Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/tty_io.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
9 | * or rs-channels. It also implements echoing, cooked mode etc. | |
10 | * | |
11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
12 | * | |
13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
14 | * tty_struct and tty_queue structures. Previously there was an array | |
15 | * of 256 tty_struct's which was statically allocated, and the | |
16 | * tty_queue structures were allocated at boot time. Both are now | |
17 | * dynamically allocated only when the tty is open. | |
18 | * | |
19 | * Also restructured routines so that there is more of a separation | |
20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
21 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
23 | * |
24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
25 | * which can be dynamically activated and de-activated by the line | |
26 | * discipline handling modules (like SLIP). | |
27 | * | |
28 | * NOTE: pay no attention to the line discipline code (yet); its | |
29 | * interface is still subject to change in this version... | |
30 | * -- TYT, 1/31/92 | |
31 | * | |
32 | * Added functionality to the OPOST tty handling. No delays, but all | |
33 | * other bits should be there. | |
34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
35 | * | |
36 | * Rewrote canonical mode and added more termios flags. | |
37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
38 | * | |
39 | * Reorganized FASYNC support so mouse code can share it. | |
40 | * -- ctm@ardi.com, 9Sep95 | |
41 | * | |
42 | * New TIOCLINUX variants added. | |
43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 44 | * |
1da177e4 LT |
45 | * Restrict vt switching via ioctl() |
46 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
47 | * | |
48 | * Move console and virtual terminal code to more appropriate files, | |
49 | * implement CONFIG_VT and generalize console device interface. | |
50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
51 | * | |
d81ed103 | 52 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
53 | * -- Bill Hawes <whawes@star.net>, June 97 |
54 | * | |
55 | * Added devfs support. | |
56 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
57 | * | |
58 | * Added support for a Unix98-style ptmx device. | |
59 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
60 | * | |
61 | * Reduced memory usage for older ARM systems | |
62 | * -- Russell King <rmk@arm.linux.org.uk> | |
63 | * | |
64 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
65 | * alloc_tty_struct() always uses kmalloc() |
66 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
67 | */ |
68 | ||
1da177e4 LT |
69 | #include <linux/types.h> |
70 | #include <linux/major.h> | |
71 | #include <linux/errno.h> | |
72 | #include <linux/signal.h> | |
73 | #include <linux/fcntl.h> | |
74 | #include <linux/sched.h> | |
75 | #include <linux/interrupt.h> | |
76 | #include <linux/tty.h> | |
77 | #include <linux/tty_driver.h> | |
78 | #include <linux/tty_flip.h> | |
79 | #include <linux/devpts_fs.h> | |
80 | #include <linux/file.h> | |
9f3acc31 | 81 | #include <linux/fdtable.h> |
1da177e4 LT |
82 | #include <linux/console.h> |
83 | #include <linux/timer.h> | |
84 | #include <linux/ctype.h> | |
85 | #include <linux/kd.h> | |
86 | #include <linux/mm.h> | |
87 | #include <linux/string.h> | |
88 | #include <linux/slab.h> | |
89 | #include <linux/poll.h> | |
90 | #include <linux/proc_fs.h> | |
91 | #include <linux/init.h> | |
92 | #include <linux/module.h> | |
1da177e4 | 93 | #include <linux/device.h> |
1da177e4 LT |
94 | #include <linux/wait.h> |
95 | #include <linux/bitops.h> | |
b20f3ae5 | 96 | #include <linux/delay.h> |
a352def2 | 97 | #include <linux/seq_file.h> |
d281da7f | 98 | #include <linux/serial.h> |
1da177e4 | 99 | |
a352def2 | 100 | #include <linux/uaccess.h> |
1da177e4 LT |
101 | #include <asm/system.h> |
102 | ||
103 | #include <linux/kbd_kern.h> | |
104 | #include <linux/vt_kern.h> | |
105 | #include <linux/selection.h> | |
1da177e4 LT |
106 | |
107 | #include <linux/kmod.h> | |
b488893a | 108 | #include <linux/nsproxy.h> |
1da177e4 LT |
109 | |
110 | #undef TTY_DEBUG_HANGUP | |
111 | ||
112 | #define TTY_PARANOIA_CHECK 1 | |
113 | #define CHECK_TTY_COUNT 1 | |
114 | ||
edc6afc5 | 115 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
116 | .c_iflag = ICRNL | IXON, |
117 | .c_oflag = OPOST | ONLCR, | |
118 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
119 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
120 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
121 | .c_cc = INIT_C_CC, |
122 | .c_ispeed = 38400, | |
123 | .c_ospeed = 38400 | |
1da177e4 LT |
124 | }; |
125 | ||
126 | EXPORT_SYMBOL(tty_std_termios); | |
127 | ||
128 | /* This list gets poked at by procfs and various bits of boot up code. This | |
129 | could do with some rationalisation such as pulling the tty proc function | |
130 | into this file */ | |
37bdfb07 | 131 | |
1da177e4 LT |
132 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
133 | ||
24ec839c | 134 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 135 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 136 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 137 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 138 | |
ee2ffa0d NP |
139 | /* Spinlock to protect the tty->tty_files list */ |
140 | DEFINE_SPINLOCK(tty_files_lock); | |
141 | ||
1da177e4 LT |
142 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
143 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
144 | ssize_t redirected_tty_write(struct file *, const char __user *, |
145 | size_t, loff_t *); | |
1da177e4 LT |
146 | static unsigned int tty_poll(struct file *, poll_table *); |
147 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 148 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 149 | #ifdef CONFIG_COMPAT |
37bdfb07 | 150 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
151 | unsigned long arg); |
152 | #else | |
153 | #define tty_compat_ioctl NULL | |
154 | #endif | |
ec79d605 | 155 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 156 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 157 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 158 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 159 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 160 | |
af9b897e AC |
161 | /** |
162 | * alloc_tty_struct - allocate a tty object | |
163 | * | |
164 | * Return a new empty tty structure. The data fields have not | |
165 | * been initialized in any way but has been zeroed | |
166 | * | |
167 | * Locking: none | |
af9b897e | 168 | */ |
1da177e4 | 169 | |
bf970ee4 | 170 | struct tty_struct *alloc_tty_struct(void) |
1da177e4 | 171 | { |
1266b1e1 | 172 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
173 | } |
174 | ||
af9b897e AC |
175 | /** |
176 | * free_tty_struct - free a disused tty | |
177 | * @tty: tty struct to free | |
178 | * | |
179 | * Free the write buffers, tty queue and tty memory itself. | |
180 | * | |
181 | * Locking: none. Must be called after tty is definitely unused | |
182 | */ | |
183 | ||
bf970ee4 | 184 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 185 | { |
30004ac9 DES |
186 | if (tty->dev) |
187 | put_device(tty->dev); | |
1da177e4 | 188 | kfree(tty->write_buf); |
33f0f88f | 189 | tty_buffer_free_all(tty); |
1da177e4 LT |
190 | kfree(tty); |
191 | } | |
192 | ||
d996b62a NP |
193 | static inline struct tty_struct *file_tty(struct file *file) |
194 | { | |
195 | return ((struct tty_file_private *)file->private_data)->tty; | |
196 | } | |
197 | ||
198 | /* Associate a new file with the tty structure */ | |
f573bd17 | 199 | int tty_add_file(struct tty_struct *tty, struct file *file) |
d996b62a NP |
200 | { |
201 | struct tty_file_private *priv; | |
202 | ||
f573bd17 PE |
203 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
204 | if (!priv) | |
205 | return -ENOMEM; | |
d996b62a NP |
206 | |
207 | priv->tty = tty; | |
208 | priv->file = file; | |
209 | file->private_data = priv; | |
210 | ||
211 | spin_lock(&tty_files_lock); | |
212 | list_add(&priv->list, &tty->tty_files); | |
213 | spin_unlock(&tty_files_lock); | |
f573bd17 PE |
214 | |
215 | return 0; | |
d996b62a NP |
216 | } |
217 | ||
218 | /* Delete file from its tty */ | |
219 | void tty_del_file(struct file *file) | |
220 | { | |
221 | struct tty_file_private *priv = file->private_data; | |
222 | ||
223 | spin_lock(&tty_files_lock); | |
224 | list_del(&priv->list); | |
225 | spin_unlock(&tty_files_lock); | |
226 | file->private_data = NULL; | |
227 | kfree(priv); | |
228 | } | |
229 | ||
230 | ||
1da177e4 LT |
231 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
232 | ||
af9b897e AC |
233 | /** |
234 | * tty_name - return tty naming | |
235 | * @tty: tty structure | |
236 | * @buf: buffer for output | |
237 | * | |
238 | * Convert a tty structure into a name. The name reflects the kernel | |
239 | * naming policy and if udev is in use may not reflect user space | |
240 | * | |
241 | * Locking: none | |
242 | */ | |
243 | ||
1da177e4 LT |
244 | char *tty_name(struct tty_struct *tty, char *buf) |
245 | { | |
246 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
247 | strcpy(buf, "NULL tty"); | |
248 | else | |
249 | strcpy(buf, tty->name); | |
250 | return buf; | |
251 | } | |
252 | ||
253 | EXPORT_SYMBOL(tty_name); | |
254 | ||
d769a669 | 255 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
256 | const char *routine) |
257 | { | |
258 | #ifdef TTY_PARANOIA_CHECK | |
259 | if (!tty) { | |
260 | printk(KERN_WARNING | |
261 | "null TTY for (%d:%d) in %s\n", | |
262 | imajor(inode), iminor(inode), routine); | |
263 | return 1; | |
264 | } | |
265 | if (tty->magic != TTY_MAGIC) { | |
266 | printk(KERN_WARNING | |
267 | "bad magic number for tty struct (%d:%d) in %s\n", | |
268 | imajor(inode), iminor(inode), routine); | |
269 | return 1; | |
270 | } | |
271 | #endif | |
272 | return 0; | |
273 | } | |
274 | ||
275 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
276 | { | |
277 | #ifdef CHECK_TTY_COUNT | |
278 | struct list_head *p; | |
279 | int count = 0; | |
37bdfb07 | 280 | |
ee2ffa0d | 281 | spin_lock(&tty_files_lock); |
1da177e4 LT |
282 | list_for_each(p, &tty->tty_files) { |
283 | count++; | |
284 | } | |
ee2ffa0d | 285 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
286 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
287 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
288 | tty->link && tty->link->count) | |
289 | count++; | |
290 | if (tty->count != count) { | |
291 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
292 | "!= #fd's(%d) in %s\n", | |
293 | tty->name, tty->count, count, routine); | |
294 | return count; | |
24ec839c | 295 | } |
1da177e4 LT |
296 | #endif |
297 | return 0; | |
298 | } | |
299 | ||
af9b897e AC |
300 | /** |
301 | * get_tty_driver - find device of a tty | |
302 | * @dev_t: device identifier | |
303 | * @index: returns the index of the tty | |
304 | * | |
305 | * This routine returns a tty driver structure, given a device number | |
306 | * and also passes back the index number. | |
307 | * | |
308 | * Locking: caller must hold tty_mutex | |
1da177e4 | 309 | */ |
af9b897e | 310 | |
1da177e4 LT |
311 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
312 | { | |
313 | struct tty_driver *p; | |
314 | ||
315 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
316 | dev_t base = MKDEV(p->major, p->minor_start); | |
317 | if (device < base || device >= base + p->num) | |
318 | continue; | |
319 | *index = device - base; | |
7d7b93c1 | 320 | return tty_driver_kref_get(p); |
1da177e4 LT |
321 | } |
322 | return NULL; | |
323 | } | |
324 | ||
f2d937f3 JW |
325 | #ifdef CONFIG_CONSOLE_POLL |
326 | ||
327 | /** | |
328 | * tty_find_polling_driver - find device of a polled tty | |
329 | * @name: name string to match | |
330 | * @line: pointer to resulting tty line nr | |
331 | * | |
332 | * This routine returns a tty driver structure, given a name | |
333 | * and the condition that the tty driver is capable of polled | |
334 | * operation. | |
335 | */ | |
336 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
337 | { | |
338 | struct tty_driver *p, *res = NULL; | |
339 | int tty_line = 0; | |
0dca0fd2 | 340 | int len; |
5f0878ac | 341 | char *str, *stp; |
f2d937f3 | 342 | |
0dca0fd2 JW |
343 | for (str = name; *str; str++) |
344 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
345 | break; | |
346 | if (!*str) | |
347 | return NULL; | |
348 | ||
349 | len = str - name; | |
350 | tty_line = simple_strtoul(str, &str, 10); | |
351 | ||
f2d937f3 JW |
352 | mutex_lock(&tty_mutex); |
353 | /* Search through the tty devices to look for a match */ | |
354 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
355 | if (strncmp(name, p->name, len) != 0) |
356 | continue; | |
5f0878ac AC |
357 | stp = str; |
358 | if (*stp == ',') | |
359 | stp++; | |
360 | if (*stp == '\0') | |
361 | stp = NULL; | |
f2d937f3 | 362 | |
6eb68d6f | 363 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 364 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 365 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
366 | *line = tty_line; |
367 | break; | |
368 | } | |
369 | } | |
370 | mutex_unlock(&tty_mutex); | |
371 | ||
372 | return res; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
375 | #endif | |
376 | ||
af9b897e AC |
377 | /** |
378 | * tty_check_change - check for POSIX terminal changes | |
379 | * @tty: tty to check | |
380 | * | |
381 | * If we try to write to, or set the state of, a terminal and we're | |
382 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
383 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
384 | * | |
978e595f | 385 | * Locking: ctrl_lock |
1da177e4 | 386 | */ |
af9b897e | 387 | |
37bdfb07 | 388 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 389 | { |
47f86834 AC |
390 | unsigned long flags; |
391 | int ret = 0; | |
392 | ||
1da177e4 LT |
393 | if (current->signal->tty != tty) |
394 | return 0; | |
47f86834 AC |
395 | |
396 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
397 | ||
ab521dc0 EB |
398 | if (!tty->pgrp) { |
399 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 400 | goto out_unlock; |
1da177e4 | 401 | } |
ab521dc0 | 402 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
403 | goto out_unlock; |
404 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 405 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
406 | goto out; |
407 | if (is_current_pgrp_orphaned()) { | |
408 | ret = -EIO; | |
409 | goto out; | |
410 | } | |
040b6362 ON |
411 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
412 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
413 | ret = -ERESTARTSYS; |
414 | out: | |
9ffee4cb AM |
415 | return ret; |
416 | out_unlock: | |
47f86834 AC |
417 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
418 | return ret; | |
1da177e4 LT |
419 | } |
420 | ||
421 | EXPORT_SYMBOL(tty_check_change); | |
422 | ||
37bdfb07 | 423 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
424 | size_t count, loff_t *ppos) |
425 | { | |
426 | return 0; | |
427 | } | |
428 | ||
