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 | ||
deb287e7 | 278 | /* Caller must hold tty_lock */ |
1da177e4 LT |
279 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
280 | { | |
281 | #ifdef CHECK_TTY_COUNT | |
282 | struct list_head *p; | |
283 | int count = 0; | |
37bdfb07 | 284 | |
ee2ffa0d | 285 | spin_lock(&tty_files_lock); |
1da177e4 LT |
286 | list_for_each(p, &tty->tty_files) { |
287 | count++; | |
288 | } | |
ee2ffa0d | 289 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
290 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
291 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
292 | tty->link && tty->link->count) | |
293 | count++; | |
294 | if (tty->count != count) { | |
295 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
296 | "!= #fd's(%d) in %s\n", | |
297 | tty->name, tty->count, count, routine); | |
298 | return count; | |
24ec839c | 299 | } |
1da177e4 LT |
300 | #endif |
301 | return 0; | |
302 | } | |
303 | ||
af9b897e AC |
304 | /** |
305 | * get_tty_driver - find device of a tty | |
306 | * @dev_t: device identifier | |
307 | * @index: returns the index of the tty | |
308 | * | |
309 | * This routine returns a tty driver structure, given a device number | |
310 | * and also passes back the index number. | |
311 | * | |
312 | * Locking: caller must hold tty_mutex | |
1da177e4 | 313 | */ |
af9b897e | 314 | |
1da177e4 LT |
315 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
316 | { | |
317 | struct tty_driver *p; | |
318 | ||
319 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
320 | dev_t base = MKDEV(p->major, p->minor_start); | |
321 | if (device < base || device >= base + p->num) | |
322 | continue; | |
323 | *index = device - base; | |
7d7b93c1 | 324 | return tty_driver_kref_get(p); |
1da177e4 LT |
325 | } |
326 | return NULL; | |
327 | } | |
328 | ||
f2d937f3 JW |
329 | #ifdef CONFIG_CONSOLE_POLL |
330 | ||
331 | /** | |
332 | * tty_find_polling_driver - find device of a polled tty | |
333 | * @name: name string to match | |
334 | * @line: pointer to resulting tty line nr | |
335 | * | |
336 | * This routine returns a tty driver structure, given a name | |
337 | * and the condition that the tty driver is capable of polled | |
338 | * operation. | |
339 | */ | |
340 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
341 | { | |
342 | struct tty_driver *p, *res = NULL; | |
343 | int tty_line = 0; | |
0dca0fd2 | 344 | int len; |
5f0878ac | 345 | char *str, *stp; |
f2d937f3 | 346 | |
0dca0fd2 JW |
347 | for (str = name; *str; str++) |
348 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
349 | break; | |
350 | if (!*str) | |
351 | return NULL; | |
352 | ||
353 | len = str - name; | |
354 | tty_line = simple_strtoul(str, &str, 10); | |
355 | ||
f2d937f3 JW |
356 | mutex_lock(&tty_mutex); |
357 | /* Search through the tty devices to look for a match */ | |
358 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
359 | if (strncmp(name, p->name, len) != 0) |
360 | continue; | |
5f0878ac AC |
361 | stp = str; |
362 | if (*stp == ',') | |
363 | stp++; | |
364 | if (*stp == '\0') | |
365 | stp = NULL; | |
f2d937f3 | 366 | |
6eb68d6f | 367 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 368 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 369 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
370 | *line = tty_line; |
371 | break; | |
372 | } | |
373 | } | |
374 | mutex_unlock(&tty_mutex); | |
375 | ||
376 | return res; | |
377 | } | |
378 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
379 | #endif | |
380 | ||
af9b897e AC |
381 | /** |
382 | * tty_check_change - check for POSIX terminal changes | |
383 | * @tty: tty to check | |
384 | * | |
385 | * If we try to write to, or set the state of, a terminal and we're | |
386 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
387 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
388 | * | |
978e595f | 389 | * Locking: ctrl_lock |
1da177e4 | 390 | */ |
af9b897e | 391 | |
37bdfb07 | 392 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 393 | { |
47f86834 AC |
394 | unsigned long flags; |
395 | int ret = 0; | |
396 | ||
1da177e4 LT |
397 | if (current->signal->tty != tty) |
398 | return 0; | |
47f86834 AC |
399 | |
400 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
401 | ||
ab521dc0 EB |
402 | if (!tty->pgrp) { |
403 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 404 | goto out_unlock; |
1da177e4 | 405 | } |
ab521dc0 | 406 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
407 | goto out_unlock; |
408 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 409 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
410 | goto out; |
411 | if (is_current_pgrp_orphaned()) { | |
412 | ret = -EIO; | |
413 | goto out; | |
414 | } | |
040b6362 ON |
415 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
416 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
417 | ret = -ERESTARTSYS; |
418 | out: | |
9ffee4cb AM |
419 | return ret; |
420 | out_unlock: | |
47f86834 AC |
421 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
422 | return ret; | |
1da177e4 LT |
423 | } |
424 | ||
425 | EXPORT_SYMBOL(tty_check_change); | |
426 | ||
37bdfb07 | 427 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
428 | size_t count, loff_t *ppos) |
429 | { | |
430 | return 0; | |
431 | } | |
432 | ||
37bdfb07 | 433 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
434 | size_t count, loff_t *ppos) |
435 | { | |
436 | return -EIO; | |
437 | } | |
438 | ||
439 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 440 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
441 | { |
442 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
443 | } | |
444 | ||
04f378b1 AC |
445 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
446 | unsigned long arg) | |
38ad2ed0 PF |
447 | { |
448 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
449 | } | |
450 | ||
37bdfb07 | 451 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 452 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
453 | { |
454 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
455 | } | |
456 | ||
62322d25 | 457 | static const struct file_operations tty_fops = { |
1da177e4 LT |
458 | .llseek = no_llseek, |
459 | .read = tty_read, | |
460 | .write = tty_write, | |
461 | .poll = tty_poll, | |
04f378b1 | 462 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 463 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
464 | .open = tty_open, |
465 | .release = tty_release, | |
466 | .fasync = tty_fasync, | |
467 | }; | |
468 | ||
62322d25 | 469 | static const struct file_operations console_fops = { |
1da177e4 LT |
470 | .llseek = no_llseek, |
471 | .read = tty_read, | |
472 | .write = redirected_tty_write, | |
473 | .poll = tty_poll, | |
04f378b1 | 474 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 475 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
476 | .open = tty_open, |
477 | .release = tty_release, | |
478 | .fasync = tty_fasync, | |
479 | }; | |
480 | ||
62322d25 | 481 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
482 | .llseek = no_llseek, |
483 | .read = hung_up_tty_read, | |
484 | .write = hung_up_tty_write, | |
485 | .poll = hung_up_tty_poll, | |
04f378b1 | 486 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 487 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
488 | .release = tty_release, |
489 | }; | |
490 | ||
491 | static DEFINE_SPINLOCK(redirect_lock); | |
492 | static struct file *redirect; | |
493 | ||
11d9befd PH |
494 | |
495 | void proc_clear_tty(struct task_struct *p) | |
496 | { | |
497 | unsigned long flags; | |
498 | struct tty_struct *tty; | |
499 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
500 | tty = p->signal->tty; | |
501 | p->signal->tty = NULL; | |
502 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
503 | tty_kref_put(tty); | |
504 | } | |
505 | ||
2c411c11 PH |
506 | /** |
507 | * proc_set_tty - set the controlling terminal | |
508 | * | |
509 | * Only callable by the session leader and only if it does not already have | |
510 | * a controlling terminal. | |
511 | * | |
e218eb32 PH |
512 | * Caller must hold: tty_lock() |
513 | * a readlock on tasklist_lock | |
2c411c11 PH |
514 | * sighand lock |
515 | */ | |
bce65f18 | 516 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 517 | { |
ae28fa72 PH |
518 | unsigned long flags; |
519 | ||
ae28fa72 | 520 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
521 | /* |
522 | * The session and fg pgrp references will be non-NULL if | |
523 | * tiocsctty() is stealing the controlling tty | |
524 | */ | |
ae28fa72 PH |
525 | put_pid(tty->session); |
526 | put_pid(tty->pgrp); | |
527 | tty->pgrp = get_pid(task_pgrp(current)); | |
528 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
529 | tty->session = get_pid(task_session(current)); | |
530 | if (current->signal->tty) { | |
531 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
532 | tty_kref_put(current->signal->tty); | |
11d9befd | 533 | } |
bce65f18 PH |
534 | put_pid(current->signal->tty_old_pgrp); |
535 | current->signal->tty = tty_kref_get(tty); | |
536 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
537 | } |
538 | ||
bce65f18 | 539 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 540 | { |
bce65f18 PH |
541 | spin_lock_irq(¤t->sighand->siglock); |
542 | __proc_set_tty(tty); | |
543 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
544 | } |
545 | ||
546 | struct tty_struct *get_current_tty(void) | |
547 | { | |
548 | struct tty_struct *tty; | |
549 | unsigned long flags; | |
550 | ||
551 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
552 | tty = tty_kref_get(current->signal->tty); | |
553 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
554 | return tty; | |
555 | } | |
556 | EXPORT_SYMBOL_GPL(get_current_tty); | |
557 | ||
558 | static void session_clear_tty(struct pid *session) | |
559 | { | |
560 | struct task_struct *p; | |
561 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
562 | proc_clear_tty(p); | |
563 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
564 | } | |
565 | ||
1da177e4 LT |
566 | /** |
567 | * tty_wakeup - request more data | |
568 | * @tty: terminal | |
569 | * | |
570 | * Internal and external helper for wakeups of tty. This function | |
571 | * informs the line discipline if present that the driver is ready | |
572 | * to receive more output data. | |
573 | */ | |
37bdfb07 | 574 | |
1da177e4 LT |
575 | void tty_wakeup(struct tty_struct *tty) |
576 | { | |
577 | struct tty_ldisc *ld; | |
37bdfb07 | 578 | |
1da177e4 LT |
579 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
580 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 581 | if (ld) { |
a352def2 AC |
582 | if (ld->ops->write_wakeup) |
583 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
584 | tty_ldisc_deref(ld); |
585 | } | |
586 | } | |
4b19449d | 587 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
588 | } |
589 | ||
590 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
591 | ||
ea648a47 PH |
592 | /** |
593 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
594 | * @tty controlling tty |
595 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 596 | * |
f91e2590 PH |
597 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
598 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
599 | * |
600 | * Returns the number of processes in the session with this tty | |
601 | * as their controlling terminal. This value is used to drop | |
602 | * tty references for those processes. | |
603 | */ | |
f91e2590 | 604 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
605 | { |
606 | struct task_struct *p; | |
ea648a47 | 607 | int refs = 0; |
f91e2590 | 608 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
609 | |
610 | read_lock(&tasklist_lock); | |
611 | if (tty->session) { | |
612 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
613 | spin_lock_irq(&p->sighand->siglock); | |
614 | if (p->signal->tty == tty) { | |
615 | p->signal->tty = NULL; | |
616 | /* We defer the dereferences outside fo | |
617 | the tasklist lock */ | |
618 | refs++; | |
619 | } | |
620 | if (!p->signal->leader) { | |
621 | spin_unlock_irq(&p->sighand->siglock); | |
622 | continue; | |
623 | } | |
624 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
625 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
626 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 627 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 628 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
629 | if (tty->pgrp) |
630 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 631 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
632 | spin_unlock_irq(&p->sighand->siglock); |
633 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
634 | } | |
635 | read_unlock(&tasklist_lock); | |
636 | ||
f91e2590 PH |
637 | if (tty_pgrp) { |
638 | if (exit_session) | |
639 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
640 | put_pid(tty_pgrp); | |
641 | } | |
642 | ||
ea648a47 PH |
643 | return refs; |
644 | } | |
645 | ||
af9b897e | 646 | /** |
11dbf203 | 647 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 648 | * @work: tty device |
af9b897e | 649 | * |
ef4f527c | 650 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
651 | * synchronous but doesn't hold any locks, so we need to make sure we |
652 | * have the appropriate locks for what we're doing. | |
653 | * | |
654 | * The hangup event clears any pending redirections onto the hung up | |
655 | * device. It ensures future writes will error and it does the needed | |
656 | * line discipline hangup and signal delivery. The tty object itself | |
657 | * remains intact. | |
658 | * | |
659 | * Locking: | |
ec79d605 | 660 | * BTM |
24ec839c PZ |
661 | * redirect lock for undoing redirection |
662 | * file list lock for manipulating list of ttys | |
137084bb | 663 | * tty_ldiscs_lock from called functions |
6a1c0680 | 664 | * termios_rwsem resetting termios data |
24ec839c PZ |
665 | * tasklist_lock to walk task list for hangup event |
666 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 667 | */ |
f91e2590 | 668 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 669 | { |
37bdfb07 | 670 | struct file *cons_filp = NULL; |
1da177e4 | 671 | struct file *filp, *f = NULL; |
d996b62a | 672 | struct tty_file_private *priv; |
1da177e4 | 673 | int closecount = 0, n; |
ea648a47 | 674 | int refs; |
1da177e4 LT |
675 | |
676 | if (!tty) | |
677 | return; | |
678 | ||
1da177e4 LT |
679 | |
680 | spin_lock(&redirect_lock); | |
d996b62a | 681 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
682 | f = redirect; |
683 | redirect = NULL; | |
684 | } | |
685 | spin_unlock(&redirect_lock); | |
37bdfb07 | 686 | |
89c8d91e | 687 | tty_lock(tty); |
11dbf203 | 688 | |
cb50e523 PH |
689 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
690 | tty_unlock(tty); | |
691 | return; | |
692 | } | |
693 | ||
ec79d605 AB |
694 | /* inuse_filps is protected by the single tty lock, |
695 | this really needs to change if we want to flush the | |
696 | workqueue with the lock held */ | |
11dbf203 | 697 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 698 | |
ee2ffa0d | 699 | spin_lock(&tty_files_lock); |
