Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | |
101 | #include <linux/kbd_kern.h> | |
102 | #include <linux/vt_kern.h> | |
103 | #include <linux/selection.h> | |
1da177e4 LT |
104 | |
105 | #include <linux/kmod.h> | |
b488893a | 106 | #include <linux/nsproxy.h> |
1da177e4 LT |
107 | |
108 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
109 | #ifdef TTY_DEBUG_HANGUP |
110 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
111 | #else | |
112 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
113 | #endif | |
1da177e4 LT |
114 | |
115 | #define TTY_PARANOIA_CHECK 1 | |
116 | #define CHECK_TTY_COUNT 1 | |
117 | ||
edc6afc5 | 118 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
119 | .c_iflag = ICRNL | IXON, |
120 | .c_oflag = OPOST | ONLCR, | |
121 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
122 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
123 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
124 | .c_cc = INIT_C_CC, |
125 | .c_ispeed = 38400, | |
126 | .c_ospeed = 38400 | |
1da177e4 LT |
127 | }; |
128 | ||
129 | EXPORT_SYMBOL(tty_std_termios); | |
130 | ||
131 | /* This list gets poked at by procfs and various bits of boot up code. This | |
132 | could do with some rationalisation such as pulling the tty proc function | |
133 | into this file */ | |
37bdfb07 | 134 | |
1da177e4 LT |
135 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
136 | ||
24ec839c | 137 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 138 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 139 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 140 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 141 | |
ee2ffa0d NP |
142 | /* Spinlock to protect the tty->tty_files list */ |
143 | DEFINE_SPINLOCK(tty_files_lock); | |
144 | ||
1da177e4 LT |
145 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
146 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
147 | ssize_t redirected_tty_write(struct file *, const char __user *, |
148 | size_t, loff_t *); | |
1da177e4 LT |
149 | static unsigned int tty_poll(struct file *, poll_table *); |
150 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 151 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 152 | #ifdef CONFIG_COMPAT |
37bdfb07 | 153 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
154 | unsigned long arg); |
155 | #else | |
156 | #define tty_compat_ioctl NULL | |
157 | #endif | |
ec79d605 | 158 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 159 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 160 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 161 | |
af9b897e AC |
162 | /** |
163 | * free_tty_struct - free a disused tty | |
164 | * @tty: tty struct to free | |
165 | * | |
166 | * Free the write buffers, tty queue and tty memory itself. | |
167 | * | |
168 | * Locking: none. Must be called after tty is definitely unused | |
169 | */ | |
170 | ||
bf970ee4 | 171 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 172 | { |
dc6802a7 DC |
173 | if (!tty) |
174 | return; | |
a211b1af | 175 | put_device(tty->dev); |
1da177e4 | 176 | kfree(tty->write_buf); |
89c8d91e | 177 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
178 | kfree(tty); |
179 | } | |
180 | ||
d996b62a NP |
181 | static inline struct tty_struct *file_tty(struct file *file) |
182 | { | |
183 | return ((struct tty_file_private *)file->private_data)->tty; | |
184 | } | |
185 | ||
fa90e1c9 | 186 | int tty_alloc_file(struct file *file) |
d996b62a NP |
187 | { |
188 | struct tty_file_private *priv; | |
189 | ||
f573bd17 PE |
190 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
191 | if (!priv) | |
192 | return -ENOMEM; | |
d996b62a | 193 | |
fa90e1c9 JS |
194 | file->private_data = priv; |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | /* Associate a new file with the tty structure */ | |
200 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
201 | { | |
202 | struct tty_file_private *priv = file->private_data; | |
203 | ||
d996b62a NP |
204 | priv->tty = tty; |
205 | priv->file = file; | |
d996b62a NP |
206 | |
207 | spin_lock(&tty_files_lock); | |
208 | list_add(&priv->list, &tty->tty_files); | |
209 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 210 | } |
f573bd17 | 211 | |
fa90e1c9 JS |
212 | /** |
213 | * tty_free_file - free file->private_data | |
214 | * | |
215 | * This shall be used only for fail path handling when tty_add_file was not | |
216 | * called yet. | |
217 | */ | |
218 | void tty_free_file(struct file *file) | |
219 | { | |
220 | struct tty_file_private *priv = file->private_data; | |
221 | ||
222 | file->private_data = NULL; | |
223 | kfree(priv); | |
d996b62a NP |
224 | } |
225 | ||
226 | /* Delete file from its tty */ | |
2520e274 | 227 | static void tty_del_file(struct file *file) |
d996b62a NP |
228 | { |
229 | struct tty_file_private *priv = file->private_data; | |
230 | ||
231 | spin_lock(&tty_files_lock); | |
232 | list_del(&priv->list); | |
233 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 234 | tty_free_file(file); |
d996b62a NP |
235 | } |
236 | ||
237 | ||
1da177e4 LT |
238 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
239 | ||
af9b897e AC |
240 | /** |
241 | * tty_name - return tty naming | |
242 | * @tty: tty structure | |
af9b897e AC |
243 | * |
244 | * Convert a tty structure into a name. The name reflects the kernel | |
245 | * naming policy and if udev is in use may not reflect user space | |
246 | * | |
247 | * Locking: none | |
248 | */ | |
249 | ||
429b4749 | 250 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
251 | { |
252 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
253 | return "NULL tty"; |
254 | return tty->name; | |
1da177e4 LT |
255 | } |
256 | ||
257 | EXPORT_SYMBOL(tty_name); | |
258 | ||
d769a669 | 259 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
260 | const char *routine) |
261 | { | |
262 | #ifdef TTY_PARANOIA_CHECK | |
263 | if (!tty) { | |
264 | printk(KERN_WARNING | |
265 | "null TTY for (%d:%d) in %s\n", | |
266 | imajor(inode), iminor(inode), routine); | |
267 | return 1; | |
268 | } | |
269 | if (tty->magic != TTY_MAGIC) { | |
270 | printk(KERN_WARNING | |
271 | "bad magic number for tty struct (%d:%d) in %s\n", | |
272 | imajor(inode), iminor(inode), routine); | |
273 | return 1; | |
274 | } | |
275 | #endif | |
276 | return 0; | |
277 | } | |
278 | ||
deb287e7 | 279 | /* Caller must hold tty_lock */ |
1da177e4 LT |
280 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
281 | { | |
282 | #ifdef CHECK_TTY_COUNT | |
283 | struct list_head *p; | |
284 | int count = 0; | |
37bdfb07 | 285 | |
ee2ffa0d | 286 | spin_lock(&tty_files_lock); |
1da177e4 LT |
287 | list_for_each(p, &tty->tty_files) { |
288 | count++; | |
289 | } | |
ee2ffa0d | 290 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
291 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
292 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
293 | tty->link && tty->link->count) | |
294 | count++; | |
295 | if (tty->count != count) { | |
296 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
297 | "!= #fd's(%d) in %s\n", | |
298 | tty->name, tty->count, count, routine); | |
299 | return count; | |
24ec839c | 300 | } |
1da177e4 LT |
301 | #endif |
302 | return 0; | |
303 | } | |
304 | ||
af9b897e AC |
305 | /** |
306 | * get_tty_driver - find device of a tty | |
307 | * @dev_t: device identifier | |
308 | * @index: returns the index of the tty | |
309 | * | |
310 | * This routine returns a tty driver structure, given a device number | |
311 | * and also passes back the index number. | |
312 | * | |
313 | * Locking: caller must hold tty_mutex | |
1da177e4 | 314 | */ |
af9b897e | 315 | |
1da177e4 LT |
316 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
317 | { | |
318 | struct tty_driver *p; | |
319 | ||
320 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
321 | dev_t base = MKDEV(p->major, p->minor_start); | |
322 | if (device < base || device >= base + p->num) | |
323 | continue; | |
324 | *index = device - base; | |
7d7b93c1 | 325 | return tty_driver_kref_get(p); |
1da177e4 LT |
326 | } |
327 | return NULL; | |
328 | } | |
329 | ||
f2d937f3 JW |
330 | #ifdef CONFIG_CONSOLE_POLL |
331 | ||
332 | /** | |
333 | * tty_find_polling_driver - find device of a polled tty | |
334 | * @name: name string to match | |
335 | * @line: pointer to resulting tty line nr | |
336 | * | |
337 | * This routine returns a tty driver structure, given a name | |
338 | * and the condition that the tty driver is capable of polled | |
339 | * operation. | |
340 | */ | |
341 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
342 | { | |
343 | struct tty_driver *p, *res = NULL; | |
344 | int tty_line = 0; | |
0dca0fd2 | 345 | int len; |
5f0878ac | 346 | char *str, *stp; |
f2d937f3 | 347 | |
0dca0fd2 JW |
348 | for (str = name; *str; str++) |
349 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
350 | break; | |
351 | if (!*str) | |
352 | return NULL; | |
353 | ||
354 | len = str - name; | |
355 | tty_line = simple_strtoul(str, &str, 10); | |
356 | ||
f2d937f3 JW |
357 | mutex_lock(&tty_mutex); |
358 | /* Search through the tty devices to look for a match */ | |
359 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
360 | if (strncmp(name, p->name, len) != 0) |
361 | continue; | |
5f0878ac AC |
362 | stp = str; |
363 | if (*stp == ',') | |
364 | stp++; | |
365 | if (*stp == '\0') | |
366 | stp = NULL; | |
f2d937f3 | 367 | |
6eb68d6f | 368 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 369 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 370 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
371 | *line = tty_line; |
372 | break; | |
373 | } | |
374 | } | |
375 | mutex_unlock(&tty_mutex); | |
376 | ||
377 | return res; | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
380 | #endif | |
381 | ||
af9b897e AC |
382 | /** |
383 | * tty_check_change - check for POSIX terminal changes | |
384 | * @tty: tty to check | |
385 | * | |
386 | * If we try to write to, or set the state of, a terminal and we're | |
387 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
388 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
389 | * | |
978e595f | 390 | * Locking: ctrl_lock |
1da177e4 | 391 | */ |
af9b897e | 392 | |
2812d9e9 | 393 | int __tty_check_change(struct tty_struct *tty, int sig) |
1da177e4 | 394 | { |
47f86834 | 395 | unsigned long flags; |
2812d9e9 | 396 | struct pid *pgrp, *tty_pgrp; |
47f86834 AC |
397 | int ret = 0; |
398 | ||
1da177e4 LT |
399 | if (current->signal->tty != tty) |
400 | return 0; | |
47f86834 | 401 | |
6719693c PD |
402 | rcu_read_lock(); |
403 | pgrp = task_pgrp(current); | |
404 | ||
47f86834 | 405 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
2812d9e9 | 406 | tty_pgrp = tty->pgrp; |
9ffee4cb | 407 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
6719693c | 408 | |
2812d9e9 PH |
409 | if (tty_pgrp && pgrp != tty->pgrp) { |
410 | if (is_ignored(sig)) { | |
411 | if (sig == SIGTTIN) | |
412 | ret = -EIO; | |
413 | } else if (is_current_pgrp_orphaned()) | |
414 | ret = -EIO; | |
415 | else { | |
416 | kill_pgrp(pgrp, sig, 1); | |
417 | set_thread_flag(TIF_SIGPENDING); | |
418 | ret = -ERESTARTSYS; | |
419 | } | |
47f86834 | 420 | } |
6719693c | 421 | rcu_read_unlock(); |
2812d9e9 PH |
422 | |
423 | if (!tty_pgrp) { | |
424 | pr_warn("%s: tty_check_change: sig=%d, tty->pgrp == NULL!\n", | |
425 | tty_name(tty), sig); | |
426 | } | |
427 | ||
47f86834 | 428 | return ret; |
1da177e4 LT |
429 | } |
430 | ||
2812d9e9 PH |
431 | int tty_check_change(struct tty_struct *tty) |
432 | { | |
433 | return __tty_check_change(tty, SIGTTOU); | |
434 | } | |
1da177e4 LT |
435 | EXPORT_SYMBOL(tty_check_change); |
436 | ||
37bdfb07 | 437 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
438 | size_t count, loff_t *ppos) |
439 | { | |
440 | return 0; | |
441 | } | |
442 | ||
37bdfb07 | 443 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
444 | size_t count, loff_t *ppos) |
445 | { | |
446 | return -EIO; | |
447 | } | |
448 | ||
449 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 450 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
451 | { |
452 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
453 | } | |
454 | ||
04f378b1 AC |
455 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
456 | unsigned long arg) | |
38ad2ed0 PF |
457 | { |
458 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
459 | } | |
460 | ||
37bdfb07 | 461 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 462 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
463 | { |
464 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
465 | } | |
466 | ||
62322d25 | 467 | static const struct file_operations tty_fops = { |
1da177e4 LT |
468 | .llseek = no_llseek, |
469 | .read = tty_read, | |
470 | .write = tty_write, | |
471 | .poll = tty_poll, | |
04f378b1 | 472 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 473 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
474 | .open = tty_open, |
475 | .release = tty_release, | |
476 | .fasync = tty_fasync, | |
477 | }; | |
478 | ||
62322d25 | 479 | static const struct file_operations console_fops = { |
1da177e4 LT |
480 | .llseek = no_llseek, |
481 | .read = tty_read, | |
482 | .write = redirected_tty_write, | |
483 | .poll = tty_poll, | |
04f378b1 | 484 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 485 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
486 | .open = tty_open, |
487 | .release = tty_release, | |
488 | .fasync = tty_fasync, | |
489 | }; | |
490 | ||
62322d25 | 491 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
492 | .llseek = no_llseek, |
493 | .read = hung_up_tty_read, | |
494 | .write = hung_up_tty_write, | |
495 | .poll = hung_up_tty_poll, | |
04f378b1 | 496 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 497 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
498 | .release = tty_release, |
499 | }; | |
500 | ||
501 | static DEFINE_SPINLOCK(redirect_lock); | |
502 | static struct file *redirect; | |
503 | ||
11d9befd PH |
504 | |
505 | void proc_clear_tty(struct task_struct *p) | |
506 | { | |
507 | unsigned long flags; | |
508 | struct tty_struct *tty; | |
509 | spin_lock_irqsave(&p->sighand->siglock, flags); | |
510 | tty = p->signal->tty; | |
511 | p->signal->tty = NULL; | |
512 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
513 | tty_kref_put(tty); | |
514 | } | |
515 | ||
2c411c11 PH |
516 | /** |
517 | * proc_set_tty - set the controlling terminal | |
518 | * | |
519 | * Only callable by the session leader and only if it does not already have | |
