Commit | Line | Data |
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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> |
a352def2 | 102 | #include <linux/uaccess.h> |
c9874d3f | 103 | #include <linux/termios_internal.h> |
360c11e2 | 104 | #include <linux/fs.h> |
1da177e4 LT |
105 | |
106 | #include <linux/kbd_kern.h> | |
107 | #include <linux/vt_kern.h> | |
108 | #include <linux/selection.h> | |
1da177e4 LT |
109 | |
110 | #include <linux/kmod.h> | |
b488893a | 111 | #include <linux/nsproxy.h> |
98602c01 | 112 | #include "tty.h" |
1da177e4 LT |
113 | |
114 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
115 | #ifdef TTY_DEBUG_HANGUP |
116 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
117 | #else | |
118 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
119 | #endif | |
1da177e4 LT |
120 | |
121 | #define TTY_PARANOIA_CHECK 1 | |
122 | #define CHECK_TTY_COUNT 1 | |
123 | ||
edc6afc5 | 124 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
125 | .c_iflag = ICRNL | IXON, |
126 | .c_oflag = OPOST | ONLCR, | |
127 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
128 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
129 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
130 | .c_cc = INIT_C_CC, |
131 | .c_ispeed = 38400, | |
133b1306 PH |
132 | .c_ospeed = 38400, |
133 | /* .c_line = N_TTY, */ | |
1da177e4 | 134 | }; |
1da177e4 LT |
135 | EXPORT_SYMBOL(tty_std_termios); |
136 | ||
137 | /* This list gets poked at by procfs and various bits of boot up code. This | |
b426a5b8 XT |
138 | * could do with some rationalisation such as pulling the tty proc function |
139 | * into this file. | |
140 | */ | |
37bdfb07 | 141 | |
1da177e4 LT |
142 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
143 | ||
d1d027ef | 144 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 145 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 146 | |
dd78b0c4 | 147 | static ssize_t tty_read(struct kiocb *, struct iov_iter *); |
9bb48c82 | 148 | static ssize_t tty_write(struct kiocb *, struct iov_iter *); |
afc9a42b | 149 | static __poll_t tty_poll(struct file *, poll_table *); |
1da177e4 | 150 | static int tty_open(struct inode *, struct file *); |
e10cc1df | 151 | #ifdef CONFIG_COMPAT |
37bdfb07 | 152 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
153 | unsigned long arg); |
154 | #else | |
155 | #define tty_compat_ioctl NULL | |
156 | #endif | |
ec79d605 | 157 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 158 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 159 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 160 | |
af9b897e | 161 | /** |
796a75a9 JS |
162 | * free_tty_struct - free a disused tty |
163 | * @tty: tty struct to free | |
af9b897e | 164 | * |
796a75a9 | 165 | * Free the write buffers, tty queue and tty memory itself. |
af9b897e | 166 | * |
796a75a9 | 167 | * Locking: none. Must be called after tty is definitely unused |
af9b897e | 168 | */ |
a3123fd0 | 169 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 170 | { |
c8b710b3 | 171 | tty_ldisc_deinit(tty); |
a211b1af | 172 | put_device(tty->dev); |
d6d9d17a | 173 | kvfree(tty->write_buf); |
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 | } | |
1da177e4 LT |
268 | #endif |
269 | return 0; | |
270 | } | |
271 | ||
deb287e7 | 272 | /* Caller must hold tty_lock */ |
b4940f6c | 273 | static void check_tty_count(struct tty_struct *tty, const char *routine) |
1da177e4 LT |
274 | { |
275 | #ifdef CHECK_TTY_COUNT | |
276 | struct list_head *p; | |
a09ac397 | 277 | int count = 0, kopen_count = 0; |
37bdfb07 | 278 | |
4a510969 | 279 | spin_lock(&tty->files_lock); |
1da177e4 LT |
280 | list_for_each(p, &tty->tty_files) { |
281 | count++; | |
282 | } | |
4a510969 | 283 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
284 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
285 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
286 | tty->link && tty->link->count) | |
287 | count++; | |
a09ac397 OK |
288 | if (tty_port_kopened(tty->port)) |
289 | kopen_count++; | |
290 | if (tty->count != (count + kopen_count)) { | |
291 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", | |
292 | routine, tty->count, count, kopen_count); | |
24ec839c | 293 | } |
1da177e4 | 294 | #endif |
1da177e4 LT |
295 | } |
296 | ||
af9b897e | 297 | /** |
796a75a9 JS |
298 | * get_tty_driver - find device of a tty |
299 | * @device: device identifier | |
300 | * @index: returns the index of the tty | |
af9b897e | 301 | * |
796a75a9 JS |
302 | * This routine returns a tty driver structure, given a device number and also |
303 | * passes back the index number. | |
af9b897e | 304 | * |
796a75a9 | 305 | * Locking: caller must hold tty_mutex |
1da177e4 LT |
306 | */ |
307 | static struct tty_driver *get_tty_driver(dev_t device, int *index) | |
308 | { | |
309 | struct tty_driver *p; | |
310 | ||
311 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
312 | dev_t base = MKDEV(p->major, p->minor_start); | |
e73b2407 | 313 | |
1da177e4 LT |
314 | if (device < base || device >= base + p->num) |
315 | continue; | |
316 | *index = device - base; | |
7d7b93c1 | 317 | return tty_driver_kref_get(p); |
1da177e4 LT |
318 | } |
319 | return NULL; | |
320 | } | |
321 | ||
fc61ed51 | 322 | /** |
796a75a9 JS |
323 | * tty_dev_name_to_number - return dev_t for device name |
324 | * @name: user space name of device under /dev | |
325 | * @number: pointer to dev_t that this function will populate | |
fc61ed51 | 326 | * |
796a75a9 JS |
327 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t like |
328 | * (4, 64) or (188, 1). If no corresponding driver is registered then the | |
329 | * function returns -%ENODEV. | |
fc61ed51 | 330 | * |
796a75a9 JS |
331 | * Locking: this acquires tty_mutex to protect the tty_drivers list from |
332 | * being modified while we are traversing it, and makes sure to | |
333 | * release it before exiting. | |
fc61ed51 OK |
334 | */ |
335 | int tty_dev_name_to_number(const char *name, dev_t *number) | |
336 | { | |
337 | struct tty_driver *p; | |
338 | int ret; | |
339 | int index, prefix_length = 0; | |
340 | const char *str; | |
341 | ||
342 | for (str = name; *str && !isdigit(*str); str++) | |
343 | ; | |
344 | ||
345 | if (!*str) | |
346 | return -EINVAL; | |
347 | ||
348 | ret = kstrtoint(str, 10, &index); | |
349 | if (ret) | |
350 | return ret; | |
351 | ||
352 | prefix_length = str - name; | |
353 | mutex_lock(&tty_mutex); | |
354 | ||
355 | list_for_each_entry(p, &tty_drivers, tty_drivers) | |
356 | if (prefix_length == strlen(p->name) && strncmp(name, | |
357 | p->name, prefix_length) == 0) { | |
358 | if (index < p->num) { | |
359 | *number = MKDEV(p->major, p->minor_start + index); | |
360 | goto out; | |
361 | } | |
362 | } | |
363 | ||
364 | /* if here then driver wasn't found */ | |
365 | ret = -ENODEV; | |
366 | out: | |
367 | mutex_unlock(&tty_mutex); | |
368 | return ret; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number); | |
371 | ||
f2d937f3 JW |
372 | #ifdef CONFIG_CONSOLE_POLL |
373 | ||
374 | /** | |
796a75a9 JS |
375 | * tty_find_polling_driver - find device of a polled tty |
376 | * @name: name string to match | |
377 | * @line: pointer to resulting tty line nr | |
f2d937f3 | 378 | * |
796a75a9 JS |
379 | * This routine returns a tty driver structure, given a name and the condition |
380 | * that the tty driver is capable of polled operation. | |
f2d937f3 JW |
381 | */ |
382 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
383 | { | |
384 | struct tty_driver *p, *res = NULL; | |
385 | int tty_line = 0; | |
0dca0fd2 | 386 | int len; |
5f0878ac | 387 | char *str, *stp; |
f2d937f3 | 388 | |
0dca0fd2 JW |
389 | for (str = name; *str; str++) |
390 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
391 | break; | |
392 | if (!*str) | |
393 | return NULL; | |
394 | ||
395 | len = str - name; | |
396 | tty_line = simple_strtoul(str, &str, 10); | |
397 | ||
f2d937f3 JW |
398 | mutex_lock(&tty_mutex); |
399 | /* Search through the tty devices to look for a match */ | |
400 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
33a1a7be | 401 | if (!len || strncmp(name, p->name, len) != 0) |
0dca0fd2 | 402 | continue; |
5f0878ac AC |
403 | stp = str; |
404 | if (*stp == ',') | |
405 | stp++; | |
406 | if (*stp == '\0') | |
407 | stp = NULL; | |
f2d937f3 | 408 | |
6eb68d6f | 409 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 410 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 411 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
412 | *line = tty_line; |
413 | break; | |
414 | } | |
415 | } | |
416 | mutex_unlock(&tty_mutex); | |
417 | ||
418 | return res; | |
419 | } | |
420 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
421 | #endif | |
422 | ||
ddc5fda7 | 423 | static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 LT |
424 | { |
425 | return 0; | |
426 | } | |
427 | ||
17749851 | 428 | static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) |
1da177e4 LT |
429 | { |
430 | return -EIO; | |
431 | } | |
432 | ||
433 | /* No kernel lock held - none needed ;) */ | |
afc9a42b | 434 | static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 435 | { |
a9a08845 | 436 | return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; |
1da177e4 LT |
437 | } |
438 | ||
04f378b1 AC |
439 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
440 | unsigned long arg) | |
38ad2ed0 PF |
441 | { |
442 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
443 | } | |
444 | ||
37bdfb07 | 445 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 446 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
447 | { |
448 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
449 | } | |
450 | ||
f557474c PH |
451 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
452 | { | |
453 | return -ENOTTY; | |
454 | } | |
455 | ||
d01c3289 MY |
456 | static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
457 | { | |
458 | struct tty_struct *tty = file_tty(file); | |
459 | ||
460 | if (tty && tty->ops && tty->ops->show_fdinfo) | |
461 | tty->ops->show_fdinfo(tty, m); | |
462 | } | |
463 | ||
62322d25 | 464 | static const struct file_operations tty_fops = { |
1da177e4 | 465 | .llseek = no_llseek, |
dd78b0c4 | 466 | .read_iter = tty_read, |
9bb48c82 | 467 | .write_iter = tty_write, |
b0072734 | 468 | .splice_read = copy_splice_read, |
9bb48c82 | 469 | .splice_write = iter_file_splice_write, |
1da177e4 | 470 | .poll = tty_poll, |
04f378b1 | 471 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 472 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
473 | .open = tty_open, |
474 | .release = tty_release, | |
475 | .fasync = tty_fasync, | |
d01c3289 | 476 | .show_fdinfo = tty_show_fdinfo, |
1da177e4 LT |
477 | }; |
478 | ||
62322d25 | 479 | static const struct file_operations console_fops = { |
1da177e4 | 480 | .llseek = no_llseek, |
dd78b0c4 | 481 | .read_iter = tty_read, |
9bb48c82 | 482 | .write_iter = redirected_tty_write, |
b0072734 | 483 | .splice_read = copy_splice_read, |
9bb48c82 | 484 | .splice_write = iter_file_splice_write, |
1da177e4 | 485 | .poll = tty_poll, |
04f378b1 | 486 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 487 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
488 | .open = tty_open, |
489 | .release = tty_release, | |
490 | .fasync = tty_fasync, | |
491 | }; | |
492 | ||
62322d25 | 493 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 | 494 | .llseek = no_llseek, |
ddc5fda7 | 495 | .read_iter = hung_up_tty_read, |
17749851 | 496 | .write_iter = hung_up_tty_write, |
1da177e4 | 497 | .poll = hung_up_tty_poll, |
04f378b1 | 498 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 499 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 500 | .release = tty_release, |
f557474c | 501 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
502 | }; |
503 | ||
504 | static DEFINE_SPINLOCK(redirect_lock); | |
505 | static struct file *redirect; | |
506 | ||
507 | /** | |
796a75a9 JS |
508 | * tty_wakeup - request more data |
509 | * @tty: terminal | |
1da177e4 | 510 | * |
796a75a9 JS |
511 | * Internal and external helper for wakeups of tty. This function informs the |
512 | * line discipline if present that the driver is ready to receive more output | |
513 | * data. | |
1da177e4 | 514 | */ |
1da177e4 LT |
515 | void tty_wakeup(struct tty_struct *tty) |
516 | { | |
517 | struct tty_ldisc *ld; | |
37bdfb07 | 518 | |
1da177e4 LT |
519 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
520 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 521 | if (ld) { |
a352def2 AC |
522 | if (ld->ops->write_wakeup) |
523 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
524 | tty_ldisc_deref(ld); |
525 | } | |
526 | } | |
a9a08845 | 527 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 | 528 | } |
1da177e4 LT |
529 | EXPORT_SYMBOL_GPL(tty_wakeup); |
530 | ||
f446776e | 531 | /** |
796a75a9 JS |
532 | * tty_release_redirect - Release a redirect on a pty if present |
533 | * @tty: tty device | |
f446776e | 534 | * |
796a75a9 JS |
535 | * This is available to the pty code so if the master closes, if the slave is a |
536 | * redirect it can release the redirect. | |
f446776e | 537 | */ |
dd9f6114 | 538 | static struct file *tty_release_redirect(struct tty_struct *tty) |
f446776e CM |
539 | { |
540 | struct file *f = NULL; | |
541 | ||
542 | spin_lock(&redirect_lock); | |
543 | if (redirect && file_tty(redirect) == tty) { | |
544 | f = redirect; | |
545 | redirect = NULL; | |
546 | } | |
547 | spin_unlock(&redirect_lock); | |
548 | ||
549 | return f; | |
550 | } | |
f446776e | 551 | |
af9b897e | 552 | /** |
796a75a9 JS |
553 | * __tty_hangup - actual handler for hangup events |
554 | * @tty: tty device | |
555 | * @exit_session: if non-zero, signal all foreground group processes | |
556 | * | |
557 | * This can be called by a "kworker" kernel thread. That is process synchronous | |
558 | * but doesn't hold any locks, so we need to make sure we have the appropriate | |
559 | * locks for what we're doing. | |
560 | * | |
561 | * The hangup event clears any pending redirections onto the hung up device. It | |
562 | * ensures future writes will error and it does the needed line discipline | |
563 | * hangup and signal delivery. The tty object itself remains intact. | |
564 | * | |
565 | * Locking: | |
566 | * * BTM | |
567 | * | |
568 | * * redirect lock for undoing redirection | |
569 | * * file list lock for manipulating list of ttys | |
570 | * * tty_ldiscs_lock from called functions | |
571 | * * termios_rwsem resetting termios data | |
572 | * * tasklist_lock to walk task list for hangup event | |
573 | * | |
574 | * * ->siglock to protect ->signal/->sighand | |
575 | * | |
1da177e4 | 576 | */ |
f91e2590 | 577 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 578 | { |
37bdfb07 | 579 | struct file *cons_filp = NULL; |
f446776e | 580 | struct file *filp, *f; |
d996b62a | 581 | struct tty_file_private *priv; |
1da177e4 | 582 | int closecount = 0, n; |
ea648a47 | 583 | int refs; |
1da177e4 LT |
584 | |
585 | if (!tty) | |
586 | return; | |
587 | ||
f446776e | 588 | f = tty_release_redirect(tty); |
37bdfb07 | 589 | |
89c8d91e | 590 | tty_lock(tty); |
11dbf203 | 591 | |
cb50e523 PH |
592 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
593 | tty_unlock(tty); | |
594 | return; | |
595 | } | |
596 | ||
28b0f8a6 TH |
597 | /* |
598 | * Some console devices aren't actually hung up for technical and | |
599 | * historical reasons, which can lead to indefinite interruptible | |
600 | * sleep in n_tty_read(). The following explicitly tells | |
601 | * n_tty_read() to abort readers. | |
602 | */ | |
603 | set_bit(TTY_HUPPING, &tty->flags); | |
604 | ||
ec79d605 | 605 | /* inuse_filps is protected by the single tty lock, |
b426a5b8 XT |
606 | * this really needs to change if we want to flush the |
607 | * workqueue with the lock held. | |
608 | */ | |
11dbf203 | 609 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 610 | |
4a510969 | 611 | spin_lock(&tty->files_lock); |
1da177e4 | 612 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
