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 | |
109 | ||
110 | #define TTY_PARANOIA_CHECK 1 | |
111 | #define CHECK_TTY_COUNT 1 | |
112 | ||
edc6afc5 | 113 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
114 | .c_iflag = ICRNL | IXON, |
115 | .c_oflag = OPOST | ONLCR, | |
116 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
117 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
118 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
119 | .c_cc = INIT_C_CC, |
120 | .c_ispeed = 38400, | |
121 | .c_ospeed = 38400 | |
1da177e4 LT |
122 | }; |
123 | ||
124 | EXPORT_SYMBOL(tty_std_termios); | |
125 | ||
126 | /* This list gets poked at by procfs and various bits of boot up code. This | |
127 | could do with some rationalisation such as pulling the tty proc function | |
128 | into this file */ | |
37bdfb07 | 129 | |
1da177e4 LT |
130 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
131 | ||
24ec839c | 132 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 133 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 134 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 135 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 136 | |
ee2ffa0d NP |
137 | /* Spinlock to protect the tty->tty_files list */ |
138 | DEFINE_SPINLOCK(tty_files_lock); | |
139 | ||
1da177e4 LT |
140 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
141 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
142 | ssize_t redirected_tty_write(struct file *, const char __user *, |
143 | size_t, loff_t *); | |
1da177e4 LT |
144 | static unsigned int tty_poll(struct file *, poll_table *); |
145 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 146 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 147 | #ifdef CONFIG_COMPAT |
37bdfb07 | 148 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
149 | unsigned long arg); |
150 | #else | |
151 | #define tty_compat_ioctl NULL | |
152 | #endif | |
ec79d605 | 153 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 154 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 155 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 156 | |
af9b897e AC |
157 | /** |
158 | * free_tty_struct - free a disused tty | |
159 | * @tty: tty struct to free | |
160 | * | |
161 | * Free the write buffers, tty queue and tty memory itself. | |
162 | * | |
163 | * Locking: none. Must be called after tty is definitely unused | |
164 | */ | |
165 | ||
bf970ee4 | 166 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 167 | { |
dc6802a7 DC |
168 | if (!tty) |
169 | return; | |
30004ac9 DES |
170 | if (tty->dev) |
171 | put_device(tty->dev); | |
1da177e4 | 172 | kfree(tty->write_buf); |
89c8d91e | 173 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
174 | kfree(tty); |
175 | } | |
176 | ||
d996b62a NP |
177 | static inline struct tty_struct *file_tty(struct file *file) |
178 | { | |
179 | return ((struct tty_file_private *)file->private_data)->tty; | |
180 | } | |
181 | ||
fa90e1c9 | 182 | int tty_alloc_file(struct file *file) |
d996b62a NP |
183 | { |
184 | struct tty_file_private *priv; | |
185 | ||
f573bd17 PE |
186 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
187 | if (!priv) | |
188 | return -ENOMEM; | |
d996b62a | 189 | |
fa90e1c9 JS |
190 | file->private_data = priv; |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* Associate a new file with the tty structure */ | |
196 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
197 | { | |
198 | struct tty_file_private *priv = file->private_data; | |
199 | ||
d996b62a NP |
200 | priv->tty = tty; |
201 | priv->file = file; | |
d996b62a NP |
202 | |
203 | spin_lock(&tty_files_lock); | |
204 | list_add(&priv->list, &tty->tty_files); | |
205 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 206 | } |
f573bd17 | 207 | |
fa90e1c9 JS |
208 | /** |
209 | * tty_free_file - free file->private_data | |
210 | * | |
211 | * This shall be used only for fail path handling when tty_add_file was not | |
212 | * called yet. | |
213 | */ | |
214 | void tty_free_file(struct file *file) | |
215 | { | |
216 | struct tty_file_private *priv = file->private_data; | |
217 | ||
218 | file->private_data = NULL; | |
219 | kfree(priv); | |
d996b62a NP |
220 | } |
221 | ||
222 | /* Delete file from its tty */ | |
2520e274 | 223 | static void tty_del_file(struct file *file) |
d996b62a NP |
224 | { |
225 | struct tty_file_private *priv = file->private_data; | |
226 | ||
227 | spin_lock(&tty_files_lock); | |
228 | list_del(&priv->list); | |
229 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 230 | tty_free_file(file); |
d996b62a NP |
231 | } |
232 | ||
233 | ||
1da177e4 LT |
234 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
235 | ||
af9b897e AC |
236 | /** |
237 | * tty_name - return tty naming | |
238 | * @tty: tty structure | |
239 | * @buf: buffer for output | |
240 | * | |
241 | * Convert a tty structure into a name. The name reflects the kernel | |
242 | * naming policy and if udev is in use may not reflect user space | |
243 | * | |
244 | * Locking: none | |
245 | */ | |
246 | ||
1da177e4 LT |
247 | char *tty_name(struct tty_struct *tty, char *buf) |
248 | { | |
249 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
250 | strcpy(buf, "NULL tty"); | |
251 | else | |
252 | strcpy(buf, tty->name); | |
253 | return buf; | |
254 | } | |
255 | ||
256 | EXPORT_SYMBOL(tty_name); | |
257 | ||
d769a669 | 258 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
259 | const char *routine) |
260 | { | |
261 | #ifdef TTY_PARANOIA_CHECK | |
262 | if (!tty) { | |
263 | printk(KERN_WARNING | |
264 | "null TTY for (%d:%d) in %s\n", | |
265 | imajor(inode), iminor(inode), routine); | |
266 | return 1; | |
267 | } | |
268 | if (tty->magic != TTY_MAGIC) { | |
269 | printk(KERN_WARNING | |
270 | "bad magic number for tty struct (%d:%d) in %s\n", | |
271 | imajor(inode), iminor(inode), routine); | |
272 | return 1; | |
273 | } | |
274 | #endif | |
275 | return 0; | |
276 | } | |
277 | ||
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 | |
ee2ffa0d | 284 | spin_lock(&tty_files_lock); |
1da177e4 LT |
285 | list_for_each(p, &tty->tty_files) { |
286 | count++; | |
287 | } | |
ee2ffa0d | 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) { | |
294 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
295 | "!= #fd's(%d) in %s\n", | |
296 | tty->name, tty->count, count, routine); | |
297 | return count; | |
24ec839c | 298 | } |
1da177e4 LT |
299 | #endif |
300 | return 0; | |
301 | } | |
302 | ||
af9b897e AC |
303 | /** |
304 | * get_tty_driver - find device of a tty | |
305 | * @dev_t: device identifier | |
306 | * @index: returns the index of the tty | |
307 | * | |
308 | * This routine returns a tty driver structure, given a device number | |
309 | * and also passes back the index number. | |
310 | * | |
311 | * Locking: caller must hold tty_mutex | |
1da177e4 | 312 | */ |
af9b897e | 313 | |
1da177e4 LT |
314 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
315 | { | |
316 | struct tty_driver *p; | |
317 | ||
318 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
319 | dev_t base = MKDEV(p->major, p->minor_start); | |
320 | if (device < base || device >= base + p->num) | |
321 | continue; | |
322 | *index = device - base; | |
7d7b93c1 | 323 | return tty_driver_kref_get(p); |
1da177e4 LT |
324 | } |
325 | return NULL; | |
326 | } | |
327 | ||
f2d937f3 JW |
328 | #ifdef CONFIG_CONSOLE_POLL |
329 | ||
330 | /** | |
331 | * tty_find_polling_driver - find device of a polled tty | |
332 | * @name: name string to match | |
333 | * @line: pointer to resulting tty line nr | |
334 | * | |
335 | * This routine returns a tty driver structure, given a name | |
336 | * and the condition that the tty driver is capable of polled | |
337 | * operation. | |
338 | */ | |
339 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
340 | { | |
341 | struct tty_driver *p, *res = NULL; | |
342 | int tty_line = 0; | |
0dca0fd2 | 343 | int len; |
5f0878ac | 344 | char *str, *stp; |
f2d937f3 | 345 | |
0dca0fd2 JW |
346 | for (str = name; *str; str++) |
347 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
348 | break; | |
349 | if (!*str) | |
350 | return NULL; | |
351 | ||
352 | len = str - name; | |
353 | tty_line = simple_strtoul(str, &str, 10); | |
354 | ||
f2d937f3 JW |
355 | mutex_lock(&tty_mutex); |
356 | /* Search through the tty devices to look for a match */ | |
357 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
358 | if (strncmp(name, p->name, len) != 0) |
359 | continue; | |
5f0878ac AC |
360 | stp = str; |
361 | if (*stp == ',') | |
362 | stp++; | |
363 | if (*stp == '\0') | |
364 | stp = NULL; | |
f2d937f3 | 365 | |
6eb68d6f | 366 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 367 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 368 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
369 | *line = tty_line; |
370 | break; | |
371 | } | |
372 | } | |
373 | mutex_unlock(&tty_mutex); | |
374 | ||
375 | return res; | |
376 | } | |
377 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
378 | #endif | |
379 | ||
af9b897e AC |
380 | /** |
381 | * tty_check_change - check for POSIX terminal changes | |
382 | * @tty: tty to check | |
383 | * | |
384 | * If we try to write to, or set the state of, a terminal and we're | |
385 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
386 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
387 | * | |
978e595f | 388 | * Locking: ctrl_lock |
1da177e4 | 389 | */ |
af9b897e | 390 | |
37bdfb07 | 391 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 392 | { |
47f86834 AC |
393 | unsigned long flags; |
394 | int ret = 0; | |
395 | ||
1da177e4 LT |
396 | if (current->signal->tty != tty) |
397 | return 0; | |
47f86834 AC |
398 | |
399 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
400 | ||
ab521dc0 EB |
401 | if (!tty->pgrp) { |
402 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 403 | goto out_unlock; |
1da177e4 | 404 | } |
ab521dc0 | 405 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
406 | goto out_unlock; |
407 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 408 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
409 | goto out; |
410 | if (is_current_pgrp_orphaned()) { | |
411 | ret = -EIO; | |
412 | goto out; | |
413 | } | |
040b6362 ON |
414 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
415 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
416 | ret = -ERESTARTSYS; |
417 | out: | |
9ffee4cb AM |
418 | return ret; |
419 | out_unlock: | |
47f86834 AC |
420 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
421 | return ret; | |
1da177e4 LT |
422 | } |
423 | ||
424 | EXPORT_SYMBOL(tty_check_change); | |
425 | ||
37bdfb07 | 426 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
427 | size_t count, loff_t *ppos) |
428 | { | |
429 | return 0; | |
430 | } | |
431 | ||
37bdfb07 | 432 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
433 | size_t count, loff_t *ppos) |
434 | { | |
435 | return -EIO; | |
436 | } | |
437 | ||
438 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 439 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
440 | { |
441 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
442 | } | |
443 | ||
04f378b1 AC |
444 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
445 | unsigned long arg) | |
38ad2ed0 PF |
446 | { |
447 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
448 | } | |
449 | ||
37bdfb07 | 450 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 451 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
452 | { |
453 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
454 | } | |
455 | ||
62322d25 | 456 | static const struct file_operations tty_fops = { |
1da177e4 LT |
457 | .llseek = no_llseek, |
458 | .read = tty_read, | |
459 | .write = tty_write, | |
460 | .poll = tty_poll, | |
04f378b1 | 461 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 462 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
463 | .open = tty_open, |
464 | .release = tty_release, | |
465 | .fasync = tty_fasync, | |
466 | }; | |
467 | ||
62322d25 | 468 | static const struct file_operations console_fops = { |
1da177e4 LT |
469 | .llseek = no_llseek, |
470 | .read = tty_read, | |
471 | .write = redirected_tty_write, | |
472 | .poll = tty_poll, | |
04f378b1 | 473 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 474 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
475 | .open = tty_open, |
476 | .release = tty_release, | |
477 | .fasync = tty_fasync, | |
478 | }; | |
479 | ||
62322d25 | 480 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
481 | .llseek = no_llseek, |
482 | .read = hung_up_tty_read, | |
483 | .write = hung_up_tty_write, | |
484 | .poll = hung_up_tty_poll, | |
04f378b1 | 485 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 486 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
487 | .release = tty_release, |
488 | }; | |
489 | ||
490 | static DEFINE_SPINLOCK(redirect_lock); | |
491 | static struct file *redirect; | |
492 | ||
11d9befd PH |
493 | |
494 | void proc_clear_tty(struct task_struct *p) | |
495 | { | |
496 | unsigned long flags; | |
497 | struct tty_struct *tty; | |
498 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
499 | tty = p->signal->tty; | |
500 | p->signal->tty = NULL; | |
501 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
502 | tty_kref_put(tty); | |
503 | } | |
504 | ||
505 | /* Called under the sighand lock */ | |
506 | ||
bce65f18 | 507 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd PH |
508 | { |
509 | if (tty) { | |
510 | unsigned long flags; | |
511 | /* We should not have a session or pgrp to put here but.... */ | |
512 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
513 | put_pid(tty->session); | |
514 | put_pid(tty->pgrp); | |
bce65f18 | 515 | tty->pgrp = get_pid(task_pgrp(current)); |
11d9befd | 516 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
bce65f18 PH |
517 | tty->session = get_pid(task_session(current)); |
518 | if (current->signal->tty) { | |
11d9befd | 519 | printk(KERN_DEBUG "tty not NULL!!\n"); |
bce65f18 | 520 | tty_kref_put(current->signal->tty); |
11d9befd PH |
521 | } |
522 | } | |
bce65f18 PH |
523 | put_pid(current->signal->tty_old_pgrp); |
524 | current->signal->tty = tty_kref_get(tty); | |
525 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
526 | } |
527 | ||
bce65f18 | 528 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 529 | { |
bce65f18 PH |
530 | spin_lock_irq(¤t->sighand->siglock); |
531 | __proc_set_tty(tty); | |
532 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
533 | } |
534 | ||
535 | struct tty_struct *get_current_tty(void) | |
536 | { | |
537 | struct tty_struct *tty; | |
538 | unsigned long flags; | |
539 | ||
540 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
541 | tty = tty_kref_get(current->signal->tty); | |
542 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
543 | return tty; | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(get_current_tty); | |
546 | ||
547 | static void session_clear_tty(struct pid *session) | |
548 | { | |
549 | struct task_struct *p; | |
550 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
551 | proc_clear_tty(p); | |
552 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
553 | } | |
554 | ||
1da177e4 LT |
555 | /** |
556 | * tty_wakeup - request more data | |
557 | * @tty: terminal | |
558 | * | |
559 | * Internal and external helper for wakeups of tty. This function | |
560 | * informs the line discipline if present that the driver is ready | |
561 | * to receive more output data. | |
562 | */ | |
37bdfb07 | 563 | |
1da177e4 LT |
564 | void tty_wakeup(struct tty_struct *tty) |
565 | { | |
566 | struct tty_ldisc *ld; | |
37bdfb07 | 567 | |
1da177e4 LT |
568 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
569 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 570 | if (ld) { |
a352def2 AC |
571 | if (ld->ops->write_wakeup) |
572 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
