_release_struct - release a tty struct |
1683 | * @tty: tty device | |
1684 | * @idx: index of the tty | |
9ed90d20 | 1685 | * |
796a75a9 JS |
1686 | * Performs the final steps to release and free a tty device. It is roughly the |
1687 | * reverse of tty_init_dev(). | |
9ed90d20 RH |
1688 | */ |
1689 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1690 | { | |
1691 | /* | |
1692 | * Ask the line discipline code to release its structures | |
1693 | */ | |
1694 | tty_ldisc_release(tty); | |
1695 | ||
1696 | /* Wait for pending work before tty destruction commmences */ | |
1697 | tty_flush_works(tty); | |
1698 | ||
1699 | tty_debug_hangup(tty, "freeing structure\n"); | |
1700 | /* | |
1701 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1702 | * the slots and preserving the termios structure. |
9ed90d20 RH |
1703 | */ |
1704 | mutex_lock(&tty_mutex); | |
1705 | release_tty(tty, idx); | |
1706 | mutex_unlock(&tty_mutex); | |
1707 | } | |
1708 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1709 | ||
eeb89d91 | 1710 | /** |
796a75a9 JS |
1711 | * tty_release - vfs callback for close |
1712 | * @inode: inode of tty | |
1713 | * @filp: file pointer for handle to tty | |
eeb89d91 | 1714 | * |
796a75a9 JS |
1715 | * Called the last time each file handle is closed that references this tty. |
1716 | * There may however be several such references. | |
eeb89d91 | 1717 | * |
796a75a9 JS |
1718 | * Locking: |
1719 | * Takes BKL. See tty_release_dev(). | |
eeb89d91 | 1720 | * |
796a75a9 JS |
1721 | * Even releasing the tty structures is a tricky business. We have to be very |
1722 | * careful that the structures are all released at the same time, as interrupts | |
1723 | * might otherwise get the wrong pointers. | |
1da177e4 LT |
1724 | * |
1725 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1726 | * lead to double frees or releasing memory still in use. | |
1727 | */ | |
eeb89d91 | 1728 | int tty_release(struct inode *inode, struct file *filp) |
1da177e4 | 1729 | { |
d996b62a | 1730 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1731 | struct tty_struct *o_tty = NULL; |
1732 | int do_sleep, final; | |
1da177e4 | 1733 | int idx; |
37b16457 | 1734 | long timeout = 0; |
494c1eac | 1735 | int once = 1; |
37bdfb07 | 1736 | |
9de44bd6 | 1737 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1738 | return 0; |
1da177e4 | 1739 | |
89c8d91e | 1740 | tty_lock(tty); |
9de44bd6 | 1741 | check_tty_count(tty, __func__); |
1da177e4 | 1742 | |
ec79d605 | 1743 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1744 | |
1745 | idx = tty->index; | |
7ffb6da9 PH |
1746 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1747 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1748 | o_tty = tty->link; | |
1da177e4 | 1749 | |
359b9fb5 | 1750 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1751 | tty_unlock(tty); |
eeb89d91 | 1752 | return 0; |
1da177e4 | 1753 | } |
1da177e4 | 1754 | |
d435cefe | 1755 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1756 | |
f34d7a5b AC |
1757 | if (tty->ops->close) |
1758 | tty->ops->close(tty, filp); | |
1da177e4 | 1759 | |
2aff5e2b PH |
1760 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1761 | tty_lock_slave(o_tty); | |
1762 | ||
1da177e4 LT |
1763 | /* |
1764 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1765 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1766 | * wait queues and kick everyone out _before_ actually starting to | |
1767 | * close. This ensures that we won't block while releasing the tty | |
1768 | * structure. | |
1769 | * | |
1770 | * The test for the o_tty closing is necessary, since the master and | |
1771 | * slave sides may close in any order. If the slave side closes out | |
1772 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1773 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1774 | * so we do it now. |
1da177e4 LT |
1775 | */ |
1776 | while (1) { | |
1da177e4 LT |
1777 | do_sleep = 0; |
1778 | ||
324c1650 | 1779 | if (tty->count <= 1) { |
1da177e4 | 1780 | if (waitqueue_active(&tty->read_wait)) { |
a9a08845 | 1781 | wake_up_poll(&tty->read_wait, EPOLLIN); |
1da177e4 LT |
1782 | do_sleep++; |
1783 | } | |
1784 | if (waitqueue_active(&tty->write_wait)) { | |
a9a08845 | 1785 | wake_up_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1786 | do_sleep++; |
1787 | } | |
1788 | } | |
7ffb6da9 | 1789 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1790 | if (waitqueue_active(&o_tty->read_wait)) { |
a9a08845 | 1791 | wake_up_poll(&o_tty->read_wait, EPOLLIN); |
1da177e4 LT |
1792 | do_sleep++; |
1793 | } | |
1794 | if (waitqueue_active(&o_tty->write_wait)) { | |
a9a08845 | 1795 | wake_up_poll(&o_tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1796 | do_sleep++; |
1797 | } | |
1798 | } | |
1799 | if (!do_sleep) | |
1800 | break; | |
1801 | ||
494c1eac PH |
1802 | if (once) { |
1803 | once = 0; | |
339f36ba | 1804 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1805 | } |
37b16457 PH |
1806 | schedule_timeout_killable(timeout); |
1807 | if (timeout < 120 * HZ) | |
1808 | timeout = 2 * timeout + 1; | |
1809 | else | |
1810 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1811 | } |
1da177e4 | 1812 | |
7ffb6da9 | 1813 | if (o_tty) { |
1da177e4 | 1814 | if (--o_tty->count < 0) { |
339f36ba | 1815 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1816 | o_tty->count = 0; |
1817 | } | |
1818 | } | |
1819 | if (--tty->count < 0) { | |
339f36ba | 1820 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1821 | tty->count = 0; |
1822 | } | |
37bdfb07 | 1823 | |
1da177e4 LT |
1824 | /* |
1825 | * We've decremented tty->count, so we need to remove this file | |
1826 | * descriptor off the tty->tty_files list; this serves two | |
1827 | * purposes: | |
1828 | * - check_tty_count sees the correct number of file descriptors | |
1829 | * associated with this tty. | |
1830 | * - do_tty_hangup no longer sees this file descriptor as | |
1831 | * something that needs to be handled for hangups. | |
1832 | */ | |
d996b62a | 1833 | tty_del_file(filp); |
1da177e4 LT |
1834 | |
1835 | /* | |
1836 | * Perform some housekeeping before deciding whether to return. | |
1837 | * | |
1da177e4 LT |
1838 | * If _either_ side is closing, make sure there aren't any |
1839 | * processes that still think tty or o_tty is their controlling | |
1840 | * tty. | |
1841 | */ | |
324c1650 | 1842 | if (!tty->count) { |
1da177e4 | 1843 | read_lock(&tasklist_lock); |
64d608db | 1844 | session_clear_tty(tty->ctrl.session); |
7ffb6da9 | 1845 | if (o_tty) |
64d608db | 1846 | session_clear_tty(o_tty->ctrl.session); |
1da177e4 LT |
1847 | read_unlock(&tasklist_lock); |
1848 | } | |
1849 | ||
324c1650 | 1850 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1851 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1852 | |
2aff5e2b PH |
1853 | tty_unlock_slave(o_tty); |
1854 | tty_unlock(tty); | |
1855 | ||
04980706 | 1856 | /* At this point, the tty->count == 0 should ensure a dead tty |
b426a5b8 XT |
1857 | * cannot be re-opened by a racing opener. |
1858 | */ | |
da965822 | 1859 | |
324c1650 | 1860 | if (!final) |
eeb89d91 | 1861 | return 0; |
37bdfb07 | 1862 | |
accff793 | 1863 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1864 | |
9ed90d20 | 1865 | tty_release_struct(tty, idx); |
eeb89d91 | 1866 | return 0; |
1da177e4 LT |
1867 | } |
1868 | ||
b82154ac | 1869 | /** |
796a75a9 JS |
1870 | * tty_open_current_tty - get locked tty of current task |
1871 | * @device: device number | |
1872 | * @filp: file pointer to tty | |
1873 | * @return: locked tty of the current task iff @device is /dev/tty | |
52494eeb | 1874 | * |
796a75a9 | 1875 | * Performs a re-open of the current task's controlling tty. |
b82154ac | 1876 | * |
796a75a9 JS |
1877 | * We cannot return driver and index like for the other nodes because devpts |
1878 | * will not work then. It expects inodes to be from devpts FS. | |
b82154ac JS |
1879 | */ |
1880 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1881 | { | |
1882 | struct tty_struct *tty; | |
52494eeb | 1883 | int retval; |
b82154ac JS |
1884 | |
1885 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1886 | return NULL; | |
1887 | ||
1888 | tty = get_current_tty(); | |
1889 | if (!tty) | |
1890 | return ERR_PTR(-ENXIO); | |
1891 | ||
1892 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1893 | /* noctty = 1; */ | |
52494eeb PH |
1894 | tty_lock(tty); |
1895 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1896 | ||
1897 | retval = tty_reopen(tty); | |
1898 | if (retval < 0) { | |
1899 | tty_unlock(tty); | |
1900 | tty = ERR_PTR(retval); | |
1901 | } | |
b82154ac JS |
1902 | return tty; |
1903 | } | |
1904 | ||
5b5e7040 | 1905 | /** |
796a75a9 JS |
1906 | * tty_lookup_driver - lookup a tty driver for a given device file |
1907 | * @device: device number | |
1908 | * @filp: file pointer to tty | |
1909 | * @index: index for the device in the @return driver | |
5b5e7040 | 1910 | * |
796a75a9 JS |
1911 | * If returned value is not erroneous, the caller is responsible to decrement |
