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> |
1da177e4 | 102 | |
a352def2 | 103 | #include <linux/uaccess.h> |
1da177e4 LT |
104 | |
105 | #include <linux/kbd_kern.h> | |
106 | #include <linux/vt_kern.h> | |
107 | #include <linux/selection.h> | |
1da177e4 LT |
108 | |
109 | #include <linux/kmod.h> | |
b488893a | 110 | #include <linux/nsproxy.h> |
98602c01 | 111 | #include "tty.h" |
1da177e4 LT |
112 | |
113 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
114 | #ifdef TTY_DEBUG_HANGUP |
115 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
116 | #else | |
117 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
118 | #endif | |
1da177e4 LT |
119 | |
120 | #define TTY_PARANOIA_CHECK 1 | |
121 | #define CHECK_TTY_COUNT 1 | |
122 | ||
edc6afc5 | 123 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
124 | .c_iflag = ICRNL | IXON, |
125 | .c_oflag = OPOST | ONLCR, | |
126 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
127 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
128 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
129 | .c_cc = INIT_C_CC, |
130 | .c_ispeed = 38400, | |
133b1306 PH |
131 | .c_ospeed = 38400, |
132 | /* .c_line = N_TTY, */ | |
1da177e4 | 133 | }; |
1da177e4 LT |
134 | EXPORT_SYMBOL(tty_std_termios); |
135 | ||
136 | /* This list gets poked at by procfs and various bits of boot up code. This | |
b426a5b8 XT |
137 | * could do with some rationalisation such as pulling the tty proc function |
138 | * into this file. | |
139 | */ | |
37bdfb07 | 140 | |
1da177e4 LT |
141 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
142 | ||
d1d027ef | 143 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 144 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 145 | |
dd78b0c4 | 146 | static ssize_t tty_read(struct kiocb *, struct iov_iter *); |
9bb48c82 | 147 | static ssize_t tty_write(struct kiocb *, struct iov_iter *); |
afc9a42b | 148 | static __poll_t tty_poll(struct file *, poll_table *); |
1da177e4 | 149 | static int tty_open(struct inode *, struct file *); |
e10cc1df | 150 | #ifdef CONFIG_COMPAT |
37bdfb07 | 151 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
152 | unsigned long arg); |
153 | #else | |
154 | #define tty_compat_ioctl NULL | |
155 | #endif | |
ec79d605 | 156 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 157 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 158 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 159 | |
af9b897e AC |
160 | /** |
161 | * free_tty_struct - free a disused tty | |
162 | * @tty: tty struct to free | |
163 | * | |
164 | * Free the write buffers, tty queue and tty memory itself. | |
165 | * | |
166 | * Locking: none. Must be called after tty is definitely unused | |
167 | */ | |
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); |
1da177e4 | 173 | kfree(tty->write_buf); |
89c8d91e | 174 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
175 | kfree(tty); |
176 | } | |
177 | ||
d996b62a NP |
178 | static inline struct tty_struct *file_tty(struct file *file) |
179 | { | |
180 | return ((struct tty_file_private *)file->private_data)->tty; | |
181 | } | |
182 | ||
fa90e1c9 | 183 | int tty_alloc_file(struct file *file) |
d996b62a NP |
184 | { |
185 | struct tty_file_private *priv; | |
186 | ||
f573bd17 PE |
187 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
188 | if (!priv) | |
189 | return -ENOMEM; | |
d996b62a | 190 | |
fa90e1c9 JS |
191 | file->private_data = priv; |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | /* Associate a new file with the tty structure */ | |
197 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
198 | { | |
199 | struct tty_file_private *priv = file->private_data; | |
200 | ||
d996b62a NP |
201 | priv->tty = tty; |
202 | priv->file = file; | |
d996b62a | 203 | |
4a510969 | 204 | spin_lock(&tty->files_lock); |
d996b62a | 205 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 206 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 207 | } |
f573bd17 | 208 | |
08aa5042 | 209 | /* |
fa90e1c9 JS |
210 | * tty_free_file - free file->private_data |
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 AC |
235 | /** |
236 | * tty_name - return tty naming | |
237 | * @tty: tty structure | |
af9b897e AC |
238 | * |
239 | * Convert a tty structure into a name. The name reflects the kernel | |
240 | * naming policy and if udev is in use may not reflect user space | |
241 | * | |
242 | * Locking: none | |
243 | */ | |
244 | ||
429b4749 | 245 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
246 | { |
247 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
248 | return "NULL tty"; |
249 | return tty->name; | |
1da177e4 | 250 | } |
1da177e4 LT |
251 | EXPORT_SYMBOL(tty_name); |
252 | ||
0a083edd PH |
253 | const char *tty_driver_name(const struct tty_struct *tty) |
254 | { | |
255 | if (!tty || !tty->driver) | |
256 | return ""; | |
257 | return tty->driver->name; | |
258 | } | |
259 | ||
82b8f888 | 260 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
261 | const char *routine) |
262 | { | |
263 | #ifdef TTY_PARANOIA_CHECK | |
264 | if (!tty) { | |
89222e62 | 265 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
266 | imajor(inode), iminor(inode), routine); |
267 | return 1; | |
268 | } | |
269 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 270 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
271 | imajor(inode), iminor(inode), routine); |
272 | return 1; | |
273 | } | |
274 | #endif | |
275 | return 0; | |
276 | } | |
277 | ||
deb287e7 | 278 | /* Caller must hold tty_lock */ |
1da177e4 LT |
279 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
280 | { | |
281 | #ifdef CHECK_TTY_COUNT | |
282 | struct list_head *p; | |
a09ac397 | 283 | int count = 0, kopen_count = 0; |
37bdfb07 | 284 | |
4a510969 | 285 | spin_lock(&tty->files_lock); |
1da177e4 LT |
286 | list_for_each(p, &tty->tty_files) { |
287 | count++; | |
288 | } | |
4a510969 | 289 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
290 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
291 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
292 | tty->link && tty->link->count) | |
293 | count++; | |
a09ac397 OK |
294 | if (tty_port_kopened(tty->port)) |
295 | kopen_count++; | |
296 | if (tty->count != (count + kopen_count)) { | |
297 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", | |
298 | routine, tty->count, count, kopen_count); | |
299 | return (count + kopen_count); | |
24ec839c | 300 | } |
1da177e4 LT |
301 | #endif |
302 | return 0; | |
303 | } | |
304 | ||
af9b897e AC |
305 | /** |
306 | * get_tty_driver - find device of a tty | |
fa441954 | 307 | * @device: device identifier |
af9b897e AC |
308 | * @index: returns the index of the tty |
309 | * | |
310 | * This routine returns a tty driver structure, given a device number | |
311 | * and also passes back the index number. | |
312 | * | |
313 | * Locking: caller must hold tty_mutex | |
1da177e4 | 314 | */ |
af9b897e | 315 | |
1da177e4 LT |
316 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
317 | { | |
318 | struct tty_driver *p; | |
319 | ||
320 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
321 | dev_t base = MKDEV(p->major, p->minor_start); | |
e73b2407 | 322 | |
1da177e4 LT |
323 | if (device < base || device >= base + p->num) |
324 | continue; | |
325 | *index = device - base; | |
7d7b93c1 | 326 | return tty_driver_kref_get(p); |
1da177e4 LT |
327 | } |
328 | return NULL; | |
329 | } | |
330 | ||
fc61ed51 OK |
331 | /** |
332 | * tty_dev_name_to_number - return dev_t for device name | |
333 | * @name: user space name of device under /dev | |
334 | * @number: pointer to dev_t that this function will populate | |
335 | * | |
336 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t | |
337 | * like (4, 64) or (188, 1). If no corresponding driver is registered then | |
338 | * the function returns -ENODEV. | |
339 | * | |
340 | * Locking: this acquires tty_mutex to protect the tty_drivers list from | |
341 | * being modified while we are traversing it, and makes sure to | |
342 | * release it before exiting. | |
343 | */ | |
344 | int tty_dev_name_to_number(const char *name, dev_t *number) | |
345 | { | |
346 | struct tty_driver *p; | |
347 | int ret; | |
348 | int index, prefix_length = 0; | |
349 | const char *str; | |
350 | ||
351 | for (str = name; *str && !isdigit(*str); str++) | |
352 | ; | |
353 | ||
354 | if (!*str) | |
355 | return -EINVAL; | |
356 | ||
357 | ret = kstrtoint(str, 10, &index); | |
358 | if (ret) | |
359 | return ret; | |
360 | ||
361 | prefix_length = str - name; | |
362 | mutex_lock(&tty_mutex); | |
363 | ||
364 | list_for_each_entry(p, &tty_drivers, tty_drivers) | |
365 | if (prefix_length == strlen(p->name) && strncmp(name, | |
366 | p->name, prefix_length) == 0) { | |
367 | if (index < p->num) { | |
368 | *number = MKDEV(p->major, p->minor_start + index); | |
369 | goto out; | |
370 | } | |
371 | } | |
372 | ||
373 | /* if here then driver wasn't found */ | |
374 | ret = -ENODEV; | |
375 | out: | |
376 | mutex_unlock(&tty_mutex); | |
377 | return ret; | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number); | |
380 | ||
f2d937f3 JW |
381 | #ifdef CONFIG_CONSOLE_POLL |
382 | ||
383 | /** | |
384 | * tty_find_polling_driver - find device of a polled tty | |
385 | * @name: name string to match | |
386 | * @line: pointer to resulting tty line nr | |
387 | * | |
388 | * This routine returns a tty driver structure, given a name | |
389 | * and the condition that the tty driver is capable of polled | |
390 | * operation. | |
391 | */ | |
392 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
393 | { | |
394 | struct tty_driver *p, *res = NULL; | |
395 | int tty_line = 0; | |
0dca0fd2 | 396 | int len; |
5f0878ac | 397 | char *str, *stp; |
f2d937f3 | 398 | |
0dca0fd2 JW |
399 | for (str = name; *str; str++) |
400 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
401 | break; | |
402 | if (!*str) | |
403 | return NULL; | |
404 | ||
405 | len = str - name; | |
406 | tty_line = simple_strtoul(str, &str, 10); | |
407 | ||
f2d937f3 JW |
408 | mutex_lock(&tty_mutex); |
409 | /* Search through the tty devices to look for a match */ | |
410 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
33a1a7be | 411 | if (!len || strncmp(name, p->name, len) != 0) |
0dca0fd2 | 412 | continue; |
5f0878ac AC |
413 | stp = str; |
414 | if (*stp == ',') | |
415 | stp++; | |
416 | if (*stp == '\0') | |
417 | stp = NULL; | |
f2d937f3 | 418 | |
6eb68d6f | 419 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 420 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 421 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
422 | *line = tty_line; |
423 | break; | |
424 | } | |
425 | } | |
426 | mutex_unlock(&tty_mutex); | |
427 | ||
428 | return res; | |
429 | } | |
430 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
431 | #endif | |
432 | ||
ddc5fda7 | 433 | static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 LT |
434 | { |
435 | return 0; | |
436 | } | |
437 | ||
17749851 | 438 | static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) |
1da177e4 LT |
439 | { |
440 | return -EIO; | |
441 | } | |
442 | ||
443 | /* No kernel lock held - none needed ;) */ | |
afc9a42b | 444 | static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 445 | { |
a9a08845 | 446 | return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; |
1da177e4 LT |
447 | } |
448 | ||
04f378b1 AC |
449 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
450 | unsigned long arg) | |
38ad2ed0 PF |
451 | { |
452 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
453 | } | |
454 | ||
37bdfb07 | 455 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 456 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
457 | { |
458 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
459 | } | |
460 | ||
f557474c PH |
461 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
462 | { | |
463 | return -ENOTTY; | |
464 | } | |
465 | ||
d01c3289 MY |
466 | static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
467 | { | |
468 | struct tty_struct *tty = file_tty(file); | |
469 | ||
470 | if (tty && tty->ops && tty->ops->show_fdinfo) | |
471 | tty->ops->show_fdinfo(tty, m); | |
472 | } | |
473 | ||
62322d25 | 474 | static const struct file_operations tty_fops = { |
1da177e4 | 475 | .llseek = no_llseek, |
dd78b0c4 | 476 | .read_iter = tty_read, |
9bb48c82 | 477 | .write_iter = tty_write, |
dd78b0c4 | 478 | .splice_read = generic_file_splice_read, |
9bb48c82 | 479 | .splice_write = iter_file_splice_write, |
1da177e4 | 480 | .poll = tty_poll, |
04f378b1 | 481 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 482 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
483 | .open = tty_open, |
484 | .release = tty_release, | |
485 | .fasync = tty_fasync, | |
d01c3289 | 486 | .show_fdinfo = tty_show_fdinfo, |
1da177e4 LT |
487 | }; |
488 | ||
62322d25 | 489 | static const struct file_operations console_fops = { |
1da177e4 | 490 | .llseek = no_llseek, |
dd78b0c4 | 491 | .read_iter = tty_read, |
9bb48c82 | 492 | .write_iter = redirected_tty_write, |
dd78b0c4 | 493 | .splice_read = generic_file_splice_read, |
9bb48c82 | 494 | .splice_write = iter_file_splice_write, |
1da177e4 | 495 | .poll = tty_poll, |
04f378b1 | 496 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 497 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
498 | .open = tty_open, |
499 | .release = tty_release, | |
500 | .fasync = tty_fasync, | |
501 | }; | |
502 | ||
62322d25 | 503 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 | 504 | .llseek = no_llseek, |
ddc5fda7 | 505 | .read_iter = hung_up_tty_read, |
17749851 | 506 | .write_iter = hung_up_tty_write, |
1da177e4 | 507 | .poll = hung_up_tty_poll, |
04f378b1 | 508 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 509 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 510 | .release = tty_release, |
f557474c | 511 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
512 | }; |
513 | ||
514 | static DEFINE_SPINLOCK(redirect_lock); | |
515 | static struct file *redirect; | |
516 | ||
517 | /** | |
518 | * tty_wakeup - request more data | |
519 | * @tty: terminal | |
520 | * | |
521 | * Internal and external helper for wakeups of tty. This function | |
522 | * informs the line discipline if present that the driver is ready | |
523 | * to receive more output data. | |
524 | */ | |
37bdfb07 | 525 | |
1da177e4 LT |
526 | void tty_wakeup(struct tty_struct *tty) |
527 | { | |
528 | struct tty_ldisc *ld; | |
37bdfb07 | 529 | |
1da177e4 LT |
530 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
531 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 532 | if (ld) { |
a352def2 AC |
533 | if (ld->ops->write_wakeup) |
534 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
535 | tty_ldisc_deref(ld); |
536 | } | |
537 | } | |
a9a08845 | 538 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 | 539 | } |
1da177e4 LT |
540 | EXPORT_SYMBOL_GPL(tty_wakeup); |
541 | ||
f446776e CM |
542 | /** |
543 | * tty_release_redirect - Release a redirect on a pty if present | |
544 | * @tty: tty device | |
545 | * | |
546 | * This is available to the pty code so if the master closes, if the | |
c776b77a | 547 | * slave is a redirect it can release the redirect. |
f446776e | 548 | */ |
dd9f6114 | 549 | static struct file *tty_release_redirect(struct tty_struct *tty) |
f446776e CM |
550 | { |
551 | struct file *f = NULL; | |
552 | ||
553 | spin_lock(&redirect_lock); | |
554 | if (redirect && file_tty(redirect) == tty) { | |
555 | f = redirect; | |
556 | redirect = NULL; | |
557 | } | |
558 | spin_unlock(&redirect_lock); | |
559 | ||
560 | return f; | |
561 | } | |
f446776e | 562 | |
af9b897e | 563 | /** |
11dbf203 | 564 | * __tty_hangup - actual handler for hangup events |
fa441954 | 565 | * @tty: tty device |
08aa5042 | 566 | * @exit_session: if non-zero, signal all foreground group processes |
af9b897e | 567 | * |
ef4f527c | 568 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
569 | * synchronous but doesn't hold any locks, so we need to make sure we |
570 | * have the appropriate locks for what we're doing. | |
