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Commit | Line | Data |
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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> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | |
101 | #include <linux/kbd_kern.h> | |
102 | #include <linux/vt_kern.h> | |
103 | #include <linux/selection.h> | |
1da177e4 LT |
104 | |
105 | #include <linux/kmod.h> | |
b488893a | 106 | #include <linux/nsproxy.h> |
1da177e4 LT |
107 | |
108 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
109 | #ifdef TTY_DEBUG_HANGUP |
110 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
111 | #else | |
112 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
113 | #endif | |
1da177e4 LT |
114 | |
115 | #define TTY_PARANOIA_CHECK 1 | |
116 | #define CHECK_TTY_COUNT 1 | |
117 | ||
edc6afc5 | 118 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
119 | .c_iflag = ICRNL | IXON, |
120 | .c_oflag = OPOST | ONLCR, | |
121 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
122 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
123 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
124 | .c_cc = INIT_C_CC, |
125 | .c_ispeed = 38400, | |
133b1306 PH |
126 | .c_ospeed = 38400, |
127 | /* .c_line = N_TTY, */ | |
1da177e4 LT |
128 | }; |
129 | ||
130 | EXPORT_SYMBOL(tty_std_termios); | |
131 | ||
132 | /* This list gets poked at by procfs and various bits of boot up code. This | |
133 | could do with some rationalisation such as pulling the tty proc function | |
134 | into this file */ | |
37bdfb07 | 135 | |
1da177e4 LT |
136 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
137 | ||
d1d027ef | 138 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 139 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 140 | |
1da177e4 LT |
141 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
142 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
143 | ssize_t redirected_tty_write(struct file *, const char __user *, |
144 | size_t, loff_t *); | |
1da177e4 LT |
145 | static unsigned int tty_poll(struct file *, poll_table *); |
146 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 147 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 148 | #ifdef CONFIG_COMPAT |
37bdfb07 | 149 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
150 | unsigned long arg); |
151 | #else | |
152 | #define tty_compat_ioctl NULL | |
153 | #endif | |
ec79d605 | 154 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 155 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 156 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 157 | |
af9b897e AC |
158 | /** |
159 | * free_tty_struct - free a disused tty | |
160 | * @tty: tty struct to free | |
161 | * | |
162 | * Free the write buffers, tty queue and tty memory itself. | |
163 | * | |
164 | * Locking: none. Must be called after tty is definitely unused | |
165 | */ | |
166 | ||
a3123fd0 | 167 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 168 | { |
c8b710b3 | 169 | tty_ldisc_deinit(tty); |
a211b1af | 170 | put_device(tty->dev); |
1da177e4 | 171 | kfree(tty->write_buf); |
89c8d91e | 172 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
173 | kfree(tty); |
174 | } | |
175 | ||
d996b62a NP |
176 | static inline struct tty_struct *file_tty(struct file *file) |
177 | { | |
178 | return ((struct tty_file_private *)file->private_data)->tty; | |
179 | } | |
180 | ||
fa90e1c9 | 181 | int tty_alloc_file(struct file *file) |
d996b62a NP |
182 | { |
183 | struct tty_file_private *priv; | |
184 | ||
f573bd17 PE |
185 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
186 | if (!priv) | |
187 | return -ENOMEM; | |
d996b62a | 188 | |
fa90e1c9 JS |
189 | file->private_data = priv; |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | /* Associate a new file with the tty structure */ | |
195 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
196 | { | |
197 | struct tty_file_private *priv = file->private_data; | |
198 | ||
d996b62a NP |
199 | priv->tty = tty; |
200 | priv->file = file; | |
d996b62a | 201 | |
4a510969 | 202 | spin_lock(&tty->files_lock); |
d996b62a | 203 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 204 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 205 | } |
f573bd17 | 206 | |
fa90e1c9 JS |
207 | /** |
208 | * tty_free_file - free file->private_data | |
209 | * | |
210 | * This shall be used only for fail path handling when tty_add_file was not | |
211 | * called yet. | |
212 | */ | |
213 | void tty_free_file(struct file *file) | |
214 | { | |
215 | struct tty_file_private *priv = file->private_data; | |
216 | ||
217 | file->private_data = NULL; | |
218 | kfree(priv); | |
d996b62a NP |
219 | } |
220 | ||
221 | /* Delete file from its tty */ | |
2520e274 | 222 | static void tty_del_file(struct file *file) |
d996b62a NP |
223 | { |
224 | struct tty_file_private *priv = file->private_data; | |
4a510969 | 225 | struct tty_struct *tty = priv->tty; |
d996b62a | 226 | |
4a510969 | 227 | spin_lock(&tty->files_lock); |
d996b62a | 228 | list_del(&priv->list); |
4a510969 | 229 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 230 | tty_free_file(file); |
d996b62a NP |
231 | } |
232 | ||
233 | ||
1da177e4 LT |
234 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
235 | ||
af9b897e AC |
236 | /** |
237 | * tty_name - return tty naming | |
238 | * @tty: tty structure | |
af9b897e AC |
239 | * |
240 | * Convert a tty structure into a name. The name reflects the kernel | |
241 | * naming policy and if udev is in use may not reflect user space | |
242 | * | |
243 | * Locking: none | |
244 | */ | |
245 | ||
429b4749 | 246 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
247 | { |
248 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
249 | return "NULL tty"; |
250 | return tty->name; | |
1da177e4 LT |
251 | } |
252 | ||
253 | EXPORT_SYMBOL(tty_name); | |
254 | ||
0a083edd PH |
255 | const char *tty_driver_name(const struct tty_struct *tty) |
256 | { | |
257 | if (!tty || !tty->driver) | |
258 | return ""; | |
259 | return tty->driver->name; | |
260 | } | |
261 | ||
82b8f888 | 262 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
263 | const char *routine) |
264 | { | |
265 | #ifdef TTY_PARANOIA_CHECK | |
266 | if (!tty) { | |
89222e62 | 267 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
268 | imajor(inode), iminor(inode), routine); |
269 | return 1; | |
270 | } | |
271 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 272 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
273 | imajor(inode), iminor(inode), routine); |
274 | return 1; | |
275 | } | |
276 | #endif | |
277 | return 0; | |
278 | } | |
279 | ||
deb287e7 | 280 | /* Caller must hold tty_lock */ |
1da177e4 LT |
281 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
282 | { | |
283 | #ifdef CHECK_TTY_COUNT | |
284 | struct list_head *p; | |
285 | int count = 0; | |
37bdfb07 | 286 | |
4a510969 | 287 | spin_lock(&tty->files_lock); |
1da177e4 LT |
288 | list_for_each(p, &tty->tty_files) { |
289 | count++; | |
290 | } | |
4a510969 | 291 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
292 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
293 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
294 | tty->link && tty->link->count) | |
295 | count++; | |
296 | if (tty->count != count) { | |
339f36ba PH |
297 | tty_warn(tty, "%s: tty->count(%d) != #fd's(%d)\n", |
298 | routine, tty->count, count); | |
1da177e4 | 299 | return count; |
24ec839c | 300 | } |
1da177e4 LT |
301 | #endif |
302 | return 0; | |
303 | } | |
304 | ||
af9b897e AC |
305 | /** |
306 | * get_tty_driver - find device of a tty | |
307 | * @dev_t: device identifier | |
308 | * @index: returns the index of the tty | |
309 | * | |
310 | * This routine returns a tty driver structure, given a device number | |
311 | * and also passes back the index number. | |
312 | * | |
313 | * Locking: caller must hold tty_mutex | |
1da177e4 | 314 | */ |
af9b897e | 315 | |
1da177e4 LT |
316 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
317 | { | |
318 | struct tty_driver *p; | |
319 | ||
320 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
321 | dev_t base = MKDEV(p->major, p->minor_start); | |
322 | if (device < base || device >= base + p->num) | |
323 | continue; | |
324 | *index = device - base; | |
7d7b93c1 | 325 | return tty_driver_kref_get(p); |
1da177e4 LT |
326 | } |
327 | return NULL; | |
328 | } | |
329 | ||
f2d937f3 JW |
330 | #ifdef CONFIG_CONSOLE_POLL |
331 | ||
332 | /** | |
333 | * tty_find_polling_driver - find device of a polled tty | |
334 | * @name: name string to match | |
335 | * @line: pointer to resulting tty line nr | |
336 | * | |
337 | * This routine returns a tty driver structure, given a name | |
338 | * and the condition that the tty driver is capable of polled | |
339 | * operation. | |
340 | */ | |
341 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
342 | { | |
343 | struct tty_driver *p, *res = NULL; | |
344 | int tty_line = 0; | |
0dca0fd2 | 345 | int len; |
5f0878ac | 346 | char *str, *stp; |
f2d937f3 | 347 | |
0dca0fd2 JW |
348 | for (str = name; *str; str++) |
349 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
350 | break; | |
351 | if (!*str) | |
352 | return NULL; | |
353 | ||
354 | len = str - name; | |
355 | tty_line = simple_strtoul(str, &str, 10); | |
356 | ||
f2d937f3 JW |
357 | mutex_lock(&tty_mutex); |
358 | /* Search through the tty devices to look for a match */ | |
359 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
360 | if (strncmp(name, p->name, len) != 0) |
361 | continue; | |
5f0878ac AC |
362 | stp = str; |
363 | if (*stp == ',') | |
364 | stp++; | |
365 | if (*stp == '\0') | |
366 | stp = NULL; | |
f2d937f3 | 367 | |
6eb68d6f | 368 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 369 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 370 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
371 | *line = tty_line; |
372 | break; | |
373 | } | |
374 | } | |
375 | mutex_unlock(&tty_mutex); | |
376 | ||
377 | return res; | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
380 | #endif | |
381 | ||
e802ca0e PH |
382 | static int is_ignored(int sig) |
383 | { | |
384 | return (sigismember(¤t->blocked, sig) || | |
385 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); | |
386 | } | |
387 | ||
af9b897e AC |
388 | /** |
389 | * tty_check_change - check for POSIX terminal changes | |
390 | * @tty: tty to check | |
391 | * | |
392 | * If we try to write to, or set the state of, a terminal and we're | |
393 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
394 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
395 | * | |
978e595f | 396 | * Locking: ctrl_lock |
1da177e4 | 397 | */ |
af9b897e | 398 | |
2812d9e9 | 399 | int __tty_check_change(struct tty_struct *tty, int sig) |
1da177e4 | 400 | { |
47f86834 | 401 | unsigned long flags; |
2812d9e9 | 402 | struct pid *pgrp, *tty_pgrp; |
47f86834 AC |
403 | int ret = 0; |
404 | ||
1da177e4 LT |
405 | if (current->signal->tty != tty) |
406 | return 0; | |
47f86834 | 407 | |
6719693c PD |
408 | rcu_read_lock(); |
409 | pgrp = task_pgrp(current); | |
410 | ||
47f86834 | 411 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
2812d9e9 | 412 | tty_pgrp = tty->pgrp; |
9ffee4cb | 413 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
6719693c | 414 | |
2812d9e9 PH |
415 | if (tty_pgrp && pgrp != tty->pgrp) { |
416 | if (is_ignored(sig)) { | |
417 | if (sig == SIGTTIN) | |
418 | ret = -EIO; | |
419 | } else if (is_current_pgrp_orphaned()) | |
420 | ret = -EIO; | |
421 | else { | |
422 | kill_pgrp(pgrp, sig, 1); | |
423 | set_thread_flag(TIF_SIGPENDING); | |
424 | ret = -ERESTARTSYS; | |
425 | } | |
47f86834 | 426 | } |
6719693c | 427 | rcu_read_unlock(); |
2812d9e9 | 428 | |
339f36ba PH |
429 | if (!tty_pgrp) |
430 | tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig); | |
2812d9e9 | 431 | |
47f86834 | 432 | return ret; |
1da177e4 LT |
433 | } |
434 | ||
2812d9e9 PH |
435 | int tty_check_change(struct tty_struct *tty) |
436 | { | |
437 | return __tty_check_change(tty, SIGTTOU); | |
438 | } | |
1da177e4 LT |
439 | EXPORT_SYMBOL(tty_check_change); |
440 | ||
37bdfb07 | 441 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
442 | size_t count, loff_t *ppos) |
443 | { | |
444 | return 0; | |
445 | } | |
446 | ||
37bdfb07 | 447 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
448 | size_t count, loff_t *ppos) |
449 | { | |
450 | return -EIO; | |
451 | } | |
452 | ||
453 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 454 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
455 | { |
456 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
457 | } | |
458 | ||
04f378b1 AC |
459 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
460 | unsigned long arg) | |
38ad2ed0 PF |
461 | { |
462 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
463 | } | |
464 | ||
37bdfb07 | 465 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 466 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
467 | { |
468 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
469 | } | |
470 | ||
f557474c PH |
471 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
472 | { | |
473 | return -ENOTTY; | |
474 | } | |
475 | ||
62322d25 | 476 | static const struct file_operations tty_fops = { |
1da177e4 LT |
477 | .llseek = no_llseek, |
478 | .read = tty_read, | |
479 | .write = tty_write, | |
480 | .poll = tty_poll, | |
04f378b1 | 481 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 482 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
483 | .open = tty_open, |
484 | .release = tty_release, | |
485 | .fasync = tty_fasync, | |
486 | }; | |
487 | ||
62322d25 | 488 | static const struct file_operations console_fops = { |
1da177e4 LT |
489 | .llseek = no_llseek, |
490 | .read = tty_read, | |
491 | .write = redirected_tty_write, | |
492 | .poll = tty_poll, | |
04f378b1 | 493 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 494 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
495 | .open = tty_open, |
496 | .release = tty_release, | |
497 | .fasync = tty_fasync, | |
498 | }; | |
499 | ||
62322d25 | 500 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
501 | .llseek = no_llseek, |
502 | .read = hung_up_tty_read, | |
503 | .write = hung_up_tty_write, | |
504 | .poll = hung_up_tty_poll, | |
04f378b1 | 505 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 506 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 507 | .release = tty_release, |
f557474c | 508 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
509 | }; |
510 | ||
511 | static DEFINE_SPINLOCK(redirect_lock); | |
512 | static struct file *redirect; | |
513 | ||
11d9befd PH |
514 | |
515 | void proc_clear_tty(struct task_struct *p) | |
516 | { | |
517 | unsigned long flags; | |
518 | struct tty_struct *tty; | |
519 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
520 | tty = p->signal->tty; | |
521 | p->signal->tty = NULL; | |
522 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
523 | tty_kref_put(tty); | |
524 | } | |
525 | ||
2c411c11 PH |
526 | /** |
527 | * proc_set_tty - set the controlling terminal | |
528 | * | |
529 | * Only callable by the session leader and only if it does not already have | |
530 | * a controlling terminal. | |
531 | * | |
e218eb32 PH |
532 | * Caller must hold: tty_lock() |
533 | * a readlock on tasklist_lock | |
2c411c11 PH |
534 | * sighand lock |
535 | */ | |
bce65f18 | 536 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 537 | { |
ae28fa72 PH |
538 | unsigned long flags; |
539 | ||
ae28fa72 | 540 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
541 | /* |
542 | * The session and fg pgrp references will be non-NULL if | |
543 | * tiocsctty() is stealing the controlling tty | |
544 | */ | |
ae28fa72 PH |
545 | put_pid(tty->session); |
546 | put_pid(tty->pgrp); | |
547 | tty->pgrp = get_pid(task_pgrp(current)); | |
548 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
549 | tty->session = get_pid(task_session(current)); | |
550 | if (current->signal->tty) { | |
e2dfa3d3 PH |
551 | tty_debug(tty, "current tty %s not NULL!!\n", |
552 | current->signal->tty->name); | |
ae28fa72 | 553 | tty_kref_put(current->signal->tty); |
11d9befd | 554 | } |
bce65f18 PH |
555 | put_pid(current->signal->tty_old_pgrp); |
556 | current->signal->tty = tty_kref_get(tty); | |
557 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
558 | } |
559 | ||
bce65f18 | 560 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 561 | { |