37bdfb07 | 429 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
430 | size_t count, loff_t *ppos) |
431 | { | |
432 | return -EIO; | |
433 | } | |
434 | ||
435 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 436 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
437 | { |
438 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
439 | } | |
440 | ||
04f378b1 AC |
441 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
442 | unsigned long arg) | |
38ad2ed0 PF |
443 | { |
444 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
445 | } | |
446 | ||
37bdfb07 | 447 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 448 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
449 | { |
450 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
451 | } | |
452 | ||
62322d25 | 453 | static const struct file_operations tty_fops = { |
1da177e4 LT |
454 | .llseek = no_llseek, |
455 | .read = tty_read, | |
456 | .write = tty_write, | |
457 | .poll = tty_poll, | |
04f378b1 | 458 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 459 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
460 | .open = tty_open, |
461 | .release = tty_release, | |
462 | .fasync = tty_fasync, | |
463 | }; | |
464 | ||
62322d25 | 465 | static const struct file_operations console_fops = { |
1da177e4 LT |
466 | .llseek = no_llseek, |
467 | .read = tty_read, | |
468 | .write = redirected_tty_write, | |
469 | .poll = tty_poll, | |
04f378b1 | 470 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 471 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
472 | .open = tty_open, |
473 | .release = tty_release, | |
474 | .fasync = tty_fasync, | |
475 | }; | |
476 | ||
62322d25 | 477 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
478 | .llseek = no_llseek, |
479 | .read = hung_up_tty_read, | |
480 | .write = hung_up_tty_write, | |
481 | .poll = hung_up_tty_poll, | |
04f378b1 | 482 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 483 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
484 | .release = tty_release, |
485 | }; | |
486 | ||
487 | static DEFINE_SPINLOCK(redirect_lock); | |
488 | static struct file *redirect; | |
489 | ||
490 | /** | |
491 | * tty_wakeup - request more data | |
492 | * @tty: terminal | |
493 | * | |
494 | * Internal and external helper for wakeups of tty. This function | |
495 | * informs the line discipline if present that the driver is ready | |
496 | * to receive more output data. | |
497 | */ | |
37bdfb07 | 498 | |
1da177e4 LT |
499 | void tty_wakeup(struct tty_struct *tty) |
500 | { | |
501 | struct tty_ldisc *ld; | |
37bdfb07 | 502 | |
1da177e4 LT |
503 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
504 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 505 | if (ld) { |
a352def2 AC |
506 | if (ld->ops->write_wakeup) |
507 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
508 | tty_ldisc_deref(ld); |
509 | } | |
510 | } | |
4b19449d | 511 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
512 | } |
513 | ||
514 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
515 | ||
af9b897e | 516 | /** |
11dbf203 | 517 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 518 | * @work: tty device |
af9b897e | 519 | * |
1bad879a | 520 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
521 | * synchronous but doesn't hold any locks, so we need to make sure we |
522 | * have the appropriate locks for what we're doing. | |
523 | * | |
524 | * The hangup event clears any pending redirections onto the hung up | |
525 | * device. It ensures future writes will error and it does the needed | |
526 | * line discipline hangup and signal delivery. The tty object itself | |
527 | * remains intact. | |
528 | * | |
529 | * Locking: | |
ec79d605 | 530 | * BTM |
24ec839c PZ |
531 | * redirect lock for undoing redirection |
532 | * file list lock for manipulating list of ttys | |
533 | * tty_ldisc_lock from called functions | |
534 | * termios_mutex resetting termios data | |
535 | * tasklist_lock to walk task list for hangup event | |
536 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 537 | */ |
11dbf203 | 538 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 539 | { |
37bdfb07 | 540 | struct file *cons_filp = NULL; |
1da177e4 LT |
541 | struct file *filp, *f = NULL; |
542 | struct task_struct *p; | |
d996b62a | 543 | struct tty_file_private *priv; |
1da177e4 | 544 | int closecount = 0, n; |
47f86834 | 545 | unsigned long flags; |
9c9f4ded | 546 | int refs = 0; |
1da177e4 LT |
547 | |
548 | if (!tty) | |
549 | return; | |
550 | ||
1da177e4 LT |
551 | |
552 | spin_lock(&redirect_lock); | |
d996b62a | 553 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
554 | f = redirect; |
555 | redirect = NULL; | |
556 | } | |
557 | spin_unlock(&redirect_lock); | |
37bdfb07 | 558 | |
11dbf203 AB |
559 | tty_lock(); |
560 | ||
acfa747b JS |
561 | /* some functions below drop BTM, so we need this bit */ |
562 | set_bit(TTY_HUPPING, &tty->flags); | |
563 | ||
ec79d605 AB |
564 | /* inuse_filps is protected by the single tty lock, |
565 | this really needs to change if we want to flush the | |
566 | workqueue with the lock held */ | |
11dbf203 | 567 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 568 | |
ee2ffa0d | 569 | spin_lock(&tty_files_lock); |
1da177e4 | 570 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
571 | list_for_each_entry(priv, &tty->tty_files, list) { |
572 | filp = priv->file; | |
1da177e4 LT |
573 | if (filp->f_op->write == redirected_tty_write) |
574 | cons_filp = filp; | |
575 | if (filp->f_op->write != tty_write) | |
576 | continue; | |
577 | closecount++; | |
ec79d605 | 578 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
579 | filp->f_op = &hung_up_tty_fops; |
580 | } | |
ee2ffa0d | 581 | spin_unlock(&tty_files_lock); |
37bdfb07 | 582 | |
acfa747b JS |
583 | /* |
584 | * it drops BTM and thus races with reopen | |
585 | * we protect the race by TTY_HUPPING | |
586 | */ | |
c65c9bc3 | 587 | tty_ldisc_hangup(tty); |
37bdfb07 | 588 | |
1da177e4 | 589 | read_lock(&tasklist_lock); |
ab521dc0 EB |
590 | if (tty->session) { |
591 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 592 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 593 | if (p->signal->tty == tty) { |
1da177e4 | 594 | p->signal->tty = NULL; |
9c9f4ded AC |
595 | /* We defer the dereferences outside fo |
596 | the tasklist lock */ | |
597 | refs++; | |
598 | } | |
24ec839c PZ |
599 | if (!p->signal->leader) { |
600 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 601 | continue; |
24ec839c PZ |
602 | } |
603 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
604 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 605 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 606 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
607 | if (tty->pgrp) |
608 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 609 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 610 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 611 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
612 | } |
613 | read_unlock(&tasklist_lock); | |
614 | ||
47f86834 | 615 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
616 | clear_bit(TTY_THROTTLED, &tty->flags); |
617 | clear_bit(TTY_PUSH, &tty->flags); | |
618 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
619 | put_pid(tty->session); |
620 | put_pid(tty->pgrp); | |
ab521dc0 EB |
621 | tty->session = NULL; |
622 | tty->pgrp = NULL; | |
1da177e4 | 623 | tty->ctrl_status = 0; |
47f86834 AC |
624 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
625 | ||
9c9f4ded AC |
626 | /* Account for the p->signal references we killed */ |
627 | while (refs--) | |
628 | tty_kref_put(tty); | |
629 | ||
1da177e4 | 630 | /* |
37bdfb07 AC |
631 | * If one of the devices matches a console pointer, we |
632 | * cannot just call hangup() because that will cause | |
633 | * tty->count and state->count to go out of sync. | |
634 | * So we just call close() the right number of times. | |
1da177e4 LT |
635 | */ |
636 | if (cons_filp) { | |
f34d7a5b | 637 | if (tty->ops->close) |
1da177e4 | 638 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
639 | tty->ops->close(tty, cons_filp); |
640 | } else if (tty->ops->hangup) | |
641 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
642 | /* |
643 | * We don't want to have driver/ldisc interactions beyond | |
644 | * the ones we did here. The driver layer expects no | |
645 | * calls after ->hangup() from the ldisc side. However we | |
646 | * can't yet guarantee all that. | |
647 | */ | |
1da177e4 | 648 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 649 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 650 | tty_ldisc_enable(tty); |
11dbf203 AB |
651 | |
652 | tty_unlock(); | |
653 | ||
1da177e4 LT |
654 | if (f) |
655 | fput(f); | |
656 | } | |
657 | ||
ddcd9fb6 AB |
658 | static void do_tty_hangup(struct work_struct *work) |
659 | { | |
660 | struct tty_struct *tty = | |
661 | container_of(work, struct tty_struct, hangup_work); | |
662 | ||
11dbf203 | 663 | __tty_hangup(tty); |
ddcd9fb6 AB |
664 | } |
665 | ||
af9b897e AC |
666 | /** |
667 | * tty_hangup - trigger a hangup event | |
668 | * @tty: tty to hangup | |
669 | * | |
670 | * A carrier loss (virtual or otherwise) has occurred on this like | |
671 | * schedule a hangup sequence to run after this event. | |
672 | */ | |
673 | ||
37bdfb07 | 674 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
675 | { |
676 | #ifdef TTY_DEBUG_HANGUP | |
677 | char buf[64]; | |
1da177e4 LT |
678 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
679 | #endif | |
680 | schedule_work(&tty->hangup_work); | |
681 | } | |
682 | ||
683 | EXPORT_SYMBOL(tty_hangup); | |
684 | ||
af9b897e AC |
685 | /** |
686 | * tty_vhangup - process vhangup | |
687 | * @tty: tty to hangup | |
688 | * | |
689 | * The user has asked via system call for the terminal to be hung up. | |
690 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 691 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
692 | */ |
693 | ||
37bdfb07 | 694 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
695 | { |
696 | #ifdef TTY_DEBUG_HANGUP | |
697 | char buf[64]; | |
698 | ||
699 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
700 | #endif | |
11dbf203 | 701 | __tty_hangup(tty); |
1da177e4 | 702 | } |
37bdfb07 | 703 | |
1da177e4 LT |
704 | EXPORT_SYMBOL(tty_vhangup); |
705 | ||
11dbf203 | 706 | |
2cb5998b AC |
707 | /** |
708 | * tty_vhangup_self - process vhangup for own ctty | |
709 | * | |
710 | * Perform a vhangup on the current controlling tty | |
711 | */ | |
712 | ||
713 | void tty_vhangup_self(void) | |
714 | { | |
715 | struct tty_struct *tty; | |
716 | ||
2cb5998b AC |
717 | tty = get_current_tty(); |
718 | if (tty) { | |
719 | tty_vhangup(tty); | |
720 | tty_kref_put(tty); | |
721 | } | |
2cb5998b AC |
722 | } |
723 | ||
af9b897e AC |
724 | /** |
725 | * tty_hung_up_p - was tty hung up | |
726 | * @filp: file pointer of tty | |
727 | * | |
728 | * Return true if the tty has been subject to a vhangup or a carrier | |
729 | * loss | |
730 | */ | |
731 | ||
37bdfb07 | 732 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
733 | { |
734 | return (filp->f_op == &hung_up_tty_fops); | |
735 | } | |
736 | ||
737 | EXPORT_SYMBOL(tty_hung_up_p); | |
738 | ||
ab521dc0 | 739 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
740 | { |
741 | struct task_struct *p; | |
ab521dc0 | 742 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 743 | proc_clear_tty(p); |
ab521dc0 | 744 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
745 | } |
746 | ||
af9b897e AC |
747 | /** |
748 | * disassociate_ctty - disconnect controlling tty | |
749 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 750 | * |
af9b897e AC |
751 | * This function is typically called only by the session leader, when |
752 | * it wants to disassociate itself from its controlling tty. | |
753 | * | |
754 | * It performs the following functions: | |
1da177e4 LT |
755 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
756 | * (2) Clears the tty from being controlling the session | |
757 | * (3) Clears the controlling tty for all processes in the | |
758 | * session group. | |
759 | * | |
af9b897e AC |
760 | * The argument on_exit is set to 1 if called when a process is |
761 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
762 | * | |
24ec839c | 763 | * Locking: |
ec79d605 AB |
764 | * BTM is taken for hysterical raisins, and held when |
765 | * called from no_tty(). | |
24ec839c PZ |
766 | * tty_mutex is taken to protect tty |
767 | * ->siglock is taken to protect ->signal/->sighand | |
768 | * tasklist_lock is taken to walk process list for sessions | |
769 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 770 | */ |
af9b897e | 771 | |
1da177e4 LT |
772 | void disassociate_ctty(int on_exit) |
773 | { | |
774 | struct tty_struct *tty; | |
ab521dc0 | 775 | struct pid *tty_pgrp = NULL; |
1da177e4 | 776 | |
5ec93d11 AC |
777 | if (!current->signal->leader) |
778 | return; | |
1da177e4 | 779 | |
24ec839c | 780 | tty = get_current_tty(); |
1da177e4 | 781 | if (tty) { |
ab521dc0 | 782 | tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 783 | if (on_exit) { |
ddcd9fb6 | 784 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 785 | tty_vhangup(tty); |
ddcd9fb6 | 786 | } |
452a00d2 | 787 | tty_kref_put(tty); |
680a9671 | 788 | } else if (on_exit) { |
ab521dc0 | 789 | struct pid *old_pgrp; |
680a9671 EB |
790 | spin_lock_irq(¤t->sighand->siglock); |
791 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 792 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 793 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 794 | if (old_pgrp) { |
ab521dc0 EB |
795 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
796 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
797 | put_pid(old_pgrp); | |
1da177e4 | 798 | } |
1da177e4 LT |
799 | return; |
800 | } | |
ab521dc0 EB |
801 | if (tty_pgrp) { |
802 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
1da177e4 | 803 | if (!on_exit) |
ab521dc0 EB |
804 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); |
805 | put_pid(tty_pgrp); | |
1da177e4 LT |
806 | } |
807 | ||
24ec839c | 808 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 809 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 810 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
811 | spin_unlock_irq(¤t->sighand->siglock); |
812 | ||
24ec839c PZ |
813 | tty = get_current_tty(); |
814 | if (tty) { | |
47f86834 AC |
815 | unsigned long flags; |
816 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
817 | put_pid(tty->session); |
818 | put_pid(tty->pgrp); | |
819 | tty->session = NULL; | |
820 | tty->pgrp = NULL; | |
47f86834 | 821 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 822 | tty_kref_put(tty); |
24ec839c PZ |
823 | } else { |
824 | #ifdef TTY_DEBUG_HANGUP | |
825 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
826 | " = NULL", tty); | |
827 | #endif | |
828 | } | |
1da177e4 LT |
829 | |
830 | /* Now clear signal->tty under the lock */ | |
831 | read_lock(&tasklist_lock); | |
ab521dc0 | 832 | session_clear_tty(task_session(current)); |
1da177e4 | 833 | read_unlock(&tasklist_lock); |
