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 | ||
f2d937f3 JW |
328 | #ifdef CONFIG_CONSOLE_POLL |
329 | ||
330 | /** | |
331 | * tty_find_polling_driver - find device of a polled tty | |
332 | * @name: name string to match | |
333 | * @line: pointer to resulting tty line nr | |
334 | * | |
335 | * This routine returns a tty driver structure, given a name | |
336 | * and the condition that the tty driver is capable of polled | |
337 | * operation. | |
338 | */ | |
339 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
340 | { | |
341 | struct tty_driver *p, *res = NULL; | |
342 | int tty_line = 0; | |
0dca0fd2 | 343 | int len; |
5f0878ac | 344 | char *str, *stp; |
f2d937f3 | 345 | |
0dca0fd2 JW |
346 | for (str = name; *str; str++) |
347 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
348 | break; | |
349 | if (!*str) | |
350 | return NULL; | |
351 | ||
352 | len = str - name; | |
353 | tty_line = simple_strtoul(str, &str, 10); | |
354 | ||
f2d937f3 JW |
355 | mutex_lock(&tty_mutex); |
356 | /* Search through the tty devices to look for a match */ | |
357 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
358 | if (strncmp(name, p->name, len) != 0) |
359 | continue; | |
5f0878ac AC |
360 | stp = str; |
361 | if (*stp == ',') | |
362 | stp++; | |
363 | if (*stp == '\0') | |
364 | stp = NULL; | |
f2d937f3 | 365 | |
6eb68d6f | 366 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 367 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 368 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
369 | *line = tty_line; |
370 | break; | |
371 | } | |
372 | } | |
373 | mutex_unlock(&tty_mutex); | |
374 | ||
375 | return res; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
378 | #endif | |
379 | ||
e802ca0e PH |
380 | static int is_ignored(int sig) |
381 | { | |
382 | return (sigismember(¤t->blocked, sig) || | |
383 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); | |
384 | } | |
385 | ||
af9b897e AC |
386 | /** |
387 | * tty_check_change - check for POSIX terminal changes | |
388 | * @tty: tty to check | |
389 | * | |
390 | * If we try to write to, or set the state of, a terminal and we're | |
391 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
392 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
393 | * | |
978e595f | 394 | * Locking: ctrl_lock |
1da177e4 | 395 | */ |
af9b897e | 396 | |
2812d9e9 | 397 | int __tty_check_change(struct tty_struct *tty, int sig) |
1da177e4 | 398 | { |
47f86834 | 399 | unsigned long flags; |
2812d9e9 | 400 | struct pid *pgrp, *tty_pgrp; |
47f86834 AC |
401 | int ret = 0; |
402 | ||
1da177e4 LT |
403 | if (current->signal->tty != tty) |
404 | return 0; | |
47f86834 | 405 | |
6719693c PD |
406 | rcu_read_lock(); |
407 | pgrp = task_pgrp(current); | |
408 | ||
47f86834 | 409 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
2812d9e9 | 410 | tty_pgrp = tty->pgrp; |
9ffee4cb | 411 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
6719693c | 412 | |
2812d9e9 PH |
413 | if (tty_pgrp && pgrp != tty->pgrp) { |
414 | if (is_ignored(sig)) { | |
415 | if (sig == SIGTTIN) | |
416 | ret = -EIO; | |
417 | } else if (is_current_pgrp_orphaned()) | |
418 | ret = -EIO; | |
419 | else { | |
420 | kill_pgrp(pgrp, sig, 1); | |
421 | set_thread_flag(TIF_SIGPENDING); | |
422 | ret = -ERESTARTSYS; | |
423 | } | |
47f86834 | 424 | } |
6719693c | 425 | rcu_read_unlock(); |
2812d9e9 | 426 | |
339f36ba PH |
427 | if (!tty_pgrp) |
428 | tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig); | |
2812d9e9 | 429 | |
47f86834 | 430 | return ret; |
1da177e4 LT |
431 | } |
432 | ||
2812d9e9 PH |
433 | int tty_check_change(struct tty_struct *tty) |
434 | { | |
435 | return __tty_check_change(tty, SIGTTOU); | |
436 | } | |
1da177e4 LT |
437 | EXPORT_SYMBOL(tty_check_change); |
438 | ||
37bdfb07 | 439 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
440 | size_t count, loff_t *ppos) |
441 | { | |
442 | return 0; | |
443 | } | |
444 | ||
37bdfb07 | 445 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
446 | size_t count, loff_t *ppos) |
447 | { | |
448 | return -EIO; | |
449 | } | |
450 | ||
451 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 452 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
453 | { |
454 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
455 | } | |
456 | ||
04f378b1 AC |
457 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
458 | unsigned long arg) | |
38ad2ed0 PF |
459 | { |
460 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
461 | } | |
462 | ||
37bdfb07 | 463 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 464 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
465 | { |
466 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
467 | } | |
468 | ||
f557474c PH |
469 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
470 | { | |
471 | return -ENOTTY; | |
472 | } | |
473 | ||
62322d25 | 474 | static const struct file_operations tty_fops = { |
1da177e4 LT |
475 | .llseek = no_llseek, |
476 | .read = tty_read, | |
477 | .write = tty_write, | |
478 | .poll = tty_poll, | |
04f378b1 | 479 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 480 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
481 | .open = tty_open, |
482 | .release = tty_release, | |
483 | .fasync = tty_fasync, | |
484 | }; | |
485 | ||
62322d25 | 486 | static const struct file_operations console_fops = { |
1da177e4 LT |
487 | .llseek = no_llseek, |
488 | .read = tty_read, | |
489 | .write = redirected_tty_write, | |
490 | .poll = tty_poll, | |
04f378b1 | 491 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 492 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
493 | .open = tty_open, |
494 | .release = tty_release, | |
495 | .fasync = tty_fasync, | |
496 | }; | |
497 | ||
62322d25 | 498 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
499 | .llseek = no_llseek, |
500 | .read = hung_up_tty_read, | |
501 | .write = hung_up_tty_write, | |
502 | .poll = hung_up_tty_poll, | |
04f378b1 | 503 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 504 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 505 | .release = tty_release, |
f557474c | 506 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
507 | }; |
508 | ||
509 | static DEFINE_SPINLOCK(redirect_lock); | |
510 | static struct file *redirect; | |
511 | ||
11d9befd PH |
512 | |
513 | void proc_clear_tty(struct task_struct *p) | |
514 | { | |
515 | unsigned long flags; | |
516 | struct tty_struct *tty; | |
517 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
518 | tty = p->signal->tty; | |
519 | p->signal->tty = NULL; | |
520 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
521 | tty_kref_put(tty); | |
522 | } | |
523 | ||
2c411c11 PH |
524 | /** |
525 | * proc_set_tty - set the controlling terminal | |
526 | * | |
527 | * Only callable by the session leader and only if it does not already have | |
528 | * a controlling terminal. | |
529 | * | |
e218eb32 PH |
530 | * Caller must hold: tty_lock() |
531 | * a readlock on tasklist_lock | |
2c411c11 PH |
532 | * sighand lock |
533 | */ | |
bce65f18 | 534 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 535 | { |
ae28fa72 PH |
536 | unsigned long flags; |
537 | ||
ae28fa72 | 538 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
539 | /* |
540 | * The session and fg pgrp references will be non-NULL if | |
541 | * tiocsctty() is stealing the controlling tty | |
542 | */ | |
ae28fa72 PH |
543 | put_pid(tty->session); |
544 | put_pid(tty->pgrp); | |
545 | tty->pgrp = get_pid(task_pgrp(current)); | |
546 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
547 | tty->session = get_pid(task_session(current)); | |
548 | if (current->signal->tty) { | |
e2dfa3d3 PH |
549 | tty_debug(tty, "current tty %s not NULL!!\n", |
550 | current->signal->tty->name); | |
ae28fa72 | 551 | tty_kref_put(current->signal->tty); |
11d9befd | 552 | } |
bce65f18 PH |
553 | put_pid(current->signal->tty_old_pgrp); |
554 | current->signal->tty = tty_kref_get(tty); | |
555 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
556 | } |
557 | ||
bce65f18 | 558 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 559 | { |
bce65f18 PH |
560 | spin_lock_irq(¤t->sighand->siglock); |
561 | __proc_set_tty(tty); | |
562 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
563 | } |
564 | ||
565 | struct tty_struct *get_current_tty(void) | |
566 | { | |
567 | struct tty_struct *tty; | |
568 | unsigned long flags; | |
569 | ||
570 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
571 | tty = tty_kref_get(current->signal->tty); | |
572 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
573 | return tty; | |
574 | } | |
575 | EXPORT_SYMBOL_GPL(get_current_tty); | |
576 | ||
577 | static void session_clear_tty(struct pid *session) | |
578 | { | |
579 | struct task_struct *p; | |
580 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
581 | proc_clear_tty(p); | |
582 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
583 | } | |
584 | ||
1da177e4 LT |
585 | /** |
586 | * tty_wakeup - request more data | |
587 | * @tty: terminal | |
588 | * | |
589 | * Internal and external helper for wakeups of tty. This function | |
590 | * informs the line discipline if present that the driver is ready | |
591 | * to receive more output data. | |
592 | */ | |
37bdfb07 | 593 | |
1da177e4 LT |
594 | void tty_wakeup(struct tty_struct *tty) |
595 | { | |
596 | struct tty_ldisc *ld; | |
37bdfb07 | 597 | |
1da177e4 LT |
598 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
599 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 600 | if (ld) { |
a352def2 AC |
601 | if (ld->ops->write_wakeup) |
602 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
603 | tty_ldisc_deref(ld); |
604 | } | |
605 | } | |
4b19449d | 606 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
607 | } |
608 | ||
609 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
610 | ||
ea648a47 PH |
611 | /** |
612 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
613 | * @tty controlling tty |
614 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 615 | * |
f91e2590 PH |
616 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
617 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
618 | * |
619 | * Returns the number of processes in the session with this tty | |
620 | * as their controlling terminal. This value is used to drop | |
621 | * tty references for those processes. | |
622 | */ | |
f91e2590 | 623 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
624 | { |
625 | struct task_struct *p; | |
ea648a47 | 626 | int refs = 0; |
f91e2590 | 627 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
628 | |
629 | read_lock(&tasklist_lock); | |
630 | if (tty->session) { | |
631 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
632 | spin_lock_irq(&p->sighand->siglock); | |
633 | if (p->signal->tty == tty) { | |
634 | p->signal->tty = NULL; | |
635 | /* We defer the dereferences outside fo | |
636 | the tasklist lock */ | |
637 | refs++; | |
638 | } | |
639 | if (!p->signal->leader) { | |
640 | spin_unlock_irq(&p->sighand->siglock); | |
641 | continue; | |
642 | } | |
643 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
644 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
645 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 646 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 647 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
648 | if (tty->pgrp) |
649 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 650 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
651 | spin_unlock_irq(&p->sighand->siglock); |
652 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
653 | } | |
654 | read_unlock(&tasklist_lock); | |
655 | ||
f91e2590 PH |
656 | if (tty_pgrp) { |
657 | if (exit_session) | |
658 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
659 | put_pid(tty_pgrp); | |
660 | } | |
661 | ||
ea648a47 PH |
662 | return refs; |
663 | } | |
664 | ||
af9b897e | 665 | /** |
11dbf203 | 666 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 667 | * @work: tty device |
af9b897e | 668 | * |
ef4f527c | 669 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
670 | * synchronous but doesn't hold any locks, so we need to make sure we |
671 | * have the appropriate locks for what we're doing. | |
672 | * | |
673 | * The hangup event clears any pending redirections onto the hung up | |
674 | * device. It ensures future writes will error and it does the needed | |
675 | * line discipline hangup and signal delivery. The tty object itself | |
676 | * remains intact. | |
677 | * | |
678 | * Locking: | |
ec79d605 | 679 | * BTM |
24ec839c PZ |
680 | * redirect lock for undoing redirection |
681 | * file list lock for manipulating list of ttys | |
137084bb | 682 | * tty_ldiscs_lock from called functions |
6a1c0680 | 683 | * termios_rwsem resetting termios data |
24ec839c PZ |
684 | * tasklist_lock to walk task list for hangup event |
685 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 686 | */ |
f91e2590 | 687 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 688 | { |
37bdfb07 | 689 | struct file *cons_filp = NULL; |
1da177e4 | 690 | struct file *filp, *f = NULL; |
d996b62a | 691 | struct tty_file_private *priv; |
1da177e4 | 692 | int closecount = 0, n; |
ea648a47 | 693 | int refs; |
1da177e4 LT |
694 | |
695 | if (!tty) | |
696 | return; | |
697 | ||
1da177e4 LT |
698 | |
699 | spin_lock(&redirect_lock); | |
d996b62a | 700 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
701 | f = redirect; |
702 | redirect = NULL; | |
703 | } | |
704 | spin_unlock(&redirect_lock); | |
37bdfb07 | 705 | |
89c8d91e | 706 | tty_lock(tty); |
11dbf203 | 707 | |
cb50e523 PH |
708 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
709 | tty_unlock(tty); | |
710 | return; | |
711 | } | |
712 | ||
ec79d605 AB |
713 | /* inuse_filps is protected by the single tty lock, |
714 | this really needs to change if we want to flush the | |
715 | workqueue with the lock held */ | |
11dbf203 | 716 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 717 | |
4a510969 | 718 | spin_lock(&tty->files_lock); |
1da177e4 | 719 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
720 | list_for_each_entry(priv, &tty->tty_files, list) { |
721 | filp = priv->file; | |
1da177e4 LT |
722 | if (filp->f_op->write == redirected_tty_write) |
723 | cons_filp = filp; | |
724 | if (filp->f_op->write != tty_write) | |
725 | continue; | |
726 | closecount++; | |
ec79d605 | 727 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
728 | filp->f_op = &hung_up_tty_fops; |
729 | } | |
4a510969 | 730 | spin_unlock(&tty->files_lock); |
37bdfb07 | 731 | |
25fdf243 PH |
732 | refs = tty_signal_session_leader(tty, exit_session); |
733 | /* Account for the p->signal references we killed */ | |
734 | while (refs--) | |
735 | tty_kref_put(tty); | |
736 | ||
892d1fa7 | 737 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 738 | |
20cc225b | 739 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 740 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 741 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
742 | put_pid(tty->session); |
743 | put_pid(tty->pgrp); | |
ab521dc0 EB |
744 | tty->session = NULL; |
745 | tty->pgrp = NULL; | |
1da177e4 | 746 | tty->ctrl_status = 0; |
20cc225b | 747 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 748 | |
1da177e4 | 749 | /* |
37bdfb07 AC |
750 | * If one of the devices matches a console pointer, we |
751 | * cannot just call hangup() because that will cause | |