571 | * | |
572 | * The hangup event clears any pending redirections onto the hung up | |
573 | * device. It ensures future writes will error and it does the needed | |
574 | * line discipline hangup and signal delivery. The tty object itself | |
575 | * remains intact. | |
576 | * | |
577 | * Locking: | |
ec79d605 | 578 | * BTM |
24ec839c PZ |
579 | * redirect lock for undoing redirection |
580 | * file list lock for manipulating list of ttys | |
137084bb | 581 | * tty_ldiscs_lock from called functions |
6a1c0680 | 582 | * termios_rwsem resetting termios data |
24ec839c PZ |
583 | * tasklist_lock to walk task list for hangup event |
584 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 585 | */ |
f91e2590 | 586 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 587 | { |
37bdfb07 | 588 | struct file *cons_filp = NULL; |
f446776e | 589 | struct file *filp, *f; |
d996b62a | 590 | struct tty_file_private *priv; |
1da177e4 | 591 | int closecount = 0, n; |
ea648a47 | 592 | int refs; |
1da177e4 LT |
593 | |
594 | if (!tty) | |
595 | return; | |
596 | ||
f446776e | 597 | f = tty_release_redirect(tty); |
37bdfb07 | 598 | |
89c8d91e | 599 | tty_lock(tty); |
11dbf203 | 600 | |
cb50e523 PH |
601 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
602 | tty_unlock(tty); | |
603 | return; | |
604 | } | |
605 | ||
28b0f8a6 TH |
606 | /* |
607 | * Some console devices aren't actually hung up for technical and | |
608 | * historical reasons, which can lead to indefinite interruptible | |
609 | * sleep in n_tty_read(). The following explicitly tells | |
610 | * n_tty_read() to abort readers. | |
611 | */ | |
612 | set_bit(TTY_HUPPING, &tty->flags); | |
613 | ||
ec79d605 | 614 | /* inuse_filps is protected by the single tty lock, |
b426a5b8 XT |
615 | * this really needs to change if we want to flush the |
616 | * workqueue with the lock held. | |
617 | */ | |
11dbf203 | 618 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 619 | |
4a510969 | 620 | spin_lock(&tty->files_lock); |
1da177e4 | 621 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
622 | list_for_each_entry(priv, &tty->tty_files, list) { |
623 | filp = priv->file; | |
9bb48c82 | 624 | if (filp->f_op->write_iter == redirected_tty_write) |
1da177e4 | 625 | cons_filp = filp; |
9bb48c82 | 626 | if (filp->f_op->write_iter != tty_write) |
1da177e4 LT |
627 | continue; |
628 | closecount++; | |
ec79d605 | 629 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
630 | filp->f_op = &hung_up_tty_fops; |
631 | } | |
4a510969 | 632 | spin_unlock(&tty->files_lock); |
37bdfb07 | 633 | |
25fdf243 PH |
634 | refs = tty_signal_session_leader(tty, exit_session); |
635 | /* Account for the p->signal references we killed */ | |
636 | while (refs--) | |
637 | tty_kref_put(tty); | |
638 | ||
892d1fa7 | 639 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 640 | |
64d608db | 641 | spin_lock_irq(&tty->ctrl.lock); |
c65c9bc3 | 642 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 643 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
64d608db JS |
644 | put_pid(tty->ctrl.session); |
645 | put_pid(tty->ctrl.pgrp); | |
646 | tty->ctrl.session = NULL; | |
647 | tty->ctrl.pgrp = NULL; | |
648 | tty->ctrl.pktstatus = 0; | |
649 | spin_unlock_irq(&tty->ctrl.lock); | |
9c9f4ded | 650 | |
1da177e4 | 651 | /* |
37bdfb07 AC |
652 | * If one of the devices matches a console pointer, we |
653 | * cannot just call hangup() because that will cause | |
654 | * tty->count and state->count to go out of sync. | |
655 | * So we just call close() the right number of times. | |
1da177e4 LT |
656 | */ |
657 | if (cons_filp) { | |
f34d7a5b | 658 | if (tty->ops->close) |
1da177e4 | 659 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
660 | tty->ops->close(tty, cons_filp); |
661 | } else if (tty->ops->hangup) | |
7c6d340f | 662 | tty->ops->hangup(tty); |
37bdfb07 | 663 | /* |
892d1fa7 PH |
664 | * We don't want to have driver/ldisc interactions beyond the ones |
665 | * we did here. The driver layer expects no calls after ->hangup() | |
666 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 667 | */ |
1da177e4 | 668 | set_bit(TTY_HUPPED, &tty->flags); |
28b0f8a6 | 669 | clear_bit(TTY_HUPPING, &tty->flags); |
89c8d91e | 670 | tty_unlock(tty); |
11dbf203 | 671 | |
1da177e4 LT |
672 | if (f) |
673 | fput(f); | |
674 | } | |
675 | ||
ddcd9fb6 AB |
676 | static void do_tty_hangup(struct work_struct *work) |
677 | { | |
678 | struct tty_struct *tty = | |
679 | container_of(work, struct tty_struct, hangup_work); | |
680 | ||
f91e2590 | 681 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
682 | } |
683 | ||
af9b897e AC |
684 | /** |
685 | * tty_hangup - trigger a hangup event | |
686 | * @tty: tty to hangup | |
687 | * | |
688 | * A carrier loss (virtual or otherwise) has occurred on this like | |
689 | * schedule a hangup sequence to run after this event. | |
690 | */ | |
691 | ||
37bdfb07 | 692 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 693 | { |
d435cefe | 694 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
695 | schedule_work(&tty->hangup_work); |
696 | } | |
1da177e4 LT |
697 | EXPORT_SYMBOL(tty_hangup); |
698 | ||
af9b897e AC |
699 | /** |
700 | * tty_vhangup - process vhangup | |
701 | * @tty: tty to hangup | |
702 | * | |
703 | * The user has asked via system call for the terminal to be hung up. | |
704 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 705 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
706 | */ |
707 | ||
37bdfb07 | 708 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 709 | { |
d435cefe | 710 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 711 | __tty_hangup(tty, 0); |
1da177e4 LT |
712 | } |
713 | EXPORT_SYMBOL(tty_vhangup); | |
714 | ||
11dbf203 | 715 | |
2cb5998b AC |
716 | /** |
717 | * tty_vhangup_self - process vhangup for own ctty | |
718 | * | |
719 | * Perform a vhangup on the current controlling tty | |
720 | */ | |
721 | ||
722 | void tty_vhangup_self(void) | |
723 | { | |
724 | struct tty_struct *tty; | |
725 | ||
2cb5998b AC |
726 | tty = get_current_tty(); |
727 | if (tty) { | |
728 | tty_vhangup(tty); | |
729 | tty_kref_put(tty); | |
730 | } | |
2cb5998b AC |
731 | } |
732 | ||
f91e2590 PH |
733 | /** |
734 | * tty_vhangup_session - hangup session leader exit | |
735 | * @tty: tty to hangup | |
736 | * | |
737 | * The session leader is exiting and hanging up its controlling terminal. | |
738 | * Every process in the foreground process group is signalled SIGHUP. | |
739 | * | |
740 | * We do this synchronously so that when the syscall returns the process | |
741 | * is complete. That guarantee is necessary for security reasons. | |
742 | */ | |
743 | ||
a1235b3e | 744 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 745 | { |
d435cefe | 746 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
747 | __tty_hangup(tty, 1); |
748 | } | |
749 | ||
af9b897e AC |
750 | /** |
751 | * tty_hung_up_p - was tty hung up | |
752 | * @filp: file pointer of tty | |
753 | * | |
754 | * Return true if the tty has been subject to a vhangup or a carrier | |
755 | * loss | |
756 | */ | |
757 | ||
37bdfb07 | 758 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 759 | { |
ed3f0af8 | 760 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 | 761 | } |
1da177e4 LT |
762 | EXPORT_SYMBOL(tty_hung_up_p); |
763 | ||
d06e256f JS |
764 | void __stop_tty(struct tty_struct *tty) |
765 | { | |
766 | if (tty->flow.stopped) | |
767 | return; | |
768 | tty->flow.stopped = true; | |
769 | if (tty->ops->stop) | |
770 | tty->ops->stop(tty); | |
771 | } | |
772 | ||
af9b897e | 773 | /** |
beb7dd86 | 774 | * stop_tty - propagate flow control |
af9b897e AC |
775 | * @tty: tty to stop |
776 | * | |
01adc807 | 777 | * Perform flow control to the driver. May be called |
af9b897e AC |
778 | * on an already stopped device and will not re-call the driver |
779 | * method. | |
780 | * | |
781 | * This functionality is used by both the line disciplines for | |
782 | * halting incoming flow and by the driver. It may therefore be | |
783 | * called from any context, may be under the tty atomic_write_lock | |
784 | * but not always. | |
785 | * | |
786 | * Locking: | |
6e94dbc7 | 787 | * flow.lock |
af9b897e | 788 | */ |
f9e053dc PH |
789 | void stop_tty(struct tty_struct *tty) |
790 | { | |
791 | unsigned long flags; | |
792 | ||
6e94dbc7 | 793 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 794 | __stop_tty(tty); |
6e94dbc7 | 795 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 796 | } |
1da177e4 LT |
797 | EXPORT_SYMBOL(stop_tty); |
798 | ||
d06e256f JS |
799 | void __start_tty(struct tty_struct *tty) |
800 | { | |
801 | if (!tty->flow.stopped || tty->flow.tco_stopped) | |
802 | return; | |
803 | tty->flow.stopped = false; | |
804 | if (tty->ops->start) | |
805 | tty->ops->start(tty); | |
806 | tty_wakeup(tty); | |
807 | } | |
808 | ||
af9b897e | 809 | /** |
beb7dd86 | 810 | * start_tty - propagate flow control |
af9b897e AC |
811 | * @tty: tty to start |
812 | * | |
01adc807 PH |
813 | * Start a tty that has been stopped if at all possible. If this |
814 | * tty was previous stopped and is now being started, the driver | |
815 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
816 | * |
817 | * Locking: | |
6e94dbc7 | 818 | * flow.lock |
af9b897e | 819 | */ |
f9e053dc PH |
820 | void start_tty(struct tty_struct *tty) |
821 | { | |
822 | unsigned long flags; | |
823 | ||
6e94dbc7 | 824 | spin_lock_irqsave(&tty->flow.lock, flags); |
f9e053dc | 825 | __start_tty(tty); |
6e94dbc7 | 826 | spin_unlock_irqrestore(&tty->flow.lock, flags); |
f9e053dc | 827 | } |
1da177e4 LT |
828 | EXPORT_SYMBOL(start_tty); |
829 | ||
c884f871 | 830 | static void tty_update_time(struct timespec64 *time) |
37b7f3c7 | 831 | { |
c884f871 | 832 | time64_t sec = ktime_get_real_seconds(); |
fbf47635 GKH |
833 | |
834 | /* | |
835 | * We only care if the two values differ in anything other than the | |
836 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
837 | * the time of the tty device, otherwise it could be construded as a | |
838 | * security leak to let userspace know the exact timing of the tty. | |
839 | */ | |
840 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
841 | time->tv_sec = sec; |
842 | } | |
843 | ||
3b830a9c LT |
844 | /* |
845 | * Iterate on the ldisc ->read() function until we've gotten all | |
846 | * the data the ldisc has for us. | |
847 | * | |
848 | * The "cookie" is something that the ldisc read function can fill | |
849 | * in to let us know that there is more data to be had. | |
850 | * | |
851 | * We promise to continue to call the ldisc until it stops returning | |
852 | * data or clears the cookie. The cookie may be something that the | |
853 | * ldisc maintains state for and needs to free. | |
854 | */ | |
dd78b0c4 LT |
855 | static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, |
856 | struct file *file, struct iov_iter *to) | |
3b830a9c LT |
857 | { |
858 | int retval = 0; | |
859 | void *cookie = NULL; | |
860 | unsigned long offset = 0; | |
861 | char kernel_buf[64]; | |
dd78b0c4 | 862 | size_t count = iov_iter_count(to); |
3b830a9c LT |
863 | |
864 | do { | |
dd78b0c4 | 865 | int size, copied; |
3b830a9c LT |
866 | |
867 | size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count; | |
868 | size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); | |
869 | if (!size) | |
870 | break; | |
871 | ||
3b830a9c | 872 | if (size < 0) { |
e71a8d5c LT |
873 | /* Did we have an earlier error (ie -EFAULT)? */ |
874 | if (retval) | |
875 | break; | |
876 | retval = size; | |
877 | ||
878 | /* | |
879 | * -EOVERFLOW means we didn't have enough space | |
880 | * for a whole packet, and we shouldn't return | |
881 | * a partial result. | |
882 | */ | |
883 | if (retval == -EOVERFLOW) | |
884 | offset = 0; | |
885 | break; | |
3b830a9c LT |
886 | } |
887 | ||
dd78b0c4 LT |
888 | copied = copy_to_iter(kernel_buf, size, to); |
889 | offset += copied; | |
890 | count -= copied; | |
3b830a9c LT |
891 | |
892 | /* | |
893 | * If the user copy failed, we still need to do another ->read() | |
894 | * call if we had a cookie to let the ldisc clear up. | |
895 | * | |
896 | * But make sure size is zeroed. | |
897 | */ | |
dd78b0c4 | 898 | if (unlikely(copied != size)) { |
3b830a9c LT |
899 | count = 0; |
900 | retval = -EFAULT; | |
901 | } | |
902 | } while (cookie); | |
903 | ||
904 | /* We always clear tty buffer in case they contained passwords */ | |
905 | memzero_explicit(kernel_buf, sizeof(kernel_buf)); | |
906 | return offset ? offset : retval; | |
907 | } | |
908 | ||
909 | ||
af9b897e AC |
910 | /** |
911 | * tty_read - read method for tty device files | |
756a4e4a JS |
912 | * @iocb: kernel I/O control block |
913 | * @to: destination for the data read | |
af9b897e AC |
914 | * |
915 | * Perform the read system call function on this terminal device. Checks | |
916 | * for hung up devices before calling the line discipline method. | |
917 | * | |
918 | * Locking: | |
47f86834 AC |
919 | * Locks the line discipline internally while needed. Multiple |
920 | * read calls may be outstanding in parallel. | |
af9b897e AC |
921 | */ |
922 | ||
dd78b0c4 | 923 | static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) |
1da177e4 LT |
924 | { |
925 | int i; | |
dd78b0c4 | 926 | struct file *file = iocb->ki_filp; |
37b7f3c7 | 927 | struct inode *inode = file_inode(file); |
d996b62a | 928 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
929 | struct tty_ldisc *ld; |
930 | ||
37b7f3c7 | 931 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 932 | return -EIO; |
18900ca6 | 933 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
934 | return -EIO; |
935 | ||
936 | /* We want to wait for the line discipline to sort out in this | |
b426a5b8 XT |
937 | * situation. |
938 | */ | |
1da177e4 | 939 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 | 940 | if (!ld) |
ddc5fda7 | 941 | return hung_up_tty_read(iocb, to); |
3b830a9c | 942 | i = -EIO; |
a352def2 | 943 | if (ld->ops->read) |
dd78b0c4 | 944 | i = iterate_tty_read(ld, tty, file, to); |
1da177e4 | 945 | tty_ldisc_deref(ld); |
b0de59b5 | 946 | |
c884f871 AB |
947 | if (i > 0) |
948 | tty_update_time(&inode->i_atime); | |
37b7f3c7 | 949 | |
1da177e4 LT |
950 | return i; |
951 | } | |
952 | ||
136d5258 | 953 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
954 | { |
955 | mutex_unlock(&tty->atomic_write_lock); | |
a9a08845 | 956 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
9c1729db AC |
957 | } |
958 | ||
136d5258 | 959 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
960 | { |
961 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
962 | if (ndelay) | |
963 | return -EAGAIN; | |
964 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
965 | return -ERESTARTSYS; | |
966 | } | |
967 | return 0; | |
968 | } | |
969 | ||
1da177e4 LT |
970 | /* |
971 | * Split writes up in sane blocksizes to avoid | |
972 | * denial-of-service type attacks | |
973 | */ | |
974 | static inline ssize_t do_tty_write( | |
975 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
976 | struct tty_struct *tty, | |
977 | struct file *file, | |
9bb48c82 | 978 | struct iov_iter *from) |
1da177e4 | 979 | { |
9bb48c82 | 980 | size_t count = iov_iter_count(from); |
9c1729db | 981 | ssize_t ret, written = 0; |
1da177e4 | 982 | unsigned int chunk; |
37bdfb07 | 983 | |
9c1729db AC |
984 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
985 | if (ret < 0) | |
986 | return ret; | |
1da177e4 LT |
987 | |
988 | /* | |
989 | * We chunk up writes into a temporary buffer. This | |
990 | * simplifies low-level drivers immensely, since they | |
991 | * don't have locking issues and user mode accesses. | |
992 | * | |
993 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
994 | * big chunk-size.. | |
995 | * | |
996 | * The default chunk-size is 2kB, because the NTTY | |
997 | * layer has problems with bigger chunks. It will | |
998 | * claim to be able to handle more characters than | |
999 | * it actually does. | |
af9b897e AC |
1000 | * |
1001 | * FIXME: This can probably go away now except that 64K chunks | |