1da177e4 | 700 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
701 | list_for_each_entry(priv, &tty->tty_files, list) { |
702 | filp = priv->file; | |
1da177e4 LT |
703 | if (filp->f_op->write == redirected_tty_write) |
704 | cons_filp = filp; | |
705 | if (filp->f_op->write != tty_write) | |
706 | continue; | |
707 | closecount++; | |
ec79d605 | 708 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
709 | filp->f_op = &hung_up_tty_fops; |
710 | } | |
ee2ffa0d | 711 | spin_unlock(&tty_files_lock); |
37bdfb07 | 712 | |
25fdf243 PH |
713 | refs = tty_signal_session_leader(tty, exit_session); |
714 | /* Account for the p->signal references we killed */ | |
715 | while (refs--) | |
716 | tty_kref_put(tty); | |
717 | ||
c65c9bc3 | 718 | tty_ldisc_hangup(tty); |
37bdfb07 | 719 | |
20cc225b | 720 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 721 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 722 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
723 | put_pid(tty->session); |
724 | put_pid(tty->pgrp); | |
ab521dc0 EB |
725 | tty->session = NULL; |
726 | tty->pgrp = NULL; | |
1da177e4 | 727 | tty->ctrl_status = 0; |
20cc225b | 728 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 729 | |
1da177e4 | 730 | /* |
37bdfb07 AC |
731 | * If one of the devices matches a console pointer, we |
732 | * cannot just call hangup() because that will cause | |
733 | * tty->count and state->count to go out of sync. | |
734 | * So we just call close() the right number of times. | |
1da177e4 LT |
735 | */ |
736 | if (cons_filp) { | |
f34d7a5b | 737 | if (tty->ops->close) |
1da177e4 | 738 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
739 | tty->ops->close(tty, cons_filp); |
740 | } else if (tty->ops->hangup) | |
7c6d340f | 741 | tty->ops->hangup(tty); |
37bdfb07 AC |
742 | /* |
743 | * We don't want to have driver/ldisc interactions beyond | |
744 | * the ones we did here. The driver layer expects no | |
745 | * calls after ->hangup() from the ldisc side. However we | |
746 | * can't yet guarantee all that. | |
747 | */ | |
1da177e4 | 748 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 749 | tty_unlock(tty); |
11dbf203 | 750 | |
1da177e4 LT |
751 | if (f) |
752 | fput(f); | |
753 | } | |
754 | ||
ddcd9fb6 AB |
755 | static void do_tty_hangup(struct work_struct *work) |
756 | { | |
757 | struct tty_struct *tty = | |
758 | container_of(work, struct tty_struct, hangup_work); | |
759 | ||
f91e2590 | 760 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
761 | } |
762 | ||
af9b897e AC |
763 | /** |
764 | * tty_hangup - trigger a hangup event | |
765 | * @tty: tty to hangup | |
766 | * | |
767 | * A carrier loss (virtual or otherwise) has occurred on this like | |
768 | * schedule a hangup sequence to run after this event. | |
769 | */ | |
770 | ||
37bdfb07 | 771 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
772 | { |
773 | #ifdef TTY_DEBUG_HANGUP | |
774 | char buf[64]; | |
1da177e4 LT |
775 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
776 | #endif | |
777 | schedule_work(&tty->hangup_work); | |
778 | } | |
779 | ||
780 | EXPORT_SYMBOL(tty_hangup); | |
781 | ||
af9b897e AC |
782 | /** |
783 | * tty_vhangup - process vhangup | |
784 | * @tty: tty to hangup | |
785 | * | |
786 | * The user has asked via system call for the terminal to be hung up. | |
787 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 788 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
789 | */ |
790 | ||
37bdfb07 | 791 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
792 | { |
793 | #ifdef TTY_DEBUG_HANGUP | |
794 | char buf[64]; | |
795 | ||
796 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
797 | #endif | |
f91e2590 | 798 | __tty_hangup(tty, 0); |
1da177e4 | 799 | } |
37bdfb07 | 800 | |
1da177e4 LT |
801 | EXPORT_SYMBOL(tty_vhangup); |
802 | ||
11dbf203 | 803 | |
2cb5998b AC |
804 | /** |
805 | * tty_vhangup_self - process vhangup for own ctty | |
806 | * | |
807 | * Perform a vhangup on the current controlling tty | |
808 | */ | |
809 | ||
810 | void tty_vhangup_self(void) | |
811 | { | |
812 | struct tty_struct *tty; | |
813 | ||
2cb5998b AC |
814 | tty = get_current_tty(); |
815 | if (tty) { | |
816 | tty_vhangup(tty); | |
817 | tty_kref_put(tty); | |
818 | } | |
2cb5998b AC |
819 | } |
820 | ||
f91e2590 PH |
821 | /** |
822 | * tty_vhangup_session - hangup session leader exit | |
823 | * @tty: tty to hangup | |
824 | * | |
825 | * The session leader is exiting and hanging up its controlling terminal. | |
826 | * Every process in the foreground process group is signalled SIGHUP. | |
827 | * | |
828 | * We do this synchronously so that when the syscall returns the process | |
829 | * is complete. That guarantee is necessary for security reasons. | |
830 | */ | |
831 | ||
44a459fd | 832 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 PH |
833 | { |
834 | #ifdef TTY_DEBUG_HANGUP | |
835 | char buf[64]; | |
836 | ||
837 | printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty, buf)); | |
838 | #endif | |
839 | __tty_hangup(tty, 1); | |
840 | } | |
841 | ||
af9b897e AC |
842 | /** |
843 | * tty_hung_up_p - was tty hung up | |
844 | * @filp: file pointer of tty | |
845 | * | |
846 | * Return true if the tty has been subject to a vhangup or a carrier | |
847 | * loss | |
848 | */ | |
849 | ||
37bdfb07 | 850 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
851 | { |
852 | return (filp->f_op == &hung_up_tty_fops); | |
853 | } | |
854 | ||
855 | EXPORT_SYMBOL(tty_hung_up_p); | |
856 | ||
af9b897e AC |
857 | /** |
858 | * disassociate_ctty - disconnect controlling tty | |
859 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 860 | * |
af9b897e AC |
861 | * This function is typically called only by the session leader, when |
862 | * it wants to disassociate itself from its controlling tty. | |
863 | * | |
864 | * It performs the following functions: | |
1da177e4 LT |
865 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
866 | * (2) Clears the tty from being controlling the session | |
867 | * (3) Clears the controlling tty for all processes in the | |
868 | * session group. | |
869 | * | |
af9b897e AC |
870 | * The argument on_exit is set to 1 if called when a process is |
871 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
872 | * | |
24ec839c | 873 | * Locking: |
ec79d605 AB |
874 | * BTM is taken for hysterical raisins, and held when |
875 | * called from no_tty(). | |
24ec839c PZ |
876 | * tty_mutex is taken to protect tty |
877 | * ->siglock is taken to protect ->signal/->sighand | |
878 | * tasklist_lock is taken to walk process list for sessions | |
879 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 880 | */ |
af9b897e | 881 | |
1da177e4 LT |
882 | void disassociate_ctty(int on_exit) |
883 | { | |
884 | struct tty_struct *tty; | |
1da177e4 | 885 | |
5ec93d11 AC |
886 | if (!current->signal->leader) |
887 | return; | |
1da177e4 | 888 | |
24ec839c | 889 | tty = get_current_tty(); |
1da177e4 | 890 | if (tty) { |
f91e2590 PH |
891 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
892 | tty_vhangup_session(tty); | |
893 | } else { | |
894 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
895 | if (tty_pgrp) { | |
896 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
897 | if (!on_exit) |
898 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
899 | put_pid(tty_pgrp); |
900 | } | |
1411dc4a | 901 | } |
f91e2590 PH |
902 | tty_kref_put(tty); |
903 | ||
680a9671 | 904 | } else if (on_exit) { |
ab521dc0 | 905 | struct pid *old_pgrp; |
680a9671 EB |
906 | spin_lock_irq(¤t->sighand->siglock); |
907 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 908 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 909 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 910 | if (old_pgrp) { |
ab521dc0 EB |
911 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
912 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
913 | put_pid(old_pgrp); | |
1da177e4 | 914 | } |
1da177e4 LT |
915 | return; |
916 | } | |
1da177e4 | 917 | |
24ec839c | 918 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 919 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 920 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 921 | |
c70dbb1e | 922 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 923 | if (tty) { |
47f86834 AC |
924 | unsigned long flags; |
925 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
926 | put_pid(tty->session); |
927 | put_pid(tty->pgrp); | |
928 | tty->session = NULL; | |
929 | tty->pgrp = NULL; | |
47f86834 | 930 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 931 | tty_kref_put(tty); |
24ec839c PZ |
932 | } else { |
933 | #ifdef TTY_DEBUG_HANGUP | |
934 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
935 | " = NULL", tty); | |
936 | #endif | |
937 | } | |
1da177e4 | 938 | |
c70dbb1e | 939 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
940 | /* Now clear signal->tty under the lock */ |
941 | read_lock(&tasklist_lock); | |
ab521dc0 | 942 | session_clear_tty(task_session(current)); |
1da177e4 | 943 | read_unlock(&tasklist_lock); |
1da177e4 LT |
944 | } |
945 | ||
98a27ba4 EB |
946 | /** |
947 | * | |
948 | * no_tty - Ensure the current process does not have a controlling tty | |
949 | */ | |
950 | void no_tty(void) | |
951 | { | |
3af502b9 AC |
952 | /* FIXME: Review locking here. The tty_lock never covered any race |
953 | between a new association and proc_clear_tty but possible we need | |
954 | to protect against this anyway */ | |
98a27ba4 | 955 | struct task_struct *tsk = current; |
5ec93d11 | 956 | disassociate_ctty(0); |
98a27ba4 EB |
957 | proc_clear_tty(tsk); |
958 | } | |
959 | ||
af9b897e AC |
960 | |
961 | /** | |
beb7dd86 | 962 | * stop_tty - propagate flow control |
af9b897e AC |
963 | * @tty: tty to stop |
964 | * | |
01adc807 | 965 | * Perform flow control to the driver. May be called |
af9b897e AC |
966 | * on an already stopped device and will not re-call the driver |
967 | * method. | |
968 | * | |
969 | * This functionality is used by both the line disciplines for | |
970 | * halting incoming flow and by the driver. It may therefore be | |
971 | * called from any context, may be under the tty atomic_write_lock | |
972 | * but not always. | |
973 | * | |
974 | * Locking: | |
f9e053dc | 975 | * flow_lock |
af9b897e AC |
976 | */ |
977 | ||
f9e053dc | 978 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 979 | { |
f9e053dc | 980 | if (tty->stopped) |
1da177e4 LT |
981 | return; |
982 | tty->stopped = 1; | |
f34d7a5b | 983 | if (tty->ops->stop) |
c961bfb1 | 984 | tty->ops->stop(tty); |
1da177e4 LT |
985 | } |
986 | ||
f9e053dc PH |
987 | void stop_tty(struct tty_struct *tty) |
988 | { | |
989 | unsigned long flags; | |
990 | ||
991 | spin_lock_irqsave(&tty->flow_lock, flags); | |
992 | __stop_tty(tty); | |
993 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
994 | } | |
1da177e4 LT |
995 | EXPORT_SYMBOL(stop_tty); |
996 | ||
af9b897e | 997 | /** |
beb7dd86 | 998 | * start_tty - propagate flow control |
af9b897e AC |
999 | * @tty: tty to start |
1000 | * | |
01adc807 PH |
1001 | * Start a tty that has been stopped if at all possible. If this |
1002 | * tty was previous stopped and is now being started, the driver | |
1003 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1004 | * |
1005 | * Locking: | |
f9e053dc | 1006 | * flow_lock |
af9b897e AC |
1007 | */ |
1008 | ||
f9e053dc | 1009 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1010 | { |
f9e053dc | 1011 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1012 | return; |
1013 | tty->stopped = 0; | |
f34d7a5b | 1014 | if (tty->ops->start) |
c961bfb1 | 1015 | tty->ops->start(tty); |
1da177e4 | 1016 | tty_wakeup(tty); |
1da177e4 LT |
1017 | } |
1018 | ||
f9e053dc PH |
1019 | void start_tty(struct tty_struct *tty) |
1020 | { | |
1021 | unsigned long flags; | |
1022 | ||
1023 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1024 | __start_tty(tty); | |
1025 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1026 | } | |
1da177e4 LT |
1027 | EXPORT_SYMBOL(start_tty); |
1028 | ||
b0b88565 | 1029 | /* We limit tty time update visibility to every 8 seconds or so. */ |
37b7f3c7 JS |
1030 | static void tty_update_time(struct timespec *time) |
1031 | { | |
b0b88565 | 1032 | unsigned long sec = get_seconds() & ~7; |
37b7f3c7 JS |
1033 | if ((long)(sec - time->tv_sec) > 0) |
1034 | time->tv_sec = sec; | |
1035 | } | |
1036 | ||
af9b897e AC |
1037 | /** |
1038 | * tty_read - read method for tty device files | |
1039 | * @file: pointer to tty file | |
1040 | * @buf: user buffer | |
1041 | * @count: size of user buffer | |
1042 | * @ppos: unused | |
1043 | * | |
1044 | * Perform the read system call function on this terminal device. Checks | |
1045 | * for hung up devices before calling the line discipline method. | |
1046 | * | |
1047 | * Locking: | |
47f86834 AC |
1048 | * Locks the line discipline internally while needed. Multiple |
1049 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1050 | */ |
1051 | ||
37bdfb07 | 1052 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1053 | loff_t *ppos) |
1054 | { | |
1055 | int i; | |
37b7f3c7 | 1056 | struct inode *inode = file_inode(file); |
d996b62a | 1057 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1058 | struct tty_ldisc *ld; |
1059 | ||
37b7f3c7 | 1060 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1061 | return -EIO; |
1062 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1063 | return -EIO; | |
1064 | ||
1065 | /* We want to wait for the line discipline to sort out in this | |
1066 | situation */ | |
1067 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 1068 | if (ld->ops->read) |
c961bfb1 | 1069 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1070 | else |
1071 | i = -EIO; | |
1072 | tty_ldisc_deref(ld); | |
b0de59b5 | 1073 | |
37b7f3c7 JS |
1074 | if (i > 0) |
1075 | tty_update_time(&inode->i_atime); | |
1076 | ||
1da177e4 LT |
1077 | return i; |
1078 | } | |
1079 | ||
136d5258 | 1080 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1081 | { |
1082 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1083 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1084 | } |
1085 | ||
136d5258 | 1086 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1087 | { |
1088 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1089 | if (ndelay) | |
1090 | return -EAGAIN; | |
1091 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1092 | return -ERESTARTSYS; | |
1093 | } | |
1094 | return 0; | |
1095 | } | |
1096 | ||
1da177e4 LT |
1097 | /* |
1098 | * Split writes up in sane blocksizes to avoid | |
1099 | * denial-of-service type attacks | |
1100 | */ | |
1101 | static inline ssize_t do_tty_write( | |
1102 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1103 | struct tty_struct *tty, | |
1104 | struct file *file, | |
1105 | const char __user *buf, | |
1106 | size_t count) | |
1107 | { | |
9c1729db | 1108 | ssize_t ret, written = 0; |
1da177e4 | 1109 | unsigned int chunk; |
37bdfb07 | 1110 | |
9c1729db AC |
1111 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1112 | if (ret < 0) | |
1113 | return ret; | |
1da177e4 LT |
1114 | |
1115 | /* | |
1116 | * We chunk up writes into a temporary buffer. This | |