573 | tty_ldisc_deref(ld); |
574 | } | |
575 | } | |
4b19449d | 576 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
577 | } |
578 | ||
579 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
580 | ||
ea648a47 PH |
581 | /** |
582 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
583 | * @tty controlling tty |
584 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 585 | * |
f91e2590 PH |
586 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
587 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
588 | * |
589 | * Returns the number of processes in the session with this tty | |
590 | * as their controlling terminal. This value is used to drop | |
591 | * tty references for those processes. | |
592 | */ | |
f91e2590 | 593 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
594 | { |
595 | struct task_struct *p; | |
ea648a47 | 596 | int refs = 0; |
f91e2590 | 597 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
598 | |
599 | read_lock(&tasklist_lock); | |
600 | if (tty->session) { | |
601 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
602 | spin_lock_irq(&p->sighand->siglock); | |
603 | if (p->signal->tty == tty) { | |
604 | p->signal->tty = NULL; | |
605 | /* We defer the dereferences outside fo | |
606 | the tasklist lock */ | |
607 | refs++; | |
608 | } | |
609 | if (!p->signal->leader) { | |
610 | spin_unlock_irq(&p->sighand->siglock); | |
611 | continue; | |
612 | } | |
613 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
614 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
615 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 616 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 617 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
618 | if (tty->pgrp) |
619 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 620 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
621 | spin_unlock_irq(&p->sighand->siglock); |
622 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
623 | } | |
624 | read_unlock(&tasklist_lock); | |
625 | ||
f91e2590 PH |
626 | if (tty_pgrp) { |
627 | if (exit_session) | |
628 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
629 | put_pid(tty_pgrp); | |
630 | } | |
631 | ||
ea648a47 PH |
632 | return refs; |
633 | } | |
634 | ||
af9b897e | 635 | /** |
11dbf203 | 636 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 637 | * @work: tty device |
af9b897e | 638 | * |
ef4f527c | 639 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
640 | * synchronous but doesn't hold any locks, so we need to make sure we |
641 | * have the appropriate locks for what we're doing. | |
642 | * | |
643 | * The hangup event clears any pending redirections onto the hung up | |
644 | * device. It ensures future writes will error and it does the needed | |
645 | * line discipline hangup and signal delivery. The tty object itself | |
646 | * remains intact. | |
647 | * | |
648 | * Locking: | |
ec79d605 | 649 | * BTM |
24ec839c PZ |
650 | * redirect lock for undoing redirection |
651 | * file list lock for manipulating list of ttys | |
137084bb | 652 | * tty_ldiscs_lock from called functions |
6a1c0680 | 653 | * termios_rwsem resetting termios data |
24ec839c PZ |
654 | * tasklist_lock to walk task list for hangup event |
655 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 656 | */ |
f91e2590 | 657 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 658 | { |
37bdfb07 | 659 | struct file *cons_filp = NULL; |
1da177e4 | 660 | struct file *filp, *f = NULL; |
d996b62a | 661 | struct tty_file_private *priv; |
1da177e4 | 662 | int closecount = 0, n; |
ea648a47 | 663 | int refs; |
1da177e4 LT |
664 | |
665 | if (!tty) | |
666 | return; | |
667 | ||
1da177e4 LT |
668 | |
669 | spin_lock(&redirect_lock); | |
d996b62a | 670 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
671 | f = redirect; |
672 | redirect = NULL; | |
673 | } | |
674 | spin_unlock(&redirect_lock); | |
37bdfb07 | 675 | |
89c8d91e | 676 | tty_lock(tty); |
11dbf203 | 677 | |
cb50e523 PH |
678 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
679 | tty_unlock(tty); | |
680 | return; | |
681 | } | |
682 | ||
acfa747b JS |
683 | /* some functions below drop BTM, so we need this bit */ |
684 | set_bit(TTY_HUPPING, &tty->flags); | |
685 | ||
ec79d605 AB |
686 | /* inuse_filps is protected by the single tty lock, |
687 | this really needs to change if we want to flush the | |
688 | workqueue with the lock held */ | |
11dbf203 | 689 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 690 | |
ee2ffa0d | 691 | spin_lock(&tty_files_lock); |
1da177e4 | 692 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
693 | list_for_each_entry(priv, &tty->tty_files, list) { |
694 | filp = priv->file; | |
1da177e4 LT |
695 | if (filp->f_op->write == redirected_tty_write) |
696 | cons_filp = filp; | |
697 | if (filp->f_op->write != tty_write) | |
698 | continue; | |
699 | closecount++; | |
ec79d605 | 700 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
701 | filp->f_op = &hung_up_tty_fops; |
702 | } | |
ee2ffa0d | 703 | spin_unlock(&tty_files_lock); |
37bdfb07 | 704 | |
25fdf243 PH |
705 | refs = tty_signal_session_leader(tty, exit_session); |
706 | /* Account for the p->signal references we killed */ | |
707 | while (refs--) | |
708 | tty_kref_put(tty); | |
709 | ||
acfa747b JS |
710 | /* |
711 | * it drops BTM and thus races with reopen | |
712 | * we protect the race by TTY_HUPPING | |
713 | */ | |
c65c9bc3 | 714 | tty_ldisc_hangup(tty); |
37bdfb07 | 715 | |
20cc225b | 716 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 717 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 718 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
719 | put_pid(tty->session); |
720 | put_pid(tty->pgrp); | |
ab521dc0 EB |
721 | tty->session = NULL; |
722 | tty->pgrp = NULL; | |
1da177e4 | 723 | tty->ctrl_status = 0; |
20cc225b | 724 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 725 | |
1da177e4 | 726 | /* |
37bdfb07 AC |
727 | * If one of the devices matches a console pointer, we |
728 | * cannot just call hangup() because that will cause | |
729 | * tty->count and state->count to go out of sync. | |
730 | * So we just call close() the right number of times. | |
1da177e4 LT |
731 | */ |
732 | if (cons_filp) { | |
f34d7a5b | 733 | if (tty->ops->close) |
1da177e4 | 734 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
735 | tty->ops->close(tty, cons_filp); |
736 | } else if (tty->ops->hangup) | |
7c6d340f | 737 | tty->ops->hangup(tty); |
37bdfb07 AC |
738 | /* |
739 | * We don't want to have driver/ldisc interactions beyond | |
740 | * the ones we did here. The driver layer expects no | |
741 | * calls after ->hangup() from the ldisc side. However we | |
742 | * can't yet guarantee all that. | |
743 | */ | |
1da177e4 | 744 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 745 | clear_bit(TTY_HUPPING, &tty->flags); |
11dbf203 | 746 | |
89c8d91e | 747 | tty_unlock(tty); |
11dbf203 | 748 | |
1da177e4 LT |
749 | if (f) |
750 | fput(f); | |
751 | } | |
752 | ||
ddcd9fb6 AB |
753 | static void do_tty_hangup(struct work_struct *work) |
754 | { | |
755 | struct tty_struct *tty = | |
756 | container_of(work, struct tty_struct, hangup_work); | |
757 | ||
f91e2590 | 758 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
759 | } |
760 | ||
af9b897e AC |
761 | /** |
762 | * tty_hangup - trigger a hangup event | |
763 | * @tty: tty to hangup | |
764 | * | |
765 | * A carrier loss (virtual or otherwise) has occurred on this like | |
766 | * schedule a hangup sequence to run after this event. | |
767 | */ | |
768 | ||
37bdfb07 | 769 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
770 | { |
771 | #ifdef TTY_DEBUG_HANGUP | |
772 | char buf[64]; | |
1da177e4 LT |
773 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
774 | #endif | |
775 | schedule_work(&tty->hangup_work); | |
776 | } | |
777 | ||
778 | EXPORT_SYMBOL(tty_hangup); | |
779 | ||
af9b897e AC |
780 | /** |
781 | * tty_vhangup - process vhangup | |
782 | * @tty: tty to hangup | |
783 | * | |
784 | * The user has asked via system call for the terminal to be hung up. | |
785 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 786 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
787 | */ |
788 | ||
37bdfb07 | 789 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
790 | { |
791 | #ifdef TTY_DEBUG_HANGUP | |
792 | char buf[64]; | |
793 | ||
794 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
795 | #endif | |
f91e2590 | 796 | __tty_hangup(tty, 0); |
1da177e4 | 797 | } |
37bdfb07 | 798 | |
1da177e4 LT |
799 | EXPORT_SYMBOL(tty_vhangup); |
800 | ||
11dbf203 | 801 | |
2cb5998b AC |
802 | /** |
803 | * tty_vhangup_self - process vhangup for own ctty | |
804 | * | |
805 | * Perform a vhangup on the current controlling tty | |
806 | */ | |
807 | ||
808 | void tty_vhangup_self(void) | |
809 | { | |
810 | struct tty_struct *tty; | |
811 | ||
2cb5998b AC |
812 | tty = get_current_tty(); |
813 | if (tty) { | |
814 | tty_vhangup(tty); | |
815 | tty_kref_put(tty); | |
816 | } | |
2cb5998b AC |
817 | } |
818 | ||
f91e2590 PH |
819 | /** |
820 | * tty_vhangup_session - hangup session leader exit | |
821 | * @tty: tty to hangup | |
822 | * | |
823 | * The session leader is exiting and hanging up its controlling terminal. | |
824 | * Every process in the foreground process group is signalled SIGHUP. | |
825 | * | |
826 | * We do this synchronously so that when the syscall returns the process | |
827 | * is complete. That guarantee is necessary for security reasons. | |
828 | */ | |
829 | ||
44a459fd | 830 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 PH |
831 | { |
832 | #ifdef TTY_DEBUG_HANGUP | |
833 | char buf[64]; | |
834 | ||
835 | printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty, buf)); | |
836 | #endif | |
837 | __tty_hangup(tty, 1); | |
838 | } | |
839 | ||
af9b897e AC |
840 | /** |
841 | * tty_hung_up_p - was tty hung up | |
842 | * @filp: file pointer of tty | |
843 | * | |
844 | * Return true if the tty has been subject to a vhangup or a carrier | |
845 | * loss | |
846 | */ | |
847 | ||
37bdfb07 | 848 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
849 | { |
850 | return (filp->f_op == &hung_up_tty_fops); | |
851 | } | |
852 | ||
853 | EXPORT_SYMBOL(tty_hung_up_p); | |
854 | ||
af9b897e AC |
855 | /** |
856 | * disassociate_ctty - disconnect controlling tty | |
857 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 858 | * |
af9b897e AC |
859 | * This function is typically called only by the session leader, when |
860 | * it wants to disassociate itself from its controlling tty. | |
861 | * | |
862 | * It performs the following functions: | |
1da177e4 LT |
863 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
864 | * (2) Clears the tty from being controlling the session | |
865 | * (3) Clears the controlling tty for all processes in the | |
866 | * session group. | |
867 | * | |
af9b897e AC |
868 | * The argument on_exit is set to 1 if called when a process is |
869 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
870 | * | |
24ec839c | 871 | * Locking: |
ec79d605 AB |
872 | * BTM is taken for hysterical raisins, and held when |
873 | * called from no_tty(). | |
24ec839c PZ |
874 | * tty_mutex is taken to protect tty |
875 | * ->siglock is taken to protect ->signal/->sighand | |
876 | * tasklist_lock is taken to walk process list for sessions | |
877 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 878 | */ |
af9b897e | 879 | |
1da177e4 LT |
880 | void disassociate_ctty(int on_exit) |
881 | { | |
882 | struct tty_struct *tty; | |
1da177e4 | 883 | |
5ec93d11 AC |
884 | if (!current->signal->leader) |
885 | return; | |
1da177e4 | 886 | |
24ec839c | 887 | tty = get_current_tty(); |
1da177e4 | 888 | if (tty) { |
f91e2590 PH |
889 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
890 | tty_vhangup_session(tty); | |
891 | } else { | |
892 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
893 | if (tty_pgrp) { | |
894 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
895 | if (!on_exit) |
896 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
897 | put_pid(tty_pgrp); |
898 | } | |
1411dc4a | 899 | } |
f91e2590 PH |
900 | tty_kref_put(tty); |
901 | ||
680a9671 | 902 | } else if (on_exit) { |
ab521dc0 | 903 | struct pid *old_pgrp; |
680a9671 EB |
904 | spin_lock_irq(¤t->sighand->siglock); |
905 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 906 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 907 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 908 | if (old_pgrp) { |
ab521dc0 EB |
909 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
910 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
911 | put_pid(old_pgrp); | |
1da177e4 | 912 | } |
1da177e4 LT |
913 | return; |
914 | } | |
1da177e4 | 915 | |
24ec839c | 916 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 917 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 918 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 919 | |
c70dbb1e | 920 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 921 | if (tty) { |
47f86834 AC |
922 | unsigned long flags; |
923 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
924 | put_pid(tty->session); |
925 | put_pid(tty->pgrp); | |
926 | tty->session = NULL; | |
927 | tty->pgrp = NULL; | |
47f86834 | 928 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 929 | tty_kref_put(tty); |
24ec839c PZ |
930 | } else { |
931 | #ifdef TTY_DEBUG_HANGUP | |
932 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
933 | " = NULL", tty); | |
934 | #endif | |
935 | } | |
1da177e4 | 936 | |
c70dbb1e | 937 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
938 | /* Now clear signal->tty under the lock */ |
939 | read_lock(&tasklist_lock); | |
ab521dc0 | 940 | session_clear_tty(task_session(current)); |
1da177e4 | 941 | read_unlock(&tasklist_lock); |
1da177e4 LT |
942 | } |
943 | ||
98a27ba4 EB |
944 | /** |
945 | * | |
946 | * no_tty - Ensure the current process does not have a controlling tty | |
947 | */ | |
948 | void no_tty(void) | |
949 | { | |
3af502b9 AC |
950 | /* FIXME: Review locking here. The tty_lock never covered any race |
951 | between a new association and proc_clear_tty but possible we need | |
952 | to protect against this anyway */ | |
98a27ba4 | 953 | struct task_struct *tsk = current; |
5ec93d11 | 954 | disassociate_ctty(0); |
98a27ba4 EB |
955 | proc_clear_tty(tsk); |
956 | } | |
957 | ||
af9b897e AC |
958 | |
959 | /** | |
beb7dd86 | 960 | * stop_tty - propagate flow control |
af9b897e AC |
961 | * @tty: tty to stop |
962 | * | |
01adc807 | 963 | * Perform flow control to the driver. May be called |
af9b897e AC |
964 | * on an already stopped device and will not re-call the driver |
965 | * method. | |
966 | * | |
967 | * This functionality is used by both the line disciplines for | |
968 | * halting incoming flow and by the driver. It may therefore be | |
969 | * called from any context, may be under the tty atomic_write_lock | |
970 | * but not always. | |
971 | * | |
972 | * Locking: | |
f9e053dc | 973 | * flow_lock |
af9b897e AC |
974 | */ |
975 | ||
f9e053dc | 976 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 977 | { |
f9e053dc | 978 | if (tty->stopped) |
1da177e4 LT |
979 | return; |
980 | tty->stopped = 1; | |
f34d7a5b AC |
981 | if (tty->ops->stop) |
982 | (tty->ops->stop)(tty); | |
1da177e4 LT |
983 | } |
984 | ||
f9e053dc PH |
985 | void stop_tty(struct tty_struct *tty) |
986 | { | |
987 | unsigned long flags; | |
988 | ||
989 | spin_lock_irqsave(&tty->flow_lock, flags); | |
990 | __stop_tty(tty); | |
991 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
992 | } | |
1da177e4 LT |
993 | EXPORT_SYMBOL(stop_tty); |
994 | ||
af9b897e | 995 | /** |
beb7dd86 | 996 | * start_tty - propagate flow control |
af9b897e AC |
997 | * @tty: tty to start |
998 | * | |
01adc807 PH |
999 | * Start a tty that has been stopped if at all possible. If this |
1000 | * tty was previous stopped and is now being started, the driver | |