bce65f18 PH |
562 | spin_lock_irq(¤t->sighand->siglock); |
563 | __proc_set_tty(tty); | |
564 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
565 | } |
566 | ||
567 | struct tty_struct *get_current_tty(void) | |
568 | { | |
569 | struct tty_struct *tty; | |
570 | unsigned long flags; | |
571 | ||
572 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
573 | tty = tty_kref_get(current->signal->tty); | |
574 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
575 | return tty; | |
576 | } | |
577 | EXPORT_SYMBOL_GPL(get_current_tty); | |
578 | ||
579 | static void session_clear_tty(struct pid *session) | |
580 | { | |
581 | struct task_struct *p; | |
582 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
583 | proc_clear_tty(p); | |
584 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
585 | } | |
586 | ||
1da177e4 LT |
587 | /** |
588 | * tty_wakeup - request more data | |
589 | * @tty: terminal | |
590 | * | |
591 | * Internal and external helper for wakeups of tty. This function | |
592 | * informs the line discipline if present that the driver is ready | |
593 | * to receive more output data. | |
594 | */ | |
37bdfb07 | 595 | |
1da177e4 LT |
596 | void tty_wakeup(struct tty_struct *tty) |
597 | { | |
598 | struct tty_ldisc *ld; | |
37bdfb07 | 599 | |
1da177e4 LT |
600 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
601 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 602 | if (ld) { |
a352def2 AC |
603 | if (ld->ops->write_wakeup) |
604 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
605 | tty_ldisc_deref(ld); |
606 | } | |
607 | } | |
4b19449d | 608 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
609 | } |
610 | ||
611 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
612 | ||
ea648a47 PH |
613 | /** |
614 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
615 | * @tty controlling tty |
616 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 617 | * |
f91e2590 PH |
618 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
619 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
620 | * |
621 | * Returns the number of processes in the session with this tty | |
622 | * as their controlling terminal. This value is used to drop | |
623 | * tty references for those processes. | |
624 | */ | |
f91e2590 | 625 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
626 | { |
627 | struct task_struct *p; | |
ea648a47 | 628 | int refs = 0; |
f91e2590 | 629 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
630 | |
631 | read_lock(&tasklist_lock); | |
632 | if (tty->session) { | |
633 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
634 | spin_lock_irq(&p->sighand->siglock); | |
635 | if (p->signal->tty == tty) { | |
636 | p->signal->tty = NULL; | |
637 | /* We defer the dereferences outside fo | |
638 | the tasklist lock */ | |
639 | refs++; | |
640 | } | |
641 | if (!p->signal->leader) { | |
642 | spin_unlock_irq(&p->sighand->siglock); | |
643 | continue; | |
644 | } | |
645 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
646 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
647 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 648 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 649 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
650 | if (tty->pgrp) |
651 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 652 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
653 | spin_unlock_irq(&p->sighand->siglock); |
654 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
655 | } | |
656 | read_unlock(&tasklist_lock); | |
657 | ||
f91e2590 PH |
658 | if (tty_pgrp) { |
659 | if (exit_session) | |
660 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
661 | put_pid(tty_pgrp); | |
662 | } | |
663 | ||
ea648a47 PH |
664 | return refs; |
665 | } | |
666 | ||
af9b897e | 667 | /** |
11dbf203 | 668 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 669 | * @work: tty device |
af9b897e | 670 | * |
ef4f527c | 671 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
672 | * synchronous but doesn't hold any locks, so we need to make sure we |
673 | * have the appropriate locks for what we're doing. | |
674 | * | |
675 | * The hangup event clears any pending redirections onto the hung up | |
676 | * device. It ensures future writes will error and it does the needed | |
677 | * line discipline hangup and signal delivery. The tty object itself | |
678 | * remains intact. | |
679 | * | |
680 | * Locking: | |
ec79d605 | 681 | * BTM |
24ec839c PZ |
682 | * redirect lock for undoing redirection |
683 | * file list lock for manipulating list of ttys | |
137084bb | 684 | * tty_ldiscs_lock from called functions |
6a1c0680 | 685 | * termios_rwsem resetting termios data |
24ec839c PZ |
686 | * tasklist_lock to walk task list for hangup event |
687 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 688 | */ |
f91e2590 | 689 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 690 | { |
37bdfb07 | 691 | struct file *cons_filp = NULL; |
1da177e4 | 692 | struct file *filp, *f = NULL; |
d996b62a | 693 | struct tty_file_private *priv; |
1da177e4 | 694 | int closecount = 0, n; |
ea648a47 | 695 | int refs; |
1da177e4 LT |
696 | |
697 | if (!tty) | |
698 | return; | |
699 | ||
1da177e4 LT |
700 | |
701 | spin_lock(&redirect_lock); | |
d996b62a | 702 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
703 | f = redirect; |
704 | redirect = NULL; | |
705 | } | |
706 | spin_unlock(&redirect_lock); | |
37bdfb07 | 707 | |
89c8d91e | 708 | tty_lock(tty); |
11dbf203 | 709 | |
cb50e523 PH |
710 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
711 | tty_unlock(tty); | |
712 | return; | |
713 | } | |
714 | ||
ec79d605 AB |
715 | /* inuse_filps is protected by the single tty lock, |
716 | this really needs to change if we want to flush the | |
717 | workqueue with the lock held */ | |
11dbf203 | 718 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 719 | |
4a510969 | 720 | spin_lock(&tty->files_lock); |
1da177e4 | 721 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
722 | list_for_each_entry(priv, &tty->tty_files, list) { |
723 | filp = priv->file; | |
1da177e4 LT |
724 | if (filp->f_op->write == redirected_tty_write) |
725 | cons_filp = filp; | |
726 | if (filp->f_op->write != tty_write) | |
727 | continue; | |
728 | closecount++; | |
ec79d605 | 729 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
730 | filp->f_op = &hung_up_tty_fops; |
731 | } | |
4a510969 | 732 | spin_unlock(&tty->files_lock); |
37bdfb07 | 733 | |
25fdf243 PH |
734 | refs = tty_signal_session_leader(tty, exit_session); |
735 | /* Account for the p->signal references we killed */ | |
736 | while (refs--) | |
737 | tty_kref_put(tty); | |
738 | ||
892d1fa7 | 739 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 740 | |
20cc225b | 741 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 742 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 743 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
744 | put_pid(tty->session); |
745 | put_pid(tty->pgrp); | |
ab521dc0 EB |
746 | tty->session = NULL; |
747 | tty->pgrp = NULL; | |
1da177e4 | 748 | tty->ctrl_status = 0; |
20cc225b | 749 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 750 | |
1da177e4 | 751 | /* |
37bdfb07 AC |
752 | * If one of the devices matches a console pointer, we |
753 | * cannot just call hangup() because that will cause | |
754 | * tty->count and state->count to go out of sync. | |
755 | * So we just call close() the right number of times. | |
1da177e4 LT |
756 | */ |
757 | if (cons_filp) { | |
f34d7a5b | 758 | if (tty->ops->close) |
1da177e4 | 759 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
760 | tty->ops->close(tty, cons_filp); |
761 | } else if (tty->ops->hangup) | |
7c6d340f | 762 | tty->ops->hangup(tty); |
37bdfb07 | 763 | /* |
892d1fa7 PH |
764 | * We don't want to have driver/ldisc interactions beyond the ones |
765 | * we did here. The driver layer expects no calls after ->hangup() | |
766 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 767 | */ |
1da177e4 | 768 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 769 | tty_unlock(tty); |
11dbf203 | 770 | |
1da177e4 LT |
771 | if (f) |
772 | fput(f); | |
773 | } | |
774 | ||
ddcd9fb6 AB |
775 | static void do_tty_hangup(struct work_struct *work) |
776 | { | |
777 | struct tty_struct *tty = | |
778 | container_of(work, struct tty_struct, hangup_work); | |
779 | ||
f91e2590 | 780 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
781 | } |
782 | ||
af9b897e AC |
783 | /** |
784 | * tty_hangup - trigger a hangup event | |
785 | * @tty: tty to hangup | |
786 | * | |
787 | * A carrier loss (virtual or otherwise) has occurred on this like | |
788 | * schedule a hangup sequence to run after this event. | |
789 | */ | |
790 | ||
37bdfb07 | 791 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 792 | { |
d435cefe | 793 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
794 | schedule_work(&tty->hangup_work); |
795 | } | |
796 | ||
797 | EXPORT_SYMBOL(tty_hangup); | |
798 | ||
af9b897e AC |
799 | /** |
800 | * tty_vhangup - process vhangup | |
801 | * @tty: tty to hangup | |
802 | * | |
803 | * The user has asked via system call for the terminal to be hung up. | |
804 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 805 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
806 | */ |
807 | ||
37bdfb07 | 808 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 809 | { |
d435cefe | 810 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 811 | __tty_hangup(tty, 0); |
1da177e4 | 812 | } |
37bdfb07 | 813 | |
1da177e4 LT |
814 | EXPORT_SYMBOL(tty_vhangup); |
815 | ||
11dbf203 | 816 | |
2cb5998b AC |
817 | /** |
818 | * tty_vhangup_self - process vhangup for own ctty | |
819 | * | |
820 | * Perform a vhangup on the current controlling tty | |
821 | */ | |
822 | ||
823 | void tty_vhangup_self(void) | |
824 | { | |
825 | struct tty_struct *tty; | |
826 | ||
2cb5998b AC |
827 | tty = get_current_tty(); |
828 | if (tty) { | |
829 | tty_vhangup(tty); | |
830 | tty_kref_put(tty); | |
831 | } | |
2cb5998b AC |
832 | } |
833 | ||
f91e2590 PH |
834 | /** |
835 | * tty_vhangup_session - hangup session leader exit | |
836 | * @tty: tty to hangup | |
837 | * | |
838 | * The session leader is exiting and hanging up its controlling terminal. | |
839 | * Every process in the foreground process group is signalled SIGHUP. | |
840 | * | |
841 | * We do this synchronously so that when the syscall returns the process | |
842 | * is complete. That guarantee is necessary for security reasons. | |
843 | */ | |
844 | ||
44a459fd | 845 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 846 | { |
d435cefe | 847 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
848 | __tty_hangup(tty, 1); |
849 | } | |
850 | ||
af9b897e AC |
851 | /** |
852 | * tty_hung_up_p - was tty hung up | |
853 | * @filp: file pointer of tty | |
854 | * | |
855 | * Return true if the tty has been subject to a vhangup or a carrier | |
856 | * loss | |
857 | */ | |
858 | ||
37bdfb07 | 859 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
860 | { |
861 | return (filp->f_op == &hung_up_tty_fops); | |
862 | } | |
863 | ||
864 | EXPORT_SYMBOL(tty_hung_up_p); | |
865 | ||
af9b897e AC |
866 | /** |
867 | * disassociate_ctty - disconnect controlling tty | |
868 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 869 | * |
af9b897e AC |
870 | * This function is typically called only by the session leader, when |
871 | * it wants to disassociate itself from its controlling tty. | |
872 | * | |
873 | * It performs the following functions: | |
1da177e4 LT |
874 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
875 | * (2) Clears the tty from being controlling the session | |
876 | * (3) Clears the controlling tty for all processes in the | |
877 | * session group. | |
878 | * | |
af9b897e AC |
879 | * The argument on_exit is set to 1 if called when a process is |
880 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
881 | * | |
24ec839c | 882 | * Locking: |
ec79d605 AB |
883 | * BTM is taken for hysterical raisins, and held when |
884 | * called from no_tty(). | |
24ec839c PZ |
885 | * tty_mutex is taken to protect tty |
886 | * ->siglock is taken to protect ->signal/->sighand | |
887 | * tasklist_lock is taken to walk process list for sessions | |
888 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 889 | */ |
af9b897e | 890 | |
1da177e4 LT |
891 | void disassociate_ctty(int on_exit) |
892 | { | |
893 | struct tty_struct *tty; | |
1da177e4 | 894 | |
5ec93d11 AC |
895 | if (!current->signal->leader) |
896 | return; | |
1da177e4 | 897 | |
24ec839c | 898 | tty = get_current_tty(); |
1da177e4 | 899 | if (tty) { |
f91e2590 PH |
900 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
901 | tty_vhangup_session(tty); | |
902 | } else { | |
903 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
904 | if (tty_pgrp) { | |
905 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
906 | if (!on_exit) |
907 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
908 | put_pid(tty_pgrp); |
909 | } | |
1411dc4a | 910 | } |
f91e2590 PH |
911 | tty_kref_put(tty); |
912 | ||
680a9671 | 913 | } else if (on_exit) { |
ab521dc0 | 914 | struct pid *old_pgrp; |
680a9671 EB |
915 | spin_lock_irq(¤t->sighand->siglock); |
916 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 917 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 918 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 919 | if (old_pgrp) { |
ab521dc0 EB |
920 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
921 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
922 | put_pid(old_pgrp); | |
1da177e4 | 923 | } |
1da177e4 LT |
924 | return; |
925 | } | |
1da177e4 | 926 | |
24ec839c | 927 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 928 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 929 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 930 | |
c70dbb1e | 931 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 932 | if (tty) { |
47f86834 AC |
933 | unsigned long flags; |
934 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
935 | put_pid(tty->session); |
936 | put_pid(tty->pgrp); | |
937 | tty->session = NULL; | |
938 | tty->pgrp = NULL; | |
47f86834 | 939 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 940 | tty_kref_put(tty); |
accff793 PH |
941 | } else |
942 | tty_debug_hangup(tty, "no current tty\n"); | |
1da177e4 | 943 | |
c70dbb1e | 944 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
945 | /* Now clear signal->tty under the lock */ |
946 | read_lock(&tasklist_lock); | |
ab521dc0 | 947 | session_clear_tty(task_session(current)); |
1da177e4 | 948 | read_unlock(&tasklist_lock); |
1da177e4 LT |
949 | } |
950 | ||
98a27ba4 EB |
951 | /** |
952 | * | |
953 | * no_tty - Ensure the current process does not have a controlling tty | |
954 | */ | |
955 | void no_tty(void) | |
956 | { | |
3af502b9 AC |
957 | /* FIXME: Review locking here. The tty_lock never covered any race |
958 | between a new association and proc_clear_tty but possible we need | |
959 | to protect against this anyway */ | |
98a27ba4 | 960 | struct task_struct *tsk = current; |
5ec93d11 | 961 | disassociate_ctty(0); |
98a27ba4 EB |
962 | proc_clear_tty(tsk); |
963 | } | |
964 | ||
af9b897e AC |
965 | |
966 | /** | |
beb7dd86 | 967 | * stop_tty - propagate flow control |
af9b897e AC |
968 | * @tty: tty to stop |
969 | * | |
01adc807 | 970 | * Perform flow control to the driver. May be called |
af9b897e AC |
971 | * on an already stopped device and will not re-call the driver |
972 | * method. | |
973 | * | |
974 | * This functionality is used by both the line disciplines for | |
975 | * halting incoming flow and by the driver. It may therefore be | |
976 | * called from any context, may be under the tty atomic_write_lock | |
977 | * but not always. | |
978 | * | |
979 | * Locking: | |
f9e053dc | 980 | * flow_lock |
af9b897e AC |
981 | */ |
982 | ||
f9e053dc | 983 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 984 | { |
f9e053dc | 985 | if (tty->stopped) |
1da177e4 LT |
986 | return; |
987 | tty->stopped = 1; | |
f34d7a5b | 988 | if (tty->ops->stop) |
c961bfb1 | 989 | tty->ops->stop(tty); |
1da177e4 LT |
990 | } |
991 | ||
f9e053dc PH |
992 | void stop_tty(struct tty_struct *tty) |
993 | { | |
994 | unsigned long flags; | |
995 | ||
996 | spin_lock_irqsave(&tty->flow_lock, flags); | |
997 | __stop_tty(tty); | |
998 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
999 | } | |