613 | list_for_each_entry(priv, &tty->tty_files, list) { |
614 | filp = priv->file; | |
9bb48c82 | 615 | if (filp->f_op->write_iter == redirected_tty_write) |
1da177e4 | 616 | cons_filp = filp; |
9bb48c82 | 617 | if (filp->f_op->write_iter != tty_write) |
1da177e4 LT |
618 | continue; |
619 | closecount++; | |
ec79d605 | 620 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
621 | filp->f_op = &hung_up_tty_fops; |
622 | } | |
4a510969 | 623 | spin_unlock(&tty->files_lock); |
37bdfb07 | 624 | |
25fdf243 PH |
625 | refs = tty_signal_session_leader(tty, exit_session); |
626 | /* Account for the p->signal references we killed */ | |
627 | while (refs--) | |
628 | tty_kref_put(tty); | |
629 | ||
892d1fa7 | 630 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 631 | |
64d608db | 632 | spin_lock_irq(&tty->ctrl.lock); |
c65c9bc3 | 633 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 634 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
64d608db JS |
635 | put_pid(tty->ctrl.session); |
636 | put_pid(tty->ctrl.pgrp); | |
637 | tty->ctrl.session = NULL; | |
638 | tty->ctrl.pgrp = NULL; | |
639 | tty->ctrl.pktstatus = 0; | |
640 | spin_unlock_irq(&tty->ctrl.lock); | |
9c9f4ded | 641 | |
1da177e4 | 642 | /* |
37bdfb07 AC |
643 | * If one of the devices matches a console pointer, we |
644 | * cannot just call hangup() because that will cause | |
645 | * tty->count and state->count to go out of sync. | |
646 | * So we just call close() the right number of times. | |
1da177e4 LT |
647 | */ |
648 | if (cons_filp) { | |
f34d7a5b | 649 | if (tty->ops->close) |
1da177e4 | 650 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
651 | tty->ops->close(tty, cons_filp); |
652 | } else if (tty->ops->hangup) | |
7c6d340f | 653 | tty->ops->hangup(tty); |
37bdfb07 | 654 | /* |
892d1fa7 PH |
655 | * We don't want to have driver/ldisc interactions beyond the ones |
656 | * we did here. The driver layer expects no calls after ->hangup() | |
657 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 658 | */ |
1da177e4 | 659 | set_bit(TTY_HUPPED, &tty->flags); |
28b0f8a6 | 660 | clear_bit(TTY_HUPPING, &tty->flags); |
89c8d91e | 661 | tty_unlock(tty); |
11dbf203 | 662 | |
1da177e4 LT |
663 | if (f) |
664 | fput(f); | |
665 | } | |
666 | ||
ddcd9fb6 AB |
667 | static void do_tty_hangup(struct work_struct *work) |
668 | { | |
669 | struct tty_struct *tty = | |
670 | container_of(work, struct tty_struct, hangup_work); | |
671 | ||
f91e2590 | 672 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
673 | } |
674 | ||
af9b897e | 675 | /** |
796a75a9 JS |
676 | * tty_hangup - trigger a hangup event |
677 | * @tty: tty to hangup | |
af9b897e | 678 | * |
796a75a9 JS |
679 | * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a |
680 | * hangup sequence to run after this event. | |
af9b897e | 681 | */ |
37bdfb07 | 682 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 683 | { |
d435cefe | 684 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
685 | schedule_work(&tty->hangup_work); |
686 | } | |
1da177e4 LT |
687 | EXPORT_SYMBOL(tty_hangup); |
688 | ||
af9b897e | 689 | /** |
796a75a9 JS |
690 | * tty_vhangup - process vhangup |
691 | * @tty: tty to hangup | |
af9b897e | 692 | * |
796a75a9 JS |
693 | * The user has asked via system call for the terminal to be hung up. We do |
694 | * this synchronously so that when the syscall returns the process is complete. | |
695 | * That guarantee is necessary for security reasons. | |
af9b897e | 696 | */ |
37bdfb07 | 697 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 698 | { |
d435cefe | 699 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 700 | __tty_hangup(tty, 0); |
1da177e4 LT |
701 | } |
702 | EXPORT_SYMBOL(tty_vhangup); | |
703 | ||
11dbf203 | 704 | |
2cb5998b | 705 | /** |
796a75a9 | 706 | * tty_vhangup_self - process vhangup for own ctty |
2cb5998b | 707 | * |
796a75a9 | 708 | * Perform a vhangup on the current controlling tty |
2cb5998b | 709 | */ |
2cb5998b AC |
710 | void tty_vhangup_self(void) |
711 | { | |
712 | struct tty_struct *tty; | |
713 | ||
2cb5998b AC |
714 | tty = get_current_tty(); |
715 | if (tty) { | |
716 | tty_vhangup(tty); | |
717 | tty_kref_put(tty); | |
718 | } | |
2cb5998b AC |
719 | } |
720 | ||
f91e2590 | 721 | /** |
796a75a9 JS |
722 | * tty_vhangup_session - hangup session leader exit |
723 | * @tty: tty to hangup | |
f91e2590 | 724 | * |
796a75a9 JS |
725 | * The session leader is exiting and hanging up its controlling terminal. |
726 | * Every process in the foreground process group is signalled %SIGHUP. | |
f91e2590 | 727 | * |
796a75a9 JS |
728 | * We do this synchronously so that when the syscall returns the process is |
729 | * complete. That guarantee is necessary for security reasons. | |
f91e2590 | 730 | */ |
a1235b3e | 731 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 732 | { |
d435cefe | 733 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
734 | __tty_hangup(tty, 1); |
735 | } | |
736 | ||
af9b897e | 737 | /** |
796a75a9 JS |
738 | * tty_hung_up_p - was tty hung up |
739 | * @filp: file pointer of tty | |
af9b897e | 740 | * |
796a75a9 | 741 | * Return: true if the tty has been subject to a vhangup or a carrier loss |
af9b897e | 742 | */ |
37bdfb07 | 743 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 744 | { |
ed3f0af8 | 745 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 | 746 | } |
1da177e4 LT |
747 | EXPORT_SYMBOL(tty_hung_up_p); |
748 | ||
d06e256f JS |
749 | void __stop_tty(struct tty_struct *tty) |
750 | { | |
751 | if (tty->flow.stopped) | |
752 | return; | |
753 | tty->flow.stopped = true; | |
754 | if (tty->ops->stop) | |
755 | tty->ops->stop(tty); | |
756 | } | |
757 | ||
af9b897e | 758 | /** |
796a75a9 JS |
759 | * stop_tty - propagate flow control |
760 | * @tty: tty to stop | |
af9b897e | 761 | * |
796a75a9 JS |
762 | * Perform flow control to the driver. May be called on an already stopped |
763 | * device and will not re-call the &tty_driver->stop() method. | |
af9b897e | 764 | * |
796a75a9 JS |
765 | * This functionality is used by both the line disciplines for halting incoming |
766 | * flow and by the driver. It may therefore be called from any context, may be | |
767 | * under the tty %atomic_write_lock but not always. | |
af9b897e | 768 | * |
796a75a9 JS |
769 | * Locking: |
770 | * flow.lock | |
af9b897e | 771 | */ |
f9e053dc PH |
772 | void stop_tty(struct tty_struct *tty) |
773 | { | |
774 | unsigned long flags; | |
775 | ||
6e94dbc7 | 776 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 777 | __stop_tty(tty); |
6e94dbc7 | 778 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 779 | } |
1da177e4 LT |
780 | EXPORT_SYMBOL(stop_tty); |
781 | ||
d06e256f JS |
782 | void __start_tty(struct tty_struct *tty) |
783 | { | |
784 | if (!tty->flow.stopped || tty->flow.tco_stopped) | |
785 | return; | |
786 | tty->flow.stopped = false; | |
787 | if (tty->ops->start) | |
788 | tty->ops->start(tty); | |
789 | tty_wakeup(tty); | |
790 | } | |
791 | ||
af9b897e | 792 | /** |
796a75a9 JS |
793 | * start_tty - propagate flow control |
794 | * @tty: tty to start | |
af9b897e | 795 | * |
796a75a9 JS |
796 | * Start a tty that has been stopped if at all possible. If @tty was previously |
797 | * stopped and is now being started, the &tty_driver->start() method is invoked | |
798 | * and the line discipline woken. | |
af9b897e | 799 | * |
796a75a9 JS |
800 | * Locking: |
801 | * flow.lock | |
af9b897e | 802 | */ |
f9e053dc PH |
803 | void start_tty(struct tty_struct *tty) |
804 | { | |
805 | unsigned long flags; | |
806 | ||
6e94dbc7 | 807 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 808 | __start_tty(tty); |
6e94dbc7 | 809 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 810 | } |
1da177e4 LT |
811 | EXPORT_SYMBOL(start_tty); |
812 | ||
360c11e2 | 813 | static void tty_update_time(struct tty_struct *tty, bool mtime) |
37b7f3c7 | 814 | { |
c884f871 | 815 | time64_t sec = ktime_get_real_seconds(); |
360c11e2 | 816 | struct tty_file_private *priv; |
fbf47635 | 817 | |
360c11e2 MS |
818 | spin_lock(&tty->files_lock); |
819 | list_for_each_entry(priv, &tty->tty_files, list) { | |
820 | struct inode *inode = file_inode(priv->file); | |
821 | struct timespec64 *time = mtime ? &inode->i_mtime : &inode->i_atime; | |
822 | ||
823 | /* | |
824 | * We only care if the two values differ in anything other than the | |
825 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
826 | * the time of the tty device, otherwise it could be construded as a | |
827 | * security leak to let userspace know the exact timing of the tty. | |
828 | */ | |
829 | if ((sec ^ time->tv_sec) & ~7) | |
830 | time->tv_sec = sec; | |
831 | } | |
832 | spin_unlock(&tty->files_lock); | |
37b7f3c7 JS |
833 | } |
834 | ||
3b830a9c LT |
835 | /* |
836 | * Iterate on the ldisc ->read() function until we've gotten all | |
837 | * the data the ldisc has for us. | |
838 | * | |
839 | * The "cookie" is something that the ldisc read function can fill | |
840 | * in to let us know that there is more data to be had. | |
841 | * | |
842 | * We promise to continue to call the ldisc until it stops returning | |
843 | * data or clears the cookie. The cookie may be something that the | |
844 | * ldisc maintains state for and needs to free. | |
845 | */ | |
24b01c5d JSS |
846 | static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, |
847 | struct file *file, struct iov_iter *to) | |
3b830a9c | 848 | { |
3b830a9c LT |
849 | void *cookie = NULL; |
850 | unsigned long offset = 0; | |
851 | char kernel_buf[64]; | |
24b01c5d | 852 | ssize_t retval = 0; |
e3afc5b0 | 853 | size_t copied, count = iov_iter_count(to); |
3b830a9c LT |
854 | |
855 | do { | |
48a6ab88 | 856 | ssize_t size = min(count, sizeof(kernel_buf)); |
3b830a9c | 857 | |
3b830a9c LT |
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 | 913 | { |
dd78b0c4 | 914 | struct file *file = iocb->ki_filp; |
37b7f3c7 | 915 | struct inode *inode = file_inode(file); |
d996b62a | 916 | struct tty_struct *tty = file_tty(file); |
1da177e4 | 917 | struct tty_ldisc *ld; |
24b01c5d | 918 | ssize_t ret; |
1da177e4 | 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); |
24b01c5d | 931 | ret = -EIO; |
a352def2 | 932 | if (ld->ops->read) |
24b01c5d | 933 | ret = iterate_tty_read(ld, tty, file, to); |
1da177e4 | 934 | tty_ldisc_deref(ld); |
b0de59b5 | 935 | |
24b01c5d | 936 | if (ret > 0) |
360c11e2 | 937 | tty_update_time(tty, false); |
37b7f3c7 | 938 | |
24b01c5d | 939 | return ret; |
1da177e4 LT |
940 | } |
941 | ||
094fb49a | 942 | 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 | ||
af815336 | 948 | int tty_write_lock(struct tty_struct *tty, bool 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 | */ | |
a32a672d JSS |
963 | static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty, |
964 | struct file *file, struct iov_iter *from) | |
1da177e4 | 965 | { |
ccc8dc00 | 966 | size_t chunk, count = iov_iter_count(from); |
9c1729db | 967 | ssize_t ret, written = 0; |
37bdfb07 | 968 | |
9c1729db AC |
969 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
970 | if (ret < 0) | |
971 | return ret; | |
1da177e4 LT |
972 | |
973 | /* | |
974 | * We chunk up writes into a temporary buffer. This | |
975 | * simplifies low-level drivers immensely, since they | |
976 | * don't have locking issues and user mode accesses. | |
977 | * | |
978 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
979 | * big chunk-size.. | |
980 | * | |
981 | * The default chunk-size is 2kB, because the NTTY | |
982 | * layer has problems with bigger chunks. It will | |
983 | * claim to be able to handle more characters than | |
984 | * it actually does. | |
985 | */ | |
986 | chunk = 2048; | |
987 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
988 | chunk = 65536; | |
989 | if (count < chunk) | |
990 | chunk = count; | |
991 | ||
70522e12 | 992 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 993 | if (tty->write_cnt < chunk) { |
402fda92 | 994 | unsigned char *buf_chunk; |
1da177e4 LT |
995 | |
996 | if (chunk < 1024) | |
997 | chunk = 1024; | |
998 | ||
d6d9d17a | 999 | buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL); |
402fda92 | 1000 | if (!buf_chunk) { |
9c1729db AC |
1001 | ret = -ENOMEM; |
1002 | goto out; | |
1da177e4 | 1003 | } |
d6d9d17a | 1004 | kvfree(tty->write_buf); |
1da177e4 | 1005 | tty->write_cnt = chunk; |
402fda92 | 1006 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1007 | } |
1008 | ||
1009 | /* Do the write .. */ | |
1010 | for (;;) { | |
ccc8dc00 | 1011 | size_t size = min(chunk, count); |
9bb48c82 | 1012 | |
1da177e4 | 1013 | ret = -EFAULT; |
9bb48c82 | 1014 | if (copy_from_iter(tty->write_buf, size, from) != size) |
1da177e4 | 1015 | break; |
9bb48c82 | 1016 | |
f47a4fd6 | 1017 | ret = ld->ops->write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1018 | if (ret <= 0) |
1019 | break; | |
9bb48c82 | 1020 | |
3342ff26 LT |
1021 | written += ret; |
1022 | if (ret > size) | |
1023 | break; | |
1024 | ||
9bb48c82 LT |
1025 | /* FIXME! Have Al check this! */ |
1026 | if (ret != size) | |
1027 | iov_iter_revert(from, size-ret); | |
1028 | ||
1da177e4 LT |
1029 | count -= ret; |
1030 | if (!count) | |
1031 | break; | |
1032 | ret = -ERESTARTSYS; | |
1033 | if (signal_pending(current)) | |
1034 | break; | |
1035 | cond_resched(); | |
1036 | } | |
37b7f3c7 | 1037 | if (written) { |
360c11e2 | 1038 | tty_update_time(tty, true); |
1da177e4 | 1039 | ret = written; |
37b7f3c7 | 1040 | } |
9c1729db AC |
1041 | out: |
1042 | tty_write_unlock(tty); | |
1da177e4 LT |
1043 | return ret; |
1044 | } | |
1045 | ||
95f9bfc6 AC |
1046 | /** |
1047 | * tty_write_message - write a message to a certain tty, not just the console. | |
1048 | * @tty: the destination tty_struct | |
1049 | * @msg: the message to write | |
1050 | * | |
796a75a9 JS |
1051 | * This is used for messages that need to be redirected to a specific tty. We |
1052 | * don't put it into the syslog queue right now maybe in the future if really | |
1053 | * needed. | |
95f9bfc6 | 1054 | * |
ec79d605 | 1055 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 | 1056 | */ |
95f9bfc6 AC |
1057 | void tty_write_message(struct tty_struct *tty, char *msg) |
1058 | { | |
95f9bfc6 AC |
1059 | if (tty) { |
1060 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1061 | tty_lock(tty); |
4b41b953 | 1062 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1063 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1064 | tty_unlock(tty); |
95f9bfc6 AC |
1065 | tty_write_unlock(tty); |
1066 | } | |
95f9bfc6 AC |
1067 | } |
1068 | ||
a9cbbb80 | 1069 | static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) |
1da177e4 | 1070 | { |
d996b62a | 1071 | struct tty_struct *tty = file_tty(file); |
395e7833 | 1072 | struct tty_ldisc *ld; |
1da177e4 | 1073 | ssize_t ret; |
37bdfb07 | 1074 | |
6131ffaa | 1075 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1076 | return -EIO; |
18900ca6 | 1077 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
5e4d5ac3 | 1078 | return -EIO; |
f34d7a5b AC |
1079 | /* Short term debug to catch buggy drivers */ |
1080 | if (tty->ops->write_room == NULL) | |
339f36ba | 1081 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1082 | ld = tty_ldisc_ref_wait(tty); |
17749851 LT |
1083 | if (!ld) |
1084 | return hung_up_tty_write(iocb, from); | |
1085 | if (!ld->ops->write) | |
1da177e4 LT |
1086 | ret = -EIO; |
1087 | else | |
a32a672d | 1088 | ret = iterate_tty_write(ld, tty, file, from); |
1da177e4 LT |
1089 | tty_ldisc_deref(ld); |
1090 | return ret; | |
1091 | } | |
1092 | ||
756a4e4a | 1093 | /** |
796a75a9 JS |
1094 | * tty_write - write method for tty device file |
1095 | * @iocb: kernel I/O control block | |
1096 | * @from: iov_iter with data to write | |
756a4e4a | 1097 | * |
796a75a9 | 1098 | * Write data to a tty device via the line discipline. |
756a4e4a | 1099 | * |
796a75a9 JS |
1100 | * Locking: |
1101 | * Locks the line discipline as required | |
1102 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1103 | * and are then processed in chunks to the device. The line | |
