Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | #include <asm/system.h> |
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 | |
110 | ||
111 | #define TTY_PARANOIA_CHECK 1 | |
112 | #define CHECK_TTY_COUNT 1 | |
113 | ||
edc6afc5 | 114 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
115 | .c_iflag = ICRNL | IXON, |
116 | .c_oflag = OPOST | ONLCR, | |
117 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
118 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
119 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
120 | .c_cc = INIT_C_CC, |
121 | .c_ispeed = 38400, | |
122 | .c_ospeed = 38400 | |
1da177e4 LT |
123 | }; |
124 | ||
125 | EXPORT_SYMBOL(tty_std_termios); | |
126 | ||
127 | /* This list gets poked at by procfs and various bits of boot up code. This | |
128 | could do with some rationalisation such as pulling the tty proc function | |
129 | into this file */ | |
37bdfb07 | 130 | |
1da177e4 LT |
131 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
132 | ||
24ec839c | 133 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 134 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 135 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 136 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 137 | |
ee2ffa0d NP |
138 | /* Spinlock to protect the tty->tty_files list */ |
139 | DEFINE_SPINLOCK(tty_files_lock); | |
140 | ||
1da177e4 LT |
141 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
142 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
143 | ssize_t redirected_tty_write(struct file *, const char __user *, |
144 | size_t, loff_t *); | |
1da177e4 LT |
145 | static unsigned int tty_poll(struct file *, poll_table *); |
146 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 147 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 148 | #ifdef CONFIG_COMPAT |
37bdfb07 | 149 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
150 | unsigned long arg); |
151 | #else | |
152 | #define tty_compat_ioctl NULL | |
153 | #endif | |
ec79d605 | 154 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 155 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 156 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 157 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 158 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 159 | |
af9b897e AC |
160 | /** |
161 | * alloc_tty_struct - allocate a tty object | |
162 | * | |
163 | * Return a new empty tty structure. The data fields have not | |
164 | * been initialized in any way but has been zeroed | |
165 | * | |
166 | * Locking: none | |
af9b897e | 167 | */ |
1da177e4 | 168 | |
bf970ee4 | 169 | struct tty_struct *alloc_tty_struct(void) |
1da177e4 | 170 | { |
1266b1e1 | 171 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
172 | } |
173 | ||
af9b897e AC |
174 | /** |
175 | * free_tty_struct - free a disused tty | |
176 | * @tty: tty struct to free | |
177 | * | |
178 | * Free the write buffers, tty queue and tty memory itself. | |
179 | * | |
180 | * Locking: none. Must be called after tty is definitely unused | |
181 | */ | |
182 | ||
bf970ee4 | 183 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 184 | { |
30004ac9 DES |
185 | if (tty->dev) |
186 | put_device(tty->dev); | |
1da177e4 | 187 | kfree(tty->write_buf); |
33f0f88f | 188 | tty_buffer_free_all(tty); |
1da177e4 LT |
189 | kfree(tty); |
190 | } | |
191 | ||
d996b62a NP |
192 | static inline struct tty_struct *file_tty(struct file *file) |
193 | { | |
194 | return ((struct tty_file_private *)file->private_data)->tty; | |
195 | } | |
196 | ||
fa90e1c9 | 197 | int tty_alloc_file(struct file *file) |
d996b62a NP |
198 | { |
199 | struct tty_file_private *priv; | |
200 | ||
f573bd17 PE |
201 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
202 | if (!priv) | |
203 | return -ENOMEM; | |
d996b62a | 204 | |
fa90e1c9 JS |
205 | file->private_data = priv; |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | /* Associate a new file with the tty structure */ | |
211 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
212 | { | |
213 | struct tty_file_private *priv = file->private_data; | |
214 | ||
d996b62a NP |
215 | priv->tty = tty; |
216 | priv->file = file; | |
d996b62a NP |
217 | |
218 | spin_lock(&tty_files_lock); | |
219 | list_add(&priv->list, &tty->tty_files); | |
220 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 221 | } |
f573bd17 | 222 | |
fa90e1c9 JS |
223 | /** |
224 | * tty_free_file - free file->private_data | |
225 | * | |
226 | * This shall be used only for fail path handling when tty_add_file was not | |
227 | * called yet. | |
228 | */ | |
229 | void tty_free_file(struct file *file) | |
230 | { | |
231 | struct tty_file_private *priv = file->private_data; | |
232 | ||
233 | file->private_data = NULL; | |
234 | kfree(priv); | |
d996b62a NP |
235 | } |
236 | ||
237 | /* Delete file from its tty */ | |
238 | void tty_del_file(struct file *file) | |
239 | { | |
240 | struct tty_file_private *priv = file->private_data; | |
241 | ||
242 | spin_lock(&tty_files_lock); | |
243 | list_del(&priv->list); | |
244 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 245 | tty_free_file(file); |
d996b62a NP |
246 | } |
247 | ||
248 | ||
1da177e4 LT |
249 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
250 | ||
af9b897e AC |
251 | /** |
252 | * tty_name - return tty naming | |
253 | * @tty: tty structure | |
254 | * @buf: buffer for output | |
255 | * | |
256 | * Convert a tty structure into a name. The name reflects the kernel | |
257 | * naming policy and if udev is in use may not reflect user space | |
258 | * | |
259 | * Locking: none | |
260 | */ | |
261 | ||
1da177e4 LT |
262 | char *tty_name(struct tty_struct *tty, char *buf) |
263 | { | |
264 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
265 | strcpy(buf, "NULL tty"); | |
266 | else | |
267 | strcpy(buf, tty->name); | |
268 | return buf; | |
269 | } | |
270 | ||
271 | EXPORT_SYMBOL(tty_name); | |
272 | ||
d769a669 | 273 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
274 | const char *routine) |
275 | { | |
276 | #ifdef TTY_PARANOIA_CHECK | |
277 | if (!tty) { | |
278 | printk(KERN_WARNING | |
279 | "null TTY for (%d:%d) in %s\n", | |
280 | imajor(inode), iminor(inode), routine); | |
281 | return 1; | |
282 | } | |
283 | if (tty->magic != TTY_MAGIC) { | |
284 | printk(KERN_WARNING | |
285 | "bad magic number for tty struct (%d:%d) in %s\n", | |
286 | imajor(inode), iminor(inode), routine); | |
287 | return 1; | |
288 | } | |
289 | #endif | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
294 | { | |
295 | #ifdef CHECK_TTY_COUNT | |
296 | struct list_head *p; | |
297 | int count = 0; | |
37bdfb07 | 298 | |
ee2ffa0d | 299 | spin_lock(&tty_files_lock); |
1da177e4 LT |
300 | list_for_each(p, &tty->tty_files) { |
301 | count++; | |
302 | } | |
ee2ffa0d | 303 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
304 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
305 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
306 | tty->link && tty->link->count) | |
307 | count++; | |
308 | if (tty->count != count) { | |
309 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
310 | "!= #fd's(%d) in %s\n", | |
311 | tty->name, tty->count, count, routine); | |
312 | return count; | |
24ec839c | 313 | } |
1da177e4 LT |
314 | #endif |
315 | return 0; | |
316 | } | |
317 | ||
af9b897e AC |
318 | /** |
319 | * get_tty_driver - find device of a tty | |
320 | * @dev_t: device identifier | |
321 | * @index: returns the index of the tty | |
322 | * | |
323 | * This routine returns a tty driver structure, given a device number | |
324 | * and also passes back the index number. | |
325 | * | |
326 | * Locking: caller must hold tty_mutex | |
1da177e4 | 327 | */ |
af9b897e | 328 | |
1da177e4 LT |
329 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
330 | { | |
331 | struct tty_driver *p; | |
332 | ||
333 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
334 | dev_t base = MKDEV(p->major, p->minor_start); | |
335 | if (device < base || device >= base + p->num) | |
336 | continue; | |
337 | *index = device - base; | |
7d7b93c1 | 338 | return tty_driver_kref_get(p); |
1da177e4 LT |
339 | } |
340 | return NULL; | |
341 | } | |
342 | ||
f2d937f3 JW |
343 | #ifdef CONFIG_CONSOLE_POLL |
344 | ||
345 | /** | |
346 | * tty_find_polling_driver - find device of a polled tty | |
347 | * @name: name string to match | |
348 | * @line: pointer to resulting tty line nr | |
349 | * | |
350 | * This routine returns a tty driver structure, given a name | |
351 | * and the condition that the tty driver is capable of polled | |
352 | * operation. | |
353 | */ | |
354 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
355 | { | |
356 | struct tty_driver *p, *res = NULL; | |
357 | int tty_line = 0; | |
0dca0fd2 | 358 | int len; |
5f0878ac | 359 | char *str, *stp; |
f2d937f3 | 360 | |
0dca0fd2 JW |
361 | for (str = name; *str; str++) |
362 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
363 | break; | |
364 | if (!*str) | |
365 | return NULL; | |
366 | ||
367 | len = str - name; | |
368 | tty_line = simple_strtoul(str, &str, 10); | |
369 | ||
f2d937f3 JW |
370 | mutex_lock(&tty_mutex); |
371 | /* Search through the tty devices to look for a match */ | |
372 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
373 | if (strncmp(name, p->name, len) != 0) |
374 | continue; | |
5f0878ac AC |
375 | stp = str; |
376 | if (*stp == ',') | |
377 | stp++; | |
378 | if (*stp == '\0') | |
379 | stp = NULL; | |
f2d937f3 | 380 | |
6eb68d6f | 381 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 382 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 383 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
384 | *line = tty_line; |
385 | break; | |
386 | } | |
387 | } | |
388 | mutex_unlock(&tty_mutex); | |
389 | ||
390 | return res; | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
393 | #endif | |
394 | ||
af9b897e AC |
395 | /** |
396 | * tty_check_change - check for POSIX terminal changes | |
397 | * @tty: tty to check | |
398 | * | |
399 | * If we try to write to, or set the state of, a terminal and we're | |
400 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
401 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
402 | * | |
978e595f | 403 | * Locking: ctrl_lock |
1da177e4 | 404 | */ |
af9b897e | 405 | |
37bdfb07 | 406 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 407 | { |
47f86834 AC |
408 | unsigned long flags; |
409 | int ret = 0; | |
410 | ||
1da177e4 LT |
411 | if (current->signal->tty != tty) |
412 | return 0; | |
47f86834 AC |
413 | |
414 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
415 | ||
ab521dc0 EB |
416 | if (!tty->pgrp) { |
417 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 418 | goto out_unlock; |
1da177e4 | 419 | } |
ab521dc0 | 420 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
421 | goto out_unlock; |
422 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 423 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
424 | goto out; |
425 | if (is_current_pgrp_orphaned()) { | |
426 | ret = -EIO; | |
427 | goto out; | |
428 | } | |
040b6362 ON |
429 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
430 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
431 | ret = -ERESTARTSYS; |
432 | out: | |
9ffee4cb AM |
433 | return ret; |
434 | out_unlock: | |
47f86834 AC |
435 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
436 | return ret; | |
1da177e4 LT |
437 | } |
438 | ||
439 | EXPORT_SYMBOL(tty_check_change); | |
440 | ||
37bdfb07 | 441 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
442 | size_t count, loff_t *ppos) |
443 | { | |
444 | return 0; | |
445 | } | |
446 | ||
37bdfb07 | 447 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
448 | size_t count, loff_t *ppos) |
449 | { | |
450 | return -EIO; | |
451 | } | |
452 | ||
453 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 454 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
455 | { |
456 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
457 | } | |
458 | ||
04f378b1 AC |
459 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
460 | unsigned long arg) | |
38ad2ed0 PF |
461 | { |
462 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
463 | } | |
464 | ||
37bdfb07 | 465 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 466 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
467 | { |
468 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
469 | } | |
470 | ||
62322d25 | 471 | static const struct file_operations tty_fops = { |
1da177e4 LT |
472 | .llseek = no_llseek, |
473 | .read = tty_read, | |
474 | .write = tty_write, | |
475 | .poll = tty_poll, | |
04f378b1 | 476 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 477 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
478 | .open = tty_open, |
479 | .release = tty_release, | |
480 | .fasync = tty_fasync, | |
481 | }; | |
482 | ||
62322d25 | 483 | static const struct file_operations console_fops = { |
1da177e4 LT |
484 | .llseek = no_llseek, |
485 | .read = tty_read, | |
486 | .write = redirected_tty_write, | |
487 | .poll = tty_poll, | |
04f378b1 | 488 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 489 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
490 | .open = tty_open, |
491 | .release = tty_release, | |
492 | .fasync = tty_fasync, | |
493 | }; | |
494 | ||
62322d25 | 495 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
496 | .llseek = no_llseek, |
497 | .read = hung_up_tty_read, | |
498 | .write = hung_up_tty_write, | |
499 | .poll = hung_up_tty_poll, | |
04f378b1 | 500 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 501 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
502 | .release = tty_release, |
503 | }; | |
504 | ||
505 | static DEFINE_SPINLOCK(redirect_lock); | |
506 | static struct file *redirect; | |
507 | ||
508 | /** | |
509 | * tty_wakeup - request more data | |
510 | * @tty: terminal | |
511 | * | |
512 | * Internal and external helper for wakeups of tty. This function | |
513 | * informs the line discipline if present that the driver is ready | |
514 | * to receive more output data. | |
515 | */ | |
37bdfb07 | 516 | |
1da177e4 LT |
517 | void tty_wakeup(struct tty_struct *tty) |
518 | { | |
519 | struct tty_ldisc *ld; | |
37bdfb07 | 520 | |
1da177e4 LT |
521 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
522 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 523 | if (ld) { |
a352def2 AC |
524 | if (ld->ops->write_wakeup) |
525 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
526 | tty_ldisc_deref(ld); |
527 | } | |
528 | } | |
4b19449d | 529 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
530 | } |
531 | ||
532 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
533 | ||
af9b897e | 534 | /** |
11dbf203 | 535 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 536 | * @work: tty device |
af9b897e | 537 | * |