1001 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1002 | * |
1003 | * Locking: | |
f9e053dc | 1004 | * flow_lock |
af9b897e AC |
1005 | */ |
1006 | ||
f9e053dc | 1007 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1008 | { |
f9e053dc | 1009 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1010 | return; |
1011 | tty->stopped = 0; | |
f34d7a5b AC |
1012 | if (tty->ops->start) |
1013 | (tty->ops->start)(tty); | |
1da177e4 | 1014 | tty_wakeup(tty); |
1da177e4 LT |
1015 | } |
1016 | ||
f9e053dc PH |
1017 | void start_tty(struct tty_struct *tty) |
1018 | { | |
1019 | unsigned long flags; | |
1020 | ||
1021 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1022 | __start_tty(tty); | |
1023 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1024 | } | |
1da177e4 LT |
1025 | EXPORT_SYMBOL(start_tty); |
1026 | ||
b0b88565 | 1027 | /* We limit tty time update visibility to every 8 seconds or so. */ |
37b7f3c7 JS |
1028 | static void tty_update_time(struct timespec *time) |
1029 | { | |
b0b88565 | 1030 | unsigned long sec = get_seconds() & ~7; |
37b7f3c7 JS |
1031 | if ((long)(sec - time->tv_sec) > 0) |
1032 | time->tv_sec = sec; | |
1033 | } | |
1034 | ||
af9b897e AC |
1035 | /** |
1036 | * tty_read - read method for tty device files | |
1037 | * @file: pointer to tty file | |
1038 | * @buf: user buffer | |
1039 | * @count: size of user buffer | |
1040 | * @ppos: unused | |
1041 | * | |
1042 | * Perform the read system call function on this terminal device. Checks | |
1043 | * for hung up devices before calling the line discipline method. | |
1044 | * | |
1045 | * Locking: | |
47f86834 AC |
1046 | * Locks the line discipline internally while needed. Multiple |
1047 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1048 | */ |
1049 | ||
37bdfb07 | 1050 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1051 | loff_t *ppos) |
1052 | { | |
1053 | int i; | |
37b7f3c7 | 1054 | struct inode *inode = file_inode(file); |
d996b62a | 1055 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1056 | struct tty_ldisc *ld; |
1057 | ||
37b7f3c7 | 1058 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1059 | return -EIO; |
1060 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1061 | return -EIO; | |
1062 | ||
1063 | /* We want to wait for the line discipline to sort out in this | |
1064 | situation */ | |
1065 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
1066 | if (ld->ops->read) |
1067 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
1068 | else |
1069 | i = -EIO; | |
1070 | tty_ldisc_deref(ld); | |
b0de59b5 | 1071 | |
37b7f3c7 JS |
1072 | if (i > 0) |
1073 | tty_update_time(&inode->i_atime); | |
1074 | ||
1da177e4 LT |
1075 | return i; |
1076 | } | |
1077 | ||
136d5258 | 1078 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1079 | { |
1080 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1081 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1082 | } |
1083 | ||
136d5258 | 1084 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1085 | { |
1086 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1087 | if (ndelay) | |
1088 | return -EAGAIN; | |
1089 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1090 | return -ERESTARTSYS; | |
1091 | } | |
1092 | return 0; | |
1093 | } | |
1094 | ||
1da177e4 LT |
1095 | /* |
1096 | * Split writes up in sane blocksizes to avoid | |
1097 | * denial-of-service type attacks | |
1098 | */ | |
1099 | static inline ssize_t do_tty_write( | |
1100 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1101 | struct tty_struct *tty, | |
1102 | struct file *file, | |
1103 | const char __user *buf, | |
1104 | size_t count) | |
1105 | { | |
9c1729db | 1106 | ssize_t ret, written = 0; |
1da177e4 | 1107 | unsigned int chunk; |
37bdfb07 | 1108 | |
9c1729db AC |
1109 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1110 | if (ret < 0) | |
1111 | return ret; | |
1da177e4 LT |
1112 | |
1113 | /* | |
1114 | * We chunk up writes into a temporary buffer. This | |
1115 | * simplifies low-level drivers immensely, since they | |
1116 | * don't have locking issues and user mode accesses. | |
1117 | * | |
1118 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1119 | * big chunk-size.. | |
1120 | * | |
1121 | * The default chunk-size is 2kB, because the NTTY | |
1122 | * layer has problems with bigger chunks. It will | |
1123 | * claim to be able to handle more characters than | |
1124 | * it actually does. | |
af9b897e AC |
1125 | * |
1126 | * FIXME: This can probably go away now except that 64K chunks | |
1127 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1128 | */ |
1129 | chunk = 2048; | |
1130 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1131 | chunk = 65536; | |
1132 | if (count < chunk) | |
1133 | chunk = count; | |
1134 | ||
70522e12 | 1135 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1136 | if (tty->write_cnt < chunk) { |
402fda92 | 1137 | unsigned char *buf_chunk; |
1da177e4 LT |
1138 | |
1139 | if (chunk < 1024) | |
1140 | chunk = 1024; | |
1141 | ||
402fda92 JW |
1142 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1143 | if (!buf_chunk) { | |
9c1729db AC |
1144 | ret = -ENOMEM; |
1145 | goto out; | |
1da177e4 LT |
1146 | } |
1147 | kfree(tty->write_buf); | |
1148 | tty->write_cnt = chunk; | |
402fda92 | 1149 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1150 | } |
1151 | ||
1152 | /* Do the write .. */ | |
1153 | for (;;) { | |
1154 | size_t size = count; | |
1155 | if (size > chunk) | |
1156 | size = chunk; | |
1157 | ret = -EFAULT; | |
1158 | if (copy_from_user(tty->write_buf, buf, size)) | |
1159 | break; | |
1da177e4 | 1160 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1161 | if (ret <= 0) |
1162 | break; | |
1163 | written += ret; | |
1164 | buf += ret; | |
1165 | count -= ret; | |
1166 | if (!count) | |
1167 | break; | |
1168 | ret = -ERESTARTSYS; | |
1169 | if (signal_pending(current)) | |
1170 | break; | |
1171 | cond_resched(); | |
1172 | } | |
37b7f3c7 JS |
1173 | if (written) { |
1174 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1175 | ret = written; |
37b7f3c7 | 1176 | } |
9c1729db AC |
1177 | out: |
1178 | tty_write_unlock(tty); | |
1da177e4 LT |
1179 | return ret; |
1180 | } | |
1181 | ||
95f9bfc6 AC |
1182 | /** |
1183 | * tty_write_message - write a message to a certain tty, not just the console. | |
1184 | * @tty: the destination tty_struct | |
1185 | * @msg: the message to write | |
1186 | * | |
1187 | * This is used for messages that need to be redirected to a specific tty. | |
1188 | * We don't put it into the syslog queue right now maybe in the future if | |
1189 | * really needed. | |
1190 | * | |
ec79d605 | 1191 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1192 | */ |
1193 | ||
1194 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1195 | { | |
95f9bfc6 AC |
1196 | if (tty) { |
1197 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1198 | tty_lock(tty); |
eeb89d91 | 1199 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
89c8d91e | 1200 | tty_unlock(tty); |
95f9bfc6 | 1201 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1202 | } else |
89c8d91e | 1203 | tty_unlock(tty); |
95f9bfc6 AC |
1204 | tty_write_unlock(tty); |
1205 | } | |
95f9bfc6 AC |
1206 | return; |
1207 | } | |
1208 | ||
1da177e4 | 1209 | |
af9b897e AC |
1210 | /** |
1211 | * tty_write - write method for tty device file | |
1212 | * @file: tty file pointer | |
1213 | * @buf: user data to write | |
1214 | * @count: bytes to write | |
1215 | * @ppos: unused | |
1216 | * | |
1217 | * Write data to a tty device via the line discipline. | |
1218 | * | |
1219 | * Locking: | |
1220 | * Locks the line discipline as required | |
1221 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1222 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1223 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1224 | */ |
1225 | ||
37bdfb07 AC |
1226 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1227 | size_t count, loff_t *ppos) | |
1da177e4 | 1228 | { |
d996b62a NP |
1229 | struct tty_struct *tty = file_tty(file); |
1230 | struct tty_ldisc *ld; | |
1da177e4 | 1231 | ssize_t ret; |
37bdfb07 | 1232 | |
6131ffaa | 1233 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1234 | return -EIO; |
f34d7a5b | 1235 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1236 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1237 | return -EIO; | |
f34d7a5b AC |
1238 | /* Short term debug to catch buggy drivers */ |
1239 | if (tty->ops->write_room == NULL) | |
1240 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1241 | tty->driver->name); | |
37bdfb07 | 1242 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1243 | if (!ld->ops->write) |
1da177e4 LT |
1244 | ret = -EIO; |
1245 | else | |
a352def2 | 1246 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1247 | tty_ldisc_deref(ld); |
1248 | return ret; | |
1249 | } | |
1250 | ||
37bdfb07 AC |
1251 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1252 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1253 | { |
1254 | struct file *p = NULL; | |
1255 | ||
1256 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1257 | if (redirect) |
1258 | p = get_file(redirect); | |
1da177e4 LT |
1259 | spin_unlock(&redirect_lock); |
1260 | ||
1261 | if (p) { | |
1262 | ssize_t res; | |
1263 | res = vfs_write(p, buf, count, &p->f_pos); | |
1264 | fput(p); | |
1265 | return res; | |
1266 | } | |
1da177e4 LT |
1267 | return tty_write(file, buf, count, ppos); |
1268 | } | |
1269 | ||
136d5258 PH |
1270 | /** |
1271 | * tty_send_xchar - send priority character | |
1272 | * | |
1273 | * Send a high priority character to the tty even if stopped | |
1274 | * | |
1275 | * Locking: none for xchar method, write ordering for write method. | |
1276 | */ | |
1277 | ||
1278 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1279 | { | |
1280 | int was_stopped = tty->stopped; | |
1281 | ||
1282 | if (tty->ops->send_xchar) { | |
1283 | tty->ops->send_xchar(tty, ch); | |
1284 | return 0; | |
1285 | } | |
1286 | ||
1287 | if (tty_write_lock(tty, 0) < 0) | |
1288 | return -ERESTARTSYS; | |
1289 | ||
1290 | if (was_stopped) | |
1291 | start_tty(tty); | |
1292 | tty->ops->write(tty, &ch, 1); | |
1293 | if (was_stopped) | |
1294 | stop_tty(tty); | |
1295 | tty_write_unlock(tty); | |
1296 | return 0; | |
1297 | } | |
1298 | ||
1da177e4 LT |
1299 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1300 | ||
af9b897e AC |
1301 | /** |
1302 | * pty_line_name - generate name for a pty | |
1303 | * @driver: the tty driver in use | |
1304 | * @index: the minor number | |
1305 | * @p: output buffer of at least 6 bytes | |
1306 | * | |
1307 | * Generate a name from a driver reference and write it to the output | |
1308 | * buffer. | |
1309 | * | |
1310 | * Locking: None | |
1311 | */ | |
1312 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1313 | { |
1314 | int i = index + driver->name_base; | |
1315 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1316 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1317 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1318 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1319 | } |
1320 | ||
af9b897e | 1321 | /** |
8b0a88d5 | 1322 | * tty_line_name - generate name for a tty |
af9b897e AC |
1323 | * @driver: the tty driver in use |
1324 | * @index: the minor number | |
1325 | * @p: output buffer of at least 7 bytes | |
1326 | * | |
1327 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1328 | * buffer. |
af9b897e AC |
1329 | * |
1330 | * Locking: None | |
1331 | */ | |
723abd87 | 1332 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1333 | { |
0019b408 | 1334 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1335 | return sprintf(p, "%s", driver->name); |
0019b408 | 1336 | else |
723abd87 HR |
1337 | return sprintf(p, "%s%d", driver->name, |
1338 | index + driver->name_base); | |
1da177e4 LT |
1339 | } |
1340 | ||
99f1fe18 AC |
1341 | /** |
1342 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1343 | * @driver: the driver for the tty | |
1344 | * @idx: the minor number | |
23499705 | 1345 | * |
99f1fe18 | 1346 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1347 | * |
99f1fe18 AC |
1348 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1349 | * be held until the 'fast-open' is also done. Will change once we | |
1350 | * have refcounting in the driver and per driver locking | |
23499705 | 1351 | */ |
a47d545f | 1352 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1353 | struct inode *inode, int idx) |
23499705 | 1354 | { |
99f1fe18 | 1355 | if (driver->ops->lookup) |
15f1a633 | 1356 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1357 | |
d4834267 | 1358 | return driver->ttys[idx]; |
23499705 SB |
1359 | } |
1360 | ||
bf970ee4 AC |
1361 | /** |
1362 | * tty_init_termios - helper for termios setup | |
1363 | * @tty: the tty to set up | |
1364 | * | |
1365 | * Initialise the termios structures for this tty. Thus runs under | |
1366 | * the tty_mutex currently so we can be relaxed about ordering. | |
1367 | */ | |
1368 | ||
1369 | int tty_init_termios(struct tty_struct *tty) | |
1370 | { | |
fe6e29fd | 1371 | struct ktermios *tp; |
bf970ee4 AC |
1372 | int idx = tty->index; |
1373 | ||
36b3c070 AC |
1374 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1375 | tty->termios = tty->driver->init_termios; | |
1376 | else { | |
1377 | /* Check for lazy saved data */ | |
1378 | tp = tty->driver->termios[idx]; | |
1379 | if (tp != NULL) | |
1380 | tty->termios = *tp; | |
1381 | else | |
1382 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1383 | } |
bf970ee4 | 1384 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1385 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1386 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
1387 | return 0; |
1388 | } | |
fe1ae7fd | 1389 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1390 | |
66d450e8 JS |
1391 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1392 | { | |
1393 | int ret = tty_init_termios(tty); | |
1394 | if (ret) | |
1395 | return ret; | |
1396 | ||
1397 | tty_driver_kref_get(driver); | |
1398 | tty->count++; | |
1399 | driver->ttys[tty->index] = tty; | |
1400 | return 0; | |
1401 | } | |
1402 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1403 | ||
99f1fe18 | 1404 | /** |
8b0a88d5 AC |
1405 | * tty_driver_install_tty() - install a tty entry in the driver |
1406 | * @driver: the driver for the tty | |
1407 | * @tty: the tty | |
1408 | * | |
1409 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1410 | * will be set by the time this is called. This method is responsible |
1411 | * for ensuring any need additional structures are allocated and | |
1412 | * configured. | |
8b0a88d5 AC |
1413 | * |
1414 | * Locking: tty_mutex for now | |
1415 | */ | |
1416 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1417 | struct tty_struct *tty) | |
1418 | { | |
66d450e8 JS |
1419 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1420 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1421 | } |
1422 | ||
1423 | /** | |
1424 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1425 | * @driver: the driver for the tty | |
1426 | * @idx: the minor number | |
1427 | * | |
1428 | * Remvoe a tty object from the driver tables. The tty->index field | |
1429 | * will be set by the time this is called. | |
1430 | * | |
1431 | * Locking: tty_mutex for now | |
1432 | */ | |
24d406a6 | 1433 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1434 | { |
1435 | if (driver->ops->remove) | |
1436 | driver->ops->remove(driver, tty); | |
1437 | else | |
1438 | driver->ttys[tty->index] = NULL; | |
1439 | } | |
1440 | ||
1441 | /* | |
1442 | * tty_reopen() - fast re-open of an open tty | |
1443 | * @tty - the tty to open | |
23499705 | 1444 | * |
99f1fe18 | 1445 | * Return 0 on success, -errno on error. |
23499705 | 1446 | * |
99f1fe18 AC |
1447 | * Locking: tty_mutex must be held from the time the tty was found |