520 | * a controlling terminal. | |
521 | * | |
e218eb32 PH |
522 | * Caller must hold: tty_lock() |
523 | * a readlock on tasklist_lock | |
2c411c11 PH |
524 | * sighand lock |
525 | */ | |
bce65f18 | 526 | static void __proc_set_tty(struct tty_struct *tty) |
11d9befd | 527 | { |
ae28fa72 PH |
528 | unsigned long flags; |
529 | ||
ae28fa72 | 530 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
a361858d PH |
531 | /* |
532 | * The session and fg pgrp references will be non-NULL if | |
533 | * tiocsctty() is stealing the controlling tty | |
534 | */ | |
ae28fa72 PH |
535 | put_pid(tty->session); |
536 | put_pid(tty->pgrp); | |
537 | tty->pgrp = get_pid(task_pgrp(current)); | |
538 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
539 | tty->session = get_pid(task_session(current)); | |
540 | if (current->signal->tty) { | |
e2dfa3d3 PH |
541 | tty_debug(tty, "current tty %s not NULL!!\n", |
542 | current->signal->tty->name); | |
ae28fa72 | 543 | tty_kref_put(current->signal->tty); |
11d9befd | 544 | } |
bce65f18 PH |
545 | put_pid(current->signal->tty_old_pgrp); |
546 | current->signal->tty = tty_kref_get(tty); | |
547 | current->signal->tty_old_pgrp = NULL; | |
11d9befd PH |
548 | } |
549 | ||
bce65f18 | 550 | static void proc_set_tty(struct tty_struct *tty) |
11d9befd | 551 | { |
bce65f18 PH |
552 | spin_lock_irq(¤t->sighand->siglock); |
553 | __proc_set_tty(tty); | |
554 | spin_unlock_irq(¤t->sighand->siglock); | |
11d9befd PH |
555 | } |
556 | ||
557 | struct tty_struct *get_current_tty(void) | |
558 | { | |
559 | struct tty_struct *tty; | |
560 | unsigned long flags; | |
561 | ||
562 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
563 | tty = tty_kref_get(current->signal->tty); | |
564 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
565 | return tty; | |
566 | } | |
567 | EXPORT_SYMBOL_GPL(get_current_tty); | |
568 | ||
569 | static void session_clear_tty(struct pid *session) | |
570 | { | |
571 | struct task_struct *p; | |
572 | do_each_pid_task(session, PIDTYPE_SID, p) { | |
573 | proc_clear_tty(p); | |
574 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
575 | } | |
576 | ||
1da177e4 LT |
577 | /** |
578 | * tty_wakeup - request more data | |
579 | * @tty: terminal | |
580 | * | |
581 | * Internal and external helper for wakeups of tty. This function | |
582 | * informs the line discipline if present that the driver is ready | |
583 | * to receive more output data. | |
584 | */ | |
37bdfb07 | 585 | |
1da177e4 LT |
586 | void tty_wakeup(struct tty_struct *tty) |
587 | { | |
588 | struct tty_ldisc *ld; | |
37bdfb07 | 589 | |
1da177e4 LT |
590 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
591 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 592 | if (ld) { |
a352def2 AC |
593 | if (ld->ops->write_wakeup) |
594 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
595 | tty_ldisc_deref(ld); |
596 | } | |
597 | } | |
4b19449d | 598 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
599 | } |
600 | ||
601 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
602 | ||
ea648a47 PH |
603 | /** |
604 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
605 | * @tty controlling tty |
606 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 607 | * |
f91e2590 PH |
608 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
609 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
610 | * |
611 | * Returns the number of processes in the session with this tty | |
612 | * as their controlling terminal. This value is used to drop | |
613 | * tty references for those processes. | |
614 | */ | |
f91e2590 | 615 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
616 | { |
617 | struct task_struct *p; | |
ea648a47 | 618 | int refs = 0; |
f91e2590 | 619 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
620 | |
621 | read_lock(&tasklist_lock); | |
622 | if (tty->session) { | |
623 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
624 | spin_lock_irq(&p->sighand->siglock); | |
625 | if (p->signal->tty == tty) { | |
626 | p->signal->tty = NULL; | |
627 | /* We defer the dereferences outside fo | |
628 | the tasklist lock */ | |
629 | refs++; | |
630 | } | |
631 | if (!p->signal->leader) { | |
632 | spin_unlock_irq(&p->sighand->siglock); | |
633 | continue; | |
634 | } | |
635 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
636 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
637 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 638 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 639 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
640 | if (tty->pgrp) |
641 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 642 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
643 | spin_unlock_irq(&p->sighand->siglock); |
644 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
645 | } | |
646 | read_unlock(&tasklist_lock); | |
647 | ||
f91e2590 PH |
648 | if (tty_pgrp) { |
649 | if (exit_session) | |
650 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
651 | put_pid(tty_pgrp); | |
652 | } | |
653 | ||
ea648a47 PH |
654 | return refs; |
655 | } | |
656 | ||
af9b897e | 657 | /** |
11dbf203 | 658 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 659 | * @work: tty device |
af9b897e | 660 | * |
ef4f527c | 661 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
662 | * synchronous but doesn't hold any locks, so we need to make sure we |
663 | * have the appropriate locks for what we're doing. | |
664 | * | |
665 | * The hangup event clears any pending redirections onto the hung up | |
666 | * device. It ensures future writes will error and it does the needed | |
667 | * line discipline hangup and signal delivery. The tty object itself | |
668 | * remains intact. | |
669 | * | |
670 | * Locking: | |
ec79d605 | 671 | * BTM |
24ec839c PZ |
672 | * redirect lock for undoing redirection |
673 | * file list lock for manipulating list of ttys | |
137084bb | 674 | * tty_ldiscs_lock from called functions |
6a1c0680 | 675 | * termios_rwsem resetting termios data |
24ec839c PZ |
676 | * tasklist_lock to walk task list for hangup event |
677 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 678 | */ |
f91e2590 | 679 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 680 | { |
37bdfb07 | 681 | struct file *cons_filp = NULL; |
1da177e4 | 682 | struct file *filp, *f = NULL; |
d996b62a | 683 | struct tty_file_private *priv; |
1da177e4 | 684 | int closecount = 0, n; |
ea648a47 | 685 | int refs; |
1da177e4 LT |
686 | |
687 | if (!tty) | |
688 | return; | |
689 | ||
1da177e4 LT |
690 | |
691 | spin_lock(&redirect_lock); | |
d996b62a | 692 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
693 | f = redirect; |
694 | redirect = NULL; | |
695 | } | |
696 | spin_unlock(&redirect_lock); | |
37bdfb07 | 697 | |
89c8d91e | 698 | tty_lock(tty); |
11dbf203 | 699 | |
cb50e523 PH |
700 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
701 | tty_unlock(tty); | |
702 | return; | |
703 | } | |
704 | ||
ec79d605 AB |
705 | /* inuse_filps is protected by the single tty lock, |
706 | this really needs to change if we want to flush the | |
707 | workqueue with the lock held */ | |
11dbf203 | 708 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 709 | |
ee2ffa0d | 710 | spin_lock(&tty_files_lock); |
1da177e4 | 711 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
712 | list_for_each_entry(priv, &tty->tty_files, list) { |
713 | filp = priv->file; | |
1da177e4 LT |
714 | if (filp->f_op->write == redirected_tty_write) |
715 | cons_filp = filp; | |
716 | if (filp->f_op->write != tty_write) | |
717 | continue; | |
718 | closecount++; | |
ec79d605 | 719 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
720 | filp->f_op = &hung_up_tty_fops; |
721 | } | |
ee2ffa0d | 722 | spin_unlock(&tty_files_lock); |
37bdfb07 | 723 | |
25fdf243 PH |
724 | refs = tty_signal_session_leader(tty, exit_session); |
725 | /* Account for the p->signal references we killed */ | |
726 | while (refs--) | |
727 | tty_kref_put(tty); | |
728 | ||
c65c9bc3 | 729 | tty_ldisc_hangup(tty); |
37bdfb07 | 730 | |
20cc225b | 731 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 732 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 733 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
734 | put_pid(tty->session); |
735 | put_pid(tty->pgrp); | |
ab521dc0 EB |
736 | tty->session = NULL; |
737 | tty->pgrp = NULL; | |
1da177e4 | 738 | tty->ctrl_status = 0; |
20cc225b | 739 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 740 | |
1da177e4 | 741 | /* |
37bdfb07 AC |
742 | * If one of the devices matches a console pointer, we |
743 | * cannot just call hangup() because that will cause | |
744 | * tty->count and state->count to go out of sync. | |
745 | * So we just call close() the right number of times. | |
1da177e4 LT |
746 | */ |
747 | if (cons_filp) { | |
f34d7a5b | 748 | if (tty->ops->close) |
1da177e4 | 749 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
750 | tty->ops->close(tty, cons_filp); |
751 | } else if (tty->ops->hangup) | |
7c6d340f | 752 | tty->ops->hangup(tty); |
37bdfb07 AC |
753 | /* |
754 | * We don't want to have driver/ldisc interactions beyond | |
755 | * the ones we did here. The driver layer expects no | |
756 | * calls after ->hangup() from the ldisc side. However we | |
757 | * can't yet guarantee all that. | |
758 | */ | |
1da177e4 | 759 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 760 | tty_unlock(tty); |
11dbf203 | 761 | |
1da177e4 LT |
762 | if (f) |
763 | fput(f); | |
764 | } | |
765 | ||
ddcd9fb6 AB |
766 | static void do_tty_hangup(struct work_struct *work) |
767 | { | |
768 | struct tty_struct *tty = | |
769 | container_of(work, struct tty_struct, hangup_work); | |
770 | ||
f91e2590 | 771 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
772 | } |
773 | ||
af9b897e AC |
774 | /** |
775 | * tty_hangup - trigger a hangup event | |
776 | * @tty: tty to hangup | |
777 | * | |
778 | * A carrier loss (virtual or otherwise) has occurred on this like | |
779 | * schedule a hangup sequence to run after this event. | |
780 | */ | |
781 | ||
37bdfb07 | 782 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 783 | { |
accff793 | 784 | tty_debug_hangup(tty, "\n"); |
1da177e4 LT |
785 | schedule_work(&tty->hangup_work); |
786 | } | |
787 | ||
788 | EXPORT_SYMBOL(tty_hangup); | |
789 | ||
af9b897e AC |
790 | /** |
791 | * tty_vhangup - process vhangup | |
792 | * @tty: tty to hangup | |
793 | * | |
794 | * The user has asked via system call for the terminal to be hung up. | |
795 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 796 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
797 | */ |
798 | ||
37bdfb07 | 799 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 800 | { |
accff793 | 801 | tty_debug_hangup(tty, "\n"); |
f91e2590 | 802 | __tty_hangup(tty, 0); |
1da177e4 | 803 | } |
37bdfb07 | 804 | |
1da177e4 LT |
805 | EXPORT_SYMBOL(tty_vhangup); |
806 | ||
11dbf203 | 807 | |
2cb5998b AC |
808 | /** |
809 | * tty_vhangup_self - process vhangup for own ctty | |
810 | * | |
811 | * Perform a vhangup on the current controlling tty | |
812 | */ | |
813 | ||
814 | void tty_vhangup_self(void) | |
815 | { | |
816 | struct tty_struct *tty; | |
817 | ||
2cb5998b AC |
818 | tty = get_current_tty(); |
819 | if (tty) { | |
820 | tty_vhangup(tty); | |
821 | tty_kref_put(tty); | |
822 | } | |
2cb5998b AC |
823 | } |
824 | ||
f91e2590 PH |
825 | /** |
826 | * tty_vhangup_session - hangup session leader exit | |
827 | * @tty: tty to hangup | |
828 | * | |
829 | * The session leader is exiting and hanging up its controlling terminal. | |
830 | * Every process in the foreground process group is signalled SIGHUP. | |
831 | * | |
832 | * We do this synchronously so that when the syscall returns the process | |
833 | * is complete. That guarantee is necessary for security reasons. | |
834 | */ | |
835 | ||
44a459fd | 836 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 837 | { |
accff793 | 838 | tty_debug_hangup(tty, "\n"); |
f91e2590 PH |
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); |
accff793 PH |
932 | } else |
933 | tty_debug_hangup(tty, "no current tty\n"); | |
1da177e4 | 934 | |
c70dbb1e | 935 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
936 | /* Now clear signal->tty under the lock */ |
937 | read_lock(&tasklist_lock); | |
ab521dc0 | 938 | session_clear_tty(task_session(current)); |
1da177e4 | 939 | read_unlock(&tasklist_lock); |
1da177e4 LT |
940 | } |
941 | ||
98a27ba4 EB |
942 | /** |
943 | * | |
944 | * no_tty - Ensure the current process does not have a controlling tty | |
945 | */ | |
946 | void no_tty(void) | |
947 | { | |
3af502b9 AC |
948 | /* FIXME: Review locking here. The tty_lock never covered any race |
949 | between a new association and proc_clear_tty but possible we need | |
950 | to protect against this anyway */ | |
98a27ba4 | 951 | struct task_struct *tsk = current; |
5ec93d11 | 952 | disassociate_ctty(0); |
98a27ba4 EB |
953 | proc_clear_tty(tsk); |
954 | } | |
955 | ||
af9b897e AC |
956 | |
957 | /** | |
beb7dd86 | 958 | * stop_tty - propagate flow control |
af9b897e AC |
959 | * @tty: tty to stop |
960 | * | |
01adc807 | 961 | * Perform flow control to the driver. May be called |
af9b897e AC |
962 | * on an already stopped device and will not re-call the driver |
963 | * method. | |
964 | * | |
965 | * This functionality is used by both the line disciplines for | |
966 | * halting incoming flow and by the driver. It may therefore be | |
967 | * called from any context, may be under the tty atomic_write_lock | |
968 | * but not always. | |
969 | * | |
970 | * Locking: | |
f9e053dc | 971 | * flow_lock |
af9b897e AC |
972 | */ |
973 | ||
f9e053dc | 974 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 975 | { |
f9e053dc | 976 | if (tty->stopped) |
1da177e4 LT |
977 | return; |
978 | tty->stopped = 1; | |
f34d7a5b | 979 | if (tty->ops->stop) |
c961bfb1 | 980 | tty->ops->stop(tty); |
1da177e4 LT |
981 | } |
982 | ||
f9e053dc PH |
983 | void stop_tty(struct tty_struct *tty) |
984 | { | |
985 | unsigned long flags; | |
986 | ||
987 | spin_lock_irqsave(&tty->flow_lock, flags); | |
988 | __stop_tty(tty); | |
989 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
990 | } | |
1da177e4 LT |
991 | EXPORT_SYMBOL(stop_tty); |
992 | ||
af9b897e | 993 | /** |
beb7dd86 | 994 | * start_tty - propagate flow control |
af9b897e AC |
995 | * @tty: tty to start |
996 | * | |
01adc807 PH |
997 | * Start a tty that has been stopped if at all possible. If this |
998 | * tty was previous stopped and is now being started, the driver | |