1bad879a | 538 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
539 | * synchronous but doesn't hold any locks, so we need to make sure we |
540 | * have the appropriate locks for what we're doing. | |
541 | * | |
542 | * The hangup event clears any pending redirections onto the hung up | |
543 | * device. It ensures future writes will error and it does the needed | |
544 | * line discipline hangup and signal delivery. The tty object itself | |
545 | * remains intact. | |
546 | * | |
547 | * Locking: | |
ec79d605 | 548 | * BTM |
24ec839c PZ |
549 | * redirect lock for undoing redirection |
550 | * file list lock for manipulating list of ttys | |
551 | * tty_ldisc_lock from called functions | |
552 | * termios_mutex resetting termios data | |
553 | * tasklist_lock to walk task list for hangup event | |
554 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 555 | */ |
11dbf203 | 556 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 557 | { |
37bdfb07 | 558 | struct file *cons_filp = NULL; |
1da177e4 LT |
559 | struct file *filp, *f = NULL; |
560 | struct task_struct *p; | |
d996b62a | 561 | struct tty_file_private *priv; |
1da177e4 | 562 | int closecount = 0, n; |
47f86834 | 563 | unsigned long flags; |
9c9f4ded | 564 | int refs = 0; |
1da177e4 LT |
565 | |
566 | if (!tty) | |
567 | return; | |
568 | ||
1da177e4 LT |
569 | |
570 | spin_lock(&redirect_lock); | |
d996b62a | 571 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
572 | f = redirect; |
573 | redirect = NULL; | |
574 | } | |
575 | spin_unlock(&redirect_lock); | |
37bdfb07 | 576 | |
11dbf203 AB |
577 | tty_lock(); |
578 | ||
acfa747b JS |
579 | /* some functions below drop BTM, so we need this bit */ |
580 | set_bit(TTY_HUPPING, &tty->flags); | |
581 | ||
ec79d605 AB |
582 | /* inuse_filps is protected by the single tty lock, |
583 | this really needs to change if we want to flush the | |
584 | workqueue with the lock held */ | |
11dbf203 | 585 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 586 | |
ee2ffa0d | 587 | spin_lock(&tty_files_lock); |
1da177e4 | 588 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
589 | list_for_each_entry(priv, &tty->tty_files, list) { |
590 | filp = priv->file; | |
1da177e4 LT |
591 | if (filp->f_op->write == redirected_tty_write) |
592 | cons_filp = filp; | |
593 | if (filp->f_op->write != tty_write) | |
594 | continue; | |
595 | closecount++; | |
ec79d605 | 596 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
597 | filp->f_op = &hung_up_tty_fops; |
598 | } | |
ee2ffa0d | 599 | spin_unlock(&tty_files_lock); |
37bdfb07 | 600 | |
acfa747b JS |
601 | /* |
602 | * it drops BTM and thus races with reopen | |
603 | * we protect the race by TTY_HUPPING | |
604 | */ | |
c65c9bc3 | 605 | tty_ldisc_hangup(tty); |
37bdfb07 | 606 | |
1da177e4 | 607 | read_lock(&tasklist_lock); |
ab521dc0 EB |
608 | if (tty->session) { |
609 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 610 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 611 | if (p->signal->tty == tty) { |
1da177e4 | 612 | p->signal->tty = NULL; |
9c9f4ded AC |
613 | /* We defer the dereferences outside fo |
614 | the tasklist lock */ | |
615 | refs++; | |
616 | } | |
24ec839c PZ |
617 | if (!p->signal->leader) { |
618 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 619 | continue; |
24ec839c PZ |
620 | } |
621 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
622 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 623 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 624 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
625 | if (tty->pgrp) |
626 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 627 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 628 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 629 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
630 | } |
631 | read_unlock(&tasklist_lock); | |
632 | ||
47f86834 | 633 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
634 | clear_bit(TTY_THROTTLED, &tty->flags); |
635 | clear_bit(TTY_PUSH, &tty->flags); | |
636 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
637 | put_pid(tty->session); |
638 | put_pid(tty->pgrp); | |
ab521dc0 EB |
639 | tty->session = NULL; |
640 | tty->pgrp = NULL; | |
1da177e4 | 641 | tty->ctrl_status = 0; |
47f86834 AC |
642 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
643 | ||
9c9f4ded AC |
644 | /* Account for the p->signal references we killed */ |
645 | while (refs--) | |
646 | tty_kref_put(tty); | |
647 | ||
1da177e4 | 648 | /* |
37bdfb07 AC |
649 | * If one of the devices matches a console pointer, we |
650 | * cannot just call hangup() because that will cause | |
651 | * tty->count and state->count to go out of sync. | |
652 | * So we just call close() the right number of times. | |
1da177e4 LT |
653 | */ |
654 | if (cons_filp) { | |
f34d7a5b | 655 | if (tty->ops->close) |
1da177e4 | 656 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
657 | tty->ops->close(tty, cons_filp); |
658 | } else if (tty->ops->hangup) | |
659 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
660 | /* |
661 | * We don't want to have driver/ldisc interactions beyond | |
662 | * the ones we did here. The driver layer expects no | |
663 | * calls after ->hangup() from the ldisc side. However we | |
664 | * can't yet guarantee all that. | |
665 | */ | |
1da177e4 | 666 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 667 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 668 | tty_ldisc_enable(tty); |
11dbf203 AB |
669 | |
670 | tty_unlock(); | |
671 | ||
1da177e4 LT |
672 | if (f) |
673 | fput(f); | |
674 | } | |
675 | ||
ddcd9fb6 AB |
676 | static void do_tty_hangup(struct work_struct *work) |
677 | { | |
678 | struct tty_struct *tty = | |
679 | container_of(work, struct tty_struct, hangup_work); | |
680 | ||
11dbf203 | 681 | __tty_hangup(tty); |
ddcd9fb6 AB |
682 | } |
683 | ||
af9b897e AC |
684 | /** |
685 | * tty_hangup - trigger a hangup event | |
686 | * @tty: tty to hangup | |
687 | * | |
688 | * A carrier loss (virtual or otherwise) has occurred on this like | |
689 | * schedule a hangup sequence to run after this event. | |
690 | */ | |
691 | ||
37bdfb07 | 692 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
693 | { |
694 | #ifdef TTY_DEBUG_HANGUP | |
695 | char buf[64]; | |
1da177e4 LT |
696 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
697 | #endif | |
698 | schedule_work(&tty->hangup_work); | |
699 | } | |
700 | ||
701 | EXPORT_SYMBOL(tty_hangup); | |
702 | ||
af9b897e AC |
703 | /** |
704 | * tty_vhangup - process vhangup | |
705 | * @tty: tty to hangup | |
706 | * | |
707 | * The user has asked via system call for the terminal to be hung up. | |
708 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 709 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
710 | */ |
711 | ||
37bdfb07 | 712 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
713 | { |
714 | #ifdef TTY_DEBUG_HANGUP | |
715 | char buf[64]; | |
716 | ||
717 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
718 | #endif | |
11dbf203 | 719 | __tty_hangup(tty); |
1da177e4 | 720 | } |
37bdfb07 | 721 | |
1da177e4 LT |
722 | EXPORT_SYMBOL(tty_vhangup); |
723 | ||
11dbf203 | 724 | |
2cb5998b AC |
725 | /** |
726 | * tty_vhangup_self - process vhangup for own ctty | |
727 | * | |
728 | * Perform a vhangup on the current controlling tty | |
729 | */ | |
730 | ||
731 | void tty_vhangup_self(void) | |
732 | { | |
733 | struct tty_struct *tty; | |
734 | ||
2cb5998b AC |
735 | tty = get_current_tty(); |
736 | if (tty) { | |
737 | tty_vhangup(tty); | |
738 | tty_kref_put(tty); | |
739 | } | |
2cb5998b AC |
740 | } |
741 | ||
af9b897e AC |
742 | /** |
743 | * tty_hung_up_p - was tty hung up | |
744 | * @filp: file pointer of tty | |
745 | * | |
746 | * Return true if the tty has been subject to a vhangup or a carrier | |
747 | * loss | |
748 | */ | |
749 | ||
37bdfb07 | 750 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
751 | { |
752 | return (filp->f_op == &hung_up_tty_fops); | |
753 | } | |
754 | ||
755 | EXPORT_SYMBOL(tty_hung_up_p); | |
756 | ||
ab521dc0 | 757 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
758 | { |
759 | struct task_struct *p; | |
ab521dc0 | 760 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 761 | proc_clear_tty(p); |
ab521dc0 | 762 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
763 | } |
764 | ||
af9b897e AC |
765 | /** |
766 | * disassociate_ctty - disconnect controlling tty | |
767 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 768 | * |
af9b897e AC |
769 | * This function is typically called only by the session leader, when |
770 | * it wants to disassociate itself from its controlling tty. | |
771 | * | |
772 | * It performs the following functions: | |
1da177e4 LT |
773 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
774 | * (2) Clears the tty from being controlling the session | |
775 | * (3) Clears the controlling tty for all processes in the | |
776 | * session group. | |
777 | * | |
af9b897e AC |
778 | * The argument on_exit is set to 1 if called when a process is |
779 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
780 | * | |
24ec839c | 781 | * Locking: |
ec79d605 AB |
782 | * BTM is taken for hysterical raisins, and held when |
783 | * called from no_tty(). | |
24ec839c PZ |
784 | * tty_mutex is taken to protect tty |
785 | * ->siglock is taken to protect ->signal/->sighand | |
786 | * tasklist_lock is taken to walk process list for sessions | |
787 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 788 | */ |
af9b897e | 789 | |
1da177e4 LT |
790 | void disassociate_ctty(int on_exit) |
791 | { | |
792 | struct tty_struct *tty; | |
ab521dc0 | 793 | struct pid *tty_pgrp = NULL; |
1da177e4 | 794 | |
5ec93d11 AC |
795 | if (!current->signal->leader) |
796 | return; | |
1da177e4 | 797 | |
24ec839c | 798 | tty = get_current_tty(); |
1da177e4 | 799 | if (tty) { |
ab521dc0 | 800 | tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 801 | if (on_exit) { |
ddcd9fb6 | 802 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 803 | tty_vhangup(tty); |
ddcd9fb6 | 804 | } |
452a00d2 | 805 | tty_kref_put(tty); |
680a9671 | 806 | } else if (on_exit) { |
ab521dc0 | 807 | struct pid *old_pgrp; |
680a9671 EB |
808 | spin_lock_irq(¤t->sighand->siglock); |
809 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 810 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 811 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 812 | if (old_pgrp) { |
ab521dc0 EB |
813 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
814 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
815 | put_pid(old_pgrp); | |
1da177e4 | 816 | } |
1da177e4 LT |
817 | return; |
818 | } | |
ab521dc0 EB |
819 | if (tty_pgrp) { |
820 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
1da177e4 | 821 | if (!on_exit) |
ab521dc0 EB |
822 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); |
823 | put_pid(tty_pgrp); | |
1da177e4 LT |
824 | } |
825 | ||
24ec839c | 826 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 827 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 828 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
829 | spin_unlock_irq(¤t->sighand->siglock); |
830 | ||
24ec839c PZ |
831 | tty = get_current_tty(); |
832 | if (tty) { | |
47f86834 AC |
833 | unsigned long flags; |
834 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
835 | put_pid(tty->session); |
836 | put_pid(tty->pgrp); | |
837 | tty->session = NULL; | |
838 | tty->pgrp = NULL; | |
47f86834 | 839 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 840 | tty_kref_put(tty); |
24ec839c PZ |
841 | } else { |
842 | #ifdef TTY_DEBUG_HANGUP | |
843 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
844 | " = NULL", tty); | |
845 | #endif | |
846 | } | |
1da177e4 LT |
847 | |
848 | /* Now clear signal->tty under the lock */ | |
849 | read_lock(&tasklist_lock); | |
ab521dc0 | 850 | session_clear_tty(task_session(current)); |
1da177e4 | 851 | read_unlock(&tasklist_lock); |
1da177e4 LT |
852 | } |
853 | ||
98a27ba4 EB |
854 | /** |
855 | * | |
856 | * no_tty - Ensure the current process does not have a controlling tty | |
857 | */ | |
858 | void no_tty(void) | |
859 | { | |
860 | struct task_struct *tsk = current; | |
ec79d605 | 861 | tty_lock(); |
5ec93d11 | 862 | disassociate_ctty(0); |
ec79d605 | 863 | tty_unlock(); |
98a27ba4 EB |
864 | proc_clear_tty(tsk); |
865 | } | |
866 | ||
af9b897e AC |
867 | |
868 | /** | |
beb7dd86 | 869 | * stop_tty - propagate flow control |
af9b897e AC |
870 | * @tty: tty to stop |
871 | * | |
872 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 873 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
874 | * on an already stopped device and will not re-call the driver |
875 | * method. | |
876 | * | |
877 | * This functionality is used by both the line disciplines for | |
878 | * halting incoming flow and by the driver. It may therefore be | |
879 | * called from any context, may be under the tty atomic_write_lock | |
880 | * but not always. | |
881 | * | |
882 | * Locking: | |
04f378b1 | 883 | * Uses the tty control lock internally |
af9b897e AC |
884 | */ |
885 | ||
1da177e4 LT |
886 | void stop_tty(struct tty_struct *tty) |
887 | { | |
04f378b1 AC |
888 | unsigned long flags; |
889 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
890 | if (tty->stopped) { | |
891 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 892 | return; |
04f378b1 | 893 | } |
1da177e4 LT |
894 | tty->stopped = 1; |
895 | if (tty->link && tty->link->packet) { | |
896 | tty->ctrl_status &= ~TIOCPKT_START; | |
897 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 898 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 899 | } |
04f378b1 | 900 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
901 | if (tty->ops->stop) |
902 | (tty->ops->stop)(tty); | |
1da177e4 LT |
903 | } |
904 | ||
905 | EXPORT_SYMBOL(stop_tty); | |
906 | ||
af9b897e | 907 | /** |
beb7dd86 | 908 | * start_tty - propagate flow control |
af9b897e AC |
909 | * @tty: tty to start |
910 | * | |
911 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 912 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
913 | * is the tty was previous stopped and is being started then the |
914 | * driver start method is invoked and the line discipline woken. | |
915 | * | |
916 | * Locking: | |
04f378b1 | 917 | * ctrl_lock |
af9b897e AC |
918 | */ |
919 | ||
1da177e4 LT |
920 | void start_tty(struct tty_struct *tty) |
921 | { | |
04f378b1 AC |
922 | unsigned long flags; |
923 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
924 | if (!tty->stopped || tty->flow_stopped) { | |
925 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 926 | return; |
04f378b1 | 927 | } |
1da177e4 LT |
928 | tty->stopped = 0; |
929 | if (tty->link && tty->link->packet) { | |
930 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