1104 | * discipline write method will not be invoked in parallel for | |
1105 | * each device. | |
756a4e4a | 1106 | */ |
a9cbbb80 LT |
1107 | static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) |
1108 | { | |
1109 | return file_tty_write(iocb->ki_filp, iocb, from); | |
1110 | } | |
1111 | ||
9bb48c82 | 1112 | ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 LT |
1113 | { |
1114 | struct file *p = NULL; | |
1115 | ||
1116 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1117 | if (redirect) |
1118 | p = get_file(redirect); | |
1da177e4 LT |
1119 | spin_unlock(&redirect_lock); |
1120 | ||
a9cbbb80 | 1121 | /* |
44969f85 | 1122 | * We know the redirected tty is just another tty, we can |
a9cbbb80 LT |
1123 | * call file_tty_write() directly with that file pointer. |
1124 | */ | |
1da177e4 LT |
1125 | if (p) { |
1126 | ssize_t res; | |
e73b2407 | 1127 | |
a9cbbb80 | 1128 | res = file_tty_write(p, iocb, iter); |
1da177e4 LT |
1129 | fput(p); |
1130 | return res; | |
1131 | } | |
9bb48c82 | 1132 | return tty_write(iocb, iter); |
1da177e4 LT |
1133 | } |
1134 | ||
796a75a9 JS |
1135 | /** |
1136 | * tty_send_xchar - send priority character | |
1137 | * @tty: the tty to send to | |
1138 | * @ch: xchar to send | |
136d5258 | 1139 | * |
796a75a9 | 1140 | * Send a high priority character to the tty even if stopped. |
136d5258 | 1141 | * |
796a75a9 | 1142 | * Locking: none for xchar method, write ordering for write method. |
136d5258 | 1143 | */ |
136d5258 PH |
1144 | int tty_send_xchar(struct tty_struct *tty, char ch) |
1145 | { | |
6e94dbc7 | 1146 | bool was_stopped = tty->flow.stopped; |
136d5258 PH |
1147 | |
1148 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1149 | down_read(&tty->termios_rwsem); |
136d5258 | 1150 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1151 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1152 | return 0; |
1153 | } | |
1154 | ||
af815336 | 1155 | if (tty_write_lock(tty, false) < 0) |
136d5258 PH |
1156 | return -ERESTARTSYS; |
1157 | ||
ee0c1a65 | 1158 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1159 | if (was_stopped) |
1160 | start_tty(tty); | |
1161 | tty->ops->write(tty, &ch, 1); | |
1162 | if (was_stopped) | |
1163 | stop_tty(tty); | |
ee0c1a65 | 1164 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1165 | tty_write_unlock(tty); |
1166 | return 0; | |
1167 | } | |
1168 | ||
af9b897e | 1169 | /** |
796a75a9 JS |
1170 | * pty_line_name - generate name for a pty |
1171 | * @driver: the tty driver in use | |
1172 | * @index: the minor number | |
1173 | * @p: output buffer of at least 6 bytes | |
af9b897e | 1174 | * |
796a75a9 JS |
1175 | * Generate a name from a @driver reference and write it to the output buffer |
1176 | * @p. | |
af9b897e | 1177 | * |
796a75a9 | 1178 | * Locking: None |
af9b897e AC |
1179 | */ |
1180 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 | 1181 | { |
a846dcf9 | 1182 | static const char ptychar[] = "pqrstuvwxyzabcde"; |
1da177e4 LT |
1183 | int i = index + driver->name_base; |
1184 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1185 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1186 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1187 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1188 | } |
1189 | ||
af9b897e | 1190 | /** |
796a75a9 JS |
1191 | * tty_line_name - generate name for a tty |
1192 | * @driver: the tty driver in use | |
1193 | * @index: the minor number | |
1194 | * @p: output buffer of at least 7 bytes | |
af9b897e | 1195 | * |
796a75a9 JS |
1196 | * Generate a name from a @driver reference and write it to the output buffer |
1197 | * @p. | |
af9b897e | 1198 | * |
796a75a9 | 1199 | * Locking: None |
af9b897e | 1200 | */ |
723abd87 | 1201 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1202 | { |
0019b408 | 1203 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1204 | return sprintf(p, "%s", driver->name); |
0019b408 | 1205 | else |
723abd87 HR |
1206 | return sprintf(p, "%s%d", driver->name, |
1207 | index + driver->name_base); | |
1da177e4 LT |
1208 | } |
1209 | ||
99f1fe18 | 1210 | /** |
796a75a9 JS |
1211 | * tty_driver_lookup_tty() - find an existing tty, if any |
1212 | * @driver: the driver for the tty | |
1213 | * @file: file object | |
1214 | * @idx: the minor number | |
23499705 | 1215 | * |
796a75a9 JS |
1216 | * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the |
1217 | * driver lookup() method returns an error. | |
23499705 | 1218 | * |
796a75a9 | 1219 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1220 | */ |
a47d545f | 1221 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1222 | struct file *file, int idx) |
23499705 | 1223 | { |
aa3cb814 PH |
1224 | struct tty_struct *tty; |
1225 | ||
db4df8e9 | 1226 | if (driver->ops->lookup) { |
12e84c71 OK |
1227 | if (!file) |
1228 | tty = ERR_PTR(-EIO); | |
1229 | else | |
1230 | tty = driver->ops->lookup(driver, file, idx); | |
db4df8e9 SS |
1231 | } else { |
1232 | if (idx >= driver->num) | |
1233 | return ERR_PTR(-EINVAL); | |
aa3cb814 | 1234 | tty = driver->ttys[idx]; |
db4df8e9 | 1235 | } |
aa3cb814 PH |
1236 | if (!IS_ERR(tty)) |
1237 | tty_kref_get(tty); | |
1238 | return tty; | |
23499705 SB |
1239 | } |
1240 | ||
bf970ee4 | 1241 | /** |
796a75a9 JS |
1242 | * tty_init_termios - helper for termios setup |
1243 | * @tty: the tty to set up | |
bf970ee4 | 1244 | * |
796a75a9 JS |
1245 | * Initialise the termios structure for this tty. This runs under the |
1246 | * %tty_mutex currently so we can be relaxed about ordering. | |
bf970ee4 | 1247 | */ |
a3123fd0 | 1248 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1249 | { |
fe6e29fd | 1250 | struct ktermios *tp; |
bf970ee4 AC |
1251 | int idx = tty->index; |
1252 | ||
36b3c070 AC |
1253 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1254 | tty->termios = tty->driver->init_termios; | |
1255 | else { | |
1256 | /* Check for lazy saved data */ | |
1257 | tp = tty->driver->termios[idx]; | |
ece53405 | 1258 | if (tp != NULL) { |
36b3c070 | 1259 | tty->termios = *tp; |
ece53405 PH |
1260 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1261 | } else | |
36b3c070 | 1262 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1263 | } |
bf970ee4 | 1264 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1265 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1266 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1267 | } |
fe1ae7fd | 1268 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1269 | |
31bc35d3 JS |
1270 | /** |
1271 | * tty_standard_install - usual tty->ops->install | |
1272 | * @driver: the driver for the tty | |
1273 | * @tty: the tty | |
1274 | * | |
1275 | * If the @driver overrides @tty->ops->install, it still can call this function | |
1276 | * to perform the standard install operations. | |
1277 | */ | |
66d450e8 JS |
1278 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1279 | { | |
a3123fd0 | 1280 | tty_init_termios(tty); |
66d450e8 JS |
1281 | tty_driver_kref_get(driver); |
1282 | tty->count++; | |
1283 | driver->ttys[tty->index] = tty; | |
1284 | return 0; | |
1285 | } | |
1286 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1287 | ||
99f1fe18 | 1288 | /** |
796a75a9 JS |
1289 | * tty_driver_install_tty() - install a tty entry in the driver |
1290 | * @driver: the driver for the tty | |
1291 | * @tty: the tty | |
8b0a88d5 | 1292 | * |
796a75a9 JS |
1293 | * Install a tty object into the driver tables. The @tty->index field will be |
1294 | * set by the time this is called. This method is responsible for ensuring any | |
1295 | * need additional structures are allocated and configured. | |
8b0a88d5 | 1296 | * |
796a75a9 | 1297 | * Locking: tty_mutex for now |
8b0a88d5 AC |
1298 | */ |
1299 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1300 | struct tty_struct *tty) | |
1301 | { | |
66d450e8 JS |
1302 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1303 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1304 | } |
1305 | ||
1306 | /** | |
796a75a9 JS |
1307 | * tty_driver_remove_tty() - remove a tty from the driver tables |
1308 | * @driver: the driver for the tty | |
1309 | * @tty: tty to remove | |
8b0a88d5 | 1310 | * |
796a75a9 JS |
1311 | * Remove a tty object from the driver tables. The tty->index field will be set |
1312 | * by the time this is called. | |
8b0a88d5 | 1313 | * |
796a75a9 | 1314 | * Locking: tty_mutex for now |
8b0a88d5 | 1315 | */ |
05de87ed | 1316 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1317 | { |
1318 | if (driver->ops->remove) | |
1319 | driver->ops->remove(driver, tty); | |
1320 | else | |
1321 | driver->ttys[tty->index] = NULL; | |
1322 | } | |
1323 | ||
fa441954 | 1324 | /** |
796a75a9 JS |
1325 | * tty_reopen() - fast re-open of an open tty |
1326 | * @tty: the tty to open | |
23499705 | 1327 | * |
796a75a9 | 1328 | * Re-opens on master ptys are not allowed and return -%EIO. |
23499705 | 1329 | * |
796a75a9 JS |
1330 | * Locking: Caller must hold tty_lock |
1331 | * Return: 0 on success, -errno on error. | |
23499705 | 1332 | */ |
99f1fe18 | 1333 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1334 | { |
1335 | struct tty_driver *driver = tty->driver; | |
d3736d82 DS |
1336 | struct tty_ldisc *ld; |
1337 | int retval = 0; | |
23499705 | 1338 | |
23499705 | 1339 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1340 | driver->subtype == PTY_TYPE_MASTER) |
1341 | return -EIO; | |
23499705 | 1342 | |
7f22f6c9 PH |
1343 | if (!tty->count) |
1344 | return -EAGAIN; | |
1345 | ||
86f2c00f PH |
1346 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1347 | return -EBUSY; | |
1348 | ||
d3736d82 DS |
1349 | ld = tty_ldisc_ref_wait(tty); |
1350 | if (ld) { | |
1351 | tty_ldisc_deref(ld); | |
1352 | } else { | |
1353 | retval = tty_ldisc_lock(tty, 5 * HZ); | |
1354 | if (retval) | |
1355 | return retval; | |
1356 | ||
1357 | if (!tty->ldisc) | |
1358 | retval = tty_ldisc_reinit(tty, tty->termios.c_line); | |
1359 | tty_ldisc_unlock(tty); | |
1360 | } | |
23499705 | 1361 | |
cf62a1a1 DS |
1362 | if (retval == 0) |
1363 | tty->count++; | |
fe324167 DS |
1364 | |
1365 | return retval; | |
23499705 SB |
1366 | } |
1367 | ||
af9b897e | 1368 | /** |
796a75a9 JS |
1369 | * tty_init_dev - initialise a tty device |
1370 | * @driver: tty driver we are opening a device on | |
1371 | * @idx: device index | |
af9b897e | 1372 | * |
796a75a9 JS |
1373 | * Prepare a tty device. This may not be a "new" clean device but could also be |
1374 | * an active device. The pty drivers require special handling because of this. | |
af9b897e | 1375 | * |
796a75a9 JS |
1376 | * Locking: |
1377 | * The function is called under the tty_mutex, which protects us from the | |
1378 | * tty struct or driver itself going away. | |
af9b897e | 1379 | * |
796a75a9 JS |
1380 | * On exit the tty device has the line discipline attached and a reference |
1381 | * count of 1. If a pair was created for pty/tty use and the other was a pty | |
1382 | * master then it too has a reference count of 1. | |
af9b897e | 1383 | * |
796a75a9 JS |
1384 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed |
1385 | * open. The new code protects the open with a mutex, so it's really quite | |
1386 | * straightforward. The mutex locking can probably be relaxed for the (most | |
1387 | * common) case of reopening a tty. | |
fa441954 | 1388 | * |
796a75a9 | 1389 | * Return: new tty structure |
1da177e4 | 1390 | */ |
593a27c4 | 1391 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1392 | { |
bf970ee4 | 1393 | struct tty_struct *tty; |
73ec06fc | 1394 | int retval; |
1da177e4 | 1395 | |
1da177e4 LT |
1396 | /* |
1397 | * First time open is complex, especially for PTY devices. | |
1398 | * This code guarantees that either everything succeeds and the | |
1399 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1400 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1401 | * may be retained.) |
1da177e4 LT |
1402 | */ |
1403 | ||
73ec06fc AC |
1404 | if (!try_module_get(driver->owner)) |
1405 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1406 | |
2c964a2f | 1407 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1408 | if (!tty) { |
1409 | retval = -ENOMEM; | |
1410 | goto err_module_put; | |
1411 | } | |
1da177e4 | 1412 | |
89c8d91e | 1413 | tty_lock(tty); |
73ec06fc | 1414 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1415 | if (retval < 0) |
c8b710b3 | 1416 | goto err_free_tty; |
8b0a88d5 | 1417 | |
04831dc1 JS |
1418 | if (!tty->port) |
1419 | tty->port = driver->ports[idx]; | |
1420 | ||
2ae0b31e JS |
1421 | if (WARN_RATELIMIT(!tty->port, |
1422 | "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", | |
1423 | __func__, tty->driver->name)) { | |
1424 | retval = -EINVAL; | |
1425 | goto err_release_lock; | |
1426 | } | |
5d4121c0 | 1427 | |
b027e229 GK |
1428 | retval = tty_ldisc_lock(tty, 5 * HZ); |
1429 | if (retval) | |
1430 | goto err_release_lock; | |
967fab69 JS |
1431 | tty->port->itty = tty; |
1432 | ||
37bdfb07 | 1433 | /* |
1da177e4 | 1434 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1435 | * If we fail here just call release_tty to clean up. No need |
1436 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1437 | */ |
bf970ee4 | 1438 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1439 | if (retval) |
d5543503 | 1440 | goto err_release_tty; |
b027e229 | 1441 | tty_ldisc_unlock(tty); |
89c8d91e | 1442 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1443 | return tty; |
1da177e4 | 1444 | |
c8b710b3 | 1445 | err_free_tty: |
89c8d91e | 1446 | tty_unlock(tty); |
d5543503 JS |
1447 | free_tty_struct(tty); |
1448 | err_module_put: | |
1da177e4 | 1449 | module_put(driver->owner); |
d5543503 | 1450 | return ERR_PTR(retval); |
1da177e4 | 1451 | |
d5698c28 | 1452 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1453 | err_release_tty: |
b027e229 | 1454 | tty_ldisc_unlock(tty); |
339f36ba PH |
1455 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1456 | retval, idx); | |
b027e229 GK |
1457 | err_release_lock: |
1458 | tty_unlock(tty); | |
d5698c28 | 1459 | release_tty(tty, idx); |
73ec06fc | 1460 | return ERR_PTR(retval); |
1da177e4 LT |
1461 | } |
1462 | ||
f51ccf46 JH |
1463 | /** |
1464 | * tty_save_termios() - save tty termios data in driver table | |
1465 | * @tty: tty whose termios data to save | |
1466 | * | |
1467 | * Locking: Caller guarantees serialisation with tty_init_termios(). | |
1468 | */ | |
1469 | void tty_save_termios(struct tty_struct *tty) | |
feebed65 AC |
1470 | { |
1471 | struct ktermios *tp; | |
1472 | int idx = tty->index; | |
36b3c070 AC |
1473 | |
1474 | /* If the port is going to reset then it has no termios to save */ | |
1475 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1476 | return; | |
1477 | ||
1478 | /* Stash the termios data */ | |
1479 | tp = tty->driver->termios[idx]; | |
1480 | if (tp == NULL) { | |
a3241891 | 1481 | tp = kmalloc(sizeof(*tp), GFP_KERNEL); |
25080652 | 1482 | if (tp == NULL) |
36b3c070 | 1483 | return; |
4ac5d705 | 1484 | tty->driver->termios[idx] = tp; |
feebed65 | 1485 | } |
36b3c070 | 1486 | *tp = tty->termios; |
feebed65 | 1487 | } |
f51ccf46 | 1488 | EXPORT_SYMBOL_GPL(tty_save_termios); |
feebed65 | 1489 | |
a2965b7b | 1490 | /** |
796a75a9 JS |
1491 | * tty_flush_works - flush all works of a tty/pty pair |
1492 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1493 | * |
796a75a9 | 1494 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1495 | */ |
1496 | static void tty_flush_works(struct tty_struct *tty) | |
1497 | { | |
1498 | flush_work(&tty->SAK_work); | |
1499 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1500 | if (tty->link) { |
1501 | flush_work(&tty->link->SAK_work); | |
1502 | flush_work(&tty->link->hangup_work); | |
1503 | } | |
a2965b7b | 1504 | } |
feebed65 | 1505 | |
af9b897e | 1506 | /** |
796a75a9 JS |
1507 | * release_one_tty - release tty structure memory |
1508 | * @work: work of tty we are obliterating | |
af9b897e | 1509 | * |
796a75a9 JS |
1510 | * Releases memory associated with a tty structure, and clears out the |