1912 | * the refcount by tty_driver_kref_put(). | |
5b5e7040 | 1913 | * |
796a75a9 JS |
1914 | * Locking: %tty_mutex protects get_tty_driver() |
1915 | * | |
1916 | * Return: driver for this inode (with increased refcount) | |
5b5e7040 JS |
1917 | */ |
1918 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1919 | int *index) |
5b5e7040 | 1920 | { |
8c8af41d | 1921 | struct tty_driver *driver = NULL; |
5b5e7040 | 1922 | |
2cd0050c | 1923 | switch (device) { |
5b5e7040 | 1924 | #ifdef CONFIG_VT |
2cd0050c | 1925 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 | 1926 | extern struct tty_driver *console_driver; |
e73b2407 | 1927 | |
5b5e7040 JS |
1928 | driver = tty_driver_kref_get(console_driver); |
1929 | *index = fg_console; | |
2cd0050c | 1930 | break; |
5b5e7040 JS |
1931 | } |
1932 | #endif | |
2cd0050c | 1933 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 | 1934 | struct tty_driver *console_driver = console_device(index); |
e73b2407 | 1935 | |
5b5e7040 JS |
1936 | if (console_driver) { |
1937 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1938 | if (driver && filp) { |
5b5e7040 JS |
1939 | /* Don't let /dev/console block */ |
1940 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1941 | break; |
5b5e7040 JS |
1942 | } |
1943 | } | |
8c8af41d LY |
1944 | if (driver) |
1945 | tty_driver_kref_put(driver); | |
5b5e7040 JS |
1946 | return ERR_PTR(-ENODEV); |
1947 | } | |
2cd0050c JS |
1948 | default: |
1949 | driver = get_tty_driver(device, index); | |
1950 | if (!driver) | |
1951 | return ERR_PTR(-ENODEV); | |
1952 | break; | |
1953 | } | |
5b5e7040 JS |
1954 | return driver; |
1955 | } | |
1956 | ||
4ea3cd65 | 1957 | static struct tty_struct *tty_kopen(dev_t device, int shared) |
a09ac397 OK |
1958 | { |
1959 | struct tty_struct *tty; | |
f1d31743 | 1960 | struct tty_driver *driver; |
a09ac397 OK |
1961 | int index = -1; |
1962 | ||
1963 | mutex_lock(&tty_mutex); | |
1964 | driver = tty_lookup_driver(device, NULL, &index); | |
1965 | if (IS_ERR(driver)) { | |
1966 | mutex_unlock(&tty_mutex); | |
1967 | return ERR_CAST(driver); | |
1968 | } | |
1969 | ||
1970 | /* check whether we're reopening an existing tty */ | |
1971 | tty = tty_driver_lookup_tty(driver, NULL, index); | |
4ea3cd65 | 1972 | if (IS_ERR(tty) || shared) |
a09ac397 OK |
1973 | goto out; |
1974 | ||
1975 | if (tty) { | |
1976 | /* drop kref from tty_driver_lookup_tty() */ | |
1977 | tty_kref_put(tty); | |
1978 | tty = ERR_PTR(-EBUSY); | |
1979 | } else { /* tty_init_dev returns tty with the tty_lock held */ | |
1980 | tty = tty_init_dev(driver, index); | |
1981 | if (IS_ERR(tty)) | |
1982 | goto out; | |
1983 | tty_port_set_kopened(tty->port, 1); | |
1984 | } | |
1985 | out: | |
1986 | mutex_unlock(&tty_mutex); | |
1987 | tty_driver_kref_put(driver); | |
1988 | return tty; | |
1989 | } | |
4ea3cd65 UKK |
1990 | |
1991 | /** | |
796a75a9 JS |
1992 | * tty_kopen_exclusive - open a tty device for kernel |
1993 | * @device: dev_t of device to open | |
4ea3cd65 | 1994 | * |
796a75a9 JS |
1995 | * Opens tty exclusively for kernel. Performs the driver lookup, makes sure |
1996 | * it's not already opened and performs the first-time tty initialization. | |
4ea3cd65 | 1997 | * |
796a75a9 JS |
1998 | * Claims the global %tty_mutex to serialize: |
1999 | * * concurrent first-time tty initialization | |
2000 | * * concurrent tty driver removal w/ lookup | |
2001 | * * concurrent tty removal from driver table | |
4ea3cd65 | 2002 | * |
796a75a9 | 2003 | * Return: the locked initialized &tty_struct |
4ea3cd65 UKK |
2004 | */ |
2005 | struct tty_struct *tty_kopen_exclusive(dev_t device) | |
2006 | { | |
2007 | return tty_kopen(device, 0); | |
2008 | } | |
2009 | EXPORT_SYMBOL_GPL(tty_kopen_exclusive); | |
2010 | ||
2011 | /** | |
796a75a9 JS |
2012 | * tty_kopen_shared - open a tty device for shared in-kernel use |
2013 | * @device: dev_t of device to open | |
4ea3cd65 | 2014 | * |
796a75a9 JS |
2015 | * Opens an already existing tty for in-kernel use. Compared to |
2016 | * tty_kopen_exclusive() above it doesn't ensure to be the only user. | |
4ea3cd65 | 2017 | * |
796a75a9 | 2018 | * Locking: identical to tty_kopen() above. |
4ea3cd65 UKK |
2019 | */ |
2020 | struct tty_struct *tty_kopen_shared(dev_t device) | |
2021 | { | |
2022 | return tty_kopen(device, 1); | |
2023 | } | |
2024 | EXPORT_SYMBOL_GPL(tty_kopen_shared); | |
a09ac397 | 2025 | |
d6203d0c | 2026 | /** |
796a75a9 JS |
2027 | * tty_open_by_driver - open a tty device |
2028 | * @device: dev_t of device to open | |
2029 | * @filp: file pointer to tty | |
2030 | * | |
2031 | * Performs the driver lookup, checks for a reopen, or otherwise performs the | |
2032 | * first-time tty initialization. | |
d6203d0c | 2033 | * |
d6203d0c | 2034 | * |
796a75a9 JS |
2035 | * Claims the global tty_mutex to serialize: |
2036 | * * concurrent first-time tty initialization | |
2037 | * * concurrent tty driver removal w/ lookup | |
2038 | * * concurrent tty removal from driver table | |
d6203d0c | 2039 | * |
796a75a9 | 2040 | * Return: the locked initialized or re-opened &tty_struct |
d6203d0c | 2041 | */ |
14ce3848 | 2042 | static struct tty_struct *tty_open_by_driver(dev_t device, |
d6203d0c PH |
2043 | struct file *filp) |
2044 | { | |
2045 | struct tty_struct *tty; | |
2046 | struct tty_driver *driver = NULL; | |
2047 | int index = -1; | |
2048 | int retval; | |
2049 | ||
2050 | mutex_lock(&tty_mutex); | |
2051 | driver = tty_lookup_driver(device, filp, &index); | |
2052 | if (IS_ERR(driver)) { | |
2053 | mutex_unlock(&tty_mutex); | |
2054 | return ERR_CAST(driver); | |
2055 | } | |
2056 | ||
2057 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 2058 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
2059 | if (IS_ERR(tty)) { |
2060 | mutex_unlock(&tty_mutex); | |
2061 | goto out; | |
2062 | } | |
2063 | ||
2064 | if (tty) { | |
a09ac397 OK |
2065 | if (tty_port_kopened(tty->port)) { |
2066 | tty_kref_put(tty); | |
2067 | mutex_unlock(&tty_mutex); | |
2068 | tty = ERR_PTR(-EBUSY); | |
2069 | goto out; | |
2070 | } | |
d6203d0c PH |
2071 | mutex_unlock(&tty_mutex); |
2072 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2073 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2074 | if (retval) { |
2075 | if (retval == -EINTR) | |
2076 | retval = -ERESTARTSYS; | |
2077 | tty = ERR_PTR(retval); | |
2078 | goto out; | |
2079 | } | |
d6203d0c PH |
2080 | retval = tty_reopen(tty); |
2081 | if (retval < 0) { | |
2082 | tty_unlock(tty); | |
2083 | tty = ERR_PTR(retval); | |
2084 | } | |
2085 | } else { /* Returns with the tty_lock held for now */ | |
2086 | tty = tty_init_dev(driver, index); | |
2087 | mutex_unlock(&tty_mutex); | |
2088 | } | |
2089 | out: | |
2090 | tty_driver_kref_put(driver); | |
2091 | return tty; | |
2092 | } | |
2093 | ||
af9b897e | 2094 | /** |
796a75a9 JS |
2095 | * tty_open - open a tty device |
2096 | * @inode: inode of device file | |
2097 | * @filp: file pointer to tty | |
1da177e4 | 2098 | * |
796a75a9 JS |
2099 | * tty_open() and tty_release() keep up the tty count that contains the number |
2100 | * of opens done on a tty. We cannot use the inode-count, as different inodes | |
2101 | * might point to the same tty. | |
1da177e4 | 2102 | * |
796a75a9 JS |
2103 | * Open-counting is needed for pty masters, as well as for keeping track of |
2104 | * serial lines: DTR is dropped when the last close happens. | |
2105 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
af9b897e | 2106 | * |
796a75a9 JS |
2107 | * The termios state of a pty is reset on the first open so that settings don't |
2108 | * persist across reuse. | |
af9b897e | 2109 | * |
796a75a9 JS |
2110 | * Locking: |
2111 | * * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev(). | |
2112 | * * @tty->count should protect the rest. | |
2113 | * * ->siglock protects ->signal/->sighand | |
89c8d91e | 2114 | * |
796a75a9 | 2115 | * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex |
1da177e4 | 2116 | */ |
eeb89d91 | 2117 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2118 | { |
b82154ac | 2119 | struct tty_struct *tty; |
1da177e4 | 2120 | int noctty, retval; |
1da177e4 | 2121 | dev_t device = inode->i_rdev; |
846c151a | 2122 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2123 | |
2124 | nonseekable_open(inode, filp); | |
37bdfb07 | 2125 | |
1da177e4 | 2126 | retry_open: |
fa90e1c9 JS |
2127 | retval = tty_alloc_file(filp); |
2128 | if (retval) | |
2129 | return -ENOMEM; | |
2130 | ||
b82154ac | 2131 | tty = tty_open_current_tty(device, filp); |
d6203d0c | 2132 | if (!tty) |
14ce3848 | 2133 | tty = tty_open_by_driver(device, filp); |
52494eeb | 2134 | |
eeb89d91 | 2135 | if (IS_ERR(tty)) { |
d6203d0c | 2136 | tty_free_file(filp); |
ba5db448 | 2137 | retval = PTR_ERR(tty); |
7f22f6c9 | 2138 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2139 | return retval; |
7f22f6c9 PH |
2140 | schedule(); |
2141 | goto retry_open; | |
eeb89d91 | 2142 | } |
1da177e4 | 2143 | |
fa90e1c9 | 2144 | tty_add_file(tty, filp); |
d996b62a | 2145 | |
9de44bd6 | 2146 | check_tty_count(tty, __func__); |
