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Commit | Line | Data |
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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> | |
3f07c014 | 72 | #include <linux/sched/signal.h> |
29930025 | 73 | #include <linux/sched/task.h> |
1da177e4 LT |
74 | #include <linux/interrupt.h> |
75 | #include <linux/tty.h> | |
76 | #include <linux/tty_driver.h> | |
77 | #include <linux/tty_flip.h> | |
78 | #include <linux/devpts_fs.h> | |
79 | #include <linux/file.h> | |
9f3acc31 | 80 | #include <linux/fdtable.h> |
1da177e4 LT |
81 | #include <linux/console.h> |
82 | #include <linux/timer.h> | |
83 | #include <linux/ctype.h> | |
84 | #include <linux/kd.h> | |
85 | #include <linux/mm.h> | |
86 | #include <linux/string.h> | |
87 | #include <linux/slab.h> | |
88 | #include <linux/poll.h> | |
89 | #include <linux/proc_fs.h> | |
90 | #include <linux/init.h> | |
91 | #include <linux/module.h> | |
1da177e4 | 92 | #include <linux/device.h> |
1da177e4 LT |
93 | #include <linux/wait.h> |
94 | #include <linux/bitops.h> | |
b20f3ae5 | 95 | #include <linux/delay.h> |
a352def2 | 96 | #include <linux/seq_file.h> |
d281da7f | 97 | #include <linux/serial.h> |
5a3c6b25 | 98 | #include <linux/ratelimit.h> |
1da177e4 | 99 | |
a352def2 | 100 | #include <linux/uaccess.h> |
1da177e4 LT |
101 | |
102 | #include <linux/kbd_kern.h> | |
103 | #include <linux/vt_kern.h> | |
104 | #include <linux/selection.h> | |
1da177e4 LT |
105 | |
106 | #include <linux/kmod.h> | |
b488893a | 107 | #include <linux/nsproxy.h> |
1da177e4 LT |
108 | |
109 | #undef TTY_DEBUG_HANGUP | |
accff793 PH |
110 | #ifdef TTY_DEBUG_HANGUP |
111 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
112 | #else | |
113 | # define tty_debug_hangup(tty, f, args...) do { } while (0) | |
114 | #endif | |
1da177e4 LT |
115 | |
116 | #define TTY_PARANOIA_CHECK 1 | |
117 | #define CHECK_TTY_COUNT 1 | |
118 | ||
edc6afc5 | 119 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
120 | .c_iflag = ICRNL | IXON, |
121 | .c_oflag = OPOST | ONLCR, | |
122 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
123 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
124 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
125 | .c_cc = INIT_C_CC, |
126 | .c_ispeed = 38400, | |
133b1306 PH |
127 | .c_ospeed = 38400, |
128 | /* .c_line = N_TTY, */ | |
1da177e4 LT |
129 | }; |
130 | ||
131 | EXPORT_SYMBOL(tty_std_termios); | |
132 | ||
133 | /* This list gets poked at by procfs and various bits of boot up code. This | |
134 | could do with some rationalisation such as pulling the tty proc function | |
135 | into this file */ | |
37bdfb07 | 136 | |
1da177e4 LT |
137 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
138 | ||
d1d027ef | 139 | /* Mutex to protect creating and releasing a tty */ |
70522e12 | 140 | DEFINE_MUTEX(tty_mutex); |
1da177e4 | 141 | |
1da177e4 LT |
142 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
143 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
144 | ssize_t redirected_tty_write(struct file *, const char __user *, |
145 | size_t, loff_t *); | |
1da177e4 LT |
146 | static unsigned int tty_poll(struct file *, poll_table *); |
147 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 148 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 149 | #ifdef CONFIG_COMPAT |
37bdfb07 | 150 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
151 | unsigned long arg); |
152 | #else | |
153 | #define tty_compat_ioctl NULL | |
154 | #endif | |
ec79d605 | 155 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 156 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 157 | static void release_tty(struct tty_struct *tty, int idx); |
1da177e4 | 158 | |
af9b897e AC |
159 | /** |
160 | * free_tty_struct - free a disused tty | |
161 | * @tty: tty struct to free | |
162 | * | |
163 | * Free the write buffers, tty queue and tty memory itself. | |
164 | * | |
165 | * Locking: none. Must be called after tty is definitely unused | |
166 | */ | |
167 | ||
a3123fd0 | 168 | static void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 169 | { |
c8b710b3 | 170 | tty_ldisc_deinit(tty); |
a211b1af | 171 | put_device(tty->dev); |
1da177e4 | 172 | kfree(tty->write_buf); |
89c8d91e | 173 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
174 | kfree(tty); |
175 | } | |
176 | ||
d996b62a NP |
177 | static inline struct tty_struct *file_tty(struct file *file) |
178 | { | |
179 | return ((struct tty_file_private *)file->private_data)->tty; | |
180 | } | |
181 | ||
fa90e1c9 | 182 | int tty_alloc_file(struct file *file) |
d996b62a NP |
183 | { |
184 | struct tty_file_private *priv; | |
185 | ||
f573bd17 PE |
186 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
187 | if (!priv) | |
188 | return -ENOMEM; | |
d996b62a | 189 | |
fa90e1c9 JS |
190 | file->private_data = priv; |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | /* Associate a new file with the tty structure */ | |
196 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
197 | { | |
198 | struct tty_file_private *priv = file->private_data; | |
199 | ||
d996b62a NP |
200 | priv->tty = tty; |
201 | priv->file = file; | |
d996b62a | 202 | |
4a510969 | 203 | spin_lock(&tty->files_lock); |
d996b62a | 204 | list_add(&priv->list, &tty->tty_files); |
4a510969 | 205 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 206 | } |
f573bd17 | 207 | |
fa90e1c9 JS |
208 | /** |
209 | * tty_free_file - free file->private_data | |
210 | * | |
211 | * This shall be used only for fail path handling when tty_add_file was not | |
212 | * called yet. | |
213 | */ | |
214 | void tty_free_file(struct file *file) | |
215 | { | |
216 | struct tty_file_private *priv = file->private_data; | |
217 | ||
218 | file->private_data = NULL; | |
219 | kfree(priv); | |
d996b62a NP |
220 | } |
221 | ||
222 | /* Delete file from its tty */ | |
2520e274 | 223 | static void tty_del_file(struct file *file) |
d996b62a NP |
224 | { |
225 | struct tty_file_private *priv = file->private_data; | |
4a510969 | 226 | struct tty_struct *tty = priv->tty; |
d996b62a | 227 | |
4a510969 | 228 | spin_lock(&tty->files_lock); |
d996b62a | 229 | list_del(&priv->list); |
4a510969 | 230 | spin_unlock(&tty->files_lock); |
fa90e1c9 | 231 | tty_free_file(file); |
d996b62a NP |
232 | } |
233 | ||
af9b897e AC |
234 | /** |
235 | * tty_name - return tty naming | |
236 | * @tty: tty structure | |
af9b897e AC |
237 | * |
238 | * Convert a tty structure into a name. The name reflects the kernel | |
239 | * naming policy and if udev is in use may not reflect user space | |
240 | * | |
241 | * Locking: none | |
242 | */ | |
243 | ||
429b4749 | 244 | const char *tty_name(const struct tty_struct *tty) |
1da177e4 LT |
245 | { |
246 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
917162c9 RV |
247 | return "NULL tty"; |
248 | return tty->name; | |
1da177e4 LT |
249 | } |
250 | ||
251 | EXPORT_SYMBOL(tty_name); | |
252 | ||
0a083edd PH |
253 | const char *tty_driver_name(const struct tty_struct *tty) |
254 | { | |
255 | if (!tty || !tty->driver) | |
256 | return ""; | |
257 | return tty->driver->name; | |
258 | } | |
259 | ||
82b8f888 | 260 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
261 | const char *routine) |
262 | { | |
263 | #ifdef TTY_PARANOIA_CHECK | |
264 | if (!tty) { | |
89222e62 | 265 | pr_warn("(%d:%d): %s: NULL tty\n", |
1da177e4 LT |
266 | imajor(inode), iminor(inode), routine); |
267 | return 1; | |
268 | } | |
269 | if (tty->magic != TTY_MAGIC) { | |
89222e62 | 270 | pr_warn("(%d:%d): %s: bad magic number\n", |
1da177e4 LT |
271 | imajor(inode), iminor(inode), routine); |
272 | return 1; | |
273 | } | |
274 | #endif | |
275 | return 0; | |
276 | } | |
277 | ||
deb287e7 | 278 | /* Caller must hold tty_lock */ |
1da177e4 LT |
279 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
280 | { | |
281 | #ifdef CHECK_TTY_COUNT | |
282 | struct list_head *p; | |
a09ac397 | 283 | int count = 0, kopen_count = 0; |
37bdfb07 | 284 | |
4a510969 | 285 | spin_lock(&tty->files_lock); |
1da177e4 LT |
286 | list_for_each(p, &tty->tty_files) { |
287 | count++; | |
288 | } | |
4a510969 | 289 | spin_unlock(&tty->files_lock); |
1da177e4 LT |
290 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
291 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
292 | tty->link && tty->link->count) | |
293 | count++; | |
a09ac397 OK |
294 | if (tty_port_kopened(tty->port)) |
295 | kopen_count++; | |
296 | if (tty->count != (count + kopen_count)) { | |
297 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", | |
298 | routine, tty->count, count, kopen_count); | |
299 | return (count + kopen_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 | ||
fc61ed51 OK |
330 | /** |
331 | * tty_dev_name_to_number - return dev_t for device name | |
332 | * @name: user space name of device under /dev | |
333 | * @number: pointer to dev_t that this function will populate | |
334 | * | |
335 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t | |
336 | * like (4, 64) or (188, 1). If no corresponding driver is registered then | |
337 | * the function returns -ENODEV. | |
338 | * | |
339 | * Locking: this acquires tty_mutex to protect the tty_drivers list from | |
340 | * being modified while we are traversing it, and makes sure to | |
341 | * release it before exiting. | |
342 | */ | |
343 | int tty_dev_name_to_number(const char *name, dev_t *number) | |
344 | { | |
345 | struct tty_driver *p; | |
346 | int ret; | |
347 | int index, prefix_length = 0; | |
348 | const char *str; | |
349 | ||
350 | for (str = name; *str && !isdigit(*str); str++) | |
351 | ; | |
352 | ||
353 | if (!*str) | |
354 | return -EINVAL; | |
355 | ||
356 | ret = kstrtoint(str, 10, &index); | |
357 | if (ret) | |
358 | return ret; | |
359 | ||
360 | prefix_length = str - name; | |
361 | mutex_lock(&tty_mutex); | |
362 | ||
363 | list_for_each_entry(p, &tty_drivers, tty_drivers) | |
364 | if (prefix_length == strlen(p->name) && strncmp(name, | |
365 | p->name, prefix_length) == 0) { | |
366 | if (index < p->num) { | |
367 | *number = MKDEV(p->major, p->minor_start + index); | |
368 | goto out; | |
369 | } | |
370 | } | |
371 | ||
372 | /* if here then driver wasn't found */ | |
373 | ret = -ENODEV; | |
374 | out: | |
375 | mutex_unlock(&tty_mutex); | |
376 | return ret; | |
377 | } | |
378 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number); | |
379 | ||
f2d937f3 JW |
380 | #ifdef CONFIG_CONSOLE_POLL |
381 | ||
382 | /** | |
383 | * tty_find_polling_driver - find device of a polled tty | |
384 | * @name: name string to match | |
385 | * @line: pointer to resulting tty line nr | |
386 | * | |
387 | * This routine returns a tty driver structure, given a name | |
388 | * and the condition that the tty driver is capable of polled | |
389 | * operation. | |
390 | */ | |
391 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
392 | { | |
393 | struct tty_driver *p, *res = NULL; | |
394 | int tty_line = 0; | |
0dca0fd2 | 395 | int len; |
5f0878ac | 396 | char *str, *stp; |
f2d937f3 | 397 | |
0dca0fd2 JW |
398 | for (str = name; *str; str++) |
399 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
400 | break; | |
401 | if (!*str) | |
402 | return NULL; | |
403 | ||
404 | len = str - name; | |
405 | tty_line = simple_strtoul(str, &str, 10); | |
406 | ||
f2d937f3 JW |
407 | mutex_lock(&tty_mutex); |
408 | /* Search through the tty devices to look for a match */ | |
409 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
410 | if (strncmp(name, p->name, len) != 0) |
411 | continue; | |
5f0878ac AC |
412 | stp = str; |
413 | if (*stp == ',') | |
414 | stp++; | |
415 | if (*stp == '\0') | |
416 | stp = NULL; | |
f2d937f3 | 417 | |
6eb68d6f | 418 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 419 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 420 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
421 | *line = tty_line; |
422 | break; | |
423 | } | |
424 | } | |
425 | mutex_unlock(&tty_mutex); | |
426 | ||
427 | return res; | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
430 | #endif | |
431 | ||
37bdfb07 | 432 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
433 | size_t count, loff_t *ppos) |
434 | { | |
435 | return 0; | |
436 | } | |
437 | ||
37bdfb07 | 438 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
439 | size_t count, loff_t *ppos) |
440 | { | |
441 | return -EIO; | |
442 | } | |
443 | ||
444 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 445 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
446 | { |
447 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
448 | } | |
449 | ||
04f378b1 AC |
450 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
451 | unsigned long arg) | |
38ad2ed0 PF |
452 | { |
453 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
454 | } | |
455 | ||
37bdfb07 | 456 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 457 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
458 | { |
459 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
460 | } | |
461 | ||
f557474c PH |
462 | static int hung_up_tty_fasync(int fd, struct file *file, int on) |
463 | { | |
464 | return -ENOTTY; | |
465 | } | |
466 | ||
d01c3289 MY |
467 | static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
468 | { | |
469 | struct tty_struct *tty = file_tty(file); | |
470 | ||
471 | if (tty && tty->ops && tty->ops->show_fdinfo) | |
472 | tty->ops->show_fdinfo(tty, m); | |
473 | } | |
474 | ||
62322d25 | 475 | static const struct file_operations tty_fops = { |
1da177e4 LT |
476 | .llseek = no_llseek, |
477 | .read = tty_read, | |
478 | .write = tty_write, | |
479 | .poll = tty_poll, | |
04f378b1 | 480 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 481 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
482 | .open = tty_open, |
483 | .release = tty_release, | |
484 | .fasync = tty_fasync, | |
d01c3289 | 485 | .show_fdinfo = tty_show_fdinfo, |
1da177e4 LT |
486 | }; |
487 | ||
62322d25 | 488 | static const struct file_operations console_fops = { |
1da177e4 LT |
489 | .llseek = no_llseek, |
490 | .read = tty_read, | |
491 | .write = redirected_tty_write, | |
492 | .poll = tty_poll, | |
04f378b1 | 493 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 494 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
495 | .open = tty_open, |
496 | .release = tty_release, | |
497 | .fasync = tty_fasync, | |
498 | }; | |
499 | ||
62322d25 | 500 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
501 | .llseek = no_llseek, |
502 | .read = hung_up_tty_read, | |
503 | .write = hung_up_tty_write, | |
504 | .poll = hung_up_tty_poll, | |
04f378b1 | 505 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 506 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 | 507 | .release = tty_release, |
f557474c | 508 | .fasync = hung_up_tty_fasync, |
1da177e4 LT |
509 | }; |
510 | ||
