Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
3f07c014 | 72 | #include <linux/sched/signal.h> |
29930025 | 73 | #include <linux/sched/task.h> |
1da177e4 LT |
74 | #include <linux/interrupt.h> |
75 | #include <linux/tty.h> | |
76 | #include <linux/tty_driver.h> | |
77 | #include <linux/tty_flip.h> | |
78 | #include <linux/devpts_fs.h> | |
79 | #include <linux/file.h> | |
9f3acc31 | 80 | #include <linux/fdtable.h> |
1da177e4 LT |
81 | #include <linux/console.h> |
82 | #include <linux/timer.h> | |
83 | #include <linux/ctype.h> | |
84 | #include <linux/kd.h> | |
85 | #include <linux/mm.h> | |
86 | #include <linux/string.h> | |
87 | #include <linux/slab.h> | |
88 | #include <linux/poll.h> | |
89 | #include <linux/proc_fs.h> | |
90 | #include <linux/init.h> | |
91 | #include <linux/module.h> | |
1da177e4 | 92 | #include <linux/device.h> |
1da177e4 LT |
93 | #include <linux/wait.h> |
94 | #include <linux/bitops.h> | |
b20f3ae5 | 95 | #include <linux/delay.h> |
a352def2 | 96 | #include <linux/seq_file.h> |
d281da7f | 97 | #include <linux/serial.h> |
5a3c6b25 | 98 | #include <linux/ratelimit.h> |
1da177e4 | 99 | |
a352def2 | 100 | #include <linux/uaccess.h> |
1da177e4 LT |
101 | |
102 | #include <linux/kbd_kern.h> | |
103 | #include <linux/vt_kern.h> | |
104 | #include <linux/selection.h> | |
1da177e4 LT |
105 | |
106 | #include <linux/kmod.h> | |
b488893a | 107 | #include <linux/nsproxy.h> |
1da177e4 LT |
108 | |
109 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
110 | #ifdef TTY_DEBUG_HANGUP |
111 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
112 | #else | |
113 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
114 | #endif | |
1da177e4 LT |
115 | |
116 | #define TTY_PARANOIA_CHECK 1 | |
117 | #define CHECK_TTY_COUNT 1 | |
118 | ||
edc6afc5 | 119 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
120 | .c_iflag = ICRNL | IXON, |
121 | .c_oflag = OPOST | ONLCR, | |
122 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
123 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
124 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
125 | .c_cc = INIT_C_CC, |
126 | .c_ispeed = 38400, | |
133b1306 PH |
127 | .c_ospeed = 38400, |
128 | /* .c_line = N_TTY, */ | |
1da177e4 LT |
129 | }; |
130 | ||
131 | EXPORT_SYMBOL(tty_std_termios); | |
132 | ||
133 | /* This list gets poked at by procfs and various bits of boot up code. This | |
134 | could do with some rationalisation such as pulling the tty proc function | |
135 | into this file */ | |
37bdfb07 | 136 | |
1da177e4 LT |
137 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
138 | ||
d1d027ef | 139 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 140 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 141 | |
1da177e4 LT |
142 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
143 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
144 | ssize_t redirected_tty_write(struct file *, const char __user *, |
145 | size_t, loff_t *); | |
1da177e4 LT |
146 | static unsigned int tty_poll(struct file *, poll_table *); |
147 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 148 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 149 | #ifdef CONFIG_COMPAT |
37bdfb07 | 150 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
151 | unsigned long arg); |
152 | #else | |
153 | #define tty_compat_ioctl NULL | |
154 | #endif | |
ec79d605 | 155 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 156 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 157 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 158 | |
af9b897e AC |
159 | /** |
160 | * free_tty_struct - free a disused tty | |
161 | * @tty: tty struct to free | |
162 | * | |
163 | * Free the write buffers, tty queue and tty memory itself. | |
164 | * | |
165 | * Locking: none. Must be called after tty is definitely unused | |
166 | */ | |
167 | ||
a3123fd0 | 168 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 169 | { |
c8b710b3 | 170 | tty_ldisc_deinit(tty); |
a211b1af | 171 | put_device(tty->dev); |
1da177e4 | 172 | kfree(tty->write_buf); |
89c8d91e | 173 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
174 | kfree(tty); |
175 | } | |
176 | ||
d996b62a NP |
177 | static inline struct tty_struct *file_tty(struct file *file) |
178 | { | |
179 | return ((struct tty_file_private *)file->private_data)->tty; | |
180 | } | |
181 | ||
fa90e1c9 | 182 | int tty_alloc_file(struct file *file) |
d996b62a NP |
183 | { |
184 | struct tty_file_private *priv; | |
185 | ||
f573bd17 PE |
186 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
187 | if (!priv) | |
188 | return -ENOMEM; | |
d996b62a | 189 | |
fa90e1c9 JS |
190 | file->private_data = priv; |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* Associate a new file with the tty structure */ | |
196 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
197 | { | |
198 | struct tty_file_private *priv = file->private_data; | |
199 | ||
d996b62a NP |
200 | priv->tty = tty; |
201 | priv->file = file; | |
d996b62a | 202 | |
4a510969 | 203 | spin_lock(&tty->files_lock); |
d996b62a | 204 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 205 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 206 | } |
f573bd17 | 207 | |
fa90e1c9 JS |
208 | /** |
209 | * tty_free_file - free file->private_data | |
210 | * | |
211 | * This shall be used only for fail path handling when tty_add_file was not | |
212 | * called yet. | |
213 | */ | |
214 | void tty_free_file(struct file *file) | |
215 | { | |
216 | struct tty_file_private *priv = file->private_data; | |
217 | ||
218 | file->private_data = NULL; | |
219 | kfree(priv); | |
d996b62a NP |
220 | } |
221 | ||
222 | /* Delete file from its tty */ | |
2520e274 | 223 | static void tty_del_file(struct file *file) |
d996b62a NP |
224 | { |
225 | struct tty_file_private *priv = file->private_data; | |
4a510969 | 226 | struct tty_struct *tty = priv->tty; |
d996b62a | 227 | |
4a510969 | 228 | spin_lock(&tty->files_lock); |
d996b62a | 229 | list_del(&priv->list); |
4a510969 | 230 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 231 | tty_free_file(file); |
d996b62a NP |
232 | } |
233 | ||
af9b897e AC |
234 | /** |
235 | * tty_name - return tty naming | |
236 | * @tty: tty structure | |
af9b897e AC |
237 | * |
238 | * Convert a tty structure into a name. The name reflects the kernel | |
239 | * naming policy and if udev is in use may not reflect user space | |
240 | * | |
241 | * Locking: none | |
242 | */ | |
243 | ||
429b4749 | 244 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
245 | { |
246 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
247 | return "NULL tty"; |
248 | return tty->name; | |
1da177e4 LT |
249 | } |
250 | ||
251 | EXPORT_SYMBOL(tty_name); | |
252 | ||
0a083edd PH |
253 | const char *tty_driver_name(const struct tty_struct *tty) |
254 | { | |
255 | if (!tty || !tty->driver) | |
256 | return ""; | |
257 | return tty->driver->name; | |
258 | } | |
259 | ||
82b8f888 | 260 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
261 | const char *routine) |
262 | { | |
263 | #ifdef TTY_PARANOIA_CHECK | |
264 | if (!tty) { | |
89222e62 | 265 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
266 | imajor(inode), iminor(inode), routine); |
267 | return 1; | |
268 | } | |
269 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 270 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
271 | imajor(inode), iminor(inode), routine); |
272 | return 1; | |
273 | } | |
274 | #endif | |
275 | return 0; | |
276 | } | |
277 | ||
deb287e7 | 278 | /* Caller must hold tty_lock */ |
1da177e4 LT |
279 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
280 | { | |
281 | #ifdef CHECK_TTY_COUNT | |
282 | struct list_head *p; | |
283 | int count = 0; | |
37bdfb07 | 284 | |
4a510969 | 285 | spin_lock(&tty->files_lock); |
1da177e4 LT |
286 | list_for_each(p, &tty->tty_files) { |
287 | count++; | |
288 | } | |
4a510969 | 289 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
290 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
291 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
292 | tty->link && tty->link->count) | |
293 | count++; | |
294 | if (tty->count != count) { | |
339f36ba PH |
295 | tty_warn(tty, "%s: tty->count(%d) != #fd's(%d)\n", |
296 | routine, tty->count, count); | |
1da177e4 | 297 | return count; |
24ec839c | 298 | } |
1da177e4 LT |
299 | #endif |
300 | return 0; | |
301 | } | |
302 | ||
af9b897e AC |
303 | /** |
304 | * get_tty_driver - find device of a tty | |
305 | * @dev_t: device identifier | |
306 | * @index: returns the index of the tty | |
307 | * | |
308 | * This routine returns a tty driver structure, given a device number | |
309 | * and also passes back the index number. | |
310 | * | |
311 | * Locking: caller must hold tty_mutex | |
1da177e4 | 312 | */ |
af9b897e | 313 | |
1da177e4 LT |
314 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
315 | { | |
316 | struct tty_driver *p; | |
317 | ||
318 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
319 | dev_t base = MKDEV(p->major, p->minor_start); | |
320 | if (device < base || device >= base + p->num) | |
321 | continue; | |
322 | *index = device - base; | |
7d7b93c1 | 323 | return tty_driver_kref_get(p); |
1da177e4 LT |
324 | } |
325 | return NULL; | |
326 | } | |
327 | ||
fc61ed51 OK |
328 | /** |
329 | * tty_dev_name_to_number - return dev_t for device name | |
330 | * @name: user space name of device under /dev | |
331 | * @number: pointer to dev_t that this function will populate | |
332 | * | |
333 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t | |
334 | * like (4, 64) or (188, 1). If no corresponding driver is registered then | |
335 | * the function returns -ENODEV. | |
336 | * | |
337 | * Locking: this acquires tty_mutex to protect the tty_drivers list from | |
338 | * being modified while we are traversing it, and makes sure to | |
339 | * release it before exiting. | |
340 | */ | |
341 | int tty_dev_name_to_number(const char *name, dev_t *number) | |
342 | { | |
343 | struct tty_driver *p; | |
344 | int ret; | |
345 | int index, prefix_length = 0; | |
346 | const char *str; | |
347 | ||
348 | for (str = name; *str && !isdigit(*str); str++) | |
349 | ; | |
350 | ||
351 | if (!*str) | |
352 | return -EINVAL; | |
353 | ||
354 | ret = kstrtoint(str, 10, &index); | |
355 | if (ret) | |
356 | return ret; | |
357 | ||
358 | prefix_length = str - name; | |
359 | mutex_lock(&tty_mutex); | |
360 | ||
361 | list_for_each_entry(p, &tty_drivers, tty_drivers) | |
362 | if (prefix_length == strlen(p->name) && strncmp(name, | |
363 | p->name, prefix_length) == 0) { | |
364 | if (index < p->num) { | |
365 | *number = MKDEV(p->major, p->minor_start + index); | |
366 | goto out; | |
367 | } | |
368 | } | |
369 | ||
370 | /* if here then driver wasn't found */ | |
371 | ret = -ENODEV; | |
372 | out: | |
373 | mutex_unlock(&tty_mutex); | |
374 | return ret; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number); | |
377 | ||
f2d937f3 JW |
378 | #ifdef CONFIG_CONSOLE_POLL |
379 | ||
380 | /** | |
381 | * tty_find_polling_driver - find device of a polled tty | |
382 | * @name: name string to match | |
383 | * @line: pointer to resulting tty line nr | |
384 | * | |
385 | * This routine returns a tty driver structure, given a name | |
386 | * and the condition that the tty driver is capable of polled | |
387 | * operation. | |
388 | */ | |
389 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
390 | { | |
391 | struct tty_driver *p, *res = NULL; | |
392 | int tty_line = 0; | |
0dca0fd2 | 393 | int len; |
5f0878ac | 394 | char *str, *stp; |
f2d937f3 | 395 | |
0dca0fd2 JW |
396 | for (str = name; *str; str++) |
397 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
398 | break; | |
399 | if (!*str) | |
400 | return NULL; | |
401 | ||
402 | len = str - name; | |
403 | tty_line = simple_strtoul(str, &str, 10); | |
404 | ||
f2d937f3 JW |
405 | mutex_lock(&tty_mutex); |
406 | /* Search through the tty devices to look for a match */ | |
407 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
408 | if (strncmp(name, p->name, len) != 0) |
409 | continue; | |
5f0878ac AC |
410 | stp = str; |
411 | if (*stp == ',') | |
412 | stp++; | |
413 | if (*stp == '\0') | |
414 | stp = NULL; | |
f2d937f3 | 415 | |
6eb68d6f | 416 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 417 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 418 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
419 | *line = tty_line; |
420 | break; | |
421 | } | |
422 | } | |
423 | mutex_unlock(&tty_mutex); | |
424 | ||
425 | return res; | |
426 | } | |
427 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
428 | #endif | |
429 | ||
37bdfb07 | 430 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
431 | size_t count, loff_t *ppos) |
432 | { | |
433 | return 0; | |
434 | } | |
435 | ||
37bdfb07 | 436 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
437 | size_t count, loff_t *ppos) |
438 | { | |
439 | return -EIO; | |
440 | } | |
441 | ||
442 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 443 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
444 | { |
445 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
446 | } | |
447 | ||
04f378b1 AC |
448 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
449 | unsigned long arg) | |
38ad2ed0 PF |
450 | { |
451 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
452 | } | |
453 | ||
37bdfb07 | 454 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 455 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
456 | { |
457 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
458 | } | |
459 | ||
f557474c PH |
460 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
461 | { | |
462 | return -ENOTTY; | |
463 | } | |
464 | ||
62322d25 | 465 | static const struct file_operations tty_fops = { |
1da177e4 LT |
466 | .llseek = no_llseek, |
467 | .read = tty_read, | |
468 | .write = tty_write, | |
469 | .poll = tty_poll, | |
04f378b1 | 470 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 471 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
472 | .open = tty_open, |
473 | .release = tty_release, | |
474 | .fasync = tty_fasync, | |
475 | }; | |
476 | ||
62322d25 | 477 | static const struct file_operations console_fops = { |
1da177e4 LT |
478 | .llseek = no_llseek, |
479 | .read = tty_read, | |
480 | .write = redirected_tty_write, | |