931 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 932 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 933 | } |
04f378b1 | 934 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
935 | if (tty->ops->start) |
936 | (tty->ops->start)(tty); | |
1da177e4 LT |
937 | /* If we have a running line discipline it may need kicking */ |
938 | tty_wakeup(tty); | |
1da177e4 LT |
939 | } |
940 | ||
941 | EXPORT_SYMBOL(start_tty); | |
942 | ||
af9b897e AC |
943 | /** |
944 | * tty_read - read method for tty device files | |
945 | * @file: pointer to tty file | |
946 | * @buf: user buffer | |
947 | * @count: size of user buffer | |
948 | * @ppos: unused | |
949 | * | |
950 | * Perform the read system call function on this terminal device. Checks | |
951 | * for hung up devices before calling the line discipline method. | |
952 | * | |
953 | * Locking: | |
47f86834 AC |
954 | * Locks the line discipline internally while needed. Multiple |
955 | * read calls may be outstanding in parallel. | |
af9b897e AC |
956 | */ |
957 | ||
37bdfb07 | 958 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
959 | loff_t *ppos) |
960 | { | |
961 | int i; | |
d996b62a NP |
962 | struct inode *inode = file->f_path.dentry->d_inode; |
963 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
964 | struct tty_ldisc *ld; |
965 | ||
1da177e4 LT |
966 | if (tty_paranoia_check(tty, inode, "tty_read")) |
967 | return -EIO; | |
968 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
969 | return -EIO; | |
970 | ||
971 | /* We want to wait for the line discipline to sort out in this | |
972 | situation */ | |
973 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
974 | if (ld->ops->read) |
975 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
976 | else |
977 | i = -EIO; | |
978 | tty_ldisc_deref(ld); | |
1da177e4 LT |
979 | if (i > 0) |
980 | inode->i_atime = current_fs_time(inode->i_sb); | |
981 | return i; | |
982 | } | |
983 | ||
9c1729db | 984 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 985 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
986 | { |
987 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 988 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
989 | } |
990 | ||
991 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 992 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
993 | { |
994 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
995 | if (ndelay) | |
996 | return -EAGAIN; | |
997 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
998 | return -ERESTARTSYS; | |
999 | } | |
1000 | return 0; | |
1001 | } | |
1002 | ||
1da177e4 LT |
1003 | /* |
1004 | * Split writes up in sane blocksizes to avoid | |
1005 | * denial-of-service type attacks | |
1006 | */ | |
1007 | static inline ssize_t do_tty_write( | |
1008 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1009 | struct tty_struct *tty, | |
1010 | struct file *file, | |
1011 | const char __user *buf, | |
1012 | size_t count) | |
1013 | { | |
9c1729db | 1014 | ssize_t ret, written = 0; |
1da177e4 | 1015 | unsigned int chunk; |
37bdfb07 | 1016 | |
9c1729db AC |
1017 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1018 | if (ret < 0) | |
1019 | return ret; | |
1da177e4 LT |
1020 | |
1021 | /* | |
1022 | * We chunk up writes into a temporary buffer. This | |
1023 | * simplifies low-level drivers immensely, since they | |
1024 | * don't have locking issues and user mode accesses. | |
1025 | * | |
1026 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1027 | * big chunk-size.. | |
1028 | * | |
1029 | * The default chunk-size is 2kB, because the NTTY | |
1030 | * layer has problems with bigger chunks. It will | |
1031 | * claim to be able to handle more characters than | |
1032 | * it actually does. | |
af9b897e AC |
1033 | * |
1034 | * FIXME: This can probably go away now except that 64K chunks | |
1035 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1036 | */ |
1037 | chunk = 2048; | |
1038 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1039 | chunk = 65536; | |
1040 | if (count < chunk) | |
1041 | chunk = count; | |
1042 | ||
70522e12 | 1043 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1044 | if (tty->write_cnt < chunk) { |
402fda92 | 1045 | unsigned char *buf_chunk; |
1da177e4 LT |
1046 | |
1047 | if (chunk < 1024) | |
1048 | chunk = 1024; | |
1049 | ||
402fda92 JW |
1050 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1051 | if (!buf_chunk) { | |
9c1729db AC |
1052 | ret = -ENOMEM; |
1053 | goto out; | |
1da177e4 LT |
1054 | } |
1055 | kfree(tty->write_buf); | |
1056 | tty->write_cnt = chunk; | |
402fda92 | 1057 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1058 | } |
1059 | ||
1060 | /* Do the write .. */ | |
1061 | for (;;) { | |
1062 | size_t size = count; | |
1063 | if (size > chunk) | |
1064 | size = chunk; | |
1065 | ret = -EFAULT; | |
1066 | if (copy_from_user(tty->write_buf, buf, size)) | |
1067 | break; | |
1da177e4 | 1068 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1069 | if (ret <= 0) |
1070 | break; | |
1071 | written += ret; | |
1072 | buf += ret; | |
1073 | count -= ret; | |
1074 | if (!count) | |
1075 | break; | |
1076 | ret = -ERESTARTSYS; | |
1077 | if (signal_pending(current)) | |
1078 | break; | |
1079 | cond_resched(); | |
1080 | } | |
1081 | if (written) { | |
a7113a96 | 1082 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1083 | inode->i_mtime = current_fs_time(inode->i_sb); |
1084 | ret = written; | |
1085 | } | |
9c1729db AC |
1086 | out: |
1087 | tty_write_unlock(tty); | |
1da177e4 LT |
1088 | return ret; |
1089 | } | |
1090 | ||
95f9bfc6 AC |
1091 | /** |
1092 | * tty_write_message - write a message to a certain tty, not just the console. | |
1093 | * @tty: the destination tty_struct | |
1094 | * @msg: the message to write | |
1095 | * | |
1096 | * This is used for messages that need to be redirected to a specific tty. | |
1097 | * We don't put it into the syslog queue right now maybe in the future if | |
1098 | * really needed. | |
1099 | * | |
ec79d605 | 1100 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1101 | */ |
1102 | ||
1103 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1104 | { | |
95f9bfc6 AC |
1105 | if (tty) { |
1106 | mutex_lock(&tty->atomic_write_lock); | |
ec79d605 | 1107 | tty_lock(); |
eeb89d91 | 1108 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
ec79d605 | 1109 | tty_unlock(); |
95f9bfc6 | 1110 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1111 | } else |
ec79d605 | 1112 | tty_unlock(); |
95f9bfc6 AC |
1113 | tty_write_unlock(tty); |
1114 | } | |
95f9bfc6 AC |
1115 | return; |
1116 | } | |
1117 | ||
1da177e4 | 1118 | |
af9b897e AC |
1119 | /** |
1120 | * tty_write - write method for tty device file | |
1121 | * @file: tty file pointer | |
1122 | * @buf: user data to write | |
1123 | * @count: bytes to write | |
1124 | * @ppos: unused | |
1125 | * | |
1126 | * Write data to a tty device via the line discipline. | |
1127 | * | |
1128 | * Locking: | |
1129 | * Locks the line discipline as required | |
1130 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1131 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1132 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1133 | */ |
1134 | ||
37bdfb07 AC |
1135 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1136 | size_t count, loff_t *ppos) | |
1da177e4 | 1137 | { |
a7113a96 | 1138 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1139 | struct tty_struct *tty = file_tty(file); |
1140 | struct tty_ldisc *ld; | |
1da177e4 | 1141 | ssize_t ret; |
37bdfb07 | 1142 | |
1da177e4 LT |
1143 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1144 | return -EIO; | |
f34d7a5b | 1145 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1146 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1147 | return -EIO; | |
f34d7a5b AC |
1148 | /* Short term debug to catch buggy drivers */ |
1149 | if (tty->ops->write_room == NULL) | |
1150 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1151 | tty->driver->name); | |
37bdfb07 | 1152 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1153 | if (!ld->ops->write) |
1da177e4 LT |
1154 | ret = -EIO; |
1155 | else | |
a352def2 | 1156 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1157 | tty_ldisc_deref(ld); |
1158 | return ret; | |
1159 | } | |
1160 | ||
37bdfb07 AC |
1161 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1162 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1163 | { |
1164 | struct file *p = NULL; | |
1165 | ||
1166 | spin_lock(&redirect_lock); | |
1167 | if (redirect) { | |
1168 | get_file(redirect); | |
1169 | p = redirect; | |
1170 | } | |
1171 | spin_unlock(&redirect_lock); | |
1172 | ||
1173 | if (p) { | |
1174 | ssize_t res; | |
1175 | res = vfs_write(p, buf, count, &p->f_pos); | |
1176 | fput(p); | |
1177 | return res; | |
1178 | } | |
1da177e4 LT |
1179 | return tty_write(file, buf, count, ppos); |
1180 | } | |
1181 | ||
1182 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1183 | ||
af9b897e AC |
1184 | /** |
1185 | * pty_line_name - generate name for a pty | |
1186 | * @driver: the tty driver in use | |
1187 | * @index: the minor number | |
1188 | * @p: output buffer of at least 6 bytes | |
1189 | * | |
1190 | * Generate a name from a driver reference and write it to the output | |
1191 | * buffer. | |
1192 | * | |
1193 | * Locking: None | |
1194 | */ | |
1195 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1196 | { |
1197 | int i = index + driver->name_base; | |
1198 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1199 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1200 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1201 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1202 | } |
1203 | ||
af9b897e | 1204 | /** |
8b0a88d5 | 1205 | * tty_line_name - generate name for a tty |
af9b897e AC |
1206 | * @driver: the tty driver in use |
1207 | * @index: the minor number | |
1208 | * @p: output buffer of at least 7 bytes | |
1209 | * | |
1210 | * Generate a name from a driver reference and write it to the output | |
1211 | * buffer. | |
1212 | * | |
1213 | * Locking: None | |
1214 | */ | |
1215 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1216 | { |
1217 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1218 | } | |
1219 | ||
99f1fe18 AC |
1220 | /** |
1221 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1222 | * @driver: the driver for the tty | |
1223 | * @idx: the minor number | |
23499705 | 1224 | * |
99f1fe18 | 1225 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1226 | * |
99f1fe18 AC |
1227 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1228 | * be held until the 'fast-open' is also done. Will change once we | |
1229 | * have refcounting in the driver and per driver locking | |
23499705 | 1230 | */ |
a47d545f | 1231 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1232 | struct inode *inode, int idx) |
23499705 SB |
1233 | { |
1234 | struct tty_struct *tty; | |
1235 | ||
99f1fe18 | 1236 | if (driver->ops->lookup) |
15f1a633 | 1237 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1238 | |
8b0a88d5 | 1239 | tty = driver->ttys[idx]; |
23499705 SB |
1240 | return tty; |
1241 | } | |
1242 | ||
bf970ee4 AC |
1243 | /** |
1244 | * tty_init_termios - helper for termios setup | |
1245 | * @tty: the tty to set up | |
1246 | * | |
1247 | * Initialise the termios structures for this tty. Thus runs under | |
1248 | * the tty_mutex currently so we can be relaxed about ordering. | |
1249 | */ | |
1250 | ||
1251 | int tty_init_termios(struct tty_struct *tty) | |
1252 | { | |
fe6e29fd | 1253 | struct ktermios *tp; |
bf970ee4 AC |
1254 | int idx = tty->index; |
1255 | ||
1256 | tp = tty->driver->termios[idx]; | |
bf970ee4 | 1257 | if (tp == NULL) { |
fe6e29fd AC |
1258 | tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
1259 | if (tp == NULL) | |
bf970ee4 | 1260 | return -ENOMEM; |
bf970ee4 AC |
1261 | memcpy(tp, &tty->driver->init_termios, |
1262 | sizeof(struct ktermios)); | |
1263 | tty->driver->termios[idx] = tp; | |
bf970ee4 AC |
1264 | } |
1265 | tty->termios = tp; | |
fe6e29fd | 1266 | tty->termios_locked = tp + 1; |
bf970ee4 AC |
1267 | |
1268 | /* Compatibility until drivers always set this */ | |
1269 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1270 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1271 | return 0; | |
1272 | } | |
fe1ae7fd | 1273 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1274 | |
99f1fe18 | 1275 | /** |
8b0a88d5 AC |
1276 | * tty_driver_install_tty() - install a tty entry in the driver |
1277 | * @driver: the driver for the tty | |
1278 | * @tty: the tty | |
1279 | * | |
1280 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1281 | * will be set by the time this is called. This method is responsible |
1282 | * for ensuring any need additional structures are allocated and | |
1283 | * configured. | |
8b0a88d5 AC |
1284 | * |
1285 | * Locking: tty_mutex for now | |
1286 | */ | |
1287 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1288 | struct tty_struct *tty) | |
1289 | { | |
bf970ee4 | 1290 | int idx = tty->index; |
eeb89d91 | 1291 | int ret; |
bf970ee4 | 1292 | |
eeb89d91 | 1293 | if (driver->ops->install) { |
eeb89d91 | 1294 | ret = driver->ops->install(driver, tty); |
eeb89d91 AC |
1295 | return ret; |
1296 | } | |
bf970ee4 AC |
1297 | |
1298 | if (tty_init_termios(tty) == 0) { | |
1299 | tty_driver_kref_get(driver); | |
1300 | tty->count++; | |
1301 | driver->ttys[idx] = tty; | |
1302 | return 0; | |
1303 | } | |
1304 | return -ENOMEM; | |
8b0a88d5 AC |
1305 | } |
1306 | ||
1307 | /** | |
1308 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1309 | * @driver: the driver for the tty | |
1310 | * @idx: the minor number | |
1311 | * | |
1312 | * Remvoe a tty object from the driver tables. The tty->index field | |
1313 | * will be set by the time this is called. | |
1314 | * | |
1315 | * Locking: tty_mutex for now | |
1316 | */ | |
24d406a6 | 1317 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1318 | { |
1319 | if (driver->ops->remove) | |
1320 | driver->ops->remove(driver, tty); | |
1321 | else | |
1322 | driver->ttys[tty->index] = NULL; | |
1323 | } | |
1324 | ||
1325 | /* | |
1326 | * tty_reopen() - fast re-open of an open tty | |
1327 | * @tty - the tty to open | |
23499705 | 1328 | * |
99f1fe18 | 1329 | * Return 0 on success, -errno on error. |
23499705 | 1330 | * |
99f1fe18 AC |
1331 | * Locking: tty_mutex must be held from the time the tty was found |
1332 | * till this open completes. | |
23499705 | 1333 | */ |
99f1fe18 | 1334 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1335 | { |
1336 | struct tty_driver *driver = tty->driver; | |
1337 | ||
e2efafbf | 1338 | if (test_bit(TTY_CLOSING, &tty->flags) || |
acfa747b | 1339 | test_bit(TTY_HUPPING, &tty->flags) || |
e2efafbf | 1340 | test_bit(TTY_LDISC_CHANGING, &tty->flags)) |
23499705 SB |