999 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
1000 | * |
1001 | * Locking: | |
f9e053dc | 1002 | * flow_lock |
af9b897e AC |
1003 | */ |
1004 | ||
f9e053dc | 1005 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 1006 | { |
f9e053dc | 1007 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
1008 | return; |
1009 | tty->stopped = 0; | |
f34d7a5b | 1010 | if (tty->ops->start) |
c961bfb1 | 1011 | tty->ops->start(tty); |
1da177e4 | 1012 | tty_wakeup(tty); |
1da177e4 LT |
1013 | } |
1014 | ||
f9e053dc PH |
1015 | void start_tty(struct tty_struct *tty) |
1016 | { | |
1017 | unsigned long flags; | |
1018 | ||
1019 | spin_lock_irqsave(&tty->flow_lock, flags); | |
1020 | __start_tty(tty); | |
1021 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
1022 | } | |
1da177e4 LT |
1023 | EXPORT_SYMBOL(start_tty); |
1024 | ||
37b7f3c7 JS |
1025 | static void tty_update_time(struct timespec *time) |
1026 | { | |
f0bf0bd0 | 1027 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
1028 | |
1029 | /* | |
1030 | * We only care if the two values differ in anything other than the | |
1031 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
1032 | * the time of the tty device, otherwise it could be construded as a | |
1033 | * security leak to let userspace know the exact timing of the tty. | |
1034 | */ | |
1035 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
1036 | time->tv_sec = sec; |
1037 | } | |
1038 | ||
af9b897e AC |
1039 | /** |
1040 | * tty_read - read method for tty device files | |
1041 | * @file: pointer to tty file | |
1042 | * @buf: user buffer | |
1043 | * @count: size of user buffer | |
1044 | * @ppos: unused | |
1045 | * | |
1046 | * Perform the read system call function on this terminal device. Checks | |
1047 | * for hung up devices before calling the line discipline method. | |
1048 | * | |
1049 | * Locking: | |
47f86834 AC |
1050 | * Locks the line discipline internally while needed. Multiple |
1051 | * read calls may be outstanding in parallel. | |
af9b897e AC |
1052 | */ |
1053 | ||
37bdfb07 | 1054 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
1055 | loff_t *ppos) |
1056 | { | |
1057 | int i; | |
37b7f3c7 | 1058 | struct inode *inode = file_inode(file); |
d996b62a | 1059 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1060 | struct tty_ldisc *ld; |
1061 | ||
37b7f3c7 | 1062 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1063 | return -EIO; |
1064 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1065 | return -EIO; | |
1066 | ||
1067 | /* We want to wait for the line discipline to sort out in this | |
1068 | situation */ | |
1069 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 1070 | if (ld->ops->read) |
c961bfb1 | 1071 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
1072 | else |
1073 | i = -EIO; | |
1074 | tty_ldisc_deref(ld); | |
b0de59b5 | 1075 | |
37b7f3c7 JS |
1076 | if (i > 0) |
1077 | tty_update_time(&inode->i_atime); | |
1078 | ||
1da177e4 LT |
1079 | return i; |
1080 | } | |
1081 | ||
136d5258 | 1082 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
1083 | { |
1084 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1085 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1086 | } |
1087 | ||
136d5258 | 1088 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
1089 | { |
1090 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1091 | if (ndelay) | |
1092 | return -EAGAIN; | |
1093 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1094 | return -ERESTARTSYS; | |
1095 | } | |
1096 | return 0; | |
1097 | } | |
1098 | ||
1da177e4 LT |
1099 | /* |
1100 | * Split writes up in sane blocksizes to avoid | |
1101 | * denial-of-service type attacks | |
1102 | */ | |
1103 | static inline ssize_t do_tty_write( | |
1104 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1105 | struct tty_struct *tty, | |
1106 | struct file *file, | |
1107 | const char __user *buf, | |
1108 | size_t count) | |
1109 | { | |
9c1729db | 1110 | ssize_t ret, written = 0; |
1da177e4 | 1111 | unsigned int chunk; |
37bdfb07 | 1112 | |
9c1729db AC |
1113 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1114 | if (ret < 0) | |
1115 | return ret; | |
1da177e4 LT |
1116 | |
1117 | /* | |
1118 | * We chunk up writes into a temporary buffer. This | |
1119 | * simplifies low-level drivers immensely, since they | |
1120 | * don't have locking issues and user mode accesses. | |
1121 | * | |
1122 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1123 | * big chunk-size.. | |
1124 | * | |
1125 | * The default chunk-size is 2kB, because the NTTY | |
1126 | * layer has problems with bigger chunks. It will | |
1127 | * claim to be able to handle more characters than | |
1128 | * it actually does. | |
af9b897e AC |
1129 | * |
1130 | * FIXME: This can probably go away now except that 64K chunks | |
1131 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1132 | */ |
1133 | chunk = 2048; | |
1134 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1135 | chunk = 65536; | |
1136 | if (count < chunk) | |
1137 | chunk = count; | |
1138 | ||
70522e12 | 1139 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1140 | if (tty->write_cnt < chunk) { |
402fda92 | 1141 | unsigned char *buf_chunk; |
1da177e4 LT |
1142 | |
1143 | if (chunk < 1024) | |
1144 | chunk = 1024; | |
1145 | ||
402fda92 JW |
1146 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1147 | if (!buf_chunk) { | |
9c1729db AC |
1148 | ret = -ENOMEM; |
1149 | goto out; | |
1da177e4 LT |
1150 | } |
1151 | kfree(tty->write_buf); | |
1152 | tty->write_cnt = chunk; | |
402fda92 | 1153 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1154 | } |
1155 | ||
1156 | /* Do the write .. */ | |
1157 | for (;;) { | |
1158 | size_t size = count; | |
1159 | if (size > chunk) | |
1160 | size = chunk; | |
1161 | ret = -EFAULT; | |
1162 | if (copy_from_user(tty->write_buf, buf, size)) | |
1163 | break; | |
1da177e4 | 1164 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1165 | if (ret <= 0) |
1166 | break; | |
1167 | written += ret; | |
1168 | buf += ret; | |
1169 | count -= ret; | |
1170 | if (!count) | |
1171 | break; | |
1172 | ret = -ERESTARTSYS; | |
1173 | if (signal_pending(current)) | |
1174 | break; | |
1175 | cond_resched(); | |
1176 | } | |
37b7f3c7 JS |
1177 | if (written) { |
1178 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1179 | ret = written; |
37b7f3c7 | 1180 | } |
9c1729db AC |
1181 | out: |
1182 | tty_write_unlock(tty); | |
1da177e4 LT |
1183 | return ret; |
1184 | } | |
1185 | ||
95f9bfc6 AC |
1186 | /** |
1187 | * tty_write_message - write a message to a certain tty, not just the console. | |
1188 | * @tty: the destination tty_struct | |
1189 | * @msg: the message to write | |
1190 | * | |
1191 | * This is used for messages that need to be redirected to a specific tty. | |
1192 | * We don't put it into the syslog queue right now maybe in the future if | |
1193 | * really needed. | |
1194 | * | |
ec79d605 | 1195 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1196 | */ |
1197 | ||
1198 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1199 | { | |
95f9bfc6 AC |
1200 | if (tty) { |
1201 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1202 | tty_lock(tty); |
4b41b953 | 1203 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 1204 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 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 | |
86f2c00f PH |
1468 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1469 | return -EBUSY; | |
1470 | ||
23499705 | 1471 | tty->count++; |
23499705 | 1472 | |
36697529 | 1473 | WARN_ON(!tty->ldisc); |
23499705 SB |
1474 | |
1475 | return 0; | |
1476 | } | |
1477 | ||
af9b897e | 1478 | /** |
d81ed103 | 1479 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1480 | * @driver: tty driver we are opening a device on |
1481 | * @idx: device index | |
15582d36 | 1482 | * @ret_tty: returned tty structure |
af9b897e AC |
1483 | * |
1484 | * Prepare a tty device. This may not be a "new" clean device but | |
1485 | * could also be an active device. The pty drivers require special | |
1486 | * handling because of this. | |
1487 | * | |
1488 | * Locking: | |
1489 | * The function is called under the tty_mutex, which | |
1490 | * protects us from the tty struct or driver itself going away. | |
1491 | * | |
1492 | * On exit the tty device has the line discipline attached and | |
1493 | * a reference count of 1. If a pair was created for pty/tty use | |
1494 | * and the other was a pty master then it too has a reference count of 1. | |
1495 | * | |
1da177e4 | 1496 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1497 | * failed open. The new code protects the open with a mutex, so it's |
1498 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1499 | * relaxed for the (most common) case of reopening a tty. |
1500 | */ | |
af9b897e | 1501 | |
593a27c4 | 1502 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1503 | { |
bf970ee4 | 1504 | struct tty_struct *tty; |
73ec06fc | 1505 | int retval; |
1da177e4 | 1506 | |
1da177e4 LT |
1507 | /* |
1508 | * First time open is complex, especially for PTY devices. | |
1509 | * This code guarantees that either everything succeeds and the | |
1510 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1511 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1512 | * and locked termios may be retained.) |
1513 | */ | |
1514 | ||
73ec06fc AC |
1515 | if (!try_module_get(driver->owner)) |
1516 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1517 | |
2c964a2f | 1518 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1519 | if (!tty) { |
1520 | retval = -ENOMEM; | |
1521 | goto err_module_put; | |
1522 | } | |
1da177e4 | 1523 | |
89c8d91e | 1524 | tty_lock(tty); |
73ec06fc | 1525 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1526 | if (retval < 0) |
a9dccddb | 1527 | goto err_deinit_tty; |
8b0a88d5 | 1528 | |
04831dc1 JS |
1529 | if (!tty->port) |
1530 | tty->port = driver->ports[idx]; | |
1531 | ||
5d4121c0 JS |
1532 | WARN_RATELIMIT(!tty->port, |
1533 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1534 | __func__, tty->driver->name); | |
1535 | ||
967fab69 JS |
1536 | tty->port->itty = tty; |
1537 | ||
37bdfb07 | 1538 | /* |
1da177e4 | 1539 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1540 | * If we fail here just call release_tty to clean up. No need |
1541 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1542 | */ |
bf970ee4 | 1543 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1544 | if (retval) |
d5543503 | 1545 | goto err_release_tty; |
89c8d91e | 1546 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1547 | return tty; |
1da177e4 | 1548 | |
a9dccddb | 1549 | err_deinit_tty: |
89c8d91e | 1550 | tty_unlock(tty); |
a9dccddb | 1551 | deinitialize_tty_struct(tty); |
d5543503 JS |
1552 | free_tty_struct(tty); |
1553 | err_module_put: | |
1da177e4 | 1554 | module_put(driver->owner); |
d5543503 | 1555 | return ERR_PTR(retval); |
1da177e4 | 1556 | |
d5698c28 | 1557 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1558 | err_release_tty: |
89c8d91e | 1559 | tty_unlock(tty); |
5a3c6b25 | 1560 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1561 | "clearing slot %d\n", idx); |
d5698c28 | 1562 | release_tty(tty, idx); |
73ec06fc | 1563 | return ERR_PTR(retval); |
1da177e4 LT |
1564 | } |
1565 | ||
feebed65 AC |
1566 | void tty_free_termios(struct tty_struct *tty) |
1567 | { | |
1568 | struct ktermios *tp; | |
1569 | int idx = tty->index; | |
36b3c070 AC |
1570 | |
1571 | /* If the port is going to reset then it has no termios to save */ | |
1572 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1573 | return; | |
1574 | ||
1575 | /* Stash the termios data */ | |
1576 | tp = tty->driver->termios[idx]; | |
1577 | if (tp == NULL) { | |
1578 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1579 | if (tp == NULL) { | |
1580 | pr_warn("tty: no memory to save termios state.\n"); | |
1581 | return; | |
1582 | } | |
4ac5d705 | 1583 | tty->driver->termios[idx] = tp; |
feebed65 | 1584 | } |
36b3c070 | 1585 | *tp = tty->termios; |
feebed65 AC |
1586 | } |
1587 | EXPORT_SYMBOL(tty_free_termios); | |
1588 | ||
a2965b7b | 1589 | /** |
949aa64f PH |
1590 | * tty_flush_works - flush all works of a tty/pty pair |
1591 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1592 | * |
949aa64f | 1593 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1594 | */ |
1595 | static void tty_flush_works(struct tty_struct *tty) | |
1596 | { | |
1597 | flush_work(&tty->SAK_work); | |
1598 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1599 | if (tty->link) { |
1600 | flush_work(&tty->link->SAK_work); | |
1601 | flush_work(&tty->link->hangup_work); | |
1602 | } | |
a2965b7b | 1603 | } |
feebed65 | 1604 | |
af9b897e | 1605 | /** |
d5698c28 | 1606 | * release_one_tty - release tty structure memory |
9c9f4ded | 1607 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1608 | * |
1609 | * Releases memory associated with a tty structure, and clears out the | |
1610 | * driver table slots. This function is called when a device is no longer | |
1611 | * in use. It also gets called when setup of a device fails. | |
1612 | * | |
1613 | * Locking: | |
af9b897e AC |
1614 | * takes the file list lock internally when working on the list |
1615 | * of ttys that the driver keeps. | |
b50989dc AC |
1616 | * |
1617 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1618 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1619 | */ |
b50989dc | 1620 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1621 | { |
b50989dc AC |
1622 | struct tty_struct *tty = |
1623 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1624 | struct tty_driver *driver = tty->driver; |
b216df53 | 1625 | struct module *owner = driver->owner; |
d5698c28 | 1626 | |
f278a2f7 DY |
1627 | if (tty->ops->cleanup) |
1628 | tty->ops->cleanup(tty); | |
1629 | ||
1da177e4 | 1630 | tty->magic = 0; |
7d7b93c1 | 1631 | tty_driver_kref_put(driver); |
b216df53 | 1632 | module_put(owner); |
d5698c28 | 1633 | |
ee2ffa0d | 1634 | spin_lock(&tty_files_lock); |
1da177e4 | 1635 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1636 | spin_unlock(&tty_files_lock); |
d5698c28 | 1637 | |
6da8d866 ON |
1638 | put_pid(tty->pgrp); |
1639 | put_pid(tty->session); | |
1da177e4 LT |
1640 | free_tty_struct(tty); |
1641 | } | |
1642 | ||
b50989dc AC |
1643 | static void queue_release_one_tty(struct kref *kref) |
1644 | { | |
1645 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1646 | |
b50989dc AC |
1647 | /* The hangup queue is now free so we can reuse it rather than |
