Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | |
101 | #include <linux/kbd_kern.h> | |
102 | #include <linux/vt_kern.h> | |
103 | #include <linux/selection.h> | |
1da177e4 LT |
104 | |
105 | #include <linux/kmod.h> | |
b488893a | 106 | #include <linux/nsproxy.h> |
1da177e4 LT |
107 | |
108 | #undef TTY_DEBUG_HANGUP | |
109 | ||
110 | #define TTY_PARANOIA_CHECK 1 | |
111 | #define CHECK_TTY_COUNT 1 | |
112 | ||
edc6afc5 | 113 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
114 | .c_iflag = ICRNL | IXON, |
115 | .c_oflag = OPOST | ONLCR, | |
116 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
117 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
118 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
119 | .c_cc = INIT_C_CC, |
120 | .c_ispeed = 38400, | |
121 | .c_ospeed = 38400 | |
1da177e4 LT |
122 | }; |
123 | ||
124 | EXPORT_SYMBOL(tty_std_termios); | |
125 | ||
126 | /* This list gets poked at by procfs and various bits of boot up code. This | |
127 | could do with some rationalisation such as pulling the tty proc function | |
128 | into this file */ | |
37bdfb07 | 129 | |
1da177e4 LT |
130 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
131 | ||
24ec839c | 132 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 133 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 134 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 135 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 136 | |
ee2ffa0d NP |
137 | /* Spinlock to protect the tty->tty_files list */ |
138 | DEFINE_SPINLOCK(tty_files_lock); | |
139 | ||
1da177e4 LT |
140 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
141 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
142 | ssize_t redirected_tty_write(struct file *, const char __user *, |
143 | size_t, loff_t *); | |
1da177e4 LT |
144 | static unsigned int tty_poll(struct file *, poll_table *); |
145 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 146 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 147 | #ifdef CONFIG_COMPAT |
37bdfb07 | 148 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
149 | unsigned long arg); |
150 | #else | |
151 | #define tty_compat_ioctl NULL | |
152 | #endif | |
ec79d605 | 153 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 154 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 155 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 156 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 157 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 158 | |
af9b897e AC |
159 | /** |
160 | * alloc_tty_struct - allocate a tty object | |
161 | * | |
162 | * Return a new empty tty structure. The data fields have not | |
163 | * been initialized in any way but has been zeroed | |
164 | * | |
165 | * Locking: none | |
af9b897e | 166 | */ |
1da177e4 | 167 | |
bf970ee4 | 168 | struct tty_struct *alloc_tty_struct(void) |
1da177e4 | 169 | { |
1266b1e1 | 170 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
171 | } |
172 | ||
af9b897e AC |
173 | /** |
174 | * free_tty_struct - free a disused tty | |
175 | * @tty: tty struct to free | |
176 | * | |
177 | * Free the write buffers, tty queue and tty memory itself. | |
178 | * | |
179 | * Locking: none. Must be called after tty is definitely unused | |
180 | */ | |
181 | ||
bf970ee4 | 182 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 183 | { |
30004ac9 DES |
184 | if (tty->dev) |
185 | put_device(tty->dev); | |
1da177e4 | 186 | kfree(tty->write_buf); |
33f0f88f | 187 | tty_buffer_free_all(tty); |
1da177e4 LT |
188 | kfree(tty); |
189 | } | |
190 | ||
d996b62a NP |
191 | static inline struct tty_struct *file_tty(struct file *file) |
192 | { | |
193 | return ((struct tty_file_private *)file->private_data)->tty; | |
194 | } | |
195 | ||
fa90e1c9 | 196 | int tty_alloc_file(struct file *file) |
d996b62a NP |
197 | { |
198 | struct tty_file_private *priv; | |
199 | ||
f573bd17 PE |
200 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
201 | if (!priv) | |
202 | return -ENOMEM; | |
d996b62a | 203 | |
fa90e1c9 JS |
204 | file->private_data = priv; |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | /* Associate a new file with the tty structure */ | |
210 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
211 | { | |
212 | struct tty_file_private *priv = file->private_data; | |
213 | ||
d996b62a NP |
214 | priv->tty = tty; |
215 | priv->file = file; | |
d996b62a NP |
216 | |
217 | spin_lock(&tty_files_lock); | |
218 | list_add(&priv->list, &tty->tty_files); | |
219 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 220 | } |
f573bd17 | 221 | |
fa90e1c9 JS |
222 | /** |
223 | * tty_free_file - free file->private_data | |
224 | * | |
225 | * This shall be used only for fail path handling when tty_add_file was not | |
226 | * called yet. | |
227 | */ | |
228 | void tty_free_file(struct file *file) | |
229 | { | |
230 | struct tty_file_private *priv = file->private_data; | |
231 | ||
232 | file->private_data = NULL; | |
233 | kfree(priv); | |
d996b62a NP |
234 | } |
235 | ||
236 | /* Delete file from its tty */ | |
237 | void tty_del_file(struct file *file) | |
238 | { | |
239 | struct tty_file_private *priv = file->private_data; | |
240 | ||
241 | spin_lock(&tty_files_lock); | |
242 | list_del(&priv->list); | |
243 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 244 | tty_free_file(file); |
d996b62a NP |
245 | } |
246 | ||
247 | ||
1da177e4 LT |
248 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
249 | ||
af9b897e AC |
250 | /** |
251 | * tty_name - return tty naming | |
252 | * @tty: tty structure | |
253 | * @buf: buffer for output | |
254 | * | |
255 | * Convert a tty structure into a name. The name reflects the kernel | |
256 | * naming policy and if udev is in use may not reflect user space | |
257 | * | |
258 | * Locking: none | |
259 | */ | |
260 | ||
1da177e4 LT |
261 | char *tty_name(struct tty_struct *tty, char *buf) |
262 | { | |
263 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
264 | strcpy(buf, "NULL tty"); | |
265 | else | |
266 | strcpy(buf, tty->name); | |
267 | return buf; | |
268 | } | |
269 | ||
270 | EXPORT_SYMBOL(tty_name); | |
271 | ||
d769a669 | 272 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
273 | const char *routine) |
274 | { | |
275 | #ifdef TTY_PARANOIA_CHECK | |
276 | if (!tty) { | |
277 | printk(KERN_WARNING | |
278 | "null TTY for (%d:%d) in %s\n", | |
279 | imajor(inode), iminor(inode), routine); | |
280 | return 1; | |
281 | } | |
282 | if (tty->magic != TTY_MAGIC) { | |
283 | printk(KERN_WARNING | |
284 | "bad magic number for tty struct (%d:%d) in %s\n", | |
285 | imajor(inode), iminor(inode), routine); | |
286 | return 1; | |
287 | } | |
288 | #endif | |
289 | return 0; | |
290 | } | |
291 | ||
292 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
293 | { | |
294 | #ifdef CHECK_TTY_COUNT | |
295 | struct list_head *p; | |
296 | int count = 0; | |
37bdfb07 | 297 | |
ee2ffa0d | 298 | spin_lock(&tty_files_lock); |
1da177e4 LT |
299 | list_for_each(p, &tty->tty_files) { |
300 | count++; | |
301 | } | |
ee2ffa0d | 302 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
303 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
304 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
305 | tty->link && tty->link->count) | |
306 | count++; | |
307 | if (tty->count != count) { | |
308 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
309 | "!= #fd's(%d) in %s\n", | |
310 | tty->name, tty->count, count, routine); | |
311 | return count; | |
24ec839c | 312 | } |
1da177e4 LT |
313 | #endif |
314 | return 0; | |
315 | } | |
316 | ||
af9b897e AC |
317 | /** |
318 | * get_tty_driver - find device of a tty | |
319 | * @dev_t: device identifier | |
320 | * @index: returns the index of the tty | |
321 | * | |
322 | * This routine returns a tty driver structure, given a device number | |
323 | * and also passes back the index number. | |
324 | * | |
325 | * Locking: caller must hold tty_mutex | |
1da177e4 | 326 | */ |
af9b897e | 327 | |
1da177e4 LT |
328 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
329 | { | |
330 | struct tty_driver *p; | |
331 | ||
332 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
333 | dev_t base = MKDEV(p->major, p->minor_start); | |
334 | if (device < base || device >= base + p->num) | |
335 | continue; | |
336 | *index = device - base; | |
7d7b93c1 | 337 | return tty_driver_kref_get(p); |
1da177e4 LT |
338 | } |
339 | return NULL; | |
340 | } | |
341 | ||
f2d937f3 JW |
342 | #ifdef CONFIG_CONSOLE_POLL |
343 | ||
344 | /** | |
345 | * tty_find_polling_driver - find device of a polled tty | |
346 | * @name: name string to match | |
347 | * @line: pointer to resulting tty line nr | |
348 | * | |
349 | * This routine returns a tty driver structure, given a name | |
350 | * and the condition that the tty driver is capable of polled | |
351 | * operation. | |
352 | */ | |
353 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
354 | { | |
355 | struct tty_driver *p, *res = NULL; | |
356 | int tty_line = 0; | |
0dca0fd2 | 357 | int len; |
5f0878ac | 358 | char *str, *stp; |
f2d937f3 | 359 | |
0dca0fd2 JW |
360 | for (str = name; *str; str++) |
361 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
362 | break; | |
363 | if (!*str) | |
364 | return NULL; | |
365 | ||
366 | len = str - name; | |
367 | tty_line = simple_strtoul(str, &str, 10); | |
368 | ||
f2d937f3 JW |
369 | mutex_lock(&tty_mutex); |
370 | /* Search through the tty devices to look for a match */ | |
371 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
372 | if (strncmp(name, p->name, len) != 0) |
373 | continue; | |
5f0878ac AC |
374 | stp = str; |
375 | if (*stp == ',') | |
376 | stp++; | |
377 | if (*stp == '\0') | |
378 | stp = NULL; | |
f2d937f3 | 379 | |