d435cefe | 2147 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2148 | |
909bc774 HRK |
2149 | if (tty->ops->open) |
2150 | retval = tty->ops->open(tty, filp); | |
2151 | else | |
2152 | retval = -ENODEV; | |
1da177e4 LT |
2153 | filp->f_flags = saved_flags; |
2154 | ||
1da177e4 | 2155 | if (retval) { |
d435cefe | 2156 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2157 | |
89c8d91e | 2158 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2159 | tty_release(inode, filp); |
64ba3dc3 | 2160 | if (retval != -ERESTARTSYS) |
1da177e4 | 2161 | return retval; |
64ba3dc3 AB |
2162 | |
2163 | if (signal_pending(current)) | |
1da177e4 | 2164 | return retval; |
64ba3dc3 | 2165 | |
1da177e4 LT |
2166 | schedule(); |
2167 | /* | |
2168 | * Need to reset f_op in case a hangup happened. | |
2169 | */ | |
1256937f | 2170 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2171 | filp->f_op = &tty_fops; |
2172 | goto retry_open; | |
2173 | } | |
d4855e1f | 2174 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2175 | |
11e1d4aa | 2176 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
2177 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
2178 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
2179 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2180 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2181 | if (!noctty) | |
2182 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 2183 | tty_unlock(tty); |
1da177e4 LT |
2184 | return 0; |
2185 | } | |
2186 | ||
39d95b9d | 2187 | |
af9b897e | 2188 | /** |
796a75a9 JS |
2189 | * tty_poll - check tty status |
2190 | * @filp: file being polled | |
2191 | * @wait: poll wait structures to update | |
af9b897e | 2192 | * |
796a75a9 JS |
2193 | * Call the line discipline polling method to obtain the poll status of the |
2194 | * device. | |
af9b897e | 2195 | * |
796a75a9 JS |
2196 | * Locking: locks called line discipline but ldisc poll method may be |
2197 | * re-entered freely by other callers. | |
af9b897e | 2198 | */ |
afc9a42b | 2199 | static __poll_t tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2200 | { |
d996b62a | 2201 | struct tty_struct *tty = file_tty(filp); |
1da177e4 | 2202 | struct tty_ldisc *ld; |
e6c8adca | 2203 | __poll_t ret = 0; |
1da177e4 | 2204 | |
6131ffaa | 2205 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2206 | return 0; |
37bdfb07 | 2207 | |
1da177e4 | 2208 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2209 | if (!ld) |
2210 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2211 | if (ld->ops->poll) |
c961bfb1 | 2212 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2213 | tty_ldisc_deref(ld); |
2214 | return ret; | |
2215 | } | |
2216 | ||
ec79d605 | 2217 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2218 | { |
d996b62a | 2219 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2220 | unsigned long flags; |
5d1e3230 | 2221 | int retval = 0; |
1da177e4 | 2222 | |
6131ffaa | 2223 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2224 | goto out; |
37bdfb07 | 2225 | |
1da177e4 LT |
2226 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2227 | if (retval <= 0) | |
5d1e3230 | 2228 | goto out; |
f6c8dbe6 | 2229 | |
1da177e4 | 2230 | if (on) { |
ab521dc0 EB |
2231 | enum pid_type type; |
2232 | struct pid *pid; | |
f6c8dbe6 | 2233 | |
64d608db JS |
2234 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
2235 | if (tty->ctrl.pgrp) { | |
2236 | pid = tty->ctrl.pgrp; | |
ab521dc0 EB |
2237 | type = PIDTYPE_PGID; |
2238 | } else { | |
2239 | pid = task_pid(current); | |
01919134 | 2240 | type = PIDTYPE_TGID; |
ab521dc0 | 2241 | } |
80e1e823 | 2242 | get_pid(pid); |
64d608db | 2243 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); |
e0b93edd | 2244 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2245 | put_pid(pid); |
e0b93edd | 2246 | retval = 0; |
1da177e4 | 2247 | } |
5d1e3230 | 2248 | out: |
ec79d605 AB |
2249 | return retval; |
2250 | } | |
2251 | ||
2252 | static int tty_fasync(int fd, struct file *filp, int on) | |
2253 | { | |
89c8d91e | 2254 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2255 | int retval = -ENOTTY; |
89c8d91e AC |
2256 | |
2257 | tty_lock(tty); | |
a8f3a297 PH |
2258 | if (!tty_hung_up_p(filp)) |
2259 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2260 | tty_unlock(tty); |
2261 | ||
5d1e3230 | 2262 | return retval; |
1da177e4 LT |
2263 | } |
2264 | ||
af9b897e | 2265 | /** |
796a75a9 JS |
2266 | * tiocsti - fake input character |
2267 | * @tty: tty to fake input into | |
2268 | * @p: pointer to character | |
af9b897e | 2269 | * |
796a75a9 | 2270 | * Fake input to a tty device. Does the necessary locking and input management. |
af9b897e | 2271 | * |
796a75a9 | 2272 | * FIXME: does not honour flow control ?? |
af9b897e | 2273 | * |
796a75a9 JS |
2274 | * Locking: |
2275 | * * Called functions take tty_ldiscs_lock | |
2276 | * * current->signal->tty check is safe without locks | |
af9b897e | 2277 | */ |
1da177e4 LT |
2278 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2279 | { | |
2280 | char ch, mbz = 0; | |
2281 | struct tty_ldisc *ld; | |
37bdfb07 | 2282 | |
1da177e4 LT |
2283 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2284 | return -EPERM; | |
2285 | if (get_user(ch, p)) | |
2286 | return -EFAULT; | |
1e641743 | 2287 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2288 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2289 | if (!ld) |
2290 | return -EIO; | |
bb2853a6 | 2291 | tty_buffer_lock_exclusive(tty->port); |
27cfb3a5 GKH |
2292 | if (ld->ops->receive_buf) |
2293 | ld->ops->receive_buf(tty, &ch, &mbz, 1); | |
bb2853a6 | 2294 | tty_buffer_unlock_exclusive(tty->port); |
1da177e4 LT |
2295 | tty_ldisc_deref(ld); |
2296 | return 0; | |
2297 | } | |
2298 | ||
af9b897e | 2299 | /** |
796a75a9 JS |
2300 | * tiocgwinsz - implement window query ioctl |
2301 | * @tty: tty | |
2302 | * @arg: user buffer for result | |
af9b897e | 2303 | * |
796a75a9 | 2304 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2305 | * |
796a75a9 JS |
2306 | * Locking: @tty->winsize_mutex is taken to ensure the winsize data is |
2307 | * consistent. | |
af9b897e | 2308 | */ |
37bdfb07 | 2309 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2310 | { |
808a0d38 AC |
2311 | int err; |
2312 | ||
dee4a0be | 2313 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2314 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2315 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 | 2316 | |
94bc2eb5 | 2317 | return err ? -EFAULT : 0; |
1da177e4 LT |
2318 | } |
2319 | ||
af9b897e | 2320 | /** |
796a75a9 JS |
2321 | * tty_do_resize - resize event |
2322 | * @tty: tty being resized | |
2323 | * @ws: new dimensions | |
8c9a9dd0 | 2324 | * |
796a75a9 JS |
2325 | * Update the termios variables and send the necessary signals to peform a |
2326 | * terminal resize correctly. | |
af9b897e | 2327 | */ |
fc6f6238 | 2328 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2329 | { |
fc6f6238 | 2330 | struct pid *pgrp; |
1da177e4 | 2331 | |
fc6f6238 | 2332 | /* Lock the tty */ |
dee4a0be | 2333 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2334 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2335 | goto done; |
47f86834 | 2336 | |
5b239542 PH |
2337 | /* Signal the foreground process group */ |
2338 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2339 | if (pgrp) |
2340 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2341 | put_pid(pgrp); |
47f86834 | 2342 | |
8c9a9dd0 | 2343 | tty->winsize = *ws; |
ca9bda00 | 2344 | done: |
dee4a0be | 2345 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2346 | return 0; |
2347 | } | |
4d334fd1 | 2348 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2349 | |
8c9a9dd0 | 2350 | /** |
796a75a9 JS |
2351 | * tiocswinsz - implement window size set ioctl |
2352 | * @tty: tty side of tty | |
2353 | * @arg: user buffer for result | |
8c9a9dd0 | 2354 | * |
796a75a9 JS |
2355 | * Copies the user idea of the window size to the kernel. Traditionally this is |
2356 | * just advisory information but for the Linux console it actually has driver | |
2357 | * level meaning and triggers a VC resize. | |
8c9a9dd0 | 2358 | * |
796a75a9 JS |
2359 | * Locking: |
2360 | * Driver dependent. The default do_resize method takes the tty termios | |
2361 | * mutex and ctrl.lock. The console takes its own lock then calls into the | |
2362 | * default method. | |
8c9a9dd0 | 2363 | */ |
fc6f6238 | 2364 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2365 | { |
2366 | struct winsize tmp_ws; | |
e73b2407 | 2367 | |
8c9a9dd0 AC |
2368 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
2369 | return -EFAULT; | |
2370 | ||
2371 | if (tty->ops->resize) | |
fc6f6238 | 2372 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2373 | else |
fc6f6238 | 2374 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2375 | } |
2376 | ||
af9b897e | 2377 | /** |
796a75a9 JS |
2378 | * tioccons - allow admin to move logical console |
2379 | * @file: the file to become console | |
af9b897e | 2380 | * |