752 | * tty->count and state->count to go out of sync. | |
753 | * So we just call close() the right number of times. | |
1da177e4 LT |
754 | */ |
755 | if (cons_filp) { | |
f34d7a5b | 756 | if (tty->ops->close) |
1da177e4 | 757 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
758 | tty->ops->close(tty, cons_filp); |
759 | } else if (tty->ops->hangup) | |
7c6d340f | 760 | tty->ops->hangup(tty); |
37bdfb07 | 761 | /* |
892d1fa7 PH |
762 | * We don't want to have driver/ldisc interactions beyond the ones |
763 | * we did here. The driver layer expects no calls after ->hangup() | |
764 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 765 | */ |
1da177e4 | 766 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 767 | tty_unlock(tty); |
11dbf203 | 768 | |
1da177e4 LT |
769 | if (f) |
770 | fput(f); | |
771 | } | |
772 | ||
ddcd9fb6 AB |
773 | static void do_tty_hangup(struct work_struct *work) |
774 | { | |
775 | struct tty_struct *tty = | |
776 | container_of(work, struct tty_struct, hangup_work); | |
777 | ||
f91e2590 | 778 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
779 | } |
780 | ||
af9b897e AC |
781 | /** |
782 | * tty_hangup - trigger a hangup event | |
783 | * @tty: tty to hangup | |
784 | * | |
785 | * A carrier loss (virtual or otherwise) has occurred on this like | |
786 | * schedule a hangup sequence to run after this event. | |
787 | */ | |
788 | ||
37bdfb07 | 789 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 790 | { |
d435cefe | 791 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
792 | schedule_work(&tty->hangup_work); |
793 | } | |
794 | ||
795 | EXPORT_SYMBOL(tty_hangup); | |
796 | ||
af9b897e AC |
797 | /** |
798 | * tty_vhangup - process vhangup | |
799 | * @tty: tty to hangup | |
800 | * | |
801 | * The user has asked via system call for the terminal to be hung up. | |
802 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 803 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
804 | */ |
805 | ||
37bdfb07 | 806 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 807 | { |
d435cefe | 808 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 809 | __tty_hangup(tty, 0); |
1da177e4 | 810 | } |
37bdfb07 | 811 | |
1da177e4 LT |
812 | EXPORT_SYMBOL(tty_vhangup); |
813 | ||
11dbf203 | 814 | |
2cb5998b AC |
815 | /** |
816 | * tty_vhangup_self - process vhangup for own ctty | |
817 | * | |
818 | * Perform a vhangup on the current controlling tty | |
819 | */ | |
820 | ||
821 | void tty_vhangup_self(void) | |
822 | { | |
823 | struct tty_struct *tty; | |
824 | ||
2cb5998b AC |
825 | tty = get_current_tty(); |
826 | if (tty) { | |
827 | tty_vhangup(tty); | |
828 | tty_kref_put(tty); | |
829 | } | |
2cb5998b AC |
830 | } |
831 | ||
f91e2590 PH |
832 | /** |
833 | * tty_vhangup_session - hangup session leader exit | |
834 | * @tty: tty to hangup | |
835 | * | |
836 | * The session leader is exiting and hanging up its controlling terminal. | |
837 | * Every process in the foreground process group is signalled SIGHUP. | |
838 | * | |
839 | * We do this synchronously so that when the syscall returns the process | |
840 | * is complete. That guarantee is necessary for security reasons. | |
841 | */ | |
842 | ||
44a459fd | 843 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 844 | { |
d435cefe | 845 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
846 | __tty_hangup(tty, 1); |
847 | } | |
848 | ||
af9b897e AC |
849 | /** |
850 | * tty_hung_up_p - was tty hung up | |
851 | * @filp: file pointer of tty | |
852 | * | |
853 | * Return true if the tty has been subject to a vhangup or a carrier | |
854 | * loss | |
855 | */ | |
856 | ||
37bdfb07 | 857 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 858 | { |
ed3f0af8 | 859 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 LT |
860 | } |
861 | ||
862 | EXPORT_SYMBOL(tty_hung_up_p); | |
863 | ||
af9b897e AC |
864 | /** |
865 | * disassociate_ctty - disconnect controlling tty | |
866 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 867 | * |
af9b897e AC |
868 | * This function is typically called only by the session leader, when |
869 | * it wants to disassociate itself from its controlling tty. | |
870 | * | |
871 | * It performs the following functions: | |
1da177e4 LT |
872 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
873 | * (2) Clears the tty from being controlling the session | |
874 | * (3) Clears the controlling tty for all processes in the | |
875 | * session group. | |
876 | * | |
af9b897e AC |
877 | * The argument on_exit is set to 1 if called when a process is |
878 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
879 | * | |
24ec839c | 880 | * Locking: |
ec79d605 AB |
881 | * BTM is taken for hysterical raisins, and held when |
882 | * called from no_tty(). | |
24ec839c PZ |
883 | * tty_mutex is taken to protect tty |
884 | * ->siglock is taken to protect ->signal/->sighand | |
885 | * tasklist_lock is taken to walk process list for sessions | |
886 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 887 | */ |
af9b897e | 888 | |
1da177e4 LT |
889 | void disassociate_ctty(int on_exit) |
890 | { | |
891 | struct tty_struct *tty; | |
1da177e4 | 892 | |
5ec93d11 AC |
893 | if (!current->signal->leader) |
894 | return; | |
1da177e4 | 895 | |
24ec839c | 896 | tty = get_current_tty(); |
1da177e4 | 897 | if (tty) { |
f91e2590 PH |
898 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
899 | tty_vhangup_session(tty); | |
900 | } else { | |
901 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
902 | if (tty_pgrp) { | |
903 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
904 | if (!on_exit) |
905 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
906 | put_pid(tty_pgrp); |
907 | } | |
1411dc4a | 908 | } |
f91e2590 PH |
909 | tty_kref_put(tty); |
910 | ||
680a9671 | 911 | } else if (on_exit) { |
ab521dc0 | 912 | struct pid *old_pgrp; |
680a9671 EB |
913 | spin_lock_irq(¤t->sighand->siglock); |
914 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 915 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 916 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 917 | if (old_pgrp) { |
ab521dc0 EB |
918 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
919 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
920 | put_pid(old_pgrp); | |
1da177e4 | 921 | } |
1da177e4 LT |
922 | return; |
923 | } | |
1da177e4 | 924 | |
24ec839c | 925 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 926 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 927 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 928 | |
c70dbb1e | 929 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 930 | if (tty) { |
47f86834 AC |
931 | unsigned long flags; |
932 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
933 | put_pid(tty->session); |
934 | put_pid(tty->pgrp); | |
935 | tty->session = NULL; | |
936 | tty->pgrp = NULL; | |
47f86834 | 937 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 938 | tty_kref_put(tty); |
accff793 PH |
939 | } else |
940 | tty_debug_hangup(tty, "no current tty\n"); | |
1da177e4 | 941 | |
c70dbb1e | 942 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
943 | /* Now clear signal->tty under the lock */ |
944 | read_lock(&tasklist_lock); | |
ab521dc0 | 945 | session_clear_tty(task_session(current)); |
1da177e4 | 946 | read_unlock(&tasklist_lock); |
1da177e4 LT |
947 | } |
948 | ||
98a27ba4 EB |
949 | /** |
950 | * | |
951 | * no_tty - Ensure the current process does not have a controlling tty | |
952 | */ | |
953 | void no_tty(void) | |
954 | { | |
3af502b9 AC |
955 | /* FIXME: Review locking here. The tty_lock never covered any race |
956 | between a new association and proc_clear_tty but possible we need | |
957 | to protect against this anyway */ | |
98a27ba4 | 958 | struct task_struct *tsk = current; |
5ec93d11 | 959 | disassociate_ctty(0); |
98a27ba4 EB |
960 | proc_clear_tty(tsk); |
961 | } | |
962 | ||
af9b897e AC |
963 | |
964 | /** | |
beb7dd86 | 965 | * stop_tty - propagate flow control |
af9b897e AC |
966 | * @tty: tty to stop |
967 | * | |
01adc807 | 968 | * Perform flow control to the driver. May be called |
af9b897e AC |
969 | * on an already stopped device and will not re-call the driver |
970 | * method. | |
971 | * | |
972 | * This functionality is used by both the line disciplines for | |
973 | * halting incoming flow and by the driver. It may therefore be | |
974 | * called from any context, may be under the tty atomic_write_lock | |
975 | * but not always. | |
976 | * | |
977 | * Locking: | |
f9e053dc | 978 | * flow_lock |
af9b897e AC |
979 | */ |
980 | ||
f9e053dc | 981 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 982 | { |
f9e053dc | 983 | if (tty->stopped) |
1da177e4 LT |
984 | return; |
985 | tty->stopped = 1; | |
f34d7a5b | 986 | if (tty->ops->stop) |
c961bfb1 | 987 | tty->ops->stop(tty); |
1da177e4 LT |
988 | } |
989 | ||
f9e053dc PH |
990 | void stop_tty(struct tty_struct *tty) |
991 | { | |
992 | unsigned long flags; | |
993 | ||
994 | spin_lock_irqsave(&tty->flow_lock, flags); | |
995 | __stop_tty(tty); | |
996 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
997 | } | |
1da177e4 LT |
998 | EXPORT_SYMBOL(stop_tty); |
999 | ||
af9b897e | 1000 | /** |
beb7dd86 | 1001 | * start_tty - propagate flow control |
af9b897e AC |
1002 | * @tty: tty to start |
1003 | * | |
01adc807 PH |
1004 | * Start a tty that has been stopped if at all possible. If this |
1005 | * tty was previous stopped and is now being started, the driver | |
1006 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1007 | * |
1008 | * Locking: | |
f9e053dc | 1009 | * flow_lock |
af9b897e AC |
1010 | */ |
1011 | ||
f9e053dc | 1012 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1013 | { |
f9e053dc | 1014 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1015 | return; |
1016 | tty->stopped = 0; | |
f34d7a5b | 1017 | if (tty->ops->start) |
c961bfb1 | 1018 | tty->ops->start(tty); |
1da177e4 | 1019 | tty_wakeup(tty); |
1da177e4 LT |
1020 | } |
1021 | ||
f9e053dc PH |
1022 | void start_tty(struct tty_struct *tty) |
1023 | { | |
1024 | unsigned long flags; | |
1025 | ||
1026 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1027 | __start_tty(tty); | |
1028 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1029 | } | |
1da177e4 LT |
1030 | EXPORT_SYMBOL(start_tty); |
1031 | ||
37b7f3c7 JS |
1032 | static void tty_update_time(struct timespec *time) |
1033 | { | |
f0bf0bd0 | 1034 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
1035 | |
1036 | /* | |
1037 | * We only care if the two values differ in anything other than the | |
1038 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
1039 | * the time of the tty device, otherwise it could be construded as a | |
1040 | * security leak to let userspace know the exact timing of the tty. | |
1041 | */ | |
1042 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
1043 | time->tv_sec = sec; |
1044 | } | |
1045 | ||
af9b897e AC |
1046 | /** |
1047 | * tty_read - read method for tty device files | |
1048 | * @file: pointer to tty file | |
1049 | * @buf: user buffer | |
1050 | * @count: size of user buffer | |
1051 | * @ppos: unused | |
1052 | * | |
1053 | * Perform the read system call function on this terminal device. Checks | |
1054 | * for hung up devices before calling the line discipline method. | |
1055 | * | |
1056 | * Locking: | |
47f86834 AC |
1057 | * Locks the line discipline internally while needed. Multiple |
1058 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1059 | */ |
1060 | ||
37bdfb07 | 1061 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1062 | loff_t *ppos) |
1063 | { | |
1064 | int i; | |
37b7f3c7 | 1065 | struct inode *inode = file_inode(file); |
d996b62a | 1066 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1067 | struct tty_ldisc *ld; |
1068 | ||
37b7f3c7 | 1069 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 1070 | return -EIO; |
18900ca6 | 1071 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
1072 | return -EIO; |
1073 | ||
1074 | /* We want to wait for the line discipline to sort out in this | |
1075 | situation */ | |
1076 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
1077 | if (!ld) |
1078 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 1079 | if (ld->ops->read) |
c961bfb1 | 1080 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1081 | else |
1082 | i = -EIO; | |
1083 | tty_ldisc_deref(ld); | |
b0de59b5 | 1084 | |
37b7f3c7 JS |
1085 | if (i > 0) |
1086 | tty_update_time(&inode->i_atime); | |
1087 | ||
1da177e4 LT |
1088 | return i; |
1089 | } | |
1090 | ||
136d5258 | 1091 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1092 | { |
1093 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1094 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1095 | } |
1096 | ||
136d5258 | 1097 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1098 | { |
1099 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1100 | if (ndelay) | |
1101 | return -EAGAIN; | |
1102 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1103 | return -ERESTARTSYS; | |
1104 | } | |
1105 | return 0; | |
1106 | } | |
1107 | ||
1da177e4 LT |
1108 | /* |
1109 | * Split writes up in sane blocksizes to avoid | |
1110 | * denial-of-service type attacks | |
1111 | */ | |
1112 | static inline ssize_t do_tty_write( | |
1113 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1114 | struct tty_struct *tty, | |
1115 | struct file *file, | |
1116 | const char __user *buf, | |
1117 | size_t count) | |
1118 | { | |
9c1729db | 1119 | ssize_t ret, written = 0; |
1da177e4 | 1120 | unsigned int chunk; |
37bdfb07 | 1121 | |
9c1729db AC |
1122 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1123 | if (ret < 0) | |
1124 | return ret; | |
1da177e4 LT |
1125 | |
1126 | /* | |
1127 | * We chunk up writes into a temporary buffer. This | |
1128 | * simplifies low-level drivers immensely, since they | |
1129 | * don't have locking issues and user mode accesses. | |
1130 | * | |
1131 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1132 | * big chunk-size.. | |
1133 | * | |
1134 | * The default chunk-size is 2kB, because the NTTY | |
1135 | * layer has problems with bigger chunks. It will | |
1136 | * claim to be able to handle more characters than | |
1137 | * it actually does. | |
af9b897e AC |
1138 | * |
1139 | * FIXME: This can probably go away now except that 64K chunks | |
1140 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1141 | */ |
1142 | chunk = 2048; | |
1143 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1144 | chunk = 65536; | |
1145 | if (count < chunk) | |
1146 | chunk = count; | |
1147 | ||
70522e12 | 1148 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1149 | if (tty->write_cnt < chunk) { |
402fda92 | 1150 | unsigned char *buf_chunk; |
1da177e4 LT |
1151 | |
1152 | if (chunk < 1024) | |
1153 | chunk = 1024; | |
1154 | ||
402fda92 JW |
1155 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1156 | if (!buf_chunk) { | |
9c1729db AC |
1157 | ret = -ENOMEM; |
1158 | goto out; | |
1da177e4 LT |
1159 | } |
1160 | kfree(tty->write_buf); | |
1161 | tty->write_cnt = chunk; | |
402fda92 | 1162 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1163 | } |
1164 | ||
1165 | /* Do the write .. */ | |
1166 | for (;;) { | |
1167 | size_t size = count; | |
1168 | if (size > chunk) | |
1169 | size = chunk; | |
1170 | ret = -EFAULT; | |
1171 | if (copy_from_user(tty->write_buf, buf, size)) | |
1172 | break; | |