6eb68d6f | 380 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 381 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 382 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
383 | *line = tty_line; |
384 | break; | |
385 | } | |
386 | } | |
387 | mutex_unlock(&tty_mutex); | |
388 | ||
389 | return res; | |
390 | } | |
391 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
392 | #endif | |
393 | ||
af9b897e AC |
394 | /** |
395 | * tty_check_change - check for POSIX terminal changes | |
396 | * @tty: tty to check | |
397 | * | |
398 | * If we try to write to, or set the state of, a terminal and we're | |
399 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
400 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
401 | * | |
978e595f | 402 | * Locking: ctrl_lock |
1da177e4 | 403 | */ |
af9b897e | 404 | |
37bdfb07 | 405 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 406 | { |
47f86834 AC |
407 | unsigned long flags; |
408 | int ret = 0; | |
409 | ||
1da177e4 LT |
410 | if (current->signal->tty != tty) |
411 | return 0; | |
47f86834 AC |
412 | |
413 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
414 | ||
ab521dc0 EB |
415 | if (!tty->pgrp) { |
416 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 417 | goto out_unlock; |
1da177e4 | 418 | } |
ab521dc0 | 419 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
420 | goto out_unlock; |
421 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 422 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
423 | goto out; |
424 | if (is_current_pgrp_orphaned()) { | |
425 | ret = -EIO; | |
426 | goto out; | |
427 | } | |
040b6362 ON |
428 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
429 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
430 | ret = -ERESTARTSYS; |
431 | out: | |
9ffee4cb AM |
432 | return ret; |
433 | out_unlock: | |
47f86834 AC |
434 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
435 | return ret; | |
1da177e4 LT |
436 | } |
437 | ||
438 | EXPORT_SYMBOL(tty_check_change); | |
439 | ||
37bdfb07 | 440 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
441 | size_t count, loff_t *ppos) |
442 | { | |
443 | return 0; | |
444 | } | |
445 | ||
37bdfb07 | 446 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
447 | size_t count, loff_t *ppos) |
448 | { | |
449 | return -EIO; | |
450 | } | |
451 | ||
452 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 453 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
454 | { |
455 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
456 | } | |
457 | ||
04f378b1 AC |
458 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
459 | unsigned long arg) | |
38ad2ed0 PF |
460 | { |
461 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
462 | } | |
463 | ||
37bdfb07 | 464 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 465 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
466 | { |
467 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
468 | } | |
469 | ||
62322d25 | 470 | static const struct file_operations tty_fops = { |
1da177e4 LT |
471 | .llseek = no_llseek, |
472 | .read = tty_read, | |
473 | .write = tty_write, | |
474 | .poll = tty_poll, | |
04f378b1 | 475 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 476 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
477 | .open = tty_open, |
478 | .release = tty_release, | |
479 | .fasync = tty_fasync, | |
480 | }; | |
481 | ||
62322d25 | 482 | static const struct file_operations console_fops = { |
1da177e4 LT |
483 | .llseek = no_llseek, |
484 | .read = tty_read, | |
485 | .write = redirected_tty_write, | |
486 | .poll = tty_poll, | |
04f378b1 | 487 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 488 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
489 | .open = tty_open, |
490 | .release = tty_release, | |
491 | .fasync = tty_fasync, | |
492 | }; | |
493 | ||
62322d25 | 494 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
495 | .llseek = no_llseek, |
496 | .read = hung_up_tty_read, | |
497 | .write = hung_up_tty_write, | |
498 | .poll = hung_up_tty_poll, | |
04f378b1 | 499 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 500 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
501 | .release = tty_release, |
502 | }; | |
503 | ||
504 | static DEFINE_SPINLOCK(redirect_lock); | |
505 | static struct file *redirect; | |
506 | ||
507 | /** | |
508 | * tty_wakeup - request more data | |
509 | * @tty: terminal | |
510 | * | |
511 | * Internal and external helper for wakeups of tty. This function | |
512 | * informs the line discipline if present that the driver is ready | |
513 | * to receive more output data. | |
514 | */ | |
37bdfb07 | 515 | |
1da177e4 LT |
516 | void tty_wakeup(struct tty_struct *tty) |
517 | { | |
518 | struct tty_ldisc *ld; | |
37bdfb07 | 519 | |
1da177e4 LT |
520 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
521 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 522 | if (ld) { |
a352def2 AC |
523 | if (ld->ops->write_wakeup) |
524 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
525 | tty_ldisc_deref(ld); |
526 | } | |
527 | } | |
4b19449d | 528 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
529 | } |
530 | ||
531 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
532 | ||
af9b897e | 533 | /** |
11dbf203 | 534 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 535 | * @work: tty device |
af9b897e | 536 | * |
1bad879a | 537 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
538 | * synchronous but doesn't hold any locks, so we need to make sure we |
539 | * have the appropriate locks for what we're doing. | |
540 | * | |
541 | * The hangup event clears any pending redirections onto the hung up | |
542 | * device. It ensures future writes will error and it does the needed | |
543 | * line discipline hangup and signal delivery. The tty object itself | |
544 | * remains intact. | |
545 | * | |
546 | * Locking: | |
ec79d605 | 547 | * BTM |
24ec839c PZ |
548 | * redirect lock for undoing redirection |
549 | * file list lock for manipulating list of ttys | |
550 | * tty_ldisc_lock from called functions | |
551 | * termios_mutex resetting termios data | |
552 | * tasklist_lock to walk task list for hangup event | |
553 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 554 | */ |
11dbf203 | 555 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 556 | { |
37bdfb07 | 557 | struct file *cons_filp = NULL; |
1da177e4 LT |
558 | struct file *filp, *f = NULL; |
559 | struct task_struct *p; | |
d996b62a | 560 | struct tty_file_private *priv; |
1da177e4 | 561 | int closecount = 0, n; |
47f86834 | 562 | unsigned long flags; |
9c9f4ded | 563 | int refs = 0; |
1da177e4 LT |
564 | |
565 | if (!tty) | |
566 | return; | |
567 | ||
1da177e4 LT |
568 | |
569 | spin_lock(&redirect_lock); | |
d996b62a | 570 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
571 | f = redirect; |
572 | redirect = NULL; | |
573 | } | |
574 | spin_unlock(&redirect_lock); | |
37bdfb07 | 575 | |
f309532b | 576 | tty_lock(); |
11dbf203 | 577 | |
acfa747b JS |
578 | /* some functions below drop BTM, so we need this bit */ |
579 | set_bit(TTY_HUPPING, &tty->flags); | |
580 | ||
ec79d605 AB |
581 | /* inuse_filps is protected by the single tty lock, |
582 | this really needs to change if we want to flush the | |
583 | workqueue with the lock held */ | |
11dbf203 | 584 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 585 | |
ee2ffa0d | 586 | spin_lock(&tty_files_lock); |
1da177e4 | 587 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
588 | list_for_each_entry(priv, &tty->tty_files, list) { |
589 | filp = priv->file; | |
1da177e4 LT |
590 | if (filp->f_op->write == redirected_tty_write) |
591 | cons_filp = filp; | |
592 | if (filp->f_op->write != tty_write) | |
593 | continue; | |
594 | closecount++; | |
ec79d605 | 595 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
596 | filp->f_op = &hung_up_tty_fops; |
597 | } | |
ee2ffa0d | 598 | spin_unlock(&tty_files_lock); |
37bdfb07 | 599 | |
acfa747b JS |
600 | /* |
601 | * it drops BTM and thus races with reopen | |
602 | * we protect the race by TTY_HUPPING | |
603 | */ | |
c65c9bc3 | 604 | tty_ldisc_hangup(tty); |
37bdfb07 | 605 | |
1da177e4 | 606 | read_lock(&tasklist_lock); |
ab521dc0 EB |
607 | if (tty->session) { |
608 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 609 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 610 | if (p->signal->tty == tty) { |
1da177e4 | 611 | p->signal->tty = NULL; |
9c9f4ded AC |
612 | /* We defer the dereferences outside fo |
613 | the tasklist lock */ | |
614 | refs++; | |
615 | } | |
24ec839c PZ |
616 | if (!p->signal->leader) { |
617 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 618 | continue; |
24ec839c PZ |
619 | } |
620 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
621 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 622 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 623 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
624 | if (tty->pgrp) |
625 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 626 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 627 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 628 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
629 | } |
630 | read_unlock(&tasklist_lock); | |
631 | ||
47f86834 | 632 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
633 | clear_bit(TTY_THROTTLED, &tty->flags); |
634 | clear_bit(TTY_PUSH, &tty->flags); | |
635 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
636 | put_pid(tty->session); |
637 | put_pid(tty->pgrp); | |
ab521dc0 EB |
638 | tty->session = NULL; |
639 | tty->pgrp = NULL; | |
1da177e4 | 640 | tty->ctrl_status = 0; |
47f86834 AC |
641 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