796a75a9 | 2381 | * Allow the administrator to move the redirected console device. |
af9b897e | 2382 | * |
796a75a9 | 2383 | * Locking: uses redirect_lock to guard the redirect information |
af9b897e | 2384 | */ |
1da177e4 LT |
2385 | static int tioccons(struct file *file) |
2386 | { | |
2387 | if (!capable(CAP_SYS_ADMIN)) | |
2388 | return -EPERM; | |
9bb48c82 | 2389 | if (file->f_op->write_iter == redirected_tty_write) { |
1da177e4 | 2390 | struct file *f; |
e73b2407 | 2391 | |
1da177e4 LT |
2392 | spin_lock(&redirect_lock); |
2393 | f = redirect; | |
2394 | redirect = NULL; | |
2395 | spin_unlock(&redirect_lock); | |
2396 | if (f) | |
2397 | fput(f); | |
2398 | return 0; | |
2399 | } | |
a9cbbb80 LT |
2400 | if (file->f_op->write_iter != tty_write) |
2401 | return -ENOTTY; | |
2402 | if (!(file->f_mode & FMODE_WRITE)) | |
2403 | return -EBADF; | |
2404 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
2405 | return -EINVAL; | |
1da177e4 LT |
2406 | spin_lock(&redirect_lock); |
2407 | if (redirect) { | |
2408 | spin_unlock(&redirect_lock); | |
2409 | return -EBUSY; | |
2410 | } | |
cb0942b8 | 2411 | redirect = get_file(file); |
1da177e4 LT |
2412 | spin_unlock(&redirect_lock); |
2413 | return 0; | |
2414 | } | |
2415 | ||
af9b897e | 2416 | /** |
796a75a9 JS |
2417 | * tiocsetd - set line discipline |
2418 | * @tty: tty device | |
2419 | * @p: pointer to user data | |
af9b897e | 2420 | * |
796a75a9 | 2421 | * Set the line discipline according to user request. |
af9b897e | 2422 | * |
796a75a9 | 2423 | * Locking: see tty_set_ldisc(), this function is just a helper |
af9b897e | 2424 | */ |
1da177e4 LT |
2425 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2426 | { | |
c12da96f | 2427 | int disc; |
04f378b1 | 2428 | int ret; |
1da177e4 | 2429 | |
c12da96f | 2430 | if (get_user(disc, p)) |
1da177e4 | 2431 | return -EFAULT; |
04f378b1 | 2432 | |
c12da96f | 2433 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2434 | |
2435 | return ret; | |
1da177e4 LT |
2436 | } |
2437 | ||
5c17c861 | 2438 | /** |
796a75a9 JS |
2439 | * tiocgetd - get line discipline |
2440 | * @tty: tty device | |
2441 | * @p: pointer to user data | |
5c17c861 | 2442 | * |
796a75a9 | 2443 | * Retrieves the line discipline id directly from the ldisc. |
5c17c861 | 2444 | * |
796a75a9 JS |
2445 | * Locking: waits for ldisc reference (in case the line discipline is changing |
2446 | * or the @tty is being hungup) | |
5c17c861 | 2447 | */ |
5c17c861 PH |
2448 | static int tiocgetd(struct tty_struct *tty, int __user *p) |
2449 | { | |
2450 | struct tty_ldisc *ld; | |
2451 | int ret; | |
2452 | ||
2453 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2454 | if (!ld) |
2455 | return -EIO; | |
5c17c861 PH |
2456 | ret = put_user(ld->ops->num, p); |
2457 | tty_ldisc_deref(ld); | |
2458 | return ret; | |
2459 | } | |
2460 | ||
af9b897e | 2461 | /** |
796a75a9 JS |
2462 | * send_break - performed time break |
2463 | * @tty: device to break on | |
2464 | * @duration: timeout in mS | |
af9b897e | 2465 | * |
796a75a9 JS |
2466 | * Perform a timed break on hardware that lacks its own driver level timed |
2467 | * break functionality. | |
af9b897e | 2468 | * |
796a75a9 JS |
2469 | * Locking: |
2470 | * @tty->atomic_write_lock serializes | |
af9b897e | 2471 | */ |
b20f3ae5 | 2472 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2473 | { |
9e98966c AC |
2474 | int retval; |
2475 | ||
2476 | if (tty->ops->break_ctl == NULL) | |
2477 | return 0; | |
2478 | ||
2479 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2480 | retval = tty->ops->break_ctl(tty, duration); | |
2481 | else { | |
2482 | /* Do the work ourselves */ | |
2483 | if (tty_write_lock(tty, 0) < 0) | |
2484 | return -EINTR; | |
2485 | retval = tty->ops->break_ctl(tty, -1); | |
2486 | if (retval) | |
2487 | goto out; | |
2488 | if (!signal_pending(current)) | |
2489 | msleep_interruptible(duration); | |
2490 | retval = tty->ops->break_ctl(tty, 0); | |
2491 | out: | |
2492 | tty_write_unlock(tty); | |
2493 | if (signal_pending(current)) | |
2494 | retval = -EINTR; | |
2495 | } | |
2496 | return retval; | |
1da177e4 LT |
2497 | } |
2498 | ||
af9b897e | 2499 | /** |
796a75a9 JS |
2500 | * tty_tiocmget - get modem status |
2501 | * @tty: tty device | |
2502 | * @p: pointer to result | |
af9b897e | 2503 | * |
796a75a9 JS |
2504 | * Obtain the modem status bits from the tty driver if the feature is |
2505 | * supported. Return -%ENOTTY if it is not available. | |
af9b897e | 2506 | * |
796a75a9 | 2507 | * Locking: none (up to the driver) |
af9b897e | 2508 | */ |
60b33c13 | 2509 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 | 2510 | { |
1b8b2086 | 2511 | int retval = -ENOTTY; |
1da177e4 | 2512 | |
f34d7a5b | 2513 | if (tty->ops->tiocmget) { |
60b33c13 | 2514 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2515 | |
2516 | if (retval >= 0) | |
2517 | retval = put_user(retval, p); | |
2518 | } | |
2519 | return retval; | |
2520 | } | |
2521 | ||
af9b897e | 2522 | /** |
796a75a9 JS |
2523 | * tty_tiocmset - set modem status |
2524 | * @tty: tty device | |
2525 | * @cmd: command - clear bits, set bits or set all | |
2526 | * @p: pointer to desired bits | |
af9b897e | 2527 | * |
796a75a9 JS |
2528 | * Set the modem status bits from the tty driver if the feature |
2529 | * is supported. Return -%ENOTTY if it is not available. | |
af9b897e | 2530 | * |
796a75a9 | 2531 | * Locking: none (up to the driver) |
af9b897e | 2532 | */ |
20b9d177 | 2533 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2534 | unsigned __user *p) |
2535 | { | |
ae677517 AC |
2536 | int retval; |
2537 | unsigned int set, clear, val; | |
1da177e4 | 2538 | |
ae677517 | 2539 | if (tty->ops->tiocmset == NULL) |
1b8b2086 | 2540 | return -ENOTTY; |
1da177e4 | 2541 | |
ae677517 AC |
2542 | retval = get_user(val, p); |
2543 | if (retval) | |
2544 | return retval; | |
2545 | set = clear = 0; | |
2546 | switch (cmd) { | |
2547 | case TIOCMBIS: | |
2548 | set = val; | |
2549 | break; | |
2550 | case TIOCMBIC: | |
2551 | clear = val; | |
2552 | break; | |
2553 | case TIOCMSET: | |
2554 | set = val; | |
2555 | clear = ~val; | |
2556 | break; | |
2557 | } | |
2558 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2559 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2560 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2561 | } |
2562 | ||
d20c219c | 2563 | /** |
796a75a9 JS |
2564 | * tty_get_icount - get tty statistics |
2565 | * @tty: tty device | |
2566 | * @icount: output parameter | |
d20c219c | 2567 | * |
796a75a9 | 2568 | * Gets a copy of the @tty's icount statistics. |
d20c219c | 2569 | * |
796a75a9 | 2570 | * Locking: none (up to the driver) |
d20c219c UKK |
2571 | */ |
2572 | int tty_get_icount(struct tty_struct *tty, | |
2573 | struct serial_icounter_struct *icount) | |
2574 | { | |
2575 | memset(icount, 0, sizeof(*icount)); | |
2576 | ||
2577 | if (tty->ops->get_icount) | |
2578 | return tty->ops->get_icount(tty, icount); | |
2579 | else | |
1b8b2086 | 2580 | return -ENOTTY; |
d20c219c UKK |
2581 | } |
2582 | EXPORT_SYMBOL_GPL(tty_get_icount); | |
2583 | ||
d281da7f AC |
2584 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2585 | { | |
d281da7f | 2586 | struct serial_icounter_struct icount; |
d20c219c UKK |
2587 | int retval; |
2588 | ||
2589 | retval = tty_get_icount(tty, &icount); | |
d281da7f AC |
2590 | if (retval != 0) |
2591 | return retval; | |
d20c219c | 2592 | |
d281da7f AC |
2593 | if (copy_to_user(arg, &icount, sizeof(icount))) |
2594 | return -EFAULT; | |
2595 | return 0; | |
2596 | } | |
2597 | ||
885c77d5 | 2598 | static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) |
8a8ae62f | 2599 | { |
8a8ae62f JS |
2600 | char comm[TASK_COMM_LEN]; |
2601 | int flags; | |
2602 | ||
885c77d5 | 2603 | flags = ss->flags & ASYNC_DEPRECATED; |
8a8ae62f | 2604 | |
1b7bc6b1 JH |
2605 | if (flags) |
2606 | pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2607 | __func__, get_task_comm(comm, current), flags); | |
885c77d5 | 2608 | |
2f46a2c1 | 2609 | if (!tty->ops->set_serial) |
930236a3 | 2610 | return -ENOTTY; |
885c77d5 JH |
2611 | |
2612 | return tty->ops->set_serial(tty, ss); | |
2613 | } | |
2614 | ||
2615 | static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2616 | { | |
2617 | struct serial_struct v; | |
2618 | ||
2619 | if (copy_from_user(&v, ss, sizeof(*ss))) | |
2620 | return -EFAULT; | |
2621 | ||
2622 | return tty_set_serial(tty, &v); | |
2f46a2c1 AV |
2623 | } |
2624 | ||
2625 | static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2626 | { | |
2627 | struct serial_struct v; | |
2628 | int err; | |
2629 | ||
a3241891 | 2630 | memset(&v, 0, sizeof(v)); |
2f46a2c1 | 2631 | if (!tty->ops->get_serial) |
930236a3 | 2632 | return -ENOTTY; |
2f46a2c1 | 2633 | err = tty->ops->get_serial(tty, &v); |
a3241891 | 2634 | if (!err && copy_to_user(ss, &v, sizeof(v))) |
2f46a2c1 AV |
2635 | err = -EFAULT; |
2636 | return err; | |
8a8ae62f JS |
2637 | } |
2638 | ||
8f166e00 PH |
2639 | /* |
2640 | * if pty, return the slave side (real_tty) | |
2641 | * otherwise, return self | |