1341 | return -EIO; |
1342 | ||
1343 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1344 | driver->subtype == PTY_TYPE_MASTER) { | |
1345 | /* | |
1346 | * special case for PTY masters: only one open permitted, | |
1347 | * and the slave side open count is incremented as well. | |
1348 | */ | |
1349 | if (tty->count) | |
1350 | return -EIO; | |
1351 | ||
1352 | tty->link->count++; | |
1353 | } | |
1354 | tty->count++; | |
1355 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1356 | ||
1aa4bed8 | 1357 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1358 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1359 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1360 | |
1361 | return 0; | |
1362 | } | |
1363 | ||
af9b897e | 1364 | /** |
d81ed103 | 1365 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1366 | * @driver: tty driver we are opening a device on |
1367 | * @idx: device index | |
15582d36 AC |
1368 | * @ret_tty: returned tty structure |
1369 | * @first_ok: ok to open a new device (used by ptmx) | |
af9b897e AC |
1370 | * |
1371 | * Prepare a tty device. This may not be a "new" clean device but | |
1372 | * could also be an active device. The pty drivers require special | |
1373 | * handling because of this. | |
1374 | * | |
1375 | * Locking: | |
1376 | * The function is called under the tty_mutex, which | |
1377 | * protects us from the tty struct or driver itself going away. | |
1378 | * | |
1379 | * On exit the tty device has the line discipline attached and | |
1380 | * a reference count of 1. If a pair was created for pty/tty use | |
1381 | * and the other was a pty master then it too has a reference count of 1. | |
1382 | * | |
1da177e4 | 1383 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1384 | * failed open. The new code protects the open with a mutex, so it's |
1385 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1386 | * relaxed for the (most common) case of reopening a tty. |
1387 | */ | |
af9b897e | 1388 | |
73ec06fc AC |
1389 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, |
1390 | int first_ok) | |
1da177e4 | 1391 | { |
bf970ee4 | 1392 | struct tty_struct *tty; |
73ec06fc | 1393 | int retval; |
1da177e4 | 1394 | |
23499705 | 1395 | /* Check if pty master is being opened multiple times */ |
15582d36 | 1396 | if (driver->subtype == PTY_TYPE_MASTER && |
eeb89d91 | 1397 | (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { |
73ec06fc | 1398 | return ERR_PTR(-EIO); |
eeb89d91 | 1399 | } |
73ec06fc | 1400 | |
1da177e4 LT |
1401 | /* |
1402 | * First time open is complex, especially for PTY devices. | |
1403 | * This code guarantees that either everything succeeds and the | |
1404 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1405 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1406 | * and locked termios may be retained.) |
1407 | */ | |
1408 | ||
73ec06fc AC |
1409 | if (!try_module_get(driver->owner)) |
1410 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1411 | |
1da177e4 | 1412 | tty = alloc_tty_struct(); |
d5543503 JS |
1413 | if (!tty) { |
1414 | retval = -ENOMEM; | |
1415 | goto err_module_put; | |
1416 | } | |
bf970ee4 | 1417 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1418 | |
73ec06fc | 1419 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1420 | if (retval < 0) |
a9dccddb | 1421 | goto err_deinit_tty; |
8b0a88d5 | 1422 | |
37bdfb07 | 1423 | /* |
1da177e4 | 1424 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1425 | * If we fail here just call release_tty to clean up. No need |
1426 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1427 | */ |
bf970ee4 | 1428 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1429 | if (retval) |
d5543503 | 1430 | goto err_release_tty; |
73ec06fc | 1431 | return tty; |
1da177e4 | 1432 | |
a9dccddb JS |
1433 | err_deinit_tty: |
1434 | deinitialize_tty_struct(tty); | |
d5543503 JS |
1435 | free_tty_struct(tty); |
1436 | err_module_put: | |
1da177e4 | 1437 | module_put(driver->owner); |
d5543503 | 1438 | return ERR_PTR(retval); |
1da177e4 | 1439 | |
d5698c28 | 1440 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1441 | err_release_tty: |
5a3c6b25 | 1442 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1443 | "clearing slot %d\n", idx); |
d5698c28 | 1444 | release_tty(tty, idx); |
73ec06fc | 1445 | return ERR_PTR(retval); |
1da177e4 LT |
1446 | } |
1447 | ||
feebed65 AC |
1448 | void tty_free_termios(struct tty_struct *tty) |
1449 | { | |
1450 | struct ktermios *tp; | |
1451 | int idx = tty->index; | |
1452 | /* Kill this flag and push into drivers for locking etc */ | |
1453 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1454 | /* FIXME: Locking on ->termios array */ | |
1455 | tp = tty->termios; | |
1456 | tty->driver->termios[idx] = NULL; | |
1457 | kfree(tp); | |
feebed65 AC |
1458 | } |
1459 | } | |
1460 | EXPORT_SYMBOL(tty_free_termios); | |
1461 | ||
1462 | void tty_shutdown(struct tty_struct *tty) | |
1463 | { | |
8b0a88d5 | 1464 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1465 | tty_free_termios(tty); |
1466 | } | |
1467 | EXPORT_SYMBOL(tty_shutdown); | |
1468 | ||
af9b897e | 1469 | /** |
d5698c28 | 1470 | * release_one_tty - release tty structure memory |
9c9f4ded | 1471 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1472 | * |
1473 | * Releases memory associated with a tty structure, and clears out the | |
1474 | * driver table slots. This function is called when a device is no longer | |
1475 | * in use. It also gets called when setup of a device fails. | |
1476 | * | |
1477 | * Locking: | |
1478 | * tty_mutex - sometimes only | |
1479 | * takes the file list lock internally when working on the list | |
1480 | * of ttys that the driver keeps. | |
b50989dc AC |
1481 | * |
1482 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1483 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1484 | */ |
b50989dc | 1485 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1486 | { |
b50989dc AC |
1487 | struct tty_struct *tty = |
1488 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1489 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1490 | |
f278a2f7 DY |
1491 | if (tty->ops->cleanup) |
1492 | tty->ops->cleanup(tty); | |
1493 | ||
1da177e4 | 1494 | tty->magic = 0; |
7d7b93c1 | 1495 | tty_driver_kref_put(driver); |
6f967f78 | 1496 | module_put(driver->owner); |
d5698c28 | 1497 | |
ee2ffa0d | 1498 | spin_lock(&tty_files_lock); |
1da177e4 | 1499 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1500 | spin_unlock(&tty_files_lock); |
d5698c28 | 1501 | |
6da8d866 ON |
1502 | put_pid(tty->pgrp); |
1503 | put_pid(tty->session); | |
1da177e4 LT |
1504 | free_tty_struct(tty); |
1505 | } | |
1506 | ||
b50989dc AC |
1507 | static void queue_release_one_tty(struct kref *kref) |
1508 | { | |
1509 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 DY |
1510 | |
1511 | if (tty->ops->shutdown) | |
1512 | tty->ops->shutdown(tty); | |
1513 | else | |
1514 | tty_shutdown(tty); | |
1515 | ||
b50989dc AC |
1516 | /* The hangup queue is now free so we can reuse it rather than |
1517 | waste a chunk of memory for each port */ | |
1518 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1519 | schedule_work(&tty->hangup_work); | |
1520 | } | |
1521 | ||
9c9f4ded AC |
1522 | /** |
1523 | * tty_kref_put - release a tty kref | |
1524 | * @tty: tty device | |
1525 | * | |
1526 | * Release a reference to a tty device and if need be let the kref | |
1527 | * layer destruct the object for us | |
1528 | */ | |
1529 | ||
1530 | void tty_kref_put(struct tty_struct *tty) | |
1531 | { | |
1532 | if (tty) | |
b50989dc | 1533 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1534 | } |
1535 | EXPORT_SYMBOL(tty_kref_put); | |
1536 | ||
d5698c28 CH |
1537 | /** |
1538 | * release_tty - release tty structure memory | |
1539 | * | |
1540 | * Release both @tty and a possible linked partner (think pty pair), | |
1541 | * and decrement the refcount of the backing module. | |
1542 | * | |
1543 | * Locking: | |
1544 | * tty_mutex - sometimes only | |
1545 | * takes the file list lock internally when working on the list | |
1546 | * of ttys that the driver keeps. | |
1547 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1548 | * |
d5698c28 CH |
1549 | */ |
1550 | static void release_tty(struct tty_struct *tty, int idx) | |
1551 | { | |
9c9f4ded AC |
1552 | /* This should always be true but check for the moment */ |
1553 | WARN_ON(tty->index != idx); | |
1554 | ||
d5698c28 | 1555 | if (tty->link) |
9c9f4ded AC |
1556 | tty_kref_put(tty->link); |
1557 | tty_kref_put(tty); | |
d5698c28 CH |
1558 | } |
1559 | ||
eeb89d91 AC |
1560 | /** |
1561 | * tty_release - vfs callback for close | |
1562 | * @inode: inode of tty | |
1563 | * @filp: file pointer for handle to tty | |
1564 | * | |
1565 | * Called the last time each file handle is closed that references | |
1566 | * this tty. There may however be several such references. | |
1567 | * | |
1568 | * Locking: | |
1569 | * Takes bkl. See tty_release_dev | |
1570 | * | |
1da177e4 LT |
1571 | * Even releasing the tty structures is a tricky business.. We have |
1572 | * to be very careful that the structures are all released at the | |
1573 | * same time, as interrupts might otherwise get the wrong pointers. | |
1574 | * | |
1575 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1576 | * lead to double frees or releasing memory still in use. | |
1577 | */ | |
eeb89d91 AC |
1578 | |
1579 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1580 | { |
d996b62a NP |
1581 | struct tty_struct *tty = file_tty(filp); |
1582 | struct tty_struct *o_tty; | |
1da177e4 | 1583 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1584 | int devpts; |
1da177e4 LT |
1585 | int idx; |
1586 | char buf[64]; | |
37bdfb07 | 1587 | |
15f1a633 | 1588 | if (tty_paranoia_check(tty, inode, "tty_release_dev")) |
eeb89d91 | 1589 | return 0; |
1da177e4 | 1590 | |
ec79d605 | 1591 | tty_lock(); |
d81ed103 | 1592 | check_tty_count(tty, "tty_release_dev"); |
1da177e4 | 1593 | |
ec79d605 | 1594 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1595 | |
1596 | idx = tty->index; | |
1597 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1598 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1599 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1600 | o_tty = tty->link; |
1601 | ||
1602 | #ifdef TTY_PARANOIA_CHECK | |
1603 | if (idx < 0 || idx >= tty->driver->num) { | |
d81ed103 | 1604 | printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " |
1da177e4 | 1605 | "free (%s)\n", tty->name); |
ec79d605 | 1606 | tty_unlock(); |
eeb89d91 | 1607 | return 0; |
1da177e4 | 1608 | } |
8b0a88d5 | 1609 | if (!devpts) { |
1da177e4 | 1610 | if (tty != tty->driver->ttys[idx]) { |
ec79d605 | 1611 | tty_unlock(); |
d81ed103 | 1612 | printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " |
1da177e4 | 1613 | "for (%s)\n", idx, tty->name); |
eeb89d91 | 1614 | return 0; |
1da177e4 LT |
1615 | } |
1616 | if (tty->termios != tty->driver->termios[idx]) { | |
ec79d605 | 1617 | tty_unlock(); |
d81ed103 | 1618 | printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " |
1da177e4 LT |
1619 | "for (%s)\n", |
1620 | idx, tty->name); | |
eeb89d91 | 1621 | return 0; |
1da177e4 | 1622 | } |
1da177e4 LT |
1623 | } |
1624 | #endif | |
1625 | ||
1626 | #ifdef TTY_DEBUG_HANGUP | |
d81ed103 | 1627 | printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", |
1da177e4 LT |
1628 | tty_name(tty, buf), tty->count); |
1629 | #endif | |
1630 | ||
1631 | #ifdef TTY_PARANOIA_CHECK | |
1632 | if (tty->driver->other && | |
1633 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1634 | if (o_tty != tty->driver->other->ttys[idx]) { | |
ec79d605 | 1635 | tty_unlock(); |
d81ed103 | 1636 | printk(KERN_DEBUG "tty_release_dev: other->table[%d] " |
1da177e4 LT |
1637 | "not o_tty for (%s)\n", |
1638 | idx, tty->name); | |
eeb89d91 | 1639 | return 0 ; |
1da177e4 LT |
1640 | } |
1641 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
ec79d605 | 1642 | tty_unlock(); |
d81ed103 | 1643 | printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " |
1da177e4 LT |
1644 | "not o_termios for (%s)\n", |
1645 | idx, tty->name); | |
eeb89d91 | 1646 | return 0; |
1da177e4 | 1647 | } |
1da177e4 | 1648 | if (o_tty->link != tty) { |
ec79d605 | 1649 | tty_unlock(); |
d81ed103 | 1650 | printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); |
eeb89d91 | 1651 | return 0; |
1da177e4 LT |
1652 | } |
1653 | } | |
1654 | #endif | |
f34d7a5b AC |
1655 | if (tty->ops->close) |
1656 | tty->ops->close(tty, filp); | |
1da177e4 | 1657 | |
ec79d605 | 1658 | tty_unlock(); |
1da177e4 LT |
1659 | /* |
1660 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1661 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1662 | * wait queues and kick everyone out _before_ actually starting to | |
1663 | * close. This ensures that we won't block while releasing the tty | |
1664 | * structure. | |
1665 | * | |
1666 | * The test for the o_tty closing is necessary, since the master and | |
1667 | * slave sides may close in any order. If the slave side closes out | |
1668 | * first, its count will be one, since the master side holds an open. | |
1669 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1670 | * so we do it now. | |
1671 | * | |
1672 | * Note that it's possible for the tty to be opened again while we're | |
1673 | * flushing out waiters. By recalculating the closing flags before | |
1674 | * each iteration we avoid any problems. | |
1675 | */ | |
1676 | while (1) { | |
1677 | /* Guard against races with tty->count changes elsewhere and | |
1678 | opens on /dev/tty */ | |
37bdfb07 | 1679 | |
70522e12 | 1680 | mutex_lock(&tty_mutex); |
ec79d605 | 1681 | tty_lock(); |
1da177e4 LT |
1682 | tty_closing = tty->count <= 1; |
1683 | o_tty_closing = o_tty && | |
1684 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1685 | do_sleep = 0; |
1686 | ||
1687 | if (tty_closing) { | |
1688 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1689 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1690 | do_sleep++; |
1691 | } | |
1692 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1693 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1694 | do_sleep++; |
1695 | } | |
1696 | } | |
1697 | if (o_tty_closing) { | |
1698 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1699 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1700 | do_sleep++; |
1701 | } | |
1702 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1703 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1704 | do_sleep++; |
1705 | } | |
1706 | } | |
1707 | if (!do_sleep) | |
1708 | break; | |
1709 | ||
d81ed103 | 1710 | printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " |
1da177e4 | 1711 | "active!\n", tty_name(tty, buf)); |
ec79d605 | 1712 | tty_unlock(); |
70522e12 | 1713 | mutex_unlock(&tty_mutex); |
1da177e4 | 1714 | schedule(); |