642 | ||
9c9f4ded AC |
643 | /* Account for the p->signal references we killed */ |
644 | while (refs--) | |
645 | tty_kref_put(tty); | |
646 | ||
1da177e4 | 647 | /* |
37bdfb07 AC |
648 | * If one of the devices matches a console pointer, we |
649 | * cannot just call hangup() because that will cause | |
650 | * tty->count and state->count to go out of sync. | |
651 | * So we just call close() the right number of times. | |
1da177e4 LT |
652 | */ |
653 | if (cons_filp) { | |
f34d7a5b | 654 | if (tty->ops->close) |
1da177e4 | 655 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
656 | tty->ops->close(tty, cons_filp); |
657 | } else if (tty->ops->hangup) | |
658 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
659 | /* |
660 | * We don't want to have driver/ldisc interactions beyond | |
661 | * the ones we did here. The driver layer expects no | |
662 | * calls after ->hangup() from the ldisc side. However we | |
663 | * can't yet guarantee all that. | |
664 | */ | |
1da177e4 | 665 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 666 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 667 | tty_ldisc_enable(tty); |
11dbf203 | 668 | |
f309532b | 669 | tty_unlock(); |
11dbf203 | 670 | |
1da177e4 LT |
671 | if (f) |
672 | fput(f); | |
673 | } | |
674 | ||
ddcd9fb6 AB |
675 | static void do_tty_hangup(struct work_struct *work) |
676 | { | |
677 | struct tty_struct *tty = | |
678 | container_of(work, struct tty_struct, hangup_work); | |
679 | ||
11dbf203 | 680 | __tty_hangup(tty); |
ddcd9fb6 AB |
681 | } |
682 | ||
af9b897e AC |
683 | /** |
684 | * tty_hangup - trigger a hangup event | |
685 | * @tty: tty to hangup | |
686 | * | |
687 | * A carrier loss (virtual or otherwise) has occurred on this like | |
688 | * schedule a hangup sequence to run after this event. | |
689 | */ | |
690 | ||
37bdfb07 | 691 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
692 | { |
693 | #ifdef TTY_DEBUG_HANGUP | |
694 | char buf[64]; | |
1da177e4 LT |
695 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
696 | #endif | |
697 | schedule_work(&tty->hangup_work); | |
698 | } | |
699 | ||
700 | EXPORT_SYMBOL(tty_hangup); | |
701 | ||
af9b897e AC |
702 | /** |
703 | * tty_vhangup - process vhangup | |
704 | * @tty: tty to hangup | |
705 | * | |
706 | * The user has asked via system call for the terminal to be hung up. | |
707 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 708 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
709 | */ |
710 | ||
37bdfb07 | 711 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
712 | { |
713 | #ifdef TTY_DEBUG_HANGUP | |
714 | char buf[64]; | |
715 | ||
716 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
717 | #endif | |
11dbf203 | 718 | __tty_hangup(tty); |
1da177e4 | 719 | } |
37bdfb07 | 720 | |
1da177e4 LT |
721 | EXPORT_SYMBOL(tty_vhangup); |
722 | ||
11dbf203 | 723 | |
2cb5998b AC |
724 | /** |
725 | * tty_vhangup_self - process vhangup for own ctty | |
726 | * | |
727 | * Perform a vhangup on the current controlling tty | |
728 | */ | |
729 | ||
730 | void tty_vhangup_self(void) | |
731 | { | |
732 | struct tty_struct *tty; | |
733 | ||
2cb5998b AC |
734 | tty = get_current_tty(); |
735 | if (tty) { | |
736 | tty_vhangup(tty); | |
737 | tty_kref_put(tty); | |
738 | } | |
2cb5998b AC |
739 | } |
740 | ||
af9b897e AC |
741 | /** |
742 | * tty_hung_up_p - was tty hung up | |
743 | * @filp: file pointer of tty | |
744 | * | |
745 | * Return true if the tty has been subject to a vhangup or a carrier | |
746 | * loss | |
747 | */ | |
748 | ||
37bdfb07 | 749 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
750 | { |
751 | return (filp->f_op == &hung_up_tty_fops); | |
752 | } | |
753 | ||
754 | EXPORT_SYMBOL(tty_hung_up_p); | |
755 | ||
ab521dc0 | 756 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
757 | { |
758 | struct task_struct *p; | |
ab521dc0 | 759 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 760 | proc_clear_tty(p); |
ab521dc0 | 761 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
762 | } |
763 | ||
af9b897e AC |
764 | /** |
765 | * disassociate_ctty - disconnect controlling tty | |
766 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 767 | * |
af9b897e AC |
768 | * This function is typically called only by the session leader, when |
769 | * it wants to disassociate itself from its controlling tty. | |
770 | * | |
771 | * It performs the following functions: | |
1da177e4 LT |
772 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
773 | * (2) Clears the tty from being controlling the session | |
774 | * (3) Clears the controlling tty for all processes in the | |
775 | * session group. | |
776 | * | |
af9b897e AC |
777 | * The argument on_exit is set to 1 if called when a process is |
778 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
779 | * | |
24ec839c | 780 | * Locking: |
ec79d605 AB |
781 | * BTM is taken for hysterical raisins, and held when |
782 | * called from no_tty(). | |
24ec839c PZ |
783 | * tty_mutex is taken to protect tty |
784 | * ->siglock is taken to protect ->signal/->sighand | |
785 | * tasklist_lock is taken to walk process list for sessions | |
786 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 787 | */ |
af9b897e | 788 | |
1da177e4 LT |
789 | void disassociate_ctty(int on_exit) |
790 | { | |
791 | struct tty_struct *tty; | |
1da177e4 | 792 | |
5ec93d11 AC |
793 | if (!current->signal->leader) |
794 | return; | |
1da177e4 | 795 | |
24ec839c | 796 | tty = get_current_tty(); |
1da177e4 | 797 | if (tty) { |
1411dc4a | 798 | struct pid *tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 799 | if (on_exit) { |
ddcd9fb6 | 800 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 801 | tty_vhangup(tty); |
ddcd9fb6 | 802 | } |
452a00d2 | 803 | tty_kref_put(tty); |
1411dc4a JS |
804 | if (tty_pgrp) { |
805 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
806 | if (!on_exit) | |
807 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
808 | put_pid(tty_pgrp); | |
809 | } | |
680a9671 | 810 | } else if (on_exit) { |
ab521dc0 | 811 | struct pid *old_pgrp; |
680a9671 EB |
812 | spin_lock_irq(¤t->sighand->siglock); |
813 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 814 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 815 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 816 | if (old_pgrp) { |
ab521dc0 EB |
817 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
818 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
819 | put_pid(old_pgrp); | |
1da177e4 | 820 | } |
1da177e4 LT |
821 | return; |
822 | } | |
1da177e4 | 823 | |
24ec839c | 824 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 825 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 826 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
827 | spin_unlock_irq(¤t->sighand->siglock); |
828 | ||
24ec839c PZ |
829 | tty = get_current_tty(); |
830 | if (tty) { | |
47f86834 AC |
831 | unsigned long flags; |
832 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
833 | put_pid(tty->session); |
834 | put_pid(tty->pgrp); | |
835 | tty->session = NULL; | |
836 | tty->pgrp = NULL; | |
47f86834 | 837 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 838 | tty_kref_put(tty); |
24ec839c PZ |
839 | } else { |
840 | #ifdef TTY_DEBUG_HANGUP | |
841 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
842 | " = NULL", tty); | |
843 | #endif | |
844 | } | |
1da177e4 LT |
845 | |
846 | /* Now clear signal->tty under the lock */ | |
847 | read_lock(&tasklist_lock); | |
ab521dc0 | 848 | session_clear_tty(task_session(current)); |
1da177e4 | 849 | read_unlock(&tasklist_lock); |
1da177e4 LT |
850 | } |
851 | ||
98a27ba4 EB |
852 | /** |
853 | * | |
854 | * no_tty - Ensure the current process does not have a controlling tty | |
855 | */ | |
856 | void no_tty(void) | |
857 | { | |
3af502b9 AC |
858 | /* FIXME: Review locking here. The tty_lock never covered any race |
859 | between a new association and proc_clear_tty but possible we need | |
860 | to protect against this anyway */ | |
98a27ba4 | 861 | struct task_struct *tsk = current; |
5ec93d11 | 862 | disassociate_ctty(0); |
98a27ba4 EB |
863 | proc_clear_tty(tsk); |
864 | } | |
865 | ||
af9b897e AC |
866 | |
867 | /** | |
beb7dd86 | 868 | * stop_tty - propagate flow control |
af9b897e AC |
869 | * @tty: tty to stop |
870 | * | |
871 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 872 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
873 | * on an already stopped device and will not re-call the driver |
874 | * method. | |
875 | * | |
876 | * This functionality is used by both the line disciplines for | |
877 | * halting incoming flow and by the driver. It may therefore be | |
878 | * called from any context, may be under the tty atomic_write_lock | |
879 | * but not always. | |
880 | * | |
881 | * Locking: | |
04f378b1 | 882 | * Uses the tty control lock internally |
af9b897e AC |
883 | */ |
884 | ||
1da177e4 LT |
885 | void stop_tty(struct tty_struct *tty) |
886 | { | |
04f378b1 AC |
887 | unsigned long flags; |
888 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
889 | if (tty->stopped) { | |
890 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 891 | return; |
04f378b1 | 892 | } |
1da177e4 LT |
893 | tty->stopped = 1; |
894 | if (tty->link && tty->link->packet) { | |
895 | tty->ctrl_status &= ~TIOCPKT_START; | |
896 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 897 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 898 | } |
04f378b1 | 899 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
900 | if (tty->ops->stop) |
901 | (tty->ops->stop)(tty); | |
1da177e4 LT |
902 | } |
903 | ||
904 | EXPORT_SYMBOL(stop_tty); | |
905 | ||
af9b897e | 906 | /** |
beb7dd86 | 907 | * start_tty - propagate flow control |