1002 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1003 | */ |
1004 | chunk = 2048; | |
1005 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1006 | chunk = 65536; | |
1007 | if (count < chunk) | |
1008 | chunk = count; | |
1009 | ||
70522e12 | 1010 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1011 | if (tty->write_cnt < chunk) { |
402fda92 | 1012 | unsigned char *buf_chunk; |
1da177e4 LT |
1013 | |
1014 | if (chunk < 1024) | |
1015 | chunk = 1024; | |
1016 | ||
402fda92 JW |
1017 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1018 | if (!buf_chunk) { | |
9c1729db AC |
1019 | ret = -ENOMEM; |
1020 | goto out; | |
1da177e4 LT |
1021 | } |
1022 | kfree(tty->write_buf); | |
1023 | tty->write_cnt = chunk; | |
402fda92 | 1024 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1025 | } |
1026 | ||
1027 | /* Do the write .. */ | |
1028 | for (;;) { | |
1029 | size_t size = count; | |
e73b2407 | 1030 | |
1da177e4 LT |
1031 | if (size > chunk) |
1032 | size = chunk; | |
9bb48c82 | 1033 | |
1da177e4 | 1034 | ret = -EFAULT; |
9bb48c82 | 1035 | if (copy_from_iter(tty->write_buf, size, from) != size) |
1da177e4 | 1036 | break; |
9bb48c82 | 1037 | |
1da177e4 | 1038 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1039 | if (ret <= 0) |
1040 | break; | |
9bb48c82 | 1041 | |
3342ff26 LT |
1042 | written += ret; |
1043 | if (ret > size) | |
1044 | break; | |
1045 | ||
9bb48c82 LT |
1046 | /* FIXME! Have Al check this! */ |
1047 | if (ret != size) | |
1048 | iov_iter_revert(from, size-ret); | |
1049 | ||
1da177e4 LT |
1050 | count -= ret; |
1051 | if (!count) | |
1052 | break; | |
1053 | ret = -ERESTARTSYS; | |
1054 | if (signal_pending(current)) | |
1055 | break; | |
1056 | cond_resched(); | |
1057 | } | |
37b7f3c7 | 1058 | if (written) { |
c884f871 | 1059 | tty_update_time(&file_inode(file)->i_mtime); |
1da177e4 | 1060 | ret = written; |
37b7f3c7 | 1061 | } |
9c1729db AC |
1062 | out: |
1063 | tty_write_unlock(tty); | |
1da177e4 LT |
1064 | return ret; |
1065 | } | |
1066 | ||
95f9bfc6 AC |
1067 | /** |
1068 | * tty_write_message - write a message to a certain tty, not just the console. | |
1069 | * @tty: the destination tty_struct | |
1070 | * @msg: the message to write | |
1071 | * | |
1072 | * This is used for messages that need to be redirected to a specific tty. | |
1073 | * We don't put it into the syslog queue right now maybe in the future if | |
1074 | * really needed. | |
1075 | * | |
ec79d605 | 1076 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1077 | */ |
1078 | ||
1079 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1080 | { | |
95f9bfc6 AC |
1081 | if (tty) { |
1082 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1083 | tty_lock(tty); |
4b41b953 | 1084 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1085 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1086 | tty_unlock(tty); |
95f9bfc6 AC |
1087 | tty_write_unlock(tty); |
1088 | } | |
95f9bfc6 AC |
1089 | } |
1090 | ||
a9cbbb80 | 1091 | static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) |
1da177e4 | 1092 | { |
d996b62a | 1093 | struct tty_struct *tty = file_tty(file); |
395e7833 | 1094 | struct tty_ldisc *ld; |
1da177e4 | 1095 | ssize_t ret; |
37bdfb07 | 1096 | |
6131ffaa | 1097 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1098 | return -EIO; |
18900ca6 | 1099 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
5e4d5ac3 | 1100 | return -EIO; |
f34d7a5b AC |
1101 | /* Short term debug to catch buggy drivers */ |
1102 | if (tty->ops->write_room == NULL) | |
339f36ba | 1103 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1104 | ld = tty_ldisc_ref_wait(tty); |
17749851 LT |
1105 | if (!ld) |
1106 | return hung_up_tty_write(iocb, from); | |
1107 | if (!ld->ops->write) | |
1da177e4 LT |
1108 | ret = -EIO; |
1109 | else | |
9bb48c82 | 1110 | ret = do_tty_write(ld->ops->write, tty, file, from); |
1da177e4 LT |
1111 | tty_ldisc_deref(ld); |
1112 | return ret; | |
1113 | } | |
1114 | ||
756a4e4a JS |
1115 | /** |
1116 | * tty_write - write method for tty device file | |
1117 | * @iocb: kernel I/O control block | |
1118 | * @from: iov_iter with data to write | |
1119 | * | |
1120 | * Write data to a tty device via the line discipline. | |
1121 | * | |
1122 | * Locking: | |
1123 | * Locks the line discipline as required | |
1124 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1125 | * and are then processed in chunks to the device. The line | |
1126 | * discipline write method will not be invoked in parallel for | |
1127 | * each device. | |
1128 | */ | |
a9cbbb80 LT |
1129 | static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) |
1130 | { | |
1131 | return file_tty_write(iocb->ki_filp, iocb, from); | |
1132 | } | |
1133 | ||
9bb48c82 | 1134 | ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 LT |
1135 | { |
1136 | struct file *p = NULL; | |
1137 | ||
1138 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1139 | if (redirect) |
1140 | p = get_file(redirect); | |
1da177e4 LT |
1141 | spin_unlock(&redirect_lock); |
1142 | ||
a9cbbb80 | 1143 | /* |
44969f85 | 1144 | * We know the redirected tty is just another tty, we can |
a9cbbb80 LT |
1145 | * call file_tty_write() directly with that file pointer. |
1146 | */ | |
1da177e4 LT |
1147 | if (p) { |
1148 | ssize_t res; | |
e73b2407 | 1149 | |
a9cbbb80 | 1150 | res = file_tty_write(p, iocb, iter); |
1da177e4 LT |
1151 | fput(p); |
1152 | return res; | |
1153 | } | |
9bb48c82 | 1154 | return tty_write(iocb, iter); |
1da177e4 LT |
1155 | } |
1156 | ||
08aa5042 | 1157 | /* |
136d5258 PH |
1158 | * tty_send_xchar - send priority character |
1159 | * | |
1160 | * Send a high priority character to the tty even if stopped | |
1161 | * | |
1162 | * Locking: none for xchar method, write ordering for write method. | |
1163 | */ | |
1164 | ||
1165 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1166 | { | |
6e94dbc7 | 1167 | bool was_stopped = tty->flow.stopped; |
136d5258 PH |
1168 | |
1169 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1170 | down_read(&tty->termios_rwsem); |
136d5258 | 1171 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1172 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1173 | return 0; |
1174 | } | |
1175 | ||
1176 | if (tty_write_lock(tty, 0) < 0) | |
1177 | return -ERESTARTSYS; | |
1178 | ||
ee0c1a65 | 1179 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1180 | if (was_stopped) |
1181 | start_tty(tty); | |
1182 | tty->ops->write(tty, &ch, 1); | |
1183 | if (was_stopped) | |
1184 | stop_tty(tty); | |
ee0c1a65 | 1185 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1186 | tty_write_unlock(tty); |
1187 | return 0; | |
1188 | } | |
1189 | ||
af9b897e AC |
1190 | /** |
1191 | * pty_line_name - generate name for a pty | |
1192 | * @driver: the tty driver in use | |
1193 | * @index: the minor number | |
1194 | * @p: output buffer of at least 6 bytes | |
1195 | * | |
1196 | * Generate a name from a driver reference and write it to the output | |
1197 | * buffer. | |
1198 | * | |
1199 | * Locking: None | |
1200 | */ | |
1201 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 | 1202 | { |
a846dcf9 | 1203 | static const char ptychar[] = "pqrstuvwxyzabcde"; |
1da177e4 LT |
1204 | int i = index + driver->name_base; |
1205 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1206 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1207 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1208 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1209 | } |
1210 | ||
af9b897e | 1211 | /** |
8b0a88d5 | 1212 | * tty_line_name - generate name for a tty |
af9b897e AC |
1213 | * @driver: the tty driver in use |
1214 | * @index: the minor number | |
1215 | * @p: output buffer of at least 7 bytes | |
1216 | * | |
1217 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1218 | * buffer. |
af9b897e AC |
1219 | * |
1220 | * Locking: None | |
1221 | */ | |
723abd87 | 1222 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1223 | { |
0019b408 | 1224 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1225 | return sprintf(p, "%s", driver->name); |
0019b408 | 1226 | else |
723abd87 HR |
1227 | return sprintf(p, "%s%d", driver->name, |
1228 | index + driver->name_base); | |
1da177e4 LT |
1229 | } |
1230 | ||
99f1fe18 AC |
1231 | /** |
1232 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1233 | * @driver: the driver for the tty | |
08aa5042 | 1234 | * @file: file object |
99f1fe18 | 1235 | * @idx: the minor number |
23499705 | 1236 | * |
aa3cb814 PH |
1237 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1238 | * driver lookup() method returns an error. | |
23499705 | 1239 | * |
aa3cb814 | 1240 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1241 | */ |
a47d545f | 1242 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1243 | struct file *file, int idx) |
23499705 | 1244 | { |
aa3cb814 PH |
1245 | struct tty_struct *tty; |
1246 | ||
99f1fe18 | 1247 | if (driver->ops->lookup) |
12e84c71 OK |
1248 | if (!file) |
1249 | tty = ERR_PTR(-EIO); | |
1250 | else | |
1251 | tty = driver->ops->lookup(driver, file, idx); | |
aa3cb814 PH |
1252 | else |
1253 | tty = driver->ttys[idx]; | |
23499705 | 1254 | |
aa3cb814 PH |
1255 | if (!IS_ERR(tty)) |
1256 | tty_kref_get(tty); | |
1257 | return tty; | |
23499705 SB |
1258 | } |
1259 | ||
bf970ee4 AC |
1260 | /** |
1261 | * tty_init_termios - helper for termios setup | |
1262 | * @tty: the tty to set up | |
1263 | * | |
8daa89e0 | 1264 | * Initialise the termios structure for this tty. This runs under |
bf970ee4 AC |
1265 | * the tty_mutex currently so we can be relaxed about ordering. |
1266 | */ | |
1267 | ||
a3123fd0 | 1268 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1269 | { |
fe6e29fd | 1270 | struct ktermios *tp; |
bf970ee4 AC |
1271 | int idx = tty->index; |
1272 | ||
36b3c070 AC |
1273 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1274 | tty->termios = tty->driver->init_termios; | |
1275 | else { | |
1276 | /* Check for lazy saved data */ | |
1277 | tp = tty->driver->termios[idx]; | |
ece53405 | 1278 | if (tp != NULL) { |
36b3c070 | 1279 | tty->termios = *tp; |
ece53405 PH |
1280 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1281 | } else | |
36b3c070 | 1282 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1283 | } |
bf970ee4 | 1284 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1285 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1286 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1287 | } |
fe1ae7fd | 1288 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1289 | |
66d450e8 JS |
1290 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1291 | { | |
a3123fd0 | 1292 | tty_init_termios(tty); |
66d450e8 JS |
1293 | tty_driver_kref_get(driver); |
1294 | tty->count++; | |
1295 | driver->ttys[tty->index] = tty; | |
1296 | return 0; | |
1297 | } | |
1298 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1299 | ||
99f1fe18 | 1300 | /** |
8b0a88d5 AC |
1301 | * tty_driver_install_tty() - install a tty entry in the driver |
1302 | * @driver: the driver for the tty | |
1303 | * @tty: the tty | |
1304 | * | |
1305 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1306 | * will be set by the time this is called. This method is responsible |
1307 | * for ensuring any need additional structures are allocated and | |
1308 | * configured. | |
8b0a88d5 AC |
1309 | * |
1310 | * Locking: tty_mutex for now | |
1311 | */ | |
1312 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1313 | struct tty_struct *tty) | |
1314 | { | |
66d450e8 JS |
1315 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1316 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1317 | } |
1318 | ||
1319 | /** | |
1320 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1321 | * @driver: the driver for the tty | |
fa441954 | 1322 | * @tty: tty to remove |
8b0a88d5 AC |
1323 | * |
1324 | * Remvoe a tty object from the driver tables. The tty->index field | |
1325 | * will be set by the time this is called. | |
1326 | * | |
1327 | * Locking: tty_mutex for now | |
1328 | */ | |
05de87ed | 1329 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1330 | { |
1331 | if (driver->ops->remove) | |
1332 | driver->ops->remove(driver, tty); | |
1333 | else | |
1334 | driver->ttys[tty->index] = NULL; | |
1335 | } | |
1336 | ||
fa441954 JS |
1337 | /** |
1338 | * tty_reopen() - fast re-open of an open tty | |
1339 | * @tty: the tty to open | |
23499705 | 1340 | * |
99f1fe18 | 1341 | * Return 0 on success, -errno on error. |
5d93e748 | 1342 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1343 | * |
5d93e748 | 1344 | * Locking: Caller must hold tty_lock |
23499705 | 1345 | */ |
99f1fe18 | 1346 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1347 | { |
1348 | struct tty_driver *driver = tty->driver; | |
d3736d82 DS |
1349 | struct tty_ldisc *ld; |
1350 | int retval = 0; | |
23499705 | 1351 | |
23499705 | 1352 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1353 | driver->subtype == PTY_TYPE_MASTER) |
1354 | return -EIO; | |
23499705 | 1355 | |
7f22f6c9 PH |
1356 | if (!tty->count) |
1357 | return -EAGAIN; | |
1358 | ||
86f2c00f PH |
1359 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1360 | return -EBUSY; | |
1361 | ||
d3736d82 DS |
1362 | ld = tty_ldisc_ref_wait(tty); |
1363 | if (ld) { | |
1364 | tty_ldisc_deref(ld); | |
1365 | } else { | |
1366 | retval = tty_ldisc_lock(tty, 5 * HZ); | |
1367 | if (retval) | |
1368 | return retval; | |
1369 | ||
1370 | if (!tty->ldisc) | |
1371 | retval = tty_ldisc_reinit(tty, tty->termios.c_line); | |
1372 | tty_ldisc_unlock(tty); | |
1373 | } | |
23499705 | 1374 | |
cf62a1a1 DS |
1375 | if (retval == 0) |
1376 | tty->count++; | |
fe324167 DS |
1377 | |
1378 | return retval; | |
23499705 SB |
1379 | } |
1380 | ||
af9b897e | 1381 | /** |
d81ed103 | 1382 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1383 | * @driver: tty driver we are opening a device on |
1384 | * @idx: device index | |
af9b897e AC |
1385 | * |
1386 | * Prepare a tty device. This may not be a "new" clean device but | |
1387 | * could also be an active device. The pty drivers require special | |
1388 | * handling because of this. | |
1389 | * | |
1390 | * Locking: | |
1391 | * The function is called under the tty_mutex, which | |
1392 | * protects us from the tty struct or driver itself going away. | |
1393 | * | |
1394 | * On exit the tty device has the line discipline attached and | |
1395 | * a reference count of 1. If a pair was created for pty/tty use | |
1396 | * and the other was a pty master then it too has a reference count of 1. | |
1397 | * | |
1da177e4 | 1398 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1399 | * failed open. The new code protects the open with a mutex, so it's |
1400 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 | 1401 | * relaxed for the (most common) case of reopening a tty. |
fa441954 JS |
1402 | * |
1403 | * Return: returned tty structure | |
1da177e4 | 1404 | */ |
af9b897e | 1405 | |
593a27c4 | 1406 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1407 | { |
bf970ee4 | 1408 | struct tty_struct *tty; |
73ec06fc | 1409 | int retval; |
1da177e4 | 1410 | |
1da177e4 LT |
1411 | /* |
1412 | * First time open is complex, especially for PTY devices. | |
1413 | * This code guarantees that either everything succeeds and the | |
1414 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1415 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1416 | * may be retained.) |
1da177e4 LT |
1417 | */ |
1418 | ||
73ec06fc AC |
1419 | if (!try_module_get(driver->owner)) |
1420 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1421 | |
2c964a2f | 1422 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1423 | if (!tty) { |
1424 | retval = -ENOMEM; | |
1425 | goto err_module_put; | |
1426 | } | |
1da177e4 | 1427 | |
89c8d91e | 1428 | tty_lock(tty); |
73ec06fc | 1429 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1430 | if (retval < 0) |
c8b710b3 | 1431 | goto err_free_tty; |
8b0a88d5 | 1432 | |
04831dc1 JS |
1433 | if (!tty->port) |
1434 | tty->port = driver->ports[idx]; | |
1435 | ||