1511 | * driver table slots. This function is called when a device is no longer | |
1512 | * in use. It also gets called when setup of a device fails. | |
af9b897e | 1513 | * |
796a75a9 JS |
1514 | * Locking: |
1515 | * takes the file list lock internally when working on the list of ttys | |
1516 | * that the driver keeps. | |
b50989dc | 1517 | * |
796a75a9 JS |
1518 | * This method gets called from a work queue so that the driver private |
1519 | * cleanup ops can sleep (needed for USB at least) | |
1da177e4 | 1520 | */ |
b50989dc | 1521 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1522 | { |
b50989dc AC |
1523 | struct tty_struct *tty = |
1524 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1525 | struct tty_driver *driver = tty->driver; |
b216df53 | 1526 | struct module *owner = driver->owner; |
d5698c28 | 1527 | |
f278a2f7 DY |
1528 | if (tty->ops->cleanup) |
1529 | tty->ops->cleanup(tty); | |
1530 | ||
7d7b93c1 | 1531 | tty_driver_kref_put(driver); |
b216df53 | 1532 | module_put(owner); |
d5698c28 | 1533 | |
4a510969 | 1534 | spin_lock(&tty->files_lock); |
1da177e4 | 1535 | list_del_init(&tty->tty_files); |
4a510969 | 1536 | spin_unlock(&tty->files_lock); |
d5698c28 | 1537 | |
64d608db JS |
1538 | put_pid(tty->ctrl.pgrp); |
1539 | put_pid(tty->ctrl.session); | |
1da177e4 LT |
1540 | free_tty_struct(tty); |
1541 | } | |
1542 | ||
b50989dc AC |
1543 | static void queue_release_one_tty(struct kref *kref) |
1544 | { | |
1545 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1546 | |
b50989dc | 1547 | /* The hangup queue is now free so we can reuse it rather than |
b426a5b8 XT |
1548 | * waste a chunk of memory for each port. |
1549 | */ | |
b50989dc AC |
1550 | INIT_WORK(&tty->hangup_work, release_one_tty); |
1551 | schedule_work(&tty->hangup_work); | |
1552 | } | |
1553 | ||
9c9f4ded | 1554 | /** |
796a75a9 JS |
1555 | * tty_kref_put - release a tty kref |
1556 | * @tty: tty device | |
9c9f4ded | 1557 | * |
796a75a9 JS |
1558 | * Release a reference to the @tty device and if need be let the kref layer |
1559 | * destruct the object for us. | |
9c9f4ded | 1560 | */ |
9c9f4ded AC |
1561 | void tty_kref_put(struct tty_struct *tty) |
1562 | { | |
1563 | if (tty) | |
b50989dc | 1564 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1565 | } |
1566 | EXPORT_SYMBOL(tty_kref_put); | |
1567 | ||
d5698c28 | 1568 | /** |
796a75a9 JS |
1569 | * release_tty - release tty structure memory |
1570 | * @tty: tty device release | |
1571 | * @idx: index of the tty device release | |
d5698c28 | 1572 | * |
796a75a9 JS |
1573 | * Release both @tty and a possible linked partner (think pty pair), |
1574 | * and decrement the refcount of the backing module. | |
9c9f4ded | 1575 | * |
796a75a9 JS |
1576 | * Locking: |
1577 | * tty_mutex | |
1578 | * takes the file list lock internally when working on the list of ttys | |
1579 | * that the driver keeps. | |
d5698c28 CH |
1580 | */ |
1581 | static void release_tty(struct tty_struct *tty, int idx) | |
1582 | { | |
9c9f4ded AC |
1583 | /* This should always be true but check for the moment */ |
1584 | WARN_ON(tty->index != idx); | |
d155255a | 1585 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1586 | if (tty->ops->shutdown) |
1587 | tty->ops->shutdown(tty); | |
f51ccf46 | 1588 | tty_save_termios(tty); |
36b3c070 | 1589 | tty_driver_remove_tty(tty->driver, tty); |
4466d6d2 MR |
1590 | if (tty->port) |
1591 | tty->port->itty = NULL; | |
64e377dc PH |
1592 | if (tty->link) |
1593 | tty->link->port->itty = NULL; | |
4466d6d2 MR |
1594 | if (tty->port) |
1595 | tty_buffer_cancel_work(tty->port); | |
2b022ab7 S |
1596 | if (tty->link) |
1597 | tty_buffer_cancel_work(tty->link->port); | |
36b3c070 | 1598 | |
a211b1af | 1599 | tty_kref_put(tty->link); |
9c9f4ded | 1600 | tty_kref_put(tty); |
d5698c28 CH |
1601 | } |
1602 | ||
955787ca | 1603 | /** |
796a75a9 JS |
1604 | * tty_release_checks - check a tty before real release |
1605 | * @tty: tty to check | |
1606 | * @idx: index of the tty | |
955787ca | 1607 | * |
796a75a9 JS |
1608 | * Performs some paranoid checking before true release of the @tty. This is a |
1609 | * no-op unless %TTY_PARANOIA_CHECK is defined. | |
955787ca | 1610 | */ |
359b9fb5 | 1611 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1612 | { |
1613 | #ifdef TTY_PARANOIA_CHECK | |
1614 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1615 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1616 | return -1; |
1617 | } | |
1618 | ||
1619 | /* not much to check for devpts */ | |
1620 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1621 | return 0; | |
1622 | ||
1623 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1624 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1625 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1626 | return -1; |
1627 | } | |
955787ca | 1628 | if (tty->driver->other) { |
359b9fb5 PH |
1629 | struct tty_struct *o_tty = tty->link; |
1630 | ||
955787ca | 1631 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1632 | tty_debug(tty, "bad other table[%d] = %p\n", |
1633 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1634 | return -1; |
1635 | } | |
955787ca | 1636 | if (o_tty->link != tty) { |
e2dfa3d3 | 1637 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1638 | return -1; |
1639 | } | |
1640 | } | |
1641 | #endif | |
1642 | return 0; | |
1643 | } | |
1644 | ||
a09ac397 | 1645 | /** |
796a75a9 JS |
1646 | * tty_kclose - closes tty opened by tty_kopen |
1647 | * @tty: tty device | |
a09ac397 | 1648 | * |
796a75a9 JS |
1649 | * Performs the final steps to release and free a tty device. It is the same as |
1650 | * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on | |
1651 | * @tty->port. | |
a09ac397 OK |
1652 | */ |
1653 | void tty_kclose(struct tty_struct *tty) | |
1654 | { | |
1655 | /* | |
1656 | * Ask the line discipline code to release its structures | |
1657 | */ | |
1658 | tty_ldisc_release(tty); | |
1659 | ||
da1bb4ed | 1660 | /* Wait for pending work before tty destruction commences */ |
a09ac397 OK |
1661 | tty_flush_works(tty); |
1662 | ||
1663 | tty_debug_hangup(tty, "freeing structure\n"); | |
1664 | /* | |
1665 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1666 | * the slots and preserving the termios structure. |
a09ac397 OK |
1667 | */ |
1668 | mutex_lock(&tty_mutex); | |
1669 | tty_port_set_kopened(tty->port, 0); | |
1670 | release_tty(tty, tty->index); | |
1671 | mutex_unlock(&tty_mutex); | |
1672 | } | |
1673 | EXPORT_SYMBOL_GPL(tty_kclose); | |
1674 | ||
9ed90d20 | 1675 | /** |
796a75a9 JS |
1676 | * tty_release_struct - release a tty struct |
1677 | * @tty: tty device | |
1678 | * @idx: index of the tty | |
9ed90d20 | 1679 | * |
796a75a9 JS |
1680 | * Performs the final steps to release and free a tty device. It is roughly the |
1681 | * reverse of tty_init_dev(). | |
9ed90d20 RH |
1682 | */ |
1683 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1684 | { | |
1685 | /* | |
1686 | * Ask the line discipline code to release its structures | |
1687 | */ | |
1688 | tty_ldisc_release(tty); | |
1689 | ||
1690 | /* Wait for pending work before tty destruction commmences */ | |
1691 | tty_flush_works(tty); | |
1692 | ||
1693 | tty_debug_hangup(tty, "freeing structure\n"); | |
1694 | /* | |
1695 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1696 | * the slots and preserving the termios structure. |
9ed90d20 RH |
1697 | */ |
1698 | mutex_lock(&tty_mutex); | |
1699 | release_tty(tty, idx); | |
1700 | mutex_unlock(&tty_mutex); | |
1701 | } | |
1702 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1703 | ||
eeb89d91 | 1704 | /** |
796a75a9 JS |
1705 | * tty_release - vfs callback for close |
1706 | * @inode: inode of tty | |
1707 | * @filp: file pointer for handle to tty | |
eeb89d91 | 1708 | * |
796a75a9 JS |
1709 | * Called the last time each file handle is closed that references this tty. |
1710 | * There may however be several such references. | |
eeb89d91 | 1711 | * |
796a75a9 JS |
1712 | * Locking: |
1713 | * Takes BKL. See tty_release_dev(). | |
eeb89d91 | 1714 | * |
796a75a9 JS |
1715 | * Even releasing the tty structures is a tricky business. We have to be very |
1716 | * careful that the structures are all released at the same time, as interrupts | |
1717 | * might otherwise get the wrong pointers. | |
1da177e4 LT |
1718 | * |
1719 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1720 | * lead to double frees or releasing memory still in use. | |
1721 | */ | |
eeb89d91 | 1722 | int tty_release(struct inode *inode, struct file *filp) |
1da177e4 | 1723 | { |
d996b62a | 1724 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1725 | struct tty_struct *o_tty = NULL; |
1726 | int do_sleep, final; | |
1da177e4 | 1727 | int idx; |
37b16457 | 1728 | long timeout = 0; |
494c1eac | 1729 | int once = 1; |
37bdfb07 | 1730 | |
9de44bd6 | 1731 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1732 | return 0; |
1da177e4 | 1733 | |
89c8d91e | 1734 | tty_lock(tty); |
9de44bd6 | 1735 | check_tty_count(tty, __func__); |
1da177e4 | 1736 | |
ec79d605 | 1737 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1738 | |
1739 | idx = tty->index; | |
7ffb6da9 PH |
1740 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1741 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1742 | o_tty = tty->link; | |
1da177e4 | 1743 | |
359b9fb5 | 1744 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1745 | tty_unlock(tty); |
eeb89d91 | 1746 | return 0; |
1da177e4 | 1747 | } |
1da177e4 | 1748 | |
d435cefe | 1749 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1750 | |
f34d7a5b AC |
1751 | if (tty->ops->close) |
1752 | tty->ops->close(tty, filp); | |
1da177e4 | 1753 | |
2aff5e2b PH |
1754 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1755 | tty_lock_slave(o_tty); | |
1756 | ||
1da177e4 LT |
1757 | /* |
1758 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1759 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1760 | * wait queues and kick everyone out _before_ actually starting to | |
1761 | * close. This ensures that we won't block while releasing the tty | |
1762 | * structure. | |
1763 | * | |
1764 | * The test for the o_tty closing is necessary, since the master and | |
1765 | * slave sides may close in any order. If the slave side closes out | |
1766 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1767 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1768 | * so we do it now. |
1da177e4 LT |
1769 | */ |
1770 | while (1) { | |
1da177e4 LT |
1771 | do_sleep = 0; |
1772 | ||
324c1650 | 1773 | if (tty->count <= 1) { |
1da177e4 | 1774 | if (waitqueue_active(&tty->read_wait)) { |
a9a08845 | 1775 | wake_up_poll(&tty->read_wait, EPOLLIN); |
1da177e4 LT |
1776 | do_sleep++; |
1777 | } | |
1778 | if (waitqueue_active(&tty->write_wait)) { | |
a9a08845 | 1779 | wake_up_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1780 | do_sleep++; |
1781 | } | |
1782 | } | |
7ffb6da9 | 1783 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1784 | if (waitqueue_active(&o_tty->read_wait)) { |
a9a08845 | 1785 | wake_up_poll(&o_tty->read_wait, EPOLLIN); |
1da177e4 LT |
1786 | do_sleep++; |
1787 | } | |
1788 | if (waitqueue_active(&o_tty->write_wait)) { | |
a9a08845 | 1789 | wake_up_poll(&o_tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1790 | do_sleep++; |
1791 | } | |
1792 | } | |
1793 | if (!do_sleep) | |
1794 | break; | |
1795 | ||
494c1eac PH |
1796 | if (once) { |
1797 | once = 0; | |
339f36ba | 1798 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1799 | } |
37b16457 PH |
1800 | schedule_timeout_killable(timeout); |
1801 | if (timeout < 120 * HZ) | |
1802 | timeout = 2 * timeout + 1; | |
1803 | else | |
1804 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1805 | } |
1da177e4 | 1806 | |
7ffb6da9 | 1807 | if (o_tty) { |
1da177e4 | 1808 | if (--o_tty->count < 0) { |
339f36ba | 1809 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1810 | o_tty->count = 0; |
1811 | } | |
1812 | } | |
1813 | if (--tty->count < 0) { | |
339f36ba | 1814 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1815 | tty->count = 0; |
1816 | } | |
37bdfb07 | 1817 | |
1da177e4 LT |
1818 | /* |
1819 | * We've decremented tty->count, so we need to remove this file | |
1820 | * descriptor off the tty->tty_files list; this serves two | |
1821 | * purposes: | |
1822 | * - check_tty_count sees the correct number of file descriptors | |
1823 | * associated with this tty. | |
1824 | * - do_tty_hangup no longer sees this file descriptor as | |
1825 | * something that needs to be handled for hangups. | |
1826 | */ | |
d996b62a | 1827 | tty_del_file(filp); |
1da177e4 LT |
1828 | |
1829 | /* | |
1830 | * Perform some housekeeping before deciding whether to return. | |
1831 | * | |
1da177e4 LT |
1832 | * If _either_ side is closing, make sure there aren't any |
1833 | * processes that still think tty or o_tty is their controlling | |
1834 | * tty. | |
1835 | */ | |
324c1650 | 1836 | if (!tty->count) { |
1da177e4 | 1837 | read_lock(&tasklist_lock); |
64d608db | 1838 | session_clear_tty(tty->ctrl.session); |
7ffb6da9 | 1839 | if (o_tty) |
64d608db | 1840 | session_clear_tty(o_tty->ctrl.session); |
1da177e4 LT |
1841 | read_unlock(&tasklist_lock); |
1842 | } | |
1843 | ||
324c1650 | 1844 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1845 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1846 | |
2aff5e2b PH |
1847 | tty_unlock_slave(o_tty); |
1848 | tty_unlock(tty); | |
1849 | ||
04980706 | 1850 | /* At this point, the tty->count == 0 should ensure a dead tty |
b426a5b8 XT |
1851 | * cannot be re-opened by a racing opener. |
1852 | */ | |
da965822 | 1853 | |
324c1650 | 1854 | if (!final) |
eeb89d91 | 1855 | return 0; |
37bdfb07 | 1856 | |
accff793 | 1857 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1858 | |
9ed90d20 | 1859 | tty_release_struct(tty, idx); |
eeb89d91 | 1860 | return 0; |
1da177e4 LT |
1861 | } |
1862 | ||
b82154ac | 1863 | /** |
796a75a9 JS |
1864 | * tty_open_current_tty - get locked tty of current task |
1865 | * @device: device number | |
1866 | * @filp: file pointer to tty | |
1867 | * @return: locked tty of the current task iff @device is /dev/tty | |
52494eeb | 1868 | * |
796a75a9 | 1869 | * Performs a re-open of the current task's controlling tty. |
b82154ac | 1870 | * |
796a75a9 JS |
1871 | * We cannot return driver and index like for the other nodes because devpts |
1872 | * will not work then. It expects inodes to be from devpts FS. | |
b82154ac JS |
1873 | */ |
1874 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1875 | { | |
1876 | struct tty_struct *tty; | |
52494eeb | 1877 | int retval; |
b82154ac JS |
1878 | |
1879 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1880 | return NULL; | |
1881 | ||
1882 | tty = get_current_tty(); | |
1883 | if (!tty) | |
1884 | return ERR_PTR(-ENXIO); | |
1885 | ||
1886 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1887 | /* noctty = 1; */ | |
52494eeb PH |
1888 | tty_lock(tty); |
1889 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1890 | ||
1891 | retval = tty_reopen(tty); | |
1892 | if (retval < 0) { | |
1893 | tty_unlock(tty); | |
1894 | tty = ERR_PTR(retval); | |
1895 | } | |
b82154ac JS |
1896 | return tty; |
1897 | } | |
1898 | ||
5b5e7040 | 1899 | /** |
796a75a9 JS |
1900 | * tty_lookup_driver - lookup a tty driver for a given device file |
1901 | * @device: device number | |
1902 | * @filp: file pointer to tty | |
1903 | * @index: index for the device in the @return driver | |
5b5e7040 | 1904 | * |
796a75a9 JS |
1905 | * If returned value is not erroneous, the caller is responsible to decrement |
1906 | * the refcount by tty_driver_kref_put(). | |
5b5e7040 | 1907 | * |
796a75a9 JS |
1908 | * Locking: %tty_mutex protects get_tty_driver() |
1909 | * | |
1910 | * Return: driver for this inode (with increased refcount) | |
5b5e7040 JS |
1911 | */ |
1912 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1913 | int *index) |
5b5e7040 | 1914 | { |
8c8af41d | 1915 | struct tty_driver *driver = NULL; |
5b5e7040 | 1916 | |
2cd0050c | 1917 | switch (device) { |
5b5e7040 | 1918 | #ifdef CONFIG_VT |