1117 | * simplifies low-level drivers immensely, since they | |
1118 | * don't have locking issues and user mode accesses. | |
1119 | * | |
1120 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1121 | * big chunk-size.. | |
1122 | * | |
1123 | * The default chunk-size is 2kB, because the NTTY | |
1124 | * layer has problems with bigger chunks. It will | |
1125 | * claim to be able to handle more characters than | |
1126 | * it actually does. | |
af9b897e AC |
1127 | * |
1128 | * FIXME: This can probably go away now except that 64K chunks | |
1129 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1130 | */ |
1131 | chunk = 2048; | |
1132 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1133 | chunk = 65536; | |
1134 | if (count < chunk) | |
1135 | chunk = count; | |
1136 | ||
70522e12 | 1137 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1138 | if (tty->write_cnt < chunk) { |
402fda92 | 1139 | unsigned char *buf_chunk; |
1da177e4 LT |
1140 | |
1141 | if (chunk < 1024) | |
1142 | chunk = 1024; | |
1143 | ||
402fda92 JW |
1144 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1145 | if (!buf_chunk) { | |
9c1729db AC |
1146 | ret = -ENOMEM; |
1147 | goto out; | |
1da177e4 LT |
1148 | } |
1149 | kfree(tty->write_buf); | |
1150 | tty->write_cnt = chunk; | |
402fda92 | 1151 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1152 | } |
1153 | ||
1154 | /* Do the write .. */ | |
1155 | for (;;) { | |
1156 | size_t size = count; | |
1157 | if (size > chunk) | |
1158 | size = chunk; | |
1159 | ret = -EFAULT; | |
1160 | if (copy_from_user(tty->write_buf, buf, size)) | |
1161 | break; | |
1da177e4 | 1162 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1163 | if (ret <= 0) |
1164 | break; | |
1165 | written += ret; | |
1166 | buf += ret; | |
1167 | count -= ret; | |
1168 | if (!count) | |
1169 | break; | |
1170 | ret = -ERESTARTSYS; | |
1171 | if (signal_pending(current)) | |
1172 | break; | |
1173 | cond_resched(); | |
1174 | } | |
37b7f3c7 JS |
1175 | if (written) { |
1176 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1177 | ret = written; |
37b7f3c7 | 1178 | } |
9c1729db AC |
1179 | out: |
1180 | tty_write_unlock(tty); | |
1da177e4 LT |
1181 | return ret; |
1182 | } | |
1183 | ||
95f9bfc6 AC |
1184 | /** |
1185 | * tty_write_message - write a message to a certain tty, not just the console. | |
1186 | * @tty: the destination tty_struct | |
1187 | * @msg: the message to write | |
1188 | * | |
1189 | * This is used for messages that need to be redirected to a specific tty. | |
1190 | * We don't put it into the syslog queue right now maybe in the future if | |
1191 | * really needed. | |
1192 | * | |
ec79d605 | 1193 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1194 | */ |
1195 | ||
1196 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1197 | { | |
95f9bfc6 AC |
1198 | if (tty) { |
1199 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1200 | tty_lock(tty); |
04980706 | 1201 | if (tty->ops->write && tty->count > 0) { |
89c8d91e | 1202 | tty_unlock(tty); |
95f9bfc6 | 1203 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1204 | } else |
89c8d91e | 1205 | tty_unlock(tty); |
95f9bfc6 AC |
1206 | tty_write_unlock(tty); |
1207 | } | |
95f9bfc6 AC |
1208 | return; |
1209 | } | |
1210 | ||
1da177e4 | 1211 | |
af9b897e AC |
1212 | /** |
1213 | * tty_write - write method for tty device file | |
1214 | * @file: tty file pointer | |
1215 | * @buf: user data to write | |
1216 | * @count: bytes to write | |
1217 | * @ppos: unused | |
1218 | * | |
1219 | * Write data to a tty device via the line discipline. | |
1220 | * | |
1221 | * Locking: | |
1222 | * Locks the line discipline as required | |
1223 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1224 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1225 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1226 | */ |
1227 | ||
37bdfb07 AC |
1228 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1229 | size_t count, loff_t *ppos) | |
1da177e4 | 1230 | { |
d996b62a NP |
1231 | struct tty_struct *tty = file_tty(file); |
1232 | struct tty_ldisc *ld; | |
1da177e4 | 1233 | ssize_t ret; |
37bdfb07 | 1234 | |
6131ffaa | 1235 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1236 | return -EIO; |
f34d7a5b | 1237 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1238 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1239 | return -EIO; | |
f34d7a5b AC |
1240 | /* Short term debug to catch buggy drivers */ |
1241 | if (tty->ops->write_room == NULL) | |
1242 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1243 | tty->driver->name); | |
37bdfb07 | 1244 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1245 | if (!ld->ops->write) |
1da177e4 LT |
1246 | ret = -EIO; |
1247 | else | |
a352def2 | 1248 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1249 | tty_ldisc_deref(ld); |
1250 | return ret; | |
1251 | } | |
1252 | ||
37bdfb07 AC |
1253 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1254 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1255 | { |
1256 | struct file *p = NULL; | |
1257 | ||
1258 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1259 | if (redirect) |
1260 | p = get_file(redirect); | |
1da177e4 LT |
1261 | spin_unlock(&redirect_lock); |
1262 | ||
1263 | if (p) { | |
1264 | ssize_t res; | |
1265 | res = vfs_write(p, buf, count, &p->f_pos); | |
1266 | fput(p); | |
1267 | return res; | |
1268 | } | |
1da177e4 LT |
1269 | return tty_write(file, buf, count, ppos); |
1270 | } | |
1271 | ||
136d5258 PH |
1272 | /** |
1273 | * tty_send_xchar - send priority character | |
1274 | * | |
1275 | * Send a high priority character to the tty even if stopped | |
1276 | * | |
1277 | * Locking: none for xchar method, write ordering for write method. | |
1278 | */ | |
1279 | ||
1280 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1281 | { | |
1282 | int was_stopped = tty->stopped; | |
1283 | ||
1284 | if (tty->ops->send_xchar) { | |
1285 | tty->ops->send_xchar(tty, ch); | |
1286 | return 0; | |
1287 | } | |
1288 | ||
1289 | if (tty_write_lock(tty, 0) < 0) | |
1290 | return -ERESTARTSYS; | |
1291 | ||
1292 | if (was_stopped) | |
1293 | start_tty(tty); | |
1294 | tty->ops->write(tty, &ch, 1); | |
1295 | if (was_stopped) | |
1296 | stop_tty(tty); | |
1297 | tty_write_unlock(tty); | |
1298 | return 0; | |
1299 | } | |
1300 | ||
1da177e4 LT |
1301 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1302 | ||
af9b897e AC |
1303 | /** |
1304 | * pty_line_name - generate name for a pty | |
1305 | * @driver: the tty driver in use | |
1306 | * @index: the minor number | |
1307 | * @p: output buffer of at least 6 bytes | |
1308 | * | |
1309 | * Generate a name from a driver reference and write it to the output | |
1310 | * buffer. | |
1311 | * | |
1312 | * Locking: None | |
1313 | */ | |
1314 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1315 | { |
1316 | int i = index + driver->name_base; | |
1317 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1318 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1319 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1320 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1321 | } |
1322 | ||
af9b897e | 1323 | /** |
8b0a88d5 | 1324 | * tty_line_name - generate name for a tty |
af9b897e AC |
1325 | * @driver: the tty driver in use |
1326 | * @index: the minor number | |
1327 | * @p: output buffer of at least 7 bytes | |
1328 | * | |
1329 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1330 | * buffer. |
af9b897e AC |
1331 | * |
1332 | * Locking: None | |
1333 | */ | |
723abd87 | 1334 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1335 | { |
0019b408 | 1336 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1337 | return sprintf(p, "%s", driver->name); |
0019b408 | 1338 | else |
723abd87 HR |
1339 | return sprintf(p, "%s%d", driver->name, |
1340 | index + driver->name_base); | |
1da177e4 LT |
1341 | } |
1342 | ||
99f1fe18 AC |
1343 | /** |
1344 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1345 | * @driver: the driver for the tty | |
1346 | * @idx: the minor number | |
23499705 | 1347 | * |
aa3cb814 PH |
1348 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1349 | * driver lookup() method returns an error. | |
23499705 | 1350 | * |
aa3cb814 | 1351 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1352 | */ |
a47d545f | 1353 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1354 | struct inode *inode, int idx) |
23499705 | 1355 | { |
aa3cb814 PH |
1356 | struct tty_struct *tty; |
1357 | ||
99f1fe18 | 1358 | if (driver->ops->lookup) |
aa3cb814 PH |
1359 | tty = driver->ops->lookup(driver, inode, idx); |
1360 | else | |
1361 | tty = driver->ttys[idx]; | |
23499705 | 1362 | |
aa3cb814 PH |
1363 | if (!IS_ERR(tty)) |
1364 | tty_kref_get(tty); | |
1365 | return tty; | |
23499705 SB |
1366 | } |
1367 | ||
bf970ee4 AC |
1368 | /** |
1369 | * tty_init_termios - helper for termios setup | |
1370 | * @tty: the tty to set up | |
1371 | * | |
1372 | * Initialise the termios structures for this tty. Thus runs under | |
1373 | * the tty_mutex currently so we can be relaxed about ordering. | |
1374 | */ | |
1375 | ||
1376 | int tty_init_termios(struct tty_struct *tty) | |
1377 | { | |
fe6e29fd | 1378 | struct ktermios *tp; |
bf970ee4 AC |
1379 | int idx = tty->index; |
1380 | ||
36b3c070 AC |
1381 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1382 | tty->termios = tty->driver->init_termios; | |
1383 | else { | |
1384 | /* Check for lazy saved data */ | |
1385 | tp = tty->driver->termios[idx]; | |
1386 | if (tp != NULL) | |
1387 | tty->termios = *tp; | |
1388 | else | |
1389 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1390 | } |
bf970ee4 | 1391 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1392 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1393 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
1394 | return 0; |
1395 | } | |
fe1ae7fd | 1396 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1397 | |
66d450e8 JS |
1398 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1399 | { | |
1400 | int ret = tty_init_termios(tty); | |
1401 | if (ret) | |
1402 | return ret; | |
1403 | ||
1404 | tty_driver_kref_get(driver); | |
1405 | tty->count++; | |
1406 | driver->ttys[tty->index] = tty; | |
1407 | return 0; | |
1408 | } | |
1409 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1410 | ||
99f1fe18 | 1411 | /** |
8b0a88d5 AC |
1412 | * tty_driver_install_tty() - install a tty entry in the driver |
1413 | * @driver: the driver for the tty | |
1414 | * @tty: the tty | |
1415 | * | |
1416 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1417 | * will be set by the time this is called. This method is responsible |
1418 | * for ensuring any need additional structures are allocated and | |
1419 | * configured. | |
8b0a88d5 AC |
1420 | * |
1421 | * Locking: tty_mutex for now | |
1422 | */ | |
1423 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1424 | struct tty_struct *tty) | |
1425 | { | |
66d450e8 JS |
1426 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1427 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1428 | } |
1429 | ||
1430 | /** | |
1431 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1432 | * @driver: the driver for the tty | |
1433 | * @idx: the minor number | |
1434 | * | |
1435 | * Remvoe a tty object from the driver tables. The tty->index field | |
1436 | * will be set by the time this is called. | |
1437 | * | |
1438 | * Locking: tty_mutex for now | |
1439 | */ | |
24d406a6 | 1440 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1441 | { |
1442 | if (driver->ops->remove) | |
1443 | driver->ops->remove(driver, tty); | |
1444 | else | |
1445 | driver->ttys[tty->index] = NULL; | |
1446 | } | |
1447 | ||
1448 | /* | |
1449 | * tty_reopen() - fast re-open of an open tty | |
1450 | * @tty - the tty to open | |
23499705 | 1451 | * |
99f1fe18 | 1452 | * Return 0 on success, -errno on error. |
5d93e748 | 1453 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1454 | * |
5d93e748 | 1455 | * Locking: Caller must hold tty_lock |
23499705 | 1456 | */ |
99f1fe18 | 1457 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1458 | { |
1459 | struct tty_driver *driver = tty->driver; | |
1460 | ||
216030ec | 1461 | if (!tty->count) |
23499705 SB |
1462 | return -EIO; |
1463 | ||
1464 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
5d93e748 PH |
1465 | driver->subtype == PTY_TYPE_MASTER) |
1466 | return -EIO; | |
23499705 | 1467 | |
23499705 | 1468 | tty->count++; |
23499705 | 1469 | |
36697529 | 1470 | WARN_ON(!tty->ldisc); |
23499705 SB |
1471 | |
1472 | return 0; | |
1473 | } | |
1474 | ||
af9b897e | 1475 | /** |
d81ed103 | 1476 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1477 | * @driver: tty driver we are opening a device on |
1478 | * @idx: device index | |
15582d36 | 1479 | * @ret_tty: returned tty structure |
af9b897e AC |
1480 | * |
1481 | * Prepare a tty device. This may not be a "new" clean device but | |
1482 | * could also be an active device. The pty drivers require special | |
1483 | * handling because of this. | |
1484 | * | |
1485 | * Locking: | |
1486 | * The function is called under the tty_mutex, which | |
1487 | * protects us from the tty struct or driver itself going away. | |
1488 | * | |
1489 | * On exit the tty device has the line discipline attached and | |
1490 | * a reference count of 1. If a pair was created for pty/tty use | |
1491 | * and the other was a pty master then it too has a reference count of 1. | |
1492 | * | |
1da177e4 | 1493 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1494 | * failed open. The new code protects the open with a mutex, so it's |
1495 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1496 | * relaxed for the (most common) case of reopening a tty. |
1497 | */ | |
af9b897e | 1498 | |
593a27c4 | 1499 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1500 | { |
bf970ee4 | 1501 | struct tty_struct *tty; |
73ec06fc | 1502 | int retval; |
1da177e4 | 1503 | |
1da177e4 LT |
1504 | /* |
1505 | * First time open is complex, especially for PTY devices. | |
1506 | * This code guarantees that either everything succeeds and the | |
1507 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1508 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1509 | * and locked termios may be retained.) |
1510 | */ | |
1511 | ||
73ec06fc AC |
1512 | if (!try_module_get(driver->owner)) |
1513 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1514 | |
2c964a2f | 1515 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1516 | if (!tty) { |
1517 | retval = -ENOMEM; | |
1518 | goto err_module_put; | |
1519 | } | |
1da177e4 | 1520 | |
89c8d91e | 1521 | tty_lock(tty); |
73ec06fc | 1522 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1523 | if (retval < 0) |
a9dccddb | 1524 | goto err_deinit_tty; |
8b0a88d5 | 1525 | |
04831dc1 JS |
1526 | if (!tty->port) |
1527 | tty->port = driver->ports[idx]; | |
1528 | ||
5d4121c0 JS |
1529 | WARN_RATELIMIT(!tty->port, |
1530 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1531 | __func__, tty->driver->name); | |
1532 | ||
967fab69 JS |
1533 | tty->port->itty = tty; |
1534 | ||
37bdfb07 | 1535 | /* |