1da177e4 | 1173 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1174 | if (ret <= 0) |
1175 | break; | |
1176 | written += ret; | |
1177 | buf += ret; | |
1178 | count -= ret; | |
1179 | if (!count) | |
1180 | break; | |
1181 | ret = -ERESTARTSYS; | |
1182 | if (signal_pending(current)) | |
1183 | break; | |
1184 | cond_resched(); | |
1185 | } | |
37b7f3c7 JS |
1186 | if (written) { |
1187 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1188 | ret = written; |
37b7f3c7 | 1189 | } |
9c1729db AC |
1190 | out: |
1191 | tty_write_unlock(tty); | |
1da177e4 LT |
1192 | return ret; |
1193 | } | |
1194 | ||
95f9bfc6 AC |
1195 | /** |
1196 | * tty_write_message - write a message to a certain tty, not just the console. | |
1197 | * @tty: the destination tty_struct | |
1198 | * @msg: the message to write | |
1199 | * | |
1200 | * This is used for messages that need to be redirected to a specific tty. | |
1201 | * We don't put it into the syslog queue right now maybe in the future if | |
1202 | * really needed. | |
1203 | * | |
ec79d605 | 1204 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1205 | */ |
1206 | ||
1207 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1208 | { | |
95f9bfc6 AC |
1209 | if (tty) { |
1210 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1211 | tty_lock(tty); |
4b41b953 | 1212 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1213 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1214 | tty_unlock(tty); |
95f9bfc6 AC |
1215 | tty_write_unlock(tty); |
1216 | } | |
95f9bfc6 AC |
1217 | return; |
1218 | } | |
1219 | ||
1da177e4 | 1220 | |
af9b897e AC |
1221 | /** |
1222 | * tty_write - write method for tty device file | |
1223 | * @file: tty file pointer | |
1224 | * @buf: user data to write | |
1225 | * @count: bytes to write | |
1226 | * @ppos: unused | |
1227 | * | |
1228 | * Write data to a tty device via the line discipline. | |
1229 | * | |
1230 | * Locking: | |
1231 | * Locks the line discipline as required | |
1232 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1233 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1234 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1235 | */ |
1236 | ||
37bdfb07 AC |
1237 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1238 | size_t count, loff_t *ppos) | |
1da177e4 | 1239 | { |
d996b62a NP |
1240 | struct tty_struct *tty = file_tty(file); |
1241 | struct tty_ldisc *ld; | |
1da177e4 | 1242 | ssize_t ret; |
37bdfb07 | 1243 | |
6131ffaa | 1244 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1245 | return -EIO; |
18900ca6 | 1246 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
37bdfb07 | 1247 | return -EIO; |
f34d7a5b AC |
1248 | /* Short term debug to catch buggy drivers */ |
1249 | if (tty->ops->write_room == NULL) | |
339f36ba | 1250 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1251 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1252 | if (!ld) |
1253 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1254 | if (!ld->ops->write) |
1da177e4 LT |
1255 | ret = -EIO; |
1256 | else | |
a352def2 | 1257 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1258 | tty_ldisc_deref(ld); |
1259 | return ret; | |
1260 | } | |
1261 | ||
37bdfb07 AC |
1262 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1263 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1264 | { |
1265 | struct file *p = NULL; | |
1266 | ||
1267 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1268 | if (redirect) |
1269 | p = get_file(redirect); | |
1da177e4 LT |
1270 | spin_unlock(&redirect_lock); |
1271 | ||
1272 | if (p) { | |
1273 | ssize_t res; | |
1274 | res = vfs_write(p, buf, count, &p->f_pos); | |
1275 | fput(p); | |
1276 | return res; | |
1277 | } | |
1da177e4 LT |
1278 | return tty_write(file, buf, count, ppos); |
1279 | } | |
1280 | ||
136d5258 PH |
1281 | /** |
1282 | * tty_send_xchar - send priority character | |
1283 | * | |
1284 | * Send a high priority character to the tty even if stopped | |
1285 | * | |
1286 | * Locking: none for xchar method, write ordering for write method. | |
1287 | */ | |
1288 | ||
1289 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1290 | { | |
1291 | int was_stopped = tty->stopped; | |
1292 | ||
1293 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1294 | down_read(&tty->termios_rwsem); |
136d5258 | 1295 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1296 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1297 | return 0; |
1298 | } | |
1299 | ||
1300 | if (tty_write_lock(tty, 0) < 0) | |
1301 | return -ERESTARTSYS; | |
1302 | ||
ee0c1a65 | 1303 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1304 | if (was_stopped) |
1305 | start_tty(tty); | |
1306 | tty->ops->write(tty, &ch, 1); | |
1307 | if (was_stopped) | |
1308 | stop_tty(tty); | |
ee0c1a65 | 1309 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1310 | tty_write_unlock(tty); |
1311 | return 0; | |
1312 | } | |
1313 | ||
1da177e4 LT |
1314 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1315 | ||
af9b897e AC |
1316 | /** |
1317 | * pty_line_name - generate name for a pty | |
1318 | * @driver: the tty driver in use | |
1319 | * @index: the minor number | |
1320 | * @p: output buffer of at least 6 bytes | |
1321 | * | |
1322 | * Generate a name from a driver reference and write it to the output | |
1323 | * buffer. | |
1324 | * | |
1325 | * Locking: None | |
1326 | */ | |
1327 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1328 | { |
1329 | int i = index + driver->name_base; | |
1330 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1331 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1332 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1333 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1334 | } |
1335 | ||
af9b897e | 1336 | /** |
8b0a88d5 | 1337 | * tty_line_name - generate name for a tty |
af9b897e AC |
1338 | * @driver: the tty driver in use |
1339 | * @index: the minor number | |
1340 | * @p: output buffer of at least 7 bytes | |
1341 | * | |
1342 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1343 | * buffer. |
af9b897e AC |
1344 | * |
1345 | * Locking: None | |
1346 | */ | |
723abd87 | 1347 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1348 | { |
0019b408 | 1349 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1350 | return sprintf(p, "%s", driver->name); |
0019b408 | 1351 | else |
723abd87 HR |
1352 | return sprintf(p, "%s%d", driver->name, |
1353 | index + driver->name_base); | |
1da177e4 LT |
1354 | } |
1355 | ||
99f1fe18 AC |
1356 | /** |
1357 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1358 | * @driver: the driver for the tty | |
1359 | * @idx: the minor number | |
23499705 | 1360 | * |
aa3cb814 PH |
1361 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1362 | * driver lookup() method returns an error. | |
23499705 | 1363 | * |
aa3cb814 | 1364 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1365 | */ |
a47d545f | 1366 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1367 | struct file *file, int idx) |
23499705 | 1368 | { |
aa3cb814 PH |
1369 | struct tty_struct *tty; |
1370 | ||
99f1fe18 | 1371 | if (driver->ops->lookup) |
8ead9dd5 | 1372 | tty = driver->ops->lookup(driver, file, idx); |
aa3cb814 PH |
1373 | else |
1374 | tty = driver->ttys[idx]; | |
23499705 | 1375 | |
aa3cb814 PH |
1376 | if (!IS_ERR(tty)) |
1377 | tty_kref_get(tty); | |
1378 | return tty; | |
23499705 SB |
1379 | } |
1380 | ||
bf970ee4 AC |
1381 | /** |
1382 | * tty_init_termios - helper for termios setup | |
1383 | * @tty: the tty to set up | |
1384 | * | |
1385 | * Initialise the termios structures for this tty. Thus runs under | |
1386 | * the tty_mutex currently so we can be relaxed about ordering. | |
1387 | */ | |
1388 | ||
a3123fd0 | 1389 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1390 | { |
fe6e29fd | 1391 | struct ktermios *tp; |
bf970ee4 AC |
1392 | int idx = tty->index; |
1393 | ||
36b3c070 AC |
1394 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1395 | tty->termios = tty->driver->init_termios; | |
1396 | else { | |
1397 | /* Check for lazy saved data */ | |
1398 | tp = tty->driver->termios[idx]; | |
ece53405 | 1399 | if (tp != NULL) { |
36b3c070 | 1400 | tty->termios = *tp; |
ece53405 PH |
1401 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1402 | } else | |
36b3c070 | 1403 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1404 | } |
bf970ee4 | 1405 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1406 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1407 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1408 | } |
fe1ae7fd | 1409 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1410 | |
66d450e8 JS |
1411 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1412 | { | |
a3123fd0 | 1413 | tty_init_termios(tty); |
66d450e8 JS |
1414 | tty_driver_kref_get(driver); |
1415 | tty->count++; | |
1416 | driver->ttys[tty->index] = tty; | |
1417 | return 0; | |
1418 | } | |
1419 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1420 | ||
99f1fe18 | 1421 | /** |
8b0a88d5 AC |
1422 | * tty_driver_install_tty() - install a tty entry in the driver |
1423 | * @driver: the driver for the tty | |
1424 | * @tty: the tty | |
1425 | * | |
1426 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1427 | * will be set by the time this is called. This method is responsible |
1428 | * for ensuring any need additional structures are allocated and | |
1429 | * configured. | |
8b0a88d5 AC |
1430 | * |
1431 | * Locking: tty_mutex for now | |
1432 | */ | |
1433 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1434 | struct tty_struct *tty) | |
1435 | { | |
66d450e8 JS |
1436 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1437 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1438 | } |
1439 | ||
1440 | /** | |
1441 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1442 | * @driver: the driver for the tty | |
1443 | * @idx: the minor number | |
1444 | * | |
1445 | * Remvoe a tty object from the driver tables. The tty->index field | |
1446 | * will be set by the time this is called. | |
1447 | * | |
1448 | * Locking: tty_mutex for now | |
1449 | */ | |
05de87ed | 1450 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1451 | { |
1452 | if (driver->ops->remove) | |
1453 | driver->ops->remove(driver, tty); | |
1454 | else | |
1455 | driver->ttys[tty->index] = NULL; | |
1456 | } | |
1457 | ||
1458 | /* | |
1459 | * tty_reopen() - fast re-open of an open tty | |
1460 | * @tty - the tty to open | |
23499705 | 1461 | * |
99f1fe18 | 1462 | * Return 0 on success, -errno on error. |
5d93e748 | 1463 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1464 | * |
5d93e748 | 1465 | * Locking: Caller must hold tty_lock |
23499705 | 1466 | */ |
99f1fe18 | 1467 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1468 | { |
1469 | struct tty_driver *driver = tty->driver; | |
1470 | ||
23499705 | 1471 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1472 | driver->subtype == PTY_TYPE_MASTER) |
1473 | return -EIO; | |
23499705 | 1474 | |
7f22f6c9 PH |
1475 | if (!tty->count) |
1476 | return -EAGAIN; | |
1477 | ||
86f2c00f PH |
1478 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1479 | return -EBUSY; | |
1480 | ||
23499705 | 1481 | tty->count++; |
23499705 | 1482 | |
892d1fa7 PH |
1483 | if (!tty->ldisc) |
1484 | return tty_ldisc_reinit(tty, tty->termios.c_line); | |
23499705 SB |
1485 | |
1486 | return 0; | |
1487 | } | |
1488 | ||
af9b897e | 1489 | /** |
d81ed103 | 1490 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1491 | * @driver: tty driver we are opening a device on |
1492 | * @idx: device index | |
15582d36 | 1493 | * @ret_tty: returned tty structure |
af9b897e AC |
1494 | * |
1495 | * Prepare a tty device. This may not be a "new" clean device but | |
1496 | * could also be an active device. The pty drivers require special | |
1497 | * handling because of this. | |
1498 | * | |
1499 | * Locking: | |
1500 | * The function is called under the tty_mutex, which | |
1501 | * protects us from the tty struct or driver itself going away. | |
1502 | * | |
1503 | * On exit the tty device has the line discipline attached and | |
1504 | * a reference count of 1. If a pair was created for pty/tty use | |
1505 | * and the other was a pty master then it too has a reference count of 1. | |
1506 | * | |
1da177e4 | 1507 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1508 | * failed open. The new code protects the open with a mutex, so it's |
1509 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1510 | * relaxed for the (most common) case of reopening a tty. |
1511 | */ | |
af9b897e | 1512 | |
593a27c4 | 1513 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1514 | { |
bf970ee4 | 1515 | struct tty_struct *tty; |
73ec06fc | 1516 | int retval; |
1da177e4 | 1517 | |
1da177e4 LT |
1518 | /* |
1519 | * First time open is complex, especially for PTY devices. | |
1520 | * This code guarantees that either everything succeeds and the | |
1521 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1522 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1523 | * and locked termios may be retained.) |
1524 | */ | |
1525 | ||
73ec06fc AC |
1526 | if (!try_module_get(driver->owner)) |
1527 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1528 | |
2c964a2f | 1529 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1530 | if (!tty) { |
1531 | retval = -ENOMEM; | |
1532 | goto err_module_put; | |
1533 | } | |
1da177e4 | 1534 | |
89c8d91e | 1535 | tty_lock(tty); |
73ec06fc | 1536 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1537 | if (retval < 0) |
c8b710b3 | 1538 | goto err_free_tty; |
8b0a88d5 | 1539 | |
04831dc1 JS |
1540 | if (!tty->port) |
1541 | tty->port = driver->ports[idx]; | |
1542 | ||
5d4121c0 JS |
1543 | WARN_RATELIMIT(!tty->port, |
1544 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1545 | __func__, tty->driver->name); | |
1546 | ||
967fab69 JS |
1547 | tty->port->itty = tty; |
1548 | ||
37bdfb07 | 1549 | /* |
1da177e4 | 1550 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1551 | * If we fail here just call release_tty to clean up. No need |
1552 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1553 | */ |
bf970ee4 | 1554 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1555 | if (retval) |
d5543503 | 1556 | goto err_release_tty; |
89c8d91e | 1557 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1558 | return tty; |
1da177e4 | 1559 | |
c8b710b3 | 1560 | err_free_tty: |
89c8d91e | 1561 | tty_unlock(tty); |
d5543503 JS |
1562 | free_tty_struct(tty); |
1563 | err_module_put: | |
1da177e4 | 1564 | module_put(driver->owner); |
d5543503 | 1565 | return ERR_PTR(retval); |
1da177e4 | 1566 | |
d5698c28 | 1567 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1568 | err_release_tty: |
89c8d91e | 1569 | tty_unlock(tty); |
339f36ba PH |
1570 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1571 | retval, idx); | |
d5698c28 | 1572 | release_tty(tty, idx); |
73ec06fc | 1573 | return ERR_PTR(retval); |
1da177e4 LT |
1574 | } |
1575 | ||
a3123fd0 | 1576 | static void tty_free_termios(struct tty_struct *tty) |
feebed65 AC |
1577 | { |
1578 | struct ktermios *tp; | |
1579 | int idx = tty->index; | |
36b3c070 AC |
1580 | |
1581 | /* If the port is going to reset then it has no termios to save */ | |
1582 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1583 | return; | |
1584 | ||
1585 | /* Stash the termios data */ | |
1586 | tp = tty->driver->termios[idx]; | |