af9b897e AC |
908 | * @tty: tty to start |
909 | * | |
910 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 911 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
912 | * is the tty was previous stopped and is being started then the |
913 | * driver start method is invoked and the line discipline woken. | |
914 | * | |
915 | * Locking: | |
04f378b1 | 916 | * ctrl_lock |
af9b897e AC |
917 | */ |
918 | ||
1da177e4 LT |
919 | void start_tty(struct tty_struct *tty) |
920 | { | |
04f378b1 AC |
921 | unsigned long flags; |
922 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
923 | if (!tty->stopped || tty->flow_stopped) { | |
924 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 925 | return; |
04f378b1 | 926 | } |
1da177e4 LT |
927 | tty->stopped = 0; |
928 | if (tty->link && tty->link->packet) { | |
929 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
930 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 931 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 932 | } |
04f378b1 | 933 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
934 | if (tty->ops->start) |
935 | (tty->ops->start)(tty); | |
1da177e4 LT |
936 | /* If we have a running line discipline it may need kicking */ |
937 | tty_wakeup(tty); | |
1da177e4 LT |
938 | } |
939 | ||
940 | EXPORT_SYMBOL(start_tty); | |
941 | ||
af9b897e AC |
942 | /** |
943 | * tty_read - read method for tty device files | |
944 | * @file: pointer to tty file | |
945 | * @buf: user buffer | |
946 | * @count: size of user buffer | |
947 | * @ppos: unused | |
948 | * | |
949 | * Perform the read system call function on this terminal device. Checks | |
950 | * for hung up devices before calling the line discipline method. | |
951 | * | |
952 | * Locking: | |
47f86834 AC |
953 | * Locks the line discipline internally while needed. Multiple |
954 | * read calls may be outstanding in parallel. | |
af9b897e AC |
955 | */ |
956 | ||
37bdfb07 | 957 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
958 | loff_t *ppos) |
959 | { | |
960 | int i; | |
d996b62a NP |
961 | struct inode *inode = file->f_path.dentry->d_inode; |
962 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
963 | struct tty_ldisc *ld; |
964 | ||
1da177e4 LT |
965 | if (tty_paranoia_check(tty, inode, "tty_read")) |
966 | return -EIO; | |
967 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
968 | return -EIO; | |
969 | ||
970 | /* We want to wait for the line discipline to sort out in this | |
971 | situation */ | |
972 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
973 | if (ld->ops->read) |
974 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
975 | else |
976 | i = -EIO; | |
977 | tty_ldisc_deref(ld); | |
1da177e4 LT |
978 | if (i > 0) |
979 | inode->i_atime = current_fs_time(inode->i_sb); | |
980 | return i; | |
981 | } | |
982 | ||
9c1729db | 983 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 984 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
985 | { |
986 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 987 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
988 | } |
989 | ||
990 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 991 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
992 | { |
993 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
994 | if (ndelay) | |
995 | return -EAGAIN; | |
996 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
997 | return -ERESTARTSYS; | |
998 | } | |
999 | return 0; | |
1000 | } | |
1001 | ||
1da177e4 LT |
1002 | /* |
1003 | * Split writes up in sane blocksizes to avoid | |
1004 | * denial-of-service type attacks | |
1005 | */ | |
1006 | static inline ssize_t do_tty_write( | |
1007 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1008 | struct tty_struct *tty, | |
1009 | struct file *file, | |
1010 | const char __user *buf, | |
1011 | size_t count) | |
1012 | { | |
9c1729db | 1013 | ssize_t ret, written = 0; |
1da177e4 | 1014 | unsigned int chunk; |
37bdfb07 | 1015 | |
9c1729db AC |
1016 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1017 | if (ret < 0) | |
1018 | return ret; | |
1da177e4 LT |
1019 | |
1020 | /* | |
1021 | * We chunk up writes into a temporary buffer. This | |
1022 | * simplifies low-level drivers immensely, since they | |
1023 | * don't have locking issues and user mode accesses. | |
1024 | * | |
1025 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1026 | * big chunk-size.. | |
1027 | * | |
1028 | * The default chunk-size is 2kB, because the NTTY | |
1029 | * layer has problems with bigger chunks. It will | |
1030 | * claim to be able to handle more characters than | |
1031 | * it actually does. | |
af9b897e AC |
1032 | * |
1033 | * FIXME: This can probably go away now except that 64K chunks | |
1034 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1035 | */ |
1036 | chunk = 2048; | |
1037 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1038 | chunk = 65536; | |
1039 | if (count < chunk) | |
1040 | chunk = count; | |
1041 | ||
70522e12 | 1042 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1043 | if (tty->write_cnt < chunk) { |
402fda92 | 1044 | unsigned char *buf_chunk; |
1da177e4 LT |
1045 | |
1046 | if (chunk < 1024) | |
1047 | chunk = 1024; | |
1048 | ||
402fda92 JW |
1049 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1050 | if (!buf_chunk) { | |
9c1729db AC |
1051 | ret = -ENOMEM; |
1052 | goto out; | |
1da177e4 LT |
1053 | } |
1054 | kfree(tty->write_buf); | |
1055 | tty->write_cnt = chunk; | |
402fda92 | 1056 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1057 | } |
1058 | ||
1059 | /* Do the write .. */ | |
1060 | for (;;) { | |
1061 | size_t size = count; | |
1062 | if (size > chunk) | |
1063 | size = chunk; | |
1064 | ret = -EFAULT; | |
1065 | if (copy_from_user(tty->write_buf, buf, size)) | |
1066 | break; | |
1da177e4 | 1067 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1068 | if (ret <= 0) |
1069 | break; | |
1070 | written += ret; | |
1071 | buf += ret; | |
1072 | count -= ret; | |
1073 | if (!count) | |
1074 | break; | |
1075 | ret = -ERESTARTSYS; | |
1076 | if (signal_pending(current)) | |
1077 | break; | |
1078 | cond_resched(); | |
1079 | } | |
1080 | if (written) { | |
a7113a96 | 1081 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1082 | inode->i_mtime = current_fs_time(inode->i_sb); |
1083 | ret = written; | |
1084 | } | |
9c1729db AC |
1085 | out: |
1086 | tty_write_unlock(tty); | |
1da177e4 LT |
1087 | return ret; |
1088 | } | |
1089 | ||
95f9bfc6 AC |
1090 | /** |
1091 | * tty_write_message - write a message to a certain tty, not just the console. | |
1092 | * @tty: the destination tty_struct | |
1093 | * @msg: the message to write | |
1094 | * | |
1095 | * This is used for messages that need to be redirected to a specific tty. | |
1096 | * We don't put it into the syslog queue right now maybe in the future if | |
1097 | * really needed. | |
1098 | * | |
ec79d605 | 1099 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1100 | */ |
1101 | ||
1102 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1103 | { | |
95f9bfc6 AC |
1104 | if (tty) { |
1105 | mutex_lock(&tty->atomic_write_lock); | |
f309532b | 1106 | tty_lock(); |
eeb89d91 | 1107 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
f309532b | 1108 | tty_unlock(); |
95f9bfc6 | 1109 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1110 | } else |
f309532b | 1111 | tty_unlock(); |
95f9bfc6 AC |
1112 | tty_write_unlock(tty); |
1113 | } | |
95f9bfc6 AC |
1114 | return; |
1115 | } | |
1116 | ||
1da177e4 | 1117 | |
af9b897e AC |
1118 | /** |
1119 | * tty_write - write method for tty device file | |
1120 | * @file: tty file pointer | |
1121 | * @buf: user data to write | |
1122 | * @count: bytes to write | |
1123 | * @ppos: unused | |
1124 | * | |
1125 | * Write data to a tty device via the line discipline. | |
1126 | * | |
1127 | * Locking: | |
1128 | * Locks the line discipline as required | |
1129 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1130 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1131 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1132 | */ |
1133 | ||
37bdfb07 AC |
1134 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1135 | size_t count, loff_t *ppos) | |
1da177e4 | 1136 | { |
a7113a96 | 1137 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1138 | struct tty_struct *tty = file_tty(file); |
1139 | struct tty_ldisc *ld; | |
1da177e4 | 1140 | ssize_t ret; |
37bdfb07 | 1141 | |
1da177e4 LT |
1142 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1143 | return -EIO; | |
f34d7a5b | 1144 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1145 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1146 | return -EIO; | |
f34d7a5b AC |
1147 | /* Short term debug to catch buggy drivers */ |
1148 | if (tty->ops->write_room == NULL) | |
1149 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1150 | tty->driver->name); | |
37bdfb07 | 1151 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1152 | if (!ld->ops->write) |
1da177e4 LT |
1153 | ret = -EIO; |
1154 | else | |
a352def2 | 1155 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1156 | tty_ldisc_deref(ld); |
1157 | return ret; | |
1158 | } | |
1159 | ||
37bdfb07 AC |
1160 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1161 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1162 | { |
1163 | struct file *p = NULL; | |
1164 | ||
1165 | spin_lock(&redirect_lock); | |
1166 | if (redirect) { | |
1167 | get_file(redirect); | |
1168 | p = redirect; | |
1169 | } | |
1170 | spin_unlock(&redirect_lock); | |
1171 | ||
1172 | if (p) { | |
1173 | ssize_t res; | |
1174 | res = vfs_write(p, buf, count, &p->f_pos); | |
1175 | fput(p); | |
1176 | return res; | |
1177 | } | |
1da177e4 LT |
