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, | |
133b1306 PH |
126 | .c_ospeed = 38400, |
127 | /* .c_line = N_TTY, */ | |
1da177e4 LT |
128 | }; |
129 | ||
130 | EXPORT_SYMBOL(tty_std_termios); | |
131 | ||
132 | /* This list gets poked at by procfs and various bits of boot up code. This | |
133 | could do with some rationalisation such as pulling the tty proc function | |
134 | into this file */ | |
37bdfb07 | 135 | |
1da177e4 LT |
136 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
137 | ||
d1d027ef | 138 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 139 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 140 | |
1da177e4 LT |
141 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
142 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
143 | ssize_t redirected_tty_write(struct file *, const char __user *, |
144 | size_t, loff_t *); | |
1da177e4 LT |
145 | static unsigned int tty_poll(struct file *, poll_table *); |
146 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 147 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 148 | #ifdef CONFIG_COMPAT |
37bdfb07 | 149 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
150 | unsigned long arg); |
151 | #else | |
152 | #define tty_compat_ioctl NULL | |
153 | #endif | |
ec79d605 | 154 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 155 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 156 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 157 | |
af9b897e AC |
158 | /** |
159 | * free_tty_struct - free a disused tty | |
160 | * @tty: tty struct to free | |
161 | * | |
162 | * Free the write buffers, tty queue and tty memory itself. | |
163 | * | |
164 | * Locking: none. Must be called after tty is definitely unused | |
165 | */ | |
166 | ||
a3123fd0 | 167 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 168 | { |
c8b710b3 | 169 | tty_ldisc_deinit(tty); |
a211b1af | 170 | put_device(tty->dev); |
1da177e4 | 171 | kfree(tty->write_buf); |
89c8d91e | 172 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
173 | kfree(tty); |
174 | } | |
175 | ||
d996b62a NP |
176 | static inline struct tty_struct *file_tty(struct file *file) |
177 | { | |
178 | return ((struct tty_file_private *)file->private_data)->tty; | |
179 | } | |
180 | ||
fa90e1c9 | 181 | int tty_alloc_file(struct file *file) |
d996b62a NP |
182 | { |
183 | struct tty_file_private *priv; | |
184 | ||
f573bd17 PE |
185 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
186 | if (!priv) | |
187 | return -ENOMEM; | |
d996b62a | 188 | |
fa90e1c9 JS |
189 | file->private_data = priv; |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
194 | /* Associate a new file with the tty structure */ | |
195 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
196 | { | |
197 | struct tty_file_private *priv = file->private_data; | |
198 | ||
d996b62a NP |
199 | priv->tty = tty; |
200 | priv->file = file; | |
d996b62a | 201 | |
4a510969 | 202 | spin_lock(&tty->files_lock); |
d996b62a | 203 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 204 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 205 | } |
f573bd17 | 206 | |
fa90e1c9 JS |
207 | /** |
208 | * tty_free_file - free file->private_data | |
209 | * | |
210 | * This shall be used only for fail path handling when tty_add_file was not | |
211 | * called yet. | |
212 | */ | |
213 | void tty_free_file(struct file *file) | |
214 | { | |
215 | struct tty_file_private *priv = file->private_data; | |
216 | ||
217 | file->private_data = NULL; | |
218 | kfree(priv); | |
d996b62a NP |
219 | } |
220 | ||
221 | /* Delete file from its tty */ | |
2520e274 | 222 | static void tty_del_file(struct file *file) |
d996b62a NP |
223 | { |
224 | struct tty_file_private *priv = file->private_data; | |
4a510969 | 225 | struct tty_struct *tty = priv->tty; |
d996b62a | 226 | |
4a510969 | 227 | spin_lock(&tty->files_lock); |
d996b62a | 228 | list_del(&priv->list); |
4a510969 | 229 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 230 | tty_free_file(file); |
d996b62a NP |
231 | } |
232 | ||
af9b897e AC |
233 | /** |
234 | * tty_name - return tty naming | |
235 | * @tty: tty structure | |
af9b897e AC |
236 | * |
237 | * Convert a tty structure into a name. The name reflects the kernel | |
238 | * naming policy and if udev is in use may not reflect user space | |
239 | * | |
240 | * Locking: none | |
241 | */ | |
242 | ||
429b4749 | 243 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
244 | { |
245 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
246 | return "NULL tty"; |
247 | return tty->name; | |
1da177e4 LT |
248 | } |
249 | ||
250 | EXPORT_SYMBOL(tty_name); | |
251 | ||
0a083edd PH |
252 | const char *tty_driver_name(const struct tty_struct *tty) |
253 | { | |
254 | if (!tty || !tty->driver) | |
255 | return ""; | |
256 | return tty->driver->name; | |
257 | } | |
258 | ||
82b8f888 | 259 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
260 | const char *routine) |
261 | { | |
262 | #ifdef TTY_PARANOIA_CHECK | |
263 | if (!tty) { | |
89222e62 | 264 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
265 | imajor(inode), iminor(inode), routine); |
266 | return 1; | |
267 | } | |
268 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 269 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
270 | imajor(inode), iminor(inode), routine); |
271 | return 1; | |
272 | } | |
273 | #endif | |
274 | return 0; | |
275 | } | |
276 | ||
deb287e7 | 277 | /* Caller must hold tty_lock */ |
1da177e4 LT |
278 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
279 | { | |
280 | #ifdef CHECK_TTY_COUNT | |
281 | struct list_head *p; | |
282 | int count = 0; | |
37bdfb07 | 283 | |
4a510969 | 284 | spin_lock(&tty->files_lock); |
1da177e4 LT |
285 | list_for_each(p, &tty->tty_files) { |
286 | count++; | |
287 | } | |
4a510969 | 288 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
289 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
290 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
291 | tty->link && tty->link->count) | |
292 | count++; | |
293 | if (tty->count != count) { | |
339f36ba PH |
294 | tty_warn(tty, "%s: tty->count(%d) != #fd's(%d)\n", |
295 | routine, tty->count, count); | |
1da177e4 | 296 | return count; |
24ec839c | 297 | } |
1da177e4 LT |
298 | #endif |
299 | return 0; | |
300 | } | |
301 | ||
af9b897e AC |
302 | /** |
303 | * get_tty_driver - find device of a tty | |
304 | * @dev_t: device identifier | |
305 | * @index: returns the index of the tty | |
306 | * | |
307 | * This routine returns a tty driver structure, given a device number | |
308 | * and also passes back the index number. | |
309 | * | |
310 | * Locking: caller must hold tty_mutex | |
1da177e4 | 311 | */ |
af9b897e | 312 | |
1da177e4 LT |
313 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
314 | { | |
315 | struct tty_driver *p; | |
316 | ||
317 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
318 | dev_t base = MKDEV(p->major, p->minor_start); | |
319 | if (device < base || device >= base + p->num) | |
320 | continue; | |
321 | *index = device - base; | |
7d7b93c1 | 322 | return tty_driver_kref_get(p); |
1da177e4 LT |
323 | } |
324 | return NULL; | |
325 | } | |
326 | ||
f2d937f3 JW |
327 | #ifdef CONFIG_CONSOLE_POLL |
328 | ||
329 | /** | |
330 | * tty_find_polling_driver - find device of a polled tty | |
331 | * @name: name string to match | |
332 | * @line: pointer to resulting tty line nr | |
333 | * | |
334 | * This routine returns a tty driver structure, given a name | |
335 | * and the condition that the tty driver is capable of polled | |
336 | * operation. | |
337 | */ | |
338 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
339 | { | |
340 | struct tty_driver *p, *res = NULL; | |
341 | int tty_line = 0; | |
0dca0fd2 | 342 | int len; |
5f0878ac | 343 | char *str, *stp; |
f2d937f3 | 344 | |
0dca0fd2 JW |
345 | for (str = name; *str; str++) |
346 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
347 | break; | |
348 | if (!*str) | |
349 | return NULL; | |
350 | ||
351 | len = str - name; | |
352 | tty_line = simple_strtoul(str, &str, 10); | |
353 | ||
f2d937f3 JW |
354 | mutex_lock(&tty_mutex); |
355 | /* Search through the tty devices to look for a match */ | |
356 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
357 | if (strncmp(name, p->name, len) != 0) |
358 | continue; | |
5f0878ac AC |
359 | stp = str; |
360 | if (*stp == ',') | |
361 | stp++; | |
362 | if (*stp == '\0') | |
363 | stp = NULL; | |
f2d937f3 | 364 | |
6eb68d6f | 365 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 366 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 367 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
368 | *line = tty_line; |
369 | break; | |
370 | } | |
371 | } | |
372 | mutex_unlock(&tty_mutex); | |
373 | ||
374 | return res; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
377 | #endif | |
378 | ||
e802ca0e PH |
379 | static int is_ignored(int sig) |
380 | { | |
381 | return (sigismember(¤t->blocked, sig) || | |
382 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); | |
383 | } | |
384 | ||
af9b897e AC |
385 | /** |
386 | * tty_check_change - check for POSIX terminal changes | |
387 | * @tty: tty to check | |
388 | * | |
389 | * If we try to write to, or set the state of, a terminal and we're | |
390 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
391 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
392 | * | |
978e595f | 393 | * Locking: ctrl_lock |
1da177e4 | 394 | */ |
af9b897e | 395 | |
2812d9e9 | 396 | int __tty_check_change(struct tty_struct *tty, int sig) |
1da177e4 | 397 | { |
47f86834 | 398 | unsigned long flags; |
2812d9e9 | 399 | struct pid *pgrp, *tty_pgrp; |
47f86834 AC |
400 | int ret = 0; |
401 | ||
1da177e4 LT |
402 | if (current->signal->tty != tty) |
403 | return 0; | |
47f86834 | 404 | |
6719693c PD |
405 | rcu_read_lock(); |
406 | pgrp = task_pgrp(current); | |
407 | ||
47f86834 | 408 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
2812d9e9 | 409 | tty_pgrp = tty->pgrp; |
9ffee4cb | 410 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
6719693c | 411 | |
2812d9e9 PH |
412 | if (tty_pgrp && pgrp != tty->pgrp) { |
413 | if (is_ignored(sig)) { | |
414 | if (sig == SIGTTIN) | |
415 | ret = -EIO; | |
416 | } else if (is_current_pgrp_orphaned()) | |
417 | ret = -EIO; | |
418 | else { | |
419 | kill_pgrp(pgrp, sig, 1); | |
420 | set_thread_flag(TIF_SIGPENDING); | |
421 | ret = -ERESTARTSYS; | |
422 | } | |
47f86834 | 423 | } |
6719693c | 424 | rcu_read_unlock(); |
2812d9e9 | 425 | |
339f36ba PH |
426 | if (!tty_pgrp) |
427 | tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig); | |
2812d9e9 | 428 | |
47f86834 | 429 | return ret; |
1da177e4 LT |
430 | } |
431 | ||
2812d9e9 PH |
432 | int tty_check_change(struct tty_struct *tty) |
433 | { | |
434 | return __tty_check_change(tty, SIGTTOU); | |
435 | } | |
1da177e4 LT |
436 | EXPORT_SYMBOL(tty_check_change); |
437 | ||
37bdfb07 | 438 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
439 | size_t count, loff_t *ppos) |
440 | { | |
441 | return 0; | |
442 | } | |
443 | ||
37bdfb07 | 444 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
445 | size_t count, loff_t *ppos) |
446 | { | |
447 | return -EIO; | |
448 | } | |
449 | ||
450 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 451 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
452 | { |
453 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
454 | } | |
455 | ||
04f378b1 AC |
456 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
457 | unsigned long arg) | |
38ad2ed0 PF |
458 | { |
459 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
460 | } | |
461 | ||
37bdfb07 | 462 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 463 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
464 | { |
465 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
466 | } | |
467 | ||
f557474c PH |
468 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
469 | { | |
470 | return -ENOTTY; | |
471 | } | |
472 | ||
62322d25 | 473 | static const struct file_operations tty_fops = { |
1da177e4 LT |
474 | .llseek = no_llseek, |
475 | .read = tty_read, | |
476 | .write = tty_write, | |
477 | .poll = tty_poll, | |
04f378b1 | 478 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 479 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
480 | .open = tty_open, |
481 | .release = tty_release, | |
482 | .fasync = tty_fasync, | |
483 | }; | |
484 | ||
62322d25 | 485 | static const struct file_operations console_fops = { |
1da177e4 LT |
486 | .llseek = no_llseek, |
487 | .read = tty_read, | |
488 | .write = redirected_tty_write, | |
489 | .poll = tty_poll, | |
04f378b1 | 490 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 491 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
492 | .open = tty_open, |
493 | .release = tty_release, | |
494 | .fasync = tty_fasync, | |
495 | }; | |
496 | ||
62322d25 | 497 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
498 | .llseek = no_llseek, |
499 | .read = hung_up_tty_read, | |
500 | .write = hung_up_tty_write, | |
501 | .poll = hung_up_tty_poll, | |
04f378b1 | 502 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 503 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 504 | .release = tty_release, |
f557474c | 505 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
506 | }; |
507 | ||
508 | static DEFINE_SPINLOCK(redirect_lock); | |
509 | static struct file *redirect; | |
510 | ||
11d9befd PH |
511 | |
512 | void proc_clear_tty(struct task_struct *p) | |
513 | { | |
514 | unsigned long flags; | |
515 | struct tty_struct *tty; | |
516 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
517 | tty = p->signal->tty; | |
518 | p->signal->tty = NULL; | |
519 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
520 | tty_kref_put(tty); | |
521 | } | |
522 | ||
2c411c11 PH |
523 | /** |
524 | * proc_set_tty - set the controlling terminal | |
525 | * | |
526 | * Only callable by the session leader and only if it does not already have | |
527 | * a controlling terminal. | |
528 | * | |
e218eb32 PH |
529 | * Caller must hold: tty_lock() |
530 | * a readlock on tasklist_lock | |
2c411c11 PH |
531 | * sighand lock |
532 | */ | |
bce65f18 | 533 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 534 | { |
ae28fa72 PH |
535 | unsigned long flags; |
536 | ||
ae28fa72 | 537 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
538 | /* |
539 | * The session and fg pgrp references will be non-NULL if | |
540 | * tiocsctty() is stealing the controlling tty | |
541 | */ | |
ae28fa72 PH |
542 | put_pid(tty->session); |
543 | put_pid(tty->pgrp); | |
544 | tty->pgrp = get_pid(task_pgrp(current)); | |
545 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
546 | tty->session = get_pid(task_session(current)); | |
547 | if (current->signal->tty) { | |
e2dfa3d3 PH |
548 | tty_debug(tty, "current tty %s not NULL!!\n", |
549 | current->signal->tty->name); | |
ae28fa72 | 550 | tty_kref_put(current->signal->tty); |
11d9befd | 551 | } |
bce65f18 PH |
552 | put_pid(current->signal->tty_old_pgrp); |
553 | current->signal->tty = tty_kref_get(tty); | |
554 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
555 | } |
556 | ||
bce65f18 | 557 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 558 | { |
bce65f18 PH |
559 | spin_lock_irq(¤t->sighand->siglock); |
560 | __proc_set_tty(tty); | |
561 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
562 | } |
563 | ||
564 | struct tty_struct *get_current_tty(void) | |
565 | { | |
566 | struct tty_struct *tty; | |
567 | unsigned long flags; | |
568 | ||
569 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
570 | tty = tty_kref_get(current->signal->tty); | |
571 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
572 | return tty; | |
573 | } | |
574 | EXPORT_SYMBOL_GPL(get_current_tty); | |
575 | ||
576 | static void session_clear_tty(struct pid *session) | |
577 | { | |
578 | struct task_struct *p; | |
579 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
580 | proc_clear_tty(p); | |
581 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
582 | } | |
583 | ||
1da177e4 LT |
584 | /** |
585 | * tty_wakeup - request more data | |
586 | * @tty: terminal | |
587 | * | |
588 | * Internal and external helper for wakeups of tty. This function | |