1448 | * till this open completes. | |
23499705 | 1449 | */ |
99f1fe18 | 1450 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1451 | { |
1452 | struct tty_driver *driver = tty->driver; | |
1453 | ||
e2efafbf | 1454 | if (test_bit(TTY_CLOSING, &tty->flags) || |
36697529 | 1455 | test_bit(TTY_HUPPING, &tty->flags)) |
23499705 SB |
1456 | return -EIO; |
1457 | ||
1458 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1459 | driver->subtype == PTY_TYPE_MASTER) { | |
1460 | /* | |
1461 | * special case for PTY masters: only one open permitted, | |
1462 | * and the slave side open count is incremented as well. | |
1463 | */ | |
1464 | if (tty->count) | |
1465 | return -EIO; | |
1466 | ||
1467 | tty->link->count++; | |
1468 | } | |
1469 | tty->count++; | |
23499705 | 1470 | |
36697529 | 1471 | WARN_ON(!tty->ldisc); |
23499705 SB |
1472 | |
1473 | return 0; | |
1474 | } | |
1475 | ||
af9b897e | 1476 | /** |
d81ed103 | 1477 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1478 | * @driver: tty driver we are opening a device on |
1479 | * @idx: device index | |
15582d36 | 1480 | * @ret_tty: returned tty structure |
af9b897e AC |
1481 | * |
1482 | * Prepare a tty device. This may not be a "new" clean device but | |
1483 | * could also be an active device. The pty drivers require special | |
1484 | * handling because of this. | |
1485 | * | |
1486 | * Locking: | |
1487 | * The function is called under the tty_mutex, which | |
1488 | * protects us from the tty struct or driver itself going away. | |
1489 | * | |
1490 | * On exit the tty device has the line discipline attached and | |
1491 | * a reference count of 1. If a pair was created for pty/tty use | |
1492 | * and the other was a pty master then it too has a reference count of 1. | |
1493 | * | |
1da177e4 | 1494 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1495 | * failed open. The new code protects the open with a mutex, so it's |
1496 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1497 | * relaxed for the (most common) case of reopening a tty. |
1498 | */ | |
af9b897e | 1499 | |
593a27c4 | 1500 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1501 | { |
bf970ee4 | 1502 | struct tty_struct *tty; |
73ec06fc | 1503 | int retval; |
1da177e4 | 1504 | |
1da177e4 LT |
1505 | /* |
1506 | * First time open is complex, especially for PTY devices. | |
1507 | * This code guarantees that either everything succeeds and the | |
1508 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1509 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1510 | * and locked termios may be retained.) |
1511 | */ | |
1512 | ||
73ec06fc AC |
1513 | if (!try_module_get(driver->owner)) |
1514 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1515 | |
2c964a2f | 1516 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1517 | if (!tty) { |
1518 | retval = -ENOMEM; | |
1519 | goto err_module_put; | |
1520 | } | |
1da177e4 | 1521 | |
89c8d91e | 1522 | tty_lock(tty); |
73ec06fc | 1523 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1524 | if (retval < 0) |
a9dccddb | 1525 | goto err_deinit_tty; |
8b0a88d5 | 1526 | |
04831dc1 JS |
1527 | if (!tty->port) |
1528 | tty->port = driver->ports[idx]; | |
1529 | ||
5d4121c0 JS |
1530 | WARN_RATELIMIT(!tty->port, |
1531 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1532 | __func__, tty->driver->name); | |
1533 | ||
967fab69 JS |
1534 | tty->port->itty = tty; |
1535 | ||
37bdfb07 | 1536 | /* |
1da177e4 | 1537 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1538 | * If we fail here just call release_tty to clean up. No need |
1539 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1540 | */ |
bf970ee4 | 1541 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1542 | if (retval) |
d5543503 | 1543 | goto err_release_tty; |
89c8d91e | 1544 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1545 | return tty; |
1da177e4 | 1546 | |
a9dccddb | 1547 | err_deinit_tty: |
89c8d91e | 1548 | tty_unlock(tty); |
a9dccddb | 1549 | deinitialize_tty_struct(tty); |
d5543503 JS |
1550 | free_tty_struct(tty); |
1551 | err_module_put: | |
1da177e4 | 1552 | module_put(driver->owner); |
d5543503 | 1553 | return ERR_PTR(retval); |
1da177e4 | 1554 | |
d5698c28 | 1555 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1556 | err_release_tty: |
89c8d91e | 1557 | tty_unlock(tty); |
5a3c6b25 | 1558 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1559 | "clearing slot %d\n", idx); |
d5698c28 | 1560 | release_tty(tty, idx); |
73ec06fc | 1561 | return ERR_PTR(retval); |
1da177e4 LT |
1562 | } |
1563 | ||
feebed65 AC |
1564 | void tty_free_termios(struct tty_struct *tty) |
1565 | { | |
1566 | struct ktermios *tp; | |
1567 | int idx = tty->index; | |
36b3c070 AC |
1568 | |
1569 | /* If the port is going to reset then it has no termios to save */ | |
1570 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1571 | return; | |
1572 | ||
1573 | /* Stash the termios data */ | |
1574 | tp = tty->driver->termios[idx]; | |
1575 | if (tp == NULL) { | |
1576 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1577 | if (tp == NULL) { | |
1578 | pr_warn("tty: no memory to save termios state.\n"); | |
1579 | return; | |
1580 | } | |
4ac5d705 | 1581 | tty->driver->termios[idx] = tp; |
feebed65 | 1582 | } |
36b3c070 | 1583 | *tp = tty->termios; |
feebed65 AC |
1584 | } |
1585 | EXPORT_SYMBOL(tty_free_termios); | |
1586 | ||
a2965b7b PH |
1587 | /** |
1588 | * tty_flush_works - flush all works of a tty | |
1589 | * @tty: tty device to flush works for | |
1590 | * | |
1591 | * Sync flush all works belonging to @tty. | |
1592 | */ | |
1593 | static void tty_flush_works(struct tty_struct *tty) | |
1594 | { | |
1595 | flush_work(&tty->SAK_work); | |
1596 | flush_work(&tty->hangup_work); | |
1597 | } | |
feebed65 | 1598 | |
af9b897e | 1599 | /** |
d5698c28 | 1600 | * release_one_tty - release tty structure memory |
9c9f4ded | 1601 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1602 | * |
1603 | * Releases memory associated with a tty structure, and clears out the | |
1604 | * driver table slots. This function is called when a device is no longer | |
1605 | * in use. It also gets called when setup of a device fails. | |
1606 | * | |
1607 | * Locking: | |
af9b897e AC |
1608 | * takes the file list lock internally when working on the list |
1609 | * of ttys that the driver keeps. | |
b50989dc AC |
1610 | * |
1611 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1612 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1613 | */ |
b50989dc | 1614 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1615 | { |
b50989dc AC |
1616 | struct tty_struct *tty = |
1617 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1618 | struct tty_driver *driver = tty->driver; |
b216df53 | 1619 | struct module *owner = driver->owner; |
d5698c28 | 1620 | |
f278a2f7 DY |
1621 | if (tty->ops->cleanup) |
1622 | tty->ops->cleanup(tty); | |
1623 | ||
1da177e4 | 1624 | tty->magic = 0; |
7d7b93c1 | 1625 | tty_driver_kref_put(driver); |
b216df53 | 1626 | module_put(owner); |
d5698c28 | 1627 | |
ee2ffa0d | 1628 | spin_lock(&tty_files_lock); |
1da177e4 | 1629 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1630 | spin_unlock(&tty_files_lock); |
d5698c28 | 1631 | |
6da8d866 ON |
1632 | put_pid(tty->pgrp); |
1633 | put_pid(tty->session); | |
1da177e4 LT |
1634 | free_tty_struct(tty); |
1635 | } | |
1636 | ||
b50989dc AC |
1637 | static void queue_release_one_tty(struct kref *kref) |
1638 | { | |
1639 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1640 | |
b50989dc AC |
1641 | /* The hangup queue is now free so we can reuse it rather than |
1642 | waste a chunk of memory for each port */ | |
1643 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1644 | schedule_work(&tty->hangup_work); | |
1645 | } | |
1646 | ||
9c9f4ded AC |
1647 | /** |
1648 | * tty_kref_put - release a tty kref | |
1649 | * @tty: tty device | |
1650 | * | |
1651 | * Release a reference to a tty device and if need be let the kref | |
1652 | * layer destruct the object for us | |
1653 | */ | |
1654 | ||
1655 | void tty_kref_put(struct tty_struct *tty) | |
1656 | { | |
1657 | if (tty) | |
b50989dc | 1658 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1659 | } |
1660 | EXPORT_SYMBOL(tty_kref_put); | |
1661 | ||
d5698c28 CH |
1662 | /** |
1663 | * release_tty - release tty structure memory | |
1664 | * | |
1665 | * Release both @tty and a possible linked partner (think pty pair), | |
1666 | * and decrement the refcount of the backing module. | |
1667 | * | |
1668 | * Locking: | |
d155255a | 1669 | * tty_mutex |
d5698c28 CH |
1670 | * takes the file list lock internally when working on the list |
1671 | * of ttys that the driver keeps. | |
9c9f4ded | 1672 | * |
d5698c28 CH |
1673 | */ |
1674 | static void release_tty(struct tty_struct *tty, int idx) | |
1675 | { | |
9c9f4ded AC |
1676 | /* This should always be true but check for the moment */ |
1677 | WARN_ON(tty->index != idx); | |
d155255a | 1678 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1679 | if (tty->ops->shutdown) |
1680 | tty->ops->shutdown(tty); | |
1681 | tty_free_termios(tty); | |
1682 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1683 | tty->port->itty = NULL; |
64e377dc PH |
1684 | if (tty->link) |
1685 | tty->link->port->itty = NULL; | |
4f98d467 | 1686 | cancel_work_sync(&tty->port->buf.work); |
36b3c070 | 1687 | |
d5698c28 | 1688 | if (tty->link) |
9c9f4ded AC |
1689 | tty_kref_put(tty->link); |
1690 | tty_kref_put(tty); | |
d5698c28 CH |
1691 | } |
1692 | ||
955787ca JS |
1693 | /** |
1694 | * tty_release_checks - check a tty before real release | |
1695 | * @tty: tty to check | |
1696 | * @o_tty: link of @tty (if any) | |
1697 | * @idx: index of the tty | |
1698 | * | |
1699 | * Performs some paranoid checking before true release of the @tty. | |
1700 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1701 | */ | |
1702 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1703 | int idx) | |
1704 | { | |
1705 | #ifdef TTY_PARANOIA_CHECK | |
1706 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1707 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1708 | __func__, tty->name); | |
955787ca JS |
1709 | return -1; |
1710 | } | |
1711 | ||
1712 | /* not much to check for devpts */ | |
1713 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1714 | return 0; | |
1715 | ||
1716 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1717 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1718 | __func__, idx, tty->name); | |
955787ca JS |
1719 | return -1; |
1720 | } | |
955787ca JS |
1721 | if (tty->driver->other) { |
1722 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1723 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1724 | __func__, idx, tty->name); | |
955787ca JS |
1725 | return -1; |
1726 | } | |
955787ca | 1727 | if (o_tty->link != tty) { |
9de44bd6 | 1728 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1729 | return -1; |
1730 | } | |
1731 | } | |
1732 | #endif | |
1733 | return 0; | |
1734 | } | |
1735 | ||
eeb89d91 AC |
1736 | /** |
1737 | * tty_release - vfs callback for close | |
1738 | * @inode: inode of tty | |
1739 | * @filp: file pointer for handle to tty | |
1740 | * | |
1741 | * Called the last time each file handle is closed that references | |
1742 | * this tty. There may however be several such references. | |
1743 | * | |
1744 | * Locking: | |
1745 | * Takes bkl. See tty_release_dev | |
1746 | * | |
1da177e4 LT |
1747 | * Even releasing the tty structures is a tricky business.. We have |
1748 | * to be very careful that the structures are all released at the | |
1749 | * same time, as interrupts might otherwise get the wrong pointers. | |
1750 | * | |
1751 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1752 | * lead to double frees or releasing memory still in use. | |
1753 | */ | |
eeb89d91 AC |
1754 | |
1755 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1756 | { |
d996b62a NP |
1757 | struct tty_struct *tty = file_tty(filp); |
1758 | struct tty_struct *o_tty; | |
1da177e4 | 1759 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
1da177e4 LT |
1760 | int idx; |
1761 | char buf[64]; | |
37bdfb07 | 1762 | |
9de44bd6 | 1763 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1764 | return 0; |
1da177e4 | 1765 | |
89c8d91e | 1766 | tty_lock(tty); |
9de44bd6 | 1767 | check_tty_count(tty, __func__); |
1da177e4 | 1768 | |
ec79d605 | 1769 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1770 | |
1771 | idx = tty->index; | |
1772 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1773 | tty->driver->subtype == PTY_TYPE_MASTER); | |
89c8d91e | 1774 | /* Review: parallel close */ |
1da177e4 LT |
1775 | o_tty = tty->link; |
1776 | ||
955787ca | 1777 | if (tty_release_checks(tty, o_tty, idx)) { |
89c8d91e | 1778 | tty_unlock(tty); |
eeb89d91 | 1779 | return 0; |
1da177e4 | 1780 | } |
1da177e4 LT |
1781 | |
1782 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1783 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1784 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1785 | #endif |
1786 | ||
f34d7a5b AC |
1787 | if (tty->ops->close) |
1788 | tty->ops->close(tty, filp); | |
1da177e4 | 1789 | |
89c8d91e | 1790 | tty_unlock(tty); |
1da177e4 LT |
1791 | /* |
1792 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1793 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1794 | * wait queues and kick everyone out _before_ actually starting to | |
1795 | * close. This ensures that we won't block while releasing the tty | |
1796 | * structure. | |
1797 | * | |
1798 | * The test for the o_tty closing is necessary, since the master and | |
1799 | * slave sides may close in any order. If the slave side closes out | |
1800 | * first, its count will be one, since the master side holds an open. | |
1801 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1802 | * so we do it now. | |
1803 | * | |
1804 | * Note that it's possible for the tty to be opened again while we're | |
1805 | * flushing out waiters. By recalculating the closing flags before | |
1806 | * each iteration we avoid any problems. | |
1807 | */ | |
1808 | while (1) { | |
1809 | /* Guard against races with tty->count changes elsewhere and | |
1810 | opens on /dev/tty */ | |
37bdfb07 | 1811 | |
70522e12 | 1812 | mutex_lock(&tty_mutex); |
89c8d91e | 1813 | tty_lock_pair(tty, o_tty); |
1da177e4 LT |
1814 | tty_closing = tty->count <= 1; |
1815 | o_tty_closing = o_tty && | |
1816 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1817 | do_sleep = 0; |
1818 | ||
1819 | if (tty_closing) { | |
1820 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1821 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1822 | do_sleep++; |
1823 | } | |
1824 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1825 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1826 | do_sleep++; |
1827 | } | |
1828 | } | |
1829 | if (o_tty_closing) { | |
1830 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1831 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1832 | do_sleep++; |
1833 | } | |
1834 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1835 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1836 | do_sleep++; |
1837 | } | |
1838 | } | |
1839 | if (!do_sleep) | |
1840 | break; | |
1841 | ||
9de44bd6 JS |
1842 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1843 | __func__, tty_name(tty, buf)); | |
89c8d91e | 1844 | tty_unlock_pair(tty, o_tty); |
70522e12 | 1845 | mutex_unlock(&tty_mutex); |
1da177e4 | 1846 | schedule(); |
37bdfb07 | 1847 | } |
1da177e4 LT |
1848 | |
1849 | /* | |
37bdfb07 AC |
1850 | * The closing flags are now consistent with the open counts on |
1851 | * both sides, and we've completed the last operation that could | |
1da177e4 | 1852 | * block, so it's safe to proceed with closing. |
d155255a AC |
1853 | * |
1854 | * We must *not* drop the tty_mutex until we ensure that a further | |
1855 | * entry into tty_open can not pick up this tty. | |
