Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
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, | |
126 | .c_ospeed = 38400 | |
1da177e4 LT |
127 | }; |
128 | ||
129 | EXPORT_SYMBOL(tty_std_termios); | |
130 | ||
131 | /* This list gets poked at by procfs and various bits of boot up code. This | |
132 | could do with some rationalisation such as pulling the tty proc function | |
133 | into this file */ | |
37bdfb07 | 134 | |
1da177e4 LT |
135 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
136 | ||
24ec839c | 137 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 138 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 139 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 140 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 141 | |
ee2ffa0d NP |
142 | /* Spinlock to protect the tty->tty_files list */ |
143 | DEFINE_SPINLOCK(tty_files_lock); | |
144 | ||
1da177e4 LT |
145 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
146 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
147 | ssize_t redirected_tty_write(struct file *, const char __user *, |
148 | size_t, loff_t *); | |
1da177e4 LT |
149 | static unsigned int tty_poll(struct file *, poll_table *); |
150 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 151 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 152 | #ifdef CONFIG_COMPAT |
37bdfb07 | 153 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
154 | unsigned long arg); |
155 | #else | |
156 | #define tty_compat_ioctl NULL | |
157 | #endif | |
ec79d605 | 158 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 159 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 160 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 161 | |
af9b897e AC |
162 | /** |
163 | * free_tty_struct - free a disused tty | |
164 | * @tty: tty struct to free | |
165 | * | |
166 | * Free the write buffers, tty queue and tty memory itself. | |
167 | * | |
168 | * Locking: none. Must be called after tty is definitely unused | |
169 | */ | |
170 | ||
bf970ee4 | 171 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 172 | { |
dc6802a7 DC |
173 | if (!tty) |
174 | return; | |
a211b1af | 175 | put_device(tty->dev); |
1da177e4 | 176 | kfree(tty->write_buf); |
89c8d91e | 177 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
178 | kfree(tty); |
179 | } | |
180 | ||
d996b62a NP |
181 | static inline struct tty_struct *file_tty(struct file *file) |
182 | { | |
183 | return ((struct tty_file_private *)file->private_data)->tty; | |
184 | } | |
185 | ||
fa90e1c9 | 186 | int tty_alloc_file(struct file *file) |
d996b62a NP |
187 | { |
188 | struct tty_file_private *priv; | |
189 | ||
f573bd17 PE |
190 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
191 | if (!priv) | |
192 | return -ENOMEM; | |
d996b62a | 193 | |
fa90e1c9 JS |
194 | file->private_data = priv; |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | /* Associate a new file with the tty structure */ | |
200 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
201 | { | |
202 | struct tty_file_private *priv = file->private_data; | |
203 | ||
d996b62a NP |
204 | priv->tty = tty; |
205 | priv->file = file; | |
d996b62a NP |
206 | |
207 | spin_lock(&tty_files_lock); | |
208 | list_add(&priv->list, &tty->tty_files); | |
209 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 210 | } |
f573bd17 | 211 | |
fa90e1c9 JS |
212 | /** |
213 | * tty_free_file - free file->private_data | |
214 | * | |
215 | * This shall be used only for fail path handling when tty_add_file was not | |
216 | * called yet. | |
217 | */ | |
218 | void tty_free_file(struct file *file) | |
219 | { | |
220 | struct tty_file_private *priv = file->private_data; | |
221 | ||
222 | file->private_data = NULL; | |
223 | kfree(priv); | |
d996b62a NP |
224 | } |
225 | ||
226 | /* Delete file from its tty */ | |
2520e274 | 227 | static void tty_del_file(struct file *file) |
d996b62a NP |
228 | { |
229 | struct tty_file_private *priv = file->private_data; | |
230 | ||
231 | spin_lock(&tty_files_lock); | |
232 | list_del(&priv->list); | |
233 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 234 | tty_free_file(file); |
d996b62a NP |
235 | } |
236 | ||
237 | ||
1da177e4 LT |
238 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
239 | ||
af9b897e AC |
240 | /** |
241 | * tty_name - return tty naming | |
242 | * @tty: tty structure | |
af9b897e AC |
243 | * |
244 | * Convert a tty structure into a name. The name reflects the kernel | |
245 | * naming policy and if udev is in use may not reflect user space | |
246 | * | |
247 | * Locking: none | |
248 | */ | |
249 | ||
429b4749 | 250 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
251 | { |
252 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
253 | return "NULL tty"; |
254 | return tty->name; | |
1da177e4 LT |
255 | } |
256 | ||
257 | EXPORT_SYMBOL(tty_name); | |
258 | ||
0a083edd PH |
259 | const char *tty_driver_name(const struct tty_struct *tty) |
260 | { | |
261 | if (!tty || !tty->driver) | |
262 | return ""; | |
263 | return tty->driver->name; | |
264 | } | |
265 | ||
82b8f888 | 266 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
267 | const char *routine) |
268 | { | |
269 | #ifdef TTY_PARANOIA_CHECK | |
270 | if (!tty) { | |
89222e62 | 271 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
272 | imajor(inode), iminor(inode), routine); |
273 | return 1; | |
274 | } | |
275 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 276 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
277 | imajor(inode), iminor(inode), routine); |
278 | return 1; | |
279 | } | |
280 | #endif | |
281 | return 0; | |
282 | } | |
283 | ||
deb287e7 | 284 | /* Caller must hold tty_lock */ |
1da177e4 LT |
285 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
286 | { | |
287 | #ifdef CHECK_TTY_COUNT | |
288 | struct list_head *p; | |
289 | int count = 0; | |
37bdfb07 | 290 | |
ee2ffa0d | 291 | spin_lock(&tty_files_lock); |
1da177e4 LT |
292 | list_for_each(p, &tty->tty_files) { |
293 | count++; | |
294 | } | |
ee2ffa0d | 295 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
296 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
297 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
298 | tty->link && tty->link->count) | |
299 | count++; | |
300 | if (tty->count != count) { | |
339f36ba PH |
301 | tty_warn(tty, "%s: tty->count(%d) != #fd's(%d)\n", |
302 | routine, tty->count, count); | |
1da177e4 | 303 | return count; |
24ec839c | 304 | } |
1da177e4 LT |
305 | #endif |
306 | return 0; | |
307 | } | |
308 | ||
af9b897e AC |
309 | /** |
310 | * get_tty_driver - find device of a tty | |
311 | * @dev_t: device identifier | |
312 | * @index: returns the index of the tty | |
313 | * | |
314 | * This routine returns a tty driver structure, given a device number | |
315 | * and also passes back the index number. | |
316 | * | |
317 | * Locking: caller must hold tty_mutex | |
1da177e4 | 318 | */ |
af9b897e | 319 | |
1da177e4 LT |
320 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
321 | { | |
322 | struct tty_driver *p; | |
323 | ||
324 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
325 | dev_t base = MKDEV(p->major, p->minor_start); | |
326 | if (device < base || device >= base + p->num) | |
327 | continue; | |
328 | *index = device - base; | |
7d7b93c1 | 329 | return tty_driver_kref_get(p); |
1da177e4 LT |
330 | } |
331 | return NULL; | |
332 | } | |
333 | ||
f2d937f3 JW |
334 | #ifdef CONFIG_CONSOLE_POLL |
335 | ||
336 | /** | |
337 | * tty_find_polling_driver - find device of a polled tty | |
338 | * @name: name string to match | |
339 | * @line: pointer to resulting tty line nr | |
340 | * | |
341 | * This routine returns a tty driver structure, given a name | |
342 | * and the condition that the tty driver is capable of polled | |
343 | * operation. | |
344 | */ | |
345 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
346 | { | |
347 | struct tty_driver *p, *res = NULL; | |
348 | int tty_line = 0; | |
0dca0fd2 | 349 | int len; |
5f0878ac | 350 | char *str, *stp; |
f2d937f3 | 351 | |
0dca0fd2 JW |
352 | for (str = name; *str; str++) |
353 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
354 | break; | |
355 | if (!*str) | |
356 | return NULL; | |
357 | ||
358 | len = str - name; | |
359 | tty_line = simple_strtoul(str, &str, 10); | |
360 | ||
f2d937f3 JW |
361 | mutex_lock(&tty_mutex); |
362 | /* Search through the tty devices to look for a match */ | |
363 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
364 | if (strncmp(name, p->name, len) != 0) |
365 | continue; | |
5f0878ac AC |
366 | stp = str; |
367 | if (*stp == ',') | |
368 | stp++; | |
369 | if (*stp == '\0') | |
370 | stp = NULL; | |
f2d937f3 | 371 | |
6eb68d6f | 372 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 373 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 374 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
375 | *line = tty_line; |
376 | break; | |
377 | } | |
378 | } | |
379 | mutex_unlock(&tty_mutex); | |
380 | ||
381 | return res; | |
382 | } | |
383 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
384 | #endif | |
385 | ||
af9b897e AC |
386 | /** |
387 | * tty_check_change - check for POSIX terminal changes | |
388 | * @tty: tty to check | |
389 | * | |
390 | * If we try to write to, or set the state of, a terminal and we're | |
391 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
392 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
393 | * | |
978e595f | 394 | * Locking: ctrl_lock |
1da177e4 | 395 | */ |
af9b897e | 396 | |
2812d9e9 | 397 | int __tty_check_change(struct tty_struct *tty, int sig) |
1da177e4 | 398 | { |
47f86834 | 399 | unsigned long flags; |
2812d9e9 | 400 | struct pid *pgrp, *tty_pgrp; |
47f86834 AC |
401 | int ret = 0; |
402 | ||
1da177e4 LT |
403 | if (current->signal->tty != tty) |
404 | return 0; | |
47f86834 | 405 | |
6719693c PD |
406 | rcu_read_lock(); |
407 | pgrp = task_pgrp(current); | |
408 | ||
47f86834 | 409 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
2812d9e9 | 410 | tty_pgrp = tty->pgrp; |
9ffee4cb | 411 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
6719693c | 412 | |
2812d9e9 PH |
413 | if (tty_pgrp && pgrp != tty->pgrp) { |
414 | if (is_ignored(sig)) { | |
415 | if (sig == SIGTTIN) | |
416 | ret = -EIO; | |
417 | } else if (is_current_pgrp_orphaned()) | |
418 | ret = -EIO; | |
419 | else { | |
420 | kill_pgrp(pgrp, sig, 1); | |
421 | set_thread_flag(TIF_SIGPENDING); | |
422 | ret = -ERESTARTSYS; | |
423 | } | |
47f86834 | 424 | } |
6719693c | 425 | rcu_read_unlock(); |
2812d9e9 | 426 | |
339f36ba PH |
427 | if (!tty_pgrp) |
428 | tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig); | |
2812d9e9 | 429 | |
47f86834 | 430 | return ret; |
1da177e4 LT |
431 | } |
432 | ||
2812d9e9 PH |
433 | int tty_check_change(struct tty_struct *tty) |
434 | { | |
435 | return __tty_check_change(tty, SIGTTOU); | |
436 | } | |
1da177e4 LT |
437 | EXPORT_SYMBOL(tty_check_change); |
438 | ||
37bdfb07 | 439 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
440 | size_t count, loff_t *ppos) |
441 | { | |
442 | return 0; | |
443 | } | |
444 | ||
37bdfb07 | 445 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
446 | size_t count, loff_t *ppos) |
447 | { | |
448 | return -EIO; | |
449 | } | |
450 | ||
451 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 452 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
453 | { |
454 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
455 | } | |
456 | ||
04f378b1 AC |
457 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
458 | unsigned long arg) | |
38ad2ed0 PF |
459 | { |
460 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
461 | } | |
462 | ||
37bdfb07 | 463 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 464 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
465 | { |
466 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
467 | } | |
468 | ||
62322d25 | 469 | static const struct file_operations tty_fops = { |
1da177e4 LT |
470 | .llseek = no_llseek, |
471 | .read = tty_read, | |
472 | .write = tty_write, | |
473 | .poll = tty_poll, | |
04f378b1 | 474 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 475 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
476 | .open = tty_open, |
477 | .release = tty_release, | |
478 | .fasync = tty_fasync, | |
479 | }; | |
480 | ||
62322d25 | 481 | static const struct file_operations console_fops = { |
1da177e4 LT |
482 | .llseek = no_llseek, |
483 | .read = tty_read, | |
484 | .write = redirected_tty_write, | |
485 | .poll = tty_poll, | |
04f378b1 | 486 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 487 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
488 | .open = tty_open, |
489 | .release = tty_release, | |
490 | .fasync = tty_fasync, | |
491 | }; | |
492 | ||
62322d25 | 493 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
494 | .llseek = no_llseek, |
495 | .read = hung_up_tty_read, | |
496 | .write = hung_up_tty_write, | |
497 | .poll = hung_up_tty_poll, | |
04f378b1 | 498 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 499 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
500 | .release = tty_release, |
501 | }; | |
502 | ||
503 | static DEFINE_SPINLOCK(redirect_lock); | |
504 | static struct file *redirect; | |
505 | ||
11d9befd PH |
506 | |
507 | void proc_clear_tty(struct task_struct *p) | |
508 | { | |
509 | unsigned long flags; | |
510 | struct tty_struct *tty; | |
511 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
512 | tty = p->signal->tty; | |
513 | p->signal->tty = NULL; | |
514 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
515 | tty_kref_put(tty); | |
516 | } | |
517 | ||
2c411c11 PH |
518 | /** |
519 | * proc_set_tty - set the controlling terminal | |
520 | * | |
521 | * Only callable by the session leader and only if it does not already have | |
522 | * a controlling terminal. | |
523 | * | |
e218eb32 PH |
524 | * Caller must hold: tty_lock() |
525 | * a readlock on tasklist_lock | |
2c411c11 PH |
526 | * sighand lock |
527 | */ | |
bce65f18 | 528 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 529 | { |
ae28fa72 PH |
530 | unsigned long flags; |
531 | ||
ae28fa72 | 532 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
533 | /* |
534 | * The session and fg pgrp references will be non-NULL if | |
535 | * tiocsctty() is stealing the controlling tty | |
536 | */ | |
ae28fa72 PH |
537 | put_pid(tty->session); |
538 | put_pid(tty->pgrp); | |
539 | tty->pgrp = get_pid(task_pgrp(current)); | |
540 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
541 | tty->session = get_pid(task_session(current)); | |
542 | if (current->signal->tty) { | |
e2dfa3d3 PH |
543 | tty_debug(tty, "current tty %s not NULL!!\n", |
544 | current->signal->tty->name); | |
ae28fa72 | 545 | tty_kref_put(current->signal->tty); |
11d9befd | 546 | } |
bce65f18 PH |
547 | put_pid(current->signal->tty_old_pgrp); |
548 | current->signal->tty = tty_kref_get(tty); | |
549 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
550 | } |
551 | ||
bce65f18 | 552 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 553 | { |
bce65f18 PH |
554 | spin_lock_irq(¤t->sighand->siglock); |
555 | __proc_set_tty(tty); | |
556 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
557 | } |
558 | ||
559 | struct tty_struct *get_current_tty(void) | |
560 | { | |
561 | struct tty_struct *tty; | |
562 | unsigned long flags; | |
563 | ||
564 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
565 | tty = tty_kref_get(current->signal->tty); | |
566 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
567 | return tty; | |
568 | } | |
569 | EXPORT_SYMBOL_GPL(get_current_tty); | |
570 | ||
571 | static void session_clear_tty(struct pid *session) | |
572 | { | |
573 | struct task_struct *p; | |
574 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
575 | proc_clear_tty(p); | |
576 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
577 | } | |
578 | ||
1da177e4 LT |
579 | /** |
580 | * tty_wakeup - request more data | |
581 | * @tty: terminal | |
582 | * | |
583 | * Internal and external helper for wakeups of tty. This function | |