1da177e4 LT |
834 | } |
835 | ||
98a27ba4 EB |
836 | /** |
837 | * | |
838 | * no_tty - Ensure the current process does not have a controlling tty | |
839 | */ | |
840 | void no_tty(void) | |
841 | { | |
842 | struct task_struct *tsk = current; | |
ec79d605 | 843 | tty_lock(); |
5ec93d11 | 844 | disassociate_ctty(0); |
ec79d605 | 845 | tty_unlock(); |
98a27ba4 EB |
846 | proc_clear_tty(tsk); |
847 | } | |
848 | ||
af9b897e AC |
849 | |
850 | /** | |
beb7dd86 | 851 | * stop_tty - propagate flow control |
af9b897e AC |
852 | * @tty: tty to stop |
853 | * | |
854 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 855 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
856 | * on an already stopped device and will not re-call the driver |
857 | * method. | |
858 | * | |
859 | * This functionality is used by both the line disciplines for | |
860 | * halting incoming flow and by the driver. It may therefore be | |
861 | * called from any context, may be under the tty atomic_write_lock | |
862 | * but not always. | |
863 | * | |
864 | * Locking: | |
04f378b1 | 865 | * Uses the tty control lock internally |
af9b897e AC |
866 | */ |
867 | ||
1da177e4 LT |
868 | void stop_tty(struct tty_struct *tty) |
869 | { | |
04f378b1 AC |
870 | unsigned long flags; |
871 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
872 | if (tty->stopped) { | |
873 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 874 | return; |
04f378b1 | 875 | } |
1da177e4 LT |
876 | tty->stopped = 1; |
877 | if (tty->link && tty->link->packet) { | |
878 | tty->ctrl_status &= ~TIOCPKT_START; | |
879 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 880 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 881 | } |
04f378b1 | 882 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
883 | if (tty->ops->stop) |
884 | (tty->ops->stop)(tty); | |
1da177e4 LT |
885 | } |
886 | ||
887 | EXPORT_SYMBOL(stop_tty); | |
888 | ||
af9b897e | 889 | /** |
beb7dd86 | 890 | * start_tty - propagate flow control |
af9b897e AC |
891 | * @tty: tty to start |
892 | * | |
893 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 894 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
895 | * is the tty was previous stopped and is being started then the |
896 | * driver start method is invoked and the line discipline woken. | |
897 | * | |
898 | * Locking: | |
04f378b1 | 899 | * ctrl_lock |
af9b897e AC |
900 | */ |
901 | ||
1da177e4 LT |
902 | void start_tty(struct tty_struct *tty) |
903 | { | |
04f378b1 AC |
904 | unsigned long flags; |
905 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
906 | if (!tty->stopped || tty->flow_stopped) { | |
907 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 908 | return; |
04f378b1 | 909 | } |
1da177e4 LT |
910 | tty->stopped = 0; |
911 | if (tty->link && tty->link->packet) { | |
912 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
913 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 914 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 915 | } |
04f378b1 | 916 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
917 | if (tty->ops->start) |
918 | (tty->ops->start)(tty); | |
1da177e4 LT |
919 | /* If we have a running line discipline it may need kicking */ |
920 | tty_wakeup(tty); | |
1da177e4 LT |
921 | } |
922 | ||
923 | EXPORT_SYMBOL(start_tty); | |
924 | ||
af9b897e AC |
925 | /** |
926 | * tty_read - read method for tty device files | |
927 | * @file: pointer to tty file | |
928 | * @buf: user buffer | |
929 | * @count: size of user buffer | |
930 | * @ppos: unused | |
931 | * | |
932 | * Perform the read system call function on this terminal device. Checks | |
933 | * for hung up devices before calling the line discipline method. | |
934 | * | |
935 | * Locking: | |
47f86834 AC |
936 | * Locks the line discipline internally while needed. Multiple |
937 | * read calls may be outstanding in parallel. | |
af9b897e AC |
938 | */ |
939 | ||
37bdfb07 | 940 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
941 | loff_t *ppos) |
942 | { | |
943 | int i; | |
d996b62a NP |
944 | struct inode *inode = file->f_path.dentry->d_inode; |
945 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
946 | struct tty_ldisc *ld; |
947 | ||
1da177e4 LT |
948 | if (tty_paranoia_check(tty, inode, "tty_read")) |
949 | return -EIO; | |
950 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
951 | return -EIO; | |
952 | ||
953 | /* We want to wait for the line discipline to sort out in this | |
954 | situation */ | |
955 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
956 | if (ld->ops->read) |
957 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
958 | else |
959 | i = -EIO; | |
960 | tty_ldisc_deref(ld); | |
1da177e4 LT |
961 | if (i > 0) |
962 | inode->i_atime = current_fs_time(inode->i_sb); | |
963 | return i; | |
964 | } | |
965 | ||
9c1729db AC |
966 | void tty_write_unlock(struct tty_struct *tty) |
967 | { | |
968 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 969 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
970 | } |
971 | ||
972 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
973 | { | |
974 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
975 | if (ndelay) | |
976 | return -EAGAIN; | |
977 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
978 | return -ERESTARTSYS; | |
979 | } | |
980 | return 0; | |
981 | } | |
982 | ||
1da177e4 LT |
983 | /* |
984 | * Split writes up in sane blocksizes to avoid | |
985 | * denial-of-service type attacks | |
986 | */ | |
987 | static inline ssize_t do_tty_write( | |
988 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
989 | struct tty_struct *tty, | |
990 | struct file *file, | |
991 | const char __user *buf, | |
992 | size_t count) | |
993 | { | |
9c1729db | 994 | ssize_t ret, written = 0; |
1da177e4 | 995 | unsigned int chunk; |
37bdfb07 | 996 | |
9c1729db AC |
997 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
998 | if (ret < 0) | |
999 | return ret; | |
1da177e4 LT |
1000 | |
1001 | /* | |
1002 | * We chunk up writes into a temporary buffer. This | |
1003 | * simplifies low-level drivers immensely, since they | |
1004 | * don't have locking issues and user mode accesses. | |
1005 | * | |
1006 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1007 | * big chunk-size.. | |
1008 | * | |
1009 | * The default chunk-size is 2kB, because the NTTY | |
1010 | * layer has problems with bigger chunks. It will | |
1011 | * claim to be able to handle more characters than | |
1012 | * it actually does. | |
af9b897e AC |
1013 | * |
1014 | * FIXME: This can probably go away now except that 64K chunks | |
1015 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1016 | */ |
1017 | chunk = 2048; | |
1018 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1019 | chunk = 65536; | |
1020 | if (count < chunk) | |
1021 | chunk = count; | |
1022 | ||
70522e12 | 1023 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1024 | if (tty->write_cnt < chunk) { |
402fda92 | 1025 | unsigned char *buf_chunk; |
1da177e4 LT |
1026 | |
1027 | if (chunk < 1024) | |
1028 | chunk = 1024; | |
1029 | ||
402fda92 JW |
1030 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1031 | if (!buf_chunk) { | |
9c1729db AC |
1032 | ret = -ENOMEM; |
1033 | goto out; | |
1da177e4 LT |
1034 | } |
1035 | kfree(tty->write_buf); | |
1036 | tty->write_cnt = chunk; | |
402fda92 | 1037 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1038 | } |
1039 | ||
1040 | /* Do the write .. */ | |
1041 | for (;;) { | |
1042 | size_t size = count; | |
1043 | if (size > chunk) | |
1044 | size = chunk; | |
1045 | ret = -EFAULT; | |
1046 | if (copy_from_user(tty->write_buf, buf, size)) | |
1047 | break; | |
1da177e4 | 1048 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1049 | if (ret <= 0) |
1050 | break; | |
1051 | written += ret; | |
1052 | buf += ret; | |
1053 | count -= ret; | |
1054 | if (!count) | |
1055 | break; | |
1056 | ret = -ERESTARTSYS; | |
1057 | if (signal_pending(current)) | |
1058 | break; | |
1059 | cond_resched(); | |
1060 | } | |
1061 | if (written) { | |
a7113a96 | 1062 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1063 | inode->i_mtime = current_fs_time(inode->i_sb); |
1064 | ret = written; | |
1065 | } | |
9c1729db AC |
1066 | out: |
1067 | tty_write_unlock(tty); | |
1da177e4 LT |
1068 | return ret; |
1069 | } | |
1070 | ||
95f9bfc6 AC |
1071 | /** |
1072 | * tty_write_message - write a message to a certain tty, not just the console. | |
1073 | * @tty: the destination tty_struct | |
1074 | * @msg: the message to write | |
1075 | * | |
1076 | * This is used for messages that need to be redirected to a specific tty. | |
1077 | * We don't put it into the syslog queue right now maybe in the future if | |
1078 | * really needed. | |
1079 | * | |
ec79d605 | 1080 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1081 | */ |
1082 | ||
1083 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1084 | { | |
95f9bfc6 AC |
1085 | if (tty) { |
1086 | mutex_lock(&tty->atomic_write_lock); | |
ec79d605 | 1087 | tty_lock(); |
eeb89d91 | 1088 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
ec79d605 | 1089 | tty_unlock(); |
95f9bfc6 | 1090 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1091 | } else |
ec79d605 | 1092 | tty_unlock(); |
95f9bfc6 AC |
1093 | tty_write_unlock(tty); |
1094 | } | |
95f9bfc6 AC |
1095 | return; |
1096 | } | |
1097 | ||
1da177e4 | 1098 | |
af9b897e AC |
1099 | /** |
1100 | * tty_write - write method for tty device file | |
1101 | * @file: tty file pointer | |
1102 | * @buf: user data to write | |
1103 | * @count: bytes to write | |
1104 | * @ppos: unused | |
1105 | * | |
1106 | * Write data to a tty device via the line discipline. | |
1107 | * | |
1108 | * Locking: | |
1109 | * Locks the line discipline as required | |
1110 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1111 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1112 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1113 | */ |
1114 | ||
37bdfb07 AC |
1115 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1116 | size_t count, loff_t *ppos) | |
1da177e4 | 1117 | { |
a7113a96 | 1118 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1119 | struct tty_struct *tty = file_tty(file); |
1120 | struct tty_ldisc *ld; | |
1da177e4 | 1121 | ssize_t ret; |
37bdfb07 | 1122 | |
1da177e4 LT |
1123 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1124 | return -EIO; | |
f34d7a5b | 1125 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1126 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1127 | return -EIO; | |
f34d7a5b AC |
1128 | /* Short term debug to catch buggy drivers */ |
1129 | if (tty->ops->write_room == NULL) | |
1130 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1131 | tty->driver->name); | |
37bdfb07 | 1132 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1133 | if (!ld->ops->write) |
1da177e4 LT |
1134 | ret = -EIO; |
1135 | else | |
a352def2 | 1136 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1137 | tty_ldisc_deref(ld); |
1138 | return ret; | |
1139 | } | |
1140 | ||
37bdfb07 AC |
1141 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1142 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1143 | { |
1144 | struct file *p = NULL; | |
1145 | ||
1146 | spin_lock(&redirect_lock); | |
1147 | if (redirect) { | |
1148 | get_file(redirect); | |
1149 | p = redirect; | |
1150 | } | |
1151 | spin_unlock(&redirect_lock); | |
1152 | ||
1153 | if (p) { | |
1154 | ssize_t res; | |
1155 | res = vfs_write(p, buf, count, &p->f_pos); | |
1156 | fput(p); | |
1157 | return res; | |
1158 | } | |
1da177e4 LT |
1159 | return tty_write(file, buf, count, ppos); |
1160 | } | |
1161 | ||
1162 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1163 | ||
af9b897e AC |
1164 | /** |
1165 | * pty_line_name - generate name for a pty | |
1166 | * @driver: the tty driver in use | |
1167 | * @index: the minor number | |
1168 | * @p: output buffer of at least 6 bytes | |
1169 | * | |
1170 | * Generate a name from a driver reference and write it to the output | |
1171 | * buffer. | |
1172 | * | |
1173 | * Locking: None | |
1174 | */ | |
1175 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1176 | { |
1177 | int i = index + driver->name_base; | |
1178 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1179 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1180 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1181 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1182 | } |
1183 | ||
af9b897e | 1184 | /** |
8b0a88d5 | 1185 | * tty_line_name - generate name for a tty |
af9b897e AC |
1186 | * @driver: the tty driver in use |
1187 | * @index: the minor number | |
1188 | * @p: output buffer of at least 7 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 tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1196 | { |
1197 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1198 | } | |
1199 | ||
99f1fe18 AC |
1200 | /** |
1201 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1202 | * @driver: the driver for the tty | |
1203 | * @idx: the minor number | |
23499705 | 1204 | * |
99f1fe18 | 1205 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1206 | * |
99f1fe18 AC |
1207 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1208 | * be held until the 'fast-open' is also done. Will change once we | |
1209 | * have refcounting in the driver and per driver locking | |
23499705 | 1210 | */ |
a47d545f | 1211 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1212 | struct inode *inode, int idx) |
23499705 SB |
1213 | { |
1214 | struct tty_struct *tty; | |
1215 | ||
99f1fe18 | 1216 | if (driver->ops->lookup) |
15f1a633 | 1217 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1218 | |
8b0a88d5 | 1219 | tty = driver->ttys[idx]; |
23499705 SB |
1220 | return tty; |
1221 | } | |
1222 | ||
bf970ee4 AC |
1223 | /** |
1224 | * tty_init_termios - helper for termios setup | |
1225 | * @tty: the tty to set up | |
1226 | * | |
1227 | * Initialise the termios structures for this tty. Thus runs under | |
1228 | * the tty_mutex currently so we can be relaxed about ordering. | |
1229 | */ | |
1230 | ||
1231 | int tty_init_termios(struct tty_struct *tty) | |
1232 | { | |
fe6e29fd | 1233 | struct ktermios *tp; |
bf970ee4 AC |
1234 | int idx = tty->index; |
1235 | ||
1236 | tp = tty->driver->termios[idx]; | |
bf970ee4 | 1237 | if (tp == NULL) { |
fe6e29fd AC |
1238 | tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
1239 | if (tp == NULL) | |
bf970ee4 | 1240 | return -ENOMEM; |
bf970ee4 AC |
1241 | memcpy(tp, &tty->driver->init_termios, |
1242 | sizeof(struct ktermios)); | |
1243 | tty->driver->termios[idx] = tp; | |
bf970ee4 AC |
1244 | } |
1245 | tty->termios = tp; | |
fe6e29fd | 1246 | tty->termios_locked = tp + 1; |
bf970ee4 AC |
1247 | |
1248 | /* Compatibility until drivers always set this */ | |
1249 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1250 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1251 | return 0; | |
1252 | } | |
fe1ae7fd | 1253 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1254 | |
99f1fe18 | 1255 | /** |
8b0a88d5 AC |
1256 | * tty_driver_install_tty() - install a tty entry in the driver |