1da177e4 | 1856 | */ |
1da177e4 LT |
1857 | if (pty_master) { |
1858 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1859 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1860 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1861 | o_tty->count = 0; |
1862 | } | |
1863 | } | |
1864 | if (--tty->count < 0) { | |
9de44bd6 JS |
1865 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1866 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1867 | tty->count = 0; |
1868 | } | |
37bdfb07 | 1869 | |
1da177e4 LT |
1870 | /* |
1871 | * We've decremented tty->count, so we need to remove this file | |
1872 | * descriptor off the tty->tty_files list; this serves two | |
1873 | * purposes: | |
1874 | * - check_tty_count sees the correct number of file descriptors | |
1875 | * associated with this tty. | |
1876 | * - do_tty_hangup no longer sees this file descriptor as | |
1877 | * something that needs to be handled for hangups. | |
1878 | */ | |
d996b62a | 1879 | tty_del_file(filp); |
1da177e4 LT |
1880 | |
1881 | /* | |
1882 | * Perform some housekeeping before deciding whether to return. | |
1883 | * | |
1884 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1885 | * case of a pty we may have to wait around for the other side | |
1886 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1887 | */ | |
37bdfb07 | 1888 | if (tty_closing) |
1da177e4 | 1889 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1890 | if (o_tty_closing) |
1da177e4 LT |
1891 | set_bit(TTY_CLOSING, &o_tty->flags); |
1892 | ||
1893 | /* | |
1894 | * If _either_ side is closing, make sure there aren't any | |
1895 | * processes that still think tty or o_tty is their controlling | |
1896 | * tty. | |
1897 | */ | |
1898 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1899 | read_lock(&tasklist_lock); |
24ec839c | 1900 | session_clear_tty(tty->session); |
1da177e4 | 1901 | if (o_tty) |
24ec839c | 1902 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1903 | read_unlock(&tasklist_lock); |
1904 | } | |
1905 | ||
70522e12 | 1906 | mutex_unlock(&tty_mutex); |
89c8d91e | 1907 | tty_unlock_pair(tty, o_tty); |
d155255a AC |
1908 | /* At this point the TTY_CLOSING flag should ensure a dead tty |
1909 | cannot be re-opened by a racing opener */ | |
da965822 | 1910 | |
1da177e4 | 1911 | /* check whether both sides are closing ... */ |
d155255a | 1912 | if (!tty_closing || (o_tty && !o_tty_closing)) |
eeb89d91 | 1913 | return 0; |
37bdfb07 | 1914 | |
1da177e4 | 1915 | #ifdef TTY_DEBUG_HANGUP |
96433d10 | 1916 | printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty, buf)); |
1da177e4 LT |
1917 | #endif |
1918 | /* | |
01e1abb2 | 1919 | * Ask the line discipline code to release its structures |
1da177e4 | 1920 | */ |
01e1abb2 | 1921 | tty_ldisc_release(tty, o_tty); |
a2965b7b PH |
1922 | |
1923 | /* Wait for pending work before tty destruction commmences */ | |
1924 | tty_flush_works(tty); | |
1925 | if (o_tty) | |
1926 | tty_flush_works(o_tty); | |
1927 | ||
96433d10 PH |
1928 | #ifdef TTY_DEBUG_HANGUP |
1929 | printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__, tty_name(tty, buf)); | |
1930 | #endif | |
1da177e4 | 1931 | /* |
d5698c28 | 1932 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1933 | * the slots and preserving the termios structure. The tty_unlock_pair |
1934 | * should be safe as we keep a kref while the tty is locked (so the | |
1935 | * unlock never unlocks a freed tty). | |
1da177e4 | 1936 | */ |
d155255a | 1937 | mutex_lock(&tty_mutex); |
d5698c28 | 1938 | release_tty(tty, idx); |
d155255a | 1939 | mutex_unlock(&tty_mutex); |
1da177e4 | 1940 | |
eeb89d91 | 1941 | return 0; |
1da177e4 LT |
1942 | } |
1943 | ||
b82154ac JS |
1944 | /** |
1945 | * tty_open_current_tty - get tty of current task for open | |
1946 | * @device: device number | |
1947 | * @filp: file pointer to tty | |
1948 | * @return: tty of the current task iff @device is /dev/tty | |
1949 | * | |
1950 | * We cannot return driver and index like for the other nodes because | |
1951 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1952 | * |
1953 | * We need to move to returning a refcounted object from all the lookup | |
1954 | * paths including this one. | |
b82154ac JS |
1955 | */ |
1956 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1957 | { | |
1958 | struct tty_struct *tty; | |
1959 | ||
1960 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1961 | return NULL; | |
1962 | ||
1963 | tty = get_current_tty(); | |
1964 | if (!tty) | |
1965 | return ERR_PTR(-ENXIO); | |
1966 | ||
1967 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1968 | /* noctty = 1; */ | |
1969 | tty_kref_put(tty); | |
1970 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1971 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1972 | return tty; |
1973 | } | |
1974 | ||
5b5e7040 JS |
1975 | /** |
1976 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1977 | * @device: device number | |
1978 | * @filp: file pointer to tty | |
1979 | * @noctty: set if the device should not become a controlling tty | |
1980 | * @index: index for the device in the @return driver | |
1981 | * @return: driver for this inode (with increased refcount) | |
1982 | * | |
1983 | * If @return is not erroneous, the caller is responsible to decrement the | |
1984 | * refcount by tty_driver_kref_put. | |
1985 | * | |
1986 | * Locking: tty_mutex protects get_tty_driver | |
1987 | */ | |
1988 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1989 | int *noctty, int *index) | |
1990 | { | |
1991 | struct tty_driver *driver; | |
1992 | ||
2cd0050c | 1993 | switch (device) { |
5b5e7040 | 1994 | #ifdef CONFIG_VT |
2cd0050c | 1995 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1996 | extern struct tty_driver *console_driver; |
1997 | driver = tty_driver_kref_get(console_driver); | |
1998 | *index = fg_console; | |
1999 | *noctty = 1; | |
2cd0050c | 2000 | break; |
5b5e7040 JS |
2001 | } |
2002 | #endif | |
2cd0050c | 2003 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
2004 | struct tty_driver *console_driver = console_device(index); |
2005 | if (console_driver) { | |
2006 | driver = tty_driver_kref_get(console_driver); | |
2007 | if (driver) { | |
2008 | /* Don't let /dev/console block */ | |
2009 | filp->f_flags |= O_NONBLOCK; | |
2010 | *noctty = 1; | |
2cd0050c | 2011 | break; |
5b5e7040 JS |
2012 | } |
2013 | } | |
2014 | return ERR_PTR(-ENODEV); | |
2015 | } | |
2cd0050c JS |
2016 | default: |
2017 | driver = get_tty_driver(device, index); | |
2018 | if (!driver) | |
2019 | return ERR_PTR(-ENODEV); | |
2020 | break; | |
2021 | } | |
5b5e7040 JS |
2022 | return driver; |
2023 | } | |
2024 | ||
af9b897e | 2025 | /** |
eeb89d91 | 2026 | * tty_open - open a tty device |
af9b897e AC |
2027 | * @inode: inode of device file |
2028 | * @filp: file pointer to tty | |
1da177e4 | 2029 | * |
af9b897e AC |
2030 | * tty_open and tty_release keep up the tty count that contains the |
2031 | * number of opens done on a tty. We cannot use the inode-count, as | |
2032 | * different inodes might point to the same tty. | |
1da177e4 | 2033 | * |
af9b897e AC |
2034 | * Open-counting is needed for pty masters, as well as for keeping |
2035 | * track of serial lines: DTR is dropped when the last close happens. | |
2036 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2037 | * | |
2038 | * The termios state of a pty is reset on first open so that | |
2039 | * settings don't persist across reuse. | |
2040 | * | |
5b5e7040 | 2041 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2042 | * tty->count should protect the rest. |
2043 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2044 | * |
2045 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2046 | * tty_mutex | |
1da177e4 | 2047 | */ |
af9b897e | 2048 | |
eeb89d91 | 2049 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2050 | { |
b82154ac | 2051 | struct tty_struct *tty; |
1da177e4 | 2052 | int noctty, retval; |
b82154ac | 2053 | struct tty_driver *driver = NULL; |
1da177e4 LT |
2054 | int index; |
2055 | dev_t device = inode->i_rdev; | |
846c151a | 2056 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2057 | |
2058 | nonseekable_open(inode, filp); | |
37bdfb07 | 2059 | |
1da177e4 | 2060 | retry_open: |
fa90e1c9 JS |
2061 | retval = tty_alloc_file(filp); |
2062 | if (retval) | |
2063 | return -ENOMEM; | |
2064 | ||
1da177e4 LT |
2065 | noctty = filp->f_flags & O_NOCTTY; |
2066 | index = -1; | |
2067 | retval = 0; | |
37bdfb07 | 2068 | |
70522e12 | 2069 | mutex_lock(&tty_mutex); |
89c8d91e | 2070 | /* This is protected by the tty_mutex */ |
b82154ac JS |
2071 | tty = tty_open_current_tty(device, filp); |
2072 | if (IS_ERR(tty)) { | |
ba5db448 JS |
2073 | retval = PTR_ERR(tty); |
2074 | goto err_unlock; | |
5b5e7040 JS |
2075 | } else if (!tty) { |
2076 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
2077 | if (IS_ERR(driver)) { | |
ba5db448 JS |
2078 | retval = PTR_ERR(driver); |
2079 | goto err_unlock; | |
1da177e4 | 2080 | } |
1da177e4 | 2081 | |
4a2b5fdd | 2082 | /* check whether we're reopening an existing tty */ |
15f1a633 | 2083 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 2084 | if (IS_ERR(tty)) { |
ba5db448 JS |
2085 | retval = PTR_ERR(tty); |
2086 | goto err_unlock; | |
808ffa3d | 2087 | } |
4a2b5fdd SB |
2088 | } |
2089 | ||
2090 | if (tty) { | |
89c8d91e | 2091 | tty_lock(tty); |
4a2b5fdd | 2092 | retval = tty_reopen(tty); |
89c8d91e AC |
2093 | if (retval < 0) { |
2094 | tty_unlock(tty); | |
4a2b5fdd | 2095 | tty = ERR_PTR(retval); |
89c8d91e AC |
2096 | } |
2097 | } else /* Returns with the tty_lock held for now */ | |
593a27c4 | 2098 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 2099 | |
70522e12 | 2100 | mutex_unlock(&tty_mutex); |
b82154ac JS |
2101 | if (driver) |
2102 | tty_driver_kref_put(driver); | |
eeb89d91 | 2103 | if (IS_ERR(tty)) { |
ba5db448 JS |
2104 | retval = PTR_ERR(tty); |
2105 | goto err_file; | |
eeb89d91 | 2106 | } |
1da177e4 | 2107 | |
fa90e1c9 | 2108 | tty_add_file(tty, filp); |
d996b62a | 2109 | |
9de44bd6 | 2110 | check_tty_count(tty, __func__); |
1da177e4 LT |
2111 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2112 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2113 | noctty = 1; | |
2114 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 2115 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 2116 | #endif |
909bc774 HRK |
2117 | if (tty->ops->open) |
2118 | retval = tty->ops->open(tty, filp); | |
2119 | else | |
2120 | retval = -ENODEV; | |
1da177e4 LT |
2121 | filp->f_flags = saved_flags; |
2122 | ||
37bdfb07 AC |
2123 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
2124 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
2125 | retval = -EBUSY; |
2126 | ||
2127 | if (retval) { | |
2128 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
2129 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
2130 | retval, tty->name); | |
1da177e4 | 2131 | #endif |
89c8d91e | 2132 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2133 | tty_release(inode, filp); |
64ba3dc3 | 2134 | if (retval != -ERESTARTSYS) |
1da177e4 | 2135 | return retval; |
64ba3dc3 AB |
2136 | |
2137 | if (signal_pending(current)) | |
1da177e4 | 2138 | return retval; |
64ba3dc3 | 2139 | |
1da177e4 LT |
2140 | schedule(); |
2141 | /* | |
2142 | * Need to reset f_op in case a hangup happened. | |
2143 | */ | |
2144 | if (filp->f_op == &hung_up_tty_fops) | |
2145 | filp->f_op = &tty_fops; | |
2146 | goto retry_open; | |
2147 | } | |
d4855e1f | 2148 | clear_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 2149 | tty_unlock(tty); |
eeb89d91 | 2150 | |
24ec839c PZ |
2151 | |
2152 | mutex_lock(&tty_mutex); | |
89c8d91e | 2153 | tty_lock(tty); |
24ec839c | 2154 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2155 | if (!noctty && |
2156 | current->signal->leader && | |
2157 | !current->signal->tty && | |
ab521dc0 | 2158 | tty->session == NULL) |
bce65f18 | 2159 | __proc_set_tty(tty); |
24ec839c | 2160 | spin_unlock_irq(¤t->sighand->siglock); |
89c8d91e | 2161 | tty_unlock(tty); |
24ec839c | 2162 | mutex_unlock(&tty_mutex); |
1da177e4 | 2163 | return 0; |
ba5db448 | 2164 | err_unlock: |
ba5db448 JS |
2165 | mutex_unlock(&tty_mutex); |
2166 | /* after locks to avoid deadlock */ | |
2167 | if (!IS_ERR_OR_NULL(driver)) | |
2168 | tty_driver_kref_put(driver); | |
2169 | err_file: | |
2170 | tty_free_file(filp); | |
2171 | return retval; | |
1da177e4 LT |
2172 | } |
2173 | ||
39d95b9d JC |
2174 | |
2175 | ||
af9b897e AC |
2176 | /** |
2177 | * tty_poll - check tty status | |
2178 | * @filp: file being polled | |
2179 | * @wait: poll wait structures to update | |
2180 | * | |
2181 | * Call the line discipline polling method to obtain the poll | |
2182 | * status of the device. | |
2183 | * | |
2184 | * Locking: locks called line discipline but ldisc poll method | |
2185 | * may be re-entered freely by other callers. | |
2186 | */ | |
2187 | ||
37bdfb07 | 2188 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2189 | { |
d996b62a | 2190 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2191 | struct tty_ldisc *ld; |
2192 | int ret = 0; | |
2193 | ||
6131ffaa | 2194 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2195 | return 0; |
37bdfb07 | 2196 | |
1da177e4 | 2197 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2198 | if (ld->ops->poll) |
2199 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2200 | tty_ldisc_deref(ld); |
2201 | return ret; | |
2202 | } | |
2203 | ||
ec79d605 | 2204 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2205 | { |
d996b62a | 2206 | struct tty_struct *tty = file_tty(filp); |
f6c8dbe6 | 2207 | struct tty_ldisc *ldisc; |
47f86834 | 2208 | unsigned long flags; |
5d1e3230 | 2209 | int retval = 0; |
1da177e4 | 2210 | |
6131ffaa | 2211 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2212 | goto out; |
37bdfb07 | 2213 | |
1da177e4 LT |
2214 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2215 | if (retval <= 0) | |
5d1e3230 | 2216 | goto out; |
1da177e4 | 2217 | |
f6c8dbe6 PH |
2218 | ldisc = tty_ldisc_ref(tty); |
2219 | if (ldisc) { | |
2220 | if (ldisc->ops->fasync) | |
2221 | ldisc->ops->fasync(tty, on); | |
2222 | tty_ldisc_deref(ldisc); | |
2223 | } | |
2224 | ||
1da177e4 | 2225 | if (on) { |
ab521dc0 EB |
2226 | enum pid_type type; |
2227 | struct pid *pid; | |
f6c8dbe6 | 2228 | |
47f86834 | 2229 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2230 | if (tty->pgrp) { |
2231 | pid = tty->pgrp; | |
2232 | type = PIDTYPE_PGID; | |
2233 | } else { | |
2234 | pid = task_pid(current); | |
2235 | type = PIDTYPE_PID; | |
2236 | } | |
80e1e823 | 2237 | get_pid(pid); |
70362511 | 2238 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2239 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2240 | put_pid(pid); |
e0b93edd | 2241 | retval = 0; |
1da177e4 | 2242 | } |
5d1e3230 | 2243 | out: |
ec79d605 AB |
2244 | return retval; |
2245 | } | |
2246 | ||
2247 | static int tty_fasync(int fd, struct file *filp, int on) | |
2248 | { | |
89c8d91e | 2249 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2250 | int retval; |
89c8d91e AC |
2251 | |
2252 | tty_lock(tty); | |
ec79d605 | 2253 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2254 | tty_unlock(tty); |
2255 | ||
5d1e3230 | 2256 | return retval; |
1da177e4 LT |
2257 | } |
2258 | ||
af9b897e AC |
2259 | /** |
2260 | * tiocsti - fake input character | |
2261 | * @tty: tty to fake input into | |
2262 | * @p: pointer to character | |
2263 | * | |
3a4fa0a2 | 2264 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2265 | * input management. |
2266 | * | |
2267 | * FIXME: does not honour flow control ?? | |
2268 | * | |
2269 | * Locking: | |
137084bb | 2270 | * Called functions take tty_ldiscs_lock |
af9b897e | 2271 | * current->signal->tty check is safe without locks |
28298232 AC |
2272 | * |
2273 | * FIXME: may race normal receive processing | |
af9b897e AC |
2274 | */ |
2275 | ||
1da177e4 LT |