584 | * informs the line discipline if present that the driver is ready | |
585 | * to receive more output data. | |
586 | */ | |
37bdfb07 | 587 | |
1da177e4 LT |
588 | void tty_wakeup(struct tty_struct *tty) |
589 | { | |
590 | struct tty_ldisc *ld; | |
37bdfb07 | 591 | |
1da177e4 LT |
592 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
593 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 594 | if (ld) { |
a352def2 AC |
595 | if (ld->ops->write_wakeup) |
596 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
597 | tty_ldisc_deref(ld); |
598 | } | |
599 | } | |
4b19449d | 600 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
601 | } |
602 | ||
603 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
604 | ||
ea648a47 PH |
605 | /** |
606 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
607 | * @tty controlling tty |
608 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 609 | * |
f91e2590 PH |
610 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
611 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
612 | * |
613 | * Returns the number of processes in the session with this tty | |
614 | * as their controlling terminal. This value is used to drop | |
615 | * tty references for those processes. | |
616 | */ | |
f91e2590 | 617 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
618 | { |
619 | struct task_struct *p; | |
ea648a47 | 620 | int refs = 0; |
f91e2590 | 621 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
622 | |
623 | read_lock(&tasklist_lock); | |
624 | if (tty->session) { | |
625 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
626 | spin_lock_irq(&p->sighand->siglock); | |
627 | if (p->signal->tty == tty) { | |
628 | p->signal->tty = NULL; | |
629 | /* We defer the dereferences outside fo | |
630 | the tasklist lock */ | |
631 | refs++; | |
632 | } | |
633 | if (!p->signal->leader) { | |
634 | spin_unlock_irq(&p->sighand->siglock); | |
635 | continue; | |
636 | } | |
637 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
638 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
639 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 640 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 641 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
642 | if (tty->pgrp) |
643 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 644 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
645 | spin_unlock_irq(&p->sighand->siglock); |
646 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
647 | } | |
648 | read_unlock(&tasklist_lock); | |
649 | ||
f91e2590 PH |
650 | if (tty_pgrp) { |
651 | if (exit_session) | |
652 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
653 | put_pid(tty_pgrp); | |
654 | } | |
655 | ||
ea648a47 PH |
656 | return refs; |
657 | } | |
658 | ||
af9b897e | 659 | /** |
11dbf203 | 660 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 661 | * @work: tty device |
af9b897e | 662 | * |
ef4f527c | 663 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
664 | * synchronous but doesn't hold any locks, so we need to make sure we |
665 | * have the appropriate locks for what we're doing. | |
666 | * | |
667 | * The hangup event clears any pending redirections onto the hung up | |
668 | * device. It ensures future writes will error and it does the needed | |
669 | * line discipline hangup and signal delivery. The tty object itself | |
670 | * remains intact. | |
671 | * | |
672 | * Locking: | |
ec79d605 | 673 | * BTM |
24ec839c PZ |
674 | * redirect lock for undoing redirection |
675 | * file list lock for manipulating list of ttys | |
137084bb | 676 | * tty_ldiscs_lock from called functions |
6a1c0680 | 677 | * termios_rwsem resetting termios data |
24ec839c PZ |
678 | * tasklist_lock to walk task list for hangup event |
679 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 680 | */ |
f91e2590 | 681 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 682 | { |
37bdfb07 | 683 | struct file *cons_filp = NULL; |
1da177e4 | 684 | struct file *filp, *f = NULL; |
d996b62a | 685 | struct tty_file_private *priv; |
1da177e4 | 686 | int closecount = 0, n; |
ea648a47 | 687 | int refs; |
1da177e4 LT |
688 | |
689 | if (!tty) | |
690 | return; | |
691 | ||
1da177e4 LT |
692 | |
693 | spin_lock(&redirect_lock); | |
d996b62a | 694 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
695 | f = redirect; |
696 | redirect = NULL; | |
697 | } | |
698 | spin_unlock(&redirect_lock); | |
37bdfb07 | 699 | |
89c8d91e | 700 | tty_lock(tty); |
11dbf203 | 701 | |
cb50e523 PH |
702 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
703 | tty_unlock(tty); | |
704 | return; | |
705 | } | |
706 | ||
ec79d605 AB |
707 | /* inuse_filps is protected by the single tty lock, |
708 | this really needs to change if we want to flush the | |
709 | workqueue with the lock held */ | |
11dbf203 | 710 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 711 | |
ee2ffa0d | 712 | spin_lock(&tty_files_lock); |
1da177e4 | 713 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
714 | list_for_each_entry(priv, &tty->tty_files, list) { |
715 | filp = priv->file; | |
1da177e4 LT |
716 | if (filp->f_op->write == redirected_tty_write) |
717 | cons_filp = filp; | |
718 | if (filp->f_op->write != tty_write) | |
719 | continue; | |
720 | closecount++; | |
ec79d605 | 721 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
722 | filp->f_op = &hung_up_tty_fops; |
723 | } | |
ee2ffa0d | 724 | spin_unlock(&tty_files_lock); |
37bdfb07 | 725 | |
25fdf243 PH |
726 | refs = tty_signal_session_leader(tty, exit_session); |
727 | /* Account for the p->signal references we killed */ | |
728 | while (refs--) | |
729 | tty_kref_put(tty); | |
730 | ||
c65c9bc3 | 731 | tty_ldisc_hangup(tty); |
37bdfb07 | 732 | |
20cc225b | 733 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 734 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 735 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
736 | put_pid(tty->session); |
737 | put_pid(tty->pgrp); | |
ab521dc0 EB |
738 | tty->session = NULL; |
739 | tty->pgrp = NULL; | |
1da177e4 | 740 | tty->ctrl_status = 0; |
20cc225b | 741 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 742 | |
1da177e4 | 743 | /* |
37bdfb07 AC |
744 | * If one of the devices matches a console pointer, we |
745 | * cannot just call hangup() because that will cause | |
746 | * tty->count and state->count to go out of sync. | |
747 | * So we just call close() the right number of times. | |
1da177e4 LT |
748 | */ |
749 | if (cons_filp) { | |
f34d7a5b | 750 | if (tty->ops->close) |
1da177e4 | 751 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
752 | tty->ops->close(tty, cons_filp); |
753 | } else if (tty->ops->hangup) | |
7c6d340f | 754 | tty->ops->hangup(tty); |
37bdfb07 AC |
755 | /* |
756 | * We don't want to have driver/ldisc interactions beyond | |
757 | * the ones we did here. The driver layer expects no | |
758 | * calls after ->hangup() from the ldisc side. However we | |
759 | * can't yet guarantee all that. | |
760 | */ | |
1da177e4 | 761 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 762 | tty_unlock(tty); |
11dbf203 | 763 | |
1da177e4 LT |
764 | if (f) |
765 | fput(f); | |
766 | } | |
767 | ||
ddcd9fb6 AB |
768 | static void do_tty_hangup(struct work_struct *work) |
769 | { | |
770 | struct tty_struct *tty = | |
771 | container_of(work, struct tty_struct, hangup_work); | |
772 | ||
f91e2590 | 773 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
774 | } |
775 | ||
af9b897e AC |
776 | /** |
777 | * tty_hangup - trigger a hangup event | |
778 | * @tty: tty to hangup | |
779 | * | |
780 | * A carrier loss (virtual or otherwise) has occurred on this like | |
781 | * schedule a hangup sequence to run after this event. | |
782 | */ | |
783 | ||
37bdfb07 | 784 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 785 | { |
d435cefe | 786 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
787 | schedule_work(&tty->hangup_work); |
788 | } | |
789 | ||
790 | EXPORT_SYMBOL(tty_hangup); | |
791 | ||
af9b897e AC |
792 | /** |
793 | * tty_vhangup - process vhangup | |
794 | * @tty: tty to hangup | |
795 | * | |
796 | * The user has asked via system call for the terminal to be hung up. | |
797 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 798 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
799 | */ |
800 | ||
37bdfb07 | 801 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 802 | { |
d435cefe | 803 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 804 | __tty_hangup(tty, 0); |
1da177e4 | 805 | } |
37bdfb07 | 806 | |
1da177e4 LT |
807 | EXPORT_SYMBOL(tty_vhangup); |
808 | ||
11dbf203 | 809 | |
2cb5998b AC |
810 | /** |
811 | * tty_vhangup_self - process vhangup for own ctty | |
812 | * | |
813 | * Perform a vhangup on the current controlling tty | |
814 | */ | |
815 | ||
816 | void tty_vhangup_self(void) | |
817 | { | |
818 | struct tty_struct *tty; | |
819 | ||
2cb5998b AC |
820 | tty = get_current_tty(); |
821 | if (tty) { | |
822 | tty_vhangup(tty); | |
823 | tty_kref_put(tty); | |
824 | } | |
2cb5998b AC |
825 | } |
826 | ||
f91e2590 PH |
827 | /** |
828 | * tty_vhangup_session - hangup session leader exit | |
829 | * @tty: tty to hangup | |
830 | * | |
831 | * The session leader is exiting and hanging up its controlling terminal. | |
832 | * Every process in the foreground process group is signalled SIGHUP. | |
833 | * | |
834 | * We do this synchronously so that when the syscall returns the process | |
835 | * is complete. That guarantee is necessary for security reasons. | |
836 | */ | |
837 | ||
44a459fd | 838 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 839 | { |
d435cefe | 840 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
841 | __tty_hangup(tty, 1); |
842 | } | |
843 | ||
af9b897e AC |
844 | /** |
845 | * tty_hung_up_p - was tty hung up | |
846 | * @filp: file pointer of tty | |
847 | * | |
848 | * Return true if the tty has been subject to a vhangup or a carrier | |
849 | * loss | |
850 | */ | |
851 | ||
37bdfb07 | 852 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
853 | { |
854 | return (filp->f_op == &hung_up_tty_fops); | |
855 | } | |
856 | ||
857 | EXPORT_SYMBOL(tty_hung_up_p); | |
858 | ||
af9b897e AC |
859 | /** |
860 | * disassociate_ctty - disconnect controlling tty | |
861 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 862 | * |
af9b897e AC |
863 | * This function is typically called only by the session leader, when |
864 | * it wants to disassociate itself from its controlling tty. | |
865 | * | |
866 | * It performs the following functions: | |
1da177e4 LT |
867 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
868 | * (2) Clears the tty from being controlling the session | |
869 | * (3) Clears the controlling tty for all processes in the | |
870 | * session group. | |
871 | * | |
af9b897e AC |
872 | * The argument on_exit is set to 1 if called when a process is |
873 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
874 | * | |
24ec839c | 875 | * Locking: |
ec79d605 AB |
876 | * BTM is taken for hysterical raisins, and held when |
877 | * called from no_tty(). | |
24ec839c PZ |
878 | * tty_mutex is taken to protect tty |
879 | * ->siglock is taken to protect ->signal/->sighand | |
880 | * tasklist_lock is taken to walk process list for sessions | |
881 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 882 | */ |
af9b897e | 883 | |
1da177e4 LT |
884 | void disassociate_ctty(int on_exit) |
885 | { | |
886 | struct tty_struct *tty; | |
1da177e4 | 887 | |
5ec93d11 AC |
888 | if (!current->signal->leader) |
889 | return; | |
1da177e4 | 890 | |
24ec839c | 891 | tty = get_current_tty(); |
1da177e4 | 892 | if (tty) { |
f91e2590 PH |
893 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
894 | tty_vhangup_session(tty); | |
895 | } else { | |
896 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
897 | if (tty_pgrp) { | |
898 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
899 | if (!on_exit) |
900 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
901 | put_pid(tty_pgrp); |
902 | } | |
1411dc4a | 903 | } |
f91e2590 PH |
904 | tty_kref_put(tty); |
905 | ||
680a9671 | 906 | } else if (on_exit) { |
ab521dc0 | 907 | struct pid *old_pgrp; |
680a9671 EB |
908 | spin_lock_irq(¤t->sighand->siglock); |
909 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 910 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 911 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 912 | if (old_pgrp) { |
ab521dc0 EB |
913 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
914 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
915 | put_pid(old_pgrp); | |
1da177e4 | 916 | } |
1da177e4 LT |
917 | return; |
918 | } | |
1da177e4 | 919 | |
24ec839c | 920 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 921 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 922 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 923 | |
c70dbb1e | 924 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 925 | if (tty) { |
47f86834 AC |
926 | unsigned long flags; |
927 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
928 | put_pid(tty->session); |
929 | put_pid(tty->pgrp); | |
930 | tty->session = NULL; | |
931 | tty->pgrp = NULL; | |
47f86834 | 932 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 933 | tty_kref_put(tty); |
accff793 PH |
934 | } else |
935 | tty_debug_hangup(tty, "no current tty\n"); | |
1da177e4 | 936 | |
c70dbb1e | 937 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
938 | /* Now clear signal->tty under the lock */ |
939 | read_lock(&tasklist_lock); | |
ab521dc0 | 940 | session_clear_tty(task_session(current)); |
1da177e4 | 941 | read_unlock(&tasklist_lock); |
1da177e4 LT |
942 | } |
943 | ||
98a27ba4 EB |
944 | /** |
945 | * | |
946 | * no_tty - Ensure the current process does not have a controlling tty | |
947 | */ | |
948 | void no_tty(void) | |
949 | { | |
3af502b9 AC |
950 | /* FIXME: Review locking here. The tty_lock never covered any race |
951 | between a new association and proc_clear_tty but possible we need | |
952 | to protect against this anyway */ | |
98a27ba4 | 953 | struct task_struct *tsk = current; |
5ec93d11 | 954 | disassociate_ctty(0); |
98a27ba4 EB |
955 | proc_clear_tty(tsk); |
956 | } | |
957 | ||
af9b897e AC |
958 | |
959 | /** | |
beb7dd86 | 960 | * stop_tty - propagate flow control |
af9b897e AC |
961 | * @tty: tty to stop |
962 | * | |
01adc807 | 963 | * Perform flow control to the driver. May be called |
af9b897e AC |
964 | * on an already stopped device and will not re-call the driver |
965 | * method. | |
966 | * | |
967 | * This functionality is used by both the line disciplines for | |
968 | * halting incoming flow and by the driver. It may therefore be | |
969 | * called from any context, may be under the tty atomic_write_lock | |
970 | * but not always. | |
971 | * | |
972 | * Locking: | |
f9e053dc | 973 | * flow_lock |
af9b897e AC |
974 | */ |
975 | ||
f9e053dc | 976 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 977 | { |
f9e053dc | 978 | if (tty->stopped) |
1da177e4 LT |
979 | return; |
980 | tty->stopped = 1; | |
f34d7a5b | 981 | if (tty->ops->stop) |
c961bfb1 | 982 | tty->ops->stop(tty); |
1da177e4 LT |
983 | } |
984 | ||
f9e053dc PH |
985 | void stop_tty(struct tty_struct *tty) |
986 | { | |
987 | unsigned long flags; | |
988 | ||
989 | spin_lock_irqsave(&tty->flow_lock, flags); | |
990 | __stop_tty(tty); | |
991 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
992 | } | |
1da177e4 LT |
993 | EXPORT_SYMBOL(stop_tty); |
994 | ||
af9b897e | 995 | /** |
beb7dd86 | 996 | * start_tty - propagate flow control |
af9b897e AC |
997 | * @tty: tty to start |
998 | * | |
01adc807 PH |
999 | * Start a tty that has been stopped if at all possible. If this |
1000 | * tty was previous stopped and is now being started, the driver | |
1001 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1002 | * |
1003 | * Locking: | |
f9e053dc | 1004 | * flow_lock |
af9b897e AC |
1005 | */ |
1006 | ||
f9e053dc | 1007 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1008 | { |
f9e053dc | 1009 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1010 | return; |
