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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. | |
36 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
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> | |
90 | #include <linux/proc_fs.h> | |
91 | #include <linux/init.h> | |
92 | #include <linux/module.h> | |
1da177e4 | 93 | #include <linux/device.h> |
1da177e4 LT |
94 | #include <linux/wait.h> |
95 | #include <linux/bitops.h> | |
b20f3ae5 | 96 | #include <linux/delay.h> |
a352def2 | 97 | #include <linux/seq_file.h> |
d281da7f | 98 | #include <linux/serial.h> |
5a3c6b25 | 99 | #include <linux/ratelimit.h> |
1da177e4 | 100 | |
a352def2 | 101 | #include <linux/uaccess.h> |
1da177e4 LT |
102 | |
103 | #include <linux/kbd_kern.h> | |
104 | #include <linux/vt_kern.h> | |
105 | #include <linux/selection.h> | |
1da177e4 LT |
106 | |
107 | #include <linux/kmod.h> | |
b488893a | 108 | #include <linux/nsproxy.h> |
1da177e4 LT |
109 | |
110 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
111 | #ifdef TTY_DEBUG_HANGUP |
112 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
113 | #else | |
114 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
115 | #endif | |
1da177e4 LT |
116 | |
117 | #define TTY_PARANOIA_CHECK 1 | |
118 | #define CHECK_TTY_COUNT 1 | |
119 | ||
edc6afc5 | 120 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
121 | .c_iflag = ICRNL | IXON, |
122 | .c_oflag = OPOST | ONLCR, | |
123 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
124 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
125 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
126 | .c_cc = INIT_C_CC, |
127 | .c_ispeed = 38400, | |
133b1306 PH |
128 | .c_ospeed = 38400, |
129 | /* .c_line = N_TTY, */ | |
1da177e4 LT |
130 | }; |
131 | ||
132 | EXPORT_SYMBOL(tty_std_termios); | |
133 | ||
134 | /* This list gets poked at by procfs and various bits of boot up code. This | |
135 | could do with some rationalisation such as pulling the tty proc function | |
136 | into this file */ | |
37bdfb07 | 137 | |
1da177e4 LT |
138 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
139 | ||
d1d027ef | 140 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 141 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 142 | |
1da177e4 LT |
143 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
144 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
145 | ssize_t redirected_tty_write(struct file *, const char __user *, |
146 | size_t, loff_t *); | |
1da177e4 LT |
147 | static unsigned int tty_poll(struct file *, poll_table *); |
148 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 149 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
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 | |
fa90e1c9 JS |
209 | /** |
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 LT |
250 | } |
251 | ||
252 | EXPORT_SYMBOL(tty_name); | |
253 | ||
0a083edd PH |
254 | const char *tty_driver_name(const struct tty_struct *tty) |
255 | { | |
256 | if (!tty || !tty->driver) | |
257 | return ""; | |
258 | return tty->driver->name; | |
259 | } | |
260 | ||
82b8f888 | 261 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
262 | const char *routine) |
263 | { | |
264 | #ifdef TTY_PARANOIA_CHECK | |
265 | if (!tty) { | |
89222e62 | 266 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
267 | imajor(inode), iminor(inode), routine); |
268 | return 1; | |
269 | } | |
270 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 271 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
272 | imajor(inode), iminor(inode), routine); |
273 | return 1; | |
274 | } | |
275 | #endif | |
276 | return 0; | |
277 | } | |
278 | ||
deb287e7 | 279 | /* Caller must hold tty_lock */ |
1da177e4 LT |
280 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
281 | { | |
282 | #ifdef CHECK_TTY_COUNT | |
283 | struct list_head *p; | |
a09ac397 | 284 | int count = 0, kopen_count = 0; |
37bdfb07 | 285 | |
4a510969 | 286 | spin_lock(&tty->files_lock); |
1da177e4 LT |
287 | list_for_each(p, &tty->tty_files) { |
288 | count++; | |
289 | } | |
4a510969 | 290 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
291 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
292 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
293 | tty->link && tty->link->count) | |
294 | count++; | |
a09ac397 OK |
295 | if (tty_port_kopened(tty->port)) |
296 | kopen_count++; | |
297 | if (tty->count != (count + kopen_count)) { | |
298 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", | |
299 | routine, tty->count, count, kopen_count); | |
300 | return (count + kopen_count); | |
24ec839c | 301 | } |
1da177e4 LT |
302 | #endif |
303 | return 0; | |
304 | } | |
305 | ||
af9b897e AC |
306 | /** |
307 | * get_tty_driver - find device of a tty | |
308 | * @dev_t: device identifier | |
309 | * @index: returns the index of the tty | |
310 | * | |
311 | * This routine returns a tty driver structure, given a device number | |
312 | * and also passes back the index number. | |
313 | * | |
314 | * Locking: caller must hold tty_mutex | |
1da177e4 | 315 | */ |
af9b897e | 316 | |
1da177e4 LT |
317 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
318 | { | |
319 | struct tty_driver *p; | |
320 | ||
321 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
322 | dev_t base = MKDEV(p->major, p->minor_start); | |
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) { | |
bccef6d6 | 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 | ||
37bdfb07 | 433 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
434 | size_t count, loff_t *ppos) |
435 | { | |
436 | return 0; | |
437 | } | |
438 | ||
37bdfb07 | 439 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
440 | size_t count, loff_t *ppos) |
441 | { | |
442 | return -EIO; | |
443 | } | |
444 | ||
445 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 446 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
447 | { |
448 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
449 | } | |
450 | ||
04f378b1 AC |
451 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
452 | unsigned long arg) | |
38ad2ed0 PF |
453 | { |
454 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
455 | } | |
456 | ||
37bdfb07 | 457 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 458 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
459 | { |
460 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
461 | } | |
462 | ||
f557474c PH |
463 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
464 | { | |
465 | return -ENOTTY; | |
466 | } | |
467 | ||
d01c3289 MY |
468 | static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
469 | { | |
470 | struct tty_struct *tty = file_tty(file); | |
471 | ||
472 | if (tty && tty->ops && tty->ops->show_fdinfo) | |
473 | tty->ops->show_fdinfo(tty, m); | |
474 | } | |
475 | ||
62322d25 | 476 | static const struct file_operations tty_fops = { |
1da177e4 LT |
477 | .llseek = no_llseek, |
478 | .read = tty_read, | |
479 | .write = tty_write, | |
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 LT |
490 | .llseek = no_llseek, |
491 | .read = tty_read, | |
492 | .write = redirected_tty_write, | |
493 | .poll = tty_poll, | |
04f378b1 | 494 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 495 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
496 | .open = tty_open, |
497 | .release = tty_release, | |
498 | .fasync = tty_fasync, | |
499 | }; | |
500 | ||
62322d25 | 501 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
502 | .llseek = no_llseek, |
503 | .read = hung_up_tty_read, | |
504 | .write = hung_up_tty_write, | |
505 | .poll = hung_up_tty_poll, | |
04f378b1 | 506 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 507 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 508 | .release = tty_release, |
f557474c | 509 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
510 | }; |
511 | ||
512 | static DEFINE_SPINLOCK(redirect_lock); | |
513 | static struct file *redirect; | |
514 | ||
d6f408ac GKH |
515 | extern void tty_sysctl_init(void); |
516 | ||
1da177e4 LT |
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 | } | |
4b19449d | 538 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
539 | } |
540 | ||
541 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
542 | ||
af9b897e | 543 | /** |
11dbf203 | 544 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 545 | * @work: tty device |
af9b897e | 546 | * |
ef4f527c | 547 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
548 | * synchronous but doesn't hold any locks, so we need to make sure we |
549 | * have the appropriate locks for what we're doing. | |
550 | * | |
551 | * The hangup event clears any pending redirections onto the hung up | |
552 | * device. It ensures future writes will error and it does the needed | |
553 | * line discipline hangup and signal delivery. The tty object itself | |
554 | * remains intact. | |
555 | * | |
556 | * Locking: | |
ec79d605 | 557 | * BTM |
24ec839c PZ |
558 | * redirect lock for undoing redirection |
559 | * file list lock for manipulating list of ttys | |
137084bb | 560 | * tty_ldiscs_lock from called functions |
6a1c0680 | 561 | * termios_rwsem resetting termios data |
24ec839c PZ |
562 | * tasklist_lock to walk task list for hangup event |
563 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 564 | */ |
f91e2590 | 565 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 566 | { |
37bdfb07 | 567 | struct file *cons_filp = NULL; |
1da177e4 | 568 | struct file *filp, *f = NULL; |
d996b62a | 569 | struct tty_file_private *priv; |
1da177e4 | 570 | int closecount = 0, n; |
ea648a47 | 571 | int refs; |
1da177e4 LT |
572 | |
573 | if (!tty) | |
574 | return; | |
575 | ||
1da177e4 LT |
576 | |
577 | spin_lock(&redirect_lock); | |
d996b62a | 578 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
579 | f = redirect; |
580 | redirect = NULL; | |
581 | } | |
582 | spin_unlock(&redirect_lock); | |
37bdfb07 | 583 | |
89c8d91e | 584 | tty_lock(tty); |
11dbf203 | 585 | |
cb50e523 PH |
586 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
587 | tty_unlock(tty); | |
588 | return; | |
589 | } | |
590 | ||
c720645a TH |
591 | /* |
592 | * Some console devices aren't actually hung up for technical and | |
593 | * historical reasons, which can lead to indefinite interruptible | |
594 | * sleep in n_tty_read(). The following explicitly tells | |
595 | * n_tty_read() to abort readers. | |
596 | */ | |
597 | set_bit(TTY_HUPPING, &tty->flags); | |
598 | ||
ec79d605 AB |
599 | /* inuse_filps is protected by the single tty lock, |
600 | this really needs to change if we want to flush the | |
601 | workqueue with the lock held */ | |
11dbf203 | 602 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 603 | |
4a510969 | 604 | spin_lock(&tty->files_lock); |
1da177e4 | 605 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
606 | list_for_each_entry(priv, &tty->tty_files, list) { |
607 | filp = priv->file; | |
1da177e4 LT |
608 | if (filp->f_op->write == redirected_tty_write) |
609 | cons_filp = filp; | |
610 | if (filp->f_op->write != tty_write) | |
611 | continue; | |
612 | closecount++; | |
ec79d605 | 613 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
614 | filp->f_op = &hung_up_tty_fops; |
615 | } | |
4a510969 | 616 | spin_unlock(&tty->files_lock); |
37bdfb07 | 617 | |
25fdf243 PH |
618 | refs = tty_signal_session_leader(tty, exit_session); |
619 | /* Account for the p->signal references we killed */ | |
620 | while (refs--) | |
621 | tty_kref_put(tty); | |
622 | ||
892d1fa7 | 623 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 624 | |
20cc225b | 625 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 626 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 627 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
628 | put_pid(tty->session); |
629 | put_pid(tty->pgrp); | |
ab521dc0 EB |
630 | tty->session = NULL; |
631 | tty->pgrp = NULL; | |
1da177e4 | 632 | tty->ctrl_status = 0; |
20cc225b | 633 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 634 | |
1da177e4 | 635 | /* |
37bdfb07 AC |
636 | * If one of the devices matches a console pointer, we |
637 | * cannot just call hangup() because that will cause | |
638 | * tty->count and state->count to go out of sync. | |
639 | * So we just call close() the right number of times. | |
1da177e4 LT |
640 | */ |
641 | if (cons_filp) { | |
f34d7a5b | 642 | if (tty->ops->close) |
1da177e4 | 643 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
644 | tty->ops->close(tty, cons_filp); |
645 | } else if (tty->ops->hangup) | |
7c6d340f | 646 | tty->ops->hangup(tty); |
37bdfb07 | 647 | /* |
892d1fa7 PH |
648 | * We don't want to have driver/ldisc interactions beyond the ones |
649 | * we did here. The driver layer expects no calls after ->hangup() | |
650 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 651 | */ |
1da177e4 | 652 | set_bit(TTY_HUPPED, &tty->flags); |
c720645a | 653 | clear_bit(TTY_HUPPING, &tty->flags); |
89c8d91e | 654 | tty_unlock(tty); |
11dbf203 | 655 | |
1da177e4 LT |
656 | if (f) |
657 | fput(f); | |
658 | } | |
659 | ||
ddcd9fb6 AB |
660 | static void do_tty_hangup(struct work_struct *work) |
661 | { | |
662 | struct tty_struct *tty = | |
663 | container_of(work, struct tty_struct, hangup_work); | |
664 | ||
f91e2590 | 665 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
666 | } |
667 | ||
af9b897e AC |
668 | /** |
669 | * tty_hangup - trigger a hangup event | |
670 | * @tty: tty to hangup | |
671 | * | |
672 | * A carrier loss (virtual or otherwise) has occurred on this like | |
673 | * schedule a hangup sequence to run after this event. | |
674 | */ | |
675 | ||
37bdfb07 | 676 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 677 | { |
d435cefe | 678 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
679 | schedule_work(&tty->hangup_work); |
680 | } | |
681 | ||
682 | EXPORT_SYMBOL(tty_hangup); | |
683 | ||
af9b897e AC |
684 | /** |
685 | * tty_vhangup - process vhangup | |
686 | * @tty: tty to hangup | |