2ae0b31e JS |
1436 | if (WARN_RATELIMIT(!tty->port, |
1437 | "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", | |
1438 | __func__, tty->driver->name)) { | |
1439 | retval = -EINVAL; | |
1440 | goto err_release_lock; | |
1441 | } | |
5d4121c0 | 1442 | |
b027e229 GK |
1443 | retval = tty_ldisc_lock(tty, 5 * HZ); |
1444 | if (retval) | |
1445 | goto err_release_lock; | |
967fab69 JS |
1446 | tty->port->itty = tty; |
1447 | ||
37bdfb07 | 1448 | /* |
1da177e4 | 1449 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1450 | * If we fail here just call release_tty to clean up. No need |
1451 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1452 | */ |
bf970ee4 | 1453 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1454 | if (retval) |
d5543503 | 1455 | goto err_release_tty; |
b027e229 | 1456 | tty_ldisc_unlock(tty); |
89c8d91e | 1457 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1458 | return tty; |
1da177e4 | 1459 | |
c8b710b3 | 1460 | err_free_tty: |
89c8d91e | 1461 | tty_unlock(tty); |
d5543503 JS |
1462 | free_tty_struct(tty); |
1463 | err_module_put: | |
1da177e4 | 1464 | module_put(driver->owner); |
d5543503 | 1465 | return ERR_PTR(retval); |
1da177e4 | 1466 | |
d5698c28 | 1467 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1468 | err_release_tty: |
b027e229 | 1469 | tty_ldisc_unlock(tty); |
339f36ba PH |
1470 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1471 | retval, idx); | |
b027e229 GK |
1472 | err_release_lock: |
1473 | tty_unlock(tty); | |
d5698c28 | 1474 | release_tty(tty, idx); |
73ec06fc | 1475 | return ERR_PTR(retval); |
1da177e4 LT |
1476 | } |
1477 | ||
f51ccf46 JH |
1478 | /** |
1479 | * tty_save_termios() - save tty termios data in driver table | |
1480 | * @tty: tty whose termios data to save | |
1481 | * | |
1482 | * Locking: Caller guarantees serialisation with tty_init_termios(). | |
1483 | */ | |
1484 | void tty_save_termios(struct tty_struct *tty) | |
feebed65 AC |
1485 | { |
1486 | struct ktermios *tp; | |
1487 | int idx = tty->index; | |
36b3c070 AC |
1488 | |
1489 | /* If the port is going to reset then it has no termios to save */ | |
1490 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1491 | return; | |
1492 | ||
1493 | /* Stash the termios data */ | |
1494 | tp = tty->driver->termios[idx]; | |
1495 | if (tp == NULL) { | |
a3241891 | 1496 | tp = kmalloc(sizeof(*tp), GFP_KERNEL); |
25080652 | 1497 | if (tp == NULL) |
36b3c070 | 1498 | return; |
4ac5d705 | 1499 | tty->driver->termios[idx] = tp; |
feebed65 | 1500 | } |
36b3c070 | 1501 | *tp = tty->termios; |
feebed65 | 1502 | } |
f51ccf46 | 1503 | EXPORT_SYMBOL_GPL(tty_save_termios); |
feebed65 | 1504 | |
a2965b7b | 1505 | /** |
949aa64f PH |
1506 | * tty_flush_works - flush all works of a tty/pty pair |
1507 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1508 | * |
949aa64f | 1509 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1510 | */ |
1511 | static void tty_flush_works(struct tty_struct *tty) | |
1512 | { | |
1513 | flush_work(&tty->SAK_work); | |
1514 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1515 | if (tty->link) { |
1516 | flush_work(&tty->link->SAK_work); | |
1517 | flush_work(&tty->link->hangup_work); | |
1518 | } | |
a2965b7b | 1519 | } |
feebed65 | 1520 | |
af9b897e | 1521 | /** |
d5698c28 | 1522 | * release_one_tty - release tty structure memory |
fa441954 | 1523 | * @work: work of tty we are obliterating |
af9b897e AC |
1524 | * |
1525 | * Releases memory associated with a tty structure, and clears out the | |
1526 | * driver table slots. This function is called when a device is no longer | |
1527 | * in use. It also gets called when setup of a device fails. | |
1528 | * | |
1529 | * Locking: | |
af9b897e AC |
1530 | * takes the file list lock internally when working on the list |
1531 | * of ttys that the driver keeps. | |
b50989dc AC |
1532 | * |
1533 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1534 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1535 | */ |
b50989dc | 1536 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1537 | { |
b50989dc AC |
1538 | struct tty_struct *tty = |
1539 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1540 | struct tty_driver *driver = tty->driver; |
b216df53 | 1541 | struct module *owner = driver->owner; |
d5698c28 | 1542 | |
f278a2f7 DY |
1543 | if (tty->ops->cleanup) |
1544 | tty->ops->cleanup(tty); | |
1545 | ||
1da177e4 | 1546 | tty->magic = 0; |
7d7b93c1 | 1547 | tty_driver_kref_put(driver); |
b216df53 | 1548 | module_put(owner); |
d5698c28 | 1549 | |
4a510969 | 1550 | spin_lock(&tty->files_lock); |
1da177e4 | 1551 | list_del_init(&tty->tty_files); |
4a510969 | 1552 | spin_unlock(&tty->files_lock); |
d5698c28 | 1553 | |
64d608db JS |
1554 | put_pid(tty->ctrl.pgrp); |
1555 | put_pid(tty->ctrl.session); | |
1da177e4 LT |
1556 | free_tty_struct(tty); |
1557 | } | |
1558 | ||
b50989dc AC |
1559 | static void queue_release_one_tty(struct kref *kref) |
1560 | { | |
1561 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1562 | |
b50989dc | 1563 | /* The hangup queue is now free so we can reuse it rather than |
b426a5b8 XT |
1564 | * waste a chunk of memory for each port. |
1565 | */ | |
b50989dc AC |
1566 | INIT_WORK(&tty->hangup_work, release_one_tty); |
1567 | schedule_work(&tty->hangup_work); | |
1568 | } | |
1569 | ||
9c9f4ded AC |
1570 | /** |
1571 | * tty_kref_put - release a tty kref | |
1572 | * @tty: tty device | |
1573 | * | |
1574 | * Release a reference to a tty device and if need be let the kref | |
1575 | * layer destruct the object for us | |
1576 | */ | |
1577 | ||
1578 | void tty_kref_put(struct tty_struct *tty) | |
1579 | { | |
1580 | if (tty) | |
b50989dc | 1581 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1582 | } |
1583 | EXPORT_SYMBOL(tty_kref_put); | |
1584 | ||
d5698c28 CH |
1585 | /** |
1586 | * release_tty - release tty structure memory | |
08aa5042 LJ |
1587 | * @tty: tty device release |
1588 | * @idx: index of the tty device release | |
d5698c28 CH |
1589 | * |
1590 | * Release both @tty and a possible linked partner (think pty pair), | |
1591 | * and decrement the refcount of the backing module. | |
1592 | * | |
1593 | * Locking: | |
d155255a | 1594 | * tty_mutex |
d5698c28 CH |
1595 | * takes the file list lock internally when working on the list |
1596 | * of ttys that the driver keeps. | |
9c9f4ded | 1597 | * |
d5698c28 CH |
1598 | */ |
1599 | static void release_tty(struct tty_struct *tty, int idx) | |
1600 | { | |
9c9f4ded AC |
1601 | /* This should always be true but check for the moment */ |
1602 | WARN_ON(tty->index != idx); | |
d155255a | 1603 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1604 | if (tty->ops->shutdown) |
1605 | tty->ops->shutdown(tty); | |
f51ccf46 | 1606 | tty_save_termios(tty); |
36b3c070 | 1607 | tty_driver_remove_tty(tty->driver, tty); |
4466d6d2 MR |
1608 | if (tty->port) |
1609 | tty->port->itty = NULL; | |
64e377dc PH |
1610 | if (tty->link) |
1611 | tty->link->port->itty = NULL; | |
4466d6d2 MR |
1612 | if (tty->port) |
1613 | tty_buffer_cancel_work(tty->port); | |
2b022ab7 S |
1614 | if (tty->link) |
1615 | tty_buffer_cancel_work(tty->link->port); | |
36b3c070 | 1616 | |
a211b1af | 1617 | tty_kref_put(tty->link); |
9c9f4ded | 1618 | tty_kref_put(tty); |
d5698c28 CH |
1619 | } |
1620 | ||
955787ca JS |
1621 | /** |
1622 | * tty_release_checks - check a tty before real release | |
1623 | * @tty: tty to check | |
955787ca JS |
1624 | * @idx: index of the tty |
1625 | * | |
1626 | * Performs some paranoid checking before true release of the @tty. | |
1627 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1628 | */ | |
359b9fb5 | 1629 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1630 | { |
1631 | #ifdef TTY_PARANOIA_CHECK | |
1632 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1633 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1634 | return -1; |
1635 | } | |
1636 | ||
1637 | /* not much to check for devpts */ | |
1638 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1639 | return 0; | |
1640 | ||
1641 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1642 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1643 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1644 | return -1; |
1645 | } | |
955787ca | 1646 | if (tty->driver->other) { |
359b9fb5 PH |
1647 | struct tty_struct *o_tty = tty->link; |
1648 | ||
955787ca | 1649 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1650 | tty_debug(tty, "bad other table[%d] = %p\n", |
1651 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1652 | return -1; |
1653 | } | |
955787ca | 1654 | if (o_tty->link != tty) { |
e2dfa3d3 | 1655 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1656 | return -1; |
1657 | } | |
1658 | } | |
1659 | #endif | |
1660 | return 0; | |
1661 | } | |
1662 | ||
a09ac397 OK |
1663 | /** |
1664 | * tty_kclose - closes tty opened by tty_kopen | |
1665 | * @tty: tty device | |
1666 | * | |
1667 | * Performs the final steps to release and free a tty device. It is the | |
1668 | * same as tty_release_struct except that it also resets TTY_PORT_KOPENED | |
1669 | * flag on tty->port. | |
1670 | */ | |
1671 | void tty_kclose(struct tty_struct *tty) | |
1672 | { | |
1673 | /* | |
1674 | * Ask the line discipline code to release its structures | |
1675 | */ | |
1676 | tty_ldisc_release(tty); | |
1677 | ||
1678 | /* Wait for pending work before tty destruction commmences */ | |
1679 | tty_flush_works(tty); | |
1680 | ||
1681 | tty_debug_hangup(tty, "freeing structure\n"); | |
1682 | /* | |
1683 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1684 | * the slots and preserving the termios structure. |
a09ac397 OK |
1685 | */ |
1686 | mutex_lock(&tty_mutex); | |
1687 | tty_port_set_kopened(tty->port, 0); | |
1688 | release_tty(tty, tty->index); | |
1689 | mutex_unlock(&tty_mutex); | |
1690 | } | |
1691 | EXPORT_SYMBOL_GPL(tty_kclose); | |
1692 | ||
9ed90d20 RH |
1693 | /** |
1694 | * tty_release_struct - release a tty struct | |
1695 | * @tty: tty device | |
1696 | * @idx: index of the tty | |
1697 | * | |
1698 | * Performs the final steps to release and free a tty device. It is | |
1699 | * roughly the reverse of tty_init_dev. | |
1700 | */ | |
1701 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1702 | { | |
1703 | /* | |
1704 | * Ask the line discipline code to release its structures | |
1705 | */ | |
1706 | tty_ldisc_release(tty); | |
1707 | ||
1708 | /* Wait for pending work before tty destruction commmences */ | |
1709 | tty_flush_works(tty); | |
1710 | ||
1711 | tty_debug_hangup(tty, "freeing structure\n"); | |
1712 | /* | |
1713 | * The release_tty function takes care of the details of clearing | |
ed069827 | 1714 | * the slots and preserving the termios structure. |
9ed90d20 RH |
1715 | */ |
1716 | mutex_lock(&tty_mutex); | |
1717 | release_tty(tty, idx); | |
1718 | mutex_unlock(&tty_mutex); | |
1719 | } | |
1720 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1721 | ||
eeb89d91 AC |
1722 | /** |
1723 | * tty_release - vfs callback for close | |
1724 | * @inode: inode of tty | |
1725 | * @filp: file pointer for handle to tty | |
1726 | * | |
1727 | * Called the last time each file handle is closed that references | |
1728 | * this tty. There may however be several such references. | |
1729 | * | |
1730 | * Locking: | |
1731 | * Takes bkl. See tty_release_dev | |
1732 | * | |
1da177e4 LT |
1733 | * Even releasing the tty structures is a tricky business.. We have |
1734 | * to be very careful that the structures are all released at the | |
1735 | * same time, as interrupts might otherwise get the wrong pointers. | |
1736 | * | |
1737 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1738 | * lead to double frees or releasing memory still in use. | |
1739 | */ | |
eeb89d91 AC |
1740 | |
1741 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1742 | { |
d996b62a | 1743 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1744 | struct tty_struct *o_tty = NULL; |
1745 | int do_sleep, final; | |
1da177e4 | 1746 | int idx; |
37b16457 | 1747 | long timeout = 0; |
494c1eac | 1748 | int once = 1; |
37bdfb07 | 1749 | |
9de44bd6 | 1750 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1751 | return 0; |
1da177e4 | 1752 | |
89c8d91e | 1753 | tty_lock(tty); |
9de44bd6 | 1754 | check_tty_count(tty, __func__); |
1da177e4 | 1755 | |
ec79d605 | 1756 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1757 | |
1758 | idx = tty->index; | |
7ffb6da9 PH |
1759 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1760 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1761 | o_tty = tty->link; | |
1da177e4 | 1762 | |
359b9fb5 | 1763 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1764 | tty_unlock(tty); |
eeb89d91 | 1765 | return 0; |
1da177e4 | 1766 | } |
1da177e4 | 1767 | |
d435cefe | 1768 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1769 | |
f34d7a5b AC |
1770 | if (tty->ops->close) |
1771 | tty->ops->close(tty, filp); | |
1da177e4 | 1772 | |
2aff5e2b PH |
1773 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1774 | tty_lock_slave(o_tty); | |
1775 | ||
1da177e4 LT |
1776 | /* |
1777 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1778 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1779 | * wait queues and kick everyone out _before_ actually starting to | |
1780 | * close. This ensures that we won't block while releasing the tty | |
1781 | * structure. | |
1782 | * | |
1783 | * The test for the o_tty closing is necessary, since the master and | |
1784 | * slave sides may close in any order. If the slave side closes out | |
1785 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1786 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1787 | * so we do it now. |
1da177e4 LT |
1788 | */ |
1789 | while (1) { | |
1da177e4 LT |
1790 | do_sleep = 0; |
1791 | ||
324c1650 | 1792 | if (tty->count <= 1) { |
1da177e4 | 1793 | if (waitqueue_active(&tty->read_wait)) { |
a9a08845 | 1794 | wake_up_poll(&tty->read_wait, EPOLLIN); |
1da177e4 LT |
1795 | do_sleep++; |
1796 | } | |
1797 | if (waitqueue_active(&tty->write_wait)) { | |
a9a08845 | 1798 | wake_up_poll(&tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1799 | do_sleep++; |
1800 | } | |
1801 | } | |
7ffb6da9 | 1802 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1803 | if (waitqueue_active(&o_tty->read_wait)) { |
a9a08845 | 1804 | wake_up_poll(&o_tty->read_wait, EPOLLIN); |
1da177e4 LT |
1805 | do_sleep++; |
1806 | } | |
1807 | if (waitqueue_active(&o_tty->write_wait)) { | |
a9a08845 | 1808 | wake_up_poll(&o_tty->write_wait, EPOLLOUT); |
1da177e4 LT |
1809 | do_sleep++; |
1810 | } | |
1811 | } | |
1812 | if (!do_sleep) | |
1813 | break; | |
1814 | ||
494c1eac PH |
1815 | if (once) { |
1816 | once = 0; | |
339f36ba | 1817 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1818 | } |
37b16457 PH |
1819 | schedule_timeout_killable(timeout); |
1820 | if (timeout < 120 * HZ) | |
1821 | timeout = 2 * timeout + 1; | |
1822 | else | |
1823 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1824 | } |
1da177e4 | 1825 | |
7ffb6da9 | 1826 | if (o_tty) { |
1da177e4 | 1827 | if (--o_tty->count < 0) { |
339f36ba | 1828 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1829 | o_tty->count = 0; |
1830 | } | |
1831 | } | |
1832 | if (--tty->count < 0) { | |
339f36ba | 1833 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1834 | tty->count = 0; |
1835 | } | |
37bdfb07 | 1836 | |
1da177e4 LT |
1837 | /* |
1838 | * We've decremented tty->count, so we need to remove this file | |
1839 | * descriptor off the tty->tty_files list; this serves two | |
1840 | * purposes: | |
1841 | * - check_tty_count sees the correct number of file descriptors | |
1842 | * associated with this tty. | |
1843 | * - do_tty_hangup no longer sees this file descriptor as | |
1844 | * something that needs to be handled for hangups. | |
1845 | */ | |
d996b62a | 1846 | tty_del_file(filp); |
1da177e4 LT |
1847 | |
1848 | /* | |
1849 | * Perform some housekeeping before deciding whether to return. | |
1850 | * | |
1da177e4 LT |
1851 | * If _either_ side is closing, make sure there aren't any |