1da177e4 LT |
1000 | EXPORT_SYMBOL(stop_tty); |
1001 | ||
af9b897e | 1002 | /** |
beb7dd86 | 1003 | * start_tty - propagate flow control |
af9b897e AC |
1004 | * @tty: tty to start |
1005 | * | |
01adc807 PH |
1006 | * Start a tty that has been stopped if at all possible. If this |
1007 | * tty was previous stopped and is now being started, the driver | |
1008 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1009 | * |
1010 | * Locking: | |
f9e053dc | 1011 | * flow_lock |
af9b897e AC |
1012 | */ |
1013 | ||
f9e053dc | 1014 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1015 | { |
f9e053dc | 1016 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1017 | return; |
1018 | tty->stopped = 0; | |
f34d7a5b | 1019 | if (tty->ops->start) |
c961bfb1 | 1020 | tty->ops->start(tty); |
1da177e4 | 1021 | tty_wakeup(tty); |
1da177e4 LT |
1022 | } |
1023 | ||
f9e053dc PH |
1024 | void start_tty(struct tty_struct *tty) |
1025 | { | |
1026 | unsigned long flags; | |
1027 | ||
1028 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1029 | __start_tty(tty); | |
1030 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1031 | } | |
1da177e4 LT |
1032 | EXPORT_SYMBOL(start_tty); |
1033 | ||
37b7f3c7 JS |
1034 | static void tty_update_time(struct timespec *time) |
1035 | { | |
f0bf0bd0 | 1036 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
1037 | |
1038 | /* | |
1039 | * We only care if the two values differ in anything other than the | |
1040 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
1041 | * the time of the tty device, otherwise it could be construded as a | |
1042 | * security leak to let userspace know the exact timing of the tty. | |
1043 | */ | |
1044 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
1045 | time->tv_sec = sec; |
1046 | } | |
1047 | ||
af9b897e AC |
1048 | /** |
1049 | * tty_read - read method for tty device files | |
1050 | * @file: pointer to tty file | |
1051 | * @buf: user buffer | |
1052 | * @count: size of user buffer | |
1053 | * @ppos: unused | |
1054 | * | |
1055 | * Perform the read system call function on this terminal device. Checks | |
1056 | * for hung up devices before calling the line discipline method. | |
1057 | * | |
1058 | * Locking: | |
47f86834 AC |
1059 | * Locks the line discipline internally while needed. Multiple |
1060 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1061 | */ |
1062 | ||
37bdfb07 | 1063 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1064 | loff_t *ppos) |
1065 | { | |
1066 | int i; | |
37b7f3c7 | 1067 | struct inode *inode = file_inode(file); |
d996b62a | 1068 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1069 | struct tty_ldisc *ld; |
1070 | ||
37b7f3c7 | 1071 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1072 | return -EIO; |
1073 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1074 | return -EIO; | |
1075 | ||
1076 | /* We want to wait for the line discipline to sort out in this | |
1077 | situation */ | |
1078 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
1079 | if (!ld) |
1080 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 1081 | if (ld->ops->read) |
c961bfb1 | 1082 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1083 | else |
1084 | i = -EIO; | |
1085 | tty_ldisc_deref(ld); | |
b0de59b5 | 1086 | |
37b7f3c7 JS |
1087 | if (i > 0) |
1088 | tty_update_time(&inode->i_atime); | |
1089 | ||
1da177e4 LT |
1090 | return i; |
1091 | } | |
1092 | ||
136d5258 | 1093 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1094 | { |
1095 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1096 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1097 | } |
1098 | ||
136d5258 | 1099 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1100 | { |
1101 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1102 | if (ndelay) | |
1103 | return -EAGAIN; | |
1104 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1105 | return -ERESTARTSYS; | |
1106 | } | |
1107 | return 0; | |
1108 | } | |
1109 | ||
1da177e4 LT |
1110 | /* |
1111 | * Split writes up in sane blocksizes to avoid | |
1112 | * denial-of-service type attacks | |
1113 | */ | |
1114 | static inline ssize_t do_tty_write( | |
1115 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1116 | struct tty_struct *tty, | |
1117 | struct file *file, | |
1118 | const char __user *buf, | |
1119 | size_t count) | |
1120 | { | |
9c1729db | 1121 | ssize_t ret, written = 0; |
1da177e4 | 1122 | unsigned int chunk; |
37bdfb07 | 1123 | |
9c1729db AC |
1124 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1125 | if (ret < 0) | |
1126 | return ret; | |
1da177e4 LT |
1127 | |
1128 | /* | |
1129 | * We chunk up writes into a temporary buffer. This | |
1130 | * simplifies low-level drivers immensely, since they | |
1131 | * don't have locking issues and user mode accesses. | |
1132 | * | |
1133 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1134 | * big chunk-size.. | |
1135 | * | |
1136 | * The default chunk-size is 2kB, because the NTTY | |
1137 | * layer has problems with bigger chunks. It will | |
1138 | * claim to be able to handle more characters than | |
1139 | * it actually does. | |
af9b897e AC |
1140 | * |
1141 | * FIXME: This can probably go away now except that 64K chunks | |
1142 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1143 | */ |
1144 | chunk = 2048; | |
1145 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1146 | chunk = 65536; | |
1147 | if (count < chunk) | |
1148 | chunk = count; | |
1149 | ||
70522e12 | 1150 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1151 | if (tty->write_cnt < chunk) { |
402fda92 | 1152 | unsigned char *buf_chunk; |
1da177e4 LT |
1153 | |
1154 | if (chunk < 1024) | |
1155 | chunk = 1024; | |
1156 | ||
402fda92 JW |
1157 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1158 | if (!buf_chunk) { | |
9c1729db AC |
1159 | ret = -ENOMEM; |
1160 | goto out; | |
1da177e4 LT |
1161 | } |
1162 | kfree(tty->write_buf); | |
1163 | tty->write_cnt = chunk; | |
402fda92 | 1164 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1165 | } |
1166 | ||
1167 | /* Do the write .. */ | |
1168 | for (;;) { | |
1169 | size_t size = count; | |
1170 | if (size > chunk) | |
1171 | size = chunk; | |
1172 | ret = -EFAULT; | |
1173 | if (copy_from_user(tty->write_buf, buf, size)) | |
1174 | break; | |
1da177e4 | 1175 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1176 | if (ret <= 0) |
1177 | break; | |
1178 | written += ret; | |
1179 | buf += ret; | |
1180 | count -= ret; | |
1181 | if (!count) | |
1182 | break; | |
1183 | ret = -ERESTARTSYS; | |
1184 | if (signal_pending(current)) | |
1185 | break; | |
1186 | cond_resched(); | |
1187 | } | |
37b7f3c7 JS |
1188 | if (written) { |
1189 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1190 | ret = written; |
37b7f3c7 | 1191 | } |
9c1729db AC |
1192 | out: |
1193 | tty_write_unlock(tty); | |
1da177e4 LT |
1194 | return ret; |
1195 | } | |
1196 | ||
95f9bfc6 AC |
1197 | /** |
1198 | * tty_write_message - write a message to a certain tty, not just the console. | |
1199 | * @tty: the destination tty_struct | |
1200 | * @msg: the message to write | |
1201 | * | |
1202 | * This is used for messages that need to be redirected to a specific tty. | |
1203 | * We don't put it into the syslog queue right now maybe in the future if | |
1204 | * really needed. | |
1205 | * | |
ec79d605 | 1206 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1207 | */ |
1208 | ||
1209 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1210 | { | |
95f9bfc6 AC |
1211 | if (tty) { |
1212 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1213 | tty_lock(tty); |
4b41b953 | 1214 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1215 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1216 | tty_unlock(tty); |
95f9bfc6 AC |
1217 | tty_write_unlock(tty); |
1218 | } | |
95f9bfc6 AC |
1219 | return; |
1220 | } | |
1221 | ||
1da177e4 | 1222 | |
af9b897e AC |
1223 | /** |
1224 | * tty_write - write method for tty device file | |
1225 | * @file: tty file pointer | |
1226 | * @buf: user data to write | |
1227 | * @count: bytes to write | |
1228 | * @ppos: unused | |
1229 | * | |
1230 | * Write data to a tty device via the line discipline. | |
1231 | * | |
1232 | * Locking: | |
1233 | * Locks the line discipline as required | |
1234 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1235 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1236 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1237 | */ |
1238 | ||
37bdfb07 AC |
1239 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1240 | size_t count, loff_t *ppos) | |
1da177e4 | 1241 | { |
d996b62a NP |
1242 | struct tty_struct *tty = file_tty(file); |
1243 | struct tty_ldisc *ld; | |
1da177e4 | 1244 | ssize_t ret; |
37bdfb07 | 1245 | |
6131ffaa | 1246 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1247 | return -EIO; |
f34d7a5b | 1248 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1249 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1250 | return -EIO; | |
f34d7a5b AC |
1251 | /* Short term debug to catch buggy drivers */ |
1252 | if (tty->ops->write_room == NULL) | |
339f36ba | 1253 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1254 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1255 | if (!ld) |
1256 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1257 | if (!ld->ops->write) |
1da177e4 LT |
1258 | ret = -EIO; |
1259 | else | |
a352def2 | 1260 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1261 | tty_ldisc_deref(ld); |
1262 | return ret; | |
1263 | } | |
1264 | ||
37bdfb07 AC |
1265 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1266 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1267 | { |
1268 | struct file *p = NULL; | |
1269 | ||
1270 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1271 | if (redirect) |
1272 | p = get_file(redirect); | |
1da177e4 LT |
1273 | spin_unlock(&redirect_lock); |
1274 | ||
1275 | if (p) { | |
1276 | ssize_t res; | |
1277 | res = vfs_write(p, buf, count, &p->f_pos); | |
1278 | fput(p); | |
1279 | return res; | |
1280 | } | |
1da177e4 LT |
1281 | return tty_write(file, buf, count, ppos); |
1282 | } | |
1283 | ||
136d5258 PH |
1284 | /** |
1285 | * tty_send_xchar - send priority character | |
1286 | * | |
1287 | * Send a high priority character to the tty even if stopped | |
1288 | * | |
1289 | * Locking: none for xchar method, write ordering for write method. | |
1290 | */ | |
1291 | ||
1292 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1293 | { | |
1294 | int was_stopped = tty->stopped; | |
1295 | ||
1296 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1297 | down_read(&tty->termios_rwsem); |
136d5258 | 1298 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1299 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1300 | return 0; |
1301 | } | |
1302 | ||
1303 | if (tty_write_lock(tty, 0) < 0) | |
1304 | return -ERESTARTSYS; | |
1305 | ||
ee0c1a65 | 1306 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1307 | if (was_stopped) |
1308 | start_tty(tty); | |
1309 | tty->ops->write(tty, &ch, 1); | |
1310 | if (was_stopped) | |
1311 | stop_tty(tty); | |
ee0c1a65 | 1312 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1313 | tty_write_unlock(tty); |
1314 | return 0; | |
1315 | } | |
1316 | ||
1da177e4 LT |
1317 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1318 | ||
af9b897e AC |
1319 | /** |
1320 | * pty_line_name - generate name for a pty | |
1321 | * @driver: the tty driver in use | |
1322 | * @index: the minor number | |
1323 | * @p: output buffer of at least 6 bytes | |
1324 | * | |
1325 | * Generate a name from a driver reference and write it to the output | |
1326 | * buffer. | |
1327 | * | |
1328 | * Locking: None | |
1329 | */ | |
1330 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1331 | { |
1332 | int i = index + driver->name_base; | |
1333 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1334 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1335 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1336 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1337 | } |
1338 | ||
af9b897e | 1339 | /** |
8b0a88d5 | 1340 | * tty_line_name - generate name for a tty |
af9b897e AC |
1341 | * @driver: the tty driver in use |
1342 | * @index: the minor number | |
1343 | * @p: output buffer of at least 7 bytes | |
1344 | * | |
1345 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1346 | * buffer. |
af9b897e AC |
1347 | * |
1348 | * Locking: None | |
1349 | */ | |
723abd87 | 1350 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1351 | { |
0019b408 | 1352 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1353 | return sprintf(p, "%s", driver->name); |
0019b408 | 1354 | else |
723abd87 HR |
1355 | return sprintf(p, "%s%d", driver->name, |
1356 | index + driver->name_base); | |
1da177e4 LT |
1357 | } |
1358 | ||
99f1fe18 AC |
1359 | /** |
1360 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1361 | * @driver: the driver for the tty | |
1362 | * @idx: the minor number | |
23499705 | 1363 | * |
aa3cb814 PH |
1364 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1365 | * driver lookup() method returns an error. | |
23499705 | 1366 | * |
aa3cb814 | 1367 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1368 | */ |
a47d545f | 1369 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1370 | struct inode *inode, int idx) |
23499705 | 1371 | { |
aa3cb814 PH |
1372 | struct tty_struct *tty; |
1373 | ||
99f1fe18 | 1374 | if (driver->ops->lookup) |
aa3cb814 PH |
1375 | tty = driver->ops->lookup(driver, inode, idx); |
1376 | else | |
1377 | tty = driver->ttys[idx]; | |
23499705 | 1378 | |
aa3cb814 PH |
1379 | if (!IS_ERR(tty)) |
1380 | tty_kref_get(tty); | |
1381 | return tty; | |
23499705 SB |
1382 | } |
1383 | ||
bf970ee4 AC |
1384 | /** |
1385 | * tty_init_termios - helper for termios setup | |
1386 | * @tty: the tty to set up | |
1387 | * | |
1388 | * Initialise the termios structures for this tty. Thus runs under | |
1389 | * the tty_mutex currently so we can be relaxed about ordering. | |
1390 | */ | |
1391 | ||
a3123fd0 | 1392 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1393 | { |
fe6e29fd | 1394 | struct ktermios *tp; |
bf970ee4 AC |
1395 | int idx = tty->index; |
1396 | ||
36b3c070 AC |
1397 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1398 | tty->termios = tty->driver->init_termios; | |
1399 | else { | |
1400 | /* Check for lazy saved data */ | |
1401 | tp = tty->driver->termios[idx]; | |
ece53405 | 1402 | if (tp != NULL) { |
36b3c070 | 1403 | tty->termios = *tp; |
ece53405 PH |
1404 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1405 | } else | |
36b3c070 | 1406 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1407 | } |
bf970ee4 | 1408 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1409 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1410 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1411 | } |
fe1ae7fd | 1412 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1413 | |
66d450e8 JS |
1414 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1415 | { | |
a3123fd0 | 1416 | tty_init_termios(tty); |
66d450e8 JS |
1417 | tty_driver_kref_get(driver); |
1418 | tty->count++; | |
1419 | driver->ttys[tty->index] = tty; | |
1420 | return 0; | |
1421 | } | |
1422 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1423 | ||
99f1fe18 | 1424 | /** |
8b0a88d5 AC |
1425 | * tty_driver_install_tty() - install a tty entry in the driver |
1426 | * @driver: the driver for the tty | |
1427 | * @tty: the tty | |
1428 | * | |
1429 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1430 | * will be set by the time this is called. This method is responsible |
1431 | * for ensuring any need additional structures are allocated and | |
1432 | * configured. | |
8b0a88d5 AC |
1433 | * |
1434 | * Locking: tty_mutex for now | |
1435 | */ | |
1436 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1437 | struct tty_struct *tty) | |
1438 | { | |
66d450e8 JS |
1439 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1440 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1441 | } |
1442 | ||
1443 | /** | |
1444 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1445 | * @driver: the driver for the tty | |
1446 | * @idx: the minor number | |
1447 | * | |
1448 | * Remvoe a tty object from the driver tables. The tty->index field | |
1449 | * will be set by the time this is called. | |
1450 | * | |
1451 | * Locking: tty_mutex for now | |