1257 | * @driver: the driver for the tty | |
1258 | * @tty: the tty | |
1259 | * | |
1260 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1261 | * will be set by the time this is called. This method is responsible |
1262 | * for ensuring any need additional structures are allocated and | |
1263 | * configured. | |
8b0a88d5 AC |
1264 | * |
1265 | * Locking: tty_mutex for now | |
1266 | */ | |
1267 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1268 | struct tty_struct *tty) | |
1269 | { | |
bf970ee4 | 1270 | int idx = tty->index; |
eeb89d91 | 1271 | int ret; |
bf970ee4 | 1272 | |
eeb89d91 | 1273 | if (driver->ops->install) { |
eeb89d91 | 1274 | ret = driver->ops->install(driver, tty); |
eeb89d91 AC |
1275 | return ret; |
1276 | } | |
bf970ee4 AC |
1277 | |
1278 | if (tty_init_termios(tty) == 0) { | |
1279 | tty_driver_kref_get(driver); | |
1280 | tty->count++; | |
1281 | driver->ttys[idx] = tty; | |
1282 | return 0; | |
1283 | } | |
1284 | return -ENOMEM; | |
8b0a88d5 AC |
1285 | } |
1286 | ||
1287 | /** | |
1288 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1289 | * @driver: the driver for the tty | |
1290 | * @idx: the minor number | |
1291 | * | |
1292 | * Remvoe a tty object from the driver tables. The tty->index field | |
1293 | * will be set by the time this is called. | |
1294 | * | |
1295 | * Locking: tty_mutex for now | |
1296 | */ | |
1297 | static void tty_driver_remove_tty(struct tty_driver *driver, | |
1298 | struct tty_struct *tty) | |
1299 | { | |
1300 | if (driver->ops->remove) | |
1301 | driver->ops->remove(driver, tty); | |
1302 | else | |
1303 | driver->ttys[tty->index] = NULL; | |
1304 | } | |
1305 | ||
1306 | /* | |
1307 | * tty_reopen() - fast re-open of an open tty | |
1308 | * @tty - the tty to open | |
23499705 | 1309 | * |
99f1fe18 | 1310 | * Return 0 on success, -errno on error. |
23499705 | 1311 | * |
99f1fe18 AC |
1312 | * Locking: tty_mutex must be held from the time the tty was found |
1313 | * till this open completes. | |
23499705 | 1314 | */ |
99f1fe18 | 1315 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1316 | { |
1317 | struct tty_driver *driver = tty->driver; | |
1318 | ||
e2efafbf | 1319 | if (test_bit(TTY_CLOSING, &tty->flags) || |
acfa747b | 1320 | test_bit(TTY_HUPPING, &tty->flags) || |
e2efafbf | 1321 | test_bit(TTY_LDISC_CHANGING, &tty->flags)) |
23499705 SB |
1322 | return -EIO; |
1323 | ||
1324 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1325 | driver->subtype == PTY_TYPE_MASTER) { | |
1326 | /* | |
1327 | * special case for PTY masters: only one open permitted, | |
1328 | * and the slave side open count is incremented as well. | |
1329 | */ | |
1330 | if (tty->count) | |
1331 | return -EIO; | |
1332 | ||
1333 | tty->link->count++; | |
1334 | } | |
1335 | tty->count++; | |
1336 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1337 | ||
1aa4bed8 | 1338 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1339 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1340 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1341 | |
1342 | return 0; | |
1343 | } | |
1344 | ||
af9b897e | 1345 | /** |
d81ed103 | 1346 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1347 | * @driver: tty driver we are opening a device on |
1348 | * @idx: device index | |
15582d36 AC |
1349 | * @ret_tty: returned tty structure |
1350 | * @first_ok: ok to open a new device (used by ptmx) | |
af9b897e AC |
1351 | * |
1352 | * Prepare a tty device. This may not be a "new" clean device but | |
1353 | * could also be an active device. The pty drivers require special | |
1354 | * handling because of this. | |
1355 | * | |
1356 | * Locking: | |
1357 | * The function is called under the tty_mutex, which | |
1358 | * protects us from the tty struct or driver itself going away. | |
1359 | * | |
1360 | * On exit the tty device has the line discipline attached and | |
1361 | * a reference count of 1. If a pair was created for pty/tty use | |
1362 | * and the other was a pty master then it too has a reference count of 1. | |
1363 | * | |
1da177e4 | 1364 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1365 | * failed open. The new code protects the open with a mutex, so it's |
1366 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1367 | * relaxed for the (most common) case of reopening a tty. |
1368 | */ | |
af9b897e | 1369 | |
73ec06fc AC |
1370 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, |
1371 | int first_ok) | |
1da177e4 | 1372 | { |
bf970ee4 | 1373 | struct tty_struct *tty; |
73ec06fc | 1374 | int retval; |
1da177e4 | 1375 | |
23499705 | 1376 | /* Check if pty master is being opened multiple times */ |
15582d36 | 1377 | if (driver->subtype == PTY_TYPE_MASTER && |
eeb89d91 | 1378 | (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { |
73ec06fc | 1379 | return ERR_PTR(-EIO); |
eeb89d91 | 1380 | } |
73ec06fc | 1381 | |
1da177e4 LT |
1382 | /* |
1383 | * First time open is complex, especially for PTY devices. | |
1384 | * This code guarantees that either everything succeeds and the | |
1385 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1386 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1387 | * and locked termios may be retained.) |
1388 | */ | |
1389 | ||
73ec06fc AC |
1390 | if (!try_module_get(driver->owner)) |
1391 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1392 | |
1da177e4 | 1393 | tty = alloc_tty_struct(); |
37bdfb07 | 1394 | if (!tty) |
1da177e4 | 1395 | goto fail_no_mem; |
bf970ee4 | 1396 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1397 | |
73ec06fc | 1398 | retval = tty_driver_install_tty(driver, tty); |
bf970ee4 AC |
1399 | if (retval < 0) { |
1400 | free_tty_struct(tty); | |
1401 | module_put(driver->owner); | |
1402 | return ERR_PTR(retval); | |
1403 | } | |
8b0a88d5 | 1404 | |
37bdfb07 | 1405 | /* |
1da177e4 | 1406 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1407 | * If we fail here just call release_tty to clean up. No need |
1408 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1409 | */ |
bf970ee4 | 1410 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 AC |
1411 | if (retval) |
1412 | goto release_mem_out; | |
73ec06fc | 1413 | return tty; |
1da177e4 | 1414 | |
1da177e4 LT |
1415 | fail_no_mem: |
1416 | module_put(driver->owner); | |
73ec06fc | 1417 | return ERR_PTR(-ENOMEM); |
1da177e4 | 1418 | |
d5698c28 | 1419 | /* call the tty release_tty routine to clean out this slot */ |
1da177e4 | 1420 | release_mem_out: |
4050914f | 1421 | if (printk_ratelimit()) |
d81ed103 | 1422 | printk(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1423 | "clearing slot %d\n", idx); |
d5698c28 | 1424 | release_tty(tty, idx); |
73ec06fc | 1425 | return ERR_PTR(retval); |
1da177e4 LT |
1426 | } |
1427 | ||
feebed65 AC |
1428 | void tty_free_termios(struct tty_struct *tty) |
1429 | { | |
1430 | struct ktermios *tp; | |
1431 | int idx = tty->index; | |
1432 | /* Kill this flag and push into drivers for locking etc */ | |
1433 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1434 | /* FIXME: Locking on ->termios array */ | |
1435 | tp = tty->termios; | |
1436 | tty->driver->termios[idx] = NULL; | |
1437 | kfree(tp); | |
feebed65 AC |
1438 | } |
1439 | } | |
1440 | EXPORT_SYMBOL(tty_free_termios); | |
1441 | ||
1442 | void tty_shutdown(struct tty_struct *tty) | |
1443 | { | |
8b0a88d5 | 1444 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1445 | tty_free_termios(tty); |
1446 | } | |
1447 | EXPORT_SYMBOL(tty_shutdown); | |
1448 | ||
af9b897e | 1449 | /** |
d5698c28 | 1450 | * release_one_tty - release tty structure memory |
9c9f4ded | 1451 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1452 | * |
1453 | * Releases memory associated with a tty structure, and clears out the | |
1454 | * driver table slots. This function is called when a device is no longer | |
1455 | * in use. It also gets called when setup of a device fails. | |
1456 | * | |
1457 | * Locking: | |
1458 | * tty_mutex - sometimes only | |
1459 | * takes the file list lock internally when working on the list | |
1460 | * of ttys that the driver keeps. | |
b50989dc AC |
1461 | * |
1462 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1463 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1464 | */ |
b50989dc | 1465 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1466 | { |
b50989dc AC |
1467 | struct tty_struct *tty = |
1468 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1469 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1470 | |
f278a2f7 DY |
1471 | if (tty->ops->cleanup) |
1472 | tty->ops->cleanup(tty); | |
1473 | ||
1da177e4 | 1474 | tty->magic = 0; |
7d7b93c1 | 1475 | tty_driver_kref_put(driver); |
6f967f78 | 1476 | module_put(driver->owner); |
d5698c28 | 1477 | |
ee2ffa0d | 1478 | spin_lock(&tty_files_lock); |
1da177e4 | 1479 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1480 | spin_unlock(&tty_files_lock); |
d5698c28 | 1481 | |
6da8d866 ON |
1482 | put_pid(tty->pgrp); |
1483 | put_pid(tty->session); | |
1da177e4 LT |
1484 | free_tty_struct(tty); |
1485 | } | |
1486 | ||
b50989dc AC |
1487 | static void queue_release_one_tty(struct kref *kref) |
1488 | { | |
1489 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 DY |
1490 | |
1491 | if (tty->ops->shutdown) | |
1492 | tty->ops->shutdown(tty); | |
1493 | else | |
1494 | tty_shutdown(tty); | |
1495 | ||
b50989dc AC |
1496 | /* The hangup queue is now free so we can reuse it rather than |
1497 | waste a chunk of memory for each port */ | |
1498 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1499 | schedule_work(&tty->hangup_work); | |
1500 | } | |
1501 | ||
9c9f4ded AC |
1502 | /** |
1503 | * tty_kref_put - release a tty kref | |
1504 | * @tty: tty device | |
1505 | * | |
1506 | * Release a reference to a tty device and if need be let the kref | |
1507 | * layer destruct the object for us | |
1508 | */ | |
1509 | ||
1510 | void tty_kref_put(struct tty_struct *tty) | |
1511 | { | |
1512 | if (tty) | |
b50989dc | 1513 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1514 | } |
1515 | EXPORT_SYMBOL(tty_kref_put); | |
1516 | ||
d5698c28 CH |
1517 | /** |
1518 | * release_tty - release tty structure memory | |
1519 | * | |
1520 | * Release both @tty and a possible linked partner (think pty pair), | |
1521 | * and decrement the refcount of the backing module. | |
1522 | * | |
1523 | * Locking: | |
1524 | * tty_mutex - sometimes only | |
1525 | * takes the file list lock internally when working on the list | |
1526 | * of ttys that the driver keeps. | |
1527 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1528 | * |
d5698c28 CH |
1529 | */ |
1530 | static void release_tty(struct tty_struct *tty, int idx) | |
1531 | { | |
9c9f4ded AC |
1532 | /* This should always be true but check for the moment */ |
1533 | WARN_ON(tty->index != idx); | |
1534 | ||
d5698c28 | 1535 | if (tty->link) |
9c9f4ded AC |
1536 | tty_kref_put(tty->link); |
1537 | tty_kref_put(tty); | |
d5698c28 CH |
1538 | } |
1539 | ||
eeb89d91 AC |
1540 | /** |
1541 | * tty_release - vfs callback for close | |
1542 | * @inode: inode of tty | |
1543 | * @filp: file pointer for handle to tty | |
1544 | * | |
1545 | * Called the last time each file handle is closed that references | |
1546 | * this tty. There may however be several such references. | |
1547 | * | |
1548 | * Locking: | |
1549 | * Takes bkl. See tty_release_dev | |
1550 | * | |
1da177e4 LT |
1551 | * Even releasing the tty structures is a tricky business.. We have |
1552 | * to be very careful that the structures are all released at the | |
1553 | * same time, as interrupts might otherwise get the wrong pointers. | |
1554 | * | |
1555 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1556 | * lead to double frees or releasing memory still in use. | |
1557 | */ | |
eeb89d91 AC |
1558 | |
1559 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1560 | { |
d996b62a NP |
1561 | struct tty_struct *tty = file_tty(filp); |
1562 | struct tty_struct *o_tty; | |
1da177e4 | 1563 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1564 | int devpts; |
1da177e4 LT |
1565 | int idx; |
1566 | char buf[64]; | |
37bdfb07 | 1567 | |
15f1a633 | 1568 | if (tty_paranoia_check(tty, inode, "tty_release_dev")) |
eeb89d91 | 1569 | return 0; |
1da177e4 | 1570 | |
ec79d605 | 1571 | tty_lock(); |
d81ed103 | 1572 | check_tty_count(tty, "tty_release_dev"); |
1da177e4 | 1573 | |
ec79d605 | 1574 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1575 | |
1576 | idx = tty->index; | |
1577 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1578 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1579 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1580 | o_tty = tty->link; |
1581 | ||
1582 | #ifdef TTY_PARANOIA_CHECK | |
1583 | if (idx < 0 || idx >= tty->driver->num) { | |
d81ed103 | 1584 | printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " |
1da177e4 | 1585 | "free (%s)\n", tty->name); |
ec79d605 | 1586 | tty_unlock(); |
eeb89d91 | 1587 | return 0; |
1da177e4 | 1588 | } |
8b0a88d5 | 1589 | if (!devpts) { |
1da177e4 | 1590 | if (tty != tty->driver->ttys[idx]) { |
ec79d605 | 1591 | tty_unlock(); |
d81ed103 | 1592 | printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " |
1da177e4 | 1593 | "for (%s)\n", idx, tty->name); |
eeb89d91 | 1594 | return 0; |
1da177e4 LT |
1595 | } |
1596 | if (tty->termios != tty->driver->termios[idx]) { | |
ec79d605 | 1597 | tty_unlock(); |
d81ed103 | 1598 | printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " |
1da177e4 LT |
1599 | "for (%s)\n", |
1600 | idx, tty->name); | |
eeb89d91 | 1601 | return 0; |
1da177e4 | 1602 | } |
1da177e4 LT |
1603 | } |
1604 | #endif | |
1605 | ||
1606 | #ifdef TTY_DEBUG_HANGUP | |
d81ed103 | 1607 | printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", |
1da177e4 LT |
1608 | tty_name(tty, buf), tty->count); |
1609 | #endif | |
1610 | ||
1611 | #ifdef TTY_PARANOIA_CHECK | |
1612 | if (tty->driver->other && | |
1613 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1614 | if (o_tty != tty->driver->other->ttys[idx]) { | |
ec79d605 | 1615 | tty_unlock(); |
d81ed103 | 1616 | printk(KERN_DEBUG "tty_release_dev: other->table[%d] " |
1da177e4 LT |
1617 | "not o_tty for (%s)\n", |
1618 | idx, tty->name); | |
eeb89d91 | 1619 | return 0 ; |
1da177e4 LT |
1620 | } |
1621 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
ec79d605 | 1622 | tty_unlock(); |
d81ed103 | 1623 | printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " |
1da177e4 LT |
1624 | "not o_termios for (%s)\n", |
1625 | idx, tty->name); | |
eeb89d91 | 1626 | return 0; |
1da177e4 | 1627 | } |
1da177e4 | 1628 | if (o_tty->link != tty) { |
ec79d605 | 1629 | tty_unlock(); |
d81ed103 | 1630 | printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); |
eeb89d91 | 1631 | return 0; |
1da177e4 LT |
1632 | } |
1633 | } | |
1634 | #endif | |
f34d7a5b AC |
1635 | if (tty->ops->close) |
1636 | tty->ops->close(tty, filp); | |
1da177e4 | 1637 | |
ec79d605 | 1638 | tty_unlock(); |
1da177e4 LT |
1639 | /* |
1640 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1641 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1642 | * wait queues and kick everyone out _before_ actually starting to | |