37bdfb07 | 1715 | } |
1da177e4 LT |
1716 | |
1717 | /* | |
37bdfb07 AC |
1718 | * The closing flags are now consistent with the open counts on |
1719 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1720 | * block, so it's safe to proceed with closing. |
1721 | */ | |
1da177e4 LT |
1722 | if (pty_master) { |
1723 | if (--o_tty->count < 0) { | |
d81ed103 | 1724 | printk(KERN_WARNING "tty_release_dev: bad pty slave count " |
1da177e4 LT |
1725 | "(%d) for %s\n", |
1726 | o_tty->count, tty_name(o_tty, buf)); | |
1727 | o_tty->count = 0; | |
1728 | } | |
1729 | } | |
1730 | if (--tty->count < 0) { | |
d81ed103 | 1731 | printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", |
1da177e4 LT |
1732 | tty->count, tty_name(tty, buf)); |
1733 | tty->count = 0; | |
1734 | } | |
37bdfb07 | 1735 | |
1da177e4 LT |
1736 | /* |
1737 | * We've decremented tty->count, so we need to remove this file | |
1738 | * descriptor off the tty->tty_files list; this serves two | |
1739 | * purposes: | |
1740 | * - check_tty_count sees the correct number of file descriptors | |
1741 | * associated with this tty. | |
1742 | * - do_tty_hangup no longer sees this file descriptor as | |
1743 | * something that needs to be handled for hangups. | |
1744 | */ | |
d996b62a | 1745 | tty_del_file(filp); |
1da177e4 LT |
1746 | |
1747 | /* | |
1748 | * Perform some housekeeping before deciding whether to return. | |
1749 | * | |
1750 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1751 | * case of a pty we may have to wait around for the other side | |
1752 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1753 | */ | |
37bdfb07 | 1754 | if (tty_closing) |
1da177e4 | 1755 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1756 | if (o_tty_closing) |
1da177e4 LT |
1757 | set_bit(TTY_CLOSING, &o_tty->flags); |
1758 | ||
1759 | /* | |
1760 | * If _either_ side is closing, make sure there aren't any | |
1761 | * processes that still think tty or o_tty is their controlling | |
1762 | * tty. | |
1763 | */ | |
1764 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1765 | read_lock(&tasklist_lock); |
24ec839c | 1766 | session_clear_tty(tty->session); |
1da177e4 | 1767 | if (o_tty) |
24ec839c | 1768 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1769 | read_unlock(&tasklist_lock); |
1770 | } | |
1771 | ||
70522e12 | 1772 | mutex_unlock(&tty_mutex); |
da965822 | 1773 | |
1da177e4 | 1774 | /* check whether both sides are closing ... */ |
eeb89d91 | 1775 | if (!tty_closing || (o_tty && !o_tty_closing)) { |
ec79d605 | 1776 | tty_unlock(); |
eeb89d91 AC |
1777 | return 0; |
1778 | } | |
37bdfb07 | 1779 | |
1da177e4 LT |
1780 | #ifdef TTY_DEBUG_HANGUP |
1781 | printk(KERN_DEBUG "freeing tty structure..."); | |
1782 | #endif | |
1783 | /* | |
01e1abb2 | 1784 | * Ask the line discipline code to release its structures |
1da177e4 | 1785 | */ |
01e1abb2 | 1786 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1787 | /* |
d5698c28 | 1788 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1789 | * the slots and preserving the termios structure. |
1790 | */ | |
d5698c28 | 1791 | release_tty(tty, idx); |
1da177e4 | 1792 | |
1da177e4 | 1793 | /* Make this pty number available for reallocation */ |
718a9163 | 1794 | if (devpts) |
15f1a633 | 1795 | devpts_kill_index(inode, idx); |
ec79d605 | 1796 | tty_unlock(); |
eeb89d91 | 1797 | return 0; |
1da177e4 LT |
1798 | } |
1799 | ||
af9b897e | 1800 | /** |
eeb89d91 | 1801 | * tty_open - open a tty device |
af9b897e AC |
1802 | * @inode: inode of device file |
1803 | * @filp: file pointer to tty | |
1da177e4 | 1804 | * |
af9b897e AC |
1805 | * tty_open and tty_release keep up the tty count that contains the |
1806 | * number of opens done on a tty. We cannot use the inode-count, as | |
1807 | * different inodes might point to the same tty. | |
1da177e4 | 1808 | * |
af9b897e AC |
1809 | * Open-counting is needed for pty masters, as well as for keeping |
1810 | * track of serial lines: DTR is dropped when the last close happens. | |
1811 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1812 | * | |
1813 | * The termios state of a pty is reset on first open so that | |
1814 | * settings don't persist across reuse. | |
1815 | * | |
d81ed103 | 1816 | * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. |
24ec839c PZ |
1817 | * tty->count should protect the rest. |
1818 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1819 | */ |
af9b897e | 1820 | |
eeb89d91 | 1821 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1822 | { |
4a2b5fdd | 1823 | struct tty_struct *tty = NULL; |
1da177e4 LT |
1824 | int noctty, retval; |
1825 | struct tty_driver *driver; | |
1826 | int index; | |
1827 | dev_t device = inode->i_rdev; | |
846c151a | 1828 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1829 | |
1830 | nonseekable_open(inode, filp); | |
37bdfb07 | 1831 | |
1da177e4 | 1832 | retry_open: |
fa90e1c9 JS |
1833 | retval = tty_alloc_file(filp); |
1834 | if (retval) | |
1835 | return -ENOMEM; | |
1836 | ||
1da177e4 LT |
1837 | noctty = filp->f_flags & O_NOCTTY; |
1838 | index = -1; | |
1839 | retval = 0; | |
37bdfb07 | 1840 | |
70522e12 | 1841 | mutex_lock(&tty_mutex); |
ec79d605 | 1842 | tty_lock(); |
1da177e4 | 1843 | |
37bdfb07 | 1844 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1845 | tty = get_current_tty(); |
1846 | if (!tty) { | |
ec79d605 | 1847 | tty_unlock(); |
70522e12 | 1848 | mutex_unlock(&tty_mutex); |
fa90e1c9 | 1849 | tty_free_file(filp); |
1da177e4 LT |
1850 | return -ENXIO; |
1851 | } | |
7d7b93c1 | 1852 | driver = tty_driver_kref_get(tty->driver); |
24ec839c | 1853 | index = tty->index; |
1da177e4 LT |
1854 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1855 | /* noctty = 1; */ | |
452a00d2 AC |
1856 | /* FIXME: Should we take a driver reference ? */ |
1857 | tty_kref_put(tty); | |
1da177e4 LT |
1858 | goto got_driver; |
1859 | } | |
1860 | #ifdef CONFIG_VT | |
37bdfb07 | 1861 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 | 1862 | extern struct tty_driver *console_driver; |
7d7b93c1 | 1863 | driver = tty_driver_kref_get(console_driver); |
1da177e4 LT |
1864 | index = fg_console; |
1865 | noctty = 1; | |
1866 | goto got_driver; | |
1867 | } | |
1868 | #endif | |
37bdfb07 | 1869 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
296fa7f6 WN |
1870 | struct tty_driver *console_driver = console_device(&index); |
1871 | if (console_driver) { | |
1872 | driver = tty_driver_kref_get(console_driver); | |
1873 | if (driver) { | |
1874 | /* Don't let /dev/console block */ | |
1875 | filp->f_flags |= O_NONBLOCK; | |
1876 | noctty = 1; | |
1877 | goto got_driver; | |
1878 | } | |
1da177e4 | 1879 | } |
ec79d605 | 1880 | tty_unlock(); |
70522e12 | 1881 | mutex_unlock(&tty_mutex); |
fa90e1c9 | 1882 | tty_free_file(filp); |
1da177e4 LT |
1883 | return -ENODEV; |
1884 | } | |
1885 | ||
1886 | driver = get_tty_driver(device, &index); | |
1887 | if (!driver) { | |
ec79d605 | 1888 | tty_unlock(); |
70522e12 | 1889 | mutex_unlock(&tty_mutex); |
fa90e1c9 | 1890 | tty_free_file(filp); |
1da177e4 LT |
1891 | return -ENODEV; |
1892 | } | |
1893 | got_driver: | |
4a2b5fdd SB |
1894 | if (!tty) { |
1895 | /* check whether we're reopening an existing tty */ | |
15f1a633 | 1896 | tty = tty_driver_lookup_tty(driver, inode, index); |
4a2b5fdd | 1897 | |
808ffa3d | 1898 | if (IS_ERR(tty)) { |
ec79d605 | 1899 | tty_unlock(); |
808ffa3d | 1900 | mutex_unlock(&tty_mutex); |
a0340703 GKH |
1901 | tty_driver_kref_put(driver); |
1902 | tty_free_file(filp); | |
4a2b5fdd | 1903 | return PTR_ERR(tty); |
808ffa3d | 1904 | } |
4a2b5fdd SB |
1905 | } |
1906 | ||
1907 | if (tty) { | |
1908 | retval = tty_reopen(tty); | |
1909 | if (retval) | |
1910 | tty = ERR_PTR(retval); | |
1911 | } else | |
1912 | tty = tty_init_dev(driver, index, 0); | |
1913 | ||
70522e12 | 1914 | mutex_unlock(&tty_mutex); |
7d7b93c1 | 1915 | tty_driver_kref_put(driver); |
eeb89d91 | 1916 | if (IS_ERR(tty)) { |
ec79d605 | 1917 | tty_unlock(); |
fa90e1c9 | 1918 | tty_free_file(filp); |
73ec06fc | 1919 | return PTR_ERR(tty); |
eeb89d91 | 1920 | } |
1da177e4 | 1921 | |
fa90e1c9 | 1922 | tty_add_file(tty, filp); |
d996b62a | 1923 | |
1da177e4 LT |
1924 | check_tty_count(tty, "tty_open"); |
1925 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1926 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1927 | noctty = 1; | |
1928 | #ifdef TTY_DEBUG_HANGUP | |
1929 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1930 | #endif | |
909bc774 HRK |
1931 | if (tty->ops->open) |
1932 | retval = tty->ops->open(tty, filp); | |
1933 | else | |
1934 | retval = -ENODEV; | |
1da177e4 LT |
1935 | filp->f_flags = saved_flags; |
1936 | ||
37bdfb07 AC |
1937 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1938 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1939 | retval = -EBUSY; |
1940 | ||
1941 | if (retval) { | |
1942 | #ifdef TTY_DEBUG_HANGUP | |
1943 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1944 | tty->name); | |
1945 | #endif | |
64ba3dc3 | 1946 | tty_unlock(); /* need to call tty_release without BTM */ |
eeb89d91 | 1947 | tty_release(inode, filp); |
64ba3dc3 | 1948 | if (retval != -ERESTARTSYS) |
1da177e4 | 1949 | return retval; |
64ba3dc3 AB |
1950 | |
1951 | if (signal_pending(current)) | |
1da177e4 | 1952 | return retval; |
64ba3dc3 | 1953 | |
1da177e4 LT |
1954 | schedule(); |
1955 | /* | |
1956 | * Need to reset f_op in case a hangup happened. | |
1957 | */ | |
64ba3dc3 | 1958 | tty_lock(); |
1da177e4 LT |
1959 | if (filp->f_op == &hung_up_tty_fops) |
1960 | filp->f_op = &tty_fops; | |
ec79d605 | 1961 | tty_unlock(); |
1da177e4 LT |
1962 | goto retry_open; |
1963 | } | |
ec79d605 | 1964 | tty_unlock(); |
eeb89d91 | 1965 | |
24ec839c PZ |
1966 | |
1967 | mutex_lock(&tty_mutex); | |
ec79d605 | 1968 | tty_lock(); |
24ec839c | 1969 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
1970 | if (!noctty && |
1971 | current->signal->leader && | |
1972 | !current->signal->tty && | |
ab521dc0 | 1973 | tty->session == NULL) |
2a65f1d9 | 1974 | __proc_set_tty(current, tty); |
24ec839c | 1975 | spin_unlock_irq(¤t->sighand->siglock); |
ec79d605 | 1976 | tty_unlock(); |
24ec839c | 1977 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1978 | return 0; |
1979 | } | |
1980 | ||
39d95b9d JC |
1981 | |
1982 | ||
af9b897e AC |
1983 | /** |
1984 | * tty_poll - check tty status | |
1985 | * @filp: file being polled | |
1986 | * @wait: poll wait structures to update | |
1987 | * | |
1988 | * Call the line discipline polling method to obtain the poll | |
1989 | * status of the device. | |
1990 | * | |
1991 | * Locking: locks called line discipline but ldisc poll method | |
1992 | * may be re-entered freely by other callers. | |
1993 | */ | |
1994 | ||
37bdfb07 | 1995 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 1996 | { |
d996b62a | 1997 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
1998 | struct tty_ldisc *ld; |
1999 | int ret = 0; | |
2000 | ||
a7113a96 | 2001 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2002 | return 0; |
37bdfb07 | 2003 | |
1da177e4 | 2004 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2005 | if (ld->ops->poll) |
2006 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2007 | tty_ldisc_deref(ld); |
2008 | return ret; | |
2009 | } | |
2010 | ||
ec79d605 | 2011 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2012 | { |
d996b62a | 2013 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2014 | unsigned long flags; |
5d1e3230 | 2015 | int retval = 0; |
1da177e4 | 2016 | |
a7113a96 | 2017 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2018 | goto out; |
37bdfb07 | 2019 | |
1da177e4 LT |
2020 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2021 | if (retval <= 0) | |
5d1e3230 | 2022 | goto out; |
1da177e4 LT |
2023 | |
2024 | if (on) { | |
ab521dc0 EB |
2025 | enum pid_type type; |
2026 | struct pid *pid; | |
1da177e4 LT |
2027 | if (!waitqueue_active(&tty->read_wait)) |
2028 | tty->minimum_to_wake = 1; | |
47f86834 | 2029 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2030 | if (tty->pgrp) { |
2031 | pid = tty->pgrp; | |
2032 | type = PIDTYPE_PGID; | |
2033 | } else { | |
2034 | pid = task_pid(current); | |
2035 | type = PIDTYPE_PID; | |
2036 | } | |
80e1e823 | 2037 | get_pid(pid); |
70362511 | 2038 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2039 | retval = __f_setown(filp, pid, type, 0); |
2040 | put_pid(pid); | |
1da177e4 | 2041 | if (retval) |
5d1e3230 | 2042 | goto out; |
1da177e4 LT |
2043 | } else { |
2044 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2045 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2046 | } | |
5d1e3230 JC |
2047 | retval = 0; |
2048 | out: | |
ec79d605 AB |
2049 | return retval; |
2050 | } | |
2051 | ||
2052 | static int tty_fasync(int fd, struct file *filp, int on) | |
2053 | { | |
2054 | int retval; | |
2055 | tty_lock(); | |
2056 | retval = __tty_fasync(fd, filp, on); | |
2057 | tty_unlock(); | |
5d1e3230 | 2058 | return retval; |
1da177e4 LT |
2059 | } |
2060 | ||
af9b897e AC |
2061 | /** |
2062 | * tiocsti - fake input character | |
2063 | * @tty: tty to fake input into | |
2064 | * @p: pointer to character | |
2065 | * | |
3a4fa0a2 | 2066 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2067 | * input management. |
2068 | * | |
2069 | * FIXME: does not honour flow control ?? | |
2070 | * | |
2071 | * Locking: | |
2072 | * Called functions take tty_ldisc_lock | |
2073 | * current->signal->tty check is safe without locks | |
28298232 AC |
2074 | * |
2075 | * FIXME: may race normal receive processing | |
af9b897e AC |
2076 | */ |
2077 | ||
1da177e4 LT |
2078 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2079 | { | |
2080 | char ch, mbz = 0; | |
2081 | struct tty_ldisc *ld; | |
37bdfb07 | 2082 | |
1da177e4 LT |
2083 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2084 | return -EPERM; | |
2085 | if (get_user(ch, p)) | |
2086 | return -EFAULT; | |
1e641743 | 2087 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2088 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2089 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2090 | tty_ldisc_deref(ld); |
2091 | return 0; | |
2092 | } | |
2093 | ||
af9b897e AC |
2094 | /** |
2095 | * tiocgwinsz - implement window query ioctl | |
2096 | * @tty; tty | |
2097 | * @arg: user buffer for result | |
2098 | * | |
808a0d38 | 2099 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2100 | * |
24ec839c | 2101 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2102 | * is consistent. |
af9b897e AC |
2103 | */ |
2104 | ||
37bdfb07 | 2105 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2106 | { |
808a0d38 AC |
2107 | int err; |
2108 | ||
5785c95b | 2109 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2110 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2111 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2112 | |