2cd0050c | 1919 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 | 1920 | extern struct tty_driver *console_driver; |
e73b2407 | 1921 | |
5b5e7040 JS |
1922 | driver = tty_driver_kref_get(console_driver); |
1923 | *index = fg_console; | |
2cd0050c | 1924 | break; |
5b5e7040 JS |
1925 | } |
1926 | #endif | |
2cd0050c | 1927 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 | 1928 | struct tty_driver *console_driver = console_device(index); |
e73b2407 | 1929 | |
5b5e7040 JS |
1930 | if (console_driver) { |
1931 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1932 | if (driver && filp) { |
5b5e7040 JS |
1933 | /* Don't let /dev/console block */ |
1934 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1935 | break; |
5b5e7040 JS |
1936 | } |
1937 | } | |
8c8af41d LY |
1938 | if (driver) |
1939 | tty_driver_kref_put(driver); | |
5b5e7040 JS |
1940 | return ERR_PTR(-ENODEV); |
1941 | } | |
2cd0050c JS |
1942 | default: |
1943 | driver = get_tty_driver(device, index); | |
1944 | if (!driver) | |
1945 | return ERR_PTR(-ENODEV); | |
1946 | break; | |
1947 | } | |
5b5e7040 JS |
1948 | return driver; |
1949 | } | |
1950 | ||
4ea3cd65 | 1951 | static struct tty_struct *tty_kopen(dev_t device, int shared) |
a09ac397 OK |
1952 | { |
1953 | struct tty_struct *tty; | |
f1d31743 | 1954 | struct tty_driver *driver; |
a09ac397 OK |
1955 | int index = -1; |
1956 | ||
1957 | mutex_lock(&tty_mutex); | |
1958 | driver = tty_lookup_driver(device, NULL, &index); | |
1959 | if (IS_ERR(driver)) { | |
1960 | mutex_unlock(&tty_mutex); | |
1961 | return ERR_CAST(driver); | |
1962 | } | |
1963 | ||
1964 | /* check whether we're reopening an existing tty */ | |
1965 | tty = tty_driver_lookup_tty(driver, NULL, index); | |
4ea3cd65 | 1966 | if (IS_ERR(tty) || shared) |
a09ac397 OK |
1967 | goto out; |
1968 | ||
1969 | if (tty) { | |
1970 | /* drop kref from tty_driver_lookup_tty() */ | |
1971 | tty_kref_put(tty); | |
1972 | tty = ERR_PTR(-EBUSY); | |
1973 | } else { /* tty_init_dev returns tty with the tty_lock held */ | |
1974 | tty = tty_init_dev(driver, index); | |
1975 | if (IS_ERR(tty)) | |
1976 | goto out; | |
1977 | tty_port_set_kopened(tty->port, 1); | |
1978 | } | |
1979 | out: | |
1980 | mutex_unlock(&tty_mutex); | |
1981 | tty_driver_kref_put(driver); | |
1982 | return tty; | |
1983 | } | |
4ea3cd65 UKK |
1984 | |
1985 | /** | |
796a75a9 JS |
1986 | * tty_kopen_exclusive - open a tty device for kernel |
1987 | * @device: dev_t of device to open | |
4ea3cd65 | 1988 | * |
796a75a9 JS |
1989 | * Opens tty exclusively for kernel. Performs the driver lookup, makes sure |
1990 | * it's not already opened and performs the first-time tty initialization. | |
4ea3cd65 | 1991 | * |
796a75a9 JS |
1992 | * Claims the global %tty_mutex to serialize: |
1993 | * * concurrent first-time tty initialization | |
1994 | * * concurrent tty driver removal w/ lookup | |
1995 | * * concurrent tty removal from driver table | |
4ea3cd65 | 1996 | * |
796a75a9 | 1997 | * Return: the locked initialized &tty_struct |
4ea3cd65 UKK |
1998 | */ |
1999 | struct tty_struct *tty_kopen_exclusive(dev_t device) | |
2000 | { | |
2001 | return tty_kopen(device, 0); | |
2002 | } | |
2003 | EXPORT_SYMBOL_GPL(tty_kopen_exclusive); | |
2004 | ||
2005 | /** | |
796a75a9 JS |
2006 | * tty_kopen_shared - open a tty device for shared in-kernel use |
2007 | * @device: dev_t of device to open | |
4ea3cd65 | 2008 | * |
796a75a9 JS |
2009 | * Opens an already existing tty for in-kernel use. Compared to |
2010 | * tty_kopen_exclusive() above it doesn't ensure to be the only user. | |
4ea3cd65 | 2011 | * |
796a75a9 | 2012 | * Locking: identical to tty_kopen() above. |
4ea3cd65 UKK |
2013 | */ |
2014 | struct tty_struct *tty_kopen_shared(dev_t device) | |
2015 | { | |
2016 | return tty_kopen(device, 1); | |
2017 | } | |
2018 | EXPORT_SYMBOL_GPL(tty_kopen_shared); | |
a09ac397 | 2019 | |
d6203d0c | 2020 | /** |
796a75a9 JS |
2021 | * tty_open_by_driver - open a tty device |
2022 | * @device: dev_t of device to open | |
2023 | * @filp: file pointer to tty | |
2024 | * | |
2025 | * Performs the driver lookup, checks for a reopen, or otherwise performs the | |
2026 | * first-time tty initialization. | |
d6203d0c | 2027 | * |
d6203d0c | 2028 | * |
796a75a9 JS |
2029 | * Claims the global tty_mutex to serialize: |
2030 | * * concurrent first-time tty initialization | |
2031 | * * concurrent tty driver removal w/ lookup | |
2032 | * * concurrent tty removal from driver table | |
d6203d0c | 2033 | * |
796a75a9 | 2034 | * Return: the locked initialized or re-opened &tty_struct |
d6203d0c | 2035 | */ |
14ce3848 | 2036 | static struct tty_struct *tty_open_by_driver(dev_t device, |
d6203d0c PH |
2037 | struct file *filp) |
2038 | { | |
2039 | struct tty_struct *tty; | |
2040 | struct tty_driver *driver = NULL; | |
2041 | int index = -1; | |
2042 | int retval; | |
2043 | ||
2044 | mutex_lock(&tty_mutex); | |
2045 | driver = tty_lookup_driver(device, filp, &index); | |
2046 | if (IS_ERR(driver)) { | |
2047 | mutex_unlock(&tty_mutex); | |
2048 | return ERR_CAST(driver); | |
2049 | } | |
2050 | ||
2051 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 2052 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
2053 | if (IS_ERR(tty)) { |
2054 | mutex_unlock(&tty_mutex); | |
2055 | goto out; | |
2056 | } | |
2057 | ||
2058 | if (tty) { | |
a09ac397 OK |
2059 | if (tty_port_kopened(tty->port)) { |
2060 | tty_kref_put(tty); | |
2061 | mutex_unlock(&tty_mutex); | |
2062 | tty = ERR_PTR(-EBUSY); | |
2063 | goto out; | |
2064 | } | |
d6203d0c PH |
2065 | mutex_unlock(&tty_mutex); |
2066 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2067 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2068 | if (retval) { |
2069 | if (retval == -EINTR) | |
2070 | retval = -ERESTARTSYS; | |
2071 | tty = ERR_PTR(retval); | |
2072 | goto out; | |
2073 | } | |
d6203d0c PH |
2074 | retval = tty_reopen(tty); |
2075 | if (retval < 0) { | |
2076 | tty_unlock(tty); | |
2077 | tty = ERR_PTR(retval); | |
2078 | } | |
2079 | } else { /* Returns with the tty_lock held for now */ | |
2080 | tty = tty_init_dev(driver, index); | |
2081 | mutex_unlock(&tty_mutex); | |
2082 | } | |
2083 | out: | |
2084 | tty_driver_kref_put(driver); | |
2085 | return tty; | |
2086 | } | |
2087 | ||
af9b897e | 2088 | /** |
796a75a9 JS |
2089 | * tty_open - open a tty device |
2090 | * @inode: inode of device file | |
2091 | * @filp: file pointer to tty | |
1da177e4 | 2092 | * |
796a75a9 JS |
2093 | * tty_open() and tty_release() keep up the tty count that contains the number |
2094 | * of opens done on a tty. We cannot use the inode-count, as different inodes | |
2095 | * might point to the same tty. | |
1da177e4 | 2096 | * |
796a75a9 JS |
2097 | * Open-counting is needed for pty masters, as well as for keeping track of |
2098 | * serial lines: DTR is dropped when the last close happens. | |
2099 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
af9b897e | 2100 | * |
796a75a9 JS |
2101 | * The termios state of a pty is reset on the first open so that settings don't |
2102 | * persist across reuse. | |
af9b897e | 2103 | * |
796a75a9 JS |
2104 | * Locking: |
2105 | * * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev(). | |
2106 | * * @tty->count should protect the rest. | |
2107 | * * ->siglock protects ->signal/->sighand | |
89c8d91e | 2108 | * |
796a75a9 | 2109 | * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex |
1da177e4 | 2110 | */ |
eeb89d91 | 2111 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2112 | { |
b82154ac | 2113 | struct tty_struct *tty; |
1da177e4 | 2114 | int noctty, retval; |
1da177e4 | 2115 | dev_t device = inode->i_rdev; |
846c151a | 2116 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2117 | |
2118 | nonseekable_open(inode, filp); | |
37bdfb07 | 2119 | |
1da177e4 | 2120 | retry_open: |
fa90e1c9 JS |
2121 | retval = tty_alloc_file(filp); |
2122 | if (retval) | |
2123 | return -ENOMEM; | |
2124 | ||
b82154ac | 2125 | tty = tty_open_current_tty(device, filp); |
d6203d0c | 2126 | if (!tty) |
14ce3848 | 2127 | tty = tty_open_by_driver(device, filp); |
52494eeb | 2128 | |
eeb89d91 | 2129 | if (IS_ERR(tty)) { |
d6203d0c | 2130 | tty_free_file(filp); |
ba5db448 | 2131 | retval = PTR_ERR(tty); |
7f22f6c9 | 2132 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2133 | return retval; |
7f22f6c9 PH |
2134 | schedule(); |
2135 | goto retry_open; | |
eeb89d91 | 2136 | } |
1da177e4 | 2137 | |
fa90e1c9 | 2138 | tty_add_file(tty, filp); |
d996b62a | 2139 | |
9de44bd6 | 2140 | check_tty_count(tty, __func__); |
d435cefe | 2141 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2142 | |
909bc774 HRK |
2143 | if (tty->ops->open) |
2144 | retval = tty->ops->open(tty, filp); | |
2145 | else | |
2146 | retval = -ENODEV; | |
1da177e4 LT |
2147 | filp->f_flags = saved_flags; |
2148 | ||
1da177e4 | 2149 | if (retval) { |
d435cefe | 2150 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2151 | |
89c8d91e | 2152 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2153 | tty_release(inode, filp); |
64ba3dc3 | 2154 | if (retval != -ERESTARTSYS) |
1da177e4 | 2155 | return retval; |
64ba3dc3 AB |
2156 | |
2157 | if (signal_pending(current)) | |
1da177e4 | 2158 | return retval; |
64ba3dc3 | 2159 | |
1da177e4 LT |
2160 | schedule(); |
2161 | /* | |
2162 | * Need to reset f_op in case a hangup happened. | |
2163 | */ | |
1256937f | 2164 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2165 | filp->f_op = &tty_fops; |
2166 | goto retry_open; | |
2167 | } | |
d4855e1f | 2168 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2169 | |
11e1d4aa | 2170 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
2171 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
2172 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
2173 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2174 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2175 | if (!noctty) | |
2176 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 2177 | tty_unlock(tty); |
1da177e4 LT |
2178 | return 0; |
2179 | } | |
2180 | ||
39d95b9d | 2181 | |
af9b897e | 2182 | /** |
796a75a9 JS |
2183 | * tty_poll - check tty status |
2184 | * @filp: file being polled | |
2185 | * @wait: poll wait structures to update | |
af9b897e | 2186 | * |
796a75a9 JS |
2187 | * Call the line discipline polling method to obtain the poll status of the |
2188 | * device. | |
af9b897e | 2189 | * |
796a75a9 JS |
2190 | * Locking: locks called line discipline but ldisc poll method may be |
2191 | * re-entered freely by other callers. | |
af9b897e | 2192 | */ |
afc9a42b | 2193 | static __poll_t tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2194 | { |
d996b62a | 2195 | struct tty_struct *tty = file_tty(filp); |
1da177e4 | 2196 | struct tty_ldisc *ld; |
e6c8adca | 2197 | __poll_t ret = 0; |
1da177e4 | 2198 | |
6131ffaa | 2199 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2200 | return 0; |
37bdfb07 | 2201 | |
1da177e4 | 2202 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2203 | if (!ld) |
2204 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2205 | if (ld->ops->poll) |
c961bfb1 | 2206 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2207 | tty_ldisc_deref(ld); |
2208 | return ret; | |
2209 | } | |
2210 | ||
ec79d605 | 2211 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2212 | { |
d996b62a | 2213 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2214 | unsigned long flags; |
5d1e3230 | 2215 | int retval = 0; |
1da177e4 | 2216 | |
6131ffaa | 2217 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2218 | goto out; |
37bdfb07 | 2219 | |
1da177e4 LT |
2220 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2221 | if (retval <= 0) | |
5d1e3230 | 2222 | goto out; |
f6c8dbe6 | 2223 | |
1da177e4 | 2224 | if (on) { |
ab521dc0 EB |
2225 | enum pid_type type; |
2226 | struct pid *pid; | |
f6c8dbe6 | 2227 | |
64d608db JS |
2228 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
2229 | if (tty->ctrl.pgrp) { | |
2230 | pid = tty->ctrl.pgrp; | |
ab521dc0 EB |
2231 | type = PIDTYPE_PGID; |
2232 | } else { | |
2233 | pid = task_pid(current); | |
01919134 | 2234 | type = PIDTYPE_TGID; |
ab521dc0 | 2235 | } |
80e1e823 | 2236 | get_pid(pid); |
64d608db | 2237 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); |
e0b93edd | 2238 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2239 | put_pid(pid); |
e0b93edd | 2240 | retval = 0; |
1da177e4 | 2241 | } |
5d1e3230 | 2242 | out: |
ec79d605 AB |
2243 | return retval; |
2244 | } | |
2245 | ||
2246 | static int tty_fasync(int fd, struct file *filp, int on) | |
2247 | { | |
89c8d91e | 2248 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2249 | int retval = -ENOTTY; |
89c8d91e AC |
2250 | |
2251 | tty_lock(tty); | |
a8f3a297 PH |
2252 | if (!tty_hung_up_p(filp)) |
2253 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2254 | tty_unlock(tty); |
2255 | ||
5d1e3230 | 2256 | return retval; |
1da177e4 LT |
2257 | } |
2258 | ||
5c30f3e4 | 2259 | static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI); |
af9b897e | 2260 | /** |
796a75a9 JS |
2261 | * tiocsti - fake input character |
2262 | * @tty: tty to fake input into | |
2263 | * @p: pointer to character | |
af9b897e | 2264 | * |
796a75a9 | 2265 | * Fake input to a tty device. Does the necessary locking and input management. |
af9b897e | 2266 | * |
796a75a9 | 2267 | * FIXME: does not honour flow control ?? |
af9b897e | 2268 | * |
796a75a9 JS |
2269 | * Locking: |
2270 | * * Called functions take tty_ldiscs_lock | |
2271 | * * current->signal->tty check is safe without locks | |
af9b897e | 2272 | */ |
1da177e4 LT |
2273 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2274 | { | |
2275 | char ch, mbz = 0; | |
2276 | struct tty_ldisc *ld; | |
37bdfb07 | 2277 | |
690c8b80 | 2278 | if (!tty_legacy_tiocsti && !capable(CAP_SYS_ADMIN)) |
83efeeeb KC |
2279 | return -EIO; |
2280 | ||
1da177e4 LT |
2281 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2282 | return -EPERM; | |
2283 | if (get_user(ch, p)) | |
2284 | return -EFAULT; | |
1e641743 | 2285 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2286 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2287 | if (!ld) |
2288 | return -EIO; | |
bb2853a6 | 2289 | tty_buffer_lock_exclusive(tty->port); |
27cfb3a5 GKH |
2290 | if (ld->ops->receive_buf) |
2291 | ld->ops->receive_buf(tty, &ch, &mbz, 1); | |
bb2853a6 | 2292 | tty_buffer_unlock_exclusive(tty->port); |
1da177e4 LT |
2293 | tty_ldisc_deref(ld); |
2294 | return 0; | |
2295 | } | |
2296 | ||
af9b897e | 2297 | /** |
796a75a9 JS |
2298 | * tiocgwinsz - implement window query ioctl |
2299 | * @tty: tty | |
2300 | * @arg: user buffer for result | |
af9b897e | 2301 | * |
796a75a9 | 2302 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2303 | * |
796a75a9 JS |
2304 | * Locking: @tty->winsize_mutex is taken to ensure the winsize data is |
2305 | * consistent. | |
af9b897e | 2306 | */ |
37bdfb07 | 2307 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2308 | { |
808a0d38 AC |
2309 | int err; |
2310 | ||
dee4a0be | 2311 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2312 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2313 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 | 2314 | |
94bc2eb5 | 2315 | return err ? -EFAULT : 0; |
1da177e4 LT |
2316 | } |
2317 | ||
af9b897e | 2318 | /** |
796a75a9 JS |
2319 | * tty_do_resize - resize event |
2320 | * @tty: tty being resized | |
2321 | * @ws: new dimensions | |
8c9a9dd0 | 2322 | * |
796a75a9 JS |
2323 | * Update the termios variables and send the necessary signals to peform a |
2324 | * terminal resize correctly. | |
af9b897e | 2325 | */ |
fc6f6238 | 2326 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2327 | { |
fc6f6238 | 2328 | struct pid *pgrp; |
1da177e4 | 2329 | |
fc6f6238 | 2330 | /* Lock the tty */ |
dee4a0be | 2331 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2332 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2333 | goto done; |
47f86834 | 2334 | |
5b239542 PH |
2335 | /* Signal the foreground process group */ |