481 | .poll = tty_poll, | |
04f378b1 | 482 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 483 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
484 | .open = tty_open, |
485 | .release = tty_release, | |
486 | .fasync = tty_fasync, | |
487 | }; | |
488 | ||
62322d25 | 489 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
490 | .llseek = no_llseek, |
491 | .read = hung_up_tty_read, | |
492 | .write = hung_up_tty_write, | |
493 | .poll = hung_up_tty_poll, | |
04f378b1 | 494 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 495 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 496 | .release = tty_release, |
f557474c | 497 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
498 | }; |
499 | ||
500 | static DEFINE_SPINLOCK(redirect_lock); | |
501 | static struct file *redirect; | |
502 | ||
503 | /** | |
504 | * tty_wakeup - request more data | |
505 | * @tty: terminal | |
506 | * | |
507 | * Internal and external helper for wakeups of tty. This function | |
508 | * informs the line discipline if present that the driver is ready | |
509 | * to receive more output data. | |
510 | */ | |
37bdfb07 | 511 | |
1da177e4 LT |
512 | void tty_wakeup(struct tty_struct *tty) |
513 | { | |
514 | struct tty_ldisc *ld; | |
37bdfb07 | 515 | |
1da177e4 LT |
516 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
517 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 518 | if (ld) { |
a352def2 AC |
519 | if (ld->ops->write_wakeup) |
520 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
521 | tty_ldisc_deref(ld); |
522 | } | |
523 | } | |
4b19449d | 524 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
525 | } |
526 | ||
527 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
528 | ||
af9b897e | 529 | /** |
11dbf203 | 530 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 531 | * @work: tty device |
af9b897e | 532 | * |
ef4f527c | 533 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
534 | * synchronous but doesn't hold any locks, so we need to make sure we |
535 | * have the appropriate locks for what we're doing. | |
536 | * | |
537 | * The hangup event clears any pending redirections onto the hung up | |
538 | * device. It ensures future writes will error and it does the needed | |
539 | * line discipline hangup and signal delivery. The tty object itself | |
540 | * remains intact. | |
541 | * | |
542 | * Locking: | |
ec79d605 | 543 | * BTM |
24ec839c PZ |
544 | * redirect lock for undoing redirection |
545 | * file list lock for manipulating list of ttys | |
137084bb | 546 | * tty_ldiscs_lock from called functions |
6a1c0680 | 547 | * termios_rwsem resetting termios data |
24ec839c PZ |
548 | * tasklist_lock to walk task list for hangup event |
549 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 550 | */ |
f91e2590 | 551 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 552 | { |
37bdfb07 | 553 | struct file *cons_filp = NULL; |
1da177e4 | 554 | struct file *filp, *f = NULL; |
d996b62a | 555 | struct tty_file_private *priv; |
1da177e4 | 556 | int closecount = 0, n; |
ea648a47 | 557 | int refs; |
1da177e4 LT |
558 | |
559 | if (!tty) | |
560 | return; | |
561 | ||
1da177e4 LT |
562 | |
563 | spin_lock(&redirect_lock); | |
d996b62a | 564 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
565 | f = redirect; |
566 | redirect = NULL; | |
567 | } | |
568 | spin_unlock(&redirect_lock); | |
37bdfb07 | 569 | |
89c8d91e | 570 | tty_lock(tty); |
11dbf203 | 571 | |
cb50e523 PH |
572 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
573 | tty_unlock(tty); | |
574 | return; | |
575 | } | |
576 | ||
ec79d605 AB |
577 | /* inuse_filps is protected by the single tty lock, |
578 | this really needs to change if we want to flush the | |
579 | workqueue with the lock held */ | |
11dbf203 | 580 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 581 | |
4a510969 | 582 | spin_lock(&tty->files_lock); |
1da177e4 | 583 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
584 | list_for_each_entry(priv, &tty->tty_files, list) { |
585 | filp = priv->file; | |
1da177e4 LT |
586 | if (filp->f_op->write == redirected_tty_write) |
587 | cons_filp = filp; | |
588 | if (filp->f_op->write != tty_write) | |
589 | continue; | |
590 | closecount++; | |
ec79d605 | 591 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
592 | filp->f_op = &hung_up_tty_fops; |
593 | } | |
4a510969 | 594 | spin_unlock(&tty->files_lock); |
37bdfb07 | 595 | |
25fdf243 PH |
596 | refs = tty_signal_session_leader(tty, exit_session); |
597 | /* Account for the p->signal references we killed */ | |
598 | while (refs--) | |
599 | tty_kref_put(tty); | |
600 | ||
892d1fa7 | 601 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 602 | |
20cc225b | 603 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 604 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 605 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
606 | put_pid(tty->session); |
607 | put_pid(tty->pgrp); | |
ab521dc0 EB |
608 | tty->session = NULL; |
609 | tty->pgrp = NULL; | |
1da177e4 | 610 | tty->ctrl_status = 0; |
20cc225b | 611 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 612 | |
1da177e4 | 613 | /* |
37bdfb07 AC |
614 | * If one of the devices matches a console pointer, we |
615 | * cannot just call hangup() because that will cause | |
616 | * tty->count and state->count to go out of sync. | |
617 | * So we just call close() the right number of times. | |
1da177e4 LT |
618 | */ |
619 | if (cons_filp) { | |
f34d7a5b | 620 | if (tty->ops->close) |
1da177e4 | 621 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
622 | tty->ops->close(tty, cons_filp); |
623 | } else if (tty->ops->hangup) | |
7c6d340f | 624 | tty->ops->hangup(tty); |
37bdfb07 | 625 | /* |
892d1fa7 PH |
626 | * We don't want to have driver/ldisc interactions beyond the ones |
627 | * we did here. The driver layer expects no calls after ->hangup() | |
628 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 629 | */ |
1da177e4 | 630 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 631 | tty_unlock(tty); |
11dbf203 | 632 | |
1da177e4 LT |
633 | if (f) |
634 | fput(f); | |
635 | } | |
636 | ||
ddcd9fb6 AB |
637 | static void do_tty_hangup(struct work_struct *work) |
638 | { | |
639 | struct tty_struct *tty = | |
640 | container_of(work, struct tty_struct, hangup_work); | |
641 | ||
f91e2590 | 642 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
643 | } |
644 | ||
af9b897e AC |
645 | /** |
646 | * tty_hangup - trigger a hangup event | |
647 | * @tty: tty to hangup | |
648 | * | |
649 | * A carrier loss (virtual or otherwise) has occurred on this like | |
650 | * schedule a hangup sequence to run after this event. | |
651 | */ | |
652 | ||
37bdfb07 | 653 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 654 | { |
d435cefe | 655 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
656 | schedule_work(&tty->hangup_work); |
657 | } | |
658 | ||
659 | EXPORT_SYMBOL(tty_hangup); | |
660 | ||
af9b897e AC |
661 | /** |
662 | * tty_vhangup - process vhangup | |
663 | * @tty: tty to hangup | |
664 | * | |
665 | * The user has asked via system call for the terminal to be hung up. | |
666 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 667 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
668 | */ |
669 | ||
37bdfb07 | 670 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 671 | { |
d435cefe | 672 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 673 | __tty_hangup(tty, 0); |
1da177e4 | 674 | } |
37bdfb07 | 675 | |
1da177e4 LT |
676 | EXPORT_SYMBOL(tty_vhangup); |
677 | ||
11dbf203 | 678 | |
2cb5998b AC |
679 | /** |
680 | * tty_vhangup_self - process vhangup for own ctty | |
681 | * | |
682 | * Perform a vhangup on the current controlling tty | |
683 | */ | |
684 | ||
685 | void tty_vhangup_self(void) | |
686 | { | |
687 | struct tty_struct *tty; | |
688 | ||
2cb5998b AC |
689 | tty = get_current_tty(); |
690 | if (tty) { | |
691 | tty_vhangup(tty); | |
692 | tty_kref_put(tty); | |
693 | } | |
2cb5998b AC |
694 | } |
695 | ||
f91e2590 PH |
696 | /** |
697 | * tty_vhangup_session - hangup session leader exit | |
698 | * @tty: tty to hangup | |
699 | * | |
700 | * The session leader is exiting and hanging up its controlling terminal. | |
701 | * Every process in the foreground process group is signalled SIGHUP. | |
702 | * | |
703 | * We do this synchronously so that when the syscall returns the process | |
704 | * is complete. That guarantee is necessary for security reasons. | |
705 | */ | |
706 | ||
a1235b3e | 707 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 708 | { |
d435cefe | 709 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
710 | __tty_hangup(tty, 1); |
711 | } | |
712 | ||
af9b897e AC |
713 | /** |
714 | * tty_hung_up_p - was tty hung up | |
715 | * @filp: file pointer of tty | |
716 | * | |
717 | * Return true if the tty has been subject to a vhangup or a carrier | |
718 | * loss | |
719 | */ | |
720 | ||
37bdfb07 | 721 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 722 | { |
ed3f0af8 | 723 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 LT |
724 | } |
725 | ||
726 | EXPORT_SYMBOL(tty_hung_up_p); | |
727 | ||
af9b897e | 728 | /** |
beb7dd86 | 729 | * stop_tty - propagate flow control |
af9b897e AC |
730 | * @tty: tty to stop |
731 | * | |
01adc807 | 732 | * Perform flow control to the driver. May be called |
af9b897e AC |
733 | * on an already stopped device and will not re-call the driver |
734 | * method. | |
735 | * | |
736 | * This functionality is used by both the line disciplines for | |
737 | * halting incoming flow and by the driver. It may therefore be | |
738 | * called from any context, may be under the tty atomic_write_lock | |
739 | * but not always. | |
740 | * | |
741 | * Locking: | |
f9e053dc | 742 | * flow_lock |
af9b897e AC |
743 | */ |
744 | ||
f9e053dc | 745 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 746 | { |
f9e053dc | 747 | if (tty->stopped) |
1da177e4 LT |
748 | return; |
749 | tty->stopped = 1; | |
f34d7a5b | 750 | if (tty->ops->stop) |
c961bfb1 | 751 | tty->ops->stop(tty); |
1da177e4 LT |
752 | } |
753 | ||
f9e053dc PH |
754 | void stop_tty(struct tty_struct *tty) |
755 | { | |
756 | unsigned long flags; | |
757 | ||
758 | spin_lock_irqsave(&tty->flow_lock, flags); | |
759 | __stop_tty(tty); | |
760 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
761 | } | |
1da177e4 LT |
762 | EXPORT_SYMBOL(stop_tty); |
763 | ||
af9b897e | 764 | /** |
beb7dd86 | 765 | * start_tty - propagate flow control |
af9b897e AC |
766 | * @tty: tty to start |
767 | * | |
01adc807 PH |
768 | * Start a tty that has been stopped if at all possible. If this |
769 | * tty was previous stopped and is now being started, the driver | |
770 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
771 | * |
772 | * Locking: | |
f9e053dc | 773 | * flow_lock |
af9b897e AC |
774 | */ |
775 | ||
f9e053dc | 776 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 777 | { |
f9e053dc | 778 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
779 | return; |
780 | tty->stopped = 0; | |
f34d7a5b | 781 | if (tty->ops->start) |
c961bfb1 | 782 | tty->ops->start(tty); |
1da177e4 | 783 | tty_wakeup(tty); |
1da177e4 LT |
784 | } |
785 | ||
f9e053dc PH |
786 | void start_tty(struct tty_struct *tty) |
787 | { | |
788 | unsigned long flags; | |
789 | ||
790 | spin_lock_irqsave(&tty->flow_lock, flags); | |
791 | __start_tty(tty); | |
792 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
793 | } | |
1da177e4 LT |
794 | EXPORT_SYMBOL(start_tty); |
795 | ||
37b7f3c7 JS |
796 | static void tty_update_time(struct timespec *time) |
797 | { | |
f0bf0bd0 | 798 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
799 | |
800 | /* | |
801 | * We only care if the two values differ in anything other than the | |
802 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
803 | * the time of the tty device, otherwise it could be construded as a | |
804 | * security leak to let userspace know the exact timing of the tty. | |
805 | */ | |
806 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
807 | time->tv_sec = sec; |
808 | } | |
809 | ||
af9b897e AC |
810 | /** |
811 | * tty_read - read method for tty device files | |
812 | * @file: pointer to tty file | |
813 | * @buf: user buffer | |
814 | * @count: size of user buffer | |
815 | * @ppos: unused | |
816 | * | |
817 | * Perform the read system call function on this terminal device. Checks | |
818 | * for hung up devices before calling the line discipline method. | |
819 | * | |
820 | * Locking: | |
47f86834 AC |
821 | * Locks the line discipline internally while needed. Multiple |
822 | * read calls may be outstanding in parallel. | |
af9b897e AC |
823 | */ |
824 | ||
37bdfb07 | 825 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
826 | loff_t *ppos) |
827 | { | |
828 | int i; | |
37b7f3c7 | 829 | struct inode *inode = file_inode(file); |
d996b62a | 830 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
831 | struct tty_ldisc *ld; |
832 | ||
37b7f3c7 | 833 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 834 | return -EIO; |
18900ca6 | 835 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
836 | return -EIO; |
837 | ||
838 | /* We want to wait for the line discipline to sort out in this | |
839 | situation */ | |
840 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
841 | if (!ld) |
842 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 843 | if (ld->ops->read) |
c961bfb1 | 844 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
845 | else |
846 | i = -EIO; | |
847 | tty_ldisc_deref(ld); | |
b0de59b5 | 848 | |
37b7f3c7 JS |
849 | if (i > 0) |
850 | tty_update_time(&inode->i_atime); | |
851 | ||
1da177e4 LT |
852 | return i; |
853 | } | |
854 | ||
136d5258 | 855 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
856 | { |
857 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 858 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
859 | } |
860 | ||
136d5258 | 861 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
862 | { |
863 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
864 | if (ndelay) | |
865 | return -EAGAIN; | |
866 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
867 | return -ERESTARTSYS; | |
868 | } | |
869 | return 0; | |
870 | } | |
871 | ||
1da177e4 LT |
872 | /* |