687 | * | |
688 | * The user has asked via system call for the terminal to be hung up. | |
689 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 690 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
691 | */ |
692 | ||
37bdfb07 | 693 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 694 | { |
d435cefe | 695 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 696 | __tty_hangup(tty, 0); |
1da177e4 | 697 | } |
37bdfb07 | 698 | |
1da177e4 LT |
699 | EXPORT_SYMBOL(tty_vhangup); |
700 | ||
11dbf203 | 701 | |
2cb5998b AC |
702 | /** |
703 | * tty_vhangup_self - process vhangup for own ctty | |
704 | * | |
705 | * Perform a vhangup on the current controlling tty | |
706 | */ | |
707 | ||
708 | void tty_vhangup_self(void) | |
709 | { | |
710 | struct tty_struct *tty; | |
711 | ||
2cb5998b AC |
712 | tty = get_current_tty(); |
713 | if (tty) { | |
714 | tty_vhangup(tty); | |
715 | tty_kref_put(tty); | |
716 | } | |
2cb5998b AC |
717 | } |
718 | ||
f91e2590 PH |
719 | /** |
720 | * tty_vhangup_session - hangup session leader exit | |
721 | * @tty: tty to hangup | |
722 | * | |
723 | * The session leader is exiting and hanging up its controlling terminal. | |
724 | * Every process in the foreground process group is signalled SIGHUP. | |
725 | * | |
726 | * We do this synchronously so that when the syscall returns the process | |
727 | * is complete. That guarantee is necessary for security reasons. | |
728 | */ | |
729 | ||
a1235b3e | 730 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 731 | { |
d435cefe | 732 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
733 | __tty_hangup(tty, 1); |
734 | } | |
735 | ||
af9b897e AC |
736 | /** |
737 | * tty_hung_up_p - was tty hung up | |
738 | * @filp: file pointer of tty | |
739 | * | |
740 | * Return true if the tty has been subject to a vhangup or a carrier | |
741 | * loss | |
742 | */ | |
743 | ||
37bdfb07 | 744 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 745 | { |
ed3f0af8 | 746 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 LT |
747 | } |
748 | ||
749 | EXPORT_SYMBOL(tty_hung_up_p); | |
750 | ||
af9b897e | 751 | /** |
beb7dd86 | 752 | * stop_tty - propagate flow control |
af9b897e AC |
753 | * @tty: tty to stop |
754 | * | |
01adc807 | 755 | * Perform flow control to the driver. May be called |
af9b897e AC |
756 | * on an already stopped device and will not re-call the driver |
757 | * method. | |
758 | * | |
759 | * This functionality is used by both the line disciplines for | |
760 | * halting incoming flow and by the driver. It may therefore be | |
761 | * called from any context, may be under the tty atomic_write_lock | |
762 | * but not always. | |
763 | * | |
764 | * Locking: | |
f9e053dc | 765 | * flow_lock |
af9b897e AC |
766 | */ |
767 | ||
f9e053dc | 768 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 769 | { |
f9e053dc | 770 | if (tty->stopped) |
1da177e4 LT |
771 | return; |
772 | tty->stopped = 1; | |
f34d7a5b | 773 | if (tty->ops->stop) |
c961bfb1 | 774 | tty->ops->stop(tty); |
1da177e4 LT |
775 | } |
776 | ||
f9e053dc PH |
777 | void stop_tty(struct tty_struct *tty) |
778 | { | |
779 | unsigned long flags; | |
780 | ||
781 | spin_lock_irqsave(&tty->flow_lock, flags); | |
782 | __stop_tty(tty); | |
783 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
784 | } | |
1da177e4 LT |
785 | EXPORT_SYMBOL(stop_tty); |
786 | ||
af9b897e | 787 | /** |
beb7dd86 | 788 | * start_tty - propagate flow control |
af9b897e AC |
789 | * @tty: tty to start |
790 | * | |
01adc807 PH |
791 | * Start a tty that has been stopped if at all possible. If this |
792 | * tty was previous stopped and is now being started, the driver | |
793 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
794 | * |
795 | * Locking: | |
f9e053dc | 796 | * flow_lock |
af9b897e AC |
797 | */ |
798 | ||
f9e053dc | 799 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 800 | { |
f9e053dc | 801 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
802 | return; |
803 | tty->stopped = 0; | |
f34d7a5b | 804 | if (tty->ops->start) |
c961bfb1 | 805 | tty->ops->start(tty); |
1da177e4 | 806 | tty_wakeup(tty); |
1da177e4 LT |
807 | } |
808 | ||
f9e053dc PH |
809 | void start_tty(struct tty_struct *tty) |
810 | { | |
811 | unsigned long flags; | |
812 | ||
813 | spin_lock_irqsave(&tty->flow_lock, flags); | |
814 | __start_tty(tty); | |
815 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
816 | } | |
1da177e4 LT |
817 | EXPORT_SYMBOL(start_tty); |
818 | ||
37b7f3c7 JS |
819 | static void tty_update_time(struct timespec *time) |
820 | { | |
f0bf0bd0 | 821 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
822 | |
823 | /* | |
824 | * We only care if the two values differ in anything other than the | |
825 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
826 | * the time of the tty device, otherwise it could be construded as a | |
827 | * security leak to let userspace know the exact timing of the tty. | |
828 | */ | |
829 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
830 | time->tv_sec = sec; |
831 | } | |
832 | ||
af9b897e AC |
833 | /** |
834 | * tty_read - read method for tty device files | |
835 | * @file: pointer to tty file | |
836 | * @buf: user buffer | |
837 | * @count: size of user buffer | |
838 | * @ppos: unused | |
839 | * | |
840 | * Perform the read system call function on this terminal device. Checks | |
841 | * for hung up devices before calling the line discipline method. | |
842 | * | |
843 | * Locking: | |
47f86834 AC |
844 | * Locks the line discipline internally while needed. Multiple |
845 | * read calls may be outstanding in parallel. | |
af9b897e AC |
846 | */ |
847 | ||
37bdfb07 | 848 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
849 | loff_t *ppos) |
850 | { | |
851 | int i; | |
37b7f3c7 | 852 | struct inode *inode = file_inode(file); |
d996b62a | 853 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
854 | struct tty_ldisc *ld; |
855 | ||
37b7f3c7 | 856 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 857 | return -EIO; |
18900ca6 | 858 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
859 | return -EIO; |
860 | ||
861 | /* We want to wait for the line discipline to sort out in this | |
862 | situation */ | |
863 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
864 | if (!ld) |
865 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 866 | if (ld->ops->read) |
c961bfb1 | 867 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
868 | else |
869 | i = -EIO; | |
870 | tty_ldisc_deref(ld); | |
b0de59b5 | 871 | |
37b7f3c7 JS |
872 | if (i > 0) |
873 | tty_update_time(&inode->i_atime); | |
874 | ||
1da177e4 LT |
875 | return i; |
876 | } | |
877 | ||
136d5258 | 878 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
879 | { |
880 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 881 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
882 | } |
883 | ||
136d5258 | 884 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
885 | { |
886 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
887 | if (ndelay) | |
888 | return -EAGAIN; | |
889 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
890 | return -ERESTARTSYS; | |
891 | } | |
892 | return 0; | |
893 | } | |
894 | ||
1da177e4 LT |
895 | /* |
896 | * Split writes up in sane blocksizes to avoid | |
897 | * denial-of-service type attacks | |
898 | */ | |
899 | static inline ssize_t do_tty_write( | |
900 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
901 | struct tty_struct *tty, | |
902 | struct file *file, | |
903 | const char __user *buf, | |
904 | size_t count) | |
905 | { | |
9c1729db | 906 | ssize_t ret, written = 0; |
1da177e4 | 907 | unsigned int chunk; |
37bdfb07 | 908 | |
9c1729db AC |
909 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
910 | if (ret < 0) | |
911 | return ret; | |
1da177e4 LT |
912 | |
913 | /* | |
914 | * We chunk up writes into a temporary buffer. This | |
915 | * simplifies low-level drivers immensely, since they | |
916 | * don't have locking issues and user mode accesses. | |
917 | * | |
918 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
919 | * big chunk-size.. | |
920 | * | |
921 | * The default chunk-size is 2kB, because the NTTY | |
922 | * layer has problems with bigger chunks. It will | |
923 | * claim to be able to handle more characters than | |
924 | * it actually does. | |
af9b897e AC |
925 | * |
926 | * FIXME: This can probably go away now except that 64K chunks | |
927 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
928 | */ |
929 | chunk = 2048; | |
930 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
931 | chunk = 65536; | |
932 | if (count < chunk) | |
933 | chunk = count; | |
934 | ||
70522e12 | 935 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 936 | if (tty->write_cnt < chunk) { |
402fda92 | 937 | unsigned char *buf_chunk; |
1da177e4 LT |
938 | |
939 | if (chunk < 1024) | |
940 | chunk = 1024; | |
941 | ||
402fda92 JW |
942 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
943 | if (!buf_chunk) { | |
9c1729db AC |
944 | ret = -ENOMEM; |
945 | goto out; | |
1da177e4 LT |
946 | } |
947 | kfree(tty->write_buf); | |
948 | tty->write_cnt = chunk; | |
402fda92 | 949 | tty->write_buf = buf_chunk; |
1da177e4 LT |
950 | } |
951 | ||
952 | /* Do the write .. */ | |
953 | for (;;) { | |
954 | size_t size = count; | |
955 | if (size > chunk) | |
956 | size = chunk; | |
957 | ret = -EFAULT; | |
958 | if (copy_from_user(tty->write_buf, buf, size)) | |
959 | break; | |
1da177e4 | 960 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
961 | if (ret <= 0) |
962 | break; | |
963 | written += ret; | |
964 | buf += ret; | |
965 | count -= ret; | |
966 | if (!count) | |
967 | break; | |
968 | ret = -ERESTARTSYS; | |
969 | if (signal_pending(current)) | |
970 | break; | |
971 | cond_resched(); | |
972 | } | |
37b7f3c7 JS |
973 | if (written) { |
974 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 975 | ret = written; |
37b7f3c7 | 976 | } |
9c1729db AC |
977 | out: |
978 | tty_write_unlock(tty); | |
1da177e4 LT |
979 | return ret; |
980 | } | |
981 | ||
95f9bfc6 AC |
982 | /** |
983 | * tty_write_message - write a message to a certain tty, not just the console. | |
984 | * @tty: the destination tty_struct | |
985 | * @msg: the message to write | |
986 | * | |
987 | * This is used for messages that need to be redirected to a specific tty. | |
988 | * We don't put it into the syslog queue right now maybe in the future if | |
989 | * really needed. | |
990 | * | |
ec79d605 | 991 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
992 | */ |
993 | ||
994 | void tty_write_message(struct tty_struct *tty, char *msg) | |
995 | { | |
95f9bfc6 AC |
996 | if (tty) { |
997 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 998 | tty_lock(tty); |
4b41b953 | 999 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1000 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1001 | tty_unlock(tty); |
95f9bfc6 AC |
1002 | tty_write_unlock(tty); |
1003 | } | |
95f9bfc6 AC |
1004 | return; |
1005 | } | |
1006 | ||
1da177e4 | 1007 | |
af9b897e AC |
1008 | /** |
1009 | * tty_write - write method for tty device file | |
1010 | * @file: tty file pointer | |
1011 | * @buf: user data to write | |
1012 | * @count: bytes to write | |
1013 | * @ppos: unused | |
1014 | * | |
1015 | * Write data to a tty device via the line discipline. | |
1016 | * | |
1017 | * Locking: | |
1018 | * Locks the line discipline as required | |
1019 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1020 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1021 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1022 | */ |
1023 | ||
37bdfb07 AC |
1024 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1025 | size_t count, loff_t *ppos) | |
1da177e4 | 1026 | { |
d996b62a NP |
1027 | struct tty_struct *tty = file_tty(file); |
1028 | struct tty_ldisc *ld; | |
1da177e4 | 1029 | ssize_t ret; |
37bdfb07 | 1030 | |
6131ffaa | 1031 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1032 | return -EIO; |
18900ca6 | 1033 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
37bdfb07 | 1034 | return -EIO; |
f34d7a5b AC |
1035 | /* Short term debug to catch buggy drivers */ |
1036 | if (tty->ops->write_room == NULL) | |
339f36ba | 1037 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1038 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1039 | if (!ld) |
1040 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1041 | if (!ld->ops->write) |
1da177e4 LT |
1042 | ret = -EIO; |
1043 | else | |
a352def2 | 1044 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1045 | tty_ldisc_deref(ld); |
1046 | return ret; | |
1047 | } | |
1048 | ||
37bdfb07 AC |
1049 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1050 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1051 | { |
1052 | struct file *p = NULL; | |
1053 | ||
1054 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1055 | if (redirect) |
1056 | p = get_file(redirect); | |
1da177e4 LT |
1057 | spin_unlock(&redirect_lock); |
1058 | ||
1059 | if (p) { | |
1060 | ssize_t res; | |
1061 | res = vfs_write(p, buf, count, &p->f_pos); | |
1062 | fput(p); | |
1063 | return res; | |
1064 | } | |
1da177e4 LT |
1065 | return tty_write(file, buf, count, ppos); |
1066 | } | |
1067 | ||
136d5258 PH |
1068 | /** |
1069 | * tty_send_xchar - send priority character | |
1070 | * | |
1071 | * Send a high priority character to the tty even if stopped | |
1072 | * | |
1073 | * Locking: none for xchar method, write ordering for write method. | |
1074 | */ | |
1075 | ||
1076 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1077 | { | |
1078 | int was_stopped = tty->stopped; | |
1079 | ||
1080 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1081 | down_read(&tty->termios_rwsem); |
136d5258 | 1082 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1083 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1084 | return 0; |
1085 | } | |
1086 | ||