2336 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2337 | if (pgrp) |
2338 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2339 | put_pid(pgrp); |
47f86834 | 2340 | |
8c9a9dd0 | 2341 | tty->winsize = *ws; |
ca9bda00 | 2342 | done: |
dee4a0be | 2343 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2344 | return 0; |
2345 | } | |
4d334fd1 | 2346 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2347 | |
8c9a9dd0 | 2348 | /** |
796a75a9 JS |
2349 | * tiocswinsz - implement window size set ioctl |
2350 | * @tty: tty side of tty | |
2351 | * @arg: user buffer for result | |
8c9a9dd0 | 2352 | * |
796a75a9 JS |
2353 | * Copies the user idea of the window size to the kernel. Traditionally this is |
2354 | * just advisory information but for the Linux console it actually has driver | |
2355 | * level meaning and triggers a VC resize. | |
8c9a9dd0 | 2356 | * |
796a75a9 JS |
2357 | * Locking: |
2358 | * Driver dependent. The default do_resize method takes the tty termios | |
2359 | * mutex and ctrl.lock. The console takes its own lock then calls into the | |
2360 | * default method. | |
8c9a9dd0 | 2361 | */ |
fc6f6238 | 2362 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2363 | { |
2364 | struct winsize tmp_ws; | |
e73b2407 | 2365 | |
8c9a9dd0 AC |
2366 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
2367 | return -EFAULT; | |
2368 | ||
2369 | if (tty->ops->resize) | |
fc6f6238 | 2370 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2371 | else |
fc6f6238 | 2372 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2373 | } |
2374 | ||
af9b897e | 2375 | /** |
796a75a9 JS |
2376 | * tioccons - allow admin to move logical console |
2377 | * @file: the file to become console | |
af9b897e | 2378 | * |
796a75a9 | 2379 | * Allow the administrator to move the redirected console device. |
af9b897e | 2380 | * |
796a75a9 | 2381 | * Locking: uses redirect_lock to guard the redirect information |
af9b897e | 2382 | */ |
1da177e4 LT |
2383 | static int tioccons(struct file *file) |
2384 | { | |
2385 | if (!capable(CAP_SYS_ADMIN)) | |
2386 | return -EPERM; | |
9bb48c82 | 2387 | if (file->f_op->write_iter == redirected_tty_write) { |
1da177e4 | 2388 | struct file *f; |
e73b2407 | 2389 | |
1da177e4 LT |
2390 | spin_lock(&redirect_lock); |
2391 | f = redirect; | |
2392 | redirect = NULL; | |
2393 | spin_unlock(&redirect_lock); | |
2394 | if (f) | |
2395 | fput(f); | |
2396 | return 0; | |
2397 | } | |
a9cbbb80 LT |
2398 | if (file->f_op->write_iter != tty_write) |
2399 | return -ENOTTY; | |
2400 | if (!(file->f_mode & FMODE_WRITE)) | |
2401 | return -EBADF; | |
2402 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
2403 | return -EINVAL; | |
1da177e4 LT |
2404 | spin_lock(&redirect_lock); |
2405 | if (redirect) { | |
2406 | spin_unlock(&redirect_lock); | |
2407 | return -EBUSY; | |
2408 | } | |
cb0942b8 | 2409 | redirect = get_file(file); |
1da177e4 LT |
2410 | spin_unlock(&redirect_lock); |
2411 | return 0; | |
2412 | } | |
2413 | ||
af9b897e | 2414 | /** |
796a75a9 JS |
2415 | * tiocsetd - set line discipline |
2416 | * @tty: tty device | |
2417 | * @p: pointer to user data | |
af9b897e | 2418 | * |
796a75a9 | 2419 | * Set the line discipline according to user request. |
af9b897e | 2420 | * |
796a75a9 | 2421 | * Locking: see tty_set_ldisc(), this function is just a helper |
af9b897e | 2422 | */ |
1da177e4 LT |
2423 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2424 | { | |
c12da96f | 2425 | int disc; |
04f378b1 | 2426 | int ret; |
1da177e4 | 2427 | |
c12da96f | 2428 | if (get_user(disc, p)) |
1da177e4 | 2429 | return -EFAULT; |
04f378b1 | 2430 | |
c12da96f | 2431 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2432 | |
2433 | return ret; | |
1da177e4 LT |
2434 | } |
2435 | ||
5c17c861 | 2436 | /** |
796a75a9 JS |
2437 | * tiocgetd - get line discipline |
2438 | * @tty: tty device | |
2439 | * @p: pointer to user data | |
5c17c861 | 2440 | * |
796a75a9 | 2441 | * Retrieves the line discipline id directly from the ldisc. |
5c17c861 | 2442 | * |
796a75a9 JS |
2443 | * Locking: waits for ldisc reference (in case the line discipline is changing |
2444 | * or the @tty is being hungup) | |
5c17c861 | 2445 | */ |
5c17c861 PH |
2446 | static int tiocgetd(struct tty_struct *tty, int __user *p) |
2447 | { | |
2448 | struct tty_ldisc *ld; | |
2449 | int ret; | |
2450 | ||
2451 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2452 | if (!ld) |
2453 | return -EIO; | |
5c17c861 PH |
2454 | ret = put_user(ld->ops->num, p); |
2455 | tty_ldisc_deref(ld); | |
2456 | return ret; | |
2457 | } | |
2458 | ||
af9b897e | 2459 | /** |
796a75a9 JS |
2460 | * send_break - performed time break |
2461 | * @tty: device to break on | |
2462 | * @duration: timeout in mS | |
af9b897e | 2463 | * |
796a75a9 JS |
2464 | * Perform a timed break on hardware that lacks its own driver level timed |
2465 | * break functionality. | |
af9b897e | 2466 | * |
796a75a9 JS |
2467 | * Locking: |
2468 | * @tty->atomic_write_lock serializes | |
af9b897e | 2469 | */ |
b20f3ae5 | 2470 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2471 | { |
9e98966c AC |
2472 | int retval; |
2473 | ||
2474 | if (tty->ops->break_ctl == NULL) | |
2475 | return 0; | |
2476 | ||
2477 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2478 | retval = tty->ops->break_ctl(tty, duration); | |
2479 | else { | |
2480 | /* Do the work ourselves */ | |
af815336 | 2481 | if (tty_write_lock(tty, false) < 0) |
9e98966c AC |
2482 | return -EINTR; |
2483 | retval = tty->ops->break_ctl(tty, -1); | |
2484 | if (retval) | |
2485 | goto out; | |
2486 | if (!signal_pending(current)) | |
2487 | msleep_interruptible(duration); | |
2488 | retval = tty->ops->break_ctl(tty, 0); | |
2489 | out: | |
2490 | tty_write_unlock(tty); | |
2491 | if (signal_pending(current)) | |
2492 | retval = -EINTR; | |
2493 | } | |
2494 | return retval; | |
1da177e4 LT |
2495 | } |
2496 | ||
af9b897e | 2497 | /** |
796a75a9 JS |
2498 | * tty_tiocmget - get modem status |
2499 | * @tty: tty device | |
2500 | * @p: pointer to result | |
af9b897e | 2501 | * |
796a75a9 JS |
2502 | * Obtain the modem status bits from the tty driver if the feature is |
2503 | * supported. Return -%ENOTTY if it is not available. | |
af9b897e | 2504 | * |
796a75a9 | 2505 | * Locking: none (up to the driver) |
af9b897e | 2506 | */ |
60b33c13 | 2507 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 | 2508 | { |
1b8b2086 | 2509 | int retval = -ENOTTY; |
1da177e4 | 2510 | |
f34d7a5b | 2511 | if (tty->ops->tiocmget) { |
60b33c13 | 2512 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2513 | |
2514 | if (retval >= 0) | |
2515 | retval = put_user(retval, p); | |
2516 | } | |
2517 | return retval; | |
2518 | } | |
2519 | ||
af9b897e | 2520 | /** |
796a75a9 JS |
2521 | * tty_tiocmset - set modem status |
2522 | * @tty: tty device | |
2523 | * @cmd: command - clear bits, set bits or set all | |
2524 | * @p: pointer to desired bits | |
af9b897e | 2525 | * |
796a75a9 JS |
2526 | * Set the modem status bits from the tty driver if the feature |
2527 | * is supported. Return -%ENOTTY if it is not available. | |
af9b897e | 2528 | * |
796a75a9 | 2529 | * Locking: none (up to the driver) |
af9b897e | 2530 | */ |
20b9d177 | 2531 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2532 | unsigned __user *p) |
2533 | { | |
ae677517 AC |
2534 | int retval; |
2535 | unsigned int set, clear, val; | |
1da177e4 | 2536 | |
ae677517 | 2537 | if (tty->ops->tiocmset == NULL) |
1b8b2086 | 2538 | return -ENOTTY; |
1da177e4 | 2539 | |
ae677517 AC |
2540 | retval = get_user(val, p); |
2541 | if (retval) | |
2542 | return retval; | |
2543 | set = clear = 0; | |
2544 | switch (cmd) { | |
2545 | case TIOCMBIS: | |
2546 | set = val; | |
2547 | break; | |
2548 | case TIOCMBIC: | |
2549 | clear = val; | |
2550 | break; | |
2551 | case TIOCMSET: | |
2552 | set = val; | |
2553 | clear = ~val; | |
2554 | break; | |
2555 | } | |
2556 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2557 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2558 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2559 | } |
2560 | ||
d20c219c | 2561 | /** |
796a75a9 JS |
2562 | * tty_get_icount - get tty statistics |
2563 | * @tty: tty device | |
2564 | * @icount: output parameter | |
d20c219c | 2565 | * |
796a75a9 | 2566 | * Gets a copy of the @tty's icount statistics. |
d20c219c | 2567 | * |
796a75a9 | 2568 | * Locking: none (up to the driver) |
d20c219c UKK |
2569 | */ |
2570 | int tty_get_icount(struct tty_struct *tty, | |
2571 | struct serial_icounter_struct *icount) | |
2572 | { | |
2573 | memset(icount, 0, sizeof(*icount)); | |
2574 | ||
2575 | if (tty->ops->get_icount) | |
2576 | return tty->ops->get_icount(tty, icount); | |
2577 | else | |
1b8b2086 | 2578 | return -ENOTTY; |
d20c219c UKK |
2579 | } |
2580 | EXPORT_SYMBOL_GPL(tty_get_icount); | |
2581 | ||
d281da7f AC |
2582 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2583 | { | |
d281da7f | 2584 | struct serial_icounter_struct icount; |
d20c219c UKK |
2585 | int retval; |
2586 | ||
2587 | retval = tty_get_icount(tty, &icount); | |
d281da7f AC |
2588 | if (retval != 0) |
2589 | return retval; | |
d20c219c | 2590 | |
d281da7f AC |
2591 | if (copy_to_user(arg, &icount, sizeof(icount))) |
2592 | return -EFAULT; | |
2593 | return 0; | |
2594 | } | |
2595 | ||
885c77d5 | 2596 | static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) |
8a8ae62f | 2597 | { |
8a8ae62f JS |
2598 | char comm[TASK_COMM_LEN]; |
2599 | int flags; | |
2600 | ||
885c77d5 | 2601 | flags = ss->flags & ASYNC_DEPRECATED; |
8a8ae62f | 2602 | |
1b7bc6b1 JH |
2603 | if (flags) |
2604 | pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2605 | __func__, get_task_comm(comm, current), flags); | |
885c77d5 | 2606 | |
2f46a2c1 | 2607 | if (!tty->ops->set_serial) |
930236a3 | 2608 | return -ENOTTY; |
885c77d5 JH |
2609 | |
2610 | return tty->ops->set_serial(tty, ss); | |
2611 | } | |
2612 | ||
2613 | static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2614 | { | |
2615 | struct serial_struct v; | |
2616 | ||
2617 | if (copy_from_user(&v, ss, sizeof(*ss))) | |
2618 | return -EFAULT; | |
2619 | ||
2620 | return tty_set_serial(tty, &v); | |
2f46a2c1 AV |
2621 | } |
2622 | ||
2623 | static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2624 | { | |
2625 | struct serial_struct v; | |
2626 | int err; | |
2627 | ||
a3241891 | 2628 | memset(&v, 0, sizeof(v)); |
2f46a2c1 | 2629 | if (!tty->ops->get_serial) |
930236a3 | 2630 | return -ENOTTY; |
2f46a2c1 | 2631 | err = tty->ops->get_serial(tty, &v); |
a3241891 | 2632 | if (!err && copy_to_user(ss, &v, sizeof(v))) |
2f46a2c1 AV |
2633 | err = -EFAULT; |
2634 | return err; | |
8a8ae62f JS |
2635 | } |
2636 | ||
8f166e00 PH |
2637 | /* |
2638 | * if pty, return the slave side (real_tty) | |
2639 | * otherwise, return self | |
2640 | */ | |
2641 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2642 | { |
2643 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2644 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2645 | tty = tty->link; | |
2646 | return tty; | |
2647 | } | |
e8b70e7d | 2648 | |
1da177e4 LT |
2649 | /* |
2650 | * Split this up, as gcc can choke on it otherwise.. | |
2651 | */ | |
04f378b1 | 2652 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2653 | { |
d996b62a NP |
2654 | struct tty_struct *tty = file_tty(file); |
2655 | struct tty_struct *real_tty; | |
1da177e4 LT |
2656 | void __user *p = (void __user *)arg; |
2657 | int retval; | |
2658 | struct tty_ldisc *ld; | |
37bdfb07 | 2659 | |
6131ffaa | 2660 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2661 | return -EINVAL; |
2662 | ||
e8b70e7d | 2663 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2664 | |
2665 | /* | |
2666 | * Factor out some common prep work | |
2667 | */ | |
2668 | switch (cmd) { | |
2669 | case TIOCSETD: | |
2670 | case TIOCSBRK: | |
2671 | case TIOCCBRK: | |
2672 | case TCSBRK: | |
37bdfb07 | 2673 | case TCSBRKP: |
1da177e4 LT |
2674 | retval = tty_check_change(tty); |
2675 | if (retval) | |
2676 | return retval; | |
2677 | if (cmd != TIOCCBRK) { | |
2678 | tty_wait_until_sent(tty, 0); | |
2679 | if (signal_pending(current)) | |
2680 | return -EINTR; | |
2681 | } | |
2682 | break; | |
2683 | } | |
2684 | ||
9e98966c AC |
2685 | /* |
2686 | * Now do the stuff. | |
2687 | */ | |
1da177e4 | 2688 | switch (cmd) { |
37bdfb07 AC |
2689 | case TIOCSTI: |
2690 | return tiocsti(tty, p); | |
2691 | case TIOCGWINSZ: | |
8f520021 | 2692 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2693 | case TIOCSWINSZ: |
fc6f6238 | 2694 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2695 | case TIOCCONS: |
2696 | return real_tty != tty ? -EINVAL : tioccons(file); | |
37bdfb07 AC |
2697 | case TIOCEXCL: |
2698 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2699 | return 0; | |
2700 | case TIOCNXCL: | |
2701 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2702 | return 0; | |
84fd7bdf CG |
2703 | case TIOCGEXCL: |
2704 | { | |
2705 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
e73b2407 | 2706 | |
84fd7bdf CG |
2707 | return put_user(excl, (int __user *)p); |
2708 | } | |
37bdfb07 | 2709 | case TIOCGETD: |
5c17c861 | 2710 | return tiocgetd(tty, p); |
37bdfb07 AC |
2711 | case TIOCSETD: |
2712 | return tiocsetd(tty, p); | |
3c95c985 KS |
2713 | case TIOCVHANGUP: |
2714 | if (!capable(CAP_SYS_ADMIN)) | |
2715 | return -EPERM; | |
2716 | tty_vhangup(tty); | |
2717 | return 0; | |
b7b8de08 WF |
2718 | case TIOCGDEV: |
2719 | { | |
2720 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
e73b2407 | 2721 | |
b7b8de08 WF |
2722 | return put_user(ret, (unsigned int __user *)p); |
2723 | } | |
37bdfb07 AC |
2724 | /* |
2725 | * Break handling | |
2726 | */ | |
2727 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2728 | if (tty->ops->break_ctl) |
9e98966c | 2729 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2730 | return 0; |
37bdfb07 | 2731 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2732 | if (tty->ops->break_ctl) |
9e98966c | 2733 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2734 | return 0; |
2735 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2736 | /* non-zero arg means wait for all output data | |
2737 | * to be sent (performed above) but don't send break. | |
2738 | * This is used by the tcdrain() termios function. | |
2739 | */ | |
2740 | if (!arg) | |
2741 | return send_break(tty, 250); | |
2742 | return 0; | |
2743 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2744 | return send_break(tty, arg ? arg*100 : 250); | |
2745 | ||
2746 | case TIOCMGET: | |
60b33c13 | 2747 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2748 | case TIOCMSET: |
2749 | case TIOCMBIC: | |
2750 | case TIOCMBIS: | |
20b9d177 | 2751 | return tty_tiocmset(tty, cmd, p); |
d281da7f | 2752 | case TIOCGICOUNT: |
a3096199 | 2753 | return tty_tiocgicount(tty, p); |
37bdfb07 AC |
2754 | case TCFLSH: |
2755 | switch (arg) { | |
2756 | case TCIFLUSH: | |
2757 | case TCIOFLUSH: | |
2758 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2759 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2760 | break; |
37bdfb07 AC |
2761 | } |
2762 | break; | |
8a8ae62f | 2763 | case TIOCSSERIAL: |
930236a3 | 2764 | return tty_tiocsserial(tty, p); |
2f46a2c1 | 2765 | case TIOCGSERIAL: |
930236a3 | 2766 | return tty_tiocgserial(tty, p); |
311fc65c EB |
2767 | case TIOCGPTPEER: |
2768 | /* Special because the struct file is needed */ | |
2769 | return ptm_open_peer(file, tty, (int)arg); | |
a1235b3e NP |
2770 | default: |
2771 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2772 | if (retval != -ENOIOCTLCMD) | |
2773 | return retval; | |
1da177e4 | 2774 | } |
f34d7a5b | 2775 | if (tty->ops->ioctl) { |
c961bfb1 | 2776 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2777 | if (retval != -ENOIOCTLCMD) |
2778 | return retval; | |
2779 | } | |
2780 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2781 | if (!ld) |
2782 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2783 | retval = -EINVAL; |
a352def2 | 2784 | if (ld->ops->ioctl) { |
d78328bc | 2785 | retval = ld->ops->ioctl(tty, cmd, arg); |