511 | static DEFINE_SPINLOCK(redirect_lock); | |
512 | static struct file *redirect; | |
513 | ||
514 | /** | |
515 | * tty_wakeup - request more data | |
516 | * @tty: terminal | |
517 | * | |
518 | * Internal and external helper for wakeups of tty. This function | |
519 | * informs the line discipline if present that the driver is ready | |
520 | * to receive more output data. | |
521 | */ | |
37bdfb07 | 522 | |
1da177e4 LT |
523 | void tty_wakeup(struct tty_struct *tty) |
524 | { | |
525 | struct tty_ldisc *ld; | |
37bdfb07 | 526 | |
1da177e4 LT |
527 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
528 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 529 | if (ld) { |
a352def2 AC |
530 | if (ld->ops->write_wakeup) |
531 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
532 | tty_ldisc_deref(ld); |
533 | } | |
534 | } | |
4b19449d | 535 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
536 | } |
537 | ||
538 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
539 | ||
af9b897e | 540 | /** |
11dbf203 | 541 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 542 | * @work: tty device |
af9b897e | 543 | * |
ef4f527c | 544 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
545 | * synchronous but doesn't hold any locks, so we need to make sure we |
546 | * have the appropriate locks for what we're doing. | |
547 | * | |
548 | * The hangup event clears any pending redirections onto the hung up | |
549 | * device. It ensures future writes will error and it does the needed | |
550 | * line discipline hangup and signal delivery. The tty object itself | |
551 | * remains intact. | |
552 | * | |
553 | * Locking: | |
ec79d605 | 554 | * BTM |
24ec839c PZ |
555 | * redirect lock for undoing redirection |
556 | * file list lock for manipulating list of ttys | |
137084bb | 557 | * tty_ldiscs_lock from called functions |
6a1c0680 | 558 | * termios_rwsem resetting termios data |
24ec839c PZ |
559 | * tasklist_lock to walk task list for hangup event |
560 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 561 | */ |
f91e2590 | 562 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 563 | { |
37bdfb07 | 564 | struct file *cons_filp = NULL; |
1da177e4 | 565 | struct file *filp, *f = NULL; |
d996b62a | 566 | struct tty_file_private *priv; |
1da177e4 | 567 | int closecount = 0, n; |
ea648a47 | 568 | int refs; |
1da177e4 LT |
569 | |
570 | if (!tty) | |
571 | return; | |
572 | ||
1da177e4 LT |
573 | |
574 | spin_lock(&redirect_lock); | |
d996b62a | 575 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
576 | f = redirect; |
577 | redirect = NULL; | |
578 | } | |
579 | spin_unlock(&redirect_lock); | |
37bdfb07 | 580 | |
89c8d91e | 581 | tty_lock(tty); |
11dbf203 | 582 | |
cb50e523 PH |
583 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
584 | tty_unlock(tty); | |
585 | return; | |
586 | } | |
587 | ||
ec79d605 AB |
588 | /* inuse_filps is protected by the single tty lock, |
589 | this really needs to change if we want to flush the | |
590 | workqueue with the lock held */ | |
11dbf203 | 591 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 592 | |
4a510969 | 593 | spin_lock(&tty->files_lock); |
1da177e4 | 594 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
595 | list_for_each_entry(priv, &tty->tty_files, list) { |
596 | filp = priv->file; | |
1da177e4 LT |
597 | if (filp->f_op->write == redirected_tty_write) |
598 | cons_filp = filp; | |
599 | if (filp->f_op->write != tty_write) | |
600 | continue; | |
601 | closecount++; | |
ec79d605 | 602 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
603 | filp->f_op = &hung_up_tty_fops; |
604 | } | |
4a510969 | 605 | spin_unlock(&tty->files_lock); |
37bdfb07 | 606 | |
25fdf243 PH |
607 | refs = tty_signal_session_leader(tty, exit_session); |
608 | /* Account for the p->signal references we killed */ | |
609 | while (refs--) | |
610 | tty_kref_put(tty); | |
611 | ||
892d1fa7 | 612 | tty_ldisc_hangup(tty, cons_filp != NULL); |
37bdfb07 | 613 | |
20cc225b | 614 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 615 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 616 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
617 | put_pid(tty->session); |
618 | put_pid(tty->pgrp); | |
ab521dc0 EB |
619 | tty->session = NULL; |
620 | tty->pgrp = NULL; | |
1da177e4 | 621 | tty->ctrl_status = 0; |
20cc225b | 622 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 623 | |
1da177e4 | 624 | /* |
37bdfb07 AC |
625 | * If one of the devices matches a console pointer, we |
626 | * cannot just call hangup() because that will cause | |
627 | * tty->count and state->count to go out of sync. | |
628 | * So we just call close() the right number of times. | |
1da177e4 LT |
629 | */ |
630 | if (cons_filp) { | |
f34d7a5b | 631 | if (tty->ops->close) |
1da177e4 | 632 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
633 | tty->ops->close(tty, cons_filp); |
634 | } else if (tty->ops->hangup) | |
7c6d340f | 635 | tty->ops->hangup(tty); |
37bdfb07 | 636 | /* |
892d1fa7 PH |
637 | * We don't want to have driver/ldisc interactions beyond the ones |
638 | * we did here. The driver layer expects no calls after ->hangup() | |
639 | * from the ldisc side, which is now guaranteed. | |
37bdfb07 | 640 | */ |
1da177e4 | 641 | set_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 642 | tty_unlock(tty); |
11dbf203 | 643 | |
1da177e4 LT |
644 | if (f) |
645 | fput(f); | |
646 | } | |
647 | ||
ddcd9fb6 AB |
648 | static void do_tty_hangup(struct work_struct *work) |
649 | { | |
650 | struct tty_struct *tty = | |
651 | container_of(work, struct tty_struct, hangup_work); | |
652 | ||
f91e2590 | 653 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
654 | } |
655 | ||
af9b897e AC |
656 | /** |
657 | * tty_hangup - trigger a hangup event | |
658 | * @tty: tty to hangup | |
659 | * | |
660 | * A carrier loss (virtual or otherwise) has occurred on this like | |
661 | * schedule a hangup sequence to run after this event. | |
662 | */ | |
663 | ||
37bdfb07 | 664 | void tty_hangup(struct tty_struct *tty) |
1da177e4 | 665 | { |
d435cefe | 666 | tty_debug_hangup(tty, "hangup\n"); |
1da177e4 LT |
667 | schedule_work(&tty->hangup_work); |
668 | } | |
669 | ||
670 | EXPORT_SYMBOL(tty_hangup); | |
671 | ||
af9b897e AC |
672 | /** |
673 | * tty_vhangup - process vhangup | |
674 | * @tty: tty to hangup | |
675 | * | |
676 | * The user has asked via system call for the terminal to be hung up. | |
677 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 678 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
679 | */ |
680 | ||
37bdfb07 | 681 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 | 682 | { |
d435cefe | 683 | tty_debug_hangup(tty, "vhangup\n"); |
f91e2590 | 684 | __tty_hangup(tty, 0); |
1da177e4 | 685 | } |
37bdfb07 | 686 | |
1da177e4 LT |
687 | EXPORT_SYMBOL(tty_vhangup); |
688 | ||
11dbf203 | 689 | |
2cb5998b AC |
690 | /** |
691 | * tty_vhangup_self - process vhangup for own ctty | |
692 | * | |
693 | * Perform a vhangup on the current controlling tty | |
694 | */ | |
695 | ||
696 | void tty_vhangup_self(void) | |
697 | { | |
698 | struct tty_struct *tty; | |
699 | ||
2cb5998b AC |
700 | tty = get_current_tty(); |
701 | if (tty) { | |
702 | tty_vhangup(tty); | |
703 | tty_kref_put(tty); | |
704 | } | |
2cb5998b AC |
705 | } |
706 | ||
f91e2590 PH |
707 | /** |
708 | * tty_vhangup_session - hangup session leader exit | |
709 | * @tty: tty to hangup | |
710 | * | |
711 | * The session leader is exiting and hanging up its controlling terminal. | |
712 | * Every process in the foreground process group is signalled SIGHUP. | |
713 | * | |
714 | * We do this synchronously so that when the syscall returns the process | |
715 | * is complete. That guarantee is necessary for security reasons. | |
716 | */ | |
717 | ||
a1235b3e | 718 | void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 | 719 | { |
d435cefe | 720 | tty_debug_hangup(tty, "session hangup\n"); |
f91e2590 PH |
721 | __tty_hangup(tty, 1); |
722 | } | |
723 | ||
af9b897e AC |
724 | /** |
725 | * tty_hung_up_p - was tty hung up | |
726 | * @filp: file pointer of tty | |
727 | * | |
728 | * Return true if the tty has been subject to a vhangup or a carrier | |
729 | * loss | |
730 | */ | |
731 | ||
37bdfb07 | 732 | int tty_hung_up_p(struct file *filp) |
1da177e4 | 733 | { |
ed3f0af8 | 734 | return (filp && filp->f_op == &hung_up_tty_fops); |
1da177e4 LT |
735 | } |
736 | ||
737 | EXPORT_SYMBOL(tty_hung_up_p); | |
738 | ||
af9b897e | 739 | /** |
beb7dd86 | 740 | * stop_tty - propagate flow control |
af9b897e AC |
741 | * @tty: tty to stop |
742 | * | |
01adc807 | 743 | * Perform flow control to the driver. May be called |
af9b897e AC |
744 | * on an already stopped device and will not re-call the driver |
745 | * method. | |
746 | * | |
747 | * This functionality is used by both the line disciplines for | |
748 | * halting incoming flow and by the driver. It may therefore be | |
749 | * called from any context, may be under the tty atomic_write_lock | |
750 | * but not always. | |
751 | * | |
752 | * Locking: | |
f9e053dc | 753 | * flow_lock |
af9b897e AC |
754 | */ |
755 | ||
f9e053dc | 756 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 757 | { |
f9e053dc | 758 | if (tty->stopped) |
1da177e4 LT |
759 | return; |
760 | tty->stopped = 1; | |
f34d7a5b | 761 | if (tty->ops->stop) |
c961bfb1 | 762 | tty->ops->stop(tty); |
1da177e4 LT |
763 | } |
764 | ||
f9e053dc PH |
765 | void stop_tty(struct tty_struct *tty) |
766 | { | |
767 | unsigned long flags; | |
768 | ||
769 | spin_lock_irqsave(&tty->flow_lock, flags); | |
770 | __stop_tty(tty); | |
771 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
772 | } | |
1da177e4 LT |
773 | EXPORT_SYMBOL(stop_tty); |
774 | ||
af9b897e | 775 | /** |
beb7dd86 | 776 | * start_tty - propagate flow control |
af9b897e AC |
777 | * @tty: tty to start |
778 | * | |
01adc807 PH |
779 | * Start a tty that has been stopped if at all possible. If this |
780 | * tty was previous stopped and is now being started, the driver | |
781 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
782 | * |
783 | * Locking: | |
f9e053dc | 784 | * flow_lock |
af9b897e AC |
785 | */ |
786 | ||
f9e053dc | 787 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 788 | { |
f9e053dc | 789 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
790 | return; |
791 | tty->stopped = 0; | |
f34d7a5b | 792 | if (tty->ops->start) |
c961bfb1 | 793 | tty->ops->start(tty); |
1da177e4 | 794 | tty_wakeup(tty); |
1da177e4 LT |
795 | } |
796 | ||
f9e053dc PH |
797 | void start_tty(struct tty_struct *tty) |
798 | { | |
799 | unsigned long flags; | |
800 | ||
801 | spin_lock_irqsave(&tty->flow_lock, flags); | |
802 | __start_tty(tty); | |
803 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
804 | } | |
1da177e4 LT |
805 | EXPORT_SYMBOL(start_tty); |
806 | ||
37b7f3c7 JS |
807 | static void tty_update_time(struct timespec *time) |
808 | { | |
f0bf0bd0 | 809 | unsigned long sec = get_seconds(); |
fbf47635 GKH |
810 | |
811 | /* | |
812 | * We only care if the two values differ in anything other than the | |
813 | * lower three bits (i.e every 8 seconds). If so, then we can update | |
814 | * the time of the tty device, otherwise it could be construded as a | |
815 | * security leak to let userspace know the exact timing of the tty. | |
816 | */ | |
817 | if ((sec ^ time->tv_sec) & ~7) | |
37b7f3c7 JS |
818 | time->tv_sec = sec; |
819 | } | |
820 | ||
af9b897e AC |
821 | /** |
822 | * tty_read - read method for tty device files | |
823 | * @file: pointer to tty file | |
824 | * @buf: user buffer | |
825 | * @count: size of user buffer | |
826 | * @ppos: unused | |
827 | * | |
828 | * Perform the read system call function on this terminal device. Checks | |
829 | * for hung up devices before calling the line discipline method. | |
830 | * | |
831 | * Locking: | |
47f86834 AC |
832 | * Locks the line discipline internally while needed. Multiple |
833 | * read calls may be outstanding in parallel. | |
af9b897e AC |
834 | */ |
835 | ||
37bdfb07 | 836 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
837 | loff_t *ppos) |
838 | { | |
839 | int i; | |
37b7f3c7 | 840 | struct inode *inode = file_inode(file); |
d996b62a | 841 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
842 | struct tty_ldisc *ld; |
843 | ||
37b7f3c7 | 844 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 | 845 | return -EIO; |
18900ca6 | 846 | if (!tty || tty_io_error(tty)) |
1da177e4 LT |
847 | return -EIO; |
848 | ||
849 | /* We want to wait for the line discipline to sort out in this | |
850 | situation */ | |
851 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
852 | if (!ld) |
853 | return hung_up_tty_read(file, buf, count, ppos); | |
a352def2 | 854 | if (ld->ops->read) |
c961bfb1 | 855 | i = ld->ops->read(tty, file, buf, count); |
1da177e4 LT |
856 | else |
857 | i = -EIO; | |
858 | tty_ldisc_deref(ld); | |
b0de59b5 | 859 | |
37b7f3c7 JS |
860 | if (i > 0) |
861 | tty_update_time(&inode->i_atime); | |
862 | ||
1da177e4 LT |
863 | return i; |
864 | } | |
865 | ||
136d5258 | 866 | static void tty_write_unlock(struct tty_struct *tty) |
9c1729db AC |
867 | { |
868 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 869 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
870 | } |
871 | ||
136d5258 | 872 | static int tty_write_lock(struct tty_struct *tty, int ndelay) |
9c1729db AC |
873 | { |
874 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
875 | if (ndelay) | |
876 | return -EAGAIN; | |
877 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
878 | return -ERESTARTSYS; | |
879 | } | |
880 | return 0; | |
881 | } | |
882 | ||
1da177e4 LT |
883 | /* |
884 | * Split writes up in sane blocksizes to avoid | |
885 | * denial-of-service type attacks | |
886 | */ | |
887 | static inline ssize_t do_tty_write( | |
888 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
889 | struct tty_struct *tty, | |
890 | struct file *file, | |
891 | const char __user *buf, | |
892 | size_t count) | |
893 | { | |
9c1729db | 894 | ssize_t ret, written = 0; |
1da177e4 | 895 | unsigned int chunk; |
37bdfb07 | 896 | |
9c1729db AC |
897 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
898 | if (ret < 0) | |
899 | return ret; | |
1da177e4 LT |
900 | |
901 | /* | |
902 | * We chunk up writes into a temporary buffer. This | |
903 | * simplifies low-level drivers immensely, since they | |
904 | * don't have locking issues and user mode accesses. | |
905 | * | |
906 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
907 | * big chunk-size.. | |
908 | * | |
909 | * The default chunk-size is 2kB, because the NTTY | |
910 | * layer has problems with bigger chunks. It will | |
911 | * claim to be able to handle more characters than | |
912 | * it actually does. | |
af9b897e AC |
913 | * |