873 | * Split writes up in sane blocksizes to avoid | |
874 | * denial-of-service type attacks | |
875 | */ | |
876 | static inline ssize_t do_tty_write( | |
877 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
878 | struct tty_struct *tty, | |
879 | struct file *file, | |
880 | const char __user *buf, | |
881 | size_t count) | |
882 | { | |
9c1729db | 883 | ssize_t ret, written = 0; |
1da177e4 | 884 | unsigned int chunk; |
37bdfb07 | 885 | |
9c1729db AC |
886 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
887 | if (ret < 0) | |
888 | return ret; | |
1da177e4 LT |
889 | |
890 | /* | |
891 | * We chunk up writes into a temporary buffer. This | |
892 | * simplifies low-level drivers immensely, since they | |
893 | * don't have locking issues and user mode accesses. | |
894 | * | |
895 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
896 | * big chunk-size.. | |
897 | * | |
898 | * The default chunk-size is 2kB, because the NTTY | |
899 | * layer has problems with bigger chunks. It will | |
900 | * claim to be able to handle more characters than | |
901 | * it actually does. | |
af9b897e AC |
902 | * |
903 | * FIXME: This can probably go away now except that 64K chunks | |
904 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
905 | */ |
906 | chunk = 2048; | |
907 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
908 | chunk = 65536; | |
909 | if (count < chunk) | |
910 | chunk = count; | |
911 | ||
70522e12 | 912 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 913 | if (tty->write_cnt < chunk) { |
402fda92 | 914 | unsigned char *buf_chunk; |
1da177e4 LT |
915 | |
916 | if (chunk < 1024) | |
917 | chunk = 1024; | |
918 | ||
402fda92 JW |
919 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
920 | if (!buf_chunk) { | |
9c1729db AC |
921 | ret = -ENOMEM; |
922 | goto out; | |
1da177e4 LT |
923 | } |
924 | kfree(tty->write_buf); | |
925 | tty->write_cnt = chunk; | |
402fda92 | 926 | tty->write_buf = buf_chunk; |
1da177e4 LT |
927 | } |
928 | ||
929 | /* Do the write .. */ | |
930 | for (;;) { | |
931 | size_t size = count; | |
932 | if (size > chunk) | |
933 | size = chunk; | |
934 | ret = -EFAULT; | |
935 | if (copy_from_user(tty->write_buf, buf, size)) | |
936 | break; | |
1da177e4 | 937 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
938 | if (ret <= 0) |
939 | break; | |
940 | written += ret; | |
941 | buf += ret; | |
942 | count -= ret; | |
943 | if (!count) | |
944 | break; | |
945 | ret = -ERESTARTSYS; | |
946 | if (signal_pending(current)) | |
947 | break; | |
948 | cond_resched(); | |
949 | } | |
37b7f3c7 JS |
950 | if (written) { |
951 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 952 | ret = written; |
37b7f3c7 | 953 | } |
9c1729db AC |
954 | out: |
955 | tty_write_unlock(tty); | |
1da177e4 LT |
956 | return ret; |
957 | } | |
958 | ||
95f9bfc6 AC |
959 | /** |
960 | * tty_write_message - write a message to a certain tty, not just the console. | |
961 | * @tty: the destination tty_struct | |
962 | * @msg: the message to write | |
963 | * | |
964 | * This is used for messages that need to be redirected to a specific tty. | |
965 | * We don't put it into the syslog queue right now maybe in the future if | |
966 | * really needed. | |
967 | * | |
ec79d605 | 968 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
969 | */ |
970 | ||
971 | void tty_write_message(struct tty_struct *tty, char *msg) | |
972 | { | |
95f9bfc6 AC |
973 | if (tty) { |
974 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 975 | tty_lock(tty); |
4b41b953 | 976 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 977 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 978 | tty_unlock(tty); |
95f9bfc6 AC |
979 | tty_write_unlock(tty); |
980 | } | |
95f9bfc6 AC |
981 | return; |
982 | } | |
983 | ||
1da177e4 | 984 | |
af9b897e AC |
985 | /** |
986 | * tty_write - write method for tty device file | |
987 | * @file: tty file pointer | |
988 | * @buf: user data to write | |
989 | * @count: bytes to write | |
990 | * @ppos: unused | |
991 | * | |
992 | * Write data to a tty device via the line discipline. | |
993 | * | |
994 | * Locking: | |
995 | * Locks the line discipline as required | |
996 | * Writes to the tty driver are serialized by the atomic_write_lock | |
997 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 998 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
999 | */ |
1000 | ||
37bdfb07 AC |
1001 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1002 | size_t count, loff_t *ppos) | |
1da177e4 | 1003 | { |
d996b62a NP |
1004 | struct tty_struct *tty = file_tty(file); |
1005 | struct tty_ldisc *ld; | |
1da177e4 | 1006 | ssize_t ret; |
37bdfb07 | 1007 | |
6131ffaa | 1008 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1009 | return -EIO; |
18900ca6 | 1010 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
37bdfb07 | 1011 | return -EIO; |
f34d7a5b AC |
1012 | /* Short term debug to catch buggy drivers */ |
1013 | if (tty->ops->write_room == NULL) | |
339f36ba | 1014 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1015 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1016 | if (!ld) |
1017 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1018 | if (!ld->ops->write) |
1da177e4 LT |
1019 | ret = -EIO; |
1020 | else | |
a352def2 | 1021 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1022 | tty_ldisc_deref(ld); |
1023 | return ret; | |
1024 | } | |
1025 | ||
37bdfb07 AC |
1026 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1027 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1028 | { |
1029 | struct file *p = NULL; | |
1030 | ||
1031 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1032 | if (redirect) |
1033 | p = get_file(redirect); | |
1da177e4 LT |
1034 | spin_unlock(&redirect_lock); |
1035 | ||
1036 | if (p) { | |
1037 | ssize_t res; | |
1038 | res = vfs_write(p, buf, count, &p->f_pos); | |
1039 | fput(p); | |
1040 | return res; | |
1041 | } | |
1da177e4 LT |
1042 | return tty_write(file, buf, count, ppos); |
1043 | } | |
1044 | ||
136d5258 PH |
1045 | /** |
1046 | * tty_send_xchar - send priority character | |
1047 | * | |
1048 | * Send a high priority character to the tty even if stopped | |
1049 | * | |
1050 | * Locking: none for xchar method, write ordering for write method. | |
1051 | */ | |
1052 | ||
1053 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1054 | { | |
1055 | int was_stopped = tty->stopped; | |
1056 | ||
1057 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1058 | down_read(&tty->termios_rwsem); |
136d5258 | 1059 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1060 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1061 | return 0; |
1062 | } | |
1063 | ||
1064 | if (tty_write_lock(tty, 0) < 0) | |
1065 | return -ERESTARTSYS; | |
1066 | ||
ee0c1a65 | 1067 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1068 | if (was_stopped) |
1069 | start_tty(tty); | |
1070 | tty->ops->write(tty, &ch, 1); | |
1071 | if (was_stopped) | |
1072 | stop_tty(tty); | |
ee0c1a65 | 1073 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1074 | tty_write_unlock(tty); |
1075 | return 0; | |
1076 | } | |
1077 | ||
1da177e4 LT |
1078 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1079 | ||
af9b897e AC |
1080 | /** |
1081 | * pty_line_name - generate name for a pty | |
1082 | * @driver: the tty driver in use | |
1083 | * @index: the minor number | |
1084 | * @p: output buffer of at least 6 bytes | |
1085 | * | |
1086 | * Generate a name from a driver reference and write it to the output | |
1087 | * buffer. | |
1088 | * | |
1089 | * Locking: None | |
1090 | */ | |
1091 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1092 | { |
1093 | int i = index + driver->name_base; | |
1094 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1095 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1096 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1097 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1098 | } |
1099 | ||
af9b897e | 1100 | /** |
8b0a88d5 | 1101 | * tty_line_name - generate name for a tty |
af9b897e AC |
1102 | * @driver: the tty driver in use |
1103 | * @index: the minor number | |
1104 | * @p: output buffer of at least 7 bytes | |
1105 | * | |
1106 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1107 | * buffer. |
af9b897e AC |
1108 | * |
1109 | * Locking: None | |
1110 | */ | |
723abd87 | 1111 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1112 | { |
0019b408 | 1113 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1114 | return sprintf(p, "%s", driver->name); |
0019b408 | 1115 | else |
723abd87 HR |
1116 | return sprintf(p, "%s%d", driver->name, |
1117 | index + driver->name_base); | |
1da177e4 LT |
1118 | } |
1119 | ||
99f1fe18 AC |
1120 | /** |
1121 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1122 | * @driver: the driver for the tty | |
1123 | * @idx: the minor number | |
23499705 | 1124 | * |
aa3cb814 PH |
1125 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1126 | * driver lookup() method returns an error. | |
23499705 | 1127 | * |
aa3cb814 | 1128 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1129 | */ |
a47d545f | 1130 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1131 | struct file *file, int idx) |
23499705 | 1132 | { |
aa3cb814 PH |
1133 | struct tty_struct *tty; |
1134 | ||
99f1fe18 | 1135 | if (driver->ops->lookup) |
12e84c71 OK |
1136 | if (!file) |
1137 | tty = ERR_PTR(-EIO); | |
1138 | else | |
1139 | tty = driver->ops->lookup(driver, file, idx); | |
aa3cb814 PH |
1140 | else |
1141 | tty = driver->ttys[idx]; | |
23499705 | 1142 | |
aa3cb814 PH |
1143 | if (!IS_ERR(tty)) |
1144 | tty_kref_get(tty); | |
1145 | return tty; | |
23499705 SB |
1146 | } |
1147 | ||
bf970ee4 AC |
1148 | /** |
1149 | * tty_init_termios - helper for termios setup | |
1150 | * @tty: the tty to set up | |
1151 | * | |
1152 | * Initialise the termios structures for this tty. Thus runs under | |
1153 | * the tty_mutex currently so we can be relaxed about ordering. | |
1154 | */ | |
1155 | ||
a3123fd0 | 1156 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1157 | { |
fe6e29fd | 1158 | struct ktermios *tp; |
bf970ee4 AC |
1159 | int idx = tty->index; |
1160 | ||
36b3c070 AC |
1161 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1162 | tty->termios = tty->driver->init_termios; | |
1163 | else { | |
1164 | /* Check for lazy saved data */ | |
1165 | tp = tty->driver->termios[idx]; | |
ece53405 | 1166 | if (tp != NULL) { |
36b3c070 | 1167 | tty->termios = *tp; |
ece53405 PH |
1168 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1169 | } else | |
36b3c070 | 1170 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1171 | } |
bf970ee4 | 1172 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1173 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1174 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1175 | } |
fe1ae7fd | 1176 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1177 | |
66d450e8 JS |
1178 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1179 | { | |
a3123fd0 | 1180 | tty_init_termios(tty); |
66d450e8 JS |
1181 | tty_driver_kref_get(driver); |
1182 | tty->count++; | |
1183 | driver->ttys[tty->index] = tty; | |
1184 | return 0; | |
1185 | } | |
1186 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1187 | ||
99f1fe18 | 1188 | /** |
8b0a88d5 AC |
1189 | * tty_driver_install_tty() - install a tty entry in the driver |
1190 | * @driver: the driver for the tty | |
1191 | * @tty: the tty | |
1192 | * | |
1193 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1194 | * will be set by the time this is called. This method is responsible |
1195 | * for ensuring any need additional structures are allocated and | |
1196 | * configured. | |
8b0a88d5 AC |
1197 | * |
1198 | * Locking: tty_mutex for now | |
1199 | */ | |
1200 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1201 | struct tty_struct *tty) | |
1202 | { | |
66d450e8 JS |
1203 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1204 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1205 | } |
1206 | ||
1207 | /** | |
1208 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1209 | * @driver: the driver for the tty | |
1210 | * @idx: the minor number | |
1211 | * | |
1212 | * Remvoe a tty object from the driver tables. The tty->index field | |
1213 | * will be set by the time this is called. | |
1214 | * | |
1215 | * Locking: tty_mutex for now | |
1216 | */ | |
05de87ed | 1217 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1218 | { |
1219 | if (driver->ops->remove) | |
1220 | driver->ops->remove(driver, tty); | |
1221 | else | |
1222 | driver->ttys[tty->index] = NULL; | |
1223 | } | |
1224 | ||
1225 | /* | |
1226 | * tty_reopen() - fast re-open of an open tty | |
1227 | * @tty - the tty to open | |
23499705 | 1228 | * |
99f1fe18 | 1229 | * Return 0 on success, -errno on error. |
5d93e748 | 1230 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1231 | * |
5d93e748 | 1232 | * Locking: Caller must hold tty_lock |
23499705 | 1233 | */ |
99f1fe18 | 1234 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1235 | { |
1236 | struct tty_driver *driver = tty->driver; | |
1237 | ||
23499705 | 1238 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1239 | driver->subtype == PTY_TYPE_MASTER) |
1240 | return -EIO; | |
23499705 | 1241 | |
7f22f6c9 PH |
1242 | if (!tty->count) |
1243 | return -EAGAIN; | |
1244 | ||
86f2c00f PH |
1245 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1246 | return -EBUSY; | |
1247 | ||
23499705 | 1248 | tty->count++; |
23499705 | 1249 | |
892d1fa7 PH |
1250 | if (!tty->ldisc) |
1251 | return tty_ldisc_reinit(tty, tty->termios.c_line); | |
23499705 SB |
1252 | |
1253 | return 0; | |
1254 | } | |
1255 | ||
af9b897e | 1256 | /** |
d81ed103 | 1257 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1258 | * @driver: tty driver we are opening a device on |
1259 | * @idx: device index | |
15582d36 | 1260 | * @ret_tty: returned tty structure |
af9b897e AC |
1261 | * |
1262 | * Prepare a tty device. This may not be a "new" clean device but | |
1263 | * could also be an active device. The pty drivers require special | |
1264 | * handling because of this. | |
1265 | * | |
1266 | * Locking: | |
1267 | * The function is called under the tty_mutex, which | |
1268 | * protects us from the tty struct or driver itself going away. | |
1269 | * | |