1852 | * processes that still think tty or o_tty is their controlling | |
1853 | * tty. | |
1854 | */ | |
324c1650 | 1855 | if (!tty->count) { |
1da177e4 | 1856 | read_lock(&tasklist_lock); |
64d608db | 1857 | session_clear_tty(tty->ctrl.session); |
7ffb6da9 | 1858 | if (o_tty) |
64d608db | 1859 | session_clear_tty(o_tty->ctrl.session); |
1da177e4 LT |
1860 | read_unlock(&tasklist_lock); |
1861 | } | |
1862 | ||
324c1650 | 1863 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1864 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1865 | |
2aff5e2b PH |
1866 | tty_unlock_slave(o_tty); |
1867 | tty_unlock(tty); | |
1868 | ||
04980706 | 1869 | /* At this point, the tty->count == 0 should ensure a dead tty |
b426a5b8 XT |
1870 | * cannot be re-opened by a racing opener. |
1871 | */ | |
da965822 | 1872 | |
324c1650 | 1873 | if (!final) |
eeb89d91 | 1874 | return 0; |
37bdfb07 | 1875 | |
accff793 | 1876 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1877 | |
9ed90d20 | 1878 | tty_release_struct(tty, idx); |
eeb89d91 | 1879 | return 0; |
1da177e4 LT |
1880 | } |
1881 | ||
b82154ac | 1882 | /** |
52494eeb | 1883 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1884 | * @device: device number |
1885 | * @filp: file pointer to tty | |
52494eeb PH |
1886 | * @return: locked tty of the current task iff @device is /dev/tty |
1887 | * | |
1888 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1889 | * |
1890 | * We cannot return driver and index like for the other nodes because | |
1891 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1892 | */ | |
1893 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1894 | { | |
1895 | struct tty_struct *tty; | |
52494eeb | 1896 | int retval; |
b82154ac JS |
1897 | |
1898 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1899 | return NULL; | |
1900 | ||
1901 | tty = get_current_tty(); | |
1902 | if (!tty) | |
1903 | return ERR_PTR(-ENXIO); | |
1904 | ||
1905 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1906 | /* noctty = 1; */ | |
52494eeb PH |
1907 | tty_lock(tty); |
1908 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1909 | ||
1910 | retval = tty_reopen(tty); | |
1911 | if (retval < 0) { | |
1912 | tty_unlock(tty); | |
1913 | tty = ERR_PTR(retval); | |
1914 | } | |
b82154ac JS |
1915 | return tty; |
1916 | } | |
1917 | ||
5b5e7040 JS |
1918 | /** |
1919 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1920 | * @device: device number | |
1921 | * @filp: file pointer to tty | |
5b5e7040 JS |
1922 | * @index: index for the device in the @return driver |
1923 | * @return: driver for this inode (with increased refcount) | |
1924 | * | |
395e7833 XT |
1925 | * If @return is not erroneous, the caller is responsible to decrement the |
1926 | * refcount by tty_driver_kref_put. | |
5b5e7040 JS |
1927 | * |
1928 | * Locking: tty_mutex protects get_tty_driver | |
1929 | */ | |
1930 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1931 | int *index) |
5b5e7040 | 1932 | { |
8c8af41d | 1933 | struct tty_driver *driver = NULL; |
5b5e7040 | 1934 | |
2cd0050c | 1935 | switch (device) { |
5b5e7040 | 1936 | #ifdef CONFIG_VT |
2cd0050c | 1937 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 | 1938 | extern struct tty_driver *console_driver; |
e73b2407 | 1939 | |
5b5e7040 JS |
1940 | driver = tty_driver_kref_get(console_driver); |
1941 | *index = fg_console; | |
2cd0050c | 1942 | break; |
5b5e7040 JS |
1943 | } |
1944 | #endif | |
2cd0050c | 1945 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 | 1946 | struct tty_driver *console_driver = console_device(index); |
e73b2407 | 1947 | |
5b5e7040 JS |
1948 | if (console_driver) { |
1949 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1950 | if (driver && filp) { |
5b5e7040 JS |
1951 | /* Don't let /dev/console block */ |
1952 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1953 | break; |
5b5e7040 JS |
1954 | } |
1955 | } | |
8c8af41d LY |
1956 | if (driver) |
1957 | tty_driver_kref_put(driver); | |
5b5e7040 JS |
1958 | return ERR_PTR(-ENODEV); |
1959 | } | |
2cd0050c JS |
1960 | default: |
1961 | driver = get_tty_driver(device, index); | |
1962 | if (!driver) | |
1963 | return ERR_PTR(-ENODEV); | |
1964 | break; | |
1965 | } | |
5b5e7040 JS |
1966 | return driver; |
1967 | } | |
1968 | ||
4ea3cd65 | 1969 | static struct tty_struct *tty_kopen(dev_t device, int shared) |
a09ac397 OK |
1970 | { |
1971 | struct tty_struct *tty; | |
f1d31743 | 1972 | struct tty_driver *driver; |
a09ac397 OK |
1973 | int index = -1; |
1974 | ||
1975 | mutex_lock(&tty_mutex); | |
1976 | driver = tty_lookup_driver(device, NULL, &index); | |
1977 | if (IS_ERR(driver)) { | |
1978 | mutex_unlock(&tty_mutex); | |
1979 | return ERR_CAST(driver); | |
1980 | } | |
1981 | ||
1982 | /* check whether we're reopening an existing tty */ | |
1983 | tty = tty_driver_lookup_tty(driver, NULL, index); | |
4ea3cd65 | 1984 | if (IS_ERR(tty) || shared) |
a09ac397 OK |
1985 | goto out; |
1986 | ||
1987 | if (tty) { | |
1988 | /* drop kref from tty_driver_lookup_tty() */ | |
1989 | tty_kref_put(tty); | |
1990 | tty = ERR_PTR(-EBUSY); | |
1991 | } else { /* tty_init_dev returns tty with the tty_lock held */ | |
1992 | tty = tty_init_dev(driver, index); | |
1993 | if (IS_ERR(tty)) | |
1994 | goto out; | |
1995 | tty_port_set_kopened(tty->port, 1); | |
1996 | } | |
1997 | out: | |
1998 | mutex_unlock(&tty_mutex); | |
1999 | tty_driver_kref_put(driver); | |
2000 | return tty; | |
2001 | } | |
4ea3cd65 UKK |
2002 | |
2003 | /** | |
2004 | * tty_kopen_exclusive - open a tty device for kernel | |
2005 | * @device: dev_t of device to open | |
2006 | * | |
2007 | * Opens tty exclusively for kernel. Performs the driver lookup, | |
2008 | * makes sure it's not already opened and performs the first-time | |
2009 | * tty initialization. | |
2010 | * | |
2011 | * Returns the locked initialized &tty_struct | |
2012 | * | |
2013 | * Claims the global tty_mutex to serialize: | |
2014 | * - concurrent first-time tty initialization | |
2015 | * - concurrent tty driver removal w/ lookup | |
2016 | * - concurrent tty removal from driver table | |
2017 | */ | |
2018 | struct tty_struct *tty_kopen_exclusive(dev_t device) | |
2019 | { | |
2020 | return tty_kopen(device, 0); | |
2021 | } | |
2022 | EXPORT_SYMBOL_GPL(tty_kopen_exclusive); | |
2023 | ||
2024 | /** | |
2025 | * tty_kopen_shared - open a tty device for shared in-kernel use | |
2026 | * @device: dev_t of device to open | |
2027 | * | |
2028 | * Opens an already existing tty for in-kernel use. Compared to | |
2029 | * tty_kopen_exclusive() above it doesn't ensure to be the only user. | |
2030 | * | |
2031 | * Locking is identical to tty_kopen() above. | |
2032 | */ | |
2033 | struct tty_struct *tty_kopen_shared(dev_t device) | |
2034 | { | |
2035 | return tty_kopen(device, 1); | |
2036 | } | |
2037 | EXPORT_SYMBOL_GPL(tty_kopen_shared); | |
a09ac397 | 2038 | |
d6203d0c PH |
2039 | /** |
2040 | * tty_open_by_driver - open a tty device | |
2041 | * @device: dev_t of device to open | |
d6203d0c PH |
2042 | * @filp: file pointer to tty |
2043 | * | |
2044 | * Performs the driver lookup, checks for a reopen, or otherwise | |
2045 | * performs the first-time tty initialization. | |
2046 | * | |
2047 | * Returns the locked initialized or re-opened &tty_struct | |
2048 | * | |
2049 | * Claims the global tty_mutex to serialize: | |
2050 | * - concurrent first-time tty initialization | |
2051 | * - concurrent tty driver removal w/ lookup | |
2052 | * - concurrent tty removal from driver table | |
2053 | */ | |
14ce3848 | 2054 | static struct tty_struct *tty_open_by_driver(dev_t device, |
d6203d0c PH |
2055 | struct file *filp) |
2056 | { | |
2057 | struct tty_struct *tty; | |
2058 | struct tty_driver *driver = NULL; | |
2059 | int index = -1; | |
2060 | int retval; | |
2061 | ||
2062 | mutex_lock(&tty_mutex); | |
2063 | driver = tty_lookup_driver(device, filp, &index); | |
2064 | if (IS_ERR(driver)) { | |
2065 | mutex_unlock(&tty_mutex); | |
2066 | return ERR_CAST(driver); | |
2067 | } | |
2068 | ||
2069 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 2070 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
2071 | if (IS_ERR(tty)) { |
2072 | mutex_unlock(&tty_mutex); | |
2073 | goto out; | |
2074 | } | |
2075 | ||
2076 | if (tty) { | |
a09ac397 OK |
2077 | if (tty_port_kopened(tty->port)) { |
2078 | tty_kref_put(tty); | |
2079 | mutex_unlock(&tty_mutex); | |
2080 | tty = ERR_PTR(-EBUSY); | |
2081 | goto out; | |
2082 | } | |
d6203d0c PH |
2083 | mutex_unlock(&tty_mutex); |
2084 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2085 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2086 | if (retval) { |
2087 | if (retval == -EINTR) | |
2088 | retval = -ERESTARTSYS; | |
2089 | tty = ERR_PTR(retval); | |
2090 | goto out; | |
2091 | } | |
d6203d0c PH |
2092 | retval = tty_reopen(tty); |
2093 | if (retval < 0) { | |
2094 | tty_unlock(tty); | |
2095 | tty = ERR_PTR(retval); | |
2096 | } | |
2097 | } else { /* Returns with the tty_lock held for now */ | |
2098 | tty = tty_init_dev(driver, index); | |
2099 | mutex_unlock(&tty_mutex); | |
2100 | } | |
2101 | out: | |
2102 | tty_driver_kref_put(driver); | |
2103 | return tty; | |
2104 | } | |
2105 | ||
af9b897e | 2106 | /** |
eeb89d91 | 2107 | * tty_open - open a tty device |
af9b897e AC |
2108 | * @inode: inode of device file |
2109 | * @filp: file pointer to tty | |
1da177e4 | 2110 | * |
af9b897e AC |
2111 | * tty_open and tty_release keep up the tty count that contains the |
2112 | * number of opens done on a tty. We cannot use the inode-count, as | |
2113 | * different inodes might point to the same tty. | |
1da177e4 | 2114 | * |
af9b897e AC |
2115 | * Open-counting is needed for pty masters, as well as for keeping |
2116 | * track of serial lines: DTR is dropped when the last close happens. | |
2117 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2118 | * | |
2119 | * The termios state of a pty is reset on first open so that | |
2120 | * settings don't persist across reuse. | |
2121 | * | |
5b5e7040 | 2122 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2123 | * tty->count should protect the rest. |
2124 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2125 | * |
2126 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2127 | * tty_mutex | |
1da177e4 | 2128 | */ |
af9b897e | 2129 | |
eeb89d91 | 2130 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2131 | { |
b82154ac | 2132 | struct tty_struct *tty; |
1da177e4 | 2133 | int noctty, retval; |
1da177e4 | 2134 | dev_t device = inode->i_rdev; |
846c151a | 2135 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2136 | |
2137 | nonseekable_open(inode, filp); | |
37bdfb07 | 2138 | |
1da177e4 | 2139 | retry_open: |
fa90e1c9 JS |
2140 | retval = tty_alloc_file(filp); |
2141 | if (retval) | |
2142 | return -ENOMEM; | |
2143 | ||
b82154ac | 2144 | tty = tty_open_current_tty(device, filp); |
d6203d0c | 2145 | if (!tty) |
14ce3848 | 2146 | tty = tty_open_by_driver(device, filp); |
52494eeb | 2147 | |
eeb89d91 | 2148 | if (IS_ERR(tty)) { |
d6203d0c | 2149 | tty_free_file(filp); |
ba5db448 | 2150 | retval = PTR_ERR(tty); |
7f22f6c9 | 2151 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2152 | return retval; |
7f22f6c9 PH |
2153 | schedule(); |
2154 | goto retry_open; | |
eeb89d91 | 2155 | } |
1da177e4 | 2156 | |
fa90e1c9 | 2157 | tty_add_file(tty, filp); |
d996b62a | 2158 | |
9de44bd6 | 2159 | check_tty_count(tty, __func__); |
d435cefe | 2160 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2161 | |
909bc774 HRK |
2162 | if (tty->ops->open) |
2163 | retval = tty->ops->open(tty, filp); | |
2164 | else | |
2165 | retval = -ENODEV; | |
1da177e4 LT |
2166 | filp->f_flags = saved_flags; |
2167 | ||
1da177e4 | 2168 | if (retval) { |
d435cefe | 2169 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2170 | |
89c8d91e | 2171 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2172 | tty_release(inode, filp); |
64ba3dc3 | 2173 | if (retval != -ERESTARTSYS) |
1da177e4 | 2174 | return retval; |
64ba3dc3 AB |
2175 | |
2176 | if (signal_pending(current)) | |
1da177e4 | 2177 | return retval; |
64ba3dc3 | 2178 | |
1da177e4 LT |
2179 | schedule(); |
2180 | /* | |
2181 | * Need to reset f_op in case a hangup happened. | |
2182 | */ | |
1256937f | 2183 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2184 | filp->f_op = &tty_fops; |
2185 | goto retry_open; | |
2186 | } | |
d4855e1f | 2187 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2188 | |
11e1d4aa | 2189 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
2190 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
2191 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
2192 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2193 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2194 | if (!noctty) | |
2195 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 2196 | tty_unlock(tty); |
1da177e4 LT |
2197 | return 0; |
2198 | } | |
2199 | ||
39d95b9d JC |
2200 | |
2201 | ||
af9b897e AC |
2202 | /** |
2203 | * tty_poll - check tty status | |
2204 | * @filp: file being polled | |
2205 | * @wait: poll wait structures to update | |
2206 | * | |
2207 | * Call the line discipline polling method to obtain the poll | |
2208 | * status of the device. | |
2209 | * | |
2210 | * Locking: locks called line discipline but ldisc poll method | |
2211 | * may be re-entered freely by other callers. | |
2212 | */ | |
2213 | ||
afc9a42b | 2214 | static __poll_t tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2215 | { |
d996b62a | 2216 | struct tty_struct *tty = file_tty(filp); |
1da177e4 | 2217 | struct tty_ldisc *ld; |
e6c8adca | 2218 | __poll_t ret = 0; |
1da177e4 | 2219 | |
6131ffaa | 2220 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2221 | return 0; |
37bdfb07 | 2222 | |
1da177e4 | 2223 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2224 | if (!ld) |
2225 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2226 | if (ld->ops->poll) |
c961bfb1 | 2227 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2228 | tty_ldisc_deref(ld); |
2229 | return ret; | |
2230 | } | |
2231 | ||
ec79d605 | 2232 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2233 | { |
d996b62a | 2234 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2235 | unsigned long flags; |
5d1e3230 | 2236 | int retval = 0; |
1da177e4 | 2237 | |
6131ffaa | 2238 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2239 | goto out; |
37bdfb07 | 2240 | |
1da177e4 LT |
2241 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2242 | if (retval <= 0) | |
5d1e3230 | 2243 | goto out; |
f6c8dbe6 | 2244 | |
1da177e4 | 2245 | if (on) { |
ab521dc0 EB |
2246 | enum pid_type type; |
2247 | struct pid *pid; | |
f6c8dbe6 | 2248 | |
64d608db JS |
2249 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
2250 | if (tty->ctrl.pgrp) { | |
2251 | pid = tty->ctrl.pgrp; | |
ab521dc0 EB |
2252 | type = PIDTYPE_PGID; |
2253 | } else { | |
2254 | pid = task_pid(current); | |
01919134 | 2255 | type = PIDTYPE_TGID; |
ab521dc0 | 2256 | } |
80e1e823 | 2257 | get_pid(pid); |
64d608db | 2258 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); |
e0b93edd | 2259 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2260 | put_pid(pid); |
e0b93edd | 2261 | retval = 0; |
1da177e4 | 2262 | } |
5d1e3230 | 2263 | out: |
ec79d605 AB |
2264 | return retval; |
2265 | } | |
2266 | ||
2267 | static int tty_fasync(int fd, struct file *filp, int on) | |
2268 | { | |
89c8d91e | 2269 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2270 | int retval = -ENOTTY; |
89c8d91e AC |
2271 | |
2272 | tty_lock(tty); | |
a8f3a297 PH |
2273 | if (!tty_hung_up_p(filp)) |
2274 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2275 | tty_unlock(tty); |
2276 | ||
5d1e3230 | 2277 | return retval; |
1da177e4 LT |
2278 | } |
2279 | ||
af9b897e AC |
2280 | /** |
2281 | * tiocsti - fake input character | |
2282 | * @tty: tty to fake input into | |
2283 | * @p: pointer to character | |
2284 | * | |
3a4fa0a2 | 2285 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2286 | * input management. |
2287 | * | |
2288 | * FIXME: does not honour flow control ?? | |