1da177e4 | 1536 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1537 | * If we fail here just call release_tty to clean up. No need |
1538 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1539 | */ |
bf970ee4 | 1540 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1541 | if (retval) |
d5543503 | 1542 | goto err_release_tty; |
89c8d91e | 1543 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1544 | return tty; |
1da177e4 | 1545 | |
a9dccddb | 1546 | err_deinit_tty: |
89c8d91e | 1547 | tty_unlock(tty); |
a9dccddb | 1548 | deinitialize_tty_struct(tty); |
d5543503 JS |
1549 | free_tty_struct(tty); |
1550 | err_module_put: | |
1da177e4 | 1551 | module_put(driver->owner); |
d5543503 | 1552 | return ERR_PTR(retval); |
1da177e4 | 1553 | |
d5698c28 | 1554 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1555 | err_release_tty: |
89c8d91e | 1556 | tty_unlock(tty); |
5a3c6b25 | 1557 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1558 | "clearing slot %d\n", idx); |
d5698c28 | 1559 | release_tty(tty, idx); |
73ec06fc | 1560 | return ERR_PTR(retval); |
1da177e4 LT |
1561 | } |
1562 | ||
feebed65 AC |
1563 | void tty_free_termios(struct tty_struct *tty) |
1564 | { | |
1565 | struct ktermios *tp; | |
1566 | int idx = tty->index; | |
36b3c070 AC |
1567 | |
1568 | /* If the port is going to reset then it has no termios to save */ | |
1569 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1570 | return; | |
1571 | ||
1572 | /* Stash the termios data */ | |
1573 | tp = tty->driver->termios[idx]; | |
1574 | if (tp == NULL) { | |
1575 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1576 | if (tp == NULL) { | |
1577 | pr_warn("tty: no memory to save termios state.\n"); | |
1578 | return; | |
1579 | } | |
4ac5d705 | 1580 | tty->driver->termios[idx] = tp; |
feebed65 | 1581 | } |
36b3c070 | 1582 | *tp = tty->termios; |
feebed65 AC |
1583 | } |
1584 | EXPORT_SYMBOL(tty_free_termios); | |
1585 | ||
a2965b7b | 1586 | /** |
949aa64f PH |
1587 | * tty_flush_works - flush all works of a tty/pty pair |
1588 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1589 | * |
949aa64f | 1590 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1591 | */ |
1592 | static void tty_flush_works(struct tty_struct *tty) | |
1593 | { | |
1594 | flush_work(&tty->SAK_work); | |
1595 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1596 | if (tty->link) { |
1597 | flush_work(&tty->link->SAK_work); | |
1598 | flush_work(&tty->link->hangup_work); | |
1599 | } | |
a2965b7b | 1600 | } |
feebed65 | 1601 | |
af9b897e | 1602 | /** |
d5698c28 | 1603 | * release_one_tty - release tty structure memory |
9c9f4ded | 1604 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1605 | * |
1606 | * Releases memory associated with a tty structure, and clears out the | |
1607 | * driver table slots. This function is called when a device is no longer | |
1608 | * in use. It also gets called when setup of a device fails. | |
1609 | * | |
1610 | * Locking: | |
af9b897e AC |
1611 | * takes the file list lock internally when working on the list |
1612 | * of ttys that the driver keeps. | |
b50989dc AC |
1613 | * |
1614 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1615 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1616 | */ |
b50989dc | 1617 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1618 | { |
b50989dc AC |
1619 | struct tty_struct *tty = |
1620 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1621 | struct tty_driver *driver = tty->driver; |
b216df53 | 1622 | struct module *owner = driver->owner; |
d5698c28 | 1623 | |
f278a2f7 DY |
1624 | if (tty->ops->cleanup) |
1625 | tty->ops->cleanup(tty); | |
1626 | ||
1da177e4 | 1627 | tty->magic = 0; |
7d7b93c1 | 1628 | tty_driver_kref_put(driver); |
b216df53 | 1629 | module_put(owner); |
d5698c28 | 1630 | |
ee2ffa0d | 1631 | spin_lock(&tty_files_lock); |
1da177e4 | 1632 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1633 | spin_unlock(&tty_files_lock); |
d5698c28 | 1634 | |
6da8d866 ON |
1635 | put_pid(tty->pgrp); |
1636 | put_pid(tty->session); | |
1da177e4 LT |
1637 | free_tty_struct(tty); |
1638 | } | |
1639 | ||
b50989dc AC |
1640 | static void queue_release_one_tty(struct kref *kref) |
1641 | { | |
1642 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1643 | |
b50989dc AC |
1644 | /* The hangup queue is now free so we can reuse it rather than |
1645 | waste a chunk of memory for each port */ | |
1646 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1647 | schedule_work(&tty->hangup_work); | |
1648 | } | |
1649 | ||
9c9f4ded AC |
1650 | /** |
1651 | * tty_kref_put - release a tty kref | |
1652 | * @tty: tty device | |
1653 | * | |
1654 | * Release a reference to a tty device and if need be let the kref | |
1655 | * layer destruct the object for us | |
1656 | */ | |
1657 | ||
1658 | void tty_kref_put(struct tty_struct *tty) | |
1659 | { | |
1660 | if (tty) | |
b50989dc | 1661 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1662 | } |
1663 | EXPORT_SYMBOL(tty_kref_put); | |
1664 | ||
d5698c28 CH |
1665 | /** |
1666 | * release_tty - release tty structure memory | |
1667 | * | |
1668 | * Release both @tty and a possible linked partner (think pty pair), | |
1669 | * and decrement the refcount of the backing module. | |
1670 | * | |
1671 | * Locking: | |
d155255a | 1672 | * tty_mutex |
d5698c28 CH |
1673 | * takes the file list lock internally when working on the list |
1674 | * of ttys that the driver keeps. | |
9c9f4ded | 1675 | * |
d5698c28 CH |
1676 | */ |
1677 | static void release_tty(struct tty_struct *tty, int idx) | |
1678 | { | |
9c9f4ded AC |
1679 | /* This should always be true but check for the moment */ |
1680 | WARN_ON(tty->index != idx); | |
d155255a | 1681 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1682 | if (tty->ops->shutdown) |
1683 | tty->ops->shutdown(tty); | |
1684 | tty_free_termios(tty); | |
1685 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1686 | tty->port->itty = NULL; |
64e377dc PH |
1687 | if (tty->link) |
1688 | tty->link->port->itty = NULL; | |
4f98d467 | 1689 | cancel_work_sync(&tty->port->buf.work); |
36b3c070 | 1690 | |
d5698c28 | 1691 | if (tty->link) |
9c9f4ded AC |
1692 | tty_kref_put(tty->link); |
1693 | tty_kref_put(tty); | |
d5698c28 CH |
1694 | } |
1695 | ||
955787ca JS |
1696 | /** |
1697 | * tty_release_checks - check a tty before real release | |
1698 | * @tty: tty to check | |
1699 | * @o_tty: link of @tty (if any) | |
1700 | * @idx: index of the tty | |
1701 | * | |
1702 | * Performs some paranoid checking before true release of the @tty. | |
1703 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1704 | */ | |
359b9fb5 | 1705 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1706 | { |
1707 | #ifdef TTY_PARANOIA_CHECK | |
1708 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1709 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1710 | __func__, tty->name); | |
955787ca JS |
1711 | return -1; |
1712 | } | |
1713 | ||
1714 | /* not much to check for devpts */ | |
1715 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1716 | return 0; | |
1717 | ||
1718 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1719 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1720 | __func__, idx, tty->name); | |
955787ca JS |
1721 | return -1; |
1722 | } | |
955787ca | 1723 | if (tty->driver->other) { |
359b9fb5 PH |
1724 | struct tty_struct *o_tty = tty->link; |
1725 | ||
955787ca | 1726 | if (o_tty != tty->driver->other->ttys[idx]) { |
9de44bd6 JS |
1727 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1728 | __func__, idx, tty->name); | |
955787ca JS |
1729 | return -1; |
1730 | } | |
955787ca | 1731 | if (o_tty->link != tty) { |
9de44bd6 | 1732 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1733 | return -1; |
1734 | } | |
1735 | } | |
1736 | #endif | |
1737 | return 0; | |
1738 | } | |
1739 | ||
eeb89d91 AC |
1740 | /** |
1741 | * tty_release - vfs callback for close | |
1742 | * @inode: inode of tty | |
1743 | * @filp: file pointer for handle to tty | |
1744 | * | |
1745 | * Called the last time each file handle is closed that references | |
1746 | * this tty. There may however be several such references. | |
1747 | * | |
1748 | * Locking: | |
1749 | * Takes bkl. See tty_release_dev | |
1750 | * | |
1da177e4 LT |
1751 | * Even releasing the tty structures is a tricky business.. We have |
1752 | * to be very careful that the structures are all released at the | |
1753 | * same time, as interrupts might otherwise get the wrong pointers. | |
1754 | * | |
1755 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1756 | * lead to double frees or releasing memory still in use. | |
1757 | */ | |
eeb89d91 AC |
1758 | |
1759 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1760 | { |
d996b62a | 1761 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1762 | struct tty_struct *o_tty = NULL; |
1763 | int do_sleep, final; | |
1da177e4 LT |
1764 | int idx; |
1765 | char buf[64]; | |
37b16457 | 1766 | long timeout = 0; |
494c1eac | 1767 | int once = 1; |
37bdfb07 | 1768 | |
9de44bd6 | 1769 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1770 | return 0; |
1da177e4 | 1771 | |
89c8d91e | 1772 | tty_lock(tty); |
9de44bd6 | 1773 | check_tty_count(tty, __func__); |
1da177e4 | 1774 | |
ec79d605 | 1775 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1776 | |
1777 | idx = tty->index; | |
7ffb6da9 PH |
1778 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1779 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1780 | o_tty = tty->link; | |
1da177e4 | 1781 | |
359b9fb5 | 1782 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1783 | tty_unlock(tty); |
eeb89d91 | 1784 | return 0; |
1da177e4 | 1785 | } |
1da177e4 LT |
1786 | |
1787 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1788 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1789 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1790 | #endif |
1791 | ||
f34d7a5b AC |
1792 | if (tty->ops->close) |
1793 | tty->ops->close(tty, filp); | |
1da177e4 | 1794 | |
2aff5e2b PH |
1795 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1796 | tty_lock_slave(o_tty); | |
1797 | ||
1da177e4 LT |
1798 | /* |
1799 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1800 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1801 | * wait queues and kick everyone out _before_ actually starting to | |
1802 | * close. This ensures that we won't block while releasing the tty | |
1803 | * structure. | |
1804 | * | |
1805 | * The test for the o_tty closing is necessary, since the master and | |
1806 | * slave sides may close in any order. If the slave side closes out | |
1807 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1808 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1809 | * so we do it now. |
1da177e4 LT |
1810 | */ |
1811 | while (1) { | |
1da177e4 LT |
1812 | do_sleep = 0; |
1813 | ||
324c1650 | 1814 | if (tty->count <= 1) { |
1da177e4 | 1815 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1816 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1817 | do_sleep++; |
1818 | } | |
1819 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1820 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1821 | do_sleep++; |
1822 | } | |
1823 | } | |
7ffb6da9 | 1824 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1825 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1826 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1827 | do_sleep++; |
1828 | } | |
1829 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1830 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1831 | do_sleep++; |
1832 | } | |
1833 | } | |
1834 | if (!do_sleep) | |
1835 | break; | |
1836 | ||
494c1eac PH |
1837 | if (once) { |
1838 | once = 0; | |
1839 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", | |
1840 | __func__, tty_name(tty, buf)); | |
1841 | } | |
37b16457 PH |
1842 | schedule_timeout_killable(timeout); |
1843 | if (timeout < 120 * HZ) | |
1844 | timeout = 2 * timeout + 1; | |
1845 | else | |
1846 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1847 | } |
1da177e4 | 1848 | |
7ffb6da9 | 1849 | if (o_tty) { |
1da177e4 | 1850 | if (--o_tty->count < 0) { |
9de44bd6 JS |
1851 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1852 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1853 | o_tty->count = 0; |
1854 | } | |
1855 | } | |
1856 | if (--tty->count < 0) { | |
9de44bd6 JS |
1857 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1858 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1859 | tty->count = 0; |
1860 | } | |
37bdfb07 | 1861 | |
1da177e4 LT |
1862 | /* |
1863 | * We've decremented tty->count, so we need to remove this file | |
1864 | * descriptor off the tty->tty_files list; this serves two | |
1865 | * purposes: | |
1866 | * - check_tty_count sees the correct number of file descriptors | |
1867 | * associated with this tty. | |
1868 | * - do_tty_hangup no longer sees this file descriptor as | |
1869 | * something that needs to be handled for hangups. | |
1870 | */ | |
d996b62a | 1871 | tty_del_file(filp); |
1da177e4 LT |
1872 | |
1873 | /* | |
1874 | * Perform some housekeeping before deciding whether to return. | |
1875 | * | |
1da177e4 LT |
1876 | * If _either_ side is closing, make sure there aren't any |
1877 | * processes that still think tty or o_tty is their controlling | |
1878 | * tty. | |
1879 | */ | |
324c1650 | 1880 | if (!tty->count) { |
1da177e4 | 1881 | read_lock(&tasklist_lock); |
24ec839c | 1882 | session_clear_tty(tty->session); |
7ffb6da9 | 1883 | if (o_tty) |
24ec839c | 1884 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1885 | read_unlock(&tasklist_lock); |
1886 | } | |
1887 | ||
324c1650 | 1888 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1889 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1890 | |
2aff5e2b PH |
1891 | tty_unlock_slave(o_tty); |
1892 | tty_unlock(tty); | |
1893 | ||
04980706 | 1894 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1895 | cannot be re-opened by a racing opener */ |
da965822 | 1896 | |
324c1650 | 1897 | if (!final) |
eeb89d91 | 1898 | return 0; |
37bdfb07 | 1899 | |
1da177e4 | 1900 | #ifdef TTY_DEBUG_HANGUP |
96433d10 | 1901 | printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty, buf)); |
1da177e4 LT |
1902 | #endif |
1903 | /* | |
01e1abb2 | 1904 | * Ask the line discipline code to release its structures |
1da177e4 | 1905 | */ |
62462aef | 1906 | tty_ldisc_release(tty); |
a2965b7b PH |
1907 | |
1908 | /* Wait for pending work before tty destruction commmences */ | |
1909 | tty_flush_works(tty); | |
a2965b7b | 1910 | |
96433d10 PH |
1911 | #ifdef TTY_DEBUG_HANGUP |
1912 | printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__, tty_name(tty, buf)); | |
1913 | #endif | |
1da177e4 | 1914 | /* |
d5698c28 | 1915 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1916 | * the slots and preserving the termios structure. The tty_unlock_pair |
1917 | * should be safe as we keep a kref while the tty is locked (so the | |
1918 | * unlock never unlocks a freed tty). | |
1da177e4 | 1919 | */ |
d155255a | 1920 | mutex_lock(&tty_mutex); |
d5698c28 | 1921 | release_tty(tty, idx); |
d155255a | 1922 | mutex_unlock(&tty_mutex); |
1da177e4 | 1923 | |
eeb89d91 | 1924 | return 0; |
1da177e4 LT |
1925 | } |