1178 | return tty_write(file, buf, count, ppos); |
1179 | } | |
1180 | ||
1181 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1182 | ||
af9b897e AC |
1183 | /** |
1184 | * pty_line_name - generate name for a pty | |
1185 | * @driver: the tty driver in use | |
1186 | * @index: the minor number | |
1187 | * @p: output buffer of at least 6 bytes | |
1188 | * | |
1189 | * Generate a name from a driver reference and write it to the output | |
1190 | * buffer. | |
1191 | * | |
1192 | * Locking: None | |
1193 | */ | |
1194 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1195 | { |
1196 | int i = index + driver->name_base; | |
1197 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1198 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1199 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1200 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1201 | } |
1202 | ||
af9b897e | 1203 | /** |
8b0a88d5 | 1204 | * tty_line_name - generate name for a tty |
af9b897e AC |
1205 | * @driver: the tty driver in use |
1206 | * @index: the minor number | |
1207 | * @p: output buffer of at least 7 bytes | |
1208 | * | |
1209 | * Generate a name from a driver reference and write it to the output | |
1210 | * buffer. | |
1211 | * | |
1212 | * Locking: None | |
1213 | */ | |
1214 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1215 | { |
1216 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1217 | } | |
1218 | ||
99f1fe18 AC |
1219 | /** |
1220 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1221 | * @driver: the driver for the tty | |
1222 | * @idx: the minor number | |
23499705 | 1223 | * |
99f1fe18 | 1224 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1225 | * |
99f1fe18 AC |
1226 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1227 | * be held until the 'fast-open' is also done. Will change once we | |
1228 | * have refcounting in the driver and per driver locking | |
23499705 | 1229 | */ |
a47d545f | 1230 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1231 | struct inode *inode, int idx) |
23499705 | 1232 | { |
99f1fe18 | 1233 | if (driver->ops->lookup) |
15f1a633 | 1234 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1235 | |
d4834267 | 1236 | return driver->ttys[idx]; |
23499705 SB |
1237 | } |
1238 | ||
bf970ee4 AC |
1239 | /** |
1240 | * tty_init_termios - helper for termios setup | |
1241 | * @tty: the tty to set up | |
1242 | * | |
1243 | * Initialise the termios structures for this tty. Thus runs under | |
1244 | * the tty_mutex currently so we can be relaxed about ordering. | |
1245 | */ | |
1246 | ||
1247 | int tty_init_termios(struct tty_struct *tty) | |
1248 | { | |
fe6e29fd | 1249 | struct ktermios *tp; |
bf970ee4 AC |
1250 | int idx = tty->index; |
1251 | ||
1252 | tp = tty->driver->termios[idx]; | |
bf970ee4 | 1253 | if (tp == NULL) { |
fe6e29fd AC |
1254 | tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
1255 | if (tp == NULL) | |
bf970ee4 | 1256 | return -ENOMEM; |
bf970ee4 AC |
1257 | memcpy(tp, &tty->driver->init_termios, |
1258 | sizeof(struct ktermios)); | |
1259 | tty->driver->termios[idx] = tp; | |
bf970ee4 AC |
1260 | } |
1261 | tty->termios = tp; | |
fe6e29fd | 1262 | tty->termios_locked = tp + 1; |
bf970ee4 AC |
1263 | |
1264 | /* Compatibility until drivers always set this */ | |
1265 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1266 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1267 | return 0; | |
1268 | } | |
fe1ae7fd | 1269 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1270 | |
66d450e8 JS |
1271 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1272 | { | |
1273 | int ret = tty_init_termios(tty); | |
1274 | if (ret) | |
1275 | return ret; | |
1276 | ||
1277 | tty_driver_kref_get(driver); | |
1278 | tty->count++; | |
1279 | driver->ttys[tty->index] = tty; | |
1280 | return 0; | |
1281 | } | |
1282 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1283 | ||
99f1fe18 | 1284 | /** |
8b0a88d5 AC |
1285 | * tty_driver_install_tty() - install a tty entry in the driver |
1286 | * @driver: the driver for the tty | |
1287 | * @tty: the tty | |
1288 | * | |
1289 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1290 | * will be set by the time this is called. This method is responsible |
1291 | * for ensuring any need additional structures are allocated and | |
1292 | * configured. | |
8b0a88d5 AC |
1293 | * |
1294 | * Locking: tty_mutex for now | |
1295 | */ | |
1296 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1297 | struct tty_struct *tty) | |
1298 | { | |
66d450e8 JS |
1299 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1300 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1301 | } |
1302 | ||
1303 | /** | |
1304 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1305 | * @driver: the driver for the tty | |
1306 | * @idx: the minor number | |
1307 | * | |
1308 | * Remvoe a tty object from the driver tables. The tty->index field | |
1309 | * will be set by the time this is called. | |
1310 | * | |
1311 | * Locking: tty_mutex for now | |
1312 | */ | |
24d406a6 | 1313 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1314 | { |
1315 | if (driver->ops->remove) | |
1316 | driver->ops->remove(driver, tty); | |
1317 | else | |
1318 | driver->ttys[tty->index] = NULL; | |
1319 | } | |
1320 | ||
1321 | /* | |
1322 | * tty_reopen() - fast re-open of an open tty | |
1323 | * @tty - the tty to open | |
23499705 | 1324 | * |
99f1fe18 | 1325 | * Return 0 on success, -errno on error. |
23499705 | 1326 | * |
99f1fe18 AC |
1327 | * Locking: tty_mutex must be held from the time the tty was found |
1328 | * till this open completes. | |
23499705 | 1329 | */ |
99f1fe18 | 1330 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1331 | { |
1332 | struct tty_driver *driver = tty->driver; | |
1333 | ||
e2efafbf | 1334 | if (test_bit(TTY_CLOSING, &tty->flags) || |
acfa747b | 1335 | test_bit(TTY_HUPPING, &tty->flags) || |
e2efafbf | 1336 | test_bit(TTY_LDISC_CHANGING, &tty->flags)) |
23499705 SB |
1337 | return -EIO; |
1338 | ||
1339 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1340 | driver->subtype == PTY_TYPE_MASTER) { | |
1341 | /* | |
1342 | * special case for PTY masters: only one open permitted, | |
1343 | * and the slave side open count is incremented as well. | |
1344 | */ | |
1345 | if (tty->count) | |
1346 | return -EIO; | |
1347 | ||
1348 | tty->link->count++; | |
1349 | } | |
1350 | tty->count++; | |
23499705 | 1351 | |
1aa4bed8 | 1352 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1353 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1354 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1355 | |
1356 | return 0; | |
1357 | } | |
1358 | ||
af9b897e | 1359 | /** |
d81ed103 | 1360 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1361 | * @driver: tty driver we are opening a device on |
1362 | * @idx: device index | |
15582d36 | 1363 | * @ret_tty: returned tty structure |
af9b897e AC |
1364 | * |
1365 | * Prepare a tty device. This may not be a "new" clean device but | |
1366 | * could also be an active device. The pty drivers require special | |
1367 | * handling because of this. | |
1368 | * | |
1369 | * Locking: | |
1370 | * The function is called under the tty_mutex, which | |
1371 | * protects us from the tty struct or driver itself going away. | |
1372 | * | |
1373 | * On exit the tty device has the line discipline attached and | |
1374 | * a reference count of 1. If a pair was created for pty/tty use | |
1375 | * and the other was a pty master then it too has a reference count of 1. | |
1376 | * | |
1da177e4 | 1377 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1378 | * failed open. The new code protects the open with a mutex, so it's |
1379 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1380 | * relaxed for the (most common) case of reopening a tty. |
1381 | */ | |
af9b897e | 1382 | |
593a27c4 | 1383 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1384 | { |
bf970ee4 | 1385 | struct tty_struct *tty; |
73ec06fc | 1386 | int retval; |
1da177e4 | 1387 | |
1da177e4 LT |
1388 | /* |
1389 | * First time open is complex, especially for PTY devices. | |
1390 | * This code guarantees that either everything succeeds and the | |
1391 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1392 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1393 | * and locked termios may be retained.) |
1394 | */ | |
1395 | ||
73ec06fc AC |
1396 | if (!try_module_get(driver->owner)) |
1397 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1398 | |
1da177e4 | 1399 | tty = alloc_tty_struct(); |
d5543503 JS |
1400 | if (!tty) { |
1401 | retval = -ENOMEM; | |
1402 | goto err_module_put; | |
1403 | } | |
bf970ee4 | 1404 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1405 | |
73ec06fc | 1406 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1407 | if (retval < 0) |
a9dccddb | 1408 | goto err_deinit_tty; |
8b0a88d5 | 1409 | |
04831dc1 JS |
1410 | if (!tty->port) |
1411 | tty->port = driver->ports[idx]; | |
1412 | ||
37bdfb07 | 1413 | /* |
1da177e4 | 1414 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1415 | * If we fail here just call release_tty to clean up. No need |
1416 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1417 | */ |
bf970ee4 | 1418 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1419 | if (retval) |
d5543503 | 1420 | goto err_release_tty; |
73ec06fc | 1421 | return tty; |
1da177e4 | 1422 | |
a9dccddb JS |
1423 | err_deinit_tty: |
1424 | deinitialize_tty_struct(tty); | |
d5543503 JS |
1425 | free_tty_struct(tty); |
1426 | err_module_put: | |
1da177e4 | 1427 | module_put(driver->owner); |
d5543503 | 1428 | return ERR_PTR(retval); |
1da177e4 | 1429 | |
d5698c28 | 1430 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1431 | err_release_tty: |