2276 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2277 | { | |
2278 | char ch, mbz = 0; | |
2279 | struct tty_ldisc *ld; | |
37bdfb07 | 2280 | |
1da177e4 LT |
2281 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2282 | return -EPERM; | |
2283 | if (get_user(ch, p)) | |
2284 | return -EFAULT; | |
1e641743 | 2285 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2286 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2287 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2288 | tty_ldisc_deref(ld); |
2289 | return 0; | |
2290 | } | |
2291 | ||
af9b897e AC |
2292 | /** |
2293 | * tiocgwinsz - implement window query ioctl | |
2294 | * @tty; tty | |
2295 | * @arg: user buffer for result | |
2296 | * | |
808a0d38 | 2297 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2298 | * |
dee4a0be | 2299 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2300 | * is consistent. |
af9b897e AC |
2301 | */ |
2302 | ||
37bdfb07 | 2303 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2304 | { |
808a0d38 AC |
2305 | int err; |
2306 | ||
dee4a0be | 2307 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2308 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2309 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2310 | |
2311 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2312 | } |
2313 | ||
af9b897e | 2314 | /** |
8c9a9dd0 AC |
2315 | * tty_do_resize - resize event |
2316 | * @tty: tty being resized | |
8c9a9dd0 AC |
2317 | * @rows: rows (character) |
2318 | * @cols: cols (character) | |
2319 | * | |
3ad2f3fb | 2320 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2321 | * peform a terminal resize correctly |
af9b897e AC |
2322 | */ |
2323 | ||
fc6f6238 | 2324 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2325 | { |
fc6f6238 | 2326 | struct pid *pgrp; |
1da177e4 | 2327 | |
fc6f6238 | 2328 | /* Lock the tty */ |
dee4a0be | 2329 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2330 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2331 | goto done; |
47f86834 | 2332 | |
5b239542 PH |
2333 | /* Signal the foreground process group */ |
2334 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2335 | if (pgrp) |
2336 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2337 | put_pid(pgrp); |
47f86834 | 2338 | |
8c9a9dd0 | 2339 | tty->winsize = *ws; |
ca9bda00 | 2340 | done: |
dee4a0be | 2341 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2342 | return 0; |
2343 | } | |
4d334fd1 | 2344 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2345 | |
8c9a9dd0 AC |
2346 | /** |
2347 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2348 | * @tty; tty side of tty |
8c9a9dd0 AC |
2349 | * @arg: user buffer for result |
2350 | * | |
2351 | * Copies the user idea of the window size to the kernel. Traditionally | |
2352 | * this is just advisory information but for the Linux console it | |
2353 | * actually has driver level meaning and triggers a VC resize. | |
2354 | * | |
2355 | * Locking: | |
25985edc | 2356 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2357 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2358 | * then calls into the default method. | |
2359 | */ | |
2360 | ||
fc6f6238 | 2361 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2362 | { |
2363 | struct winsize tmp_ws; | |
2364 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2365 | return -EFAULT; | |
2366 | ||
2367 | if (tty->ops->resize) | |
fc6f6238 | 2368 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2369 | else |
fc6f6238 | 2370 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2371 | } |
2372 | ||
af9b897e AC |
2373 | /** |
2374 | * tioccons - allow admin to move logical console | |
2375 | * @file: the file to become console | |
2376 | * | |
25985edc | 2377 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2378 | * |
2379 | * Locking: uses redirect_lock to guard the redirect information | |
2380 | */ | |
2381 | ||
1da177e4 LT |
2382 | static int tioccons(struct file *file) |
2383 | { | |
2384 | if (!capable(CAP_SYS_ADMIN)) | |
2385 | return -EPERM; | |
2386 | if (file->f_op->write == redirected_tty_write) { | |
2387 | struct file *f; | |
2388 | spin_lock(&redirect_lock); | |
2389 | f = redirect; | |
2390 | redirect = NULL; | |
2391 | spin_unlock(&redirect_lock); | |
2392 | if (f) | |
2393 | fput(f); | |
2394 | return 0; | |
2395 | } | |
2396 | spin_lock(&redirect_lock); | |
2397 | if (redirect) { | |
2398 | spin_unlock(&redirect_lock); | |
2399 | return -EBUSY; | |
2400 | } | |
cb0942b8 | 2401 | redirect = get_file(file); |
1da177e4 LT |
2402 | spin_unlock(&redirect_lock); |
2403 | return 0; | |
2404 | } | |
2405 | ||
af9b897e AC |
2406 | /** |
2407 | * fionbio - non blocking ioctl | |
2408 | * @file: file to set blocking value | |
2409 | * @p: user parameter | |
2410 | * | |
2411 | * Historical tty interfaces had a blocking control ioctl before | |
2412 | * the generic functionality existed. This piece of history is preserved | |
2413 | * in the expected tty API of posix OS's. | |
2414 | * | |
6146b9af | 2415 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2416 | */ |
1da177e4 LT |
2417 | |
2418 | static int fionbio(struct file *file, int __user *p) | |
2419 | { | |
2420 | int nonblock; | |
2421 | ||
2422 | if (get_user(nonblock, p)) | |
2423 | return -EFAULT; | |
2424 | ||
db1dd4d3 | 2425 | spin_lock(&file->f_lock); |
1da177e4 LT |
2426 | if (nonblock) |
2427 | file->f_flags |= O_NONBLOCK; | |
2428 | else | |
2429 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2430 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2431 | return 0; |
2432 | } | |
2433 | ||
af9b897e AC |
2434 | /** |
2435 | * tiocsctty - set controlling tty | |
2436 | * @tty: tty structure | |
2437 | * @arg: user argument | |
2438 | * | |
2439 | * This ioctl is used to manage job control. It permits a session | |
2440 | * leader to set this tty as the controlling tty for the session. | |
2441 | * | |
2442 | * Locking: | |
28298232 | 2443 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2444 | * Takes tasklist_lock internally to walk sessions |
2445 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2446 | */ |
2447 | ||
1da177e4 LT |
2448 | static int tiocsctty(struct tty_struct *tty, int arg) |
2449 | { | |
24ec839c | 2450 | int ret = 0; |
ab521dc0 | 2451 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2452 | return ret; |
2453 | ||
2454 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2455 | /* |
2456 | * The process must be a session leader and | |
2457 | * not have a controlling tty already. | |
2458 | */ | |
24ec839c PZ |
2459 | if (!current->signal->leader || current->signal->tty) { |
2460 | ret = -EPERM; | |
2461 | goto unlock; | |
2462 | } | |
2463 | ||
ab521dc0 | 2464 | if (tty->session) { |
1da177e4 LT |
2465 | /* |
2466 | * This tty is already the controlling | |
2467 | * tty for another session group! | |
2468 | */ | |
37bdfb07 | 2469 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2470 | /* |
2471 | * Steal it away | |
2472 | */ | |
1da177e4 | 2473 | read_lock(&tasklist_lock); |
24ec839c | 2474 | session_clear_tty(tty->session); |
1da177e4 | 2475 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2476 | } else { |
2477 | ret = -EPERM; | |
2478 | goto unlock; | |
2479 | } | |
1da177e4 | 2480 | } |
bce65f18 | 2481 | proc_set_tty(tty); |
24ec839c | 2482 | unlock: |
28298232 | 2483 | mutex_unlock(&tty_mutex); |
24ec839c | 2484 | return ret; |
1da177e4 LT |
2485 | } |
2486 | ||
5d0fdf1e AC |
2487 | /** |
2488 | * tty_get_pgrp - return a ref counted pgrp pid | |
2489 | * @tty: tty to read | |
2490 | * | |
2491 | * Returns a refcounted instance of the pid struct for the process | |
2492 | * group controlling the tty. | |
2493 | */ | |
2494 | ||
2495 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2496 | { | |
2497 | unsigned long flags; | |
2498 | struct pid *pgrp; | |
2499 | ||
2500 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2501 | pgrp = get_pid(tty->pgrp); | |
2502 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2503 | ||
2504 | return pgrp; | |
2505 | } | |
2506 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2507 | ||
af9b897e AC |
2508 | /** |
2509 | * tiocgpgrp - get process group | |
2510 | * @tty: tty passed by user | |
25985edc | 2511 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2512 | * @p: returned pid |
2513 | * | |
2514 | * Obtain the process group of the tty. If there is no process group | |
2515 | * return an error. | |
2516 | * | |
24ec839c | 2517 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2518 | */ |
2519 | ||
1da177e4 LT |
2520 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2521 | { | |
5d0fdf1e AC |
2522 | struct pid *pid; |
2523 | int ret; | |
1da177e4 LT |
2524 | /* |
2525 | * (tty == real_tty) is a cheap way of | |
2526 | * testing if the tty is NOT a master pty. | |
2527 | */ | |
2528 | if (tty == real_tty && current->signal->tty != real_tty) | |
2529 | return -ENOTTY; | |
5d0fdf1e AC |
2530 | pid = tty_get_pgrp(real_tty); |
2531 | ret = put_user(pid_vnr(pid), p); | |
2532 | put_pid(pid); | |
2533 | return ret; | |
1da177e4 LT |
2534 | } |
2535 | ||
af9b897e AC |
2536 | /** |
2537 | * tiocspgrp - attempt to set process group | |
2538 | * @tty: tty passed by user | |
2539 | * @real_tty: tty side device matching tty passed by user | |
2540 | * @p: pid pointer | |
2541 | * | |
2542 | * Set the process group of the tty to the session passed. Only | |
2543 | * permitted where the tty session is our session. | |
2544 | * | |
47f86834 | 2545 | * Locking: RCU, ctrl lock |
af9b897e AC |
2546 | */ |
2547 | ||
1da177e4 LT |
2548 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2549 | { | |
04a2e6a5 EB |
2550 | struct pid *pgrp; |
2551 | pid_t pgrp_nr; | |
1da177e4 | 2552 | int retval = tty_check_change(real_tty); |
47f86834 | 2553 | unsigned long flags; |
1da177e4 LT |
2554 | |
2555 | if (retval == -EIO) | |
2556 | return -ENOTTY; | |
2557 | if (retval) | |
2558 | return retval; | |
2559 | if (!current->signal->tty || | |
2560 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2561 | (real_tty->session != task_session(current))) |
1da177e4 | 2562 | return -ENOTTY; |
04a2e6a5 | 2563 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2564 | return -EFAULT; |
04a2e6a5 | 2565 | if (pgrp_nr < 0) |
1da177e4 | 2566 | return -EINVAL; |
04a2e6a5 | 2567 | rcu_read_lock(); |
b488893a | 2568 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2569 | retval = -ESRCH; |
2570 | if (!pgrp) | |
2571 | goto out_unlock; | |
2572 | retval = -EPERM; | |
2573 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2574 | goto out_unlock; | |
2575 | retval = 0; | |
47f86834 | 2576 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2577 | put_pid(real_tty->pgrp); |
2578 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2579 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2580 | out_unlock: |
2581 | rcu_read_unlock(); | |
2582 | return retval; | |
1da177e4 LT |
2583 | } |
2584 | ||
af9b897e AC |
2585 | /** |
2586 | * tiocgsid - get session id | |
2587 | * @tty: tty passed by user | |
25985edc | 2588 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2589 | * @p: pointer to returned session id |
2590 | * | |
2591 | * Obtain the session id of the tty. If there is no session | |
2592 | * return an error. | |
2593 | * | |
24ec839c | 2594 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2595 | */ |
2596 | ||
1da177e4 LT |
2597 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2598 | { | |
2599 | /* | |
2600 | * (tty == real_tty) is a cheap way of | |
2601 | * testing if the tty is NOT a master pty. | |
2602 | */ | |
2603 | if (tty == real_tty && current->signal->tty != real_tty) | |
2604 | return -ENOTTY; | |
ab521dc0 | 2605 | if (!real_tty->session) |
1da177e4 | 2606 | return -ENOTTY; |
b488893a | 2607 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2608 | } |
2609 | ||
af9b897e AC |
2610 | /** |
2611 | * tiocsetd - set line discipline | |
2612 | * @tty: tty device | |
2613 | * @p: pointer to user data | |
2614 | * | |
2615 | * Set the line discipline according to user request. | |
2616 | * | |
2617 | * Locking: see tty_set_ldisc, this function is just a helper | |
2618 | */ | |
2619 | ||
1da177e4 LT |
2620 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2621 | { | |
2622 | int ldisc; | |
04f378b1 | 2623 | int ret; |
1da177e4 LT |
2624 | |
2625 | if (get_user(ldisc, p)) | |
2626 | return -EFAULT; | |
04f378b1 | 2627 | |
04f378b1 | 2628 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2629 | |
2630 | return ret; | |
1da177e4 LT |
2631 | } |
2632 | ||
af9b897e AC |
2633 | /** |
2634 | * send_break - performed time break | |
2635 | * @tty: device to break on | |
2636 | * @duration: timeout in mS | |
2637 | * | |
2638 | * Perform a timed break on hardware that lacks its own driver level | |
2639 | * timed break functionality. | |
2640 | * | |
2641 | * Locking: | |
28298232 | 2642 | * atomic_write_lock serializes |
af9b897e | 2643 | * |
af9b897e AC |
2644 | */ |
2645 | ||
b20f3ae5 | 2646 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2647 | { |
9e98966c AC |
2648 | int retval; |
2649 | ||
2650 | if (tty->ops->break_ctl == NULL) | |
2651 | return 0; | |
2652 | ||
2653 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2654 | retval = tty->ops->break_ctl(tty, duration); | |
2655 | else { | |
2656 | /* Do the work ourselves */ | |
2657 | if (tty_write_lock(tty, 0) < 0) | |
2658 | return -EINTR; | |
2659 | retval = tty->ops->break_ctl(tty, -1); | |
2660 | if (retval) | |
2661 | goto out; | |
2662 | if (!signal_pending(current)) | |
2663 | msleep_interruptible(duration); | |
2664 | retval = tty->ops->break_ctl(tty, 0); | |
2665 | out: | |
2666 | tty_write_unlock(tty); | |
2667 | if (signal_pending(current)) | |
2668 | retval = -EINTR; | |
2669 | } | |
2670 | return retval; | |
1da177e4 LT |
2671 | } |
2672 | ||
af9b897e | 2673 | /** |
f34d7a5b | 2674 | * tty_tiocmget - get modem status |
af9b897e AC |
2675 | * @tty: tty device |
2676 | * @file: user file pointer | |
2677 | * @p: pointer to result | |
2678 | * | |
2679 | * Obtain the modem status bits from the tty driver if the feature | |
2680 | * is supported. Return -EINVAL if it is not available. | |
2681 | * | |
2682 | * Locking: none (up to the driver) | |
2683 | */ | |
2684 | ||
60b33c13 | 2685 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2686 | { |
2687 | int retval = -EINVAL; | |
2688 | ||
f34d7a5b | 2689 | if (tty->ops->tiocmget) { |
60b33c13 | 2690 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2691 | |
2692 | if (retval >= 0) | |
2693 | retval = put_user(retval, p); | |
2694 | } | |
2695 | return retval; | |
2696 | } | |
2697 | ||
af9b897e | 2698 | /** |
f34d7a5b | 2699 | * tty_tiocmset - set modem status |
af9b897e | 2700 | * @tty: tty device |
af9b897e AC |
2701 | * @cmd: command - clear bits, set bits or set all |
2702 | * @p: pointer to desired bits | |
2703 | * | |
2704 | * Set the modem status bits from the tty driver if the feature | |
2705 | * is supported. Return -EINVAL if it is not available. | |
2706 | * | |
2707 | * Locking: none (up to the driver) | |
2708 | */ | |
2709 | ||
20b9d177 | 2710 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2711 | unsigned __user *p) |
2712 | { | |
ae677517 AC |
2713 | int retval; |
2714 | unsigned int set, clear, val; | |
1da177e4 | 2715 | |
ae677517 AC |
2716 | if (tty->ops->tiocmset == NULL) |
2717 | return -EINVAL; | |
1da177e4 | 2718 | |
ae677517 AC |
2719 | retval = get_user(val, p); |
2720 | if (retval) | |
2721 | return retval; | |
2722 | set = clear = 0; | |
2723 | switch (cmd) { | |
2724 | case TIOCMBIS: | |
2725 | set = val; | |
2726 | break; | |
2727 | case TIOCMBIC: | |
2728 | clear = val; | |
2729 | break; | |
2730 | case TIOCMSET: | |
2731 | set = val; | |
2732 | clear = ~val; | |
2733 | break; | |
2734 | } | |
2735 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2736 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2737 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2738 | } |