1643 | * close. This ensures that we won't block while releasing the tty | |
1644 | * structure. | |
1645 | * | |
1646 | * The test for the o_tty closing is necessary, since the master and | |
1647 | * slave sides may close in any order. If the slave side closes out | |
1648 | * first, its count will be one, since the master side holds an open. | |
1649 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1650 | * so we do it now. | |
1651 | * | |
1652 | * Note that it's possible for the tty to be opened again while we're | |
1653 | * flushing out waiters. By recalculating the closing flags before | |
1654 | * each iteration we avoid any problems. | |
1655 | */ | |
1656 | while (1) { | |
1657 | /* Guard against races with tty->count changes elsewhere and | |
1658 | opens on /dev/tty */ | |
37bdfb07 | 1659 | |
70522e12 | 1660 | mutex_lock(&tty_mutex); |
ec79d605 | 1661 | tty_lock(); |
1da177e4 LT |
1662 | tty_closing = tty->count <= 1; |
1663 | o_tty_closing = o_tty && | |
1664 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1665 | do_sleep = 0; |
1666 | ||
1667 | if (tty_closing) { | |
1668 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1669 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1670 | do_sleep++; |
1671 | } | |
1672 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1673 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1674 | do_sleep++; |
1675 | } | |
1676 | } | |
1677 | if (o_tty_closing) { | |
1678 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1679 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1680 | do_sleep++; |
1681 | } | |
1682 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1683 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1684 | do_sleep++; |
1685 | } | |
1686 | } | |
1687 | if (!do_sleep) | |
1688 | break; | |
1689 | ||
d81ed103 | 1690 | printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " |
1da177e4 | 1691 | "active!\n", tty_name(tty, buf)); |
ec79d605 | 1692 | tty_unlock(); |
70522e12 | 1693 | mutex_unlock(&tty_mutex); |
1da177e4 | 1694 | schedule(); |
37bdfb07 | 1695 | } |
1da177e4 LT |
1696 | |
1697 | /* | |
37bdfb07 AC |
1698 | * The closing flags are now consistent with the open counts on |
1699 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1700 | * block, so it's safe to proceed with closing. |
1701 | */ | |
1da177e4 LT |
1702 | if (pty_master) { |
1703 | if (--o_tty->count < 0) { | |
d81ed103 | 1704 | printk(KERN_WARNING "tty_release_dev: bad pty slave count " |
1da177e4 LT |
1705 | "(%d) for %s\n", |
1706 | o_tty->count, tty_name(o_tty, buf)); | |
1707 | o_tty->count = 0; | |
1708 | } | |
1709 | } | |
1710 | if (--tty->count < 0) { | |
d81ed103 | 1711 | printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", |
1da177e4 LT |
1712 | tty->count, tty_name(tty, buf)); |
1713 | tty->count = 0; | |
1714 | } | |
37bdfb07 | 1715 | |
1da177e4 LT |
1716 | /* |
1717 | * We've decremented tty->count, so we need to remove this file | |
1718 | * descriptor off the tty->tty_files list; this serves two | |
1719 | * purposes: | |
1720 | * - check_tty_count sees the correct number of file descriptors | |
1721 | * associated with this tty. | |
1722 | * - do_tty_hangup no longer sees this file descriptor as | |
1723 | * something that needs to be handled for hangups. | |
1724 | */ | |
d996b62a | 1725 | tty_del_file(filp); |
1da177e4 LT |
1726 | |
1727 | /* | |
1728 | * Perform some housekeeping before deciding whether to return. | |
1729 | * | |
1730 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1731 | * case of a pty we may have to wait around for the other side | |
1732 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1733 | */ | |
37bdfb07 | 1734 | if (tty_closing) |
1da177e4 | 1735 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1736 | if (o_tty_closing) |
1da177e4 LT |
1737 | set_bit(TTY_CLOSING, &o_tty->flags); |
1738 | ||
1739 | /* | |
1740 | * If _either_ side is closing, make sure there aren't any | |
1741 | * processes that still think tty or o_tty is their controlling | |
1742 | * tty. | |
1743 | */ | |
1744 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1745 | read_lock(&tasklist_lock); |
24ec839c | 1746 | session_clear_tty(tty->session); |
1da177e4 | 1747 | if (o_tty) |
24ec839c | 1748 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1749 | read_unlock(&tasklist_lock); |
1750 | } | |
1751 | ||
70522e12 | 1752 | mutex_unlock(&tty_mutex); |
da965822 | 1753 | |
1da177e4 | 1754 | /* check whether both sides are closing ... */ |
eeb89d91 | 1755 | if (!tty_closing || (o_tty && !o_tty_closing)) { |
ec79d605 | 1756 | tty_unlock(); |
eeb89d91 AC |
1757 | return 0; |
1758 | } | |
37bdfb07 | 1759 | |
1da177e4 LT |
1760 | #ifdef TTY_DEBUG_HANGUP |
1761 | printk(KERN_DEBUG "freeing tty structure..."); | |
1762 | #endif | |
1763 | /* | |
01e1abb2 | 1764 | * Ask the line discipline code to release its structures |
1da177e4 | 1765 | */ |
01e1abb2 | 1766 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1767 | /* |
d5698c28 | 1768 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1769 | * the slots and preserving the termios structure. |
1770 | */ | |
d5698c28 | 1771 | release_tty(tty, idx); |
1da177e4 | 1772 | |
1da177e4 | 1773 | /* Make this pty number available for reallocation */ |
718a9163 | 1774 | if (devpts) |
15f1a633 | 1775 | devpts_kill_index(inode, idx); |
ec79d605 | 1776 | tty_unlock(); |
eeb89d91 | 1777 | return 0; |
1da177e4 LT |
1778 | } |
1779 | ||
af9b897e | 1780 | /** |
eeb89d91 | 1781 | * tty_open - open a tty device |
af9b897e AC |
1782 | * @inode: inode of device file |
1783 | * @filp: file pointer to tty | |
1da177e4 | 1784 | * |
af9b897e AC |
1785 | * tty_open and tty_release keep up the tty count that contains the |
1786 | * number of opens done on a tty. We cannot use the inode-count, as | |
1787 | * different inodes might point to the same tty. | |
1da177e4 | 1788 | * |
af9b897e AC |
1789 | * Open-counting is needed for pty masters, as well as for keeping |
1790 | * track of serial lines: DTR is dropped when the last close happens. | |
1791 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1792 | * | |
1793 | * The termios state of a pty is reset on first open so that | |
1794 | * settings don't persist across reuse. | |
1795 | * | |
d81ed103 | 1796 | * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. |
24ec839c PZ |
1797 | * tty->count should protect the rest. |
1798 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1799 | */ |
af9b897e | 1800 | |
eeb89d91 | 1801 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1802 | { |
4a2b5fdd | 1803 | struct tty_struct *tty = NULL; |
1da177e4 LT |
1804 | int noctty, retval; |
1805 | struct tty_driver *driver; | |
1806 | int index; | |
1807 | dev_t device = inode->i_rdev; | |
846c151a | 1808 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1809 | |
1810 | nonseekable_open(inode, filp); | |
37bdfb07 | 1811 | |
1da177e4 LT |
1812 | retry_open: |
1813 | noctty = filp->f_flags & O_NOCTTY; | |
1814 | index = -1; | |
1815 | retval = 0; | |
37bdfb07 | 1816 | |
70522e12 | 1817 | mutex_lock(&tty_mutex); |
ec79d605 | 1818 | tty_lock(); |
1da177e4 | 1819 | |
37bdfb07 | 1820 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1821 | tty = get_current_tty(); |
1822 | if (!tty) { | |
ec79d605 | 1823 | tty_unlock(); |
70522e12 | 1824 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1825 | return -ENXIO; |
1826 | } | |
7d7b93c1 | 1827 | driver = tty_driver_kref_get(tty->driver); |
24ec839c | 1828 | index = tty->index; |
1da177e4 LT |
1829 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1830 | /* noctty = 1; */ | |
452a00d2 AC |
1831 | /* FIXME: Should we take a driver reference ? */ |
1832 | tty_kref_put(tty); | |
1da177e4 LT |
1833 | goto got_driver; |
1834 | } | |
1835 | #ifdef CONFIG_VT | |
37bdfb07 | 1836 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 | 1837 | extern struct tty_driver *console_driver; |
7d7b93c1 | 1838 | driver = tty_driver_kref_get(console_driver); |
1da177e4 LT |
1839 | index = fg_console; |
1840 | noctty = 1; | |
1841 | goto got_driver; | |
1842 | } | |
1843 | #endif | |
37bdfb07 | 1844 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
296fa7f6 WN |
1845 | struct tty_driver *console_driver = console_device(&index); |
1846 | if (console_driver) { | |
1847 | driver = tty_driver_kref_get(console_driver); | |
1848 | if (driver) { | |
1849 | /* Don't let /dev/console block */ | |
1850 | filp->f_flags |= O_NONBLOCK; | |
1851 | noctty = 1; | |
1852 | goto got_driver; | |
1853 | } | |
1da177e4 | 1854 | } |
ec79d605 | 1855 | tty_unlock(); |
70522e12 | 1856 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1857 | return -ENODEV; |
1858 | } | |
1859 | ||
1860 | driver = get_tty_driver(device, &index); | |
1861 | if (!driver) { | |
ec79d605 | 1862 | tty_unlock(); |
70522e12 | 1863 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1864 | return -ENODEV; |
1865 | } | |
1866 | got_driver: | |
4a2b5fdd SB |
1867 | if (!tty) { |
1868 | /* check whether we're reopening an existing tty */ | |
15f1a633 | 1869 | tty = tty_driver_lookup_tty(driver, inode, index); |
4a2b5fdd | 1870 | |
808ffa3d | 1871 | if (IS_ERR(tty)) { |
ec79d605 | 1872 | tty_unlock(); |
808ffa3d | 1873 | mutex_unlock(&tty_mutex); |
4a2b5fdd | 1874 | return PTR_ERR(tty); |
808ffa3d | 1875 | } |
4a2b5fdd SB |
1876 | } |
1877 | ||
1878 | if (tty) { | |
1879 | retval = tty_reopen(tty); | |
1880 | if (retval) | |
1881 | tty = ERR_PTR(retval); | |
1882 | } else | |
1883 | tty = tty_init_dev(driver, index, 0); | |
1884 | ||
70522e12 | 1885 | mutex_unlock(&tty_mutex); |
7d7b93c1 | 1886 | tty_driver_kref_put(driver); |
eeb89d91 | 1887 | if (IS_ERR(tty)) { |
ec79d605 | 1888 | tty_unlock(); |
73ec06fc | 1889 | return PTR_ERR(tty); |
eeb89d91 | 1890 | } |
1da177e4 | 1891 | |
f573bd17 PE |
1892 | retval = tty_add_file(tty, filp); |
1893 | if (retval) { | |
1894 | tty_unlock(); | |
1895 | return retval; | |
1896 | } | |
d996b62a | 1897 | |
1da177e4 LT |
1898 | check_tty_count(tty, "tty_open"); |
1899 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1900 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1901 | noctty = 1; | |
1902 | #ifdef TTY_DEBUG_HANGUP | |
1903 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1904 | #endif | |
1905 | if (!retval) { | |
f34d7a5b AC |
1906 | if (tty->ops->open) |
1907 | retval = tty->ops->open(tty, filp); | |
1da177e4 LT |
1908 | else |
1909 | retval = -ENODEV; | |
1910 | } | |
1911 | filp->f_flags = saved_flags; | |
1912 | ||
37bdfb07 AC |
1913 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1914 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1915 | retval = -EBUSY; |
1916 | ||
1917 | if (retval) { | |
1918 | #ifdef TTY_DEBUG_HANGUP | |
1919 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1920 | tty->name); | |
1921 | #endif | |
64ba3dc3 | 1922 | tty_unlock(); /* need to call tty_release without BTM */ |
eeb89d91 | 1923 | tty_release(inode, filp); |
64ba3dc3 | 1924 | if (retval != -ERESTARTSYS) |
1da177e4 | 1925 | return retval; |
64ba3dc3 AB |
1926 | |
1927 | if (signal_pending(current)) | |
1da177e4 | 1928 | return retval; |
64ba3dc3 | 1929 | |
1da177e4 LT |
1930 | schedule(); |
1931 | /* | |
1932 | * Need to reset f_op in case a hangup happened. | |
1933 | */ | |
64ba3dc3 | 1934 | tty_lock(); |
1da177e4 LT |
1935 | if (filp->f_op == &hung_up_tty_fops) |
1936 | filp->f_op = &tty_fops; | |
ec79d605 | 1937 | tty_unlock(); |
1da177e4 LT |
1938 | goto retry_open; |
1939 | } | |
ec79d605 | 1940 | tty_unlock(); |
eeb89d91 | 1941 | |
24ec839c PZ |
1942 | |
1943 | mutex_lock(&tty_mutex); | |
ec79d605 | 1944 | tty_lock(); |
24ec839c | 1945 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
1946 | if (!noctty && |
1947 | current->signal->leader && | |
1948 | !current->signal->tty && | |
ab521dc0 | 1949 | tty->session == NULL) |
2a65f1d9 | 1950 | __proc_set_tty(current, tty); |
24ec839c | 1951 | spin_unlock_irq(¤t->sighand->siglock); |
ec79d605 | 1952 | tty_unlock(); |
24ec839c | 1953 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1954 | return 0; |
1955 | } | |
1956 | ||
39d95b9d JC |
1957 | |
1958 | ||
af9b897e AC |
1959 | /** |
1960 | * tty_poll - check tty status | |
1961 | * @filp: file being polled | |
1962 | * @wait: poll wait structures to update | |
1963 | * | |
1964 | * Call the line discipline polling method to obtain the poll | |
1965 | * status of the device. | |
1966 | * | |
1967 | * Locking: locks called line discipline but ldisc poll method | |
1968 | * may be re-entered freely by other callers. | |
1969 | */ | |
1970 | ||
37bdfb07 | 1971 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 1972 | { |
d996b62a | 1973 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
1974 | struct tty_ldisc *ld; |
1975 | int ret = 0; | |
1976 | ||
a7113a96 | 1977 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 1978 | return 0; |
37bdfb07 | 1979 | |
1da177e4 | 1980 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
1981 | if (ld->ops->poll) |
1982 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
1983 | tty_ldisc_deref(ld); |
1984 | return ret; | |
1985 | } | |
1986 | ||
ec79d605 | 1987 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 1988 | { |
d996b62a | 1989 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 1990 | unsigned long flags; |
5d1e3230 | 1991 | int retval = 0; |
1da177e4 | 1992 | |
a7113a96 | 1993 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 1994 | goto out; |
37bdfb07 | 1995 | |
1da177e4 LT |
1996 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
1997 | if (retval <= 0) | |
5d1e3230 | 1998 | goto out; |
1da177e4 LT |
1999 | |
2000 | if (on) { | |
ab521dc0 EB |
2001 | enum pid_type type; |
2002 | struct pid *pid; | |
1da177e4 LT |
2003 | if (!waitqueue_active(&tty->read_wait)) |
2004 | tty->minimum_to_wake = 1; | |
47f86834 | 2005 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2006 | if (tty->pgrp) { |
2007 | pid = tty->pgrp; | |
2008 | type = PIDTYPE_PGID; | |
2009 | } else { | |
2010 | pid = task_pid(current); | |
2011 | type = PIDTYPE_PID; | |
2012 | } | |
80e1e823 | 2013 | get_pid(pid); |
70362511 | 2014 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2015 | retval = __f_setown(filp, pid, type, 0); |
2016 | put_pid(pid); | |
1da177e4 | 2017 | if (retval) |
5d1e3230 | 2018 | goto out; |
1da177e4 LT |
2019 | } else { |
2020 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2021 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2022 | } | |
5d1e3230 JC |
2023 | retval = 0; |
2024 | out: | |
ec79d605 AB |
2025 | return retval; |
2026 | } | |
2027 | ||
2028 | static int tty_fasync(int fd, struct file *filp, int on) | |
2029 | { | |
2030 | int retval; | |
2031 | tty_lock(); | |
2032 | retval = __tty_fasync(fd, filp, on); | |
2033 | tty_unlock(); | |
5d1e3230 | 2034 | return retval; |
1da177e4 LT |
2035 | } |
2036 | ||
af9b897e AC |
2037 | /** |
2038 | * tiocsti - fake input character | |
2039 | * @tty: tty to fake input into | |
2040 | * @p: pointer to character | |
2041 | * | |
3a4fa0a2 | 2042 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2043 | * input management. |
2044 | * | |
2045 | * FIXME: does not honour flow control ?? | |
2046 | * | |