1452 | */ | |
05de87ed | 1453 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1454 | { |
1455 | if (driver->ops->remove) | |
1456 | driver->ops->remove(driver, tty); | |
1457 | else | |
1458 | driver->ttys[tty->index] = NULL; | |
1459 | } | |
1460 | ||
1461 | /* | |
1462 | * tty_reopen() - fast re-open of an open tty | |
1463 | * @tty - the tty to open | |
23499705 | 1464 | * |
99f1fe18 | 1465 | * Return 0 on success, -errno on error. |
5d93e748 | 1466 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1467 | * |
5d93e748 | 1468 | * Locking: Caller must hold tty_lock |
23499705 | 1469 | */ |
99f1fe18 | 1470 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1471 | { |
1472 | struct tty_driver *driver = tty->driver; | |
1473 | ||
23499705 | 1474 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1475 | driver->subtype == PTY_TYPE_MASTER) |
1476 | return -EIO; | |
23499705 | 1477 | |
7f22f6c9 PH |
1478 | if (!tty->count) |
1479 | return -EAGAIN; | |
1480 | ||
86f2c00f PH |
1481 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1482 | return -EBUSY; | |
1483 | ||
23499705 | 1484 | tty->count++; |
23499705 | 1485 | |
892d1fa7 PH |
1486 | if (!tty->ldisc) |
1487 | return tty_ldisc_reinit(tty, tty->termios.c_line); | |
23499705 SB |
1488 | |
1489 | return 0; | |
1490 | } | |
1491 | ||
af9b897e | 1492 | /** |
d81ed103 | 1493 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1494 | * @driver: tty driver we are opening a device on |
1495 | * @idx: device index | |
15582d36 | 1496 | * @ret_tty: returned tty structure |
af9b897e AC |
1497 | * |
1498 | * Prepare a tty device. This may not be a "new" clean device but | |
1499 | * could also be an active device. The pty drivers require special | |
1500 | * handling because of this. | |
1501 | * | |
1502 | * Locking: | |
1503 | * The function is called under the tty_mutex, which | |
1504 | * protects us from the tty struct or driver itself going away. | |
1505 | * | |
1506 | * On exit the tty device has the line discipline attached and | |
1507 | * a reference count of 1. If a pair was created for pty/tty use | |
1508 | * and the other was a pty master then it too has a reference count of 1. | |
1509 | * | |
1da177e4 | 1510 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1511 | * failed open. The new code protects the open with a mutex, so it's |
1512 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1513 | * relaxed for the (most common) case of reopening a tty. |
1514 | */ | |
af9b897e | 1515 | |
593a27c4 | 1516 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1517 | { |
bf970ee4 | 1518 | struct tty_struct *tty; |
73ec06fc | 1519 | int retval; |
1da177e4 | 1520 | |
1da177e4 LT |
1521 | /* |
1522 | * First time open is complex, especially for PTY devices. | |
1523 | * This code guarantees that either everything succeeds and the | |
1524 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1525 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1526 | * and locked termios may be retained.) |
1527 | */ | |
1528 | ||
73ec06fc AC |
1529 | if (!try_module_get(driver->owner)) |
1530 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1531 | |
2c964a2f | 1532 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1533 | if (!tty) { |
1534 | retval = -ENOMEM; | |
1535 | goto err_module_put; | |
1536 | } | |
1da177e4 | 1537 | |
89c8d91e | 1538 | tty_lock(tty); |
73ec06fc | 1539 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1540 | if (retval < 0) |
c8b710b3 | 1541 | goto err_free_tty; |
8b0a88d5 | 1542 | |
04831dc1 JS |
1543 | if (!tty->port) |
1544 | tty->port = driver->ports[idx]; | |
1545 | ||
5d4121c0 JS |
1546 | WARN_RATELIMIT(!tty->port, |
1547 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1548 | __func__, tty->driver->name); | |
1549 | ||
967fab69 JS |
1550 | tty->port->itty = tty; |
1551 | ||
37bdfb07 | 1552 | /* |
1da177e4 | 1553 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1554 | * If we fail here just call release_tty to clean up. No need |
1555 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1556 | */ |
bf970ee4 | 1557 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1558 | if (retval) |
d5543503 | 1559 | goto err_release_tty; |
89c8d91e | 1560 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1561 | return tty; |
1da177e4 | 1562 | |
c8b710b3 | 1563 | err_free_tty: |
89c8d91e | 1564 | tty_unlock(tty); |
d5543503 JS |
1565 | free_tty_struct(tty); |
1566 | err_module_put: | |
1da177e4 | 1567 | module_put(driver->owner); |
d5543503 | 1568 | return ERR_PTR(retval); |
1da177e4 | 1569 | |
d5698c28 | 1570 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1571 | err_release_tty: |
89c8d91e | 1572 | tty_unlock(tty); |
339f36ba PH |
1573 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1574 | retval, idx); | |
d5698c28 | 1575 | release_tty(tty, idx); |
73ec06fc | 1576 | return ERR_PTR(retval); |
1da177e4 LT |
1577 | } |
1578 | ||
a3123fd0 | 1579 | static void tty_free_termios(struct tty_struct *tty) |
feebed65 AC |
1580 | { |
1581 | struct ktermios *tp; | |
1582 | int idx = tty->index; | |
36b3c070 AC |
1583 | |
1584 | /* If the port is going to reset then it has no termios to save */ | |
1585 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1586 | return; | |
1587 | ||
1588 | /* Stash the termios data */ | |
1589 | tp = tty->driver->termios[idx]; | |
1590 | if (tp == NULL) { | |
1591 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1592 | if (tp == NULL) |
36b3c070 | 1593 | return; |
4ac5d705 | 1594 | tty->driver->termios[idx] = tp; |
feebed65 | 1595 | } |
36b3c070 | 1596 | *tp = tty->termios; |
feebed65 | 1597 | } |
feebed65 | 1598 | |
a2965b7b | 1599 | /** |
949aa64f PH |
1600 | * tty_flush_works - flush all works of a tty/pty pair |
1601 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1602 | * |
949aa64f | 1603 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1604 | */ |
1605 | static void tty_flush_works(struct tty_struct *tty) | |
1606 | { | |
1607 | flush_work(&tty->SAK_work); | |
1608 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1609 | if (tty->link) { |
1610 | flush_work(&tty->link->SAK_work); | |
1611 | flush_work(&tty->link->hangup_work); | |
1612 | } | |
a2965b7b | 1613 | } |
feebed65 | 1614 | |
af9b897e | 1615 | /** |
d5698c28 | 1616 | * release_one_tty - release tty structure memory |
9c9f4ded | 1617 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1618 | * |
1619 | * Releases memory associated with a tty structure, and clears out the | |
1620 | * driver table slots. This function is called when a device is no longer | |
1621 | * in use. It also gets called when setup of a device fails. | |
1622 | * | |
1623 | * Locking: | |
af9b897e AC |
1624 | * takes the file list lock internally when working on the list |
1625 | * of ttys that the driver keeps. | |
b50989dc AC |
1626 | * |
1627 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1628 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1629 | */ |
b50989dc | 1630 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1631 | { |
b50989dc AC |
1632 | struct tty_struct *tty = |
1633 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1634 | struct tty_driver *driver = tty->driver; |
b216df53 | 1635 | struct module *owner = driver->owner; |
d5698c28 | 1636 | |
f278a2f7 DY |
1637 | if (tty->ops->cleanup) |
1638 | tty->ops->cleanup(tty); | |
1639 | ||
1da177e4 | 1640 | tty->magic = 0; |
7d7b93c1 | 1641 | tty_driver_kref_put(driver); |
b216df53 | 1642 | module_put(owner); |
d5698c28 | 1643 | |
4a510969 | 1644 | spin_lock(&tty->files_lock); |
1da177e4 | 1645 | list_del_init(&tty->tty_files); |
4a510969 | 1646 | spin_unlock(&tty->files_lock); |
d5698c28 | 1647 | |
6da8d866 ON |
1648 | put_pid(tty->pgrp); |
1649 | put_pid(tty->session); | |
1da177e4 LT |
1650 | free_tty_struct(tty); |
1651 | } | |
1652 | ||
b50989dc AC |
1653 | static void queue_release_one_tty(struct kref *kref) |
1654 | { | |
1655 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1656 | |
b50989dc AC |
1657 | /* The hangup queue is now free so we can reuse it rather than |
1658 | waste a chunk of memory for each port */ | |
1659 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1660 | schedule_work(&tty->hangup_work); | |
1661 | } | |
1662 | ||
9c9f4ded AC |
1663 | /** |
1664 | * tty_kref_put - release a tty kref | |
1665 | * @tty: tty device | |
1666 | * | |
1667 | * Release a reference to a tty device and if need be let the kref | |
1668 | * layer destruct the object for us | |
1669 | */ | |
1670 | ||
1671 | void tty_kref_put(struct tty_struct *tty) | |
1672 | { | |
1673 | if (tty) | |
b50989dc | 1674 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1675 | } |
1676 | EXPORT_SYMBOL(tty_kref_put); | |
1677 | ||
d5698c28 CH |
1678 | /** |
1679 | * release_tty - release tty structure memory | |
1680 | * | |
1681 | * Release both @tty and a possible linked partner (think pty pair), | |
1682 | * and decrement the refcount of the backing module. | |
1683 | * | |
1684 | * Locking: | |
d155255a | 1685 | * tty_mutex |
d5698c28 CH |
1686 | * takes the file list lock internally when working on the list |
1687 | * of ttys that the driver keeps. | |
9c9f4ded | 1688 | * |
d5698c28 CH |
1689 | */ |
1690 | static void release_tty(struct tty_struct *tty, int idx) | |
1691 | { | |
9c9f4ded AC |
1692 | /* This should always be true but check for the moment */ |
1693 | WARN_ON(tty->index != idx); | |
d155255a | 1694 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1695 | if (tty->ops->shutdown) |
1696 | tty->ops->shutdown(tty); | |
1697 | tty_free_termios(tty); | |
1698 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1699 | tty->port->itty = NULL; |
64e377dc PH |
1700 | if (tty->link) |
1701 | tty->link->port->itty = NULL; | |
e176058f | 1702 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1703 | |
a211b1af | 1704 | tty_kref_put(tty->link); |
9c9f4ded | 1705 | tty_kref_put(tty); |
d5698c28 CH |
1706 | } |
1707 | ||
955787ca JS |
1708 | /** |
1709 | * tty_release_checks - check a tty before real release | |
1710 | * @tty: tty to check | |
1711 | * @o_tty: link of @tty (if any) | |
1712 | * @idx: index of the tty | |
1713 | * | |
1714 | * Performs some paranoid checking before true release of the @tty. | |
1715 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1716 | */ | |
359b9fb5 | 1717 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1718 | { |
1719 | #ifdef TTY_PARANOIA_CHECK | |
1720 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1721 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1722 | return -1; |
1723 | } | |
1724 | ||
1725 | /* not much to check for devpts */ | |
1726 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1727 | return 0; | |
1728 | ||
1729 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1730 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1731 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1732 | return -1; |
1733 | } | |
955787ca | 1734 | if (tty->driver->other) { |
359b9fb5 PH |
1735 | struct tty_struct *o_tty = tty->link; |
1736 | ||
955787ca | 1737 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1738 | tty_debug(tty, "bad other table[%d] = %p\n", |
1739 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1740 | return -1; |
1741 | } | |
955787ca | 1742 | if (o_tty->link != tty) { |
e2dfa3d3 | 1743 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1744 | return -1; |
1745 | } | |
1746 | } | |
1747 | #endif | |
1748 | return 0; | |
1749 | } | |
1750 | ||
eeb89d91 AC |
1751 | /** |
1752 | * tty_release - vfs callback for close | |
1753 | * @inode: inode of tty | |
1754 | * @filp: file pointer for handle to tty | |
1755 | * | |
1756 | * Called the last time each file handle is closed that references | |
1757 | * this tty. There may however be several such references. | |
1758 | * | |
1759 | * Locking: | |
1760 | * Takes bkl. See tty_release_dev | |
1761 | * | |
1da177e4 LT |
1762 | * Even releasing the tty structures is a tricky business.. We have |
1763 | * to be very careful that the structures are all released at the | |
1764 | * same time, as interrupts might otherwise get the wrong pointers. | |
1765 | * | |
1766 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1767 | * lead to double frees or releasing memory still in use. | |
1768 | */ | |
eeb89d91 AC |
1769 | |
1770 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1771 | { |
d996b62a | 1772 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1773 | struct tty_struct *o_tty = NULL; |
1774 | int do_sleep, final; | |
1da177e4 | 1775 | int idx; |
37b16457 | 1776 | long timeout = 0; |
494c1eac | 1777 | int once = 1; |
37bdfb07 | 1778 | |
9de44bd6 | 1779 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1780 | return 0; |
1da177e4 | 1781 | |
89c8d91e | 1782 | tty_lock(tty); |
9de44bd6 | 1783 | check_tty_count(tty, __func__); |
1da177e4 | 1784 | |
ec79d605 | 1785 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1786 | |
1787 | idx = tty->index; | |
7ffb6da9 PH |
1788 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1789 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1790 | o_tty = tty->link; | |
1da177e4 | 1791 | |
359b9fb5 | 1792 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1793 | tty_unlock(tty); |
eeb89d91 | 1794 | return 0; |
1da177e4 | 1795 | } |
1da177e4 | 1796 | |
d435cefe | 1797 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1798 | |
f34d7a5b AC |
1799 | if (tty->ops->close) |
1800 | tty->ops->close(tty, filp); | |
1da177e4 | 1801 | |
2aff5e2b PH |
1802 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1803 | tty_lock_slave(o_tty); | |
1804 | ||
1da177e4 LT |
1805 | /* |
1806 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1807 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1808 | * wait queues and kick everyone out _before_ actually starting to | |
1809 | * close. This ensures that we won't block while releasing the tty | |
1810 | * structure. | |
1811 | * | |
1812 | * The test for the o_tty closing is necessary, since the master and | |
1813 | * slave sides may close in any order. If the slave side closes out | |
1814 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1815 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1816 | * so we do it now. |
1da177e4 LT |
1817 | */ |
1818 | while (1) { | |
1da177e4 LT |
1819 | do_sleep = 0; |
1820 | ||
324c1650 | 1821 | if (tty->count <= 1) { |
1da177e4 | 1822 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1823 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1824 | do_sleep++; |
1825 | } | |
1826 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1827 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1828 | do_sleep++; |
1829 | } | |
1830 | } | |
7ffb6da9 | 1831 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1832 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1833 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1834 | do_sleep++; |
1835 | } | |
1836 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1837 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1838 | do_sleep++; |
1839 | } | |
1840 | } | |
1841 | if (!do_sleep) | |
1842 | break; | |
1843 | ||
494c1eac PH |
1844 | if (once) { |
1845 | once = 0; | |
339f36ba | 1846 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1847 | } |
37b16457 PH |
1848 | schedule_timeout_killable(timeout); |
1849 | if (timeout < 120 * HZ) | |
1850 | timeout = 2 * timeout + 1; | |
1851 | else | |
1852 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1853 | } |
1da177e4 | 1854 | |
7ffb6da9 | 1855 | if (o_tty) { |
1da177e4 | 1856 | if (--o_tty->count < 0) { |
339f36ba | 1857 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1858 | o_tty->count = 0; |
1859 | } | |
1860 | } | |
1861 | if (--tty->count < 0) { | |
339f36ba | 1862 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1863 | tty->count = 0; |
1864 | } | |
37bdfb07 | 1865 | |
1da177e4 LT |
1866 | /* |
1867 | * We've decremented tty->count, so we need to remove this file | |
1868 | * descriptor off the tty->tty_files list; this serves two | |
1869 | * purposes: | |
1870 | * - check_tty_count sees the correct number of file descriptors | |
1871 | * associated with this tty. | |
1872 | * - do_tty_hangup no longer sees this file descriptor as | |
1873 | * something that needs to be handled for hangups. | |
1874 | */ | |
d996b62a | 1875 | tty_del_file(filp); |
1da177e4 LT |
1876 | |
1877 | /* | |
1878 | * Perform some housekeeping before deciding whether to return. | |
1879 | * | |