1da177e4 | 2786 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2787 | retval = -ENOTTY; |
1da177e4 LT |
2788 | } |
2789 | tty_ldisc_deref(ld); | |
2790 | return retval; | |
2791 | } | |
2792 | ||
e10cc1df | 2793 | #ifdef CONFIG_COMPAT |
77654350 AV |
2794 | |
2795 | struct serial_struct32 { | |
52b52e91 GS |
2796 | compat_int_t type; |
2797 | compat_int_t line; | |
2798 | compat_uint_t port; | |
2799 | compat_int_t irq; | |
2800 | compat_int_t flags; | |
2801 | compat_int_t xmit_fifo_size; | |
2802 | compat_int_t custom_divisor; | |
2803 | compat_int_t baud_base; | |
2804 | unsigned short close_delay; | |
2805 | char io_type; | |
2806 | char reserved_char; | |
2807 | compat_int_t hub6; | |
2808 | unsigned short closing_wait; /* time to wait before closing */ | |
2809 | unsigned short closing_wait2; /* no longer used... */ | |
2810 | compat_uint_t iomem_base; | |
2811 | unsigned short iomem_reg_shift; | |
2812 | unsigned int port_high; | |
2813 | /* compat_ulong_t iomap_base FIXME */ | |
2814 | compat_int_t reserved; | |
77654350 AV |
2815 | }; |
2816 | ||
2817 | static int compat_tty_tiocsserial(struct tty_struct *tty, | |
2818 | struct serial_struct32 __user *ss) | |
2819 | { | |
77654350 AV |
2820 | struct serial_struct32 v32; |
2821 | struct serial_struct v; | |
77654350 | 2822 | |
a3241891 | 2823 | if (copy_from_user(&v32, ss, sizeof(*ss))) |
77654350 AV |
2824 | return -EFAULT; |
2825 | ||
2826 | memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); | |
2827 | v.iomem_base = compat_ptr(v32.iomem_base); | |
2828 | v.iomem_reg_shift = v32.iomem_reg_shift; | |
2829 | v.port_high = v32.port_high; | |
2830 | v.iomap_base = 0; | |
2831 | ||
885c77d5 | 2832 | return tty_set_serial(tty, &v); |
77654350 AV |
2833 | } |
2834 | ||
2835 | static int compat_tty_tiocgserial(struct tty_struct *tty, | |
2836 | struct serial_struct32 __user *ss) | |
2837 | { | |
2838 | struct serial_struct32 v32; | |
2839 | struct serial_struct v; | |
2840 | int err; | |
17329563 EB |
2841 | |
2842 | memset(&v, 0, sizeof(v)); | |
2843 | memset(&v32, 0, sizeof(v32)); | |
77654350 | 2844 | |
6e622cd8 | 2845 | if (!tty->ops->get_serial) |
77654350 AV |
2846 | return -ENOTTY; |
2847 | err = tty->ops->get_serial(tty, &v); | |
2848 | if (!err) { | |
2849 | memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); | |
2850 | v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? | |
2851 | 0xfffffff : ptr_to_compat(v.iomem_base); | |
2852 | v32.iomem_reg_shift = v.iomem_reg_shift; | |
2853 | v32.port_high = v.port_high; | |
a3241891 | 2854 | if (copy_to_user(ss, &v32, sizeof(v32))) |
77654350 AV |
2855 | err = -EFAULT; |
2856 | } | |
2857 | return err; | |
2858 | } | |
37bdfb07 | 2859 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2860 | unsigned long arg) |
2861 | { | |
d996b62a | 2862 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2863 | struct tty_ldisc *ld; |
2864 | int retval = -ENOIOCTLCMD; | |
2865 | ||
e2112038 | 2866 | switch (cmd) { |
c7dc504e | 2867 | case TIOCOUTQ: |
e2112038 AV |
2868 | case TIOCSTI: |
2869 | case TIOCGWINSZ: | |
2870 | case TIOCSWINSZ: | |
2871 | case TIOCGEXCL: | |
2872 | case TIOCGETD: | |
2873 | case TIOCSETD: | |
2874 | case TIOCGDEV: | |
2875 | case TIOCMGET: | |
2876 | case TIOCMSET: | |
2877 | case TIOCMBIC: | |
2878 | case TIOCMBIS: | |
2879 | case TIOCGICOUNT: | |
2880 | case TIOCGPGRP: | |
2881 | case TIOCSPGRP: | |
2882 | case TIOCGSID: | |
2883 | case TIOCSERGETLSR: | |
2884 | case TIOCGRS485: | |
2885 | case TIOCSRS485: | |
2886 | #ifdef TIOCGETP | |
2887 | case TIOCGETP: | |
2888 | case TIOCSETP: | |
2889 | case TIOCSETN: | |
2890 | #endif | |
2891 | #ifdef TIOCGETC | |
2892 | case TIOCGETC: | |
2893 | case TIOCSETC: | |
2894 | #endif | |
2895 | #ifdef TIOCGLTC | |
2896 | case TIOCGLTC: | |
2897 | case TIOCSLTC: | |
2898 | #endif | |
2899 | case TCSETSF: | |
2900 | case TCSETSW: | |
2901 | case TCSETS: | |
2902 | case TCGETS: | |
2903 | #ifdef TCGETS2 | |
2904 | case TCGETS2: | |
2905 | case TCSETSF2: | |
2906 | case TCSETSW2: | |
2907 | case TCSETS2: | |
2908 | #endif | |
2909 | case TCGETA: | |
2910 | case TCSETAF: | |
2911 | case TCSETAW: | |
2912 | case TCSETA: | |
2913 | case TIOCGLCKTRMIOS: | |
2914 | case TIOCSLCKTRMIOS: | |
2915 | #ifdef TCGETX | |
2916 | case TCGETX: | |
2917 | case TCSETX: | |
2918 | case TCSETXW: | |
2919 | case TCSETXF: | |
2920 | #endif | |
2921 | case TIOCGSOFTCAR: | |
2922 | case TIOCSSOFTCAR: | |
b7aff093 AB |
2923 | |
2924 | case PPPIOCGCHAN: | |
2925 | case PPPIOCGUNIT: | |
e2112038 AV |
2926 | return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
2927 | case TIOCCONS: | |
2928 | case TIOCEXCL: | |
2929 | case TIOCNXCL: | |
2930 | case TIOCVHANGUP: | |
2931 | case TIOCSBRK: | |
2932 | case TIOCCBRK: | |
2933 | case TCSBRK: | |
2934 | case TCSBRKP: | |
2935 | case TCFLSH: | |
2936 | case TIOCGPTPEER: | |
2937 | case TIOCNOTTY: | |
2938 | case TIOCSCTTY: | |
2939 | case TCXONC: | |
2940 | case TIOCMIWAIT: | |
2941 | case TIOCSERCONFIG: | |
2942 | return tty_ioctl(file, cmd, arg); | |
2943 | } | |
2944 | ||
6131ffaa | 2945 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2946 | return -EINVAL; |
2947 | ||
77654350 AV |
2948 | switch (cmd) { |
2949 | case TIOCSSERIAL: | |
2950 | return compat_tty_tiocsserial(tty, compat_ptr(arg)); | |
2951 | case TIOCGSERIAL: | |
2952 | return compat_tty_tiocgserial(tty, compat_ptr(arg)); | |
2953 | } | |
f34d7a5b | 2954 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2955 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2956 | if (retval != -ENOIOCTLCMD) |
2957 | return retval; | |
2958 | } | |
2959 | ||
2960 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2961 | if (!ld) |
2962 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 | 2963 | if (ld->ops->compat_ioctl) |
d78328bc | 2964 | retval = ld->ops->compat_ioctl(tty, cmd, arg); |
f0193d3e | 2965 | if (retval == -ENOIOCTLCMD && ld->ops->ioctl) |
d78328bc JS |
2966 | retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd), |
2967 | arg); | |
e10cc1df PF |
2968 | tty_ldisc_deref(ld); |
2969 | ||
2970 | return retval; | |
2971 | } | |
2972 | #endif | |
1da177e4 | 2973 | |
c3c073f8 AV |
2974 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2975 | { | |
dd78b0c4 | 2976 | if (likely(file->f_op->read_iter != tty_read)) |
c3c073f8 AV |
2977 | return 0; |
2978 | return file_tty(file) != t ? 0 : fd + 1; | |
2979 | } | |
d91c1a3e | 2980 | |
1da177e4 LT |
2981 | /* |
2982 | * This implements the "Secure Attention Key" --- the idea is to | |
2983 | * prevent trojan horses by killing all processes associated with this | |
2984 | * tty when the user hits the "Secure Attention Key". Required for | |
2985 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2986 | * |
1da177e4 LT |
2987 | * This code could be nicer; ideally it should send a HUP, wait a few |
2988 | * seconds, then send a INT, and then a KILL signal. But you then | |
2989 | * have to coordinate with the init process, since all processes associated | |
2990 | * with the current tty must be dead before the new getty is allowed | |
2991 | * to spawn. | |
2992 | * | |
2993 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2994 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2995 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2996 | * | |
2997 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2998 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2999 | */ | |
8b6312f4 | 3000 | void __do_SAK(struct tty_struct *tty) |
1da177e4 | 3001 | { |
652486fb | 3002 | struct task_struct *g, *p; |
ab521dc0 | 3003 | struct pid *session; |
954a0881 | 3004 | int i; |
c8bcd9c5 | 3005 | unsigned long flags; |
37bdfb07 | 3006 | |
64d608db JS |
3007 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
3008 | session = get_pid(tty->ctrl.session); | |
3009 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
37bdfb07 | 3010 | |
b3f13deb | 3011 | tty_ldisc_flush(tty); |
1da177e4 | 3012 | |
f34d7a5b | 3013 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3014 | |
1da177e4 | 3015 | read_lock(&tasklist_lock); |
652486fb | 3016 | /* Kill the entire session */ |
ab521dc0 | 3017 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3018 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3019 | task_pid_nr(p), p->comm); | |
a8ebd171 | 3020 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
ab521dc0 | 3021 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3022 | |
3023 | /* Now kill any processes that happen to have the tty open */ | |
5ffd2c37 | 3024 | for_each_process_thread(g, p) { |
652486fb | 3025 | if (p->signal->tty == tty) { |
9b42bb75 PH |
3026 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3027 | task_pid_nr(p), p->comm); | |
954a0881 JS |
3028 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, |
3029 | PIDTYPE_SID); | |
1da177e4 LT |
3030 | continue; |
3031 | } | |
3032 | task_lock(p); | |
c3c073f8 AV |
3033 | i = iterate_fd(p->files, 0, this_tty, tty); |
3034 | if (i != 0) { | |
9b42bb75 PH |
3035 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3036 | task_pid_nr(p), p->comm, i - 1); | |
954a0881 JS |
3037 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, |
3038 | PIDTYPE_SID); | |
1da177e4 LT |
3039 | } |
3040 | task_unlock(p); | |
5ffd2c37 | 3041 | } |
1da177e4 | 3042 | read_unlock(&tasklist_lock); |
c8bcd9c5 | 3043 | put_pid(session); |
1da177e4 LT |
3044 | } |
3045 | ||
8b6312f4 EB |
3046 | static void do_SAK_work(struct work_struct *work) |
3047 | { | |
3048 | struct tty_struct *tty = | |
3049 | container_of(work, struct tty_struct, SAK_work); | |
3050 | __do_SAK(tty); | |
3051 | } | |
3052 | ||
1da177e4 LT |
3053 | /* |
3054 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3055 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3056 | * the values which we write to it will be identical to the values which it | |
3057 | * already has. --akpm | |
3058 | */ | |
3059 | void do_SAK(struct tty_struct *tty) | |
3060 | { | |
3061 | if (!tty) | |
3062 | return; | |
1da177e4 LT |
3063 | schedule_work(&tty->SAK_work); |
3064 | } | |
1da177e4 LT |
3065 | EXPORT_SYMBOL(do_SAK); |
3066 | ||
30004ac9 DES |
3067 | /* Must put_device() after it's unused! */ |
3068 | static struct device *tty_get_device(struct tty_struct *tty) | |
3069 | { | |
3070 | dev_t devt = tty_devnum(tty); | |
e73b2407 | 3071 | |
862d8312 | 3072 | return class_find_device_by_devt(&tty_class, devt); |
30004ac9 DES |
3073 | } |
3074 | ||
3075 | ||
796a75a9 JS |
3076 | /** |
3077 | * alloc_tty_struct - allocate a new tty | |
3078 | * @driver: driver which will handle the returned tty | |
3079 | * @idx: minor of the tty | |
af9b897e | 3080 | * |
796a75a9 | 3081 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3082 | * |
796a75a9 | 3083 | * Locking: none - @tty in question is not exposed at this point |
1da177e4 | 3084 | */ |
2c964a2f | 3085 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3086 | { |
2c964a2f RV |
3087 | struct tty_struct *tty; |
3088 | ||
c72d8592 | 3089 | tty = kzalloc(sizeof(*tty), GFP_KERNEL_ACCOUNT); |
2c964a2f RV |
3090 | if (!tty) |
3091 | return NULL; | |
3092 | ||
9c9f4ded | 3093 | kref_init(&tty->kref); |
903f9db1 TH |
3094 | if (tty_ldisc_init(tty)) { |
3095 | kfree(tty); | |
3096 | return NULL; | |
3097 | } | |
64d608db JS |
3098 | tty->ctrl.session = NULL; |
3099 | tty->ctrl.pgrp = NULL; | |
89c8d91e | 3100 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3101 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3102 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3103 | mutex_init(&tty->winsize_mutex); |
36697529 | 3104 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3105 | init_waitqueue_head(&tty->write_wait); |
3106 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3107 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3108 | mutex_init(&tty->atomic_write_lock); |
64d608db | 3109 | spin_lock_init(&tty->ctrl.lock); |
6e94dbc7 | 3110 | spin_lock_init(&tty->flow.lock); |
4a510969 | 3111 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3112 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3113 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3114 | |
3115 | tty->driver = driver; | |
3116 | tty->ops = driver->ops; | |
3117 | tty->index = idx; | |
3118 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3119 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3120 | |
3121 | return tty; | |
1da177e4 LT |
3122 | } |
3123 | ||
f34d7a5b | 3124 | /** |
796a75a9 JS |
3125 | * tty_put_char - write one character to a tty |
3126 | * @tty: tty | |
3127 | * @ch: character to write | |
3128 | * | |
3129 | * Write one byte to the @tty using the provided @tty->ops->put_char() method | |
3130 | * if present. | |
f34d7a5b | 3131 | * |
796a75a9 JS |
3132 | * Note: the specific put_char operation in the driver layer may go |
3133 | * away soon. Don't call it directly, use this method | |
f34d7a5b | 3134 | * |
796a75a9 | 3135 | * Return: the number of characters successfully output. |
1da177e4 | 3136 | */ |
f34d7a5b | 3137 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3138 | { |
f34d7a5b AC |
3139 | if (tty->ops->put_char) |
3140 | return tty->ops->put_char(tty, ch); | |
3141 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3142 | } |
f34d7a5b AC |
3143 | EXPORT_SYMBOL_GPL(tty_put_char); |
3144 | ||
7e73eca6 JS |
3145 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3146 | unsigned int index, unsigned int count) | |
3147 | { | |
c1a752ba LY |
3148 | int err; |
3149 | ||
7e73eca6 | 3150 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3151 | driver->cdevs[index] = cdev_alloc(); |
3152 | if (!driver->cdevs[index]) | |
3153 | return -ENOMEM; | |
c1a752ba | 3154 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3155 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3156 | err = cdev_add(driver->cdevs[index], dev, count); |
3157 | if (err) | |
3158 | kobject_put(&driver->cdevs[index]->kobj); | |
3159 | return err; | |
7e73eca6 JS |
3160 | } |
3161 | ||
1da177e4 | 3162 | /** |
796a75a9 JS |
3163 | * tty_register_device - register a tty device |
3164 | * @driver: the tty driver that describes the tty device | |
3165 | * @index: the index in the tty driver for this tty device | |
3166 | * @device: a struct device that is associated with this tty device. | |
3167 | * This field is optional, if there is no known struct device | |
3168 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3169 | * |
796a75a9 JS |
3170 | * This call is required to be made to register an individual tty device |
3171 | * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3172 | * that bit is not set, this function should not be called by a tty | |
3173 | * driver. | |
1cdcb6b4 | 3174 | * |
796a75a9 | 3175 | * Locking: ?? |
af9b897e | 3176 | * |
796a75a9 JS |
3177 | * Return: A pointer to the struct device for this tty device (or |
3178 | * ERR_PTR(-EFOO) on error). | |
1da177e4 | 3179 | */ |
01107d34 GKH |
3180 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3181 | struct device *device) | |
1da177e4 | 3182 | { |
6915c0e4 TH |
3183 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3184 | } | |
3185 | EXPORT_SYMBOL(tty_register_device); | |
3186 | ||
b1b79916 TH |
3187 | static void tty_device_create_release(struct device *dev) |
3188 | { | |
83db1df4 | 3189 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3190 | kfree(dev); |
3191 | } | |
3192 | ||
6915c0e4 | 3193 | /** |
796a75a9 JS |
3194 | * tty_register_device_attr - register a tty device |
3195 | * @driver: the tty driver that describes the tty device | |
3196 | * @index: the index in the tty driver for this tty device | |
3197 | * @device: a struct device that is associated with this tty device. | |
3198 | * This field is optional, if there is no known struct device | |
3199 | * for this tty device it can be set to %NULL safely. | |
3200 | * @drvdata: Driver data to be set to device. | |
3201 | * @attr_grp: Attribute group to be set on device. | |
6915c0e4 | 3202 | * |
796a75a9 JS |
3203 | * This call is required to be made to register an individual tty device if the |