589 | * informs the line discipline if present that the driver is ready | |
590 | * to receive more output data. | |
591 | */ | |
37bdfb07 | 592 | |
1da177e4 LT |
593 | void tty_wakeup(struct tty_struct *tty) |
594 | { | |
595 | struct tty_ldisc *ld; | |
37bdfb07 | 596 | |
1da177e4 LT |
597 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
598 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 599 | if (ld) { |
a352def2 AC |
600 | if (ld->ops->write_wakeup) |
601 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
602 | tty_ldisc_deref(ld); |
603 | } | |
604 | } | |
4b19449d | 605 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
606 | } |
607 | ||
608 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
609 | ||
ea648a47 PH |
610 | /** |
611 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
612 | * @tty controlling tty |
613 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 614 | * |
f91e2590 PH |
615 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
616 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
617 | * |
618 | * Returns the number of processes in the session with this tty | |
619 | * as their controlling terminal. This value is used to drop | |
620 | * tty references for those processes. | |
621 | */ | |
f91e2590 | 622 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
623 | { |
624 | struct task_struct *p; | |
ea648a47 | 625 | int refs = 0; |
f91e2590 | 626 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
627 | |
628 | read_lock(&tasklist_lock); | |
629 | if (tty->session) { | |
630 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
631 | spin_lock_irq(&p->sighand->siglock); | |
632 | if (p->signal->tty == tty) { | |
633 | p->signal->tty = NULL; | |
634 | /* We defer the dereferences outside fo | |
635 | the tasklist lock */ | |
636 | refs++; | |
637 | } | |
638 | if (!p->signal->leader) { | |
639 | spin_unlock_irq(&p->sighand->siglock); | |
640 | continue; | |
641 | } | |
642 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
643 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
644 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 645 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 646 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
647 | if (tty->pgrp) |
648 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 649 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
650 | spin_unlock_irq(&p->sighand->siglock); |
651 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
652 | } | |
653 | read_unlock(&tasklist_lock); | |
654 | ||
f91e2590 PH |
655 | if (tty_pgrp) { |
656 | if (exit_session) | |
657 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
658 | put_pid(tty_pgrp); | |
659 | } | |
660 | ||
ea648a47 PH |
661 | return refs; |
662 | } | |
663 | ||
af9b897e | 664 | /** |
11dbf203 | 665 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 666 | * @work: tty device |
af9b897e | 667 | * |
ef4f527c | 668 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
669 | * synchronous but doesn't hold any locks, so we need to make sure we |
670 | * have the appropriate locks for what we're doing. | |
671 | * | |
672 | * The hangup event clears any pending redirections onto the hung up | |
673 | * device. It ensures future writes will error and it does the needed | |
674 | * line discipline hangup and signal delivery. The tty object itself | |
675 | * remains intact. | |
676 | * | |
677 | * Locking: | |
ec79d605 | 678 | * BTM |
24ec839c PZ |
679 | * redirect lock for undoing redirection |
680 | * file list lock for manipulating list of ttys | |
137084bb | 681 | * tty_ldiscs_lock from called functions |
6a1c0680 | 682 | * termios_rwsem resetting termios data |
24ec839c PZ |
683 | * tasklist_lock to walk task list for hangup event |
684 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 685 | */ |
f91e2590 | 686 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 687 | { |
37bdfb07 | 688 | struct file *cons_filp = NULL; |
1da177e4 | 689 | struct file *filp, *f = NULL; |
d996b62a | 690 | struct tty_file_private *priv; |
1da177e4 | 691 | int closecount = 0, n; |
ea648a47 | 692 | int refs; |
1da177e4 LT |
693 | |
694 | if (!tty) | |
695 | return; | |
696 | ||
1da177e4 LT |
697 | |
698 | spin_lock(&redirect_lock); | |
d996b62a | 699 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
700 | f = redirect; |
701 | redirect = NULL; | |
702 | } | |
703 | spin_unlock(&redirect_lock); | |
37bdfb07 | 704 | |
89c8d91e | 705 | tty_lock(tty); |
11dbf203 | 706 | |
cb50e523 PH |
707 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
708 | tty_unlock(tty); | |
709 | return; | |
710 | } | |
711 | ||
ec79d605 AB |
712 | /* inuse_filps is protected by the single tty lock, |
713 | this really needs to change if we want to flush the | |
714 | workqueue with the lock held */ | |
11dbf203 | 715 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 716 | |
4a510969 | 717 | spin_lock(&tty->files_lock); |
1da177e4 | 718 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
719 | list_for_each_entry(priv, &tty->tty_files, list) { |
720 | filp = priv->file; | |
1da177e4 LT |
721 | if (filp->f_op->write == redirected_tty_write) |
722 | cons_filp = filp; | |
723 | if (filp->f_op->write != tty_write) | |
724 | continue; | |
725 | closecount++; | |
ec79d605 | 726 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
727 | filp->f_op = &hung_up_tty_fops; |
728 | } | |
4a510969 | 729 | spin_unlock(&tty->files_lock); |
37bdfb07 | 730 | |
25fdf243 PH |
731 | refs = tty_signal_session_leader(tty, exit_session); |
732 | /* Account for the p->signal references we killed */ | |
733 | while (refs--) | |
734 | tty_kref_put(tty); | |
735 | ||
892d1fa7 | 736 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 737 | |
20cc225b | 738 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 739 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 740 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
741 | put_pid(tty->session); |
742 | put_pid(tty->pgrp); | |
ab521dc0 EB |
743 | tty->session = NULL; |
744 | tty->pgrp = NULL; | |
1da177e4 | 745 | tty->ctrl_status = 0; |
20cc225b | 746 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 747 | |
1da177e4 | 748 | /* |
37bdfb07 AC |
749 | * If one of the devices matches a console pointer, we |
750 | * cannot just call hangup() because that will cause | |
751 | * tty->count and state->count to go out of sync. | |
752 | * So we just call close() the right number of times. | |
1da177e4 LT |
753 | */ |
754 | if (cons_filp) { | |
f34d7a5b | 755 | if (tty->ops->close) |
1da177e4 | 756 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
757 | tty->ops->close(tty, cons_filp); |
758 | } else if (tty->ops->hangup) | |
7c6d340f | 759 | tty->ops->hangup(tty); |
37bdfb07 | 760 | /* |
892d1fa7 PH |
761 | * We don't want to have driver/ldisc interactions beyond the ones |
762 | * we did here. The driver layer expects no calls after ->hangup() | |
763 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 764 | */ |
1da177e4 | 765 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 766 | tty_unlock(tty); |
11dbf203 | 767 | |
1da177e4 LT |
768 | if (f) |
769 | fput(f); | |
770 | } | |
771 | ||
ddcd9fb6 AB |
772 | static void do_tty_hangup(struct work_struct *work) |
773 | { | |
774 | struct tty_struct *tty = | |
775 | container_of(work, struct tty_struct, hangup_work); | |
776 | ||
f91e2590 | 777 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
778 | } |
779 | ||
af9b897e AC |
780 | /** |
781 | * tty_hangup - trigger a hangup event | |
782 | * @tty: tty to hangup | |
783 | * | |
784 | * A carrier loss (virtual or otherwise) has occurred on this like | |
785 | * schedule a hangup sequence to run after this event. | |
786 | */ | |
787 | ||
37bdfb07 | 788 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 789 | { |
d435cefe | 790 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
791 | schedule_work(&tty->hangup_work); |
792 | } | |
793 | ||
794 | EXPORT_SYMBOL(tty_hangup); | |
795 | ||
af9b897e AC |
796 | /** |
797 | * tty_vhangup - process vhangup | |
798 | * @tty: tty to hangup | |
799 | * | |
800 | * The user has asked via system call for the terminal to be hung up. | |
801 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 802 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
803 | */ |
804 | ||
37bdfb07 | 805 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 806 | { |
d435cefe | 807 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 808 | __tty_hangup(tty, 0); |
1da177e4 | 809 | } |
37bdfb07 | 810 | |
1da177e4 LT |
811 | EXPORT_SYMBOL(tty_vhangup); |
812 | ||
11dbf203 | 813 | |
2cb5998b AC |
814 | /** |
815 | * tty_vhangup_self - process vhangup for own ctty | |
816 | * | |
817 | * Perform a vhangup on the current controlling tty | |
818 | */ | |
819 | ||
820 | void tty_vhangup_self(void) | |
821 | { | |
822 | struct tty_struct *tty; | |
823 | ||
2cb5998b AC |
824 | tty = get_current_tty(); |
825 | if (tty) { | |
826 | tty_vhangup(tty); | |
827 | tty_kref_put(tty); | |
828 | } | |
2cb5998b AC |
829 | } |
830 | ||
f91e2590 PH |
831 | /** |
832 | * tty_vhangup_session - hangup session leader exit | |
833 | * @tty: tty to hangup | |
834 | * | |
835 | * The session leader is exiting and hanging up its controlling terminal. | |
836 | * Every process in the foreground process group is signalled SIGHUP. | |
837 | * | |
838 | * We do this synchronously so that when the syscall returns the process | |
839 | * is complete. That guarantee is necessary for security reasons. | |
840 | */ | |
841 | ||
44a459fd | 842 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 843 | { |
d435cefe | 844 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
845 | __tty_hangup(tty, 1); |
846 | } | |
847 | ||
af9b897e AC |
848 | /** |
849 | * tty_hung_up_p - was tty hung up | |
850 | * @filp: file pointer of tty | |
851 | * | |
852 | * Return true if the tty has been subject to a vhangup or a carrier | |
853 | * loss | |
854 | */ | |
855 | ||
37bdfb07 | 856 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
857 | { |
858 | return (filp->f_op == &hung_up_tty_fops); | |
859 | } | |
860 | ||
861 | EXPORT_SYMBOL(tty_hung_up_p); | |
862 | ||
af9b897e AC |
863 | /** |
864 | * disassociate_ctty - disconnect controlling tty | |
865 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 866 | * |
af9b897e AC |
867 | * This function is typically called only by the session leader, when |
868 | * it wants to disassociate itself from its controlling tty. | |
869 | * | |
870 | * It performs the following functions: | |
1da177e4 LT |
871 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
872 | * (2) Clears the tty from being controlling the session | |
873 | * (3) Clears the controlling tty for all processes in the | |
874 | * session group. | |
875 | * | |
af9b897e AC |
876 | * The argument on_exit is set to 1 if called when a process is |
877 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
878 | * | |
24ec839c | 879 | * Locking: |
ec79d605 AB |
880 | * BTM is taken for hysterical raisins, and held when |
881 | * called from no_tty(). | |
24ec839c PZ |
882 | * tty_mutex is taken to protect tty |
883 | * ->siglock is taken to protect ->signal/->sighand | |
884 | * tasklist_lock is taken to walk process list for sessions | |
885 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 886 | */ |
af9b897e | 887 | |
1da177e4 LT |
888 | void disassociate_ctty(int on_exit) |
889 | { | |
890 | struct tty_struct *tty; | |
1da177e4 | 891 | |
5ec93d11 AC |
892 | if (!current->signal->leader) |
893 | return; | |
1da177e4 | 894 | |
24ec839c | 895 | tty = get_current_tty(); |
1da177e4 | 896 | if (tty) { |
f91e2590 PH |
897 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
898 | tty_vhangup_session(tty); | |
899 | } else { | |
900 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
901 | if (tty_pgrp) { | |
902 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
903 | if (!on_exit) |
904 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
905 | put_pid(tty_pgrp); |
906 | } | |
1411dc4a | 907 | } |
f91e2590 PH |
908 | tty_kref_put(tty); |
909 | ||
680a9671 | 910 | } else if (on_exit) { |
ab521dc0 | 911 | struct pid *old_pgrp; |
680a9671 EB |
912 | spin_lock_irq(¤t->sighand->siglock); |
913 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 914 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 915 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 916 | if (old_pgrp) { |
ab521dc0 EB |
917 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
918 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
919 | put_pid(old_pgrp); | |
1da177e4 | 920 | } |
1da177e4 LT |
921 | return; |
922 | } | |
1da177e4 | 923 | |
24ec839c | 924 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 925 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 926 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 927 | |
c70dbb1e | 928 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 929 | if (tty) { |
47f86834 AC |
930 | unsigned long flags; |
931 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
932 | put_pid(tty->session); |
933 | put_pid(tty->pgrp); | |
934 | tty->session = NULL; | |
935 | tty->pgrp = NULL; | |
47f86834 | 936 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 937 | tty_kref_put(tty); |
accff793 PH |
938 | } else |
939 | tty_debug_hangup(tty, "no current tty\n"); | |
1da177e4 | 940 | |
c70dbb1e | 941 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
942 | /* Now clear signal->tty under the lock */ |
943 | read_lock(&tasklist_lock); | |
ab521dc0 | 944 | session_clear_tty(task_session(current)); |
1da177e4 | 945 | read_unlock(&tasklist_lock); |
1da177e4 LT |
946 | } |
947 | ||
98a27ba4 EB |
948 | /** |
949 | * | |
950 | * no_tty - Ensure the current process does not have a controlling tty | |
951 | */ | |
952 | void no_tty(void) | |
953 | { | |
3af502b9 AC |
954 | /* FIXME: Review locking here. The tty_lock never covered any race |
955 | between a new association and proc_clear_tty but possible we need | |
956 | to protect against this anyway */ | |
98a27ba4 | 957 | struct task_struct *tsk = current; |
5ec93d11 | 958 | disassociate_ctty(0); |
98a27ba4 EB |
959 | proc_clear_tty(tsk); |
960 | } | |
961 | ||
af9b897e AC |
962 | |
963 | /** | |
beb7dd86 | 964 | * stop_tty - propagate flow control |
af9b897e AC |
965 | * @tty: tty to stop |
966 | * | |
01adc807 | 967 | * Perform flow control to the driver. May be called |
af9b897e AC |
968 | * on an already stopped device and will not re-call the driver |
969 | * method. | |
970 | * | |
971 | * This functionality is used by both the line disciplines for | |
972 | * halting incoming flow and by the driver. It may therefore be | |
973 | * called from any context, may be under the tty atomic_write_lock | |
974 | * but not always. | |
975 | * | |
976 | * Locking: | |
f9e053dc | 977 | * flow_lock |
af9b897e AC |
978 | */ |
979 | ||
f9e053dc | 980 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 981 | { |
f9e053dc | 982 | if (tty->stopped) |
1da177e4 LT |
983 | return; |
984 | tty->stopped = 1; | |
f34d7a5b | 985 | if (tty->ops->stop) |
c961bfb1 | 986 | tty->ops->stop(tty); |
1da177e4 LT |
987 | } |
988 | ||
f9e053dc PH |
989 | void stop_tty(struct tty_struct *tty) |
990 | { | |
991 | unsigned long flags; | |
992 | ||
993 | spin_lock_irqsave(&tty->flow_lock, flags); | |
994 | __stop_tty(tty); | |
995 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
996 | } | |
1da177e4 LT |
997 | EXPORT_SYMBOL(stop_tty); |
998 | ||
af9b897e | 999 | /** |
beb7dd86 | 1000 | * start_tty - propagate flow control |
af9b897e AC |
1001 | * @tty: tty to start |
1002 | * | |
01adc807 PH |
1003 | * Start a tty that has been stopped if at all possible. If this |
1004 | * tty was previous stopped and is now being started, the driver | |
1005 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1006 | * |
1007 | * Locking: | |
f9e053dc | 1008 | * flow_lock |
af9b897e AC |
1009 | */ |
1010 | ||
f9e053dc | 1011 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1012 | { |
f9e053dc | 1013 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1014 | return; |
1015 | tty->stopped = 0; | |
f34d7a5b | 1016 | if (tty->ops->start) |
c961bfb1 | 1017 | tty->ops->start(tty); |