914 | * FIXME: This can probably go away now except that 64K chunks | |
915 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
916 | */ |
917 | chunk = 2048; | |
918 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
919 | chunk = 65536; | |
920 | if (count < chunk) | |
921 | chunk = count; | |
922 | ||
70522e12 | 923 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 924 | if (tty->write_cnt < chunk) { |
402fda92 | 925 | unsigned char *buf_chunk; |
1da177e4 LT |
926 | |
927 | if (chunk < 1024) | |
928 | chunk = 1024; | |
929 | ||
402fda92 JW |
930 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
931 | if (!buf_chunk) { | |
9c1729db AC |
932 | ret = -ENOMEM; |
933 | goto out; | |
1da177e4 LT |
934 | } |
935 | kfree(tty->write_buf); | |
936 | tty->write_cnt = chunk; | |
402fda92 | 937 | tty->write_buf = buf_chunk; |
1da177e4 LT |
938 | } |
939 | ||
940 | /* Do the write .. */ | |
941 | for (;;) { | |
942 | size_t size = count; | |
943 | if (size > chunk) | |
944 | size = chunk; | |
945 | ret = -EFAULT; | |
946 | if (copy_from_user(tty->write_buf, buf, size)) | |
947 | break; | |
1da177e4 | 948 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
949 | if (ret <= 0) |
950 | break; | |
951 | written += ret; | |
952 | buf += ret; | |
953 | count -= ret; | |
954 | if (!count) | |
955 | break; | |
956 | ret = -ERESTARTSYS; | |
957 | if (signal_pending(current)) | |
958 | break; | |
959 | cond_resched(); | |
960 | } | |
37b7f3c7 JS |
961 | if (written) { |
962 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 963 | ret = written; |
37b7f3c7 | 964 | } |
9c1729db AC |
965 | out: |
966 | tty_write_unlock(tty); | |
1da177e4 LT |
967 | return ret; |
968 | } | |
969 | ||
95f9bfc6 AC |
970 | /** |
971 | * tty_write_message - write a message to a certain tty, not just the console. | |
972 | * @tty: the destination tty_struct | |
973 | * @msg: the message to write | |
974 | * | |
975 | * This is used for messages that need to be redirected to a specific tty. | |
976 | * We don't put it into the syslog queue right now maybe in the future if | |
977 | * really needed. | |
978 | * | |
ec79d605 | 979 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
980 | */ |
981 | ||
982 | void tty_write_message(struct tty_struct *tty, char *msg) | |
983 | { | |
95f9bfc6 AC |
984 | if (tty) { |
985 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 986 | tty_lock(tty); |
4b41b953 | 987 | if (tty->ops->write && tty->count > 0) |
95f9bfc6 | 988 | tty->ops->write(tty, msg, strlen(msg)); |
4b41b953 | 989 | tty_unlock(tty); |
95f9bfc6 AC |
990 | tty_write_unlock(tty); |
991 | } | |
95f9bfc6 AC |
992 | return; |
993 | } | |
994 | ||
1da177e4 | 995 | |
af9b897e AC |
996 | /** |
997 | * tty_write - write method for tty device file | |
998 | * @file: tty file pointer | |
999 | * @buf: user data to write | |
1000 | * @count: bytes to write | |
1001 | * @ppos: unused | |
1002 | * | |
1003 | * Write data to a tty device via the line discipline. | |
1004 | * | |
1005 | * Locking: | |
1006 | * Locks the line discipline as required | |
1007 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1008 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1009 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1010 | */ |
1011 | ||
37bdfb07 AC |
1012 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1013 | size_t count, loff_t *ppos) | |
1da177e4 | 1014 | { |
d996b62a NP |
1015 | struct tty_struct *tty = file_tty(file); |
1016 | struct tty_ldisc *ld; | |
1da177e4 | 1017 | ssize_t ret; |
37bdfb07 | 1018 | |
6131ffaa | 1019 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1020 | return -EIO; |
18900ca6 | 1021 | if (!tty || !tty->ops->write || tty_io_error(tty)) |
37bdfb07 | 1022 | return -EIO; |
f34d7a5b AC |
1023 | /* Short term debug to catch buggy drivers */ |
1024 | if (tty->ops->write_room == NULL) | |
339f36ba | 1025 | tty_err(tty, "missing write_room method\n"); |
37bdfb07 | 1026 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
1027 | if (!ld) |
1028 | return hung_up_tty_write(file, buf, count, ppos); | |
a352def2 | 1029 | if (!ld->ops->write) |
1da177e4 LT |
1030 | ret = -EIO; |
1031 | else | |
a352def2 | 1032 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1033 | tty_ldisc_deref(ld); |
1034 | return ret; | |
1035 | } | |
1036 | ||
37bdfb07 AC |
1037 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1038 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1039 | { |
1040 | struct file *p = NULL; | |
1041 | ||
1042 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1043 | if (redirect) |
1044 | p = get_file(redirect); | |
1da177e4 LT |
1045 | spin_unlock(&redirect_lock); |
1046 | ||
1047 | if (p) { | |
1048 | ssize_t res; | |
1049 | res = vfs_write(p, buf, count, &p->f_pos); | |
1050 | fput(p); | |
1051 | return res; | |
1052 | } | |
1da177e4 LT |
1053 | return tty_write(file, buf, count, ppos); |
1054 | } | |
1055 | ||
136d5258 PH |
1056 | /** |
1057 | * tty_send_xchar - send priority character | |
1058 | * | |
1059 | * Send a high priority character to the tty even if stopped | |
1060 | * | |
1061 | * Locking: none for xchar method, write ordering for write method. | |
1062 | */ | |
1063 | ||
1064 | int tty_send_xchar(struct tty_struct *tty, char ch) | |
1065 | { | |
1066 | int was_stopped = tty->stopped; | |
1067 | ||
1068 | if (tty->ops->send_xchar) { | |
ee0c1a65 | 1069 | down_read(&tty->termios_rwsem); |
136d5258 | 1070 | tty->ops->send_xchar(tty, ch); |
ee0c1a65 | 1071 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1072 | return 0; |
1073 | } | |
1074 | ||
1075 | if (tty_write_lock(tty, 0) < 0) | |
1076 | return -ERESTARTSYS; | |
1077 | ||
ee0c1a65 | 1078 | down_read(&tty->termios_rwsem); |
136d5258 PH |
1079 | if (was_stopped) |
1080 | start_tty(tty); | |
1081 | tty->ops->write(tty, &ch, 1); | |
1082 | if (was_stopped) | |
1083 | stop_tty(tty); | |
ee0c1a65 | 1084 | up_read(&tty->termios_rwsem); |
136d5258 PH |
1085 | tty_write_unlock(tty); |
1086 | return 0; | |
1087 | } | |
1088 | ||
1da177e4 LT |
1089 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1090 | ||
af9b897e AC |
1091 | /** |
1092 | * pty_line_name - generate name for a pty | |
1093 | * @driver: the tty driver in use | |
1094 | * @index: the minor number | |
1095 | * @p: output buffer of at least 6 bytes | |
1096 | * | |
1097 | * Generate a name from a driver reference and write it to the output | |
1098 | * buffer. | |
1099 | * | |
1100 | * Locking: None | |
1101 | */ | |
1102 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1103 | { |
1104 | int i = index + driver->name_base; | |
1105 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1106 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1107 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1108 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1109 | } |
1110 | ||
af9b897e | 1111 | /** |
8b0a88d5 | 1112 | * tty_line_name - generate name for a tty |
af9b897e AC |
1113 | * @driver: the tty driver in use |
1114 | * @index: the minor number | |
1115 | * @p: output buffer of at least 7 bytes | |
1116 | * | |
1117 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1118 | * buffer. |
af9b897e AC |
1119 | * |
1120 | * Locking: None | |
1121 | */ | |
723abd87 | 1122 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1123 | { |
0019b408 | 1124 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1125 | return sprintf(p, "%s", driver->name); |
0019b408 | 1126 | else |
723abd87 HR |
1127 | return sprintf(p, "%s%d", driver->name, |
1128 | index + driver->name_base); | |
1da177e4 LT |
1129 | } |
1130 | ||
99f1fe18 AC |
1131 | /** |
1132 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1133 | * @driver: the driver for the tty | |
1134 | * @idx: the minor number | |
23499705 | 1135 | * |
aa3cb814 PH |
1136 | * Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
1137 | * driver lookup() method returns an error. | |
23499705 | 1138 | * |
aa3cb814 | 1139 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
23499705 | 1140 | */ |
a47d545f | 1141 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
8ead9dd5 | 1142 | struct file *file, int idx) |
23499705 | 1143 | { |
aa3cb814 PH |
1144 | struct tty_struct *tty; |
1145 | ||
99f1fe18 | 1146 | if (driver->ops->lookup) |
12e84c71 OK |
1147 | if (!file) |
1148 | tty = ERR_PTR(-EIO); | |
1149 | else | |
1150 | tty = driver->ops->lookup(driver, file, idx); | |
aa3cb814 PH |
1151 | else |
1152 | tty = driver->ttys[idx]; | |
23499705 | 1153 | |
aa3cb814 PH |
1154 | if (!IS_ERR(tty)) |
1155 | tty_kref_get(tty); | |
1156 | return tty; | |
23499705 SB |
1157 | } |
1158 | ||
bf970ee4 AC |
1159 | /** |
1160 | * tty_init_termios - helper for termios setup | |
1161 | * @tty: the tty to set up | |
1162 | * | |
1163 | * Initialise the termios structures for this tty. Thus runs under | |
1164 | * the tty_mutex currently so we can be relaxed about ordering. | |
1165 | */ | |
1166 | ||
a3123fd0 | 1167 | void tty_init_termios(struct tty_struct *tty) |
bf970ee4 | 1168 | { |
fe6e29fd | 1169 | struct ktermios *tp; |
bf970ee4 AC |
1170 | int idx = tty->index; |
1171 | ||
36b3c070 AC |
1172 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1173 | tty->termios = tty->driver->init_termios; | |
1174 | else { | |
1175 | /* Check for lazy saved data */ | |
1176 | tp = tty->driver->termios[idx]; | |
ece53405 | 1177 | if (tp != NULL) { |
36b3c070 | 1178 | tty->termios = *tp; |
ece53405 PH |
1179 | tty->termios.c_line = tty->driver->init_termios.c_line; |
1180 | } else | |
36b3c070 | 1181 | tty->termios = tty->driver->init_termios; |
bf970ee4 | 1182 | } |
bf970ee4 | 1183 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1184 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1185 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 | 1186 | } |
fe1ae7fd | 1187 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1188 | |
66d450e8 JS |
1189 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1190 | { | |
a3123fd0 | 1191 | tty_init_termios(tty); |
66d450e8 JS |
1192 | tty_driver_kref_get(driver); |
1193 | tty->count++; | |
1194 | driver->ttys[tty->index] = tty; | |
1195 | return 0; | |
1196 | } | |
1197 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1198 | ||
99f1fe18 | 1199 | /** |
8b0a88d5 AC |
1200 | * tty_driver_install_tty() - install a tty entry in the driver |
1201 | * @driver: the driver for the tty | |
1202 | * @tty: the tty | |
1203 | * | |
1204 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1205 | * will be set by the time this is called. This method is responsible |
1206 | * for ensuring any need additional structures are allocated and | |
1207 | * configured. | |
8b0a88d5 AC |
1208 | * |
1209 | * Locking: tty_mutex for now | |
1210 | */ | |
1211 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1212 | struct tty_struct *tty) | |
1213 | { | |
66d450e8 JS |
1214 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1215 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1216 | } |
1217 | ||
1218 | /** | |
1219 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1220 | * @driver: the driver for the tty | |
1221 | * @idx: the minor number | |
1222 | * | |
1223 | * Remvoe a tty object from the driver tables. The tty->index field | |
1224 | * will be set by the time this is called. | |
1225 | * | |
1226 | * Locking: tty_mutex for now | |
1227 | */ | |
05de87ed | 1228 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1229 | { |
1230 | if (driver->ops->remove) | |
1231 | driver->ops->remove(driver, tty); | |
1232 | else | |
1233 | driver->ttys[tty->index] = NULL; | |
1234 | } | |
1235 | ||
1236 | /* | |
1237 | * tty_reopen() - fast re-open of an open tty | |
1238 | * @tty - the tty to open | |
23499705 | 1239 | * |
99f1fe18 | 1240 | * Return 0 on success, -errno on error. |
5d93e748 | 1241 | * Re-opens on master ptys are not allowed and return -EIO. |
23499705 | 1242 | * |
5d93e748 | 1243 | * Locking: Caller must hold tty_lock |
23499705 | 1244 | */ |
99f1fe18 | 1245 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1246 | { |
1247 | struct tty_driver *driver = tty->driver; | |
1248 | ||
23499705 | 1249 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
5d93e748 PH |
1250 | driver->subtype == PTY_TYPE_MASTER) |
1251 | return -EIO; | |
23499705 | 1252 | |
7f22f6c9 PH |
1253 | if (!tty->count) |
1254 | return -EAGAIN; | |
1255 | ||
86f2c00f PH |
1256 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1257 | return -EBUSY; | |
1258 | ||
23499705 | 1259 | tty->count++; |
23499705 | 1260 | |
892d1fa7 PH |
1261 | if (!tty->ldisc) |
1262 | return tty_ldisc_reinit(tty, tty->termios.c_line); | |
23499705 SB |
1263 | |
1264 | return 0; | |
1265 | } | |
1266 | ||
af9b897e | 1267 | /** |
d81ed103 | 1268 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1269 | * @driver: tty driver we are opening a device on |
1270 | * @idx: device index | |
15582d36 | 1271 | * @ret_tty: returned tty structure |
af9b897e AC |
1272 | * |
1273 | * Prepare a tty device. This may not be a "new" clean device but | |
1274 | * could also be an active device. The pty drivers require special | |
1275 | * handling because of this. | |
1276 | * | |
1277 | * Locking: | |
1278 | * The function is called under the tty_mutex, which | |
1279 | * protects us from the tty struct or driver itself going away. | |
1280 | * | |
1281 | * On exit the tty device has the line discipline attached and | |
1282 | * a reference count of 1. If a pair was created for pty/tty use | |
1283 | * and the other was a pty master then it too has a reference count of 1. | |
1284 | * | |
1da177e4 | 1285 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1286 | * failed open. The new code protects the open with a mutex, so it's |
1287 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1288 | * relaxed for the (most common) case of reopening a tty. |
1289 | */ | |
af9b897e | 1290 | |
593a27c4 | 1291 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1292 | { |
bf970ee4 | 1293 | struct tty_struct *tty; |
73ec06fc | 1294 | int retval; |
1da177e4 | 1295 | |
1da177e4 LT |
1296 | /* |
1297 | * First time open is complex, especially for PTY devices. | |
1298 | * This code guarantees that either everything succeeds and the | |
1299 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1300 | * and the allocated memory released. (Except that the termios |
16b00ae8 | 1301 | * may be retained.) |
1da177e4 LT |
1302 | */ |
1303 | ||
73ec06fc AC |
1304 | if (!try_module_get(driver->owner)) |
1305 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1306 | |
2c964a2f | 1307 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1308 | if (!tty) { |
1309 | retval = -ENOMEM; | |
1310 | goto err_module_put; | |
1311 | } | |
1da177e4 | 1312 | |
89c8d91e | 1313 | tty_lock(tty); |
73ec06fc | 1314 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1315 | if (retval < 0) |
c8b710b3 | 1316 | goto err_free_tty; |