3204 | * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is | |
3205 | * not set, this function should not be called by a tty driver. | |
6915c0e4 | 3206 | * |
796a75a9 | 3207 | * Locking: ?? |
6915c0e4 | 3208 | * |
796a75a9 JS |
3209 | * Return: A pointer to the struct device for this tty device (or |
3210 | * ERR_PTR(-EFOO) on error). | |
6915c0e4 TH |
3211 | */ |
3212 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3213 | unsigned index, struct device *device, | |
3214 | void *drvdata, | |
3215 | const struct attribute_group **attr_grp) | |
3216 | { | |
1da177e4 | 3217 | char name[64]; |
6915c0e4 | 3218 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 3219 | struct ktermios *tp; |
6a7e6f78 JH |
3220 | struct device *dev; |
3221 | int retval; | |
1da177e4 LT |
3222 | |
3223 | if (index >= driver->num) { | |
656fb867 PH |
3224 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3225 | driver->name, index); | |
1cdcb6b4 | 3226 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3227 | } |
3228 | ||
1da177e4 LT |
3229 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3230 | pty_line_name(driver, index, name); | |
3231 | else | |
3232 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3233 | |
6915c0e4 | 3234 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
3235 | if (!dev) |
3236 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 3237 | |
6915c0e4 | 3238 | dev->devt = devt; |
862d8312 | 3239 | dev->class = &tty_class; |
6915c0e4 | 3240 | dev->parent = device; |
b1b79916 | 3241 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3242 | dev_set_name(dev, "%s", name); |
3243 | dev->groups = attr_grp; | |
3244 | dev_set_drvdata(dev, drvdata); | |
3245 | ||
6a7e6f78 JH |
3246 | dev_set_uevent_suppress(dev, 1); |
3247 | ||
6915c0e4 TH |
3248 | retval = device_register(dev); |
3249 | if (retval) | |
6a7e6f78 JH |
3250 | goto err_put; |
3251 | ||
3252 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
3253 | /* |
3254 | * Free any saved termios data so that the termios state is | |
3255 | * reset when reusing a minor number. | |
3256 | */ | |
3257 | tp = driver->termios[index]; | |
3258 | if (tp) { | |
3259 | driver->termios[index] = NULL; | |
3260 | kfree(tp); | |
3261 | } | |
3262 | ||
6a7e6f78 JH |
3263 | retval = tty_cdev_add(driver, devt, index, 1); |
3264 | if (retval) | |
3265 | goto err_del; | |
3266 | } | |
3267 | ||
3268 | dev_set_uevent_suppress(dev, 0); | |
3269 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
3270 | |
3271 | return dev; | |
3272 | ||
6a7e6f78 JH |
3273 | err_del: |
3274 | device_del(dev); | |
3275 | err_put: | |
6915c0e4 | 3276 | put_device(dev); |
6a7e6f78 | 3277 | |
6915c0e4 | 3278 | return ERR_PTR(retval); |
1da177e4 | 3279 | } |
6915c0e4 | 3280 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3281 | |
3282 | /** | |
796a75a9 JS |
3283 | * tty_unregister_device - unregister a tty device |
3284 | * @driver: the tty driver that describes the tty device | |
3285 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3286 | * |
796a75a9 JS |
3287 | * If a tty device is registered with a call to tty_register_device() then |
3288 | * this function must be called when the tty device is gone. | |
af9b897e | 3289 | * |
796a75a9 | 3290 | * Locking: ?? |
1da177e4 LT |
3291 | */ |
3292 | void tty_unregister_device(struct tty_driver *driver, unsigned index) | |
3293 | { | |
862d8312 | 3294 | device_destroy(&tty_class, MKDEV(driver->major, driver->minor_start) + index); |
a3a10ce3 RW |
3295 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3296 | cdev_del(driver->cdevs[index]); | |
3297 | driver->cdevs[index] = NULL; | |
3298 | } | |
1da177e4 | 3299 | } |
1da177e4 LT |
3300 | EXPORT_SYMBOL(tty_unregister_device); |
3301 | ||
7f0bc6a6 JS |
3302 | /** |
3303 | * __tty_alloc_driver -- allocate tty driver | |
3304 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 3305 | * @owner: module which is responsible for this driver |
796a75a9 | 3306 | * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags |
7f0bc6a6 JS |
3307 | * |
3308 | * This should not be called directly, some of the provided macros should be | |
796a75a9 | 3309 | * used instead. Use IS_ERR() and friends on @retval. |
7f0bc6a6 JS |
3310 | */ |
3311 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3312 | unsigned long flags) | |
1da177e4 LT |
3313 | { |
3314 | struct tty_driver *driver; | |
7e73eca6 | 3315 | unsigned int cdevs = 1; |
16a02081 | 3316 | int err; |
1da177e4 | 3317 | |
0019b408 | 3318 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3319 | return ERR_PTR(-EINVAL); |
3320 | ||
a3241891 | 3321 | driver = kzalloc(sizeof(*driver), GFP_KERNEL); |
7f0bc6a6 JS |
3322 | if (!driver) |
3323 | return ERR_PTR(-ENOMEM); | |
3324 | ||
3325 | kref_init(&driver->kref); | |
7f0bc6a6 JS |
3326 | driver->num = lines; |
3327 | driver->owner = owner; | |
3328 | driver->flags = flags; | |
16a02081 JS |
3329 | |
3330 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3331 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3332 | GFP_KERNEL); | |
3333 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3334 | GFP_KERNEL); | |
3335 | if (!driver->ttys || !driver->termios) { | |
3336 | err = -ENOMEM; | |
3337 | goto err_free_all; | |
3338 | } | |
3339 | } | |
3340 | ||
3341 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3342 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3343 | GFP_KERNEL); | |
3344 | if (!driver->ports) { | |
3345 | err = -ENOMEM; | |
3346 | goto err_free_all; | |
3347 | } | |
7e73eca6 JS |
3348 | cdevs = lines; |
3349 | } | |
3350 | ||
3351 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3352 | if (!driver->cdevs) { | |
3353 | err = -ENOMEM; | |
3354 | goto err_free_all; | |
16a02081 | 3355 | } |
7f0bc6a6 | 3356 | |
1da177e4 | 3357 | return driver; |
16a02081 JS |
3358 | err_free_all: |
3359 | kfree(driver->ports); | |
3360 | kfree(driver->ttys); | |
3361 | kfree(driver->termios); | |
a3a10ce3 | 3362 | kfree(driver->cdevs); |
16a02081 JS |
3363 | kfree(driver); |
3364 | return ERR_PTR(err); | |
1da177e4 | 3365 | } |
7f0bc6a6 | 3366 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3367 | |
7d7b93c1 | 3368 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3369 | { |
7d7b93c1 AC |
3370 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3371 | int i; | |
3372 | struct ktermios *tp; | |
7d7b93c1 AC |
3373 | |
3374 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
3375 | for (i = 0; i < driver->num; i++) { |
3376 | tp = driver->termios[i]; | |
3377 | if (tp) { | |
3378 | driver->termios[i] = NULL; | |
3379 | kfree(tp); | |
3380 | } | |
7d7b93c1 AC |
3381 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3382 | tty_unregister_device(driver, i); | |
3383 | } | |
7d7b93c1 | 3384 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3385 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3386 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3387 | } |
7e73eca6 | 3388 | kfree(driver->cdevs); |
04831dc1 | 3389 | kfree(driver->ports); |
16a02081 JS |
3390 | kfree(driver->termios); |
3391 | kfree(driver->ttys); | |
1da177e4 LT |
3392 | kfree(driver); |
3393 | } | |
3394 | ||
38581283 JS |
3395 | /** |
3396 | * tty_driver_kref_put -- drop a reference to a tty driver | |
3397 | * @driver: driver of which to drop the reference | |
3398 | * | |
3399 | * The final put will destroy and free up the driver. | |
3400 | */ | |
7d7b93c1 AC |
3401 | void tty_driver_kref_put(struct tty_driver *driver) |
3402 | { | |
3403 | kref_put(&driver->kref, destruct_tty_driver); | |
3404 | } | |
3405 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3406 | ||
38581283 JS |
3407 | /** |
3408 | * tty_register_driver -- register a tty driver | |
3409 | * @driver: driver to register | |
3410 | * | |
1da177e4 LT |
3411 | * Called by a tty driver to register itself. |
3412 | */ | |
3413 | int tty_register_driver(struct tty_driver *driver) | |
3414 | { | |
3415 | int error; | |
37bdfb07 | 3416 | int i; |
1da177e4 | 3417 | dev_t dev; |
b670bde0 | 3418 | struct device *d; |
1da177e4 | 3419 | |
1da177e4 | 3420 | if (!driver->major) { |
37bdfb07 AC |
3421 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3422 | driver->num, driver->name); | |
1da177e4 LT |
3423 | if (!error) { |
3424 | driver->major = MAJOR(dev); | |
3425 | driver->minor_start = MINOR(dev); | |
3426 | } | |
3427 | } else { | |
3428 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3429 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3430 | } |
9bb8a3d4 | 3431 | if (error < 0) |
16a02081 | 3432 | goto err; |
1da177e4 | 3433 | |
7e73eca6 JS |
3434 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3435 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3436 | if (error) | |
3437 | goto err_unreg_char; | |
3438 | } | |
1da177e4 | 3439 | |
ca509f69 | 3440 | mutex_lock(&tty_mutex); |
1da177e4 | 3441 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3442 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3443 | |
3444 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3445 | for (i = 0; i < driver->num; i++) { |
3446 | d = tty_register_device(driver, i, NULL); | |
3447 | if (IS_ERR(d)) { | |
3448 | error = PTR_ERR(d); | |
16a02081 | 3449 | goto err_unreg_devs; |
b670bde0 VK |
3450 | } |
3451 | } | |
1da177e4 LT |
3452 | } |
3453 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3454 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3455 | return 0; |
b670bde0 | 3456 | |
16a02081 | 3457 | err_unreg_devs: |
b670bde0 VK |
3458 | for (i--; i >= 0; i--) |
3459 | tty_unregister_device(driver, i); | |
3460 | ||
3461 | mutex_lock(&tty_mutex); | |
3462 | list_del(&driver->tty_drivers); | |
3463 | mutex_unlock(&tty_mutex); | |
3464 | ||
9bb8a3d4 | 3465 | err_unreg_char: |
b670bde0 | 3466 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3467 | err: |
b670bde0 | 3468 | return error; |
1da177e4 | 3469 | } |
1da177e4 LT |
3470 | EXPORT_SYMBOL(tty_register_driver); |
3471 | ||
38581283 JS |
3472 | /** |
3473 | * tty_unregister_driver -- unregister a tty driver | |
3474 | * @driver: driver to unregister | |
3475 | * | |
1da177e4 LT |
3476 | * Called by a tty driver to unregister itself. |
3477 | */ | |
a872ab4d | 3478 | void tty_unregister_driver(struct tty_driver *driver) |
1da177e4 | 3479 | { |
1da177e4 LT |
3480 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3481 | driver->num); | |
ca509f69 | 3482 | mutex_lock(&tty_mutex); |
1da177e4 | 3483 | list_del(&driver->tty_drivers); |
ca509f69 | 3484 | mutex_unlock(&tty_mutex); |
1da177e4 | 3485 | } |
1da177e4 LT |
3486 | EXPORT_SYMBOL(tty_unregister_driver); |
3487 | ||
24ec839c PZ |
3488 | dev_t tty_devnum(struct tty_struct *tty) |
3489 | { | |
3490 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3491 | } | |
3492 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3493 | |
d81ed103 AC |
3494 | void tty_default_fops(struct file_operations *fops) |
3495 | { | |
3496 | *fops = tty_fops; | |
3497 | } | |
3498 | ||
ff62b8e6 | 3499 | static char *tty_devnode(const struct device *dev, umode_t *mode) |
e454cea2 KS |
3500 | { |
3501 | if (!mode) | |
3502 | return NULL; | |
3503 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3504 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3505 | *mode = 0666; | |
3506 | return NULL; | |
3507 | } | |
3508 | ||
862d8312 GKH |
3509 | const struct class tty_class = { |
3510 | .name = "tty", | |
3511 | .devnode = tty_devnode, | |
3512 | }; | |
3513 | ||
1da177e4 LT |
3514 | static int __init tty_class_init(void) |
3515 | { | |
862d8312 | 3516 | return class_register(&tty_class); |
1da177e4 LT |
3517 | } |
3518 | ||
3519 | postcore_initcall(tty_class_init); | |
3520 | ||
3521 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3522 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3523 | |
fbc92a34 KS |
3524 | static ssize_t show_cons_active(struct device *dev, |
3525 | struct device_attribute *attr, char *buf) | |
3526 | { | |
3527 | struct console *cs[16]; | |
3528 | int i = 0; | |
3529 | struct console *c; | |
3530 | ssize_t count = 0; | |
3531 | ||
d25a2e74 | 3532 | /* |
7c2af0f6 | 3533 | * Hold the console_list_lock to guarantee that no consoles are |
d25a2e74 JO |
3534 | * unregistered until all console processing is complete. |
3535 | * This also allows safe traversal of the console list and | |
3536 | * race-free reading of @flags. | |
d25a2e74 | 3537 | */ |
7c2af0f6 JO |
3538 | console_list_lock(); |
3539 | ||
a2a6a822 | 3540 | for_each_console(c) { |
fbc92a34 KS |
3541 | if (!c->device) |
3542 | continue; | |
3543 | if (!c->write) | |
3544 | continue; | |
3545 | if ((c->flags & CON_ENABLED) == 0) | |
3546 | continue; | |
3547 | cs[i++] = c; | |
3548 | if (i >= ARRAY_SIZE(cs)) | |
3549 | break; | |
3550 | } | |
7c2af0f6 JO |
3551 | |
3552 | /* | |
3553 | * Take console_lock to serialize device() callback with | |
3554 | * other console operations. For example, fg_console is | |
3555 | * modified under console_lock when switching vt. | |
3556 | */ | |
3557 | console_lock(); | |
723abd87 HR |
3558 | while (i--) { |
3559 | int index = cs[i]->index; | |
3560 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3561 | ||
3562 | /* don't resolve tty0 as some programs depend on it */ | |
3563 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3564 | count += tty_line_name(drv, index, buf + count); | |
3565 | else | |
3566 | count += sprintf(buf + count, "%s%d", | |
3567 | cs[i]->name, cs[i]->index); | |
3568 | ||
3569 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3570 | } | |
ac751efa | 3571 | console_unlock(); |
fbc92a34 | 3572 | |
7c2af0f6 JO |
3573 | console_list_unlock(); |
3574 | ||
fbc92a34 KS |
3575 | return count; |
3576 | } | |
3577 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3578 | ||
1083a7be TI |
3579 | static struct attribute *cons_dev_attrs[] = { |
3580 | &dev_attr_active.attr, | |
3581 | NULL | |
3582 | }; | |
3583 | ||
3584 | ATTRIBUTE_GROUPS(cons_dev); | |
3585 | ||
fbc92a34 KS |
3586 | static struct device *consdev; |
3587 | ||
3588 | void console_sysfs_notify(void) | |
3589 | { | |
3590 | if (consdev) | |
3591 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3592 | } | |
3593 | ||
5fd8c2d3 | 3594 | static struct ctl_table tty_table[] = { |
83efeeeb KC |
3595 | { |
3596 | .procname = "legacy_tiocsti", | |
3597 | .data = &tty_legacy_tiocsti, | |
3598 | .maxlen = sizeof(tty_legacy_tiocsti), | |
3599 | .mode = 0644, | |
3600 | .proc_handler = proc_dobool, | |
3601 | }, | |
5fd8c2d3 KC |
3602 | { |
3603 | .procname = "ldisc_autoload", | |
3604 | .data = &tty_ldisc_autoload, | |
3605 | .maxlen = sizeof(tty_ldisc_autoload), | |
3606 | .mode = 0644, | |
3607 | .proc_handler = proc_dointvec, | |
3608 | .extra1 = SYSCTL_ZERO, | |
3609 | .extra2 = SYSCTL_ONE, | |
3610 | }, | |
3611 | { } | |
3612 | }; | |
3613 | ||
1da177e4 LT |
3614 | /* |
3615 | * Ok, now we can initialize the rest of the tty devices and can count | |
3616 | * on memory allocations, interrupts etc.. | |
3617 | */ | |
31d1d48e | 3618 | int __init tty_init(void) |
1da177e4 | 3619 | { |
6d12b774 | 3620 | register_sysctl_init("dev/tty", tty_table); |
1da177e4 LT |
3621 | cdev_init(&tty_cdev, &tty_fops); |
3622 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3623 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3624 | panic("Couldn't register /dev/tty driver\n"); | |
862d8312 | 3625 | device_create(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3626 | |
3627 | cdev_init(&console_cdev, &console_fops); | |
3628 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3629 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3630 | panic("Couldn't register /dev/console driver\n"); | |
862d8312 | 3631 | consdev = device_create_with_groups(&tty_class, NULL, |
1083a7be TI |
3632 | MKDEV(TTYAUX_MAJOR, 1), NULL, |
3633 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3634 | if (IS_ERR(consdev)) |
3635 | consdev = NULL; | |
1da177e4 | 3636 | |
1da177e4 | 3637 | #ifdef CONFIG_VT |
d81ed103 | 3638 | vty_init(&console_fops); |
1da177e4 LT |
3639 | #endif |
3640 | return 0; | |
3641 | } |