1587 | if (tp == NULL) { | |
1588 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1589 | if (tp == NULL) |
36b3c070 | 1590 | return; |
4ac5d705 | 1591 | tty->driver->termios[idx] = tp; |
feebed65 | 1592 | } |
36b3c070 | 1593 | *tp = tty->termios; |
feebed65 | 1594 | } |
feebed65 | 1595 | |
a2965b7b | 1596 | /** |
949aa64f PH |
1597 | * tty_flush_works - flush all works of a tty/pty pair |
1598 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1599 | * |
949aa64f | 1600 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1601 | */ |
1602 | static void tty_flush_works(struct tty_struct *tty) | |
1603 | { | |
1604 | flush_work(&tty->SAK_work); | |
1605 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1606 | if (tty->link) { |
1607 | flush_work(&tty->link->SAK_work); | |
1608 | flush_work(&tty->link->hangup_work); | |
1609 | } | |
a2965b7b | 1610 | } |
feebed65 | 1611 | |
af9b897e | 1612 | /** |
d5698c28 | 1613 | * release_one_tty - release tty structure memory |
9c9f4ded | 1614 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1615 | * |
1616 | * Releases memory associated with a tty structure, and clears out the | |
1617 | * driver table slots. This function is called when a device is no longer | |
1618 | * in use. It also gets called when setup of a device fails. | |
1619 | * | |
1620 | * Locking: | |
af9b897e AC |
1621 | * takes the file list lock internally when working on the list |
1622 | * of ttys that the driver keeps. | |
b50989dc AC |
1623 | * |
1624 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1625 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1626 | */ |
b50989dc | 1627 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1628 | { |
b50989dc AC |
1629 | struct tty_struct *tty = |
1630 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1631 | struct tty_driver *driver = tty->driver; |
b216df53 | 1632 | struct module *owner = driver->owner; |
d5698c28 | 1633 | |
f278a2f7 DY |
1634 | if (tty->ops->cleanup) |
1635 | tty->ops->cleanup(tty); | |
1636 | ||
1da177e4 | 1637 | tty->magic = 0; |
7d7b93c1 | 1638 | tty_driver_kref_put(driver); |
b216df53 | 1639 | module_put(owner); |
d5698c28 | 1640 | |
4a510969 | 1641 | spin_lock(&tty->files_lock); |
1da177e4 | 1642 | list_del_init(&tty->tty_files); |
4a510969 | 1643 | spin_unlock(&tty->files_lock); |
d5698c28 | 1644 | |
6da8d866 ON |
1645 | put_pid(tty->pgrp); |
1646 | put_pid(tty->session); | |
1da177e4 LT |
1647 | free_tty_struct(tty); |
1648 | } | |
1649 | ||
b50989dc AC |
1650 | static void queue_release_one_tty(struct kref *kref) |
1651 | { | |
1652 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1653 | |
b50989dc AC |
1654 | /* The hangup queue is now free so we can reuse it rather than |
1655 | waste a chunk of memory for each port */ | |
1656 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1657 | schedule_work(&tty->hangup_work); | |
1658 | } | |
1659 | ||
9c9f4ded AC |
1660 | /** |
1661 | * tty_kref_put - release a tty kref | |
1662 | * @tty: tty device | |
1663 | * | |
1664 | * Release a reference to a tty device and if need be let the kref | |
1665 | * layer destruct the object for us | |
1666 | */ | |
1667 | ||
1668 | void tty_kref_put(struct tty_struct *tty) | |
1669 | { | |
1670 | if (tty) | |
b50989dc | 1671 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1672 | } |
1673 | EXPORT_SYMBOL(tty_kref_put); | |
1674 | ||
d5698c28 CH |
1675 | /** |
1676 | * release_tty - release tty structure memory | |
1677 | * | |
1678 | * Release both @tty and a possible linked partner (think pty pair), | |
1679 | * and decrement the refcount of the backing module. | |
1680 | * | |
1681 | * Locking: | |
d155255a | 1682 | * tty_mutex |
d5698c28 CH |
1683 | * takes the file list lock internally when working on the list |
1684 | * of ttys that the driver keeps. | |
9c9f4ded | 1685 | * |
d5698c28 CH |
1686 | */ |
1687 | static void release_tty(struct tty_struct *tty, int idx) | |
1688 | { | |
9c9f4ded AC |
1689 | /* This should always be true but check for the moment */ |
1690 | WARN_ON(tty->index != idx); | |
d155255a | 1691 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1692 | if (tty->ops->shutdown) |
1693 | tty->ops->shutdown(tty); | |
1694 | tty_free_termios(tty); | |
1695 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1696 | tty->port->itty = NULL; |
64e377dc PH |
1697 | if (tty->link) |
1698 | tty->link->port->itty = NULL; | |
e176058f | 1699 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1700 | |
a211b1af | 1701 | tty_kref_put(tty->link); |
9c9f4ded | 1702 | tty_kref_put(tty); |
d5698c28 CH |
1703 | } |
1704 | ||
955787ca JS |
1705 | /** |
1706 | * tty_release_checks - check a tty before real release | |
1707 | * @tty: tty to check | |
1708 | * @o_tty: link of @tty (if any) | |
1709 | * @idx: index of the tty | |
1710 | * | |
1711 | * Performs some paranoid checking before true release of the @tty. | |
1712 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1713 | */ | |
359b9fb5 | 1714 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1715 | { |
1716 | #ifdef TTY_PARANOIA_CHECK | |
1717 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1718 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1719 | return -1; |
1720 | } | |
1721 | ||
1722 | /* not much to check for devpts */ | |
1723 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1724 | return 0; | |
1725 | ||
1726 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1727 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1728 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1729 | return -1; |
1730 | } | |
955787ca | 1731 | if (tty->driver->other) { |
359b9fb5 PH |
1732 | struct tty_struct *o_tty = tty->link; |
1733 | ||
955787ca | 1734 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1735 | tty_debug(tty, "bad other table[%d] = %p\n", |
1736 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1737 | return -1; |
1738 | } | |
955787ca | 1739 | if (o_tty->link != tty) { |
e2dfa3d3 | 1740 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1741 | return -1; |
1742 | } | |
1743 | } | |
1744 | #endif | |
1745 | return 0; | |
1746 | } | |
1747 | ||
9ed90d20 RH |
1748 | /** |
1749 | * tty_release_struct - release a tty struct | |
1750 | * @tty: tty device | |
1751 | * @idx: index of the tty | |
1752 | * | |
1753 | * Performs the final steps to release and free a tty device. It is | |
1754 | * roughly the reverse of tty_init_dev. | |
1755 | */ | |
1756 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1757 | { | |
1758 | /* | |
1759 | * Ask the line discipline code to release its structures | |
1760 | */ | |
1761 | tty_ldisc_release(tty); | |
1762 | ||
1763 | /* Wait for pending work before tty destruction commmences */ | |
1764 | tty_flush_works(tty); | |
1765 | ||
1766 | tty_debug_hangup(tty, "freeing structure\n"); | |
1767 | /* | |
1768 | * The release_tty function takes care of the details of clearing | |
1769 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1770 | * should be safe as we keep a kref while the tty is locked (so the | |
1771 | * unlock never unlocks a freed tty). | |
1772 | */ | |
1773 | mutex_lock(&tty_mutex); | |
1774 | release_tty(tty, idx); | |
1775 | mutex_unlock(&tty_mutex); | |
1776 | } | |
1777 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1778 | ||
eeb89d91 AC |
1779 | /** |
1780 | * tty_release - vfs callback for close | |
1781 | * @inode: inode of tty | |
1782 | * @filp: file pointer for handle to tty | |
1783 | * | |
1784 | * Called the last time each file handle is closed that references | |
1785 | * this tty. There may however be several such references. | |
1786 | * | |
1787 | * Locking: | |
1788 | * Takes bkl. See tty_release_dev | |
1789 | * | |
1da177e4 LT |
1790 | * Even releasing the tty structures is a tricky business.. We have |
1791 | * to be very careful that the structures are all released at the | |
1792 | * same time, as interrupts might otherwise get the wrong pointers. | |
1793 | * | |
1794 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1795 | * lead to double frees or releasing memory still in use. | |
1796 | */ | |
eeb89d91 AC |
1797 | |
1798 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1799 | { |
d996b62a | 1800 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1801 | struct tty_struct *o_tty = NULL; |
1802 | int do_sleep, final; | |
1da177e4 | 1803 | int idx; |
37b16457 | 1804 | long timeout = 0; |
494c1eac | 1805 | int once = 1; |
37bdfb07 | 1806 | |
9de44bd6 | 1807 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1808 | return 0; |
1da177e4 | 1809 | |
89c8d91e | 1810 | tty_lock(tty); |
9de44bd6 | 1811 | check_tty_count(tty, __func__); |
1da177e4 | 1812 | |
ec79d605 | 1813 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1814 | |
1815 | idx = tty->index; | |
7ffb6da9 PH |
1816 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1817 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1818 | o_tty = tty->link; | |
1da177e4 | 1819 | |
359b9fb5 | 1820 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1821 | tty_unlock(tty); |
eeb89d91 | 1822 | return 0; |
1da177e4 | 1823 | } |
1da177e4 | 1824 | |
d435cefe | 1825 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1826 | |
f34d7a5b AC |
1827 | if (tty->ops->close) |
1828 | tty->ops->close(tty, filp); | |
1da177e4 | 1829 | |
2aff5e2b PH |
1830 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1831 | tty_lock_slave(o_tty); | |
1832 | ||
1da177e4 LT |
1833 | /* |
1834 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1835 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1836 | * wait queues and kick everyone out _before_ actually starting to | |
1837 | * close. This ensures that we won't block while releasing the tty | |
1838 | * structure. | |
1839 | * | |
1840 | * The test for the o_tty closing is necessary, since the master and | |
1841 | * slave sides may close in any order. If the slave side closes out | |
1842 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1843 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1844 | * so we do it now. |
1da177e4 LT |
1845 | */ |
1846 | while (1) { | |
1da177e4 LT |
1847 | do_sleep = 0; |
1848 | ||
324c1650 | 1849 | if (tty->count <= 1) { |
1da177e4 | 1850 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1851 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1852 | do_sleep++; |
1853 | } | |
1854 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1855 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1856 | do_sleep++; |
1857 | } | |
1858 | } | |
7ffb6da9 | 1859 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1860 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1861 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1862 | do_sleep++; |
1863 | } | |
1864 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1865 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1866 | do_sleep++; |
1867 | } | |
1868 | } | |
1869 | if (!do_sleep) | |
1870 | break; | |
1871 | ||
494c1eac PH |
1872 | if (once) { |
1873 | once = 0; | |
339f36ba | 1874 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1875 | } |
37b16457 PH |
1876 | schedule_timeout_killable(timeout); |
1877 | if (timeout < 120 * HZ) | |
1878 | timeout = 2 * timeout + 1; | |
1879 | else | |
1880 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1881 | } |
1da177e4 | 1882 | |
7ffb6da9 | 1883 | if (o_tty) { |
1da177e4 | 1884 | if (--o_tty->count < 0) { |
339f36ba | 1885 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1886 | o_tty->count = 0; |
1887 | } | |
1888 | } | |
1889 | if (--tty->count < 0) { | |
339f36ba | 1890 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1891 | tty->count = 0; |
1892 | } | |
37bdfb07 | 1893 | |
1da177e4 LT |
1894 | /* |
1895 | * We've decremented tty->count, so we need to remove this file | |
1896 | * descriptor off the tty->tty_files list; this serves two | |
1897 | * purposes: | |
1898 | * - check_tty_count sees the correct number of file descriptors | |
1899 | * associated with this tty. | |
1900 | * - do_tty_hangup no longer sees this file descriptor as | |
1901 | * something that needs to be handled for hangups. | |
1902 | */ | |
d996b62a | 1903 | tty_del_file(filp); |
1da177e4 LT |
1904 | |
1905 | /* | |
1906 | * Perform some housekeeping before deciding whether to return. | |
1907 | * | |
1da177e4 LT |
1908 | * If _either_ side is closing, make sure there aren't any |
1909 | * processes that still think tty or o_tty is their controlling | |
1910 | * tty. | |
1911 | */ | |
324c1650 | 1912 | if (!tty->count) { |
1da177e4 | 1913 | read_lock(&tasklist_lock); |
24ec839c | 1914 | session_clear_tty(tty->session); |
7ffb6da9 | 1915 | if (o_tty) |
24ec839c | 1916 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1917 | read_unlock(&tasklist_lock); |
1918 | } | |
1919 | ||
324c1650 | 1920 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1921 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1922 | |
2aff5e2b PH |
1923 | tty_unlock_slave(o_tty); |
1924 | tty_unlock(tty); | |
1925 | ||
04980706 | 1926 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1927 | cannot be re-opened by a racing opener */ |
da965822 | 1928 | |
324c1650 | 1929 | if (!final) |
eeb89d91 | 1930 | return 0; |
37bdfb07 | 1931 | |
accff793 | 1932 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1933 | |
9ed90d20 | 1934 | tty_release_struct(tty, idx); |
eeb89d91 | 1935 | return 0; |
1da177e4 LT |
1936 | } |
1937 | ||
b82154ac | 1938 | /** |
52494eeb | 1939 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1940 | * @device: device number |
1941 | * @filp: file pointer to tty | |
52494eeb PH |
1942 | * @return: locked tty of the current task iff @device is /dev/tty |
1943 | * | |
1944 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1945 | * |
1946 | * We cannot return driver and index like for the other nodes because | |
1947 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1948 | */ | |
1949 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1950 | { | |
1951 | struct tty_struct *tty; | |
52494eeb | 1952 | int retval; |
b82154ac JS |
1953 | |
1954 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1955 | return NULL; | |
1956 | ||
1957 | tty = get_current_tty(); | |
1958 | if (!tty) | |
1959 | return ERR_PTR(-ENXIO); | |
1960 | ||
1961 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1962 | /* noctty = 1; */ | |
52494eeb PH |
1963 | tty_lock(tty); |
1964 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1965 | ||
1966 | retval = tty_reopen(tty); | |
1967 | if (retval < 0) { | |
1968 | tty_unlock(tty); | |
1969 | tty = ERR_PTR(retval); | |
1970 | } | |
b82154ac JS |
1971 | return tty; |
1972 | } | |
1973 | ||
5b5e7040 JS |
1974 | /** |
1975 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1976 | * @device: device number | |
1977 | * @filp: file pointer to tty | |
5b5e7040 JS |
1978 | * @index: index for the device in the @return driver |
1979 | * @return: driver for this inode (with increased refcount) | |
1980 | * | |
1981 | * If @return is not erroneous, the caller is responsible to decrement the | |
1982 | * refcount by tty_driver_kref_put. | |
1983 | * | |
1984 | * Locking: tty_mutex protects get_tty_driver | |
1985 | */ | |
1986 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1987 | int *index) |
5b5e7040 JS |
1988 | { |
1989 | struct tty_driver *driver; | |
1990 | ||
2cd0050c | 1991 | switch (device) { |
5b5e7040 | 1992 | #ifdef CONFIG_VT |