1da177e4 | 1018 | tty_wakeup(tty); |
1da177e4 LT |
1019 | } |
1020 | ||
f9e053dc PH |
1021 | void start_tty(struct tty_struct *tty) |
1022 | { | |
1023 | unsigned long flags; | |
1024 | ||
1025 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1026 | __start_tty(tty); | |
1027 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1028 | } | |
1da177e4 LT |
1029 | EXPORT_SYMBOL(start_tty); |
1030 | ||
37b7f3c7 JS |
1031 | static void tty_update_time(struct timespec *time) |
1032 | { | |
f0bf0bd0 | 1033 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
1034 | |
1035 | /* | |
1036 | * We only care if the two values differ in anything other than the | |
1037 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
1038 | * the time of the tty device, otherwise it could be construded as a | |
1039 | * security leak to let userspace know the exact timing of the tty. | |
1040 | */ | |
1041 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
1042 | time->tv_sec = sec; |
1043 | } | |
1044 | ||
af9b897e AC |
1045 | /** |
1046 | * tty_read - read method for tty device files | |
1047 | * @file: pointer to tty file | |
1048 | * @buf: user buffer | |
1049 | * @count: size of user buffer | |
1050 | * @ppos: unused | |
1051 | * | |
1052 | * Perform the read system call function on this terminal device. Checks | |
1053 | * for hung up devices before calling the line discipline method. | |
1054 | * | |
1055 | * Locking: | |
47f86834 AC |
1056 | * Locks the line discipline internally while needed. Multiple |
1057 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1058 | */ |
1059 | ||
37bdfb07 | 1060 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1061 | loff_t *ppos) |
1062 | { | |
1063 | int i; | |
37b7f3c7 | 1064 | struct inode *inode = file_inode(file); |
d996b62a | 1065 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1066 | struct tty_ldisc *ld; |
1067 | ||
37b7f3c7 | 1068 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 1069 | return -EIO; |
18900ca6 | 1070 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
1071 | return -EIO; |
1072 | ||
1073 | /* We want to wait for the line discipline to sort out in this | |
1074 | situation */ | |
1075 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
1076 | if (!ld) |
1077 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 1078 | if (ld->ops->read) |
c961bfb1 | 1079 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1080 | else |
1081 | i = -EIO; | |
1082 | tty_ldisc_deref(ld); | |
b0de59b5 | 1083 | |
37b7f3c7 JS |
1084 | if (i > 0) |
1085 | tty_update_time(&inode->i_atime); | |
1086 | ||
1da177e4 LT |
1087 | return i; |
1088 | } | |
1089 | ||
136d5258 | 1090 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1091 | { |
1092 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1093 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1094 | } |
1095 | ||
136d5258 | 1096 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1097 | { |
1098 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1099 | if (ndelay) | |
1100 | return -EAGAIN; | |
1101 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1102 | return -ERESTARTSYS; | |
1103 | } | |
1104 | return 0; | |
1105 | } | |
1106 | ||
1da177e4 LT |
1107 | /* |
1108 | * Split writes up in sane blocksizes to avoid | |
1109 | * denial-of-service type attacks | |
1110 | */ | |
1111 | static inline ssize_t do_tty_write( | |
1112 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1113 | struct tty_struct *tty, | |
1114 | struct file *file, | |
1115 | const char __user *buf, | |
1116 | size_t count) | |
1117 | { | |
9c1729db | 1118 | ssize_t ret, written = 0; |
1da177e4 | 1119 | unsigned int chunk; |
37bdfb07 | 1120 | |
9c1729db AC |
1121 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1122 | if (ret < 0) | |
1123 | return ret; | |
1da177e4 LT |
1124 | |
1125 | /* | |
1126 | * We chunk up writes into a temporary buffer. This | |
1127 | * simplifies low-level drivers immensely, since they | |
1128 | * don't have locking issues and user mode accesses. | |
1129 | * | |
1130 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1131 | * big chunk-size.. | |
1132 | * | |
1133 | * The default chunk-size is 2kB, because the NTTY | |
1134 | * layer has problems with bigger chunks. It will | |
1135 | * claim to be able to handle more characters than | |
1136 | * it actually does. | |
af9b897e AC |
1137 | * |
1138 | * FIXME: This can probably go away now except that 64K chunks | |
1139 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1140 | */ |
1141 | chunk = 2048; | |
1142 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1143 | chunk = 65536; | |
1144 | if (count < chunk) | |
1145 | chunk = count; | |
1146 | ||
70522e12 | 1147 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1148 | if (tty->write_cnt < chunk) { |
402fda92 | 1149 | unsigned char *buf_chunk; |
1da177e4 LT |
1150 | |
1151 | if (chunk < 1024) | |
1152 | chunk = 1024; | |
1153 | ||
402fda92 JW |
1154 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1155 | if (!buf_chunk) { | |
9c1729db AC |
1156 | ret = -ENOMEM; |
1157 | goto out; | |
1da177e4 LT |
1158 | } |
1159 | kfree(tty->write_buf); | |
1160 | tty->write_cnt = chunk; | |
402fda92 | 1161 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1162 | } |
1163 | ||
1164 | /* Do the write .. */ | |
1165 | for (;;) { | |
1166 | size_t size = count; | |
1167 | if (size > chunk) | |
1168 | size = chunk; | |
1169 | ret = -EFAULT; | |
1170 | if (copy_from_user(tty->write_buf, buf, size)) | |
1171 | break; | |
1da177e4 | 1172 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1173 | if (ret <= 0) |
1174 | break; | |
1175 | written += ret; | |
1176 | buf += ret; | |
1177 | count -= ret; | |
1178 | if (!count) | |
1179 | break; | |
1180 | ret = -ERESTARTSYS; | |
1181 | if (signal_pending(current)) | |
1182 | break; | |
1183 | cond_resched(); | |
1184 | } | |
37b7f3c7 JS |
1185 | if (written) { |
1186 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1187 | ret = written; |
37b7f3c7 | 1188 | } |
9c1729db AC |
1189 | out: |
1190 | tty_write_unlock(tty); | |
1da177e4 LT |
1191 | return ret; |
1192 | } | |
1193 | ||
95f9bfc6 AC |
1194 | /** |
1195 | * tty_write_message - write a message to a certain tty, not just the console. | |
1196 | * @tty: the destination tty_struct | |
1197 | * @msg: the message to write | |
1198 | * | |
1199 | * This is used for messages that need to be redirected to a specific tty. | |
1200 | * We don't put it into the syslog queue right now maybe in the future if | |
1201 | * really needed. | |
1202 | * | |
ec79d605 | 1203 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1204 | */ |
1205 | ||
1206 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1207 | { | |
95f9bfc6 AC |
1208 | if (tty) { |
1209 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1210 | tty_lock(tty); |
4b41b953 | 1211 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1212 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 1213 | tty_unlock(tty); |
95f9bfc6 AC |
1214 | tty_write_unlock(tty); |
1215 | } | |
95f9bfc6 AC |
1216 | return; |
1217 | } | |
1218 | ||
1da177e4 | 1219 | |
af9b897e AC |
1220 | /** |
1221 | * tty_write - write method for tty device file | |
1222 | * @file: tty file pointer | |
1223 | * @buf: user data to write | |
1224 | * @count: bytes to write | |
1225 | * @ppos: unused | |
1226 | * | |
1227 | * Write data to a tty device via the line discipline. | |
1228 | * | |
1229 | * Locking: | |
1230 | * Locks the line discipline as required | |
1231 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1232 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1233 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1234 | */ |
1235 | ||
37bdfb07 AC |
1236 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1237 | size_t count, loff_t *ppos) | |
1da177e4 | 1238 | { |
d996b62a NP |
1239 | struct tty_struct *tty = file_tty(file); |
1240 | struct tty_ldisc *ld; | |
1da177e4 | 1241 | ssize_t ret; |
37bdfb07 | 1242 | |
6131ffaa | 1243 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1244 | return -EIO; |
18900ca6 | 1245 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
37bdfb07 | 1246 | return -EIO; |
f34d7a5b AC |
1247 | /* Short term debug to catch buggy drivers */ |
1248 | if (tty->ops->write_room == NULL) | |
339f36ba | 1249 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1250 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1251 | if (!ld) |
1252 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1253 | if (!ld->ops->write) |
1da177e4 LT |
1254 | ret = -EIO; |
1255 | else | |
a352def2 | 1256 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1257 | tty_ldisc_deref(ld); |
1258 | return ret; | |
1259 | } | |
1260 | ||
37bdfb07 AC |
1261 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1262 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1263 | { |
1264 | struct file *p = NULL; | |
1265 | ||
1266 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1267 | if (redirect) |
1268 | p = get_file(redirect); | |
1da177e4 LT |
1269 | spin_unlock(&redirect_lock); |
1270 | ||
1271 | if (p) { | |
1272 | ssize_t res; | |
1273 | res = vfs_write(p, buf, count, &p->f_pos); | |
1274 | fput(p); | |
1275 | return res; | |
1276 | } | |
1da177e4 LT |
1277 | return tty_write(file, buf, count, ppos); |
1278 | } | |
1279 | ||
136d5258 PH |
1280 | /** |
1281 | * tty_send_xchar - send priority character | |
1282 | * | |
1283 | * Send a high priority character to the tty even if stopped | |
1284 | * | |
1285 | * Locking: none for xchar method, write ordering for write method. | |
1286 | */ | |
1287 | ||
1288 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1289 | { | |
1290 | int was_stopped = tty->stopped; | |
1291 | ||
1292 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1293 | down_read(&tty->termios_rwsem); |
136d5258 | 1294 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1295 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1296 | return 0; |
1297 | } | |
1298 | ||
1299 | if (tty_write_lock(tty, 0) < 0) | |
1300 | return -ERESTARTSYS; | |
1301 | ||
ee0c1a65 | 1302 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1303 | if (was_stopped) |
1304 | start_tty(tty); | |
1305 | tty->ops->write(tty, &ch, 1); | |
1306 | if (was_stopped) | |
1307 | stop_tty(tty); | |
ee0c1a65 | 1308 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1309 | tty_write_unlock(tty); |
1310 | return 0; | |
1311 | } | |
1312 | ||
1da177e4 LT |
1313 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1314 | ||
af9b897e AC |
1315 | /** |
1316 | * pty_line_name - generate name for a pty | |
1317 | * @driver: the tty driver in use | |
1318 | * @index: the minor number | |
1319 | * @p: output buffer of at least 6 bytes | |
1320 | * | |
1321 | * Generate a name from a driver reference and write it to the output | |
1322 | * buffer. | |
1323 | * | |
1324 | * Locking: None | |
1325 | */ | |
1326 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1327 | { |
1328 | int i = index + driver->name_base; | |
1329 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1330 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1331 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1332 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1333 | } |
1334 | ||
af9b897e | 1335 | /** |
8b0a88d5 | 1336 | * tty_line_name - generate name for a tty |
af9b897e AC |
1337 | * @driver: the tty driver in use |
1338 | * @index: the minor number | |
1339 | * @p: output buffer of at least 7 bytes | |
1340 | * | |
1341 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1342 | * buffer. |
af9b897e AC |
1343 | * |
1344 | * Locking: None | |
1345 | */ | |
723abd87 | 1346 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1347 | { |
0019b408 | 1348 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1349 | return sprintf(p, "%s", driver->name); |
0019b408 | 1350 | else |
723abd87 HR |
1351 | return sprintf(p, "%s%d", driver->name, |
1352 | index + driver->name_base); | |
1da177e4 LT |
1353 | } |
1354 | ||
99f1fe18 AC |
1355 | /** |
1356 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1357 | * @driver: the driver for the tty | |
1358 | * @idx: the minor number | |
23499705 | 1359 | * |
aa3cb814 PH |
1360 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1361 | * driver lookup() method returns an error. | |
23499705 | 1362 | * |
aa3cb814 | 1363 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1364 | */ |
a47d545f | 1365 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1366 | struct file *file, int idx) |
23499705 | 1367 | { |
aa3cb814 PH |
1368 | struct tty_struct *tty; |
1369 | ||
99f1fe18 | 1370 | if (driver->ops->lookup) |
8ead9dd5 | 1371 | tty = driver->ops->lookup(driver, file, idx); |
aa3cb814 PH |
1372 | else |
1373 | tty = driver->ttys[idx]; | |
23499705 | 1374 | |
aa3cb814 PH |
1375 | if (!IS_ERR(tty)) |
1376 | tty_kref_get(tty); | |
1377 | return tty; | |
23499705 SB |
1378 | } |
1379 | ||
bf970ee4 AC |
1380 | /** |
1381 | * tty_init_termios - helper for termios setup | |
1382 | * @tty: the tty to set up | |
1383 | * | |
1384 | * Initialise the termios structures for this tty. Thus runs under | |
1385 | * the tty_mutex currently so we can be relaxed about ordering. | |
1386 | */ | |
1387 | ||
a3123fd0 | 1388 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1389 | { |
fe6e29fd | 1390 | struct ktermios *tp; |
bf970ee4 AC |
1391 | int idx = tty->index; |
1392 | ||
36b3c070 AC |
1393 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1394 | tty->termios = tty->driver->init_termios; | |
1395 | else { | |
1396 | /* Check for lazy saved data */ | |
1397 | tp = tty->driver->termios[idx]; | |
ece53405 | 1398 | if (tp != NULL) { |
36b3c070 | 1399 | tty->termios = *tp; |
ece53405 PH |
1400 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1401 | } else | |
36b3c070 | 1402 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1403 | } |
bf970ee4 | 1404 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1405 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1406 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1407 | } |
fe1ae7fd | 1408 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1409 | |
66d450e8 JS |
1410 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1411 | { | |
a3123fd0 | 1412 | tty_init_termios(tty); |
66d450e8 JS |
1413 | tty_driver_kref_get(driver); |
1414 | tty->count++; | |
1415 | driver->ttys[tty->index] = tty; | |
1416 | return 0; | |
1417 | } | |
1418 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1419 | ||
99f1fe18 | 1420 | /** |
8b0a88d5 AC |
1421 | * tty_driver_install_tty() - install a tty entry in the driver |
1422 | * @driver: the driver for the tty | |
1423 | * @tty: the tty | |
1424 | * | |
1425 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1426 | * will be set by the time this is called. This method is responsible |
1427 | * for ensuring any need additional structures are allocated and | |
1428 | * configured. | |
8b0a88d5 AC |
1429 | * |
1430 | * Locking: tty_mutex for now | |
1431 | */ | |
1432 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1433 | struct tty_struct *tty) | |
1434 | { | |
66d450e8 JS |
1435 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1436 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1437 | } |
1438 | ||
1439 | /** | |
1440 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1441 | * @driver: the driver for the tty | |
1442 | * @idx: the minor number | |
1443 | * | |
1444 | * Remvoe a tty object from the driver tables. The tty->index field | |
1445 | * will be set by the time this is called. | |
1446 | * | |
1447 | * Locking: tty_mutex for now | |
1448 | */ | |
05de87ed | 1449 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1450 | { |
1451 | if (driver->ops->remove) | |
1452 | driver->ops->remove(driver, tty); | |
1453 | else | |
1454 | driver->ttys[tty->index] = NULL; | |
1455 | } | |
1456 | ||
1457 | /* | |
1458 | * tty_reopen() - fast re-open of an open tty | |
1459 | * @tty - the tty to open | |
23499705 | 1460 | * |
99f1fe18 | 1461 | * Return 0 on success, -errno on error. |
5d93e748 | 1462 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1463 | * |
5d93e748 | 1464 | * Locking: Caller must hold tty_lock |
23499705 | 1465 | */ |
99f1fe18 | 1466 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1467 | { |