1648 | waste a chunk of memory for each port */ | |
1649 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1650 | schedule_work(&tty->hangup_work); | |
1651 | } | |
1652 | ||
9c9f4ded AC |
1653 | /** |
1654 | * tty_kref_put - release a tty kref | |
1655 | * @tty: tty device | |
1656 | * | |
1657 | * Release a reference to a tty device and if need be let the kref | |
1658 | * layer destruct the object for us | |
1659 | */ | |
1660 | ||
1661 | void tty_kref_put(struct tty_struct *tty) | |
1662 | { | |
1663 | if (tty) | |
b50989dc | 1664 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1665 | } |
1666 | EXPORT_SYMBOL(tty_kref_put); | |
1667 | ||
d5698c28 CH |
1668 | /** |
1669 | * release_tty - release tty structure memory | |
1670 | * | |
1671 | * Release both @tty and a possible linked partner (think pty pair), | |
1672 | * and decrement the refcount of the backing module. | |
1673 | * | |
1674 | * Locking: | |
d155255a | 1675 | * tty_mutex |
d5698c28 CH |
1676 | * takes the file list lock internally when working on the list |
1677 | * of ttys that the driver keeps. | |
9c9f4ded | 1678 | * |
d5698c28 CH |
1679 | */ |
1680 | static void release_tty(struct tty_struct *tty, int idx) | |
1681 | { | |
9c9f4ded AC |
1682 | /* This should always be true but check for the moment */ |
1683 | WARN_ON(tty->index != idx); | |
d155255a | 1684 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1685 | if (tty->ops->shutdown) |
1686 | tty->ops->shutdown(tty); | |
1687 | tty_free_termios(tty); | |
1688 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1689 | tty->port->itty = NULL; |
64e377dc PH |
1690 | if (tty->link) |
1691 | tty->link->port->itty = NULL; | |
4f98d467 | 1692 | cancel_work_sync(&tty->port->buf.work); |
36b3c070 | 1693 | |
a211b1af | 1694 | tty_kref_put(tty->link); |
9c9f4ded | 1695 | tty_kref_put(tty); |
d5698c28 CH |
1696 | } |
1697 | ||
955787ca JS |
1698 | /** |
1699 | * tty_release_checks - check a tty before real release | |
1700 | * @tty: tty to check | |
1701 | * @o_tty: link of @tty (if any) | |
1702 | * @idx: index of the tty | |
1703 | * | |
1704 | * Performs some paranoid checking before true release of the @tty. | |
1705 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1706 | */ | |
359b9fb5 | 1707 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1708 | { |
1709 | #ifdef TTY_PARANOIA_CHECK | |
1710 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1711 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1712 | return -1; |
1713 | } | |
1714 | ||
1715 | /* not much to check for devpts */ | |
1716 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1717 | return 0; | |
1718 | ||
1719 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1720 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1721 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1722 | return -1; |
1723 | } | |
955787ca | 1724 | if (tty->driver->other) { |
359b9fb5 PH |
1725 | struct tty_struct *o_tty = tty->link; |
1726 | ||
955787ca | 1727 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1728 | tty_debug(tty, "bad other table[%d] = %p\n", |
1729 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1730 | return -1; |
1731 | } | |
955787ca | 1732 | if (o_tty->link != tty) { |
e2dfa3d3 | 1733 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1734 | return -1; |
1735 | } | |
1736 | } | |
1737 | #endif | |
1738 | return 0; | |
1739 | } | |
1740 | ||
eeb89d91 AC |
1741 | /** |
1742 | * tty_release - vfs callback for close | |
1743 | * @inode: inode of tty | |
1744 | * @filp: file pointer for handle to tty | |
1745 | * | |
1746 | * Called the last time each file handle is closed that references | |
1747 | * this tty. There may however be several such references. | |
1748 | * | |
1749 | * Locking: | |
1750 | * Takes bkl. See tty_release_dev | |
1751 | * | |
1da177e4 LT |
1752 | * Even releasing the tty structures is a tricky business.. We have |
1753 | * to be very careful that the structures are all released at the | |
1754 | * same time, as interrupts might otherwise get the wrong pointers. | |
1755 | * | |
1756 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1757 | * lead to double frees or releasing memory still in use. | |
1758 | */ | |
eeb89d91 AC |
1759 | |
1760 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1761 | { |
d996b62a | 1762 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1763 | struct tty_struct *o_tty = NULL; |
1764 | int do_sleep, final; | |
1da177e4 | 1765 | int idx; |
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 | 1786 | |
accff793 | 1787 | tty_debug_hangup(tty, "(tty count=%d)...\n", tty->count); |
1da177e4 | 1788 | |
f34d7a5b AC |
1789 | if (tty->ops->close) |
1790 | tty->ops->close(tty, filp); | |
1da177e4 | 1791 | |
2aff5e2b PH |
1792 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1793 | tty_lock_slave(o_tty); | |
1794 | ||
1da177e4 LT |
1795 | /* |
1796 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1797 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1798 | * wait queues and kick everyone out _before_ actually starting to | |
1799 | * close. This ensures that we won't block while releasing the tty | |
1800 | * structure. | |
1801 | * | |
1802 | * The test for the o_tty closing is necessary, since the master and | |
1803 | * slave sides may close in any order. If the slave side closes out | |
1804 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1805 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1806 | * so we do it now. |
1da177e4 LT |
1807 | */ |
1808 | while (1) { | |
1da177e4 LT |
1809 | do_sleep = 0; |
1810 | ||
324c1650 | 1811 | if (tty->count <= 1) { |
1da177e4 | 1812 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1813 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1814 | do_sleep++; |
1815 | } | |
1816 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1817 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1818 | do_sleep++; |
1819 | } | |
1820 | } | |
7ffb6da9 | 1821 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1822 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1823 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1824 | do_sleep++; |
1825 | } | |
1826 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1827 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1828 | do_sleep++; |
1829 | } | |
1830 | } | |
1831 | if (!do_sleep) | |
1832 | break; | |
1833 | ||
494c1eac PH |
1834 | if (once) { |
1835 | once = 0; | |
1836 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", | |
429b4749 | 1837 | __func__, tty_name(tty)); |
494c1eac | 1838 | } |
37b16457 PH |
1839 | schedule_timeout_killable(timeout); |
1840 | if (timeout < 120 * HZ) | |
1841 | timeout = 2 * timeout + 1; | |
1842 | else | |
1843 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1844 | } |
1da177e4 | 1845 | |
7ffb6da9 | 1846 | if (o_tty) { |
1da177e4 | 1847 | if (--o_tty->count < 0) { |
9de44bd6 | 1848 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
429b4749 | 1849 | __func__, o_tty->count, tty_name(o_tty)); |
1da177e4 LT |
1850 | o_tty->count = 0; |
1851 | } | |
1852 | } | |
1853 | if (--tty->count < 0) { | |
9de44bd6 | 1854 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
429b4749 | 1855 | __func__, tty->count, tty_name(tty)); |
1da177e4 LT |
1856 | tty->count = 0; |
1857 | } | |
37bdfb07 | 1858 | |
1da177e4 LT |
1859 | /* |
1860 | * We've decremented tty->count, so we need to remove this file | |
1861 | * descriptor off the tty->tty_files list; this serves two | |
1862 | * purposes: | |
1863 | * - check_tty_count sees the correct number of file descriptors | |
1864 | * associated with this tty. | |
1865 | * - do_tty_hangup no longer sees this file descriptor as | |
1866 | * something that needs to be handled for hangups. | |
1867 | */ | |
d996b62a | 1868 | tty_del_file(filp); |
1da177e4 LT |
1869 | |
1870 | /* | |
1871 | * Perform some housekeeping before deciding whether to return. | |
1872 | * | |
1da177e4 LT |
1873 | * If _either_ side is closing, make sure there aren't any |
1874 | * processes that still think tty or o_tty is their controlling | |
1875 | * tty. | |
1876 | */ | |
324c1650 | 1877 | if (!tty->count) { |
1da177e4 | 1878 | read_lock(&tasklist_lock); |
24ec839c | 1879 | session_clear_tty(tty->session); |
7ffb6da9 | 1880 | if (o_tty) |
24ec839c | 1881 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1882 | read_unlock(&tasklist_lock); |
1883 | } | |
1884 | ||
324c1650 | 1885 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1886 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1887 | |
2aff5e2b PH |
1888 | tty_unlock_slave(o_tty); |
1889 | tty_unlock(tty); | |
1890 | ||
04980706 | 1891 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1892 | cannot be re-opened by a racing opener */ |
da965822 | 1893 | |
324c1650 | 1894 | if (!final) |
eeb89d91 | 1895 | return 0; |
37bdfb07 | 1896 | |
accff793 | 1897 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1898 | /* |
01e1abb2 | 1899 | * Ask the line discipline code to release its structures |
1da177e4 | 1900 | */ |
62462aef | 1901 | tty_ldisc_release(tty); |
a2965b7b PH |
1902 | |
1903 | /* Wait for pending work before tty destruction commmences */ | |
1904 | tty_flush_works(tty); | |
a2965b7b | 1905 | |
accff793 | 1906 | tty_debug_hangup(tty, "freeing structure...\n"); |
1da177e4 | 1907 | /* |
d5698c28 | 1908 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1909 | * the slots and preserving the termios structure. The tty_unlock_pair |
1910 | * should be safe as we keep a kref while the tty is locked (so the | |
1911 | * unlock never unlocks a freed tty). | |
1da177e4 | 1912 | */ |
d155255a | 1913 | mutex_lock(&tty_mutex); |
d5698c28 | 1914 | release_tty(tty, idx); |
d155255a | 1915 | mutex_unlock(&tty_mutex); |
1da177e4 | 1916 | |
eeb89d91 | 1917 | return 0; |
1da177e4 LT |
1918 | } |
1919 | ||
b82154ac | 1920 | /** |
52494eeb | 1921 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1922 | * @device: device number |
1923 | * @filp: file pointer to tty | |
52494eeb PH |
1924 | * @return: locked tty of the current task iff @device is /dev/tty |
1925 | * | |
1926 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1927 | * |
1928 | * We cannot return driver and index like for the other nodes because | |
1929 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1930 | */ | |
1931 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1932 | { | |
1933 | struct tty_struct *tty; | |
52494eeb | 1934 | int retval; |
b82154ac JS |
1935 | |
1936 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1937 | return NULL; | |
1938 | ||
1939 | tty = get_current_tty(); | |
1940 | if (!tty) | |
1941 | return ERR_PTR(-ENXIO); | |
1942 | ||
1943 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1944 | /* noctty = 1; */ | |
52494eeb PH |
1945 | tty_lock(tty); |
1946 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1947 | ||
1948 | retval = tty_reopen(tty); | |
1949 | if (retval < 0) { | |
1950 | tty_unlock(tty); | |
1951 | tty = ERR_PTR(retval); | |
1952 | } | |
b82154ac JS |
1953 | return tty; |
1954 | } | |
1955 | ||
5b5e7040 JS |
1956 | /** |
1957 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1958 | * @device: device number | |
1959 | * @filp: file pointer to tty | |
1960 | * @noctty: set if the device should not become a controlling tty | |
1961 | * @index: index for the device in the @return driver | |
1962 | * @return: driver for this inode (with increased refcount) | |
1963 | * | |
1964 | * If @return is not erroneous, the caller is responsible to decrement the | |
1965 | * refcount by tty_driver_kref_put. | |
1966 | * | |
1967 | * Locking: tty_mutex protects get_tty_driver | |
1968 | */ | |
1969 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1970 | int *noctty, int *index) | |
1971 | { | |
1972 | struct tty_driver *driver; | |
1973 | ||
2cd0050c | 1974 | switch (device) { |
5b5e7040 | 1975 | #ifdef CONFIG_VT |
2cd0050c | 1976 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1977 | extern struct tty_driver *console_driver; |
1978 | driver = tty_driver_kref_get(console_driver); | |
1979 | *index = fg_console; | |
1980 | *noctty = 1; | |
2cd0050c | 1981 | break; |
5b5e7040 JS |
1982 | } |
1983 | #endif | |
2cd0050c | 1984 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1985 | struct tty_driver *console_driver = console_device(index); |
1986 | if (console_driver) { | |
1987 | driver = tty_driver_kref_get(console_driver); | |
1988 | if (driver) { | |
1989 | /* Don't let /dev/console block */ | |
1990 | filp->f_flags |= O_NONBLOCK; | |
1991 | *noctty = 1; | |
2cd0050c | 1992 | break; |
5b5e7040 JS |
1993 | } |
1994 | } | |
1995 | return ERR_PTR(-ENODEV); | |
1996 | } | |
2cd0050c JS |
1997 | default: |
1998 | driver = get_tty_driver(device, index); | |
1999 | if (!driver) | |
2000 | return ERR_PTR(-ENODEV); | |
2001 | break; | |
2002 | } | |
5b5e7040 JS |
2003 | return driver; |
2004 | } | |
2005 | ||
af9b897e | 2006 | /** |
eeb89d91 | 2007 | * tty_open - open a tty device |
af9b897e AC |
2008 | * @inode: inode of device file |
2009 | * @filp: file pointer to tty | |
1da177e4 | 2010 | * |
af9b897e AC |
2011 | * tty_open and tty_release keep up the tty count that contains the |
2012 | * number of opens done on a tty. We cannot use the inode-count, as | |
2013 | * different inodes might point to the same tty. | |
1da177e4 | 2014 | * |
af9b897e AC |
2015 | * Open-counting is needed for pty masters, as well as for keeping |
2016 | * track of serial lines: DTR is dropped when the last close happens. | |
2017 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2018 | * | |
2019 | * The termios state of a pty is reset on first open so that | |
2020 | * settings don't persist across reuse. | |
2021 | * | |
5b5e7040 | 2022 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
2023 | * tty->count should protect the rest. |
2024 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
2025 | * |
2026 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
2027 | * tty_mutex | |
1da177e4 | 2028 | */ |
af9b897e | 2029 | |
eeb89d91 | 2030 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 2031 | { |
b82154ac | 2032 | struct tty_struct *tty; |
1da177e4 | 2033 | int noctty, retval; |
b82154ac | 2034 | struct tty_driver *driver = NULL; |
1da177e4 LT |
2035 | int index; |
2036 | dev_t device = inode->i_rdev; | |
846c151a | 2037 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
2038 | |
2039 | nonseekable_open(inode, filp); | |
37bdfb07 | 2040 | |
1da177e4 | 2041 | retry_open: |
fa90e1c9 JS |
2042 | retval = tty_alloc_file(filp); |