2cd0050c | 1993 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1994 | extern struct tty_driver *console_driver; |
1995 | driver = tty_driver_kref_get(console_driver); | |
1996 | *index = fg_console; | |
2cd0050c | 1997 | break; |
5b5e7040 JS |
1998 | } |
1999 | #endif | |
2cd0050c | 2000 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
2001 | struct tty_driver *console_driver = console_device(index); |
2002 | if (console_driver) { | |
2003 | driver = tty_driver_kref_get(console_driver); | |
2004 | if (driver) { | |
2005 | /* Don't let /dev/console block */ | |
2006 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 2007 | break; |
5b5e7040 JS |
2008 | } |
2009 | } | |
2010 | return ERR_PTR(-ENODEV); | |
2011 | } | |
2cd0050c JS |
2012 | default: |
2013 | driver = get_tty_driver(device, index); | |
2014 | if (!driver) | |
2015 | return ERR_PTR(-ENODEV); | |
2016 | break; | |
2017 | } | |
5b5e7040 JS |
2018 | return driver; |
2019 | } | |
2020 | ||
d6203d0c PH |
2021 | /** |
2022 | * tty_open_by_driver - open a tty device | |
2023 | * @device: dev_t of device to open | |
2024 | * @inode: inode of device file | |
2025 | * @filp: file pointer to tty | |
2026 | * | |
2027 | * Performs the driver lookup, checks for a reopen, or otherwise | |
2028 | * performs the first-time tty initialization. | |
2029 | * | |
2030 | * Returns the locked initialized or re-opened &tty_struct | |
2031 | * | |
2032 | * Claims the global tty_mutex to serialize: | |
2033 | * - concurrent first-time tty initialization | |
2034 | * - concurrent tty driver removal w/ lookup | |
2035 | * - concurrent tty removal from driver table | |
2036 | */ | |
2037 | static struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, | |
2038 | struct file *filp) | |
2039 | { | |
2040 | struct tty_struct *tty; | |
2041 | struct tty_driver *driver = NULL; | |
2042 | int index = -1; | |
2043 | int retval; | |
2044 | ||
2045 | mutex_lock(&tty_mutex); | |
2046 | driver = tty_lookup_driver(device, filp, &index); | |
2047 | if (IS_ERR(driver)) { | |
2048 | mutex_unlock(&tty_mutex); | |
2049 | return ERR_CAST(driver); | |
2050 | } | |
2051 | ||
2052 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 2053 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
2054 | if (IS_ERR(tty)) { |
2055 | mutex_unlock(&tty_mutex); | |
2056 | goto out; | |
2057 | } | |
2058 | ||
2059 | if (tty) { | |
2060 | mutex_unlock(&tty_mutex); | |
2061 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2062 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2063 | if (retval) { |
2064 | if (retval == -EINTR) | |
2065 | retval = -ERESTARTSYS; | |
2066 | tty = ERR_PTR(retval); | |
2067 | goto out; | |
2068 | } | |
d6203d0c PH |
2069 | retval = tty_reopen(tty); |
2070 | if (retval < 0) { | |
2071 | tty_unlock(tty); | |
2072 | tty = ERR_PTR(retval); | |
2073 | } | |
2074 | } else { /* Returns with the tty_lock held for now */ | |
2075 | tty = tty_init_dev(driver, index); | |
2076 | mutex_unlock(&tty_mutex); | |
2077 | } | |
2078 | out: | |
2079 | tty_driver_kref_put(driver); | |
2080 | return tty; | |
2081 | } | |
2082 | ||
af9b897e | 2083 | /** |
eeb89d91 | 2084 | * tty_open - open a tty device |
af9b897e AC |
2085 | * @inode: inode of device file |
2086 | * @filp: file pointer to tty | |
1da177e4 | 2087 | * |
af9b897e AC |
2088 | * tty_open and tty_release keep up the tty count that contains the |
2089 | * number of opens done on a tty. We cannot use the inode-count, as | |
2090 | * different inodes might point to the same tty. | |
1da177e4 | 2091 | * |
af9b897e AC |
2092 | * Open-counting is needed for pty masters, as well as for keeping |
2093 | * track of serial lines: DTR is dropped when the last close happens. | |
2094 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2095 | * | |
2096 | * The termios state of a pty is reset on first open so that | |
2097 | * settings don't persist across reuse. | |
2098 | * | |
5b5e7040 | 2099 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2100 | * tty->count should protect the rest. |
2101 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2102 | * |
2103 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2104 | * tty_mutex | |
1da177e4 | 2105 | */ |
af9b897e | 2106 | |
eeb89d91 | 2107 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2108 | { |
b82154ac | 2109 | struct tty_struct *tty; |
1da177e4 | 2110 | int noctty, retval; |
1da177e4 | 2111 | dev_t device = inode->i_rdev; |
846c151a | 2112 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2113 | |
2114 | nonseekable_open(inode, filp); | |
37bdfb07 | 2115 | |
1da177e4 | 2116 | retry_open: |
fa90e1c9 JS |
2117 | retval = tty_alloc_file(filp); |
2118 | if (retval) | |
2119 | return -ENOMEM; | |
2120 | ||
b82154ac | 2121 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
2122 | if (!tty) |
2123 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 2124 | |
eeb89d91 | 2125 | if (IS_ERR(tty)) { |
d6203d0c | 2126 | tty_free_file(filp); |
ba5db448 | 2127 | retval = PTR_ERR(tty); |
7f22f6c9 | 2128 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2129 | return retval; |
7f22f6c9 PH |
2130 | schedule(); |
2131 | goto retry_open; | |
eeb89d91 | 2132 | } |
1da177e4 | 2133 | |
fa90e1c9 | 2134 | tty_add_file(tty, filp); |
d996b62a | 2135 | |
9de44bd6 | 2136 | check_tty_count(tty, __func__); |
d435cefe | 2137 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2138 | |
909bc774 HRK |
2139 | if (tty->ops->open) |
2140 | retval = tty->ops->open(tty, filp); | |
2141 | else | |
2142 | retval = -ENODEV; | |
1da177e4 LT |
2143 | filp->f_flags = saved_flags; |
2144 | ||
1da177e4 | 2145 | if (retval) { |
d435cefe | 2146 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2147 | |
89c8d91e | 2148 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2149 | tty_release(inode, filp); |
64ba3dc3 | 2150 | if (retval != -ERESTARTSYS) |
1da177e4 | 2151 | return retval; |
64ba3dc3 AB |
2152 | |
2153 | if (signal_pending(current)) | |
1da177e4 | 2154 | return retval; |
64ba3dc3 | 2155 | |
1da177e4 LT |
2156 | schedule(); |
2157 | /* | |
2158 | * Need to reset f_op in case a hangup happened. | |
2159 | */ | |
1256937f | 2160 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2161 | filp->f_op = &tty_fops; |
2162 | goto retry_open; | |
2163 | } | |
d4855e1f | 2164 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2165 | |
24ec839c | 2166 | |
2c411c11 | 2167 | read_lock(&tasklist_lock); |
24ec839c | 2168 | spin_lock_irq(¤t->sighand->siglock); |
11e1d4aa | 2169 | noctty = (filp->f_flags & O_NOCTTY) || |
da5a0fc6 | 2170 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
11e1d4aa PH |
2171 | device == MKDEV(TTYAUX_MAJOR, 1) || |
2172 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2173 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2174 | ||
1da177e4 LT |
2175 | if (!noctty && |
2176 | current->signal->leader && | |
2177 | !current->signal->tty && | |
0c556271 JH |
2178 | tty->session == NULL) { |
2179 | /* | |
2180 | * Don't let a process that only has write access to the tty | |
2181 | * obtain the privileges associated with having a tty as | |
2182 | * controlling terminal (being able to reopen it with full | |
2183 | * access through /dev/tty, being able to perform pushback). | |
2184 | * Many distributions set the group of all ttys to "tty" and | |
2185 | * grant write-only access to all terminals for setgid tty | |
2186 | * binaries, which should not imply full privileges on all ttys. | |
2187 | * | |
2188 | * This could theoretically break old code that performs open() | |
2189 | * on a write-only file descriptor. In that case, it might be | |
2190 | * necessary to also permit this if | |
2191 | * inode_permission(inode, MAY_READ) == 0. | |
2192 | */ | |
2193 | if (filp->f_mode & FMODE_READ) | |
2194 | __proc_set_tty(tty); | |
2195 | } | |
24ec839c | 2196 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2197 | read_unlock(&tasklist_lock); |
89c8d91e | 2198 | tty_unlock(tty); |
1da177e4 LT |
2199 | return 0; |
2200 | } | |
2201 | ||
39d95b9d JC |
2202 | |
2203 | ||
af9b897e AC |
2204 | /** |
2205 | * tty_poll - check tty status | |
2206 | * @filp: file being polled | |
2207 | * @wait: poll wait structures to update | |
2208 | * | |
2209 | * Call the line discipline polling method to obtain the poll | |
2210 | * status of the device. | |
2211 | * | |
2212 | * Locking: locks called line discipline but ldisc poll method | |
2213 | * may be re-entered freely by other callers. | |
2214 | */ | |
2215 | ||
37bdfb07 | 2216 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2217 | { |
d996b62a | 2218 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2219 | struct tty_ldisc *ld; |
2220 | int ret = 0; | |
2221 | ||
6131ffaa | 2222 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2223 | return 0; |
37bdfb07 | 2224 | |
1da177e4 | 2225 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2226 | if (!ld) |
2227 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2228 | if (ld->ops->poll) |
c961bfb1 | 2229 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2230 | tty_ldisc_deref(ld); |
2231 | return ret; | |
2232 | } | |
2233 | ||
ec79d605 | 2234 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2235 | { |
d996b62a | 2236 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2237 | unsigned long flags; |
5d1e3230 | 2238 | int retval = 0; |
1da177e4 | 2239 | |
6131ffaa | 2240 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2241 | goto out; |
37bdfb07 | 2242 | |
1da177e4 LT |
2243 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2244 | if (retval <= 0) | |
5d1e3230 | 2245 | goto out; |
f6c8dbe6 | 2246 | |
1da177e4 | 2247 | if (on) { |
ab521dc0 EB |
2248 | enum pid_type type; |
2249 | struct pid *pid; | |
f6c8dbe6 | 2250 | |
47f86834 | 2251 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2252 | if (tty->pgrp) { |
2253 | pid = tty->pgrp; | |
2254 | type = PIDTYPE_PGID; | |
2255 | } else { | |
2256 | pid = task_pid(current); | |
2257 | type = PIDTYPE_PID; | |
2258 | } | |
80e1e823 | 2259 | get_pid(pid); |
70362511 | 2260 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2261 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2262 | put_pid(pid); |
e0b93edd | 2263 | retval = 0; |
1da177e4 | 2264 | } |
5d1e3230 | 2265 | out: |
ec79d605 AB |
2266 | return retval; |
2267 | } | |
2268 | ||
2269 | static int tty_fasync(int fd, struct file *filp, int on) | |
2270 | { | |
89c8d91e | 2271 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2272 | int retval = -ENOTTY; |
89c8d91e AC |
2273 | |
2274 | tty_lock(tty); | |
a8f3a297 PH |
2275 | if (!tty_hung_up_p(filp)) |
2276 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2277 | tty_unlock(tty); |
2278 | ||
5d1e3230 | 2279 | return retval; |
1da177e4 LT |
2280 | } |
2281 | ||
af9b897e AC |
2282 | /** |
2283 | * tiocsti - fake input character | |
2284 | * @tty: tty to fake input into | |
2285 | * @p: pointer to character | |
2286 | * | |
3a4fa0a2 | 2287 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2288 | * input management. |
2289 | * | |
2290 | * FIXME: does not honour flow control ?? | |
2291 | * | |
2292 | * Locking: | |
137084bb | 2293 | * Called functions take tty_ldiscs_lock |
af9b897e | 2294 | * current->signal->tty check is safe without locks |
28298232 AC |
2295 | * |
2296 | * FIXME: may race normal receive processing | |
af9b897e AC |
2297 | */ |
2298 | ||
1da177e4 LT |
2299 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2300 | { | |
2301 | char ch, mbz = 0; | |
2302 | struct tty_ldisc *ld; | |
37bdfb07 | 2303 | |
1da177e4 LT |
2304 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2305 | return -EPERM; | |
2306 | if (get_user(ch, p)) | |
2307 | return -EFAULT; | |
1e641743 | 2308 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2309 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2310 | if (!ld) |
2311 | return -EIO; | |
a352def2 | 2312 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2313 | tty_ldisc_deref(ld); |
2314 | return 0; | |
2315 | } | |
2316 | ||
af9b897e AC |
2317 | /** |
2318 | * tiocgwinsz - implement window query ioctl | |
2319 | * @tty; tty | |
2320 | * @arg: user buffer for result | |
2321 | * | |
808a0d38 | 2322 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2323 | * |
dee4a0be | 2324 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2325 | * is consistent. |
af9b897e AC |
2326 | */ |
2327 | ||
37bdfb07 | 2328 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2329 | { |
808a0d38 AC |
2330 | int err; |
2331 | ||
dee4a0be | 2332 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2333 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2334 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2335 | |
2336 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2337 | } |
2338 | ||
af9b897e | 2339 | /** |
8c9a9dd0 AC |
2340 | * tty_do_resize - resize event |
2341 | * @tty: tty being resized | |
8c9a9dd0 AC |
2342 | * @rows: rows (character) |
2343 | * @cols: cols (character) | |
2344 | * | |
3ad2f3fb | 2345 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2346 | * peform a terminal resize correctly |
af9b897e AC |
2347 | */ |
2348 | ||
fc6f6238 | 2349 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2350 | { |
fc6f6238 | 2351 | struct pid *pgrp; |
1da177e4 | 2352 | |
fc6f6238 | 2353 | /* Lock the tty */ |
dee4a0be | 2354 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2355 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2356 | goto done; |
47f86834 | 2357 | |
5b239542 PH |
2358 | /* Signal the foreground process group */ |
2359 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2360 | if (pgrp) |
2361 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2362 | put_pid(pgrp); |
47f86834 | 2363 | |
8c9a9dd0 | 2364 | tty->winsize = *ws; |
ca9bda00 | 2365 | done: |
dee4a0be | 2366 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2367 | return 0; |
2368 | } | |
4d334fd1 | 2369 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2370 | |
8c9a9dd0 AC |
2371 | /** |
2372 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2373 | * @tty; tty side of tty |
8c9a9dd0 AC |
2374 | * @arg: user buffer for result |
2375 | * | |
2376 | * Copies the user idea of the window size to the kernel. Traditionally | |
2377 | * this is just advisory information but for the Linux console it | |
2378 | * actually has driver level meaning and triggers a VC resize. | |
2379 | * | |
2380 | * Locking: | |
25985edc | 2381 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2382 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2383 | * then calls into the default method. | |
2384 | */ | |
2385 | ||
fc6f6238 | 2386 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2387 | { |
2388 | struct winsize tmp_ws; | |
2389 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2390 | return -EFAULT; | |
2391 | ||
2392 | if (tty->ops->resize) | |
fc6f6238 | 2393 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2394 | else |
fc6f6238 | 2395 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2396 | } |
2397 | ||
af9b897e AC |
2398 | /** |
2399 | * tioccons - allow admin to move logical console | |
2400 | * @file: the file to become console | |
2401 | * | |
25985edc | 2402 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2403 | * |
2404 | * Locking: uses redirect_lock to guard the redirect information | |
2405 | */ | |
2406 | ||
1da177e4 LT |
2407 | static int tioccons(struct file *file) |
2408 | { | |
2409 | if (!capable(CAP_SYS_ADMIN)) | |
2410 | return -EPERM; | |