1087 | if (tty_write_lock(tty, 0) < 0) | |
1088 | return -ERESTARTSYS; | |
1089 | ||
ee0c1a65 | 1090 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1091 | if (was_stopped) |
1092 | start_tty(tty); | |
1093 | tty->ops->write(tty, &ch, 1); | |
1094 | if (was_stopped) | |
1095 | stop_tty(tty); | |
ee0c1a65 | 1096 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1097 | tty_write_unlock(tty); |
1098 | return 0; | |
1099 | } | |
1100 | ||
1da177e4 LT |
1101 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1102 | ||
af9b897e AC |
1103 | /** |
1104 | * pty_line_name - generate name for a pty | |
1105 | * @driver: the tty driver in use | |
1106 | * @index: the minor number | |
1107 | * @p: output buffer of at least 6 bytes | |
1108 | * | |
1109 | * Generate a name from a driver reference and write it to the output | |
1110 | * buffer. | |
1111 | * | |
1112 | * Locking: None | |
1113 | */ | |
1114 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1115 | { |
1116 | int i = index + driver->name_base; | |
1117 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1118 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1119 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1120 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1121 | } |
1122 | ||
af9b897e | 1123 | /** |
8b0a88d5 | 1124 | * tty_line_name - generate name for a tty |
af9b897e AC |
1125 | * @driver: the tty driver in use |
1126 | * @index: the minor number | |
1127 | * @p: output buffer of at least 7 bytes | |
1128 | * | |
1129 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1130 | * buffer. |
af9b897e AC |
1131 | * |
1132 | * Locking: None | |
1133 | */ | |
723abd87 | 1134 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1135 | { |
0019b408 | 1136 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1137 | return sprintf(p, "%s", driver->name); |
0019b408 | 1138 | else |
723abd87 HR |
1139 | return sprintf(p, "%s%d", driver->name, |
1140 | index + driver->name_base); | |
1da177e4 LT |
1141 | } |
1142 | ||
99f1fe18 AC |
1143 | /** |
1144 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1145 | * @driver: the driver for the tty | |
1146 | * @idx: the minor number | |
23499705 | 1147 | * |
aa3cb814 PH |
1148 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1149 | * driver lookup() method returns an error. | |
23499705 | 1150 | * |
aa3cb814 | 1151 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1152 | */ |
a47d545f | 1153 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1154 | struct file *file, int idx) |
23499705 | 1155 | { |
aa3cb814 PH |
1156 | struct tty_struct *tty; |
1157 | ||
99f1fe18 | 1158 | if (driver->ops->lookup) |
12e84c71 OK |
1159 | if (!file) |
1160 | tty = ERR_PTR(-EIO); | |
1161 | else | |
1162 | tty = driver->ops->lookup(driver, file, idx); | |
aa3cb814 PH |
1163 | else |
1164 | tty = driver->ttys[idx]; | |
23499705 | 1165 | |
aa3cb814 PH |
1166 | if (!IS_ERR(tty)) |
1167 | tty_kref_get(tty); | |
1168 | return tty; | |
23499705 SB |
1169 | } |
1170 | ||
bf970ee4 AC |
1171 | /** |
1172 | * tty_init_termios - helper for termios setup | |
1173 | * @tty: the tty to set up | |
1174 | * | |
1175 | * Initialise the termios structures for this tty. Thus runs under | |
1176 | * the tty_mutex currently so we can be relaxed about ordering. | |
1177 | */ | |
1178 | ||
a3123fd0 | 1179 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1180 | { |
fe6e29fd | 1181 | struct ktermios *tp; |
bf970ee4 AC |
1182 | int idx = tty->index; |
1183 | ||
36b3c070 AC |
1184 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1185 | tty->termios = tty->driver->init_termios; | |
1186 | else { | |
1187 | /* Check for lazy saved data */ | |
1188 | tp = tty->driver->termios[idx]; | |
ece53405 | 1189 | if (tp != NULL) { |
36b3c070 | 1190 | tty->termios = *tp; |
ece53405 PH |
1191 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1192 | } else | |
36b3c070 | 1193 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1194 | } |
bf970ee4 | 1195 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1196 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1197 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1198 | } |
fe1ae7fd | 1199 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1200 | |
66d450e8 JS |
1201 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1202 | { | |
a3123fd0 | 1203 | tty_init_termios(tty); |
66d450e8 JS |
1204 | tty_driver_kref_get(driver); |
1205 | tty->count++; | |
1206 | driver->ttys[tty->index] = tty; | |
1207 | return 0; | |
1208 | } | |
1209 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1210 | ||
99f1fe18 | 1211 | /** |
8b0a88d5 AC |
1212 | * tty_driver_install_tty() - install a tty entry in the driver |
1213 | * @driver: the driver for the tty | |
1214 | * @tty: the tty | |
1215 | * | |
1216 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1217 | * will be set by the time this is called. This method is responsible |
1218 | * for ensuring any need additional structures are allocated and | |
1219 | * configured. | |
8b0a88d5 AC |
1220 | * |
1221 | * Locking: tty_mutex for now | |
1222 | */ | |
1223 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1224 | struct tty_struct *tty) | |
1225 | { | |
66d450e8 JS |
1226 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1227 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1228 | } |
1229 | ||
1230 | /** | |
1231 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1232 | * @driver: the driver for the tty | |
1233 | * @idx: the minor number | |
1234 | * | |
1235 | * Remvoe a tty object from the driver tables. The tty->index field | |
1236 | * will be set by the time this is called. | |
1237 | * | |
1238 | * Locking: tty_mutex for now | |
1239 | */ | |
05de87ed | 1240 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1241 | { |
1242 | if (driver->ops->remove) | |
1243 | driver->ops->remove(driver, tty); | |
1244 | else | |
1245 | driver->ttys[tty->index] = NULL; | |
1246 | } | |
1247 | ||
1248 | /* | |
1249 | * tty_reopen() - fast re-open of an open tty | |
1250 | * @tty - the tty to open | |
23499705 | 1251 | * |
99f1fe18 | 1252 | * Return 0 on success, -errno on error. |
5d93e748 | 1253 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1254 | * |
5d93e748 | 1255 | * Locking: Caller must hold tty_lock |
23499705 | 1256 | */ |
99f1fe18 | 1257 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1258 | { |
1259 | struct tty_driver *driver = tty->driver; | |
1c5346bc DS |
1260 | struct tty_ldisc *ld; |
1261 | int retval = 0; | |
23499705 | 1262 | |
23499705 | 1263 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1264 | driver->subtype == PTY_TYPE_MASTER) |
1265 | return -EIO; | |
23499705 | 1266 | |
7f22f6c9 PH |
1267 | if (!tty->count) |
1268 | return -EAGAIN; | |
1269 | ||
86f2c00f PH |
1270 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1271 | return -EBUSY; | |
1272 | ||
1c5346bc DS |
1273 | ld = tty_ldisc_ref_wait(tty); |
1274 | if (ld) { | |
1275 | tty_ldisc_deref(ld); | |
1276 | } else { | |
1277 | retval = tty_ldisc_lock(tty, 5 * HZ); | |
1278 | if (retval) | |
1279 | return retval; | |
1280 | ||
1281 | if (!tty->ldisc) | |
1282 | retval = tty_ldisc_reinit(tty, tty->termios.c_line); | |
1283 | tty_ldisc_unlock(tty); | |
1284 | } | |
23499705 | 1285 | |
0f023e06 DS |
1286 | if (retval == 0) |
1287 | tty->count++; | |
529f88e1 DS |
1288 | |
1289 | return retval; | |
23499705 SB |
1290 | } |
1291 | ||
af9b897e | 1292 | /** |
d81ed103 | 1293 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1294 | * @driver: tty driver we are opening a device on |
1295 | * @idx: device index | |
15582d36 | 1296 | * @ret_tty: returned tty structure |
af9b897e AC |
1297 | * |
1298 | * Prepare a tty device. This may not be a "new" clean device but | |
1299 | * could also be an active device. The pty drivers require special | |
1300 | * handling because of this. | |
1301 | * | |
1302 | * Locking: | |
1303 | * The function is called under the tty_mutex, which | |
1304 | * protects us from the tty struct or driver itself going away. | |
1305 | * | |
1306 | * On exit the tty device has the line discipline attached and | |
1307 | * a reference count of 1. If a pair was created for pty/tty use | |
1308 | * and the other was a pty master then it too has a reference count of 1. | |
1309 | * | |
1da177e4 | 1310 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1311 | * failed open. The new code protects the open with a mutex, so it's |
1312 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1313 | * relaxed for the (most common) case of reopening a tty. |
1314 | */ | |
af9b897e | 1315 | |
593a27c4 | 1316 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1317 | { |
bf970ee4 | 1318 | struct tty_struct *tty; |
73ec06fc | 1319 | int retval; |
1da177e4 | 1320 | |
1da177e4 LT |
1321 | /* |
1322 | * First time open is complex, especially for PTY devices. | |
1323 | * This code guarantees that either everything succeeds and the | |
1324 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1325 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1326 | * may be retained.) |
1da177e4 LT |
1327 | */ |
1328 | ||
73ec06fc AC |
1329 | if (!try_module_get(driver->owner)) |
1330 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1331 | |
2c964a2f | 1332 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1333 | if (!tty) { |
1334 | retval = -ENOMEM; | |
1335 | goto err_module_put; | |
1336 | } | |
1da177e4 | 1337 | |
89c8d91e | 1338 | tty_lock(tty); |
73ec06fc | 1339 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1340 | if (retval < 0) |
c8b710b3 | 1341 | goto err_free_tty; |
8b0a88d5 | 1342 | |
04831dc1 JS |
1343 | if (!tty->port) |
1344 | tty->port = driver->ports[idx]; | |
1345 | ||
5d4121c0 JS |
1346 | WARN_RATELIMIT(!tty->port, |
1347 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1348 | __func__, tty->driver->name); | |
1349 | ||
c9a742ab GK |
1350 | retval = tty_ldisc_lock(tty, 5 * HZ); |
1351 | if (retval) | |
1352 | goto err_release_lock; | |
967fab69 JS |
1353 | tty->port->itty = tty; |
1354 | ||
37bdfb07 | 1355 | /* |
1da177e4 | 1356 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1357 | * If we fail here just call release_tty to clean up. No need |
1358 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1359 | */ |
bf970ee4 | 1360 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1361 | if (retval) |
d5543503 | 1362 | goto err_release_tty; |
c9a742ab | 1363 | tty_ldisc_unlock(tty); |
89c8d91e | 1364 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1365 | return tty; |
1da177e4 | 1366 | |
c8b710b3 | 1367 | err_free_tty: |
89c8d91e | 1368 | tty_unlock(tty); |
d5543503 JS |
1369 | free_tty_struct(tty); |
1370 | err_module_put: | |
1da177e4 | 1371 | module_put(driver->owner); |
d5543503 | 1372 | return ERR_PTR(retval); |
1da177e4 | 1373 | |
d5698c28 | 1374 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1375 | err_release_tty: |
c9a742ab | 1376 | tty_ldisc_unlock(tty); |
339f36ba PH |
1377 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1378 | retval, idx); | |
c9a742ab GK |
1379 | err_release_lock: |
1380 | tty_unlock(tty); | |
d5698c28 | 1381 | release_tty(tty, idx); |
73ec06fc | 1382 | return ERR_PTR(retval); |
1da177e4 LT |
1383 | } |
1384 | ||
9061295a JH |
1385 | /** |
1386 | * tty_save_termios() - save tty termios data in driver table | |
1387 | * @tty: tty whose termios data to save | |
1388 | * | |
1389 | * Locking: Caller guarantees serialisation with tty_init_termios(). | |
1390 | */ | |
1391 | void tty_save_termios(struct tty_struct *tty) | |
feebed65 AC |
1392 | { |
1393 | struct ktermios *tp; | |
1394 | int idx = tty->index; | |
36b3c070 AC |
1395 | |
1396 | /* If the port is going to reset then it has no termios to save */ | |
1397 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1398 | return; | |
1399 | ||
1400 | /* Stash the termios data */ | |
1401 | tp = tty->driver->termios[idx]; | |
1402 | if (tp == NULL) { | |
1403 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1404 | if (tp == NULL) |
36b3c070 | 1405 | return; |
4ac5d705 | 1406 | tty->driver->termios[idx] = tp; |
feebed65 | 1407 | } |
36b3c070 | 1408 | *tp = tty->termios; |
feebed65 | 1409 | } |
9061295a | 1410 | EXPORT_SYMBOL_GPL(tty_save_termios); |
feebed65 | 1411 | |
a2965b7b | 1412 | /** |
949aa64f PH |
1413 | * tty_flush_works - flush all works of a tty/pty pair |
1414 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1415 | * |
949aa64f | 1416 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1417 | */ |
1418 | static void tty_flush_works(struct tty_struct *tty) | |
1419 | { | |
1420 | flush_work(&tty->SAK_work); | |
1421 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1422 | if (tty->link) { |
1423 | flush_work(&tty->link->SAK_work); | |
1424 | flush_work(&tty->link->hangup_work); | |
1425 | } | |
a2965b7b | 1426 | } |
feebed65 | 1427 | |
af9b897e | 1428 | /** |
d5698c28 | 1429 | * release_one_tty - release tty structure memory |
9c9f4ded | 1430 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1431 | * |
1432 | * Releases memory associated with a tty structure, and clears out the | |
1433 | * driver table slots. This function is called when a device is no longer | |
1434 | * in use. It also gets called when setup of a device fails. | |
1435 | * | |
1436 | * Locking: | |
af9b897e AC |
1437 | * takes the file list lock internally when working on the list |
1438 | * of ttys that the driver keeps. | |
b50989dc AC |
1439 | * |
1440 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1441 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1442 | */ |
b50989dc | 1443 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1444 | { |
b50989dc AC |
1445 | struct tty_struct *tty = |
1446 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1447 | struct tty_driver *driver = tty->driver; |
b216df53 | 1448 | struct module *owner = driver->owner; |
d5698c28 | 1449 | |
f278a2f7 DY |
1450 | if (tty->ops->cleanup) |
1451 | tty->ops->cleanup(tty); | |