1011 | tty->stopped = 0; | |
f34d7a5b | 1012 | if (tty->ops->start) |
c961bfb1 | 1013 | tty->ops->start(tty); |
1da177e4 | 1014 | tty_wakeup(tty); |
1da177e4 LT |
1015 | } |
1016 | ||
f9e053dc PH |
1017 | void start_tty(struct tty_struct *tty) |
1018 | { | |
1019 | unsigned long flags; | |
1020 | ||
1021 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1022 | __start_tty(tty); | |
1023 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1024 | } | |
1da177e4 LT |
1025 | EXPORT_SYMBOL(start_tty); |
1026 | ||
37b7f3c7 JS |
1027 | static void tty_update_time(struct timespec *time) |
1028 | { | |
f0bf0bd0 | 1029 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
1030 | |
1031 | /* | |
1032 | * We only care if the two values differ in anything other than the | |
1033 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
1034 | * the time of the tty device, otherwise it could be construded as a | |
1035 | * security leak to let userspace know the exact timing of the tty. | |
1036 | */ | |
1037 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
1038 | time->tv_sec = sec; |
1039 | } | |
1040 | ||
af9b897e AC |
1041 | /** |
1042 | * tty_read - read method for tty device files | |
1043 | * @file: pointer to tty file | |
1044 | * @buf: user buffer | |
1045 | * @count: size of user buffer | |
1046 | * @ppos: unused | |
1047 | * | |
1048 | * Perform the read system call function on this terminal device. Checks | |
1049 | * for hung up devices before calling the line discipline method. | |
1050 | * | |
1051 | * Locking: | |
47f86834 AC |
1052 | * Locks the line discipline internally while needed. Multiple |
1053 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1054 | */ |
1055 | ||
37bdfb07 | 1056 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1057 | loff_t *ppos) |
1058 | { | |
1059 | int i; | |
37b7f3c7 | 1060 | struct inode *inode = file_inode(file); |
d996b62a | 1061 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1062 | struct tty_ldisc *ld; |
1063 | ||
37b7f3c7 | 1064 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1065 | return -EIO; |
1066 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1067 | return -EIO; | |
1068 | ||
1069 | /* We want to wait for the line discipline to sort out in this | |
1070 | situation */ | |
1071 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 1072 | if (ld->ops->read) |
c961bfb1 | 1073 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1074 | else |
1075 | i = -EIO; | |
1076 | tty_ldisc_deref(ld); | |
b0de59b5 | 1077 | |
37b7f3c7 JS |
1078 | if (i > 0) |
1079 | tty_update_time(&inode->i_atime); | |
1080 | ||
1da177e4 LT |
1081 | return i; |
1082 | } | |
1083 | ||
136d5258 | 1084 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1085 | { |
1086 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1087 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1088 | } |
1089 | ||
136d5258 | 1090 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1091 | { |
1092 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1093 | if (ndelay) | |
1094 | return -EAGAIN; | |
1095 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1096 | return -ERESTARTSYS; | |
1097 | } | |
1098 | return 0; | |
1099 | } | |
1100 | ||
1da177e4 LT |
1101 | /* |
1102 | * Split writes up in sane blocksizes to avoid | |
1103 | * denial-of-service type attacks | |
1104 | */ | |
1105 | static inline ssize_t do_tty_write( | |
1106 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1107 | struct tty_struct *tty, | |
1108 | struct file *file, | |
1109 | const char __user *buf, | |
1110 | size_t count) | |
1111 | { | |
9c1729db | 1112 | ssize_t ret, written = 0; |
1da177e4 | 1113 | unsigned int chunk; |
37bdfb07 | 1114 | |
9c1729db AC |
1115 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1116 | if (ret < 0) | |
1117 | return ret; | |
1da177e4 LT |
1118 | |
1119 | /* | |
1120 | * We chunk up writes into a temporary buffer. This | |
1121 | * simplifies low-level drivers immensely, since they | |
1122 | * don't have locking issues and user mode accesses. | |
1123 | * | |
1124 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1125 | * big chunk-size.. | |
1126 | * | |
1127 | * The default chunk-size is 2kB, because the NTTY | |
1128 | * layer has problems with bigger chunks. It will | |
1129 | * claim to be able to handle more characters than | |
1130 | * it actually does. | |
af9b897e AC |
1131 | * |
1132 | * FIXME: This can probably go away now except that 64K chunks | |
1133 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1134 | */ |
1135 | chunk = 2048; | |
1136 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1137 | chunk = 65536; | |
1138 | if (count < chunk) | |
1139 | chunk = count; | |
1140 | ||
70522e12 | 1141 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1142 | if (tty->write_cnt < chunk) { |
402fda92 | 1143 | unsigned char *buf_chunk; |
1da177e4 LT |
1144 | |
1145 | if (chunk < 1024) | |
1146 | chunk = 1024; | |
1147 | ||
402fda92 JW |
1148 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1149 | if (!buf_chunk) { | |
9c1729db AC |
1150 | ret = -ENOMEM; |
1151 | goto out; | |
1da177e4 LT |
1152 | } |
1153 | kfree(tty->write_buf); | |
1154 | tty->write_cnt = chunk; | |
402fda92 | 1155 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1156 | } |
1157 | ||
1158 | /* Do the write .. */ | |
1159 | for (;;) { | |
1160 | size_t size = count; | |
1161 | if (size > chunk) | |
1162 | size = chunk; | |
1163 | ret = -EFAULT; | |
1164 | if (copy_from_user(tty->write_buf, buf, size)) | |
1165 | break; | |
1da177e4 | 1166 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1167 | if (ret <= 0) |
1168 | break; | |
1169 | written += ret; | |
1170 | buf += ret; | |
1171 | count -= ret; | |
1172 | if (!count) | |
1173 | break; | |
1174 | ret = -ERESTARTSYS; | |
1175 | if (signal_pending(current)) | |
1176 | break; | |
1177 | cond_resched(); | |
1178 | } | |
37b7f3c7 JS |
1179 | if (written) { |
1180 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1181 | ret = written; |
37b7f3c7 | 1182 | } |
9c1729db AC |
1183 | out: |
1184 | tty_write_unlock(tty); | |
1da177e4 LT |
1185 | return ret; |
1186 | } | |
1187 | ||
95f9bfc6 AC |
1188 | /** |
1189 | * tty_write_message - write a message to a certain tty, not just the console. | |
1190 | * @tty: the destination tty_struct | |
1191 | * @msg: the message to write | |
1192 | * | |
1193 | * This is used for messages that need to be redirected to a specific tty. | |
1194 | * We don't put it into the syslog queue right now maybe in the future if | |
1195 | * really needed. | |
1196 | * | |
ec79d605 | 1197 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1198 | */ |
1199 | ||
1200 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1201 | { | |
95f9bfc6 AC |
1202 | if (tty) { |
1203 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1204 | tty_lock(tty); |
4b41b953 | 1205 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1206 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1207 | tty_unlock(tty); |
95f9bfc6 AC |
1208 | tty_write_unlock(tty); |
1209 | } | |
95f9bfc6 AC |
1210 | return; |
1211 | } | |
1212 | ||
1da177e4 | 1213 | |
af9b897e AC |
1214 | /** |
1215 | * tty_write - write method for tty device file | |
1216 | * @file: tty file pointer | |
1217 | * @buf: user data to write | |
1218 | * @count: bytes to write | |
1219 | * @ppos: unused | |
1220 | * | |
1221 | * Write data to a tty device via the line discipline. | |
1222 | * | |
1223 | * Locking: | |
1224 | * Locks the line discipline as required | |
1225 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1226 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1227 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1228 | */ |
1229 | ||
37bdfb07 AC |
1230 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1231 | size_t count, loff_t *ppos) | |
1da177e4 | 1232 | { |
d996b62a NP |
1233 | struct tty_struct *tty = file_tty(file); |
1234 | struct tty_ldisc *ld; | |
1da177e4 | 1235 | ssize_t ret; |
37bdfb07 | 1236 | |
6131ffaa | 1237 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1238 | return -EIO; |
f34d7a5b | 1239 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1240 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1241 | return -EIO; | |
f34d7a5b AC |
1242 | /* Short term debug to catch buggy drivers */ |
1243 | if (tty->ops->write_room == NULL) | |
339f36ba | 1244 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1245 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1246 | if (!ld->ops->write) |
1da177e4 LT |
1247 | ret = -EIO; |
1248 | else | |
a352def2 | 1249 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1250 | tty_ldisc_deref(ld); |
1251 | return ret; | |
1252 | } | |
1253 | ||
37bdfb07 AC |
1254 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1255 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1256 | { |
1257 | struct file *p = NULL; | |
1258 | ||
1259 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1260 | if (redirect) |
1261 | p = get_file(redirect); | |
1da177e4 LT |
1262 | spin_unlock(&redirect_lock); |
1263 | ||
1264 | if (p) { | |
1265 | ssize_t res; | |
1266 | res = vfs_write(p, buf, count, &p->f_pos); | |
1267 | fput(p); | |
1268 | return res; | |
1269 | } | |
1da177e4 LT |
1270 | return tty_write(file, buf, count, ppos); |
1271 | } | |
1272 | ||
136d5258 PH |
1273 | /** |
1274 | * tty_send_xchar - send priority character | |
1275 | * | |
1276 | * Send a high priority character to the tty even if stopped | |
1277 | * | |
1278 | * Locking: none for xchar method, write ordering for write method. | |
1279 | */ | |
1280 | ||
1281 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1282 | { | |
1283 | int was_stopped = tty->stopped; | |
1284 | ||
1285 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1286 | down_read(&tty->termios_rwsem); |
136d5258 | 1287 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1288 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1289 | return 0; |
1290 | } | |
1291 | ||
1292 | if (tty_write_lock(tty, 0) < 0) | |
1293 | return -ERESTARTSYS; | |
1294 | ||
ee0c1a65 | 1295 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1296 | if (was_stopped) |
1297 | start_tty(tty); | |
1298 | tty->ops->write(tty, &ch, 1); | |
1299 | if (was_stopped) | |
1300 | stop_tty(tty); | |
ee0c1a65 | 1301 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1302 | tty_write_unlock(tty); |
1303 | return 0; | |
1304 | } | |
1305 | ||
1da177e4 LT |
1306 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1307 | ||
af9b897e AC |
1308 | /** |
1309 | * pty_line_name - generate name for a pty | |
1310 | * @driver: the tty driver in use | |
1311 | * @index: the minor number | |
1312 | * @p: output buffer of at least 6 bytes | |
1313 | * | |
1314 | * Generate a name from a driver reference and write it to the output | |
1315 | * buffer. | |
1316 | * | |
1317 | * Locking: None | |
1318 | */ | |
1319 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1320 | { |
1321 | int i = index + driver->name_base; | |
1322 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1323 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1324 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1325 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1326 | } |
1327 | ||
af9b897e | 1328 | /** |
8b0a88d5 | 1329 | * tty_line_name - generate name for a tty |
af9b897e AC |
1330 | * @driver: the tty driver in use |
1331 | * @index: the minor number | |
1332 | * @p: output buffer of at least 7 bytes | |
1333 | * | |
1334 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1335 | * buffer. |
af9b897e AC |
1336 | * |
1337 | * Locking: None | |
1338 | */ | |
723abd87 | 1339 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1340 | { |
0019b408 | 1341 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1342 | return sprintf(p, "%s", driver->name); |
0019b408 | 1343 | else |
723abd87 HR |
1344 | return sprintf(p, "%s%d", driver->name, |
1345 | index + driver->name_base); | |
1da177e4 LT |
1346 | } |
1347 | ||
99f1fe18 AC |
1348 | /** |
1349 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1350 | * @driver: the driver for the tty | |
1351 | * @idx: the minor number | |
23499705 | 1352 | * |
aa3cb814 PH |
1353 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1354 | * driver lookup() method returns an error. | |
23499705 | 1355 | * |
aa3cb814 | 1356 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1357 | */ |
a47d545f | 1358 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1359 | struct inode *inode, int idx) |
23499705 | 1360 | { |
aa3cb814 PH |
1361 | struct tty_struct *tty; |
1362 | ||
99f1fe18 | 1363 | if (driver->ops->lookup) |
aa3cb814 PH |
1364 | tty = driver->ops->lookup(driver, inode, idx); |
1365 | else | |
1366 | tty = driver->ttys[idx]; | |
23499705 | 1367 | |
aa3cb814 PH |
1368 | if (!IS_ERR(tty)) |
1369 | tty_kref_get(tty); | |
1370 | return tty; | |
23499705 SB |
1371 | } |
1372 | ||
bf970ee4 AC |
1373 | /** |
1374 | * tty_init_termios - helper for termios setup | |
1375 | * @tty: the tty to set up | |
1376 | * | |
1377 | * Initialise the termios structures for this tty. Thus runs under | |
1378 | * the tty_mutex currently so we can be relaxed about ordering. | |
1379 | */ | |
1380 | ||
1381 | int tty_init_termios(struct tty_struct *tty) | |
1382 | { | |
fe6e29fd | 1383 | struct ktermios *tp; |
bf970ee4 AC |
1384 | int idx = tty->index; |
1385 | ||
36b3c070 AC |
1386 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1387 | tty->termios = tty->driver->init_termios; | |
1388 | else { | |
1389 | /* Check for lazy saved data */ | |
1390 | tp = tty->driver->termios[idx]; | |
1391 | if (tp != NULL) | |
1392 | tty->termios = *tp; | |
1393 | else | |
1394 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1395 | } |
bf970ee4 | 1396 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1397 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1398 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
1399 | return 0; |
1400 | } | |
fe1ae7fd | 1401 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1402 | |
66d450e8 JS |
1403 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1404 | { | |
1405 | int ret = tty_init_termios(tty); | |
1406 | if (ret) | |
1407 | return ret; | |
1408 | ||
1409 | tty_driver_kref_get(driver); | |
1410 | tty->count++; | |
1411 | driver->ttys[tty->index] = tty; | |
1412 | return 0; | |
1413 | } | |
1414 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1415 | ||
99f1fe18 | 1416 | /** |
8b0a88d5 AC |
1417 | * tty_driver_install_tty() - install a tty entry in the driver |
1418 | * @driver: the driver for the tty | |
1419 | * @tty: the tty | |
1420 | * | |
1421 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1422 | * will be set by the time this is called. This method is responsible |
1423 | * for ensuring any need additional structures are allocated and | |
1424 | * configured. | |
8b0a88d5 AC |
1425 | * |
1426 | * Locking: tty_mutex for now | |
1427 | */ | |
1428 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1429 | struct tty_struct *tty) | |
1430 | { | |
66d450e8 JS |
1431 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1432 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1433 | } |
1434 | ||
1435 | /** | |
1436 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1437 | * @driver: the driver for the tty | |
1438 | * @idx: the minor number | |
1439 | * | |
1440 | * Remvoe a tty object from the driver tables. The tty->index field | |
1441 | * will be set by the time this is called. | |
1442 | * | |
1443 | * Locking: tty_mutex for now | |
1444 | */ | |
24d406a6 | 1445 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1446 | { |
1447 | if (driver->ops->remove) | |
1448 | driver->ops->remove(driver, tty); | |
1449 | else | |
1450 | driver->ttys[tty->index] = NULL; | |
1451 | } | |
1452 | ||
1453 | /* | |
1454 | * tty_reopen() - fast re-open of an open tty | |
1455 | * @tty - the tty to open | |
23499705 | 1456 | * |
99f1fe18 | 1457 | * Return 0 on success, -errno on error. |
5d93e748 | 1458 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1459 | * |
5d93e748 | 1460 | * Locking: Caller must hold tty_lock |