5a3c6b25 | 1432 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1433 | "clearing slot %d\n", idx); |
d5698c28 | 1434 | release_tty(tty, idx); |
73ec06fc | 1435 | return ERR_PTR(retval); |
1da177e4 LT |
1436 | } |
1437 | ||
feebed65 AC |
1438 | void tty_free_termios(struct tty_struct *tty) |
1439 | { | |
1440 | struct ktermios *tp; | |
1441 | int idx = tty->index; | |
1442 | /* Kill this flag and push into drivers for locking etc */ | |
1443 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1444 | /* FIXME: Locking on ->termios array */ | |
1445 | tp = tty->termios; | |
1446 | tty->driver->termios[idx] = NULL; | |
1447 | kfree(tp); | |
feebed65 AC |
1448 | } |
1449 | } | |
1450 | EXPORT_SYMBOL(tty_free_termios); | |
1451 | ||
1452 | void tty_shutdown(struct tty_struct *tty) | |
1453 | { | |
8b0a88d5 | 1454 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1455 | tty_free_termios(tty); |
1456 | } | |
1457 | EXPORT_SYMBOL(tty_shutdown); | |
1458 | ||
af9b897e | 1459 | /** |
d5698c28 | 1460 | * release_one_tty - release tty structure memory |
9c9f4ded | 1461 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1462 | * |
1463 | * Releases memory associated with a tty structure, and clears out the | |
1464 | * driver table slots. This function is called when a device is no longer | |
1465 | * in use. It also gets called when setup of a device fails. | |
1466 | * | |
1467 | * Locking: | |
1468 | * tty_mutex - sometimes only | |
1469 | * takes the file list lock internally when working on the list | |
1470 | * of ttys that the driver keeps. | |
b50989dc AC |
1471 | * |
1472 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1473 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1474 | */ |
b50989dc | 1475 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1476 | { |
b50989dc AC |
1477 | struct tty_struct *tty = |
1478 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1479 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1480 | |
f278a2f7 DY |
1481 | if (tty->ops->cleanup) |
1482 | tty->ops->cleanup(tty); | |
1483 | ||
1da177e4 | 1484 | tty->magic = 0; |
7d7b93c1 | 1485 | tty_driver_kref_put(driver); |
6f967f78 | 1486 | module_put(driver->owner); |
d5698c28 | 1487 | |
ee2ffa0d | 1488 | spin_lock(&tty_files_lock); |
1da177e4 | 1489 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1490 | spin_unlock(&tty_files_lock); |
d5698c28 | 1491 | |
6da8d866 ON |
1492 | put_pid(tty->pgrp); |
1493 | put_pid(tty->session); | |
1da177e4 LT |
1494 | free_tty_struct(tty); |
1495 | } | |
1496 | ||
b50989dc AC |
1497 | static void queue_release_one_tty(struct kref *kref) |
1498 | { | |
1499 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 DY |
1500 | |
1501 | if (tty->ops->shutdown) | |
1502 | tty->ops->shutdown(tty); | |
1503 | else | |
1504 | tty_shutdown(tty); | |
1505 | ||
b50989dc AC |
1506 | /* The hangup queue is now free so we can reuse it rather than |
1507 | waste a chunk of memory for each port */ | |
1508 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1509 | schedule_work(&tty->hangup_work); | |
1510 | } | |
1511 | ||
9c9f4ded AC |
1512 | /** |
1513 | * tty_kref_put - release a tty kref | |
1514 | * @tty: tty device | |
1515 | * | |
1516 | * Release a reference to a tty device and if need be let the kref | |
1517 | * layer destruct the object for us | |
1518 | */ | |
1519 | ||
1520 | void tty_kref_put(struct tty_struct *tty) | |
1521 | { | |
1522 | if (tty) | |
b50989dc | 1523 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1524 | } |
1525 | EXPORT_SYMBOL(tty_kref_put); | |
1526 | ||
d5698c28 CH |
1527 | /** |
1528 | * release_tty - release tty structure memory | |
1529 | * | |
1530 | * Release both @tty and a possible linked partner (think pty pair), | |
1531 | * and decrement the refcount of the backing module. | |
1532 | * | |
1533 | * Locking: | |
1534 | * tty_mutex - sometimes only | |
1535 | * takes the file list lock internally when working on the list | |
1536 | * of ttys that the driver keeps. | |
1537 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1538 | * |
d5698c28 CH |
1539 | */ |
1540 | static void release_tty(struct tty_struct *tty, int idx) | |
1541 | { | |
9c9f4ded AC |
1542 | /* This should always be true but check for the moment */ |
1543 | WARN_ON(tty->index != idx); | |
1544 | ||
d5698c28 | 1545 | if (tty->link) |
9c9f4ded AC |
1546 | tty_kref_put(tty->link); |
1547 | tty_kref_put(tty); | |
d5698c28 CH |
1548 | } |
1549 | ||
955787ca JS |
1550 | /** |
1551 | * tty_release_checks - check a tty before real release | |
1552 | * @tty: tty to check | |
1553 | * @o_tty: link of @tty (if any) | |
1554 | * @idx: index of the tty | |
1555 | * | |
1556 | * Performs some paranoid checking before true release of the @tty. | |
1557 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1558 | */ | |
1559 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1560 | int idx) | |
1561 | { | |
1562 | #ifdef TTY_PARANOIA_CHECK | |
1563 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1564 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1565 | __func__, tty->name); | |
955787ca JS |
1566 | return -1; |
1567 | } | |
1568 | ||
1569 | /* not much to check for devpts */ | |
1570 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1571 | return 0; | |
1572 | ||
1573 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1574 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1575 | __func__, idx, tty->name); | |
955787ca JS |
1576 | return -1; |
1577 | } | |
1578 | if (tty->termios != tty->driver->termios[idx]) { | |
9de44bd6 JS |
1579 | printk(KERN_DEBUG "%s: driver.termios[%d] not termios for (%s)\n", |
1580 | __func__, idx, tty->name); | |
955787ca JS |
1581 | return -1; |
1582 | } | |
1583 | if (tty->driver->other) { | |
1584 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1585 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1586 | __func__, idx, tty->name); | |
955787ca JS |
1587 | return -1; |
1588 | } | |
1589 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
9de44bd6 JS |
1590 | printk(KERN_DEBUG "%s: other->termios[%d] not o_termios for (%s)\n", |
1591 | __func__, idx, tty->name); | |
955787ca JS |
1592 | return -1; |
1593 | } | |
1594 | if (o_tty->link != tty) { | |
9de44bd6 | 1595 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1596 | return -1; |
1597 | } | |
1598 | } | |
1599 | #endif | |
1600 | return 0; | |
1601 | } | |
1602 | ||
eeb89d91 AC |
1603 | /** |
1604 | * tty_release - vfs callback for close | |
1605 | * @inode: inode of tty | |
1606 | * @filp: file pointer for handle to tty | |
1607 | * | |
1608 | * Called the last time each file handle is closed that references | |
1609 | * this tty. There may however be several such references. | |
1610 | * | |
1611 | * Locking: | |
1612 | * Takes bkl. See tty_release_dev | |
1613 | * | |
1da177e4 LT |
1614 | * Even releasing the tty structures is a tricky business.. We have |
1615 | * to be very careful that the structures are all released at the | |
1616 | * same time, as interrupts might otherwise get the wrong pointers. | |
1617 | * | |
1618 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1619 | * lead to double frees or releasing memory still in use. | |
1620 | */ | |
eeb89d91 AC |
1621 | |
1622 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1623 | { |
d996b62a NP |
1624 | struct tty_struct *tty = file_tty(filp); |
1625 | struct tty_struct *o_tty; | |
1da177e4 | 1626 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1627 | int devpts; |
1da177e4 LT |
1628 | int idx; |
1629 | char buf[64]; | |
37bdfb07 | 1630 | |
9de44bd6 | 1631 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1632 | return 0; |
1da177e4 | 1633 | |
f309532b | 1634 | tty_lock(); |
9de44bd6 | 1635 | check_tty_count(tty, __func__); |
1da177e4 | 1636 | |
ec79d605 | 1637 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1638 | |
1639 | idx = tty->index; | |
1640 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1641 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1642 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1643 | o_tty = tty->link; |
1644 | ||
955787ca | 1645 | if (tty_release_checks(tty, o_tty, idx)) { |
f309532b | 1646 | tty_unlock(); |
eeb89d91 | 1647 | return 0; |
1da177e4 | 1648 | } |
1da177e4 LT |
1649 | |
1650 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1651 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1652 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1653 | #endif |
1654 | ||
f34d7a5b AC |
1655 | if (tty->ops->close) |
1656 | tty->ops->close(tty, filp); | |
1da177e4 | 1657 | |
f309532b | 1658 | tty_unlock(); |
1da177e4 LT |
1659 | /* |
1660 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1661 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1662 | * wait queues and kick everyone out _before_ actually starting to | |
1663 | * close. This ensures that we won't block while releasing the tty | |
1664 | * structure. | |
1665 | * | |
1666 | * The test for the o_tty closing is necessary, since the master and | |
1667 | * slave sides may close in any order. If the slave side closes out | |
1668 | * first, its count will be one, since the master side holds an open. | |
1669 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1670 | * so we do it now. | |
1671 | * | |
1672 | * Note that it's possible for the tty to be opened again while we're | |
1673 | * flushing out waiters. By recalculating the closing flags before | |
1674 | * each iteration we avoid any problems. | |
1675 | */ | |
1676 | while (1) { | |
1677 | /* Guard against races with tty->count changes elsewhere and | |
1678 | opens on /dev/tty */ | |
37bdfb07 | 1679 | |
70522e12 | 1680 | mutex_lock(&tty_mutex); |
f309532b | 1681 | tty_lock(); |