1468 | struct tty_driver *driver = tty->driver; | |
1469 | ||
23499705 | 1470 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1471 | driver->subtype == PTY_TYPE_MASTER) |
1472 | return -EIO; | |
23499705 | 1473 | |
7f22f6c9 PH |
1474 | if (!tty->count) |
1475 | return -EAGAIN; | |
1476 | ||
86f2c00f PH |
1477 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1478 | return -EBUSY; | |
1479 | ||
23499705 | 1480 | tty->count++; |
23499705 | 1481 | |
892d1fa7 PH |
1482 | if (!tty->ldisc) |
1483 | return tty_ldisc_reinit(tty, tty->termios.c_line); | |
23499705 SB |
1484 | |
1485 | return 0; | |
1486 | } | |
1487 | ||
af9b897e | 1488 | /** |
d81ed103 | 1489 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1490 | * @driver: tty driver we are opening a device on |
1491 | * @idx: device index | |
15582d36 | 1492 | * @ret_tty: returned tty structure |
af9b897e AC |
1493 | * |
1494 | * Prepare a tty device. This may not be a "new" clean device but | |
1495 | * could also be an active device. The pty drivers require special | |
1496 | * handling because of this. | |
1497 | * | |
1498 | * Locking: | |
1499 | * The function is called under the tty_mutex, which | |
1500 | * protects us from the tty struct or driver itself going away. | |
1501 | * | |
1502 | * On exit the tty device has the line discipline attached and | |
1503 | * a reference count of 1. If a pair was created for pty/tty use | |
1504 | * and the other was a pty master then it too has a reference count of 1. | |
1505 | * | |
1da177e4 | 1506 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1507 | * failed open. The new code protects the open with a mutex, so it's |
1508 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1509 | * relaxed for the (most common) case of reopening a tty. |
1510 | */ | |
af9b897e | 1511 | |
593a27c4 | 1512 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1513 | { |
bf970ee4 | 1514 | struct tty_struct *tty; |
73ec06fc | 1515 | int retval; |
1da177e4 | 1516 | |
1da177e4 LT |
1517 | /* |
1518 | * First time open is complex, especially for PTY devices. | |
1519 | * This code guarantees that either everything succeeds and the | |
1520 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1521 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1522 | * and locked termios may be retained.) |
1523 | */ | |
1524 | ||
73ec06fc AC |
1525 | if (!try_module_get(driver->owner)) |
1526 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1527 | |
2c964a2f | 1528 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1529 | if (!tty) { |
1530 | retval = -ENOMEM; | |
1531 | goto err_module_put; | |
1532 | } | |
1da177e4 | 1533 | |
89c8d91e | 1534 | tty_lock(tty); |
73ec06fc | 1535 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1536 | if (retval < 0) |
c8b710b3 | 1537 | goto err_free_tty; |
8b0a88d5 | 1538 | |
04831dc1 JS |
1539 | if (!tty->port) |
1540 | tty->port = driver->ports[idx]; | |
1541 | ||
5d4121c0 JS |
1542 | WARN_RATELIMIT(!tty->port, |
1543 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1544 | __func__, tty->driver->name); | |
1545 | ||
967fab69 JS |
1546 | tty->port->itty = tty; |
1547 | ||
37bdfb07 | 1548 | /* |
1da177e4 | 1549 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1550 | * If we fail here just call release_tty to clean up. No need |
1551 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1552 | */ |
bf970ee4 | 1553 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1554 | if (retval) |
d5543503 | 1555 | goto err_release_tty; |
89c8d91e | 1556 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1557 | return tty; |
1da177e4 | 1558 | |
c8b710b3 | 1559 | err_free_tty: |
89c8d91e | 1560 | tty_unlock(tty); |
d5543503 JS |
1561 | free_tty_struct(tty); |
1562 | err_module_put: | |
1da177e4 | 1563 | module_put(driver->owner); |
d5543503 | 1564 | return ERR_PTR(retval); |
1da177e4 | 1565 | |
d5698c28 | 1566 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1567 | err_release_tty: |
89c8d91e | 1568 | tty_unlock(tty); |
339f36ba PH |
1569 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1570 | retval, idx); | |
d5698c28 | 1571 | release_tty(tty, idx); |
73ec06fc | 1572 | return ERR_PTR(retval); |
1da177e4 LT |
1573 | } |
1574 | ||
a3123fd0 | 1575 | static void tty_free_termios(struct tty_struct *tty) |
feebed65 AC |
1576 | { |
1577 | struct ktermios *tp; | |
1578 | int idx = tty->index; | |
36b3c070 AC |
1579 | |
1580 | /* If the port is going to reset then it has no termios to save */ | |
1581 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1582 | return; | |
1583 | ||
1584 | /* Stash the termios data */ | |
1585 | tp = tty->driver->termios[idx]; | |
1586 | if (tp == NULL) { | |
1587 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1588 | if (tp == NULL) |
36b3c070 | 1589 | return; |
4ac5d705 | 1590 | tty->driver->termios[idx] = tp; |
feebed65 | 1591 | } |
36b3c070 | 1592 | *tp = tty->termios; |
feebed65 | 1593 | } |
feebed65 | 1594 | |
a2965b7b | 1595 | /** |
949aa64f PH |
1596 | * tty_flush_works - flush all works of a tty/pty pair |
1597 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1598 | * |
949aa64f | 1599 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1600 | */ |
1601 | static void tty_flush_works(struct tty_struct *tty) | |
1602 | { | |
1603 | flush_work(&tty->SAK_work); | |
1604 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1605 | if (tty->link) { |
1606 | flush_work(&tty->link->SAK_work); | |
1607 | flush_work(&tty->link->hangup_work); | |
1608 | } | |
a2965b7b | 1609 | } |
feebed65 | 1610 | |
af9b897e | 1611 | /** |
d5698c28 | 1612 | * release_one_tty - release tty structure memory |
9c9f4ded | 1613 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1614 | * |
1615 | * Releases memory associated with a tty structure, and clears out the | |
1616 | * driver table slots. This function is called when a device is no longer | |
1617 | * in use. It also gets called when setup of a device fails. | |
1618 | * | |
1619 | * Locking: | |
af9b897e AC |
1620 | * takes the file list lock internally when working on the list |
1621 | * of ttys that the driver keeps. | |
b50989dc AC |
1622 | * |
1623 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1624 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1625 | */ |
b50989dc | 1626 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1627 | { |
b50989dc AC |
1628 | struct tty_struct *tty = |
1629 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1630 | struct tty_driver *driver = tty->driver; |
b216df53 | 1631 | struct module *owner = driver->owner; |
d5698c28 | 1632 | |
f278a2f7 DY |
1633 | if (tty->ops->cleanup) |
1634 | tty->ops->cleanup(tty); | |
1635 | ||
1da177e4 | 1636 | tty->magic = 0; |
7d7b93c1 | 1637 | tty_driver_kref_put(driver); |
b216df53 | 1638 | module_put(owner); |
d5698c28 | 1639 | |
4a510969 | 1640 | spin_lock(&tty->files_lock); |
1da177e4 | 1641 | list_del_init(&tty->tty_files); |
4a510969 | 1642 | spin_unlock(&tty->files_lock); |
d5698c28 | 1643 | |
6da8d866 ON |
1644 | put_pid(tty->pgrp); |
1645 | put_pid(tty->session); | |
1da177e4 LT |
1646 | free_tty_struct(tty); |
1647 | } | |
1648 | ||
b50989dc AC |
1649 | static void queue_release_one_tty(struct kref *kref) |
1650 | { | |
1651 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1652 | |
b50989dc AC |
1653 | /* The hangup queue is now free so we can reuse it rather than |
1654 | waste a chunk of memory for each port */ | |
1655 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1656 | schedule_work(&tty->hangup_work); | |
1657 | } | |
1658 | ||
9c9f4ded AC |
1659 | /** |
1660 | * tty_kref_put - release a tty kref | |
1661 | * @tty: tty device | |
1662 | * | |
1663 | * Release a reference to a tty device and if need be let the kref | |
1664 | * layer destruct the object for us | |
1665 | */ | |
1666 | ||
1667 | void tty_kref_put(struct tty_struct *tty) | |
1668 | { | |
1669 | if (tty) | |
b50989dc | 1670 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1671 | } |
1672 | EXPORT_SYMBOL(tty_kref_put); | |
1673 | ||
d5698c28 CH |
1674 | /** |
1675 | * release_tty - release tty structure memory | |
1676 | * | |
1677 | * Release both @tty and a possible linked partner (think pty pair), | |
1678 | * and decrement the refcount of the backing module. | |
1679 | * | |
1680 | * Locking: | |
d155255a | 1681 | * tty_mutex |
d5698c28 CH |
1682 | * takes the file list lock internally when working on the list |
1683 | * of ttys that the driver keeps. | |
9c9f4ded | 1684 | * |
d5698c28 CH |
1685 | */ |
1686 | static void release_tty(struct tty_struct *tty, int idx) | |
1687 | { | |
9c9f4ded AC |
1688 | /* This should always be true but check for the moment */ |
1689 | WARN_ON(tty->index != idx); | |
d155255a | 1690 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1691 | if (tty->ops->shutdown) |
1692 | tty->ops->shutdown(tty); | |
1693 | tty_free_termios(tty); | |
1694 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1695 | tty->port->itty = NULL; |
64e377dc PH |
1696 | if (tty->link) |
1697 | tty->link->port->itty = NULL; | |
e176058f | 1698 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1699 | |
a211b1af | 1700 | tty_kref_put(tty->link); |
9c9f4ded | 1701 | tty_kref_put(tty); |
d5698c28 CH |
1702 | } |
1703 | ||
955787ca JS |
1704 | /** |
1705 | * tty_release_checks - check a tty before real release | |
1706 | * @tty: tty to check | |
1707 | * @o_tty: link of @tty (if any) | |
1708 | * @idx: index of the tty | |
1709 | * | |
1710 | * Performs some paranoid checking before true release of the @tty. | |
1711 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1712 | */ | |
359b9fb5 | 1713 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1714 | { |
1715 | #ifdef TTY_PARANOIA_CHECK | |
1716 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1717 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1718 | return -1; |
1719 | } | |
1720 | ||
1721 | /* not much to check for devpts */ | |
1722 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1723 | return 0; | |
1724 | ||
1725 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1726 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1727 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1728 | return -1; |
1729 | } | |
955787ca | 1730 | if (tty->driver->other) { |
359b9fb5 PH |
1731 | struct tty_struct *o_tty = tty->link; |
1732 | ||
955787ca | 1733 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1734 | tty_debug(tty, "bad other table[%d] = %p\n", |
1735 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1736 | return -1; |
1737 | } | |
955787ca | 1738 | if (o_tty->link != tty) { |
e2dfa3d3 | 1739 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1740 | return -1; |
1741 | } | |
1742 | } | |
1743 | #endif | |
1744 | return 0; | |
1745 | } | |
1746 | ||
eeb89d91 AC |
1747 | /** |
1748 | * tty_release - vfs callback for close | |
1749 | * @inode: inode of tty | |
1750 | * @filp: file pointer for handle to tty | |
1751 | * | |
1752 | * Called the last time each file handle is closed that references | |
1753 | * this tty. There may however be several such references. | |
1754 | * | |
1755 | * Locking: | |
1756 | * Takes bkl. See tty_release_dev | |
1757 | * | |
1da177e4 LT |
1758 | * Even releasing the tty structures is a tricky business.. We have |
1759 | * to be very careful that the structures are all released at the | |
1760 | * same time, as interrupts might otherwise get the wrong pointers. | |
1761 | * | |
1762 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1763 | * lead to double frees or releasing memory still in use. | |
1764 | */ | |
eeb89d91 AC |
1765 | |
1766 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1767 | { |
d996b62a | 1768 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1769 | struct tty_struct *o_tty = NULL; |
1770 | int do_sleep, final; | |
1da177e4 | 1771 | int idx; |
37b16457 | 1772 | long timeout = 0; |
494c1eac | 1773 | int once = 1; |
37bdfb07 | 1774 | |
9de44bd6 | 1775 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1776 | return 0; |
1da177e4 | 1777 | |
89c8d91e | 1778 | tty_lock(tty); |
9de44bd6 | 1779 | check_tty_count(tty, __func__); |
1da177e4 | 1780 | |
ec79d605 | 1781 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1782 | |
1783 | idx = tty->index; | |
7ffb6da9 PH |
1784 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1785 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1786 | o_tty = tty->link; | |
1da177e4 | 1787 | |
359b9fb5 | 1788 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1789 | tty_unlock(tty); |
eeb89d91 | 1790 | return 0; |
1da177e4 | 1791 | } |
1da177e4 | 1792 | |
d435cefe | 1793 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1794 | |
f34d7a5b AC |
1795 | if (tty->ops->close) |
1796 | tty->ops->close(tty, filp); | |
1da177e4 | 1797 | |
2aff5e2b PH |
1798 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1799 | tty_lock_slave(o_tty); | |
1800 | ||
1da177e4 LT |
1801 | /* |
1802 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1803 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1804 | * wait queues and kick everyone out _before_ actually starting to | |
1805 | * close. This ensures that we won't block while releasing the tty | |
1806 | * structure. | |
1807 | * | |
1808 | * The test for the o_tty closing is necessary, since the master and | |
1809 | * slave sides may close in any order. If the slave side closes out | |
1810 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1811 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1812 | * so we do it now. |
1da177e4 LT |
1813 | */ |
1814 | while (1) { | |
1da177e4 LT |
1815 | do_sleep = 0; |
1816 | ||
324c1650 | 1817 | if (tty->count <= 1) { |
1da177e4 | 1818 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1819 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1820 | do_sleep++; |
1821 | } | |
1822 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1823 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1824 | do_sleep++; |
1825 | } | |
1826 | } | |
7ffb6da9 | 1827 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1828 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1829 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1830 | do_sleep++; |
1831 | } | |
1832 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1833 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1834 | do_sleep++; |
1835 | } | |
1836 | } | |
1837 | if (!do_sleep) | |
1838 | break; | |
1839 | ||
494c1eac PH |
1840 | if (once) { |
1841 | once = 0; | |
339f36ba | 1842 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1843 | } |
37b16457 PH |
1844 | schedule_timeout_killable(timeout); |
1845 | if (timeout < 120 * HZ) | |
1846 | timeout = 2 * timeout + 1; | |
1847 | else | |
1848 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1849 | } |
1da177e4 | 1850 | |
7ffb6da9 | 1851 | if (o_tty) { |
1da177e4 | 1852 | if (--o_tty->count < 0) { |
339f36ba | 1853 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1854 | o_tty->count = 0; |
1855 | } | |
1856 | } | |
1857 | if (--tty->count < 0) { | |
339f36ba | 1858 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1859 | tty->count = 0; |
1860 | } | |
37bdfb07 | 1861 | |
1da177e4 LT |
1862 | /* |
1863 | * We've decremented tty->count, so we need to remove this file | |
1864 | * descriptor off the tty->tty_files list; this serves two | |
1865 | * purposes: | |
1866 | * - check_tty_count sees the correct number of file descriptors | |
1867 | * associated with this tty. | |
1868 | * - do_tty_hangup no longer sees this file descriptor as | |
1869 | * something that needs to be handled for hangups. | |
1870 | */ | |
d996b62a | 1871 | tty_del_file(filp); |
1da177e4 LT |
1872 | |
1873 | /* | |
1874 | * Perform some housekeeping before deciding whether to return. | |
1875 | * | |
1da177e4 LT |
1876 | * If _either_ side is closing, make sure there aren't any |
1877 | * processes that still think tty or o_tty is their controlling | |
1878 | * tty. | |
1879 | */ | |
324c1650 | 1880 | if (!tty->count) { |
1da177e4 | 1881 | read_lock(&tasklist_lock); |
24ec839c | 1882 | session_clear_tty(tty->session); |
7ffb6da9 | 1883 | if (o_tty) |
24ec839c | 1884 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1885 | read_unlock(&tasklist_lock); |