2289 | * | |
2290 | * Locking: | |
137084bb | 2291 | * Called functions take tty_ldiscs_lock |
af9b897e AC |
2292 | * current->signal->tty check is safe without locks |
2293 | */ | |
2294 | ||
1da177e4 LT |
2295 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2296 | { | |
2297 | char ch, mbz = 0; | |
2298 | struct tty_ldisc *ld; | |
37bdfb07 | 2299 | |
1da177e4 LT |
2300 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2301 | return -EPERM; | |
2302 | if (get_user(ch, p)) | |
2303 | return -EFAULT; | |
1e641743 | 2304 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2305 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2306 | if (!ld) |
2307 | return -EIO; | |
bb2853a6 | 2308 | tty_buffer_lock_exclusive(tty->port); |
27cfb3a5 GKH |
2309 | if (ld->ops->receive_buf) |
2310 | ld->ops->receive_buf(tty, &ch, &mbz, 1); | |
bb2853a6 | 2311 | tty_buffer_unlock_exclusive(tty->port); |
1da177e4 LT |
2312 | tty_ldisc_deref(ld); |
2313 | return 0; | |
2314 | } | |
2315 | ||
af9b897e AC |
2316 | /** |
2317 | * tiocgwinsz - implement window query ioctl | |
fa441954 | 2318 | * @tty: tty |
af9b897e AC |
2319 | * @arg: user buffer for result |
2320 | * | |
808a0d38 | 2321 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2322 | * |
dee4a0be | 2323 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2324 | * is consistent. |
af9b897e AC |
2325 | */ |
2326 | ||
37bdfb07 | 2327 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2328 | { |
808a0d38 AC |
2329 | int err; |
2330 | ||
dee4a0be | 2331 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2332 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2333 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 | 2334 | |
94bc2eb5 | 2335 | return err ? -EFAULT : 0; |
1da177e4 LT |
2336 | } |
2337 | ||
af9b897e | 2338 | /** |
8c9a9dd0 AC |
2339 | * tty_do_resize - resize event |
2340 | * @tty: tty being resized | |
fa441954 | 2341 | * @ws: new dimensions |
8c9a9dd0 | 2342 | * |
3ad2f3fb | 2343 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2344 | * peform a terminal resize correctly |
af9b897e AC |
2345 | */ |
2346 | ||
fc6f6238 | 2347 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2348 | { |
fc6f6238 | 2349 | struct pid *pgrp; |
1da177e4 | 2350 | |
fc6f6238 | 2351 | /* Lock the tty */ |
dee4a0be | 2352 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2353 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2354 | goto done; |
47f86834 | 2355 | |
5b239542 PH |
2356 | /* Signal the foreground process group */ |
2357 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2358 | if (pgrp) |
2359 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2360 | put_pid(pgrp); |
47f86834 | 2361 | |
8c9a9dd0 | 2362 | tty->winsize = *ws; |
ca9bda00 | 2363 | done: |
dee4a0be | 2364 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2365 | return 0; |
2366 | } | |
4d334fd1 | 2367 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2368 | |
8c9a9dd0 AC |
2369 | /** |
2370 | * tiocswinsz - implement window size set ioctl | |
fa441954 | 2371 | * @tty: tty side of tty |
8c9a9dd0 AC |
2372 | * @arg: user buffer for result |
2373 | * | |
2374 | * Copies the user idea of the window size to the kernel. Traditionally | |
2375 | * this is just advisory information but for the Linux console it | |
2376 | * actually has driver level meaning and triggers a VC resize. | |
2377 | * | |
2378 | * Locking: | |
25985edc | 2379 | * Driver dependent. The default do_resize method takes the |
64d608db | 2380 | * tty termios mutex and ctrl.lock. The console takes its own lock |
8c9a9dd0 AC |
2381 | * then calls into the default method. |
2382 | */ | |
2383 | ||
fc6f6238 | 2384 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2385 | { |
2386 | struct winsize tmp_ws; | |
e73b2407 | 2387 | |
8c9a9dd0 AC |
2388 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
2389 | return -EFAULT; | |
2390 | ||
2391 | if (tty->ops->resize) | |
fc6f6238 | 2392 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2393 | else |
fc6f6238 | 2394 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2395 | } |
2396 | ||
af9b897e AC |
2397 | /** |
2398 | * tioccons - allow admin to move logical console | |
2399 | * @file: the file to become console | |
2400 | * | |
25985edc | 2401 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2402 | * |
2403 | * Locking: uses redirect_lock to guard the redirect information | |
2404 | */ | |
2405 | ||
1da177e4 LT |
2406 | static int tioccons(struct file *file) |
2407 | { | |
2408 | if (!capable(CAP_SYS_ADMIN)) | |
2409 | return -EPERM; | |
9bb48c82 | 2410 | if (file->f_op->write_iter == redirected_tty_write) { |
1da177e4 | 2411 | struct file *f; |
e73b2407 | 2412 | |
1da177e4 LT |
2413 | spin_lock(&redirect_lock); |
2414 | f = redirect; | |
2415 | redirect = NULL; | |
2416 | spin_unlock(&redirect_lock); | |
2417 | if (f) | |
2418 | fput(f); | |
2419 | return 0; | |
2420 | } | |
a9cbbb80 LT |
2421 | if (file->f_op->write_iter != tty_write) |
2422 | return -ENOTTY; | |
2423 | if (!(file->f_mode & FMODE_WRITE)) | |
2424 | return -EBADF; | |
2425 | if (!(file->f_mode & FMODE_CAN_WRITE)) | |
2426 | return -EINVAL; | |
1da177e4 LT |
2427 | spin_lock(&redirect_lock); |
2428 | if (redirect) { | |
2429 | spin_unlock(&redirect_lock); | |
2430 | return -EBUSY; | |
2431 | } | |
cb0942b8 | 2432 | redirect = get_file(file); |
1da177e4 LT |
2433 | spin_unlock(&redirect_lock); |
2434 | return 0; | |
2435 | } | |
2436 | ||
af9b897e AC |
2437 | /** |
2438 | * tiocsetd - set line discipline | |
2439 | * @tty: tty device | |
2440 | * @p: pointer to user data | |
2441 | * | |
2442 | * Set the line discipline according to user request. | |
2443 | * | |
2444 | * Locking: see tty_set_ldisc, this function is just a helper | |
2445 | */ | |
2446 | ||
1da177e4 LT |
2447 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2448 | { | |
c12da96f | 2449 | int disc; |
04f378b1 | 2450 | int ret; |
1da177e4 | 2451 | |
c12da96f | 2452 | if (get_user(disc, p)) |
1da177e4 | 2453 | return -EFAULT; |
04f378b1 | 2454 | |
c12da96f | 2455 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2456 | |
2457 | return ret; | |
1da177e4 LT |
2458 | } |
2459 | ||
5c17c861 PH |
2460 | /** |
2461 | * tiocgetd - get line discipline | |
2462 | * @tty: tty device | |
2463 | * @p: pointer to user data | |
2464 | * | |
2465 | * Retrieves the line discipline id directly from the ldisc. | |
2466 | * | |
2467 | * Locking: waits for ldisc reference (in case the line discipline | |
2468 | * is changing or the tty is being hungup) | |
2469 | */ | |
2470 | ||
2471 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2472 | { | |
2473 | struct tty_ldisc *ld; | |
2474 | int ret; | |
2475 | ||
2476 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2477 | if (!ld) |
2478 | return -EIO; | |
5c17c861 PH |
2479 | ret = put_user(ld->ops->num, p); |
2480 | tty_ldisc_deref(ld); | |
2481 | return ret; | |
2482 | } | |
2483 | ||
af9b897e AC |
2484 | /** |
2485 | * send_break - performed time break | |
2486 | * @tty: device to break on | |
2487 | * @duration: timeout in mS | |
2488 | * | |
2489 | * Perform a timed break on hardware that lacks its own driver level | |
2490 | * timed break functionality. | |
2491 | * | |
2492 | * Locking: | |
28298232 | 2493 | * atomic_write_lock serializes |
af9b897e | 2494 | * |
af9b897e AC |
2495 | */ |
2496 | ||
b20f3ae5 | 2497 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2498 | { |
9e98966c AC |
2499 | int retval; |
2500 | ||
2501 | if (tty->ops->break_ctl == NULL) | |
2502 | return 0; | |
2503 | ||
2504 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2505 | retval = tty->ops->break_ctl(tty, duration); | |
2506 | else { | |
2507 | /* Do the work ourselves */ | |
2508 | if (tty_write_lock(tty, 0) < 0) | |
2509 | return -EINTR; | |
2510 | retval = tty->ops->break_ctl(tty, -1); | |
2511 | if (retval) | |
2512 | goto out; | |
2513 | if (!signal_pending(current)) | |
2514 | msleep_interruptible(duration); | |
2515 | retval = tty->ops->break_ctl(tty, 0); | |
2516 | out: | |
2517 | tty_write_unlock(tty); | |
2518 | if (signal_pending(current)) | |
2519 | retval = -EINTR; | |
2520 | } | |
2521 | return retval; | |
1da177e4 LT |
2522 | } |
2523 | ||
af9b897e | 2524 | /** |
f34d7a5b | 2525 | * tty_tiocmget - get modem status |
af9b897e | 2526 | * @tty: tty device |
af9b897e AC |
2527 | * @p: pointer to result |
2528 | * | |
2529 | * Obtain the modem status bits from the tty driver if the feature | |
1b8b2086 | 2530 | * is supported. Return -ENOTTY if it is not available. |
af9b897e AC |
2531 | * |
2532 | * Locking: none (up to the driver) | |
2533 | */ | |
2534 | ||
60b33c13 | 2535 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 | 2536 | { |
1b8b2086 | 2537 | int retval = -ENOTTY; |
1da177e4 | 2538 | |
f34d7a5b | 2539 | if (tty->ops->tiocmget) { |
60b33c13 | 2540 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2541 | |
2542 | if (retval >= 0) | |
2543 | retval = put_user(retval, p); | |
2544 | } | |
2545 | return retval; | |
2546 | } | |
2547 | ||
af9b897e | 2548 | /** |
f34d7a5b | 2549 | * tty_tiocmset - set modem status |
af9b897e | 2550 | * @tty: tty device |
af9b897e AC |
2551 | * @cmd: command - clear bits, set bits or set all |
2552 | * @p: pointer to desired bits | |
2553 | * | |
2554 | * Set the modem status bits from the tty driver if the feature | |
1b8b2086 | 2555 | * is supported. Return -ENOTTY if it is not available. |
af9b897e AC |
2556 | * |
2557 | * Locking: none (up to the driver) | |
2558 | */ | |
2559 | ||
20b9d177 | 2560 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2561 | unsigned __user *p) |
2562 | { | |
ae677517 AC |
2563 | int retval; |
2564 | unsigned int set, clear, val; | |
1da177e4 | 2565 | |
ae677517 | 2566 | if (tty->ops->tiocmset == NULL) |
1b8b2086 | 2567 | return -ENOTTY; |
1da177e4 | 2568 | |
ae677517 AC |
2569 | retval = get_user(val, p); |
2570 | if (retval) | |
2571 | return retval; | |
2572 | set = clear = 0; | |
2573 | switch (cmd) { | |
2574 | case TIOCMBIS: | |
2575 | set = val; | |
2576 | break; | |
2577 | case TIOCMBIC: | |
2578 | clear = val; | |
2579 | break; | |
2580 | case TIOCMSET: | |
2581 | set = val; | |
2582 | clear = ~val; | |
2583 | break; | |
2584 | } | |
2585 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2586 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2587 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2588 | } |
2589 | ||
d20c219c UKK |
2590 | /** |
2591 | * tty_get_icount - get tty statistics | |
2592 | * @tty: tty device | |
2593 | * @icount: output parameter | |
2594 | * | |
2595 | * Gets a copy of the tty's icount statistics. | |
2596 | * | |
2597 | * Locking: none (up to the driver) | |
2598 | */ | |
2599 | int tty_get_icount(struct tty_struct *tty, | |
2600 | struct serial_icounter_struct *icount) | |
2601 | { | |
2602 | memset(icount, 0, sizeof(*icount)); | |
2603 | ||
2604 | if (tty->ops->get_icount) | |
2605 | return tty->ops->get_icount(tty, icount); | |
2606 | else | |
1b8b2086 | 2607 | return -ENOTTY; |
d20c219c UKK |
2608 | } |
2609 | EXPORT_SYMBOL_GPL(tty_get_icount); | |
2610 | ||
d281da7f AC |
2611 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2612 | { | |
d281da7f | 2613 | struct serial_icounter_struct icount; |
d20c219c UKK |
2614 | int retval; |
2615 | ||
2616 | retval = tty_get_icount(tty, &icount); | |
d281da7f AC |
2617 | if (retval != 0) |
2618 | return retval; | |
d20c219c | 2619 | |
d281da7f AC |
2620 | if (copy_to_user(arg, &icount, sizeof(icount))) |
2621 | return -EFAULT; | |
2622 | return 0; | |
2623 | } | |
2624 | ||
885c77d5 | 2625 | static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss) |
8a8ae62f | 2626 | { |
8a8ae62f JS |
2627 | char comm[TASK_COMM_LEN]; |
2628 | int flags; | |
2629 | ||
885c77d5 | 2630 | flags = ss->flags & ASYNC_DEPRECATED; |
8a8ae62f | 2631 | |
1b7bc6b1 JH |
2632 | if (flags) |
2633 | pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2634 | __func__, get_task_comm(comm, current), flags); | |
885c77d5 | 2635 | |
2f46a2c1 | 2636 | if (!tty->ops->set_serial) |
930236a3 | 2637 | return -ENOTTY; |
885c77d5 JH |
2638 | |
2639 | return tty->ops->set_serial(tty, ss); | |
2640 | } | |
2641 | ||
2642 | static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2643 | { | |
2644 | struct serial_struct v; | |
2645 | ||
2646 | if (copy_from_user(&v, ss, sizeof(*ss))) | |
2647 | return -EFAULT; | |
2648 | ||
2649 | return tty_set_serial(tty, &v); | |
2f46a2c1 AV |
2650 | } |
2651 | ||
2652 | static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) | |
2653 | { | |
2654 | struct serial_struct v; | |
2655 | int err; | |
2656 | ||
a3241891 | 2657 | memset(&v, 0, sizeof(v)); |
2f46a2c1 | 2658 | if (!tty->ops->get_serial) |
930236a3 | 2659 | return -ENOTTY; |
2f46a2c1 | 2660 | err = tty->ops->get_serial(tty, &v); |
a3241891 | 2661 | if (!err && copy_to_user(ss, &v, sizeof(v))) |
2f46a2c1 AV |
2662 | err = -EFAULT; |
2663 | return err; | |
8a8ae62f JS |
2664 | } |
2665 | ||
8f166e00 PH |
2666 | /* |
2667 | * if pty, return the slave side (real_tty) | |
2668 | * otherwise, return self | |
2669 | */ | |
2670 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2671 | { |
2672 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2673 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2674 | tty = tty->link; | |
2675 | return tty; | |
2676 | } | |
e8b70e7d | 2677 | |
1da177e4 LT |
2678 | /* |
2679 | * Split this up, as gcc can choke on it otherwise.. | |
2680 | */ | |
04f378b1 | 2681 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2682 | { |
d996b62a NP |
2683 | struct tty_struct *tty = file_tty(file); |
2684 | struct tty_struct *real_tty; | |
1da177e4 LT |
2685 | void __user *p = (void __user *)arg; |
2686 | int retval; | |
2687 | struct tty_ldisc *ld; | |
37bdfb07 | 2688 | |
6131ffaa | 2689 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2690 | return -EINVAL; |
2691 | ||
e8b70e7d | 2692 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2693 | |
2694 | /* | |
2695 | * Factor out some common prep work | |
2696 | */ | |
2697 | switch (cmd) { | |
2698 | case TIOCSETD: | |
2699 | case TIOCSBRK: | |
2700 | case TIOCCBRK: | |
2701 | case TCSBRK: | |
37bdfb07 | 2702 | case TCSBRKP: |
1da177e4 LT |
2703 | retval = tty_check_change(tty); |
2704 | if (retval) | |
2705 | return retval; | |
2706 | if (cmd != TIOCCBRK) { | |
2707 | tty_wait_until_sent(tty, 0); | |
2708 | if (signal_pending(current)) | |
2709 | return -EINTR; | |
2710 | } | |
2711 | break; | |
2712 | } | |
2713 | ||
9e98966c AC |
2714 | /* |
2715 | * Now do the stuff. | |
2716 | */ | |
1da177e4 | 2717 | switch (cmd) { |
37bdfb07 AC |
2718 | case TIOCSTI: |
2719 | return tiocsti(tty, p); | |
2720 | case TIOCGWINSZ: | |
8f520021 | 2721 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2722 | case TIOCSWINSZ: |
fc6f6238 | 2723 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2724 | case TIOCCONS: |
2725 | return real_tty != tty ? -EINVAL : tioccons(file); | |
37bdfb07 AC |
2726 | case TIOCEXCL: |
2727 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2728 | return 0; | |
2729 | case TIOCNXCL: | |
2730 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2731 | return 0; | |
84fd7bdf CG |
2732 | case TIOCGEXCL: |
2733 | { | |
2734 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
e73b2407 | 2735 | |
84fd7bdf CG |
2736 | return put_user(excl, (int __user *)p); |
2737 | } | |
37bdfb07 | 2738 | case TIOCGETD: |
5c17c861 | 2739 | return tiocgetd(tty, p); |
37bdfb07 AC |
2740 | case TIOCSETD: |
2741 | return tiocsetd(tty, p); | |
3c95c985 KS |
2742 | case TIOCVHANGUP: |
2743 | if (!capable(CAP_SYS_ADMIN)) | |
2744 | return -EPERM; | |
2745 | tty_vhangup(tty); | |
2746 | return 0; | |
b7b8de08 WF |
2747 | case TIOCGDEV: |
2748 | { | |
2749 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
e73b2407 | 2750 | |
b7b8de08 WF |
2751 | return put_user(ret, (unsigned int __user *)p); |
2752 | } | |
37bdfb07 AC |
2753 | /* |
2754 | * Break handling | |
2755 | */ | |
2756 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2757 | if (tty->ops->break_ctl) |