1270 | * On exit the tty device has the line discipline attached and | |
1271 | * a reference count of 1. If a pair was created for pty/tty use | |
1272 | * and the other was a pty master then it too has a reference count of 1. | |
1273 | * | |
1da177e4 | 1274 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1275 | * failed open. The new code protects the open with a mutex, so it's |
1276 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1277 | * relaxed for the (most common) case of reopening a tty. |
1278 | */ | |
af9b897e | 1279 | |
593a27c4 | 1280 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1281 | { |
bf970ee4 | 1282 | struct tty_struct *tty; |
73ec06fc | 1283 | int retval; |
1da177e4 | 1284 | |
1da177e4 LT |
1285 | /* |
1286 | * First time open is complex, especially for PTY devices. | |
1287 | * This code guarantees that either everything succeeds and the | |
1288 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1289 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1290 | * may be retained.) |
1da177e4 LT |
1291 | */ |
1292 | ||
73ec06fc AC |
1293 | if (!try_module_get(driver->owner)) |
1294 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1295 | |
2c964a2f | 1296 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1297 | if (!tty) { |
1298 | retval = -ENOMEM; | |
1299 | goto err_module_put; | |
1300 | } | |
1da177e4 | 1301 | |
89c8d91e | 1302 | tty_lock(tty); |
73ec06fc | 1303 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1304 | if (retval < 0) |
c8b710b3 | 1305 | goto err_free_tty; |
8b0a88d5 | 1306 | |
04831dc1 JS |
1307 | if (!tty->port) |
1308 | tty->port = driver->ports[idx]; | |
1309 | ||
5d4121c0 JS |
1310 | WARN_RATELIMIT(!tty->port, |
1311 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1312 | __func__, tty->driver->name); | |
1313 | ||
967fab69 JS |
1314 | tty->port->itty = tty; |
1315 | ||
37bdfb07 | 1316 | /* |
1da177e4 | 1317 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1318 | * If we fail here just call release_tty to clean up. No need |
1319 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1320 | */ |
bf970ee4 | 1321 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1322 | if (retval) |
d5543503 | 1323 | goto err_release_tty; |
89c8d91e | 1324 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1325 | return tty; |
1da177e4 | 1326 | |
c8b710b3 | 1327 | err_free_tty: |
89c8d91e | 1328 | tty_unlock(tty); |
d5543503 JS |
1329 | free_tty_struct(tty); |
1330 | err_module_put: | |
1da177e4 | 1331 | module_put(driver->owner); |
d5543503 | 1332 | return ERR_PTR(retval); |
1da177e4 | 1333 | |
d5698c28 | 1334 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1335 | err_release_tty: |
89c8d91e | 1336 | tty_unlock(tty); |
339f36ba PH |
1337 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1338 | retval, idx); | |
d5698c28 | 1339 | release_tty(tty, idx); |
73ec06fc | 1340 | return ERR_PTR(retval); |
1da177e4 LT |
1341 | } |
1342 | ||
a3123fd0 | 1343 | static void tty_free_termios(struct tty_struct *tty) |
feebed65 AC |
1344 | { |
1345 | struct ktermios *tp; | |
1346 | int idx = tty->index; | |
36b3c070 AC |
1347 | |
1348 | /* If the port is going to reset then it has no termios to save */ | |
1349 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1350 | return; | |
1351 | ||
1352 | /* Stash the termios data */ | |
1353 | tp = tty->driver->termios[idx]; | |
1354 | if (tp == NULL) { | |
1355 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1356 | if (tp == NULL) |
36b3c070 | 1357 | return; |
4ac5d705 | 1358 | tty->driver->termios[idx] = tp; |
feebed65 | 1359 | } |
36b3c070 | 1360 | *tp = tty->termios; |
feebed65 | 1361 | } |
feebed65 | 1362 | |
a2965b7b | 1363 | /** |
949aa64f PH |
1364 | * tty_flush_works - flush all works of a tty/pty pair |
1365 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1366 | * |
949aa64f | 1367 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1368 | */ |
1369 | static void tty_flush_works(struct tty_struct *tty) | |
1370 | { | |
1371 | flush_work(&tty->SAK_work); | |
1372 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1373 | if (tty->link) { |
1374 | flush_work(&tty->link->SAK_work); | |
1375 | flush_work(&tty->link->hangup_work); | |
1376 | } | |
a2965b7b | 1377 | } |
feebed65 | 1378 | |
af9b897e | 1379 | /** |
d5698c28 | 1380 | * release_one_tty - release tty structure memory |
9c9f4ded | 1381 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1382 | * |
1383 | * Releases memory associated with a tty structure, and clears out the | |
1384 | * driver table slots. This function is called when a device is no longer | |
1385 | * in use. It also gets called when setup of a device fails. | |
1386 | * | |
1387 | * Locking: | |
af9b897e AC |
1388 | * takes the file list lock internally when working on the list |
1389 | * of ttys that the driver keeps. | |
b50989dc AC |
1390 | * |
1391 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1392 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1393 | */ |
b50989dc | 1394 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1395 | { |
b50989dc AC |
1396 | struct tty_struct *tty = |
1397 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1398 | struct tty_driver *driver = tty->driver; |
b216df53 | 1399 | struct module *owner = driver->owner; |
d5698c28 | 1400 | |
f278a2f7 DY |
1401 | if (tty->ops->cleanup) |
1402 | tty->ops->cleanup(tty); | |
1403 | ||
1da177e4 | 1404 | tty->magic = 0; |
7d7b93c1 | 1405 | tty_driver_kref_put(driver); |
b216df53 | 1406 | module_put(owner); |
d5698c28 | 1407 | |
4a510969 | 1408 | spin_lock(&tty->files_lock); |
1da177e4 | 1409 | list_del_init(&tty->tty_files); |
4a510969 | 1410 | spin_unlock(&tty->files_lock); |
d5698c28 | 1411 | |
6da8d866 ON |
1412 | put_pid(tty->pgrp); |
1413 | put_pid(tty->session); | |
1da177e4 LT |
1414 | free_tty_struct(tty); |
1415 | } | |
1416 | ||
b50989dc AC |
1417 | static void queue_release_one_tty(struct kref *kref) |
1418 | { | |
1419 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1420 | |
b50989dc AC |
1421 | /* The hangup queue is now free so we can reuse it rather than |
1422 | waste a chunk of memory for each port */ | |
1423 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1424 | schedule_work(&tty->hangup_work); | |
1425 | } | |
1426 | ||
9c9f4ded AC |
1427 | /** |
1428 | * tty_kref_put - release a tty kref | |
1429 | * @tty: tty device | |
1430 | * | |
1431 | * Release a reference to a tty device and if need be let the kref | |
1432 | * layer destruct the object for us | |
1433 | */ | |
1434 | ||
1435 | void tty_kref_put(struct tty_struct *tty) | |
1436 | { | |
1437 | if (tty) | |
b50989dc | 1438 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1439 | } |
1440 | EXPORT_SYMBOL(tty_kref_put); | |
1441 | ||
d5698c28 CH |
1442 | /** |
1443 | * release_tty - release tty structure memory | |
1444 | * | |
1445 | * Release both @tty and a possible linked partner (think pty pair), | |
1446 | * and decrement the refcount of the backing module. | |
1447 | * | |
1448 | * Locking: | |
d155255a | 1449 | * tty_mutex |
d5698c28 CH |
1450 | * takes the file list lock internally when working on the list |
1451 | * of ttys that the driver keeps. | |
9c9f4ded | 1452 | * |
d5698c28 CH |
1453 | */ |
1454 | static void release_tty(struct tty_struct *tty, int idx) | |
1455 | { | |
9c9f4ded AC |
1456 | /* This should always be true but check for the moment */ |
1457 | WARN_ON(tty->index != idx); | |
d155255a | 1458 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1459 | if (tty->ops->shutdown) |
1460 | tty->ops->shutdown(tty); | |
1461 | tty_free_termios(tty); | |
1462 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1463 | tty->port->itty = NULL; |
64e377dc PH |
1464 | if (tty->link) |
1465 | tty->link->port->itty = NULL; | |
e176058f | 1466 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1467 | |
a211b1af | 1468 | tty_kref_put(tty->link); |
9c9f4ded | 1469 | tty_kref_put(tty); |
d5698c28 CH |
1470 | } |
1471 | ||
955787ca JS |
1472 | /** |
1473 | * tty_release_checks - check a tty before real release | |
1474 | * @tty: tty to check | |
1475 | * @o_tty: link of @tty (if any) | |
1476 | * @idx: index of the tty | |
1477 | * | |
1478 | * Performs some paranoid checking before true release of the @tty. | |
1479 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1480 | */ | |
359b9fb5 | 1481 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1482 | { |
1483 | #ifdef TTY_PARANOIA_CHECK | |
1484 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1485 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1486 | return -1; |
1487 | } | |
1488 | ||
1489 | /* not much to check for devpts */ | |
1490 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1491 | return 0; | |
1492 | ||
1493 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1494 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1495 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1496 | return -1; |
1497 | } | |
955787ca | 1498 | if (tty->driver->other) { |
359b9fb5 PH |
1499 | struct tty_struct *o_tty = tty->link; |
1500 | ||
955787ca | 1501 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1502 | tty_debug(tty, "bad other table[%d] = %p\n", |
1503 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1504 | return -1; |
1505 | } | |
955787ca | 1506 | if (o_tty->link != tty) { |
e2dfa3d3 | 1507 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1508 | return -1; |
1509 | } | |
1510 | } | |
1511 | #endif | |
1512 | return 0; | |
1513 | } | |
1514 | ||
9ed90d20 RH |
1515 | /** |
1516 | * tty_release_struct - release a tty struct | |
1517 | * @tty: tty device | |
1518 | * @idx: index of the tty | |
1519 | * | |
1520 | * Performs the final steps to release and free a tty device. It is | |
1521 | * roughly the reverse of tty_init_dev. | |
1522 | */ | |
1523 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1524 | { | |
1525 | /* | |
1526 | * Ask the line discipline code to release its structures | |
1527 | */ | |
1528 | tty_ldisc_release(tty); | |
1529 | ||
1530 | /* Wait for pending work before tty destruction commmences */ | |
1531 | tty_flush_works(tty); | |
1532 | ||
1533 | tty_debug_hangup(tty, "freeing structure\n"); | |
1534 | /* | |
1535 | * The release_tty function takes care of the details of clearing | |
1536 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1537 | * should be safe as we keep a kref while the tty is locked (so the | |
1538 | * unlock never unlocks a freed tty). | |
1539 | */ | |
1540 | mutex_lock(&tty_mutex); | |
1541 | release_tty(tty, idx); | |
1542 | mutex_unlock(&tty_mutex); | |
1543 | } | |
1544 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1545 | ||
eeb89d91 AC |
1546 | /** |
1547 | * tty_release - vfs callback for close | |
1548 | * @inode: inode of tty | |
1549 | * @filp: file pointer for handle to tty | |
1550 | * | |
1551 | * Called the last time each file handle is closed that references | |
1552 | * this tty. There may however be several such references. | |
1553 | * | |
1554 | * Locking: | |
1555 | * Takes bkl. See tty_release_dev | |
1556 | * | |
1da177e4 LT |
1557 | * Even releasing the tty structures is a tricky business.. We have |
1558 | * to be very careful that the structures are all released at the | |
1559 | * same time, as interrupts might otherwise get the wrong pointers. | |
1560 | * | |
1561 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1562 | * lead to double frees or releasing memory still in use. | |
1563 | */ | |
eeb89d91 AC |
1564 | |
1565 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1566 | { |
d996b62a | 1567 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1568 | struct tty_struct *o_tty = NULL; |
1569 | int do_sleep, final; | |
1da177e4 | 1570 | int idx; |
37b16457 | 1571 | long timeout = 0; |
494c1eac | 1572 | int once = 1; |
37bdfb07 | 1573 | |
9de44bd6 | 1574 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1575 | return 0; |
1da177e4 | 1576 | |
89c8d91e | 1577 | tty_lock(tty); |
9de44bd6 | 1578 | check_tty_count(tty, __func__); |
1da177e4 | 1579 | |
ec79d605 | 1580 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1581 | |
1582 | idx = tty->index; | |
7ffb6da9 PH |
1583 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1584 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1585 | o_tty = tty->link; | |
1da177e4 | 1586 | |
359b9fb5 | 1587 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1588 | tty_unlock(tty); |
eeb89d91 | 1589 | return 0; |
1da177e4 | 1590 | } |
1da177e4 | 1591 | |
d435cefe | 1592 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1593 | |
f34d7a5b AC |
1594 | if (tty->ops->close) |
1595 | tty->ops->close(tty, filp); | |
1da177e4 | 1596 | |
2aff5e2b PH |
1597 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1598 | tty_lock_slave(o_tty); | |
1599 | ||
1da177e4 LT |
1600 | /* |
1601 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1602 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1603 | * wait queues and kick everyone out _before_ actually starting to | |
1604 | * close. This ensures that we won't block while releasing the tty | |
1605 | * structure. | |
1606 | * | |
1607 | * The test for the o_tty closing is necessary, since the master and | |
1608 | * slave sides may close in any order. If the slave side closes out | |
1609 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1610 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1611 | * so we do it now. |
1da177e4 LT |
1612 | */ |
1613 | while (1) { | |
1da177e4 LT |
1614 | do_sleep = 0; |
1615 | ||
324c1650 | 1616 | if (tty->count <= 1) { |
1da177e4 | 1617 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1618 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1619 | do_sleep++; |
1620 | } | |
1621 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1622 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1623 | do_sleep++; |
1624 | } | |
1625 | } | |
7ffb6da9 | 1626 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1627 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1628 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1629 | do_sleep++; |
1630 | } | |
1631 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1632 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1633 | do_sleep++; |
1634 | } | |
1635 | } | |
1636 | if (!do_sleep) | |
1637 | break; | |
1638 | ||
494c1eac PH |