2043 | if (retval) | |
2044 | return -ENOMEM; | |
2045 | ||
1da177e4 LT |
2046 | noctty = filp->f_flags & O_NOCTTY; |
2047 | index = -1; | |
2048 | retval = 0; | |
37bdfb07 | 2049 | |
b82154ac | 2050 | tty = tty_open_current_tty(device, filp); |
52494eeb PH |
2051 | if (!tty) { |
2052 | mutex_lock(&tty_mutex); | |
5b5e7040 JS |
2053 | driver = tty_lookup_driver(device, filp, &noctty, &index); |
2054 | if (IS_ERR(driver)) { | |
ba5db448 JS |
2055 | retval = PTR_ERR(driver); |
2056 | goto err_unlock; | |
1da177e4 | 2057 | } |
1da177e4 | 2058 | |
4a2b5fdd | 2059 | /* check whether we're reopening an existing tty */ |
15f1a633 | 2060 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 2061 | if (IS_ERR(tty)) { |
ba5db448 JS |
2062 | retval = PTR_ERR(tty); |
2063 | goto err_unlock; | |
808ffa3d | 2064 | } |
4a2b5fdd | 2065 | |
52494eeb | 2066 | if (tty) { |
aa3cb814 | 2067 | mutex_unlock(&tty_mutex); |
52494eeb | 2068 | tty_lock(tty); |
aa3cb814 PH |
2069 | /* safe to drop the kref from tty_driver_lookup_tty() */ |
2070 | tty_kref_put(tty); | |
52494eeb PH |
2071 | retval = tty_reopen(tty); |
2072 | if (retval < 0) { | |
2073 | tty_unlock(tty); | |
2074 | tty = ERR_PTR(retval); | |
2075 | } | |
aa3cb814 | 2076 | } else { /* Returns with the tty_lock held for now */ |
52494eeb | 2077 | tty = tty_init_dev(driver, index); |
aa3cb814 PH |
2078 | mutex_unlock(&tty_mutex); |
2079 | } | |
4a2b5fdd | 2080 | |
b82154ac | 2081 | tty_driver_kref_put(driver); |
52494eeb PH |
2082 | } |
2083 | ||
eeb89d91 | 2084 | if (IS_ERR(tty)) { |
ba5db448 JS |
2085 | retval = PTR_ERR(tty); |
2086 | goto err_file; | |
eeb89d91 | 2087 | } |
1da177e4 | 2088 | |
fa90e1c9 | 2089 | tty_add_file(tty, filp); |
d996b62a | 2090 | |
9de44bd6 | 2091 | check_tty_count(tty, __func__); |
1da177e4 LT |
2092 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2093 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2094 | noctty = 1; | |
accff793 PH |
2095 | |
2096 | tty_debug_hangup(tty, "(tty count=%d)\n", tty->count); | |
2097 | ||
909bc774 HRK |
2098 | if (tty->ops->open) |
2099 | retval = tty->ops->open(tty, filp); | |
2100 | else | |
2101 | retval = -ENODEV; | |
1da177e4 LT |
2102 | filp->f_flags = saved_flags; |
2103 | ||
1da177e4 | 2104 | if (retval) { |
accff793 PH |
2105 | tty_debug_hangup(tty, "error %d, releasing...\n", retval); |
2106 | ||
89c8d91e | 2107 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2108 | tty_release(inode, filp); |
64ba3dc3 | 2109 | if (retval != -ERESTARTSYS) |
1da177e4 | 2110 | return retval; |
64ba3dc3 AB |
2111 | |
2112 | if (signal_pending(current)) | |
1da177e4 | 2113 | return retval; |
64ba3dc3 | 2114 | |
1da177e4 LT |
2115 | schedule(); |
2116 | /* | |
2117 | * Need to reset f_op in case a hangup happened. | |
2118 | */ | |
1256937f | 2119 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2120 | filp->f_op = &tty_fops; |
2121 | goto retry_open; | |
2122 | } | |
d4855e1f | 2123 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2124 | |
24ec839c | 2125 | |
2c411c11 | 2126 | read_lock(&tasklist_lock); |
24ec839c | 2127 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2128 | if (!noctty && |
2129 | current->signal->leader && | |
2130 | !current->signal->tty && | |
0c556271 JH |
2131 | tty->session == NULL) { |
2132 | /* | |
2133 | * Don't let a process that only has write access to the tty | |
2134 | * obtain the privileges associated with having a tty as | |
2135 | * controlling terminal (being able to reopen it with full | |
2136 | * access through /dev/tty, being able to perform pushback). | |
2137 | * Many distributions set the group of all ttys to "tty" and | |
2138 | * grant write-only access to all terminals for setgid tty | |
2139 | * binaries, which should not imply full privileges on all ttys. | |
2140 | * | |
2141 | * This could theoretically break old code that performs open() | |
2142 | * on a write-only file descriptor. In that case, it might be | |
2143 | * necessary to also permit this if | |
2144 | * inode_permission(inode, MAY_READ) == 0. | |
2145 | */ | |
2146 | if (filp->f_mode & FMODE_READ) | |
2147 | __proc_set_tty(tty); | |
2148 | } | |
24ec839c | 2149 | spin_unlock_irq(¤t->sighand->siglock); |
2c411c11 | 2150 | read_unlock(&tasklist_lock); |
89c8d91e | 2151 | tty_unlock(tty); |
1da177e4 | 2152 | return 0; |
ba5db448 | 2153 | err_unlock: |
ba5db448 JS |
2154 | mutex_unlock(&tty_mutex); |
2155 | /* after locks to avoid deadlock */ | |
2156 | if (!IS_ERR_OR_NULL(driver)) | |
2157 | tty_driver_kref_put(driver); | |
2158 | err_file: | |
2159 | tty_free_file(filp); | |
2160 | return retval; | |
1da177e4 LT |
2161 | } |
2162 | ||
39d95b9d JC |
2163 | |
2164 | ||
af9b897e AC |
2165 | /** |
2166 | * tty_poll - check tty status | |
2167 | * @filp: file being polled | |
2168 | * @wait: poll wait structures to update | |
2169 | * | |
2170 | * Call the line discipline polling method to obtain the poll | |
2171 | * status of the device. | |
2172 | * | |
2173 | * Locking: locks called line discipline but ldisc poll method | |
2174 | * may be re-entered freely by other callers. | |
2175 | */ | |
2176 | ||
37bdfb07 | 2177 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2178 | { |
d996b62a | 2179 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2180 | struct tty_ldisc *ld; |
2181 | int ret = 0; | |
2182 | ||
6131ffaa | 2183 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2184 | return 0; |
37bdfb07 | 2185 | |
1da177e4 | 2186 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2187 | if (ld->ops->poll) |
c961bfb1 | 2188 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2189 | tty_ldisc_deref(ld); |
2190 | return ret; | |
2191 | } | |
2192 | ||
ec79d605 | 2193 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2194 | { |
d996b62a | 2195 | struct tty_struct *tty = file_tty(filp); |
f6c8dbe6 | 2196 | struct tty_ldisc *ldisc; |
47f86834 | 2197 | unsigned long flags; |
5d1e3230 | 2198 | int retval = 0; |
1da177e4 | 2199 | |
6131ffaa | 2200 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2201 | goto out; |
37bdfb07 | 2202 | |
1da177e4 LT |
2203 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2204 | if (retval <= 0) | |
5d1e3230 | 2205 | goto out; |
1da177e4 | 2206 | |
f6c8dbe6 PH |
2207 | ldisc = tty_ldisc_ref(tty); |
2208 | if (ldisc) { | |
2209 | if (ldisc->ops->fasync) | |
2210 | ldisc->ops->fasync(tty, on); | |
2211 | tty_ldisc_deref(ldisc); | |
2212 | } | |
2213 | ||
1da177e4 | 2214 | if (on) { |
ab521dc0 EB |
2215 | enum pid_type type; |
2216 | struct pid *pid; | |
f6c8dbe6 | 2217 | |
47f86834 | 2218 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2219 | if (tty->pgrp) { |
2220 | pid = tty->pgrp; | |
2221 | type = PIDTYPE_PGID; | |
2222 | } else { | |
2223 | pid = task_pid(current); | |
2224 | type = PIDTYPE_PID; | |
2225 | } | |
80e1e823 | 2226 | get_pid(pid); |
70362511 | 2227 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2228 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2229 | put_pid(pid); |
e0b93edd | 2230 | retval = 0; |
1da177e4 | 2231 | } |
5d1e3230 | 2232 | out: |
ec79d605 AB |
2233 | return retval; |
2234 | } | |
2235 | ||
2236 | static int tty_fasync(int fd, struct file *filp, int on) | |
2237 | { | |
89c8d91e | 2238 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2239 | int retval; |
89c8d91e AC |
2240 | |
2241 | tty_lock(tty); | |
ec79d605 | 2242 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2243 | tty_unlock(tty); |
2244 | ||
5d1e3230 | 2245 | return retval; |
1da177e4 LT |
2246 | } |
2247 | ||
af9b897e AC |
2248 | /** |
2249 | * tiocsti - fake input character | |
2250 | * @tty: tty to fake input into | |
2251 | * @p: pointer to character | |
2252 | * | |
3a4fa0a2 | 2253 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2254 | * input management. |
2255 | * | |
2256 | * FIXME: does not honour flow control ?? | |
2257 | * | |
2258 | * Locking: | |
137084bb | 2259 | * Called functions take tty_ldiscs_lock |
af9b897e | 2260 | * current->signal->tty check is safe without locks |
28298232 AC |
2261 | * |
2262 | * FIXME: may race normal receive processing | |
af9b897e AC |
2263 | */ |
2264 | ||
1da177e4 LT |
2265 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2266 | { | |
2267 | char ch, mbz = 0; | |
2268 | struct tty_ldisc *ld; | |
37bdfb07 | 2269 | |
1da177e4 LT |
2270 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2271 | return -EPERM; | |
2272 | if (get_user(ch, p)) | |
2273 | return -EFAULT; | |
1e641743 | 2274 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2275 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2276 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2277 | tty_ldisc_deref(ld); |
2278 | return 0; | |
2279 | } | |
2280 | ||
af9b897e AC |
2281 | /** |
2282 | * tiocgwinsz - implement window query ioctl | |
2283 | * @tty; tty | |
2284 | * @arg: user buffer for result | |
2285 | * | |
808a0d38 | 2286 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2287 | * |
dee4a0be | 2288 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2289 | * is consistent. |
af9b897e AC |
2290 | */ |
2291 | ||
37bdfb07 | 2292 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2293 | { |
808a0d38 AC |
2294 | int err; |
2295 | ||
dee4a0be | 2296 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2297 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2298 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2299 | |
2300 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2301 | } |
2302 | ||
af9b897e | 2303 | /** |
8c9a9dd0 AC |
2304 | * tty_do_resize - resize event |
2305 | * @tty: tty being resized | |
8c9a9dd0 AC |
2306 | * @rows: rows (character) |
2307 | * @cols: cols (character) | |
2308 | * | |
3ad2f3fb | 2309 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2310 | * peform a terminal resize correctly |
af9b897e AC |
2311 | */ |
2312 | ||
fc6f6238 | 2313 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2314 | { |
fc6f6238 | 2315 | struct pid *pgrp; |
1da177e4 | 2316 | |
fc6f6238 | 2317 | /* Lock the tty */ |
dee4a0be | 2318 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2319 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2320 | goto done; |
47f86834 | 2321 | |
5b239542 PH |
2322 | /* Signal the foreground process group */ |
2323 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2324 | if (pgrp) |
2325 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2326 | put_pid(pgrp); |
47f86834 | 2327 | |
8c9a9dd0 | 2328 | tty->winsize = *ws; |
ca9bda00 | 2329 | done: |
dee4a0be | 2330 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2331 | return 0; |
2332 | } | |
4d334fd1 | 2333 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2334 | |
8c9a9dd0 AC |
2335 | /** |
2336 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2337 | * @tty; tty side of tty |
8c9a9dd0 AC |
2338 | * @arg: user buffer for result |
2339 | * | |
2340 | * Copies the user idea of the window size to the kernel. Traditionally | |
2341 | * this is just advisory information but for the Linux console it | |
2342 | * actually has driver level meaning and triggers a VC resize. | |
2343 | * | |
2344 | * Locking: | |
25985edc | 2345 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2346 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2347 | * then calls into the default method. | |
2348 | */ | |
2349 | ||
fc6f6238 | 2350 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2351 | { |
2352 | struct winsize tmp_ws; | |
2353 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2354 | return -EFAULT; | |
2355 | ||
2356 | if (tty->ops->resize) | |
fc6f6238 | 2357 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2358 | else |
fc6f6238 | 2359 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2360 | } |
2361 | ||
af9b897e AC |
2362 | /** |
2363 | * tioccons - allow admin to move logical console | |
2364 | * @file: the file to become console | |
2365 | * | |
25985edc | 2366 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2367 | * |
2368 | * Locking: uses redirect_lock to guard the redirect information | |
2369 | */ | |
2370 | ||
1da177e4 LT |
2371 | static int tioccons(struct file *file) |
2372 | { | |
2373 | if (!capable(CAP_SYS_ADMIN)) | |
2374 | return -EPERM; | |
2375 | if (file->f_op->write == redirected_tty_write) { | |
2376 | struct file *f; | |
2377 | spin_lock(&redirect_lock); | |
2378 | f = redirect; | |
2379 | redirect = NULL; | |
2380 | spin_unlock(&redirect_lock); | |
2381 | if (f) | |
2382 | fput(f); | |
2383 | return 0; | |
2384 | } | |
2385 | spin_lock(&redirect_lock); | |
2386 | if (redirect) { | |
2387 | spin_unlock(&redirect_lock); | |
2388 | return -EBUSY; | |
2389 | } | |
cb0942b8 | 2390 | redirect = get_file(file); |
1da177e4 LT |
2391 | spin_unlock(&redirect_lock); |
2392 | return 0; | |
2393 | } | |
2394 | ||
af9b897e AC |
2395 | /** |
2396 | * fionbio - non blocking ioctl | |
2397 | * @file: file to set blocking value | |
2398 | * @p: user parameter | |
2399 | * | |
2400 | * Historical tty interfaces had a blocking control ioctl before | |
2401 | * the generic functionality existed. This piece of history is preserved | |
2402 | * in the expected tty API of posix OS's. | |
2403 | * | |
6146b9af | 2404 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2405 | */ |
1da177e4 LT |
2406 | |
2407 | static int fionbio(struct file *file, int __user *p) | |
2408 | { | |
2409 | int nonblock; | |
2410 | ||
2411 | if (get_user(nonblock, p)) | |
2412 | return -EFAULT; | |
2413 | ||
db1dd4d3 | 2414 | spin_lock(&file->f_lock); |
1da177e4 LT |
2415 | if (nonblock) |
2416 | file->f_flags |= O_NONBLOCK; | |
2417 | else | |
2418 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2419 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2420 | return 0; |
2421 | } | |
2422 | ||
af9b897e AC |
2423 | /** |
2424 | * tiocsctty - set controlling tty | |
2425 | * @tty: tty structure | |
2426 | * @arg: user argument | |
2427 | * | |
2428 | * This ioctl is used to manage job control. It permits a session | |
2429 | * leader to set this tty as the controlling tty for the session. | |
2430 | * | |
2431 | * Locking: | |
e218eb32 | 2432 | * Takes tty_lock() to serialize proc_set_tty() for this tty |
24ec839c PZ |
2433 | * Takes tasklist_lock internally to walk sessions |
2434 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2435 | */ |
2436 | ||
0c556271 | 2437 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) |
1da177e4 | 2438 | { |
24ec839c | 2439 | int ret = 0; |
24ec839c | 2440 | |
e218eb32 | 2441 | tty_lock(tty); |
2c411c11 PH |
2442 | read_lock(&tasklist_lock); |
2443 | ||