2411 | if (file->f_op->write == redirected_tty_write) { | |
2412 | struct file *f; | |
2413 | spin_lock(&redirect_lock); | |
2414 | f = redirect; | |
2415 | redirect = NULL; | |
2416 | spin_unlock(&redirect_lock); | |
2417 | if (f) | |
2418 | fput(f); | |
2419 | return 0; | |
2420 | } | |
2421 | spin_lock(&redirect_lock); | |
2422 | if (redirect) { | |
2423 | spin_unlock(&redirect_lock); | |
2424 | return -EBUSY; | |
2425 | } | |
cb0942b8 | 2426 | redirect = get_file(file); |
1da177e4 LT |
2427 | spin_unlock(&redirect_lock); |
2428 | return 0; | |
2429 | } | |
2430 | ||
af9b897e AC |
2431 | /** |
2432 | * fionbio - non blocking ioctl | |
2433 | * @file: file to set blocking value | |
2434 | * @p: user parameter | |
2435 | * | |
2436 | * Historical tty interfaces had a blocking control ioctl before | |
2437 | * the generic functionality existed. This piece of history is preserved | |
2438 | * in the expected tty API of posix OS's. | |
2439 | * | |
6146b9af | 2440 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2441 | */ |
1da177e4 LT |
2442 | |
2443 | static int fionbio(struct file *file, int __user *p) | |
2444 | { | |
2445 | int nonblock; | |
2446 | ||
2447 | if (get_user(nonblock, p)) | |
2448 | return -EFAULT; | |
2449 | ||
db1dd4d3 | 2450 | spin_lock(&file->f_lock); |
1da177e4 LT |
2451 | if (nonblock) |
2452 | file->f_flags |= O_NONBLOCK; | |
2453 | else | |
2454 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2455 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2456 | return 0; |
2457 | } | |
2458 | ||
af9b897e AC |
2459 | /** |
2460 | * tiocsctty - set controlling tty | |
2461 | * @tty: tty structure | |
2462 | * @arg: user argument | |
2463 | * | |
2464 | * This ioctl is used to manage job control. It permits a session | |
2465 | * leader to set this tty as the controlling tty for the session. | |
2466 | * | |
2467 | * Locking: | |
e218eb32 | 2468 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2469 | * Takes tasklist_lock internally to walk sessions |
2470 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2471 | */ |
2472 | ||
0c556271 | 2473 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) |
1da177e4 | 2474 | { |
24ec839c | 2475 | int ret = 0; |
24ec839c | 2476 | |
e218eb32 | 2477 | tty_lock(tty); |
2c411c11 PH |
2478 | read_lock(&tasklist_lock); |
2479 | ||
2480 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2481 | goto unlock; | |
2482 | ||
1da177e4 LT |
2483 | /* |
2484 | * The process must be a session leader and | |
2485 | * not have a controlling tty already. | |
2486 | */ | |
24ec839c PZ |
2487 | if (!current->signal->leader || current->signal->tty) { |
2488 | ret = -EPERM; | |
2489 | goto unlock; | |
2490 | } | |
2491 | ||
ab521dc0 | 2492 | if (tty->session) { |
1da177e4 LT |
2493 | /* |
2494 | * This tty is already the controlling | |
2495 | * tty for another session group! | |
2496 | */ | |
37bdfb07 | 2497 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2498 | /* |
2499 | * Steal it away | |
2500 | */ | |
24ec839c | 2501 | session_clear_tty(tty->session); |
24ec839c PZ |
2502 | } else { |
2503 | ret = -EPERM; | |
2504 | goto unlock; | |
2505 | } | |
1da177e4 | 2506 | } |
0c556271 JH |
2507 | |
2508 | /* See the comment in tty_open(). */ | |
2509 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
2510 | ret = -EPERM; | |
2511 | goto unlock; | |
2512 | } | |
2513 | ||
bce65f18 | 2514 | proc_set_tty(tty); |
24ec839c | 2515 | unlock: |
2c411c11 | 2516 | read_unlock(&tasklist_lock); |
e218eb32 | 2517 | tty_unlock(tty); |
24ec839c | 2518 | return ret; |
1da177e4 LT |
2519 | } |
2520 | ||
5d0fdf1e AC |
2521 | /** |
2522 | * tty_get_pgrp - return a ref counted pgrp pid | |
2523 | * @tty: tty to read | |
2524 | * | |
2525 | * Returns a refcounted instance of the pid struct for the process | |
2526 | * group controlling the tty. | |
2527 | */ | |
2528 | ||
2529 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2530 | { | |
2531 | unsigned long flags; | |
2532 | struct pid *pgrp; | |
2533 | ||
2534 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2535 | pgrp = get_pid(tty->pgrp); | |
2536 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2537 | ||
2538 | return pgrp; | |
2539 | } | |
2540 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2541 | ||
e1c2296c PH |
2542 | /* |
2543 | * This checks not only the pgrp, but falls back on the pid if no | |
2544 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2545 | * without this... | |
2546 | * | |
2547 | * The caller must hold rcu lock or the tasklist lock. | |
2548 | */ | |
2549 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2550 | { | |
2551 | struct task_struct *p; | |
2552 | struct pid *sid = NULL; | |
2553 | ||
2554 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2555 | if (p == NULL) | |
2556 | p = pid_task(pgrp, PIDTYPE_PID); | |
2557 | if (p != NULL) | |
2558 | sid = task_session(p); | |
2559 | ||
2560 | return sid; | |
2561 | } | |
2562 | ||
af9b897e AC |
2563 | /** |
2564 | * tiocgpgrp - get process group | |
2565 | * @tty: tty passed by user | |
25985edc | 2566 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2567 | * @p: returned pid |
2568 | * | |
2569 | * Obtain the process group of the tty. If there is no process group | |
2570 | * return an error. | |
2571 | * | |
24ec839c | 2572 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2573 | */ |
2574 | ||
1da177e4 LT |
2575 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2576 | { | |
5d0fdf1e AC |
2577 | struct pid *pid; |
2578 | int ret; | |
1da177e4 LT |
2579 | /* |
2580 | * (tty == real_tty) is a cheap way of | |
2581 | * testing if the tty is NOT a master pty. | |
2582 | */ | |
2583 | if (tty == real_tty && current->signal->tty != real_tty) | |
2584 | return -ENOTTY; | |
5d0fdf1e AC |
2585 | pid = tty_get_pgrp(real_tty); |
2586 | ret = put_user(pid_vnr(pid), p); | |
2587 | put_pid(pid); | |
2588 | return ret; | |
1da177e4 LT |
2589 | } |
2590 | ||
af9b897e AC |
2591 | /** |
2592 | * tiocspgrp - attempt to set process group | |
2593 | * @tty: tty passed by user | |
2594 | * @real_tty: tty side device matching tty passed by user | |
2595 | * @p: pid pointer | |
2596 | * | |
2597 | * Set the process group of the tty to the session passed. Only | |
2598 | * permitted where the tty session is our session. | |
2599 | * | |
47f86834 | 2600 | * Locking: RCU, ctrl lock |
af9b897e AC |
2601 | */ |
2602 | ||
1da177e4 LT |
2603 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2604 | { | |
04a2e6a5 EB |
2605 | struct pid *pgrp; |
2606 | pid_t pgrp_nr; | |
1da177e4 LT |
2607 | int retval = tty_check_change(real_tty); |
2608 | ||
2609 | if (retval == -EIO) | |
2610 | return -ENOTTY; | |
2611 | if (retval) | |
2612 | return retval; | |
2613 | if (!current->signal->tty || | |
2614 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2615 | (real_tty->session != task_session(current))) |
1da177e4 | 2616 | return -ENOTTY; |
04a2e6a5 | 2617 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2618 | return -EFAULT; |
04a2e6a5 | 2619 | if (pgrp_nr < 0) |
1da177e4 | 2620 | return -EINVAL; |
04a2e6a5 | 2621 | rcu_read_lock(); |
b488893a | 2622 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2623 | retval = -ESRCH; |
2624 | if (!pgrp) | |
2625 | goto out_unlock; | |
2626 | retval = -EPERM; | |
2627 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2628 | goto out_unlock; | |
2629 | retval = 0; | |
1e86b5bf | 2630 | spin_lock_irq(&tty->ctrl_lock); |
ab521dc0 EB |
2631 | put_pid(real_tty->pgrp); |
2632 | real_tty->pgrp = get_pid(pgrp); | |
1e86b5bf | 2633 | spin_unlock_irq(&tty->ctrl_lock); |
04a2e6a5 EB |
2634 | out_unlock: |
2635 | rcu_read_unlock(); | |
2636 | return retval; | |
1da177e4 LT |
2637 | } |
2638 | ||
af9b897e AC |
2639 | /** |
2640 | * tiocgsid - get session id | |
2641 | * @tty: tty passed by user | |
25985edc | 2642 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2643 | * @p: pointer to returned session id |
2644 | * | |
2645 | * Obtain the session id of the tty. If there is no session | |
2646 | * return an error. | |
2647 | * | |
24ec839c | 2648 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2649 | */ |
2650 | ||
1da177e4 LT |
2651 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2652 | { | |
2653 | /* | |
2654 | * (tty == real_tty) is a cheap way of | |
2655 | * testing if the tty is NOT a master pty. | |
2656 | */ | |
2657 | if (tty == real_tty && current->signal->tty != real_tty) | |
2658 | return -ENOTTY; | |
ab521dc0 | 2659 | if (!real_tty->session) |
1da177e4 | 2660 | return -ENOTTY; |
b488893a | 2661 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2662 | } |
2663 | ||
af9b897e AC |
2664 | /** |
2665 | * tiocsetd - set line discipline | |
2666 | * @tty: tty device | |
2667 | * @p: pointer to user data | |
2668 | * | |
2669 | * Set the line discipline according to user request. | |
2670 | * | |
2671 | * Locking: see tty_set_ldisc, this function is just a helper | |
2672 | */ | |
2673 | ||
1da177e4 LT |
2674 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2675 | { | |
c12da96f | 2676 | int disc; |
04f378b1 | 2677 | int ret; |
1da177e4 | 2678 | |
c12da96f | 2679 | if (get_user(disc, p)) |
1da177e4 | 2680 | return -EFAULT; |
04f378b1 | 2681 | |
c12da96f | 2682 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2683 | |
2684 | return ret; | |
1da177e4 LT |
2685 | } |
2686 | ||
5c17c861 PH |
2687 | /** |
2688 | * tiocgetd - get line discipline | |
2689 | * @tty: tty device | |
2690 | * @p: pointer to user data | |
2691 | * | |
2692 | * Retrieves the line discipline id directly from the ldisc. | |
2693 | * | |
2694 | * Locking: waits for ldisc reference (in case the line discipline | |
2695 | * is changing or the tty is being hungup) | |
2696 | */ | |
2697 | ||
2698 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2699 | { | |
2700 | struct tty_ldisc *ld; | |
2701 | int ret; | |
2702 | ||
2703 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2704 | if (!ld) |
2705 | return -EIO; | |
5c17c861 PH |
2706 | ret = put_user(ld->ops->num, p); |
2707 | tty_ldisc_deref(ld); | |
2708 | return ret; | |
2709 | } | |
2710 | ||
af9b897e AC |
2711 | /** |
2712 | * send_break - performed time break | |
2713 | * @tty: device to break on | |
2714 | * @duration: timeout in mS | |
2715 | * | |
2716 | * Perform a timed break on hardware that lacks its own driver level | |
2717 | * timed break functionality. | |
2718 | * | |
2719 | * Locking: | |
28298232 | 2720 | * atomic_write_lock serializes |
af9b897e | 2721 | * |
af9b897e AC |
2722 | */ |
2723 | ||
b20f3ae5 | 2724 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2725 | { |
9e98966c AC |
2726 | int retval; |
2727 | ||
2728 | if (tty->ops->break_ctl == NULL) | |
2729 | return 0; | |
2730 | ||
2731 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2732 | retval = tty->ops->break_ctl(tty, duration); | |
2733 | else { | |
2734 | /* Do the work ourselves */ | |
2735 | if (tty_write_lock(tty, 0) < 0) | |
2736 | return -EINTR; | |
2737 | retval = tty->ops->break_ctl(tty, -1); | |
2738 | if (retval) | |
2739 | goto out; | |
2740 | if (!signal_pending(current)) | |
2741 | msleep_interruptible(duration); | |
2742 | retval = tty->ops->break_ctl(tty, 0); | |
2743 | out: | |
2744 | tty_write_unlock(tty); | |
2745 | if (signal_pending(current)) | |
2746 | retval = -EINTR; | |
2747 | } | |
2748 | return retval; | |
1da177e4 LT |
2749 | } |
2750 | ||
af9b897e | 2751 | /** |
f34d7a5b | 2752 | * tty_tiocmget - get modem status |
af9b897e AC |
2753 | * @tty: tty device |
2754 | * @file: user file pointer | |
2755 | * @p: pointer to result | |
2756 | * | |
2757 | * Obtain the modem status bits from the tty driver if the feature | |
2758 | * is supported. Return -EINVAL if it is not available. | |
2759 | * | |
2760 | * Locking: none (up to the driver) | |
2761 | */ | |
2762 | ||
60b33c13 | 2763 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2764 | { |
2765 | int retval = -EINVAL; | |
2766 | ||
f34d7a5b | 2767 | if (tty->ops->tiocmget) { |
60b33c13 | 2768 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2769 | |
2770 | if (retval >= 0) | |
2771 | retval = put_user(retval, p); | |
2772 | } | |
2773 | return retval; | |
2774 | } | |
2775 | ||
af9b897e | 2776 | /** |
f34d7a5b | 2777 | * tty_tiocmset - set modem status |
af9b897e | 2778 | * @tty: tty device |
af9b897e AC |
2779 | * @cmd: command - clear bits, set bits or set all |
2780 | * @p: pointer to desired bits | |
2781 | * | |
2782 | * Set the modem status bits from the tty driver if the feature | |
2783 | * is supported. Return -EINVAL if it is not available. | |
2784 | * | |
2785 | * Locking: none (up to the driver) | |
2786 | */ | |
2787 | ||
20b9d177 | 2788 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2789 | unsigned __user *p) |
2790 | { | |
ae677517 AC |
2791 | int retval; |
2792 | unsigned int set, clear, val; | |
1da177e4 | 2793 | |
ae677517 AC |
2794 | if (tty->ops->tiocmset == NULL) |
2795 | return -EINVAL; | |
1da177e4 | 2796 | |
ae677517 AC |
2797 | retval = get_user(val, p); |
2798 | if (retval) | |
2799 | return retval; | |
2800 | set = clear = 0; | |
2801 | switch (cmd) { | |
2802 | case TIOCMBIS: | |
2803 | set = val; | |
2804 | break; | |
2805 | case TIOCMBIC: | |
2806 | clear = val; | |
2807 | break; | |
2808 | case TIOCMSET: | |
2809 | set = val; | |
2810 | clear = ~val; | |
2811 | break; | |
2812 | } | |
2813 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2814 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2815 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2816 | } |
2817 | ||
d281da7f AC |
2818 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2819 | { | |
2820 | int retval = -EINVAL; | |
2821 | struct serial_icounter_struct icount; | |
2822 | memset(&icount, 0, sizeof(icount)); | |
2823 | if (tty->ops->get_icount) | |
2824 | retval = tty->ops->get_icount(tty, &icount); | |
2825 | if (retval != 0) | |
2826 | return retval; | |
2827 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2828 | return -EFAULT; | |
2829 | return 0; | |
2830 | } | |
2831 | ||
8a8ae62f JS |
2832 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2833 | { | |
2834 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2835 | DEFAULT_RATELIMIT_INTERVAL, | |
2836 | DEFAULT_RATELIMIT_BURST); | |
2837 | char comm[TASK_COMM_LEN]; | |
2838 | int flags; | |
2839 | ||
2840 | if (get_user(flags, &ss->flags)) | |
2841 | return; | |
2842 | ||
2843 | flags &= ASYNC_DEPRECATED; | |
2844 | ||
2845 | if (flags && __ratelimit(&depr_flags)) | |
2846 | pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2847 | __func__, get_task_comm(comm, current), flags); | |
2848 | } | |
2849 | ||
8f166e00 PH |
2850 | /* |
2851 | * if pty, return the slave side (real_tty) | |
2852 | * otherwise, return self | |
2853 | */ | |
2854 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2855 | { |
2856 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2857 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2858 | tty = tty->link; | |
2859 | return tty; | |
2860 | } | |
e8b70e7d | 2861 | |
1da177e4 LT |
2862 | /* |
2863 | * Split this up, as gcc can choke on it otherwise.. | |
2864 | */ | |
04f378b1 | 2865 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2866 | { |
d996b62a NP |
2867 | struct tty_struct *tty = file_tty(file); |
2868 | struct tty_struct *real_tty; | |
1da177e4 LT |
2869 | void __user *p = (void __user *)arg; |
2870 | int retval; | |
2871 | struct tty_ldisc *ld; | |
37bdfb07 | 2872 | |