1639 | if (once) { |
1640 | once = 0; | |
339f36ba | 1641 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1642 | } |
37b16457 PH |
1643 | schedule_timeout_killable(timeout); |
1644 | if (timeout < 120 * HZ) | |
1645 | timeout = 2 * timeout + 1; | |
1646 | else | |
1647 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1648 | } |
1da177e4 | 1649 | |
7ffb6da9 | 1650 | if (o_tty) { |
1da177e4 | 1651 | if (--o_tty->count < 0) { |
339f36ba | 1652 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1653 | o_tty->count = 0; |
1654 | } | |
1655 | } | |
1656 | if (--tty->count < 0) { | |
339f36ba | 1657 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1658 | tty->count = 0; |
1659 | } | |
37bdfb07 | 1660 | |
1da177e4 LT |
1661 | /* |
1662 | * We've decremented tty->count, so we need to remove this file | |
1663 | * descriptor off the tty->tty_files list; this serves two | |
1664 | * purposes: | |
1665 | * - check_tty_count sees the correct number of file descriptors | |
1666 | * associated with this tty. | |
1667 | * - do_tty_hangup no longer sees this file descriptor as | |
1668 | * something that needs to be handled for hangups. | |
1669 | */ | |
d996b62a | 1670 | tty_del_file(filp); |
1da177e4 LT |
1671 | |
1672 | /* | |
1673 | * Perform some housekeeping before deciding whether to return. | |
1674 | * | |
1da177e4 LT |
1675 | * If _either_ side is closing, make sure there aren't any |
1676 | * processes that still think tty or o_tty is their controlling | |
1677 | * tty. | |
1678 | */ | |
324c1650 | 1679 | if (!tty->count) { |
1da177e4 | 1680 | read_lock(&tasklist_lock); |
24ec839c | 1681 | session_clear_tty(tty->session); |
7ffb6da9 | 1682 | if (o_tty) |
24ec839c | 1683 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1684 | read_unlock(&tasklist_lock); |
1685 | } | |
1686 | ||
324c1650 | 1687 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1688 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1689 | |
2aff5e2b PH |
1690 | tty_unlock_slave(o_tty); |
1691 | tty_unlock(tty); | |
1692 | ||
04980706 | 1693 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1694 | cannot be re-opened by a racing opener */ |
da965822 | 1695 | |
324c1650 | 1696 | if (!final) |
eeb89d91 | 1697 | return 0; |
37bdfb07 | 1698 | |
accff793 | 1699 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1700 | |
9ed90d20 | 1701 | tty_release_struct(tty, idx); |
eeb89d91 | 1702 | return 0; |
1da177e4 LT |
1703 | } |
1704 | ||
b82154ac | 1705 | /** |
52494eeb | 1706 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1707 | * @device: device number |
1708 | * @filp: file pointer to tty | |
52494eeb PH |
1709 | * @return: locked tty of the current task iff @device is /dev/tty |
1710 | * | |
1711 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1712 | * |
1713 | * We cannot return driver and index like for the other nodes because | |
1714 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1715 | */ | |
1716 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1717 | { | |
1718 | struct tty_struct *tty; | |
52494eeb | 1719 | int retval; |
b82154ac JS |
1720 | |
1721 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1722 | return NULL; | |
1723 | ||
1724 | tty = get_current_tty(); | |
1725 | if (!tty) | |
1726 | return ERR_PTR(-ENXIO); | |
1727 | ||
1728 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1729 | /* noctty = 1; */ | |
52494eeb PH |
1730 | tty_lock(tty); |
1731 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1732 | ||
1733 | retval = tty_reopen(tty); | |
1734 | if (retval < 0) { | |
1735 | tty_unlock(tty); | |
1736 | tty = ERR_PTR(retval); | |
1737 | } | |
b82154ac JS |
1738 | return tty; |
1739 | } | |
1740 | ||
5b5e7040 JS |
1741 | /** |
1742 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1743 | * @device: device number | |
1744 | * @filp: file pointer to tty | |
5b5e7040 JS |
1745 | * @index: index for the device in the @return driver |
1746 | * @return: driver for this inode (with increased refcount) | |
1747 | * | |
1748 | * If @return is not erroneous, the caller is responsible to decrement the | |
1749 | * refcount by tty_driver_kref_put. | |
1750 | * | |
1751 | * Locking: tty_mutex protects get_tty_driver | |
1752 | */ | |
1753 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1754 | int *index) |
5b5e7040 JS |
1755 | { |
1756 | struct tty_driver *driver; | |
1757 | ||
2cd0050c | 1758 | switch (device) { |
5b5e7040 | 1759 | #ifdef CONFIG_VT |
2cd0050c | 1760 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1761 | extern struct tty_driver *console_driver; |
1762 | driver = tty_driver_kref_get(console_driver); | |
1763 | *index = fg_console; | |
2cd0050c | 1764 | break; |
5b5e7040 JS |
1765 | } |
1766 | #endif | |
2cd0050c | 1767 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1768 | struct tty_driver *console_driver = console_device(index); |
1769 | if (console_driver) { | |
1770 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1771 | if (driver && filp) { |
5b5e7040 JS |
1772 | /* Don't let /dev/console block */ |
1773 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1774 | break; |
5b5e7040 JS |
1775 | } |
1776 | } | |
1777 | return ERR_PTR(-ENODEV); | |
1778 | } | |
2cd0050c JS |
1779 | default: |
1780 | driver = get_tty_driver(device, index); | |
1781 | if (!driver) | |
1782 | return ERR_PTR(-ENODEV); | |
1783 | break; | |
1784 | } | |
5b5e7040 JS |
1785 | return driver; |
1786 | } | |
1787 | ||
d6203d0c PH |
1788 | /** |
1789 | * tty_open_by_driver - open a tty device | |
1790 | * @device: dev_t of device to open | |
1791 | * @inode: inode of device file | |
1792 | * @filp: file pointer to tty | |
1793 | * | |
1794 | * Performs the driver lookup, checks for a reopen, or otherwise | |
1795 | * performs the first-time tty initialization. | |
1796 | * | |
1797 | * Returns the locked initialized or re-opened &tty_struct | |
1798 | * | |
1799 | * Claims the global tty_mutex to serialize: | |
1800 | * - concurrent first-time tty initialization | |
1801 | * - concurrent tty driver removal w/ lookup | |
1802 | * - concurrent tty removal from driver table | |
1803 | */ | |
12e84c71 | 1804 | struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, |
d6203d0c PH |
1805 | struct file *filp) |
1806 | { | |
1807 | struct tty_struct *tty; | |
1808 | struct tty_driver *driver = NULL; | |
1809 | int index = -1; | |
1810 | int retval; | |
1811 | ||
1812 | mutex_lock(&tty_mutex); | |
1813 | driver = tty_lookup_driver(device, filp, &index); | |
1814 | if (IS_ERR(driver)) { | |
1815 | mutex_unlock(&tty_mutex); | |
1816 | return ERR_CAST(driver); | |
1817 | } | |
1818 | ||
1819 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 1820 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
1821 | if (IS_ERR(tty)) { |
1822 | mutex_unlock(&tty_mutex); | |
1823 | goto out; | |
1824 | } | |
1825 | ||
1826 | if (tty) { | |
1827 | mutex_unlock(&tty_mutex); | |
1828 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 1829 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
1830 | if (retval) { |
1831 | if (retval == -EINTR) | |
1832 | retval = -ERESTARTSYS; | |
1833 | tty = ERR_PTR(retval); | |
1834 | goto out; | |
1835 | } | |
d6203d0c PH |
1836 | retval = tty_reopen(tty); |
1837 | if (retval < 0) { | |
1838 | tty_unlock(tty); | |
1839 | tty = ERR_PTR(retval); | |
1840 | } | |
1841 | } else { /* Returns with the tty_lock held for now */ | |
1842 | tty = tty_init_dev(driver, index); | |
1843 | mutex_unlock(&tty_mutex); | |
1844 | } | |
1845 | out: | |
1846 | tty_driver_kref_put(driver); | |
1847 | return tty; | |
1848 | } | |
12e84c71 | 1849 | EXPORT_SYMBOL_GPL(tty_open_by_driver); |
d6203d0c | 1850 | |
af9b897e | 1851 | /** |
eeb89d91 | 1852 | * tty_open - open a tty device |
af9b897e AC |
1853 | * @inode: inode of device file |
1854 | * @filp: file pointer to tty | |
1da177e4 | 1855 | * |
af9b897e AC |
1856 | * tty_open and tty_release keep up the tty count that contains the |
1857 | * number of opens done on a tty. We cannot use the inode-count, as | |
1858 | * different inodes might point to the same tty. | |
1da177e4 | 1859 | * |
af9b897e AC |
1860 | * Open-counting is needed for pty masters, as well as for keeping |
1861 | * track of serial lines: DTR is dropped when the last close happens. | |
1862 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1863 | * | |
1864 | * The termios state of a pty is reset on first open so that | |
1865 | * settings don't persist across reuse. | |
1866 | * | |
5b5e7040 | 1867 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1868 | * tty->count should protect the rest. |
1869 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
1870 | * |
1871 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
1872 | * tty_mutex | |
1da177e4 | 1873 | */ |
af9b897e | 1874 | |
eeb89d91 | 1875 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1876 | { |
b82154ac | 1877 | struct tty_struct *tty; |
1da177e4 | 1878 | int noctty, retval; |
1da177e4 | 1879 | dev_t device = inode->i_rdev; |
846c151a | 1880 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1881 | |
1882 | nonseekable_open(inode, filp); | |
37bdfb07 | 1883 | |
1da177e4 | 1884 | retry_open: |
fa90e1c9 JS |
1885 | retval = tty_alloc_file(filp); |
1886 | if (retval) | |
1887 | return -ENOMEM; | |
1888 | ||
b82154ac | 1889 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
1890 | if (!tty) |
1891 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 1892 | |
eeb89d91 | 1893 | if (IS_ERR(tty)) { |
d6203d0c | 1894 | tty_free_file(filp); |
ba5db448 | 1895 | retval = PTR_ERR(tty); |
7f22f6c9 | 1896 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 1897 | return retval; |
7f22f6c9 PH |
1898 | schedule(); |
1899 | goto retry_open; | |
eeb89d91 | 1900 | } |
1da177e4 | 1901 | |
fa90e1c9 | 1902 | tty_add_file(tty, filp); |
d996b62a | 1903 | |
9de44bd6 | 1904 | check_tty_count(tty, __func__); |
d435cefe | 1905 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 1906 | |
909bc774 HRK |
1907 | if (tty->ops->open) |
1908 | retval = tty->ops->open(tty, filp); | |
1909 | else | |
1910 | retval = -ENODEV; | |
1da177e4 LT |
1911 | filp->f_flags = saved_flags; |
1912 | ||
1da177e4 | 1913 | if (retval) { |
d435cefe | 1914 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 1915 | |
89c8d91e | 1916 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 1917 | tty_release(inode, filp); |
64ba3dc3 | 1918 | if (retval != -ERESTARTSYS) |
1da177e4 | 1919 | return retval; |
64ba3dc3 AB |
1920 | |
1921 | if (signal_pending(current)) | |
1da177e4 | 1922 | return retval; |
64ba3dc3 | 1923 | |
1da177e4 LT |
1924 | schedule(); |
1925 | /* | |
1926 | * Need to reset f_op in case a hangup happened. | |
1927 | */ | |
1256937f | 1928 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
1929 | filp->f_op = &tty_fops; |
1930 | goto retry_open; | |
1931 | } | |
d4855e1f | 1932 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 1933 | |
11e1d4aa | 1934 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
1935 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
1936 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
1937 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1938 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1939 | if (!noctty) | |
1940 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 1941 | tty_unlock(tty); |
1da177e4 LT |
1942 | return 0; |
1943 | } | |
1944 | ||
39d95b9d JC |
1945 | |
1946 | ||
af9b897e AC |
1947 | /** |
1948 | * tty_poll - check tty status | |
1949 | * @filp: file being polled | |
1950 | * @wait: poll wait structures to update | |
1951 | * | |
1952 | * Call the line discipline polling method to obtain the poll | |
1953 | * status of the device. | |
1954 | * | |
1955 | * Locking: locks called line discipline but ldisc poll method | |
1956 | * may be re-entered freely by other callers. | |
1957 | */ | |
1958 | ||
37bdfb07 | 1959 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 1960 | { |
d996b62a | 1961 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
1962 | struct tty_ldisc *ld; |
1963 | int ret = 0; | |
1964 | ||
6131ffaa | 1965 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 1966 | return 0; |
37bdfb07 | 1967 | |
1da177e4 | 1968 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1969 | if (!ld) |
1970 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 1971 | if (ld->ops->poll) |
c961bfb1 | 1972 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
1973 | tty_ldisc_deref(ld); |
1974 | return ret; | |
1975 | } | |
1976 | ||
ec79d605 | 1977 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 1978 | { |
d996b62a | 1979 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 1980 | unsigned long flags; |
5d1e3230 | 1981 | int retval = 0; |
1da177e4 | 1982 | |
6131ffaa | 1983 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 1984 | goto out; |
37bdfb07 | 1985 | |
1da177e4 LT |
1986 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
1987 | if (retval <= 0) | |
5d1e3230 | 1988 | goto out; |
f6c8dbe6 | 1989 | |
1da177e4 | 1990 | if (on) { |
ab521dc0 EB |
1991 | enum pid_type type; |
1992 | struct pid *pid; | |
f6c8dbe6 | 1993 | |
47f86834 | 1994 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
1995 | if (tty->pgrp) { |
1996 | pid = tty->pgrp; | |
1997 | type = PIDTYPE_PGID; | |
1998 | } else { | |
1999 | pid = task_pid(current); | |
2000 | type = PIDTYPE_PID; | |
2001 | } | |
80e1e823 | 2002 | get_pid(pid); |
70362511 | 2003 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2004 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2005 | put_pid(pid); |
e0b93edd | 2006 | retval = 0; |
1da177e4 | 2007 | } |
5d1e3230 | 2008 | out: |
ec79d605 AB |
2009 | return retval; |
2010 | } | |
2011 | ||
2012 | static int tty_fasync(int fd, struct file *filp, int on) | |
2013 | { | |
89c8d91e | 2014 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2015 | int retval = -ENOTTY; |
89c8d91e AC |
2016 | |
2017 | tty_lock(tty); | |
a8f3a297 PH |
2018 | if (!tty_hung_up_p(filp)) |
2019 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2020 | tty_unlock(tty); |
2021 | ||
5d1e3230 | 2022 | return retval; |
1da177e4 LT |
2023 | } |
2024 | ||
af9b897e AC |
2025 | /** |
2026 | * tiocsti - fake input character | |
2027 | * @tty: tty to fake input into | |
2028 | * @p: pointer to character | |
2029 | * | |