23499705 | 1461 | */ |
99f1fe18 | 1462 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1463 | { |
1464 | struct tty_driver *driver = tty->driver; | |
1465 | ||
216030ec | 1466 | if (!tty->count) |
23499705 SB |
1467 | return -EIO; |
1468 | ||
1469 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
5d93e748 PH |
1470 | driver->subtype == PTY_TYPE_MASTER) |
1471 | return -EIO; | |
23499705 | 1472 | |
86f2c00f PH |
1473 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1474 | return -EBUSY; | |
1475 | ||
23499705 | 1476 | tty->count++; |
23499705 | 1477 | |
36697529 | 1478 | WARN_ON(!tty->ldisc); |
23499705 SB |
1479 | |
1480 | return 0; | |
1481 | } | |
1482 | ||
af9b897e | 1483 | /** |
d81ed103 | 1484 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1485 | * @driver: tty driver we are opening a device on |
1486 | * @idx: device index | |
15582d36 | 1487 | * @ret_tty: returned tty structure |
af9b897e AC |
1488 | * |
1489 | * Prepare a tty device. This may not be a "new" clean device but | |
1490 | * could also be an active device. The pty drivers require special | |
1491 | * handling because of this. | |
1492 | * | |
1493 | * Locking: | |
1494 | * The function is called under the tty_mutex, which | |
1495 | * protects us from the tty struct or driver itself going away. | |
1496 | * | |
1497 | * On exit the tty device has the line discipline attached and | |
1498 | * a reference count of 1. If a pair was created for pty/tty use | |
1499 | * and the other was a pty master then it too has a reference count of 1. | |
1500 | * | |
1da177e4 | 1501 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1502 | * failed open. The new code protects the open with a mutex, so it's |
1503 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1504 | * relaxed for the (most common) case of reopening a tty. |
1505 | */ | |
af9b897e | 1506 | |
593a27c4 | 1507 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1508 | { |
bf970ee4 | 1509 | struct tty_struct *tty; |
73ec06fc | 1510 | int retval; |
1da177e4 | 1511 | |
1da177e4 LT |
1512 | /* |
1513 | * First time open is complex, especially for PTY devices. | |
1514 | * This code guarantees that either everything succeeds and the | |
1515 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1516 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1517 | * and locked termios may be retained.) |
1518 | */ | |
1519 | ||
73ec06fc AC |
1520 | if (!try_module_get(driver->owner)) |
1521 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1522 | |
2c964a2f | 1523 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1524 | if (!tty) { |
1525 | retval = -ENOMEM; | |
1526 | goto err_module_put; | |
1527 | } | |
1da177e4 | 1528 | |
89c8d91e | 1529 | tty_lock(tty); |
73ec06fc | 1530 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1531 | if (retval < 0) |
a9dccddb | 1532 | goto err_deinit_tty; |
8b0a88d5 | 1533 | |
04831dc1 JS |
1534 | if (!tty->port) |
1535 | tty->port = driver->ports[idx]; | |
1536 | ||
5d4121c0 JS |
1537 | WARN_RATELIMIT(!tty->port, |
1538 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1539 | __func__, tty->driver->name); | |
1540 | ||
967fab69 JS |
1541 | tty->port->itty = tty; |
1542 | ||
37bdfb07 | 1543 | /* |
1da177e4 | 1544 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1545 | * If we fail here just call release_tty to clean up. No need |
1546 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1547 | */ |
bf970ee4 | 1548 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1549 | if (retval) |
d5543503 | 1550 | goto err_release_tty; |
89c8d91e | 1551 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1552 | return tty; |
1da177e4 | 1553 | |
a9dccddb | 1554 | err_deinit_tty: |
89c8d91e | 1555 | tty_unlock(tty); |
a9dccddb | 1556 | deinitialize_tty_struct(tty); |
d5543503 JS |
1557 | free_tty_struct(tty); |
1558 | err_module_put: | |
1da177e4 | 1559 | module_put(driver->owner); |
d5543503 | 1560 | return ERR_PTR(retval); |
1da177e4 | 1561 | |
d5698c28 | 1562 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1563 | err_release_tty: |
89c8d91e | 1564 | tty_unlock(tty); |
339f36ba PH |
1565 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1566 | retval, idx); | |
d5698c28 | 1567 | release_tty(tty, idx); |
73ec06fc | 1568 | return ERR_PTR(retval); |
1da177e4 LT |
1569 | } |
1570 | ||
feebed65 AC |
1571 | void tty_free_termios(struct tty_struct *tty) |
1572 | { | |
1573 | struct ktermios *tp; | |
1574 | int idx = tty->index; | |
36b3c070 AC |
1575 | |
1576 | /* If the port is going to reset then it has no termios to save */ | |
1577 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1578 | return; | |
1579 | ||
1580 | /* Stash the termios data */ | |
1581 | tp = tty->driver->termios[idx]; | |
1582 | if (tp == NULL) { | |
1583 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1584 | if (tp == NULL) |
36b3c070 | 1585 | return; |
4ac5d705 | 1586 | tty->driver->termios[idx] = tp; |
feebed65 | 1587 | } |
36b3c070 | 1588 | *tp = tty->termios; |
feebed65 AC |
1589 | } |
1590 | EXPORT_SYMBOL(tty_free_termios); | |
1591 | ||
a2965b7b | 1592 | /** |
949aa64f PH |
1593 | * tty_flush_works - flush all works of a tty/pty pair |
1594 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1595 | * |
949aa64f | 1596 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1597 | */ |
1598 | static void tty_flush_works(struct tty_struct *tty) | |
1599 | { | |
1600 | flush_work(&tty->SAK_work); | |
1601 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1602 | if (tty->link) { |
1603 | flush_work(&tty->link->SAK_work); | |
1604 | flush_work(&tty->link->hangup_work); | |
1605 | } | |
a2965b7b | 1606 | } |
feebed65 | 1607 | |
af9b897e | 1608 | /** |
d5698c28 | 1609 | * release_one_tty - release tty structure memory |
9c9f4ded | 1610 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1611 | * |
1612 | * Releases memory associated with a tty structure, and clears out the | |
1613 | * driver table slots. This function is called when a device is no longer | |
1614 | * in use. It also gets called when setup of a device fails. | |
1615 | * | |
1616 | * Locking: | |
af9b897e AC |
1617 | * takes the file list lock internally when working on the list |
1618 | * of ttys that the driver keeps. | |
b50989dc AC |
1619 | * |
1620 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1621 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1622 | */ |
b50989dc | 1623 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1624 | { |
b50989dc AC |
1625 | struct tty_struct *tty = |
1626 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1627 | struct tty_driver *driver = tty->driver; |
b216df53 | 1628 | struct module *owner = driver->owner; |
d5698c28 | 1629 | |
f278a2f7 DY |
1630 | if (tty->ops->cleanup) |
1631 | tty->ops->cleanup(tty); | |
1632 | ||
1da177e4 | 1633 | tty->magic = 0; |
7d7b93c1 | 1634 | tty_driver_kref_put(driver); |
b216df53 | 1635 | module_put(owner); |
d5698c28 | 1636 | |
ee2ffa0d | 1637 | spin_lock(&tty_files_lock); |
1da177e4 | 1638 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1639 | spin_unlock(&tty_files_lock); |
d5698c28 | 1640 | |
6da8d866 ON |
1641 | put_pid(tty->pgrp); |
1642 | put_pid(tty->session); | |
1da177e4 LT |
1643 | free_tty_struct(tty); |
1644 | } | |
1645 | ||
b50989dc AC |
1646 | static void queue_release_one_tty(struct kref *kref) |
1647 | { | |
1648 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1649 | |
b50989dc AC |
1650 | /* The hangup queue is now free so we can reuse it rather than |
1651 | waste a chunk of memory for each port */ | |
1652 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1653 | schedule_work(&tty->hangup_work); | |
1654 | } | |
1655 | ||
9c9f4ded AC |
1656 | /** |
1657 | * tty_kref_put - release a tty kref | |
1658 | * @tty: tty device | |
1659 | * | |
1660 | * Release a reference to a tty device and if need be let the kref | |
1661 | * layer destruct the object for us | |
1662 | */ | |
1663 | ||
1664 | void tty_kref_put(struct tty_struct *tty) | |
1665 | { | |
1666 | if (tty) | |
b50989dc | 1667 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1668 | } |
1669 | EXPORT_SYMBOL(tty_kref_put); | |
1670 | ||
d5698c28 CH |
1671 | /** |
1672 | * release_tty - release tty structure memory | |
1673 | * | |
1674 | * Release both @tty and a possible linked partner (think pty pair), | |
1675 | * and decrement the refcount of the backing module. | |
1676 | * | |
1677 | * Locking: | |
d155255a | 1678 | * tty_mutex |
d5698c28 CH |
1679 | * takes the file list lock internally when working on the list |
1680 | * of ttys that the driver keeps. | |
9c9f4ded | 1681 | * |
d5698c28 CH |
1682 | */ |
1683 | static void release_tty(struct tty_struct *tty, int idx) | |
1684 | { | |
9c9f4ded AC |
1685 | /* This should always be true but check for the moment */ |
1686 | WARN_ON(tty->index != idx); | |
d155255a | 1687 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1688 | if (tty->ops->shutdown) |
1689 | tty->ops->shutdown(tty); | |
1690 | tty_free_termios(tty); | |
1691 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1692 | tty->port->itty = NULL; |
64e377dc PH |
1693 | if (tty->link) |
1694 | tty->link->port->itty = NULL; | |
e176058f | 1695 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1696 | |
a211b1af | 1697 | tty_kref_put(tty->link); |
9c9f4ded | 1698 | tty_kref_put(tty); |
d5698c28 CH |
1699 | } |
1700 | ||
955787ca JS |
1701 | /** |
1702 | * tty_release_checks - check a tty before real release | |
1703 | * @tty: tty to check | |
1704 | * @o_tty: link of @tty (if any) | |
1705 | * @idx: index of the tty | |
1706 | * | |
1707 | * Performs some paranoid checking before true release of the @tty. | |
1708 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1709 | */ | |
359b9fb5 | 1710 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1711 | { |
1712 | #ifdef TTY_PARANOIA_CHECK | |
1713 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1714 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1715 | return -1; |
1716 | } | |
1717 | ||
1718 | /* not much to check for devpts */ | |
1719 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1720 | return 0; | |
1721 | ||
1722 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1723 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1724 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1725 | return -1; |
1726 | } | |
955787ca | 1727 | if (tty->driver->other) { |
359b9fb5 PH |
1728 | struct tty_struct *o_tty = tty->link; |
1729 | ||
955787ca | 1730 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1731 | tty_debug(tty, "bad other table[%d] = %p\n", |
1732 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1733 | return -1; |
1734 | } | |
955787ca | 1735 | if (o_tty->link != tty) { |
e2dfa3d3 | 1736 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1737 | return -1; |
1738 | } | |
1739 | } | |
1740 | #endif | |
1741 | return 0; | |
1742 | } | |
1743 | ||
eeb89d91 AC |
1744 | /** |
1745 | * tty_release - vfs callback for close | |
1746 | * @inode: inode of tty | |
1747 | * @filp: file pointer for handle to tty | |
1748 | * | |
1749 | * Called the last time each file handle is closed that references | |
1750 | * this tty. There may however be several such references. | |
1751 | * | |
1752 | * Locking: | |
1753 | * Takes bkl. See tty_release_dev | |
1754 | * | |
1da177e4 LT |
1755 | * Even releasing the tty structures is a tricky business.. We have |
1756 | * to be very careful that the structures are all released at the | |
1757 | * same time, as interrupts might otherwise get the wrong pointers. | |
1758 | * | |
1759 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1760 | * lead to double frees or releasing memory still in use. | |
1761 | */ | |
eeb89d91 AC |
1762 | |
1763 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1764 | { |
d996b62a | 1765 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1766 | struct tty_struct *o_tty = NULL; |
1767 | int do_sleep, final; | |
1da177e4 | 1768 | int idx; |
37b16457 | 1769 | long timeout = 0; |
494c1eac | 1770 | int once = 1; |
37bdfb07 | 1771 | |
9de44bd6 | 1772 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1773 | return 0; |
1da177e4 | 1774 | |
89c8d91e | 1775 | tty_lock(tty); |
9de44bd6 | 1776 | check_tty_count(tty, __func__); |
1da177e4 | 1777 | |
ec79d605 | 1778 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1779 | |
1780 | idx = tty->index; | |
7ffb6da9 PH |
1781 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1782 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1783 | o_tty = tty->link; | |
1da177e4 | 1784 | |
359b9fb5 | 1785 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1786 | tty_unlock(tty); |
eeb89d91 | 1787 | return 0; |
1da177e4 | 1788 | } |
1da177e4 | 1789 | |
d435cefe | 1790 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1791 | |
f34d7a5b AC |
1792 | if (tty->ops->close) |
1793 | tty->ops->close(tty, filp); | |
1da177e4 | 1794 | |
2aff5e2b PH |
1795 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1796 | tty_lock_slave(o_tty); | |
1797 | ||
1da177e4 LT |
1798 | /* |
1799 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1800 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1801 | * wait queues and kick everyone out _before_ actually starting to | |
1802 | * close. This ensures that we won't block while releasing the tty | |
1803 | * structure. | |
1804 | * | |
1805 | * The test for the o_tty closing is necessary, since the master and | |
1806 | * slave sides may close in any order. If the slave side closes out | |
1807 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1808 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1809 | * so we do it now. |
1da177e4 LT |
1810 | */ |
1811 | while (1) { | |
1da177e4 LT |
1812 | do_sleep = 0; |
1813 | ||
324c1650 | 1814 | if (tty->count <= 1) { |
1da177e4 | 1815 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1816 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1817 | do_sleep++; |
1818 | } | |
1819 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1820 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1821 | do_sleep++; |
1822 | } | |
1823 | } | |
7ffb6da9 | 1824 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1825 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1826 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1827 | do_sleep++; |
1828 | } | |
1829 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1830 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1831 | do_sleep++; |
1832 | } | |
1833 | } | |
1834 | if (!do_sleep) | |
1835 | break; | |
1836 | ||
494c1eac PH |
1837 | if (once) { |
1838 | once = 0; | |
339f36ba | 1839 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1840 | } |
37b16457 PH |
1841 | schedule_timeout_killable(timeout); |
1842 | if (timeout < 120 * HZ) | |
1843 | timeout = 2 * timeout + 1; | |
1844 | else | |
1845 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1846 | } |
1da177e4 | 1847 | |
7ffb6da9 | 1848 | if (o_tty) { |
1da177e4 | 1849 | if (--o_tty->count < 0) { |
339f36ba | 1850 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1851 | o_tty->count = 0; |
1852 | } | |
1853 | } | |
1854 | if (--tty->count < 0) { | |
339f36ba | 1855 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1856 | tty->count = 0; |
1857 | } | |
37bdfb07 | 1858 | |
1da177e4 LT |
1859 | /* |
1860 | * We've decremented tty->count, so we need to remove this file | |
1861 | * descriptor off the tty->tty_files list; this serves two | |
1862 | * purposes: | |
1863 | * - check_tty_count sees the correct number of file descriptors | |
1864 | * associated with this tty. | |
1865 | * - do_tty_hangup no longer sees this file descriptor as | |
1866 | * something that needs to be handled for hangups. | |
1867 | */ | |
d996b62a | 1868 | tty_del_file(filp); |
1da177e4 LT |
1869 | |
1870 | /* | |
1871 | * Perform some housekeeping before deciding whether to return. | |
1872 | * | |
1da177e4 LT |
1873 | * If _either_ side is closing, make sure there aren't any |
1874 | * processes that still think tty or o_tty is their controlling | |
1875 | * tty. | |