2642 | */ | |
2643 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2644 | { |
2645 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2646 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2647 | tty = tty->link; | |
2648 | return tty; | |
2649 | } | |
e8b70e7d | 2650 | |
1da177e4 LT |
2651 | /* |
2652 | * Split this up, as gcc can choke on it otherwise.. | |
2653 | */ | |
04f378b1 | 2654 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2655 | { |
d996b62a NP |
2656 | struct tty_struct *tty = file_tty(file); |
2657 | struct tty_struct *real_tty; | |
1da177e4 LT |
2658 | void __user *p = (void __user *)arg; |
2659 | int retval; | |
2660 | struct tty_ldisc *ld; | |
37bdfb07 | 2661 | |
6131ffaa | 2662 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2663 | return -EINVAL; |
2664 | ||
e8b70e7d | 2665 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2666 | |
2667 | /* | |
2668 | * Factor out some common prep work | |
2669 | */ | |
2670 | switch (cmd) { | |
2671 | case TIOCSETD: | |
2672 | case TIOCSBRK: | |
2673 | case TIOCCBRK: | |
2674 | case TCSBRK: | |
37bdfb07 | 2675 | case TCSBRKP: |
1da177e4 LT |
2676 | retval = tty_check_change(tty); |
2677 | if (retval) | |
2678 | return retval; | |
2679 | if (cmd != TIOCCBRK) { | |
2680 | tty_wait_until_sent(tty, 0); | |
2681 | if (signal_pending(current)) | |
2682 | return -EINTR; | |
2683 | } | |
2684 | break; | |
2685 | } | |
2686 | ||
9e98966c AC |
2687 | /* |
2688 | * Now do the stuff. | |
2689 | */ | |
1da177e4 | 2690 | switch (cmd) { |
37bdfb07 AC |
2691 | case TIOCSTI: |
2692 | return tiocsti(tty, p); | |
2693 | case TIOCGWINSZ: | |
8f520021 | 2694 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2695 | case TIOCSWINSZ: |
fc6f6238 | 2696 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2697 | case TIOCCONS: |
2698 | return real_tty != tty ? -EINVAL : tioccons(file); | |
37bdfb07 AC |
2699 | case TIOCEXCL: |
2700 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2701 | return 0; | |
2702 | case TIOCNXCL: | |
2703 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2704 | return 0; | |
84fd7bdf CG |
2705 | case TIOCGEXCL: |
2706 | { | |
2707 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
e73b2407 | 2708 | |
84fd7bdf CG |
2709 | return put_user(excl, (int __user *)p); |
2710 | } | |
37bdfb07 | 2711 | case TIOCGETD: |
5c17c861 | 2712 | return tiocgetd(tty, p); |
37bdfb07 AC |
2713 | case TIOCSETD: |
2714 | return tiocsetd(tty, p); | |
3c95c985 KS |
2715 | case TIOCVHANGUP: |
2716 | if (!capable(CAP_SYS_ADMIN)) | |
2717 | return -EPERM; | |
2718 | tty_vhangup(tty); | |
2719 | return 0; | |
b7b8de08 WF |
2720 | case TIOCGDEV: |
2721 | { | |
2722 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
e73b2407 | 2723 | |
b7b8de08 WF |
2724 | return put_user(ret, (unsigned int __user *)p); |
2725 | } | |
37bdfb07 AC |
2726 | /* |
2727 | * Break handling | |
2728 | */ | |
2729 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2730 | if (tty->ops->break_ctl) |
9e98966c | 2731 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2732 | return 0; |
37bdfb07 | 2733 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2734 | if (tty->ops->break_ctl) |
9e98966c | 2735 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2736 | return 0; |
2737 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2738 | /* non-zero arg means wait for all output data | |
2739 | * to be sent (performed above) but don't send break. | |
2740 | * This is used by the tcdrain() termios function. | |
2741 | */ | |
2742 | if (!arg) | |
2743 | return send_break(tty, 250); | |
2744 | return 0; | |
2745 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2746 | return send_break(tty, arg ? arg*100 : 250); | |
2747 | ||
2748 | case TIOCMGET: | |
60b33c13 | 2749 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2750 | case TIOCMSET: |
2751 | case TIOCMBIC: | |
2752 | case TIOCMBIS: | |
20b9d177 | 2753 | return tty_tiocmset(tty, cmd, p); |
d281da7f | 2754 | case TIOCGICOUNT: |
a3096199 | 2755 | return tty_tiocgicount(tty, p); |
37bdfb07 AC |
2756 | case TCFLSH: |
2757 | switch (arg) { | |
2758 | case TCIFLUSH: | |
2759 | case TCIOFLUSH: | |
2760 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2761 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2762 | break; |
37bdfb07 AC |
2763 | } |
2764 | break; | |
8a8ae62f | 2765 | case TIOCSSERIAL: |
930236a3 | 2766 | return tty_tiocsserial(tty, p); |
2f46a2c1 | 2767 | case TIOCGSERIAL: |
930236a3 | 2768 | return tty_tiocgserial(tty, p); |
311fc65c EB |
2769 | case TIOCGPTPEER: |
2770 | /* Special because the struct file is needed */ | |
2771 | return ptm_open_peer(file, tty, (int)arg); | |
a1235b3e NP |
2772 | default: |
2773 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2774 | if (retval != -ENOIOCTLCMD) | |
2775 | return retval; | |
1da177e4 | 2776 | } |
f34d7a5b | 2777 | if (tty->ops->ioctl) { |
c961bfb1 | 2778 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2779 | if (retval != -ENOIOCTLCMD) |
2780 | return retval; | |
2781 | } | |
2782 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2783 | if (!ld) |
2784 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2785 | retval = -EINVAL; |
a352def2 | 2786 | if (ld->ops->ioctl) { |
d78328bc | 2787 | retval = ld->ops->ioctl(tty, cmd, arg); |
1da177e4 | 2788 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2789 | retval = -ENOTTY; |
1da177e4 LT |
2790 | } |
2791 | tty_ldisc_deref(ld); | |
2792 | return retval; | |
2793 | } | |
2794 | ||
e10cc1df | 2795 | #ifdef CONFIG_COMPAT |
77654350 AV |
2796 | |
2797 | struct serial_struct32 { | |
52b52e91 GS |
2798 | compat_int_t type; |
2799 | compat_int_t line; | |
2800 | compat_uint_t port; | |
2801 | compat_int_t irq; | |
2802 | compat_int_t flags; | |
2803 | compat_int_t xmit_fifo_size; | |
2804 | compat_int_t custom_divisor; | |
2805 | compat_int_t baud_base; | |
2806 | unsigned short close_delay; | |
2807 | char io_type; | |
2808 | char reserved_char; | |
2809 | compat_int_t hub6; | |
2810 | unsigned short closing_wait; /* time to wait before closing */ | |
2811 | unsigned short closing_wait2; /* no longer used... */ | |
2812 | compat_uint_t iomem_base; | |
2813 | unsigned short iomem_reg_shift; | |
2814 | unsigned int port_high; | |
2815 | /* compat_ulong_t iomap_base FIXME */ | |
2816 | compat_int_t reserved; | |
77654350 AV |
2817 | }; |
2818 | ||
2819 | static int compat_tty_tiocsserial(struct tty_struct *tty, | |
2820 | struct serial_struct32 __user *ss) | |
2821 | { | |
77654350 AV |
2822 | struct serial_struct32 v32; |
2823 | struct serial_struct v; | |
77654350 | 2824 | |
a3241891 | 2825 | if (copy_from_user(&v32, ss, sizeof(*ss))) |
77654350 AV |
2826 | return -EFAULT; |
2827 | ||
2828 | memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); | |
2829 | v.iomem_base = compat_ptr(v32.iomem_base); | |
2830 | v.iomem_reg_shift = v32.iomem_reg_shift; | |
2831 | v.port_high = v32.port_high; | |
2832 | v.iomap_base = 0; | |
2833 | ||
885c77d5 | 2834 | return tty_set_serial(tty, &v); |
77654350 AV |
2835 | } |
2836 | ||
2837 | static int compat_tty_tiocgserial(struct tty_struct *tty, | |
2838 | struct serial_struct32 __user *ss) | |
2839 | { | |
2840 | struct serial_struct32 v32; | |
2841 | struct serial_struct v; | |
2842 | int err; | |
17329563 EB |
2843 | |
2844 | memset(&v, 0, sizeof(v)); | |
2845 | memset(&v32, 0, sizeof(v32)); | |
77654350 | 2846 | |
6e622cd8 | 2847 | if (!tty->ops->get_serial) |
77654350 AV |
2848 | return -ENOTTY; |
2849 | err = tty->ops->get_serial(tty, &v); | |
2850 | if (!err) { | |
2851 | memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); | |
2852 | v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? | |
2853 | 0xfffffff : ptr_to_compat(v.iomem_base); | |
2854 | v32.iomem_reg_shift = v.iomem_reg_shift; | |
2855 | v32.port_high = v.port_high; | |
a3241891 | 2856 | if (copy_to_user(ss, &v32, sizeof(v32))) |
77654350 AV |
2857 | err = -EFAULT; |
2858 | } | |
2859 | return err; | |
2860 | } | |
37bdfb07 | 2861 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2862 | unsigned long arg) |
2863 | { | |
d996b62a | 2864 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2865 | struct tty_ldisc *ld; |
2866 | int retval = -ENOIOCTLCMD; | |
2867 | ||
e2112038 | 2868 | switch (cmd) { |
c7dc504e | 2869 | case TIOCOUTQ: |
e2112038 AV |
2870 | case TIOCSTI: |
2871 | case TIOCGWINSZ: | |
2872 | case TIOCSWINSZ: | |
2873 | case TIOCGEXCL: | |
2874 | case TIOCGETD: | |
2875 | case TIOCSETD: | |
2876 | case TIOCGDEV: | |
2877 | case TIOCMGET: | |
2878 | case TIOCMSET: | |
2879 | case TIOCMBIC: | |
2880 | case TIOCMBIS: | |
2881 | case TIOCGICOUNT: | |
2882 | case TIOCGPGRP: | |
2883 | case TIOCSPGRP: | |
2884 | case TIOCGSID: | |
2885 | case TIOCSERGETLSR: | |
2886 | case TIOCGRS485: | |
2887 | case TIOCSRS485: | |
2888 | #ifdef TIOCGETP | |
2889 | case TIOCGETP: | |
2890 | case TIOCSETP: | |
2891 | case TIOCSETN: | |
2892 | #endif | |
2893 | #ifdef TIOCGETC | |
2894 | case TIOCGETC: | |
2895 | case TIOCSETC: | |
2896 | #endif | |