8b0a88d5 | 1317 | |
04831dc1 JS |
1318 | if (!tty->port) |
1319 | tty->port = driver->ports[idx]; | |
1320 | ||
5d4121c0 JS |
1321 | WARN_RATELIMIT(!tty->port, |
1322 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1323 | __func__, tty->driver->name); | |
1324 | ||
967fab69 JS |
1325 | tty->port->itty = tty; |
1326 | ||
37bdfb07 | 1327 | /* |
1da177e4 | 1328 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1329 | * If we fail here just call release_tty to clean up. No need |
1330 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1331 | */ |
bf970ee4 | 1332 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1333 | if (retval) |
d5543503 | 1334 | goto err_release_tty; |
89c8d91e | 1335 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1336 | return tty; |
1da177e4 | 1337 | |
c8b710b3 | 1338 | err_free_tty: |
89c8d91e | 1339 | tty_unlock(tty); |
d5543503 JS |
1340 | free_tty_struct(tty); |
1341 | err_module_put: | |
1da177e4 | 1342 | module_put(driver->owner); |
d5543503 | 1343 | return ERR_PTR(retval); |
1da177e4 | 1344 | |
d5698c28 | 1345 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1346 | err_release_tty: |
89c8d91e | 1347 | tty_unlock(tty); |
339f36ba PH |
1348 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
1349 | retval, idx); | |
d5698c28 | 1350 | release_tty(tty, idx); |
73ec06fc | 1351 | return ERR_PTR(retval); |
1da177e4 LT |
1352 | } |
1353 | ||
a3123fd0 | 1354 | static void tty_free_termios(struct tty_struct *tty) |
feebed65 AC |
1355 | { |
1356 | struct ktermios *tp; | |
1357 | int idx = tty->index; | |
36b3c070 AC |
1358 | |
1359 | /* If the port is going to reset then it has no termios to save */ | |
1360 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1361 | return; | |
1362 | ||
1363 | /* Stash the termios data */ | |
1364 | tp = tty->driver->termios[idx]; | |
1365 | if (tp == NULL) { | |
1366 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
25080652 | 1367 | if (tp == NULL) |
36b3c070 | 1368 | return; |
4ac5d705 | 1369 | tty->driver->termios[idx] = tp; |
feebed65 | 1370 | } |
36b3c070 | 1371 | *tp = tty->termios; |
feebed65 | 1372 | } |
feebed65 | 1373 | |
a2965b7b | 1374 | /** |
949aa64f PH |
1375 | * tty_flush_works - flush all works of a tty/pty pair |
1376 | * @tty: tty device to flush works for (or either end of a pty pair) | |
a2965b7b | 1377 | * |
949aa64f | 1378 | * Sync flush all works belonging to @tty (and the 'other' tty). |
a2965b7b PH |
1379 | */ |
1380 | static void tty_flush_works(struct tty_struct *tty) | |
1381 | { | |
1382 | flush_work(&tty->SAK_work); | |
1383 | flush_work(&tty->hangup_work); | |
949aa64f PH |
1384 | if (tty->link) { |
1385 | flush_work(&tty->link->SAK_work); | |
1386 | flush_work(&tty->link->hangup_work); | |
1387 | } | |
a2965b7b | 1388 | } |
feebed65 | 1389 | |
af9b897e | 1390 | /** |
d5698c28 | 1391 | * release_one_tty - release tty structure memory |
9c9f4ded | 1392 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1393 | * |
1394 | * Releases memory associated with a tty structure, and clears out the | |
1395 | * driver table slots. This function is called when a device is no longer | |
1396 | * in use. It also gets called when setup of a device fails. | |
1397 | * | |
1398 | * Locking: | |
af9b897e AC |
1399 | * takes the file list lock internally when working on the list |
1400 | * of ttys that the driver keeps. | |
b50989dc AC |
1401 | * |
1402 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1403 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1404 | */ |
b50989dc | 1405 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1406 | { |
b50989dc AC |
1407 | struct tty_struct *tty = |
1408 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1409 | struct tty_driver *driver = tty->driver; |
b216df53 | 1410 | struct module *owner = driver->owner; |
d5698c28 | 1411 | |
f278a2f7 DY |
1412 | if (tty->ops->cleanup) |
1413 | tty->ops->cleanup(tty); | |
1414 | ||
1da177e4 | 1415 | tty->magic = 0; |
7d7b93c1 | 1416 | tty_driver_kref_put(driver); |
b216df53 | 1417 | module_put(owner); |
d5698c28 | 1418 | |
4a510969 | 1419 | spin_lock(&tty->files_lock); |
1da177e4 | 1420 | list_del_init(&tty->tty_files); |
4a510969 | 1421 | spin_unlock(&tty->files_lock); |
d5698c28 | 1422 | |
6da8d866 ON |
1423 | put_pid(tty->pgrp); |
1424 | put_pid(tty->session); | |
1da177e4 LT |
1425 | free_tty_struct(tty); |
1426 | } | |
1427 | ||
b50989dc AC |
1428 | static void queue_release_one_tty(struct kref *kref) |
1429 | { | |
1430 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1431 | |
b50989dc AC |
1432 | /* The hangup queue is now free so we can reuse it rather than |
1433 | waste a chunk of memory for each port */ | |
1434 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1435 | schedule_work(&tty->hangup_work); | |
1436 | } | |
1437 | ||
9c9f4ded AC |
1438 | /** |
1439 | * tty_kref_put - release a tty kref | |
1440 | * @tty: tty device | |
1441 | * | |
1442 | * Release a reference to a tty device and if need be let the kref | |
1443 | * layer destruct the object for us | |
1444 | */ | |
1445 | ||
1446 | void tty_kref_put(struct tty_struct *tty) | |
1447 | { | |
1448 | if (tty) | |
b50989dc | 1449 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1450 | } |
1451 | EXPORT_SYMBOL(tty_kref_put); | |
1452 | ||
d5698c28 CH |
1453 | /** |
1454 | * release_tty - release tty structure memory | |
1455 | * | |
1456 | * Release both @tty and a possible linked partner (think pty pair), | |
1457 | * and decrement the refcount of the backing module. | |
1458 | * | |
1459 | * Locking: | |
d155255a | 1460 | * tty_mutex |
d5698c28 CH |
1461 | * takes the file list lock internally when working on the list |
1462 | * of ttys that the driver keeps. | |
9c9f4ded | 1463 | * |
d5698c28 CH |
1464 | */ |
1465 | static void release_tty(struct tty_struct *tty, int idx) | |
1466 | { | |
9c9f4ded AC |
1467 | /* This should always be true but check for the moment */ |
1468 | WARN_ON(tty->index != idx); | |
d155255a | 1469 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1470 | if (tty->ops->shutdown) |
1471 | tty->ops->shutdown(tty); | |
1472 | tty_free_termios(tty); | |
1473 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1474 | tty->port->itty = NULL; |
64e377dc PH |
1475 | if (tty->link) |
1476 | tty->link->port->itty = NULL; | |
e176058f | 1477 | tty_buffer_cancel_work(tty->port); |
36b3c070 | 1478 | |
a211b1af | 1479 | tty_kref_put(tty->link); |
9c9f4ded | 1480 | tty_kref_put(tty); |
d5698c28 CH |
1481 | } |
1482 | ||
955787ca JS |
1483 | /** |
1484 | * tty_release_checks - check a tty before real release | |
1485 | * @tty: tty to check | |
1486 | * @o_tty: link of @tty (if any) | |
1487 | * @idx: index of the tty | |
1488 | * | |
1489 | * Performs some paranoid checking before true release of the @tty. | |
1490 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1491 | */ | |
359b9fb5 | 1492 | static int tty_release_checks(struct tty_struct *tty, int idx) |
955787ca JS |
1493 | { |
1494 | #ifdef TTY_PARANOIA_CHECK | |
1495 | if (idx < 0 || idx >= tty->driver->num) { | |
e2dfa3d3 | 1496 | tty_debug(tty, "bad idx %d\n", idx); |
955787ca JS |
1497 | return -1; |
1498 | } | |
1499 | ||
1500 | /* not much to check for devpts */ | |
1501 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1502 | return 0; | |
1503 | ||
1504 | if (tty != tty->driver->ttys[idx]) { | |
e2dfa3d3 PH |
1505 | tty_debug(tty, "bad driver table[%d] = %p\n", |
1506 | idx, tty->driver->ttys[idx]); | |
955787ca JS |
1507 | return -1; |
1508 | } | |
955787ca | 1509 | if (tty->driver->other) { |
359b9fb5 PH |
1510 | struct tty_struct *o_tty = tty->link; |
1511 | ||
955787ca | 1512 | if (o_tty != tty->driver->other->ttys[idx]) { |
e2dfa3d3 PH |
1513 | tty_debug(tty, "bad other table[%d] = %p\n", |
1514 | idx, tty->driver->other->ttys[idx]); | |
955787ca JS |
1515 | return -1; |
1516 | } | |
955787ca | 1517 | if (o_tty->link != tty) { |
e2dfa3d3 | 1518 | tty_debug(tty, "bad link = %p\n", o_tty->link); |
955787ca JS |
1519 | return -1; |
1520 | } | |
1521 | } | |
1522 | #endif | |
1523 | return 0; | |
1524 | } | |
1525 | ||
a09ac397 OK |
1526 | /** |
1527 | * tty_kclose - closes tty opened by tty_kopen | |
1528 | * @tty: tty device | |
1529 | * | |
1530 | * Performs the final steps to release and free a tty device. It is the | |
1531 | * same as tty_release_struct except that it also resets TTY_PORT_KOPENED | |
1532 | * flag on tty->port. | |
1533 | */ | |
1534 | void tty_kclose(struct tty_struct *tty) | |
1535 | { | |
1536 | /* | |
1537 | * Ask the line discipline code to release its structures | |
1538 | */ | |
1539 | tty_ldisc_release(tty); | |
1540 | ||
1541 | /* Wait for pending work before tty destruction commmences */ | |
1542 | tty_flush_works(tty); | |
1543 | ||
1544 | tty_debug_hangup(tty, "freeing structure\n"); | |
1545 | /* | |
1546 | * The release_tty function takes care of the details of clearing | |
1547 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1548 | * should be safe as we keep a kref while the tty is locked (so the | |
1549 | * unlock never unlocks a freed tty). | |
1550 | */ | |
1551 | mutex_lock(&tty_mutex); | |
1552 | tty_port_set_kopened(tty->port, 0); | |
1553 | release_tty(tty, tty->index); | |
1554 | mutex_unlock(&tty_mutex); | |
1555 | } | |
1556 | EXPORT_SYMBOL_GPL(tty_kclose); | |
1557 | ||
9ed90d20 RH |
1558 | /** |
1559 | * tty_release_struct - release a tty struct | |
1560 | * @tty: tty device | |
1561 | * @idx: index of the tty | |
1562 | * | |
1563 | * Performs the final steps to release and free a tty device. It is | |
1564 | * roughly the reverse of tty_init_dev. | |
1565 | */ | |
1566 | void tty_release_struct(struct tty_struct *tty, int idx) | |
1567 | { | |
1568 | /* | |
1569 | * Ask the line discipline code to release its structures | |
1570 | */ | |
1571 | tty_ldisc_release(tty); | |
1572 | ||
1573 | /* Wait for pending work before tty destruction commmences */ | |
1574 | tty_flush_works(tty); | |
1575 | ||
1576 | tty_debug_hangup(tty, "freeing structure\n"); | |
1577 | /* | |
1578 | * The release_tty function takes care of the details of clearing | |
1579 | * the slots and preserving the termios structure. The tty_unlock_pair | |
1580 | * should be safe as we keep a kref while the tty is locked (so the | |
1581 | * unlock never unlocks a freed tty). | |
1582 | */ | |
1583 | mutex_lock(&tty_mutex); | |
1584 | release_tty(tty, idx); | |
1585 | mutex_unlock(&tty_mutex); | |
1586 | } | |
1587 | EXPORT_SYMBOL_GPL(tty_release_struct); | |
1588 | ||
eeb89d91 AC |
1589 | /** |
1590 | * tty_release - vfs callback for close | |
1591 | * @inode: inode of tty | |
1592 | * @filp: file pointer for handle to tty | |
1593 | * | |
1594 | * Called the last time each file handle is closed that references | |
1595 | * this tty. There may however be several such references. | |
1596 | * | |
1597 | * Locking: | |
1598 | * Takes bkl. See tty_release_dev | |
1599 | * | |
1da177e4 LT |
1600 | * Even releasing the tty structures is a tricky business.. We have |
1601 | * to be very careful that the structures are all released at the | |
1602 | * same time, as interrupts might otherwise get the wrong pointers. | |
1603 | * | |
1604 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1605 | * lead to double frees or releasing memory still in use. | |
1606 | */ | |
eeb89d91 AC |
1607 | |
1608 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1609 | { |
d996b62a | 1610 | struct tty_struct *tty = file_tty(filp); |
7ffb6da9 PH |
1611 | struct tty_struct *o_tty = NULL; |
1612 | int do_sleep, final; | |
1da177e4 | 1613 | int idx; |
37b16457 | 1614 | long timeout = 0; |
494c1eac | 1615 | int once = 1; |
37bdfb07 | 1616 | |
9de44bd6 | 1617 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1618 | return 0; |
1da177e4 | 1619 | |
89c8d91e | 1620 | tty_lock(tty); |
9de44bd6 | 1621 | check_tty_count(tty, __func__); |
1da177e4 | 1622 | |
ec79d605 | 1623 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1624 | |
1625 | idx = tty->index; | |
7ffb6da9 PH |
1626 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1627 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1628 | o_tty = tty->link; | |
1da177e4 | 1629 | |
359b9fb5 | 1630 | if (tty_release_checks(tty, idx)) { |
89c8d91e | 1631 | tty_unlock(tty); |
eeb89d91 | 1632 | return 0; |
1da177e4 | 1633 | } |
1da177e4 | 1634 | |
d435cefe | 1635 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
1da177e4 | 1636 | |
f34d7a5b AC |
1637 | if (tty->ops->close) |
1638 | tty->ops->close(tty, filp); | |
1da177e4 | 1639 | |
2aff5e2b PH |
1640 | /* If tty is pty master, lock the slave pty (stable lock order) */ |
1641 | tty_lock_slave(o_tty); | |
1642 | ||
1da177e4 LT |
1643 | /* |
1644 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1645 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1646 | * wait queues and kick everyone out _before_ actually starting to | |
1647 | * close. This ensures that we won't block while releasing the tty | |
1648 | * structure. | |
1649 | * | |
1650 | * The test for the o_tty closing is necessary, since the master and | |
1651 | * slave sides may close in any order. If the slave side closes out | |
1652 | * first, its count will be one, since the master side holds an open. | |
324c1650 | 1653 | * Thus this test wouldn't be triggered at the time the slave closed, |
1da177e4 | 1654 | * so we do it now. |
1da177e4 LT |
1655 | */ |
1656 | while (1) { | |
1da177e4 LT |
1657 | do_sleep = 0; |
1658 | ||
324c1650 | 1659 | if (tty->count <= 1) { |
1da177e4 | 1660 | if (waitqueue_active(&tty->read_wait)) { |
4b19449d | 1661 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1662 | do_sleep++; |
1663 | } | |
1664 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1665 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1666 | do_sleep++; |
1667 | } | |
1668 | } | |
7ffb6da9 | 1669 | if (o_tty && o_tty->count <= 1) { |
1da177e4 | 1670 | if (waitqueue_active(&o_tty->read_wait)) { |
4b19449d | 1671 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1672 | do_sleep++; |
1673 | } | |
1674 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1675 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1676 | do_sleep++; |
1677 | } | |
1678 | } | |
1679 | if (!do_sleep) | |
1680 | break; | |
1681 | ||
494c1eac PH |
1682 | if (once) { |
1683 | once = 0; | |
339f36ba | 1684 | tty_warn(tty, "read/write wait queue active!\n"); |
494c1eac | 1685 | } |
37b16457 PH |
1686 | schedule_timeout_killable(timeout); |
1687 | if (timeout < 120 * HZ) | |
1688 | timeout = 2 * timeout + 1; | |
1689 | else | |
1690 | timeout = MAX_SCHEDULE_TIMEOUT; | |
37bdfb07 | 1691 | } |
1da177e4 | 1692 | |
7ffb6da9 | 1693 | if (o_tty) { |
1da177e4 | 1694 | if (--o_tty->count < 0) { |
339f36ba | 1695 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
1da177e4 LT |