1926 | ||
b82154ac | 1927 | /** |
52494eeb | 1928 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1929 | * @device: device number |
1930 | * @filp: file pointer to tty | |
52494eeb PH |
1931 | * @return: locked tty of the current task iff @device is /dev/tty |
1932 | * | |
1933 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1934 | * |
1935 | * We cannot return driver and index like for the other nodes because | |
1936 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1937 | */ | |
1938 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1939 | { | |
1940 | struct tty_struct *tty; | |
52494eeb | 1941 | int retval; |
b82154ac JS |
1942 | |
1943 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1944 | return NULL; | |
1945 | ||
1946 | tty = get_current_tty(); | |
1947 | if (!tty) | |
1948 | return ERR_PTR(-ENXIO); | |
1949 | ||
1950 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1951 | /* noctty = 1; */ | |
52494eeb PH |
1952 | tty_lock(tty); |
1953 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1954 | ||
1955 | retval = tty_reopen(tty); | |
1956 | if (retval < 0) { | |
1957 | tty_unlock(tty); | |
1958 | tty = ERR_PTR(retval); | |
1959 | } | |
b82154ac JS |
1960 | return tty; |
1961 | } | |
1962 | ||
5b5e7040 JS |
1963 | /** |
1964 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1965 | * @device: device number | |
1966 | * @filp: file pointer to tty | |
1967 | * @noctty: set if the device should not become a controlling tty | |
1968 | * @index: index for the device in the @return driver | |
1969 | * @return: driver for this inode (with increased refcount) | |
1970 | * | |
1971 | * If @return is not erroneous, the caller is responsible to decrement the | |
1972 | * refcount by tty_driver_kref_put. | |
1973 | * | |
1974 | * Locking: tty_mutex protects get_tty_driver | |
1975 | */ | |
1976 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1977 | int *noctty, int *index) | |
1978 | { | |
1979 | struct tty_driver *driver; | |
1980 | ||
2cd0050c | 1981 | switch (device) { |
5b5e7040 | 1982 | #ifdef CONFIG_VT |
2cd0050c | 1983 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1984 | extern struct tty_driver *console_driver; |
1985 | driver = tty_driver_kref_get(console_driver); | |
1986 | *index = fg_console; | |
1987 | *noctty = 1; | |
2cd0050c | 1988 | break; |
5b5e7040 JS |
1989 | } |
1990 | #endif | |
2cd0050c | 1991 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1992 | struct tty_driver *console_driver = console_device(index); |
1993 | if (console_driver) { | |
1994 | driver = tty_driver_kref_get(console_driver); | |
1995 | if (driver) { | |
1996 | /* Don't let /dev/console block */ | |
1997 | filp->f_flags |= O_NONBLOCK; | |
1998 | *noctty = 1; | |
2cd0050c | 1999 | break; |
5b5e7040 JS |
2000 | } |
2001 | } | |
2002 | return ERR_PTR(-ENODEV); | |
2003 | } | |
2cd0050c JS |
2004 | default: |
2005 | driver = get_tty_driver(device, index); | |
2006 | if (!driver) | |
2007 | return ERR_PTR(-ENODEV); | |
2008 | break; | |
2009 | } | |
5b5e7040 JS |
2010 | return driver; |
2011 | } | |
2012 | ||
af9b897e | 2013 | /** |
eeb89d91 | 2014 | * tty_open - open a tty device |
af9b897e AC |
2015 | * @inode: inode of device file |
2016 | * @filp: file pointer to tty | |
1da177e4 | 2017 | * |
af9b897e AC |
2018 | * tty_open and tty_release keep up the tty count that contains the |
2019 | * number of opens done on a tty. We cannot use the inode-count, as | |
2020 | * different inodes might point to the same tty. | |
1da177e4 | 2021 | * |
af9b897e AC |
2022 | * Open-counting is needed for pty masters, as well as for keeping |
2023 | * track of serial lines: DTR is dropped when the last close happens. | |
2024 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2025 | * | |
2026 | * The termios state of a pty is reset on first open so that | |
2027 | * settings don't persist across reuse. | |
2028 | * | |
5b5e7040 | 2029 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2030 | * tty->count should protect the rest. |
2031 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2032 | * |
2033 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2034 | * tty_mutex | |
1da177e4 | 2035 | */ |
af9b897e | 2036 | |
eeb89d91 | 2037 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2038 | { |
b82154ac | 2039 | struct tty_struct *tty; |
1da177e4 | 2040 | int noctty, retval; |
b82154ac | 2041 | struct tty_driver *driver = NULL; |
1da177e4 LT |
2042 | int index; |
2043 | dev_t device = inode->i_rdev; | |
846c151a | 2044 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2045 | |
2046 | nonseekable_open(inode, filp); | |
37bdfb07 | 2047 | |
1da177e4 | 2048 | retry_open: |
fa90e1c9 JS |
2049 | retval = tty_alloc_file(filp); |
2050 | if (retval) | |
2051 | return -ENOMEM; | |
2052 | ||
1da177e4 LT |
2053 | noctty = filp->f_flags & O_NOCTTY; |
2054 | index = -1; | |
2055 | retval = 0; | |
37bdfb07 | 2056 | |
b82154ac | 2057 | tty = tty_open_current_tty(device, filp); |
52494eeb PH |
2058 | if (!tty) { |
2059 | mutex_lock(&tty_mutex); | |
5b5e7040 JS |
2060 | driver = tty_lookup_driver(device, filp, &noctty, &index); |
2061 | if (IS_ERR(driver)) { | |
ba5db448 JS |
2062 | retval = PTR_ERR(driver); |
2063 | goto err_unlock; | |
1da177e4 | 2064 | } |
1da177e4 | 2065 | |
4a2b5fdd | 2066 | /* check whether we're reopening an existing tty */ |
15f1a633 | 2067 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 2068 | if (IS_ERR(tty)) { |
ba5db448 JS |
2069 | retval = PTR_ERR(tty); |
2070 | goto err_unlock; | |
808ffa3d | 2071 | } |
4a2b5fdd | 2072 | |
52494eeb | 2073 | if (tty) { |
aa3cb814 | 2074 | mutex_unlock(&tty_mutex); |
52494eeb | 2075 | tty_lock(tty); |
aa3cb814 PH |
2076 | /* safe to drop the kref from tty_driver_lookup_tty() */ |
2077 | tty_kref_put(tty); | |
52494eeb PH |
2078 | retval = tty_reopen(tty); |
2079 | if (retval < 0) { | |
2080 | tty_unlock(tty); | |
2081 | tty = ERR_PTR(retval); | |
2082 | } | |
aa3cb814 | 2083 | } else { /* Returns with the tty_lock held for now */ |
52494eeb | 2084 | tty = tty_init_dev(driver, index); |
aa3cb814 PH |
2085 | mutex_unlock(&tty_mutex); |
2086 | } | |
4a2b5fdd | 2087 | |
b82154ac | 2088 | tty_driver_kref_put(driver); |
52494eeb PH |
2089 | } |
2090 | ||
eeb89d91 | 2091 | if (IS_ERR(tty)) { |
ba5db448 JS |
2092 | retval = PTR_ERR(tty); |
2093 | goto err_file; | |
eeb89d91 | 2094 | } |
1da177e4 | 2095 | |
fa90e1c9 | 2096 | tty_add_file(tty, filp); |
d996b62a | 2097 | |
9de44bd6 | 2098 | check_tty_count(tty, __func__); |
1da177e4 LT |
2099 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2100 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2101 | noctty = 1; | |
2102 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 2103 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 2104 | #endif |
909bc774 HRK |
2105 | if (tty->ops->open) |
2106 | retval = tty->ops->open(tty, filp); | |
2107 | else | |
2108 | retval = -ENODEV; | |
1da177e4 LT |
2109 | filp->f_flags = saved_flags; |
2110 | ||
37bdfb07 AC |
2111 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
2112 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
2113 | retval = -EBUSY; |
2114 | ||
2115 | if (retval) { | |
2116 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
2117 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
2118 | retval, tty->name); | |
1da177e4 | 2119 | #endif |
89c8d91e | 2120 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2121 | tty_release(inode, filp); |
64ba3dc3 | 2122 | if (retval != -ERESTARTSYS) |
1da177e4 | 2123 | return retval; |
64ba3dc3 AB |
2124 | |
2125 | if (signal_pending(current)) | |
1da177e4 | 2126 | return retval; |
64ba3dc3 | 2127 | |
1da177e4 LT |
2128 | schedule(); |
2129 | /* | |
2130 | * Need to reset f_op in case a hangup happened. | |
2131 | */ | |
1256937f | 2132 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2133 | filp->f_op = &tty_fops; |
2134 | goto retry_open; | |
2135 | } | |
d4855e1f | 2136 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2137 | |
24ec839c | 2138 | |
2c411c11 | 2139 | read_lock(&tasklist_lock); |
24ec839c | 2140 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2141 | if (!noctty && |
2142 | current->signal->leader && | |
2143 | !current->signal->tty && | |
ab521dc0 | 2144 | tty->session == NULL) |
bce65f18 | 2145 | __proc_set_tty(tty); |
24ec839c | 2146 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2147 | read_unlock(&tasklist_lock); |
89c8d91e | 2148 | tty_unlock(tty); |
1da177e4 | 2149 | return 0; |
ba5db448 | 2150 | err_unlock: |
ba5db448 JS |
2151 | mutex_unlock(&tty_mutex); |
2152 | /* after locks to avoid deadlock */ | |
2153 | if (!IS_ERR_OR_NULL(driver)) | |
2154 | tty_driver_kref_put(driver); | |
2155 | err_file: | |
2156 | tty_free_file(filp); | |
2157 | return retval; | |
1da177e4 LT |
2158 | } |
2159 | ||
39d95b9d JC |
2160 | |
2161 | ||
af9b897e AC |
2162 | /** |
2163 | * tty_poll - check tty status | |
2164 | * @filp: file being polled | |
2165 | * @wait: poll wait structures to update | |
2166 | * | |
2167 | * Call the line discipline polling method to obtain the poll | |
2168 | * status of the device. | |
2169 | * | |
2170 | * Locking: locks called line discipline but ldisc poll method | |
2171 | * may be re-entered freely by other callers. | |
2172 | */ | |
2173 | ||
37bdfb07 | 2174 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2175 | { |
d996b62a | 2176 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2177 | struct tty_ldisc *ld; |
2178 | int ret = 0; | |
2179 | ||
6131ffaa | 2180 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2181 | return 0; |
37bdfb07 | 2182 | |
1da177e4 | 2183 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2184 | if (ld->ops->poll) |
c961bfb1 | 2185 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2186 | tty_ldisc_deref(ld); |
2187 | return ret; | |
2188 | } | |
2189 | ||
ec79d605 | 2190 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2191 | { |
d996b62a | 2192 | struct tty_struct *tty = file_tty(filp); |
f6c8dbe6 | 2193 | struct tty_ldisc *ldisc; |
47f86834 | 2194 | unsigned long flags; |
5d1e3230 | 2195 | int retval = 0; |
1da177e4 | 2196 | |
6131ffaa | 2197 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2198 | goto out; |
37bdfb07 | 2199 | |
1da177e4 LT |
2200 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2201 | if (retval <= 0) | |
5d1e3230 | 2202 | goto out; |
1da177e4 | 2203 | |
f6c8dbe6 PH |
2204 | ldisc = tty_ldisc_ref(tty); |
2205 | if (ldisc) { | |
2206 | if (ldisc->ops->fasync) | |
2207 | ldisc->ops->fasync(tty, on); | |
2208 | tty_ldisc_deref(ldisc); | |
2209 | } | |
2210 | ||
1da177e4 | 2211 | if (on) { |
ab521dc0 EB |
2212 | enum pid_type type; |
2213 | struct pid *pid; | |
f6c8dbe6 | 2214 | |
47f86834 | 2215 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2216 | if (tty->pgrp) { |
2217 | pid = tty->pgrp; | |
2218 | type = PIDTYPE_PGID; | |
2219 | } else { | |
2220 | pid = task_pid(current); | |
2221 | type = PIDTYPE_PID; | |
2222 | } | |
80e1e823 | 2223 | get_pid(pid); |
70362511 | 2224 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2225 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2226 | put_pid(pid); |
e0b93edd | 2227 | retval = 0; |
1da177e4 | 2228 | } |
5d1e3230 | 2229 | out: |
ec79d605 AB |
2230 | return retval; |
2231 | } | |
2232 | ||
2233 | static int tty_fasync(int fd, struct file *filp, int on) | |
2234 | { | |
89c8d91e | 2235 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2236 | int retval; |
89c8d91e AC |
2237 | |
2238 | tty_lock(tty); | |
ec79d605 | 2239 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2240 | tty_unlock(tty); |
2241 | ||
5d1e3230 | 2242 | return retval; |
1da177e4 LT |
2243 | } |
2244 | ||
af9b897e AC |
2245 | /** |
2246 | * tiocsti - fake input character | |
2247 | * @tty: tty to fake input into | |
2248 | * @p: pointer to character | |
2249 | * | |
3a4fa0a2 | 2250 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2251 | * input management. |
2252 | * | |
2253 | * FIXME: does not honour flow control ?? | |
2254 | * | |
2255 | * Locking: | |
137084bb | 2256 | * Called functions take tty_ldiscs_lock |
af9b897e | 2257 | * current->signal->tty check is safe without locks |
28298232 AC |
2258 | * |
2259 | * FIXME: may race normal receive processing | |
af9b897e AC |
2260 | */ |
2261 | ||
1da177e4 LT |
2262 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2263 | { | |
2264 | char ch, mbz = 0; | |
2265 | struct tty_ldisc *ld; | |
37bdfb07 | 2266 | |
1da177e4 LT |
2267 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2268 | return -EPERM; | |
2269 | if (get_user(ch, p)) | |
2270 | return -EFAULT; | |
1e641743 | 2271 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2272 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2273 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2274 | tty_ldisc_deref(ld); |
2275 | return 0; | |
2276 | } | |
2277 | ||
af9b897e AC |
2278 | /** |
2279 | * tiocgwinsz - implement window query ioctl | |
2280 | * @tty; tty | |
2281 | * @arg: user buffer for result | |
2282 | * | |
808a0d38 | 2283 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2284 | * |
dee4a0be | 2285 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2286 | * is consistent. |
af9b897e AC |
2287 | */ |
2288 | ||
37bdfb07 | 2289 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2290 | { |
808a0d38 AC |
2291 | int err; |
2292 | ||
dee4a0be | 2293 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2294 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2295 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2296 | |
2297 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2298 | } |
2299 | ||
af9b897e | 2300 | /** |
8c9a9dd0 AC |
2301 | * tty_do_resize - resize event |
2302 | * @tty: tty being resized | |
8c9a9dd0 AC |
2303 | * @rows: rows (character) |
2304 | * @cols: cols (character) | |
2305 | * | |
3ad2f3fb | 2306 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2307 | * peform a terminal resize correctly |
af9b897e AC |
2308 | */ |
2309 | ||
fc6f6238 | 2310 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2311 | { |
fc6f6238 | 2312 | struct pid *pgrp; |
1da177e4 | 2313 | |
fc6f6238 | 2314 | /* Lock the tty */ |
dee4a0be | 2315 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2316 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2317 | goto done; |
47f86834 | 2318 | |
5b239542 PH |
2319 | /* Signal the foreground process group */ |
2320 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2321 | if (pgrp) |
2322 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2323 | put_pid(pgrp); |
47f86834 | 2324 | |
8c9a9dd0 | 2325 | tty->winsize = *ws; |
ca9bda00 | 2326 | done: |
dee4a0be | 2327 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2328 | return 0; |
2329 | } | |
4d334fd1 | 2330 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2331 | |
8c9a9dd0 AC |
2332 | /** |
2333 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2334 | * @tty; tty side of tty |
8c9a9dd0 AC |
2335 | * @arg: user buffer for result |
2336 | * | |
2337 | * Copies the user idea of the window size to the kernel. Traditionally | |
2338 | * this is just advisory information but for the Linux console it | |
2339 | * actually has driver level meaning and triggers a VC resize. | |