2897 | #ifdef TIOCGLTC | |
2898 | case TIOCGLTC: | |
2899 | case TIOCSLTC: | |
2900 | #endif | |
2901 | case TCSETSF: | |
2902 | case TCSETSW: | |
2903 | case TCSETS: | |
2904 | case TCGETS: | |
2905 | #ifdef TCGETS2 | |
2906 | case TCGETS2: | |
2907 | case TCSETSF2: | |
2908 | case TCSETSW2: | |
2909 | case TCSETS2: | |
2910 | #endif | |
2911 | case TCGETA: | |
2912 | case TCSETAF: | |
2913 | case TCSETAW: | |
2914 | case TCSETA: | |
2915 | case TIOCGLCKTRMIOS: | |
2916 | case TIOCSLCKTRMIOS: | |
2917 | #ifdef TCGETX | |
2918 | case TCGETX: | |
2919 | case TCSETX: | |
2920 | case TCSETXW: | |
2921 | case TCSETXF: | |
2922 | #endif | |
2923 | case TIOCGSOFTCAR: | |
2924 | case TIOCSSOFTCAR: | |
b7aff093 AB |
2925 | |
2926 | case PPPIOCGCHAN: | |
2927 | case PPPIOCGUNIT: | |
e2112038 AV |
2928 | return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
2929 | case TIOCCONS: | |
2930 | case TIOCEXCL: | |
2931 | case TIOCNXCL: | |
2932 | case TIOCVHANGUP: | |
2933 | case TIOCSBRK: | |
2934 | case TIOCCBRK: | |
2935 | case TCSBRK: | |
2936 | case TCSBRKP: | |
2937 | case TCFLSH: | |
2938 | case TIOCGPTPEER: | |
2939 | case TIOCNOTTY: | |
2940 | case TIOCSCTTY: | |
2941 | case TCXONC: | |
2942 | case TIOCMIWAIT: | |
2943 | case TIOCSERCONFIG: | |
2944 | return tty_ioctl(file, cmd, arg); | |
2945 | } | |
2946 | ||
6131ffaa | 2947 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2948 | return -EINVAL; |
2949 | ||
77654350 AV |
2950 | switch (cmd) { |
2951 | case TIOCSSERIAL: | |
2952 | return compat_tty_tiocsserial(tty, compat_ptr(arg)); | |
2953 | case TIOCGSERIAL: | |
2954 | return compat_tty_tiocgserial(tty, compat_ptr(arg)); | |
2955 | } | |
f34d7a5b | 2956 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2957 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2958 | if (retval != -ENOIOCTLCMD) |
2959 | return retval; | |
2960 | } | |
2961 | ||
2962 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2963 | if (!ld) |
2964 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 | 2965 | if (ld->ops->compat_ioctl) |
d78328bc | 2966 | retval = ld->ops->compat_ioctl(tty, cmd, arg); |
f0193d3e | 2967 | if (retval == -ENOIOCTLCMD && ld->ops->ioctl) |
d78328bc JS |
2968 | retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd), |
2969 | arg); | |
e10cc1df PF |
2970 | tty_ldisc_deref(ld); |
2971 | ||
2972 | return retval; | |
2973 | } | |
2974 | #endif | |
1da177e4 | 2975 | |
c3c073f8 AV |
2976 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2977 | { | |
dd78b0c4 | 2978 | if (likely(file->f_op->read_iter != tty_read)) |
c3c073f8 AV |
2979 | return 0; |
2980 | return file_tty(file) != t ? 0 : fd + 1; | |
2981 | } | |
d91c1a3e | 2982 | |
1da177e4 LT |
2983 | /* |
2984 | * This implements the "Secure Attention Key" --- the idea is to | |
2985 | * prevent trojan horses by killing all processes associated with this | |
2986 | * tty when the user hits the "Secure Attention Key". Required for | |
2987 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2988 | * |
1da177e4 LT |
2989 | * This code could be nicer; ideally it should send a HUP, wait a few |
2990 | * seconds, then send a INT, and then a KILL signal. But you then | |
2991 | * have to coordinate with the init process, since all processes associated | |
2992 | * with the current tty must be dead before the new getty is allowed | |
2993 | * to spawn. | |
2994 | * | |
2995 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2996 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2997 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2998 | * | |
2999 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3000 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3001 | */ | |
8b6312f4 | 3002 | void __do_SAK(struct tty_struct *tty) |
1da177e4 | 3003 | { |
652486fb | 3004 | struct task_struct *g, *p; |
ab521dc0 | 3005 | struct pid *session; |
954a0881 | 3006 | int i; |
c8bcd9c5 | 3007 | unsigned long flags; |
37bdfb07 | 3008 | |
64d608db JS |
3009 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
3010 | session = get_pid(tty->ctrl.session); | |
3011 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
37bdfb07 | 3012 | |
b3f13deb | 3013 | tty_ldisc_flush(tty); |
1da177e4 | 3014 | |
f34d7a5b | 3015 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3016 | |
1da177e4 | 3017 | read_lock(&tasklist_lock); |
652486fb | 3018 | /* Kill the entire session */ |
ab521dc0 | 3019 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3020 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3021 | task_pid_nr(p), p->comm); | |
a8ebd171 | 3022 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
ab521dc0 | 3023 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3024 | |
3025 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3026 | do_each_thread(g, p) { |
3027 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3028 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3029 | task_pid_nr(p), p->comm); | |
954a0881 JS |
3030 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, |
3031 | PIDTYPE_SID); | |
1da177e4 LT |
3032 | continue; |
3033 | } | |
3034 | task_lock(p); | |
c3c073f8 AV |
3035 | i = iterate_fd(p->files, 0, this_tty, tty); |
3036 | if (i != 0) { | |
9b42bb75 PH |
3037 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3038 | task_pid_nr(p), p->comm, i - 1); | |
954a0881 JS |
3039 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, |
3040 | PIDTYPE_SID); | |
1da177e4 LT |
3041 | } |
3042 | task_unlock(p); | |
652486fb | 3043 | } while_each_thread(g, p); |
1da177e4 | 3044 | read_unlock(&tasklist_lock); |
c8bcd9c5 | 3045 | put_pid(session); |
1da177e4 LT |
3046 | } |
3047 | ||
8b6312f4 EB |
3048 | static void do_SAK_work(struct work_struct *work) |
3049 | { | |
3050 | struct tty_struct *tty = | |
3051 | container_of(work, struct tty_struct, SAK_work); | |
3052 | __do_SAK(tty); | |
3053 | } | |
3054 | ||
1da177e4 LT |
3055 | /* |
3056 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3057 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3058 | * the values which we write to it will be identical to the values which it | |
3059 | * already has. --akpm | |
3060 | */ | |
3061 | void do_SAK(struct tty_struct *tty) | |
3062 | { | |
3063 | if (!tty) | |
3064 | return; | |
1da177e4 LT |
3065 | schedule_work(&tty->SAK_work); |
3066 | } | |
1da177e4 LT |
3067 | EXPORT_SYMBOL(do_SAK); |
3068 | ||
30004ac9 DES |
3069 | /* Must put_device() after it's unused! */ |
3070 | static struct device *tty_get_device(struct tty_struct *tty) | |
3071 | { | |
3072 | dev_t devt = tty_devnum(tty); | |
e73b2407 | 3073 | |
4495dfdd | 3074 | return class_find_device_by_devt(tty_class, devt); |
30004ac9 DES |
3075 | } |
3076 | ||
3077 | ||
796a75a9 JS |
3078 | /** |
3079 | * alloc_tty_struct - allocate a new tty | |
3080 | * @driver: driver which will handle the returned tty | |
3081 | * @idx: minor of the tty | |
af9b897e | 3082 | * |
796a75a9 | 3083 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3084 | * |
796a75a9 | 3085 | * Locking: none - @tty in question is not exposed at this point |
1da177e4 | 3086 | */ |
2c964a2f | 3087 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3088 | { |
2c964a2f RV |
3089 | struct tty_struct *tty; |
3090 | ||
c72d8592 | 3091 | tty = kzalloc(sizeof(*tty), GFP_KERNEL_ACCOUNT); |
2c964a2f RV |
3092 | if (!tty) |
3093 | return NULL; | |
3094 | ||
9c9f4ded | 3095 | kref_init(&tty->kref); |
1da177e4 | 3096 | tty->magic = TTY_MAGIC; |
903f9db1 TH |
3097 | if (tty_ldisc_init(tty)) { |
3098 | kfree(tty); | |
3099 | return NULL; | |
3100 | } | |
64d608db JS |
3101 | tty->ctrl.session = NULL; |
3102 | tty->ctrl.pgrp = NULL; | |
89c8d91e | 3103 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3104 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3105 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3106 | mutex_init(&tty->winsize_mutex); |
36697529 | 3107 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3108 | init_waitqueue_head(&tty->write_wait); |
3109 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3110 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3111 | mutex_init(&tty->atomic_write_lock); |
64d608db | 3112 | spin_lock_init(&tty->ctrl.lock); |
6e94dbc7 | 3113 | spin_lock_init(&tty->flow.lock); |
4a510969 | 3114 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3115 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3116 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3117 | |
3118 | tty->driver = driver; | |
3119 | tty->ops = driver->ops; | |
3120 | tty->index = idx; | |
3121 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3122 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3123 | |
3124 | return tty; | |
1da177e4 LT |
3125 | } |
3126 | ||
f34d7a5b | 3127 | /** |
796a75a9 JS |
3128 | * tty_put_char - write one character to a tty |
3129 | * @tty: tty | |
3130 | * @ch: character to write | |
3131 | * | |
3132 | * Write one byte to the @tty using the provided @tty->ops->put_char() method | |
3133 | * if present. | |
f34d7a5b | 3134 | * |
796a75a9 JS |