1da177e4 LT |
1880 | * If _either_ side is closing, make sure there aren't any |
1881 | * processes that still think tty or o_tty is their controlling | |
1882 | * tty. | |
1883 | */ | |
324c1650 | 1884 | if (!tty->count) { |
1da177e4 | 1885 | read_lock(&tasklist_lock); |
24ec839c | 1886 | session_clear_tty(tty->session); |
7ffb6da9 | 1887 | if (o_tty) |
24ec839c | 1888 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1889 | read_unlock(&tasklist_lock); |
1890 | } | |
1891 | ||
324c1650 | 1892 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1893 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1894 | |
2aff5e2b PH |
1895 | tty_unlock_slave(o_tty); |
1896 | tty_unlock(tty); | |
1897 | ||
04980706 | 1898 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1899 | cannot be re-opened by a racing opener */ |
da965822 | 1900 | |
324c1650 | 1901 | if (!final) |
eeb89d91 | 1902 | return 0; |
37bdfb07 | 1903 | |
accff793 | 1904 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1905 | /* |
01e1abb2 | 1906 | * Ask the line discipline code to release its structures |
1da177e4 | 1907 | */ |
62462aef | 1908 | tty_ldisc_release(tty); |
a2965b7b PH |
1909 | |
1910 | /* Wait for pending work before tty destruction commmences */ | |
1911 | tty_flush_works(tty); | |
a2965b7b | 1912 | |
d435cefe | 1913 | tty_debug_hangup(tty, "freeing structure\n"); |
1da177e4 | 1914 | /* |
d5698c28 | 1915 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1916 | * the slots and preserving the termios structure. The tty_unlock_pair |
1917 | * should be safe as we keep a kref while the tty is locked (so the | |
1918 | * unlock never unlocks a freed tty). | |
1da177e4 | 1919 | */ |
d155255a | 1920 | mutex_lock(&tty_mutex); |
d5698c28 | 1921 | release_tty(tty, idx); |
d155255a | 1922 | mutex_unlock(&tty_mutex); |
1da177e4 | 1923 | |
eeb89d91 | 1924 | return 0; |
1da177e4 LT |
1925 | } |
1926 | ||
b82154ac | 1927 | /** |
52494eeb | 1928 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1929 | * @device: device number |
1930 | * @filp: file pointer to tty | |
52494eeb PH |
1931 | * @return: locked tty of the current task iff @device is /dev/tty |
1932 | * | |
1933 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1934 | * |
1935 | * We cannot return driver and index like for the other nodes because | |
1936 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1937 | */ | |
1938 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1939 | { | |
1940 | struct tty_struct *tty; | |
52494eeb | 1941 | int retval; |
b82154ac JS |
1942 | |
1943 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1944 | return NULL; | |
1945 | ||
1946 | tty = get_current_tty(); | |
1947 | if (!tty) | |
1948 | return ERR_PTR(-ENXIO); | |
1949 | ||
1950 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1951 | /* noctty = 1; */ | |
52494eeb PH |
1952 | tty_lock(tty); |
1953 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1954 | ||
1955 | retval = tty_reopen(tty); | |
1956 | if (retval < 0) { | |
1957 | tty_unlock(tty); | |
1958 | tty = ERR_PTR(retval); | |
1959 | } | |
b82154ac JS |
1960 | return tty; |
1961 | } | |
1962 | ||
5b5e7040 JS |
1963 | /** |
1964 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1965 | * @device: device number | |
1966 | * @filp: file pointer to tty | |
1967 | * @noctty: set if the device should not become a controlling tty | |
1968 | * @index: index for the device in the @return driver | |
1969 | * @return: driver for this inode (with increased refcount) | |
1970 | * | |
1971 | * If @return is not erroneous, the caller is responsible to decrement the | |
1972 | * refcount by tty_driver_kref_put. | |
1973 | * | |
1974 | * Locking: tty_mutex protects get_tty_driver | |
1975 | */ | |
1976 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1977 | int *index) |
5b5e7040 JS |
1978 | { |
1979 | struct tty_driver *driver; | |
1980 | ||
2cd0050c | 1981 | switch (device) { |
5b5e7040 | 1982 | #ifdef CONFIG_VT |
2cd0050c | 1983 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1984 | extern struct tty_driver *console_driver; |
1985 | driver = tty_driver_kref_get(console_driver); | |
1986 | *index = fg_console; | |
2cd0050c | 1987 | break; |
5b5e7040 JS |
1988 | } |
1989 | #endif | |
2cd0050c | 1990 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1991 | struct tty_driver *console_driver = console_device(index); |
1992 | if (console_driver) { | |
1993 | driver = tty_driver_kref_get(console_driver); | |
1994 | if (driver) { | |
1995 | /* Don't let /dev/console block */ | |
1996 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1997 | break; |
5b5e7040 JS |
1998 | } |
1999 | } | |
2000 | return ERR_PTR(-ENODEV); | |
2001 | } | |
2cd0050c JS |
2002 | default: |
2003 | driver = get_tty_driver(device, index); | |
2004 | if (!driver) | |
2005 | return ERR_PTR(-ENODEV); | |
2006 | break; | |
2007 | } | |
5b5e7040 JS |
2008 | return driver; |
2009 | } | |
2010 | ||
d6203d0c PH |
2011 | /** |
2012 | * tty_open_by_driver - open a tty device | |
2013 | * @device: dev_t of device to open | |
2014 | * @inode: inode of device file | |
2015 | * @filp: file pointer to tty | |
2016 | * | |
2017 | * Performs the driver lookup, checks for a reopen, or otherwise | |
2018 | * performs the first-time tty initialization. | |
2019 | * | |
2020 | * Returns the locked initialized or re-opened &tty_struct | |
2021 | * | |
2022 | * Claims the global tty_mutex to serialize: | |
2023 | * - concurrent first-time tty initialization | |
2024 | * - concurrent tty driver removal w/ lookup | |
2025 | * - concurrent tty removal from driver table | |
2026 | */ | |
2027 | static struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, | |
2028 | struct file *filp) | |
2029 | { | |
2030 | struct tty_struct *tty; | |
2031 | struct tty_driver *driver = NULL; | |
2032 | int index = -1; | |
2033 | int retval; | |
2034 | ||
2035 | mutex_lock(&tty_mutex); | |
2036 | driver = tty_lookup_driver(device, filp, &index); | |
2037 | if (IS_ERR(driver)) { | |
2038 | mutex_unlock(&tty_mutex); | |
2039 | return ERR_CAST(driver); | |
2040 | } | |
2041 | ||
2042 | /* check whether we're reopening an existing tty */ | |
2043 | tty = tty_driver_lookup_tty(driver, inode, index); | |
2044 | if (IS_ERR(tty)) { | |
2045 | mutex_unlock(&tty_mutex); | |
2046 | goto out; | |
2047 | } | |
2048 | ||
2049 | if (tty) { | |
2050 | mutex_unlock(&tty_mutex); | |
2051 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2052 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2053 | if (retval) { |
2054 | if (retval == -EINTR) | |
2055 | retval = -ERESTARTSYS; | |
2056 | tty = ERR_PTR(retval); | |
2057 | goto out; | |
2058 | } | |
d6203d0c PH |
2059 | retval = tty_reopen(tty); |
2060 | if (retval < 0) { | |
2061 | tty_unlock(tty); | |
2062 | tty = ERR_PTR(retval); | |
2063 | } | |
2064 | } else { /* Returns with the tty_lock held for now */ | |
2065 | tty = tty_init_dev(driver, index); | |
2066 | mutex_unlock(&tty_mutex); | |
2067 | } | |
2068 | out: | |
2069 | tty_driver_kref_put(driver); | |
2070 | return tty; | |
2071 | } | |
2072 | ||
af9b897e | 2073 | /** |
eeb89d91 | 2074 | * tty_open - open a tty device |
af9b897e AC |
2075 | * @inode: inode of device file |
2076 | * @filp: file pointer to tty | |
1da177e4 | 2077 | * |
af9b897e AC |
2078 | * tty_open and tty_release keep up the tty count that contains the |
2079 | * number of opens done on a tty. We cannot use the inode-count, as | |
2080 | * different inodes might point to the same tty. | |
1da177e4 | 2081 | * |
af9b897e AC |
2082 | * Open-counting is needed for pty masters, as well as for keeping |
2083 | * track of serial lines: DTR is dropped when the last close happens. | |
2084 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2085 | * | |
2086 | * The termios state of a pty is reset on first open so that | |
2087 | * settings don't persist across reuse. | |
2088 | * | |
5b5e7040 | 2089 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2090 | * tty->count should protect the rest. |
2091 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2092 | * |
2093 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2094 | * tty_mutex | |
1da177e4 | 2095 | */ |
af9b897e | 2096 | |
eeb89d91 | 2097 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2098 | { |
b82154ac | 2099 | struct tty_struct *tty; |
1da177e4 | 2100 | int noctty, retval; |
1da177e4 | 2101 | dev_t device = inode->i_rdev; |
846c151a | 2102 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2103 | |
2104 | nonseekable_open(inode, filp); | |
37bdfb07 | 2105 | |
1da177e4 | 2106 | retry_open: |
fa90e1c9 JS |
2107 | retval = tty_alloc_file(filp); |
2108 | if (retval) | |
2109 | return -ENOMEM; | |
2110 | ||
b82154ac | 2111 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
2112 | if (!tty) |
2113 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 2114 | |
eeb89d91 | 2115 | if (IS_ERR(tty)) { |
d6203d0c | 2116 | tty_free_file(filp); |
ba5db448 | 2117 | retval = PTR_ERR(tty); |
7f22f6c9 | 2118 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2119 | return retval; |
7f22f6c9 PH |
2120 | schedule(); |
2121 | goto retry_open; | |
eeb89d91 | 2122 | } |
1da177e4 | 2123 | |
fa90e1c9 | 2124 | tty_add_file(tty, filp); |
d996b62a | 2125 | |
9de44bd6 | 2126 | check_tty_count(tty, __func__); |
d435cefe | 2127 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2128 | |
909bc774 HRK |
2129 | if (tty->ops->open) |
2130 | retval = tty->ops->open(tty, filp); | |
2131 | else | |
2132 | retval = -ENODEV; | |
1da177e4 LT |
2133 | filp->f_flags = saved_flags; |
2134 | ||
1da177e4 | 2135 | if (retval) { |
d435cefe | 2136 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2137 | |
89c8d91e | 2138 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2139 | tty_release(inode, filp); |
64ba3dc3 | 2140 | if (retval != -ERESTARTSYS) |
1da177e4 | 2141 | return retval; |
64ba3dc3 AB |
2142 | |
2143 | if (signal_pending(current)) | |
1da177e4 | 2144 | return retval; |
64ba3dc3 | 2145 | |
1da177e4 LT |
2146 | schedule(); |
2147 | /* | |
2148 | * Need to reset f_op in case a hangup happened. | |
2149 | */ | |
1256937f | 2150 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2151 | filp->f_op = &tty_fops; |
2152 | goto retry_open; | |
2153 | } | |
d4855e1f | 2154 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2155 | |
24ec839c | 2156 | |
2c411c11 | 2157 | read_lock(&tasklist_lock); |
24ec839c | 2158 | spin_lock_irq(¤t->sighand->siglock); |
11e1d4aa | 2159 | noctty = (filp->f_flags & O_NOCTTY) || |
da5a0fc6 | 2160 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
11e1d4aa PH |
2161 | device == MKDEV(TTYAUX_MAJOR, 1) || |
2162 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2163 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2164 | ||
1da177e4 LT |
2165 | if (!noctty && |
2166 | current->signal->leader && | |
2167 | !current->signal->tty && | |
0c556271 JH |
2168 | tty->session == NULL) { |
2169 | /* | |
2170 | * Don't let a process that only has write access to the tty | |
2171 | * obtain the privileges associated with having a tty as | |
2172 | * controlling terminal (being able to reopen it with full | |
2173 | * access through /dev/tty, being able to perform pushback). | |
2174 | * Many distributions set the group of all ttys to "tty" and | |
2175 | * grant write-only access to all terminals for setgid tty | |
2176 | * binaries, which should not imply full privileges on all ttys. | |
2177 | * | |
2178 | * This could theoretically break old code that performs open() | |
2179 | * on a write-only file descriptor. In that case, it might be | |
2180 | * necessary to also permit this if | |
2181 | * inode_permission(inode, MAY_READ) == 0. | |
2182 | */ | |
2183 | if (filp->f_mode & FMODE_READ) | |
2184 | __proc_set_tty(tty); | |
2185 | } | |
24ec839c | 2186 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2187 | read_unlock(&tasklist_lock); |
89c8d91e | 2188 | tty_unlock(tty); |
1da177e4 LT |
2189 | return 0; |
2190 | } | |
2191 | ||
39d95b9d JC |
2192 | |
2193 | ||
af9b897e AC |
2194 | /** |
2195 | * tty_poll - check tty status | |
2196 | * @filp: file being polled | |
2197 | * @wait: poll wait structures to update | |
2198 | * | |
2199 | * Call the line discipline polling method to obtain the poll | |
2200 | * status of the device. | |
2201 | * | |
2202 | * Locking: locks called line discipline but ldisc poll method | |
2203 | * may be re-entered freely by other callers. | |
2204 | */ | |
2205 | ||
37bdfb07 | 2206 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2207 | { |
d996b62a | 2208 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2209 | struct tty_ldisc *ld; |
2210 | int ret = 0; | |
2211 | ||
6131ffaa | 2212 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2213 | return 0; |
37bdfb07 | 2214 | |
1da177e4 | 2215 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2216 | if (!ld) |
2217 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2218 | if (ld->ops->poll) |
c961bfb1 | 2219 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2220 | tty_ldisc_deref(ld); |
2221 | return ret; | |
2222 | } | |
2223 | ||
ec79d605 | 2224 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2225 | { |
d996b62a | 2226 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2227 | unsigned long flags; |
5d1e3230 | 2228 | int retval = 0; |
1da177e4 | 2229 | |
6131ffaa | 2230 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2231 | goto out; |
37bdfb07 | 2232 | |
1da177e4 LT |
2233 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2234 | if (retval <= 0) | |
5d1e3230 | 2235 | goto out; |
f6c8dbe6 | 2236 | |
1da177e4 | 2237 | if (on) { |
ab521dc0 EB |
2238 | enum pid_type type; |
2239 | struct pid *pid; | |
f6c8dbe6 | 2240 | |
47f86834 | 2241 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2242 | if (tty->pgrp) { |
2243 | pid = tty->pgrp; | |
2244 | type = PIDTYPE_PGID; | |
2245 | } else { | |
2246 | pid = task_pid(current); | |
2247 | type = PIDTYPE_PID; | |
2248 | } | |
80e1e823 | 2249 | get_pid(pid); |
70362511 | 2250 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2251 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2252 | put_pid(pid); |
e0b93edd | 2253 | retval = 0; |
1da177e4 | 2254 | } |
5d1e3230 | 2255 | out: |
ec79d605 AB |
2256 | return retval; |
2257 | } | |
2258 | ||
2259 | static int tty_fasync(int fd, struct file *filp, int on) | |
2260 | { | |
89c8d91e | 2261 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2262 | int retval = -ENOTTY; |
89c8d91e AC |
2263 | |
2264 | tty_lock(tty); | |
a8f3a297 PH |
2265 | if (!tty_hung_up_p(filp)) |
2266 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2267 | tty_unlock(tty); |
2268 | ||
5d1e3230 | 2269 | return retval; |
1da177e4 LT |
2270 | } |
2271 | ||
af9b897e AC |
2272 | /** |
2273 | * tiocsti - fake input character | |
2274 | * @tty: tty to fake input into | |
2275 | * @p: pointer to character | |
2276 | * | |
3a4fa0a2 | 2277 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2278 | * input management. |
2279 | * | |
2280 | * FIXME: does not honour flow control ?? | |
2281 | * | |
2282 | * Locking: | |
137084bb | 2283 | * Called functions take tty_ldiscs_lock |
af9b897e | 2284 | * current->signal->tty check is safe without locks |
28298232 AC |
2285 | * |
2286 | * FIXME: may race normal receive processing | |
af9b897e AC |
2287 | */ |
2288 | ||
1da177e4 LT |
2289 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2290 | { | |
2291 | char ch, mbz = 0; | |
2292 | struct tty_ldisc *ld; | |
37bdfb07 | 2293 | |
1da177e4 LT |
2294 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2295 | return -EPERM; | |
2296 | if (get_user(ch, p)) | |
2297 | return -EFAULT; | |
1e641743 | 2298 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2299 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2300 | if (!ld) |
2301 | return -EIO; | |
a352def2 | 2302 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2303 | tty_ldisc_deref(ld); |
2304 | return 0; | |
2305 | } | |
2306 | ||
af9b897e AC |
2307 | /** |
2308 | * tiocgwinsz - implement window query ioctl | |
2309 | * @tty; tty | |
2310 | * @arg: user buffer for result | |
2311 | * | |
808a0d38 | 2312 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2313 | * |
dee4a0be | 2314 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2315 | * is consistent. |
af9b897e AC |
2316 | */ |
2317 | ||
37bdfb07 | 2318 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2319 | { |
808a0d38 AC |
2320 | int err; |
2321 | ||