2047 | * Locking: | |
2048 | * Called functions take tty_ldisc_lock | |
2049 | * current->signal->tty check is safe without locks | |
28298232 AC |
2050 | * |
2051 | * FIXME: may race normal receive processing | |
af9b897e AC |
2052 | */ |
2053 | ||
1da177e4 LT |
2054 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2055 | { | |
2056 | char ch, mbz = 0; | |
2057 | struct tty_ldisc *ld; | |
37bdfb07 | 2058 | |
1da177e4 LT |
2059 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2060 | return -EPERM; | |
2061 | if (get_user(ch, p)) | |
2062 | return -EFAULT; | |
1e641743 | 2063 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2064 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2065 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2066 | tty_ldisc_deref(ld); |
2067 | return 0; | |
2068 | } | |
2069 | ||
af9b897e AC |
2070 | /** |
2071 | * tiocgwinsz - implement window query ioctl | |
2072 | * @tty; tty | |
2073 | * @arg: user buffer for result | |
2074 | * | |
808a0d38 | 2075 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2076 | * |
24ec839c | 2077 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2078 | * is consistent. |
af9b897e AC |
2079 | */ |
2080 | ||
37bdfb07 | 2081 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2082 | { |
808a0d38 AC |
2083 | int err; |
2084 | ||
5785c95b | 2085 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2086 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2087 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2088 | |
2089 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2090 | } |
2091 | ||
af9b897e | 2092 | /** |
8c9a9dd0 AC |
2093 | * tty_do_resize - resize event |
2094 | * @tty: tty being resized | |
8c9a9dd0 AC |
2095 | * @rows: rows (character) |
2096 | * @cols: cols (character) | |
2097 | * | |
3ad2f3fb | 2098 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2099 | * peform a terminal resize correctly |
af9b897e AC |
2100 | */ |
2101 | ||
fc6f6238 | 2102 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2103 | { |
fc6f6238 | 2104 | struct pid *pgrp; |
47f86834 | 2105 | unsigned long flags; |
1da177e4 | 2106 | |
fc6f6238 AC |
2107 | /* Lock the tty */ |
2108 | mutex_lock(&tty->termios_mutex); | |
2109 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2110 | goto done; |
47f86834 AC |
2111 | /* Get the PID values and reference them so we can |
2112 | avoid holding the tty ctrl lock while sending signals */ | |
2113 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2114 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2115 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2116 | ||
2117 | if (pgrp) | |
2118 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2119 | put_pid(pgrp); |
47f86834 | 2120 | |
8c9a9dd0 | 2121 | tty->winsize = *ws; |
ca9bda00 | 2122 | done: |
fc6f6238 | 2123 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2124 | return 0; |
2125 | } | |
2126 | ||
8c9a9dd0 AC |
2127 | /** |
2128 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2129 | * @tty; tty side of tty |
8c9a9dd0 AC |
2130 | * @arg: user buffer for result |
2131 | * | |
2132 | * Copies the user idea of the window size to the kernel. Traditionally | |
2133 | * this is just advisory information but for the Linux console it | |
2134 | * actually has driver level meaning and triggers a VC resize. | |
2135 | * | |
2136 | * Locking: | |
2137 | * Driver dependant. The default do_resize method takes the | |
2138 | * tty termios mutex and ctrl_lock. The console takes its own lock | |
2139 | * then calls into the default method. | |
2140 | */ | |
2141 | ||
fc6f6238 | 2142 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2143 | { |
2144 | struct winsize tmp_ws; | |
2145 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2146 | return -EFAULT; | |
2147 | ||
2148 | if (tty->ops->resize) | |
fc6f6238 | 2149 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2150 | else |
fc6f6238 | 2151 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2152 | } |
2153 | ||
af9b897e AC |
2154 | /** |
2155 | * tioccons - allow admin to move logical console | |
2156 | * @file: the file to become console | |
2157 | * | |
2158 | * Allow the adminstrator to move the redirected console device | |
2159 | * | |
2160 | * Locking: uses redirect_lock to guard the redirect information | |
2161 | */ | |
2162 | ||
1da177e4 LT |
2163 | static int tioccons(struct file *file) |
2164 | { | |
2165 | if (!capable(CAP_SYS_ADMIN)) | |
2166 | return -EPERM; | |
2167 | if (file->f_op->write == redirected_tty_write) { | |
2168 | struct file *f; | |
2169 | spin_lock(&redirect_lock); | |
2170 | f = redirect; | |
2171 | redirect = NULL; | |
2172 | spin_unlock(&redirect_lock); | |
2173 | if (f) | |
2174 | fput(f); | |
2175 | return 0; | |
2176 | } | |
2177 | spin_lock(&redirect_lock); | |
2178 | if (redirect) { | |
2179 | spin_unlock(&redirect_lock); | |
2180 | return -EBUSY; | |
2181 | } | |
2182 | get_file(file); | |
2183 | redirect = file; | |
2184 | spin_unlock(&redirect_lock); | |
2185 | return 0; | |
2186 | } | |
2187 | ||
af9b897e AC |
2188 | /** |
2189 | * fionbio - non blocking ioctl | |
2190 | * @file: file to set blocking value | |
2191 | * @p: user parameter | |
2192 | * | |
2193 | * Historical tty interfaces had a blocking control ioctl before | |
2194 | * the generic functionality existed. This piece of history is preserved | |
2195 | * in the expected tty API of posix OS's. | |
2196 | * | |
6146b9af | 2197 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2198 | */ |
1da177e4 LT |
2199 | |
2200 | static int fionbio(struct file *file, int __user *p) | |
2201 | { | |
2202 | int nonblock; | |
2203 | ||
2204 | if (get_user(nonblock, p)) | |
2205 | return -EFAULT; | |
2206 | ||
db1dd4d3 | 2207 | spin_lock(&file->f_lock); |
1da177e4 LT |
2208 | if (nonblock) |
2209 | file->f_flags |= O_NONBLOCK; | |
2210 | else | |
2211 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2212 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2213 | return 0; |
2214 | } | |
2215 | ||
af9b897e AC |
2216 | /** |
2217 | * tiocsctty - set controlling tty | |
2218 | * @tty: tty structure | |
2219 | * @arg: user argument | |
2220 | * | |
2221 | * This ioctl is used to manage job control. It permits a session | |
2222 | * leader to set this tty as the controlling tty for the session. | |
2223 | * | |
2224 | * Locking: | |
28298232 | 2225 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2226 | * Takes tasklist_lock internally to walk sessions |
2227 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2228 | */ |
2229 | ||
1da177e4 LT |
2230 | static int tiocsctty(struct tty_struct *tty, int arg) |
2231 | { | |
24ec839c | 2232 | int ret = 0; |
ab521dc0 | 2233 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2234 | return ret; |
2235 | ||
2236 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2237 | /* |
2238 | * The process must be a session leader and | |
2239 | * not have a controlling tty already. | |
2240 | */ | |
24ec839c PZ |
2241 | if (!current->signal->leader || current->signal->tty) { |
2242 | ret = -EPERM; | |
2243 | goto unlock; | |
2244 | } | |
2245 | ||
ab521dc0 | 2246 | if (tty->session) { |
1da177e4 LT |
2247 | /* |
2248 | * This tty is already the controlling | |
2249 | * tty for another session group! | |
2250 | */ | |
37bdfb07 | 2251 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2252 | /* |
2253 | * Steal it away | |
2254 | */ | |
1da177e4 | 2255 | read_lock(&tasklist_lock); |
24ec839c | 2256 | session_clear_tty(tty->session); |
1da177e4 | 2257 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2258 | } else { |
2259 | ret = -EPERM; | |
2260 | goto unlock; | |
2261 | } | |
1da177e4 | 2262 | } |
24ec839c PZ |
2263 | proc_set_tty(current, tty); |
2264 | unlock: | |
28298232 | 2265 | mutex_unlock(&tty_mutex); |
24ec839c | 2266 | return ret; |
1da177e4 LT |
2267 | } |
2268 | ||
5d0fdf1e AC |
2269 | /** |
2270 | * tty_get_pgrp - return a ref counted pgrp pid | |
2271 | * @tty: tty to read | |
2272 | * | |
2273 | * Returns a refcounted instance of the pid struct for the process | |
2274 | * group controlling the tty. | |
2275 | */ | |
2276 | ||
2277 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2278 | { | |
2279 | unsigned long flags; | |
2280 | struct pid *pgrp; | |
2281 | ||
2282 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2283 | pgrp = get_pid(tty->pgrp); | |
2284 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2285 | ||
2286 | return pgrp; | |
2287 | } | |
2288 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2289 | ||
af9b897e AC |
2290 | /** |
2291 | * tiocgpgrp - get process group | |
2292 | * @tty: tty passed by user | |
2293 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2294 | * @p: returned pid | |
2295 | * | |
2296 | * Obtain the process group of the tty. If there is no process group | |
2297 | * return an error. | |
2298 | * | |
24ec839c | 2299 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2300 | */ |
2301 | ||
1da177e4 LT |
2302 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2303 | { | |
5d0fdf1e AC |
2304 | struct pid *pid; |
2305 | int ret; | |
1da177e4 LT |
2306 | /* |
2307 | * (tty == real_tty) is a cheap way of | |
2308 | * testing if the tty is NOT a master pty. | |
2309 | */ | |
2310 | if (tty == real_tty && current->signal->tty != real_tty) | |
2311 | return -ENOTTY; | |
5d0fdf1e AC |
2312 | pid = tty_get_pgrp(real_tty); |
2313 | ret = put_user(pid_vnr(pid), p); | |
2314 | put_pid(pid); | |
2315 | return ret; | |
1da177e4 LT |
2316 | } |
2317 | ||
af9b897e AC |
2318 | /** |
2319 | * tiocspgrp - attempt to set process group | |
2320 | * @tty: tty passed by user | |
2321 | * @real_tty: tty side device matching tty passed by user | |
2322 | * @p: pid pointer | |
2323 | * | |
2324 | * Set the process group of the tty to the session passed. Only | |
2325 | * permitted where the tty session is our session. | |
2326 | * | |
47f86834 | 2327 | * Locking: RCU, ctrl lock |
af9b897e AC |
2328 | */ |
2329 | ||
1da177e4 LT |
2330 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2331 | { | |
04a2e6a5 EB |
2332 | struct pid *pgrp; |
2333 | pid_t pgrp_nr; | |
1da177e4 | 2334 | int retval = tty_check_change(real_tty); |
47f86834 | 2335 | unsigned long flags; |
1da177e4 LT |
2336 | |
2337 | if (retval == -EIO) | |
2338 | return -ENOTTY; | |
2339 | if (retval) | |
2340 | return retval; | |
2341 | if (!current->signal->tty || | |
2342 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2343 | (real_tty->session != task_session(current))) |
1da177e4 | 2344 | return -ENOTTY; |
04a2e6a5 | 2345 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2346 | return -EFAULT; |
04a2e6a5 | 2347 | if (pgrp_nr < 0) |
1da177e4 | 2348 | return -EINVAL; |
04a2e6a5 | 2349 | rcu_read_lock(); |
b488893a | 2350 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2351 | retval = -ESRCH; |
2352 | if (!pgrp) | |
2353 | goto out_unlock; | |
2354 | retval = -EPERM; | |
2355 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2356 | goto out_unlock; | |
2357 | retval = 0; | |
47f86834 | 2358 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2359 | put_pid(real_tty->pgrp); |
2360 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2361 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2362 | out_unlock: |
2363 | rcu_read_unlock(); | |
2364 | return retval; | |
1da177e4 LT |
2365 | } |
2366 | ||
af9b897e AC |
2367 | /** |
2368 | * tiocgsid - get session id | |
2369 | * @tty: tty passed by user | |
2370 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2371 | * @p: pointer to returned session id | |
2372 | * | |
2373 | * Obtain the session id of the tty. If there is no session | |
2374 | * return an error. | |
2375 | * | |
24ec839c | 2376 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2377 | */ |
2378 | ||
1da177e4 LT |
2379 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2380 | { | |
2381 | /* | |
2382 | * (tty == real_tty) is a cheap way of | |
2383 | * testing if the tty is NOT a master pty. | |
2384 | */ | |
2385 | if (tty == real_tty && current->signal->tty != real_tty) | |
2386 | return -ENOTTY; | |
ab521dc0 | 2387 | if (!real_tty->session) |
1da177e4 | 2388 | return -ENOTTY; |
b488893a | 2389 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2390 | } |
2391 | ||
af9b897e AC |
2392 | /** |
2393 | * tiocsetd - set line discipline | |
2394 | * @tty: tty device | |
2395 | * @p: pointer to user data | |
2396 | * | |
2397 | * Set the line discipline according to user request. | |
2398 | * | |
2399 | * Locking: see tty_set_ldisc, this function is just a helper | |
2400 | */ | |
2401 | ||
1da177e4 LT |
2402 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2403 | { | |
2404 | int ldisc; | |
04f378b1 | 2405 | int ret; |
1da177e4 LT |
2406 | |
2407 | if (get_user(ldisc, p)) | |
2408 | return -EFAULT; | |
04f378b1 | 2409 | |
04f378b1 | 2410 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2411 | |
2412 | return ret; | |
1da177e4 LT |
2413 | } |
2414 | ||
af9b897e AC |
2415 | /** |
2416 | * send_break - performed time break | |
2417 | * @tty: device to break on | |
2418 | * @duration: timeout in mS | |
2419 | * | |
2420 | * Perform a timed break on hardware that lacks its own driver level | |
2421 | * timed break functionality. | |
2422 | * | |
2423 | * Locking: | |
28298232 | 2424 | * atomic_write_lock serializes |
af9b897e | 2425 | * |
af9b897e AC |
2426 | */ |
2427 | ||
b20f3ae5 | 2428 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2429 | { |
9e98966c AC |
2430 | int retval; |
2431 | ||
2432 | if (tty->ops->break_ctl == NULL) | |
2433 | return 0; | |
2434 | ||
2435 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2436 | retval = tty->ops->break_ctl(tty, duration); | |
2437 | else { | |
2438 | /* Do the work ourselves */ | |
2439 | if (tty_write_lock(tty, 0) < 0) | |
2440 | return -EINTR; | |
2441 | retval = tty->ops->break_ctl(tty, -1); | |
2442 | if (retval) | |
2443 | goto out; | |
2444 | if (!signal_pending(current)) | |
2445 | msleep_interruptible(duration); | |
2446 | retval = tty->ops->break_ctl(tty, 0); | |
2447 | out: | |
2448 | tty_write_unlock(tty); | |
2449 | if (signal_pending(current)) | |
2450 | retval = -EINTR; | |
2451 | } | |
2452 | return retval; | |
1da177e4 LT |
2453 | } |
2454 | ||
af9b897e | 2455 | /** |
f34d7a5b | 2456 | * tty_tiocmget - get modem status |
af9b897e AC |
2457 | * @tty: tty device |
2458 | * @file: user file pointer | |
2459 | * @p: pointer to result | |
2460 | * | |
2461 | * Obtain the modem status bits from the tty driver if the feature | |
2462 | * is supported. Return -EINVAL if it is not available. | |
2463 | * | |
2464 | * Locking: none (up to the driver) | |
2465 | */ | |
2466 | ||
60b33c13 | 2467 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2468 | { |
2469 | int retval = -EINVAL; | |
2470 | ||
f34d7a5b | 2471 | if (tty->ops->tiocmget) { |
60b33c13 | 2472 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2473 | |
2474 | if (retval >= 0) | |
2475 | retval = put_user(retval, p); | |
2476 | } | |
2477 | return retval; | |
2478 | } | |
2479 | ||
af9b897e | 2480 | /** |
f34d7a5b | 2481 | * tty_tiocmset - set modem status |
af9b897e | 2482 | * @tty: tty device |