2113 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2114 | } |
2115 | ||
af9b897e | 2116 | /** |
8c9a9dd0 AC |
2117 | * tty_do_resize - resize event |
2118 | * @tty: tty being resized | |
8c9a9dd0 AC |
2119 | * @rows: rows (character) |
2120 | * @cols: cols (character) | |
2121 | * | |
3ad2f3fb | 2122 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2123 | * peform a terminal resize correctly |
af9b897e AC |
2124 | */ |
2125 | ||
fc6f6238 | 2126 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2127 | { |
fc6f6238 | 2128 | struct pid *pgrp; |
47f86834 | 2129 | unsigned long flags; |
1da177e4 | 2130 | |
fc6f6238 AC |
2131 | /* Lock the tty */ |
2132 | mutex_lock(&tty->termios_mutex); | |
2133 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2134 | goto done; |
47f86834 AC |
2135 | /* Get the PID values and reference them so we can |
2136 | avoid holding the tty ctrl lock while sending signals */ | |
2137 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2138 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2139 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2140 | ||
2141 | if (pgrp) | |
2142 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2143 | put_pid(pgrp); |
47f86834 | 2144 | |
8c9a9dd0 | 2145 | tty->winsize = *ws; |
ca9bda00 | 2146 | done: |
fc6f6238 | 2147 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2148 | return 0; |
2149 | } | |
2150 | ||
8c9a9dd0 AC |
2151 | /** |
2152 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2153 | * @tty; tty side of tty |
8c9a9dd0 AC |
2154 | * @arg: user buffer for result |
2155 | * | |
2156 | * Copies the user idea of the window size to the kernel. Traditionally | |
2157 | * this is just advisory information but for the Linux console it | |
2158 | * actually has driver level meaning and triggers a VC resize. | |
2159 | * | |
2160 | * Locking: | |
25985edc | 2161 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2162 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2163 | * then calls into the default method. | |
2164 | */ | |
2165 | ||
fc6f6238 | 2166 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2167 | { |
2168 | struct winsize tmp_ws; | |
2169 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2170 | return -EFAULT; | |
2171 | ||
2172 | if (tty->ops->resize) | |
fc6f6238 | 2173 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2174 | else |
fc6f6238 | 2175 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2176 | } |
2177 | ||
af9b897e AC |
2178 | /** |
2179 | * tioccons - allow admin to move logical console | |
2180 | * @file: the file to become console | |
2181 | * | |
25985edc | 2182 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2183 | * |
2184 | * Locking: uses redirect_lock to guard the redirect information | |
2185 | */ | |
2186 | ||
1da177e4 LT |
2187 | static int tioccons(struct file *file) |
2188 | { | |
2189 | if (!capable(CAP_SYS_ADMIN)) | |
2190 | return -EPERM; | |
2191 | if (file->f_op->write == redirected_tty_write) { | |
2192 | struct file *f; | |
2193 | spin_lock(&redirect_lock); | |
2194 | f = redirect; | |
2195 | redirect = NULL; | |
2196 | spin_unlock(&redirect_lock); | |
2197 | if (f) | |
2198 | fput(f); | |
2199 | return 0; | |
2200 | } | |
2201 | spin_lock(&redirect_lock); | |
2202 | if (redirect) { | |
2203 | spin_unlock(&redirect_lock); | |
2204 | return -EBUSY; | |
2205 | } | |
2206 | get_file(file); | |
2207 | redirect = file; | |
2208 | spin_unlock(&redirect_lock); | |
2209 | return 0; | |
2210 | } | |
2211 | ||
af9b897e AC |
2212 | /** |
2213 | * fionbio - non blocking ioctl | |
2214 | * @file: file to set blocking value | |
2215 | * @p: user parameter | |
2216 | * | |
2217 | * Historical tty interfaces had a blocking control ioctl before | |
2218 | * the generic functionality existed. This piece of history is preserved | |
2219 | * in the expected tty API of posix OS's. | |
2220 | * | |
6146b9af | 2221 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2222 | */ |
1da177e4 LT |
2223 | |
2224 | static int fionbio(struct file *file, int __user *p) | |
2225 | { | |
2226 | int nonblock; | |
2227 | ||
2228 | if (get_user(nonblock, p)) | |
2229 | return -EFAULT; | |
2230 | ||
db1dd4d3 | 2231 | spin_lock(&file->f_lock); |
1da177e4 LT |
2232 | if (nonblock) |
2233 | file->f_flags |= O_NONBLOCK; | |
2234 | else | |
2235 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2236 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2237 | return 0; |
2238 | } | |
2239 | ||
af9b897e AC |
2240 | /** |
2241 | * tiocsctty - set controlling tty | |
2242 | * @tty: tty structure | |
2243 | * @arg: user argument | |
2244 | * | |
2245 | * This ioctl is used to manage job control. It permits a session | |
2246 | * leader to set this tty as the controlling tty for the session. | |
2247 | * | |
2248 | * Locking: | |
28298232 | 2249 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2250 | * Takes tasklist_lock internally to walk sessions |
2251 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2252 | */ |
2253 | ||
1da177e4 LT |
2254 | static int tiocsctty(struct tty_struct *tty, int arg) |
2255 | { | |
24ec839c | 2256 | int ret = 0; |
ab521dc0 | 2257 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2258 | return ret; |
2259 | ||
2260 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2261 | /* |
2262 | * The process must be a session leader and | |
2263 | * not have a controlling tty already. | |
2264 | */ | |
24ec839c PZ |
2265 | if (!current->signal->leader || current->signal->tty) { |
2266 | ret = -EPERM; | |
2267 | goto unlock; | |
2268 | } | |
2269 | ||
ab521dc0 | 2270 | if (tty->session) { |
1da177e4 LT |
2271 | /* |
2272 | * This tty is already the controlling | |
2273 | * tty for another session group! | |
2274 | */ | |
37bdfb07 | 2275 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2276 | /* |
2277 | * Steal it away | |
2278 | */ | |
1da177e4 | 2279 | read_lock(&tasklist_lock); |
24ec839c | 2280 | session_clear_tty(tty->session); |
1da177e4 | 2281 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2282 | } else { |
2283 | ret = -EPERM; | |
2284 | goto unlock; | |
2285 | } | |
1da177e4 | 2286 | } |
24ec839c PZ |
2287 | proc_set_tty(current, tty); |
2288 | unlock: | |
28298232 | 2289 | mutex_unlock(&tty_mutex); |
24ec839c | 2290 | return ret; |
1da177e4 LT |
2291 | } |
2292 | ||
5d0fdf1e AC |
2293 | /** |
2294 | * tty_get_pgrp - return a ref counted pgrp pid | |
2295 | * @tty: tty to read | |
2296 | * | |
2297 | * Returns a refcounted instance of the pid struct for the process | |
2298 | * group controlling the tty. | |
2299 | */ | |
2300 | ||
2301 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2302 | { | |
2303 | unsigned long flags; | |
2304 | struct pid *pgrp; | |
2305 | ||
2306 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2307 | pgrp = get_pid(tty->pgrp); | |
2308 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2309 | ||
2310 | return pgrp; | |
2311 | } | |
2312 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2313 | ||
af9b897e AC |
2314 | /** |
2315 | * tiocgpgrp - get process group | |
2316 | * @tty: tty passed by user | |
25985edc | 2317 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2318 | * @p: returned pid |
2319 | * | |
2320 | * Obtain the process group of the tty. If there is no process group | |
2321 | * return an error. | |
2322 | * | |
24ec839c | 2323 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2324 | */ |
2325 | ||
1da177e4 LT |
2326 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2327 | { | |
5d0fdf1e AC |
2328 | struct pid *pid; |
2329 | int ret; | |
1da177e4 LT |
2330 | /* |
2331 | * (tty == real_tty) is a cheap way of | |
2332 | * testing if the tty is NOT a master pty. | |
2333 | */ | |
2334 | if (tty == real_tty && current->signal->tty != real_tty) | |
2335 | return -ENOTTY; | |
5d0fdf1e AC |
2336 | pid = tty_get_pgrp(real_tty); |
2337 | ret = put_user(pid_vnr(pid), p); | |
2338 | put_pid(pid); | |
2339 | return ret; | |
1da177e4 LT |
2340 | } |
2341 | ||
af9b897e AC |
2342 | /** |
2343 | * tiocspgrp - attempt to set process group | |
2344 | * @tty: tty passed by user | |
2345 | * @real_tty: tty side device matching tty passed by user | |
2346 | * @p: pid pointer | |
2347 | * | |
2348 | * Set the process group of the tty to the session passed. Only | |
2349 | * permitted where the tty session is our session. | |
2350 | * | |
47f86834 | 2351 | * Locking: RCU, ctrl lock |
af9b897e AC |
2352 | */ |
2353 | ||
1da177e4 LT |
2354 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2355 | { | |
04a2e6a5 EB |
2356 | struct pid *pgrp; |
2357 | pid_t pgrp_nr; | |
1da177e4 | 2358 | int retval = tty_check_change(real_tty); |
47f86834 | 2359 | unsigned long flags; |
1da177e4 LT |
2360 | |
2361 | if (retval == -EIO) | |
2362 | return -ENOTTY; | |
2363 | if (retval) | |
2364 | return retval; | |
2365 | if (!current->signal->tty || | |
2366 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2367 | (real_tty->session != task_session(current))) |
1da177e4 | 2368 | return -ENOTTY; |
04a2e6a5 | 2369 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2370 | return -EFAULT; |
04a2e6a5 | 2371 | if (pgrp_nr < 0) |
1da177e4 | 2372 | return -EINVAL; |
04a2e6a5 | 2373 | rcu_read_lock(); |
b488893a | 2374 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2375 | retval = -ESRCH; |
2376 | if (!pgrp) | |
2377 | goto out_unlock; | |
2378 | retval = -EPERM; | |
2379 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2380 | goto out_unlock; | |
2381 | retval = 0; | |
47f86834 | 2382 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2383 | put_pid(real_tty->pgrp); |
2384 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2385 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2386 | out_unlock: |
2387 | rcu_read_unlock(); | |
2388 | return retval; | |
1da177e4 LT |
2389 | } |
2390 | ||
af9b897e AC |
2391 | /** |
2392 | * tiocgsid - get session id | |
2393 | * @tty: tty passed by user | |
25985edc | 2394 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2395 | * @p: pointer to returned session id |
2396 | * | |
2397 | * Obtain the session id of the tty. If there is no session | |
2398 | * return an error. | |
2399 | * | |
24ec839c | 2400 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2401 | */ |
2402 | ||
1da177e4 LT |
2403 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2404 | { | |
2405 | /* | |
2406 | * (tty == real_tty) is a cheap way of | |
2407 | * testing if the tty is NOT a master pty. | |
2408 | */ | |
2409 | if (tty == real_tty && current->signal->tty != real_tty) | |
2410 | return -ENOTTY; | |
ab521dc0 | 2411 | if (!real_tty->session) |
1da177e4 | 2412 | return -ENOTTY; |
b488893a | 2413 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2414 | } |
2415 | ||
af9b897e AC |
2416 | /** |
2417 | * tiocsetd - set line discipline | |
2418 | * @tty: tty device | |
2419 | * @p: pointer to user data | |
2420 | * | |
2421 | * Set the line discipline according to user request. | |
2422 | * | |
2423 | * Locking: see tty_set_ldisc, this function is just a helper | |
2424 | */ | |
2425 | ||
1da177e4 LT |
2426 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2427 | { | |
2428 | int ldisc; | |
04f378b1 | 2429 | int ret; |
1da177e4 LT |
2430 | |
2431 | if (get_user(ldisc, p)) | |
2432 | return -EFAULT; | |
04f378b1 | 2433 | |
04f378b1 | 2434 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2435 | |
2436 | return ret; | |
1da177e4 LT |
2437 | } |
2438 | ||
af9b897e AC |
2439 | /** |
2440 | * send_break - performed time break | |
2441 | * @tty: device to break on | |
2442 | * @duration: timeout in mS | |
2443 | * | |
2444 | * Perform a timed break on hardware that lacks its own driver level | |
2445 | * timed break functionality. | |
2446 | * | |
2447 | * Locking: | |
28298232 | 2448 | * atomic_write_lock serializes |
af9b897e | 2449 | * |
af9b897e AC |
2450 | */ |
2451 | ||
b20f3ae5 | 2452 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2453 | { |
9e98966c AC |
2454 | int retval; |
2455 | ||
2456 | if (tty->ops->break_ctl == NULL) | |
2457 | return 0; | |
2458 | ||
2459 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2460 | retval = tty->ops->break_ctl(tty, duration); | |
2461 | else { | |
2462 | /* Do the work ourselves */ | |
2463 | if (tty_write_lock(tty, 0) < 0) | |
2464 | return -EINTR; | |
2465 | retval = tty->ops->break_ctl(tty, -1); | |
2466 | if (retval) | |
2467 | goto out; | |
2468 | if (!signal_pending(current)) | |
2469 | msleep_interruptible(duration); | |
2470 | retval = tty->ops->break_ctl(tty, 0); | |
2471 | out: | |
2472 | tty_write_unlock(tty); | |
2473 | if (signal_pending(current)) | |
2474 | retval = -EINTR; | |
2475 | } | |
2476 | return retval; | |
1da177e4 LT |
2477 | } |
2478 | ||
af9b897e | 2479 | /** |
f34d7a5b | 2480 | * tty_tiocmget - get modem status |
af9b897e AC |
2481 | * @tty: tty device |
2482 | * @file: user file pointer | |
2483 | * @p: pointer to result | |
2484 | * | |
2485 | * Obtain the modem status bits from the tty driver if the feature | |
2486 | * is supported. Return -EINVAL if it is not available. | |
2487 | * | |
2488 | * Locking: none (up to the driver) | |
2489 | */ | |
2490 | ||
60b33c13 | 2491 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2492 | { |
2493 | int retval = -EINVAL; | |
2494 | ||
f34d7a5b | 2495 | if (tty->ops->tiocmget) { |
60b33c13 | 2496 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2497 | |
2498 | if (retval >= 0) | |
2499 | retval = put_user(retval, p); | |
2500 | } | |
2501 | return retval; | |
2502 | } | |
2503 | ||
af9b897e | 2504 | /** |
f34d7a5b | 2505 | * tty_tiocmset - set modem status |
af9b897e | 2506 | * @tty: tty device |
af9b897e AC |
2507 | * @cmd: command - clear bits, set bits or set all |
2508 | * @p: pointer to desired bits | |
2509 | * | |
2510 | * Set the modem status bits from the tty driver if the feature | |
2511 | * is supported. Return -EINVAL if it is not available. | |
2512 | * | |
2513 | * Locking: none (up to the driver) | |
2514 | */ | |
2515 | ||
20b9d177 | 2516 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2517 | unsigned __user *p) |
2518 | { | |
ae677517 AC |
2519 | int retval; |
2520 | unsigned int set, clear, val; | |
1da177e4 | 2521 | |
ae677517 AC |
2522 | if (tty->ops->tiocmset == NULL) |
2523 | return -EINVAL; | |
1da177e4 | 2524 | |
ae677517 AC |
2525 | retval = get_user(val, p); |
2526 | if (retval) | |
2527 | return retval; | |
2528 | set = clear = 0; | |
2529 | switch (cmd) { | |
2530 | case TIOCMBIS: | |
2531 | set = val; | |
2532 | break; | |
2533 | case TIOCMBIC: | |
2534 | clear = val; | |
2535 | break; | |
2536 | case TIOCMSET: | |
2537 | set = val; | |
2538 | clear = ~val; | |
2539 | break; | |
2540 | } | |
2541 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2542 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2543 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2544 | } |