1da177e4 LT |
1682 | tty_closing = tty->count <= 1; |
1683 | o_tty_closing = o_tty && | |
1684 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1685 | do_sleep = 0; |
1686 | ||
1687 | if (tty_closing) { | |
1688 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1689 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1690 | do_sleep++; |
1691 | } | |
1692 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1693 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1694 | do_sleep++; |
1695 | } | |
1696 | } | |
1697 | if (o_tty_closing) { | |
1698 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1699 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1700 | do_sleep++; |
1701 | } | |
1702 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1703 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1704 | do_sleep++; |
1705 | } | |
1706 | } | |
1707 | if (!do_sleep) | |
1708 | break; | |
1709 | ||
9de44bd6 JS |
1710 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1711 | __func__, tty_name(tty, buf)); | |
f309532b | 1712 | tty_unlock(); |
70522e12 | 1713 | mutex_unlock(&tty_mutex); |
1da177e4 | 1714 | schedule(); |
37bdfb07 | 1715 | } |
1da177e4 LT |
1716 | |
1717 | /* | |
37bdfb07 AC |
1718 | * The closing flags are now consistent with the open counts on |
1719 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1720 | * block, so it's safe to proceed with closing. |
1721 | */ | |
1da177e4 LT |
1722 | if (pty_master) { |
1723 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1724 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1725 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1726 | o_tty->count = 0; |
1727 | } | |
1728 | } | |
1729 | if (--tty->count < 0) { | |
9de44bd6 JS |
1730 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1731 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1732 | tty->count = 0; |
1733 | } | |
37bdfb07 | 1734 | |
1da177e4 LT |
1735 | /* |
1736 | * We've decremented tty->count, so we need to remove this file | |
1737 | * descriptor off the tty->tty_files list; this serves two | |
1738 | * purposes: | |
1739 | * - check_tty_count sees the correct number of file descriptors | |
1740 | * associated with this tty. | |
1741 | * - do_tty_hangup no longer sees this file descriptor as | |
1742 | * something that needs to be handled for hangups. | |
1743 | */ | |
d996b62a | 1744 | tty_del_file(filp); |
1da177e4 LT |
1745 | |
1746 | /* | |
1747 | * Perform some housekeeping before deciding whether to return. | |
1748 | * | |
1749 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1750 | * case of a pty we may have to wait around for the other side | |
1751 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1752 | */ | |
37bdfb07 | 1753 | if (tty_closing) |
1da177e4 | 1754 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1755 | if (o_tty_closing) |
1da177e4 LT |
1756 | set_bit(TTY_CLOSING, &o_tty->flags); |
1757 | ||
1758 | /* | |
1759 | * If _either_ side is closing, make sure there aren't any | |
1760 | * processes that still think tty or o_tty is their controlling | |
1761 | * tty. | |
1762 | */ | |
1763 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1764 | read_lock(&tasklist_lock); |
24ec839c | 1765 | session_clear_tty(tty->session); |
1da177e4 | 1766 | if (o_tty) |
24ec839c | 1767 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1768 | read_unlock(&tasklist_lock); |
1769 | } | |
1770 | ||
70522e12 | 1771 | mutex_unlock(&tty_mutex); |
da965822 | 1772 | |
1da177e4 | 1773 | /* check whether both sides are closing ... */ |
eeb89d91 | 1774 | if (!tty_closing || (o_tty && !o_tty_closing)) { |
f309532b | 1775 | tty_unlock(); |
eeb89d91 AC |
1776 | return 0; |
1777 | } | |
37bdfb07 | 1778 | |
1da177e4 | 1779 | #ifdef TTY_DEBUG_HANGUP |
9de44bd6 | 1780 | printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__); |
1da177e4 LT |
1781 | #endif |
1782 | /* | |
01e1abb2 | 1783 | * Ask the line discipline code to release its structures |
1da177e4 | 1784 | */ |
01e1abb2 | 1785 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1786 | /* |
d5698c28 | 1787 | * The release_tty function takes care of the details of clearing |
f309532b | 1788 | * the slots and preserving the termios structure. |
1da177e4 | 1789 | */ |
d5698c28 | 1790 | release_tty(tty, idx); |
1da177e4 | 1791 | |
1da177e4 | 1792 | /* Make this pty number available for reallocation */ |
718a9163 | 1793 | if (devpts) |
15f1a633 | 1794 | devpts_kill_index(inode, idx); |
f309532b | 1795 | tty_unlock(); |
eeb89d91 | 1796 | return 0; |
1da177e4 LT |
1797 | } |
1798 | ||
b82154ac JS |
1799 | /** |
1800 | * tty_open_current_tty - get tty of current task for open | |
1801 | * @device: device number | |
1802 | * @filp: file pointer to tty | |
1803 | * @return: tty of the current task iff @device is /dev/tty | |
1804 | * | |
1805 | * We cannot return driver and index like for the other nodes because | |
1806 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1807 | * |
1808 | * We need to move to returning a refcounted object from all the lookup | |
1809 | * paths including this one. | |
b82154ac JS |
1810 | */ |
1811 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1812 | { | |
1813 | struct tty_struct *tty; | |
1814 | ||
1815 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1816 | return NULL; | |
1817 | ||
1818 | tty = get_current_tty(); | |
1819 | if (!tty) | |
1820 | return ERR_PTR(-ENXIO); | |
1821 | ||
1822 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1823 | /* noctty = 1; */ | |
1824 | tty_kref_put(tty); | |
1825 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1826 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1827 | return tty; |
1828 | } | |
1829 | ||
5b5e7040 JS |
1830 | /** |
1831 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1832 | * @device: device number | |
1833 | * @filp: file pointer to tty | |
1834 | * @noctty: set if the device should not become a controlling tty | |
1835 | * @index: index for the device in the @return driver | |
1836 | * @return: driver for this inode (with increased refcount) | |
1837 | * | |
1838 | * If @return is not erroneous, the caller is responsible to decrement the | |
1839 | * refcount by tty_driver_kref_put. | |
1840 | * | |
1841 | * Locking: tty_mutex protects get_tty_driver | |
1842 | */ | |
1843 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1844 | int *noctty, int *index) | |
1845 | { | |
1846 | struct tty_driver *driver; | |
1847 | ||
2cd0050c | 1848 | switch (device) { |
5b5e7040 | 1849 | #ifdef CONFIG_VT |
2cd0050c | 1850 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1851 | extern struct tty_driver *console_driver; |
1852 | driver = tty_driver_kref_get(console_driver); | |
1853 | *index = fg_console; | |
1854 | *noctty = 1; | |
2cd0050c | 1855 | break; |
5b5e7040 JS |
1856 | } |
1857 | #endif | |
2cd0050c | 1858 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1859 | struct tty_driver *console_driver = console_device(index); |
1860 | if (console_driver) { | |
1861 | driver = tty_driver_kref_get(console_driver); | |
1862 | if (driver) { | |
1863 | /* Don't let /dev/console block */ | |
1864 | filp->f_flags |= O_NONBLOCK; | |
1865 | *noctty = 1; | |
2cd0050c | 1866 | break; |
5b5e7040 JS |
1867 | } |
1868 | } | |
1869 | return ERR_PTR(-ENODEV); | |
1870 | } | |
2cd0050c JS |
1871 | default: |
1872 | driver = get_tty_driver(device, index); | |
1873 | if (!driver) | |
1874 | return ERR_PTR(-ENODEV); | |
1875 | break; | |
1876 | } | |
5b5e7040 JS |
1877 | return driver; |
1878 | } | |
1879 | ||
af9b897e | 1880 | /** |
eeb89d91 | 1881 | * tty_open - open a tty device |
af9b897e AC |
1882 | * @inode: inode of device file |
1883 | * @filp: file pointer to tty | |
1da177e4 | 1884 | * |
af9b897e AC |
1885 | * tty_open and tty_release keep up the tty count that contains the |
1886 | * number of opens done on a tty. We cannot use the inode-count, as | |
1887 | * different inodes might point to the same tty. | |
1da177e4 | 1888 | * |
af9b897e AC |
1889 | * Open-counting is needed for pty masters, as well as for keeping |
1890 | * track of serial lines: DTR is dropped when the last close happens. | |
1891 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1892 | * | |
1893 | * The termios state of a pty is reset on first open so that | |
1894 | * settings don't persist across reuse. | |
1895 | * | |
5b5e7040 | 1896 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1897 | * tty->count should protect the rest. |
1898 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1899 | */ |
af9b897e | 1900 | |
eeb89d91 | 1901 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1902 | { |
b82154ac | 1903 | struct tty_struct *tty; |
1da177e4 | 1904 | int noctty, retval; |
b82154ac | 1905 | struct tty_driver *driver = NULL; |
1da177e4 LT |
1906 | int index; |
1907 | dev_t device = inode->i_rdev; | |
846c151a | 1908 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1909 | |
1910 | nonseekable_open(inode, filp); | |
37bdfb07 | 1911 | |
1da177e4 | 1912 | retry_open: |
fa90e1c9 JS |
1913 | retval = tty_alloc_file(filp); |
1914 | if (retval) | |
1915 | return -ENOMEM; | |
1916 | ||
1da177e4 LT |
1917 | noctty = filp->f_flags & O_NOCTTY; |
1918 | index = -1; | |
1919 | retval = 0; | |
37bdfb07 | 1920 | |
70522e12 | 1921 | mutex_lock(&tty_mutex); |
f309532b LT |
1922 | tty_lock(); |
1923 | ||
b82154ac JS |
1924 | tty = tty_open_current_tty(device, filp); |
1925 | if (IS_ERR(tty)) { | |
ba5db448 JS |
1926 | retval = PTR_ERR(tty); |
1927 | goto err_unlock; | |
5b5e7040 JS |
1928 | } else if (!tty) { |
1929 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
1930 | if (IS_ERR(driver)) { | |
ba5db448 JS |
1931 | retval = PTR_ERR(driver); |
1932 | goto err_unlock; | |