1886 | } | |
1887 | ||
324c1650 | 1888 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1889 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1890 | |
2aff5e2b PH |
1891 | tty_unlock_slave(o_tty); |
1892 | tty_unlock(tty); | |
1893 | ||
04980706 | 1894 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1895 | cannot be re-opened by a racing opener */ |
da965822 | 1896 | |
324c1650 | 1897 | if (!final) |
eeb89d91 | 1898 | return 0; |
37bdfb07 | 1899 | |
accff793 | 1900 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1901 | /* |
01e1abb2 | 1902 | * Ask the line discipline code to release its structures |
1da177e4 | 1903 | */ |
62462aef | 1904 | tty_ldisc_release(tty); |
a2965b7b PH |
1905 | |
1906 | /* Wait for pending work before tty destruction commmences */ | |
1907 | tty_flush_works(tty); | |
a2965b7b | 1908 | |
d435cefe | 1909 | tty_debug_hangup(tty, "freeing structure\n"); |
1da177e4 | 1910 | /* |
d5698c28 | 1911 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1912 | * the slots and preserving the termios structure. The tty_unlock_pair |
1913 | * should be safe as we keep a kref while the tty is locked (so the | |
1914 | * unlock never unlocks a freed tty). | |
1da177e4 | 1915 | */ |
d155255a | 1916 | mutex_lock(&tty_mutex); |
d5698c28 | 1917 | release_tty(tty, idx); |
d155255a | 1918 | mutex_unlock(&tty_mutex); |
1da177e4 | 1919 | |
eeb89d91 | 1920 | return 0; |
1da177e4 LT |
1921 | } |
1922 | ||
b82154ac | 1923 | /** |
52494eeb | 1924 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1925 | * @device: device number |
1926 | * @filp: file pointer to tty | |
52494eeb PH |
1927 | * @return: locked tty of the current task iff @device is /dev/tty |
1928 | * | |
1929 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1930 | * |
1931 | * We cannot return driver and index like for the other nodes because | |
1932 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1933 | */ | |
1934 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1935 | { | |
1936 | struct tty_struct *tty; | |
52494eeb | 1937 | int retval; |
b82154ac JS |
1938 | |
1939 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1940 | return NULL; | |
1941 | ||
1942 | tty = get_current_tty(); | |
1943 | if (!tty) | |
1944 | return ERR_PTR(-ENXIO); | |
1945 | ||
1946 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1947 | /* noctty = 1; */ | |
52494eeb PH |
1948 | tty_lock(tty); |
1949 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1950 | ||
1951 | retval = tty_reopen(tty); | |
1952 | if (retval < 0) { | |
1953 | tty_unlock(tty); | |
1954 | tty = ERR_PTR(retval); | |
1955 | } | |
b82154ac JS |
1956 | return tty; |
1957 | } | |
1958 | ||
5b5e7040 JS |
1959 | /** |
1960 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1961 | * @device: device number | |
1962 | * @filp: file pointer to tty | |
5b5e7040 JS |
1963 | * @index: index for the device in the @return driver |
1964 | * @return: driver for this inode (with increased refcount) | |
1965 | * | |
1966 | * If @return is not erroneous, the caller is responsible to decrement the | |
1967 | * refcount by tty_driver_kref_put. | |
1968 | * | |
1969 | * Locking: tty_mutex protects get_tty_driver | |
1970 | */ | |
1971 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1972 | int *index) |
5b5e7040 JS |
1973 | { |
1974 | struct tty_driver *driver; | |
1975 | ||
2cd0050c | 1976 | switch (device) { |
5b5e7040 | 1977 | #ifdef CONFIG_VT |
2cd0050c | 1978 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1979 | extern struct tty_driver *console_driver; |
1980 | driver = tty_driver_kref_get(console_driver); | |
1981 | *index = fg_console; | |
2cd0050c | 1982 | break; |
5b5e7040 JS |
1983 | } |
1984 | #endif | |
2cd0050c | 1985 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1986 | struct tty_driver *console_driver = console_device(index); |
1987 | if (console_driver) { | |
1988 | driver = tty_driver_kref_get(console_driver); | |
1989 | if (driver) { | |
1990 | /* Don't let /dev/console block */ | |
1991 | filp->f_flags |= O_NONBLOCK; | |
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 | ||
d6203d0c PH |
2006 | /** |
2007 | * tty_open_by_driver - open a tty device | |
2008 | * @device: dev_t of device to open | |
2009 | * @inode: inode of device file | |
2010 | * @filp: file pointer to tty | |
2011 | * | |
2012 | * Performs the driver lookup, checks for a reopen, or otherwise | |
2013 | * performs the first-time tty initialization. | |
2014 | * | |
2015 | * Returns the locked initialized or re-opened &tty_struct | |
2016 | * | |
2017 | * Claims the global tty_mutex to serialize: | |
2018 | * - concurrent first-time tty initialization | |
2019 | * - concurrent tty driver removal w/ lookup | |
2020 | * - concurrent tty removal from driver table | |
2021 | */ | |
2022 | static struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, | |
2023 | struct file *filp) | |
2024 | { | |
2025 | struct tty_struct *tty; | |
2026 | struct tty_driver *driver = NULL; | |
2027 | int index = -1; | |
2028 | int retval; | |
2029 | ||
2030 | mutex_lock(&tty_mutex); | |
2031 | driver = tty_lookup_driver(device, filp, &index); | |
2032 | if (IS_ERR(driver)) { | |
2033 | mutex_unlock(&tty_mutex); | |
2034 | return ERR_CAST(driver); | |
2035 | } | |
2036 | ||
2037 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 2038 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
2039 | if (IS_ERR(tty)) { |
2040 | mutex_unlock(&tty_mutex); | |
2041 | goto out; | |
2042 | } | |
2043 | ||
2044 | if (tty) { | |
2045 | mutex_unlock(&tty_mutex); | |
2046 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 2047 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
2048 | if (retval) { |
2049 | if (retval == -EINTR) | |
2050 | retval = -ERESTARTSYS; | |
2051 | tty = ERR_PTR(retval); | |
2052 | goto out; | |
2053 | } | |
d6203d0c PH |
2054 | retval = tty_reopen(tty); |
2055 | if (retval < 0) { | |
2056 | tty_unlock(tty); | |
2057 | tty = ERR_PTR(retval); | |
2058 | } | |
2059 | } else { /* Returns with the tty_lock held for now */ | |
2060 | tty = tty_init_dev(driver, index); | |
2061 | mutex_unlock(&tty_mutex); | |
2062 | } | |
2063 | out: | |
2064 | tty_driver_kref_put(driver); | |
2065 | return tty; | |
2066 | } | |
2067 | ||
af9b897e | 2068 | /** |
eeb89d91 | 2069 | * tty_open - open a tty device |
af9b897e AC |
2070 | * @inode: inode of device file |
2071 | * @filp: file pointer to tty | |
1da177e4 | 2072 | * |
af9b897e AC |
2073 | * tty_open and tty_release keep up the tty count that contains the |
2074 | * number of opens done on a tty. We cannot use the inode-count, as | |
2075 | * different inodes might point to the same tty. | |
1da177e4 | 2076 | * |
af9b897e AC |
2077 | * Open-counting is needed for pty masters, as well as for keeping |
2078 | * track of serial lines: DTR is dropped when the last close happens. | |
2079 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2080 | * | |
2081 | * The termios state of a pty is reset on first open so that | |
2082 | * settings don't persist across reuse. | |
2083 | * | |
5b5e7040 | 2084 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2085 | * tty->count should protect the rest. |
2086 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2087 | * |
2088 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2089 | * tty_mutex | |
1da177e4 | 2090 | */ |
af9b897e | 2091 | |
eeb89d91 | 2092 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2093 | { |
b82154ac | 2094 | struct tty_struct *tty; |
1da177e4 | 2095 | int noctty, retval; |
1da177e4 | 2096 | dev_t device = inode->i_rdev; |
846c151a | 2097 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2098 | |
2099 | nonseekable_open(inode, filp); | |
37bdfb07 | 2100 | |
1da177e4 | 2101 | retry_open: |
fa90e1c9 JS |
2102 | retval = tty_alloc_file(filp); |
2103 | if (retval) | |
2104 | return -ENOMEM; | |
2105 | ||
b82154ac | 2106 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
2107 | if (!tty) |
2108 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 2109 | |
eeb89d91 | 2110 | if (IS_ERR(tty)) { |
d6203d0c | 2111 | tty_free_file(filp); |
ba5db448 | 2112 | retval = PTR_ERR(tty); |
7f22f6c9 | 2113 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 2114 | return retval; |
7f22f6c9 PH |
2115 | schedule(); |
2116 | goto retry_open; | |
eeb89d91 | 2117 | } |
1da177e4 | 2118 | |
fa90e1c9 | 2119 | tty_add_file(tty, filp); |
d996b62a | 2120 | |
9de44bd6 | 2121 | check_tty_count(tty, __func__); |
d435cefe | 2122 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2123 | |
909bc774 HRK |
2124 | if (tty->ops->open) |
2125 | retval = tty->ops->open(tty, filp); | |
2126 | else | |
2127 | retval = -ENODEV; | |
1da177e4 LT |
2128 | filp->f_flags = saved_flags; |
2129 | ||
1da177e4 | 2130 | if (retval) { |
d435cefe | 2131 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2132 | |
89c8d91e | 2133 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2134 | tty_release(inode, filp); |
64ba3dc3 | 2135 | if (retval != -ERESTARTSYS) |
1da177e4 | 2136 | return retval; |
64ba3dc3 AB |
2137 | |
2138 | if (signal_pending(current)) | |
1da177e4 | 2139 | return retval; |
64ba3dc3 | 2140 | |
1da177e4 LT |
2141 | schedule(); |
2142 | /* | |
2143 | * Need to reset f_op in case a hangup happened. | |
2144 | */ | |
1256937f | 2145 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2146 | filp->f_op = &tty_fops; |
2147 | goto retry_open; | |
2148 | } | |
d4855e1f | 2149 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2150 | |
24ec839c | 2151 | |
2c411c11 | 2152 | read_lock(&tasklist_lock); |
24ec839c | 2153 | spin_lock_irq(¤t->sighand->siglock); |
11e1d4aa | 2154 | noctty = (filp->f_flags & O_NOCTTY) || |
da5a0fc6 | 2155 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
11e1d4aa PH |
2156 | device == MKDEV(TTYAUX_MAJOR, 1) || |
2157 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2158 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2159 | ||
1da177e4 LT |
2160 | if (!noctty && |
2161 | current->signal->leader && | |
2162 | !current->signal->tty && | |
0c556271 JH |
2163 | tty->session == NULL) { |
2164 | /* | |
2165 | * Don't let a process that only has write access to the tty | |
2166 | * obtain the privileges associated with having a tty as | |
2167 | * controlling terminal (being able to reopen it with full | |
2168 | * access through /dev/tty, being able to perform pushback). | |
2169 | * Many distributions set the group of all ttys to "tty" and | |
2170 | * grant write-only access to all terminals for setgid tty | |
2171 | * binaries, which should not imply full privileges on all ttys. | |
2172 | * | |
2173 | * This could theoretically break old code that performs open() | |
2174 | * on a write-only file descriptor. In that case, it might be | |
2175 | * necessary to also permit this if | |
2176 | * inode_permission(inode, MAY_READ) == 0. | |
2177 | */ | |
2178 | if (filp->f_mode & FMODE_READ) | |
2179 | __proc_set_tty(tty); | |
2180 | } | |
24ec839c | 2181 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2182 | read_unlock(&tasklist_lock); |
89c8d91e | 2183 | tty_unlock(tty); |
1da177e4 LT |
2184 | return 0; |
2185 | } | |
2186 | ||
39d95b9d JC |
2187 | |
2188 | ||
af9b897e AC |
2189 | /** |
2190 | * tty_poll - check tty status | |
2191 | * @filp: file being polled | |
2192 | * @wait: poll wait structures to update | |
2193 | * | |
2194 | * Call the line discipline polling method to obtain the poll | |
2195 | * status of the device. | |
2196 | * | |
2197 | * Locking: locks called line discipline but ldisc poll method | |
2198 | * may be re-entered freely by other callers. | |
2199 | */ | |
2200 | ||
37bdfb07 | 2201 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2202 | { |
d996b62a | 2203 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2204 | struct tty_ldisc *ld; |
2205 | int ret = 0; | |
2206 | ||
6131ffaa | 2207 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2208 | return 0; |
37bdfb07 | 2209 | |
1da177e4 | 2210 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2211 | if (!ld) |
2212 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2213 | if (ld->ops->poll) |
c961bfb1 | 2214 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2215 | tty_ldisc_deref(ld); |
2216 | return ret; | |
2217 | } | |
2218 | ||
ec79d605 | 2219 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2220 | { |
d996b62a | 2221 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2222 | unsigned long flags; |
5d1e3230 | 2223 | int retval = 0; |
1da177e4 | 2224 | |
6131ffaa | 2225 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2226 | goto out; |
37bdfb07 | 2227 | |
1da177e4 LT |
2228 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2229 | if (retval <= 0) | |
5d1e3230 | 2230 | goto out; |
f6c8dbe6 | 2231 | |
1da177e4 | 2232 | if (on) { |
ab521dc0 EB |
2233 | enum pid_type type; |
2234 | struct pid *pid; | |
f6c8dbe6 | 2235 | |
47f86834 | 2236 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2237 | if (tty->pgrp) { |
2238 | pid = tty->pgrp; | |
2239 | type = PIDTYPE_PGID; | |
2240 | } else { | |
2241 | pid = task_pid(current); | |
2242 | type = PIDTYPE_PID; | |
2243 | } | |
80e1e823 | 2244 | get_pid(pid); |
70362511 | 2245 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2246 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2247 | put_pid(pid); |
e0b93edd | 2248 | retval = 0; |
1da177e4 | 2249 | } |
5d1e3230 | 2250 | out: |
ec79d605 AB |
2251 | return retval; |
2252 | } | |
2253 | ||
2254 | static int tty_fasync(int fd, struct file *filp, int on) | |
2255 | { | |
89c8d91e | 2256 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2257 | int retval = -ENOTTY; |
89c8d91e AC |
2258 | |
2259 | tty_lock(tty); | |
a8f3a297 PH |
2260 | if (!tty_hung_up_p(filp)) |
2261 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2262 | tty_unlock(tty); |
2263 | ||
5d1e3230 | 2264 | return retval; |
1da177e4 LT |
2265 | } |
2266 | ||
af9b897e AC |
2267 | /** |
2268 | * tiocsti - fake input character | |
2269 | * @tty: tty to fake input into | |
2270 | * @p: pointer to character | |
2271 | * | |
3a4fa0a2 | 2272 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2273 | * input management. |
2274 | * | |
2275 | * FIXME: does not honour flow control ?? | |
2276 | * | |
2277 | * Locking: | |
137084bb | 2278 | * Called functions take tty_ldiscs_lock |
af9b897e | 2279 | * current->signal->tty check is safe without locks |
28298232 AC |
2280 | * |
2281 | * FIXME: may race normal receive processing | |
af9b897e AC |
2282 | */ |
2283 | ||
1da177e4 LT |
2284 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2285 | { | |
2286 | char ch, mbz = 0; | |
2287 | struct tty_ldisc *ld; | |
37bdfb07 | 2288 | |
1da177e4 LT |
2289 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2290 | return -EPERM; | |
2291 | if (get_user(ch, p)) | |
2292 | return -EFAULT; | |
1e641743 | 2293 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2294 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2295 | if (!ld) |
2296 | return -EIO; | |
a352def2 | 2297 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2298 | tty_ldisc_deref(ld); |
2299 | return 0; | |
2300 | } | |
2301 | ||
af9b897e AC |
2302 | /** |
2303 | * tiocgwinsz - implement window query ioctl | |
2304 | * @tty; tty | |
2305 | * @arg: user buffer for result | |
2306 | * | |
808a0d38 | 2307 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2308 | * |
dee4a0be | 2309 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2310 | * is consistent. |
af9b897e AC |
2311 | */ |
2312 | ||
37bdfb07 | 2313 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2314 | { |
808a0d38 AC |
2315 | int err; |
2316 | ||
dee4a0be | 2317 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2318 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2319 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2320 | |
2321 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2322 | } |
2323 | ||
af9b897e | 2324 | /** |
8c9a9dd0 AC |
2325 | * tty_do_resize - resize event |
2326 | * @tty: tty being resized | |
8c9a9dd0 AC |
2327 | * @rows: rows (character) |
2328 | * @cols: cols (character) | |
2329 | * | |
3ad2f3fb | 2330 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2331 | * peform a terminal resize correctly |