1452 | ||
1da177e4 | 1453 | tty->magic = 0; |
7d7b93c1 | 1454 | tty_driver_kref_put(driver); |
b216df53 | 1455 | module_put(owner); |
d5698c28 | 1456 | |
4a510969 | 1457 | spin_lock(&tty->files_lock); |
1da177e4 | 1458 | list_del_init(&tty->tty_files); |
4a510969 | 1459 | spin_unlock(&tty->files_lock); |
d5698c28 | 1460 | |
6da8d866 ON |
1461 | put_pid(tty->pgrp); |
1462 | put_pid(tty->session); | |
1da177e4 LT |
1463 | free_tty_struct(tty); |
1464 | } | |
1465 | ||
b50989dc AC |
1466 | static void queue_release_one_tty(struct kref *kref) |
1467 | { | |
1468 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1469 | |
b50989dc AC |
1470 | /* The hangup queue is now free so we can reuse it rather than |
1471 | waste a chunk of memory for each port */ | |
1472 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1473 | schedule_work(&tty->hangup_work); | |
1474 | } | |
1475 | ||
9c9f4ded AC |
1476 | /** |
1477 | * tty_kref_put - release a tty kref | |
1478 | * @tty: tty device | |
1479 | * | |
1480 | * Release a reference to a tty device and if need be let the kref | |
1481 | * layer destruct the object for us | |
1482 | */ | |
1483 | ||
1484 | void tty_kref_put(struct tty_struct *tty) | |
1485 | { | |
1486 | if (tty) | |
b50989dc | 1487 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1488 | } |
1489 | EXPORT_SYMBOL(tty_kref_put); | |
1490 | ||
d5698c28 CH |
1491 | /** |
1492 | * release_tty - release tty structure memory | |
1493 | * | |
1494 | * Release both @tty and a possible linked partner (think pty pair), | |
1495 | * and decrement the refcount of the backing module. | |
1496 | * | |
1497 | * Locking: | |
d155255a | 1498 | * tty_mutex |
d5698c28 CH |
1499 | * takes the file list lock internally when working on the list |
1500 | * of ttys that the driver keeps. | |
9c9f4ded | 1501 | * |
d5698c28 CH |
1502 | */ |
1503 | static void release_tty(struct tty_struct *tty, int idx) | |
1504 | { | |
9c9f4ded AC |
1505 | /* This should always be true but check for the moment */ |
1506 | WARN_ON(tty->index != idx); | |
d155255a | 1507 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1508 | if (tty->ops->shutdown) |
1509 | tty->ops->shutdown(tty); | |
9061295a | 1510 | tty_save_termios(tty); |
36b3c070 | 1511 | tty_driver_remove_tty(tty->driver, tty); |
967fab69 | 1512 | tty->port->itty = NULL; |
64e377dc PH |
1513 | if (tty->link) |
1514 | tty->link->port->itty = NULL; | |
e176058f | 1515 | tty_buffer_cancel_work(tty->port); |
f1a4ea79 S |
1516 | if (tty->link) |
1517 | tty_buffer_cancel_work(tty->link->port); | |
36b3c070 | 1518 | |
a211b1af | 1519 | tty_kref_put(tty->link); |
9c9f4ded | 1520 | tty_kref_put(tty); |
d5698c28 CH |
1521 | } |
1522 | ||
955787ca JS |
1523 | /** |
1524 | * tty_release_checks - check a tty before real release | |
1525 | * @tty: tty to check | |
1526 | * @o_tty: link of @tty (if any) | |
1527 | * @idx: index of the tty | |
1528 | * | |
1529 | * Performs some paranoid checking before true release of the @tty. | |
1530 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1531 | */ | |
359b9fb5 | 1532 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1533 | { |
1534 | #ifdef TTY_PARANOIA_CHECK | |
1535 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1536 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1537 | return -1; |
1538 | } | |
1539 | ||
1540 | /* not much to check for devpts */ | |
1541 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1542 | return 0; | |
1543 | ||
1544 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1545 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1546 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1547 | return -1; |
1548 | } | |
955787ca | 1549 | if (tty->driver->other) { |
359b9fb5 PH |
1550 | struct tty_struct *o_tty = tty->link; |
1551 | ||
955787ca | 1552 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1553 | tty_debug(tty, "bad other table[%d] = %p\n", |
1554 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1555 | return -1; |
1556 | } | |
955787ca | 1557 | if (o_tty->link != tty) { |
e2dfa3d3 | 1558 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1559 | return -1; |
1560 | } | |
1561 | } | |
1562 | #endif | |
1563 | return 0; | |
1564 | } | |
1565 | ||
a09ac397 OK |
1566 | /** |
1567 | * tty_kclose - closes tty opened by tty_kopen | |
1568 | * @tty: tty device | |
1569 | * | |
1570 | * Performs the final steps to release and free a tty device. It is the | |
1571 | * same as tty_release_struct except that it also resets TTY_PORT_KOPENED | |
1572 | * flag on tty->port. | |
1573 | */ | |
1574 | void tty_kclose(struct tty_struct *tty) | |
1575 | { | |
1576 | /* | |
1577 | * Ask the line discipline code to release its structures | |
1578 | */ | |
1579 | tty_ldisc_release(tty); | |
1580 | ||
1581 | /* Wait for pending work before tty destruction commmences */ | |
1582 | tty_flush_works(tty); | |
1583 | ||
1584 | tty_debug_hangup(tty, "freeing structure\n"); | |
1585 | /* | |
1586 | * The release_tty function takes care of the details of clearing | |
1587 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1588 | * should be safe as we keep a kref while the tty is locked (so the | |
1589 | * unlock never unlocks a freed tty). | |
1590 | */ | |
1591 | mutex_lock(&tty_mutex); | |
1592 | tty_port_set_kopened(tty->port, 0); | |
1593 | release_tty(tty, tty->index); | |
1594 | mutex_unlock(&tty_mutex); | |
1595 | } | |
1596 | EXPORT_SYMBOL_GPL(tty_kclose); | |
1597 | ||
9ed90d20 RH |
1598 | /** |
1599 | * tty_release_struct - release a tty struct | |
1600 | * @tty: tty device | |
1601 | * @idx: index of the tty | |
1602 | * | |
1603 | * Performs the final steps to release and free a tty device. It is | |
1604 | * roughly the reverse of tty_init_dev. | |
1605 | */ | |
1606 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1607 | { | |
1608 | /* | |
1609 | * Ask the line discipline code to release its structures | |
1610 | */ | |
1611 | tty_ldisc_release(tty); | |
1612 | ||
1613 | /* Wait for pending work before tty destruction commmences */ | |
1614 | tty_flush_works(tty); | |
1615 | ||
1616 | tty_debug_hangup(tty, "freeing structure\n"); | |
1617 | /* | |
1618 | * The release_tty function takes care of the details of clearing | |
1619 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1620 | * should be safe as we keep a kref while the tty is locked (so the | |
1621 | * unlock never unlocks a freed tty). | |
1622 | */ | |
1623 | mutex_lock(&tty_mutex); | |
1624 | release_tty(tty, idx); | |
1625 | mutex_unlock(&tty_mutex); | |
1626 | } | |
1627 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1628 | ||
eeb89d91 AC |
1629 | /** |
1630 | * tty_release - vfs callback for close | |
1631 | * @inode: inode of tty | |
1632 | * @filp: file pointer for handle to tty | |
1633 | * | |
1634 | * Called the last time each file handle is closed that references | |
1635 | * this tty. There may however be several such references. | |
1636 | * | |
1637 | * Locking: | |
1638 | * Takes bkl. See tty_release_dev | |
1639 | * | |
1da177e4 LT |
1640 | * Even releasing the tty structures is a tricky business.. We have |
1641 | * to be very careful that the structures are all released at the | |
1642 | * same time, as interrupts might otherwise get the wrong pointers. | |
1643 | * | |
1644 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1645 | * lead to double frees or releasing memory still in use. | |
1646 | */ | |
eeb89d91 AC |
1647 | |
1648 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1649 | { |
d996b62a | 1650 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1651 | struct tty_struct *o_tty = NULL; |
1652 | int do_sleep, final; | |
1da177e4 | 1653 | int idx; |
37b16457 | 1654 | long timeout = 0; |
494c1eac | 1655 | int once = 1; |
37bdfb07 | 1656 | |
9de44bd6 | 1657 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1658 | return 0; |
1da177e4 | 1659 | |
89c8d91e | 1660 | tty_lock(tty); |
9de44bd6 | 1661 | check_tty_count(tty, __func__); |
1da177e4 | 1662 | |
ec79d605 | 1663 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1664 | |
1665 | idx = tty->index; | |
7ffb6da9 PH |
1666 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1667 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1668 | o_tty = tty->link; | |
1da177e4 | 1669 | |
359b9fb5 | 1670 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1671 | tty_unlock(tty); |
eeb89d91 | 1672 | return 0; |
1da177e4 | 1673 | } |
1da177e4 | 1674 | |
d435cefe | 1675 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1676 | |
f34d7a5b AC |
1677 | if (tty->ops->close) |
1678 | tty->ops->close(tty, filp); | |
1da177e4 | 1679 | |
2aff5e2b PH |
1680 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1681 | tty_lock_slave(o_tty); | |
1682 | ||
1da177e4 LT |
1683 | /* |
1684 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1685 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1686 | * wait queues and kick everyone out _before_ actually starting to | |
1687 | * close. This ensures that we won't block while releasing the tty | |
1688 | * structure. | |
1689 | * | |
1690 | * The test for the o_tty closing is necessary, since the master and | |
1691 | * slave sides may close in any order. If the slave side closes out | |
1692 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1693 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1694 | * so we do it now. |
1da177e4 LT |
1695 | */ |
1696 | while (1) { | |
1da177e4 LT |
1697 | do_sleep = 0; |
1698 | ||
324c1650 | 1699 | if (tty->count <= 1) { |
1da177e4 | 1700 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1701 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1702 | do_sleep++; |
1703 | } | |
1704 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1705 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1706 | do_sleep++; |
1707 | } | |
1708 | } | |
7ffb6da9 | 1709 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1710 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1711 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1712 | do_sleep++; |
1713 | } | |
1714 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1715 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1716 | do_sleep++; |
1717 | } | |
1718 | } | |
1719 | if (!do_sleep) | |
1720 | break; | |
1721 | ||
494c1eac PH |
1722 | if (once) { |
1723 | once = 0; | |
339f36ba | 1724 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1725 | } |
37b16457 PH |
1726 | schedule_timeout_killable(timeout); |
1727 | if (timeout < 120 * HZ) | |
1728 | timeout = 2 * timeout + 1; | |
1729 | else | |
1730 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1731 | } |
1da177e4 | 1732 | |
7ffb6da9 | 1733 | if (o_tty) { |
1da177e4 | 1734 | if (--o_tty->count < 0) { |
339f36ba | 1735 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1736 | o_tty->count = 0; |
1737 | } | |
1738 | } | |
1739 | if (--tty->count < 0) { | |
339f36ba | 1740 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1741 | tty->count = 0; |
1742 | } | |
37bdfb07 | 1743 | |
1da177e4 LT |
1744 | /* |
1745 | * We've decremented tty->count, so we need to remove this file | |
1746 | * descriptor off the tty->tty_files list; this serves two | |
1747 | * purposes: | |
1748 | * - check_tty_count sees the correct number of file descriptors | |
1749 | * associated with this tty. | |
1750 | * - do_tty_hangup no longer sees this file descriptor as | |
1751 | * something that needs to be handled for hangups. | |
1752 | */ | |
d996b62a | 1753 | tty_del_file(filp); |
1da177e4 LT |
1754 | |
1755 | /* | |
1756 | * Perform some housekeeping before deciding whether to return. | |
1757 | * | |
1da177e4 LT |
1758 | * If _either_ side is closing, make sure there aren't any |
1759 | * processes that still think tty or o_tty is their controlling | |
1760 | * tty. | |
1761 | */ | |
324c1650 | 1762 | if (!tty->count) { |
1da177e4 | 1763 | read_lock(&tasklist_lock); |
24ec839c | 1764 | session_clear_tty(tty->session); |
7ffb6da9 | 1765 | if (o_tty) |
24ec839c | 1766 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1767 | read_unlock(&tasklist_lock); |
1768 | } | |
1769 | ||
324c1650 | 1770 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1771 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1772 | |
2aff5e2b PH |
1773 | tty_unlock_slave(o_tty); |
1774 | tty_unlock(tty); | |
1775 | ||
04980706 | 1776 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1777 | cannot be re-opened by a racing opener */ |
da965822 | 1778 | |
324c1650 | 1779 | if (!final) |
eeb89d91 | 1780 | return 0; |
37bdfb07 | 1781 | |
accff793 | 1782 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1783 | |
9ed90d20 | 1784 | tty_release_struct(tty, idx); |
eeb89d91 | 1785 | return 0; |
1da177e4 LT |
1786 | } |
1787 | ||
b82154ac | 1788 | /** |
52494eeb | 1789 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1790 | * @device: device number |
1791 | * @filp: file pointer to tty | |
52494eeb PH |
1792 | * @return: locked tty of the current task iff @device is /dev/tty |
1793 | * | |
1794 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1795 | * |
1796 | * We cannot return driver and index like for the other nodes because | |
1797 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1798 | */ | |
1799 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1800 | { | |
1801 | struct tty_struct *tty; | |
52494eeb | 1802 | int retval; |
b82154ac JS |
1803 | |
1804 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1805 | return NULL; | |
1806 | ||
1807 | tty = get_current_tty(); | |
1808 | if (!tty) | |
1809 | return ERR_PTR(-ENXIO); | |
1810 | ||
1811 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1812 | /* noctty = 1; */ | |
52494eeb PH |
1813 | tty_lock(tty); |
1814 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1815 | ||
1816 | retval = tty_reopen(tty); | |
1817 | if (retval < 0) { | |
1818 | tty_unlock(tty); | |
1819 | tty = ERR_PTR(retval); | |
1820 | } | |
b82154ac JS |
1821 | return tty; |