2444 | if (current->signal->leader && (task_session(current) == tty->session)) | |
2445 | goto unlock; | |
2446 | ||
1da177e4 LT |
2447 | /* |
2448 | * The process must be a session leader and | |
2449 | * not have a controlling tty already. | |
2450 | */ | |
24ec839c PZ |
2451 | if (!current->signal->leader || current->signal->tty) { |
2452 | ret = -EPERM; | |
2453 | goto unlock; | |
2454 | } | |
2455 | ||
ab521dc0 | 2456 | if (tty->session) { |
1da177e4 LT |
2457 | /* |
2458 | * This tty is already the controlling | |
2459 | * tty for another session group! | |
2460 | */ | |
37bdfb07 | 2461 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2462 | /* |
2463 | * Steal it away | |
2464 | */ | |
24ec839c | 2465 | session_clear_tty(tty->session); |
24ec839c PZ |
2466 | } else { |
2467 | ret = -EPERM; | |
2468 | goto unlock; | |
2469 | } | |
1da177e4 | 2470 | } |
0c556271 JH |
2471 | |
2472 | /* See the comment in tty_open(). */ | |
2473 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
2474 | ret = -EPERM; | |
2475 | goto unlock; | |
2476 | } | |
2477 | ||
bce65f18 | 2478 | proc_set_tty(tty); |
24ec839c | 2479 | unlock: |
2c411c11 | 2480 | read_unlock(&tasklist_lock); |
e218eb32 | 2481 | tty_unlock(tty); |
24ec839c | 2482 | return ret; |
1da177e4 LT |
2483 | } |
2484 | ||
5d0fdf1e AC |
2485 | /** |
2486 | * tty_get_pgrp - return a ref counted pgrp pid | |
2487 | * @tty: tty to read | |
2488 | * | |
2489 | * Returns a refcounted instance of the pid struct for the process | |
2490 | * group controlling the tty. | |
2491 | */ | |
2492 | ||
2493 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2494 | { | |
2495 | unsigned long flags; | |
2496 | struct pid *pgrp; | |
2497 | ||
2498 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2499 | pgrp = get_pid(tty->pgrp); | |
2500 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2501 | ||
2502 | return pgrp; | |
2503 | } | |
2504 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2505 | ||
e1c2296c PH |
2506 | /* |
2507 | * This checks not only the pgrp, but falls back on the pid if no | |
2508 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
2509 | * without this... | |
2510 | * | |
2511 | * The caller must hold rcu lock or the tasklist lock. | |
2512 | */ | |
2513 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
2514 | { | |
2515 | struct task_struct *p; | |
2516 | struct pid *sid = NULL; | |
2517 | ||
2518 | p = pid_task(pgrp, PIDTYPE_PGID); | |
2519 | if (p == NULL) | |
2520 | p = pid_task(pgrp, PIDTYPE_PID); | |
2521 | if (p != NULL) | |
2522 | sid = task_session(p); | |
2523 | ||
2524 | return sid; | |
2525 | } | |
2526 | ||
af9b897e AC |
2527 | /** |
2528 | * tiocgpgrp - get process group | |
2529 | * @tty: tty passed by user | |
25985edc | 2530 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2531 | * @p: returned pid |
2532 | * | |
2533 | * Obtain the process group of the tty. If there is no process group | |
2534 | * return an error. | |
2535 | * | |
24ec839c | 2536 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2537 | */ |
2538 | ||
1da177e4 LT |
2539 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2540 | { | |
5d0fdf1e AC |
2541 | struct pid *pid; |
2542 | int ret; | |
1da177e4 LT |
2543 | /* |
2544 | * (tty == real_tty) is a cheap way of | |
2545 | * testing if the tty is NOT a master pty. | |
2546 | */ | |
2547 | if (tty == real_tty && current->signal->tty != real_tty) | |
2548 | return -ENOTTY; | |
5d0fdf1e AC |
2549 | pid = tty_get_pgrp(real_tty); |
2550 | ret = put_user(pid_vnr(pid), p); | |
2551 | put_pid(pid); | |
2552 | return ret; | |
1da177e4 LT |
2553 | } |
2554 | ||
af9b897e AC |
2555 | /** |
2556 | * tiocspgrp - attempt to set process group | |
2557 | * @tty: tty passed by user | |
2558 | * @real_tty: tty side device matching tty passed by user | |
2559 | * @p: pid pointer | |
2560 | * | |
2561 | * Set the process group of the tty to the session passed. Only | |
2562 | * permitted where the tty session is our session. | |
2563 | * | |
47f86834 | 2564 | * Locking: RCU, ctrl lock |
af9b897e AC |
2565 | */ |
2566 | ||
1da177e4 LT |
2567 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2568 | { | |
04a2e6a5 EB |
2569 | struct pid *pgrp; |
2570 | pid_t pgrp_nr; | |
1da177e4 LT |
2571 | int retval = tty_check_change(real_tty); |
2572 | ||
2573 | if (retval == -EIO) | |
2574 | return -ENOTTY; | |
2575 | if (retval) | |
2576 | return retval; | |
2577 | if (!current->signal->tty || | |
2578 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2579 | (real_tty->session != task_session(current))) |
1da177e4 | 2580 | return -ENOTTY; |
04a2e6a5 | 2581 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2582 | return -EFAULT; |
04a2e6a5 | 2583 | if (pgrp_nr < 0) |
1da177e4 | 2584 | return -EINVAL; |
04a2e6a5 | 2585 | rcu_read_lock(); |
b488893a | 2586 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2587 | retval = -ESRCH; |
2588 | if (!pgrp) | |
2589 | goto out_unlock; | |
2590 | retval = -EPERM; | |
2591 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2592 | goto out_unlock; | |
2593 | retval = 0; | |
1e86b5bf | 2594 | spin_lock_irq(&tty->ctrl_lock); |
ab521dc0 EB |
2595 | put_pid(real_tty->pgrp); |
2596 | real_tty->pgrp = get_pid(pgrp); | |
1e86b5bf | 2597 | spin_unlock_irq(&tty->ctrl_lock); |
04a2e6a5 EB |
2598 | out_unlock: |
2599 | rcu_read_unlock(); | |
2600 | return retval; | |
1da177e4 LT |
2601 | } |
2602 | ||
af9b897e AC |
2603 | /** |
2604 | * tiocgsid - get session id | |
2605 | * @tty: tty passed by user | |
25985edc | 2606 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2607 | * @p: pointer to returned session id |
2608 | * | |
2609 | * Obtain the session id of the tty. If there is no session | |
2610 | * return an error. | |
2611 | * | |
24ec839c | 2612 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2613 | */ |
2614 | ||
1da177e4 LT |
2615 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2616 | { | |
2617 | /* | |
2618 | * (tty == real_tty) is a cheap way of | |
2619 | * testing if the tty is NOT a master pty. | |
2620 | */ | |
2621 | if (tty == real_tty && current->signal->tty != real_tty) | |
2622 | return -ENOTTY; | |
ab521dc0 | 2623 | if (!real_tty->session) |
1da177e4 | 2624 | return -ENOTTY; |
b488893a | 2625 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2626 | } |
2627 | ||
af9b897e AC |
2628 | /** |
2629 | * tiocsetd - set line discipline | |
2630 | * @tty: tty device | |
2631 | * @p: pointer to user data | |
2632 | * | |
2633 | * Set the line discipline according to user request. | |
2634 | * | |
2635 | * Locking: see tty_set_ldisc, this function is just a helper | |
2636 | */ | |
2637 | ||
1da177e4 LT |
2638 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2639 | { | |
2640 | int ldisc; | |
04f378b1 | 2641 | int ret; |
1da177e4 LT |
2642 | |
2643 | if (get_user(ldisc, p)) | |
2644 | return -EFAULT; | |
04f378b1 | 2645 | |
04f378b1 | 2646 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2647 | |
2648 | return ret; | |
1da177e4 LT |
2649 | } |
2650 | ||
af9b897e AC |
2651 | /** |
2652 | * send_break - performed time break | |
2653 | * @tty: device to break on | |
2654 | * @duration: timeout in mS | |
2655 | * | |
2656 | * Perform a timed break on hardware that lacks its own driver level | |
2657 | * timed break functionality. | |
2658 | * | |
2659 | * Locking: | |
28298232 | 2660 | * atomic_write_lock serializes |
af9b897e | 2661 | * |
af9b897e AC |
2662 | */ |
2663 | ||
b20f3ae5 | 2664 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2665 | { |
9e98966c AC |
2666 | int retval; |
2667 | ||
2668 | if (tty->ops->break_ctl == NULL) | |
2669 | return 0; | |
2670 | ||
2671 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2672 | retval = tty->ops->break_ctl(tty, duration); | |
2673 | else { | |
2674 | /* Do the work ourselves */ | |
2675 | if (tty_write_lock(tty, 0) < 0) | |
2676 | return -EINTR; | |
2677 | retval = tty->ops->break_ctl(tty, -1); | |
2678 | if (retval) | |
2679 | goto out; | |
2680 | if (!signal_pending(current)) | |
2681 | msleep_interruptible(duration); | |
2682 | retval = tty->ops->break_ctl(tty, 0); | |
2683 | out: | |
2684 | tty_write_unlock(tty); | |
2685 | if (signal_pending(current)) | |
2686 | retval = -EINTR; | |
2687 | } | |
2688 | return retval; | |
1da177e4 LT |
2689 | } |
2690 | ||
af9b897e | 2691 | /** |
f34d7a5b | 2692 | * tty_tiocmget - get modem status |
af9b897e AC |
2693 | * @tty: tty device |
2694 | * @file: user file pointer | |
2695 | * @p: pointer to result | |
2696 | * | |
2697 | * Obtain the modem status bits from the tty driver if the feature | |
2698 | * is supported. Return -EINVAL if it is not available. | |
2699 | * | |
2700 | * Locking: none (up to the driver) | |
2701 | */ | |
2702 | ||
60b33c13 | 2703 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2704 | { |
2705 | int retval = -EINVAL; | |
2706 | ||
f34d7a5b | 2707 | if (tty->ops->tiocmget) { |
60b33c13 | 2708 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2709 | |
2710 | if (retval >= 0) | |
2711 | retval = put_user(retval, p); | |
2712 | } | |
2713 | return retval; | |
2714 | } | |
2715 | ||
af9b897e | 2716 | /** |
f34d7a5b | 2717 | * tty_tiocmset - set modem status |
af9b897e | 2718 | * @tty: tty device |
af9b897e AC |
2719 | * @cmd: command - clear bits, set bits or set all |
2720 | * @p: pointer to desired bits | |
2721 | * | |
2722 | * Set the modem status bits from the tty driver if the feature | |
2723 | * is supported. Return -EINVAL if it is not available. | |
2724 | * | |
2725 | * Locking: none (up to the driver) | |
2726 | */ | |
2727 | ||
20b9d177 | 2728 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2729 | unsigned __user *p) |
2730 | { | |
ae677517 AC |
2731 | int retval; |
2732 | unsigned int set, clear, val; | |
1da177e4 | 2733 | |
ae677517 AC |
2734 | if (tty->ops->tiocmset == NULL) |
2735 | return -EINVAL; | |
1da177e4 | 2736 | |
ae677517 AC |
2737 | retval = get_user(val, p); |
2738 | if (retval) | |
2739 | return retval; | |
2740 | set = clear = 0; | |
2741 | switch (cmd) { | |
2742 | case TIOCMBIS: | |
2743 | set = val; | |
2744 | break; | |
2745 | case TIOCMBIC: | |
2746 | clear = val; | |
2747 | break; | |
2748 | case TIOCMSET: | |
2749 | set = val; | |
2750 | clear = ~val; | |
2751 | break; | |
2752 | } | |
2753 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2754 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2755 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2756 | } |
2757 | ||
d281da7f AC |
2758 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2759 | { | |
2760 | int retval = -EINVAL; | |
2761 | struct serial_icounter_struct icount; | |
2762 | memset(&icount, 0, sizeof(icount)); | |
2763 | if (tty->ops->get_icount) | |
2764 | retval = tty->ops->get_icount(tty, &icount); | |
2765 | if (retval != 0) | |
2766 | return retval; | |
2767 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2768 | return -EFAULT; | |
2769 | return 0; | |
2770 | } | |
2771 | ||
8a8ae62f JS |
2772 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2773 | { | |
2774 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2775 | DEFAULT_RATELIMIT_INTERVAL, | |
2776 | DEFAULT_RATELIMIT_BURST); | |
2777 | char comm[TASK_COMM_LEN]; | |
2778 | int flags; | |
2779 | ||
2780 | if (get_user(flags, &ss->flags)) | |
2781 | return; | |
2782 | ||
2783 | flags &= ASYNC_DEPRECATED; | |
2784 | ||
2785 | if (flags && __ratelimit(&depr_flags)) | |
2786 | pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", | |
2787 | __func__, get_task_comm(comm, current), flags); | |
2788 | } | |
2789 | ||
8f166e00 PH |
2790 | /* |
2791 | * if pty, return the slave side (real_tty) | |
2792 | * otherwise, return self | |
2793 | */ | |
2794 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2795 | { |
2796 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2797 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2798 | tty = tty->link; | |
2799 | return tty; | |
2800 | } | |
e8b70e7d | 2801 | |
1da177e4 LT |
2802 | /* |
2803 | * Split this up, as gcc can choke on it otherwise.. | |
2804 | */ | |
04f378b1 | 2805 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2806 | { |
d996b62a NP |
2807 | struct tty_struct *tty = file_tty(file); |
2808 | struct tty_struct *real_tty; | |
1da177e4 LT |
2809 | void __user *p = (void __user *)arg; |
2810 | int retval; | |
2811 | struct tty_ldisc *ld; | |
37bdfb07 | 2812 | |
6131ffaa | 2813 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2814 | return -EINVAL; |
2815 | ||
e8b70e7d | 2816 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2817 | |
2818 | /* | |
2819 | * Factor out some common prep work | |
2820 | */ | |
2821 | switch (cmd) { | |
2822 | case TIOCSETD: | |
2823 | case TIOCSBRK: | |
2824 | case TIOCCBRK: | |
2825 | case TCSBRK: | |
37bdfb07 | 2826 | case TCSBRKP: |
1da177e4 LT |
2827 | retval = tty_check_change(tty); |
2828 | if (retval) | |
2829 | return retval; | |
2830 | if (cmd != TIOCCBRK) { | |
2831 | tty_wait_until_sent(tty, 0); | |
2832 | if (signal_pending(current)) | |
2833 | return -EINTR; | |
2834 | } | |
2835 | break; | |
2836 | } | |
2837 | ||
9e98966c AC |
2838 | /* |
2839 | * Now do the stuff. | |
2840 | */ | |
1da177e4 | 2841 | switch (cmd) { |
37bdfb07 AC |
2842 | case TIOCSTI: |
2843 | return tiocsti(tty, p); | |
2844 | case TIOCGWINSZ: | |
8f520021 | 2845 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2846 | case TIOCSWINSZ: |
fc6f6238 | 2847 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2848 | case TIOCCONS: |
2849 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2850 | case FIONBIO: | |
2851 | return fionbio(file, p); | |
2852 | case TIOCEXCL: | |
2853 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2854 | return 0; | |
2855 | case TIOCNXCL: | |
2856 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2857 | return 0; | |
84fd7bdf CG |
2858 | case TIOCGEXCL: |
2859 | { | |
2860 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2861 | return put_user(excl, (int __user *)p); | |
2862 | } | |
37bdfb07 AC |
2863 | case TIOCNOTTY: |
2864 | if (current->signal->tty != tty) | |
2865 | return -ENOTTY; | |
2866 | no_tty(); | |
2867 | return 0; | |
2868 | case TIOCSCTTY: | |
0c556271 | 2869 | return tiocsctty(tty, file, arg); |
37bdfb07 AC |
2870 | case TIOCGPGRP: |
2871 | return tiocgpgrp(tty, real_tty, p); | |
2872 | case TIOCSPGRP: | |
2873 | return tiocspgrp(tty, real_tty, p); | |
2874 | case TIOCGSID: | |
2875 | return tiocgsid(tty, real_tty, p); | |
2876 | case TIOCGETD: | |
c65c9bc3 | 2877 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2878 | case TIOCSETD: |