1696 | o_tty->count = 0; |
1697 | } | |
1698 | } | |
1699 | if (--tty->count < 0) { | |
339f36ba | 1700 | tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
1da177e4 LT |
1701 | tty->count = 0; |
1702 | } | |
37bdfb07 | 1703 | |
1da177e4 LT |
1704 | /* |
1705 | * We've decremented tty->count, so we need to remove this file | |
1706 | * descriptor off the tty->tty_files list; this serves two | |
1707 | * purposes: | |
1708 | * - check_tty_count sees the correct number of file descriptors | |
1709 | * associated with this tty. | |
1710 | * - do_tty_hangup no longer sees this file descriptor as | |
1711 | * something that needs to be handled for hangups. | |
1712 | */ | |
d996b62a | 1713 | tty_del_file(filp); |
1da177e4 LT |
1714 | |
1715 | /* | |
1716 | * Perform some housekeeping before deciding whether to return. | |
1717 | * | |
1da177e4 LT |
1718 | * If _either_ side is closing, make sure there aren't any |
1719 | * processes that still think tty or o_tty is their controlling | |
1720 | * tty. | |
1721 | */ | |
324c1650 | 1722 | if (!tty->count) { |
1da177e4 | 1723 | read_lock(&tasklist_lock); |
24ec839c | 1724 | session_clear_tty(tty->session); |
7ffb6da9 | 1725 | if (o_tty) |
24ec839c | 1726 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1727 | read_unlock(&tasklist_lock); |
1728 | } | |
1729 | ||
324c1650 | 1730 | /* check whether both sides are closing ... */ |
7ffb6da9 | 1731 | final = !tty->count && !(o_tty && o_tty->count); |
324c1650 | 1732 | |
2aff5e2b PH |
1733 | tty_unlock_slave(o_tty); |
1734 | tty_unlock(tty); | |
1735 | ||
04980706 | 1736 | /* At this point, the tty->count == 0 should ensure a dead tty |
d155255a | 1737 | cannot be re-opened by a racing opener */ |
da965822 | 1738 | |
324c1650 | 1739 | if (!final) |
eeb89d91 | 1740 | return 0; |
37bdfb07 | 1741 | |
accff793 | 1742 | tty_debug_hangup(tty, "final close\n"); |
1da177e4 | 1743 | |
9ed90d20 | 1744 | tty_release_struct(tty, idx); |
eeb89d91 | 1745 | return 0; |
1da177e4 LT |
1746 | } |
1747 | ||
b82154ac | 1748 | /** |
52494eeb | 1749 | * tty_open_current_tty - get locked tty of current task |
b82154ac JS |
1750 | * @device: device number |
1751 | * @filp: file pointer to tty | |
52494eeb PH |
1752 | * @return: locked tty of the current task iff @device is /dev/tty |
1753 | * | |
1754 | * Performs a re-open of the current task's controlling tty. | |
b82154ac JS |
1755 | * |
1756 | * We cannot return driver and index like for the other nodes because | |
1757 | * devpts will not work then. It expects inodes to be from devpts FS. | |
1758 | */ | |
1759 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1760 | { | |
1761 | struct tty_struct *tty; | |
52494eeb | 1762 | int retval; |
b82154ac JS |
1763 | |
1764 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1765 | return NULL; | |
1766 | ||
1767 | tty = get_current_tty(); | |
1768 | if (!tty) | |
1769 | return ERR_PTR(-ENXIO); | |
1770 | ||
1771 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1772 | /* noctty = 1; */ | |
52494eeb PH |
1773 | tty_lock(tty); |
1774 | tty_kref_put(tty); /* safe to drop the kref now */ | |
1775 | ||
1776 | retval = tty_reopen(tty); | |
1777 | if (retval < 0) { | |
1778 | tty_unlock(tty); | |
1779 | tty = ERR_PTR(retval); | |
1780 | } | |
b82154ac JS |
1781 | return tty; |
1782 | } | |
1783 | ||
5b5e7040 JS |
1784 | /** |
1785 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1786 | * @device: device number | |
1787 | * @filp: file pointer to tty | |
5b5e7040 JS |
1788 | * @index: index for the device in the @return driver |
1789 | * @return: driver for this inode (with increased refcount) | |
1790 | * | |
1791 | * If @return is not erroneous, the caller is responsible to decrement the | |
1792 | * refcount by tty_driver_kref_put. | |
1793 | * | |
1794 | * Locking: tty_mutex protects get_tty_driver | |
1795 | */ | |
1796 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
11e1d4aa | 1797 | int *index) |
5b5e7040 JS |
1798 | { |
1799 | struct tty_driver *driver; | |
1800 | ||
2cd0050c | 1801 | switch (device) { |
5b5e7040 | 1802 | #ifdef CONFIG_VT |
2cd0050c | 1803 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1804 | extern struct tty_driver *console_driver; |
1805 | driver = tty_driver_kref_get(console_driver); | |
1806 | *index = fg_console; | |
2cd0050c | 1807 | break; |
5b5e7040 JS |
1808 | } |
1809 | #endif | |
2cd0050c | 1810 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1811 | struct tty_driver *console_driver = console_device(index); |
1812 | if (console_driver) { | |
1813 | driver = tty_driver_kref_get(console_driver); | |
12e84c71 | 1814 | if (driver && filp) { |
5b5e7040 JS |
1815 | /* Don't let /dev/console block */ |
1816 | filp->f_flags |= O_NONBLOCK; | |
2cd0050c | 1817 | break; |
5b5e7040 JS |
1818 | } |
1819 | } | |
1820 | return ERR_PTR(-ENODEV); | |
1821 | } | |
2cd0050c JS |
1822 | default: |
1823 | driver = get_tty_driver(device, index); | |
1824 | if (!driver) | |
1825 | return ERR_PTR(-ENODEV); | |
1826 | break; | |
1827 | } | |
5b5e7040 JS |
1828 | return driver; |
1829 | } | |
1830 | ||
a09ac397 OK |
1831 | /** |
1832 | * tty_kopen - open a tty device for kernel | |
1833 | * @device: dev_t of device to open | |
1834 | * | |
1835 | * Opens tty exclusively for kernel. Performs the driver lookup, | |
1836 | * makes sure it's not already opened and performs the first-time | |
1837 | * tty initialization. | |
1838 | * | |
1839 | * Returns the locked initialized &tty_struct | |
1840 | * | |
1841 | * Claims the global tty_mutex to serialize: | |
1842 | * - concurrent first-time tty initialization | |
1843 | * - concurrent tty driver removal w/ lookup | |
1844 | * - concurrent tty removal from driver table | |
1845 | */ | |
1846 | struct tty_struct *tty_kopen(dev_t device) | |
1847 | { | |
1848 | struct tty_struct *tty; | |
1849 | struct tty_driver *driver = NULL; | |
1850 | int index = -1; | |
1851 | ||
1852 | mutex_lock(&tty_mutex); | |
1853 | driver = tty_lookup_driver(device, NULL, &index); | |
1854 | if (IS_ERR(driver)) { | |
1855 | mutex_unlock(&tty_mutex); | |
1856 | return ERR_CAST(driver); | |
1857 | } | |
1858 | ||
1859 | /* check whether we're reopening an existing tty */ | |
1860 | tty = tty_driver_lookup_tty(driver, NULL, index); | |
1861 | if (IS_ERR(tty)) | |
1862 | goto out; | |
1863 | ||
1864 | if (tty) { | |
1865 | /* drop kref from tty_driver_lookup_tty() */ | |
1866 | tty_kref_put(tty); | |
1867 | tty = ERR_PTR(-EBUSY); | |
1868 | } else { /* tty_init_dev returns tty with the tty_lock held */ | |
1869 | tty = tty_init_dev(driver, index); | |
1870 | if (IS_ERR(tty)) | |
1871 | goto out; | |
1872 | tty_port_set_kopened(tty->port, 1); | |
1873 | } | |
1874 | out: | |
1875 | mutex_unlock(&tty_mutex); | |
1876 | tty_driver_kref_put(driver); | |
1877 | return tty; | |
1878 | } | |
1879 | EXPORT_SYMBOL_GPL(tty_kopen); | |
1880 | ||
d6203d0c PH |
1881 | /** |
1882 | * tty_open_by_driver - open a tty device | |
1883 | * @device: dev_t of device to open | |
1884 | * @inode: inode of device file | |
1885 | * @filp: file pointer to tty | |
1886 | * | |
1887 | * Performs the driver lookup, checks for a reopen, or otherwise | |
1888 | * performs the first-time tty initialization. | |
1889 | * | |
1890 | * Returns the locked initialized or re-opened &tty_struct | |
1891 | * | |
1892 | * Claims the global tty_mutex to serialize: | |
1893 | * - concurrent first-time tty initialization | |
1894 | * - concurrent tty driver removal w/ lookup | |
1895 | * - concurrent tty removal from driver table | |
1896 | */ | |
a033c3b1 | 1897 | static struct tty_struct *tty_open_by_driver(dev_t device, struct inode *inode, |
d6203d0c PH |
1898 | struct file *filp) |
1899 | { | |
1900 | struct tty_struct *tty; | |
1901 | struct tty_driver *driver = NULL; | |
1902 | int index = -1; | |
1903 | int retval; | |
1904 | ||
1905 | mutex_lock(&tty_mutex); | |
1906 | driver = tty_lookup_driver(device, filp, &index); | |
1907 | if (IS_ERR(driver)) { | |
1908 | mutex_unlock(&tty_mutex); | |
1909 | return ERR_CAST(driver); | |
1910 | } | |
1911 | ||
1912 | /* check whether we're reopening an existing tty */ | |
8ead9dd5 | 1913 | tty = tty_driver_lookup_tty(driver, filp, index); |
d6203d0c PH |
1914 | if (IS_ERR(tty)) { |
1915 | mutex_unlock(&tty_mutex); | |
1916 | goto out; | |
1917 | } | |
1918 | ||
1919 | if (tty) { | |
a09ac397 OK |
1920 | if (tty_port_kopened(tty->port)) { |
1921 | tty_kref_put(tty); | |
1922 | mutex_unlock(&tty_mutex); | |
1923 | tty = ERR_PTR(-EBUSY); | |
1924 | goto out; | |
1925 | } | |
d6203d0c PH |
1926 | mutex_unlock(&tty_mutex); |
1927 | retval = tty_lock_interruptible(tty); | |
5e00bbfb | 1928 | tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
d6203d0c PH |
1929 | if (retval) { |
1930 | if (retval == -EINTR) | |
1931 | retval = -ERESTARTSYS; | |
1932 | tty = ERR_PTR(retval); | |
1933 | goto out; | |
1934 | } | |
d6203d0c PH |
1935 | retval = tty_reopen(tty); |
1936 | if (retval < 0) { | |
1937 | tty_unlock(tty); | |
1938 | tty = ERR_PTR(retval); | |
1939 | } | |
1940 | } else { /* Returns with the tty_lock held for now */ | |
1941 | tty = tty_init_dev(driver, index); | |
1942 | mutex_unlock(&tty_mutex); | |
1943 | } | |
1944 | out: | |
1945 | tty_driver_kref_put(driver); | |
1946 | return tty; | |
1947 | } | |
1948 | ||
af9b897e | 1949 | /** |
eeb89d91 | 1950 | * tty_open - open a tty device |
af9b897e AC |
1951 | * @inode: inode of device file |
1952 | * @filp: file pointer to tty | |
1da177e4 | 1953 | * |
af9b897e AC |
1954 | * tty_open and tty_release keep up the tty count that contains the |
1955 | * number of opens done on a tty. We cannot use the inode-count, as | |
1956 | * different inodes might point to the same tty. | |
1da177e4 | 1957 | * |
af9b897e AC |
1958 | * Open-counting is needed for pty masters, as well as for keeping |
1959 | * track of serial lines: DTR is dropped when the last close happens. | |
1960 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1961 | * | |
1962 | * The termios state of a pty is reset on first open so that | |
1963 | * settings don't persist across reuse. | |
1964 | * | |
5b5e7040 | 1965 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1966 | * tty->count should protect the rest. |
1967 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
1968 | * |
1969 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
1970 | * tty_mutex | |
1da177e4 | 1971 | */ |
af9b897e | 1972 | |
eeb89d91 | 1973 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1974 | { |
b82154ac | 1975 | struct tty_struct *tty; |
1da177e4 | 1976 | int noctty, retval; |
1da177e4 | 1977 | dev_t device = inode->i_rdev; |
846c151a | 1978 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1979 | |
1980 | nonseekable_open(inode, filp); | |
37bdfb07 | 1981 | |
1da177e4 | 1982 | retry_open: |
fa90e1c9 JS |
1983 | retval = tty_alloc_file(filp); |
1984 | if (retval) | |
1985 | return -ENOMEM; | |
1986 | ||
b82154ac | 1987 | tty = tty_open_current_tty(device, filp); |
d6203d0c PH |
1988 | if (!tty) |
1989 | tty = tty_open_by_driver(device, inode, filp); | |
52494eeb | 1990 | |
eeb89d91 | 1991 | if (IS_ERR(tty)) { |
d6203d0c | 1992 | tty_free_file(filp); |
ba5db448 | 1993 | retval = PTR_ERR(tty); |
7f22f6c9 | 1994 | if (retval != -EAGAIN || signal_pending(current)) |
d6203d0c | 1995 | return retval; |
7f22f6c9 PH |
1996 | schedule(); |
1997 | goto retry_open; | |
eeb89d91 | 1998 | } |
1da177e4 | 1999 | |
fa90e1c9 | 2000 | tty_add_file(tty, filp); |
d996b62a | 2001 | |
9de44bd6 | 2002 | check_tty_count(tty, __func__); |
d435cefe | 2003 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
accff793 | 2004 | |
909bc774 HRK |
2005 | if (tty->ops->open) |
2006 | retval = tty->ops->open(tty, filp); | |
2007 | else | |
2008 | retval = -ENODEV; | |
1da177e4 LT |
2009 | filp->f_flags = saved_flags; |
2010 | ||
1da177e4 | 2011 | if (retval) { |
d435cefe | 2012 | tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
accff793 | 2013 | |
89c8d91e | 2014 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2015 | tty_release(inode, filp); |
64ba3dc3 | 2016 | if (retval != -ERESTARTSYS) |
1da177e4 | 2017 | return retval; |
64ba3dc3 AB |
2018 | |
2019 | if (signal_pending(current)) | |
1da177e4 | 2020 | return retval; |
64ba3dc3 | 2021 | |
1da177e4 LT |
2022 | schedule(); |
2023 | /* | |
2024 | * Need to reset f_op in case a hangup happened. | |
2025 | */ | |
1256937f | 2026 | if (tty_hung_up_p(filp)) |
1da177e4 LT |
2027 | filp->f_op = &tty_fops; |
2028 | goto retry_open; | |
2029 | } | |
d4855e1f | 2030 | clear_bit(TTY_HUPPED, &tty->flags); |
eeb89d91 | 2031 | |
11e1d4aa | 2032 | noctty = (filp->f_flags & O_NOCTTY) || |
a1235b3e NP |
2033 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
2034 | device == MKDEV(TTYAUX_MAJOR, 1) || | |
2035 | (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2036 | tty->driver->subtype == PTY_TYPE_MASTER); | |
2037 | if (!noctty) | |
2038 | tty_open_proc_set_tty(filp, tty); | |
89c8d91e | 2039 | tty_unlock(tty); |
1da177e4 LT |
2040 | return 0; |
2041 | } | |
2042 | ||
39d95b9d JC |
2043 | |
2044 | ||
af9b897e AC |
2045 | /** |
2046 | * tty_poll - check tty status | |
2047 | * @filp: file being polled | |
2048 | * @wait: poll wait structures to update | |
2049 | * | |
2050 | * Call the line discipline polling method to obtain the poll | |
2051 | * status of the device. | |
2052 | * | |
2053 | * Locking: locks called line discipline but ldisc poll method | |
2054 | * may be re-entered freely by other callers. | |
2055 | */ | |
2056 | ||
37bdfb07 | 2057 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2058 | { |
d996b62a | 2059 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2060 | struct tty_ldisc *ld; |
2061 | int ret = 0; | |
2062 | ||
6131ffaa | 2063 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2064 | return 0; |
37bdfb07 | 2065 | |
1da177e4 | 2066 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2067 | if (!ld) |
2068 | return hung_up_tty_poll(filp, wait); | |
a352def2 | 2069 | if (ld->ops->poll) |
c961bfb1 | 2070 | ret = ld->ops->poll(tty, filp, wait); |
1da177e4 LT |
2071 | tty_ldisc_deref(ld); |
2072 | return ret; | |
2073 | } | |
2074 | ||
ec79d605 | 2075 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2076 | { |
d996b62a | 2077 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2078 | unsigned long flags; |
5d1e3230 | 2079 | int retval = 0; |
1da177e4 | 2080 | |
6131ffaa | 2081 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2082 | goto out; |
37bdfb07 | 2083 | |
1da177e4 LT |
2084 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2085 | if (retval <= 0) | |
5d1e3230 | 2086 | goto out; |
f6c8dbe6 | 2087 | |
1da177e4 | 2088 | if (on) { |
ab521dc0 EB |
2089 | enum pid_type type; |
2090 | struct pid *pid; | |
f6c8dbe6 | 2091 | |
47f86834 | 2092 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2093 | if (tty->pgrp) { |