1822 | } | |
1823 | ||
5b5e7040 JS |
1824 | /** |
1825 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1826 | * @device: device number | |
1827 | * @filp: file pointer to tty | |
5b5e7040 JS |
1828 | * @index: index for the device in the @return driver |
1829 | * @return: driver for this inode (with increased refcount) | |
1830 | * | |
1831 | * If @return is not erroneous, the caller is responsible to decrement the | |
1832 | * refcount by tty_driver_kref_put. | |
1833 | * | |
1834 | * Locking: tty_mutex protects get_tty_driver | |
1835 | */ | |
1836 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1837 | int *index) |
5b5e7040 JS |
1838 | { |
1839 | struct tty_driver *driver; | |
1840 | ||
2cd0050c | 1841 | switch (device) { |
5b5e7040 | 1842 | #ifdef CONFIG_VT |
2cd0050c | 1843 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1844 | extern struct tty_driver *console_driver; |
1845 | driver = tty_driver_kref_get(console_driver); | |
1846 | *index = fg_console; | |
2cd0050c | 1847 | break; |
5b5e7040 JS |
1848 | } |
1849 | #endif | |
2cd0050c | 1850 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1851 | struct tty_driver *console_driver = console_device(index); |
1852 | if (console_driver) { | |
1853 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1854 | if (driver && filp) { |
5b5e7040 JS |
1855 | /* Don't let /dev/console block */ |
1856 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1857 | break; |
5b5e7040 JS |
1858 | } |
1859 | } | |
1860 | return ERR_PTR(-ENODEV); | |
1861 | } | |
2cd0050c JS |
1862 | default: |
1863 | driver = get_tty_driver(device, index); | |
1864 | if (!driver) | |
1865 | return ERR_PTR(-ENODEV); | |
1866 | break; | |
1867 | } | |
5b5e7040 JS |
1868 | return driver; |
1869 | } | |
1870 | ||
a09ac397 OK |
1871 | /** |
1872 | * tty_kopen - open a tty device for kernel | |
1873 | * @device: dev_t of device to open | |
1874 | * | |
1875 | * Opens tty exclusively for kernel. Performs the driver lookup, | |
1876 | * makes sure it's not already opened and performs the first-time | |
1877 | * tty initialization. | |
1878 | * | |
1879 | * Returns the locked initialized &tty_struct | |
1880 | * | |
1881 | * Claims the global tty_mutex to serialize: | |
1882 | * - concurrent first-time tty initialization | |
1883 | * - concurrent tty driver removal w/ lookup | |
1884 | * - concurrent tty removal from driver table | |
1885 | */ | |
1886 | struct tty_struct *tty_kopen(dev_t device) | |
1887 | { | |
1888 | struct tty_struct *tty; | |
1889 | struct tty_driver *driver = NULL; | |
1890 | int index = -1; | |
1891 | ||
1892 | mutex_lock(&tty_mutex); | |
1893 | driver = tty_lookup_driver(device, NULL, &index); | |
1894 | if (IS_ERR(driver)) { | |
1895 | mutex_unlock(&tty_mutex); | |
1896 | return ERR_CAST(driver); | |
1897 | } | |
1898 | ||
1899 | /* check whether we're reopening an existing tty */ | |
1900 | tty = tty_driver_lookup_tty(driver, NULL, index); | |
1901 | if (IS_ERR(tty)) | |
1902 | goto out; | |
1903 | ||
1904 | if (tty) { | |
1905 | /* drop kref from tty_driver_lookup_tty() */ | |
1906 | tty_kref_put(tty); | |
1907 | tty = ERR_PTR(-EBUSY); | |
1908 | } else { /* tty_init_dev returns tty with the tty_lock held */ | |
1909 | tty = tty_init_dev(driver, index); | |
1910 | if (IS_ERR(tty)) | |
1911 | goto out; | |
1912 | tty_port_set_kopened(tty->port, 1); | |
1913 | } | |
1914 | out: | |
1915 | mutex_unlock(&tty_mutex); | |
1916 | tty_driver_kref_put(driver); | |
1917 | return tty; | |
1918 | } | |
1919 | EXPORT_SYMBOL_GPL(tty_kopen); | |
1920 | ||
d6203d0c PH |
1921 | /** |
1922 | * tty_open_by_driver - open a tty device | |
1923 | * @device: dev_t of device to open | |
1924 | * @inode: inode of device file | |
1925 | * @filp: file pointer to tty | |
1926 | * | |
1927 | * Performs the driver lookup, checks for a reopen, or otherwise | |
1928 | * performs the first-time tty initialization. | |
1929 | * | |
1930 | * Returns the locked initialized or re-opened &tty_struct | |
1931 | * | |
1932 | * Claims the global tty_mutex to serialize: | |
1933 | * - concurrent first-time tty initialization | |
1934 | * - concurrent tty driver removal w/ lookup | |
1935 | * - concurrent tty removal from driver table | |
1936 | */ | |
a033c3b1 | 1937 | static struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, |
d6203d0c PH |
1938 | struct file *filp) |
1939 | { | |
1940 | struct tty_struct *tty; | |
1941 | struct tty_driver *driver = NULL; | |
1942 | int index = -1; | |
1943 | int retval; | |
1944 | ||
1945 | mutex_lock(&tty_mutex); | |
1946 | driver = tty_lookup_driver(device, filp, &index); | |
1947 | if (IS_ERR(driver)) { | |
1948 | mutex_unlock(&tty_mutex); | |
1949 | return ERR_CAST(driver); | |
1950 | } | |
1951 | ||
1952 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 1953 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
1954 | if (IS_ERR(tty)) { |
1955 | mutex_unlock(&tty_mutex); | |
1956 | goto out; | |
1957 | } | |
1958 | ||
1959 | if (tty) { | |
a09ac397 OK |
1960 | if (tty_port_kopened(tty->port)) { |
1961 | tty_kref_put(tty); | |
1962 | mutex_unlock(&tty_mutex); | |
1963 | tty = ERR_PTR(-EBUSY); | |
1964 | goto out; | |
1965 | } | |
d6203d0c PH |
1966 | mutex_unlock(&tty_mutex); |
1967 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 1968 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
1969 | if (retval) { |
1970 | if (retval == -EINTR) | |
1971 | retval = -ERESTARTSYS; | |
1972 | tty = ERR_PTR(retval); | |
1973 | goto out; | |
1974 | } | |
d6203d0c PH |
1975 | retval = tty_reopen(tty); |
1976 | if (retval < 0) { | |
1977 | tty_unlock(tty); | |
1978 | tty = ERR_PTR(retval); | |
1979 | } | |
1980 | } else { /* Returns with the tty_lock held for now */ | |
1981 | tty = tty_init_dev(driver, index); | |
1982 | mutex_unlock(&tty_mutex); | |
1983 | } | |
1984 | out: | |
1985 | tty_driver_kref_put(driver); | |
1986 | return tty; | |
1987 | } | |
1988 | ||
af9b897e | 1989 | /** |
eeb89d91 | 1990 | * tty_open - open a tty device |
af9b897e AC |
1991 | * @inode: inode of device file |
1992 | * @filp: file pointer to tty | |
1da177e4 | 1993 | * |
af9b897e AC |
1994 | * tty_open and tty_release keep up the tty count that contains the |
1995 | * number of opens done on a tty. We cannot use the inode-count, as | |
1996 | * different inodes might point to the same tty. | |
1da177e4 | 1997 | * |
af9b897e AC |
1998 | * Open-counting is needed for pty masters, as well as for keeping |
1999 | * track of serial lines: DTR is dropped when the last close happens. | |
2000 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2001 | * | |
2002 | * The termios state of a pty is reset on first open so that | |
2003 | * settings don't persist across reuse. | |
2004 | * | |
5b5e7040 | 2005 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2006 | * tty->count should protect the rest. |
2007 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2008 | * |
2009 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2010 | * tty_mutex | |
1da177e4 | 2011 | */ |
af9b897e | 2012 | |
eeb89d91 | 2013 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2014 | { |
b82154ac | 2015 | struct tty_struct *tty; |
1da177e4 | 2016 | int noctty, retval; |
1da177e4 | 2017 | dev_t device = inode->i_rdev; |
846c151a | 2018 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2019 | |
2020 | nonseekable_open(inode, filp); | |
37bdfb07 | 2021 | |
1da177e4 | 2022 | retry_open: |
fa90e1c9 JS |
2023 | retval = tty_alloc_file(filp); |
2024 | if (retval) | |
2025 | return -ENOMEM; | |
2026 | ||
b82154ac | 2027 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
2028 | if (!tty) |
2029 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 2030 | |
eeb89d91 | 2031 | if (IS_ERR(tty)) { |
d6203d0c | 2032 | tty_free_file(filp); |
ba5db448 | 2033 | retval = PTR_ERR(tty); |
7f22f6c9 | 2034 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2035 | return retval; |
7f22f6c9 PH |
2036 | schedule(); |
2037 | goto retry_open; | |
eeb89d91 | 2038 | } |
1da177e4 | 2039 | |
fa90e1c9 | 2040 | tty_add_file(tty, filp); |
d996b62a | 2041 | |
9de44bd6 | 2042 | check_tty_count(tty, __func__); |
d435cefe | 2043 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2044 | |
909bc774 HRK |
2045 | if (tty->ops->open) |
2046 | retval = tty->ops->open(tty, filp); | |
2047 | else | |
2048 | retval = -ENODEV; | |
1da177e4 LT |
2049 | filp->f_flags = saved_flags; |
2050 | ||
1da177e4 | 2051 | if (retval) { |
d435cefe | 2052 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2053 | |
89c8d91e | 2054 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2055 | tty_release(inode, filp); |
64ba3dc3 | 2056 | if (retval != -ERESTARTSYS) |
1da177e4 | 2057 | return retval; |
64ba3dc3 AB |
2058 | |
2059 | if (signal_pending(current)) | |
1da177e4 | 2060 | return retval; |
64ba3dc3 | 2061 | |
1da177e4 LT |
2062 | schedule(); |
2063 | /* | |
2064 | * Need to reset f_op in case a hangup happened. | |
2065 | */ | |
1256937f | 2066 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2067 | filp->f_op = &tty_fops; |
2068 | goto retry_open; | |
2069 | } | |
d4855e1f | 2070 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2071 | |
11e1d4aa | 2072 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
2073 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
2074 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
2075 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2076 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2077 | if (!noctty) | |
2078 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 2079 | tty_unlock(tty); |
1da177e4 LT |
2080 | return 0; |
2081 | } | |
2082 | ||
39d95b9d JC |
2083 | |
2084 | ||
af9b897e AC |
2085 | /** |
2086 | * tty_poll - check tty status | |
2087 | * @filp: file being polled | |
2088 | * @wait: poll wait structures to update | |
2089 | * | |
2090 | * Call the line discipline polling method to obtain the poll | |
2091 | * status of the device. | |
2092 | * | |
2093 | * Locking: locks called line discipline but ldisc poll method | |
2094 | * may be re-entered freely by other callers. | |
2095 | */ | |
2096 | ||
37bdfb07 | 2097 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2098 | { |
d996b62a | 2099 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2100 | struct tty_ldisc *ld; |
2101 | int ret = 0; | |
2102 | ||
6131ffaa | 2103 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2104 | return 0; |
37bdfb07 | 2105 | |
1da177e4 | 2106 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2107 | if (!ld) |
2108 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2109 | if (ld->ops->poll) |
c961bfb1 | 2110 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2111 | tty_ldisc_deref(ld); |
2112 | return ret; | |
2113 | } | |
2114 | ||
ec79d605 | 2115 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2116 | { |
d996b62a | 2117 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2118 | unsigned long flags; |
5d1e3230 | 2119 | int retval = 0; |
1da177e4 | 2120 | |
6131ffaa | 2121 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2122 | goto out; |
37bdfb07 | 2123 | |
1da177e4 LT |
2124 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2125 | if (retval <= 0) | |
5d1e3230 | 2126 | goto out; |
f6c8dbe6 | 2127 | |
1da177e4 | 2128 | if (on) { |
ab521dc0 EB |
2129 | enum pid_type type; |
2130 | struct pid *pid; | |
f6c8dbe6 | 2131 | |
47f86834 | 2132 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2133 | if (tty->pgrp) { |
2134 | pid = tty->pgrp; | |
2135 | type = PIDTYPE_PGID; | |
2136 | } else { | |
2137 | pid = task_pid(current); | |
2138 | type = PIDTYPE_PID; | |
2139 | } | |
80e1e823 | 2140 | get_pid(pid); |
70362511 | 2141 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2142 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2143 | put_pid(pid); |
e0b93edd | 2144 | retval = 0; |
1da177e4 | 2145 | } |
5d1e3230 | 2146 | out: |
ec79d605 AB |
2147 | return retval; |
2148 | } | |
2149 | ||
2150 | static int tty_fasync(int fd, struct file *filp, int on) | |
2151 | { | |
89c8d91e | 2152 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2153 | int retval = -ENOTTY; |
89c8d91e AC |
2154 | |
2155 | tty_lock(tty); | |
a8f3a297 PH |
2156 | if (!tty_hung_up_p(filp)) |
2157 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2158 | tty_unlock(tty); |
2159 | ||
5d1e3230 | 2160 | return retval; |
1da177e4 LT |
2161 | } |
2162 | ||
af9b897e AC |
2163 | /** |
2164 | * tiocsti - fake input character | |
2165 | * @tty: tty to fake input into | |
2166 | * @p: pointer to character | |
2167 | * | |
3a4fa0a2 | 2168 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2169 | * input management. |
2170 | * | |
2171 | * FIXME: does not honour flow control ?? | |
2172 | * | |
2173 | * Locking: | |
137084bb | 2174 | * Called functions take tty_ldiscs_lock |
af9b897e | 2175 | * current->signal->tty check is safe without locks |
28298232 AC |
2176 | * |
2177 | * FIXME: may race normal receive processing | |
af9b897e AC |
2178 | */ |
2179 | ||
1da177e4 LT |
2180 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2181 | { | |
2182 | char ch, mbz = 0; | |
2183 | struct tty_ldisc *ld; | |
37bdfb07 | 2184 | |
1da177e4 LT |
2185 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2186 | return -EPERM; | |
2187 | if (get_user(ch, p)) | |
2188 | return -EFAULT; | |
1e641743 | 2189 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2190 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2191 | if (!ld) |
2192 | return -EIO; | |
ea8f67b2 GKH |
2193 | if (ld->ops->receive_buf) |
2194 | ld->ops->receive_buf(tty, &ch, &mbz, 1); | |
1da177e4 LT |
2195 | tty_ldisc_deref(ld); |
2196 | return 0; | |
2197 | } | |
2198 | ||
af9b897e AC |
2199 | /** |
2200 | * tiocgwinsz - implement window query ioctl | |
2201 | * @tty; tty | |
2202 | * @arg: user buffer for result | |
2203 | * | |
808a0d38 | 2204 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2205 | * |
dee4a0be | 2206 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2207 | * is consistent. |