dee4a0be | 2322 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2323 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2324 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2325 | |
2326 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2327 | } |
2328 | ||
af9b897e | 2329 | /** |
8c9a9dd0 AC |
2330 | * tty_do_resize - resize event |
2331 | * @tty: tty being resized | |
8c9a9dd0 AC |
2332 | * @rows: rows (character) |
2333 | * @cols: cols (character) | |
2334 | * | |
3ad2f3fb | 2335 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2336 | * peform a terminal resize correctly |
af9b897e AC |
2337 | */ |
2338 | ||
fc6f6238 | 2339 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2340 | { |
fc6f6238 | 2341 | struct pid *pgrp; |
1da177e4 | 2342 | |
fc6f6238 | 2343 | /* Lock the tty */ |
dee4a0be | 2344 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2345 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2346 | goto done; |
47f86834 | 2347 | |
5b239542 PH |
2348 | /* Signal the foreground process group */ |
2349 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2350 | if (pgrp) |
2351 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2352 | put_pid(pgrp); |
47f86834 | 2353 | |
8c9a9dd0 | 2354 | tty->winsize = *ws; |
ca9bda00 | 2355 | done: |
dee4a0be | 2356 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2357 | return 0; |
2358 | } | |
4d334fd1 | 2359 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2360 | |
8c9a9dd0 AC |
2361 | /** |
2362 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2363 | * @tty; tty side of tty |
8c9a9dd0 AC |
2364 | * @arg: user buffer for result |
2365 | * | |
2366 | * Copies the user idea of the window size to the kernel. Traditionally | |
2367 | * this is just advisory information but for the Linux console it | |
2368 | * actually has driver level meaning and triggers a VC resize. | |
2369 | * | |
2370 | * Locking: | |
25985edc | 2371 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2372 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2373 | * then calls into the default method. | |
2374 | */ | |
2375 | ||
fc6f6238 | 2376 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2377 | { |
2378 | struct winsize tmp_ws; | |
2379 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2380 | return -EFAULT; | |
2381 | ||
2382 | if (tty->ops->resize) | |
fc6f6238 | 2383 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2384 | else |
fc6f6238 | 2385 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2386 | } |
2387 | ||
af9b897e AC |
2388 | /** |
2389 | * tioccons - allow admin to move logical console | |
2390 | * @file: the file to become console | |
2391 | * | |
25985edc | 2392 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2393 | * |
2394 | * Locking: uses redirect_lock to guard the redirect information | |
2395 | */ | |
2396 | ||
1da177e4 LT |
2397 | static int tioccons(struct file *file) |
2398 | { | |
2399 | if (!capable(CAP_SYS_ADMIN)) | |
2400 | return -EPERM; | |
2401 | if (file->f_op->write == redirected_tty_write) { | |
2402 | struct file *f; | |
2403 | spin_lock(&redirect_lock); | |
2404 | f = redirect; | |
2405 | redirect = NULL; | |
2406 | spin_unlock(&redirect_lock); | |
2407 | if (f) | |
2408 | fput(f); | |
2409 | return 0; | |
2410 | } | |
2411 | spin_lock(&redirect_lock); | |
2412 | if (redirect) { | |
2413 | spin_unlock(&redirect_lock); | |
2414 | return -EBUSY; | |
2415 | } | |
cb0942b8 | 2416 | redirect = get_file(file); |
1da177e4 LT |
2417 | spin_unlock(&redirect_lock); |
2418 | return 0; | |
2419 | } | |
2420 | ||
af9b897e AC |
2421 | /** |
2422 | * fionbio - non blocking ioctl | |
2423 | * @file: file to set blocking value | |
2424 | * @p: user parameter | |
2425 | * | |
2426 | * Historical tty interfaces had a blocking control ioctl before | |
2427 | * the generic functionality existed. This piece of history is preserved | |
2428 | * in the expected tty API of posix OS's. | |
2429 | * | |
6146b9af | 2430 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2431 | */ |
1da177e4 LT |
2432 | |
2433 | static int fionbio(struct file *file, int __user *p) | |
2434 | { | |
2435 | int nonblock; | |
2436 | ||
2437 | if (get_user(nonblock, p)) | |
2438 | return -EFAULT; | |
2439 | ||
db1dd4d3 | 2440 | spin_lock(&file->f_lock); |
1da177e4 LT |
2441 | if (nonblock) |
2442 | file->f_flags |= O_NONBLOCK; | |
2443 | else | |
2444 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2445 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2446 | return 0; |
2447 | } | |
2448 | ||
af9b897e AC |
2449 | /** |
2450 | * tiocsctty - set controlling tty | |
2451 | * @tty: tty structure | |
2452 | * @arg: user argument | |
2453 | * | |
2454 | * This ioctl is used to manage job control. It permits a session | |
2455 | * leader to set this tty as the controlling tty for the session. | |
2456 | * | |
2457 | * Locking: | |
e218eb32 | 2458 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2459 | * Takes tasklist_lock internally to walk sessions |
2460 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2461 | */ |
2462 | ||
0c556271 | 2463 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) |
1da177e4 | 2464 | { |
24ec839c | 2465 | int ret = 0; |
24ec839c | 2466 | |
e218eb32 | 2467 | tty_lock(tty); |
2c411c11 PH |
2468 | read_lock(&tasklist_lock); |
2469 | ||
2470 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2471 | goto unlock; | |
2472 | ||
1da177e4 LT |
2473 | /* |
2474 | * The process must be a session leader and | |
2475 | * not have a controlling tty already. | |
2476 | */ | |
24ec839c PZ |
2477 | if (!current->signal->leader || current->signal->tty) { |
2478 | ret = -EPERM; | |
2479 | goto unlock; | |
2480 | } | |
2481 | ||
ab521dc0 | 2482 | if (tty->session) { |
1da177e4 LT |
2483 | /* |
2484 | * This tty is already the controlling | |
2485 | * tty for another session group! | |
2486 | */ | |
37bdfb07 | 2487 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2488 | /* |
2489 | * Steal it away | |
2490 | */ | |
24ec839c | 2491 | session_clear_tty(tty->session); |
24ec839c PZ |
2492 | } else { |
2493 | ret = -EPERM; | |
2494 | goto unlock; | |
2495 | } | |
1da177e4 | 2496 | } |
0c556271 JH |
2497 | |
2498 | /* See the comment in tty_open(). */ | |
2499 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
2500 | ret = -EPERM; | |
2501 | goto unlock; | |
2502 | } | |
2503 | ||
bce65f18 | 2504 | proc_set_tty(tty); |
24ec839c | 2505 | unlock: |
2c411c11 | 2506 | read_unlock(&tasklist_lock); |
e218eb32 | 2507 | tty_unlock(tty); |
24ec839c | 2508 | return ret; |
1da177e4 LT |
2509 | } |
2510 | ||
5d0fdf1e AC |
2511 | /** |
2512 | * tty_get_pgrp - return a ref counted pgrp pid | |
2513 | * @tty: tty to read | |
2514 | * | |
2515 | * Returns a refcounted instance of the pid struct for the process | |
2516 | * group controlling the tty. | |
2517 | */ | |
2518 | ||
2519 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2520 | { | |
2521 | unsigned long flags; | |
2522 | struct pid *pgrp; | |
2523 | ||
2524 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2525 | pgrp = get_pid(tty->pgrp); | |
2526 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2527 | ||
2528 | return pgrp; | |
2529 | } | |
2530 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2531 | ||
e1c2296c PH |
2532 | /* |
2533 | * This checks not only the pgrp, but falls back on the pid if no | |
2534 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2535 | * without this... | |
2536 | * | |
2537 | * The caller must hold rcu lock or the tasklist lock. | |
2538 | */ | |
2539 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2540 | { | |
2541 | struct task_struct *p; | |
2542 | struct pid *sid = NULL; | |
2543 | ||
2544 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2545 | if (p == NULL) | |
2546 | p = pid_task(pgrp, PIDTYPE_PID); | |
2547 | if (p != NULL) | |
2548 | sid = task_session(p); | |
2549 | ||
2550 | return sid; | |
2551 | } | |
2552 | ||
af9b897e AC |
2553 | /** |
2554 | * tiocgpgrp - get process group | |
2555 | * @tty: tty passed by user | |
25985edc | 2556 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2557 | * @p: returned pid |
2558 | * | |
2559 | * Obtain the process group of the tty. If there is no process group | |
2560 | * return an error. | |
2561 | * | |
24ec839c | 2562 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2563 | */ |
2564 | ||
1da177e4 LT |
2565 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2566 | { | |
5d0fdf1e AC |
2567 | struct pid *pid; |
2568 | int ret; | |
1da177e4 LT |
2569 | /* |
2570 | * (tty == real_tty) is a cheap way of | |
2571 | * testing if the tty is NOT a master pty. | |
2572 | */ | |
2573 | if (tty == real_tty && current->signal->tty != real_tty) | |
2574 | return -ENOTTY; | |
5d0fdf1e AC |
2575 | pid = tty_get_pgrp(real_tty); |
2576 | ret = put_user(pid_vnr(pid), p); | |
2577 | put_pid(pid); | |
2578 | return ret; | |
1da177e4 LT |
2579 | } |
2580 | ||
af9b897e AC |
2581 | /** |
2582 | * tiocspgrp - attempt to set process group | |
2583 | * @tty: tty passed by user | |
2584 | * @real_tty: tty side device matching tty passed by user | |
2585 | * @p: pid pointer | |
2586 | * | |
2587 | * Set the process group of the tty to the session passed. Only | |
2588 | * permitted where the tty session is our session. | |
2589 | * | |
47f86834 | 2590 | * Locking: RCU, ctrl lock |
af9b897e AC |
2591 | */ |
2592 | ||
1da177e4 LT |
2593 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2594 | { | |
04a2e6a5 EB |
2595 | struct pid *pgrp; |
2596 | pid_t pgrp_nr; | |
1da177e4 LT |
2597 | int retval = tty_check_change(real_tty); |
2598 | ||
2599 | if (retval == -EIO) | |
2600 | return -ENOTTY; | |
2601 | if (retval) | |
2602 | return retval; | |
2603 | if (!current->signal->tty || | |
2604 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2605 | (real_tty->session != task_session(current))) |
1da177e4 | 2606 | return -ENOTTY; |
04a2e6a5 | 2607 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2608 | return -EFAULT; |
04a2e6a5 | 2609 | if (pgrp_nr < 0) |
1da177e4 | 2610 | return -EINVAL; |
04a2e6a5 | 2611 | rcu_read_lock(); |
b488893a | 2612 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2613 | retval = -ESRCH; |
2614 | if (!pgrp) | |
2615 | goto out_unlock; | |
2616 | retval = -EPERM; | |
2617 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2618 | goto out_unlock; | |
2619 | retval = 0; | |
1e86b5bf | 2620 | spin_lock_irq(&tty->ctrl_lock); |
ab521dc0 EB |
2621 | put_pid(real_tty->pgrp); |
2622 | real_tty->pgrp = get_pid(pgrp); | |
1e86b5bf | 2623 | spin_unlock_irq(&tty->ctrl_lock); |
04a2e6a5 EB |
2624 | out_unlock: |
2625 | rcu_read_unlock(); | |
2626 | return retval; | |
1da177e4 LT |
2627 | } |
2628 | ||
af9b897e AC |
2629 | /** |
2630 | * tiocgsid - get session id | |
2631 | * @tty: tty passed by user | |
25985edc | 2632 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2633 | * @p: pointer to returned session id |
2634 | * | |
2635 | * Obtain the session id of the tty. If there is no session | |
2636 | * return an error. | |
2637 | * | |
24ec839c | 2638 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2639 | */ |
2640 | ||
1da177e4 LT |
2641 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2642 | { | |
2643 | /* | |
2644 | * (tty == real_tty) is a cheap way of | |
2645 | * testing if the tty is NOT a master pty. | |
2646 | */ | |
2647 | if (tty == real_tty && current->signal->tty != real_tty) | |
2648 | return -ENOTTY; | |
ab521dc0 | 2649 | if (!real_tty->session) |
1da177e4 | 2650 | return -ENOTTY; |
b488893a | 2651 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2652 | } |
2653 | ||
af9b897e AC |
2654 | /** |
2655 | * tiocsetd - set line discipline | |
2656 | * @tty: tty device | |
2657 | * @p: pointer to user data | |
2658 | * | |
2659 | * Set the line discipline according to user request. | |
2660 | * | |
2661 | * Locking: see tty_set_ldisc, this function is just a helper | |
2662 | */ | |
2663 | ||
1da177e4 LT |
2664 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2665 | { | |
c12da96f | 2666 | int disc; |
04f378b1 | 2667 | int ret; |
1da177e4 | 2668 | |
c12da96f | 2669 | if (get_user(disc, p)) |
1da177e4 | 2670 | return -EFAULT; |
04f378b1 | 2671 | |
c12da96f | 2672 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2673 | |
2674 | return ret; | |
1da177e4 LT |
2675 | } |
2676 | ||
5c17c861 PH |
2677 | /** |
2678 | * tiocgetd - get line discipline | |
2679 | * @tty: tty device | |
2680 | * @p: pointer to user data | |
2681 | * | |
2682 | * Retrieves the line discipline id directly from the ldisc. | |
2683 | * | |
2684 | * Locking: waits for ldisc reference (in case the line discipline | |
2685 | * is changing or the tty is being hungup) | |
2686 | */ | |
2687 | ||
2688 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2689 | { | |
2690 | struct tty_ldisc *ld; | |
2691 | int ret; | |
2692 | ||
2693 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2694 | if (!ld) |
2695 | return -EIO; | |
5c17c861 PH |
2696 | ret = put_user(ld->ops->num, p); |
2697 | tty_ldisc_deref(ld); | |
2698 | return ret; | |
2699 | } | |
2700 | ||
af9b897e AC |
2701 | /** |
2702 | * send_break - performed time break | |
2703 | * @tty: device to break on | |
2704 | * @duration: timeout in mS | |
2705 | * | |
2706 | * Perform a timed break on hardware that lacks its own driver level | |
2707 | * timed break functionality. | |
2708 | * | |
2709 | * Locking: | |
28298232 | 2710 | * atomic_write_lock serializes |
af9b897e | 2711 | * |
af9b897e AC |
2712 | */ |
2713 | ||
b20f3ae5 | 2714 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2715 | { |
9e98966c AC |
2716 | int retval; |
2717 | ||
2718 | if (tty->ops->break_ctl == NULL) | |
2719 | return 0; | |
2720 | ||
2721 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2722 | retval = tty->ops->break_ctl(tty, duration); | |
2723 | else { | |
2724 | /* Do the work ourselves */ | |
2725 | if (tty_write_lock(tty, 0) < 0) | |
2726 | return -EINTR; | |
2727 | retval = tty->ops->break_ctl(tty, -1); | |
2728 | if (retval) | |
2729 | goto out; | |
2730 | if (!signal_pending(current)) | |
2731 | msleep_interruptible(duration); | |
2732 | retval = tty->ops->break_ctl(tty, 0); | |
2733 | out: | |
2734 | tty_write_unlock(tty); | |
2735 | if (signal_pending(current)) | |
2736 | retval = -EINTR; | |
2737 | } | |
2738 | return retval; | |
1da177e4 LT |
2739 | } |
2740 | ||
af9b897e | 2741 | /** |
f34d7a5b | 2742 | * tty_tiocmget - get modem status |
af9b897e AC |
2743 | * @tty: tty device |
2744 | * @file: user file pointer | |
2745 | * @p: pointer to result | |
2746 | * | |
2747 | * Obtain the modem status bits from the tty driver if the feature | |
2748 | * is supported. Return -EINVAL if it is not available. | |
2749 | * | |
2750 | * Locking: none (up to the driver) | |
2751 | */ | |
2752 | ||
60b33c13 | 2753 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2754 | { |
2755 | int retval = -EINVAL; | |
2756 | ||
f34d7a5b | 2757 | if (tty->ops->tiocmget) { |
60b33c13 | 2758 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2759 | |
2760 | if (retval >= 0) | |
2761 | retval = put_user(retval, p); | |
2762 | } | |
2763 | return retval; | |
2764 | } | |
2765 | ||
af9b897e | 2766 | /** |
f34d7a5b | 2767 | * tty_tiocmset - set modem status |
af9b897e | 2768 | * @tty: tty device |
af9b897e AC |
2769 | * @cmd: command - clear bits, set bits or set all |
2770 | * @p: pointer to desired bits | |
2771 | * | |
2772 | * Set the modem status bits from the tty driver if the feature | |
2773 | * is supported. Return -EINVAL if it is not available. | |
2774 | * | |
2775 | * Locking: none (up to the driver) | |
2776 | */ | |
2777 | ||
20b9d177 | 2778 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2779 | unsigned __user *p) |
2780 | { | |
ae677517 AC |
2781 | int retval; |
2782 | unsigned int set, clear, val; | |
1da177e4 | 2783 | |
ae677517 AC |
2784 | if (tty->ops->tiocmset == NULL) |
2785 | return -EINVAL; | |
1da177e4 | 2786 | |
ae677517 AC |
2787 | retval = get_user(val, p); |
2788 | if (retval) | |
2789 | return retval; | |
2790 | set = clear = 0; | |
2791 | switch (cmd) { | |
2792 | case TIOCMBIS: | |
2793 | set = val; | |
2794 | break; | |
2795 | case TIOCMBIC: | |
2796 | clear = val; | |
2797 | break; | |
2798 | case TIOCMSET: | |
2799 | set = val; | |
2800 | clear = ~val; | |
2801 | break; | |
2802 | } | |
2803 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2804 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2805 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2806 | } |