3a4fa0a2 | 2030 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2031 | * input management. |
2032 | * | |
2033 | * FIXME: does not honour flow control ?? | |
2034 | * | |
2035 | * Locking: | |
137084bb | 2036 | * Called functions take tty_ldiscs_lock |
af9b897e | 2037 | * current->signal->tty check is safe without locks |
28298232 AC |
2038 | * |
2039 | * FIXME: may race normal receive processing | |
af9b897e AC |
2040 | */ |
2041 | ||
1da177e4 LT |
2042 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2043 | { | |
2044 | char ch, mbz = 0; | |
2045 | struct tty_ldisc *ld; | |
37bdfb07 | 2046 | |
1da177e4 LT |
2047 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2048 | return -EPERM; | |
2049 | if (get_user(ch, p)) | |
2050 | return -EFAULT; | |
1e641743 | 2051 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2052 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2053 | if (!ld) |
2054 | return -EIO; | |
a352def2 | 2055 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2056 | tty_ldisc_deref(ld); |
2057 | return 0; | |
2058 | } | |
2059 | ||
af9b897e AC |
2060 | /** |
2061 | * tiocgwinsz - implement window query ioctl | |
2062 | * @tty; tty | |
2063 | * @arg: user buffer for result | |
2064 | * | |
808a0d38 | 2065 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2066 | * |
dee4a0be | 2067 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2068 | * is consistent. |
af9b897e AC |
2069 | */ |
2070 | ||
37bdfb07 | 2071 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2072 | { |
808a0d38 AC |
2073 | int err; |
2074 | ||
dee4a0be | 2075 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2076 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2077 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2078 | |
2079 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2080 | } |
2081 | ||
af9b897e | 2082 | /** |
8c9a9dd0 AC |
2083 | * tty_do_resize - resize event |
2084 | * @tty: tty being resized | |
8c9a9dd0 AC |
2085 | * @rows: rows (character) |
2086 | * @cols: cols (character) | |
2087 | * | |
3ad2f3fb | 2088 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2089 | * peform a terminal resize correctly |
af9b897e AC |
2090 | */ |
2091 | ||
fc6f6238 | 2092 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2093 | { |
fc6f6238 | 2094 | struct pid *pgrp; |
1da177e4 | 2095 | |
fc6f6238 | 2096 | /* Lock the tty */ |
dee4a0be | 2097 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2098 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2099 | goto done; |
47f86834 | 2100 | |
5b239542 PH |
2101 | /* Signal the foreground process group */ |
2102 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2103 | if (pgrp) |
2104 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2105 | put_pid(pgrp); |
47f86834 | 2106 | |
8c9a9dd0 | 2107 | tty->winsize = *ws; |
ca9bda00 | 2108 | done: |
dee4a0be | 2109 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2110 | return 0; |
2111 | } | |
4d334fd1 | 2112 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2113 | |
8c9a9dd0 AC |
2114 | /** |
2115 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2116 | * @tty; tty side of tty |
8c9a9dd0 AC |
2117 | * @arg: user buffer for result |
2118 | * | |
2119 | * Copies the user idea of the window size to the kernel. Traditionally | |
2120 | * this is just advisory information but for the Linux console it | |
2121 | * actually has driver level meaning and triggers a VC resize. | |
2122 | * | |
2123 | * Locking: | |
25985edc | 2124 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2125 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2126 | * then calls into the default method. | |
2127 | */ | |
2128 | ||
fc6f6238 | 2129 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2130 | { |
2131 | struct winsize tmp_ws; | |
2132 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2133 | return -EFAULT; | |
2134 | ||
2135 | if (tty->ops->resize) | |
fc6f6238 | 2136 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2137 | else |
fc6f6238 | 2138 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2139 | } |
2140 | ||
af9b897e AC |
2141 | /** |
2142 | * tioccons - allow admin to move logical console | |
2143 | * @file: the file to become console | |
2144 | * | |
25985edc | 2145 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2146 | * |
2147 | * Locking: uses redirect_lock to guard the redirect information | |
2148 | */ | |
2149 | ||
1da177e4 LT |
2150 | static int tioccons(struct file *file) |
2151 | { | |
2152 | if (!capable(CAP_SYS_ADMIN)) | |
2153 | return -EPERM; | |
2154 | if (file->f_op->write == redirected_tty_write) { | |
2155 | struct file *f; | |
2156 | spin_lock(&redirect_lock); | |
2157 | f = redirect; | |
2158 | redirect = NULL; | |
2159 | spin_unlock(&redirect_lock); | |
2160 | if (f) | |
2161 | fput(f); | |
2162 | return 0; | |
2163 | } | |
2164 | spin_lock(&redirect_lock); | |
2165 | if (redirect) { | |
2166 | spin_unlock(&redirect_lock); | |
2167 | return -EBUSY; | |
2168 | } | |
cb0942b8 | 2169 | redirect = get_file(file); |
1da177e4 LT |
2170 | spin_unlock(&redirect_lock); |
2171 | return 0; | |
2172 | } | |
2173 | ||
af9b897e AC |
2174 | /** |
2175 | * fionbio - non blocking ioctl | |
2176 | * @file: file to set blocking value | |
2177 | * @p: user parameter | |
2178 | * | |
2179 | * Historical tty interfaces had a blocking control ioctl before | |
2180 | * the generic functionality existed. This piece of history is preserved | |
2181 | * in the expected tty API of posix OS's. | |
2182 | * | |
6146b9af | 2183 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2184 | */ |
1da177e4 LT |
2185 | |
2186 | static int fionbio(struct file *file, int __user *p) | |
2187 | { | |
2188 | int nonblock; | |
2189 | ||
2190 | if (get_user(nonblock, p)) | |
2191 | return -EFAULT; | |
2192 | ||
db1dd4d3 | 2193 | spin_lock(&file->f_lock); |
1da177e4 LT |
2194 | if (nonblock) |
2195 | file->f_flags |= O_NONBLOCK; | |
2196 | else | |
2197 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2198 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2199 | return 0; |
2200 | } | |
2201 | ||
af9b897e AC |
2202 | /** |
2203 | * tiocsetd - set line discipline | |
2204 | * @tty: tty device | |
2205 | * @p: pointer to user data | |
2206 | * | |
2207 | * Set the line discipline according to user request. | |
2208 | * | |
2209 | * Locking: see tty_set_ldisc, this function is just a helper | |
2210 | */ | |
2211 | ||
1da177e4 LT |
2212 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2213 | { | |
c12da96f | 2214 | int disc; |
04f378b1 | 2215 | int ret; |
1da177e4 | 2216 | |
c12da96f | 2217 | if (get_user(disc, p)) |
1da177e4 | 2218 | return -EFAULT; |
04f378b1 | 2219 | |
c12da96f | 2220 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2221 | |
2222 | return ret; | |
1da177e4 LT |
2223 | } |
2224 | ||
5c17c861 PH |
2225 | /** |
2226 | * tiocgetd - get line discipline | |
2227 | * @tty: tty device | |
2228 | * @p: pointer to user data | |
2229 | * | |
2230 | * Retrieves the line discipline id directly from the ldisc. | |
2231 | * | |
2232 | * Locking: waits for ldisc reference (in case the line discipline | |
2233 | * is changing or the tty is being hungup) | |
2234 | */ | |
2235 | ||
2236 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2237 | { | |
2238 | struct tty_ldisc *ld; | |
2239 | int ret; | |
2240 | ||
2241 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2242 | if (!ld) |
2243 | return -EIO; | |
5c17c861 PH |
2244 | ret = put_user(ld->ops->num, p); |
2245 | tty_ldisc_deref(ld); | |
2246 | return ret; | |
2247 | } | |
2248 | ||
af9b897e AC |
2249 | /** |
2250 | * send_break - performed time break | |
2251 | * @tty: device to break on | |
2252 | * @duration: timeout in mS | |
2253 | * | |
2254 | * Perform a timed break on hardware that lacks its own driver level | |
2255 | * timed break functionality. | |
2256 | * | |
2257 | * Locking: | |
28298232 | 2258 | * atomic_write_lock serializes |
af9b897e | 2259 | * |
af9b897e AC |
2260 | */ |
2261 | ||
b20f3ae5 | 2262 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2263 | { |
9e98966c AC |
2264 | int retval; |
2265 | ||
2266 | if (tty->ops->break_ctl == NULL) | |
2267 | return 0; | |
2268 | ||
2269 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2270 | retval = tty->ops->break_ctl(tty, duration); | |
2271 | else { | |
2272 | /* Do the work ourselves */ | |
2273 | if (tty_write_lock(tty, 0) < 0) | |
2274 | return -EINTR; | |
2275 | retval = tty->ops->break_ctl(tty, -1); | |
2276 | if (retval) | |
2277 | goto out; | |
2278 | if (!signal_pending(current)) | |
2279 | msleep_interruptible(duration); | |
2280 | retval = tty->ops->break_ctl(tty, 0); | |
2281 | out: | |
2282 | tty_write_unlock(tty); | |
2283 | if (signal_pending(current)) | |
2284 | retval = -EINTR; | |
2285 | } | |
2286 | return retval; | |
1da177e4 LT |
2287 | } |
2288 | ||
af9b897e | 2289 | /** |
f34d7a5b | 2290 | * tty_tiocmget - get modem status |
af9b897e AC |
2291 | * @tty: tty device |
2292 | * @file: user file pointer | |
2293 | * @p: pointer to result | |
2294 | * | |
2295 | * Obtain the modem status bits from the tty driver if the feature | |
2296 | * is supported. Return -EINVAL if it is not available. | |
2297 | * | |
2298 | * Locking: none (up to the driver) | |
2299 | */ | |
2300 | ||
60b33c13 | 2301 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2302 | { |
2303 | int retval = -EINVAL; | |
2304 | ||
f34d7a5b | 2305 | if (tty->ops->tiocmget) { |
60b33c13 | 2306 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2307 | |
2308 | if (retval >= 0) | |
2309 | retval = put_user(retval, p); | |
2310 | } | |
2311 | return retval; | |
2312 | } | |
2313 | ||
af9b897e | 2314 | /** |
f34d7a5b | 2315 | * tty_tiocmset - set modem status |
af9b897e | 2316 | * @tty: tty device |
af9b897e AC |
2317 | * @cmd: command - clear bits, set bits or set all |
2318 | * @p: pointer to desired bits | |
2319 | * | |
2320 | * Set the modem status bits from the tty driver if the feature | |
2321 | * is supported. Return -EINVAL if it is not available. | |
2322 | * | |
2323 | * Locking: none (up to the driver) | |
2324 | */ | |
2325 | ||
20b9d177 | 2326 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2327 | unsigned __user *p) |
2328 | { | |
ae677517 AC |
2329 | int retval; |
2330 | unsigned int set, clear, val; | |
1da177e4 | 2331 | |
ae677517 AC |
2332 | if (tty->ops->tiocmset == NULL) |
2333 | return -EINVAL; | |
1da177e4 | 2334 | |
ae677517 AC |
2335 | retval = get_user(val, p); |
2336 | if (retval) | |
2337 | return retval; | |
2338 | set = clear = 0; | |
2339 | switch (cmd) { | |
2340 | case TIOCMBIS: | |
2341 | set = val; | |
2342 | break; | |
2343 | case TIOCMBIC: | |
2344 | clear = val; | |
2345 | break; | |
2346 | case TIOCMSET: | |
2347 | set = val; | |
2348 | clear = ~val; | |
2349 | break; | |
2350 | } | |
2351 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2352 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2353 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2354 | } |
2355 | ||
d281da7f AC |
2356 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2357 | { | |
2358 | int retval = -EINVAL; | |
2359 | struct serial_icounter_struct icount; | |
2360 | memset(&icount, 0, sizeof(icount)); | |
2361 | if (tty->ops->get_icount) | |
2362 | retval = tty->ops->get_icount(tty, &icount); | |
2363 | if (retval != 0) | |
2364 | return retval; | |
2365 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2366 | return -EFAULT; | |
2367 | return 0; | |
2368 | } | |
2369 | ||
8a8ae62f JS |
2370 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2371 | { | |
2372 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2373 | DEFAULT_RATELIMIT_INTERVAL, | |
2374 | DEFAULT_RATELIMIT_BURST); | |
2375 | char comm[TASK_COMM_LEN]; | |
2376 | int flags; | |
2377 | ||
2378 | if (get_user(flags, &ss->flags)) | |
2379 | return; | |
2380 | ||
2381 | flags &= ASYNC_DEPRECATED; | |
2382 | ||
2383 | if (flags && __ratelimit(&depr_flags)) | |
d437fa91 JP |
2384 | pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", |
2385 | __func__, get_task_comm(comm, current), flags); | |
8a8ae62f JS |
2386 | } |
2387 | ||
8f166e00 PH |
2388 | /* |
2389 | * if pty, return the slave side (real_tty) | |
2390 | * otherwise, return self | |
2391 | */ | |
2392 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2393 | { |
2394 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2395 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2396 | tty = tty->link; | |
2397 | return tty; | |
2398 | } | |
e8b70e7d | 2399 | |
1da177e4 LT |
2400 | /* |
2401 | * Split this up, as gcc can choke on it otherwise.. | |
2402 | */ | |
04f378b1 | 2403 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2404 | { |
d996b62a NP |
2405 | struct tty_struct *tty = file_tty(file); |
2406 | struct tty_struct *real_tty; | |
1da177e4 LT |
2407 | void __user *p = (void __user *)arg; |
2408 | int retval; | |
2409 | struct tty_ldisc *ld; | |
37bdfb07 | 2410 | |
6131ffaa | 2411 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2412 | return -EINVAL; |
2413 | ||
e8b70e7d | 2414 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2415 | |
2416 | /* | |
2417 | * Factor out some common prep work | |
2418 | */ | |
2419 | switch (cmd) { | |
2420 | case TIOCSETD: | |
2421 | case TIOCSBRK: | |
2422 | case TIOCCBRK: | |
2423 | case TCSBRK: | |
37bdfb07 | 2424 | case TCSBRKP: |
1da177e4 LT |
2425 | retval = tty_check_change(tty); |
2426 | if (retval) | |
2427 | return retval; | |
2428 | if (cmd != TIOCCBRK) { | |
2429 | tty_wait_until_sent(tty, 0); | |
2430 | if (signal_pending(current)) | |
2431 | return -EINTR; | |
2432 | } | |
2433 | break; | |
2434 | } | |
2435 | ||
9e98966c AC |
2436 | /* |
2437 | * Now do the stuff. | |
2438 | */ | |
1da177e4 | 2439 | switch (cmd) { |
37bdfb07 AC |
2440 | case TIOCSTI: |
2441 | return tiocsti(tty, p); | |
2442 | case TIOCGWINSZ: | |
8f520021 | 2443 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2444 | case TIOCSWINSZ: |
fc6f6238 | 2445 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2446 | case TIOCCONS: |
2447 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2448 | case FIONBIO: | |
2449 | return fionbio(file, p); | |
2450 | case TIOCEXCL: | |
2451 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2452 | return 0; | |
2453 | case TIOCNXCL: | |