1876 | */ | |
324c1650 | 1877 | if (!tty->count) { |
1da177e4 | 1878 | read_lock(&tasklist_lock); |
24ec839c | 1879 | session_clear_tty(tty->session); |
7ffb6da9 | 1880 | if (o_tty) |
24ec839c | 1881 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1882 | read_unlock(&tasklist_lock); |
1883 | } | |
1884 | ||
324c1650 | 1885 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1886 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1887 | |
2aff5e2b PH |
1888 | tty_unlock_slave(o_tty); |
1889 | tty_unlock(tty); | |
1890 | ||
04980706 | 1891 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1892 | cannot be re-opened by a racing opener */ |
da965822 | 1893 | |
324c1650 | 1894 | if (!final) |
eeb89d91 | 1895 | return 0; |
37bdfb07 | 1896 | |
accff793 | 1897 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1898 | /* |
01e1abb2 | 1899 | * Ask the line discipline code to release its structures |
1da177e4 | 1900 | */ |
62462aef | 1901 | tty_ldisc_release(tty); |
a2965b7b PH |
1902 | |
1903 | /* Wait for pending work before tty destruction commmences */ | |
1904 | tty_flush_works(tty); | |
a2965b7b | 1905 | |
d435cefe | 1906 | tty_debug_hangup(tty, "freeing structure\n"); |
1da177e4 | 1907 | /* |
d5698c28 | 1908 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1909 | * the slots and preserving the termios structure. The tty_unlock_pair |
1910 | * should be safe as we keep a kref while the tty is locked (so the | |
1911 | * unlock never unlocks a freed tty). | |
1da177e4 | 1912 | */ |
d155255a | 1913 | mutex_lock(&tty_mutex); |
d5698c28 | 1914 | release_tty(tty, idx); |
d155255a | 1915 | mutex_unlock(&tty_mutex); |
1da177e4 | 1916 | |
eeb89d91 | 1917 | return 0; |
1da177e4 LT |
1918 | } |
1919 | ||
b82154ac | 1920 | /** |
52494eeb | 1921 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1922 | * @device: device number |
1923 | * @filp: file pointer to tty | |
52494eeb PH |
1924 | * @return: locked tty of the current task iff @device is /dev/tty |
1925 | * | |
1926 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1927 | * |
1928 | * We cannot return driver and index like for the other nodes because | |
1929 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1930 | */ | |
1931 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1932 | { | |
1933 | struct tty_struct *tty; | |
52494eeb | 1934 | int retval; |
b82154ac JS |
1935 | |
1936 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1937 | return NULL; | |
1938 | ||
1939 | tty = get_current_tty(); | |
1940 | if (!tty) | |
1941 | return ERR_PTR(-ENXIO); | |
1942 | ||
1943 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1944 | /* noctty = 1; */ | |
52494eeb PH |
1945 | tty_lock(tty); |
1946 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1947 | ||
1948 | retval = tty_reopen(tty); | |
1949 | if (retval < 0) { | |
1950 | tty_unlock(tty); | |
1951 | tty = ERR_PTR(retval); | |
1952 | } | |
b82154ac JS |
1953 | return tty; |
1954 | } | |
1955 | ||
5b5e7040 JS |
1956 | /** |
1957 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1958 | * @device: device number | |
1959 | * @filp: file pointer to tty | |
1960 | * @noctty: set if the device should not become a controlling tty | |
1961 | * @index: index for the device in the @return driver | |
1962 | * @return: driver for this inode (with increased refcount) | |
1963 | * | |
1964 | * If @return is not erroneous, the caller is responsible to decrement the | |
1965 | * refcount by tty_driver_kref_put. | |
1966 | * | |
1967 | * Locking: tty_mutex protects get_tty_driver | |
1968 | */ | |
1969 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1970 | int *noctty, int *index) | |
1971 | { | |
1972 | struct tty_driver *driver; | |
1973 | ||
2cd0050c | 1974 | switch (device) { |
5b5e7040 | 1975 | #ifdef CONFIG_VT |
2cd0050c | 1976 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1977 | extern struct tty_driver *console_driver; |
1978 | driver = tty_driver_kref_get(console_driver); | |
1979 | *index = fg_console; | |
1980 | *noctty = 1; | |
2cd0050c | 1981 | break; |
5b5e7040 JS |
1982 | } |
1983 | #endif | |
2cd0050c | 1984 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1985 | struct tty_driver *console_driver = console_device(index); |
1986 | if (console_driver) { | |
1987 | driver = tty_driver_kref_get(console_driver); | |
1988 | if (driver) { | |
1989 | /* Don't let /dev/console block */ | |
1990 | filp->f_flags |= O_NONBLOCK; | |
1991 | *noctty = 1; | |
2cd0050c | 1992 | break; |
5b5e7040 JS |
1993 | } |
1994 | } | |
1995 | return ERR_PTR(-ENODEV); | |
1996 | } | |
2cd0050c JS |
1997 | default: |
1998 | driver = get_tty_driver(device, index); | |
1999 | if (!driver) | |
2000 | return ERR_PTR(-ENODEV); | |
2001 | break; | |
2002 | } | |
5b5e7040 JS |
2003 | return driver; |
2004 | } | |
2005 | ||
af9b897e | 2006 | /** |
eeb89d91 | 2007 | * tty_open - open a tty device |
af9b897e AC |
2008 | * @inode: inode of device file |
2009 | * @filp: file pointer to tty | |
1da177e4 | 2010 | * |
af9b897e AC |
2011 | * tty_open and tty_release keep up the tty count that contains the |
2012 | * number of opens done on a tty. We cannot use the inode-count, as | |
2013 | * different inodes might point to the same tty. | |
1da177e4 | 2014 | * |
af9b897e AC |
2015 | * Open-counting is needed for pty masters, as well as for keeping |
2016 | * track of serial lines: DTR is dropped when the last close happens. | |
2017 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2018 | * | |
2019 | * The termios state of a pty is reset on first open so that | |
2020 | * settings don't persist across reuse. | |
2021 | * | |
5b5e7040 | 2022 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2023 | * tty->count should protect the rest. |
2024 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2025 | * |
2026 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2027 | * tty_mutex | |
1da177e4 | 2028 | */ |
af9b897e | 2029 | |
eeb89d91 | 2030 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2031 | { |
b82154ac | 2032 | struct tty_struct *tty; |
1da177e4 | 2033 | int noctty, retval; |
b82154ac | 2034 | struct tty_driver *driver = NULL; |
1da177e4 LT |
2035 | int index; |
2036 | dev_t device = inode->i_rdev; | |
846c151a | 2037 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2038 | |
2039 | nonseekable_open(inode, filp); | |
37bdfb07 | 2040 | |
1da177e4 | 2041 | retry_open: |
fa90e1c9 JS |
2042 | retval = tty_alloc_file(filp); |
2043 | if (retval) | |
2044 | return -ENOMEM; | |
2045 | ||
1da177e4 LT |
2046 | noctty = filp->f_flags & O_NOCTTY; |
2047 | index = -1; | |
2048 | retval = 0; | |
37bdfb07 | 2049 | |
b82154ac | 2050 | tty = tty_open_current_tty(device, filp); |
52494eeb PH |
2051 | if (!tty) { |
2052 | mutex_lock(&tty_mutex); | |
5b5e7040 JS |
2053 | driver = tty_lookup_driver(device, filp, &noctty, &index); |
2054 | if (IS_ERR(driver)) { | |
ba5db448 JS |
2055 | retval = PTR_ERR(driver); |
2056 | goto err_unlock; | |
1da177e4 | 2057 | } |
1da177e4 | 2058 | |
4a2b5fdd | 2059 | /* check whether we're reopening an existing tty */ |
15f1a633 | 2060 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 2061 | if (IS_ERR(tty)) { |
ba5db448 JS |
2062 | retval = PTR_ERR(tty); |
2063 | goto err_unlock; | |
808ffa3d | 2064 | } |
4a2b5fdd | 2065 | |
52494eeb | 2066 | if (tty) { |
aa3cb814 | 2067 | mutex_unlock(&tty_mutex); |
52494eeb | 2068 | tty_lock(tty); |
aa3cb814 PH |
2069 | /* safe to drop the kref from tty_driver_lookup_tty() */ |
2070 | tty_kref_put(tty); | |
52494eeb PH |
2071 | retval = tty_reopen(tty); |
2072 | if (retval < 0) { | |
2073 | tty_unlock(tty); | |
2074 | tty = ERR_PTR(retval); | |
2075 | } | |
aa3cb814 | 2076 | } else { /* Returns with the tty_lock held for now */ |
52494eeb | 2077 | tty = tty_init_dev(driver, index); |
aa3cb814 PH |
2078 | mutex_unlock(&tty_mutex); |
2079 | } | |
4a2b5fdd | 2080 | |
b82154ac | 2081 | tty_driver_kref_put(driver); |
52494eeb PH |
2082 | } |
2083 | ||
eeb89d91 | 2084 | if (IS_ERR(tty)) { |
ba5db448 JS |
2085 | retval = PTR_ERR(tty); |
2086 | goto err_file; | |
eeb89d91 | 2087 | } |
1da177e4 | 2088 | |
fa90e1c9 | 2089 | tty_add_file(tty, filp); |
d996b62a | 2090 | |
9de44bd6 | 2091 | check_tty_count(tty, __func__); |
1da177e4 LT |
2092 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2093 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2094 | noctty = 1; | |
accff793 | 2095 | |
d435cefe | 2096 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2097 | |
909bc774 HRK |
2098 | if (tty->ops->open) |
2099 | retval = tty->ops->open(tty, filp); | |
2100 | else | |
2101 | retval = -ENODEV; | |
1da177e4 LT |
2102 | filp->f_flags = saved_flags; |
2103 | ||
1da177e4 | 2104 | if (retval) { |
d435cefe | 2105 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2106 | |
89c8d91e | 2107 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2108 | tty_release(inode, filp); |
64ba3dc3 | 2109 | if (retval != -ERESTARTSYS) |
1da177e4 | 2110 | return retval; |
64ba3dc3 AB |
2111 | |
2112 | if (signal_pending(current)) | |
1da177e4 | 2113 | return retval; |
64ba3dc3 | 2114 | |
1da177e4 LT |
2115 | schedule(); |
2116 | /* | |
2117 | * Need to reset f_op in case a hangup happened. | |
2118 | */ | |
1256937f | 2119 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2120 | filp->f_op = &tty_fops; |
2121 | goto retry_open; | |
2122 | } | |
d4855e1f | 2123 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2124 | |
24ec839c | 2125 | |
2c411c11 | 2126 | read_lock(&tasklist_lock); |
24ec839c | 2127 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2128 | if (!noctty && |
2129 | current->signal->leader && | |
2130 | !current->signal->tty && | |
0c556271 JH |
2131 | tty->session == NULL) { |
2132 | /* | |
2133 | * Don't let a process that only has write access to the tty | |
2134 | * obtain the privileges associated with having a tty as | |
2135 | * controlling terminal (being able to reopen it with full | |
2136 | * access through /dev/tty, being able to perform pushback). | |
2137 | * Many distributions set the group of all ttys to "tty" and | |
2138 | * grant write-only access to all terminals for setgid tty | |
2139 | * binaries, which should not imply full privileges on all ttys. | |
2140 | * | |
2141 | * This could theoretically break old code that performs open() | |
2142 | * on a write-only file descriptor. In that case, it might be | |
2143 | * necessary to also permit this if | |
2144 | * inode_permission(inode, MAY_READ) == 0. | |
2145 | */ | |
2146 | if (filp->f_mode & FMODE_READ) | |
2147 | __proc_set_tty(tty); | |
2148 | } | |
24ec839c | 2149 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2150 | read_unlock(&tasklist_lock); |
89c8d91e | 2151 | tty_unlock(tty); |
1da177e4 | 2152 | return 0; |
ba5db448 | 2153 | err_unlock: |
ba5db448 JS |
2154 | mutex_unlock(&tty_mutex); |
2155 | /* after locks to avoid deadlock */ | |
2156 | if (!IS_ERR_OR_NULL(driver)) | |
2157 | tty_driver_kref_put(driver); | |
2158 | err_file: | |
2159 | tty_free_file(filp); | |
2160 | return retval; | |
1da177e4 LT |
2161 | } |
2162 | ||
39d95b9d JC |
2163 | |
2164 | ||
af9b897e AC |
2165 | /** |
2166 | * tty_poll - check tty status | |
2167 | * @filp: file being polled | |
2168 | * @wait: poll wait structures to update | |
2169 | * | |
2170 | * Call the line discipline polling method to obtain the poll | |
2171 | * status of the device. | |
2172 | * | |
2173 | * Locking: locks called line discipline but ldisc poll method | |
2174 | * may be re-entered freely by other callers. | |
2175 | */ | |
2176 | ||
37bdfb07 | 2177 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2178 | { |
d996b62a | 2179 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2180 | struct tty_ldisc *ld; |
2181 | int ret = 0; | |
2182 | ||
6131ffaa | 2183 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2184 | return 0; |
37bdfb07 | 2185 | |
1da177e4 | 2186 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2187 | if (ld->ops->poll) |
c961bfb1 | 2188 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2189 | tty_ldisc_deref(ld); |
2190 | return ret; | |
2191 | } | |
2192 | ||
ec79d605 | 2193 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2194 | { |
d996b62a | 2195 | struct tty_struct *tty = file_tty(filp); |
f6c8dbe6 | 2196 | struct tty_ldisc *ldisc; |
47f86834 | 2197 | unsigned long flags; |
5d1e3230 | 2198 | int retval = 0; |
1da177e4 | 2199 | |
6131ffaa | 2200 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2201 | goto out; |
37bdfb07 | 2202 | |
1da177e4 LT |
2203 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2204 | if (retval <= 0) | |
5d1e3230 | 2205 | goto out; |
1da177e4 | 2206 | |
f6c8dbe6 PH |
2207 | ldisc = tty_ldisc_ref(tty); |
2208 | if (ldisc) { | |
2209 | if (ldisc->ops->fasync) | |
2210 | ldisc->ops->fasync(tty, on); | |
2211 | tty_ldisc_deref(ldisc); | |
2212 | } | |
2213 | ||
1da177e4 | 2214 | if (on) { |
ab521dc0 EB |
2215 | enum pid_type type; |
2216 | struct pid *pid; | |
f6c8dbe6 | 2217 | |
47f86834 | 2218 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2219 | if (tty->pgrp) { |
2220 | pid = tty->pgrp; | |
2221 | type = PIDTYPE_PGID; | |
2222 | } else { | |
2223 | pid = task_pid(current); | |
2224 | type = PIDTYPE_PID; | |
2225 | } | |
80e1e823 | 2226 | get_pid(pid); |
70362511 | 2227 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2228 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2229 | put_pid(pid); |
e0b93edd | 2230 | retval = 0; |
1da177e4 | 2231 | } |
5d1e3230 | 2232 | out: |
ec79d605 AB |
2233 | return retval; |
2234 | } | |
2235 | ||
2236 | static int tty_fasync(int fd, struct file *filp, int on) | |
2237 | { | |
89c8d91e | 2238 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2239 | int retval; |
89c8d91e AC |
2240 | |
2241 | tty_lock(tty); | |
ec79d605 | 2242 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2243 | tty_unlock(tty); |
2244 | ||
5d1e3230 | 2245 | return retval; |
1da177e4 LT |
2246 | } |
2247 | ||
af9b897e AC |
2248 | /** |
2249 | * tiocsti - fake input character | |
2250 | * @tty: tty to fake input into | |
2251 | * @p: pointer to character | |
2252 | * | |
3a4fa0a2 | 2253 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2254 | * input management. |
2255 | * | |
2256 | * FIXME: does not honour flow control ?? | |
2257 | * | |
2258 | * Locking: | |
137084bb | 2259 | * Called functions take tty_ldiscs_lock |
af9b897e | 2260 | * current->signal->tty check is safe without locks |
28298232 AC |
2261 | * |
2262 | * FIXME: may race normal receive processing | |
af9b897e AC |
2263 | */ |
2264 | ||
1da177e4 LT |
2265 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2266 | { | |
2267 | char ch, mbz = 0; | |
2268 | struct tty_ldisc *ld; | |
37bdfb07 | 2269 | |
1da177e4 LT |
2270 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2271 | return -EPERM; | |
2272 | if (get_user(ch, p)) | |
2273 | return -EFAULT; | |
1e641743 | 2274 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2275 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2276 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2277 | tty_ldisc_deref(ld); |
2278 | return 0; | |
2279 | } | |
2280 | ||
af9b897e AC |
2281 | /** |
2282 | * tiocgwinsz - implement window query ioctl | |
2283 | * @tty; tty | |
2284 | * @arg: user buffer for result | |
2285 | * | |
808a0d38 | 2286 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2287 | * |
dee4a0be | 2288 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2289 | * is consistent. |
af9b897e AC |
2290 | */ |
2291 | ||
37bdfb07 | 2292 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2293 | { |
808a0d38 AC |
2294 | int err; |
2295 | ||
dee4a0be | 2296 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2297 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2298 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2299 | |
2300 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2301 | } |
2302 | ||
af9b897e | 2303 | /** |
8c9a9dd0 AC |
2304 | * tty_do_resize - resize event |
2305 | * @tty: tty being resized | |
8c9a9dd0 AC |
2306 | * @rows: rows (character) |
2307 | * @cols: cols (character) | |
2308 | * | |