af9b897e AC |
2483 | * @cmd: command - clear bits, set bits or set all |
2484 | * @p: pointer to desired bits | |
2485 | * | |
2486 | * Set the modem status bits from the tty driver if the feature | |
2487 | * is supported. Return -EINVAL if it is not available. | |
2488 | * | |
2489 | * Locking: none (up to the driver) | |
2490 | */ | |
2491 | ||
20b9d177 | 2492 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2493 | unsigned __user *p) |
2494 | { | |
ae677517 AC |
2495 | int retval; |
2496 | unsigned int set, clear, val; | |
1da177e4 | 2497 | |
ae677517 AC |
2498 | if (tty->ops->tiocmset == NULL) |
2499 | return -EINVAL; | |
1da177e4 | 2500 | |
ae677517 AC |
2501 | retval = get_user(val, p); |
2502 | if (retval) | |
2503 | return retval; | |
2504 | set = clear = 0; | |
2505 | switch (cmd) { | |
2506 | case TIOCMBIS: | |
2507 | set = val; | |
2508 | break; | |
2509 | case TIOCMBIC: | |
2510 | clear = val; | |
2511 | break; | |
2512 | case TIOCMSET: | |
2513 | set = val; | |
2514 | clear = ~val; | |
2515 | break; | |
2516 | } | |
2517 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2518 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2519 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2520 | } |
2521 | ||
d281da7f AC |
2522 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2523 | { | |
2524 | int retval = -EINVAL; | |
2525 | struct serial_icounter_struct icount; | |
2526 | memset(&icount, 0, sizeof(icount)); | |
2527 | if (tty->ops->get_icount) | |
2528 | retval = tty->ops->get_icount(tty, &icount); | |
2529 | if (retval != 0) | |
2530 | return retval; | |
2531 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2532 | return -EFAULT; | |
2533 | return 0; | |
2534 | } | |
2535 | ||
e8b70e7d AC |
2536 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2537 | { | |
2538 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2539 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2540 | tty = tty->link; | |
2541 | return tty; | |
2542 | } | |
2543 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2544 | ||
2545 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2546 | { | |
2547 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2548 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2549 | return tty; | |
2550 | return tty->link; | |
2551 | } | |
2552 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2553 | ||
1da177e4 LT |
2554 | /* |
2555 | * Split this up, as gcc can choke on it otherwise.. | |
2556 | */ | |
04f378b1 | 2557 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2558 | { |
d996b62a NP |
2559 | struct tty_struct *tty = file_tty(file); |
2560 | struct tty_struct *real_tty; | |
1da177e4 LT |
2561 | void __user *p = (void __user *)arg; |
2562 | int retval; | |
2563 | struct tty_ldisc *ld; | |
04f378b1 | 2564 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2565 | |
1da177e4 LT |
2566 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2567 | return -EINVAL; | |
2568 | ||
e8b70e7d | 2569 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2570 | |
2571 | /* | |
2572 | * Factor out some common prep work | |
2573 | */ | |
2574 | switch (cmd) { | |
2575 | case TIOCSETD: | |
2576 | case TIOCSBRK: | |
2577 | case TIOCCBRK: | |
2578 | case TCSBRK: | |
37bdfb07 | 2579 | case TCSBRKP: |
1da177e4 LT |
2580 | retval = tty_check_change(tty); |
2581 | if (retval) | |
2582 | return retval; | |
2583 | if (cmd != TIOCCBRK) { | |
2584 | tty_wait_until_sent(tty, 0); | |
2585 | if (signal_pending(current)) | |
2586 | return -EINTR; | |
2587 | } | |
2588 | break; | |
2589 | } | |
2590 | ||
9e98966c AC |
2591 | /* |
2592 | * Now do the stuff. | |
2593 | */ | |
1da177e4 | 2594 | switch (cmd) { |
37bdfb07 AC |
2595 | case TIOCSTI: |
2596 | return tiocsti(tty, p); | |
2597 | case TIOCGWINSZ: | |
8f520021 | 2598 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2599 | case TIOCSWINSZ: |
fc6f6238 | 2600 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2601 | case TIOCCONS: |
2602 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2603 | case FIONBIO: | |
2604 | return fionbio(file, p); | |
2605 | case TIOCEXCL: | |
2606 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2607 | return 0; | |
2608 | case TIOCNXCL: | |
2609 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2610 | return 0; | |
2611 | case TIOCNOTTY: | |
2612 | if (current->signal->tty != tty) | |
2613 | return -ENOTTY; | |
2614 | no_tty(); | |
2615 | return 0; | |
2616 | case TIOCSCTTY: | |
2617 | return tiocsctty(tty, arg); | |
2618 | case TIOCGPGRP: | |
2619 | return tiocgpgrp(tty, real_tty, p); | |
2620 | case TIOCSPGRP: | |
2621 | return tiocspgrp(tty, real_tty, p); | |
2622 | case TIOCGSID: | |
2623 | return tiocgsid(tty, real_tty, p); | |
2624 | case TIOCGETD: | |
c65c9bc3 | 2625 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2626 | case TIOCSETD: |
2627 | return tiocsetd(tty, p); | |
3c95c985 KS |
2628 | case TIOCVHANGUP: |
2629 | if (!capable(CAP_SYS_ADMIN)) | |
2630 | return -EPERM; | |
2631 | tty_vhangup(tty); | |
2632 | return 0; | |
b7b8de08 WF |
2633 | case TIOCGDEV: |
2634 | { | |
2635 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2636 | return put_user(ret, (unsigned int __user *)p); | |
2637 | } | |
37bdfb07 AC |
2638 | /* |
2639 | * Break handling | |
2640 | */ | |
2641 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2642 | if (tty->ops->break_ctl) |
9e98966c | 2643 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2644 | return 0; |
37bdfb07 | 2645 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2646 | if (tty->ops->break_ctl) |
9e98966c | 2647 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2648 | return 0; |
2649 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2650 | /* non-zero arg means wait for all output data | |
2651 | * to be sent (performed above) but don't send break. | |
2652 | * This is used by the tcdrain() termios function. | |
2653 | */ | |
2654 | if (!arg) | |
2655 | return send_break(tty, 250); | |
2656 | return 0; | |
2657 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2658 | return send_break(tty, arg ? arg*100 : 250); | |
2659 | ||
2660 | case TIOCMGET: | |
60b33c13 | 2661 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2662 | case TIOCMSET: |
2663 | case TIOCMBIC: | |
2664 | case TIOCMBIS: | |
20b9d177 | 2665 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2666 | case TIOCGICOUNT: |
2667 | retval = tty_tiocgicount(tty, p); | |
2668 | /* For the moment allow fall through to the old method */ | |
2669 | if (retval != -EINVAL) | |
2670 | return retval; | |
2671 | break; | |
37bdfb07 AC |
2672 | case TCFLSH: |
2673 | switch (arg) { | |
2674 | case TCIFLUSH: | |
2675 | case TCIOFLUSH: | |
2676 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2677 | tty_buffer_flush(tty); | |
c5c34d48 | 2678 | break; |
37bdfb07 AC |
2679 | } |
2680 | break; | |
1da177e4 | 2681 | } |
f34d7a5b | 2682 | if (tty->ops->ioctl) { |
6caa76b7 | 2683 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2684 | if (retval != -ENOIOCTLCMD) |
2685 | return retval; | |
2686 | } | |
2687 | ld = tty_ldisc_ref_wait(tty); | |
2688 | retval = -EINVAL; | |
a352def2 AC |
2689 | if (ld->ops->ioctl) { |
2690 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2691 | if (retval == -ENOIOCTLCMD) |
2692 | retval = -EINVAL; | |
2693 | } | |
2694 | tty_ldisc_deref(ld); | |
2695 | return retval; | |
2696 | } | |
2697 | ||
e10cc1df | 2698 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2699 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2700 | unsigned long arg) |
2701 | { | |
2702 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2703 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2704 | struct tty_ldisc *ld; |
2705 | int retval = -ENOIOCTLCMD; | |
2706 | ||
2707 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2708 | return -EINVAL; | |
2709 | ||
f34d7a5b | 2710 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2711 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2712 | if (retval != -ENOIOCTLCMD) |
2713 | return retval; | |
2714 | } | |
2715 | ||
2716 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2717 | if (ld->ops->compat_ioctl) |
2718 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
e10cc1df PF |
2719 | tty_ldisc_deref(ld); |
2720 | ||
2721 | return retval; | |
2722 | } | |
2723 | #endif | |
1da177e4 LT |
2724 | |
2725 | /* | |
2726 | * This implements the "Secure Attention Key" --- the idea is to | |
2727 | * prevent trojan horses by killing all processes associated with this | |
2728 | * tty when the user hits the "Secure Attention Key". Required for | |
2729 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2730 | * |
1da177e4 LT |
2731 | * This code could be nicer; ideally it should send a HUP, wait a few |
2732 | * seconds, then send a INT, and then a KILL signal. But you then | |
2733 | * have to coordinate with the init process, since all processes associated | |
2734 | * with the current tty must be dead before the new getty is allowed | |
2735 | * to spawn. | |
2736 | * | |
2737 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2738 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2739 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2740 | * | |
2741 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2742 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2743 | */ | |
8b6312f4 | 2744 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2745 | { |
2746 | #ifdef TTY_SOFT_SAK | |
2747 | tty_hangup(tty); | |
2748 | #else | |
652486fb | 2749 | struct task_struct *g, *p; |
ab521dc0 | 2750 | struct pid *session; |
1da177e4 LT |
2751 | int i; |
2752 | struct file *filp; | |
badf1662 | 2753 | struct fdtable *fdt; |
37bdfb07 | 2754 | |
1da177e4 LT |
2755 | if (!tty) |
2756 | return; | |
24ec839c | 2757 | session = tty->session; |
37bdfb07 | 2758 | |
b3f13deb | 2759 | tty_ldisc_flush(tty); |
1da177e4 | 2760 | |
f34d7a5b | 2761 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2762 | |
1da177e4 | 2763 | read_lock(&tasklist_lock); |
652486fb | 2764 | /* Kill the entire session */ |
ab521dc0 | 2765 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2766 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2767 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2768 | task_pid_nr(p), p->comm); |
652486fb | 2769 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2770 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2771 | /* Now kill any processes that happen to have the |
2772 | * tty open. | |
2773 | */ | |
2774 | do_each_thread(g, p) { | |
2775 | if (p->signal->tty == tty) { | |
1da177e4 | 2776 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2777 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2778 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2779 | send_sig(SIGKILL, p, 1); |
2780 | continue; | |
2781 | } | |
2782 | task_lock(p); | |
2783 | if (p->files) { | |
ca99c1da DS |
2784 | /* |
2785 | * We don't take a ref to the file, so we must | |
2786 | * hold ->file_lock instead. | |
2787 | */ | |
2788 | spin_lock(&p->files->file_lock); | |
badf1662 | 2789 | fdt = files_fdtable(p->files); |
37bdfb07 | 2790 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2791 | filp = fcheck_files(p->files, i); |
2792 | if (!filp) | |
2793 | continue; | |
2794 | if (filp->f_op->read == tty_read && | |
d996b62a | 2795 | file_tty(filp) == tty) { |
1da177e4 LT |
2796 | printk(KERN_NOTICE "SAK: killed process %d" |
2797 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2798 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2799 | force_sig(SIGKILL, p); |
1da177e4 LT |
2800 | break; |
2801 | } | |
2802 | } | |
ca99c1da | 2803 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2804 | } |
2805 | task_unlock(p); | |
652486fb | 2806 | } while_each_thread(g, p); |
1da177e4 LT |
2807 | read_unlock(&tasklist_lock); |
2808 | #endif | |
2809 | } | |
2810 | ||
8b6312f4 EB |
2811 | static void do_SAK_work(struct work_struct *work) |
2812 | { | |
2813 | struct tty_struct *tty = | |
2814 | container_of(work, struct tty_struct, SAK_work); | |
2815 | __do_SAK(tty); | |
2816 | } | |
2817 | ||
1da177e4 LT |
2818 | /* |
2819 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2820 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2821 | * the values which we write to it will be identical to the values which it | |
2822 | * already has. --akpm | |
2823 | */ | |
2824 | void do_SAK(struct tty_struct *tty) | |
2825 | { | |
2826 | if (!tty) | |
2827 | return; | |
1da177e4 LT |
2828 | schedule_work(&tty->SAK_work); |
2829 | } | |
2830 | ||
2831 | EXPORT_SYMBOL(do_SAK); | |
2832 | ||
30004ac9 DES |
2833 | static int dev_match_devt(struct device *dev, void *data) |
2834 | { | |
2835 | dev_t *devt = data; | |
2836 | return dev->devt == *devt; | |
2837 | } | |
2838 | ||
2839 | /* Must put_device() after it's unused! */ | |
2840 | static struct device *tty_get_device(struct tty_struct *tty) | |
2841 | { | |
2842 | dev_t devt = tty_devnum(tty); | |
2843 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2844 | } | |
2845 | ||
2846 | ||
af9b897e AC |
2847 | /** |
2848 | * initialize_tty_struct | |
2849 | * @tty: tty to initialize | |
2850 | * | |
2851 | * This subroutine initializes a tty structure that has been newly | |
2852 | * allocated. | |
2853 | * | |
2854 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2855 | */ |
af9b897e | 2856 | |
bf970ee4 AC |
2857 | void initialize_tty_struct(struct tty_struct *tty, |
2858 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2859 | { |
2860 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2861 | kref_init(&tty->kref); |
1da177e4 | 2862 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2863 | tty_ldisc_init(tty); |
ab521dc0 EB |
2864 | tty->session = NULL; |
2865 | tty->pgrp = NULL; | |
1da177e4 | 2866 | tty->overrun_time = jiffies; |
33f0f88f AC |
2867 | tty->buf.head = tty->buf.tail = NULL; |
2868 | tty_buffer_init(tty); | |
5785c95b | 2869 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2870 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2871 | init_waitqueue_head(&tty->write_wait); |
2872 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2873 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2874 | mutex_init(&tty->atomic_read_lock); |
2875 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2876 | mutex_init(&tty->output_lock); |
2877 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2878 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2879 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2880 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2881 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2882 | |
2883 | tty->driver = driver; | |
2884 | tty->ops = driver->ops; | |
2885 | tty->index = idx; | |
2886 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2887 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2888 | } |
2889 | ||
f34d7a5b AC |
2890 | /** |
2891 | * tty_put_char - write one character to a tty | |
2892 | * @tty: tty | |
2893 | * @ch: character | |
2894 | * | |
2895 | * Write one byte to the tty using the provided put_char method | |
2896 | * if present. Returns the number of characters successfully output. | |