2340 | * | |
2341 | * Locking: | |
25985edc | 2342 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2343 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2344 | * then calls into the default method. | |
2345 | */ | |
2346 | ||
fc6f6238 | 2347 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2348 | { |
2349 | struct winsize tmp_ws; | |
2350 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2351 | return -EFAULT; | |
2352 | ||
2353 | if (tty->ops->resize) | |
fc6f6238 | 2354 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2355 | else |
fc6f6238 | 2356 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2357 | } |
2358 | ||
af9b897e AC |
2359 | /** |
2360 | * tioccons - allow admin to move logical console | |
2361 | * @file: the file to become console | |
2362 | * | |
25985edc | 2363 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2364 | * |
2365 | * Locking: uses redirect_lock to guard the redirect information | |
2366 | */ | |
2367 | ||
1da177e4 LT |
2368 | static int tioccons(struct file *file) |
2369 | { | |
2370 | if (!capable(CAP_SYS_ADMIN)) | |
2371 | return -EPERM; | |
2372 | if (file->f_op->write == redirected_tty_write) { | |
2373 | struct file *f; | |
2374 | spin_lock(&redirect_lock); | |
2375 | f = redirect; | |
2376 | redirect = NULL; | |
2377 | spin_unlock(&redirect_lock); | |
2378 | if (f) | |
2379 | fput(f); | |
2380 | return 0; | |
2381 | } | |
2382 | spin_lock(&redirect_lock); | |
2383 | if (redirect) { | |
2384 | spin_unlock(&redirect_lock); | |
2385 | return -EBUSY; | |
2386 | } | |
cb0942b8 | 2387 | redirect = get_file(file); |
1da177e4 LT |
2388 | spin_unlock(&redirect_lock); |
2389 | return 0; | |
2390 | } | |
2391 | ||
af9b897e AC |
2392 | /** |
2393 | * fionbio - non blocking ioctl | |
2394 | * @file: file to set blocking value | |
2395 | * @p: user parameter | |
2396 | * | |
2397 | * Historical tty interfaces had a blocking control ioctl before | |
2398 | * the generic functionality existed. This piece of history is preserved | |
2399 | * in the expected tty API of posix OS's. | |
2400 | * | |
6146b9af | 2401 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2402 | */ |
1da177e4 LT |
2403 | |
2404 | static int fionbio(struct file *file, int __user *p) | |
2405 | { | |
2406 | int nonblock; | |
2407 | ||
2408 | if (get_user(nonblock, p)) | |
2409 | return -EFAULT; | |
2410 | ||
db1dd4d3 | 2411 | spin_lock(&file->f_lock); |
1da177e4 LT |
2412 | if (nonblock) |
2413 | file->f_flags |= O_NONBLOCK; | |
2414 | else | |
2415 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2416 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2417 | return 0; |
2418 | } | |
2419 | ||
af9b897e AC |
2420 | /** |
2421 | * tiocsctty - set controlling tty | |
2422 | * @tty: tty structure | |
2423 | * @arg: user argument | |
2424 | * | |
2425 | * This ioctl is used to manage job control. It permits a session | |
2426 | * leader to set this tty as the controlling tty for the session. | |
2427 | * | |
2428 | * Locking: | |
e218eb32 | 2429 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2430 | * Takes tasklist_lock internally to walk sessions |
2431 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2432 | */ |
2433 | ||
1da177e4 LT |
2434 | static int tiocsctty(struct tty_struct *tty, int arg) |
2435 | { | |
24ec839c | 2436 | int ret = 0; |
24ec839c | 2437 | |
e218eb32 | 2438 | tty_lock(tty); |
2c411c11 PH |
2439 | read_lock(&tasklist_lock); |
2440 | ||
2441 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2442 | goto unlock; | |
2443 | ||
1da177e4 LT |
2444 | /* |
2445 | * The process must be a session leader and | |
2446 | * not have a controlling tty already. | |
2447 | */ | |
24ec839c PZ |
2448 | if (!current->signal->leader || current->signal->tty) { |
2449 | ret = -EPERM; | |
2450 | goto unlock; | |
2451 | } | |
2452 | ||
ab521dc0 | 2453 | if (tty->session) { |
1da177e4 LT |
2454 | /* |
2455 | * This tty is already the controlling | |
2456 | * tty for another session group! | |
2457 | */ | |
37bdfb07 | 2458 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2459 | /* |
2460 | * Steal it away | |
2461 | */ | |
24ec839c | 2462 | session_clear_tty(tty->session); |
24ec839c PZ |
2463 | } else { |
2464 | ret = -EPERM; | |
2465 | goto unlock; | |
2466 | } | |
1da177e4 | 2467 | } |
bce65f18 | 2468 | proc_set_tty(tty); |
24ec839c | 2469 | unlock: |
2c411c11 | 2470 | read_unlock(&tasklist_lock); |
e218eb32 | 2471 | tty_unlock(tty); |
24ec839c | 2472 | return ret; |
1da177e4 LT |
2473 | } |
2474 | ||
5d0fdf1e AC |
2475 | /** |
2476 | * tty_get_pgrp - return a ref counted pgrp pid | |
2477 | * @tty: tty to read | |
2478 | * | |
2479 | * Returns a refcounted instance of the pid struct for the process | |
2480 | * group controlling the tty. | |
2481 | */ | |
2482 | ||
2483 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2484 | { | |
2485 | unsigned long flags; | |
2486 | struct pid *pgrp; | |
2487 | ||
2488 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2489 | pgrp = get_pid(tty->pgrp); | |
2490 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2491 | ||
2492 | return pgrp; | |
2493 | } | |
2494 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2495 | ||
e1c2296c PH |
2496 | /* |
2497 | * This checks not only the pgrp, but falls back on the pid if no | |
2498 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2499 | * without this... | |
2500 | * | |
2501 | * The caller must hold rcu lock or the tasklist lock. | |
2502 | */ | |
2503 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2504 | { | |
2505 | struct task_struct *p; | |
2506 | struct pid *sid = NULL; | |
2507 | ||
2508 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2509 | if (p == NULL) | |
2510 | p = pid_task(pgrp, PIDTYPE_PID); | |
2511 | if (p != NULL) | |
2512 | sid = task_session(p); | |
2513 | ||
2514 | return sid; | |
2515 | } | |
2516 | ||
af9b897e AC |
2517 | /** |
2518 | * tiocgpgrp - get process group | |
2519 | * @tty: tty passed by user | |
25985edc | 2520 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2521 | * @p: returned pid |
2522 | * | |
2523 | * Obtain the process group of the tty. If there is no process group | |
2524 | * return an error. | |
2525 | * | |
24ec839c | 2526 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2527 | */ |
2528 | ||
1da177e4 LT |
2529 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2530 | { | |
5d0fdf1e AC |
2531 | struct pid *pid; |
2532 | int ret; | |
1da177e4 LT |
2533 | /* |
2534 | * (tty == real_tty) is a cheap way of | |
2535 | * testing if the tty is NOT a master pty. | |
2536 | */ | |
2537 | if (tty == real_tty && current->signal->tty != real_tty) | |
2538 | return -ENOTTY; | |
5d0fdf1e AC |
2539 | pid = tty_get_pgrp(real_tty); |
2540 | ret = put_user(pid_vnr(pid), p); | |
2541 | put_pid(pid); | |
2542 | return ret; | |
1da177e4 LT |
2543 | } |
2544 | ||
af9b897e AC |
2545 | /** |
2546 | * tiocspgrp - attempt to set process group | |
2547 | * @tty: tty passed by user | |
2548 | * @real_tty: tty side device matching tty passed by user | |
2549 | * @p: pid pointer | |
2550 | * | |
2551 | * Set the process group of the tty to the session passed. Only | |
2552 | * permitted where the tty session is our session. | |
2553 | * | |
47f86834 | 2554 | * Locking: RCU, ctrl lock |
af9b897e AC |
2555 | */ |
2556 | ||
1da177e4 LT |
2557 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2558 | { | |
04a2e6a5 EB |
2559 | struct pid *pgrp; |
2560 | pid_t pgrp_nr; | |
1da177e4 | 2561 | int retval = tty_check_change(real_tty); |
47f86834 | 2562 | unsigned long flags; |
1da177e4 LT |
2563 | |
2564 | if (retval == -EIO) | |
2565 | return -ENOTTY; | |
2566 | if (retval) | |
2567 | return retval; | |
2568 | if (!current->signal->tty || | |
2569 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2570 | (real_tty->session != task_session(current))) |
1da177e4 | 2571 | return -ENOTTY; |
04a2e6a5 | 2572 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2573 | return -EFAULT; |
04a2e6a5 | 2574 | if (pgrp_nr < 0) |
1da177e4 | 2575 | return -EINVAL; |
04a2e6a5 | 2576 | rcu_read_lock(); |
b488893a | 2577 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2578 | retval = -ESRCH; |
2579 | if (!pgrp) | |
2580 | goto out_unlock; | |
2581 | retval = -EPERM; | |
2582 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2583 | goto out_unlock; | |
2584 | retval = 0; | |
47f86834 | 2585 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2586 | put_pid(real_tty->pgrp); |
2587 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2588 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2589 | out_unlock: |
2590 | rcu_read_unlock(); | |
2591 | return retval; | |
1da177e4 LT |
2592 | } |
2593 | ||
af9b897e AC |
2594 | /** |
2595 | * tiocgsid - get session id | |
2596 | * @tty: tty passed by user | |
25985edc | 2597 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2598 | * @p: pointer to returned session id |
2599 | * | |
2600 | * Obtain the session id of the tty. If there is no session | |
2601 | * return an error. | |
2602 | * | |
24ec839c | 2603 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2604 | */ |
2605 | ||
1da177e4 LT |
2606 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2607 | { | |
2608 | /* | |
2609 | * (tty == real_tty) is a cheap way of | |
2610 | * testing if the tty is NOT a master pty. | |
2611 | */ | |
2612 | if (tty == real_tty && current->signal->tty != real_tty) | |
2613 | return -ENOTTY; | |
ab521dc0 | 2614 | if (!real_tty->session) |
1da177e4 | 2615 | return -ENOTTY; |
b488893a | 2616 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2617 | } |
2618 | ||
af9b897e AC |
2619 | /** |
2620 | * tiocsetd - set line discipline | |
2621 | * @tty: tty device | |
2622 | * @p: pointer to user data | |
2623 | * | |
2624 | * Set the line discipline according to user request. | |
2625 | * | |
2626 | * Locking: see tty_set_ldisc, this function is just a helper | |
2627 | */ | |
2628 | ||
1da177e4 LT |
2629 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2630 | { | |
2631 | int ldisc; | |
04f378b1 | 2632 | int ret; |
1da177e4 LT |
2633 | |
2634 | if (get_user(ldisc, p)) | |
2635 | return -EFAULT; | |
04f378b1 | 2636 | |
04f378b1 | 2637 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2638 | |
2639 | return ret; | |
1da177e4 LT |
2640 | } |
2641 | ||
af9b897e AC |
2642 | /** |
2643 | * send_break - performed time break | |
2644 | * @tty: device to break on | |
2645 | * @duration: timeout in mS | |
2646 | * | |
2647 | * Perform a timed break on hardware that lacks its own driver level | |
2648 | * timed break functionality. | |
2649 | * | |
2650 | * Locking: | |
28298232 | 2651 | * atomic_write_lock serializes |
af9b897e | 2652 | * |
af9b897e AC |
2653 | */ |
2654 | ||
b20f3ae5 | 2655 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2656 | { |
9e98966c AC |
2657 | int retval; |
2658 | ||
2659 | if (tty->ops->break_ctl == NULL) | |
2660 | return 0; | |
2661 | ||
2662 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2663 | retval = tty->ops->break_ctl(tty, duration); | |
2664 | else { | |
2665 | /* Do the work ourselves */ | |
2666 | if (tty_write_lock(tty, 0) < 0) | |
2667 | return -EINTR; | |
2668 | retval = tty->ops->break_ctl(tty, -1); | |
2669 | if (retval) | |
2670 | goto out; | |
2671 | if (!signal_pending(current)) | |
2672 | msleep_interruptible(duration); | |
2673 | retval = tty->ops->break_ctl(tty, 0); | |
2674 | out: | |
2675 | tty_write_unlock(tty); | |
2676 | if (signal_pending(current)) | |
2677 | retval = -EINTR; | |
2678 | } | |
2679 | return retval; | |
1da177e4 LT |
2680 | } |
2681 | ||
af9b897e | 2682 | /** |
f34d7a5b | 2683 | * tty_tiocmget - get modem status |
af9b897e AC |
2684 | * @tty: tty device |
2685 | * @file: user file pointer | |
2686 | * @p: pointer to result | |
2687 | * | |
2688 | * Obtain the modem status bits from the tty driver if the feature | |
2689 | * is supported. Return -EINVAL if it is not available. | |
2690 | * | |
2691 | * Locking: none (up to the driver) | |
2692 | */ | |
2693 | ||
60b33c13 | 2694 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2695 | { |
2696 | int retval = -EINVAL; | |
2697 | ||
f34d7a5b | 2698 | if (tty->ops->tiocmget) { |
60b33c13 | 2699 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2700 | |
2701 | if (retval >= 0) | |
2702 | retval = put_user(retval, p); | |
2703 | } | |
2704 | return retval; | |
2705 | } | |
2706 | ||
af9b897e | 2707 | /** |
f34d7a5b | 2708 | * tty_tiocmset - set modem status |
af9b897e | 2709 | * @tty: tty device |
af9b897e AC |
2710 | * @cmd: command - clear bits, set bits or set all |
2711 | * @p: pointer to desired bits | |
2712 | * | |
2713 | * Set the modem status bits from the tty driver if the feature | |
2714 | * is supported. Return -EINVAL if it is not available. | |
2715 | * | |
2716 | * Locking: none (up to the driver) | |
2717 | */ | |
2718 | ||
20b9d177 | 2719 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2720 | unsigned __user *p) |
2721 | { | |
ae677517 AC |
2722 | int retval; |
2723 | unsigned int set, clear, val; | |
1da177e4 | 2724 | |
ae677517 AC |
2725 | if (tty->ops->tiocmset == NULL) |
2726 | return -EINVAL; | |
1da177e4 | 2727 | |
ae677517 AC |
2728 | retval = get_user(val, p); |
2729 | if (retval) | |
2730 | return retval; | |
2731 | set = clear = 0; | |
2732 | switch (cmd) { | |
2733 | case TIOCMBIS: | |
2734 | set = val; | |
2735 | break; | |
2736 | case TIOCMBIC: | |
2737 | clear = val; | |
2738 | break; | |
2739 | case TIOCMSET: | |
2740 | set = val; | |
2741 | clear = ~val; | |
2742 | break; | |
2743 | } | |
2744 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2745 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2746 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2747 | } |
2748 | ||
d281da7f AC |
2749 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2750 | { | |
2751 | int retval = -EINVAL; | |
2752 | struct serial_icounter_struct icount; | |
2753 | memset(&icount, 0, sizeof(icount)); | |
2754 | if (tty->ops->get_icount) | |
2755 | retval = tty->ops->get_icount(tty, &icount); | |
2756 | if (retval != 0) | |
2757 | return retval; | |
2758 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2759 | return -EFAULT; | |
2760 | return 0; | |
2761 | } | |
2762 | ||
8f166e00 PH |
2763 | /* |
2764 | * if pty, return the slave side (real_tty) | |
2765 | * otherwise, return self | |
2766 | */ | |
2767 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2768 | { |
2769 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2770 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2771 | tty = tty->link; | |
2772 | return tty; | |
2773 | } | |
e8b70e7d | 2774 | |
1da177e4 LT |
2775 | /* |
2776 | * Split this up, as gcc can choke on it otherwise.. | |
2777 | */ | |
04f378b1 | 2778 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2779 | { |
d996b62a NP |
2780 | struct tty_struct *tty = file_tty(file); |
2781 | struct tty_struct *real_tty; | |
1da177e4 LT |
2782 | void __user *p = (void __user *)arg; |
2783 | int retval; | |
2784 | struct tty_ldisc *ld; | |
37bdfb07 | 2785 | |
6131ffaa | 2786 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2787 | return -EINVAL; |
2788 | ||