2545 | ||
d281da7f AC |
2546 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2547 | { | |
2548 | int retval = -EINVAL; | |
2549 | struct serial_icounter_struct icount; | |
2550 | memset(&icount, 0, sizeof(icount)); | |
2551 | if (tty->ops->get_icount) | |
2552 | retval = tty->ops->get_icount(tty, &icount); | |
2553 | if (retval != 0) | |
2554 | return retval; | |
2555 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2556 | return -EFAULT; | |
2557 | return 0; | |
2558 | } | |
2559 | ||
e8b70e7d AC |
2560 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2561 | { | |
2562 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2563 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2564 | tty = tty->link; | |
2565 | return tty; | |
2566 | } | |
2567 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2568 | ||
2569 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2570 | { | |
2571 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2572 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2573 | return tty; | |
2574 | return tty->link; | |
2575 | } | |
2576 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2577 | ||
1da177e4 LT |
2578 | /* |
2579 | * Split this up, as gcc can choke on it otherwise.. | |
2580 | */ | |
04f378b1 | 2581 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2582 | { |
d996b62a NP |
2583 | struct tty_struct *tty = file_tty(file); |
2584 | struct tty_struct *real_tty; | |
1da177e4 LT |
2585 | void __user *p = (void __user *)arg; |
2586 | int retval; | |
2587 | struct tty_ldisc *ld; | |
04f378b1 | 2588 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2589 | |
1da177e4 LT |
2590 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2591 | return -EINVAL; | |
2592 | ||
e8b70e7d | 2593 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2594 | |
2595 | /* | |
2596 | * Factor out some common prep work | |
2597 | */ | |
2598 | switch (cmd) { | |
2599 | case TIOCSETD: | |
2600 | case TIOCSBRK: | |
2601 | case TIOCCBRK: | |
2602 | case TCSBRK: | |
37bdfb07 | 2603 | case TCSBRKP: |
1da177e4 LT |
2604 | retval = tty_check_change(tty); |
2605 | if (retval) | |
2606 | return retval; | |
2607 | if (cmd != TIOCCBRK) { | |
2608 | tty_wait_until_sent(tty, 0); | |
2609 | if (signal_pending(current)) | |
2610 | return -EINTR; | |
2611 | } | |
2612 | break; | |
2613 | } | |
2614 | ||
9e98966c AC |
2615 | /* |
2616 | * Now do the stuff. | |
2617 | */ | |
1da177e4 | 2618 | switch (cmd) { |
37bdfb07 AC |
2619 | case TIOCSTI: |
2620 | return tiocsti(tty, p); | |
2621 | case TIOCGWINSZ: | |
8f520021 | 2622 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2623 | case TIOCSWINSZ: |
fc6f6238 | 2624 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2625 | case TIOCCONS: |
2626 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2627 | case FIONBIO: | |
2628 | return fionbio(file, p); | |
2629 | case TIOCEXCL: | |
2630 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2631 | return 0; | |
2632 | case TIOCNXCL: | |
2633 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2634 | return 0; | |
2635 | case TIOCNOTTY: | |
2636 | if (current->signal->tty != tty) | |
2637 | return -ENOTTY; | |
2638 | no_tty(); | |
2639 | return 0; | |
2640 | case TIOCSCTTY: | |
2641 | return tiocsctty(tty, arg); | |
2642 | case TIOCGPGRP: | |
2643 | return tiocgpgrp(tty, real_tty, p); | |
2644 | case TIOCSPGRP: | |
2645 | return tiocspgrp(tty, real_tty, p); | |
2646 | case TIOCGSID: | |
2647 | return tiocgsid(tty, real_tty, p); | |
2648 | case TIOCGETD: | |
c65c9bc3 | 2649 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2650 | case TIOCSETD: |
2651 | return tiocsetd(tty, p); | |
3c95c985 KS |
2652 | case TIOCVHANGUP: |
2653 | if (!capable(CAP_SYS_ADMIN)) | |
2654 | return -EPERM; | |
2655 | tty_vhangup(tty); | |
2656 | return 0; | |
b7b8de08 WF |
2657 | case TIOCGDEV: |
2658 | { | |
2659 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2660 | return put_user(ret, (unsigned int __user *)p); | |
2661 | } | |
37bdfb07 AC |
2662 | /* |
2663 | * Break handling | |
2664 | */ | |
2665 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2666 | if (tty->ops->break_ctl) |
9e98966c | 2667 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2668 | return 0; |
37bdfb07 | 2669 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2670 | if (tty->ops->break_ctl) |
9e98966c | 2671 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2672 | return 0; |
2673 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2674 | /* non-zero arg means wait for all output data | |
2675 | * to be sent (performed above) but don't send break. | |
2676 | * This is used by the tcdrain() termios function. | |
2677 | */ | |
2678 | if (!arg) | |
2679 | return send_break(tty, 250); | |
2680 | return 0; | |
2681 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2682 | return send_break(tty, arg ? arg*100 : 250); | |
2683 | ||
2684 | case TIOCMGET: | |
60b33c13 | 2685 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2686 | case TIOCMSET: |
2687 | case TIOCMBIC: | |
2688 | case TIOCMBIS: | |
20b9d177 | 2689 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2690 | case TIOCGICOUNT: |
2691 | retval = tty_tiocgicount(tty, p); | |
2692 | /* For the moment allow fall through to the old method */ | |
2693 | if (retval != -EINVAL) | |
2694 | return retval; | |
2695 | break; | |
37bdfb07 AC |
2696 | case TCFLSH: |
2697 | switch (arg) { | |
2698 | case TCIFLUSH: | |
2699 | case TCIOFLUSH: | |
2700 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2701 | tty_buffer_flush(tty); | |
c5c34d48 | 2702 | break; |
37bdfb07 AC |
2703 | } |
2704 | break; | |
1da177e4 | 2705 | } |
f34d7a5b | 2706 | if (tty->ops->ioctl) { |
6caa76b7 | 2707 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2708 | if (retval != -ENOIOCTLCMD) |
2709 | return retval; | |
2710 | } | |
2711 | ld = tty_ldisc_ref_wait(tty); | |
2712 | retval = -EINVAL; | |
a352def2 AC |
2713 | if (ld->ops->ioctl) { |
2714 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2715 | if (retval == -ENOIOCTLCMD) |
2716 | retval = -EINVAL; | |
2717 | } | |
2718 | tty_ldisc_deref(ld); | |
2719 | return retval; | |
2720 | } | |
2721 | ||
e10cc1df | 2722 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2723 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2724 | unsigned long arg) |
2725 | { | |
2726 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2727 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2728 | struct tty_ldisc *ld; |
2729 | int retval = -ENOIOCTLCMD; | |
2730 | ||
2731 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2732 | return -EINVAL; | |
2733 | ||
f34d7a5b | 2734 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2735 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2736 | if (retval != -ENOIOCTLCMD) |
2737 | return retval; | |
2738 | } | |
2739 | ||
2740 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2741 | if (ld->ops->compat_ioctl) |
2742 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2743 | else |
2744 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2745 | tty_ldisc_deref(ld); |
2746 | ||
2747 | return retval; | |
2748 | } | |
2749 | #endif | |
1da177e4 LT |
2750 | |
2751 | /* | |
2752 | * This implements the "Secure Attention Key" --- the idea is to | |
2753 | * prevent trojan horses by killing all processes associated with this | |
2754 | * tty when the user hits the "Secure Attention Key". Required for | |
2755 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2756 | * |
1da177e4 LT |
2757 | * This code could be nicer; ideally it should send a HUP, wait a few |
2758 | * seconds, then send a INT, and then a KILL signal. But you then | |
2759 | * have to coordinate with the init process, since all processes associated | |
2760 | * with the current tty must be dead before the new getty is allowed | |
2761 | * to spawn. | |
2762 | * | |
2763 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2764 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2765 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2766 | * | |
2767 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2768 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2769 | */ | |
8b6312f4 | 2770 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2771 | { |
2772 | #ifdef TTY_SOFT_SAK | |
2773 | tty_hangup(tty); | |
2774 | #else | |
652486fb | 2775 | struct task_struct *g, *p; |
ab521dc0 | 2776 | struct pid *session; |
1da177e4 LT |
2777 | int i; |
2778 | struct file *filp; | |
badf1662 | 2779 | struct fdtable *fdt; |
37bdfb07 | 2780 | |
1da177e4 LT |
2781 | if (!tty) |
2782 | return; | |
24ec839c | 2783 | session = tty->session; |
37bdfb07 | 2784 | |
b3f13deb | 2785 | tty_ldisc_flush(tty); |
1da177e4 | 2786 | |
f34d7a5b | 2787 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2788 | |
1da177e4 | 2789 | read_lock(&tasklist_lock); |
652486fb | 2790 | /* Kill the entire session */ |
ab521dc0 | 2791 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2792 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2793 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2794 | task_pid_nr(p), p->comm); |
652486fb | 2795 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2796 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2797 | /* Now kill any processes that happen to have the |
2798 | * tty open. | |
2799 | */ | |
2800 | do_each_thread(g, p) { | |
2801 | if (p->signal->tty == tty) { | |
1da177e4 | 2802 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2803 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2804 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2805 | send_sig(SIGKILL, p, 1); |
2806 | continue; | |
2807 | } | |
2808 | task_lock(p); | |
2809 | if (p->files) { | |
ca99c1da DS |
2810 | /* |
2811 | * We don't take a ref to the file, so we must | |
2812 | * hold ->file_lock instead. | |
2813 | */ | |
2814 | spin_lock(&p->files->file_lock); | |
badf1662 | 2815 | fdt = files_fdtable(p->files); |
37bdfb07 | 2816 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2817 | filp = fcheck_files(p->files, i); |
2818 | if (!filp) | |
2819 | continue; | |
2820 | if (filp->f_op->read == tty_read && | |
d996b62a | 2821 | file_tty(filp) == tty) { |
1da177e4 LT |
2822 | printk(KERN_NOTICE "SAK: killed process %d" |
2823 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2824 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2825 | force_sig(SIGKILL, p); |
1da177e4 LT |
2826 | break; |
2827 | } | |
2828 | } | |
ca99c1da | 2829 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2830 | } |
2831 | task_unlock(p); | |
652486fb | 2832 | } while_each_thread(g, p); |
1da177e4 LT |
2833 | read_unlock(&tasklist_lock); |
2834 | #endif | |
2835 | } | |
2836 | ||
8b6312f4 EB |
2837 | static void do_SAK_work(struct work_struct *work) |
2838 | { | |
2839 | struct tty_struct *tty = | |
2840 | container_of(work, struct tty_struct, SAK_work); | |
2841 | __do_SAK(tty); | |
2842 | } | |
2843 | ||
1da177e4 LT |
2844 | /* |
2845 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2846 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2847 | * the values which we write to it will be identical to the values which it | |
2848 | * already has. --akpm | |
2849 | */ | |
2850 | void do_SAK(struct tty_struct *tty) | |
2851 | { | |
2852 | if (!tty) | |
2853 | return; | |
1da177e4 LT |
2854 | schedule_work(&tty->SAK_work); |
2855 | } | |
2856 | ||
2857 | EXPORT_SYMBOL(do_SAK); | |
2858 | ||
30004ac9 DES |
2859 | static int dev_match_devt(struct device *dev, void *data) |
2860 | { | |
2861 | dev_t *devt = data; | |
2862 | return dev->devt == *devt; | |
2863 | } | |
2864 | ||
2865 | /* Must put_device() after it's unused! */ | |
2866 | static struct device *tty_get_device(struct tty_struct *tty) | |
2867 | { | |
2868 | dev_t devt = tty_devnum(tty); | |
2869 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2870 | } | |
2871 | ||
2872 | ||
af9b897e AC |
2873 | /** |
2874 | * initialize_tty_struct | |
2875 | * @tty: tty to initialize | |
2876 | * | |
2877 | * This subroutine initializes a tty structure that has been newly | |
2878 | * allocated. | |
2879 | * | |
2880 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2881 | */ |
af9b897e | 2882 | |
bf970ee4 AC |
2883 | void initialize_tty_struct(struct tty_struct *tty, |
2884 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2885 | { |
2886 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2887 | kref_init(&tty->kref); |
1da177e4 | 2888 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2889 | tty_ldisc_init(tty); |
ab521dc0 EB |
2890 | tty->session = NULL; |
2891 | tty->pgrp = NULL; | |
1da177e4 | 2892 | tty->overrun_time = jiffies; |
33f0f88f AC |
2893 | tty->buf.head = tty->buf.tail = NULL; |
2894 | tty_buffer_init(tty); | |
5785c95b | 2895 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2896 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2897 | init_waitqueue_head(&tty->write_wait); |
2898 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2899 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2900 | mutex_init(&tty->atomic_read_lock); |
2901 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2902 | mutex_init(&tty->output_lock); |
2903 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2904 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2905 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2906 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2907 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2908 | |
2909 | tty->driver = driver; | |
2910 | tty->ops = driver->ops; | |
2911 | tty->index = idx; | |
2912 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2913 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2914 | } |
2915 | ||
6716671d JS |
2916 | /** |
2917 | * deinitialize_tty_struct | |
2918 | * @tty: tty to deinitialize | |
2919 | * | |
2920 | * This subroutine deinitializes a tty structure that has been newly | |
2921 | * allocated but tty_release cannot be called on that yet. | |
2922 | * | |
2923 | * Locking: none - tty in question must not be exposed at this point | |
2924 | */ | |
2925 | void deinitialize_tty_struct(struct tty_struct *tty) | |
2926 | { | |
2927 | tty_ldisc_deinit(tty); | |
2928 | } | |
2929 | ||
f34d7a5b AC |
2930 | /** |
2931 | * tty_put_char - write one character to a tty | |
2932 | * @tty: tty | |
2933 | * @ch: character | |
2934 | * | |
2935 | * Write one byte to the tty using the provided put_char method | |
2936 | * if present. Returns the number of characters successfully output. | |
2937 | * | |
2938 | * Note: the specific put_char operation in the driver layer may go | |
2939 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2940 | */ |
af9b897e | 2941 | |
f34d7a5b | 2942 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2943 | { |
f34d7a5b AC |
2944 | if (tty->ops->put_char) |
2945 | return tty->ops->put_char(tty, ch); | |