3ad2f3fb | 2309 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2310 | * peform a terminal resize correctly |
af9b897e AC |
2311 | */ |
2312 | ||
fc6f6238 | 2313 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2314 | { |
fc6f6238 | 2315 | struct pid *pgrp; |
1da177e4 | 2316 | |
fc6f6238 | 2317 | /* Lock the tty */ |
dee4a0be | 2318 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2319 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2320 | goto done; |
47f86834 | 2321 | |
5b239542 PH |
2322 | /* Signal the foreground process group */ |
2323 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2324 | if (pgrp) |
2325 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2326 | put_pid(pgrp); |
47f86834 | 2327 | |
8c9a9dd0 | 2328 | tty->winsize = *ws; |
ca9bda00 | 2329 | done: |
dee4a0be | 2330 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2331 | return 0; |
2332 | } | |
4d334fd1 | 2333 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2334 | |
8c9a9dd0 AC |
2335 | /** |
2336 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2337 | * @tty; tty side of tty |
8c9a9dd0 AC |
2338 | * @arg: user buffer for result |
2339 | * | |
2340 | * Copies the user idea of the window size to the kernel. Traditionally | |
2341 | * this is just advisory information but for the Linux console it | |
2342 | * actually has driver level meaning and triggers a VC resize. | |
2343 | * | |
2344 | * Locking: | |
25985edc | 2345 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2346 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2347 | * then calls into the default method. | |
2348 | */ | |
2349 | ||
fc6f6238 | 2350 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2351 | { |
2352 | struct winsize tmp_ws; | |
2353 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2354 | return -EFAULT; | |
2355 | ||
2356 | if (tty->ops->resize) | |
fc6f6238 | 2357 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2358 | else |
fc6f6238 | 2359 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2360 | } |
2361 | ||
af9b897e AC |
2362 | /** |
2363 | * tioccons - allow admin to move logical console | |
2364 | * @file: the file to become console | |
2365 | * | |
25985edc | 2366 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2367 | * |
2368 | * Locking: uses redirect_lock to guard the redirect information | |
2369 | */ | |
2370 | ||
1da177e4 LT |
2371 | static int tioccons(struct file *file) |
2372 | { | |
2373 | if (!capable(CAP_SYS_ADMIN)) | |
2374 | return -EPERM; | |
2375 | if (file->f_op->write == redirected_tty_write) { | |
2376 | struct file *f; | |
2377 | spin_lock(&redirect_lock); | |
2378 | f = redirect; | |
2379 | redirect = NULL; | |
2380 | spin_unlock(&redirect_lock); | |
2381 | if (f) | |
2382 | fput(f); | |
2383 | return 0; | |
2384 | } | |
2385 | spin_lock(&redirect_lock); | |
2386 | if (redirect) { | |
2387 | spin_unlock(&redirect_lock); | |
2388 | return -EBUSY; | |
2389 | } | |
cb0942b8 | 2390 | redirect = get_file(file); |
1da177e4 LT |
2391 | spin_unlock(&redirect_lock); |
2392 | return 0; | |
2393 | } | |
2394 | ||
af9b897e AC |
2395 | /** |
2396 | * fionbio - non blocking ioctl | |
2397 | * @file: file to set blocking value | |
2398 | * @p: user parameter | |
2399 | * | |
2400 | * Historical tty interfaces had a blocking control ioctl before | |
2401 | * the generic functionality existed. This piece of history is preserved | |
2402 | * in the expected tty API of posix OS's. | |
2403 | * | |
6146b9af | 2404 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2405 | */ |
1da177e4 LT |
2406 | |
2407 | static int fionbio(struct file *file, int __user *p) | |
2408 | { | |
2409 | int nonblock; | |
2410 | ||
2411 | if (get_user(nonblock, p)) | |
2412 | return -EFAULT; | |
2413 | ||
db1dd4d3 | 2414 | spin_lock(&file->f_lock); |
1da177e4 LT |
2415 | if (nonblock) |
2416 | file->f_flags |= O_NONBLOCK; | |
2417 | else | |
2418 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2419 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2420 | return 0; |
2421 | } | |
2422 | ||
af9b897e AC |
2423 | /** |
2424 | * tiocsctty - set controlling tty | |
2425 | * @tty: tty structure | |
2426 | * @arg: user argument | |
2427 | * | |
2428 | * This ioctl is used to manage job control. It permits a session | |
2429 | * leader to set this tty as the controlling tty for the session. | |
2430 | * | |
2431 | * Locking: | |
e218eb32 | 2432 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2433 | * Takes tasklist_lock internally to walk sessions |
2434 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2435 | */ |
2436 | ||
0c556271 | 2437 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) |
1da177e4 | 2438 | { |
24ec839c | 2439 | int ret = 0; |
24ec839c | 2440 | |
e218eb32 | 2441 | tty_lock(tty); |
2c411c11 PH |
2442 | read_lock(&tasklist_lock); |
2443 | ||
2444 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2445 | goto unlock; | |
2446 | ||
1da177e4 LT |
2447 | /* |
2448 | * The process must be a session leader and | |
2449 | * not have a controlling tty already. | |
2450 | */ | |
24ec839c PZ |
2451 | if (!current->signal->leader || current->signal->tty) { |
2452 | ret = -EPERM; | |
2453 | goto unlock; | |
2454 | } | |
2455 | ||
ab521dc0 | 2456 | if (tty->session) { |
1da177e4 LT |
2457 | /* |
2458 | * This tty is already the controlling | |
2459 | * tty for another session group! | |
2460 | */ | |
37bdfb07 | 2461 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2462 | /* |
2463 | * Steal it away | |
2464 | */ | |
24ec839c | 2465 | session_clear_tty(tty->session); |
24ec839c PZ |
2466 | } else { |
2467 | ret = -EPERM; | |
2468 | goto unlock; | |
2469 | } | |
1da177e4 | 2470 | } |
0c556271 JH |
2471 | |
2472 | /* See the comment in tty_open(). */ | |
2473 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
2474 | ret = -EPERM; | |
2475 | goto unlock; | |
2476 | } | |
2477 | ||
bce65f18 | 2478 | proc_set_tty(tty); |
24ec839c | 2479 | unlock: |
2c411c11 | 2480 | read_unlock(&tasklist_lock); |
e218eb32 | 2481 | tty_unlock(tty); |
24ec839c | 2482 | return ret; |
1da177e4 LT |
2483 | } |
2484 | ||
5d0fdf1e AC |
2485 | /** |
2486 | * tty_get_pgrp - return a ref counted pgrp pid | |
2487 | * @tty: tty to read | |
2488 | * | |
2489 | * Returns a refcounted instance of the pid struct for the process | |
2490 | * group controlling the tty. | |
2491 | */ | |
2492 | ||
2493 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2494 | { | |
2495 | unsigned long flags; | |
2496 | struct pid *pgrp; | |
2497 | ||
2498 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2499 | pgrp = get_pid(tty->pgrp); | |
2500 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2501 | ||
2502 | return pgrp; | |
2503 | } | |
2504 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2505 | ||
e1c2296c PH |
2506 | /* |
2507 | * This checks not only the pgrp, but falls back on the pid if no | |
2508 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2509 | * without this... | |
2510 | * | |
2511 | * The caller must hold rcu lock or the tasklist lock. | |
2512 | */ | |
2513 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2514 | { | |
2515 | struct task_struct *p; | |
2516 | struct pid *sid = NULL; | |
2517 | ||
2518 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2519 | if (p == NULL) | |
2520 | p = pid_task(pgrp, PIDTYPE_PID); | |
2521 | if (p != NULL) | |
2522 | sid = task_session(p); | |
2523 | ||
2524 | return sid; | |
2525 | } | |
2526 | ||
af9b897e AC |
2527 | /** |
2528 | * tiocgpgrp - get process group | |
2529 | * @tty: tty passed by user | |
25985edc | 2530 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2531 | * @p: returned pid |
2532 | * | |
2533 | * Obtain the process group of the tty. If there is no process group | |
2534 | * return an error. | |
2535 | * | |
24ec839c | 2536 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2537 | */ |
2538 | ||
1da177e4 LT |
2539 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2540 | { | |
5d0fdf1e AC |
2541 | struct pid *pid; |
2542 | int ret; | |
1da177e4 LT |
2543 | /* |
2544 | * (tty == real_tty) is a cheap way of | |
2545 | * testing if the tty is NOT a master pty. | |
2546 | */ | |
2547 | if (tty == real_tty && current->signal->tty != real_tty) | |
2548 | return -ENOTTY; | |
5d0fdf1e AC |
2549 | pid = tty_get_pgrp(real_tty); |
2550 | ret = put_user(pid_vnr(pid), p); | |
2551 | put_pid(pid); | |
2552 | return ret; | |
1da177e4 LT |
2553 | } |
2554 | ||
af9b897e AC |
2555 | /** |
2556 | * tiocspgrp - attempt to set process group | |
2557 | * @tty: tty passed by user | |
2558 | * @real_tty: tty side device matching tty passed by user | |
2559 | * @p: pid pointer | |
2560 | * | |
2561 | * Set the process group of the tty to the session passed. Only | |
2562 | * permitted where the tty session is our session. | |
2563 | * | |
47f86834 | 2564 | * Locking: RCU, ctrl lock |
af9b897e AC |
2565 | */ |
2566 | ||
1da177e4 LT |
2567 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2568 | { | |
04a2e6a5 EB |
2569 | struct pid *pgrp; |
2570 | pid_t pgrp_nr; | |
1da177e4 LT |
2571 | int retval = tty_check_change(real_tty); |
2572 | ||
2573 | if (retval == -EIO) | |
2574 | return -ENOTTY; | |
2575 | if (retval) | |
2576 | return retval; | |
2577 | if (!current->signal->tty || | |
2578 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2579 | (real_tty->session != task_session(current))) |
1da177e4 | 2580 | return -ENOTTY; |
04a2e6a5 | 2581 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2582 | return -EFAULT; |
04a2e6a5 | 2583 | if (pgrp_nr < 0) |
1da177e4 | 2584 | return -EINVAL; |
04a2e6a5 | 2585 | rcu_read_lock(); |
b488893a | 2586 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2587 | retval = -ESRCH; |
2588 | if (!pgrp) | |
2589 | goto out_unlock; | |
2590 | retval = -EPERM; | |
2591 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2592 | goto out_unlock; | |
2593 | retval = 0; | |
1e86b5bf | 2594 | spin_lock_irq(&tty->ctrl_lock); |
ab521dc0 EB |
2595 | put_pid(real_tty->pgrp); |
2596 | real_tty->pgrp = get_pid(pgrp); | |
1e86b5bf | 2597 | spin_unlock_irq(&tty->ctrl_lock); |
04a2e6a5 EB |
2598 | out_unlock: |
2599 | rcu_read_unlock(); | |
2600 | return retval; | |
1da177e4 LT |
2601 | } |
2602 | ||
af9b897e AC |
2603 | /** |
2604 | * tiocgsid - get session id | |
2605 | * @tty: tty passed by user | |
25985edc | 2606 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2607 | * @p: pointer to returned session id |
2608 | * | |
2609 | * Obtain the session id of the tty. If there is no session | |
2610 | * return an error. | |
2611 | * | |
24ec839c | 2612 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2613 | */ |
2614 | ||
1da177e4 LT |
2615 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2616 | { | |
2617 | /* | |
2618 | * (tty == real_tty) is a cheap way of | |
2619 | * testing if the tty is NOT a master pty. | |
2620 | */ | |
2621 | if (tty == real_tty && current->signal->tty != real_tty) | |
2622 | return -ENOTTY; | |
ab521dc0 | 2623 | if (!real_tty->session) |
1da177e4 | 2624 | return -ENOTTY; |
b488893a | 2625 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2626 | } |
2627 | ||
af9b897e AC |
2628 | /** |
2629 | * tiocsetd - set line discipline | |
2630 | * @tty: tty device | |
2631 | * @p: pointer to user data | |
2632 | * | |
2633 | * Set the line discipline according to user request. | |
2634 | * | |
2635 | * Locking: see tty_set_ldisc, this function is just a helper | |
2636 | */ | |
2637 | ||
1da177e4 LT |
2638 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2639 | { | |
2640 | int ldisc; | |
04f378b1 | 2641 | int ret; |
1da177e4 LT |
2642 | |
2643 | if (get_user(ldisc, p)) | |
2644 | return -EFAULT; | |
04f378b1 | 2645 | |
04f378b1 | 2646 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2647 | |
2648 | return ret; | |
1da177e4 LT |
2649 | } |
2650 | ||
af9b897e AC |
2651 | /** |
2652 | * send_break - performed time break | |
2653 | * @tty: device to break on | |
2654 | * @duration: timeout in mS | |
2655 | * | |
2656 | * Perform a timed break on hardware that lacks its own driver level | |
2657 | * timed break functionality. | |
2658 | * | |
2659 | * Locking: | |
28298232 | 2660 | * atomic_write_lock serializes |
af9b897e | 2661 | * |
af9b897e AC |
2662 | */ |
2663 | ||
b20f3ae5 | 2664 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2665 | { |
9e98966c AC |
2666 | int retval; |
2667 | ||
2668 | if (tty->ops->break_ctl == NULL) | |
2669 | return 0; | |
2670 | ||
2671 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2672 | retval = tty->ops->break_ctl(tty, duration); | |
2673 | else { | |
2674 | /* Do the work ourselves */ | |
2675 | if (tty_write_lock(tty, 0) < 0) | |
2676 | return -EINTR; | |
2677 | retval = tty->ops->break_ctl(tty, -1); | |
2678 | if (retval) | |
2679 | goto out; | |
2680 | if (!signal_pending(current)) | |
2681 | msleep_interruptible(duration); | |
2682 | retval = tty->ops->break_ctl(tty, 0); | |
2683 | out: | |
2684 | tty_write_unlock(tty); | |
2685 | if (signal_pending(current)) | |
2686 | retval = -EINTR; | |
2687 | } | |
2688 | return retval; | |
1da177e4 LT |
2689 | } |
2690 | ||
af9b897e | 2691 | /** |
f34d7a5b | 2692 | * tty_tiocmget - get modem status |
af9b897e AC |
2693 | * @tty: tty device |
2694 | * @file: user file pointer | |
2695 | * @p: pointer to result | |
2696 | * | |
2697 | * Obtain the modem status bits from the tty driver if the feature | |
2698 | * is supported. Return -EINVAL if it is not available. | |
2699 | * | |
2700 | * Locking: none (up to the driver) | |
2701 | */ | |
2702 | ||
60b33c13 | 2703 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2704 | { |
2705 | int retval = -EINVAL; | |
2706 | ||
f34d7a5b | 2707 | if (tty->ops->tiocmget) { |
60b33c13 | 2708 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2709 | |
2710 | if (retval >= 0) | |
2711 | retval = put_user(retval, p); | |
2712 | } | |
2713 | return retval; | |
2714 | } | |
2715 | ||
af9b897e | 2716 | /** |
f34d7a5b | 2717 | * tty_tiocmset - set modem status |
af9b897e | 2718 | * @tty: tty device |
af9b897e AC |
2719 | * @cmd: command - clear bits, set bits or set all |
2720 | * @p: pointer to desired bits | |
2721 | * | |
2722 | * Set the modem status bits from the tty driver if the feature | |
2723 | * is supported. Return -EINVAL if it is not available. | |
2724 | * | |
2725 | * Locking: none (up to the driver) | |
2726 | */ | |
2727 | ||
20b9d177 | 2728 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2729 | unsigned __user *p) |
2730 | { | |
ae677517 AC |
2731 | int retval; |
2732 | unsigned int set, clear, val; | |
1da177e4 | 2733 | |
ae677517 AC |
2734 | if (tty->ops->tiocmset == NULL) |
2735 | return -EINVAL; | |
1da177e4 | 2736 | |
ae677517 AC |
2737 | retval = get_user(val, p); |
2738 | if (retval) | |
2739 | return retval; | |
2740 | set = clear = 0; | |
2741 | switch (cmd) { | |
2742 | case TIOCMBIS: | |
2743 | set = val; | |
2744 | break; | |
2745 | case TIOCMBIC: | |
2746 | clear = val; | |
2747 | break; | |
2748 | case TIOCMSET: | |
2749 | set = val; | |
2750 | clear = ~val; | |
2751 | break; | |
2752 | } | |
2753 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2754 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2755 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2756 | } |
2757 | ||
d281da7f AC |
2758 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2759 | { | |
2760 | int retval = -EINVAL; | |
2761 | struct serial_icounter_struct icount; | |
2762 | memset(&icount, 0, sizeof(icount)); | |
2763 | if (tty->ops->get_icount) | |
2764 | retval = tty->ops->get_icount(tty, &icount); | |
2765 | if (retval != 0) | |
2766 | return retval; | |
2767 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2768 | return -EFAULT; | |
2769 | return 0; | |
2770 | } | |
2771 | ||
8a8ae62f JS |
2772 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2773 | { | |
2774 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2775 | DEFAULT_RATELIMIT_INTERVAL, | |
2776 | DEFAULT_RATELIMIT_BURST); | |
2777 | char comm[TASK_COMM_LEN]; | |
2778 | int flags; | |
2779 | ||
2780 | if (get_user(flags, &ss->flags)) | |
2781 | return; | |
2782 | ||