af9b897e AC |
2332 | */ |
2333 | ||
fc6f6238 | 2334 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2335 | { |
fc6f6238 | 2336 | struct pid *pgrp; |
1da177e4 | 2337 | |
fc6f6238 | 2338 | /* Lock the tty */ |
dee4a0be | 2339 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2340 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2341 | goto done; |
47f86834 | 2342 | |
5b239542 PH |
2343 | /* Signal the foreground process group */ |
2344 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2345 | if (pgrp) |
2346 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2347 | put_pid(pgrp); |
47f86834 | 2348 | |
8c9a9dd0 | 2349 | tty->winsize = *ws; |
ca9bda00 | 2350 | done: |
dee4a0be | 2351 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2352 | return 0; |
2353 | } | |
4d334fd1 | 2354 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2355 | |
8c9a9dd0 AC |
2356 | /** |
2357 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2358 | * @tty; tty side of tty |
8c9a9dd0 AC |
2359 | * @arg: user buffer for result |
2360 | * | |
2361 | * Copies the user idea of the window size to the kernel. Traditionally | |
2362 | * this is just advisory information but for the Linux console it | |
2363 | * actually has driver level meaning and triggers a VC resize. | |
2364 | * | |
2365 | * Locking: | |
25985edc | 2366 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2367 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2368 | * then calls into the default method. | |
2369 | */ | |
2370 | ||
fc6f6238 | 2371 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2372 | { |
2373 | struct winsize tmp_ws; | |
2374 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2375 | return -EFAULT; | |
2376 | ||
2377 | if (tty->ops->resize) | |
fc6f6238 | 2378 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2379 | else |
fc6f6238 | 2380 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2381 | } |
2382 | ||
af9b897e AC |
2383 | /** |
2384 | * tioccons - allow admin to move logical console | |
2385 | * @file: the file to become console | |
2386 | * | |
25985edc | 2387 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2388 | * |
2389 | * Locking: uses redirect_lock to guard the redirect information | |
2390 | */ | |
2391 | ||
1da177e4 LT |
2392 | static int tioccons(struct file *file) |
2393 | { | |
2394 | if (!capable(CAP_SYS_ADMIN)) | |
2395 | return -EPERM; | |
2396 | if (file->f_op->write == redirected_tty_write) { | |
2397 | struct file *f; | |
2398 | spin_lock(&redirect_lock); | |
2399 | f = redirect; | |
2400 | redirect = NULL; | |
2401 | spin_unlock(&redirect_lock); | |
2402 | if (f) | |
2403 | fput(f); | |
2404 | return 0; | |
2405 | } | |
2406 | spin_lock(&redirect_lock); | |
2407 | if (redirect) { | |
2408 | spin_unlock(&redirect_lock); | |
2409 | return -EBUSY; | |
2410 | } | |
cb0942b8 | 2411 | redirect = get_file(file); |
1da177e4 LT |
2412 | spin_unlock(&redirect_lock); |
2413 | return 0; | |
2414 | } | |
2415 | ||
af9b897e AC |
2416 | /** |
2417 | * fionbio - non blocking ioctl | |
2418 | * @file: file to set blocking value | |
2419 | * @p: user parameter | |
2420 | * | |
2421 | * Historical tty interfaces had a blocking control ioctl before | |
2422 | * the generic functionality existed. This piece of history is preserved | |
2423 | * in the expected tty API of posix OS's. | |
2424 | * | |
6146b9af | 2425 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2426 | */ |
1da177e4 LT |
2427 | |
2428 | static int fionbio(struct file *file, int __user *p) | |
2429 | { | |
2430 | int nonblock; | |
2431 | ||
2432 | if (get_user(nonblock, p)) | |
2433 | return -EFAULT; | |
2434 | ||
db1dd4d3 | 2435 | spin_lock(&file->f_lock); |
1da177e4 LT |
2436 | if (nonblock) |
2437 | file->f_flags |= O_NONBLOCK; | |
2438 | else | |
2439 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2440 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2441 | return 0; |
2442 | } | |
2443 | ||
af9b897e AC |
2444 | /** |
2445 | * tiocsctty - set controlling tty | |
2446 | * @tty: tty structure | |
2447 | * @arg: user argument | |
2448 | * | |
2449 | * This ioctl is used to manage job control. It permits a session | |
2450 | * leader to set this tty as the controlling tty for the session. | |
2451 | * | |
2452 | * Locking: | |
e218eb32 | 2453 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2454 | * Takes tasklist_lock internally to walk sessions |
2455 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2456 | */ |
2457 | ||
0c556271 | 2458 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) |
1da177e4 | 2459 | { |
24ec839c | 2460 | int ret = 0; |
24ec839c | 2461 | |
e218eb32 | 2462 | tty_lock(tty); |
2c411c11 PH |
2463 | read_lock(&tasklist_lock); |
2464 | ||
2465 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2466 | goto unlock; | |
2467 | ||
1da177e4 LT |
2468 | /* |
2469 | * The process must be a session leader and | |
2470 | * not have a controlling tty already. | |
2471 | */ | |
24ec839c PZ |
2472 | if (!current->signal->leader || current->signal->tty) { |
2473 | ret = -EPERM; | |
2474 | goto unlock; | |
2475 | } | |
2476 | ||
ab521dc0 | 2477 | if (tty->session) { |
1da177e4 LT |
2478 | /* |
2479 | * This tty is already the controlling | |
2480 | * tty for another session group! | |
2481 | */ | |
37bdfb07 | 2482 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2483 | /* |
2484 | * Steal it away | |
2485 | */ | |
24ec839c | 2486 | session_clear_tty(tty->session); |
24ec839c PZ |
2487 | } else { |
2488 | ret = -EPERM; | |
2489 | goto unlock; | |
2490 | } | |
1da177e4 | 2491 | } |
0c556271 JH |
2492 | |
2493 | /* See the comment in tty_open(). */ | |
2494 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
2495 | ret = -EPERM; | |
2496 | goto unlock; | |
2497 | } | |
2498 | ||
bce65f18 | 2499 | proc_set_tty(tty); |
24ec839c | 2500 | unlock: |
2c411c11 | 2501 | read_unlock(&tasklist_lock); |
e218eb32 | 2502 | tty_unlock(tty); |
24ec839c | 2503 | return ret; |
1da177e4 LT |
2504 | } |
2505 | ||
5d0fdf1e AC |
2506 | /** |
2507 | * tty_get_pgrp - return a ref counted pgrp pid | |
2508 | * @tty: tty to read | |
2509 | * | |
2510 | * Returns a refcounted instance of the pid struct for the process | |
2511 | * group controlling the tty. | |
2512 | */ | |
2513 | ||
2514 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2515 | { | |
2516 | unsigned long flags; | |
2517 | struct pid *pgrp; | |
2518 | ||
2519 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2520 | pgrp = get_pid(tty->pgrp); | |
2521 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2522 | ||
2523 | return pgrp; | |
2524 | } | |
2525 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2526 | ||
e1c2296c PH |
2527 | /* |
2528 | * This checks not only the pgrp, but falls back on the pid if no | |
2529 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2530 | * without this... | |
2531 | * | |
2532 | * The caller must hold rcu lock or the tasklist lock. | |
2533 | */ | |
2534 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2535 | { | |
2536 | struct task_struct *p; | |
2537 | struct pid *sid = NULL; | |
2538 | ||
2539 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2540 | if (p == NULL) | |
2541 | p = pid_task(pgrp, PIDTYPE_PID); | |
2542 | if (p != NULL) | |
2543 | sid = task_session(p); | |
2544 | ||
2545 | return sid; | |
2546 | } | |
2547 | ||
af9b897e AC |
2548 | /** |
2549 | * tiocgpgrp - get process group | |
2550 | * @tty: tty passed by user | |
25985edc | 2551 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2552 | * @p: returned pid |
2553 | * | |
2554 | * Obtain the process group of the tty. If there is no process group | |
2555 | * return an error. | |
2556 | * | |
24ec839c | 2557 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2558 | */ |
2559 | ||
1da177e4 LT |
2560 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2561 | { | |
5d0fdf1e AC |
2562 | struct pid *pid; |
2563 | int ret; | |
1da177e4 LT |
2564 | /* |
2565 | * (tty == real_tty) is a cheap way of | |
2566 | * testing if the tty is NOT a master pty. | |
2567 | */ | |
2568 | if (tty == real_tty && current->signal->tty != real_tty) | |
2569 | return -ENOTTY; | |
5d0fdf1e AC |
2570 | pid = tty_get_pgrp(real_tty); |
2571 | ret = put_user(pid_vnr(pid), p); | |
2572 | put_pid(pid); | |
2573 | return ret; | |
1da177e4 LT |
2574 | } |
2575 | ||
af9b897e AC |
2576 | /** |
2577 | * tiocspgrp - attempt to set process group | |
2578 | * @tty: tty passed by user | |
2579 | * @real_tty: tty side device matching tty passed by user | |
2580 | * @p: pid pointer | |
2581 | * | |
2582 | * Set the process group of the tty to the session passed. Only | |
2583 | * permitted where the tty session is our session. | |
2584 | * | |
47f86834 | 2585 | * Locking: RCU, ctrl lock |
af9b897e AC |
2586 | */ |
2587 | ||
1da177e4 LT |
2588 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2589 | { | |
04a2e6a5 EB |
2590 | struct pid *pgrp; |
2591 | pid_t pgrp_nr; | |
1da177e4 LT |
2592 | int retval = tty_check_change(real_tty); |
2593 | ||
2594 | if (retval == -EIO) | |
2595 | return -ENOTTY; | |
2596 | if (retval) | |
2597 | return retval; | |
2598 | if (!current->signal->tty || | |
2599 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2600 | (real_tty->session != task_session(current))) |
1da177e4 | 2601 | return -ENOTTY; |
04a2e6a5 | 2602 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2603 | return -EFAULT; |
04a2e6a5 | 2604 | if (pgrp_nr < 0) |
1da177e4 | 2605 | return -EINVAL; |
04a2e6a5 | 2606 | rcu_read_lock(); |
b488893a | 2607 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2608 | retval = -ESRCH; |
2609 | if (!pgrp) | |
2610 | goto out_unlock; | |
2611 | retval = -EPERM; | |
2612 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2613 | goto out_unlock; | |
2614 | retval = 0; | |
1e86b5bf | 2615 | spin_lock_irq(&tty->ctrl_lock); |
ab521dc0 EB |
2616 | put_pid(real_tty->pgrp); |
2617 | real_tty->pgrp = get_pid(pgrp); | |
1e86b5bf | 2618 | spin_unlock_irq(&tty->ctrl_lock); |
04a2e6a5 EB |
2619 | out_unlock: |
2620 | rcu_read_unlock(); | |
2621 | return retval; | |
1da177e4 LT |
2622 | } |
2623 | ||
af9b897e AC |
2624 | /** |
2625 | * tiocgsid - get session id | |
2626 | * @tty: tty passed by user | |
25985edc | 2627 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2628 | * @p: pointer to returned session id |
2629 | * | |
2630 | * Obtain the session id of the tty. If there is no session | |
2631 | * return an error. | |
2632 | * | |
24ec839c | 2633 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2634 | */ |
2635 | ||
1da177e4 LT |
2636 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2637 | { | |
2638 | /* | |
2639 | * (tty == real_tty) is a cheap way of | |
2640 | * testing if the tty is NOT a master pty. | |
2641 | */ | |
2642 | if (tty == real_tty && current->signal->tty != real_tty) | |
2643 | return -ENOTTY; | |
ab521dc0 | 2644 | if (!real_tty->session) |
1da177e4 | 2645 | return -ENOTTY; |
b488893a | 2646 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2647 | } |
2648 | ||
af9b897e AC |
2649 | /** |
2650 | * tiocsetd - set line discipline | |
2651 | * @tty: tty device | |
2652 | * @p: pointer to user data | |
2653 | * | |
2654 | * Set the line discipline according to user request. | |
2655 | * | |
2656 | * Locking: see tty_set_ldisc, this function is just a helper | |
2657 | */ | |
2658 | ||
1da177e4 LT |
2659 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2660 | { | |
c12da96f | 2661 | int disc; |
04f378b1 | 2662 | int ret; |
1da177e4 | 2663 | |
c12da96f | 2664 | if (get_user(disc, p)) |
1da177e4 | 2665 | return -EFAULT; |
04f378b1 | 2666 | |
c12da96f | 2667 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2668 | |
2669 | return ret; | |
1da177e4 LT |
2670 | } |
2671 | ||
5c17c861 PH |
2672 | /** |
2673 | * tiocgetd - get line discipline | |
2674 | * @tty: tty device | |
2675 | * @p: pointer to user data | |
2676 | * | |
2677 | * Retrieves the line discipline id directly from the ldisc. | |
2678 | * | |
2679 | * Locking: waits for ldisc reference (in case the line discipline | |
2680 | * is changing or the tty is being hungup) | |
2681 | */ | |
2682 | ||
2683 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2684 | { | |
2685 | struct tty_ldisc *ld; | |
2686 | int ret; | |
2687 | ||
2688 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2689 | if (!ld) |
2690 | return -EIO; | |
5c17c861 PH |
2691 | ret = put_user(ld->ops->num, p); |
2692 | tty_ldisc_deref(ld); | |
2693 | return ret; | |
2694 | } | |
2695 | ||
af9b897e AC |
2696 | /** |
2697 | * send_break - performed time break | |
2698 | * @tty: device to break on | |
2699 | * @duration: timeout in mS | |
2700 | * | |
2701 | * Perform a timed break on hardware that lacks its own driver level | |
2702 | * timed break functionality. | |
2703 | * | |
2704 | * Locking: | |
28298232 | 2705 | * atomic_write_lock serializes |
af9b897e | 2706 | * |
af9b897e AC |
2707 | */ |
2708 | ||
b20f3ae5 | 2709 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2710 | { |
9e98966c AC |
2711 | int retval; |
2712 | ||
2713 | if (tty->ops->break_ctl == NULL) | |
2714 | return 0; | |
2715 | ||
2716 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2717 | retval = tty->ops->break_ctl(tty, duration); | |
2718 | else { | |
2719 | /* Do the work ourselves */ | |
2720 | if (tty_write_lock(tty, 0) < 0) | |
2721 | return -EINTR; | |
2722 | retval = tty->ops->break_ctl(tty, -1); | |
2723 | if (retval) | |
2724 | goto out; | |
2725 | if (!signal_pending(current)) | |
2726 | msleep_interruptible(duration); | |
2727 | retval = tty->ops->break_ctl(tty, 0); | |
2728 | out: | |
2729 | tty_write_unlock(tty); | |
2730 | if (signal_pending(current)) | |
2731 | retval = -EINTR; | |
2732 | } | |
2733 | return retval; | |
1da177e4 LT |
2734 | } |
2735 | ||
af9b897e | 2736 | /** |
f34d7a5b | 2737 | * tty_tiocmget - get modem status |
af9b897e AC |
2738 | * @tty: tty device |
2739 | * @file: user file pointer | |
2740 | * @p: pointer to result | |
2741 | * | |
2742 | * Obtain the modem status bits from the tty driver if the feature | |
2743 | * is supported. Return -EINVAL if it is not available. | |
2744 | * | |
2745 | * Locking: none (up to the driver) | |
2746 | */ | |
2747 | ||
60b33c13 | 2748 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2749 | { |
2750 | int retval = -EINVAL; | |
2751 | ||
f34d7a5b | 2752 | if (tty->ops->tiocmget) { |
60b33c13 | 2753 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2754 | |
2755 | if (retval >= 0) | |
2756 | retval = put_user(retval, p); | |
2757 | } | |
2758 | return retval; | |
2759 | } | |
2760 | ||
af9b897e | 2761 | /** |
f34d7a5b | 2762 | * tty_tiocmset - set modem status |
af9b897e | 2763 | * @tty: tty device |
af9b897e AC |
2764 | * @cmd: command - clear bits, set bits or set all |
2765 | * @p: pointer to desired bits | |
2766 | * | |
2767 | * Set the modem status bits from the tty driver if the feature | |
2768 | * is supported. Return -EINVAL if it is not available. | |
2769 | * | |
2770 | * Locking: none (up to the driver) | |
2771 | */ | |
2772 | ||
20b9d177 | 2773 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2774 | unsigned __user *p) |
2775 | { | |
ae677517 AC |
2776 | int retval; |
2777 | unsigned int set, clear, val; | |
1da177e4 | 2778 | |
ae677517 AC |
2779 | if (tty->ops->tiocmset == NULL) |
2780 | return -EINVAL; | |
1da177e4 | 2781 | |
ae677517 AC |
2782 | retval = get_user(val, p); |
2783 | if (retval) | |
2784 | return retval; | |
2785 | set = clear = 0; | |
2786 | switch (cmd) { | |
2787 | case TIOCMBIS: | |
2788 | set = val; | |
2789 | break; | |
2790 | case TIOCMBIC: | |
2791 | clear = val; | |
2792 | break; | |
2793 | case TIOCMSET: | |
2794 | set = val; | |
2795 | clear = ~val; | |
2796 | break; | |
2797 | } | |
2798 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2799 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2800 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2801 | } |
2802 | ||
d281da7f AC |
2803 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2804 | { | |
2805 | int retval = -EINVAL; | |
2806 | struct serial_icounter_struct icount; | |
2807 | memset(&icount, 0, sizeof(icount)); | |
2808 | if (tty->ops->get_icount) | |
2809 | retval = tty->ops->get_icount(tty, &icount); | |