2879 | return tiocsetd(tty, p); | |
3c95c985 KS |
2880 | case TIOCVHANGUP: |
2881 | if (!capable(CAP_SYS_ADMIN)) | |
2882 | return -EPERM; | |
2883 | tty_vhangup(tty); | |
2884 | return 0; | |
b7b8de08 WF |
2885 | case TIOCGDEV: |
2886 | { | |
2887 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2888 | return put_user(ret, (unsigned int __user *)p); | |
2889 | } | |
37bdfb07 AC |
2890 | /* |
2891 | * Break handling | |
2892 | */ | |
2893 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2894 | if (tty->ops->break_ctl) |
9e98966c | 2895 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2896 | return 0; |
37bdfb07 | 2897 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2898 | if (tty->ops->break_ctl) |
9e98966c | 2899 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2900 | return 0; |
2901 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2902 | /* non-zero arg means wait for all output data | |
2903 | * to be sent (performed above) but don't send break. | |
2904 | * This is used by the tcdrain() termios function. | |
2905 | */ | |
2906 | if (!arg) | |
2907 | return send_break(tty, 250); | |
2908 | return 0; | |
2909 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2910 | return send_break(tty, arg ? arg*100 : 250); | |
2911 | ||
2912 | case TIOCMGET: | |
60b33c13 | 2913 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2914 | case TIOCMSET: |
2915 | case TIOCMBIC: | |
2916 | case TIOCMBIS: | |
20b9d177 | 2917 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2918 | case TIOCGICOUNT: |
2919 | retval = tty_tiocgicount(tty, p); | |
2920 | /* For the moment allow fall through to the old method */ | |
2921 | if (retval != -EINVAL) | |
2922 | return retval; | |
2923 | break; | |
37bdfb07 AC |
2924 | case TCFLSH: |
2925 | switch (arg) { | |
2926 | case TCIFLUSH: | |
2927 | case TCIOFLUSH: | |
2928 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2929 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2930 | break; |
37bdfb07 AC |
2931 | } |
2932 | break; | |
8a8ae62f JS |
2933 | case TIOCSSERIAL: |
2934 | tty_warn_deprecated_flags(p); | |
2935 | break; | |
1da177e4 | 2936 | } |
f34d7a5b | 2937 | if (tty->ops->ioctl) { |
c961bfb1 | 2938 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2939 | if (retval != -ENOIOCTLCMD) |
2940 | return retval; | |
2941 | } | |
2942 | ld = tty_ldisc_ref_wait(tty); | |
2943 | retval = -EINVAL; | |
a352def2 AC |
2944 | if (ld->ops->ioctl) { |
2945 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2946 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2947 | retval = -ENOTTY; |
1da177e4 LT |
2948 | } |
2949 | tty_ldisc_deref(ld); | |
2950 | return retval; | |
2951 | } | |
2952 | ||
e10cc1df | 2953 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2954 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2955 | unsigned long arg) |
2956 | { | |
d996b62a | 2957 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2958 | struct tty_ldisc *ld; |
2959 | int retval = -ENOIOCTLCMD; | |
2960 | ||
6131ffaa | 2961 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2962 | return -EINVAL; |
2963 | ||
f34d7a5b | 2964 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2965 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2966 | if (retval != -ENOIOCTLCMD) |
2967 | return retval; | |
2968 | } | |
2969 | ||
2970 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2971 | if (ld->ops->compat_ioctl) |
2972 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2973 | else |
2974 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2975 | tty_ldisc_deref(ld); |
2976 | ||
2977 | return retval; | |
2978 | } | |
2979 | #endif | |
1da177e4 | 2980 | |
c3c073f8 AV |
2981 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2982 | { | |
2983 | if (likely(file->f_op->read != tty_read)) | |
2984 | return 0; | |
2985 | return file_tty(file) != t ? 0 : fd + 1; | |
2986 | } | |
2987 | ||
1da177e4 LT |
2988 | /* |
2989 | * This implements the "Secure Attention Key" --- the idea is to | |
2990 | * prevent trojan horses by killing all processes associated with this | |
2991 | * tty when the user hits the "Secure Attention Key". Required for | |
2992 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2993 | * |
1da177e4 LT |
2994 | * This code could be nicer; ideally it should send a HUP, wait a few |
2995 | * seconds, then send a INT, and then a KILL signal. But you then | |
2996 | * have to coordinate with the init process, since all processes associated | |
2997 | * with the current tty must be dead before the new getty is allowed | |
2998 | * to spawn. | |
2999 | * | |
3000 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
3001 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
3002 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
3003 | * | |
3004 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
3005 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
3006 | */ | |
8b6312f4 | 3007 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
3008 | { |
3009 | #ifdef TTY_SOFT_SAK | |
3010 | tty_hangup(tty); | |
3011 | #else | |
652486fb | 3012 | struct task_struct *g, *p; |
ab521dc0 | 3013 | struct pid *session; |
1da177e4 | 3014 | int i; |
37bdfb07 | 3015 | |
1da177e4 LT |
3016 | if (!tty) |
3017 | return; | |
24ec839c | 3018 | session = tty->session; |
37bdfb07 | 3019 | |
b3f13deb | 3020 | tty_ldisc_flush(tty); |
1da177e4 | 3021 | |
f34d7a5b | 3022 | tty_driver_flush_buffer(tty); |
37bdfb07 | 3023 | |
1da177e4 | 3024 | read_lock(&tasklist_lock); |
652486fb | 3025 | /* Kill the entire session */ |
ab521dc0 | 3026 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 3027 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 3028 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 3029 | task_pid_nr(p), p->comm); |
652486fb | 3030 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 3031 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
3032 | /* Now kill any processes that happen to have the |
3033 | * tty open. | |
3034 | */ | |
3035 | do_each_thread(g, p) { | |
3036 | if (p->signal->tty == tty) { | |
1da177e4 | 3037 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 3038 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 3039 | task_pid_nr(p), p->comm); |
1da177e4 LT |
3040 | send_sig(SIGKILL, p, 1); |
3041 | continue; | |
3042 | } | |
3043 | task_lock(p); | |
c3c073f8 AV |
3044 | i = iterate_fd(p->files, 0, this_tty, tty); |
3045 | if (i != 0) { | |
3046 | printk(KERN_NOTICE "SAK: killed process %d" | |
3047 | " (%s): fd#%d opened to the tty\n", | |
3048 | task_pid_nr(p), p->comm, i - 1); | |
3049 | force_sig(SIGKILL, p); | |
1da177e4 LT |
3050 | } |
3051 | task_unlock(p); | |
652486fb | 3052 | } while_each_thread(g, p); |
1da177e4 LT |
3053 | read_unlock(&tasklist_lock); |
3054 | #endif | |
3055 | } | |
3056 | ||
8b6312f4 EB |
3057 | static void do_SAK_work(struct work_struct *work) |
3058 | { | |
3059 | struct tty_struct *tty = | |
3060 | container_of(work, struct tty_struct, SAK_work); | |
3061 | __do_SAK(tty); | |
3062 | } | |
3063 | ||
1da177e4 LT |
3064 | /* |
3065 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
3066 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
3067 | * the values which we write to it will be identical to the values which it | |
3068 | * already has. --akpm | |
3069 | */ | |
3070 | void do_SAK(struct tty_struct *tty) | |
3071 | { | |
3072 | if (!tty) | |
3073 | return; | |
1da177e4 LT |
3074 | schedule_work(&tty->SAK_work); |
3075 | } | |
3076 | ||
3077 | EXPORT_SYMBOL(do_SAK); | |
3078 | ||
6e9430ac | 3079 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 3080 | { |
6e9430ac | 3081 | const dev_t *devt = data; |
30004ac9 DES |
3082 | return dev->devt == *devt; |
3083 | } | |
3084 | ||
3085 | /* Must put_device() after it's unused! */ | |
3086 | static struct device *tty_get_device(struct tty_struct *tty) | |
3087 | { | |
3088 | dev_t devt = tty_devnum(tty); | |
3089 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
3090 | } | |
3091 | ||
3092 | ||
af9b897e | 3093 | /** |
2c964a2f | 3094 | * alloc_tty_struct |
af9b897e | 3095 | * |
2c964a2f | 3096 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 3097 | * |
2c964a2f | 3098 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 3099 | */ |
af9b897e | 3100 | |
2c964a2f | 3101 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 3102 | { |
2c964a2f RV |
3103 | struct tty_struct *tty; |
3104 | ||
3105 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
3106 | if (!tty) | |
3107 | return NULL; | |
3108 | ||
9c9f4ded | 3109 | kref_init(&tty->kref); |
1da177e4 | 3110 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3111 | tty_ldisc_init(tty); |
ab521dc0 EB |
3112 | tty->session = NULL; |
3113 | tty->pgrp = NULL; | |
89c8d91e | 3114 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3115 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3116 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3117 | mutex_init(&tty->winsize_mutex); |
36697529 | 3118 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3119 | init_waitqueue_head(&tty->write_wait); |
3120 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3121 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3122 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3123 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3124 | spin_lock_init(&tty->flow_lock); |
1da177e4 | 3125 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3126 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3127 | |
3128 | tty->driver = driver; | |
3129 | tty->ops = driver->ops; | |
3130 | tty->index = idx; | |
3131 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3132 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3133 | |
3134 | return tty; | |
1da177e4 LT |
3135 | } |
3136 | ||
6716671d JS |
3137 | /** |
3138 | * deinitialize_tty_struct | |
3139 | * @tty: tty to deinitialize | |
3140 | * | |
3141 | * This subroutine deinitializes a tty structure that has been newly | |
3142 | * allocated but tty_release cannot be called on that yet. | |
3143 | * | |
3144 | * Locking: none - tty in question must not be exposed at this point | |
3145 | */ | |
3146 | void deinitialize_tty_struct(struct tty_struct *tty) | |
3147 | { | |
3148 | tty_ldisc_deinit(tty); | |
3149 | } | |
3150 | ||
f34d7a5b AC |
3151 | /** |
3152 | * tty_put_char - write one character to a tty | |
3153 | * @tty: tty | |
3154 | * @ch: character | |
3155 | * | |
3156 | * Write one byte to the tty using the provided put_char method | |
3157 | * if present. Returns the number of characters successfully output. | |
3158 | * | |
3159 | * Note: the specific put_char operation in the driver layer may go | |
3160 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3161 | */ |
af9b897e | 3162 | |
f34d7a5b | 3163 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3164 | { |
f34d7a5b AC |
3165 | if (tty->ops->put_char) |
3166 | return tty->ops->put_char(tty, ch); | |
3167 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3168 | } |
f34d7a5b AC |
3169 | EXPORT_SYMBOL_GPL(tty_put_char); |
3170 | ||
d81ed103 | 3171 | struct class *tty_class; |
1da177e4 | 3172 | |
7e73eca6 JS |
3173 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3174 | unsigned int index, unsigned int count) | |
3175 | { | |
c1a752ba LY |
3176 | int err; |
3177 | ||
7e73eca6 | 3178 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
3179 | driver->cdevs[index] = cdev_alloc(); |
3180 | if (!driver->cdevs[index]) | |
3181 | return -ENOMEM; | |
c1a752ba | 3182 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 3183 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
3184 | err = cdev_add(driver->cdevs[index], dev, count); |
3185 | if (err) | |
3186 | kobject_put(&driver->cdevs[index]->kobj); | |
3187 | return err; | |
7e73eca6 JS |
3188 | } |
3189 | ||
1da177e4 | 3190 | /** |
af9b897e AC |
3191 | * tty_register_device - register a tty device |
3192 | * @driver: the tty driver that describes the tty device | |
3193 | * @index: the index in the tty driver for this tty device | |
3194 | * @device: a struct device that is associated with this tty device. | |
3195 | * This field is optional, if there is no known struct device | |
3196 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3197 | * |
01107d34 GKH |
3198 | * Returns a pointer to the struct device for this tty device |
3199 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3200 | * |
af9b897e AC |
3201 | * This call is required to be made to register an individual tty device |
3202 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3203 | * that bit is not set, this function should not be called by a tty | |
3204 | * driver. | |
3205 | * | |
3206 | * Locking: ?? | |
1da177e4 | 3207 | */ |
af9b897e | 3208 | |
01107d34 GKH |
3209 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3210 | struct device *device) | |
1da177e4 | 3211 | { |
6915c0e4 TH |
3212 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3213 | } | |
3214 | EXPORT_SYMBOL(tty_register_device); | |
3215 | ||
b1b79916 TH |
3216 | static void tty_device_create_release(struct device *dev) |
3217 | { | |
3218 | pr_debug("device: '%s': %s\n", dev_name(dev), __func__); | |
3219 | kfree(dev); | |
3220 | } | |
3221 | ||
6915c0e4 TH |
3222 | /** |
3223 | * tty_register_device_attr - register a tty device | |
3224 | * @driver: the tty driver that describes the tty device | |
3225 | * @index: the index in the tty driver for this tty device | |
3226 | * @device: a struct device that is associated with this tty device. | |
3227 | * This field is optional, if there is no known struct device | |
3228 | * for this tty device it can be set to NULL safely. | |
3229 | * @drvdata: Driver data to be set to device. | |
3230 | * @attr_grp: Attribute group to be set on device. | |
3231 | * | |
3232 | * Returns a pointer to the struct device for this tty device | |
3233 | * (or ERR_PTR(-EFOO) on error). | |
3234 | * | |
3235 | * This call is required to be made to register an individual tty device | |
3236 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3237 | * that bit is not set, this function should not be called by a tty | |
3238 | * driver. | |
3239 | * | |
3240 | * Locking: ?? | |
3241 | */ | |
3242 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3243 | unsigned index, struct device *device, | |
3244 | void *drvdata, | |
3245 | const struct attribute_group **attr_grp) | |
3246 | { | |
1da177e4 | 3247 | char name[64]; |
6915c0e4 TH |
3248 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3249 | struct device *dev = NULL; | |
3250 | int retval = -ENODEV; | |