2807 | ||
d281da7f AC |
2808 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2809 | { | |
2810 | int retval = -EINVAL; | |
2811 | struct serial_icounter_struct icount; | |
2812 | memset(&icount, 0, sizeof(icount)); | |
2813 | if (tty->ops->get_icount) | |
2814 | retval = tty->ops->get_icount(tty, &icount); | |
2815 | if (retval != 0) | |
2816 | return retval; | |
2817 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2818 | return -EFAULT; | |
2819 | return 0; | |
2820 | } | |
2821 | ||
8a8ae62f JS |
2822 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2823 | { | |
2824 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2825 | DEFAULT_RATELIMIT_INTERVAL, | |
2826 | DEFAULT_RATELIMIT_BURST); | |
2827 | char comm[TASK_COMM_LEN]; | |
2828 | int flags; | |
2829 | ||
2830 | if (get_user(flags, &ss->flags)) | |
2831 | return; | |
2832 | ||
2833 | flags &= ASYNC_DEPRECATED; | |
2834 | ||
2835 | if (flags && __ratelimit(&depr_flags)) | |
2836 | pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2837 | __func__, get_task_comm(comm, current), flags); | |
2838 | } | |
2839 | ||
8f166e00 PH |
2840 | /* |
2841 | * if pty, return the slave side (real_tty) | |
2842 | * otherwise, return self | |
2843 | */ | |
2844 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2845 | { |
2846 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2847 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2848 | tty = tty->link; | |
2849 | return tty; | |
2850 | } | |
e8b70e7d | 2851 | |
1da177e4 LT |
2852 | /* |
2853 | * Split this up, as gcc can choke on it otherwise.. | |
2854 | */ | |
04f378b1 | 2855 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2856 | { |
d996b62a NP |
2857 | struct tty_struct *tty = file_tty(file); |
2858 | struct tty_struct *real_tty; | |
1da177e4 LT |
2859 | void __user *p = (void __user *)arg; |
2860 | int retval; | |
2861 | struct tty_ldisc *ld; | |
37bdfb07 | 2862 | |
6131ffaa | 2863 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2864 | return -EINVAL; |
2865 | ||
e8b70e7d | 2866 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2867 | |
2868 | /* | |
2869 | * Factor out some common prep work | |
2870 | */ | |
2871 | switch (cmd) { | |
2872 | case TIOCSETD: | |
2873 | case TIOCSBRK: | |
2874 | case TIOCCBRK: | |
2875 | case TCSBRK: | |
37bdfb07 | 2876 | case TCSBRKP: |
1da177e4 LT |
2877 | retval = tty_check_change(tty); |
2878 | if (retval) | |
2879 | return retval; | |
2880 | if (cmd != TIOCCBRK) { | |
2881 | tty_wait_until_sent(tty, 0); | |
2882 | if (signal_pending(current)) | |
2883 | return -EINTR; | |
2884 | } | |
2885 | break; | |
2886 | } | |
2887 | ||
9e98966c AC |
2888 | /* |
2889 | * Now do the stuff. | |
2890 | */ | |
1da177e4 | 2891 | switch (cmd) { |
37bdfb07 AC |
2892 | case TIOCSTI: |
2893 | return tiocsti(tty, p); | |
2894 | case TIOCGWINSZ: | |
8f520021 | 2895 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2896 | case TIOCSWINSZ: |
fc6f6238 | 2897 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2898 | case TIOCCONS: |
2899 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2900 | case FIONBIO: | |
2901 | return fionbio(file, p); | |
2902 | case TIOCEXCL: | |
2903 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2904 | return 0; | |
2905 | case TIOCNXCL: | |
2906 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2907 | return 0; | |
84fd7bdf CG |
2908 | case TIOCGEXCL: |
2909 | { | |
2910 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2911 | return put_user(excl, (int __user *)p); | |
2912 | } | |
37bdfb07 AC |
2913 | case TIOCNOTTY: |
2914 | if (current->signal->tty != tty) | |
2915 | return -ENOTTY; | |
2916 | no_tty(); | |
2917 | return 0; | |
2918 | case TIOCSCTTY: | |
d1d3a0f7 | 2919 | return tiocsctty(real_tty, file, arg); |
37bdfb07 AC |
2920 | case TIOCGPGRP: |
2921 | return tiocgpgrp(tty, real_tty, p); | |
2922 | case TIOCSPGRP: | |
2923 | return tiocspgrp(tty, real_tty, p); | |
2924 | case TIOCGSID: | |
2925 | return tiocgsid(tty, real_tty, p); | |
2926 | case TIOCGETD: | |
5c17c861 | 2927 | return tiocgetd(tty, p); |
37bdfb07 AC |
2928 | case TIOCSETD: |
2929 | return tiocsetd(tty, p); | |
3c95c985 KS |
2930 | case TIOCVHANGUP: |
2931 | if (!capable(CAP_SYS_ADMIN)) | |
2932 | return -EPERM; | |
2933 | tty_vhangup(tty); | |
2934 | return 0; | |
b7b8de08 WF |
2935 | case TIOCGDEV: |
2936 | { | |
2937 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2938 | return put_user(ret, (unsigned int __user *)p); | |
2939 | } | |
37bdfb07 AC |
2940 | /* |
2941 | * Break handling | |
2942 | */ | |
2943 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2944 | if (tty->ops->break_ctl) |
9e98966c | 2945 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2946 | return 0; |
37bdfb07 | 2947 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2948 | if (tty->ops->break_ctl) |
9e98966c | 2949 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2950 | return 0; |
2951 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2952 | /* non-zero arg means wait for all output data | |
2953 | * to be sent (performed above) but don't send break. | |
2954 | * This is used by the tcdrain() termios function. | |
2955 | */ | |
2956 | if (!arg) | |
2957 | return send_break(tty, 250); | |
2958 | return 0; | |
2959 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2960 | return send_break(tty, arg ? arg*100 : 250); | |
2961 | ||
2962 | case TIOCMGET: | |
60b33c13 | 2963 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2964 | case TIOCMSET: |
2965 | case TIOCMBIC: | |
2966 | case TIOCMBIS: | |
20b9d177 | 2967 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2968 | case TIOCGICOUNT: |
2969 | retval = tty_tiocgicount(tty, p); | |
2970 | /* For the moment allow fall through to the old method */ | |
2971 | if (retval != -EINVAL) | |
2972 | return retval; | |
2973 | break; | |
37bdfb07 AC |
2974 | case TCFLSH: |
2975 | switch (arg) { | |
2976 | case TCIFLUSH: | |
2977 | case TCIOFLUSH: | |
2978 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2979 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2980 | break; |
37bdfb07 AC |
2981 | } |
2982 | break; | |
8a8ae62f JS |
2983 | case TIOCSSERIAL: |
2984 | tty_warn_deprecated_flags(p); | |
2985 | break; | |
1da177e4 | 2986 | } |
f34d7a5b | 2987 | if (tty->ops->ioctl) { |
c961bfb1 | 2988 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2989 | if (retval != -ENOIOCTLCMD) |
2990 | return retval; | |
2991 | } | |
2992 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2993 | if (!ld) |
2994 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2995 | retval = -EINVAL; |
a352def2 AC |
2996 | if (ld->ops->ioctl) { |
2997 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2998 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2999 | retval = -ENOTTY; |
1da177e4 LT |
3000 | } |
3001 | tty_ldisc_deref(ld); | |
3002 | return retval; | |
3003 | } | |
3004 | ||
e10cc1df | 3005 | #ifdef CONFIG_COMPAT |
37bdfb07 | 3006 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
3007 | unsigned long arg) |
3008 | { | |
d996b62a | 3009 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
3010 | struct tty_ldisc *ld; |
3011 | int retval = -ENOIOCTLCMD; | |
3012 | ||
6131ffaa | 3013 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
3014 | return -EINVAL; |
3015 | ||
f34d7a5b | 3016 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 3017 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
3018 | if (retval != -ENOIOCTLCMD) |
3019 | return retval; | |
3020 | } | |
3021 | ||
3022 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
3023 | if (!ld) |
3024 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
3025 | if (ld->ops->compat_ioctl) |
3026 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
3027 | else |
3028 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
3029 | tty_ldisc_deref(ld); |
3030 | ||
3031 | return retval; | |
3032 | } | |
3033 | #endif | |
1da177e4 | 3034 | |
c3c073f8 AV |
3035 | static int this_tty(const void *t, struct file *file, unsigned fd) |
3036 | { | |
3037 | if (likely(file->f_op->read != tty_read)) | |
3038 | return 0; | |
3039 | return file_tty(file) != t ? 0 : fd + 1; | |
3040 | } | |
3041 | ||
1da177e4 LT |
3042 | /* |
3043 | * This implements the "Secure Attention Key" --- the idea is to | |
3044 | * prevent trojan horses by killing all processes associated with this | |
3045 | * tty when the user hits the "Secure Attention Key". Required for | |
3046 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 3047 | * |
1da177e4 LT |
3048 | * This code could be nicer; ideally it should send a HUP, wait a few |
3049 | * seconds, then send a INT, and then a KILL signal. But you then | |
3050 | * have to coordinate with the init process, since all processes associated | |
3051 | * with the current tty must be dead before the new getty is allowed | |
3052 | * to spawn. | |
3053 | * | |
3054 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3055 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3056 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3057 | * | |
3058 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3059 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3060 | */ | |
8b6312f4 | 3061 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
3062 | { |
3063 | #ifdef TTY_SOFT_SAK | |
3064 | tty_hangup(tty); | |
3065 | #else | |
652486fb | 3066 | struct task_struct *g, *p; |
ab521dc0 | 3067 | struct pid *session; |
1da177e4 | 3068 | int i; |
37bdfb07 | 3069 | |
1da177e4 LT |
3070 | if (!tty) |
3071 | return; | |
24ec839c | 3072 | session = tty->session; |
37bdfb07 | 3073 | |
b3f13deb | 3074 | tty_ldisc_flush(tty); |
1da177e4 | 3075 | |
f34d7a5b | 3076 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3077 | |
1da177e4 | 3078 | read_lock(&tasklist_lock); |
652486fb | 3079 | /* Kill the entire session */ |
ab521dc0 | 3080 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3081 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3082 | task_pid_nr(p), p->comm); | |
652486fb | 3083 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3084 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3085 | |
3086 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3087 | do_each_thread(g, p) { |
3088 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3089 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3090 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
3091 | send_sig(SIGKILL, p, 1); |
3092 | continue; | |
3093 | } | |
3094 | task_lock(p); | |
c3c073f8 AV |
3095 | i = iterate_fd(p->files, 0, this_tty, tty); |
3096 | if (i != 0) { | |
9b42bb75 PH |
3097 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3098 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 3099 | force_sig(SIGKILL, p); |
1da177e4 LT |
3100 | } |
3101 | task_unlock(p); | |
652486fb | 3102 | } while_each_thread(g, p); |
1da177e4 LT |
3103 | read_unlock(&tasklist_lock); |
3104 | #endif | |
3105 | } | |
3106 | ||
8b6312f4 EB |
3107 | static void do_SAK_work(struct work_struct *work) |
3108 | { | |
3109 | struct tty_struct *tty = | |
3110 | container_of(work, struct tty_struct, SAK_work); | |
3111 | __do_SAK(tty); | |
3112 | } | |
3113 | ||
1da177e4 LT |
3114 | /* |
3115 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3116 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3117 | * the values which we write to it will be identical to the values which it | |
3118 | * already has. --akpm | |
3119 | */ | |
3120 | void do_SAK(struct tty_struct *tty) | |
3121 | { | |
3122 | if (!tty) | |
3123 | return; | |
1da177e4 LT |
3124 | schedule_work(&tty->SAK_work); |
3125 | } | |
3126 | ||
3127 | EXPORT_SYMBOL(do_SAK); | |
3128 | ||
6e9430ac | 3129 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3130 | { |
6e9430ac | 3131 | const dev_t *devt = data; |
30004ac9 DES |
3132 | return dev->devt == *devt; |
3133 | } | |
3134 | ||
3135 | /* Must put_device() after it's unused! */ | |
3136 | static struct device *tty_get_device(struct tty_struct *tty) | |
3137 | { | |
3138 | dev_t devt = tty_devnum(tty); | |
3139 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3140 | } | |
3141 | ||
3142 | ||
af9b897e | 3143 | /** |
2c964a2f | 3144 | * alloc_tty_struct |
af9b897e | 3145 | * |
2c964a2f | 3146 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3147 | * |
2c964a2f | 3148 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3149 | */ |
af9b897e | 3150 | |
2c964a2f | 3151 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3152 | { |
2c964a2f RV |
3153 | struct tty_struct *tty; |
3154 | ||
3155 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3156 | if (!tty) | |
3157 | return NULL; | |
3158 | ||
9c9f4ded | 3159 | kref_init(&tty->kref); |
1da177e4 | 3160 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3161 | tty_ldisc_init(tty); |
ab521dc0 EB |
3162 | tty->session = NULL; |
3163 | tty->pgrp = NULL; | |
89c8d91e | 3164 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3165 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3166 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3167 | mutex_init(&tty->winsize_mutex); |
36697529 | 3168 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3169 | init_waitqueue_head(&tty->write_wait); |
3170 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3171 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3172 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3173 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3174 | spin_lock_init(&tty->flow_lock); |
4a510969 | 3175 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3176 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3177 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3178 | |
3179 | tty->driver = driver; | |
3180 | tty->ops = driver->ops; | |
3181 | tty->index = idx; | |
3182 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3183 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3184 | |
3185 | return tty; | |
1da177e4 LT |
3186 | } |
3187 | ||
f34d7a5b AC |
3188 | /** |
3189 | * tty_put_char - write one character to a tty | |
3190 | * @tty: tty | |
3191 | * @ch: character | |
3192 | * | |
3193 | * Write one byte to the tty using the provided put_char method | |
3194 | * if present. Returns the number of characters successfully output. | |
3195 | * | |
3196 | * Note: the specific put_char operation in the driver layer may go | |
3197 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3198 | */ |
af9b897e | 3199 | |
f34d7a5b | 3200 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3201 | { |
f34d7a5b AC |
3202 | if (tty->ops->put_char) |
3203 | return tty->ops->put_char(tty, ch); | |
3204 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3205 | } |
f34d7a5b AC |
3206 | EXPORT_SYMBOL_GPL(tty_put_char); |
3207 | ||
d81ed103 | 3208 | struct class *tty_class; |
1da177e4 | 3209 | |
7e73eca6 JS |
3210 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3211 | unsigned int index, unsigned int count) | |
3212 | { | |
c1a752ba LY |
3213 | int err; |
3214 | ||
7e73eca6 | 3215 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3216 | driver->cdevs[index] = cdev_alloc(); |
3217 | if (!driver->cdevs[index]) | |
3218 | return -ENOMEM; | |
c1a752ba | 3219 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3220 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3221 | err = cdev_add(driver->cdevs[index], dev, count); |
3222 | if (err) | |
3223 | kobject_put(&driver->cdevs[index]->kobj); | |
3224 | return err; | |
7e73eca6 JS |
3225 | } |
3226 | ||
1da177e4 | 3227 | /** |
af9b897e AC |
3228 | * tty_register_device - register a tty device |
3229 | * @driver: the tty driver that describes the tty device | |
3230 | * @index: the index in the tty driver for this tty device | |
3231 | * @device: a struct device that is associated with this tty device. | |
3232 | * This field is optional, if there is no known struct device | |
3233 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3234 | * |
01107d34 GKH |
3235 | * Returns a pointer to the struct device for this tty device |
3236 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3237 | * |
af9b897e AC |
3238 | * This call is required to be made to register an individual tty device |
3239 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3240 | * that bit is not set, this function should not be called by a tty | |
3241 | * driver. | |
3242 | * | |
3243 | * Locking: ?? | |