2810 | if (retval != 0) | |
2811 | return retval; | |
2812 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2813 | return -EFAULT; | |
2814 | return 0; | |
2815 | } | |
2816 | ||
8a8ae62f JS |
2817 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2818 | { | |
2819 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2820 | DEFAULT_RATELIMIT_INTERVAL, | |
2821 | DEFAULT_RATELIMIT_BURST); | |
2822 | char comm[TASK_COMM_LEN]; | |
2823 | int flags; | |
2824 | ||
2825 | if (get_user(flags, &ss->flags)) | |
2826 | return; | |
2827 | ||
2828 | flags &= ASYNC_DEPRECATED; | |
2829 | ||
2830 | if (flags && __ratelimit(&depr_flags)) | |
2831 | pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2832 | __func__, get_task_comm(comm, current), flags); | |
2833 | } | |
2834 | ||
8f166e00 PH |
2835 | /* |
2836 | * if pty, return the slave side (real_tty) | |
2837 | * otherwise, return self | |
2838 | */ | |
2839 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2840 | { |
2841 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2842 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2843 | tty = tty->link; | |
2844 | return tty; | |
2845 | } | |
e8b70e7d | 2846 | |
1da177e4 LT |
2847 | /* |
2848 | * Split this up, as gcc can choke on it otherwise.. | |
2849 | */ | |
04f378b1 | 2850 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2851 | { |
d996b62a NP |
2852 | struct tty_struct *tty = file_tty(file); |
2853 | struct tty_struct *real_tty; | |
1da177e4 LT |
2854 | void __user *p = (void __user *)arg; |
2855 | int retval; | |
2856 | struct tty_ldisc *ld; | |
37bdfb07 | 2857 | |
6131ffaa | 2858 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2859 | return -EINVAL; |
2860 | ||
e8b70e7d | 2861 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2862 | |
2863 | /* | |
2864 | * Factor out some common prep work | |
2865 | */ | |
2866 | switch (cmd) { | |
2867 | case TIOCSETD: | |
2868 | case TIOCSBRK: | |
2869 | case TIOCCBRK: | |
2870 | case TCSBRK: | |
37bdfb07 | 2871 | case TCSBRKP: |
1da177e4 LT |
2872 | retval = tty_check_change(tty); |
2873 | if (retval) | |
2874 | return retval; | |
2875 | if (cmd != TIOCCBRK) { | |
2876 | tty_wait_until_sent(tty, 0); | |
2877 | if (signal_pending(current)) | |
2878 | return -EINTR; | |
2879 | } | |
2880 | break; | |
2881 | } | |
2882 | ||
9e98966c AC |
2883 | /* |
2884 | * Now do the stuff. | |
2885 | */ | |
1da177e4 | 2886 | switch (cmd) { |
37bdfb07 AC |
2887 | case TIOCSTI: |
2888 | return tiocsti(tty, p); | |
2889 | case TIOCGWINSZ: | |
8f520021 | 2890 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2891 | case TIOCSWINSZ: |
fc6f6238 | 2892 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2893 | case TIOCCONS: |
2894 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2895 | case FIONBIO: | |
2896 | return fionbio(file, p); | |
2897 | case TIOCEXCL: | |
2898 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2899 | return 0; | |
2900 | case TIOCNXCL: | |
2901 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2902 | return 0; | |
84fd7bdf CG |
2903 | case TIOCGEXCL: |
2904 | { | |
2905 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2906 | return put_user(excl, (int __user *)p); | |
2907 | } | |
37bdfb07 AC |
2908 | case TIOCNOTTY: |
2909 | if (current->signal->tty != tty) | |
2910 | return -ENOTTY; | |
2911 | no_tty(); | |
2912 | return 0; | |
2913 | case TIOCSCTTY: | |
d1d3a0f7 | 2914 | return tiocsctty(real_tty, file, arg); |
37bdfb07 AC |
2915 | case TIOCGPGRP: |
2916 | return tiocgpgrp(tty, real_tty, p); | |
2917 | case TIOCSPGRP: | |
2918 | return tiocspgrp(tty, real_tty, p); | |
2919 | case TIOCGSID: | |
2920 | return tiocgsid(tty, real_tty, p); | |
2921 | case TIOCGETD: | |
5c17c861 | 2922 | return tiocgetd(tty, p); |
37bdfb07 AC |
2923 | case TIOCSETD: |
2924 | return tiocsetd(tty, p); | |
3c95c985 KS |
2925 | case TIOCVHANGUP: |
2926 | if (!capable(CAP_SYS_ADMIN)) | |
2927 | return -EPERM; | |
2928 | tty_vhangup(tty); | |
2929 | return 0; | |
b7b8de08 WF |
2930 | case TIOCGDEV: |
2931 | { | |
2932 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2933 | return put_user(ret, (unsigned int __user *)p); | |
2934 | } | |
37bdfb07 AC |
2935 | /* |
2936 | * Break handling | |
2937 | */ | |
2938 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2939 | if (tty->ops->break_ctl) |
9e98966c | 2940 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2941 | return 0; |
37bdfb07 | 2942 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2943 | if (tty->ops->break_ctl) |
9e98966c | 2944 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2945 | return 0; |
2946 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2947 | /* non-zero arg means wait for all output data | |
2948 | * to be sent (performed above) but don't send break. | |
2949 | * This is used by the tcdrain() termios function. | |
2950 | */ | |
2951 | if (!arg) | |
2952 | return send_break(tty, 250); | |
2953 | return 0; | |
2954 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2955 | return send_break(tty, arg ? arg*100 : 250); | |
2956 | ||
2957 | case TIOCMGET: | |
60b33c13 | 2958 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2959 | case TIOCMSET: |
2960 | case TIOCMBIC: | |
2961 | case TIOCMBIS: | |
20b9d177 | 2962 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2963 | case TIOCGICOUNT: |
2964 | retval = tty_tiocgicount(tty, p); | |
2965 | /* For the moment allow fall through to the old method */ | |
2966 | if (retval != -EINVAL) | |
2967 | return retval; | |
2968 | break; | |
37bdfb07 AC |
2969 | case TCFLSH: |
2970 | switch (arg) { | |
2971 | case TCIFLUSH: | |
2972 | case TCIOFLUSH: | |
2973 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2974 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2975 | break; |
37bdfb07 AC |
2976 | } |
2977 | break; | |
8a8ae62f JS |
2978 | case TIOCSSERIAL: |
2979 | tty_warn_deprecated_flags(p); | |
2980 | break; | |
1da177e4 | 2981 | } |
f34d7a5b | 2982 | if (tty->ops->ioctl) { |
c961bfb1 | 2983 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2984 | if (retval != -ENOIOCTLCMD) |
2985 | return retval; | |
2986 | } | |
2987 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2988 | if (!ld) |
2989 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2990 | retval = -EINVAL; |
a352def2 AC |
2991 | if (ld->ops->ioctl) { |
2992 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2993 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2994 | retval = -ENOTTY; |
1da177e4 LT |
2995 | } |
2996 | tty_ldisc_deref(ld); | |
2997 | return retval; | |
2998 | } | |
2999 | ||
e10cc1df | 3000 | #ifdef CONFIG_COMPAT |
37bdfb07 | 3001 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
3002 | unsigned long arg) |
3003 | { | |
d996b62a | 3004 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
3005 | struct tty_ldisc *ld; |
3006 | int retval = -ENOIOCTLCMD; | |
3007 | ||
6131ffaa | 3008 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
3009 | return -EINVAL; |
3010 | ||
f34d7a5b | 3011 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 3012 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
3013 | if (retval != -ENOIOCTLCMD) |
3014 | return retval; | |
3015 | } | |
3016 | ||
3017 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
3018 | if (!ld) |
3019 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
3020 | if (ld->ops->compat_ioctl) |
3021 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
3022 | else |
3023 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
3024 | tty_ldisc_deref(ld); |
3025 | ||
3026 | return retval; | |
3027 | } | |
3028 | #endif | |
1da177e4 | 3029 | |
c3c073f8 AV |
3030 | static int this_tty(const void *t, struct file *file, unsigned fd) |
3031 | { | |
3032 | if (likely(file->f_op->read != tty_read)) | |
3033 | return 0; | |
3034 | return file_tty(file) != t ? 0 : fd + 1; | |
3035 | } | |
3036 | ||
1da177e4 LT |
3037 | /* |
3038 | * This implements the "Secure Attention Key" --- the idea is to | |
3039 | * prevent trojan horses by killing all processes associated with this | |
3040 | * tty when the user hits the "Secure Attention Key". Required for | |
3041 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 3042 | * |
1da177e4 LT |
3043 | * This code could be nicer; ideally it should send a HUP, wait a few |
3044 | * seconds, then send a INT, and then a KILL signal. But you then | |
3045 | * have to coordinate with the init process, since all processes associated | |
3046 | * with the current tty must be dead before the new getty is allowed | |
3047 | * to spawn. | |
3048 | * | |
3049 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3050 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3051 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3052 | * | |
3053 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3054 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3055 | */ | |
8b6312f4 | 3056 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
3057 | { |
3058 | #ifdef TTY_SOFT_SAK | |
3059 | tty_hangup(tty); | |
3060 | #else | |
652486fb | 3061 | struct task_struct *g, *p; |
ab521dc0 | 3062 | struct pid *session; |
1da177e4 | 3063 | int i; |
37bdfb07 | 3064 | |
1da177e4 LT |
3065 | if (!tty) |
3066 | return; | |
24ec839c | 3067 | session = tty->session; |
37bdfb07 | 3068 | |
b3f13deb | 3069 | tty_ldisc_flush(tty); |
1da177e4 | 3070 | |
f34d7a5b | 3071 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3072 | |
1da177e4 | 3073 | read_lock(&tasklist_lock); |
652486fb | 3074 | /* Kill the entire session */ |
ab521dc0 | 3075 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
3076 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
3077 | task_pid_nr(p), p->comm); | |
652486fb | 3078 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3079 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
3080 | |
3081 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
3082 | do_each_thread(g, p) { |
3083 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
3084 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
3085 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
3086 | send_sig(SIGKILL, p, 1); |
3087 | continue; | |
3088 | } | |
3089 | task_lock(p); | |
c3c073f8 AV |
3090 | i = iterate_fd(p->files, 0, this_tty, tty); |
3091 | if (i != 0) { | |
9b42bb75 PH |
3092 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
3093 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 3094 | force_sig(SIGKILL, p); |
1da177e4 LT |
3095 | } |
3096 | task_unlock(p); | |
652486fb | 3097 | } while_each_thread(g, p); |
1da177e4 LT |
3098 | read_unlock(&tasklist_lock); |
3099 | #endif | |
3100 | } | |
3101 | ||
8b6312f4 EB |
3102 | static void do_SAK_work(struct work_struct *work) |
3103 | { | |
3104 | struct tty_struct *tty = | |
3105 | container_of(work, struct tty_struct, SAK_work); | |
3106 | __do_SAK(tty); | |
3107 | } | |
3108 | ||
1da177e4 LT |
3109 | /* |
3110 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3111 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3112 | * the values which we write to it will be identical to the values which it | |
3113 | * already has. --akpm | |
3114 | */ | |
3115 | void do_SAK(struct tty_struct *tty) | |
3116 | { | |
3117 | if (!tty) | |
3118 | return; | |
1da177e4 LT |
3119 | schedule_work(&tty->SAK_work); |
3120 | } | |
3121 | ||
3122 | EXPORT_SYMBOL(do_SAK); | |
3123 | ||
6e9430ac | 3124 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3125 | { |
6e9430ac | 3126 | const dev_t *devt = data; |
30004ac9 DES |
3127 | return dev->devt == *devt; |
3128 | } | |
3129 | ||
3130 | /* Must put_device() after it's unused! */ | |
3131 | static struct device *tty_get_device(struct tty_struct *tty) | |
3132 | { | |
3133 | dev_t devt = tty_devnum(tty); | |
3134 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3135 | } | |
3136 | ||
3137 | ||
af9b897e | 3138 | /** |
2c964a2f | 3139 | * alloc_tty_struct |
af9b897e | 3140 | * |
2c964a2f | 3141 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3142 | * |
2c964a2f | 3143 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3144 | */ |
af9b897e | 3145 | |
2c964a2f | 3146 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3147 | { |
2c964a2f RV |
3148 | struct tty_struct *tty; |
3149 | ||
3150 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3151 | if (!tty) | |
3152 | return NULL; | |
3153 | ||
9c9f4ded | 3154 | kref_init(&tty->kref); |
1da177e4 | 3155 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3156 | tty_ldisc_init(tty); |
ab521dc0 EB |
3157 | tty->session = NULL; |
3158 | tty->pgrp = NULL; | |
89c8d91e | 3159 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3160 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3161 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3162 | mutex_init(&tty->winsize_mutex); |
36697529 | 3163 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3164 | init_waitqueue_head(&tty->write_wait); |
3165 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3166 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3167 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3168 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3169 | spin_lock_init(&tty->flow_lock); |
4a510969 | 3170 | spin_lock_init(&tty->files_lock); |
1da177e4 | 3171 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3172 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3173 | |
3174 | tty->driver = driver; | |
3175 | tty->ops = driver->ops; | |
3176 | tty->index = idx; | |
3177 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3178 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3179 | |
3180 | return tty; | |
1da177e4 LT |
3181 | } |
3182 | ||
f34d7a5b AC |
3183 | /** |
3184 | * tty_put_char - write one character to a tty | |
3185 | * @tty: tty | |
3186 | * @ch: character | |
3187 | * | |
3188 | * Write one byte to the tty using the provided put_char method | |
3189 | * if present. Returns the number of characters successfully output. | |
3190 | * | |
3191 | * Note: the specific put_char operation in the driver layer may go | |
3192 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3193 | */ |
af9b897e | 3194 | |
f34d7a5b | 3195 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3196 | { |
f34d7a5b AC |
3197 | if (tty->ops->put_char) |
3198 | return tty->ops->put_char(tty, ch); | |
3199 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3200 | } |
f34d7a5b AC |
3201 | EXPORT_SYMBOL_GPL(tty_put_char); |
3202 | ||
d81ed103 | 3203 | struct class *tty_class; |
1da177e4 | 3204 | |
7e73eca6 JS |
3205 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3206 | unsigned int index, unsigned int count) | |
3207 | { | |
c1a752ba LY |
3208 | int err; |
3209 | ||
7e73eca6 | 3210 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3211 | driver->cdevs[index] = cdev_alloc(); |
3212 | if (!driver->cdevs[index]) | |
3213 | return -ENOMEM; | |
c1a752ba | 3214 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3215 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3216 | err = cdev_add(driver->cdevs[index], dev, count); |
3217 | if (err) | |
3218 | kobject_put(&driver->cdevs[index]->kobj); | |
3219 | return err; | |
7e73eca6 JS |
3220 | } |
3221 | ||
1da177e4 | 3222 | /** |
af9b897e AC |
3223 | * tty_register_device - register a tty device |
3224 | * @driver: the tty driver that describes the tty device | |
3225 | * @index: the index in the tty driver for this tty device | |
3226 | * @device: a struct device that is associated with this tty device. | |
3227 | * This field is optional, if there is no known struct device | |
3228 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3229 | * |
01107d34 GKH |
3230 | * Returns a pointer to the struct device for this tty device |
3231 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3232 | * |
af9b897e AC |
3233 | * This call is required to be made to register an individual tty device |
3234 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3235 | * that bit is not set, this function should not be called by a tty | |
3236 | * driver. | |
3237 | * | |
3238 | * Locking: ?? | |
1da177e4 | 3239 | */ |
af9b897e | 3240 | |
01107d34 GKH |
3241 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3242 | struct device *device) | |
1da177e4 | 3243 | { |
6915c0e4 TH |