2739 | ||
d281da7f AC |
2740 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2741 | { | |
2742 | int retval = -EINVAL; | |
2743 | struct serial_icounter_struct icount; | |
2744 | memset(&icount, 0, sizeof(icount)); | |
2745 | if (tty->ops->get_icount) | |
2746 | retval = tty->ops->get_icount(tty, &icount); | |
2747 | if (retval != 0) | |
2748 | return retval; | |
2749 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2750 | return -EFAULT; | |
2751 | return 0; | |
2752 | } | |
2753 | ||
8f166e00 PH |
2754 | /* |
2755 | * if pty, return the slave side (real_tty) | |
2756 | * otherwise, return self | |
2757 | */ | |
2758 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2759 | { |
2760 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2761 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2762 | tty = tty->link; | |
2763 | return tty; | |
2764 | } | |
e8b70e7d | 2765 | |
1da177e4 LT |
2766 | /* |
2767 | * Split this up, as gcc can choke on it otherwise.. | |
2768 | */ | |
04f378b1 | 2769 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2770 | { |
d996b62a NP |
2771 | struct tty_struct *tty = file_tty(file); |
2772 | struct tty_struct *real_tty; | |
1da177e4 LT |
2773 | void __user *p = (void __user *)arg; |
2774 | int retval; | |
2775 | struct tty_ldisc *ld; | |
37bdfb07 | 2776 | |
6131ffaa | 2777 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2778 | return -EINVAL; |
2779 | ||
e8b70e7d | 2780 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2781 | |
2782 | /* | |
2783 | * Factor out some common prep work | |
2784 | */ | |
2785 | switch (cmd) { | |
2786 | case TIOCSETD: | |
2787 | case TIOCSBRK: | |
2788 | case TIOCCBRK: | |
2789 | case TCSBRK: | |
37bdfb07 | 2790 | case TCSBRKP: |
1da177e4 LT |
2791 | retval = tty_check_change(tty); |
2792 | if (retval) | |
2793 | return retval; | |
2794 | if (cmd != TIOCCBRK) { | |
2795 | tty_wait_until_sent(tty, 0); | |
2796 | if (signal_pending(current)) | |
2797 | return -EINTR; | |
2798 | } | |
2799 | break; | |
2800 | } | |
2801 | ||
9e98966c AC |
2802 | /* |
2803 | * Now do the stuff. | |
2804 | */ | |
1da177e4 | 2805 | switch (cmd) { |
37bdfb07 AC |
2806 | case TIOCSTI: |
2807 | return tiocsti(tty, p); | |
2808 | case TIOCGWINSZ: | |
8f520021 | 2809 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2810 | case TIOCSWINSZ: |
fc6f6238 | 2811 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2812 | case TIOCCONS: |
2813 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2814 | case FIONBIO: | |
2815 | return fionbio(file, p); | |
2816 | case TIOCEXCL: | |
2817 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2818 | return 0; | |
2819 | case TIOCNXCL: | |
2820 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2821 | return 0; | |
84fd7bdf CG |
2822 | case TIOCGEXCL: |
2823 | { | |
2824 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2825 | return put_user(excl, (int __user *)p); | |
2826 | } | |
37bdfb07 AC |
2827 | case TIOCNOTTY: |
2828 | if (current->signal->tty != tty) | |
2829 | return -ENOTTY; | |
2830 | no_tty(); | |
2831 | return 0; | |
2832 | case TIOCSCTTY: | |
2833 | return tiocsctty(tty, arg); | |
2834 | case TIOCGPGRP: | |
2835 | return tiocgpgrp(tty, real_tty, p); | |
2836 | case TIOCSPGRP: | |
2837 | return tiocspgrp(tty, real_tty, p); | |
2838 | case TIOCGSID: | |
2839 | return tiocgsid(tty, real_tty, p); | |
2840 | case TIOCGETD: | |
c65c9bc3 | 2841 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2842 | case TIOCSETD: |
2843 | return tiocsetd(tty, p); | |
3c95c985 KS |
2844 | case TIOCVHANGUP: |
2845 | if (!capable(CAP_SYS_ADMIN)) | |
2846 | return -EPERM; | |
2847 | tty_vhangup(tty); | |
2848 | return 0; | |
b7b8de08 WF |
2849 | case TIOCGDEV: |
2850 | { | |
2851 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2852 | return put_user(ret, (unsigned int __user *)p); | |
2853 | } | |
37bdfb07 AC |
2854 | /* |
2855 | * Break handling | |
2856 | */ | |
2857 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2858 | if (tty->ops->break_ctl) |
9e98966c | 2859 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2860 | return 0; |
37bdfb07 | 2861 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2862 | if (tty->ops->break_ctl) |
9e98966c | 2863 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2864 | return 0; |
2865 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2866 | /* non-zero arg means wait for all output data | |
2867 | * to be sent (performed above) but don't send break. | |
2868 | * This is used by the tcdrain() termios function. | |
2869 | */ | |
2870 | if (!arg) | |
2871 | return send_break(tty, 250); | |
2872 | return 0; | |
2873 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2874 | return send_break(tty, arg ? arg*100 : 250); | |
2875 | ||
2876 | case TIOCMGET: | |
60b33c13 | 2877 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2878 | case TIOCMSET: |
2879 | case TIOCMBIC: | |
2880 | case TIOCMBIS: | |
20b9d177 | 2881 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2882 | case TIOCGICOUNT: |
2883 | retval = tty_tiocgicount(tty, p); | |
2884 | /* For the moment allow fall through to the old method */ | |
2885 | if (retval != -EINVAL) | |
2886 | return retval; | |
2887 | break; | |
37bdfb07 AC |
2888 | case TCFLSH: |
2889 | switch (arg) { | |
2890 | case TCIFLUSH: | |
2891 | case TCIOFLUSH: | |
2892 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2893 | tty_buffer_flush(tty); | |
c5c34d48 | 2894 | break; |
37bdfb07 AC |
2895 | } |
2896 | break; | |
1da177e4 | 2897 | } |
f34d7a5b | 2898 | if (tty->ops->ioctl) { |
6caa76b7 | 2899 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2900 | if (retval != -ENOIOCTLCMD) |
2901 | return retval; | |
2902 | } | |
2903 | ld = tty_ldisc_ref_wait(tty); | |
2904 | retval = -EINVAL; | |
a352def2 AC |
2905 | if (ld->ops->ioctl) { |
2906 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2907 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2908 | retval = -ENOTTY; |
1da177e4 LT |
2909 | } |
2910 | tty_ldisc_deref(ld); | |
2911 | return retval; | |
2912 | } | |
2913 | ||
e10cc1df | 2914 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2915 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2916 | unsigned long arg) |
2917 | { | |
d996b62a | 2918 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2919 | struct tty_ldisc *ld; |
2920 | int retval = -ENOIOCTLCMD; | |
2921 | ||
6131ffaa | 2922 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2923 | return -EINVAL; |
2924 | ||
f34d7a5b | 2925 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2926 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2927 | if (retval != -ENOIOCTLCMD) |
2928 | return retval; | |
2929 | } | |
2930 | ||
2931 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2932 | if (ld->ops->compat_ioctl) |
2933 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2934 | else |
2935 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2936 | tty_ldisc_deref(ld); |
2937 | ||
2938 | return retval; | |
2939 | } | |
2940 | #endif | |
1da177e4 | 2941 | |
c3c073f8 AV |
2942 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2943 | { | |
2944 | if (likely(file->f_op->read != tty_read)) | |
2945 | return 0; | |
2946 | return file_tty(file) != t ? 0 : fd + 1; | |
2947 | } | |
2948 | ||
1da177e4 LT |
2949 | /* |
2950 | * This implements the "Secure Attention Key" --- the idea is to | |
2951 | * prevent trojan horses by killing all processes associated with this | |
2952 | * tty when the user hits the "Secure Attention Key". Required for | |
2953 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2954 | * |
1da177e4 LT |
2955 | * This code could be nicer; ideally it should send a HUP, wait a few |
2956 | * seconds, then send a INT, and then a KILL signal. But you then | |
2957 | * have to coordinate with the init process, since all processes associated | |
2958 | * with the current tty must be dead before the new getty is allowed | |
2959 | * to spawn. | |
2960 | * | |
2961 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2962 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2963 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2964 | * | |
2965 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2966 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2967 | */ | |
8b6312f4 | 2968 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2969 | { |
2970 | #ifdef TTY_SOFT_SAK | |
2971 | tty_hangup(tty); | |
2972 | #else | |
652486fb | 2973 | struct task_struct *g, *p; |
ab521dc0 | 2974 | struct pid *session; |
1da177e4 | 2975 | int i; |
37bdfb07 | 2976 | |
1da177e4 LT |
2977 | if (!tty) |
2978 | return; | |
24ec839c | 2979 | session = tty->session; |
37bdfb07 | 2980 | |
b3f13deb | 2981 | tty_ldisc_flush(tty); |
1da177e4 | 2982 | |
f34d7a5b | 2983 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2984 | |
1da177e4 | 2985 | read_lock(&tasklist_lock); |
652486fb | 2986 | /* Kill the entire session */ |
ab521dc0 | 2987 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2988 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2989 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2990 | task_pid_nr(p), p->comm); |
652486fb | 2991 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2992 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2993 | /* Now kill any processes that happen to have the |
2994 | * tty open. | |
2995 | */ | |
2996 | do_each_thread(g, p) { | |
2997 | if (p->signal->tty == tty) { | |
1da177e4 | 2998 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2999 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 3000 | task_pid_nr(p), p->comm); |
1da177e4 LT |
3001 | send_sig(SIGKILL, p, 1); |
3002 | continue; | |
3003 | } | |
3004 | task_lock(p); | |
c3c073f8 AV |
3005 | i = iterate_fd(p->files, 0, this_tty, tty); |
3006 | if (i != 0) { | |
3007 | printk(KERN_NOTICE "SAK: killed process %d" | |
3008 | " (%s): fd#%d opened to the tty\n", | |
3009 | task_pid_nr(p), p->comm, i - 1); | |
3010 | force_sig(SIGKILL, p); | |
1da177e4 LT |
3011 | } |
3012 | task_unlock(p); | |
652486fb | 3013 | } while_each_thread(g, p); |
1da177e4 LT |
3014 | read_unlock(&tasklist_lock); |
3015 | #endif | |
3016 | } | |
3017 | ||
8b6312f4 EB |
3018 | static void do_SAK_work(struct work_struct *work) |
3019 | { | |
3020 | struct tty_struct *tty = | |
3021 | container_of(work, struct tty_struct, SAK_work); | |
3022 | __do_SAK(tty); | |
3023 | } | |
3024 | ||
1da177e4 LT |
3025 | /* |
3026 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3027 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3028 | * the values which we write to it will be identical to the values which it | |
3029 | * already has. --akpm | |
3030 | */ | |
3031 | void do_SAK(struct tty_struct *tty) | |
3032 | { | |
3033 | if (!tty) | |
3034 | return; | |
1da177e4 LT |
3035 | schedule_work(&tty->SAK_work); |
3036 | } | |
3037 | ||
3038 | EXPORT_SYMBOL(do_SAK); | |
3039 | ||
6e9430ac | 3040 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3041 | { |
6e9430ac | 3042 | const dev_t *devt = data; |
30004ac9 DES |
3043 | return dev->devt == *devt; |
3044 | } | |
3045 | ||
3046 | /* Must put_device() after it's unused! */ | |
3047 | static struct device *tty_get_device(struct tty_struct *tty) | |
3048 | { | |
3049 | dev_t devt = tty_devnum(tty); | |
3050 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3051 | } | |
3052 | ||
3053 | ||
af9b897e | 3054 | /** |
2c964a2f | 3055 | * alloc_tty_struct |
af9b897e | 3056 | * |
2c964a2f | 3057 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3058 | * |
2c964a2f | 3059 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3060 | */ |
af9b897e | 3061 | |
2c964a2f | 3062 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3063 | { |
2c964a2f RV |
3064 | struct tty_struct *tty; |
3065 | ||
3066 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3067 | if (!tty) | |
3068 | return NULL; | |
3069 | ||
9c9f4ded | 3070 | kref_init(&tty->kref); |
1da177e4 | 3071 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3072 | tty_ldisc_init(tty); |
ab521dc0 EB |
3073 | tty->session = NULL; |
3074 | tty->pgrp = NULL; | |
89c8d91e | 3075 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3076 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3077 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3078 | mutex_init(&tty->winsize_mutex); |
36697529 | 3079 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3080 | init_waitqueue_head(&tty->write_wait); |
3081 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3082 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3083 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3084 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3085 | spin_lock_init(&tty->flow_lock); |
1da177e4 | 3086 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3087 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3088 | |
3089 | tty->driver = driver; | |
3090 | tty->ops = driver->ops; | |
3091 | tty->index = idx; | |
3092 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3093 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3094 | |
3095 | return tty; | |
1da177e4 LT |
3096 | } |
3097 | ||
6716671d JS |
3098 | /** |
3099 | * deinitialize_tty_struct | |
3100 | * @tty: tty to deinitialize | |
3101 | * | |
3102 | * This subroutine deinitializes a tty structure that has been newly | |
3103 | * allocated but tty_release cannot be called on that yet. | |
3104 | * | |
3105 | * Locking: none - tty in question must not be exposed at this point | |
3106 | */ | |
3107 | void deinitialize_tty_struct(struct tty_struct *tty) | |
3108 | { | |
3109 | tty_ldisc_deinit(tty); | |
3110 | } | |
3111 | ||
f34d7a5b AC |
3112 | /** |
3113 | * tty_put_char - write one character to a tty | |
3114 | * @tty: tty | |
3115 | * @ch: character | |
3116 | * | |
3117 | * Write one byte to the tty using the provided put_char method | |
3118 | * if present. Returns the number of characters successfully output. | |
3119 | * | |
3120 | * Note: the specific put_char operation in the driver layer may go | |
3121 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3122 | */ |
af9b897e | 3123 | |
f34d7a5b | 3124 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3125 | { |
f34d7a5b AC |
3126 | if (tty->ops->put_char) |
3127 | return tty->ops->put_char(tty, ch); | |
3128 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3129 | } |
f34d7a5b AC |
3130 | EXPORT_SYMBOL_GPL(tty_put_char); |
3131 | ||
d81ed103 | 3132 | struct class *tty_class; |
1da177e4 | 3133 | |
7e73eca6 JS |
3134 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3135 | unsigned int index, unsigned int count) | |
3136 | { | |
3137 | /* init here, since reused cdevs cause crashes */ | |
3138 | cdev_init(&driver->cdevs[index], &tty_fops); | |
3139 | driver->cdevs[index].owner = driver->owner; | |
3140 | return cdev_add(&driver->cdevs[index], dev, count); | |
3141 | } | |
3142 | ||
1da177e4 | 3143 | /** |
af9b897e AC |
3144 | * tty_register_device - register a tty device |
3145 | * @driver: the tty driver that describes the tty device | |
3146 | * @index: the index in the tty driver for this tty device | |
3147 | * @device: a struct device that is associated with this tty device. | |
3148 | * This field is optional, if there is no known struct device | |
3149 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3150 | * |
01107d34 GKH |
3151 | * Returns a pointer to the struct device for this tty device |
3152 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3153 | * |
af9b897e AC |
3154 | * This call is required to be made to register an individual tty device |
3155 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3156 | * that bit is not set, this function should not be called by a tty | |
3157 | * driver. | |
3158 | * | |
3159 | * Locking: ?? | |
1da177e4 | 3160 | */ |
af9b897e | 3161 | |
01107d34 GKH |
3162 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3163 | struct device *device) | |