2897 | * | |
2898 | * Note: the specific put_char operation in the driver layer may go | |
2899 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2900 | */ |
af9b897e | 2901 | |
f34d7a5b | 2902 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2903 | { |
f34d7a5b AC |
2904 | if (tty->ops->put_char) |
2905 | return tty->ops->put_char(tty, ch); | |
2906 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2907 | } |
f34d7a5b AC |
2908 | EXPORT_SYMBOL_GPL(tty_put_char); |
2909 | ||
d81ed103 | 2910 | struct class *tty_class; |
1da177e4 LT |
2911 | |
2912 | /** | |
af9b897e AC |
2913 | * tty_register_device - register a tty device |
2914 | * @driver: the tty driver that describes the tty device | |
2915 | * @index: the index in the tty driver for this tty device | |
2916 | * @device: a struct device that is associated with this tty device. | |
2917 | * This field is optional, if there is no known struct device | |
2918 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2919 | * |
01107d34 GKH |
2920 | * Returns a pointer to the struct device for this tty device |
2921 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2922 | * |
af9b897e AC |
2923 | * This call is required to be made to register an individual tty device |
2924 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2925 | * that bit is not set, this function should not be called by a tty | |
2926 | * driver. | |
2927 | * | |
2928 | * Locking: ?? | |
1da177e4 | 2929 | */ |
af9b897e | 2930 | |
01107d34 GKH |
2931 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2932 | struct device *device) | |
1da177e4 LT |
2933 | { |
2934 | char name[64]; | |
2935 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2936 | ||
2937 | if (index >= driver->num) { | |
2938 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2939 | " (%d).\n", index); | |
1cdcb6b4 | 2940 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2941 | } |
2942 | ||
1da177e4 LT |
2943 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2944 | pty_line_name(driver, index, name); | |
2945 | else | |
2946 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2947 | |
03457cd4 | 2948 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 2949 | } |
7d7b93c1 | 2950 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
2951 | |
2952 | /** | |
af9b897e AC |
2953 | * tty_unregister_device - unregister 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 | |
1da177e4 | 2956 | * |
af9b897e AC |
2957 | * If a tty device is registered with a call to tty_register_device() then |
2958 | * this function must be called when the tty device is gone. | |
2959 | * | |
2960 | * Locking: ?? | |
1da177e4 | 2961 | */ |
af9b897e | 2962 | |
1da177e4 LT |
2963 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2964 | { | |
37bdfb07 AC |
2965 | device_destroy(tty_class, |
2966 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 2967 | } |
1da177e4 LT |
2968 | EXPORT_SYMBOL(tty_unregister_device); |
2969 | ||
2970 | struct tty_driver *alloc_tty_driver(int lines) | |
2971 | { | |
2972 | struct tty_driver *driver; | |
2973 | ||
506eb99a | 2974 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 2975 | if (driver) { |
7d7b93c1 | 2976 | kref_init(&driver->kref); |
1da177e4 LT |
2977 | driver->magic = TTY_DRIVER_MAGIC; |
2978 | driver->num = lines; | |
2979 | /* later we'll move allocation of tables here */ | |
2980 | } | |
2981 | return driver; | |
2982 | } | |
7d7b93c1 | 2983 | EXPORT_SYMBOL(alloc_tty_driver); |
1da177e4 | 2984 | |
7d7b93c1 | 2985 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 2986 | { |
7d7b93c1 AC |
2987 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
2988 | int i; | |
2989 | struct ktermios *tp; | |
2990 | void *p; | |
2991 | ||
2992 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
2993 | /* | |
2994 | * Free the termios and termios_locked structures because | |
2995 | * we don't want to get memory leaks when modular tty | |
2996 | * drivers are removed from the kernel. | |
2997 | */ | |
2998 | for (i = 0; i < driver->num; i++) { | |
2999 | tp = driver->termios[i]; | |
3000 | if (tp) { | |
3001 | driver->termios[i] = NULL; | |
3002 | kfree(tp); | |
3003 | } | |
7d7b93c1 AC |
3004 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3005 | tty_unregister_device(driver, i); | |
3006 | } | |
3007 | p = driver->ttys; | |
3008 | proc_tty_unregister_driver(driver); | |
3009 | driver->ttys = NULL; | |
fe6e29fd | 3010 | driver->termios = NULL; |
7d7b93c1 AC |
3011 | kfree(p); |
3012 | cdev_del(&driver->cdev); | |
3013 | } | |
1da177e4 LT |
3014 | kfree(driver); |
3015 | } | |
3016 | ||
7d7b93c1 AC |
3017 | void tty_driver_kref_put(struct tty_driver *driver) |
3018 | { | |
3019 | kref_put(&driver->kref, destruct_tty_driver); | |
3020 | } | |
3021 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3022 | ||
b68e31d0 JD |
3023 | void tty_set_operations(struct tty_driver *driver, |
3024 | const struct tty_operations *op) | |
1da177e4 | 3025 | { |
f34d7a5b AC |
3026 | driver->ops = op; |
3027 | }; | |
7d7b93c1 | 3028 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3029 | |
7d7b93c1 AC |
3030 | void put_tty_driver(struct tty_driver *d) |
3031 | { | |
3032 | tty_driver_kref_put(d); | |
3033 | } | |
1da177e4 | 3034 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3035 | |
3036 | /* | |
3037 | * Called by a tty driver to register itself. | |
3038 | */ | |
3039 | int tty_register_driver(struct tty_driver *driver) | |
3040 | { | |
3041 | int error; | |
37bdfb07 | 3042 | int i; |
1da177e4 LT |
3043 | dev_t dev; |
3044 | void **p = NULL; | |
b670bde0 | 3045 | struct device *d; |
1da177e4 | 3046 | |
543691a6 | 3047 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 3048 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
3049 | if (!p) |
3050 | return -ENOMEM; | |
1da177e4 LT |
3051 | } |
3052 | ||
3053 | if (!driver->major) { | |
37bdfb07 AC |
3054 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3055 | driver->num, driver->name); | |
1da177e4 LT |
3056 | if (!error) { |
3057 | driver->major = MAJOR(dev); | |
3058 | driver->minor_start = MINOR(dev); | |
3059 | } | |
3060 | } else { | |
3061 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3062 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
3063 | } |
3064 | if (error < 0) { | |
3065 | kfree(p); | |
3066 | return error; | |
3067 | } | |
3068 | ||
3069 | if (p) { | |
3070 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3071 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
3072 | } else { |
3073 | driver->ttys = NULL; | |
3074 | driver->termios = NULL; | |
1da177e4 LT |
3075 | } |
3076 | ||
3077 | cdev_init(&driver->cdev, &tty_fops); | |
3078 | driver->cdev.owner = driver->owner; | |
3079 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3080 | if (error) { | |
1da177e4 LT |
3081 | unregister_chrdev_region(dev, driver->num); |
3082 | driver->ttys = NULL; | |
fe6e29fd | 3083 | driver->termios = NULL; |
1da177e4 LT |
3084 | kfree(p); |
3085 | return error; | |
3086 | } | |
3087 | ||
ca509f69 | 3088 | mutex_lock(&tty_mutex); |
1da177e4 | 3089 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3090 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3091 | |
3092 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3093 | for (i = 0; i < driver->num; i++) { |
3094 | d = tty_register_device(driver, i, NULL); | |
3095 | if (IS_ERR(d)) { | |
3096 | error = PTR_ERR(d); | |
3097 | goto err; | |
3098 | } | |
3099 | } | |
1da177e4 LT |
3100 | } |
3101 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3102 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3103 | return 0; |
b670bde0 VK |
3104 | |
3105 | err: | |
3106 | for (i--; i >= 0; i--) | |
3107 | tty_unregister_device(driver, i); | |
3108 | ||
3109 | mutex_lock(&tty_mutex); | |
3110 | list_del(&driver->tty_drivers); | |
3111 | mutex_unlock(&tty_mutex); | |
3112 | ||
3113 | unregister_chrdev_region(dev, driver->num); | |
3114 | driver->ttys = NULL; | |
3115 | driver->termios = NULL; | |
3116 | kfree(p); | |
3117 | return error; | |
1da177e4 LT |
3118 | } |
3119 | ||
3120 | EXPORT_SYMBOL(tty_register_driver); | |
3121 | ||
3122 | /* | |
3123 | * Called by a tty driver to unregister itself. | |
3124 | */ | |
3125 | int tty_unregister_driver(struct tty_driver *driver) | |
3126 | { | |
7d7b93c1 AC |
3127 | #if 0 |
3128 | /* FIXME */ | |
1da177e4 LT |
3129 | if (driver->refcount) |
3130 | return -EBUSY; | |
7d7b93c1 | 3131 | #endif |
1da177e4 LT |
3132 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3133 | driver->num); | |
ca509f69 | 3134 | mutex_lock(&tty_mutex); |
1da177e4 | 3135 | list_del(&driver->tty_drivers); |
ca509f69 | 3136 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3137 | return 0; |
3138 | } | |
7d7b93c1 | 3139 | |
1da177e4 LT |
3140 | EXPORT_SYMBOL(tty_unregister_driver); |
3141 | ||
24ec839c PZ |
3142 | dev_t tty_devnum(struct tty_struct *tty) |
3143 | { | |
3144 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3145 | } | |
3146 | EXPORT_SYMBOL(tty_devnum); | |
3147 | ||
3148 | void proc_clear_tty(struct task_struct *p) | |
3149 | { | |
7c3b1dcf | 3150 | unsigned long flags; |
9c9f4ded | 3151 | struct tty_struct *tty; |
7c3b1dcf | 3152 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3153 | tty = p->signal->tty; |
24ec839c | 3154 | p->signal->tty = NULL; |
7c3b1dcf | 3155 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3156 | tty_kref_put(tty); |
24ec839c | 3157 | } |
24ec839c | 3158 | |
47f86834 AC |
3159 | /* Called under the sighand lock */ |
3160 | ||
2a65f1d9 | 3161 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3162 | { |
3163 | if (tty) { | |
47f86834 AC |
3164 | unsigned long flags; |
3165 | /* We should not have a session or pgrp to put here but.... */ | |
3166 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3167 | put_pid(tty->session); |
3168 | put_pid(tty->pgrp); | |
ab521dc0 | 3169 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3170 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3171 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3172 | if (tsk->signal->tty) { |
3173 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3174 | tty_kref_put(tsk->signal->tty); | |
3175 | } | |
24ec839c | 3176 | } |
2a65f1d9 | 3177 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3178 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3179 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3180 | } |
3181 | ||
98a27ba4 | 3182 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3183 | { |
3184 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3185 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3186 | spin_unlock_irq(&tsk->sighand->siglock); |
3187 | } | |
3188 | ||
3189 | struct tty_struct *get_current_tty(void) | |
3190 | { | |
3191 | struct tty_struct *tty; | |
934e6ebf AC |
3192 | unsigned long flags; |
3193 | ||
3194 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3195 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3196 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3197 | return tty; |
3198 | } | |
a311f743 | 3199 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3200 | |
d81ed103 AC |
3201 | void tty_default_fops(struct file_operations *fops) |
3202 | { | |
3203 | *fops = tty_fops; | |
3204 | } | |
3205 | ||
1da177e4 LT |
3206 | /* |
3207 | * Initialize the console device. This is called *early*, so | |
3208 | * we can't necessarily depend on lots of kernel help here. | |
3209 | * Just do some early initializations, and do the complex setup | |
3210 | * later. | |
3211 | */ | |
3212 | void __init console_init(void) | |
3213 | { | |
3214 | initcall_t *call; | |
3215 | ||
3216 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3217 | tty_ldisc_begin(); |
1da177e4 LT |
3218 | |
3219 | /* | |
37bdfb07 | 3220 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3221 | * inform about problems etc.. |
3222 | */ | |
1da177e4 LT |
3223 | call = __con_initcall_start; |
3224 | while (call < __con_initcall_end) { | |
3225 | (*call)(); | |
3226 | call++; | |
3227 | } | |
3228 | } | |
3229 | ||
e454cea2 KS |
3230 | static char *tty_devnode(struct device *dev, mode_t *mode) |
3231 | { | |
3232 | if (!mode) | |
3233 | return NULL; | |
3234 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3235 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3236 | *mode = 0666; | |
3237 | return NULL; | |
3238 | } | |
3239 | ||
1da177e4 LT |
3240 | static int __init tty_class_init(void) |
3241 | { | |
7fe845d1 | 3242 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3243 | if (IS_ERR(tty_class)) |
3244 | return PTR_ERR(tty_class); | |
e454cea2 | 3245 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3246 | return 0; |
3247 | } | |
3248 | ||
3249 | postcore_initcall(tty_class_init); | |
3250 | ||
3251 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3252 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3253 | |
fbc92a34 KS |
3254 | static ssize_t show_cons_active(struct device *dev, |
3255 | struct device_attribute *attr, char *buf) | |
3256 | { | |
3257 | struct console *cs[16]; | |
3258 | int i = 0; | |
3259 | struct console *c; | |
3260 | ssize_t count = 0; | |
3261 | ||
ac751efa | 3262 | console_lock(); |
a2a6a822 | 3263 | for_each_console(c) { |
fbc92a34 KS |
3264 | if (!c->device) |
3265 | continue; | |
3266 | if (!c->write) | |
3267 | continue; | |
3268 | if ((c->flags & CON_ENABLED) == 0) | |
3269 | continue; | |
3270 | cs[i++] = c; | |
3271 | if (i >= ARRAY_SIZE(cs)) | |
3272 | break; | |
3273 | } | |
3274 | while (i--) | |
3275 | count += sprintf(buf + count, "%s%d%c", | |
3276 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3277 | console_unlock(); |
fbc92a34 KS |
3278 | |
3279 | return count; | |
3280 | } | |
3281 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3282 | ||
3283 | static struct device *consdev; | |
3284 | ||
3285 | void console_sysfs_notify(void) | |
3286 | { | |
3287 | if (consdev) | |
3288 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3289 | } | |
3290 | ||
1da177e4 LT |
3291 | /* |
3292 | * Ok, now we can initialize the rest of the tty devices and can count | |
3293 | * on memory allocations, interrupts etc.. | |
3294 | */ | |
31d1d48e | 3295 | int __init tty_init(void) |
1da177e4 LT |
3296 | { |
3297 | cdev_init(&tty_cdev, &tty_fops); | |
3298 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3299 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3300 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3301 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3302 | |
3303 | cdev_init(&console_cdev, &console_fops); | |
3304 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3305 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3306 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3307 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3308 | "console"); |
fbc92a34 KS |
3309 | if (IS_ERR(consdev)) |
3310 | consdev = NULL; | |
3311 | else | |
a2a6a822 | 3312 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3313 | |
1da177e4 | 3314 | #ifdef CONFIG_VT |
d81ed103 | 3315 | vty_init(&console_fops); |
1da177e4 LT |
3316 | #endif |
3317 | return 0; | |
3318 | } | |
31d1d48e | 3319 |