3244 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3245 | } | |
3246 | EXPORT_SYMBOL(tty_register_device); | |
3247 | ||
b1b79916 TH |
3248 | static void tty_device_create_release(struct device *dev) |
3249 | { | |
83db1df4 | 3250 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
3251 | kfree(dev); |
3252 | } | |
3253 | ||
6915c0e4 TH |
3254 | /** |
3255 | * tty_register_device_attr - register a tty device | |
3256 | * @driver: the tty driver that describes the tty device | |
3257 | * @index: the index in the tty driver for this tty device | |
3258 | * @device: a struct device that is associated with this tty device. | |
3259 | * This field is optional, if there is no known struct device | |
3260 | * for this tty device it can be set to NULL safely. | |
3261 | * @drvdata: Driver data to be set to device. | |
3262 | * @attr_grp: Attribute group to be set on device. | |
3263 | * | |
3264 | * Returns a pointer to the struct device for this tty device | |
3265 | * (or ERR_PTR(-EFOO) on error). | |
3266 | * | |
3267 | * This call is required to be made to register an individual tty device | |
3268 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3269 | * that bit is not set, this function should not be called by a tty | |
3270 | * driver. | |
3271 | * | |
3272 | * Locking: ?? | |
3273 | */ | |
3274 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3275 | unsigned index, struct device *device, | |
3276 | void *drvdata, | |
3277 | const struct attribute_group **attr_grp) | |
3278 | { | |
1da177e4 | 3279 | char name[64]; |
6915c0e4 TH |
3280 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3281 | struct device *dev = NULL; | |
3282 | int retval = -ENODEV; | |
7e73eca6 | 3283 | bool cdev = false; |
1da177e4 LT |
3284 | |
3285 | if (index >= driver->num) { | |
656fb867 PH |
3286 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
3287 | driver->name, index); | |
1cdcb6b4 | 3288 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3289 | } |
3290 | ||
1da177e4 LT |
3291 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3292 | pty_line_name(driver, index, name); | |
3293 | else | |
3294 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3295 | |
7e73eca6 | 3296 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3297 | retval = tty_cdev_add(driver, devt, index, 1); |
3298 | if (retval) | |
3299 | goto error; | |
7e73eca6 JS |
3300 | cdev = true; |
3301 | } | |
3302 | ||
6915c0e4 TH |
3303 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3304 | if (!dev) { | |
3305 | retval = -ENOMEM; | |
3306 | goto error; | |
3307 | } | |
7e73eca6 | 3308 | |
6915c0e4 TH |
3309 | dev->devt = devt; |
3310 | dev->class = tty_class; | |
3311 | dev->parent = device; | |
b1b79916 | 3312 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3313 | dev_set_name(dev, "%s", name); |
3314 | dev->groups = attr_grp; | |
3315 | dev_set_drvdata(dev, drvdata); | |
3316 | ||
3317 | retval = device_register(dev); | |
3318 | if (retval) | |
3319 | goto error; | |
3320 | ||
3321 | return dev; | |
3322 | ||
3323 | error: | |
3324 | put_device(dev); | |
a3a10ce3 RW |
3325 | if (cdev) { |
3326 | cdev_del(driver->cdevs[index]); | |
3327 | driver->cdevs[index] = NULL; | |
3328 | } | |
6915c0e4 | 3329 | return ERR_PTR(retval); |
1da177e4 | 3330 | } |
6915c0e4 | 3331 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3332 | |
3333 | /** | |
af9b897e AC |
3334 | * tty_unregister_device - unregister a tty device |
3335 | * @driver: the tty driver that describes the tty device | |
3336 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3337 | * |
af9b897e AC |
3338 | * If a tty device is registered with a call to tty_register_device() then |
3339 | * this function must be called when the tty device is gone. | |
3340 | * | |
3341 | * Locking: ?? | |
1da177e4 | 3342 | */ |
af9b897e | 3343 | |
1da177e4 LT |
3344 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3345 | { | |
37bdfb07 AC |
3346 | device_destroy(tty_class, |
3347 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3348 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3349 | cdev_del(driver->cdevs[index]); | |
3350 | driver->cdevs[index] = NULL; | |
3351 | } | |
1da177e4 | 3352 | } |
1da177e4 LT |
3353 | EXPORT_SYMBOL(tty_unregister_device); |
3354 | ||
7f0bc6a6 JS |
3355 | /** |
3356 | * __tty_alloc_driver -- allocate tty driver | |
3357 | * @lines: count of lines this driver can handle at most | |
3358 | * @owner: module which is repsonsible for this driver | |
3359 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3360 | * | |
3361 | * This should not be called directly, some of the provided macros should be | |
3362 | * used instead. Use IS_ERR and friends on @retval. | |
3363 | */ | |
3364 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3365 | unsigned long flags) | |
1da177e4 LT |
3366 | { |
3367 | struct tty_driver *driver; | |
7e73eca6 | 3368 | unsigned int cdevs = 1; |
16a02081 | 3369 | int err; |
1da177e4 | 3370 | |
0019b408 | 3371 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3372 | return ERR_PTR(-EINVAL); |
3373 | ||
506eb99a | 3374 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3375 | if (!driver) |
3376 | return ERR_PTR(-ENOMEM); | |
3377 | ||
3378 | kref_init(&driver->kref); | |
3379 | driver->magic = TTY_DRIVER_MAGIC; | |
3380 | driver->num = lines; | |
3381 | driver->owner = owner; | |
3382 | driver->flags = flags; | |
16a02081 JS |
3383 | |
3384 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3385 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3386 | GFP_KERNEL); | |
3387 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3388 | GFP_KERNEL); | |
3389 | if (!driver->ttys || !driver->termios) { | |
3390 | err = -ENOMEM; | |
3391 | goto err_free_all; | |
3392 | } | |
3393 | } | |
3394 | ||
3395 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3396 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3397 | GFP_KERNEL); | |
3398 | if (!driver->ports) { | |
3399 | err = -ENOMEM; | |
3400 | goto err_free_all; | |
3401 | } | |
7e73eca6 JS |
3402 | cdevs = lines; |
3403 | } | |
3404 | ||
3405 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3406 | if (!driver->cdevs) { | |
3407 | err = -ENOMEM; | |
3408 | goto err_free_all; | |
16a02081 | 3409 | } |
7f0bc6a6 | 3410 | |
1da177e4 | 3411 | return driver; |
16a02081 JS |
3412 | err_free_all: |
3413 | kfree(driver->ports); | |
3414 | kfree(driver->ttys); | |
3415 | kfree(driver->termios); | |
a3a10ce3 | 3416 | kfree(driver->cdevs); |
16a02081 JS |
3417 | kfree(driver); |
3418 | return ERR_PTR(err); | |
1da177e4 | 3419 | } |
7f0bc6a6 | 3420 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3421 | |
7d7b93c1 | 3422 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3423 | { |
7d7b93c1 AC |
3424 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3425 | int i; | |
3426 | struct ktermios *tp; | |
7d7b93c1 AC |
3427 | |
3428 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3429 | /* | |
3430 | * Free the termios and termios_locked structures because | |
3431 | * we don't want to get memory leaks when modular tty | |
3432 | * drivers are removed from the kernel. | |
3433 | */ | |
3434 | for (i = 0; i < driver->num; i++) { | |
3435 | tp = driver->termios[i]; | |
3436 | if (tp) { | |
3437 | driver->termios[i] = NULL; | |
3438 | kfree(tp); | |
3439 | } | |
7d7b93c1 AC |
3440 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3441 | tty_unregister_device(driver, i); | |
3442 | } | |
7d7b93c1 | 3443 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3444 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3445 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3446 | } |
7e73eca6 | 3447 | kfree(driver->cdevs); |
04831dc1 | 3448 | kfree(driver->ports); |
16a02081 JS |
3449 | kfree(driver->termios); |
3450 | kfree(driver->ttys); | |
1da177e4 LT |
3451 | kfree(driver); |
3452 | } | |
3453 | ||
7d7b93c1 AC |
3454 | void tty_driver_kref_put(struct tty_driver *driver) |
3455 | { | |
3456 | kref_put(&driver->kref, destruct_tty_driver); | |
3457 | } | |
3458 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3459 | ||
b68e31d0 JD |
3460 | void tty_set_operations(struct tty_driver *driver, |
3461 | const struct tty_operations *op) | |
1da177e4 | 3462 | { |
f34d7a5b AC |
3463 | driver->ops = op; |
3464 | }; | |
7d7b93c1 | 3465 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3466 | |
7d7b93c1 AC |
3467 | void put_tty_driver(struct tty_driver *d) |
3468 | { | |
3469 | tty_driver_kref_put(d); | |
3470 | } | |
1da177e4 | 3471 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3472 | |
3473 | /* | |
3474 | * Called by a tty driver to register itself. | |
3475 | */ | |
3476 | int tty_register_driver(struct tty_driver *driver) | |
3477 | { | |
3478 | int error; | |
37bdfb07 | 3479 | int i; |
1da177e4 | 3480 | dev_t dev; |
b670bde0 | 3481 | struct device *d; |
1da177e4 | 3482 | |
1da177e4 | 3483 | if (!driver->major) { |
37bdfb07 AC |
3484 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3485 | driver->num, driver->name); | |
1da177e4 LT |
3486 | if (!error) { |
3487 | driver->major = MAJOR(dev); | |
3488 | driver->minor_start = MINOR(dev); | |
3489 | } | |
3490 | } else { | |
3491 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3492 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3493 | } |
9bb8a3d4 | 3494 | if (error < 0) |
16a02081 | 3495 | goto err; |
1da177e4 | 3496 | |
7e73eca6 JS |
3497 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3498 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3499 | if (error) | |
3500 | goto err_unreg_char; | |
3501 | } | |
1da177e4 | 3502 | |
ca509f69 | 3503 | mutex_lock(&tty_mutex); |
1da177e4 | 3504 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3505 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3506 | |
3507 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3508 | for (i = 0; i < driver->num; i++) { |
3509 | d = tty_register_device(driver, i, NULL); | |
3510 | if (IS_ERR(d)) { | |
3511 | error = PTR_ERR(d); | |
16a02081 | 3512 | goto err_unreg_devs; |
b670bde0 VK |
3513 | } |
3514 | } | |
1da177e4 LT |
3515 | } |
3516 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3517 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3518 | return 0; |
b670bde0 | 3519 | |
16a02081 | 3520 | err_unreg_devs: |
b670bde0 VK |
3521 | for (i--; i >= 0; i--) |
3522 | tty_unregister_device(driver, i); | |
3523 | ||
3524 | mutex_lock(&tty_mutex); | |
3525 | list_del(&driver->tty_drivers); | |
3526 | mutex_unlock(&tty_mutex); | |
3527 | ||
9bb8a3d4 | 3528 | err_unreg_char: |
b670bde0 | 3529 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3530 | err: |
b670bde0 | 3531 | return error; |
1da177e4 | 3532 | } |
1da177e4 LT |
3533 | EXPORT_SYMBOL(tty_register_driver); |
3534 | ||
3535 | /* | |
3536 | * Called by a tty driver to unregister itself. | |
3537 | */ | |
3538 | int tty_unregister_driver(struct tty_driver *driver) | |
3539 | { | |
7d7b93c1 AC |
3540 | #if 0 |
3541 | /* FIXME */ | |
1da177e4 LT |
3542 | if (driver->refcount) |
3543 | return -EBUSY; | |
7d7b93c1 | 3544 | #endif |
1da177e4 LT |
3545 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3546 | driver->num); | |
ca509f69 | 3547 | mutex_lock(&tty_mutex); |
1da177e4 | 3548 | list_del(&driver->tty_drivers); |
ca509f69 | 3549 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3550 | return 0; |
3551 | } | |
7d7b93c1 | 3552 | |
1da177e4 LT |
3553 | EXPORT_SYMBOL(tty_unregister_driver); |
3554 | ||
24ec839c PZ |
3555 | dev_t tty_devnum(struct tty_struct *tty) |
3556 | { | |
3557 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3558 | } | |
3559 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3560 | |
d81ed103 AC |
3561 | void tty_default_fops(struct file_operations *fops) |
3562 | { | |
3563 | *fops = tty_fops; | |
3564 | } | |
3565 | ||
1da177e4 LT |
3566 | /* |
3567 | * Initialize the console device. This is called *early*, so | |
3568 | * we can't necessarily depend on lots of kernel help here. | |
3569 | * Just do some early initializations, and do the complex setup | |
3570 | * later. | |
3571 | */ | |
3572 | void __init console_init(void) | |
3573 | { | |
3574 | initcall_t *call; | |
3575 | ||
3576 | /* Setup the default TTY line discipline. */ | |
27228732 | 3577 | n_tty_init(); |
1da177e4 LT |
3578 | |
3579 | /* | |
37bdfb07 | 3580 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3581 | * inform about problems etc.. |
3582 | */ | |
1da177e4 LT |
3583 | call = __con_initcall_start; |
3584 | while (call < __con_initcall_end) { | |
3585 | (*call)(); | |
3586 | call++; | |
3587 | } | |
3588 | } | |
3589 | ||
2c9ede55 | 3590 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3591 | { |
3592 | if (!mode) | |
3593 | return NULL; | |
3594 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3595 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3596 | *mode = 0666; | |
3597 | return NULL; | |
3598 | } | |
3599 | ||
1da177e4 LT |
3600 | static int __init tty_class_init(void) |
3601 | { | |
7fe845d1 | 3602 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3603 | if (IS_ERR(tty_class)) |
3604 | return PTR_ERR(tty_class); | |
e454cea2 | 3605 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3606 | return 0; |
3607 | } | |
3608 | ||
3609 | postcore_initcall(tty_class_init); | |
3610 | ||
3611 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3612 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3613 | |
fbc92a34 KS |
3614 | static ssize_t show_cons_active(struct device *dev, |
3615 | struct device_attribute *attr, char *buf) | |
3616 | { | |
3617 | struct console *cs[16]; | |
3618 | int i = 0; | |
3619 | struct console *c; | |
3620 | ssize_t count = 0; | |
3621 | ||
ac751efa | 3622 | console_lock(); |
a2a6a822 | 3623 | for_each_console(c) { |
fbc92a34 KS |
3624 | if (!c->device) |
3625 | continue; | |
3626 | if (!c->write) | |
3627 | continue; | |
3628 | if ((c->flags & CON_ENABLED) == 0) | |
3629 | continue; | |
3630 | cs[i++] = c; | |
3631 | if (i >= ARRAY_SIZE(cs)) | |
3632 | break; | |
3633 | } | |
723abd87 HR |
3634 | while (i--) { |
3635 | int index = cs[i]->index; | |
3636 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3637 | ||
3638 | /* don't resolve tty0 as some programs depend on it */ | |
3639 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3640 | count += tty_line_name(drv, index, buf + count); | |
3641 | else | |
3642 | count += sprintf(buf + count, "%s%d", | |
3643 | cs[i]->name, cs[i]->index); | |
3644 | ||
3645 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3646 | } | |
ac751efa | 3647 | console_unlock(); |
fbc92a34 KS |
3648 | |
3649 | return count; | |
3650 | } | |
3651 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3652 | ||
1083a7be TI |
3653 | static struct attribute *cons_dev_attrs[] = { |
3654 | &dev_attr_active.attr, | |
3655 | NULL | |
3656 | }; | |
3657 | ||
3658 | ATTRIBUTE_GROUPS(cons_dev); | |
3659 | ||
fbc92a34 KS |
3660 | static struct device *consdev; |
3661 | ||
3662 | void console_sysfs_notify(void) | |
3663 | { | |
3664 | if (consdev) | |
3665 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3666 | } | |
3667 | ||
1da177e4 LT |
3668 | /* |
3669 | * Ok, now we can initialize the rest of the tty devices and can count | |
3670 | * on memory allocations, interrupts etc.. | |
3671 | */ | |
31d1d48e | 3672 | int __init tty_init(void) |
1da177e4 LT |
3673 | { |
3674 | cdev_init(&tty_cdev, &tty_fops); | |
3675 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3676 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3677 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3678 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3679 | |
3680 | cdev_init(&console_cdev, &console_fops); | |
3681 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3682 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3683 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3684 | consdev = device_create_with_groups(tty_class, NULL, |
3685 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3686 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3687 | if (IS_ERR(consdev)) |
3688 | consdev = NULL; | |
1da177e4 | 3689 | |
1da177e4 | 3690 | #ifdef CONFIG_VT |
d81ed103 | 3691 | vty_init(&console_fops); |
1da177e4 LT |
3692 | #endif |
3693 | return 0; | |
3694 | } | |
31d1d48e | 3695 |