9e98966c | 2758 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2759 | return 0; |
37bdfb07 | 2760 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2761 | if (tty->ops->break_ctl) |
9e98966c | 2762 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2763 | return 0; |
2764 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2765 | /* non-zero arg means wait for all output data | |
2766 | * to be sent (performed above) but don't send break. | |
2767 | * This is used by the tcdrain() termios function. | |
2768 | */ | |
2769 | if (!arg) | |
2770 | return send_break(tty, 250); | |
2771 | return 0; | |
2772 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2773 | return send_break(tty, arg ? arg*100 : 250); | |
2774 | ||
2775 | case TIOCMGET: | |
60b33c13 | 2776 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2777 | case TIOCMSET: |
2778 | case TIOCMBIC: | |
2779 | case TIOCMBIS: | |
20b9d177 | 2780 | return tty_tiocmset(tty, cmd, p); |
d281da7f | 2781 | case TIOCGICOUNT: |
a3096199 | 2782 | return tty_tiocgicount(tty, p); |
37bdfb07 AC |
2783 | case TCFLSH: |
2784 | switch (arg) { | |
2785 | case TCIFLUSH: | |
2786 | case TCIOFLUSH: | |
2787 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2788 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2789 | break; |
37bdfb07 AC |
2790 | } |
2791 | break; | |
8a8ae62f | 2792 | case TIOCSSERIAL: |
930236a3 | 2793 | return tty_tiocsserial(tty, p); |
2f46a2c1 | 2794 | case TIOCGSERIAL: |
930236a3 | 2795 | return tty_tiocgserial(tty, p); |
311fc65c EB |
2796 | case TIOCGPTPEER: |
2797 | /* Special because the struct file is needed */ | |
2798 | return ptm_open_peer(file, tty, (int)arg); | |
a1235b3e NP |
2799 | default: |
2800 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2801 | if (retval != -ENOIOCTLCMD) | |
2802 | return retval; | |
1da177e4 | 2803 | } |
f34d7a5b | 2804 | if (tty->ops->ioctl) { |
c961bfb1 | 2805 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2806 | if (retval != -ENOIOCTLCMD) |
2807 | return retval; | |
2808 | } | |
2809 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2810 | if (!ld) |
2811 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2812 | retval = -EINVAL; |
a352def2 AC |
2813 | if (ld->ops->ioctl) { |
2814 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2815 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2816 | retval = -ENOTTY; |
1da177e4 LT |
2817 | } |
2818 | tty_ldisc_deref(ld); | |
2819 | return retval; | |
2820 | } | |
2821 | ||
e10cc1df | 2822 | #ifdef CONFIG_COMPAT |
77654350 AV |
2823 | |
2824 | struct serial_struct32 { | |
52b52e91 GS |
2825 | compat_int_t type; |
2826 | compat_int_t line; | |
2827 | compat_uint_t port; | |
2828 | compat_int_t irq; | |
2829 | compat_int_t flags; | |
2830 | compat_int_t xmit_fifo_size; | |
2831 | compat_int_t custom_divisor; | |
2832 | compat_int_t baud_base; | |
2833 | unsigned short close_delay; | |
2834 | char io_type; | |
2835 | char reserved_char; | |
2836 | compat_int_t hub6; | |
2837 | unsigned short closing_wait; /* time to wait before closing */ | |
2838 | unsigned short closing_wait2; /* no longer used... */ | |
2839 | compat_uint_t iomem_base; | |
2840 | unsigned short iomem_reg_shift; | |
2841 | unsigned int port_high; | |
2842 | /* compat_ulong_t iomap_base FIXME */ | |
2843 | compat_int_t reserved; | |
77654350 AV |
2844 | }; |
2845 | ||
2846 | static int compat_tty_tiocsserial(struct tty_struct *tty, | |
2847 | struct serial_struct32 __user *ss) | |
2848 | { | |
77654350 AV |
2849 | struct serial_struct32 v32; |
2850 | struct serial_struct v; | |
77654350 | 2851 | |
a3241891 | 2852 | if (copy_from_user(&v32, ss, sizeof(*ss))) |
77654350 AV |
2853 | return -EFAULT; |
2854 | ||
2855 | memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); | |
2856 | v.iomem_base = compat_ptr(v32.iomem_base); | |
2857 | v.iomem_reg_shift = v32.iomem_reg_shift; | |
2858 | v.port_high = v32.port_high; | |
2859 | v.iomap_base = 0; | |
2860 | ||
885c77d5 | 2861 | return tty_set_serial(tty, &v); |
77654350 AV |
2862 | } |
2863 | ||
2864 | static int compat_tty_tiocgserial(struct tty_struct *tty, | |
2865 | struct serial_struct32 __user *ss) | |
2866 | { | |
2867 | struct serial_struct32 v32; | |
2868 | struct serial_struct v; | |
2869 | int err; | |
17329563 EB |
2870 | |
2871 | memset(&v, 0, sizeof(v)); | |
2872 | memset(&v32, 0, sizeof(v32)); | |
77654350 | 2873 | |
6e622cd8 | 2874 | if (!tty->ops->get_serial) |
77654350 AV |
2875 | return -ENOTTY; |
2876 | err = tty->ops->get_serial(tty, &v); | |
2877 | if (!err) { | |
2878 | memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); | |
2879 | v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? | |
2880 | 0xfffffff : ptr_to_compat(v.iomem_base); | |
2881 | v32.iomem_reg_shift = v.iomem_reg_shift; | |
2882 | v32.port_high = v.port_high; | |
a3241891 | 2883 | if (copy_to_user(ss, &v32, sizeof(v32))) |
77654350 AV |
2884 | err = -EFAULT; |
2885 | } | |
2886 | return err; | |
2887 | } | |
37bdfb07 | 2888 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2889 | unsigned long arg) |
2890 | { | |
d996b62a | 2891 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2892 | struct tty_ldisc *ld; |
2893 | int retval = -ENOIOCTLCMD; | |
2894 | ||
e2112038 | 2895 | switch (cmd) { |
c7dc504e | 2896 | case TIOCOUTQ: |
e2112038 AV |
2897 | case TIOCSTI: |
2898 | case TIOCGWINSZ: | |
2899 | case TIOCSWINSZ: | |
2900 | case TIOCGEXCL: | |
2901 | case TIOCGETD: | |
2902 | case TIOCSETD: | |
2903 | case TIOCGDEV: | |
2904 | case TIOCMGET: | |
2905 | case TIOCMSET: | |
2906 | case TIOCMBIC: | |
2907 | case TIOCMBIS: | |
2908 | case TIOCGICOUNT: | |
2909 | case TIOCGPGRP: | |
2910 | case TIOCSPGRP: | |
2911 | case TIOCGSID: | |
2912 | case TIOCSERGETLSR: | |
2913 | case TIOCGRS485: | |
2914 | case TIOCSRS485: | |
2915 | #ifdef TIOCGETP | |
2916 | case TIOCGETP: | |
2917 | case TIOCSETP: | |
2918 | case TIOCSETN: | |
2919 | #endif | |
2920 | #ifdef TIOCGETC | |
2921 | case TIOCGETC: | |
2922 | case TIOCSETC: | |
2923 | #endif | |
2924 | #ifdef TIOCGLTC | |
2925 | case TIOCGLTC: | |
2926 | case TIOCSLTC: | |
2927 | #endif | |
2928 | case TCSETSF: | |
2929 | case TCSETSW: | |
2930 | case TCSETS: | |
2931 | case TCGETS: | |
2932 | #ifdef TCGETS2 | |
2933 | case TCGETS2: | |
2934 | case TCSETSF2: | |
2935 | case TCSETSW2: | |
2936 | case TCSETS2: | |
2937 | #endif | |
2938 | case TCGETA: | |
2939 | case TCSETAF: | |
2940 | case TCSETAW: | |
2941 | case TCSETA: | |
2942 | case TIOCGLCKTRMIOS: | |
2943 | case TIOCSLCKTRMIOS: | |
2944 | #ifdef TCGETX | |
2945 | case TCGETX: | |
2946 | case TCSETX: | |
2947 | case TCSETXW: | |
2948 | case TCSETXF: | |
2949 | #endif | |
2950 | case TIOCGSOFTCAR: | |
2951 | case TIOCSSOFTCAR: | |
b7aff093 AB |
2952 | |
2953 | case PPPIOCGCHAN: | |
2954 | case PPPIOCGUNIT: | |
e2112038 AV |
2955 | return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
2956 | case TIOCCONS: | |
2957 | case TIOCEXCL: | |
2958 | case TIOCNXCL: | |
2959 | case TIOCVHANGUP: | |
2960 | case TIOCSBRK: | |
2961 | case TIOCCBRK: | |
2962 | case TCSBRK: | |
2963 | case TCSBRKP: | |
2964 | case TCFLSH: | |
2965 | case TIOCGPTPEER: | |
2966 | case TIOCNOTTY: | |
2967 | case TIOCSCTTY: | |
2968 | case TCXONC: | |
2969 | case TIOCMIWAIT: | |
2970 | case TIOCSERCONFIG: | |
2971 | return tty_ioctl(file, cmd, arg); | |
2972 | } | |
2973 | ||
6131ffaa | 2974 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2975 | return -EINVAL; |
2976 | ||
77654350 AV |
2977 | switch (cmd) { |
2978 | case TIOCSSERIAL: | |
2979 | return compat_tty_tiocsserial(tty, compat_ptr(arg)); | |
2980 | case TIOCGSERIAL: | |
2981 | return compat_tty_tiocgserial(tty, compat_ptr(arg)); | |
2982 | } | |
f34d7a5b | 2983 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2984 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2985 | if (retval != -ENOIOCTLCMD) |
2986 | return retval; | |
2987 | } | |
2988 | ||
2989 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2990 | if (!ld) |
2991 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
2992 | if (ld->ops->compat_ioctl) |
2993 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
f0193d3e AV |
2994 | if (retval == -ENOIOCTLCMD && ld->ops->ioctl) |
2995 | retval = ld->ops->ioctl(tty, file, | |
2996 | (unsigned long)compat_ptr(cmd), arg); | |
e10cc1df PF |
2997 | tty_ldisc_deref(ld); |
2998 | ||
2999 | return retval; | |
3000 | } | |
3001 | #endif | |
1da177e4 | 3002 | |
c3c073f8 AV |
3003 | static int this_tty(const void *t, struct file *file, unsigned fd) |
3004 | { | |
dd78b0c4 | 3005 | if (likely(file->f_op->read_iter != tty_read)) |
c3c073f8 AV |
3006 | return 0; |
3007 | return file_tty(file) != t ? 0 : fd + 1; | |
3008 | } | |
d91c1a3e | 3009 | |
1da177e4 LT |
3010 | /* |
3011 | * This implements the "Secure Attention Key" --- the idea is to | |
3012 | * prevent trojan horses by killing all processes associated with this | |
3013 | * tty when the user hits the "Secure Attention Key". Required for | |
3014 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 3015 | * |
1da177e4 LT |
3016 | * This code could be nicer; ideally it should send a HUP, wait a few |
3017 | * seconds, then send a INT, and then a KILL signal. But you then | |
3018 | * have to coordinate with the init process, since all processes associated | |
3019 | * with the current tty must be dead before the new getty is allowed | |
3020 | * to spawn. | |
3021 | * | |
3022 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3023 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3024 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3025 | * | |
3026 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3027 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3028 | */ | |
8b6312f4 | 3029 | void __do_SAK(struct tty_struct *tty) |
1da177e4 | 3030 | { |
652486fb | 3031 | struct task_struct *g, *p; |
ab521dc0 | 3032 | struct pid *session; |
1da177e4 | 3033 | int i; |
c8bcd9c5 | 3034 | unsigned long flags; |
37bdfb07 | 3035 | |
64d608db JS |
3036 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
3037 | session = get_pid(tty->ctrl.session); | |
3038 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
37bdfb07 | 3039 | |
b3f13deb | 3040 | tty_ldisc_flush(tty); |
1da177e4 | 3041 | |
f34d7a5b | 3042 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3043 | |
1da177e4 | 3044 | read_lock(&tasklist_lock); |
652486fb | 3045 | /* Kill the entire session */ |
ab521dc0 | 3046 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3047 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3048 | task_pid_nr(p), p->comm); | |
a8ebd171 | 3049 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
ab521dc0 | 3050 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3051 | |
3052 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3053 | do_each_thread(g, p) { |
3054 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3055 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3056 | task_pid_nr(p), p->comm); | |
a8ebd171 | 3057 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
1da177e4 LT |
3058 | continue; |
3059 | } | |
3060 | task_lock(p); | |
c3c073f8 AV |
3061 | i = iterate_fd(p->files, 0, this_tty, tty); |
3062 | if (i != 0) { | |
9b42bb75 PH |
3063 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3064 | task_pid_nr(p), p->comm, i - 1); | |
a8ebd171 | 3065 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
1da177e4 LT |
3066 | } |
3067 | task_unlock(p); | |
652486fb | 3068 | } while_each_thread(g, p); |
1da177e4 | 3069 | read_unlock(&tasklist_lock); |
c8bcd9c5 | 3070 | put_pid(session); |
1da177e4 LT |
3071 | } |
3072 | ||
8b6312f4 EB |
3073 | static void do_SAK_work(struct work_struct *work) |
3074 | { | |
3075 | struct tty_struct *tty = | |
3076 | container_of(work, struct tty_struct, SAK_work); | |
3077 | __do_SAK(tty); | |
3078 | } | |
3079 | ||
1da177e4 LT |
3080 | /* |
3081 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3082 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3083 | * the values which we write to it will be identical to the values which it | |
3084 | * already has. --akpm | |
3085 | */ | |
3086 | void do_SAK(struct tty_struct *tty) | |
3087 | { | |
3088 | if (!tty) | |
3089 | return; | |
1da177e4 LT |
3090 | schedule_work(&tty->SAK_work); |
3091 | } | |
1da177e4 LT |
3092 | EXPORT_SYMBOL(do_SAK); |
3093 | ||
30004ac9 DES |
3094 | /* Must put_device() after it's unused! */ |
3095 | static struct device *tty_get_device(struct tty_struct *tty) | |
3096 | { | |
3097 | dev_t devt = tty_devnum(tty); | |
e73b2407 | 3098 | |
4495dfdd | 3099 | return class_find_device_by_devt(tty_class, devt); |
30004ac9 DES |
3100 | } |
3101 | ||
3102 | ||
08aa5042 | 3103 | /* |
2c964a2f | 3104 | * alloc_tty_struct |
af9b897e | 3105 | * |
2c964a2f | 3106 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3107 | * |
2c964a2f | 3108 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3109 | */ |
af9b897e | 3110 | |
2c964a2f | 3111 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3112 | { |
2c964a2f RV |
3113 | struct tty_struct *tty; |
3114 | ||
3115 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3116 | if (!tty) | |
3117 | return NULL; | |
3118 | ||
9c9f4ded | 3119 | kref_init(&tty->kref); |
1da177e4 | 3120 | tty->magic = TTY_MAGIC; |
903f9db1 TH |
3121 | if (tty_ldisc_init(tty)) { |
3122 | kfree(tty); | |
3123 | return NULL; | |
3124 | } | |
64d608db JS |
3125 | tty->ctrl.session = NULL; |
3126 | tty->ctrl.pgrp = NULL; | |
89c8d91e | 3127 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3128 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3129 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3130 | mutex_init(&tty->winsize_mutex); |
36697529 | 3131 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3132 | init_waitqueue_head(&tty->write_wait); |
3133 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3134 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3135 | mutex_init(&tty->atomic_write_lock); |
64d608db | 3136 | spin_lock_init(&tty->ctrl.lock); |
6e94dbc7 | 3137 | spin_lock_init(&tty->flow.lock); |
4a510969 | 3138 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3139 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3140 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3141 | |
3142 | tty->driver = driver; | |
3143 | tty->ops = driver->ops; | |
3144 | tty->index = idx; | |
3145 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3146 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3147 | |
3148 | return tty; | |
1da177e4 LT |
3149 | } |
3150 | ||
f34d7a5b AC |
3151 | /** |
3152 | * tty_put_char - write one character to a tty | |
3153 | * @tty: tty | |
3154 | * @ch: character | |
3155 | * | |
3156 | * Write one byte to the tty using the provided put_char method | |
3157 | * if present. Returns the number of characters successfully output. | |
3158 | * | |
3159 | * Note: the specific put_char operation in the driver layer may go | |
3160 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3161 | */ |
af9b897e | 3162 | |
f34d7a5b | 3163 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3164 | { |
f34d7a5b AC |
3165 | if (tty->ops->put_char) |
3166 | return tty->ops->put_char(tty, ch); | |
3167 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3168 | } |
f34d7a5b AC |
3169 | EXPORT_SYMBOL_GPL(tty_put_char); |
3170 | ||
d81ed103 | 3171 | struct class *tty_class; |
1da177e4 | 3172 | |
7e73eca6 JS |
3173 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3174 | unsigned int index, unsigned int count) | |
3175 | { | |
c1a752ba LY |
3176 | int err; |
3177 | ||
7e73eca6 | 3178 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3179 | driver->cdevs[index] = cdev_alloc(); |
3180 | if (!driver->cdevs[index]) | |
3181 | return -ENOMEM; | |
c1a752ba | 3182 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3183 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3184 | err = cdev_add(driver->cdevs[index], dev, count); |
3185 | if (err) | |
3186 | kobject_put(&driver->cdevs[index]->kobj); | |
3187 | return err; | |
7e73eca6 JS |
3188 | } |
3189 | ||
1da177e4 | 3190 | /** |
af9b897e AC |
3191 | * tty_register_device - register a tty device |