2783 | flags &= ASYNC_DEPRECATED; | |
2784 | ||
2785 | if (flags && __ratelimit(&depr_flags)) | |
2786 | pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2787 | __func__, get_task_comm(comm, current), flags); | |
2788 | } | |
2789 | ||
8f166e00 PH |
2790 | /* |
2791 | * if pty, return the slave side (real_tty) | |
2792 | * otherwise, return self | |
2793 | */ | |
2794 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2795 | { |
2796 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2797 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2798 | tty = tty->link; | |
2799 | return tty; | |
2800 | } | |
e8b70e7d | 2801 | |
1da177e4 LT |
2802 | /* |
2803 | * Split this up, as gcc can choke on it otherwise.. | |
2804 | */ | |
04f378b1 | 2805 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2806 | { |
d996b62a NP |
2807 | struct tty_struct *tty = file_tty(file); |
2808 | struct tty_struct *real_tty; | |
1da177e4 LT |
2809 | void __user *p = (void __user *)arg; |
2810 | int retval; | |
2811 | struct tty_ldisc *ld; | |
37bdfb07 | 2812 | |
6131ffaa | 2813 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2814 | return -EINVAL; |
2815 | ||
e8b70e7d | 2816 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2817 | |
2818 | /* | |
2819 | * Factor out some common prep work | |
2820 | */ | |
2821 | switch (cmd) { | |
2822 | case TIOCSETD: | |
2823 | case TIOCSBRK: | |
2824 | case TIOCCBRK: | |
2825 | case TCSBRK: | |
37bdfb07 | 2826 | case TCSBRKP: |
1da177e4 LT |
2827 | retval = tty_check_change(tty); |
2828 | if (retval) | |
2829 | return retval; | |
2830 | if (cmd != TIOCCBRK) { | |
2831 | tty_wait_until_sent(tty, 0); | |
2832 | if (signal_pending(current)) | |
2833 | return -EINTR; | |
2834 | } | |
2835 | break; | |
2836 | } | |
2837 | ||
9e98966c AC |
2838 | /* |
2839 | * Now do the stuff. | |
2840 | */ | |
1da177e4 | 2841 | switch (cmd) { |
37bdfb07 AC |
2842 | case TIOCSTI: |
2843 | return tiocsti(tty, p); | |
2844 | case TIOCGWINSZ: | |
8f520021 | 2845 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2846 | case TIOCSWINSZ: |
fc6f6238 | 2847 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2848 | case TIOCCONS: |
2849 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2850 | case FIONBIO: | |
2851 | return fionbio(file, p); | |
2852 | case TIOCEXCL: | |
2853 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2854 | return 0; | |
2855 | case TIOCNXCL: | |
2856 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2857 | return 0; | |
84fd7bdf CG |
2858 | case TIOCGEXCL: |
2859 | { | |
2860 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2861 | return put_user(excl, (int __user *)p); | |
2862 | } | |
37bdfb07 AC |
2863 | case TIOCNOTTY: |
2864 | if (current->signal->tty != tty) | |
2865 | return -ENOTTY; | |
2866 | no_tty(); | |
2867 | return 0; | |
2868 | case TIOCSCTTY: | |
0c556271 | 2869 | return tiocsctty(tty, file, arg); |
37bdfb07 AC |
2870 | case TIOCGPGRP: |
2871 | return tiocgpgrp(tty, real_tty, p); | |
2872 | case TIOCSPGRP: | |
2873 | return tiocspgrp(tty, real_tty, p); | |
2874 | case TIOCGSID: | |
2875 | return tiocgsid(tty, real_tty, p); | |
2876 | case TIOCGETD: | |
c65c9bc3 | 2877 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2878 | case TIOCSETD: |
2879 | return tiocsetd(tty, p); | |
3c95c985 KS |
2880 | case TIOCVHANGUP: |
2881 | if (!capable(CAP_SYS_ADMIN)) | |
2882 | return -EPERM; | |
2883 | tty_vhangup(tty); | |
2884 | return 0; | |
b7b8de08 WF |
2885 | case TIOCGDEV: |
2886 | { | |
2887 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2888 | return put_user(ret, (unsigned int __user *)p); | |
2889 | } | |
37bdfb07 AC |
2890 | /* |
2891 | * Break handling | |
2892 | */ | |
2893 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2894 | if (tty->ops->break_ctl) |
9e98966c | 2895 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2896 | return 0; |
37bdfb07 | 2897 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2898 | if (tty->ops->break_ctl) |
9e98966c | 2899 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2900 | return 0; |
2901 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2902 | /* non-zero arg means wait for all output data | |
2903 | * to be sent (performed above) but don't send break. | |
2904 | * This is used by the tcdrain() termios function. | |
2905 | */ | |
2906 | if (!arg) | |
2907 | return send_break(tty, 250); | |
2908 | return 0; | |
2909 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2910 | return send_break(tty, arg ? arg*100 : 250); | |
2911 | ||
2912 | case TIOCMGET: | |
60b33c13 | 2913 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2914 | case TIOCMSET: |
2915 | case TIOCMBIC: | |
2916 | case TIOCMBIS: | |
20b9d177 | 2917 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2918 | case TIOCGICOUNT: |
2919 | retval = tty_tiocgicount(tty, p); | |
2920 | /* For the moment allow fall through to the old method */ | |
2921 | if (retval != -EINVAL) | |
2922 | return retval; | |
2923 | break; | |
37bdfb07 AC |
2924 | case TCFLSH: |
2925 | switch (arg) { | |
2926 | case TCIFLUSH: | |
2927 | case TCIOFLUSH: | |
2928 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2929 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2930 | break; |
37bdfb07 AC |
2931 | } |
2932 | break; | |
8a8ae62f JS |
2933 | case TIOCSSERIAL: |
2934 | tty_warn_deprecated_flags(p); | |
2935 | break; | |
1da177e4 | 2936 | } |
f34d7a5b | 2937 | if (tty->ops->ioctl) { |
c961bfb1 | 2938 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2939 | if (retval != -ENOIOCTLCMD) |
2940 | return retval; | |
2941 | } | |
2942 | ld = tty_ldisc_ref_wait(tty); | |
2943 | retval = -EINVAL; | |
a352def2 AC |
2944 | if (ld->ops->ioctl) { |
2945 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2946 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2947 | retval = -ENOTTY; |
1da177e4 LT |
2948 | } |
2949 | tty_ldisc_deref(ld); | |
2950 | return retval; | |
2951 | } | |
2952 | ||
e10cc1df | 2953 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2954 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2955 | unsigned long arg) |
2956 | { | |
d996b62a | 2957 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2958 | struct tty_ldisc *ld; |
2959 | int retval = -ENOIOCTLCMD; | |
2960 | ||
6131ffaa | 2961 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2962 | return -EINVAL; |
2963 | ||
f34d7a5b | 2964 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2965 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2966 | if (retval != -ENOIOCTLCMD) |
2967 | return retval; | |
2968 | } | |
2969 | ||
2970 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2971 | if (ld->ops->compat_ioctl) |
2972 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2973 | else |
2974 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2975 | tty_ldisc_deref(ld); |
2976 | ||
2977 | return retval; | |
2978 | } | |
2979 | #endif | |
1da177e4 | 2980 | |
c3c073f8 AV |
2981 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2982 | { | |
2983 | if (likely(file->f_op->read != tty_read)) | |
2984 | return 0; | |
2985 | return file_tty(file) != t ? 0 : fd + 1; | |
2986 | } | |
2987 | ||
1da177e4 LT |
2988 | /* |
2989 | * This implements the "Secure Attention Key" --- the idea is to | |
2990 | * prevent trojan horses by killing all processes associated with this | |
2991 | * tty when the user hits the "Secure Attention Key". Required for | |
2992 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2993 | * |
1da177e4 LT |
2994 | * This code could be nicer; ideally it should send a HUP, wait a few |
2995 | * seconds, then send a INT, and then a KILL signal. But you then | |
2996 | * have to coordinate with the init process, since all processes associated | |
2997 | * with the current tty must be dead before the new getty is allowed | |
2998 | * to spawn. | |
2999 | * | |
3000 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3001 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3002 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3003 | * | |
3004 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3005 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3006 | */ | |
8b6312f4 | 3007 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
3008 | { |
3009 | #ifdef TTY_SOFT_SAK | |
3010 | tty_hangup(tty); | |
3011 | #else | |
652486fb | 3012 | struct task_struct *g, *p; |
ab521dc0 | 3013 | struct pid *session; |
1da177e4 | 3014 | int i; |
37bdfb07 | 3015 | |
1da177e4 LT |
3016 | if (!tty) |
3017 | return; | |
24ec839c | 3018 | session = tty->session; |
37bdfb07 | 3019 | |
b3f13deb | 3020 | tty_ldisc_flush(tty); |
1da177e4 | 3021 | |
f34d7a5b | 3022 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3023 | |
1da177e4 | 3024 | read_lock(&tasklist_lock); |
652486fb | 3025 | /* Kill the entire session */ |
ab521dc0 | 3026 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3027 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3028 | task_pid_nr(p), p->comm); | |
652486fb | 3029 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3030 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3031 | |
3032 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3033 | do_each_thread(g, p) { |
3034 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3035 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3036 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
3037 | send_sig(SIGKILL, p, 1); |
3038 | continue; | |
3039 | } | |
3040 | task_lock(p); | |
c3c073f8 AV |
3041 | i = iterate_fd(p->files, 0, this_tty, tty); |
3042 | if (i != 0) { | |
9b42bb75 PH |
3043 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3044 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 3045 | force_sig(SIGKILL, p); |
1da177e4 LT |
3046 | } |
3047 | task_unlock(p); | |
652486fb | 3048 | } while_each_thread(g, p); |
1da177e4 LT |
3049 | read_unlock(&tasklist_lock); |
3050 | #endif | |
3051 | } | |
3052 | ||
8b6312f4 EB |
3053 | static void do_SAK_work(struct work_struct *work) |
3054 | { | |
3055 | struct tty_struct *tty = | |
3056 | container_of(work, struct tty_struct, SAK_work); | |
3057 | __do_SAK(tty); | |
3058 | } | |
3059 | ||
1da177e4 LT |
3060 | /* |
3061 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3062 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3063 | * the values which we write to it will be identical to the values which it | |
3064 | * already has. --akpm | |
3065 | */ | |
3066 | void do_SAK(struct tty_struct *tty) | |
3067 | { | |
3068 | if (!tty) | |
3069 | return; | |
1da177e4 LT |
3070 | schedule_work(&tty->SAK_work); |
3071 | } | |
3072 | ||
3073 | EXPORT_SYMBOL(do_SAK); | |
3074 | ||
6e9430ac | 3075 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3076 | { |
6e9430ac | 3077 | const dev_t *devt = data; |
30004ac9 DES |
3078 | return dev->devt == *devt; |
3079 | } | |
3080 | ||
3081 | /* Must put_device() after it's unused! */ | |
3082 | static struct device *tty_get_device(struct tty_struct *tty) | |
3083 | { | |
3084 | dev_t devt = tty_devnum(tty); | |
3085 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3086 | } | |
3087 | ||
3088 | ||
af9b897e | 3089 | /** |
2c964a2f | 3090 | * alloc_tty_struct |
af9b897e | 3091 | * |
2c964a2f | 3092 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3093 | * |
2c964a2f | 3094 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3095 | */ |
af9b897e | 3096 | |
2c964a2f | 3097 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3098 | { |
2c964a2f RV |
3099 | struct tty_struct *tty; |
3100 | ||
3101 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3102 | if (!tty) | |
3103 | return NULL; | |
3104 | ||
9c9f4ded | 3105 | kref_init(&tty->kref); |
1da177e4 | 3106 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3107 | tty_ldisc_init(tty); |
ab521dc0 EB |
3108 | tty->session = NULL; |
3109 | tty->pgrp = NULL; | |
89c8d91e | 3110 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3111 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3112 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3113 | mutex_init(&tty->winsize_mutex); |
36697529 | 3114 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3115 | init_waitqueue_head(&tty->write_wait); |
3116 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3117 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3118 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3119 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3120 | spin_lock_init(&tty->flow_lock); |
1da177e4 | 3121 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3122 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3123 | |
3124 | tty->driver = driver; | |
3125 | tty->ops = driver->ops; | |
3126 | tty->index = idx; | |
3127 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3128 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3129 | |
3130 | return tty; | |
1da177e4 LT |
3131 | } |
3132 | ||
6716671d JS |
3133 | /** |
3134 | * deinitialize_tty_struct | |
3135 | * @tty: tty to deinitialize | |
3136 | * | |
3137 | * This subroutine deinitializes a tty structure that has been newly | |
3138 | * allocated but tty_release cannot be called on that yet. | |
3139 | * | |
3140 | * Locking: none - tty in question must not be exposed at this point | |
3141 | */ | |
3142 | void deinitialize_tty_struct(struct tty_struct *tty) | |
3143 | { | |
3144 | tty_ldisc_deinit(tty); | |
3145 | } | |
3146 | ||
f34d7a5b AC |
3147 | /** |
3148 | * tty_put_char - write one character to a tty | |
3149 | * @tty: tty | |
3150 | * @ch: character | |
3151 | * | |
3152 | * Write one byte to the tty using the provided put_char method | |
3153 | * if present. Returns the number of characters successfully output. | |
3154 | * | |
3155 | * Note: the specific put_char operation in the driver layer may go | |
3156 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3157 | */ |
af9b897e | 3158 | |
f34d7a5b | 3159 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3160 | { |
f34d7a5b AC |
3161 | if (tty->ops->put_char) |
3162 | return tty->ops->put_char(tty, ch); | |
3163 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3164 | } |
f34d7a5b AC |
3165 | EXPORT_SYMBOL_GPL(tty_put_char); |
3166 | ||
d81ed103 | 3167 | struct class *tty_class; |
1da177e4 | 3168 | |
7e73eca6 JS |
3169 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3170 | unsigned int index, unsigned int count) | |
3171 | { | |
c1a752ba LY |
3172 | int err; |
3173 | ||
7e73eca6 | 3174 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3175 | driver->cdevs[index] = cdev_alloc(); |
3176 | if (!driver->cdevs[index]) | |
3177 | return -ENOMEM; | |
c1a752ba | 3178 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3179 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3180 | err = cdev_add(driver->cdevs[index], dev, count); |
3181 | if (err) | |
3182 | kobject_put(&driver->cdevs[index]->kobj); | |
3183 | return err; | |
7e73eca6 JS |
3184 | } |
3185 | ||
1da177e4 | 3186 | /** |
af9b897e AC |
3187 | * tty_register_device - register a tty device |
3188 | * @driver: the tty driver that describes the tty device | |
3189 | * @index: the index in the tty driver for this tty device | |
3190 | * @device: a struct device that is associated with this tty device. | |
3191 | * This field is optional, if there is no known struct device | |
3192 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3193 | * |
01107d34 GKH |
3194 | * Returns a pointer to the struct device for this tty device |
3195 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3196 | * |
af9b897e AC |
3197 | * This call is required to be made to register an individual tty device |
3198 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3199 | * that bit is not set, this function should not be called by a tty | |
3200 | * driver. | |
3201 | * | |
3202 | * Locking: ?? | |
1da177e4 | 3203 | */ |
af9b897e | 3204 | |
01107d34 GKH |
3205 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3206 | struct device *device) | |
1da177e4 | 3207 | { |
6915c0e4 TH |
3208 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3209 | } | |
3210 | EXPORT_SYMBOL(tty_register_device); | |
3211 | ||
b1b79916 TH |