1da177e4 | 3164 | { |
6915c0e4 TH |
3165 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3166 | } | |
3167 | EXPORT_SYMBOL(tty_register_device); | |
3168 | ||
b1b79916 TH |
3169 | static void tty_device_create_release(struct device *dev) |
3170 | { | |
3171 | pr_debug("device: '%s': %s\n", dev_name(dev), __func__); | |
3172 | kfree(dev); | |
3173 | } | |
3174 | ||
6915c0e4 TH |
3175 | /** |
3176 | * tty_register_device_attr - register a tty device | |
3177 | * @driver: the tty driver that describes the tty device | |
3178 | * @index: the index in the tty driver for this tty device | |
3179 | * @device: a struct device that is associated with this tty device. | |
3180 | * This field is optional, if there is no known struct device | |
3181 | * for this tty device it can be set to NULL safely. | |
3182 | * @drvdata: Driver data to be set to device. | |
3183 | * @attr_grp: Attribute group to be set on device. | |
3184 | * | |
3185 | * Returns a pointer to the struct device for this tty device | |
3186 | * (or ERR_PTR(-EFOO) on error). | |
3187 | * | |
3188 | * This call is required to be made to register an individual tty device | |
3189 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3190 | * that bit is not set, this function should not be called by a tty | |
3191 | * driver. | |
3192 | * | |
3193 | * Locking: ?? | |
3194 | */ | |
3195 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3196 | unsigned index, struct device *device, | |
3197 | void *drvdata, | |
3198 | const struct attribute_group **attr_grp) | |
3199 | { | |
1da177e4 | 3200 | char name[64]; |
6915c0e4 TH |
3201 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3202 | struct device *dev = NULL; | |
3203 | int retval = -ENODEV; | |
7e73eca6 | 3204 | bool cdev = false; |
1da177e4 LT |
3205 | |
3206 | if (index >= driver->num) { | |
3207 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3208 | " (%d).\n", index); | |
1cdcb6b4 | 3209 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3210 | } |
3211 | ||
1da177e4 LT |
3212 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3213 | pty_line_name(driver, index, name); | |
3214 | else | |
3215 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3216 | |
7e73eca6 | 3217 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3218 | retval = tty_cdev_add(driver, devt, index, 1); |
3219 | if (retval) | |
3220 | goto error; | |
7e73eca6 JS |
3221 | cdev = true; |
3222 | } | |
3223 | ||
6915c0e4 TH |
3224 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3225 | if (!dev) { | |
3226 | retval = -ENOMEM; | |
3227 | goto error; | |
3228 | } | |
7e73eca6 | 3229 | |
6915c0e4 TH |
3230 | dev->devt = devt; |
3231 | dev->class = tty_class; | |
3232 | dev->parent = device; | |
b1b79916 | 3233 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3234 | dev_set_name(dev, "%s", name); |
3235 | dev->groups = attr_grp; | |
3236 | dev_set_drvdata(dev, drvdata); | |
3237 | ||
3238 | retval = device_register(dev); | |
3239 | if (retval) | |
3240 | goto error; | |
3241 | ||
3242 | return dev; | |
3243 | ||
3244 | error: | |
3245 | put_device(dev); | |
3246 | if (cdev) | |
3247 | cdev_del(&driver->cdevs[index]); | |
3248 | return ERR_PTR(retval); | |
1da177e4 | 3249 | } |
6915c0e4 | 3250 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3251 | |
3252 | /** | |
af9b897e AC |
3253 | * tty_unregister_device - unregister a tty device |
3254 | * @driver: the tty driver that describes the tty device | |
3255 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3256 | * |
af9b897e AC |
3257 | * If a tty device is registered with a call to tty_register_device() then |
3258 | * this function must be called when the tty device is gone. | |
3259 | * | |
3260 | * Locking: ?? | |
1da177e4 | 3261 | */ |
af9b897e | 3262 | |
1da177e4 LT |
3263 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3264 | { | |
37bdfb07 AC |
3265 | device_destroy(tty_class, |
3266 | MKDEV(driver->major, driver->minor_start) + index); | |
7e73eca6 JS |
3267 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) |
3268 | cdev_del(&driver->cdevs[index]); | |
1da177e4 | 3269 | } |
1da177e4 LT |
3270 | EXPORT_SYMBOL(tty_unregister_device); |
3271 | ||
7f0bc6a6 JS |
3272 | /** |
3273 | * __tty_alloc_driver -- allocate tty driver | |
3274 | * @lines: count of lines this driver can handle at most | |
3275 | * @owner: module which is repsonsible for this driver | |
3276 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3277 | * | |
3278 | * This should not be called directly, some of the provided macros should be | |
3279 | * used instead. Use IS_ERR and friends on @retval. | |
3280 | */ | |
3281 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3282 | unsigned long flags) | |
1da177e4 LT |
3283 | { |
3284 | struct tty_driver *driver; | |
7e73eca6 | 3285 | unsigned int cdevs = 1; |
16a02081 | 3286 | int err; |
1da177e4 | 3287 | |
0019b408 | 3288 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3289 | return ERR_PTR(-EINVAL); |
3290 | ||
506eb99a | 3291 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3292 | if (!driver) |
3293 | return ERR_PTR(-ENOMEM); | |
3294 | ||
3295 | kref_init(&driver->kref); | |
3296 | driver->magic = TTY_DRIVER_MAGIC; | |
3297 | driver->num = lines; | |
3298 | driver->owner = owner; | |
3299 | driver->flags = flags; | |
16a02081 JS |
3300 | |
3301 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3302 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3303 | GFP_KERNEL); | |
3304 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3305 | GFP_KERNEL); | |
3306 | if (!driver->ttys || !driver->termios) { | |
3307 | err = -ENOMEM; | |
3308 | goto err_free_all; | |
3309 | } | |
3310 | } | |
3311 | ||
3312 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3313 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3314 | GFP_KERNEL); | |
3315 | if (!driver->ports) { | |
3316 | err = -ENOMEM; | |
3317 | goto err_free_all; | |
3318 | } | |
7e73eca6 JS |
3319 | cdevs = lines; |
3320 | } | |
3321 | ||
3322 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3323 | if (!driver->cdevs) { | |
3324 | err = -ENOMEM; | |
3325 | goto err_free_all; | |
16a02081 | 3326 | } |
7f0bc6a6 | 3327 | |
1da177e4 | 3328 | return driver; |
16a02081 JS |
3329 | err_free_all: |
3330 | kfree(driver->ports); | |
3331 | kfree(driver->ttys); | |
3332 | kfree(driver->termios); | |
3333 | kfree(driver); | |
3334 | return ERR_PTR(err); | |
1da177e4 | 3335 | } |
7f0bc6a6 | 3336 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3337 | |
7d7b93c1 | 3338 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3339 | { |
7d7b93c1 AC |
3340 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3341 | int i; | |
3342 | struct ktermios *tp; | |
7d7b93c1 AC |
3343 | |
3344 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3345 | /* | |
3346 | * Free the termios and termios_locked structures because | |
3347 | * we don't want to get memory leaks when modular tty | |
3348 | * drivers are removed from the kernel. | |
3349 | */ | |
3350 | for (i = 0; i < driver->num; i++) { | |
3351 | tp = driver->termios[i]; | |
3352 | if (tp) { | |
3353 | driver->termios[i] = NULL; | |
3354 | kfree(tp); | |
3355 | } | |
7d7b93c1 AC |
3356 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3357 | tty_unregister_device(driver, i); | |
3358 | } | |
7d7b93c1 | 3359 | proc_tty_unregister_driver(driver); |
7e73eca6 JS |
3360 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
3361 | cdev_del(&driver->cdevs[0]); | |
7d7b93c1 | 3362 | } |
7e73eca6 | 3363 | kfree(driver->cdevs); |
04831dc1 | 3364 | kfree(driver->ports); |
16a02081 JS |
3365 | kfree(driver->termios); |
3366 | kfree(driver->ttys); | |
1da177e4 LT |
3367 | kfree(driver); |
3368 | } | |
3369 | ||
7d7b93c1 AC |
3370 | void tty_driver_kref_put(struct tty_driver *driver) |
3371 | { | |
3372 | kref_put(&driver->kref, destruct_tty_driver); | |
3373 | } | |
3374 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3375 | ||
b68e31d0 JD |
3376 | void tty_set_operations(struct tty_driver *driver, |
3377 | const struct tty_operations *op) | |
1da177e4 | 3378 | { |
f34d7a5b AC |
3379 | driver->ops = op; |
3380 | }; | |
7d7b93c1 | 3381 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3382 | |
7d7b93c1 AC |
3383 | void put_tty_driver(struct tty_driver *d) |
3384 | { | |
3385 | tty_driver_kref_put(d); | |
3386 | } | |
1da177e4 | 3387 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3388 | |
3389 | /* | |
3390 | * Called by a tty driver to register itself. | |
3391 | */ | |
3392 | int tty_register_driver(struct tty_driver *driver) | |
3393 | { | |
3394 | int error; | |
37bdfb07 | 3395 | int i; |
1da177e4 | 3396 | dev_t dev; |
b670bde0 | 3397 | struct device *d; |
1da177e4 | 3398 | |
1da177e4 | 3399 | if (!driver->major) { |
37bdfb07 AC |
3400 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3401 | driver->num, driver->name); | |
1da177e4 LT |
3402 | if (!error) { |
3403 | driver->major = MAJOR(dev); | |
3404 | driver->minor_start = MINOR(dev); | |
3405 | } | |
3406 | } else { | |
3407 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3408 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3409 | } |
9bb8a3d4 | 3410 | if (error < 0) |
16a02081 | 3411 | goto err; |
1da177e4 | 3412 | |
7e73eca6 JS |
3413 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3414 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3415 | if (error) | |
3416 | goto err_unreg_char; | |
3417 | } | |
1da177e4 | 3418 | |
ca509f69 | 3419 | mutex_lock(&tty_mutex); |
1da177e4 | 3420 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3421 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3422 | |
3423 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3424 | for (i = 0; i < driver->num; i++) { |
3425 | d = tty_register_device(driver, i, NULL); | |
3426 | if (IS_ERR(d)) { | |
3427 | error = PTR_ERR(d); | |
16a02081 | 3428 | goto err_unreg_devs; |
b670bde0 VK |
3429 | } |
3430 | } | |
1da177e4 LT |
3431 | } |
3432 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3433 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3434 | return 0; |
b670bde0 | 3435 | |
16a02081 | 3436 | err_unreg_devs: |
b670bde0 VK |
3437 | for (i--; i >= 0; i--) |
3438 | tty_unregister_device(driver, i); | |
3439 | ||
3440 | mutex_lock(&tty_mutex); | |
3441 | list_del(&driver->tty_drivers); | |
3442 | mutex_unlock(&tty_mutex); | |
3443 | ||
9bb8a3d4 | 3444 | err_unreg_char: |
b670bde0 | 3445 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3446 | err: |
b670bde0 | 3447 | return error; |
1da177e4 | 3448 | } |
1da177e4 LT |
3449 | EXPORT_SYMBOL(tty_register_driver); |
3450 | ||
3451 | /* | |
3452 | * Called by a tty driver to unregister itself. | |
3453 | */ | |
3454 | int tty_unregister_driver(struct tty_driver *driver) | |
3455 | { | |
7d7b93c1 AC |
3456 | #if 0 |
3457 | /* FIXME */ | |
1da177e4 LT |
3458 | if (driver->refcount) |
3459 | return -EBUSY; | |
7d7b93c1 | 3460 | #endif |
1da177e4 LT |
3461 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3462 | driver->num); | |
ca509f69 | 3463 | mutex_lock(&tty_mutex); |
1da177e4 | 3464 | list_del(&driver->tty_drivers); |
ca509f69 | 3465 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3466 | return 0; |
3467 | } | |
7d7b93c1 | 3468 | |
1da177e4 LT |
3469 | EXPORT_SYMBOL(tty_unregister_driver); |
3470 | ||
24ec839c PZ |
3471 | dev_t tty_devnum(struct tty_struct *tty) |
3472 | { | |
3473 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3474 | } | |
3475 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3476 | |
d81ed103 AC |
3477 | void tty_default_fops(struct file_operations *fops) |
3478 | { | |
3479 | *fops = tty_fops; | |
3480 | } | |
3481 | ||
1da177e4 LT |
3482 | /* |
3483 | * Initialize the console device. This is called *early*, so | |
3484 | * we can't necessarily depend on lots of kernel help here. | |
3485 | * Just do some early initializations, and do the complex setup | |
3486 | * later. | |
3487 | */ | |
3488 | void __init console_init(void) | |
3489 | { | |
3490 | initcall_t *call; | |
3491 | ||
3492 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3493 | tty_ldisc_begin(); |
1da177e4 LT |
3494 | |
3495 | /* | |
37bdfb07 | 3496 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3497 | * inform about problems etc.. |
3498 | */ | |
1da177e4 LT |
3499 | call = __con_initcall_start; |
3500 | while (call < __con_initcall_end) { | |
3501 | (*call)(); | |
3502 | call++; | |
3503 | } | |
3504 | } | |
3505 | ||
2c9ede55 | 3506 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3507 | { |
3508 | if (!mode) | |
3509 | return NULL; | |
3510 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3511 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3512 | *mode = 0666; | |
3513 | return NULL; | |
3514 | } | |
3515 | ||
1da177e4 LT |
3516 | static int __init tty_class_init(void) |
3517 | { | |
7fe845d1 | 3518 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3519 | if (IS_ERR(tty_class)) |
3520 | return PTR_ERR(tty_class); | |
e454cea2 | 3521 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3522 | return 0; |
3523 | } | |
3524 | ||
3525 | postcore_initcall(tty_class_init); | |
3526 | ||
3527 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3528 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3529 | |
fbc92a34 KS |
3530 | static ssize_t show_cons_active(struct device *dev, |
3531 | struct device_attribute *attr, char *buf) | |
3532 | { | |
3533 | struct console *cs[16]; | |
3534 | int i = 0; | |
3535 | struct console *c; | |
3536 | ssize_t count = 0; | |
3537 | ||
ac751efa | 3538 | console_lock(); |
a2a6a822 | 3539 | for_each_console(c) { |
fbc92a34 KS |
3540 | if (!c->device) |
3541 | continue; | |
3542 | if (!c->write) | |
3543 | continue; | |
3544 | if ((c->flags & CON_ENABLED) == 0) | |
3545 | continue; | |
3546 | cs[i++] = c; | |
3547 | if (i >= ARRAY_SIZE(cs)) | |
3548 | break; | |
3549 | } | |
723abd87 HR |
3550 | while (i--) { |
3551 | int index = cs[i]->index; | |
3552 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3553 | ||
3554 | /* don't resolve tty0 as some programs depend on it */ | |
3555 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3556 | count += tty_line_name(drv, index, buf + count); | |
3557 | else | |
3558 | count += sprintf(buf + count, "%s%d", | |
3559 | cs[i]->name, cs[i]->index); | |
3560 | ||
3561 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3562 | } | |
ac751efa | 3563 | console_unlock(); |
fbc92a34 KS |
3564 | |
3565 | return count; | |
3566 | } | |
3567 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3568 | ||
3569 | static struct device *consdev; | |
3570 | ||
3571 | void console_sysfs_notify(void) | |
3572 | { | |
3573 | if (consdev) | |
3574 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3575 | } | |
3576 | ||
1da177e4 LT |
3577 | /* |
3578 | * Ok, now we can initialize the rest of the tty devices and can count | |
3579 | * on memory allocations, interrupts etc.. | |
3580 | */ | |
31d1d48e | 3581 | int __init tty_init(void) |
1da177e4 LT |
3582 | { |
3583 | cdev_init(&tty_cdev, &tty_fops); | |
3584 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3585 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3586 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3587 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3588 | |
3589 | cdev_init(&console_cdev, &console_fops); | |
3590 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3591 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3592 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3593 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3594 | "console"); |
fbc92a34 KS |
3595 | if (IS_ERR(consdev)) |
3596 | consdev = NULL; | |
3597 | else | |
a2a6a822 | 3598 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3599 | |
1da177e4 | 3600 | #ifdef CONFIG_VT |
d81ed103 | 3601 | vty_init(&console_fops); |
1da177e4 LT |
3602 | #endif |
3603 | return 0; | |
3604 | } | |
31d1d48e | 3605 |