e8b70e7d | 2789 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2790 | |
2791 | /* | |
2792 | * Factor out some common prep work | |
2793 | */ | |
2794 | switch (cmd) { | |
2795 | case TIOCSETD: | |
2796 | case TIOCSBRK: | |
2797 | case TIOCCBRK: | |
2798 | case TCSBRK: | |
37bdfb07 | 2799 | case TCSBRKP: |
1da177e4 LT |
2800 | retval = tty_check_change(tty); |
2801 | if (retval) | |
2802 | return retval; | |
2803 | if (cmd != TIOCCBRK) { | |
2804 | tty_wait_until_sent(tty, 0); | |
2805 | if (signal_pending(current)) | |
2806 | return -EINTR; | |
2807 | } | |
2808 | break; | |
2809 | } | |
2810 | ||
9e98966c AC |
2811 | /* |
2812 | * Now do the stuff. | |
2813 | */ | |
1da177e4 | 2814 | switch (cmd) { |
37bdfb07 AC |
2815 | case TIOCSTI: |
2816 | return tiocsti(tty, p); | |
2817 | case TIOCGWINSZ: | |
8f520021 | 2818 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2819 | case TIOCSWINSZ: |
fc6f6238 | 2820 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2821 | case TIOCCONS: |
2822 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2823 | case FIONBIO: | |
2824 | return fionbio(file, p); | |
2825 | case TIOCEXCL: | |
2826 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2827 | return 0; | |
2828 | case TIOCNXCL: | |
2829 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2830 | return 0; | |
84fd7bdf CG |
2831 | case TIOCGEXCL: |
2832 | { | |
2833 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2834 | return put_user(excl, (int __user *)p); | |
2835 | } | |
37bdfb07 AC |
2836 | case TIOCNOTTY: |
2837 | if (current->signal->tty != tty) | |
2838 | return -ENOTTY; | |
2839 | no_tty(); | |
2840 | return 0; | |
2841 | case TIOCSCTTY: | |
2842 | return tiocsctty(tty, arg); | |
2843 | case TIOCGPGRP: | |
2844 | return tiocgpgrp(tty, real_tty, p); | |
2845 | case TIOCSPGRP: | |
2846 | return tiocspgrp(tty, real_tty, p); | |
2847 | case TIOCGSID: | |
2848 | return tiocgsid(tty, real_tty, p); | |
2849 | case TIOCGETD: | |
c65c9bc3 | 2850 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2851 | case TIOCSETD: |
2852 | return tiocsetd(tty, p); | |
3c95c985 KS |
2853 | case TIOCVHANGUP: |
2854 | if (!capable(CAP_SYS_ADMIN)) | |
2855 | return -EPERM; | |
2856 | tty_vhangup(tty); | |
2857 | return 0; | |
b7b8de08 WF |
2858 | case TIOCGDEV: |
2859 | { | |
2860 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2861 | return put_user(ret, (unsigned int __user *)p); | |
2862 | } | |
37bdfb07 AC |
2863 | /* |
2864 | * Break handling | |
2865 | */ | |
2866 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2867 | if (tty->ops->break_ctl) |
9e98966c | 2868 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2869 | return 0; |
37bdfb07 | 2870 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2871 | if (tty->ops->break_ctl) |
9e98966c | 2872 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2873 | return 0; |
2874 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2875 | /* non-zero arg means wait for all output data | |
2876 | * to be sent (performed above) but don't send break. | |
2877 | * This is used by the tcdrain() termios function. | |
2878 | */ | |
2879 | if (!arg) | |
2880 | return send_break(tty, 250); | |
2881 | return 0; | |
2882 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2883 | return send_break(tty, arg ? arg*100 : 250); | |
2884 | ||
2885 | case TIOCMGET: | |
60b33c13 | 2886 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2887 | case TIOCMSET: |
2888 | case TIOCMBIC: | |
2889 | case TIOCMBIS: | |
20b9d177 | 2890 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2891 | case TIOCGICOUNT: |
2892 | retval = tty_tiocgicount(tty, p); | |
2893 | /* For the moment allow fall through to the old method */ | |
2894 | if (retval != -EINVAL) | |
2895 | return retval; | |
2896 | break; | |
37bdfb07 AC |
2897 | case TCFLSH: |
2898 | switch (arg) { | |
2899 | case TCIFLUSH: | |
2900 | case TCIOFLUSH: | |
2901 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2902 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2903 | break; |
37bdfb07 AC |
2904 | } |
2905 | break; | |
1da177e4 | 2906 | } |
f34d7a5b | 2907 | if (tty->ops->ioctl) { |
c961bfb1 | 2908 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2909 | if (retval != -ENOIOCTLCMD) |
2910 | return retval; | |
2911 | } | |
2912 | ld = tty_ldisc_ref_wait(tty); | |
2913 | retval = -EINVAL; | |
a352def2 AC |
2914 | if (ld->ops->ioctl) { |
2915 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2916 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2917 | retval = -ENOTTY; |
1da177e4 LT |
2918 | } |
2919 | tty_ldisc_deref(ld); | |
2920 | return retval; | |
2921 | } | |
2922 | ||
e10cc1df | 2923 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2924 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2925 | unsigned long arg) |
2926 | { | |
d996b62a | 2927 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2928 | struct tty_ldisc *ld; |
2929 | int retval = -ENOIOCTLCMD; | |
2930 | ||
6131ffaa | 2931 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2932 | return -EINVAL; |
2933 | ||
f34d7a5b | 2934 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2935 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2936 | if (retval != -ENOIOCTLCMD) |
2937 | return retval; | |
2938 | } | |
2939 | ||
2940 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2941 | if (ld->ops->compat_ioctl) |
2942 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2943 | else |
2944 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2945 | tty_ldisc_deref(ld); |
2946 | ||
2947 | return retval; | |
2948 | } | |
2949 | #endif | |
1da177e4 | 2950 | |
c3c073f8 AV |
2951 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2952 | { | |
2953 | if (likely(file->f_op->read != tty_read)) | |
2954 | return 0; | |
2955 | return file_tty(file) != t ? 0 : fd + 1; | |
2956 | } | |
2957 | ||
1da177e4 LT |
2958 | /* |
2959 | * This implements the "Secure Attention Key" --- the idea is to | |
2960 | * prevent trojan horses by killing all processes associated with this | |
2961 | * tty when the user hits the "Secure Attention Key". Required for | |
2962 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2963 | * |
1da177e4 LT |
2964 | * This code could be nicer; ideally it should send a HUP, wait a few |
2965 | * seconds, then send a INT, and then a KILL signal. But you then | |
2966 | * have to coordinate with the init process, since all processes associated | |
2967 | * with the current tty must be dead before the new getty is allowed | |
2968 | * to spawn. | |
2969 | * | |
2970 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2971 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2972 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2973 | * | |
2974 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2975 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2976 | */ | |
8b6312f4 | 2977 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2978 | { |
2979 | #ifdef TTY_SOFT_SAK | |
2980 | tty_hangup(tty); | |
2981 | #else | |
652486fb | 2982 | struct task_struct *g, *p; |
ab521dc0 | 2983 | struct pid *session; |
1da177e4 | 2984 | int i; |
37bdfb07 | 2985 | |
1da177e4 LT |
2986 | if (!tty) |
2987 | return; | |
24ec839c | 2988 | session = tty->session; |
37bdfb07 | 2989 | |
b3f13deb | 2990 | tty_ldisc_flush(tty); |
1da177e4 | 2991 | |
f34d7a5b | 2992 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2993 | |
1da177e4 | 2994 | read_lock(&tasklist_lock); |
652486fb | 2995 | /* Kill the entire session */ |
ab521dc0 | 2996 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2997 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2998 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2999 | task_pid_nr(p), p->comm); |
652486fb | 3000 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3001 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
3002 | /* Now kill any processes that happen to have the |
3003 | * tty open. | |
3004 | */ | |
3005 | do_each_thread(g, p) { | |
3006 | if (p->signal->tty == tty) { | |
1da177e4 | 3007 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 3008 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 3009 | task_pid_nr(p), p->comm); |
1da177e4 LT |
3010 | send_sig(SIGKILL, p, 1); |
3011 | continue; | |
3012 | } | |
3013 | task_lock(p); | |
c3c073f8 AV |
3014 | i = iterate_fd(p->files, 0, this_tty, tty); |
3015 | if (i != 0) { | |
3016 | printk(KERN_NOTICE "SAK: killed process %d" | |
3017 | " (%s): fd#%d opened to the tty\n", | |
3018 | task_pid_nr(p), p->comm, i - 1); | |
3019 | force_sig(SIGKILL, p); | |
1da177e4 LT |
3020 | } |
3021 | task_unlock(p); | |
652486fb | 3022 | } while_each_thread(g, p); |
1da177e4 LT |
3023 | read_unlock(&tasklist_lock); |
3024 | #endif | |
3025 | } | |
3026 | ||
8b6312f4 EB |
3027 | static void do_SAK_work(struct work_struct *work) |
3028 | { | |
3029 | struct tty_struct *tty = | |
3030 | container_of(work, struct tty_struct, SAK_work); | |
3031 | __do_SAK(tty); | |
3032 | } | |
3033 | ||
1da177e4 LT |
3034 | /* |
3035 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3036 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3037 | * the values which we write to it will be identical to the values which it | |
3038 | * already has. --akpm | |
3039 | */ | |
3040 | void do_SAK(struct tty_struct *tty) | |
3041 | { | |
3042 | if (!tty) | |
3043 | return; | |
1da177e4 LT |
3044 | schedule_work(&tty->SAK_work); |
3045 | } | |
3046 | ||
3047 | EXPORT_SYMBOL(do_SAK); | |
3048 | ||
6e9430ac | 3049 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3050 | { |
6e9430ac | 3051 | const dev_t *devt = data; |
30004ac9 DES |
3052 | return dev->devt == *devt; |
3053 | } | |
3054 | ||
3055 | /* Must put_device() after it's unused! */ | |
3056 | static struct device *tty_get_device(struct tty_struct *tty) | |
3057 | { | |
3058 | dev_t devt = tty_devnum(tty); | |
3059 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3060 | } | |
3061 | ||
3062 | ||
af9b897e | 3063 | /** |
2c964a2f | 3064 | * alloc_tty_struct |
af9b897e | 3065 | * |
2c964a2f | 3066 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3067 | * |
2c964a2f | 3068 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3069 | */ |
af9b897e | 3070 | |
2c964a2f | 3071 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3072 | { |
2c964a2f RV |
3073 | struct tty_struct *tty; |
3074 | ||
3075 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3076 | if (!tty) | |
3077 | return NULL; | |
3078 | ||
9c9f4ded | 3079 | kref_init(&tty->kref); |
1da177e4 | 3080 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3081 | tty_ldisc_init(tty); |
ab521dc0 EB |
3082 | tty->session = NULL; |
3083 | tty->pgrp = NULL; | |
89c8d91e | 3084 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3085 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3086 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3087 | mutex_init(&tty->winsize_mutex); |
36697529 | 3088 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3089 | init_waitqueue_head(&tty->write_wait); |
3090 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3091 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3092 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3093 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3094 | spin_lock_init(&tty->flow_lock); |
1da177e4 | 3095 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3096 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3097 | |
3098 | tty->driver = driver; | |
3099 | tty->ops = driver->ops; | |
3100 | tty->index = idx; | |
3101 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3102 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3103 | |
3104 | return tty; | |
1da177e4 LT |
3105 | } |
3106 | ||
6716671d JS |
3107 | /** |
3108 | * deinitialize_tty_struct | |
3109 | * @tty: tty to deinitialize | |
3110 | * | |
3111 | * This subroutine deinitializes a tty structure that has been newly | |
3112 | * allocated but tty_release cannot be called on that yet. | |
3113 | * | |
3114 | * Locking: none - tty in question must not be exposed at this point | |
3115 | */ | |
3116 | void deinitialize_tty_struct(struct tty_struct *tty) | |
3117 | { | |
3118 | tty_ldisc_deinit(tty); | |
3119 | } | |
3120 | ||
f34d7a5b AC |
3121 | /** |
3122 | * tty_put_char - write one character to a tty | |
3123 | * @tty: tty | |
3124 | * @ch: character | |
3125 | * | |
3126 | * Write one byte to the tty using the provided put_char method | |
3127 | * if present. Returns the number of characters successfully output. | |
3128 | * | |
3129 | * Note: the specific put_char operation in the driver layer may go | |
3130 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3131 | */ |
af9b897e | 3132 | |
f34d7a5b | 3133 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3134 | { |
f34d7a5b AC |
3135 | if (tty->ops->put_char) |
3136 | return tty->ops->put_char(tty, ch); | |
3137 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3138 | } |
f34d7a5b AC |
3139 | EXPORT_SYMBOL_GPL(tty_put_char); |
3140 | ||
d81ed103 | 3141 | struct class *tty_class; |
1da177e4 | 3142 | |
7e73eca6 JS |
3143 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3144 | unsigned int index, unsigned int count) | |
3145 | { | |
3146 | /* init here, since reused cdevs cause crashes */ | |
3147 | cdev_init(&driver->cdevs[index], &tty_fops); | |
3148 | driver->cdevs[index].owner = driver->owner; | |
3149 | return cdev_add(&driver->cdevs[index], dev, count); | |
3150 | } | |
3151 | ||
1da177e4 | 3152 | /** |
af9b897e AC |
3153 | * tty_register_device - register a tty device |
3154 | * @driver: the tty driver that describes the tty device | |
3155 | * @index: the index in the tty driver for this tty device | |
3156 | * @device: a struct device that is associated with this tty device. | |
3157 | * This field is optional, if there is no known struct device | |
3158 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3159 | * |
01107d34 GKH |
3160 | * Returns a pointer to the struct device for this tty device |
3161 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3162 | * |
af9b897e AC |
3163 | * This call is required to be made to register an individual tty device |
3164 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3165 | * that bit is not set, this function should not be called by a tty | |
3166 | * driver. | |
3167 | * | |
3168 | * Locking: ?? | |
1da177e4 | 3169 | */ |
af9b897e | 3170 | |
01107d34 GKH |
3171 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3172 | struct device *device) | |
1da177e4 | 3173 | { |
6915c0e4 TH |
3174 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3175 | } | |
3176 | EXPORT_SYMBOL(tty_register_device); | |
3177 | ||
b1b79916 TH |
3178 | static void tty_device_create_release(struct device *dev) |
3179 | { | |
3180 | pr_debug("device: '%s': %s\n", dev_name(dev), __func__); | |
3181 | kfree(dev); | |
3182 | } | |
3183 | ||
6915c0e4 TH |
3184 | /** |
3185 | * tty_register_device_attr - register a tty device | |
3186 | * @driver: the tty driver that describes the tty device | |
3187 | * @index: the index in the tty driver for this tty device | |
3188 | * @device: a struct device that is associated with this tty device. | |
3189 | * This field is optional, if there is no known struct device | |