3135 | * Note: the specific put_char operation in the driver layer may go |
3136 | * away soon. Don't call it directly, use this method | |
f34d7a5b | 3137 | * |
796a75a9 | 3138 | * Return: the number of characters successfully output. |
1da177e4 | 3139 | */ |
f34d7a5b | 3140 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3141 | { |
f34d7a5b AC |
3142 | if (tty->ops->put_char) |
3143 | return tty->ops->put_char(tty, ch); | |
3144 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3145 | } |
f34d7a5b AC |
3146 | EXPORT_SYMBOL_GPL(tty_put_char); |
3147 | ||
d81ed103 | 3148 | struct class *tty_class; |
1da177e4 | 3149 | |
7e73eca6 JS |
3150 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3151 | unsigned int index, unsigned int count) | |
3152 | { | |
c1a752ba LY |
3153 | int err; |
3154 | ||
7e73eca6 | 3155 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3156 | driver->cdevs[index] = cdev_alloc(); |
3157 | if (!driver->cdevs[index]) | |
3158 | return -ENOMEM; | |
c1a752ba | 3159 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3160 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3161 | err = cdev_add(driver->cdevs[index], dev, count); |
3162 | if (err) | |
3163 | kobject_put(&driver->cdevs[index]->kobj); | |
3164 | return err; | |
7e73eca6 JS |
3165 | } |
3166 | ||
1da177e4 | 3167 | /** |
796a75a9 JS |
3168 | * tty_register_device - register a tty device |
3169 | * @driver: the tty driver that describes the tty device | |
3170 | * @index: the index in the tty driver for this tty device | |
3171 | * @device: a struct device that is associated with this tty device. | |
3172 | * This field is optional, if there is no known struct device | |
3173 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3174 | * |
796a75a9 JS |
3175 | * This call is required to be made to register an individual tty device |
3176 | * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3177 | * that bit is not set, this function should not be called by a tty | |
3178 | * driver. | |
1cdcb6b4 | 3179 | * |
796a75a9 | 3180 | * Locking: ?? |
af9b897e | 3181 | * |
796a75a9 JS |
3182 | * Return: A pointer to the struct device for this tty device (or |
3183 | * ERR_PTR(-EFOO) on error). | |
1da177e4 | 3184 | */ |
01107d34 GKH |
3185 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3186 | struct device *device) | |
1da177e4 | 3187 | { |
6915c0e4 TH |
3188 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3189 | } | |
3190 | EXPORT_SYMBOL(tty_register_device); | |
3191 | ||
b1b79916 TH |
3192 | static void tty_device_create_release(struct device *dev) |
3193 | { | |
83db1df4 | 3194 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3195 | kfree(dev); |
3196 | } | |
3197 | ||
6915c0e4 | 3198 | /** |
796a75a9 JS |
3199 | * tty_register_device_attr - register a tty device |
3200 | * @driver: the tty driver that describes the tty device | |
3201 | * @index: the index in the tty driver for this tty device | |
3202 | * @device: a struct device that is associated with this tty device. | |
3203 | * This field is optional, if there is no known struct device | |
3204 | * for this tty device it can be set to %NULL safely. | |
3205 | * @drvdata: Driver data to be set to device. | |
3206 | * @attr_grp: Attribute group to be set on device. | |
6915c0e4 | 3207 | * |
796a75a9 JS |
3208 | * This call is required to be made to register an individual tty device if the |
3209 | * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is | |
3210 | * not set, this function should not be called by a tty driver. | |
6915c0e4 | 3211 | * |
796a75a9 | 3212 | * Locking: ?? |
6915c0e4 | 3213 | * |
796a75a9 JS |
3214 | * Return: A pointer to the struct device for this tty device (or |
3215 | * ERR_PTR(-EFOO) on error). | |
6915c0e4 TH |
3216 | */ |
3217 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3218 | unsigned index, struct device *device, | |
3219 | void *drvdata, | |
3220 | const struct attribute_group **attr_grp) | |
3221 | { | |
1da177e4 | 3222 | char name[64]; |
6915c0e4 | 3223 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 3224 | struct ktermios *tp; |
6a7e6f78 JH |
3225 | struct device *dev; |
3226 | int retval; | |
1da177e4 LT |
3227 | |
3228 | if (index >= driver->num) { | |
656fb867 PH |
3229 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3230 | driver->name, index); | |
1cdcb6b4 | 3231 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3232 | } |
3233 | ||
1da177e4 LT |
3234 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3235 | pty_line_name(driver, index, name); | |
3236 | else | |
3237 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3238 | |
6915c0e4 | 3239 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
3240 | if (!dev) |
3241 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 3242 | |
6915c0e4 TH |
3243 | dev->devt = devt; |
3244 | dev->class = tty_class; | |
3245 | dev->parent = device; | |
b1b79916 | 3246 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3247 | dev_set_name(dev, "%s", name); |
3248 | dev->groups = attr_grp; | |
3249 | dev_set_drvdata(dev, drvdata); | |
3250 | ||
6a7e6f78 JH |
3251 | dev_set_uevent_suppress(dev, 1); |
3252 | ||
6915c0e4 TH |
3253 | retval = device_register(dev); |
3254 | if (retval) | |
6a7e6f78 JH |
3255 | goto err_put; |
3256 | ||
3257 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
3258 | /* |
3259 | * Free any saved termios data so that the termios state is | |
3260 | * reset when reusing a minor number. | |
3261 | */ | |
3262 | tp = driver->termios[index]; | |
3263 | if (tp) { | |
3264 | driver->termios[index] = NULL; | |
3265 | kfree(tp); | |
3266 | } | |
3267 | ||
6a7e6f78 JH |
3268 | retval = tty_cdev_add(driver, devt, index, 1); |
3269 | if (retval) | |
3270 | goto err_del; | |
3271 | } | |
3272 | ||
3273 | dev_set_uevent_suppress(dev, 0); | |
3274 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
3275 | |
3276 | return dev; | |
3277 | ||
6a7e6f78 JH |
3278 | err_del: |
3279 | device_del(dev); | |
3280 | err_put: | |
6915c0e4 | 3281 | put_device(dev); |
6a7e6f78 | 3282 | |
6915c0e4 | 3283 | return ERR_PTR(retval); |
1da177e4 | 3284 | } |
6915c0e4 | 3285 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3286 | |
3287 | /** | |
796a75a9 JS |
3288 | * tty_unregister_device - unregister a tty device |
3289 | * @driver: the tty driver that describes the tty device | |
3290 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3291 | * |
796a75a9 JS |
3292 | * If a tty device is registered with a call to tty_register_device() then |
3293 | * this function must be called when the tty device is gone. | |
af9b897e | 3294 | * |
796a75a9 | 3295 | * Locking: ?? |
1da177e4 LT |
3296 | */ |
3297 | void tty_unregister_device(struct tty_driver *driver, unsigned index) | |
3298 | { | |
37bdfb07 AC |
3299 | device_destroy(tty_class, |
3300 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3301 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3302 | cdev_del(driver->cdevs[index]); | |
3303 | driver->cdevs[index] = NULL; | |
3304 | } | |
1da177e4 | 3305 | } |
1da177e4 LT |
3306 | EXPORT_SYMBOL(tty_unregister_device); |
3307 | ||
7f0bc6a6 JS |
3308 | /** |
3309 | * __tty_alloc_driver -- allocate tty driver | |
3310 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 3311 | * @owner: module which is responsible for this driver |
796a75a9 | 3312 | * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags |
7f0bc6a6 JS |
3313 | * |
3314 | * This should not be called directly, some of the provided macros should be | |
796a75a9 | 3315 | * used instead. Use IS_ERR() and friends on @retval. |
7f0bc6a6 JS |
3316 | */ |
3317 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3318 | unsigned long flags) | |
1da177e4 LT |
3319 | { |
3320 | struct tty_driver *driver; | |
7e73eca6 | 3321 | unsigned int cdevs = 1; |
16a02081 | 3322 | int err; |
1da177e4 | 3323 | |
0019b408 | 3324 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3325 | return ERR_PTR(-EINVAL); |
3326 | ||
a3241891 | 3327 | driver = kzalloc(sizeof(*driver), GFP_KERNEL); |
7f0bc6a6 JS |
3328 | if (!driver) |
3329 | return ERR_PTR(-ENOMEM); | |
3330 | ||
3331 | kref_init(&driver->kref); | |
3332 | driver->magic = TTY_DRIVER_MAGIC; | |
3333 | driver->num = lines; | |
3334 | driver->owner = owner; | |
3335 | driver->flags = flags; | |
16a02081 JS |
3336 | |
3337 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3338 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3339 | GFP_KERNEL); | |
3340 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3341 | GFP_KERNEL); | |
3342 | if (!driver->ttys || !driver->termios) { | |
3343 | err = -ENOMEM; | |
3344 | goto err_free_all; | |
3345 | } | |
3346 | } | |
3347 | ||
3348 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3349 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3350 | GFP_KERNEL); | |
3351 | if (!driver->ports) { | |
3352 | err = -ENOMEM; | |
3353 | goto err_free_all; | |
3354 | } | |
7e73eca6 JS |
3355 | cdevs = lines; |
3356 | } | |
3357 | ||
3358 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3359 | if (!driver->cdevs) { | |