2454 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2455 | return 0; | |
84fd7bdf CG |
2456 | case TIOCGEXCL: |
2457 | { | |
2458 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2459 | return put_user(excl, (int __user *)p); | |
2460 | } | |
37bdfb07 | 2461 | case TIOCGETD: |
5c17c861 | 2462 | return tiocgetd(tty, p); |
37bdfb07 AC |
2463 | case TIOCSETD: |
2464 | return tiocsetd(tty, p); | |
3c95c985 KS |
2465 | case TIOCVHANGUP: |
2466 | if (!capable(CAP_SYS_ADMIN)) | |
2467 | return -EPERM; | |
2468 | tty_vhangup(tty); | |
2469 | return 0; | |
b7b8de08 WF |
2470 | case TIOCGDEV: |
2471 | { | |
2472 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2473 | return put_user(ret, (unsigned int __user *)p); | |
2474 | } | |
37bdfb07 AC |
2475 | /* |
2476 | * Break handling | |
2477 | */ | |
2478 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2479 | if (tty->ops->break_ctl) |
9e98966c | 2480 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2481 | return 0; |
37bdfb07 | 2482 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2483 | if (tty->ops->break_ctl) |
9e98966c | 2484 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2485 | return 0; |
2486 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2487 | /* non-zero arg means wait for all output data | |
2488 | * to be sent (performed above) but don't send break. | |
2489 | * This is used by the tcdrain() termios function. | |
2490 | */ | |
2491 | if (!arg) | |
2492 | return send_break(tty, 250); | |
2493 | return 0; | |
2494 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2495 | return send_break(tty, arg ? arg*100 : 250); | |
2496 | ||
2497 | case TIOCMGET: | |
60b33c13 | 2498 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2499 | case TIOCMSET: |
2500 | case TIOCMBIC: | |
2501 | case TIOCMBIS: | |
20b9d177 | 2502 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2503 | case TIOCGICOUNT: |
2504 | retval = tty_tiocgicount(tty, p); | |
2505 | /* For the moment allow fall through to the old method */ | |
2506 | if (retval != -EINVAL) | |
2507 | return retval; | |
2508 | break; | |
37bdfb07 AC |
2509 | case TCFLSH: |
2510 | switch (arg) { | |
2511 | case TCIFLUSH: | |
2512 | case TCIOFLUSH: | |
2513 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2514 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2515 | break; |
37bdfb07 AC |
2516 | } |
2517 | break; | |
8a8ae62f JS |
2518 | case TIOCSSERIAL: |
2519 | tty_warn_deprecated_flags(p); | |
2520 | break; | |
a1235b3e NP |
2521 | default: |
2522 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2523 | if (retval != -ENOIOCTLCMD) | |
2524 | return retval; | |
1da177e4 | 2525 | } |
f34d7a5b | 2526 | if (tty->ops->ioctl) { |
c961bfb1 | 2527 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2528 | if (retval != -ENOIOCTLCMD) |
2529 | return retval; | |
2530 | } | |
2531 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2532 | if (!ld) |
2533 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2534 | retval = -EINVAL; |
a352def2 AC |
2535 | if (ld->ops->ioctl) { |
2536 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2537 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2538 | retval = -ENOTTY; |
1da177e4 LT |
2539 | } |
2540 | tty_ldisc_deref(ld); | |
2541 | return retval; | |
2542 | } | |
2543 | ||
e10cc1df | 2544 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2545 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2546 | unsigned long arg) |
2547 | { | |
d996b62a | 2548 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2549 | struct tty_ldisc *ld; |
2550 | int retval = -ENOIOCTLCMD; | |
2551 | ||
6131ffaa | 2552 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2553 | return -EINVAL; |
2554 | ||
f34d7a5b | 2555 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2556 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2557 | if (retval != -ENOIOCTLCMD) |
2558 | return retval; | |
2559 | } | |
2560 | ||
2561 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2562 | if (!ld) |
2563 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
2564 | if (ld->ops->compat_ioctl) |
2565 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2566 | else |
2567 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2568 | tty_ldisc_deref(ld); |
2569 | ||
2570 | return retval; | |
2571 | } | |
2572 | #endif | |
1da177e4 | 2573 | |
c3c073f8 AV |
2574 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2575 | { | |
2576 | if (likely(file->f_op->read != tty_read)) | |
2577 | return 0; | |
2578 | return file_tty(file) != t ? 0 : fd + 1; | |
2579 | } | |
2580 | ||
1da177e4 LT |
2581 | /* |
2582 | * This implements the "Secure Attention Key" --- the idea is to | |
2583 | * prevent trojan horses by killing all processes associated with this | |
2584 | * tty when the user hits the "Secure Attention Key". Required for | |
2585 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2586 | * |
1da177e4 LT |
2587 | * This code could be nicer; ideally it should send a HUP, wait a few |
2588 | * seconds, then send a INT, and then a KILL signal. But you then | |
2589 | * have to coordinate with the init process, since all processes associated | |
2590 | * with the current tty must be dead before the new getty is allowed | |
2591 | * to spawn. | |
2592 | * | |
2593 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2594 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2595 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2596 | * | |
2597 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2598 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2599 | */ | |
8b6312f4 | 2600 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2601 | { |
2602 | #ifdef TTY_SOFT_SAK | |
2603 | tty_hangup(tty); | |
2604 | #else | |
652486fb | 2605 | struct task_struct *g, *p; |
ab521dc0 | 2606 | struct pid *session; |
1da177e4 | 2607 | int i; |
37bdfb07 | 2608 | |
1da177e4 LT |
2609 | if (!tty) |
2610 | return; | |
24ec839c | 2611 | session = tty->session; |
37bdfb07 | 2612 | |
b3f13deb | 2613 | tty_ldisc_flush(tty); |
1da177e4 | 2614 | |
f34d7a5b | 2615 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2616 | |
1da177e4 | 2617 | read_lock(&tasklist_lock); |
652486fb | 2618 | /* Kill the entire session */ |
ab521dc0 | 2619 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
2620 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
2621 | task_pid_nr(p), p->comm); | |
652486fb | 2622 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2623 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
2624 | |
2625 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
2626 | do_each_thread(g, p) { |
2627 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
2628 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
2629 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
2630 | send_sig(SIGKILL, p, 1); |
2631 | continue; | |
2632 | } | |
2633 | task_lock(p); | |
c3c073f8 AV |
2634 | i = iterate_fd(p->files, 0, this_tty, tty); |
2635 | if (i != 0) { | |
9b42bb75 PH |
2636 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
2637 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 2638 | force_sig(SIGKILL, p); |
1da177e4 LT |
2639 | } |
2640 | task_unlock(p); | |
652486fb | 2641 | } while_each_thread(g, p); |
1da177e4 LT |
2642 | read_unlock(&tasklist_lock); |
2643 | #endif | |
2644 | } | |
2645 | ||
8b6312f4 EB |
2646 | static void do_SAK_work(struct work_struct *work) |
2647 | { | |
2648 | struct tty_struct *tty = | |
2649 | container_of(work, struct tty_struct, SAK_work); | |
2650 | __do_SAK(tty); | |
2651 | } | |
2652 | ||
1da177e4 LT |
2653 | /* |
2654 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2655 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2656 | * the values which we write to it will be identical to the values which it | |
2657 | * already has. --akpm | |
2658 | */ | |
2659 | void do_SAK(struct tty_struct *tty) | |
2660 | { | |
2661 | if (!tty) | |
2662 | return; | |
1da177e4 LT |
2663 | schedule_work(&tty->SAK_work); |
2664 | } | |
2665 | ||
2666 | EXPORT_SYMBOL(do_SAK); | |
2667 | ||
6e9430ac | 2668 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 2669 | { |
6e9430ac | 2670 | const dev_t *devt = data; |
30004ac9 DES |
2671 | return dev->devt == *devt; |
2672 | } | |
2673 | ||
2674 | /* Must put_device() after it's unused! */ | |
2675 | static struct device *tty_get_device(struct tty_struct *tty) | |
2676 | { | |
2677 | dev_t devt = tty_devnum(tty); | |
2678 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2679 | } | |
2680 | ||
2681 | ||
af9b897e | 2682 | /** |
2c964a2f | 2683 | * alloc_tty_struct |
af9b897e | 2684 | * |
2c964a2f | 2685 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 2686 | * |
2c964a2f | 2687 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 2688 | */ |
af9b897e | 2689 | |
2c964a2f | 2690 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 2691 | { |
2c964a2f RV |
2692 | struct tty_struct *tty; |
2693 | ||
2694 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
2695 | if (!tty) | |
2696 | return NULL; | |
2697 | ||
9c9f4ded | 2698 | kref_init(&tty->kref); |
1da177e4 | 2699 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2700 | tty_ldisc_init(tty); |
ab521dc0 EB |
2701 | tty->session = NULL; |
2702 | tty->pgrp = NULL; | |
89c8d91e | 2703 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 2704 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 2705 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 2706 | mutex_init(&tty->winsize_mutex); |
36697529 | 2707 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
2708 | init_waitqueue_head(&tty->write_wait); |
2709 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2710 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 2711 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 2712 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 2713 | spin_lock_init(&tty->flow_lock); |
4a510969 | 2714 | spin_lock_init(&tty->files_lock); |
1da177e4 | 2715 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2716 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2717 | |
2718 | tty->driver = driver; | |
2719 | tty->ops = driver->ops; | |
2720 | tty->index = idx; | |
2721 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2722 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
2723 | |
2724 | return tty; | |
1da177e4 LT |
2725 | } |
2726 | ||
f34d7a5b AC |
2727 | /** |
2728 | * tty_put_char - write one character to a tty | |
2729 | * @tty: tty | |
2730 | * @ch: character | |
2731 | * | |
2732 | * Write one byte to the tty using the provided put_char method | |
2733 | * if present. Returns the number of characters successfully output. | |
2734 | * | |
2735 | * Note: the specific put_char operation in the driver layer may go | |
2736 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2737 | */ |
af9b897e | 2738 | |
f34d7a5b | 2739 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2740 | { |
f34d7a5b AC |
2741 | if (tty->ops->put_char) |
2742 | return tty->ops->put_char(tty, ch); | |
2743 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2744 | } |
f34d7a5b AC |
2745 | EXPORT_SYMBOL_GPL(tty_put_char); |
2746 | ||
d81ed103 | 2747 | struct class *tty_class; |
1da177e4 | 2748 | |
7e73eca6 JS |
2749 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
2750 | unsigned int index, unsigned int count) | |
2751 | { | |
c1a752ba LY |
2752 | int err; |
2753 | ||
7e73eca6 | 2754 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
2755 | driver->cdevs[index] = cdev_alloc(); |
2756 | if (!driver->cdevs[index]) | |
2757 | return -ENOMEM; | |
c1a752ba | 2758 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 2759 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
2760 | err = cdev_add(driver->cdevs[index], dev, count); |
2761 | if (err) | |
2762 | kobject_put(&driver->cdevs[index]->kobj); | |
2763 | return err; | |
7e73eca6 JS |
2764 | } |
2765 | ||
1da177e4 | 2766 | /** |
af9b897e AC |
2767 | * tty_register_device - register a tty device |
2768 | * @driver: the tty driver that describes the tty device | |
2769 | * @index: the index in the tty driver for this tty device | |
2770 | * @device: a struct device that is associated with this tty device. | |
2771 | * This field is optional, if there is no known struct device | |
2772 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2773 | * |
01107d34 GKH |
2774 | * Returns a pointer to the struct device for this tty device |
2775 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2776 | * |
af9b897e AC |
2777 | * This call is required to be made to register an individual tty device |
2778 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2779 | * that bit is not set, this function should not be called by a tty | |
2780 | * driver. | |
2781 | * | |
2782 | * Locking: ?? | |
1da177e4 | 2783 | */ |
af9b897e | 2784 | |
01107d34 GKH |
2785 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2786 | struct device *device) | |
1da177e4 | 2787 | { |
6915c0e4 TH |
2788 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
2789 | } | |
2790 | EXPORT_SYMBOL(tty_register_device); | |
2791 | ||
b1b79916 TH |
2792 | static void tty_device_create_release(struct device *dev) |
2793 | { | |
83db1df4 | 2794 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
2795 | kfree(dev); |
2796 | } | |
2797 | ||
6915c0e4 TH |
2798 | /** |
2799 | * tty_register_device_attr - register a tty device | |
2800 | * @driver: the tty driver that describes the tty device | |
2801 | * @index: the index in the tty driver for this tty device | |
2802 | * @device: a struct device that is associated with this tty device. | |
2803 | * This field is optional, if there is no known struct device | |
2804 | * for this tty device it can be set to NULL safely. | |
2805 | * @drvdata: Driver data to be set to device. | |
2806 | * @attr_grp: Attribute group to be set on device. | |
2807 | * | |
2808 | * Returns a pointer to the struct device for this tty device | |
2809 | * (or ERR_PTR(-EFOO) on error). | |
2810 | * | |
2811 | * This call is required to be made to register an individual tty device | |
2812 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2813 | * that bit is not set, this function should not be called by a tty | |
2814 | * driver. | |
2815 | * | |
2816 | * Locking: ?? | |
2817 | */ | |
2818 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