1da177e4 | 3244 | */ |
af9b897e | 3245 | |
01107d34 GKH |
3246 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3247 | struct device *device) | |
1da177e4 | 3248 | { |
6915c0e4 TH |
3249 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3250 | } | |
3251 | EXPORT_SYMBOL(tty_register_device); | |
3252 | ||
b1b79916 TH |
3253 | static void tty_device_create_release(struct device *dev) |
3254 | { | |
83db1df4 | 3255 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3256 | kfree(dev); |
3257 | } | |
3258 | ||
6915c0e4 TH |
3259 | /** |
3260 | * tty_register_device_attr - register a tty device | |
3261 | * @driver: the tty driver that describes the tty device | |
3262 | * @index: the index in the tty driver for this tty device | |
3263 | * @device: a struct device that is associated with this tty device. | |
3264 | * This field is optional, if there is no known struct device | |
3265 | * for this tty device it can be set to NULL safely. | |
3266 | * @drvdata: Driver data to be set to device. | |
3267 | * @attr_grp: Attribute group to be set on device. | |
3268 | * | |
3269 | * Returns a pointer to the struct device for this tty device | |
3270 | * (or ERR_PTR(-EFOO) on error). | |
3271 | * | |
3272 | * This call is required to be made to register an individual tty device | |
3273 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3274 | * that bit is not set, this function should not be called by a tty | |
3275 | * driver. | |
3276 | * | |
3277 | * Locking: ?? | |
3278 | */ | |
3279 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3280 | unsigned index, struct device *device, | |
3281 | void *drvdata, | |
3282 | const struct attribute_group **attr_grp) | |
3283 | { | |
1da177e4 | 3284 | char name[64]; |
6915c0e4 TH |
3285 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3286 | struct device *dev = NULL; | |
3287 | int retval = -ENODEV; | |
7e73eca6 | 3288 | bool cdev = false; |
1da177e4 LT |
3289 | |
3290 | if (index >= driver->num) { | |
656fb867 PH |
3291 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3292 | driver->name, index); | |
1cdcb6b4 | 3293 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3294 | } |
3295 | ||
1da177e4 LT |
3296 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3297 | pty_line_name(driver, index, name); | |
3298 | else | |
3299 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3300 | |
7e73eca6 | 3301 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3302 | retval = tty_cdev_add(driver, devt, index, 1); |
3303 | if (retval) | |
3304 | goto error; | |
7e73eca6 JS |
3305 | cdev = true; |
3306 | } | |
3307 | ||
6915c0e4 TH |
3308 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3309 | if (!dev) { | |
3310 | retval = -ENOMEM; | |
3311 | goto error; | |
3312 | } | |
7e73eca6 | 3313 | |
6915c0e4 TH |
3314 | dev->devt = devt; |
3315 | dev->class = tty_class; | |
3316 | dev->parent = device; | |
b1b79916 | 3317 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3318 | dev_set_name(dev, "%s", name); |
3319 | dev->groups = attr_grp; | |
3320 | dev_set_drvdata(dev, drvdata); | |
3321 | ||
3322 | retval = device_register(dev); | |
3323 | if (retval) | |
3324 | goto error; | |
3325 | ||
3326 | return dev; | |
3327 | ||
3328 | error: | |
3329 | put_device(dev); | |
a3a10ce3 RW |
3330 | if (cdev) { |
3331 | cdev_del(driver->cdevs[index]); | |
3332 | driver->cdevs[index] = NULL; | |
3333 | } | |
6915c0e4 | 3334 | return ERR_PTR(retval); |
1da177e4 | 3335 | } |
6915c0e4 | 3336 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3337 | |
3338 | /** | |
af9b897e AC |
3339 | * tty_unregister_device - unregister a tty device |
3340 | * @driver: the tty driver that describes the tty device | |
3341 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3342 | * |
af9b897e AC |
3343 | * If a tty device is registered with a call to tty_register_device() then |
3344 | * this function must be called when the tty device is gone. | |
3345 | * | |
3346 | * Locking: ?? | |
1da177e4 | 3347 | */ |
af9b897e | 3348 | |
1da177e4 LT |
3349 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3350 | { | |
37bdfb07 AC |
3351 | device_destroy(tty_class, |
3352 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3353 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3354 | cdev_del(driver->cdevs[index]); | |
3355 | driver->cdevs[index] = NULL; | |
3356 | } | |
1da177e4 | 3357 | } |
1da177e4 LT |
3358 | EXPORT_SYMBOL(tty_unregister_device); |
3359 | ||
7f0bc6a6 JS |
3360 | /** |
3361 | * __tty_alloc_driver -- allocate tty driver | |
3362 | * @lines: count of lines this driver can handle at most | |
3363 | * @owner: module which is repsonsible for this driver | |
3364 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3365 | * | |
3366 | * This should not be called directly, some of the provided macros should be | |
3367 | * used instead. Use IS_ERR and friends on @retval. | |
3368 | */ | |
3369 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3370 | unsigned long flags) | |
1da177e4 LT |
3371 | { |
3372 | struct tty_driver *driver; | |
7e73eca6 | 3373 | unsigned int cdevs = 1; |
16a02081 | 3374 | int err; |
1da177e4 | 3375 | |
0019b408 | 3376 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3377 | return ERR_PTR(-EINVAL); |
3378 | ||
506eb99a | 3379 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3380 | if (!driver) |
3381 | return ERR_PTR(-ENOMEM); | |
3382 | ||
3383 | kref_init(&driver->kref); | |
3384 | driver->magic = TTY_DRIVER_MAGIC; | |
3385 | driver->num = lines; | |
3386 | driver->owner = owner; | |
3387 | driver->flags = flags; | |
16a02081 JS |
3388 | |
3389 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3390 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3391 | GFP_KERNEL); | |
3392 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3393 | GFP_KERNEL); | |
3394 | if (!driver->ttys || !driver->termios) { | |
3395 | err = -ENOMEM; | |
3396 | goto err_free_all; | |
3397 | } | |
3398 | } | |
3399 | ||
3400 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3401 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3402 | GFP_KERNEL); | |
3403 | if (!driver->ports) { | |
3404 | err = -ENOMEM; | |
3405 | goto err_free_all; | |
3406 | } | |
7e73eca6 JS |
3407 | cdevs = lines; |
3408 | } | |
3409 | ||
3410 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3411 | if (!driver->cdevs) { | |
3412 | err = -ENOMEM; | |
3413 | goto err_free_all; | |
16a02081 | 3414 | } |
7f0bc6a6 | 3415 | |
1da177e4 | 3416 | return driver; |
16a02081 JS |
3417 | err_free_all: |
3418 | kfree(driver->ports); | |
3419 | kfree(driver->ttys); | |
3420 | kfree(driver->termios); | |
a3a10ce3 | 3421 | kfree(driver->cdevs); |
16a02081 JS |
3422 | kfree(driver); |
3423 | return ERR_PTR(err); | |
1da177e4 | 3424 | } |
7f0bc6a6 | 3425 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3426 | |
7d7b93c1 | 3427 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3428 | { |
7d7b93c1 AC |
3429 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3430 | int i; | |
3431 | struct ktermios *tp; | |
7d7b93c1 AC |
3432 | |
3433 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3434 | /* | |
3435 | * Free the termios and termios_locked structures because | |
3436 | * we don't want to get memory leaks when modular tty | |
3437 | * drivers are removed from the kernel. | |
3438 | */ | |
3439 | for (i = 0; i < driver->num; i++) { | |
3440 | tp = driver->termios[i]; | |
3441 | if (tp) { | |
3442 | driver->termios[i] = NULL; | |
3443 | kfree(tp); | |
3444 | } | |
7d7b93c1 AC |
3445 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3446 | tty_unregister_device(driver, i); | |
3447 | } | |
7d7b93c1 | 3448 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3449 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3450 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3451 | } |
7e73eca6 | 3452 | kfree(driver->cdevs); |
04831dc1 | 3453 | kfree(driver->ports); |
16a02081 JS |
3454 | kfree(driver->termios); |
3455 | kfree(driver->ttys); | |
1da177e4 LT |
3456 | kfree(driver); |
3457 | } | |
3458 | ||
7d7b93c1 AC |
3459 | void tty_driver_kref_put(struct tty_driver *driver) |
3460 | { | |
3461 | kref_put(&driver->kref, destruct_tty_driver); | |
3462 | } | |
3463 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3464 | ||
b68e31d0 JD |
3465 | void tty_set_operations(struct tty_driver *driver, |
3466 | const struct tty_operations *op) | |
1da177e4 | 3467 | { |
f34d7a5b AC |
3468 | driver->ops = op; |
3469 | }; | |
7d7b93c1 | 3470 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3471 | |
7d7b93c1 AC |
3472 | void put_tty_driver(struct tty_driver *d) |
3473 | { | |
3474 | tty_driver_kref_put(d); | |
3475 | } | |
1da177e4 | 3476 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3477 | |
3478 | /* | |
3479 | * Called by a tty driver to register itself. | |
3480 | */ | |
3481 | int tty_register_driver(struct tty_driver *driver) | |
3482 | { | |
3483 | int error; | |
37bdfb07 | 3484 | int i; |
1da177e4 | 3485 | dev_t dev; |
b670bde0 | 3486 | struct device *d; |
1da177e4 | 3487 | |
1da177e4 | 3488 | if (!driver->major) { |
37bdfb07 AC |
3489 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3490 | driver->num, driver->name); | |
1da177e4 LT |
3491 | if (!error) { |
3492 | driver->major = MAJOR(dev); | |
3493 | driver->minor_start = MINOR(dev); | |
3494 | } | |
3495 | } else { | |
3496 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3497 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3498 | } |
9bb8a3d4 | 3499 | if (error < 0) |
16a02081 | 3500 | goto err; |
1da177e4 | 3501 | |
7e73eca6 JS |
3502 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3503 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3504 | if (error) | |
3505 | goto err_unreg_char; | |
3506 | } | |
1da177e4 | 3507 | |
ca509f69 | 3508 | mutex_lock(&tty_mutex); |
1da177e4 | 3509 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3510 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3511 | |
3512 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3513 | for (i = 0; i < driver->num; i++) { |
3514 | d = tty_register_device(driver, i, NULL); | |
3515 | if (IS_ERR(d)) { | |
3516 | error = PTR_ERR(d); | |
16a02081 | 3517 | goto err_unreg_devs; |
b670bde0 VK |
3518 | } |
3519 | } | |
1da177e4 LT |
3520 | } |
3521 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3522 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3523 | return 0; |
b670bde0 | 3524 | |
16a02081 | 3525 | err_unreg_devs: |
b670bde0 VK |
3526 | for (i--; i >= 0; i--) |
3527 | tty_unregister_device(driver, i); | |
3528 | ||
3529 | mutex_lock(&tty_mutex); | |
3530 | list_del(&driver->tty_drivers); | |
3531 | mutex_unlock(&tty_mutex); | |
3532 | ||
9bb8a3d4 | 3533 | err_unreg_char: |
b670bde0 | 3534 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3535 | err: |
b670bde0 | 3536 | return error; |
1da177e4 | 3537 | } |
1da177e4 LT |
3538 | EXPORT_SYMBOL(tty_register_driver); |
3539 | ||
3540 | /* | |
3541 | * Called by a tty driver to unregister itself. | |
3542 | */ | |
3543 | int tty_unregister_driver(struct tty_driver *driver) | |
3544 | { | |
7d7b93c1 AC |
3545 | #if 0 |
3546 | /* FIXME */ | |
1da177e4 LT |
3547 | if (driver->refcount) |
3548 | return -EBUSY; | |
7d7b93c1 | 3549 | #endif |
1da177e4 LT |
3550 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3551 | driver->num); | |
ca509f69 | 3552 | mutex_lock(&tty_mutex); |
1da177e4 | 3553 | list_del(&driver->tty_drivers); |
ca509f69 | 3554 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3555 | return 0; |
3556 | } | |
7d7b93c1 | 3557 | |
1da177e4 LT |
3558 | EXPORT_SYMBOL(tty_unregister_driver); |
3559 | ||
24ec839c PZ |
3560 | dev_t tty_devnum(struct tty_struct *tty) |
3561 | { | |
3562 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3563 | } | |
3564 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3565 | |
d81ed103 AC |
3566 | void tty_default_fops(struct file_operations *fops) |
3567 | { | |
3568 | *fops = tty_fops; | |
3569 | } | |
3570 | ||
1da177e4 LT |
3571 | /* |
3572 | * Initialize the console device. This is called *early*, so | |
3573 | * we can't necessarily depend on lots of kernel help here. | |
3574 | * Just do some early initializations, and do the complex setup | |
3575 | * later. | |
3576 | */ | |
3577 | void __init console_init(void) | |
3578 | { | |
3579 | initcall_t *call; | |
3580 | ||
3581 | /* Setup the default TTY line discipline. */ | |
27228732 | 3582 | n_tty_init(); |
1da177e4 LT |
3583 | |
3584 | /* | |
37bdfb07 | 3585 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3586 | * inform about problems etc.. |
3587 | */ | |
1da177e4 LT |
3588 | call = __con_initcall_start; |
3589 | while (call < __con_initcall_end) { | |
3590 | (*call)(); | |
3591 | call++; | |
3592 | } | |
3593 | } | |
3594 | ||
2c9ede55 | 3595 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3596 | { |
3597 | if (!mode) | |
3598 | return NULL; | |
3599 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3600 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3601 | *mode = 0666; | |
3602 | return NULL; | |
3603 | } | |
3604 | ||
1da177e4 LT |
3605 | static int __init tty_class_init(void) |
3606 | { | |
7fe845d1 | 3607 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3608 | if (IS_ERR(tty_class)) |
3609 | return PTR_ERR(tty_class); | |
e454cea2 | 3610 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3611 | return 0; |
3612 | } | |
3613 | ||
3614 | postcore_initcall(tty_class_init); | |
3615 | ||
3616 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3617 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3618 | |
fbc92a34 KS |
3619 | static ssize_t show_cons_active(struct device *dev, |
3620 | struct device_attribute *attr, char *buf) | |
3621 | { | |
3622 | struct console *cs[16]; | |
3623 | int i = 0; | |
3624 | struct console *c; | |
3625 | ssize_t count = 0; | |
3626 | ||
ac751efa | 3627 | console_lock(); |
a2a6a822 | 3628 | for_each_console(c) { |
fbc92a34 KS |
3629 | if (!c->device) |
3630 | continue; | |
3631 | if (!c->write) | |
3632 | continue; | |
3633 | if ((c->flags & CON_ENABLED) == 0) | |
3634 | continue; | |
3635 | cs[i++] = c; | |
3636 | if (i >= ARRAY_SIZE(cs)) | |
3637 | break; | |
3638 | } | |
723abd87 HR |
3639 | while (i--) { |
3640 | int index = cs[i]->index; | |
3641 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3642 | ||
3643 | /* don't resolve tty0 as some programs depend on it */ | |
3644 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3645 | count += tty_line_name(drv, index, buf + count); | |
3646 | else | |
3647 | count += sprintf(buf + count, "%s%d", | |
3648 | cs[i]->name, cs[i]->index); | |
3649 | ||
3650 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3651 | } | |
ac751efa | 3652 | console_unlock(); |
fbc92a34 KS |
3653 | |
3654 | return count; | |
3655 | } | |
3656 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3657 | ||
1083a7be TI |
3658 | static struct attribute *cons_dev_attrs[] = { |
3659 | &dev_attr_active.attr, | |
3660 | NULL | |
3661 | }; | |
3662 | ||
3663 | ATTRIBUTE_GROUPS(cons_dev); | |
3664 | ||
fbc92a34 KS |
3665 | static struct device *consdev; |
3666 | ||
3667 | void console_sysfs_notify(void) | |
3668 | { | |
3669 | if (consdev) | |
3670 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3671 | } | |
3672 | ||
1da177e4 LT |
3673 | /* |
3674 | * Ok, now we can initialize the rest of the tty devices and can count | |
3675 | * on memory allocations, interrupts etc.. | |
3676 | */ | |
31d1d48e | 3677 | int __init tty_init(void) |
1da177e4 LT |
3678 | { |
3679 | cdev_init(&tty_cdev, &tty_fops); | |
3680 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3681 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3682 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3683 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3684 | |
3685 | cdev_init(&console_cdev, &console_fops); | |
3686 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3687 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3688 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3689 | consdev = device_create_with_groups(tty_class, NULL, |
3690 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3691 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3692 | if (IS_ERR(consdev)) |
3693 | consdev = NULL; | |
1da177e4 | 3694 | |
1da177e4 | 3695 | #ifdef CONFIG_VT |
d81ed103 | 3696 | vty_init(&console_fops); |
1da177e4 LT |
3697 | #endif |
3698 | return 0; | |
3699 | } | |
31d1d48e | 3700 |