3360 | err = -ENOMEM; | |
3361 | goto err_free_all; | |
16a02081 | 3362 | } |
7f0bc6a6 | 3363 | |
1da177e4 | 3364 | return driver; |
16a02081 JS |
3365 | err_free_all: |
3366 | kfree(driver->ports); | |
3367 | kfree(driver->ttys); | |
3368 | kfree(driver->termios); | |
a3a10ce3 | 3369 | kfree(driver->cdevs); |
16a02081 JS |
3370 | kfree(driver); |
3371 | return ERR_PTR(err); | |
1da177e4 | 3372 | } |
7f0bc6a6 | 3373 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3374 | |
7d7b93c1 | 3375 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3376 | { |
7d7b93c1 AC |
3377 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3378 | int i; | |
3379 | struct ktermios *tp; | |
7d7b93c1 AC |
3380 | |
3381 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
3382 | for (i = 0; i < driver->num; i++) { |
3383 | tp = driver->termios[i]; | |
3384 | if (tp) { | |
3385 | driver->termios[i] = NULL; | |
3386 | kfree(tp); | |
3387 | } | |
7d7b93c1 AC |
3388 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3389 | tty_unregister_device(driver, i); | |
3390 | } | |
7d7b93c1 | 3391 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3392 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3393 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3394 | } |
7e73eca6 | 3395 | kfree(driver->cdevs); |
04831dc1 | 3396 | kfree(driver->ports); |
16a02081 JS |
3397 | kfree(driver->termios); |
3398 | kfree(driver->ttys); | |
1da177e4 LT |
3399 | kfree(driver); |
3400 | } | |
3401 | ||
38581283 JS |
3402 | /** |
3403 | * tty_driver_kref_put -- drop a reference to a tty driver | |
3404 | * @driver: driver of which to drop the reference | |
3405 | * | |
3406 | * The final put will destroy and free up the driver. | |
3407 | */ | |
7d7b93c1 AC |
3408 | void tty_driver_kref_put(struct tty_driver *driver) |
3409 | { | |
3410 | kref_put(&driver->kref, destruct_tty_driver); | |
3411 | } | |
3412 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3413 | ||
38581283 JS |
3414 | /** |
3415 | * tty_register_driver -- register a tty driver | |
3416 | * @driver: driver to register | |
3417 | * | |
1da177e4 LT |
3418 | * Called by a tty driver to register itself. |
3419 | */ | |
3420 | int tty_register_driver(struct tty_driver *driver) | |
3421 | { | |
3422 | int error; | |
37bdfb07 | 3423 | int i; |
1da177e4 | 3424 | dev_t dev; |
b670bde0 | 3425 | struct device *d; |
1da177e4 | 3426 | |
1da177e4 | 3427 | if (!driver->major) { |
37bdfb07 AC |
3428 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3429 | driver->num, driver->name); | |
1da177e4 LT |
3430 | if (!error) { |
3431 | driver->major = MAJOR(dev); | |
3432 | driver->minor_start = MINOR(dev); | |
3433 | } | |
3434 | } else { | |
3435 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3436 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3437 | } |
9bb8a3d4 | 3438 | if (error < 0) |
16a02081 | 3439 | goto err; |
1da177e4 | 3440 | |
7e73eca6 JS |
3441 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3442 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3443 | if (error) | |
3444 | goto err_unreg_char; | |
3445 | } | |
1da177e4 | 3446 | |
ca509f69 | 3447 | mutex_lock(&tty_mutex); |
1da177e4 | 3448 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3449 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3450 | |
3451 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3452 | for (i = 0; i < driver->num; i++) { |
3453 | d = tty_register_device(driver, i, NULL); | |
3454 | if (IS_ERR(d)) { | |
3455 | error = PTR_ERR(d); | |
16a02081 | 3456 | goto err_unreg_devs; |
b670bde0 VK |
3457 | } |
3458 | } | |
1da177e4 LT |
3459 | } |
3460 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3461 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3462 | return 0; |
b670bde0 | 3463 | |
16a02081 | 3464 | err_unreg_devs: |
b670bde0 VK |
3465 | for (i--; i >= 0; i--) |
3466 | tty_unregister_device(driver, i); | |
3467 | ||
3468 | mutex_lock(&tty_mutex); | |
3469 | list_del(&driver->tty_drivers); | |
3470 | mutex_unlock(&tty_mutex); | |
3471 | ||
9bb8a3d4 | 3472 | err_unreg_char: |
b670bde0 | 3473 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3474 | err: |
b670bde0 | 3475 | return error; |
1da177e4 | 3476 | } |
1da177e4 LT |
3477 | EXPORT_SYMBOL(tty_register_driver); |
3478 | ||
38581283 JS |
3479 | /** |
3480 | * tty_unregister_driver -- unregister a tty driver | |
3481 | * @driver: driver to unregister | |
3482 | * | |
1da177e4 LT |
3483 | * Called by a tty driver to unregister itself. |
3484 | */ | |
a872ab4d | 3485 | void tty_unregister_driver(struct tty_driver *driver) |
1da177e4 | 3486 | { |
1da177e4 LT |
3487 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3488 | driver->num); | |
ca509f69 | 3489 | mutex_lock(&tty_mutex); |
1da177e4 | 3490 | list_del(&driver->tty_drivers); |
ca509f69 | 3491 | mutex_unlock(&tty_mutex); |
1da177e4 | 3492 | } |
1da177e4 LT |
3493 | EXPORT_SYMBOL(tty_unregister_driver); |
3494 | ||
24ec839c PZ |
3495 | dev_t tty_devnum(struct tty_struct *tty) |
3496 | { | |
3497 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3498 | } | |
3499 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3500 | |
d81ed103 AC |
3501 | void tty_default_fops(struct file_operations *fops) |
3502 | { | |
3503 | *fops = tty_fops; | |
3504 | } | |
3505 | ||
2c9ede55 | 3506 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3507 | { |
3508 | if (!mode) | |
3509 | return NULL; | |
3510 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3511 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3512 | *mode = 0666; | |
3513 | return NULL; | |
3514 | } | |
3515 | ||
1da177e4 LT |
3516 | static int __init tty_class_init(void) |
3517 | { | |
7fe845d1 | 3518 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3519 | if (IS_ERR(tty_class)) |
3520 | return PTR_ERR(tty_class); | |
e454cea2 | 3521 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3522 | return 0; |
3523 | } | |
3524 | ||
3525 | postcore_initcall(tty_class_init); | |
3526 | ||
3527 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3528 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3529 | |
fbc92a34 KS |
3530 | static ssize_t show_cons_active(struct device *dev, |
3531 | struct device_attribute *attr, char *buf) | |
3532 | { | |
3533 | struct console *cs[16]; | |
3534 | int i = 0; | |
3535 | struct console *c; | |
3536 | ssize_t count = 0; | |
3537 | ||
ac751efa | 3538 | console_lock(); |
a2a6a822 | 3539 | for_each_console(c) { |
fbc92a34 KS |
3540 | if (!c->device) |
3541 | continue; | |
3542 | if (!c->write) | |
3543 | continue; | |
3544 | if ((c->flags & CON_ENABLED) == 0) | |
3545 | continue; | |
3546 | cs[i++] = c; | |
3547 | if (i >= ARRAY_SIZE(cs)) | |
3548 | break; | |
3549 | } | |
723abd87 HR |
3550 | while (i--) { |
3551 | int index = cs[i]->index; | |
3552 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3553 | ||
3554 | /* don't resolve tty0 as some programs depend on it */ | |
3555 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3556 | count += tty_line_name(drv, index, buf + count); | |
3557 | else | |
3558 | count += sprintf(buf + count, "%s%d", | |
3559 | cs[i]->name, cs[i]->index); | |
3560 | ||
3561 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3562 | } | |
ac751efa | 3563 | console_unlock(); |
fbc92a34 KS |
3564 | |
3565 | return count; | |
3566 | } | |
3567 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3568 | ||
1083a7be TI |
3569 | static struct attribute *cons_dev_attrs[] = { |
3570 | &dev_attr_active.attr, | |
3571 | NULL | |
3572 | }; | |
3573 | ||
3574 | ATTRIBUTE_GROUPS(cons_dev); | |
3575 | ||
fbc92a34 KS |
3576 | static struct device *consdev; |
3577 | ||
3578 | void console_sysfs_notify(void) | |
3579 | { | |
3580 | if (consdev) | |
3581 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3582 | } | |
3583 | ||
1da177e4 LT |
3584 | /* |
3585 | * Ok, now we can initialize the rest of the tty devices and can count | |
3586 | * on memory allocations, interrupts etc.. | |
3587 | */ | |
31d1d48e | 3588 | int __init tty_init(void) |
1da177e4 | 3589 | { |
7c0cca7c | 3590 | tty_sysctl_init(); |
1da177e4 LT |
3591 | cdev_init(&tty_cdev, &tty_fops); |
3592 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3593 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3594 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3595 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3596 | |
3597 | cdev_init(&console_cdev, &console_fops); | |
3598 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3599 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3600 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3601 | consdev = device_create_with_groups(tty_class, NULL, |
3602 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3603 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3604 | if (IS_ERR(consdev)) |
3605 | consdev = NULL; | |
1da177e4 | 3606 | |
1da177e4 | 3607 | #ifdef CONFIG_VT |
d81ed103 | 3608 | vty_init(&console_fops); |
1da177e4 LT |
3609 | #endif |
3610 | return 0; | |
3611 | } | |
31d1d48e | 3612 |