3192 | * @driver: the tty driver that describes the tty device | |
3193 | * @index: the index in the tty driver for this tty device | |
3194 | * @device: a struct device that is associated with this tty device. | |
3195 | * This field is optional, if there is no known struct device | |
3196 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3197 | * |
01107d34 GKH |
3198 | * Returns a pointer to the struct device for this tty device |
3199 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3200 | * |
af9b897e AC |
3201 | * This call is required to be made to register an individual tty device |
3202 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3203 | * that bit is not set, this function should not be called by a tty | |
3204 | * driver. | |
3205 | * | |
3206 | * Locking: ?? | |
1da177e4 | 3207 | */ |
af9b897e | 3208 | |
01107d34 GKH |
3209 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3210 | struct device *device) | |
1da177e4 | 3211 | { |
6915c0e4 TH |
3212 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3213 | } | |
3214 | EXPORT_SYMBOL(tty_register_device); | |
3215 | ||
b1b79916 TH |
3216 | static void tty_device_create_release(struct device *dev) |
3217 | { | |
83db1df4 | 3218 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3219 | kfree(dev); |
3220 | } | |
3221 | ||
6915c0e4 TH |
3222 | /** |
3223 | * tty_register_device_attr - register a tty device | |
3224 | * @driver: the tty driver that describes the tty device | |
3225 | * @index: the index in the tty driver for this tty device | |
3226 | * @device: a struct device that is associated with this tty device. | |
3227 | * This field is optional, if there is no known struct device | |
3228 | * for this tty device it can be set to NULL safely. | |
3229 | * @drvdata: Driver data to be set to device. | |
3230 | * @attr_grp: Attribute group to be set on device. | |
3231 | * | |
3232 | * Returns a pointer to the struct device for this tty device | |
3233 | * (or ERR_PTR(-EFOO) on error). | |
3234 | * | |
3235 | * This call is required to be made to register an individual tty device | |
3236 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3237 | * that bit is not set, this function should not be called by a tty | |
3238 | * driver. | |
3239 | * | |
3240 | * Locking: ?? | |
3241 | */ | |
3242 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3243 | unsigned index, struct device *device, | |
3244 | void *drvdata, | |
3245 | const struct attribute_group **attr_grp) | |
3246 | { | |
1da177e4 | 3247 | char name[64]; |
6915c0e4 | 3248 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 3249 | struct ktermios *tp; |
6a7e6f78 JH |
3250 | struct device *dev; |
3251 | int retval; | |
1da177e4 LT |
3252 | |
3253 | if (index >= driver->num) { | |
656fb867 PH |
3254 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3255 | driver->name, index); | |
1cdcb6b4 | 3256 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3257 | } |
3258 | ||
1da177e4 LT |
3259 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3260 | pty_line_name(driver, index, name); | |
3261 | else | |
3262 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3263 | |
6915c0e4 | 3264 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
3265 | if (!dev) |
3266 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 3267 | |
6915c0e4 TH |
3268 | dev->devt = devt; |
3269 | dev->class = tty_class; | |
3270 | dev->parent = device; | |
b1b79916 | 3271 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3272 | dev_set_name(dev, "%s", name); |
3273 | dev->groups = attr_grp; | |
3274 | dev_set_drvdata(dev, drvdata); | |
3275 | ||
6a7e6f78 JH |
3276 | dev_set_uevent_suppress(dev, 1); |
3277 | ||
6915c0e4 TH |
3278 | retval = device_register(dev); |
3279 | if (retval) | |
6a7e6f78 JH |
3280 | goto err_put; |
3281 | ||
3282 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
3283 | /* |
3284 | * Free any saved termios data so that the termios state is | |
3285 | * reset when reusing a minor number. | |
3286 | */ | |
3287 | tp = driver->termios[index]; | |
3288 | if (tp) { | |
3289 | driver->termios[index] = NULL; | |
3290 | kfree(tp); | |
3291 | } | |
3292 | ||
6a7e6f78 JH |
3293 | retval = tty_cdev_add(driver, devt, index, 1); |
3294 | if (retval) | |
3295 | goto err_del; | |
3296 | } | |
3297 | ||
3298 | dev_set_uevent_suppress(dev, 0); | |
3299 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
3300 | |
3301 | return dev; | |
3302 | ||
6a7e6f78 JH |
3303 | err_del: |
3304 | device_del(dev); | |
3305 | err_put: | |
6915c0e4 | 3306 | put_device(dev); |
6a7e6f78 | 3307 | |
6915c0e4 | 3308 | return ERR_PTR(retval); |
1da177e4 | 3309 | } |
6915c0e4 | 3310 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3311 | |
3312 | /** | |
395e7833 XT |
3313 | * tty_unregister_device - unregister a tty device |
3314 | * @driver: the tty driver that describes the tty device | |
3315 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3316 | * |
395e7833 | 3317 | * If a tty device is registered with a call to tty_register_device() then |
af9b897e AC |
3318 | * this function must be called when the tty device is gone. |
3319 | * | |
3320 | * Locking: ?? | |
1da177e4 | 3321 | */ |
af9b897e | 3322 | |
1da177e4 LT |
3323 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3324 | { | |
37bdfb07 AC |
3325 | device_destroy(tty_class, |
3326 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3327 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3328 | cdev_del(driver->cdevs[index]); | |
3329 | driver->cdevs[index] = NULL; | |
3330 | } | |
1da177e4 | 3331 | } |
1da177e4 LT |
3332 | EXPORT_SYMBOL(tty_unregister_device); |
3333 | ||
7f0bc6a6 JS |
3334 | /** |
3335 | * __tty_alloc_driver -- allocate tty driver | |
3336 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 3337 | * @owner: module which is responsible for this driver |
7f0bc6a6 JS |
3338 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags |
3339 | * | |
3340 | * This should not be called directly, some of the provided macros should be | |
3341 | * used instead. Use IS_ERR and friends on @retval. | |
3342 | */ | |
3343 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3344 | unsigned long flags) | |
1da177e4 LT |
3345 | { |
3346 | struct tty_driver *driver; | |
7e73eca6 | 3347 | unsigned int cdevs = 1; |
16a02081 | 3348 | int err; |
1da177e4 | 3349 | |
0019b408 | 3350 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3351 | return ERR_PTR(-EINVAL); |
3352 | ||
a3241891 | 3353 | driver = kzalloc(sizeof(*driver), GFP_KERNEL); |
7f0bc6a6 JS |
3354 | if (!driver) |
3355 | return ERR_PTR(-ENOMEM); | |
3356 | ||
3357 | kref_init(&driver->kref); | |
3358 | driver->magic = TTY_DRIVER_MAGIC; | |
3359 | driver->num = lines; | |
3360 | driver->owner = owner; | |
3361 | driver->flags = flags; | |
16a02081 JS |
3362 | |
3363 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3364 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3365 | GFP_KERNEL); | |
3366 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3367 | GFP_KERNEL); | |
3368 | if (!driver->ttys || !driver->termios) { | |
3369 | err = -ENOMEM; | |
3370 | goto err_free_all; | |
3371 | } | |
3372 | } | |
3373 | ||
3374 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3375 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3376 | GFP_KERNEL); | |
3377 | if (!driver->ports) { | |
3378 | err = -ENOMEM; | |
3379 | goto err_free_all; | |
3380 | } | |
7e73eca6 JS |
3381 | cdevs = lines; |
3382 | } | |
3383 | ||
3384 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3385 | if (!driver->cdevs) { | |
3386 | err = -ENOMEM; | |
3387 | goto err_free_all; | |
16a02081 | 3388 | } |
7f0bc6a6 | 3389 | |
1da177e4 | 3390 | return driver; |
16a02081 JS |
3391 | err_free_all: |
3392 | kfree(driver->ports); | |
3393 | kfree(driver->ttys); | |
3394 | kfree(driver->termios); | |
a3a10ce3 | 3395 | kfree(driver->cdevs); |
16a02081 JS |
3396 | kfree(driver); |
3397 | return ERR_PTR(err); | |
1da177e4 | 3398 | } |
7f0bc6a6 | 3399 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3400 | |
7d7b93c1 | 3401 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3402 | { |
7d7b93c1 AC |
3403 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3404 | int i; | |
3405 | struct ktermios *tp; | |
7d7b93c1 AC |
3406 | |
3407 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
3408 | for (i = 0; i < driver->num; i++) { |
3409 | tp = driver->termios[i]; | |
3410 | if (tp) { | |
3411 | driver->termios[i] = NULL; | |
3412 | kfree(tp); | |
3413 | } | |
7d7b93c1 AC |
3414 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3415 | tty_unregister_device(driver, i); | |
3416 | } | |
7d7b93c1 | 3417 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3418 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3419 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3420 | } |
7e73eca6 | 3421 | kfree(driver->cdevs); |
04831dc1 | 3422 | kfree(driver->ports); |
16a02081 JS |
3423 | kfree(driver->termios); |
3424 | kfree(driver->ttys); | |
1da177e4 LT |
3425 | kfree(driver); |
3426 | } | |
3427 | ||
7d7b93c1 AC |
3428 | void tty_driver_kref_put(struct tty_driver *driver) |
3429 | { | |
3430 | kref_put(&driver->kref, destruct_tty_driver); | |
3431 | } | |
3432 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3433 | ||
1da177e4 LT |
3434 | /* |
3435 | * Called by a tty driver to register itself. | |
3436 | */ | |
3437 | int tty_register_driver(struct tty_driver *driver) | |
3438 | { | |
3439 | int error; | |
37bdfb07 | 3440 | int i; |
1da177e4 | 3441 | dev_t dev; |
b670bde0 | 3442 | struct device *d; |
1da177e4 | 3443 | |
1da177e4 | 3444 | if (!driver->major) { |
37bdfb07 AC |
3445 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3446 | driver->num, driver->name); | |
1da177e4 LT |
3447 | if (!error) { |
3448 | driver->major = MAJOR(dev); | |
3449 | driver->minor_start = MINOR(dev); | |
3450 | } | |
3451 | } else { | |
3452 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3453 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3454 | } |
9bb8a3d4 | 3455 | if (error < 0) |
16a02081 | 3456 | goto err; |
1da177e4 | 3457 | |
7e73eca6 JS |
3458 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3459 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3460 | if (error) | |
3461 | goto err_unreg_char; | |
3462 | } | |
1da177e4 | 3463 | |
ca509f69 | 3464 | mutex_lock(&tty_mutex); |
1da177e4 | 3465 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3466 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3467 | |
3468 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3469 | for (i = 0; i < driver->num; i++) { |
3470 | d = tty_register_device(driver, i, NULL); | |
3471 | if (IS_ERR(d)) { | |
3472 | error = PTR_ERR(d); | |
16a02081 | 3473 | goto err_unreg_devs; |
b670bde0 VK |
3474 | } |
3475 | } | |
1da177e4 LT |
3476 | } |
3477 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3478 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3479 | return 0; |
b670bde0 | 3480 | |
16a02081 | 3481 | err_unreg_devs: |
b670bde0 VK |
3482 | for (i--; i >= 0; i--) |
3483 | tty_unregister_device(driver, i); | |
3484 | ||
3485 | mutex_lock(&tty_mutex); | |
3486 | list_del(&driver->tty_drivers); | |
3487 | mutex_unlock(&tty_mutex); | |
3488 | ||
9bb8a3d4 | 3489 | err_unreg_char: |
b670bde0 | 3490 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3491 | err: |
b670bde0 | 3492 | return error; |
1da177e4 | 3493 | } |
1da177e4 LT |
3494 | EXPORT_SYMBOL(tty_register_driver); |
3495 | ||
3496 | /* | |
3497 | * Called by a tty driver to unregister itself. | |
3498 | */ | |
a872ab4d | 3499 | void tty_unregister_driver(struct tty_driver *driver) |
1da177e4 | 3500 | { |
1da177e4 LT |
3501 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3502 | driver->num); | |
ca509f69 | 3503 | mutex_lock(&tty_mutex); |
1da177e4 | 3504 | list_del(&driver->tty_drivers); |
ca509f69 | 3505 | mutex_unlock(&tty_mutex); |
1da177e4 | 3506 | } |
1da177e4 LT |
3507 | EXPORT_SYMBOL(tty_unregister_driver); |
3508 | ||
24ec839c PZ |
3509 | dev_t tty_devnum(struct tty_struct *tty) |
3510 | { | |
3511 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3512 | } | |
3513 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3514 | |
d81ed103 AC |
3515 | void tty_default_fops(struct file_operations *fops) |
3516 | { | |
3517 | *fops = tty_fops; | |
3518 | } | |
3519 | ||
2c9ede55 | 3520 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3521 | { |
3522 | if (!mode) | |
3523 | return NULL; | |
3524 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3525 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3526 | *mode = 0666; | |
3527 | return NULL; | |
3528 | } | |
3529 | ||
1da177e4 LT |
3530 | static int __init tty_class_init(void) |
3531 | { | |
7fe845d1 | 3532 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3533 | if (IS_ERR(tty_class)) |
3534 | return PTR_ERR(tty_class); | |
e454cea2 | 3535 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3536 | return 0; |
3537 | } | |
3538 | ||
3539 | postcore_initcall(tty_class_init); | |
3540 | ||
3541 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3542 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3543 | |
fbc92a34 KS |
3544 | static ssize_t show_cons_active(struct device *dev, |
3545 | struct device_attribute *attr, char *buf) | |
3546 | { | |
3547 | struct console *cs[16]; | |
3548 | int i = 0; | |
3549 | struct console *c; | |
3550 | ssize_t count = 0; | |
3551 | ||
ac751efa | 3552 | console_lock(); |
a2a6a822 | 3553 | for_each_console(c) { |
fbc92a34 KS |
3554 | if (!c->device) |
3555 | continue; | |
3556 | if (!c->write) | |
3557 | continue; | |
3558 | if ((c->flags & CON_ENABLED) == 0) | |
3559 | continue; | |
3560 | cs[i++] = c; | |
3561 | if (i >= ARRAY_SIZE(cs)) | |
3562 | break; | |
3563 | } | |
723abd87 HR |
3564 | while (i--) { |
3565 | int index = cs[i]->index; | |
3566 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3567 | ||
3568 | /* don't resolve tty0 as some programs depend on it */ | |
3569 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3570 | count += tty_line_name(drv, index, buf + count); | |
3571 | else | |
3572 | count += sprintf(buf + count, "%s%d", | |
3573 | cs[i]->name, cs[i]->index); | |
3574 | ||
3575 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3576 | } | |
ac751efa | 3577 | console_unlock(); |
fbc92a34 KS |
3578 | |
3579 | return count; | |
3580 | } | |
3581 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3582 | ||
1083a7be TI |
3583 | static struct attribute *cons_dev_attrs[] = { |
3584 | &dev_attr_active.attr, | |
3585 | NULL | |
3586 | }; | |
3587 | ||
3588 | ATTRIBUTE_GROUPS(cons_dev); | |
3589 | ||
fbc92a34 KS |
3590 | static struct device *consdev; |
3591 | ||
3592 | void console_sysfs_notify(void) | |
3593 | { | |
3594 | if (consdev) | |
3595 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3596 | } | |
3597 | ||
1da177e4 LT |
3598 | /* |
3599 | * Ok, now we can initialize the rest of the tty devices and can count | |
3600 | * on memory allocations, interrupts etc.. | |
3601 | */ | |
31d1d48e | 3602 | int __init tty_init(void) |
1da177e4 | 3603 | { |
7c0cca7c | 3604 | tty_sysctl_init(); |
1da177e4 LT |
3605 | cdev_init(&tty_cdev, &tty_fops); |
3606 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3607 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3608 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3609 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3610 | |
3611 | cdev_init(&console_cdev, &console_fops); | |
3612 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3613 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3614 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3615 | consdev = device_create_with_groups(tty_class, NULL, |
3616 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3617 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3618 | if (IS_ERR(consdev)) |
3619 | consdev = NULL; | |
1da177e4 | 3620 | |
1da177e4 | 3621 | #ifdef CONFIG_VT |
d81ed103 | 3622 | vty_init(&console_fops); |
1da177e4 LT |
3623 | #endif |
3624 | return 0; | |
3625 | } | |
31d1d48e | 3626 |