3212 | static void tty_device_create_release(struct device *dev) |
3213 | { | |
3214 | pr_debug("device: '%s': %s\n", dev_name(dev), __func__); | |
3215 | kfree(dev); | |
3216 | } | |
3217 | ||
6915c0e4 TH |
3218 | /** |
3219 | * tty_register_device_attr - register a tty device | |
3220 | * @driver: the tty driver that describes the tty device | |
3221 | * @index: the index in the tty driver for this tty device | |
3222 | * @device: a struct device that is associated with this tty device. | |
3223 | * This field is optional, if there is no known struct device | |
3224 | * for this tty device it can be set to NULL safely. | |
3225 | * @drvdata: Driver data to be set to device. | |
3226 | * @attr_grp: Attribute group to be set on device. | |
3227 | * | |
3228 | * Returns a pointer to the struct device for this tty device | |
3229 | * (or ERR_PTR(-EFOO) on error). | |
3230 | * | |
3231 | * This call is required to be made to register an individual tty device | |
3232 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3233 | * that bit is not set, this function should not be called by a tty | |
3234 | * driver. | |
3235 | * | |
3236 | * Locking: ?? | |
3237 | */ | |
3238 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3239 | unsigned index, struct device *device, | |
3240 | void *drvdata, | |
3241 | const struct attribute_group **attr_grp) | |
3242 | { | |
1da177e4 | 3243 | char name[64]; |
6915c0e4 TH |
3244 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3245 | struct device *dev = NULL; | |
3246 | int retval = -ENODEV; | |
7e73eca6 | 3247 | bool cdev = false; |
1da177e4 LT |
3248 | |
3249 | if (index >= driver->num) { | |
656fb867 PH |
3250 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3251 | driver->name, index); | |
1cdcb6b4 | 3252 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3253 | } |
3254 | ||
1da177e4 LT |
3255 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3256 | pty_line_name(driver, index, name); | |
3257 | else | |
3258 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3259 | |
7e73eca6 | 3260 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3261 | retval = tty_cdev_add(driver, devt, index, 1); |
3262 | if (retval) | |
3263 | goto error; | |
7e73eca6 JS |
3264 | cdev = true; |
3265 | } | |
3266 | ||
6915c0e4 TH |
3267 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3268 | if (!dev) { | |
3269 | retval = -ENOMEM; | |
3270 | goto error; | |
3271 | } | |
7e73eca6 | 3272 | |
6915c0e4 TH |
3273 | dev->devt = devt; |
3274 | dev->class = tty_class; | |
3275 | dev->parent = device; | |
b1b79916 | 3276 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3277 | dev_set_name(dev, "%s", name); |
3278 | dev->groups = attr_grp; | |
3279 | dev_set_drvdata(dev, drvdata); | |
3280 | ||
3281 | retval = device_register(dev); | |
3282 | if (retval) | |
3283 | goto error; | |
3284 | ||
3285 | return dev; | |
3286 | ||
3287 | error: | |
3288 | put_device(dev); | |
a3a10ce3 RW |
3289 | if (cdev) { |
3290 | cdev_del(driver->cdevs[index]); | |
3291 | driver->cdevs[index] = NULL; | |
3292 | } | |
6915c0e4 | 3293 | return ERR_PTR(retval); |
1da177e4 | 3294 | } |
6915c0e4 | 3295 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3296 | |
3297 | /** | |
af9b897e AC |
3298 | * tty_unregister_device - unregister a tty device |
3299 | * @driver: the tty driver that describes the tty device | |
3300 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3301 | * |
af9b897e AC |
3302 | * If a tty device is registered with a call to tty_register_device() then |
3303 | * this function must be called when the tty device is gone. | |
3304 | * | |
3305 | * Locking: ?? | |
1da177e4 | 3306 | */ |
af9b897e | 3307 | |
1da177e4 LT |
3308 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3309 | { | |
37bdfb07 AC |
3310 | device_destroy(tty_class, |
3311 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3312 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3313 | cdev_del(driver->cdevs[index]); | |
3314 | driver->cdevs[index] = NULL; | |
3315 | } | |
1da177e4 | 3316 | } |
1da177e4 LT |
3317 | EXPORT_SYMBOL(tty_unregister_device); |
3318 | ||
7f0bc6a6 JS |
3319 | /** |
3320 | * __tty_alloc_driver -- allocate tty driver | |
3321 | * @lines: count of lines this driver can handle at most | |
3322 | * @owner: module which is repsonsible for this driver | |
3323 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3324 | * | |
3325 | * This should not be called directly, some of the provided macros should be | |
3326 | * used instead. Use IS_ERR and friends on @retval. | |
3327 | */ | |
3328 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3329 | unsigned long flags) | |
1da177e4 LT |
3330 | { |
3331 | struct tty_driver *driver; | |
7e73eca6 | 3332 | unsigned int cdevs = 1; |
16a02081 | 3333 | int err; |
1da177e4 | 3334 | |
0019b408 | 3335 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3336 | return ERR_PTR(-EINVAL); |
3337 | ||
506eb99a | 3338 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3339 | if (!driver) |
3340 | return ERR_PTR(-ENOMEM); | |
3341 | ||
3342 | kref_init(&driver->kref); | |
3343 | driver->magic = TTY_DRIVER_MAGIC; | |
3344 | driver->num = lines; | |
3345 | driver->owner = owner; | |
3346 | driver->flags = flags; | |
16a02081 JS |
3347 | |
3348 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3349 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3350 | GFP_KERNEL); | |
3351 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3352 | GFP_KERNEL); | |
3353 | if (!driver->ttys || !driver->termios) { | |
3354 | err = -ENOMEM; | |
3355 | goto err_free_all; | |
3356 | } | |
3357 | } | |
3358 | ||
3359 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3360 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3361 | GFP_KERNEL); | |
3362 | if (!driver->ports) { | |
3363 | err = -ENOMEM; | |
3364 | goto err_free_all; | |
3365 | } | |
7e73eca6 JS |
3366 | cdevs = lines; |
3367 | } | |
3368 | ||
3369 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3370 | if (!driver->cdevs) { | |
3371 | err = -ENOMEM; | |
3372 | goto err_free_all; | |
16a02081 | 3373 | } |
7f0bc6a6 | 3374 | |
1da177e4 | 3375 | return driver; |
16a02081 JS |
3376 | err_free_all: |
3377 | kfree(driver->ports); | |
3378 | kfree(driver->ttys); | |
3379 | kfree(driver->termios); | |
a3a10ce3 | 3380 | kfree(driver->cdevs); |
16a02081 JS |
3381 | kfree(driver); |
3382 | return ERR_PTR(err); | |
1da177e4 | 3383 | } |
7f0bc6a6 | 3384 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3385 | |
7d7b93c1 | 3386 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3387 | { |
7d7b93c1 AC |
3388 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3389 | int i; | |
3390 | struct ktermios *tp; | |
7d7b93c1 AC |
3391 | |
3392 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3393 | /* | |
3394 | * Free the termios and termios_locked structures because | |
3395 | * we don't want to get memory leaks when modular tty | |
3396 | * drivers are removed from the kernel. | |
3397 | */ | |
3398 | for (i = 0; i < driver->num; i++) { | |
3399 | tp = driver->termios[i]; | |
3400 | if (tp) { | |
3401 | driver->termios[i] = NULL; | |
3402 | kfree(tp); | |
3403 | } | |
7d7b93c1 AC |
3404 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3405 | tty_unregister_device(driver, i); | |
3406 | } | |
7d7b93c1 | 3407 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3408 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3409 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3410 | } |
7e73eca6 | 3411 | kfree(driver->cdevs); |
04831dc1 | 3412 | kfree(driver->ports); |
16a02081 JS |
3413 | kfree(driver->termios); |
3414 | kfree(driver->ttys); | |
1da177e4 LT |
3415 | kfree(driver); |
3416 | } | |
3417 | ||
7d7b93c1 AC |
3418 | void tty_driver_kref_put(struct tty_driver *driver) |
3419 | { | |
3420 | kref_put(&driver->kref, destruct_tty_driver); | |
3421 | } | |
3422 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3423 | ||
b68e31d0 JD |
3424 | void tty_set_operations(struct tty_driver *driver, |
3425 | const struct tty_operations *op) | |
1da177e4 | 3426 | { |
f34d7a5b AC |
3427 | driver->ops = op; |
3428 | }; | |
7d7b93c1 | 3429 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3430 | |
7d7b93c1 AC |
3431 | void put_tty_driver(struct tty_driver *d) |
3432 | { | |
3433 | tty_driver_kref_put(d); | |
3434 | } | |
1da177e4 | 3435 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3436 | |
3437 | /* | |
3438 | * Called by a tty driver to register itself. | |
3439 | */ | |
3440 | int tty_register_driver(struct tty_driver *driver) | |
3441 | { | |
3442 | int error; | |
37bdfb07 | 3443 | int i; |
1da177e4 | 3444 | dev_t dev; |
b670bde0 | 3445 | struct device *d; |
1da177e4 | 3446 | |
1da177e4 | 3447 | if (!driver->major) { |
37bdfb07 AC |
3448 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3449 | driver->num, driver->name); | |
1da177e4 LT |
3450 | if (!error) { |
3451 | driver->major = MAJOR(dev); | |
3452 | driver->minor_start = MINOR(dev); | |
3453 | } | |
3454 | } else { | |
3455 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3456 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3457 | } |
9bb8a3d4 | 3458 | if (error < 0) |
16a02081 | 3459 | goto err; |
1da177e4 | 3460 | |
7e73eca6 JS |
3461 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3462 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3463 | if (error) | |
3464 | goto err_unreg_char; | |
3465 | } | |
1da177e4 | 3466 | |
ca509f69 | 3467 | mutex_lock(&tty_mutex); |
1da177e4 | 3468 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3469 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3470 | |
3471 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3472 | for (i = 0; i < driver->num; i++) { |
3473 | d = tty_register_device(driver, i, NULL); | |
3474 | if (IS_ERR(d)) { | |
3475 | error = PTR_ERR(d); | |
16a02081 | 3476 | goto err_unreg_devs; |
b670bde0 VK |
3477 | } |
3478 | } | |
1da177e4 LT |
3479 | } |
3480 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3481 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3482 | return 0; |
b670bde0 | 3483 | |
16a02081 | 3484 | err_unreg_devs: |
b670bde0 VK |
3485 | for (i--; i >= 0; i--) |
3486 | tty_unregister_device(driver, i); | |
3487 | ||
3488 | mutex_lock(&tty_mutex); | |
3489 | list_del(&driver->tty_drivers); | |
3490 | mutex_unlock(&tty_mutex); | |
3491 | ||
9bb8a3d4 | 3492 | err_unreg_char: |
b670bde0 | 3493 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3494 | err: |
b670bde0 | 3495 | return error; |
1da177e4 | 3496 | } |
1da177e4 LT |
3497 | EXPORT_SYMBOL(tty_register_driver); |
3498 | ||
3499 | /* | |
3500 | * Called by a tty driver to unregister itself. | |
3501 | */ | |
3502 | int tty_unregister_driver(struct tty_driver *driver) | |
3503 | { | |
7d7b93c1 AC |
3504 | #if 0 |
3505 | /* FIXME */ | |
1da177e4 LT |
3506 | if (driver->refcount) |
3507 | return -EBUSY; | |
7d7b93c1 | 3508 | #endif |
1da177e4 LT |
3509 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3510 | driver->num); | |
ca509f69 | 3511 | mutex_lock(&tty_mutex); |
1da177e4 | 3512 | list_del(&driver->tty_drivers); |
ca509f69 | 3513 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3514 | return 0; |
3515 | } | |
7d7b93c1 | 3516 | |
1da177e4 LT |
3517 | EXPORT_SYMBOL(tty_unregister_driver); |
3518 | ||
24ec839c PZ |
3519 | dev_t tty_devnum(struct tty_struct *tty) |
3520 | { | |
3521 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3522 | } | |
3523 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3524 | |
d81ed103 AC |
3525 | void tty_default_fops(struct file_operations *fops) |
3526 | { | |
3527 | *fops = tty_fops; | |
3528 | } | |
3529 | ||
1da177e4 LT |
3530 | /* |
3531 | * Initialize the console device. This is called *early*, so | |
3532 | * we can't necessarily depend on lots of kernel help here. | |
3533 | * Just do some early initializations, and do the complex setup | |
3534 | * later. | |
3535 | */ | |
3536 | void __init console_init(void) | |
3537 | { | |
3538 | initcall_t *call; | |
3539 | ||
3540 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3541 | tty_ldisc_begin(); |
1da177e4 LT |
3542 | |
3543 | /* | |
37bdfb07 | 3544 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3545 | * inform about problems etc.. |
3546 | */ | |
1da177e4 LT |
3547 | call = __con_initcall_start; |
3548 | while (call < __con_initcall_end) { | |
3549 | (*call)(); | |
3550 | call++; | |
3551 | } | |
3552 | } | |
3553 | ||
2c9ede55 | 3554 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3555 | { |
3556 | if (!mode) | |
3557 | return NULL; | |
3558 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3559 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3560 | *mode = 0666; | |
3561 | return NULL; | |
3562 | } | |
3563 | ||
1da177e4 LT |
3564 | static int __init tty_class_init(void) |
3565 | { | |
7fe845d1 | 3566 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3567 | if (IS_ERR(tty_class)) |
3568 | return PTR_ERR(tty_class); | |
e454cea2 | 3569 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3570 | return 0; |
3571 | } | |
3572 | ||
3573 | postcore_initcall(tty_class_init); | |
3574 | ||
3575 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3576 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3577 | |
fbc92a34 KS |
3578 | static ssize_t show_cons_active(struct device *dev, |
3579 | struct device_attribute *attr, char *buf) | |
3580 | { | |
3581 | struct console *cs[16]; | |
3582 | int i = 0; | |
3583 | struct console *c; | |
3584 | ssize_t count = 0; | |
3585 | ||
ac751efa | 3586 | console_lock(); |
a2a6a822 | 3587 | for_each_console(c) { |
fbc92a34 KS |
3588 | if (!c->device) |
3589 | continue; | |
3590 | if (!c->write) | |
3591 | continue; | |
3592 | if ((c->flags & CON_ENABLED) == 0) | |
3593 | continue; | |
3594 | cs[i++] = c; | |
3595 | if (i >= ARRAY_SIZE(cs)) | |
3596 | break; | |
3597 | } | |
723abd87 HR |
3598 | while (i--) { |
3599 | int index = cs[i]->index; | |
3600 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3601 | ||
3602 | /* don't resolve tty0 as some programs depend on it */ | |
3603 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3604 | count += tty_line_name(drv, index, buf + count); | |
3605 | else | |
3606 | count += sprintf(buf + count, "%s%d", | |
3607 | cs[i]->name, cs[i]->index); | |
3608 | ||
3609 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3610 | } | |
ac751efa | 3611 | console_unlock(); |
fbc92a34 KS |
3612 | |
3613 | return count; | |
3614 | } | |
3615 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3616 | ||
1083a7be TI |
3617 | static struct attribute *cons_dev_attrs[] = { |
3618 | &dev_attr_active.attr, | |
3619 | NULL | |
3620 | }; | |
3621 | ||
3622 | ATTRIBUTE_GROUPS(cons_dev); | |
3623 | ||
fbc92a34 KS |
3624 | static struct device *consdev; |
3625 | ||
3626 | void console_sysfs_notify(void) | |
3627 | { | |
3628 | if (consdev) | |
3629 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3630 | } | |
3631 | ||
1da177e4 LT |
3632 | /* |
3633 | * Ok, now we can initialize the rest of the tty devices and can count | |
3634 | * on memory allocations, interrupts etc.. | |
3635 | */ | |
31d1d48e | 3636 | int __init tty_init(void) |
1da177e4 LT |
3637 | { |
3638 | cdev_init(&tty_cdev, &tty_fops); | |
3639 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3640 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3641 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3642 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3643 | |
3644 | cdev_init(&console_cdev, &console_fops); | |
3645 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3646 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3647 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3648 | consdev = device_create_with_groups(tty_class, NULL, |
3649 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3650 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3651 | if (IS_ERR(consdev)) |
3652 | consdev = NULL; | |
1da177e4 | 3653 | |
1da177e4 | 3654 | #ifdef CONFIG_VT |
d81ed103 | 3655 | vty_init(&console_fops); |
1da177e4 LT |
3656 | #endif |
3657 | return 0; | |
3658 | } | |
31d1d48e | 3659 |