2094 | pid = tty->pgrp; | |
2095 | type = PIDTYPE_PGID; | |
2096 | } else { | |
2097 | pid = task_pid(current); | |
2098 | type = PIDTYPE_PID; | |
2099 | } | |
80e1e823 | 2100 | get_pid(pid); |
70362511 | 2101 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
e0b93edd | 2102 | __f_setown(filp, pid, type, 0); |
80e1e823 | 2103 | put_pid(pid); |
e0b93edd | 2104 | retval = 0; |
1da177e4 | 2105 | } |
5d1e3230 | 2106 | out: |
ec79d605 AB |
2107 | return retval; |
2108 | } | |
2109 | ||
2110 | static int tty_fasync(int fd, struct file *filp, int on) | |
2111 | { | |
89c8d91e | 2112 | struct tty_struct *tty = file_tty(filp); |
a8f3a297 | 2113 | int retval = -ENOTTY; |
89c8d91e AC |
2114 | |
2115 | tty_lock(tty); | |
a8f3a297 PH |
2116 | if (!tty_hung_up_p(filp)) |
2117 | retval = __tty_fasync(fd, filp, on); | |
89c8d91e AC |
2118 | tty_unlock(tty); |
2119 | ||
5d1e3230 | 2120 | return retval; |
1da177e4 LT |
2121 | } |
2122 | ||
af9b897e AC |
2123 | /** |
2124 | * tiocsti - fake input character | |
2125 | * @tty: tty to fake input into | |
2126 | * @p: pointer to character | |
2127 | * | |
3a4fa0a2 | 2128 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2129 | * input management. |
2130 | * | |
2131 | * FIXME: does not honour flow control ?? | |
2132 | * | |
2133 | * Locking: | |
137084bb | 2134 | * Called functions take tty_ldiscs_lock |
af9b897e | 2135 | * current->signal->tty check is safe without locks |
28298232 AC |
2136 | * |
2137 | * FIXME: may race normal receive processing | |
af9b897e AC |
2138 | */ |
2139 | ||
1da177e4 LT |
2140 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2141 | { | |
2142 | char ch, mbz = 0; | |
2143 | struct tty_ldisc *ld; | |
37bdfb07 | 2144 | |
1da177e4 LT |
2145 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2146 | return -EPERM; | |
2147 | if (get_user(ch, p)) | |
2148 | return -EFAULT; | |
1e641743 | 2149 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2150 | ld = tty_ldisc_ref_wait(tty); |
e55afd11 PH |
2151 | if (!ld) |
2152 | return -EIO; | |
a352def2 | 2153 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2154 | tty_ldisc_deref(ld); |
2155 | return 0; | |
2156 | } | |
2157 | ||
af9b897e AC |
2158 | /** |
2159 | * tiocgwinsz - implement window query ioctl | |
2160 | * @tty; tty | |
2161 | * @arg: user buffer for result | |
2162 | * | |
808a0d38 | 2163 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2164 | * |
dee4a0be | 2165 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2166 | * is consistent. |
af9b897e AC |
2167 | */ |
2168 | ||
37bdfb07 | 2169 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2170 | { |
808a0d38 AC |
2171 | int err; |
2172 | ||
dee4a0be | 2173 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2174 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2175 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2176 | |
2177 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2178 | } |
2179 | ||
af9b897e | 2180 | /** |
8c9a9dd0 AC |
2181 | * tty_do_resize - resize event |
2182 | * @tty: tty being resized | |
8c9a9dd0 AC |
2183 | * @rows: rows (character) |
2184 | * @cols: cols (character) | |
2185 | * | |
3ad2f3fb | 2186 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2187 | * peform a terminal resize correctly |
af9b897e AC |
2188 | */ |
2189 | ||
fc6f6238 | 2190 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2191 | { |
fc6f6238 | 2192 | struct pid *pgrp; |
1da177e4 | 2193 | |
fc6f6238 | 2194 | /* Lock the tty */ |
dee4a0be | 2195 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2196 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2197 | goto done; |
47f86834 | 2198 | |
5b239542 PH |
2199 | /* Signal the foreground process group */ |
2200 | pgrp = tty_get_pgrp(tty); | |
47f86834 AC |
2201 | if (pgrp) |
2202 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2203 | put_pid(pgrp); |
47f86834 | 2204 | |
8c9a9dd0 | 2205 | tty->winsize = *ws; |
ca9bda00 | 2206 | done: |
dee4a0be | 2207 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2208 | return 0; |
2209 | } | |
4d334fd1 | 2210 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2211 | |
8c9a9dd0 AC |
2212 | /** |
2213 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2214 | * @tty; tty side of tty |
8c9a9dd0 AC |
2215 | * @arg: user buffer for result |
2216 | * | |
2217 | * Copies the user idea of the window size to the kernel. Traditionally | |
2218 | * this is just advisory information but for the Linux console it | |
2219 | * actually has driver level meaning and triggers a VC resize. | |
2220 | * | |
2221 | * Locking: | |
25985edc | 2222 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2223 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2224 | * then calls into the default method. | |
2225 | */ | |
2226 | ||
fc6f6238 | 2227 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2228 | { |
2229 | struct winsize tmp_ws; | |
2230 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2231 | return -EFAULT; | |
2232 | ||
2233 | if (tty->ops->resize) | |
fc6f6238 | 2234 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2235 | else |
fc6f6238 | 2236 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2237 | } |
2238 | ||
af9b897e AC |
2239 | /** |
2240 | * tioccons - allow admin to move logical console | |
2241 | * @file: the file to become console | |
2242 | * | |
25985edc | 2243 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2244 | * |
2245 | * Locking: uses redirect_lock to guard the redirect information | |
2246 | */ | |
2247 | ||
1da177e4 LT |
2248 | static int tioccons(struct file *file) |
2249 | { | |
2250 | if (!capable(CAP_SYS_ADMIN)) | |
2251 | return -EPERM; | |
2252 | if (file->f_op->write == redirected_tty_write) { | |
2253 | struct file *f; | |
2254 | spin_lock(&redirect_lock); | |
2255 | f = redirect; | |
2256 | redirect = NULL; | |
2257 | spin_unlock(&redirect_lock); | |
2258 | if (f) | |
2259 | fput(f); | |
2260 | return 0; | |
2261 | } | |
2262 | spin_lock(&redirect_lock); | |
2263 | if (redirect) { | |
2264 | spin_unlock(&redirect_lock); | |
2265 | return -EBUSY; | |
2266 | } | |
cb0942b8 | 2267 | redirect = get_file(file); |
1da177e4 LT |
2268 | spin_unlock(&redirect_lock); |
2269 | return 0; | |
2270 | } | |
2271 | ||
af9b897e AC |
2272 | /** |
2273 | * fionbio - non blocking ioctl | |
2274 | * @file: file to set blocking value | |
2275 | * @p: user parameter | |
2276 | * | |
2277 | * Historical tty interfaces had a blocking control ioctl before | |
2278 | * the generic functionality existed. This piece of history is preserved | |
2279 | * in the expected tty API of posix OS's. | |
2280 | * | |
6146b9af | 2281 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2282 | */ |
1da177e4 LT |
2283 | |
2284 | static int fionbio(struct file *file, int __user *p) | |
2285 | { | |
2286 | int nonblock; | |
2287 | ||
2288 | if (get_user(nonblock, p)) | |
2289 | return -EFAULT; | |
2290 | ||
db1dd4d3 | 2291 | spin_lock(&file->f_lock); |
1da177e4 LT |
2292 | if (nonblock) |
2293 | file->f_flags |= O_NONBLOCK; | |
2294 | else | |
2295 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2296 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2297 | return 0; |
2298 | } | |
2299 | ||
af9b897e AC |
2300 | /** |
2301 | * tiocsetd - set line discipline | |
2302 | * @tty: tty device | |
2303 | * @p: pointer to user data | |
2304 | * | |
2305 | * Set the line discipline according to user request. | |
2306 | * | |
2307 | * Locking: see tty_set_ldisc, this function is just a helper | |
2308 | */ | |
2309 | ||
1da177e4 LT |
2310 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2311 | { | |
c12da96f | 2312 | int disc; |
04f378b1 | 2313 | int ret; |
1da177e4 | 2314 | |
c12da96f | 2315 | if (get_user(disc, p)) |
1da177e4 | 2316 | return -EFAULT; |
04f378b1 | 2317 | |
c12da96f | 2318 | ret = tty_set_ldisc(tty, disc); |
04f378b1 AC |
2319 | |
2320 | return ret; | |
1da177e4 LT |
2321 | } |
2322 | ||
5c17c861 PH |
2323 | /** |
2324 | * tiocgetd - get line discipline | |
2325 | * @tty: tty device | |
2326 | * @p: pointer to user data | |
2327 | * | |
2328 | * Retrieves the line discipline id directly from the ldisc. | |
2329 | * | |
2330 | * Locking: waits for ldisc reference (in case the line discipline | |
2331 | * is changing or the tty is being hungup) | |
2332 | */ | |
2333 | ||
2334 | static int tiocgetd(struct tty_struct *tty, int __user *p) | |
2335 | { | |
2336 | struct tty_ldisc *ld; | |
2337 | int ret; | |
2338 | ||
2339 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2340 | if (!ld) |
2341 | return -EIO; | |
5c17c861 PH |
2342 | ret = put_user(ld->ops->num, p); |
2343 | tty_ldisc_deref(ld); | |
2344 | return ret; | |
2345 | } | |
2346 | ||
af9b897e AC |
2347 | /** |
2348 | * send_break - performed time break | |
2349 | * @tty: device to break on | |
2350 | * @duration: timeout in mS | |
2351 | * | |
2352 | * Perform a timed break on hardware that lacks its own driver level | |
2353 | * timed break functionality. | |
2354 | * | |
2355 | * Locking: | |
28298232 | 2356 | * atomic_write_lock serializes |
af9b897e | 2357 | * |
af9b897e AC |
2358 | */ |
2359 | ||
b20f3ae5 | 2360 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2361 | { |
9e98966c AC |
2362 | int retval; |
2363 | ||
2364 | if (tty->ops->break_ctl == NULL) | |
2365 | return 0; | |
2366 | ||
2367 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2368 | retval = tty->ops->break_ctl(tty, duration); | |
2369 | else { | |
2370 | /* Do the work ourselves */ | |
2371 | if (tty_write_lock(tty, 0) < 0) | |
2372 | return -EINTR; | |
2373 | retval = tty->ops->break_ctl(tty, -1); | |
2374 | if (retval) | |
2375 | goto out; | |
2376 | if (!signal_pending(current)) | |
2377 | msleep_interruptible(duration); | |
2378 | retval = tty->ops->break_ctl(tty, 0); | |
2379 | out: | |
2380 | tty_write_unlock(tty); | |
2381 | if (signal_pending(current)) | |
2382 | retval = -EINTR; | |
2383 | } | |
2384 | return retval; | |
1da177e4 LT |
2385 | } |
2386 | ||
af9b897e | 2387 | /** |
f34d7a5b | 2388 | * tty_tiocmget - get modem status |
af9b897e AC |
2389 | * @tty: tty device |
2390 | * @file: user file pointer | |
2391 | * @p: pointer to result | |
2392 | * | |
2393 | * Obtain the modem status bits from the tty driver if the feature | |
2394 | * is supported. Return -EINVAL if it is not available. | |
2395 | * | |
2396 | * Locking: none (up to the driver) | |
2397 | */ | |
2398 | ||
60b33c13 | 2399 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2400 | { |
2401 | int retval = -EINVAL; | |
2402 | ||
f34d7a5b | 2403 | if (tty->ops->tiocmget) { |
60b33c13 | 2404 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2405 | |
2406 | if (retval >= 0) | |
2407 | retval = put_user(retval, p); | |
2408 | } | |
2409 | return retval; | |
2410 | } | |
2411 | ||
af9b897e | 2412 | /** |
f34d7a5b | 2413 | * tty_tiocmset - set modem status |
af9b897e | 2414 | * @tty: tty device |
af9b897e AC |
2415 | * @cmd: command - clear bits, set bits or set all |
2416 | * @p: pointer to desired bits | |
2417 | * | |
2418 | * Set the modem status bits from the tty driver if the feature | |
2419 | * is supported. Return -EINVAL if it is not available. | |
2420 | * | |
2421 | * Locking: none (up to the driver) | |
2422 | */ | |
2423 | ||
20b9d177 | 2424 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2425 | unsigned __user *p) |
2426 | { | |
ae677517 AC |
2427 | int retval; |
2428 | unsigned int set, clear, val; | |
1da177e4 | 2429 | |
ae677517 AC |
2430 | if (tty->ops->tiocmset == NULL) |
2431 | return -EINVAL; | |
1da177e4 | 2432 | |
ae677517 AC |
2433 | retval = get_user(val, p); |
2434 | if (retval) | |
2435 | return retval; | |
2436 | set = clear = 0; | |
2437 | switch (cmd) { | |
2438 | case TIOCMBIS: | |
2439 | set = val; | |
2440 | break; | |
2441 | case TIOCMBIC: | |
2442 | clear = val; | |
2443 | break; | |
2444 | case TIOCMSET: | |
2445 | set = val; | |
2446 | clear = ~val; | |
2447 | break; | |
2448 | } | |
2449 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2450 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2451 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2452 | } |
2453 | ||
d281da7f AC |
2454 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2455 | { | |
2456 | int retval = -EINVAL; | |
2457 | struct serial_icounter_struct icount; | |
2458 | memset(&icount, 0, sizeof(icount)); | |
2459 | if (tty->ops->get_icount) | |
2460 | retval = tty->ops->get_icount(tty, &icount); | |
2461 | if (retval != 0) | |
2462 | return retval; | |
2463 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2464 | return -EFAULT; | |
2465 | return 0; | |
2466 | } | |
2467 | ||
8a8ae62f JS |
2468 | static void tty_warn_deprecated_flags(struct serial_struct __user *ss) |
2469 | { | |
2470 | static DEFINE_RATELIMIT_STATE(depr_flags, | |
2471 | DEFAULT_RATELIMIT_INTERVAL, | |
2472 | DEFAULT_RATELIMIT_BURST); | |
2473 | char comm[TASK_COMM_LEN]; | |
2474 | int flags; | |
2475 | ||
2476 | if (get_user(flags, &ss->flags)) | |
2477 | return; | |
2478 | ||
2479 | flags &= ASYNC_DEPRECATED; | |
2480 | ||
2481 | if (flags && __ratelimit(&depr_flags)) | |
d437fa91 JP |
2482 | pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", |
2483 | __func__, get_task_comm(comm, current), flags); | |
8a8ae62f JS |
2484 | } |
2485 | ||
8f166e00 PH |
2486 | /* |
2487 | * if pty, return the slave side (real_tty) | |
2488 | * otherwise, return self | |
2489 | */ | |
2490 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) | |
e8b70e7d AC |
2491 | { |
2492 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2493 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2494 | tty = tty->link; | |
2495 | return tty; | |
2496 | } | |
e8b70e7d | 2497 | |
1da177e4 LT |
2498 | /* |
2499 | * Split this up, as gcc can choke on it otherwise.. | |
2500 | */ | |
04f378b1 | 2501 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2502 | { |
d996b62a NP |
2503 | struct tty_struct *tty = file_tty(file); |
2504 | struct tty_struct *real_tty; | |
1da177e4 LT |
2505 | void __user *p = (void __user *)arg; |
2506 | int retval; | |
2507 | struct tty_ldisc *ld; | |
37bdfb07 | 2508 | |
6131ffaa | 2509 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2510 | return -EINVAL; |
2511 | ||
e8b70e7d | 2512 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2513 | |
2514 | /* | |
2515 | * Factor out some common prep work | |
2516 | */ | |
2517 | switch (cmd) { | |
2518 | case TIOCSETD: | |
2519 | case TIOCSBRK: | |
2520 | case TIOCCBRK: | |
2521 | case TCSBRK: | |
37bdfb07 | 2522 | case TCSBRKP: |
1da177e4 LT |
2523 | retval = tty_check_change(tty); |
2524 | if (retval) | |
2525 | return retval; | |
2526 | if (cmd != TIOCCBRK) { | |
2527 | tty_wait_until_sent(tty, 0); | |
2528 | if (signal_pending(current)) | |
2529 | return -EINTR; | |
2530 | } | |
2531 | break; | |
2532 | } | |