af9b897e AC |
2208 | */ |
2209 | ||
37bdfb07 | 2210 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2211 | { |
808a0d38 AC |
2212 | int err; |
2213 | ||
dee4a0be | 2214 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2215 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2216 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2217 | |
2218 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2219 | } |
2220 | ||
af9b897e | 2221 | /** |
8c9a9dd0 AC |
2222 | * tty_do_resize - resize event |
2223 | * @tty: tty being resized | |
8c9a9dd0 AC |
2224 | * @rows: rows (character) |
2225 | * @cols: cols (character) | |
2226 | * | |
3ad2f3fb | 2227 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2228 | * peform a terminal resize correctly |
af9b897e AC |
2229 | */ |
2230 | ||
fc6f6238 | 2231 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2232 | { |
fc6f6238 | 2233 | struct pid *pgrp; |
1da177e4 | 2234 | |
fc6f6238 | 2235 | /* Lock the tty */ |
dee4a0be | 2236 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2237 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2238 | goto done; |
47f86834 | 2239 | |
5b239542 PH |
2240 | /* Signal the foreground process group */ |
2241 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2242 | if (pgrp) |
2243 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2244 | put_pid(pgrp); |
47f86834 | 2245 | |
8c9a9dd0 | 2246 | tty->winsize = *ws; |
ca9bda00 | 2247 | done: |
dee4a0be | 2248 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2249 | return 0; |
2250 | } | |
4d334fd1 | 2251 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2252 | |
8c9a9dd0 AC |
2253 | /** |
2254 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2255 | * @tty; tty side of tty |
8c9a9dd0 AC |
2256 | * @arg: user buffer for result |
2257 | * | |
2258 | * Copies the user idea of the window size to the kernel. Traditionally | |
2259 | * this is just advisory information but for the Linux console it | |
2260 | * actually has driver level meaning and triggers a VC resize. | |
2261 | * | |
2262 | * Locking: | |
25985edc | 2263 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2264 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2265 | * then calls into the default method. | |
2266 | */ | |
2267 | ||
fc6f6238 | 2268 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2269 | { |
2270 | struct winsize tmp_ws; | |
2271 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2272 | return -EFAULT; | |
2273 | ||
2274 | if (tty->ops->resize) | |
fc6f6238 | 2275 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2276 | else |
fc6f6238 | 2277 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2278 | } |
2279 | ||
af9b897e AC |
2280 | /** |
2281 | * tioccons - allow admin to move logical console | |
2282 | * @file: the file to become console | |
2283 | * | |
25985edc | 2284 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2285 | * |
2286 | * Locking: uses redirect_lock to guard the redirect information | |
2287 | */ | |
2288 | ||
1da177e4 LT |
2289 | static int tioccons(struct file *file) |
2290 | { | |
2291 | if (!capable(CAP_SYS_ADMIN)) | |
2292 | return -EPERM; | |
2293 | if (file->f_op->write == redirected_tty_write) { | |
2294 | struct file *f; | |
2295 | spin_lock(&redirect_lock); | |
2296 | f = redirect; | |
2297 | redirect = NULL; | |
2298 | spin_unlock(&redirect_lock); | |
2299 | if (f) | |
2300 | fput(f); | |
2301 | return 0; | |
2302 | } | |
2303 | spin_lock(&redirect_lock); | |
2304 | if (redirect) { | |
2305 | spin_unlock(&redirect_lock); | |
2306 | return -EBUSY; | |
2307 | } | |
cb0942b8 | 2308 | redirect = get_file(file); |
1da177e4 LT |
2309 | spin_unlock(&redirect_lock); |
2310 | return 0; | |
2311 | } | |
2312 | ||
af9b897e AC |
2313 | /** |
2314 | * fionbio - non blocking ioctl | |
2315 | * @file: file to set blocking value | |
2316 | * @p: user parameter | |
2317 | * | |
2318 | * Historical tty interfaces had a blocking control ioctl before | |
2319 | * the generic functionality existed. This piece of history is preserved | |
2320 | * in the expected tty API of posix OS's. | |
2321 | * | |
6146b9af | 2322 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2323 | */ |
1da177e4 LT |
2324 | |
2325 | static int fionbio(struct file *file, int __user *p) | |
2326 | { | |
2327 | int nonblock; | |
2328 | ||
2329 | if (get_user(nonblock, p)) | |
2330 | return -EFAULT; | |
2331 | ||
db1dd4d3 | 2332 | spin_lock(&file->f_lock); |
1da177e4 LT |
2333 | if (nonblock) |
2334 | file->f_flags |= O_NONBLOCK; | |
2335 | else | |
2336 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2337 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2338 | return 0; |
2339 | } | |
2340 | ||
af9b897e AC |
2341 | /** |
2342 | * tiocsetd - set line discipline | |
2343 | * @tty: tty device | |
2344 | * @p: pointer to user data | |
2345 | * | |
2346 | * Set the line discipline according to user request. | |
2347 | * | |
2348 | * Locking: see tty_set_ldisc, this function is just a helper | |
2349 | */ | |
2350 | ||
1da177e4 LT |
2351 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2352 | { | |
c12da96f | 2353 | int disc; |
04f378b1 | 2354 | int ret; |
1da177e4 | 2355 | |
c12da96f | 2356 | if (get_user(disc, p)) |
1da177e4 | 2357 | return -EFAULT; |
04f378b1 | 2358 | |
c12da96f | 2359 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2360 | |
2361 | return ret; | |
1da177e4 LT |
2362 | } |
2363 | ||
5c17c861 PH |
2364 | /** |
2365 | * tiocgetd - get line discipline | |
2366 | * @tty: tty device | |
2367 | * @p: pointer to user data | |
2368 | * | |
2369 | * Retrieves the line discipline id directly from the ldisc. | |
2370 | * | |
2371 | * Locking: waits for ldisc reference (in case the line discipline | |
2372 | * is changing or the tty is being hungup) | |
2373 | */ | |
2374 | ||
2375 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2376 | { | |
2377 | struct tty_ldisc *ld; | |
2378 | int ret; | |
2379 | ||
2380 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2381 | if (!ld) |
2382 | return -EIO; | |
5c17c861 PH |
2383 | ret = put_user(ld->ops->num, p); |
2384 | tty_ldisc_deref(ld); | |
2385 | return ret; | |
2386 | } | |
2387 | ||
af9b897e AC |
2388 | /** |
2389 | * send_break - performed time break | |
2390 | * @tty: device to break on | |
2391 | * @duration: timeout in mS | |
2392 | * | |
2393 | * Perform a timed break on hardware that lacks its own driver level | |
2394 | * timed break functionality. | |
2395 | * | |
2396 | * Locking: | |
28298232 | 2397 | * atomic_write_lock serializes |
af9b897e | 2398 | * |
af9b897e AC |
2399 | */ |
2400 | ||
b20f3ae5 | 2401 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2402 | { |
9e98966c AC |
2403 | int retval; |
2404 | ||
2405 | if (tty->ops->break_ctl == NULL) | |
2406 | return 0; | |
2407 | ||
2408 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2409 | retval = tty->ops->break_ctl(tty, duration); | |
2410 | else { | |
2411 | /* Do the work ourselves */ | |
2412 | if (tty_write_lock(tty, 0) < 0) | |
2413 | return -EINTR; | |
2414 | retval = tty->ops->break_ctl(tty, -1); | |
2415 | if (retval) | |
2416 | goto out; | |
2417 | if (!signal_pending(current)) | |
2418 | msleep_interruptible(duration); | |
2419 | retval = tty->ops->break_ctl(tty, 0); | |
2420 | out: | |
2421 | tty_write_unlock(tty); | |
2422 | if (signal_pending(current)) | |
2423 | retval = -EINTR; | |
2424 | } | |
2425 | return retval; | |
1da177e4 LT |
2426 | } |
2427 | ||
af9b897e | 2428 | /** |
f34d7a5b | 2429 | * tty_tiocmget - get modem status |
af9b897e AC |
2430 | * @tty: tty device |
2431 | * @file: user file pointer | |
2432 | * @p: pointer to result | |
2433 | * | |
2434 | * Obtain the modem status bits from the tty driver if the feature | |
2435 | * is supported. Return -EINVAL if it is not available. | |
2436 | * | |
2437 | * Locking: none (up to the driver) | |
2438 | */ | |
2439 | ||
60b33c13 | 2440 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2441 | { |
2442 | int retval = -EINVAL; | |
2443 | ||
f34d7a5b | 2444 | if (tty->ops->tiocmget) { |
60b33c13 | 2445 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2446 | |
2447 | if (retval >= 0) | |
2448 | retval = put_user(retval, p); | |
2449 | } | |
2450 | return retval; | |
2451 | } | |
2452 | ||
af9b897e | 2453 | /** |
f34d7a5b | 2454 | * tty_tiocmset - set modem status |
af9b897e | 2455 | * @tty: tty device |
af9b897e AC |
2456 | * @cmd: command - clear bits, set bits or set all |
2457 | * @p: pointer to desired bits | |
2458 | * | |
2459 | * Set the modem status bits from the tty driver if the feature | |
2460 | * is supported. Return -EINVAL if it is not available. | |
2461 | * | |
2462 | * Locking: none (up to the driver) | |
2463 | */ | |
2464 | ||
20b9d177 | 2465 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2466 | unsigned __user *p) |
2467 | { | |
ae677517 AC |
2468 | int retval; |
2469 | unsigned int set, clear, val; | |
1da177e4 | 2470 | |
ae677517 AC |
2471 | if (tty->ops->tiocmset == NULL) |
2472 | return -EINVAL; | |
1da177e4 | 2473 | |
ae677517 AC |
2474 | retval = get_user(val, p); |
2475 | if (retval) | |
2476 | return retval; | |
2477 | set = clear = 0; | |
2478 | switch (cmd) { | |
2479 | case TIOCMBIS: | |
2480 | set = val; | |
2481 | break; | |
2482 | case TIOCMBIC: | |
2483 | clear = val; | |
2484 | break; | |
2485 | case TIOCMSET: | |
2486 | set = val; | |
2487 | clear = ~val; | |
2488 | break; | |
2489 | } | |
2490 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2491 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2492 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2493 | } |
2494 | ||
d281da7f AC |
2495 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2496 | { | |
2497 | int retval = -EINVAL; | |
2498 | struct serial_icounter_struct icount; | |
2499 | memset(&icount, 0, sizeof(icount)); | |
2500 | if (tty->ops->get_icount) | |
2501 | retval = tty->ops->get_icount(tty, &icount); | |
2502 | if (retval != 0) | |
2503 | return retval; | |
2504 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2505 | return -EFAULT; | |
2506 | return 0; | |
2507 | } | |
2508 | ||
8a8ae62f JS |
2509 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2510 | { | |
2511 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2512 | DEFAULT_RATELIMIT_INTERVAL, | |
2513 | DEFAULT_RATELIMIT_BURST); | |
2514 | char comm[TASK_COMM_LEN]; | |
2515 | int flags; | |
2516 | ||
2517 | if (get_user(flags, &ss->flags)) | |
2518 | return; | |
2519 | ||
2520 | flags &= ASYNC_DEPRECATED; | |
2521 | ||
2522 | if (flags && __ratelimit(&depr_flags)) | |
d437fa91 JP |
2523 | pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", |
2524 | __func__, get_task_comm(comm, current), flags); | |
8a8ae62f JS |
2525 | } |
2526 | ||
8f166e00 PH |
2527 | /* |
2528 | * if pty, return the slave side (real_tty) | |
2529 | * otherwise, return self | |
2530 | */ | |
2531 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2532 | { |
2533 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2534 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2535 | tty = tty->link; | |
2536 | return tty; | |
2537 | } | |
e8b70e7d | 2538 | |
1da177e4 LT |
2539 | /* |
2540 | * Split this up, as gcc can choke on it otherwise.. | |
2541 | */ | |
04f378b1 | 2542 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2543 | { |
d996b62a NP |
2544 | struct tty_struct *tty = file_tty(file); |
2545 | struct tty_struct *real_tty; | |
1da177e4 LT |
2546 | void __user *p = (void __user *)arg; |
2547 | int retval; | |
2548 | struct tty_ldisc *ld; | |
37bdfb07 | 2549 | |
6131ffaa | 2550 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2551 | return -EINVAL; |
2552 | ||
e8b70e7d | 2553 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2554 | |
2555 | /* | |
2556 | * Factor out some common prep work | |
2557 | */ | |
2558 | switch (cmd) { | |
2559 | case TIOCSETD: | |
2560 | case TIOCSBRK: | |
2561 | case TIOCCBRK: | |
2562 | case TCSBRK: | |
37bdfb07 | 2563 | case TCSBRKP: |
1da177e4 LT |
2564 | retval = tty_check_change(tty); |
2565 | if (retval) | |
2566 | return retval; | |
2567 | if (cmd != TIOCCBRK) { | |
2568 | tty_wait_until_sent(tty, 0); | |
2569 | if (signal_pending(current)) | |
2570 | return -EINTR; | |
2571 | } | |
2572 | break; | |
2573 | } | |
2574 | ||
9e98966c AC |
2575 | /* |
2576 | * Now do the stuff. | |
2577 | */ | |
1da177e4 | 2578 | switch (cmd) { |
37bdfb07 AC |
2579 | case TIOCSTI: |
2580 | return tiocsti(tty, p); | |
2581 | case TIOCGWINSZ: | |
8f520021 | 2582 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2583 | case TIOCSWINSZ: |
fc6f6238 | 2584 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2585 | case TIOCCONS: |
2586 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2587 | case FIONBIO: | |
2588 | return fionbio(file, p); | |
2589 | case TIOCEXCL: | |
2590 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2591 | return 0; | |
2592 | case TIOCNXCL: | |
2593 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2594 | return 0; | |
84fd7bdf CG |
2595 | case TIOCGEXCL: |
2596 | { | |
2597 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2598 | return put_user(excl, (int __user *)p); | |
2599 | } | |
37bdfb07 | 2600 | case TIOCGETD: |
5c17c861 | 2601 | return tiocgetd(tty, p); |
37bdfb07 AC |
2602 | case TIOCSETD: |
2603 | return tiocsetd(tty, p); | |
3c95c985 KS |
2604 | case TIOCVHANGUP: |
2605 | if (!capable(CAP_SYS_ADMIN)) | |
2606 | return -EPERM; | |
2607 | tty_vhangup(tty); | |
2608 | return 0; | |
b7b8de08 WF |
2609 | case TIOCGDEV: |
2610 | { | |
2611 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2612 | return put_user(ret, (unsigned int __user *)p); | |
2613 | } | |
37bdfb07 AC |
2614 | /* |
2615 | * Break handling | |
2616 | */ | |
2617 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2618 | if (tty->ops->break_ctl) |
9e98966c | 2619 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2620 | return 0; |