2819 | unsigned index, struct device *device, | |
2820 | void *drvdata, | |
2821 | const struct attribute_group **attr_grp) | |
2822 | { | |
1da177e4 | 2823 | char name[64]; |
6915c0e4 | 2824 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 2825 | struct ktermios *tp; |
6a7e6f78 JH |
2826 | struct device *dev; |
2827 | int retval; | |
1da177e4 LT |
2828 | |
2829 | if (index >= driver->num) { | |
656fb867 PH |
2830 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
2831 | driver->name, index); | |
1cdcb6b4 | 2832 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2833 | } |
2834 | ||
1da177e4 LT |
2835 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2836 | pty_line_name(driver, index, name); | |
2837 | else | |
2838 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2839 | |
6915c0e4 | 2840 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
2841 | if (!dev) |
2842 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 2843 | |
6915c0e4 TH |
2844 | dev->devt = devt; |
2845 | dev->class = tty_class; | |
2846 | dev->parent = device; | |
b1b79916 | 2847 | dev->release = tty_device_create_release; |
6915c0e4 TH |
2848 | dev_set_name(dev, "%s", name); |
2849 | dev->groups = attr_grp; | |
2850 | dev_set_drvdata(dev, drvdata); | |
2851 | ||
6a7e6f78 JH |
2852 | dev_set_uevent_suppress(dev, 1); |
2853 | ||
6915c0e4 TH |
2854 | retval = device_register(dev); |
2855 | if (retval) | |
6a7e6f78 JH |
2856 | goto err_put; |
2857 | ||
2858 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
2859 | /* |
2860 | * Free any saved termios data so that the termios state is | |
2861 | * reset when reusing a minor number. | |
2862 | */ | |
2863 | tp = driver->termios[index]; | |
2864 | if (tp) { | |
2865 | driver->termios[index] = NULL; | |
2866 | kfree(tp); | |
2867 | } | |
2868 | ||
6a7e6f78 JH |
2869 | retval = tty_cdev_add(driver, devt, index, 1); |
2870 | if (retval) | |
2871 | goto err_del; | |
2872 | } | |
2873 | ||
2874 | dev_set_uevent_suppress(dev, 0); | |
2875 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
2876 | |
2877 | return dev; | |
2878 | ||
6a7e6f78 JH |
2879 | err_del: |
2880 | device_del(dev); | |
2881 | err_put: | |
6915c0e4 | 2882 | put_device(dev); |
6a7e6f78 | 2883 | |
6915c0e4 | 2884 | return ERR_PTR(retval); |
1da177e4 | 2885 | } |
6915c0e4 | 2886 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
2887 | |
2888 | /** | |
af9b897e AC |
2889 | * tty_unregister_device - unregister a tty device |
2890 | * @driver: the tty driver that describes the tty device | |
2891 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2892 | * |
af9b897e AC |
2893 | * If a tty device is registered with a call to tty_register_device() then |
2894 | * this function must be called when the tty device is gone. | |
2895 | * | |
2896 | * Locking: ?? | |
1da177e4 | 2897 | */ |
af9b897e | 2898 | |
1da177e4 LT |
2899 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2900 | { | |
37bdfb07 AC |
2901 | device_destroy(tty_class, |
2902 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
2903 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
2904 | cdev_del(driver->cdevs[index]); | |
2905 | driver->cdevs[index] = NULL; | |
2906 | } | |
1da177e4 | 2907 | } |
1da177e4 LT |
2908 | EXPORT_SYMBOL(tty_unregister_device); |
2909 | ||
7f0bc6a6 JS |
2910 | /** |
2911 | * __tty_alloc_driver -- allocate tty driver | |
2912 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 2913 | * @owner: module which is responsible for this driver |
7f0bc6a6 JS |
2914 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags |
2915 | * | |
2916 | * This should not be called directly, some of the provided macros should be | |
2917 | * used instead. Use IS_ERR and friends on @retval. | |
2918 | */ | |
2919 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
2920 | unsigned long flags) | |
1da177e4 LT |
2921 | { |
2922 | struct tty_driver *driver; | |
7e73eca6 | 2923 | unsigned int cdevs = 1; |
16a02081 | 2924 | int err; |
1da177e4 | 2925 | |
0019b408 | 2926 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
2927 | return ERR_PTR(-EINVAL); |
2928 | ||
506eb99a | 2929 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
2930 | if (!driver) |
2931 | return ERR_PTR(-ENOMEM); | |
2932 | ||
2933 | kref_init(&driver->kref); | |
2934 | driver->magic = TTY_DRIVER_MAGIC; | |
2935 | driver->num = lines; | |
2936 | driver->owner = owner; | |
2937 | driver->flags = flags; | |
16a02081 JS |
2938 | |
2939 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
2940 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
2941 | GFP_KERNEL); | |
2942 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
2943 | GFP_KERNEL); | |
2944 | if (!driver->ttys || !driver->termios) { | |
2945 | err = -ENOMEM; | |
2946 | goto err_free_all; | |
2947 | } | |
2948 | } | |
2949 | ||
2950 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
2951 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
2952 | GFP_KERNEL); | |
2953 | if (!driver->ports) { | |
2954 | err = -ENOMEM; | |
2955 | goto err_free_all; | |
2956 | } | |
7e73eca6 JS |
2957 | cdevs = lines; |
2958 | } | |
2959 | ||
2960 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
2961 | if (!driver->cdevs) { | |
2962 | err = -ENOMEM; | |
2963 | goto err_free_all; | |
16a02081 | 2964 | } |
7f0bc6a6 | 2965 | |
1da177e4 | 2966 | return driver; |
16a02081 JS |
2967 | err_free_all: |
2968 | kfree(driver->ports); | |
2969 | kfree(driver->ttys); | |
2970 | kfree(driver->termios); | |
a3a10ce3 | 2971 | kfree(driver->cdevs); |
16a02081 JS |
2972 | kfree(driver); |
2973 | return ERR_PTR(err); | |
1da177e4 | 2974 | } |
7f0bc6a6 | 2975 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 2976 | |
7d7b93c1 | 2977 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 2978 | { |
7d7b93c1 AC |
2979 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
2980 | int i; | |
2981 | struct ktermios *tp; | |
7d7b93c1 AC |
2982 | |
2983 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
2984 | for (i = 0; i < driver->num; i++) { |
2985 | tp = driver->termios[i]; | |
2986 | if (tp) { | |
2987 | driver->termios[i] = NULL; | |
2988 | kfree(tp); | |
2989 | } | |
7d7b93c1 AC |
2990 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
2991 | tty_unregister_device(driver, i); | |
2992 | } | |
7d7b93c1 | 2993 | proc_tty_unregister_driver(driver); |
7e73eca6 | 2994 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 2995 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 2996 | } |
7e73eca6 | 2997 | kfree(driver->cdevs); |
04831dc1 | 2998 | kfree(driver->ports); |
16a02081 JS |
2999 | kfree(driver->termios); |
3000 | kfree(driver->ttys); | |
1da177e4 LT |
3001 | kfree(driver); |
3002 | } | |
3003 | ||
7d7b93c1 AC |
3004 | void tty_driver_kref_put(struct tty_driver *driver) |
3005 | { | |
3006 | kref_put(&driver->kref, destruct_tty_driver); | |
3007 | } | |
3008 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3009 | ||
b68e31d0 JD |
3010 | void tty_set_operations(struct tty_driver *driver, |
3011 | const struct tty_operations *op) | |
1da177e4 | 3012 | { |
f34d7a5b AC |
3013 | driver->ops = op; |
3014 | }; | |
7d7b93c1 | 3015 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3016 | |
7d7b93c1 AC |
3017 | void put_tty_driver(struct tty_driver *d) |
3018 | { | |
3019 | tty_driver_kref_put(d); | |
3020 | } | |
1da177e4 | 3021 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3022 | |
3023 | /* | |
3024 | * Called by a tty driver to register itself. | |
3025 | */ | |
3026 | int tty_register_driver(struct tty_driver *driver) | |
3027 | { | |
3028 | int error; | |
37bdfb07 | 3029 | int i; |
1da177e4 | 3030 | dev_t dev; |
b670bde0 | 3031 | struct device *d; |
1da177e4 | 3032 | |
1da177e4 | 3033 | if (!driver->major) { |
37bdfb07 AC |
3034 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3035 | driver->num, driver->name); | |
1da177e4 LT |
3036 | if (!error) { |
3037 | driver->major = MAJOR(dev); | |
3038 | driver->minor_start = MINOR(dev); | |
3039 | } | |
3040 | } else { | |
3041 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3042 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3043 | } |
9bb8a3d4 | 3044 | if (error < 0) |
16a02081 | 3045 | goto err; |
1da177e4 | 3046 | |
7e73eca6 JS |
3047 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3048 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3049 | if (error) | |
3050 | goto err_unreg_char; | |
3051 | } | |
1da177e4 | 3052 | |
ca509f69 | 3053 | mutex_lock(&tty_mutex); |
1da177e4 | 3054 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3055 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3056 | |
3057 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3058 | for (i = 0; i < driver->num; i++) { |
3059 | d = tty_register_device(driver, i, NULL); | |
3060 | if (IS_ERR(d)) { | |
3061 | error = PTR_ERR(d); | |
16a02081 | 3062 | goto err_unreg_devs; |
b670bde0 VK |
3063 | } |
3064 | } | |
1da177e4 LT |
3065 | } |
3066 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3067 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3068 | return 0; |
b670bde0 | 3069 | |
16a02081 | 3070 | err_unreg_devs: |
b670bde0 VK |
3071 | for (i--; i >= 0; i--) |
3072 | tty_unregister_device(driver, i); | |
3073 | ||
3074 | mutex_lock(&tty_mutex); | |
3075 | list_del(&driver->tty_drivers); | |
3076 | mutex_unlock(&tty_mutex); | |
3077 | ||
9bb8a3d4 | 3078 | err_unreg_char: |
b670bde0 | 3079 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3080 | err: |
b670bde0 | 3081 | return error; |
1da177e4 | 3082 | } |
1da177e4 LT |
3083 | EXPORT_SYMBOL(tty_register_driver); |
3084 | ||
3085 | /* | |
3086 | * Called by a tty driver to unregister itself. | |
3087 | */ | |
3088 | int tty_unregister_driver(struct tty_driver *driver) | |
3089 | { | |
7d7b93c1 AC |
3090 | #if 0 |
3091 | /* FIXME */ | |
1da177e4 LT |
3092 | if (driver->refcount) |
3093 | return -EBUSY; | |
7d7b93c1 | 3094 | #endif |
1da177e4 LT |
3095 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3096 | driver->num); | |
ca509f69 | 3097 | mutex_lock(&tty_mutex); |
1da177e4 | 3098 | list_del(&driver->tty_drivers); |
ca509f69 | 3099 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3100 | return 0; |
3101 | } | |
7d7b93c1 | 3102 | |
1da177e4 LT |
3103 | EXPORT_SYMBOL(tty_unregister_driver); |
3104 | ||
24ec839c PZ |
3105 | dev_t tty_devnum(struct tty_struct *tty) |
3106 | { | |
3107 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3108 | } | |
3109 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3110 | |
d81ed103 AC |
3111 | void tty_default_fops(struct file_operations *fops) |
3112 | { | |
3113 | *fops = tty_fops; | |
3114 | } | |
3115 | ||
2c9ede55 | 3116 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3117 | { |
3118 | if (!mode) | |
3119 | return NULL; | |
3120 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3121 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3122 | *mode = 0666; | |
3123 | return NULL; | |
3124 | } | |
3125 | ||
1da177e4 LT |
3126 | static int __init tty_class_init(void) |
3127 | { | |
7fe845d1 | 3128 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3129 | if (IS_ERR(tty_class)) |
3130 | return PTR_ERR(tty_class); | |
e454cea2 | 3131 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3132 | return 0; |
3133 | } | |
3134 | ||
3135 | postcore_initcall(tty_class_init); | |
3136 | ||
3137 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3138 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3139 | |
fbc92a34 KS |
3140 | static ssize_t show_cons_active(struct device *dev, |
3141 | struct device_attribute *attr, char *buf) | |
3142 | { | |
3143 | struct console *cs[16]; | |
3144 | int i = 0; | |
3145 | struct console *c; | |
3146 | ssize_t count = 0; | |
3147 | ||
ac751efa | 3148 | console_lock(); |
a2a6a822 | 3149 | for_each_console(c) { |
fbc92a34 KS |
3150 | if (!c->device) |
3151 | continue; | |
3152 | if (!c->write) | |
3153 | continue; | |
3154 | if ((c->flags & CON_ENABLED) == 0) | |
3155 | continue; | |
3156 | cs[i++] = c; | |
3157 | if (i >= ARRAY_SIZE(cs)) | |
3158 | break; | |
3159 | } | |
723abd87 HR |
3160 | while (i--) { |
3161 | int index = cs[i]->index; | |
3162 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3163 | ||
3164 | /* don't resolve tty0 as some programs depend on it */ | |
3165 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3166 | count += tty_line_name(drv, index, buf + count); | |
3167 | else | |
3168 | count += sprintf(buf + count, "%s%d", | |
3169 | cs[i]->name, cs[i]->index); | |
3170 | ||
3171 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3172 | } | |
ac751efa | 3173 | console_unlock(); |
fbc92a34 KS |
3174 | |
3175 | return count; | |
3176 | } | |
3177 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3178 | ||
1083a7be TI |
3179 | static struct attribute *cons_dev_attrs[] = { |
3180 | &dev_attr_active.attr, | |
3181 | NULL | |
3182 | }; | |
3183 | ||
3184 | ATTRIBUTE_GROUPS(cons_dev); | |
3185 | ||
fbc92a34 KS |
3186 | static struct device *consdev; |
3187 | ||
3188 | void console_sysfs_notify(void) | |
3189 | { | |
3190 | if (consdev) | |
3191 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3192 | } | |
3193 | ||
1da177e4 LT |
3194 | /* |
3195 | * Ok, now we can initialize the rest of the tty devices and can count | |
3196 | * on memory allocations, interrupts etc.. | |
3197 | */ | |
31d1d48e | 3198 | int __init tty_init(void) |
1da177e4 LT |
3199 | { |
3200 | cdev_init(&tty_cdev, &tty_fops); | |
3201 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3202 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3203 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3204 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3205 | |
3206 | cdev_init(&console_cdev, &console_fops); | |
3207 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3208 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3209 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3210 | consdev = device_create_with_groups(tty_class, NULL, |
3211 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3212 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3213 | if (IS_ERR(consdev)) |
3214 | consdev = NULL; | |
1da177e4 | 3215 | |
1da177e4 | 3216 | #ifdef CONFIG_VT |
d81ed103 | 3217 | vty_init(&console_fops); |
1da177e4 LT |
3218 | #endif |
3219 | return 0; | |
3220 | } | |
31d1d48e | 3221 |