2533 | ||
9e98966c AC |
2534 | /* |
2535 | * Now do the stuff. | |
2536 | */ | |
1da177e4 | 2537 | switch (cmd) { |
37bdfb07 AC |
2538 | case TIOCSTI: |
2539 | return tiocsti(tty, p); | |
2540 | case TIOCGWINSZ: | |
8f520021 | 2541 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2542 | case TIOCSWINSZ: |
fc6f6238 | 2543 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2544 | case TIOCCONS: |
2545 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2546 | case FIONBIO: | |
2547 | return fionbio(file, p); | |
2548 | case TIOCEXCL: | |
2549 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2550 | return 0; | |
2551 | case TIOCNXCL: | |
2552 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2553 | return 0; | |
84fd7bdf CG |
2554 | case TIOCGEXCL: |
2555 | { | |
2556 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2557 | return put_user(excl, (int __user *)p); | |
2558 | } | |
37bdfb07 | 2559 | case TIOCGETD: |
5c17c861 | 2560 | return tiocgetd(tty, p); |
37bdfb07 AC |
2561 | case TIOCSETD: |
2562 | return tiocsetd(tty, p); | |
3c95c985 KS |
2563 | case TIOCVHANGUP: |
2564 | if (!capable(CAP_SYS_ADMIN)) | |
2565 | return -EPERM; | |
2566 | tty_vhangup(tty); | |
2567 | return 0; | |
b7b8de08 WF |
2568 | case TIOCGDEV: |
2569 | { | |
2570 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2571 | return put_user(ret, (unsigned int __user *)p); | |
2572 | } | |
37bdfb07 AC |
2573 | /* |
2574 | * Break handling | |
2575 | */ | |
2576 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2577 | if (tty->ops->break_ctl) |
9e98966c | 2578 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2579 | return 0; |
37bdfb07 | 2580 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2581 | if (tty->ops->break_ctl) |
9e98966c | 2582 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2583 | return 0; |
2584 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2585 | /* non-zero arg means wait for all output data | |
2586 | * to be sent (performed above) but don't send break. | |
2587 | * This is used by the tcdrain() termios function. | |
2588 | */ | |
2589 | if (!arg) | |
2590 | return send_break(tty, 250); | |
2591 | return 0; | |
2592 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2593 | return send_break(tty, arg ? arg*100 : 250); | |
2594 | ||
2595 | case TIOCMGET: | |
60b33c13 | 2596 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2597 | case TIOCMSET: |
2598 | case TIOCMBIC: | |
2599 | case TIOCMBIS: | |
20b9d177 | 2600 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2601 | case TIOCGICOUNT: |
2602 | retval = tty_tiocgicount(tty, p); | |
2603 | /* For the moment allow fall through to the old method */ | |
2604 | if (retval != -EINVAL) | |
2605 | return retval; | |
2606 | break; | |
37bdfb07 AC |
2607 | case TCFLSH: |
2608 | switch (arg) { | |
2609 | case TCIFLUSH: | |
2610 | case TCIOFLUSH: | |
2611 | /* flush tty buffer and allow ldisc to process ioctl */ | |
86c80a8e | 2612 | tty_buffer_flush(tty, NULL); |
c5c34d48 | 2613 | break; |
37bdfb07 AC |
2614 | } |
2615 | break; | |
8a8ae62f JS |
2616 | case TIOCSSERIAL: |
2617 | tty_warn_deprecated_flags(p); | |
2618 | break; | |
311fc65c EB |
2619 | case TIOCGPTPEER: |
2620 | /* Special because the struct file is needed */ | |
2621 | return ptm_open_peer(file, tty, (int)arg); | |
a1235b3e NP |
2622 | default: |
2623 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); | |
2624 | if (retval != -ENOIOCTLCMD) | |
2625 | return retval; | |
1da177e4 | 2626 | } |
f34d7a5b | 2627 | if (tty->ops->ioctl) { |
c961bfb1 | 2628 | retval = tty->ops->ioctl(tty, cmd, arg); |
1da177e4 LT |
2629 | if (retval != -ENOIOCTLCMD) |
2630 | return retval; | |
2631 | } | |
2632 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2633 | if (!ld) |
2634 | return hung_up_tty_ioctl(file, cmd, arg); | |
1da177e4 | 2635 | retval = -EINVAL; |
a352def2 AC |
2636 | if (ld->ops->ioctl) { |
2637 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2638 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2639 | retval = -ENOTTY; |
1da177e4 LT |
2640 | } |
2641 | tty_ldisc_deref(ld); | |
2642 | return retval; | |
2643 | } | |
2644 | ||
e10cc1df | 2645 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2646 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2647 | unsigned long arg) |
2648 | { | |
d996b62a | 2649 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2650 | struct tty_ldisc *ld; |
2651 | int retval = -ENOIOCTLCMD; | |
2652 | ||
6131ffaa | 2653 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2654 | return -EINVAL; |
2655 | ||
f34d7a5b | 2656 | if (tty->ops->compat_ioctl) { |
c961bfb1 | 2657 | retval = tty->ops->compat_ioctl(tty, cmd, arg); |
e10cc1df PF |
2658 | if (retval != -ENOIOCTLCMD) |
2659 | return retval; | |
2660 | } | |
2661 | ||
2662 | ld = tty_ldisc_ref_wait(tty); | |
e55afd11 PH |
2663 | if (!ld) |
2664 | return hung_up_tty_compat_ioctl(file, cmd, arg); | |
a352def2 AC |
2665 | if (ld->ops->compat_ioctl) |
2666 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2667 | else |
2668 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2669 | tty_ldisc_deref(ld); |
2670 | ||
2671 | return retval; | |
2672 | } | |
2673 | #endif | |
1da177e4 | 2674 | |
c3c073f8 AV |
2675 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2676 | { | |
2677 | if (likely(file->f_op->read != tty_read)) | |
2678 | return 0; | |
2679 | return file_tty(file) != t ? 0 : fd + 1; | |
2680 | } | |
2681 | ||
1da177e4 LT |
2682 | /* |
2683 | * This implements the "Secure Attention Key" --- the idea is to | |
2684 | * prevent trojan horses by killing all processes associated with this | |
2685 | * tty when the user hits the "Secure Attention Key". Required for | |
2686 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2687 | * |
1da177e4 LT |
2688 | * This code could be nicer; ideally it should send a HUP, wait a few |
2689 | * seconds, then send a INT, and then a KILL signal. But you then | |
2690 | * have to coordinate with the init process, since all processes associated | |
2691 | * with the current tty must be dead before the new getty is allowed | |
2692 | * to spawn. | |
2693 | * | |
2694 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2695 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2696 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2697 | * | |
2698 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2699 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2700 | */ | |
8b6312f4 | 2701 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2702 | { |
2703 | #ifdef TTY_SOFT_SAK | |
2704 | tty_hangup(tty); | |
2705 | #else | |
652486fb | 2706 | struct task_struct *g, *p; |
ab521dc0 | 2707 | struct pid *session; |
1da177e4 | 2708 | int i; |
37bdfb07 | 2709 | |
1da177e4 LT |
2710 | if (!tty) |
2711 | return; | |
24ec839c | 2712 | session = tty->session; |
37bdfb07 | 2713 | |
b3f13deb | 2714 | tty_ldisc_flush(tty); |
1da177e4 | 2715 | |
f34d7a5b | 2716 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2717 | |
1da177e4 | 2718 | read_lock(&tasklist_lock); |
652486fb | 2719 | /* Kill the entire session */ |
ab521dc0 | 2720 | do_each_pid_task(session, PIDTYPE_SID, p) { |
9b42bb75 PH |
2721 | tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
2722 | task_pid_nr(p), p->comm); | |
652486fb | 2723 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2724 | } while_each_pid_task(session, PIDTYPE_SID, p); |
9b42bb75 PH |
2725 | |
2726 | /* Now kill any processes that happen to have the tty open */ | |
652486fb EB |
2727 | do_each_thread(g, p) { |
2728 | if (p->signal->tty == tty) { | |
9b42bb75 PH |
2729 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
2730 | task_pid_nr(p), p->comm); | |
1da177e4 LT |
2731 | send_sig(SIGKILL, p, 1); |
2732 | continue; | |
2733 | } | |
2734 | task_lock(p); | |
c3c073f8 AV |
2735 | i = iterate_fd(p->files, 0, this_tty, tty); |
2736 | if (i != 0) { | |
9b42bb75 PH |
2737 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
2738 | task_pid_nr(p), p->comm, i - 1); | |
c3c073f8 | 2739 | force_sig(SIGKILL, p); |
1da177e4 LT |
2740 | } |
2741 | task_unlock(p); | |
652486fb | 2742 | } while_each_thread(g, p); |
1da177e4 LT |
2743 | read_unlock(&tasklist_lock); |
2744 | #endif | |
2745 | } | |
2746 | ||
8b6312f4 EB |
2747 | static void do_SAK_work(struct work_struct *work) |
2748 | { | |
2749 | struct tty_struct *tty = | |
2750 | container_of(work, struct tty_struct, SAK_work); | |
2751 | __do_SAK(tty); | |
2752 | } | |
2753 | ||
1da177e4 LT |
2754 | /* |
2755 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2756 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2757 | * the values which we write to it will be identical to the values which it | |
2758 | * already has. --akpm | |
2759 | */ | |
2760 | void do_SAK(struct tty_struct *tty) | |
2761 | { | |
2762 | if (!tty) | |
2763 | return; | |
1da177e4 LT |
2764 | schedule_work(&tty->SAK_work); |
2765 | } | |
2766 | ||
2767 | EXPORT_SYMBOL(do_SAK); | |
2768 | ||
6e9430ac | 2769 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 2770 | { |
6e9430ac | 2771 | const dev_t *devt = data; |
30004ac9 DB |
2772 | return dev->devt == *devt; |
2773 | } | |
2774 | ||
2775 | /* Must put_device() after it's unused! */ | |
2776 | static struct device *tty_get_device(struct tty_struct *tty) | |
2777 | { | |
2778 | dev_t devt = tty_devnum(tty); | |
2779 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2780 | } | |
2781 | ||
2782 | ||
af9b897e | 2783 | /** |
2c964a2f | 2784 | * alloc_tty_struct |
af9b897e | 2785 | * |
2c964a2f | 2786 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 2787 | * |
2c964a2f | 2788 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 2789 | */ |
af9b897e | 2790 | |
2c964a2f | 2791 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 2792 | { |
2c964a2f RV |
2793 | struct tty_struct *tty; |
2794 | ||
2795 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
2796 | if (!tty) | |
2797 | return NULL; | |
2798 | ||
9c9f4ded | 2799 | kref_init(&tty->kref); |
1da177e4 | 2800 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2801 | tty_ldisc_init(tty); |
ab521dc0 EB |
2802 | tty->session = NULL; |
2803 | tty->pgrp = NULL; | |
89c8d91e | 2804 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 2805 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 2806 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 2807 | mutex_init(&tty->winsize_mutex); |
36697529 | 2808 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
2809 | init_waitqueue_head(&tty->write_wait); |
2810 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2811 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 2812 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 2813 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 2814 | spin_lock_init(&tty->flow_lock); |
4a510969 | 2815 | spin_lock_init(&tty->files_lock); |
1da177e4 | 2816 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2817 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2818 | |
2819 | tty->driver = driver; | |
2820 | tty->ops = driver->ops; | |
2821 | tty->index = idx; | |
2822 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2823 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
2824 | |
2825 | return tty; | |
1da177e4 LT |
2826 | } |
2827 | ||
f34d7a5b AC |
2828 | /** |
2829 | * tty_put_char - write one character to a tty | |
2830 | * @tty: tty | |
2831 | * @ch: character | |
2832 | * | |
2833 | * Write one byte to the tty using the provided put_char method | |
2834 | * if present. Returns the number of characters successfully output. | |
2835 | * | |
2836 | * Note: the specific put_char operation in the driver layer may go | |
2837 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2838 | */ |
af9b897e | 2839 | |
f34d7a5b | 2840 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2841 | { |
f34d7a5b AC |
2842 | if (tty->ops->put_char) |
2843 | return tty->ops->put_char(tty, ch); | |
2844 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2845 | } |
f34d7a5b AC |
2846 | EXPORT_SYMBOL_GPL(tty_put_char); |
2847 | ||
d81ed103 | 2848 | struct class *tty_class; |
1da177e4 | 2849 | |
7e73eca6 JS |
2850 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
2851 | unsigned int index, unsigned int count) | |
2852 | { | |
c1a752ba LY |
2853 | int err; |
2854 | ||
7e73eca6 | 2855 | /* init here, since reused cdevs cause crashes */ |
a3a10ce3 RW |
2856 | driver->cdevs[index] = cdev_alloc(); |
2857 | if (!driver->cdevs[index]) | |
2858 | return -ENOMEM; | |
c1a752ba | 2859 | driver->cdevs[index]->ops = &tty_fops; |
a3a10ce3 | 2860 | driver->cdevs[index]->owner = driver->owner; |
c1a752ba LY |
2861 | err = cdev_add(driver->cdevs[index], dev, count); |
2862 | if (err) | |
2863 | kobject_put(&driver->cdevs[index]->kobj); | |
2864 | return err; | |
7e73eca6 JS |
2865 | } |
2866 | ||
1da177e4 | 2867 | /** |
af9b897e AC |
2868 | * tty_register_device - register a tty device |
2869 | * @driver: the tty driver that describes the tty device | |
2870 | * @index: the index in the tty driver for this tty device | |
2871 | * @device: a struct device that is associated with this tty device. | |
2872 | * This field is optional, if there is no known struct device | |
2873 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2874 | * |
01107d34 GKH |
2875 | * Returns a pointer to the struct device for this tty device |
2876 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2877 | * |
af9b897e AC |
2878 | * This call is required to be made to register an individual tty device |
2879 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2880 | * that bit is not set, this function should not be called by a tty | |
2881 | * driver. | |
2882 | * | |
2883 | * Locking: ?? | |
1da177e4 | 2884 | */ |
af9b897e | 2885 | |
01107d34 GKH |
2886 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2887 | struct device *device) | |
1da177e4 | 2888 | { |
6915c0e4 TH |
2889 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
2890 | } | |
2891 | EXPORT_SYMBOL(tty_register_device); | |
2892 | ||
b1b79916 TH |
2893 | static void tty_device_create_release(struct device *dev) |
2894 | { | |
83db1df4 | 2895 | dev_dbg(dev, "releasing...\n"); |
b1b79916 TH |
2896 | kfree(dev); |
2897 | } | |
2898 | ||
6915c0e4 TH |
2899 | /** |
2900 | * tty_register_device_attr - register a tty device | |
2901 | * @driver: the tty driver that describes the tty device | |
2902 | * @index: the index in the tty driver for this tty device | |
2903 | * @device: a struct device that is associated with this tty device. | |
2904 | * This field is optional, if there is no known struct device | |
2905 | * for this tty device it can be set to NULL safely. | |
2906 | * @drvdata: Driver data to be set to device. | |
2907 | * @attr_grp: Attribute group to be set on device. | |
2908 | * | |
2909 | * Returns a pointer to the struct device for this tty device | |