2946 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2947 | } |
f34d7a5b AC |
2948 | EXPORT_SYMBOL_GPL(tty_put_char); |
2949 | ||
d81ed103 | 2950 | struct class *tty_class; |
1da177e4 LT |
2951 | |
2952 | /** | |
af9b897e AC |
2953 | * tty_register_device - register a tty device |
2954 | * @driver: the tty driver that describes the tty device | |
2955 | * @index: the index in the tty driver for this tty device | |
2956 | * @device: a struct device that is associated with this tty device. | |
2957 | * This field is optional, if there is no known struct device | |
2958 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2959 | * |
01107d34 GKH |
2960 | * Returns a pointer to the struct device for this tty device |
2961 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2962 | * |
af9b897e AC |
2963 | * This call is required to be made to register an individual tty device |
2964 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2965 | * that bit is not set, this function should not be called by a tty | |
2966 | * driver. | |
2967 | * | |
2968 | * Locking: ?? | |
1da177e4 | 2969 | */ |
af9b897e | 2970 | |
01107d34 GKH |
2971 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2972 | struct device *device) | |
1da177e4 LT |
2973 | { |
2974 | char name[64]; | |
2975 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2976 | ||
2977 | if (index >= driver->num) { | |
2978 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2979 | " (%d).\n", index); | |
1cdcb6b4 | 2980 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2981 | } |
2982 | ||
1da177e4 LT |
2983 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2984 | pty_line_name(driver, index, name); | |
2985 | else | |
2986 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2987 | |
03457cd4 | 2988 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 2989 | } |
7d7b93c1 | 2990 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
2991 | |
2992 | /** | |
af9b897e AC |
2993 | * tty_unregister_device - unregister a tty device |
2994 | * @driver: the tty driver that describes the tty device | |
2995 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2996 | * |
af9b897e AC |
2997 | * If a tty device is registered with a call to tty_register_device() then |
2998 | * this function must be called when the tty device is gone. | |
2999 | * | |
3000 | * Locking: ?? | |
1da177e4 | 3001 | */ |
af9b897e | 3002 | |
1da177e4 LT |
3003 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3004 | { | |
37bdfb07 AC |
3005 | device_destroy(tty_class, |
3006 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 3007 | } |
1da177e4 LT |
3008 | EXPORT_SYMBOL(tty_unregister_device); |
3009 | ||
3010 | struct tty_driver *alloc_tty_driver(int lines) | |
3011 | { | |
3012 | struct tty_driver *driver; | |
3013 | ||
506eb99a | 3014 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 3015 | if (driver) { |
7d7b93c1 | 3016 | kref_init(&driver->kref); |
1da177e4 LT |
3017 | driver->magic = TTY_DRIVER_MAGIC; |
3018 | driver->num = lines; | |
3019 | /* later we'll move allocation of tables here */ | |
3020 | } | |
3021 | return driver; | |
3022 | } | |
7d7b93c1 | 3023 | EXPORT_SYMBOL(alloc_tty_driver); |
1da177e4 | 3024 | |
7d7b93c1 | 3025 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3026 | { |
7d7b93c1 AC |
3027 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3028 | int i; | |
3029 | struct ktermios *tp; | |
3030 | void *p; | |
3031 | ||
3032 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3033 | /* | |
3034 | * Free the termios and termios_locked structures because | |
3035 | * we don't want to get memory leaks when modular tty | |
3036 | * drivers are removed from the kernel. | |
3037 | */ | |
3038 | for (i = 0; i < driver->num; i++) { | |
3039 | tp = driver->termios[i]; | |
3040 | if (tp) { | |
3041 | driver->termios[i] = NULL; | |
3042 | kfree(tp); | |
3043 | } | |
7d7b93c1 AC |
3044 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3045 | tty_unregister_device(driver, i); | |
3046 | } | |
3047 | p = driver->ttys; | |
3048 | proc_tty_unregister_driver(driver); | |
3049 | driver->ttys = NULL; | |
fe6e29fd | 3050 | driver->termios = NULL; |
7d7b93c1 AC |
3051 | kfree(p); |
3052 | cdev_del(&driver->cdev); | |
3053 | } | |
1da177e4 LT |
3054 | kfree(driver); |
3055 | } | |
3056 | ||
7d7b93c1 AC |
3057 | void tty_driver_kref_put(struct tty_driver *driver) |
3058 | { | |
3059 | kref_put(&driver->kref, destruct_tty_driver); | |
3060 | } | |
3061 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3062 | ||
b68e31d0 JD |
3063 | void tty_set_operations(struct tty_driver *driver, |
3064 | const struct tty_operations *op) | |
1da177e4 | 3065 | { |
f34d7a5b AC |
3066 | driver->ops = op; |
3067 | }; | |
7d7b93c1 | 3068 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3069 | |
7d7b93c1 AC |
3070 | void put_tty_driver(struct tty_driver *d) |
3071 | { | |
3072 | tty_driver_kref_put(d); | |
3073 | } | |
1da177e4 | 3074 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3075 | |
3076 | /* | |
3077 | * Called by a tty driver to register itself. | |
3078 | */ | |
3079 | int tty_register_driver(struct tty_driver *driver) | |
3080 | { | |
3081 | int error; | |
37bdfb07 | 3082 | int i; |
1da177e4 LT |
3083 | dev_t dev; |
3084 | void **p = NULL; | |
b670bde0 | 3085 | struct device *d; |
1da177e4 | 3086 | |
543691a6 | 3087 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 3088 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
3089 | if (!p) |
3090 | return -ENOMEM; | |
1da177e4 LT |
3091 | } |
3092 | ||
3093 | if (!driver->major) { | |
37bdfb07 AC |
3094 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3095 | driver->num, driver->name); | |
1da177e4 LT |
3096 | if (!error) { |
3097 | driver->major = MAJOR(dev); | |
3098 | driver->minor_start = MINOR(dev); | |
3099 | } | |
3100 | } else { | |
3101 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3102 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
3103 | } |
3104 | if (error < 0) { | |
3105 | kfree(p); | |
3106 | return error; | |
3107 | } | |
3108 | ||
3109 | if (p) { | |
3110 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3111 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
3112 | } else { |
3113 | driver->ttys = NULL; | |
3114 | driver->termios = NULL; | |
1da177e4 LT |
3115 | } |
3116 | ||
3117 | cdev_init(&driver->cdev, &tty_fops); | |
3118 | driver->cdev.owner = driver->owner; | |
3119 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3120 | if (error) { | |
1da177e4 LT |
3121 | unregister_chrdev_region(dev, driver->num); |
3122 | driver->ttys = NULL; | |
fe6e29fd | 3123 | driver->termios = NULL; |
1da177e4 LT |
3124 | kfree(p); |
3125 | return error; | |
3126 | } | |
3127 | ||
ca509f69 | 3128 | mutex_lock(&tty_mutex); |
1da177e4 | 3129 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3130 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3131 | |
3132 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3133 | for (i = 0; i < driver->num; i++) { |
3134 | d = tty_register_device(driver, i, NULL); | |
3135 | if (IS_ERR(d)) { | |
3136 | error = PTR_ERR(d); | |
3137 | goto err; | |
3138 | } | |
3139 | } | |
1da177e4 LT |
3140 | } |
3141 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3142 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3143 | return 0; |
b670bde0 VK |
3144 | |
3145 | err: | |
3146 | for (i--; i >= 0; i--) | |
3147 | tty_unregister_device(driver, i); | |
3148 | ||
3149 | mutex_lock(&tty_mutex); | |
3150 | list_del(&driver->tty_drivers); | |
3151 | mutex_unlock(&tty_mutex); | |
3152 | ||
3153 | unregister_chrdev_region(dev, driver->num); | |
3154 | driver->ttys = NULL; | |
3155 | driver->termios = NULL; | |
3156 | kfree(p); | |
3157 | return error; | |
1da177e4 LT |
3158 | } |
3159 | ||
3160 | EXPORT_SYMBOL(tty_register_driver); | |
3161 | ||
3162 | /* | |
3163 | * Called by a tty driver to unregister itself. | |
3164 | */ | |
3165 | int tty_unregister_driver(struct tty_driver *driver) | |
3166 | { | |
7d7b93c1 AC |
3167 | #if 0 |
3168 | /* FIXME */ | |
1da177e4 LT |
3169 | if (driver->refcount) |
3170 | return -EBUSY; | |
7d7b93c1 | 3171 | #endif |
1da177e4 LT |
3172 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3173 | driver->num); | |
ca509f69 | 3174 | mutex_lock(&tty_mutex); |
1da177e4 | 3175 | list_del(&driver->tty_drivers); |
ca509f69 | 3176 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3177 | return 0; |
3178 | } | |
7d7b93c1 | 3179 | |
1da177e4 LT |
3180 | EXPORT_SYMBOL(tty_unregister_driver); |
3181 | ||
24ec839c PZ |
3182 | dev_t tty_devnum(struct tty_struct *tty) |
3183 | { | |
3184 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3185 | } | |
3186 | EXPORT_SYMBOL(tty_devnum); | |
3187 | ||
3188 | void proc_clear_tty(struct task_struct *p) | |
3189 | { | |
7c3b1dcf | 3190 | unsigned long flags; |
9c9f4ded | 3191 | struct tty_struct *tty; |
7c3b1dcf | 3192 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3193 | tty = p->signal->tty; |
24ec839c | 3194 | p->signal->tty = NULL; |
7c3b1dcf | 3195 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3196 | tty_kref_put(tty); |
24ec839c | 3197 | } |
24ec839c | 3198 | |
47f86834 AC |
3199 | /* Called under the sighand lock */ |
3200 | ||
2a65f1d9 | 3201 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3202 | { |
3203 | if (tty) { | |
47f86834 AC |
3204 | unsigned long flags; |
3205 | /* We should not have a session or pgrp to put here but.... */ | |
3206 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3207 | put_pid(tty->session); |
3208 | put_pid(tty->pgrp); | |
ab521dc0 | 3209 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3210 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3211 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3212 | if (tsk->signal->tty) { |
3213 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3214 | tty_kref_put(tsk->signal->tty); | |
3215 | } | |
24ec839c | 3216 | } |
2a65f1d9 | 3217 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3218 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3219 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3220 | } |
3221 | ||
98a27ba4 | 3222 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3223 | { |
3224 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3225 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3226 | spin_unlock_irq(&tsk->sighand->siglock); |
3227 | } | |
3228 | ||
3229 | struct tty_struct *get_current_tty(void) | |
3230 | { | |
3231 | struct tty_struct *tty; | |
934e6ebf AC |
3232 | unsigned long flags; |
3233 | ||
3234 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3235 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3236 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3237 | return tty; |
3238 | } | |
a311f743 | 3239 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3240 | |
d81ed103 AC |
3241 | void tty_default_fops(struct file_operations *fops) |
3242 | { | |
3243 | *fops = tty_fops; | |
3244 | } | |
3245 | ||
1da177e4 LT |
3246 | /* |
3247 | * Initialize the console device. This is called *early*, so | |
3248 | * we can't necessarily depend on lots of kernel help here. | |
3249 | * Just do some early initializations, and do the complex setup | |
3250 | * later. | |
3251 | */ | |
3252 | void __init console_init(void) | |
3253 | { | |
3254 | initcall_t *call; | |
3255 | ||
3256 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3257 | tty_ldisc_begin(); |
1da177e4 LT |
3258 | |
3259 | /* | |
37bdfb07 | 3260 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3261 | * inform about problems etc.. |
3262 | */ | |
1da177e4 LT |
3263 | call = __con_initcall_start; |
3264 | while (call < __con_initcall_end) { | |
3265 | (*call)(); | |
3266 | call++; | |
3267 | } | |
3268 | } | |
3269 | ||
e454cea2 KS |
3270 | static char *tty_devnode(struct device *dev, mode_t *mode) |
3271 | { | |
3272 | if (!mode) | |
3273 | return NULL; | |
3274 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3275 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3276 | *mode = 0666; | |
3277 | return NULL; | |
3278 | } | |
3279 | ||
1da177e4 LT |
3280 | static int __init tty_class_init(void) |
3281 | { | |
7fe845d1 | 3282 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3283 | if (IS_ERR(tty_class)) |
3284 | return PTR_ERR(tty_class); | |
e454cea2 | 3285 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3286 | return 0; |
3287 | } | |
3288 | ||
3289 | postcore_initcall(tty_class_init); | |
3290 | ||
3291 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3292 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3293 | |
fbc92a34 KS |
3294 | static ssize_t show_cons_active(struct device *dev, |
3295 | struct device_attribute *attr, char *buf) | |
3296 | { | |
3297 | struct console *cs[16]; | |
3298 | int i = 0; | |
3299 | struct console *c; | |
3300 | ssize_t count = 0; | |
3301 | ||
ac751efa | 3302 | console_lock(); |
a2a6a822 | 3303 | for_each_console(c) { |
fbc92a34 KS |
3304 | if (!c->device) |
3305 | continue; | |
3306 | if (!c->write) | |
3307 | continue; | |
3308 | if ((c->flags & CON_ENABLED) == 0) | |
3309 | continue; | |
3310 | cs[i++] = c; | |
3311 | if (i >= ARRAY_SIZE(cs)) | |
3312 | break; | |
3313 | } | |
3314 | while (i--) | |
3315 | count += sprintf(buf + count, "%s%d%c", | |
3316 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3317 | console_unlock(); |
fbc92a34 KS |
3318 | |
3319 | return count; | |
3320 | } | |
3321 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3322 | ||
3323 | static struct device *consdev; | |
3324 | ||
3325 | void console_sysfs_notify(void) | |
3326 | { | |
3327 | if (consdev) | |
3328 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3329 | } | |
3330 | ||
1da177e4 LT |
3331 | /* |
3332 | * Ok, now we can initialize the rest of the tty devices and can count | |
3333 | * on memory allocations, interrupts etc.. | |
3334 | */ | |
31d1d48e | 3335 | int __init tty_init(void) |
1da177e4 LT |
3336 | { |
3337 | cdev_init(&tty_cdev, &tty_fops); | |
3338 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3339 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3340 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3341 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3342 | |
3343 | cdev_init(&console_cdev, &console_fops); | |
3344 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3345 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3346 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3347 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3348 | "console"); |
fbc92a34 KS |
3349 | if (IS_ERR(consdev)) |
3350 | consdev = NULL; | |
3351 | else | |
a2a6a822 | 3352 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3353 | |
1da177e4 | 3354 | #ifdef CONFIG_VT |
d81ed103 | 3355 | vty_init(&console_fops); |
1da177e4 LT |
3356 | #endif |
3357 | return 0; | |
3358 | } | |
31d1d48e | 3359 |