6131ffaa | 2873 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2874 | return -EINVAL; |
2875 | ||
e8b70e7d | 2876 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2877 | |
2878 | /* | |
2879 | * Factor out some common prep work | |
2880 | */ | |
2881 | switch (cmd) { | |
2882 | case TIOCSETD: | |
2883 | case TIOCSBRK: | |
2884 | case TIOCCBRK: | |
2885 | case TCSBRK: | |
37bdfb07 | 2886 | case TCSBRKP: |
1da177e4 LT |
2887 | retval = tty_check_change(tty); |
2888 | if (retval) | |
2889 | return retval; | |
2890 | if (cmd != TIOCCBRK) { | |
2891 | tty_wait_until_sent(tty, 0); | |
2892 | if (signal_pending(current)) | |
2893 | return -EINTR; | |
2894 | } | |
2895 | break; | |
2896 | } | |
2897 | ||
9e98966c AC |
2898 | /* |
2899 | * Now do the stuff. | |
2900 | */ | |
1da177e4 | 2901 | switch (cmd) { |
37bdfb07 AC |
2902 | case TIOCSTI: |
2903 | return tiocsti(tty, p); | |
2904 | case TIOCGWINSZ: | |
8f520021 | 2905 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2906 | case TIOCSWINSZ: |
fc6f6238 | 2907 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2908 | case TIOCCONS: |
2909 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2910 | case FIONBIO: | |
2911 | return fionbio(file, p); | |
2912 | case TIOCEXCL: | |
2913 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2914 | return 0; | |
2915 | case TIOCNXCL: | |
2916 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2917 | return 0; | |
84fd7bdf CG |
2918 | case TIOCGEXCL: |
2919 | { | |
2920 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2921 | return put_user(excl, (int __user *)p); | |
2922 | } | |
37bdfb07 AC |
2923 | case TIOCNOTTY: |
2924 | if (current->signal->tty != tty) | |
2925 | return -ENOTTY; | |
2926 | no_tty(); | |
2927 | return 0; | |
2928 | case TIOCSCTTY: | |
d1d3a0f7 | 2929 | return tiocsctty(real_tty, file, arg); |
37bdfb07 AC |
2930 | case TIOCGPGRP: |
2931 | return tiocgpgrp(tty, real_tty, p); | |
2932 | case TIOCSPGRP: | |
2933 | return tiocspgrp(tty, real_tty, p); | |
2934 | case TIOCGSID: | |
2935 | return tiocgsid(tty, real_tty, p); | |
2936 | case TIOCGETD: | |
5c17c861 | 2937 | return tiocgetd(tty, p); |
37bdfb07 AC |
2938 | case TIOCSETD: |
2939 | return tiocsetd(tty, p); | |
3c95c985 KS |
2940 | case TIOCVHANGUP: |
2941 | if (!capable(CAP_SYS_ADMIN)) | |
2942 | return -EPERM; | |
2943 | tty_vhangup(tty); | |
2944 | return 0; | |
b7b8de08 WF |
2945 | case TIOCGDEV: |
2946 | { | |
2947 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2948 | return put_user(ret, (unsigned int __user *)p); | |
2949 | } | |
37bdfb07 AC |
2950 | /* |
2951 | * Break handling | |
2952 | */ | |
2953 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2954 | if (tty->ops->break_ctl) |
9e98966c | 2955 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2956 | return 0; |
37bdfb07 | 2957 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2958 | if (tty->ops->break_ctl) |
9e98966c | 2959 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2960 | return 0; |
2961 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2962 | /* non-zero arg means wait for all output data | |
2963 | * to be sent (performed above) but don't send break. | |
2964 | * This is used by the tcdrain() termios function. | |
2965 | */ | |
2966 | if (!arg) | |
2967 | return send_break(tty, 250); | |
2968 | return 0; | |
2969 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2970 | return send_break(tty, arg ? arg*100 : 250); | |
2971 | ||
2972 | case TIOCMGET: | |
60b33c13 | 2973 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2974 | case TIOCMSET: |
2975 | case TIOCMBIC: | |
2976 | case TIOCMBIS: | |
20b9d177 | 2977 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2978 | case TIOCGICOUNT: |
2979 | retval = tty_tiocgicount(tty, p); | |
2980 | /* For the moment allow fall through to the old method */ | |
2981 | if (retval != -EINVAL) | |
2982 | return retval; | |
2983 | break; | |
37bdfb07 AC |
2984 | case TCFLSH: |
2985 | switch (arg) { | |
2986 | case TCIFLUSH: | |
2987 | case TCIOFLUSH: | |
2988 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2989 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2990 | break; |
37bdfb07 AC |
2991 | } |
2992 | break; | |
8a8ae62f JS |
2993 | case TIOCSSERIAL: |
2994 | tty_warn_deprecated_flags(p); | |
2995 | break; | |
1da177e4 | 2996 | } |
f34d7a5b | 2997 | if (tty->ops->ioctl) { |
c961bfb1 | 2998 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2999 | if (retval != -ENOIOCTLCMD) |
3000 | return retval; | |
3001 | } | |
3002 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
3003 | if (!ld) |
3004 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 3005 | retval = -EINVAL; |
a352def2 AC |
3006 | if (ld->ops->ioctl) { |
3007 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 3008 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 3009 | retval = -ENOTTY; |
1da177e4 LT |
3010 | } |
3011 | tty_ldisc_deref(ld); | |
3012 | return retval; | |
3013 | } | |
3014 | ||
e10cc1df | 3015 | #ifdef CONFIG_COMPAT |
37bdfb07 | 3016 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
3017 | unsigned long arg) |
3018 | { | |
d996b62a | 3019 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
3020 | struct tty_ldisc *ld; |
3021 | int retval = -ENOIOCTLCMD; | |
3022 | ||
6131ffaa | 3023 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
3024 | return -EINVAL; |
3025 | ||
f34d7a5b | 3026 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 3027 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
3028 | if (retval != -ENOIOCTLCMD) |
3029 | return retval; | |
3030 | } | |
3031 | ||
3032 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
3033 | if (!ld) |
3034 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
3035 | if (ld->ops->compat_ioctl) |
3036 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
3037 | else |
3038 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
3039 | tty_ldisc_deref(ld); |
3040 | ||
3041 | return retval; | |
3042 | } | |
3043 | #endif | |
1da177e4 | 3044 | |
c3c073f8 AV |
3045 | static int this_tty(const void *t, struct file *file, unsigned fd) |
3046 | { | |
3047 | if (likely(file->f_op->read != tty_read)) | |
3048 | return 0; | |
3049 | return file_tty(file) != t ? 0 : fd + 1; | |
3050 | } | |
3051 | ||
1da177e4 LT |
3052 | /* |
3053 | * This implements the "Secure Attention Key" --- the idea is to | |
3054 | * prevent trojan horses by killing all processes associated with this | |
3055 | * tty when the user hits the "Secure Attention Key". Required for | |
3056 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 3057 | * |
1da177e4 LT |
3058 | * This code could be nicer; ideally it should send a HUP, wait a few |
3059 | * seconds, then send a INT, and then a KILL signal. But you then | |
3060 | * have to coordinate with the init process, since all processes associated | |
3061 | * with the current tty must be dead before the new getty is allowed | |
3062 | * to spawn. | |
3063 | * | |
3064 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3065 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3066 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3067 | * | |
3068 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3069 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3070 | */ | |
8b6312f4 | 3071 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
3072 | { |
3073 | #ifdef TTY_SOFT_SAK | |
3074 | tty_hangup(tty); | |
3075 | #else | |
652486fb | 3076 | struct task_struct *g, *p; |
ab521dc0 | 3077 | struct pid *session; |
1da177e4 | 3078 | int i; |
37bdfb07 | 3079 | |
1da177e4 LT |
3080 | if (!tty) |
3081 | return; | |
24ec839c | 3082 | session = tty->session; |
37bdfb07 | 3083 | |
b3f13deb | 3084 | tty_ldisc_flush(tty); |
1da177e4 | 3085 | |
f34d7a5b | 3086 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3087 | |
1da177e4 | 3088 | read_lock(&tasklist_lock); |
652486fb | 3089 | /* Kill the entire session */ |
ab521dc0 | 3090 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3091 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3092 | task_pid_nr(p), p->comm); | |
652486fb | 3093 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3094 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3095 | |
3096 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3097 | do_each_thread(g, p) { |
3098 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3099 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3100 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
3101 | send_sig(SIGKILL, p, 1); |
3102 | continue; | |
3103 | } | |
3104 | task_lock(p); | |
c3c073f8 AV |
3105 | i = iterate_fd(p->files, 0, this_tty, tty); |
3106 | if (i != 0) { | |
9b42bb75 PH |
3107 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3108 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 3109 | force_sig(SIGKILL, p); |
1da177e4 LT |
3110 | } |
3111 | task_unlock(p); | |
652486fb | 3112 | } while_each_thread(g, p); |
1da177e4 LT |
3113 | read_unlock(&tasklist_lock); |
3114 | #endif | |
3115 | } | |
3116 | ||
8b6312f4 EB |
3117 | static void do_SAK_work(struct work_struct *work) |
3118 | { | |
3119 | struct tty_struct *tty = | |
3120 | container_of(work, struct tty_struct, SAK_work); | |
3121 | __do_SAK(tty); | |
3122 | } | |
3123 | ||
1da177e4 LT |
3124 | /* |
3125 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3126 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3127 | * the values which we write to it will be identical to the values which it | |
3128 | * already has. --akpm | |
3129 | */ | |
3130 | void do_SAK(struct tty_struct *tty) | |
3131 | { | |
3132 | if (!tty) | |
3133 | return; | |
1da177e4 LT |
3134 | schedule_work(&tty->SAK_work); |
3135 | } | |
3136 | ||
3137 | EXPORT_SYMBOL(do_SAK); | |
3138 | ||
6e9430ac | 3139 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3140 | { |
6e9430ac | 3141 | const dev_t *devt = data; |
30004ac9 DES |
3142 | return dev->devt == *devt; |
3143 | } | |
3144 | ||
3145 | /* Must put_device() after it's unused! */ | |
3146 | static struct device *tty_get_device(struct tty_struct *tty) | |
3147 | { | |
3148 | dev_t devt = tty_devnum(tty); | |
3149 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3150 | } | |
3151 | ||
3152 | ||
af9b897e | 3153 | /** |
2c964a2f | 3154 | * alloc_tty_struct |
af9b897e | 3155 | * |
2c964a2f | 3156 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3157 | * |
2c964a2f | 3158 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3159 | */ |
af9b897e | 3160 | |
2c964a2f | 3161 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3162 | { |
2c964a2f RV |
3163 | struct tty_struct *tty; |
3164 | ||
3165 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3166 | if (!tty) | |
3167 | return NULL; | |
3168 | ||
9c9f4ded | 3169 | kref_init(&tty->kref); |
1da177e4 | 3170 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3171 | tty_ldisc_init(tty); |
ab521dc0 EB |
3172 | tty->session = NULL; |
3173 | tty->pgrp = NULL; | |
89c8d91e | 3174 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3175 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3176 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3177 | mutex_init(&tty->winsize_mutex); |
36697529 | 3178 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3179 | init_waitqueue_head(&tty->write_wait); |
3180 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3181 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3182 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3183 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3184 | spin_lock_init(&tty->flow_lock); |
4a510969 | 3185 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3186 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3187 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3188 | |
3189 | tty->driver = driver; | |
3190 | tty->ops = driver->ops; | |
3191 | tty->index = idx; | |
3192 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3193 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3194 | |
3195 | return tty; | |
1da177e4 LT |
3196 | } |
3197 | ||
f34d7a5b AC |
3198 | /** |
3199 | * tty_put_char - write one character to a tty | |
3200 | * @tty: tty | |
3201 | * @ch: character | |
3202 | * | |
3203 | * Write one byte to the tty using the provided put_char method | |
3204 | * if present. Returns the number of characters successfully output. | |
3205 | * | |
3206 | * Note: the specific put_char operation in the driver layer may go | |
3207 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3208 | */ |
af9b897e | 3209 | |
f34d7a5b | 3210 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3211 | { |
f34d7a5b AC |
3212 | if (tty->ops->put_char) |
3213 | return tty->ops->put_char(tty, ch); | |
3214 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3215 | } |
f34d7a5b AC |
3216 | EXPORT_SYMBOL_GPL(tty_put_char); |
3217 | ||
d81ed103 | 3218 | struct class *tty_class; |
1da177e4 | 3219 | |
7e73eca6 JS |
3220 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3221 | unsigned int index, unsigned int count) | |
3222 | { | |
c1a752ba LY |
3223 | int err; |
3224 | ||
7e73eca6 | 3225 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3226 | driver->cdevs[index] = cdev_alloc(); |
3227 | if (!driver->cdevs[index]) | |
3228 | return -ENOMEM; | |
c1a752ba | 3229 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3230 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3231 | err = cdev_add(driver->cdevs[index], dev, count); |
3232 | if (err) | |
3233 | kobject_put(&driver->cdevs[index]->kobj); | |
3234 | return err; | |
7e73eca6 JS |
3235 | } |
3236 | ||
1da177e4 | 3237 | /** |
af9b897e AC |
3238 | * tty_register_device - register a tty device |
3239 | * @driver: the tty driver that describes the tty device | |
3240 | * @index: the index in the tty driver for this tty device | |
3241 | * @device: a struct device that is associated with this tty device. | |
3242 | * This field is optional, if there is no known struct device | |
3243 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3244 | * |
01107d34 GKH |
3245 | * Returns a pointer to the struct device for this tty device |
3246 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3247 | * |
af9b897e AC |
3248 | * This call is required to be made to register an individual tty device |
3249 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3250 | * that bit is not set, this function should not be called by a tty | |
3251 | * driver. | |
3252 | * | |
3253 | * Locking: ?? | |
1da177e4 | 3254 | */ |
af9b897e | 3255 | |
01107d34 GKH |
3256 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3257 | struct device *device) | |
1da177e4 | 3258 | { |
6915c0e4 TH |
3259 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3260 | } | |
3261 | EXPORT_SYMBOL(tty_register_device); | |
3262 | ||
b1b79916 TH |
3263 | static void tty_device_create_release(struct device *dev) |
3264 | { | |
83db1df4 | 3265 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3266 | kfree(dev); |
3267 | } | |
3268 | ||
6915c0e4 TH |
3269 | /** |
3270 | * tty_register_device_attr - register a tty device | |
3271 | * @driver: the tty driver that describes the tty device | |
3272 | * @index: the index in the tty driver for this tty device | |
3273 | * @device: a struct device that is associated with this tty device. | |
3274 | * This field is optional, if there is no known struct device | |
3275 | * for this tty device it can be set to NULL safely. | |
3276 | * @drvdata: Driver data to be set to device. | |