37bdfb07 | 2621 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2622 | if (tty->ops->break_ctl) |
9e98966c | 2623 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2624 | return 0; |
2625 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2626 | /* non-zero arg means wait for all output data | |
2627 | * to be sent (performed above) but don't send break. | |
2628 | * This is used by the tcdrain() termios function. | |
2629 | */ | |
2630 | if (!arg) | |
2631 | return send_break(tty, 250); | |
2632 | return 0; | |
2633 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2634 | return send_break(tty, arg ? arg*100 : 250); | |
2635 | ||
2636 | case TIOCMGET: | |
60b33c13 | 2637 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2638 | case TIOCMSET: |
2639 | case TIOCMBIC: | |
2640 | case TIOCMBIS: | |
20b9d177 | 2641 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2642 | case TIOCGICOUNT: |
2643 | retval = tty_tiocgicount(tty, p); | |
2644 | /* For the moment allow fall through to the old method */ | |
2645 | if (retval != -EINVAL) | |
2646 | return retval; | |
2647 | break; | |
37bdfb07 AC |
2648 | case TCFLSH: |
2649 | switch (arg) { | |
2650 | case TCIFLUSH: | |
2651 | case TCIOFLUSH: | |
2652 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2653 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2654 | break; |
37bdfb07 AC |
2655 | } |
2656 | break; | |
8a8ae62f JS |
2657 | case TIOCSSERIAL: |
2658 | tty_warn_deprecated_flags(p); | |
2659 | break; | |
311fc65c EB |
2660 | case TIOCGPTPEER: |
2661 | /* Special because the struct file is needed */ | |
2662 | return ptm_open_peer(file, tty, (int)arg); | |
a1235b3e NP |
2663 | default: |
2664 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2665 | if (retval != -ENOIOCTLCMD) | |
2666 | return retval; | |
1da177e4 | 2667 | } |
f34d7a5b | 2668 | if (tty->ops->ioctl) { |
c961bfb1 | 2669 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2670 | if (retval != -ENOIOCTLCMD) |
2671 | return retval; | |
2672 | } | |
2673 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2674 | if (!ld) |
2675 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2676 | retval = -EINVAL; |
a352def2 AC |
2677 | if (ld->ops->ioctl) { |
2678 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2679 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2680 | retval = -ENOTTY; |
1da177e4 LT |
2681 | } |
2682 | tty_ldisc_deref(ld); | |
2683 | return retval; | |
2684 | } | |
2685 | ||
e10cc1df | 2686 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2687 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2688 | unsigned long arg) |
2689 | { | |
d996b62a | 2690 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2691 | struct tty_ldisc *ld; |
2692 | int retval = -ENOIOCTLCMD; | |
2693 | ||
6131ffaa | 2694 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2695 | return -EINVAL; |
2696 | ||
f34d7a5b | 2697 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2698 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2699 | if (retval != -ENOIOCTLCMD) |
2700 | return retval; | |
2701 | } | |
2702 | ||
2703 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2704 | if (!ld) |
2705 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
2706 | if (ld->ops->compat_ioctl) |
2707 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2708 | else |
2709 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2710 | tty_ldisc_deref(ld); |
2711 | ||
2712 | return retval; | |
2713 | } | |
2714 | #endif | |
1da177e4 | 2715 | |
c3c073f8 AV |
2716 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2717 | { | |
2718 | if (likely(file->f_op->read != tty_read)) | |
2719 | return 0; | |
2720 | return file_tty(file) != t ? 0 : fd + 1; | |
2721 | } | |
2722 | ||
1da177e4 LT |
2723 | /* |
2724 | * This implements the "Secure Attention Key" --- the idea is to | |
2725 | * prevent trojan horses by killing all processes associated with this | |
2726 | * tty when the user hits the "Secure Attention Key". Required for | |
2727 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2728 | * |
1da177e4 LT |
2729 | * This code could be nicer; ideally it should send a HUP, wait a few |
2730 | * seconds, then send a INT, and then a KILL signal. But you then | |
2731 | * have to coordinate with the init process, since all processes associated | |
2732 | * with the current tty must be dead before the new getty is allowed | |
2733 | * to spawn. | |
2734 | * | |
2735 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2736 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2737 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2738 | * | |
2739 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2740 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2741 | */ | |
8b6312f4 | 2742 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2743 | { |
2744 | #ifdef TTY_SOFT_SAK | |
2745 | tty_hangup(tty); | |
2746 | #else | |
652486fb | 2747 | struct task_struct *g, *p; |
ab521dc0 | 2748 | struct pid *session; |
1da177e4 | 2749 | int i; |
37bdfb07 | 2750 | |
1da177e4 LT |
2751 | if (!tty) |
2752 | return; | |
24ec839c | 2753 | session = tty->session; |
37bdfb07 | 2754 | |
b3f13deb | 2755 | tty_ldisc_flush(tty); |
1da177e4 | 2756 | |
f34d7a5b | 2757 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2758 | |
1da177e4 | 2759 | read_lock(&tasklist_lock); |
652486fb | 2760 | /* Kill the entire session */ |
ab521dc0 | 2761 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
2762 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
2763 | task_pid_nr(p), p->comm); | |
652486fb | 2764 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2765 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
2766 | |
2767 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
2768 | do_each_thread(g, p) { |
2769 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
2770 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
2771 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
2772 | send_sig(SIGKILL, p, 1); |
2773 | continue; | |
2774 | } | |
2775 | task_lock(p); | |
c3c073f8 AV |
2776 | i = iterate_fd(p->files, 0, this_tty, tty); |
2777 | if (i != 0) { | |
9b42bb75 PH |
2778 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
2779 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 2780 | force_sig(SIGKILL, p); |
1da177e4 LT |
2781 | } |
2782 | task_unlock(p); | |
652486fb | 2783 | } while_each_thread(g, p); |
1da177e4 LT |
2784 | read_unlock(&tasklist_lock); |
2785 | #endif | |
2786 | } | |
2787 | ||
8b6312f4 EB |
2788 | static void do_SAK_work(struct work_struct *work) |
2789 | { | |
2790 | struct tty_struct *tty = | |
2791 | container_of(work, struct tty_struct, SAK_work); | |
2792 | __do_SAK(tty); | |
2793 | } | |
2794 | ||
1da177e4 LT |
2795 | /* |
2796 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2797 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2798 | * the values which we write to it will be identical to the values which it | |
2799 | * already has. --akpm | |
2800 | */ | |
2801 | void do_SAK(struct tty_struct *tty) | |
2802 | { | |
2803 | if (!tty) | |
2804 | return; | |
1da177e4 LT |
2805 | schedule_work(&tty->SAK_work); |
2806 | } | |
2807 | ||
2808 | EXPORT_SYMBOL(do_SAK); | |
2809 | ||
6e9430ac | 2810 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 2811 | { |
6e9430ac | 2812 | const dev_t *devt = data; |
30004ac9 DES |
2813 | return dev->devt == *devt; |
2814 | } | |
2815 | ||
2816 | /* Must put_device() after it's unused! */ | |
2817 | static struct device *tty_get_device(struct tty_struct *tty) | |
2818 | { | |
2819 | dev_t devt = tty_devnum(tty); | |
2820 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2821 | } | |
2822 | ||
2823 | ||
af9b897e | 2824 | /** |
2c964a2f | 2825 | * alloc_tty_struct |
af9b897e | 2826 | * |
2c964a2f | 2827 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 2828 | * |
2c964a2f | 2829 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 2830 | */ |
af9b897e | 2831 | |
2c964a2f | 2832 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 2833 | { |
2c964a2f RV |
2834 | struct tty_struct *tty; |
2835 | ||
2836 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
2837 | if (!tty) | |
2838 | return NULL; | |
2839 | ||
9c9f4ded | 2840 | kref_init(&tty->kref); |
1da177e4 | 2841 | tty->magic = TTY_MAGIC; |
f46dad0d TH |
2842 | if (tty_ldisc_init(tty)) { |
2843 | kfree(tty); | |
2844 | return NULL; | |
2845 | } | |
ab521dc0 EB |
2846 | tty->session = NULL; |
2847 | tty->pgrp = NULL; | |
89c8d91e | 2848 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 2849 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 2850 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 2851 | mutex_init(&tty->winsize_mutex); |
36697529 | 2852 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
2853 | init_waitqueue_head(&tty->write_wait); |
2854 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2855 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 2856 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 2857 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 2858 | spin_lock_init(&tty->flow_lock); |
4a510969 | 2859 | spin_lock_init(&tty->files_lock); |
1da177e4 | 2860 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2861 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2862 | |
2863 | tty->driver = driver; | |
2864 | tty->ops = driver->ops; | |
2865 | tty->index = idx; | |
2866 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2867 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
2868 | |
2869 | return tty; | |
1da177e4 LT |
2870 | } |
2871 | ||
f34d7a5b AC |
2872 | /** |
2873 | * tty_put_char - write one character to a tty | |
2874 | * @tty: tty | |
2875 | * @ch: character | |
2876 | * | |
2877 | * Write one byte to the tty using the provided put_char method | |
2878 | * if present. Returns the number of characters successfully output. | |
2879 | * | |
2880 | * Note: the specific put_char operation in the driver layer may go | |
2881 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2882 | */ |
af9b897e | 2883 | |
f34d7a5b | 2884 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2885 | { |
f34d7a5b AC |
2886 | if (tty->ops->put_char) |
2887 | return tty->ops->put_char(tty, ch); | |
2888 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2889 | } |
f34d7a5b AC |
2890 | EXPORT_SYMBOL_GPL(tty_put_char); |
2891 | ||
d81ed103 | 2892 | struct class *tty_class; |
1da177e4 | 2893 | |
7e73eca6 JS |
2894 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
2895 | unsigned int index, unsigned int count) | |
2896 | { | |
c1a752ba LY |
2897 | int err; |
2898 | ||
7e73eca6 | 2899 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
2900 | driver->cdevs[index] = cdev_alloc(); |
2901 | if (!driver->cdevs[index]) | |
2902 | return -ENOMEM; | |
c1a752ba | 2903 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 2904 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
2905 | err = cdev_add(driver->cdevs[index], dev, count); |
2906 | if (err) | |
2907 | kobject_put(&driver->cdevs[index]->kobj); | |
2908 | return err; | |
7e73eca6 JS |
2909 | } |
2910 | ||
1da177e4 | 2911 | /** |
af9b897e AC |
2912 | * tty_register_device - register a tty device |
2913 | * @driver: the tty driver that describes the tty device | |
2914 | * @index: the index in the tty driver for this tty device | |
2915 | * @device: a struct device that is associated with this tty device. | |
2916 | * This field is optional, if there is no known struct device | |
2917 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2918 | * |
01107d34 GKH |
2919 | * Returns a pointer to the struct device for this tty device |
2920 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2921 | * |
af9b897e AC |
2922 | * This call is required to be made to register an individual tty device |
2923 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2924 | * that bit is not set, this function should not be called by a tty | |
2925 | * driver. | |
2926 | * | |
2927 | * Locking: ?? | |
1da177e4 | 2928 | */ |
af9b897e | 2929 | |
01107d34 GKH |
2930 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2931 | struct device *device) | |
1da177e4 | 2932 | { |
6915c0e4 TH |
2933 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
2934 | } | |
2935 | EXPORT_SYMBOL(tty_register_device); | |
2936 | ||
b1b79916 TH |
2937 | static void tty_device_create_release(struct device *dev) |
2938 | { | |
83db1df4 | 2939 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
2940 | kfree(dev); |
2941 | } | |
2942 | ||
6915c0e4 TH |
2943 | /** |
2944 | * tty_register_device_attr - register a tty device | |
2945 | * @driver: the tty driver that describes the tty device | |
2946 | * @index: the index in the tty driver for this tty device | |
2947 | * @device: a struct device that is associated with this tty device. | |
2948 | * This field is optional, if there is no known struct device | |
2949 | * for this tty device it can be set to NULL safely. | |
2950 | * @drvdata: Driver data to be set to device. | |
2951 | * @attr_grp: Attribute group to be set on device. | |
2952 | * | |
2953 | * Returns a pointer to the struct device for this tty device | |
2954 | * (or ERR_PTR(-EFOO) on error). | |
2955 | * | |
2956 | * This call is required to be made to register an individual tty device | |
2957 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2958 | * that bit is not set, this function should not be called by a tty | |
2959 | * driver. | |
2960 | * | |
2961 | * Locking: ?? | |
2962 | */ | |
2963 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
2964 | unsigned index, struct device *device, | |
2965 | void *drvdata, | |
2966 | const struct attribute_group **attr_grp) | |
2967 | { | |
1da177e4 | 2968 | char name[64]; |
6915c0e4 | 2969 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 2970 | struct ktermios *tp; |
6a7e6f78 JH |
2971 | struct device *dev; |
2972 | int retval; | |
1da177e4 LT |
2973 | |
2974 | if (index >= driver->num) { | |