2910 | * (or ERR_PTR(-EFOO) on error). | |
2911 | * | |
2912 | * This call is required to be made to register an individual tty device | |
2913 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2914 | * that bit is not set, this function should not be called by a tty | |
2915 | * driver. | |
2916 | * | |
2917 | * Locking: ?? | |
2918 | */ | |
2919 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
2920 | unsigned index, struct device *device, | |
2921 | void *drvdata, | |
2922 | const struct attribute_group **attr_grp) | |
2923 | { | |
1da177e4 | 2924 | char name[64]; |
6915c0e4 | 2925 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
93857edd | 2926 | struct ktermios *tp; |
6a7e6f78 JH |
2927 | struct device *dev; |
2928 | int retval; | |
1da177e4 LT |
2929 | |
2930 | if (index >= driver->num) { | |
656fb867 PH |
2931 | pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
2932 | driver->name, index); | |
1cdcb6b4 | 2933 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2934 | } |
2935 | ||
1da177e4 LT |
2936 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2937 | pty_line_name(driver, index, name); | |
2938 | else | |
2939 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2940 | |
6915c0e4 | 2941 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
6a7e6f78 JH |
2942 | if (!dev) |
2943 | return ERR_PTR(-ENOMEM); | |
7e73eca6 | 2944 | |
6915c0e4 TH |
2945 | dev->devt = devt; |
2946 | dev->class = tty_class; | |
2947 | dev->parent = device; | |
b1b79916 | 2948 | dev->release = tty_device_create_release; |
6915c0e4 TH |
2949 | dev_set_name(dev, "%s", name); |
2950 | dev->groups = attr_grp; | |
2951 | dev_set_drvdata(dev, drvdata); | |
2952 | ||
6a7e6f78 JH |
2953 | dev_set_uevent_suppress(dev, 1); |
2954 | ||
6915c0e4 TH |
2955 | retval = device_register(dev); |
2956 | if (retval) | |
6a7e6f78 JH |
2957 | goto err_put; |
2958 | ||
2959 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
93857edd JH |
2960 | /* |
2961 | * Free any saved termios data so that the termios state is | |
2962 | * reset when reusing a minor number. | |
2963 | */ | |
2964 | tp = driver->termios[index]; | |
2965 | if (tp) { | |
2966 | driver->termios[index] = NULL; | |
2967 | kfree(tp); | |
2968 | } | |
2969 | ||
6a7e6f78 JH |
2970 | retval = tty_cdev_add(driver, devt, index, 1); |
2971 | if (retval) | |
2972 | goto err_del; | |
2973 | } | |
2974 | ||
2975 | dev_set_uevent_suppress(dev, 0); | |
2976 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
6915c0e4 TH |
2977 | |
2978 | return dev; | |
2979 | ||
6a7e6f78 JH |
2980 | err_del: |
2981 | device_del(dev); | |
2982 | err_put: | |
6915c0e4 | 2983 | put_device(dev); |
6a7e6f78 | 2984 | |
6915c0e4 | 2985 | return ERR_PTR(retval); |
1da177e4 | 2986 | } |
6915c0e4 | 2987 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
2988 | |
2989 | /** | |
af9b897e AC |
2990 | * tty_unregister_device - unregister a tty device |
2991 | * @driver: the tty driver that describes the tty device | |
2992 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2993 | * |
af9b897e AC |
2994 | * If a tty device is registered with a call to tty_register_device() then |
2995 | * this function must be called when the tty device is gone. | |
2996 | * | |
2997 | * Locking: ?? | |
1da177e4 | 2998 | */ |
af9b897e | 2999 | |
1da177e4 LT |
3000 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3001 | { | |
37bdfb07 AC |
3002 | device_destroy(tty_class, |
3003 | MKDEV(driver->major, driver->minor_start) + index); | |
a3a10ce3 RW |
3004 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3005 | cdev_del(driver->cdevs[index]); | |
3006 | driver->cdevs[index] = NULL; | |
3007 | } | |
1da177e4 | 3008 | } |
1da177e4 LT |
3009 | EXPORT_SYMBOL(tty_unregister_device); |
3010 | ||
7f0bc6a6 JS |
3011 | /** |
3012 | * __tty_alloc_driver -- allocate tty driver | |
3013 | * @lines: count of lines this driver can handle at most | |
87838ae3 | 3014 | * @owner: module which is responsible for this driver |
7f0bc6a6 JS |
3015 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags |
3016 | * | |
3017 | * This should not be called directly, some of the provided macros should be | |
3018 | * used instead. Use IS_ERR and friends on @retval. | |
3019 | */ | |
3020 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3021 | unsigned long flags) | |
1da177e4 LT |
3022 | { |
3023 | struct tty_driver *driver; | |
7e73eca6 | 3024 | unsigned int cdevs = 1; |
16a02081 | 3025 | int err; |
1da177e4 | 3026 | |
0019b408 | 3027 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3028 | return ERR_PTR(-EINVAL); |
3029 | ||
506eb99a | 3030 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3031 | if (!driver) |
3032 | return ERR_PTR(-ENOMEM); | |
3033 | ||
3034 | kref_init(&driver->kref); | |
3035 | driver->magic = TTY_DRIVER_MAGIC; | |
3036 | driver->num = lines; | |
3037 | driver->owner = owner; | |
3038 | driver->flags = flags; | |
16a02081 JS |
3039 | |
3040 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3041 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3042 | GFP_KERNEL); | |
3043 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3044 | GFP_KERNEL); | |
3045 | if (!driver->ttys || !driver->termios) { | |
3046 | err = -ENOMEM; | |
3047 | goto err_free_all; | |
3048 | } | |
3049 | } | |
3050 | ||
3051 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3052 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3053 | GFP_KERNEL); | |
3054 | if (!driver->ports) { | |
3055 | err = -ENOMEM; | |
3056 | goto err_free_all; | |
3057 | } | |
7e73eca6 JS |
3058 | cdevs = lines; |
3059 | } | |
3060 | ||
3061 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3062 | if (!driver->cdevs) { | |
3063 | err = -ENOMEM; | |
3064 | goto err_free_all; | |
16a02081 | 3065 | } |
7f0bc6a6 | 3066 | |
1da177e4 | 3067 | return driver; |
16a02081 JS |
3068 | err_free_all: |
3069 | kfree(driver->ports); | |
3070 | kfree(driver->ttys); | |
3071 | kfree(driver->termios); | |
a3a10ce3 | 3072 | kfree(driver->cdevs); |
16a02081 JS |
3073 | kfree(driver); |
3074 | return ERR_PTR(err); | |
1da177e4 | 3075 | } |
7f0bc6a6 | 3076 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3077 | |
7d7b93c1 | 3078 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3079 | { |
7d7b93c1 AC |
3080 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3081 | int i; | |
3082 | struct ktermios *tp; | |
7d7b93c1 AC |
3083 | |
3084 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
7d7b93c1 AC |
3085 | for (i = 0; i < driver->num; i++) { |
3086 | tp = driver->termios[i]; | |
3087 | if (tp) { | |
3088 | driver->termios[i] = NULL; | |
3089 | kfree(tp); | |
3090 | } | |
7d7b93c1 AC |
3091 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3092 | tty_unregister_device(driver, i); | |
3093 | } | |
7d7b93c1 | 3094 | proc_tty_unregister_driver(driver); |
7e73eca6 | 3095 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
a3a10ce3 | 3096 | cdev_del(driver->cdevs[0]); |
7d7b93c1 | 3097 | } |
7e73eca6 | 3098 | kfree(driver->cdevs); |
04831dc1 | 3099 | kfree(driver->ports); |
16a02081 JS |
3100 | kfree(driver->termios); |
3101 | kfree(driver->ttys); | |
1da177e4 LT |
3102 | kfree(driver); |
3103 | } | |
3104 | ||
7d7b93c1 AC |
3105 | void tty_driver_kref_put(struct tty_driver *driver) |
3106 | { | |
3107 | kref_put(&driver->kref, destruct_tty_driver); | |
3108 | } | |
3109 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3110 | ||
b68e31d0 JD |
3111 | void tty_set_operations(struct tty_driver *driver, |
3112 | const struct tty_operations *op) | |
1da177e4 | 3113 | { |
f34d7a5b AC |
3114 | driver->ops = op; |
3115 | }; | |
7d7b93c1 | 3116 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3117 | |
7d7b93c1 AC |
3118 | void put_tty_driver(struct tty_driver *d) |
3119 | { | |
3120 | tty_driver_kref_put(d); | |
3121 | } | |
1da177e4 | 3122 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3123 | |
3124 | /* | |
3125 | * Called by a tty driver to register itself. | |
3126 | */ | |
3127 | int tty_register_driver(struct tty_driver *driver) | |
3128 | { | |
3129 | int error; | |
37bdfb07 | 3130 | int i; |
1da177e4 | 3131 | dev_t dev; |
b670bde0 | 3132 | struct device *d; |
1da177e4 | 3133 | |
1da177e4 | 3134 | if (!driver->major) { |
37bdfb07 AC |
3135 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3136 | driver->num, driver->name); | |
1da177e4 LT |
3137 | if (!error) { |
3138 | driver->major = MAJOR(dev); | |
3139 | driver->minor_start = MINOR(dev); | |
3140 | } | |
3141 | } else { | |
3142 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3143 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3144 | } |
9bb8a3d4 | 3145 | if (error < 0) |
16a02081 | 3146 | goto err; |
1da177e4 | 3147 | |
7e73eca6 JS |
3148 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3149 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3150 | if (error) | |
3151 | goto err_unreg_char; | |
3152 | } | |
1da177e4 | 3153 | |
ca509f69 | 3154 | mutex_lock(&tty_mutex); |
1da177e4 | 3155 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3156 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3157 | |
3158 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3159 | for (i = 0; i < driver->num; i++) { |
3160 | d = tty_register_device(driver, i, NULL); | |
3161 | if (IS_ERR(d)) { | |
3162 | error = PTR_ERR(d); | |
16a02081 | 3163 | goto err_unreg_devs; |
b670bde0 VK |
3164 | } |
3165 | } | |
1da177e4 LT |
3166 | } |
3167 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3168 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3169 | return 0; |
b670bde0 | 3170 | |
16a02081 | 3171 | err_unreg_devs: |
b670bde0 VK |
3172 | for (i--; i >= 0; i--) |
3173 | tty_unregister_device(driver, i); | |
3174 | ||
3175 | mutex_lock(&tty_mutex); | |
3176 | list_del(&driver->tty_drivers); | |
3177 | mutex_unlock(&tty_mutex); | |
3178 | ||
9bb8a3d4 | 3179 | err_unreg_char: |
b670bde0 | 3180 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3181 | err: |
b670bde0 | 3182 | return error; |
1da177e4 | 3183 | } |
1da177e4 LT |
3184 | EXPORT_SYMBOL(tty_register_driver); |
3185 | ||
3186 | /* | |
3187 | * Called by a tty driver to unregister itself. | |
3188 | */ | |
3189 | int tty_unregister_driver(struct tty_driver *driver) | |
3190 | { | |
7d7b93c1 AC |
3191 | #if 0 |
3192 | /* FIXME */ | |
1da177e4 LT |
3193 | if (driver->refcount) |
3194 | return -EBUSY; | |
7d7b93c1 | 3195 | #endif |
1da177e4 LT |
3196 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3197 | driver->num); | |
ca509f69 | 3198 | mutex_lock(&tty_mutex); |
1da177e4 | 3199 | list_del(&driver->tty_drivers); |
ca509f69 | 3200 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3201 | return 0; |
3202 | } | |
7d7b93c1 | 3203 | |
1da177e4 LT |
3204 | EXPORT_SYMBOL(tty_unregister_driver); |
3205 | ||
24ec839c PZ |
3206 | dev_t tty_devnum(struct tty_struct *tty) |
3207 | { | |
3208 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3209 | } | |
3210 | EXPORT_SYMBOL(tty_devnum); | |
1da177e4 | 3211 | |
d81ed103 AC |
3212 | void tty_default_fops(struct file_operations *fops) |
3213 | { | |
3214 | *fops = tty_fops; | |
3215 | } | |
3216 | ||
2c9ede55 | 3217 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3218 | { |
3219 | if (!mode) | |
3220 | return NULL; | |
3221 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3222 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3223 | *mode = 0666; | |
3224 | return NULL; | |
3225 | } | |
3226 | ||
1da177e4 LT |
3227 | static int __init tty_class_init(void) |
3228 | { | |
7fe845d1 | 3229 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3230 | if (IS_ERR(tty_class)) |
3231 | return PTR_ERR(tty_class); | |
e454cea2 | 3232 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3233 | return 0; |
3234 | } | |
3235 | ||
3236 | postcore_initcall(tty_class_init); | |
3237 | ||
3238 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3239 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3240 | |
fbc92a34 KS |
3241 | static ssize_t show_cons_active(struct device *dev, |
3242 | struct device_attribute *attr, char *buf) | |
3243 | { | |
3244 | struct console *cs[16]; | |
3245 | int i = 0; | |
3246 | struct console *c; | |
3247 | ssize_t count = 0; | |
3248 | ||
ac751efa | 3249 | console_lock(); |
a2a6a822 | 3250 | for_each_console(c) { |
fbc92a34 KS |
3251 | if (!c->device) |
3252 | continue; | |
3253 | if (!c->write) | |
3254 | continue; | |
3255 | if ((c->flags & CON_ENABLED) == 0) | |
3256 | continue; | |
3257 | cs[i++] = c; | |
3258 | if (i >= ARRAY_SIZE(cs)) | |
3259 | break; | |
3260 | } | |
723abd87 HR |
3261 | while (i--) { |
3262 | int index = cs[i]->index; | |
3263 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3264 | ||
3265 | /* don't resolve tty0 as some programs depend on it */ | |
3266 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3267 | count += tty_line_name(drv, index, buf + count); | |
3268 | else | |
3269 | count += sprintf(buf + count, "%s%d", | |
3270 | cs[i]->name, cs[i]->index); | |
3271 | ||
3272 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3273 | } | |
ac751efa | 3274 | console_unlock(); |
fbc92a34 KS |
3275 | |
3276 | return count; | |
3277 | } | |
3278 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3279 | ||
1083a7be TI |
3280 | static struct attribute *cons_dev_attrs[] = { |
3281 | &dev_attr_active.attr, | |
3282 | NULL | |
3283 | }; | |
3284 | ||
3285 | ATTRIBUTE_GROUPS(cons_dev); | |
3286 | ||
fbc92a34 KS |
3287 | static struct device *consdev; |
3288 | ||
3289 | void console_sysfs_notify(void) | |
3290 | { | |
3291 | if (consdev) | |
3292 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3293 | } | |
3294 | ||
1da177e4 LT |
3295 | /* |
3296 | * Ok, now we can initialize the rest of the tty devices and can count | |
3297 | * on memory allocations, interrupts etc.. | |
3298 | */ | |
31d1d48e | 3299 | int __init tty_init(void) |
1da177e4 LT |
3300 | { |
3301 | cdev_init(&tty_cdev, &tty_fops); | |
3302 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3303 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3304 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3305 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3306 | |
3307 | cdev_init(&console_cdev, &console_fops); | |
3308 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3309 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3310 | panic("Couldn't register /dev/console driver\n"); | |
1083a7be TI |
3311 | consdev = device_create_with_groups(tty_class, NULL, |
3312 | MKDEV(TTYAUX_MAJOR, 1), NULL, | |
3313 | cons_dev_groups, "console"); | |
fbc92a34 KS |
3314 | if (IS_ERR(consdev)) |
3315 | consdev = NULL; | |
1da177e4 | 3316 | |
1da177e4 | 3317 | #ifdef CONFIG_VT |
d81ed103 | 3318 | vty_init(&console_fops); |
1da177e4 LT |
3319 | #endif |
3320 | return 0; | |
3321 | } | |
31d1d48e | 3322 |