7e73eca6 | 3251 | bool cdev = false; |
1da177e4 LT |
3252 | |
3253 | if (index >= driver->num) { | |
3254 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3255 | " (%d).\n", index); | |
1cdcb6b4 | 3256 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3257 | } |
3258 | ||
1da177e4 LT |
3259 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3260 | pty_line_name(driver, index, name); | |
3261 | else | |
3262 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3263 | |
7e73eca6 | 3264 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3265 | retval = tty_cdev_add(driver, devt, index, 1); |
3266 | if (retval) | |
3267 | goto error; | |
7e73eca6 JS |
3268 | cdev = true; |
3269 | } | |
3270 | ||
6915c0e4 TH |
3271 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3272 | if (!dev) { | |
3273 | retval = -ENOMEM; | |
3274 | goto error; | |
3275 | } | |
7e73eca6 | 3276 | |
6915c0e4 TH |
3277 | dev->devt = devt; |
3278 | dev->class = tty_class; | |
3279 | dev->parent = device; | |
b1b79916 | 3280 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3281 | dev_set_name(dev, "%s", name); |
3282 | dev->groups = attr_grp; | |
3283 | dev_set_drvdata(dev, drvdata); | |
3284 | ||
3285 | retval = device_register(dev); | |
3286 | if (retval) | |
3287 | goto error; | |
3288 | ||
3289 | return dev; | |
3290 | ||
3291 | error: | |
3292 | put_device(dev); | |
a3a10ce3 RW |
3293 | if (cdev) { |
3294 | cdev_del(driver->cdevs[index]); | |
3295 | driver->cdevs[index] = NULL; | |
3296 | } | |
6915c0e4 | 3297 | return ERR_PTR(retval); |
1da177e4 | 3298 | } |
6915c0e4 | 3299 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3300 | |
3301 | /** | |
af9b897e AC |
3302 | * tty_unregister_device - unregister a tty device |
3303 | * @driver: the tty driver that describes the tty device | |
3304 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3305 | * |
af9b897e AC |
3306 | * If a tty device is registered with a call to tty_register_device() then |
3307 | * this function must be called when the tty device is gone. | |
3308 | * | |
3309 | * Locking: ?? | |
1da177e4 | 3310 | */ |
af9b897e | 3311 | |
1da177e4 LT |
3312 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3313 | { | |
37bdfb07 AC |
3314 | device_destroy(tty_class, |
3315 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3316 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3317 | cdev_del(driver->cdevs[index]); | |
3318 | driver->cdevs[index] = NULL; | |
3319 | } | |
1da177e4 | 3320 | } |
1da177e4 LT |
3321 | EXPORT_SYMBOL(tty_unregister_device); |
3322 | ||
7f0bc6a6 JS |
3323 | /** |
3324 | * __tty_alloc_driver -- allocate tty driver | |
3325 | * @lines: count of lines this driver can handle at most | |
3326 | * @owner: module which is repsonsible for this driver | |
3327 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3328 | * | |
3329 | * This should not be called directly, some of the provided macros should be | |
3330 | * used instead. Use IS_ERR and friends on @retval. | |
3331 | */ | |
3332 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3333 | unsigned long flags) | |
1da177e4 LT |
3334 | { |
3335 | struct tty_driver *driver; | |
7e73eca6 | 3336 | unsigned int cdevs = 1; |
16a02081 | 3337 | int err; |
1da177e4 | 3338 | |
0019b408 | 3339 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3340 | return ERR_PTR(-EINVAL); |
3341 | ||
506eb99a | 3342 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3343 | if (!driver) |
3344 | return ERR_PTR(-ENOMEM); | |
3345 | ||
3346 | kref_init(&driver->kref); | |
3347 | driver->magic = TTY_DRIVER_MAGIC; | |
3348 | driver->num = lines; | |
3349 | driver->owner = owner; | |
3350 | driver->flags = flags; | |
16a02081 JS |
3351 | |
3352 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3353 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3354 | GFP_KERNEL); | |
3355 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3356 | GFP_KERNEL); | |
3357 | if (!driver->ttys || !driver->termios) { | |
3358 | err = -ENOMEM; | |
3359 | goto err_free_all; | |
3360 | } | |
3361 | } | |
3362 | ||
3363 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3364 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3365 | GFP_KERNEL); | |
3366 | if (!driver->ports) { | |
3367 | err = -ENOMEM; | |
3368 | goto err_free_all; | |
3369 | } | |
7e73eca6 JS |
3370 | cdevs = lines; |
3371 | } | |
3372 | ||
3373 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3374 | if (!driver->cdevs) { | |
3375 | err = -ENOMEM; | |
3376 | goto err_free_all; | |
16a02081 | 3377 | } |
7f0bc6a6 | 3378 | |
1da177e4 | 3379 | return driver; |
16a02081 JS |
3380 | err_free_all: |
3381 | kfree(driver->ports); | |
3382 | kfree(driver->ttys); | |
3383 | kfree(driver->termios); | |
a3a10ce3 | 3384 | kfree(driver->cdevs); |
16a02081 JS |
3385 | kfree(driver); |
3386 | return ERR_PTR(err); | |
1da177e4 | 3387 | } |
7f0bc6a6 | 3388 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3389 | |
7d7b93c1 | 3390 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3391 | { |
7d7b93c1 AC |
3392 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3393 | int i; | |
3394 | struct ktermios *tp; | |
7d7b93c1 AC |
3395 | |
3396 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3397 | /* | |
3398 | * Free the termios and termios_locked structures because | |
3399 | * we don't want to get memory leaks when modular tty | |
3400 | * drivers are removed from the kernel. | |
3401 | */ | |
3402 | for (i = 0; i < driver->num; i++) { | |
3403 | tp = driver->termios[i]; | |
3404 | if (tp) { | |
3405 | driver->termios[i] = NULL; | |
3406 | kfree(tp); | |
3407 | } | |
7d7b93c1 AC |
3408 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3409 | tty_unregister_device(driver, i); | |
3410 | } | |
7d7b93c1 | 3411 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3412 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3413 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3414 | } |
7e73eca6 | 3415 | kfree(driver->cdevs); |
04831dc1 | 3416 | kfree(driver->ports); |
16a02081 JS |
3417 | kfree(driver->termios); |
3418 | kfree(driver->ttys); | |
1da177e4 LT |
3419 | kfree(driver); |
3420 | } | |
3421 | ||
7d7b93c1 AC |
3422 | void tty_driver_kref_put(struct tty_driver *driver) |
3423 | { | |
3424 | kref_put(&driver->kref, destruct_tty_driver); | |
3425 | } | |
3426 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3427 | ||
b68e31d0 JD |
3428 | void tty_set_operations(struct tty_driver *driver, |
3429 | const struct tty_operations *op) | |
1da177e4 | 3430 | { |
f34d7a5b AC |
3431 | driver->ops = op; |
3432 | }; | |
7d7b93c1 | 3433 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3434 | |
7d7b93c1 AC |
3435 | void put_tty_driver(struct tty_driver *d) |
3436 | { | |
3437 | tty_driver_kref_put(d); | |
3438 | } | |
1da177e4 | 3439 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3440 | |
3441 | /* | |
3442 | * Called by a tty driver to register itself. | |
3443 | */ | |
3444 | int tty_register_driver(struct tty_driver *driver) | |
3445 | { | |
3446 | int error; | |
37bdfb07 | 3447 | int i; |
1da177e4 | 3448 | dev_t dev; |
b670bde0 | 3449 | struct device *d; |
1da177e4 | 3450 | |
1da177e4 | 3451 | if (!driver->major) { |
37bdfb07 AC |
3452 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3453 | driver->num, driver->name); | |
1da177e4 LT |
3454 | if (!error) { |
3455 | driver->major = MAJOR(dev); | |
3456 | driver->minor_start = MINOR(dev); | |
3457 | } | |
3458 | } else { | |
3459 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3460 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3461 | } |
9bb8a3d4 | 3462 | if (error < 0) |
16a02081 | 3463 | goto err; |
1da177e4 | 3464 | |
7e73eca6 JS |
3465 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3466 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3467 | if (error) | |
3468 | goto err_unreg_char; | |
3469 | } | |
1da177e4 | 3470 | |
ca509f69 | 3471 | mutex_lock(&tty_mutex); |
1da177e4 | 3472 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3473 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3474 | |
3475 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3476 | for (i = 0; i < driver->num; i++) { |
3477 | d = tty_register_device(driver, i, NULL); | |
3478 | if (IS_ERR(d)) { | |
3479 | error = PTR_ERR(d); | |
16a02081 | 3480 | goto err_unreg_devs; |
b670bde0 VK |
3481 | } |
3482 | } | |
1da177e4 LT |
3483 | } |
3484 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3485 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3486 | return 0; |
b670bde0 | 3487 | |
16a02081 | 3488 | err_unreg_devs: |
b670bde0 VK |
3489 | for (i--; i >= 0; i--) |
3490 | tty_unregister_device(driver, i); | |
3491 | ||
3492 | mutex_lock(&tty_mutex); | |
3493 | list_del(&driver->tty_drivers); | |
3494 | mutex_unlock(&tty_mutex); | |
3495 | ||
9bb8a3d4 | 3496 | err_unreg_char: |
b670bde0 | 3497 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3498 | err: |
b670bde0 | 3499 | return error; |
1da177e4 | 3500 | } |
1da177e4 LT |
3501 | EXPORT_SYMBOL(tty_register_driver); |
3502 | ||
3503 | /* | |
3504 | * Called by a tty driver to unregister itself. | |
3505 | */ | |
3506 | int tty_unregister_driver(struct tty_driver *driver) | |
3507 | { | |
7d7b93c1 AC |
3508 | #if 0 |
3509 | /* FIXME */ | |
1da177e4 LT |
3510 | if (driver->refcount) |
3511 | return -EBUSY; | |
7d7b93c1 | 3512 | #endif |
1da177e4 LT |
3513 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3514 | driver->num); | |
ca509f69 | 3515 | mutex_lock(&tty_mutex); |
1da177e4 | 3516 | list_del(&driver->tty_drivers); |
ca509f69 | 3517 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3518 | return 0; |
3519 | } | |
7d7b93c1 | 3520 | |
1da177e4 LT |
3521 | EXPORT_SYMBOL(tty_unregister_driver); |
3522 | ||
24ec839c PZ |
3523 | dev_t tty_devnum(struct tty_struct *tty) |
3524 | { | |
3525 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3526 | } | |
3527 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3528 | |
d81ed103 AC |
3529 | void tty_default_fops(struct file_operations *fops) |
3530 | { | |
3531 | *fops = tty_fops; | |
3532 | } | |
3533 | ||
1da177e4 LT |
3534 | /* |
3535 | * Initialize the console device. This is called *early*, so | |
3536 | * we can't necessarily depend on lots of kernel help here. | |
3537 | * Just do some early initializations, and do the complex setup | |
3538 | * later. | |
3539 | */ | |
3540 | void __init console_init(void) | |
3541 | { | |
3542 | initcall_t *call; | |
3543 | ||
3544 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3545 | tty_ldisc_begin(); |
1da177e4 LT |
3546 | |
3547 | /* | |
37bdfb07 | 3548 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3549 | * inform about problems etc.. |
3550 | */ | |
1da177e4 LT |
3551 | call = __con_initcall_start; |
3552 | while (call < __con_initcall_end) { | |
3553 | (*call)(); | |
3554 | call++; | |
3555 | } | |
3556 | } | |
3557 | ||
2c9ede55 | 3558 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3559 | { |
3560 | if (!mode) | |
3561 | return NULL; | |
3562 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3563 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3564 | *mode = 0666; | |
3565 | return NULL; | |
3566 | } | |
3567 | ||
1da177e4 LT |
3568 | static int __init tty_class_init(void) |
3569 | { | |
7fe845d1 | 3570 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3571 | if (IS_ERR(tty_class)) |
3572 | return PTR_ERR(tty_class); | |
e454cea2 | 3573 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3574 | return 0; |
3575 | } | |
3576 | ||
3577 | postcore_initcall(tty_class_init); | |
3578 | ||
3579 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3580 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3581 | |
fbc92a34 KS |
3582 | static ssize_t show_cons_active(struct device *dev, |
3583 | struct device_attribute *attr, char *buf) | |
3584 | { | |
3585 | struct console *cs[16]; | |
3586 | int i = 0; | |
3587 | struct console *c; | |
3588 | ssize_t count = 0; | |
3589 | ||
ac751efa | 3590 | console_lock(); |
a2a6a822 | 3591 | for_each_console(c) { |
fbc92a34 KS |
3592 | if (!c->device) |
3593 | continue; | |
3594 | if (!c->write) | |
3595 | continue; | |
3596 | if ((c->flags & CON_ENABLED) == 0) | |
3597 | continue; | |
3598 | cs[i++] = c; | |
3599 | if (i >= ARRAY_SIZE(cs)) | |
3600 | break; | |
3601 | } | |
723abd87 HR |
3602 | while (i--) { |
3603 | int index = cs[i]->index; | |
3604 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3605 | ||
3606 | /* don't resolve tty0 as some programs depend on it */ | |
3607 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3608 | count += tty_line_name(drv, index, buf + count); | |
3609 | else | |
3610 | count += sprintf(buf + count, "%s%d", | |
3611 | cs[i]->name, cs[i]->index); | |
3612 | ||
3613 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3614 | } | |
ac751efa | 3615 | console_unlock(); |
fbc92a34 KS |
3616 | |
3617 | return count; | |
3618 | } | |
3619 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3620 | ||
1083a7be TI |
3621 | static struct attribute *cons_dev_attrs[] = { |
3622 | &dev_attr_active.attr, | |
3623 | NULL | |
3624 | }; | |
3625 | ||
3626 | ATTRIBUTE_GROUPS(cons_dev); | |
3627 | ||
fbc92a34 KS |
3628 | static struct device *consdev; |
3629 | ||
3630 | void console_sysfs_notify(void) | |
3631 | { | |
3632 | if (consdev) | |
3633 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3634 | } | |
3635 | ||
1da177e4 LT |
3636 | /* |
3637 | * Ok, now we can initialize the rest of the tty devices and can count | |
3638 | * on memory allocations, interrupts etc.. | |
3639 | */ | |
31d1d48e | 3640 | int __init tty_init(void) |
1da177e4 LT |
3641 | { |
3642 | cdev_init(&tty_cdev, &tty_fops); | |
3643 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3644 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3645 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3646 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3647 | |
3648 | cdev_init(&console_cdev, &console_fops); | |
3649 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3650 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3651 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3652 | consdev = device_create_with_groups(tty_class, NULL, |
3653 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3654 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3655 | if (IS_ERR(consdev)) |
3656 | consdev = NULL; | |
1da177e4 | 3657 | |
1da177e4 | 3658 | #ifdef CONFIG_VT |
d81ed103 | 3659 | vty_init(&console_fops); |
1da177e4 LT |
3660 | #endif |
3661 | return 0; | |
3662 | } | |
31d1d48e | 3663 |