3277 | * @attr_grp: Attribute group to be set on device. | |
3278 | * | |
3279 | * Returns a pointer to the struct device for this tty device | |
3280 | * (or ERR_PTR(-EFOO) on error). | |
3281 | * | |
3282 | * This call is required to be made to register an individual tty device | |
3283 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3284 | * that bit is not set, this function should not be called by a tty | |
3285 | * driver. | |
3286 | * | |
3287 | * Locking: ?? | |
3288 | */ | |
3289 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3290 | unsigned index, struct device *device, | |
3291 | void *drvdata, | |
3292 | const struct attribute_group **attr_grp) | |
3293 | { | |
1da177e4 | 3294 | char name[64]; |
6915c0e4 TH |
3295 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3296 | struct device *dev = NULL; | |
3297 | int retval = -ENODEV; | |
7e73eca6 | 3298 | bool cdev = false; |
1da177e4 LT |
3299 | |
3300 | if (index >= driver->num) { | |
656fb867 PH |
3301 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3302 | driver->name, index); | |
1cdcb6b4 | 3303 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3304 | } |
3305 | ||
1da177e4 LT |
3306 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3307 | pty_line_name(driver, index, name); | |
3308 | else | |
3309 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3310 | |
7e73eca6 | 3311 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3312 | retval = tty_cdev_add(driver, devt, index, 1); |
3313 | if (retval) | |
3314 | goto error; | |
7e73eca6 JS |
3315 | cdev = true; |
3316 | } | |
3317 | ||
6915c0e4 TH |
3318 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3319 | if (!dev) { | |
3320 | retval = -ENOMEM; | |
3321 | goto error; | |
3322 | } | |
7e73eca6 | 3323 | |
6915c0e4 TH |
3324 | dev->devt = devt; |
3325 | dev->class = tty_class; | |
3326 | dev->parent = device; | |
b1b79916 | 3327 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3328 | dev_set_name(dev, "%s", name); |
3329 | dev->groups = attr_grp; | |
3330 | dev_set_drvdata(dev, drvdata); | |
3331 | ||
3332 | retval = device_register(dev); | |
3333 | if (retval) | |
3334 | goto error; | |
3335 | ||
3336 | return dev; | |
3337 | ||
3338 | error: | |
3339 | put_device(dev); | |
a3a10ce3 RW |
3340 | if (cdev) { |
3341 | cdev_del(driver->cdevs[index]); | |
3342 | driver->cdevs[index] = NULL; | |
3343 | } | |
6915c0e4 | 3344 | return ERR_PTR(retval); |
1da177e4 | 3345 | } |
6915c0e4 | 3346 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3347 | |
3348 | /** | |
af9b897e AC |
3349 | * tty_unregister_device - unregister a tty device |
3350 | * @driver: the tty driver that describes the tty device | |
3351 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3352 | * |
af9b897e AC |
3353 | * If a tty device is registered with a call to tty_register_device() then |
3354 | * this function must be called when the tty device is gone. | |
3355 | * | |
3356 | * Locking: ?? | |
1da177e4 | 3357 | */ |
af9b897e | 3358 | |
1da177e4 LT |
3359 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3360 | { | |
37bdfb07 AC |
3361 | device_destroy(tty_class, |
3362 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3363 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3364 | cdev_del(driver->cdevs[index]); | |
3365 | driver->cdevs[index] = NULL; | |
3366 | } | |
1da177e4 | 3367 | } |
1da177e4 LT |
3368 | EXPORT_SYMBOL(tty_unregister_device); |
3369 | ||
7f0bc6a6 JS |
3370 | /** |
3371 | * __tty_alloc_driver -- allocate tty driver | |
3372 | * @lines: count of lines this driver can handle at most | |
3373 | * @owner: module which is repsonsible for this driver | |
3374 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3375 | * | |
3376 | * This should not be called directly, some of the provided macros should be | |
3377 | * used instead. Use IS_ERR and friends on @retval. | |
3378 | */ | |
3379 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3380 | unsigned long flags) | |
1da177e4 LT |
3381 | { |
3382 | struct tty_driver *driver; | |
7e73eca6 | 3383 | unsigned int cdevs = 1; |
16a02081 | 3384 | int err; |
1da177e4 | 3385 | |
0019b408 | 3386 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3387 | return ERR_PTR(-EINVAL); |
3388 | ||
506eb99a | 3389 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3390 | if (!driver) |
3391 | return ERR_PTR(-ENOMEM); | |
3392 | ||
3393 | kref_init(&driver->kref); | |
3394 | driver->magic = TTY_DRIVER_MAGIC; | |
3395 | driver->num = lines; | |
3396 | driver->owner = owner; | |
3397 | driver->flags = flags; | |
16a02081 JS |
3398 | |
3399 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3400 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3401 | GFP_KERNEL); | |
3402 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3403 | GFP_KERNEL); | |
3404 | if (!driver->ttys || !driver->termios) { | |
3405 | err = -ENOMEM; | |
3406 | goto err_free_all; | |
3407 | } | |
3408 | } | |
3409 | ||
3410 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3411 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3412 | GFP_KERNEL); | |
3413 | if (!driver->ports) { | |
3414 | err = -ENOMEM; | |
3415 | goto err_free_all; | |
3416 | } | |
7e73eca6 JS |
3417 | cdevs = lines; |
3418 | } | |
3419 | ||
3420 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3421 | if (!driver->cdevs) { | |
3422 | err = -ENOMEM; | |
3423 | goto err_free_all; | |
16a02081 | 3424 | } |
7f0bc6a6 | 3425 | |
1da177e4 | 3426 | return driver; |
16a02081 JS |
3427 | err_free_all: |
3428 | kfree(driver->ports); | |
3429 | kfree(driver->ttys); | |
3430 | kfree(driver->termios); | |
a3a10ce3 | 3431 | kfree(driver->cdevs); |
16a02081 JS |
3432 | kfree(driver); |
3433 | return ERR_PTR(err); | |
1da177e4 | 3434 | } |
7f0bc6a6 | 3435 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3436 | |
7d7b93c1 | 3437 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3438 | { |
7d7b93c1 AC |
3439 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3440 | int i; | |
3441 | struct ktermios *tp; | |
7d7b93c1 AC |
3442 | |
3443 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3444 | /* | |
3445 | * Free the termios and termios_locked structures because | |
3446 | * we don't want to get memory leaks when modular tty | |
3447 | * drivers are removed from the kernel. | |
3448 | */ | |
3449 | for (i = 0; i < driver->num; i++) { | |
3450 | tp = driver->termios[i]; | |
3451 | if (tp) { | |
3452 | driver->termios[i] = NULL; | |
3453 | kfree(tp); | |
3454 | } | |
7d7b93c1 AC |
3455 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3456 | tty_unregister_device(driver, i); | |
3457 | } | |
7d7b93c1 | 3458 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3459 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3460 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3461 | } |
7e73eca6 | 3462 | kfree(driver->cdevs); |
04831dc1 | 3463 | kfree(driver->ports); |
16a02081 JS |
3464 | kfree(driver->termios); |
3465 | kfree(driver->ttys); | |
1da177e4 LT |
3466 | kfree(driver); |
3467 | } | |
3468 | ||
7d7b93c1 AC |
3469 | void tty_driver_kref_put(struct tty_driver *driver) |
3470 | { | |
3471 | kref_put(&driver->kref, destruct_tty_driver); | |
3472 | } | |
3473 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3474 | ||
b68e31d0 JD |
3475 | void tty_set_operations(struct tty_driver *driver, |
3476 | const struct tty_operations *op) | |
1da177e4 | 3477 | { |
f34d7a5b AC |
3478 | driver->ops = op; |
3479 | }; | |
7d7b93c1 | 3480 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3481 | |
7d7b93c1 AC |
3482 | void put_tty_driver(struct tty_driver *d) |
3483 | { | |
3484 | tty_driver_kref_put(d); | |
3485 | } | |
1da177e4 | 3486 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3487 | |
3488 | /* | |
3489 | * Called by a tty driver to register itself. | |
3490 | */ | |
3491 | int tty_register_driver(struct tty_driver *driver) | |
3492 | { | |
3493 | int error; | |
37bdfb07 | 3494 | int i; |
1da177e4 | 3495 | dev_t dev; |
b670bde0 | 3496 | struct device *d; |
1da177e4 | 3497 | |
1da177e4 | 3498 | if (!driver->major) { |
37bdfb07 AC |
3499 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3500 | driver->num, driver->name); | |
1da177e4 LT |
3501 | if (!error) { |
3502 | driver->major = MAJOR(dev); | |
3503 | driver->minor_start = MINOR(dev); | |
3504 | } | |
3505 | } else { | |
3506 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3507 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3508 | } |
9bb8a3d4 | 3509 | if (error < 0) |
16a02081 | 3510 | goto err; |
1da177e4 | 3511 | |
7e73eca6 JS |
3512 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3513 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3514 | if (error) | |
3515 | goto err_unreg_char; | |
3516 | } | |
1da177e4 | 3517 | |
ca509f69 | 3518 | mutex_lock(&tty_mutex); |
1da177e4 | 3519 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3520 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3521 | |
3522 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3523 | for (i = 0; i < driver->num; i++) { |
3524 | d = tty_register_device(driver, i, NULL); | |
3525 | if (IS_ERR(d)) { | |
3526 | error = PTR_ERR(d); | |
16a02081 | 3527 | goto err_unreg_devs; |
b670bde0 VK |
3528 | } |
3529 | } | |
1da177e4 LT |
3530 | } |
3531 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3532 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3533 | return 0; |
b670bde0 | 3534 | |
16a02081 | 3535 | err_unreg_devs: |
b670bde0 VK |
3536 | for (i--; i >= 0; i--) |
3537 | tty_unregister_device(driver, i); | |
3538 | ||
3539 | mutex_lock(&tty_mutex); | |
3540 | list_del(&driver->tty_drivers); | |
3541 | mutex_unlock(&tty_mutex); | |
3542 | ||
9bb8a3d4 | 3543 | err_unreg_char: |
b670bde0 | 3544 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3545 | err: |
b670bde0 | 3546 | return error; |
1da177e4 | 3547 | } |
1da177e4 LT |
3548 | EXPORT_SYMBOL(tty_register_driver); |
3549 | ||
3550 | /* | |
3551 | * Called by a tty driver to unregister itself. | |
3552 | */ | |
3553 | int tty_unregister_driver(struct tty_driver *driver) | |
3554 | { | |
7d7b93c1 AC |
3555 | #if 0 |
3556 | /* FIXME */ | |
1da177e4 LT |
3557 | if (driver->refcount) |
3558 | return -EBUSY; | |
7d7b93c1 | 3559 | #endif |
1da177e4 LT |
3560 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3561 | driver->num); | |
ca509f69 | 3562 | mutex_lock(&tty_mutex); |
1da177e4 | 3563 | list_del(&driver->tty_drivers); |
ca509f69 | 3564 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3565 | return 0; |
3566 | } | |
7d7b93c1 | 3567 | |
1da177e4 LT |
3568 | EXPORT_SYMBOL(tty_unregister_driver); |
3569 | ||
24ec839c PZ |
3570 | dev_t tty_devnum(struct tty_struct *tty) |
3571 | { | |
3572 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3573 | } | |
3574 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3575 | |
d81ed103 AC |
3576 | void tty_default_fops(struct file_operations *fops) |
3577 | { | |
3578 | *fops = tty_fops; | |
3579 | } | |
3580 | ||
1da177e4 LT |
3581 | /* |
3582 | * Initialize the console device. This is called *early*, so | |
3583 | * we can't necessarily depend on lots of kernel help here. | |
3584 | * Just do some early initializations, and do the complex setup | |
3585 | * later. | |
3586 | */ | |
3587 | void __init console_init(void) | |
3588 | { | |
3589 | initcall_t *call; | |
3590 | ||
3591 | /* Setup the default TTY line discipline. */ | |
27228732 | 3592 | n_tty_init(); |
1da177e4 LT |
3593 | |
3594 | /* | |
37bdfb07 | 3595 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3596 | * inform about problems etc.. |
3597 | */ | |
1da177e4 LT |
3598 | call = __con_initcall_start; |
3599 | while (call < __con_initcall_end) { | |
3600 | (*call)(); | |
3601 | call++; | |
3602 | } | |
3603 | } | |
3604 | ||
2c9ede55 | 3605 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3606 | { |
3607 | if (!mode) | |
3608 | return NULL; | |
3609 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3610 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3611 | *mode = 0666; | |
3612 | return NULL; | |
3613 | } | |
3614 | ||
1da177e4 LT |
3615 | static int __init tty_class_init(void) |
3616 | { | |
7fe845d1 | 3617 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3618 | if (IS_ERR(tty_class)) |
3619 | return PTR_ERR(tty_class); | |
e454cea2 | 3620 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3621 | return 0; |
3622 | } | |
3623 | ||
3624 | postcore_initcall(tty_class_init); | |
3625 | ||
3626 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3627 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3628 | |
fbc92a34 KS |
3629 | static ssize_t show_cons_active(struct device *dev, |
3630 | struct device_attribute *attr, char *buf) | |
3631 | { | |
3632 | struct console *cs[16]; | |
3633 | int i = 0; | |
3634 | struct console *c; | |
3635 | ssize_t count = 0; | |
3636 | ||
ac751efa | 3637 | console_lock(); |
a2a6a822 | 3638 | for_each_console(c) { |
fbc92a34 KS |
3639 | if (!c->device) |
3640 | continue; | |
3641 | if (!c->write) | |
3642 | continue; | |
3643 | if ((c->flags & CON_ENABLED) == 0) | |
3644 | continue; | |
3645 | cs[i++] = c; | |
3646 | if (i >= ARRAY_SIZE(cs)) | |
3647 | break; | |
3648 | } | |
723abd87 HR |
3649 | while (i--) { |
3650 | int index = cs[i]->index; | |
3651 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3652 | ||
3653 | /* don't resolve tty0 as some programs depend on it */ | |
3654 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3655 | count += tty_line_name(drv, index, buf + count); | |
3656 | else | |
3657 | count += sprintf(buf + count, "%s%d", | |
3658 | cs[i]->name, cs[i]->index); | |
3659 | ||
3660 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3661 | } | |
ac751efa | 3662 | console_unlock(); |
fbc92a34 KS |
3663 | |
3664 | return count; | |
3665 | } | |
3666 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3667 | ||
1083a7be TI |
3668 | static struct attribute *cons_dev_attrs[] = { |
3669 | &dev_attr_active.attr, | |
3670 | NULL | |
3671 | }; | |
3672 | ||
3673 | ATTRIBUTE_GROUPS(cons_dev); | |
3674 | ||
fbc92a34 KS |
3675 | static struct device *consdev; |
3676 | ||
3677 | void console_sysfs_notify(void) | |
3678 | { | |
3679 | if (consdev) | |
3680 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3681 | } | |
3682 | ||
1da177e4 LT |
3683 | /* |
3684 | * Ok, now we can initialize the rest of the tty devices and can count | |
3685 | * on memory allocations, interrupts etc.. | |
3686 | */ | |
31d1d48e | 3687 | int __init tty_init(void) |
1da177e4 LT |
3688 | { |
3689 | cdev_init(&tty_cdev, &tty_fops); | |
3690 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3691 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3692 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3693 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3694 | |
3695 | cdev_init(&console_cdev, &console_fops); | |
3696 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3697 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3698 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3699 | consdev = device_create_with_groups(tty_class, NULL, |
3700 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3701 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3702 | if (IS_ERR(consdev)) |
3703 | consdev = NULL; | |
1da177e4 | 3704 | |
1da177e4 | 3705 | #ifdef CONFIG_VT |
d81ed103 | 3706 | vty_init(&console_fops); |
1da177e4 LT |
3707 | #endif |
3708 | return 0; | |
3709 | } | |
31d1d48e | 3710 |