3190 | * for this tty device it can be set to NULL safely. | |
3191 | * @drvdata: Driver data to be set to device. | |
3192 | * @attr_grp: Attribute group to be set on device. | |
3193 | * | |
3194 | * Returns a pointer to the struct device for this tty device | |
3195 | * (or ERR_PTR(-EFOO) on error). | |
3196 | * | |
3197 | * This call is required to be made to register an individual tty device | |
3198 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3199 | * that bit is not set, this function should not be called by a tty | |
3200 | * driver. | |
3201 | * | |
3202 | * Locking: ?? | |
3203 | */ | |
3204 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3205 | unsigned index, struct device *device, | |
3206 | void *drvdata, | |
3207 | const struct attribute_group **attr_grp) | |
3208 | { | |
1da177e4 | 3209 | char name[64]; |
6915c0e4 TH |
3210 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3211 | struct device *dev = NULL; | |
3212 | int retval = -ENODEV; | |
7e73eca6 | 3213 | bool cdev = false; |
1da177e4 LT |
3214 | |
3215 | if (index >= driver->num) { | |
3216 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3217 | " (%d).\n", index); | |
1cdcb6b4 | 3218 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3219 | } |
3220 | ||
1da177e4 LT |
3221 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3222 | pty_line_name(driver, index, name); | |
3223 | else | |
3224 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3225 | |
7e73eca6 | 3226 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3227 | retval = tty_cdev_add(driver, devt, index, 1); |
3228 | if (retval) | |
3229 | goto error; | |
7e73eca6 JS |
3230 | cdev = true; |
3231 | } | |
3232 | ||
6915c0e4 TH |
3233 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3234 | if (!dev) { | |
3235 | retval = -ENOMEM; | |
3236 | goto error; | |
3237 | } | |
7e73eca6 | 3238 | |
6915c0e4 TH |
3239 | dev->devt = devt; |
3240 | dev->class = tty_class; | |
3241 | dev->parent = device; | |
b1b79916 | 3242 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3243 | dev_set_name(dev, "%s", name); |
3244 | dev->groups = attr_grp; | |
3245 | dev_set_drvdata(dev, drvdata); | |
3246 | ||
3247 | retval = device_register(dev); | |
3248 | if (retval) | |
3249 | goto error; | |
3250 | ||
3251 | return dev; | |
3252 | ||
3253 | error: | |
3254 | put_device(dev); | |
3255 | if (cdev) | |
3256 | cdev_del(&driver->cdevs[index]); | |
3257 | return ERR_PTR(retval); | |
1da177e4 | 3258 | } |
6915c0e4 | 3259 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3260 | |
3261 | /** | |
af9b897e AC |
3262 | * tty_unregister_device - unregister a tty device |
3263 | * @driver: the tty driver that describes the tty device | |
3264 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3265 | * |
af9b897e AC |
3266 | * If a tty device is registered with a call to tty_register_device() then |
3267 | * this function must be called when the tty device is gone. | |
3268 | * | |
3269 | * Locking: ?? | |
1da177e4 | 3270 | */ |
af9b897e | 3271 | |
1da177e4 LT |
3272 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3273 | { | |
37bdfb07 AC |
3274 | device_destroy(tty_class, |
3275 | MKDEV(driver->major, driver->minor_start) + index); | |
7e73eca6 JS |
3276 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) |
3277 | cdev_del(&driver->cdevs[index]); | |
1da177e4 | 3278 | } |
1da177e4 LT |
3279 | EXPORT_SYMBOL(tty_unregister_device); |
3280 | ||
7f0bc6a6 JS |
3281 | /** |
3282 | * __tty_alloc_driver -- allocate tty driver | |
3283 | * @lines: count of lines this driver can handle at most | |
3284 | * @owner: module which is repsonsible for this driver | |
3285 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3286 | * | |
3287 | * This should not be called directly, some of the provided macros should be | |
3288 | * used instead. Use IS_ERR and friends on @retval. | |
3289 | */ | |
3290 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3291 | unsigned long flags) | |
1da177e4 LT |
3292 | { |
3293 | struct tty_driver *driver; | |
7e73eca6 | 3294 | unsigned int cdevs = 1; |
16a02081 | 3295 | int err; |
1da177e4 | 3296 | |
0019b408 | 3297 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3298 | return ERR_PTR(-EINVAL); |
3299 | ||
506eb99a | 3300 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3301 | if (!driver) |
3302 | return ERR_PTR(-ENOMEM); | |
3303 | ||
3304 | kref_init(&driver->kref); | |
3305 | driver->magic = TTY_DRIVER_MAGIC; | |
3306 | driver->num = lines; | |
3307 | driver->owner = owner; | |
3308 | driver->flags = flags; | |
16a02081 JS |
3309 | |
3310 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3311 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3312 | GFP_KERNEL); | |
3313 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3314 | GFP_KERNEL); | |
3315 | if (!driver->ttys || !driver->termios) { | |
3316 | err = -ENOMEM; | |
3317 | goto err_free_all; | |
3318 | } | |
3319 | } | |
3320 | ||
3321 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3322 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3323 | GFP_KERNEL); | |
3324 | if (!driver->ports) { | |
3325 | err = -ENOMEM; | |
3326 | goto err_free_all; | |
3327 | } | |
7e73eca6 JS |
3328 | cdevs = lines; |
3329 | } | |
3330 | ||
3331 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3332 | if (!driver->cdevs) { | |
3333 | err = -ENOMEM; | |
3334 | goto err_free_all; | |
16a02081 | 3335 | } |
7f0bc6a6 | 3336 | |
1da177e4 | 3337 | return driver; |
16a02081 JS |
3338 | err_free_all: |
3339 | kfree(driver->ports); | |
3340 | kfree(driver->ttys); | |
3341 | kfree(driver->termios); | |
3342 | kfree(driver); | |
3343 | return ERR_PTR(err); | |
1da177e4 | 3344 | } |
7f0bc6a6 | 3345 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3346 | |
7d7b93c1 | 3347 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3348 | { |
7d7b93c1 AC |
3349 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3350 | int i; | |
3351 | struct ktermios *tp; | |
7d7b93c1 AC |
3352 | |
3353 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3354 | /* | |
3355 | * Free the termios and termios_locked structures because | |
3356 | * we don't want to get memory leaks when modular tty | |
3357 | * drivers are removed from the kernel. | |
3358 | */ | |
3359 | for (i = 0; i < driver->num; i++) { | |
3360 | tp = driver->termios[i]; | |
3361 | if (tp) { | |
3362 | driver->termios[i] = NULL; | |
3363 | kfree(tp); | |
3364 | } | |
7d7b93c1 AC |
3365 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3366 | tty_unregister_device(driver, i); | |
3367 | } | |
7d7b93c1 | 3368 | proc_tty_unregister_driver(driver); |
7e73eca6 JS |
3369 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
3370 | cdev_del(&driver->cdevs[0]); | |
7d7b93c1 | 3371 | } |
7e73eca6 | 3372 | kfree(driver->cdevs); |
04831dc1 | 3373 | kfree(driver->ports); |
16a02081 JS |
3374 | kfree(driver->termios); |
3375 | kfree(driver->ttys); | |
1da177e4 LT |
3376 | kfree(driver); |
3377 | } | |
3378 | ||
7d7b93c1 AC |
3379 | void tty_driver_kref_put(struct tty_driver *driver) |
3380 | { | |
3381 | kref_put(&driver->kref, destruct_tty_driver); | |
3382 | } | |
3383 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3384 | ||
b68e31d0 JD |
3385 | void tty_set_operations(struct tty_driver *driver, |
3386 | const struct tty_operations *op) | |
1da177e4 | 3387 | { |
f34d7a5b AC |
3388 | driver->ops = op; |
3389 | }; | |
7d7b93c1 | 3390 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3391 | |
7d7b93c1 AC |
3392 | void put_tty_driver(struct tty_driver *d) |
3393 | { | |
3394 | tty_driver_kref_put(d); | |
3395 | } | |
1da177e4 | 3396 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3397 | |
3398 | /* | |
3399 | * Called by a tty driver to register itself. | |
3400 | */ | |
3401 | int tty_register_driver(struct tty_driver *driver) | |
3402 | { | |
3403 | int error; | |
37bdfb07 | 3404 | int i; |
1da177e4 | 3405 | dev_t dev; |
b670bde0 | 3406 | struct device *d; |
1da177e4 | 3407 | |
1da177e4 | 3408 | if (!driver->major) { |
37bdfb07 AC |
3409 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3410 | driver->num, driver->name); | |
1da177e4 LT |
3411 | if (!error) { |
3412 | driver->major = MAJOR(dev); | |
3413 | driver->minor_start = MINOR(dev); | |
3414 | } | |
3415 | } else { | |
3416 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3417 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3418 | } |
9bb8a3d4 | 3419 | if (error < 0) |
16a02081 | 3420 | goto err; |
1da177e4 | 3421 | |
7e73eca6 JS |
3422 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3423 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3424 | if (error) | |
3425 | goto err_unreg_char; | |
3426 | } | |
1da177e4 | 3427 | |
ca509f69 | 3428 | mutex_lock(&tty_mutex); |
1da177e4 | 3429 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3430 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3431 | |
3432 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3433 | for (i = 0; i < driver->num; i++) { |
3434 | d = tty_register_device(driver, i, NULL); | |
3435 | if (IS_ERR(d)) { | |
3436 | error = PTR_ERR(d); | |
16a02081 | 3437 | goto err_unreg_devs; |
b670bde0 VK |
3438 | } |
3439 | } | |
1da177e4 LT |
3440 | } |
3441 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3442 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3443 | return 0; |
b670bde0 | 3444 | |
16a02081 | 3445 | err_unreg_devs: |
b670bde0 VK |
3446 | for (i--; i >= 0; i--) |
3447 | tty_unregister_device(driver, i); | |
3448 | ||
3449 | mutex_lock(&tty_mutex); | |
3450 | list_del(&driver->tty_drivers); | |
3451 | mutex_unlock(&tty_mutex); | |
3452 | ||
9bb8a3d4 | 3453 | err_unreg_char: |
b670bde0 | 3454 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3455 | err: |
b670bde0 | 3456 | return error; |
1da177e4 | 3457 | } |
1da177e4 LT |
3458 | EXPORT_SYMBOL(tty_register_driver); |
3459 | ||
3460 | /* | |
3461 | * Called by a tty driver to unregister itself. | |
3462 | */ | |
3463 | int tty_unregister_driver(struct tty_driver *driver) | |
3464 | { | |
7d7b93c1 AC |
3465 | #if 0 |
3466 | /* FIXME */ | |
1da177e4 LT |
3467 | if (driver->refcount) |
3468 | return -EBUSY; | |
7d7b93c1 | 3469 | #endif |
1da177e4 LT |
3470 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3471 | driver->num); | |
ca509f69 | 3472 | mutex_lock(&tty_mutex); |
1da177e4 | 3473 | list_del(&driver->tty_drivers); |
ca509f69 | 3474 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3475 | return 0; |
3476 | } | |
7d7b93c1 | 3477 | |
1da177e4 LT |
3478 | EXPORT_SYMBOL(tty_unregister_driver); |
3479 | ||
24ec839c PZ |
3480 | dev_t tty_devnum(struct tty_struct *tty) |
3481 | { | |
3482 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3483 | } | |
3484 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3485 | |
d81ed103 AC |
3486 | void tty_default_fops(struct file_operations *fops) |
3487 | { | |
3488 | *fops = tty_fops; | |
3489 | } | |
3490 | ||
1da177e4 LT |
3491 | /* |
3492 | * Initialize the console device. This is called *early*, so | |
3493 | * we can't necessarily depend on lots of kernel help here. | |
3494 | * Just do some early initializations, and do the complex setup | |
3495 | * later. | |
3496 | */ | |
3497 | void __init console_init(void) | |
3498 | { | |
3499 | initcall_t *call; | |
3500 | ||
3501 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3502 | tty_ldisc_begin(); |
1da177e4 LT |
3503 | |
3504 | /* | |
37bdfb07 | 3505 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3506 | * inform about problems etc.. |
3507 | */ | |
1da177e4 LT |
3508 | call = __con_initcall_start; |
3509 | while (call < __con_initcall_end) { | |
3510 | (*call)(); | |
3511 | call++; | |
3512 | } | |
3513 | } | |
3514 | ||
2c9ede55 | 3515 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3516 | { |
3517 | if (!mode) | |
3518 | return NULL; | |
3519 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3520 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3521 | *mode = 0666; | |
3522 | return NULL; | |
3523 | } | |
3524 | ||
1da177e4 LT |
3525 | static int __init tty_class_init(void) |
3526 | { | |
7fe845d1 | 3527 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3528 | if (IS_ERR(tty_class)) |
3529 | return PTR_ERR(tty_class); | |
e454cea2 | 3530 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3531 | return 0; |
3532 | } | |
3533 | ||
3534 | postcore_initcall(tty_class_init); | |
3535 | ||
3536 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3537 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3538 | |
fbc92a34 KS |
3539 | static ssize_t show_cons_active(struct device *dev, |
3540 | struct device_attribute *attr, char *buf) | |
3541 | { | |
3542 | struct console *cs[16]; | |
3543 | int i = 0; | |
3544 | struct console *c; | |
3545 | ssize_t count = 0; | |
3546 | ||
ac751efa | 3547 | console_lock(); |
a2a6a822 | 3548 | for_each_console(c) { |
fbc92a34 KS |
3549 | if (!c->device) |
3550 | continue; | |
3551 | if (!c->write) | |
3552 | continue; | |
3553 | if ((c->flags & CON_ENABLED) == 0) | |
3554 | continue; | |
3555 | cs[i++] = c; | |
3556 | if (i >= ARRAY_SIZE(cs)) | |
3557 | break; | |
3558 | } | |
723abd87 HR |
3559 | while (i--) { |
3560 | int index = cs[i]->index; | |
3561 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3562 | ||
3563 | /* don't resolve tty0 as some programs depend on it */ | |
3564 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3565 | count += tty_line_name(drv, index, buf + count); | |
3566 | else | |
3567 | count += sprintf(buf + count, "%s%d", | |
3568 | cs[i]->name, cs[i]->index); | |
3569 | ||
3570 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3571 | } | |
ac751efa | 3572 | console_unlock(); |
fbc92a34 KS |
3573 | |
3574 | return count; | |
3575 | } | |
3576 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3577 | ||
3578 | static struct device *consdev; | |
3579 | ||
3580 | void console_sysfs_notify(void) | |
3581 | { | |
3582 | if (consdev) | |
3583 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3584 | } | |
3585 | ||
1da177e4 LT |
3586 | /* |
3587 | * Ok, now we can initialize the rest of the tty devices and can count | |
3588 | * on memory allocations, interrupts etc.. | |
3589 | */ | |
31d1d48e | 3590 | int __init tty_init(void) |
1da177e4 LT |
3591 | { |
3592 | cdev_init(&tty_cdev, &tty_fops); | |
3593 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3594 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3595 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3596 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3597 | |
3598 | cdev_init(&console_cdev, &console_fops); | |
3599 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3600 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3601 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3602 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3603 | "console"); |
fbc92a34 KS |
3604 | if (IS_ERR(consdev)) |
3605 | consdev = NULL; | |
3606 | else | |
a2a6a822 | 3607 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3608 | |
1da177e4 | 3609 | #ifdef CONFIG_VT |
d81ed103 | 3610 | vty_init(&console_fops); |
1da177e4 LT |
3611 | #endif |
3612 | return 0; | |
3613 | } | |
31d1d48e | 3614 |