656fb867 PH |
2975 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
2976 | driver->name, index); | |
1cdcb6b4 | 2977 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2978 | } |
2979 | ||
1da177e4 LT |
2980 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2981 | pty_line_name(driver, index, name); | |
2982 | else | |
2983 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2984 | |
6915c0e4 | 2985 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
2986 | if (!dev) |
2987 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 2988 | |
6915c0e4 TH |
2989 | dev->devt = devt; |
2990 | dev->class = tty_class; | |
2991 | dev->parent = device; | |
b1b79916 | 2992 | dev->release = tty_device_create_release; |
6915c0e4 TH |
2993 | dev_set_name(dev, "%s", name); |
2994 | dev->groups = attr_grp; | |
2995 | dev_set_drvdata(dev, drvdata); | |
2996 | ||
6a7e6f78 JH |
2997 | dev_set_uevent_suppress(dev, 1); |
2998 | ||
6915c0e4 TH |
2999 | retval = device_register(dev); |
3000 | if (retval) | |
6a7e6f78 JH |
3001 | goto err_put; |
3002 | ||
3003 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
3004 | /* |
3005 | * Free any saved termios data so that the termios state is | |
3006 | * reset when reusing a minor number. | |
3007 | */ | |
3008 | tp = driver->termios[index]; | |
3009 | if (tp) { | |
3010 | driver->termios[index] = NULL; | |
3011 | kfree(tp); | |
3012 | } | |
3013 | ||
6a7e6f78 JH |
3014 | retval = tty_cdev_add(driver, devt, index, 1); |
3015 | if (retval) | |
3016 | goto err_del; | |
3017 | } | |
3018 | ||
3019 | dev_set_uevent_suppress(dev, 0); | |
3020 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
3021 | |
3022 | return dev; | |
3023 | ||
6a7e6f78 JH |
3024 | err_del: |
3025 | device_del(dev); | |
3026 | err_put: | |
6915c0e4 | 3027 | put_device(dev); |
6a7e6f78 | 3028 | |
6915c0e4 | 3029 | return ERR_PTR(retval); |
1da177e4 | 3030 | } |
6915c0e4 | 3031 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3032 | |
3033 | /** | |
af9b897e AC |
3034 | * tty_unregister_device - unregister a tty device |
3035 | * @driver: the tty driver that describes the tty device | |
3036 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3037 | * |
af9b897e AC |
3038 | * If a tty device is registered with a call to tty_register_device() then |
3039 | * this function must be called when the tty device is gone. | |
3040 | * | |
3041 | * Locking: ?? | |
1da177e4 | 3042 | */ |
af9b897e | 3043 | |
1da177e4 LT |
3044 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3045 | { | |
37bdfb07 AC |
3046 | device_destroy(tty_class, |
3047 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3048 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3049 | cdev_del(driver->cdevs[index]); | |
3050 | driver->cdevs[index] = NULL; | |
3051 | } | |
1da177e4 | 3052 | } |
1da177e4 LT |
3053 | EXPORT_SYMBOL(tty_unregister_device); |
3054 | ||
7f0bc6a6 JS |
3055 | /** |
3056 | * __tty_alloc_driver -- allocate tty driver | |
3057 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 3058 | * @owner: module which is responsible for this driver |
7f0bc6a6 JS |
3059 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags |
3060 | * | |
3061 | * This should not be called directly, some of the provided macros should be | |
3062 | * used instead. Use IS_ERR and friends on @retval. | |
3063 | */ | |
3064 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3065 | unsigned long flags) | |
1da177e4 LT |
3066 | { |
3067 | struct tty_driver *driver; | |
7e73eca6 | 3068 | unsigned int cdevs = 1; |
16a02081 | 3069 | int err; |
1da177e4 | 3070 | |
0019b408 | 3071 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3072 | return ERR_PTR(-EINVAL); |
3073 | ||
506eb99a | 3074 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3075 | if (!driver) |
3076 | return ERR_PTR(-ENOMEM); | |
3077 | ||
3078 | kref_init(&driver->kref); | |
3079 | driver->magic = TTY_DRIVER_MAGIC; | |
3080 | driver->num = lines; | |
3081 | driver->owner = owner; | |
3082 | driver->flags = flags; | |
16a02081 JS |
3083 | |
3084 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3085 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3086 | GFP_KERNEL); | |
3087 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3088 | GFP_KERNEL); | |
3089 | if (!driver->ttys || !driver->termios) { | |
3090 | err = -ENOMEM; | |
3091 | goto err_free_all; | |
3092 | } | |
3093 | } | |
3094 | ||
3095 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3096 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3097 | GFP_KERNEL); | |
3098 | if (!driver->ports) { | |
3099 | err = -ENOMEM; | |
3100 | goto err_free_all; | |
3101 | } | |
7e73eca6 JS |
3102 | cdevs = lines; |
3103 | } | |
3104 | ||
3105 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3106 | if (!driver->cdevs) { | |
3107 | err = -ENOMEM; | |
3108 | goto err_free_all; | |
16a02081 | 3109 | } |
7f0bc6a6 | 3110 | |
1da177e4 | 3111 | return driver; |
16a02081 JS |
3112 | err_free_all: |
3113 | kfree(driver->ports); | |
3114 | kfree(driver->ttys); | |
3115 | kfree(driver->termios); | |
a3a10ce3 | 3116 | kfree(driver->cdevs); |
16a02081 JS |
3117 | kfree(driver); |
3118 | return ERR_PTR(err); | |
1da177e4 | 3119 | } |
7f0bc6a6 | 3120 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3121 | |
7d7b93c1 | 3122 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3123 | { |
7d7b93c1 AC |
3124 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3125 | int i; | |
3126 | struct ktermios *tp; | |
7d7b93c1 AC |
3127 | |
3128 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
3129 | for (i = 0; i < driver->num; i++) { |
3130 | tp = driver->termios[i]; | |
3131 | if (tp) { | |
3132 | driver->termios[i] = NULL; | |
3133 | kfree(tp); | |
3134 | } | |
7d7b93c1 AC |
3135 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3136 | tty_unregister_device(driver, i); | |
3137 | } | |
7d7b93c1 | 3138 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3139 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3140 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3141 | } |
7e73eca6 | 3142 | kfree(driver->cdevs); |
04831dc1 | 3143 | kfree(driver->ports); |
16a02081 JS |
3144 | kfree(driver->termios); |
3145 | kfree(driver->ttys); | |
1da177e4 LT |
3146 | kfree(driver); |
3147 | } | |
3148 | ||
7d7b93c1 AC |
3149 | void tty_driver_kref_put(struct tty_driver *driver) |
3150 | { | |
3151 | kref_put(&driver->kref, destruct_tty_driver); | |
3152 | } | |
3153 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3154 | ||
b68e31d0 JD |
3155 | void tty_set_operations(struct tty_driver *driver, |
3156 | const struct tty_operations *op) | |
1da177e4 | 3157 | { |
f34d7a5b AC |
3158 | driver->ops = op; |
3159 | }; | |
7d7b93c1 | 3160 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3161 | |
7d7b93c1 AC |
3162 | void put_tty_driver(struct tty_driver *d) |
3163 | { | |
3164 | tty_driver_kref_put(d); | |
3165 | } | |
1da177e4 | 3166 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3167 | |
3168 | /* | |
3169 | * Called by a tty driver to register itself. | |
3170 | */ | |
3171 | int tty_register_driver(struct tty_driver *driver) | |
3172 | { | |
3173 | int error; | |
37bdfb07 | 3174 | int i; |
1da177e4 | 3175 | dev_t dev; |
b670bde0 | 3176 | struct device *d; |
1da177e4 | 3177 | |
1da177e4 | 3178 | if (!driver->major) { |
37bdfb07 AC |
3179 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3180 | driver->num, driver->name); | |
1da177e4 LT |
3181 | if (!error) { |
3182 | driver->major = MAJOR(dev); | |
3183 | driver->minor_start = MINOR(dev); | |
3184 | } | |
3185 | } else { | |
3186 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3187 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3188 | } |
9bb8a3d4 | 3189 | if (error < 0) |
16a02081 | 3190 | goto err; |
1da177e4 | 3191 | |
7e73eca6 JS |
3192 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3193 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3194 | if (error) | |
3195 | goto err_unreg_char; | |
3196 | } | |
1da177e4 | 3197 | |
ca509f69 | 3198 | mutex_lock(&tty_mutex); |
1da177e4 | 3199 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3200 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3201 | |
3202 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3203 | for (i = 0; i < driver->num; i++) { |
3204 | d = tty_register_device(driver, i, NULL); | |
3205 | if (IS_ERR(d)) { | |
3206 | error = PTR_ERR(d); | |
16a02081 | 3207 | goto err_unreg_devs; |
b670bde0 VK |
3208 | } |
3209 | } | |
1da177e4 LT |
3210 | } |
3211 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3212 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3213 | return 0; |
b670bde0 | 3214 | |
16a02081 | 3215 | err_unreg_devs: |
b670bde0 VK |
3216 | for (i--; i >= 0; i--) |
3217 | tty_unregister_device(driver, i); | |
3218 | ||
3219 | mutex_lock(&tty_mutex); | |
3220 | list_del(&driver->tty_drivers); | |
3221 | mutex_unlock(&tty_mutex); | |
3222 | ||
9bb8a3d4 | 3223 | err_unreg_char: |
b670bde0 | 3224 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3225 | err: |
b670bde0 | 3226 | return error; |
1da177e4 | 3227 | } |
1da177e4 LT |
3228 | EXPORT_SYMBOL(tty_register_driver); |
3229 | ||
3230 | /* | |
3231 | * Called by a tty driver to unregister itself. | |
3232 | */ | |
3233 | int tty_unregister_driver(struct tty_driver *driver) | |
3234 | { | |
7d7b93c1 AC |
3235 | #if 0 |
3236 | /* FIXME */ | |
1da177e4 LT |
3237 | if (driver->refcount) |
3238 | return -EBUSY; | |
7d7b93c1 | 3239 | #endif |
1da177e4 LT |
3240 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3241 | driver->num); | |
ca509f69 | 3242 | mutex_lock(&tty_mutex); |
1da177e4 | 3243 | list_del(&driver->tty_drivers); |
ca509f69 | 3244 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3245 | return 0; |
3246 | } | |
7d7b93c1 | 3247 | |
1da177e4 LT |
3248 | EXPORT_SYMBOL(tty_unregister_driver); |
3249 | ||
24ec839c PZ |
3250 | dev_t tty_devnum(struct tty_struct *tty) |
3251 | { | |
3252 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3253 | } | |
3254 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3255 | |
d81ed103 AC |
3256 | void tty_default_fops(struct file_operations *fops) |
3257 | { | |
3258 | *fops = tty_fops; | |
3259 | } | |
3260 | ||
2c9ede55 | 3261 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3262 | { |
3263 | if (!mode) | |
3264 | return NULL; | |
3265 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3266 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3267 | *mode = 0666; | |
3268 | return NULL; | |
3269 | } | |
3270 | ||
1da177e4 LT |
3271 | static int __init tty_class_init(void) |
3272 | { | |
7fe845d1 | 3273 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3274 | if (IS_ERR(tty_class)) |
3275 | return PTR_ERR(tty_class); | |
e454cea2 | 3276 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3277 | return 0; |
3278 | } | |
3279 | ||
3280 | postcore_initcall(tty_class_init); | |
3281 | ||
3282 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3283 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3284 | |
fbc92a34 KS |
3285 | static ssize_t show_cons_active(struct device *dev, |
3286 | struct device_attribute *attr, char *buf) | |
3287 | { | |
3288 | struct console *cs[16]; | |
3289 | int i = 0; | |
3290 | struct console *c; | |
3291 | ssize_t count = 0; | |
3292 | ||
ac751efa | 3293 | console_lock(); |
a2a6a822 | 3294 | for_each_console(c) { |
fbc92a34 KS |
3295 | if (!c->device) |
3296 | continue; | |
3297 | if (!c->write) | |
3298 | continue; | |
3299 | if ((c->flags & CON_ENABLED) == 0) | |
3300 | continue; | |
3301 | cs[i++] = c; | |
3302 | if (i >= ARRAY_SIZE(cs)) | |
3303 | break; | |
3304 | } | |
723abd87 HR |
3305 | while (i--) { |
3306 | int index = cs[i]->index; | |
3307 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3308 | ||
3309 | /* don't resolve tty0 as some programs depend on it */ | |
3310 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3311 | count += tty_line_name(drv, index, buf + count); | |
3312 | else | |
3313 | count += sprintf(buf + count, "%s%d", | |
3314 | cs[i]->name, cs[i]->index); | |
3315 | ||
3316 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3317 | } | |
ac751efa | 3318 | console_unlock(); |
fbc92a34 KS |
3319 | |
3320 | return count; | |
3321 | } | |
3322 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3323 | ||
1083a7be TI |
3324 | static struct attribute *cons_dev_attrs[] = { |
3325 | &dev_attr_active.attr, | |
3326 | NULL | |
3327 | }; | |
3328 | ||
3329 | ATTRIBUTE_GROUPS(cons_dev); | |
3330 | ||
fbc92a34 KS |
3331 | static struct device *consdev; |
3332 | ||
3333 | void console_sysfs_notify(void) | |
3334 | { | |
3335 | if (consdev) | |
3336 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3337 | } | |
3338 | ||
1da177e4 LT |
3339 | /* |
3340 | * Ok, now we can initialize the rest of the tty devices and can count | |
3341 | * on memory allocations, interrupts etc.. | |
3342 | */ | |
31d1d48e | 3343 | int __init tty_init(void) |
1da177e4 | 3344 | { |
d6f408ac | 3345 | tty_sysctl_init(); |
1da177e4 LT |
3346 | cdev_init(&tty_cdev, &tty_fops); |
3347 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3348 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3349 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3350 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3351 | |
3352 | cdev_init(&console_cdev, &console_fops); | |
3353 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3354 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3355 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3356 | consdev = device_create_with_groups(tty_class, NULL, |
3357 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3358 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3359 | if (IS_ERR(consdev)) |
3360 | consdev = NULL; | |
1da177e4 | 3361 | |
1da177e4 | 3362 | #ifdef CONFIG_VT |
d81ed103 | 3363 | vty_init(&console_fops); |
1da177e4 LT |
3364 | #endif |
3365 | return 0; | |
3366 | } | |
31d1d48e | 3367 |