1da177e4 | 1933 | } |
1da177e4 | 1934 | |
4a2b5fdd | 1935 | /* check whether we're reopening an existing tty */ |
15f1a633 | 1936 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 1937 | if (IS_ERR(tty)) { |
ba5db448 JS |
1938 | retval = PTR_ERR(tty); |
1939 | goto err_unlock; | |
808ffa3d | 1940 | } |
4a2b5fdd SB |
1941 | } |
1942 | ||
1943 | if (tty) { | |
1944 | retval = tty_reopen(tty); | |
f309532b | 1945 | if (retval) |
4a2b5fdd | 1946 | tty = ERR_PTR(retval); |
f309532b | 1947 | } else |
593a27c4 | 1948 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 1949 | |
70522e12 | 1950 | mutex_unlock(&tty_mutex); |
b82154ac JS |
1951 | if (driver) |
1952 | tty_driver_kref_put(driver); | |
eeb89d91 | 1953 | if (IS_ERR(tty)) { |
f309532b | 1954 | tty_unlock(); |
ba5db448 JS |
1955 | retval = PTR_ERR(tty); |
1956 | goto err_file; | |
eeb89d91 | 1957 | } |
1da177e4 | 1958 | |
fa90e1c9 | 1959 | tty_add_file(tty, filp); |
d996b62a | 1960 | |
9de44bd6 | 1961 | check_tty_count(tty, __func__); |
1da177e4 LT |
1962 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1963 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1964 | noctty = 1; | |
1965 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 1966 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 1967 | #endif |
909bc774 HRK |
1968 | if (tty->ops->open) |
1969 | retval = tty->ops->open(tty, filp); | |
1970 | else | |
1971 | retval = -ENODEV; | |
1da177e4 LT |
1972 | filp->f_flags = saved_flags; |
1973 | ||
37bdfb07 AC |
1974 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1975 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1976 | retval = -EBUSY; |
1977 | ||
1978 | if (retval) { | |
1979 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1980 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
1981 | retval, tty->name); | |
1da177e4 | 1982 | #endif |
f309532b | 1983 | tty_unlock(); /* need to call tty_release without BTM */ |
eeb89d91 | 1984 | tty_release(inode, filp); |
64ba3dc3 | 1985 | if (retval != -ERESTARTSYS) |
1da177e4 | 1986 | return retval; |
64ba3dc3 AB |
1987 | |
1988 | if (signal_pending(current)) | |
1da177e4 | 1989 | return retval; |
64ba3dc3 | 1990 | |
1da177e4 LT |
1991 | schedule(); |
1992 | /* | |
1993 | * Need to reset f_op in case a hangup happened. | |
1994 | */ | |
f309532b | 1995 | tty_lock(); |
1da177e4 LT |
1996 | if (filp->f_op == &hung_up_tty_fops) |
1997 | filp->f_op = &tty_fops; | |
f309532b | 1998 | tty_unlock(); |
1da177e4 LT |
1999 | goto retry_open; |
2000 | } | |
f309532b | 2001 | tty_unlock(); |
eeb89d91 | 2002 | |
24ec839c PZ |
2003 | |
2004 | mutex_lock(&tty_mutex); | |
f309532b | 2005 | tty_lock(); |
24ec839c | 2006 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2007 | if (!noctty && |
2008 | current->signal->leader && | |
2009 | !current->signal->tty && | |
ab521dc0 | 2010 | tty->session == NULL) |
2a65f1d9 | 2011 | __proc_set_tty(current, tty); |
24ec839c | 2012 | spin_unlock_irq(¤t->sighand->siglock); |
f309532b | 2013 | tty_unlock(); |
24ec839c | 2014 | mutex_unlock(&tty_mutex); |
1da177e4 | 2015 | return 0; |
ba5db448 | 2016 | err_unlock: |
f309532b | 2017 | tty_unlock(); |
ba5db448 JS |
2018 | mutex_unlock(&tty_mutex); |
2019 | /* after locks to avoid deadlock */ | |
2020 | if (!IS_ERR_OR_NULL(driver)) | |
2021 | tty_driver_kref_put(driver); | |
2022 | err_file: | |
2023 | tty_free_file(filp); | |
2024 | return retval; | |
1da177e4 LT |
2025 | } |
2026 | ||
39d95b9d JC |
2027 | |
2028 | ||
af9b897e AC |
2029 | /** |
2030 | * tty_poll - check tty status | |
2031 | * @filp: file being polled | |
2032 | * @wait: poll wait structures to update | |
2033 | * | |
2034 | * Call the line discipline polling method to obtain the poll | |
2035 | * status of the device. | |
2036 | * | |
2037 | * Locking: locks called line discipline but ldisc poll method | |
2038 | * may be re-entered freely by other callers. | |
2039 | */ | |
2040 | ||
37bdfb07 | 2041 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2042 | { |
d996b62a | 2043 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2044 | struct tty_ldisc *ld; |
2045 | int ret = 0; | |
2046 | ||
a7113a96 | 2047 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2048 | return 0; |
37bdfb07 | 2049 | |
1da177e4 | 2050 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2051 | if (ld->ops->poll) |
2052 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2053 | tty_ldisc_deref(ld); |
2054 | return ret; | |
2055 | } | |
2056 | ||
ec79d605 | 2057 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2058 | { |
d996b62a | 2059 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2060 | unsigned long flags; |
5d1e3230 | 2061 | int retval = 0; |
1da177e4 | 2062 | |
a7113a96 | 2063 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2064 | goto out; |
37bdfb07 | 2065 | |
1da177e4 LT |
2066 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2067 | if (retval <= 0) | |
5d1e3230 | 2068 | goto out; |
1da177e4 LT |
2069 | |
2070 | if (on) { | |
ab521dc0 EB |
2071 | enum pid_type type; |
2072 | struct pid *pid; | |
1da177e4 LT |
2073 | if (!waitqueue_active(&tty->read_wait)) |
2074 | tty->minimum_to_wake = 1; | |
47f86834 | 2075 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2076 | if (tty->pgrp) { |
2077 | pid = tty->pgrp; | |
2078 | type = PIDTYPE_PGID; | |
2079 | } else { | |
2080 | pid = task_pid(current); | |
2081 | type = PIDTYPE_PID; | |
2082 | } | |
80e1e823 | 2083 | get_pid(pid); |
70362511 | 2084 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2085 | retval = __f_setown(filp, pid, type, 0); |
2086 | put_pid(pid); | |
1da177e4 | 2087 | if (retval) |
5d1e3230 | 2088 | goto out; |
1da177e4 LT |
2089 | } else { |
2090 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2091 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2092 | } | |
5d1e3230 JC |
2093 | retval = 0; |
2094 | out: | |
ec79d605 AB |
2095 | return retval; |
2096 | } | |
2097 | ||
2098 | static int tty_fasync(int fd, struct file *filp, int on) | |
2099 | { | |
2100 | int retval; | |
f309532b | 2101 | tty_lock(); |
ec79d605 | 2102 | retval = __tty_fasync(fd, filp, on); |
f309532b | 2103 | tty_unlock(); |
5d1e3230 | 2104 | return retval; |
1da177e4 LT |
2105 | } |
2106 | ||
af9b897e AC |
2107 | /** |
2108 | * tiocsti - fake input character | |
2109 | * @tty: tty to fake input into | |
2110 | * @p: pointer to character | |
2111 | * | |
3a4fa0a2 | 2112 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2113 | * input management. |
2114 | * | |
2115 | * FIXME: does not honour flow control ?? | |
2116 | * | |
2117 | * Locking: | |
2118 | * Called functions take tty_ldisc_lock | |
2119 | * current->signal->tty check is safe without locks | |
28298232 AC |
2120 | * |
2121 | * FIXME: may race normal receive processing | |
af9b897e AC |
2122 | */ |
2123 | ||
1da177e4 LT |
2124 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2125 | { | |
2126 | char ch, mbz = 0; | |
2127 | struct tty_ldisc *ld; | |
37bdfb07 | 2128 | |
1da177e4 LT |
2129 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2130 | return -EPERM; | |
2131 | if (get_user(ch, p)) | |
2132 | return -EFAULT; | |
1e641743 | 2133 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2134 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2135 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2136 | tty_ldisc_deref(ld); |
2137 | return 0; | |
2138 | } | |
2139 | ||
af9b897e AC |
2140 | /** |
2141 | * tiocgwinsz - implement window query ioctl | |
2142 | * @tty; tty | |
2143 | * @arg: user buffer for result | |
2144 | * | |
808a0d38 | 2145 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2146 | * |
24ec839c | 2147 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2148 | * is consistent. |
af9b897e AC |
2149 | */ |
2150 | ||
37bdfb07 | 2151 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2152 | { |
808a0d38 AC |
2153 | int err; |
2154 | ||
5785c95b | 2155 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2156 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2157 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2158 | |
2159 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2160 | } |
2161 | ||
af9b897e | 2162 | /** |
8c9a9dd0 AC |
2163 | * tty_do_resize - resize event |
2164 | * @tty: tty being resized | |
8c9a9dd0 AC |
2165 | * @rows: rows (character) |
2166 | * @cols: cols (character) | |
2167 | * | |
3ad2f3fb | 2168 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2169 | * peform a terminal resize correctly |
af9b897e AC |
2170 | */ |
2171 | ||
fc6f6238 | 2172 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2173 | { |
fc6f6238 | 2174 | struct pid *pgrp; |
47f86834 | 2175 | unsigned long flags; |
1da177e4 | 2176 | |
fc6f6238 AC |
2177 | /* Lock the tty */ |
2178 | mutex_lock(&tty->termios_mutex); | |
2179 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2180 | goto done; |
47f86834 AC |
2181 | /* Get the PID values and reference them so we can |
2182 | avoid holding the tty ctrl lock while sending signals */ | |
2183 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2184 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2185 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2186 | ||
2187 | if (pgrp) | |
2188 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2189 | put_pid(pgrp); |
47f86834 | 2190 | |
8c9a9dd0 | 2191 | tty->winsize = *ws; |
ca9bda00 | 2192 | done: |
fc6f6238 | 2193 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2194 | return 0; |
2195 | } | |
2196 | ||
8c9a9dd0 AC |
2197 | /** |
2198 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2199 | * @tty; tty side of tty |
8c9a9dd0 AC |
2200 | * @arg: user buffer for result |
2201 | * | |
2202 | * Copies the user idea of the window size to the kernel. Traditionally | |
2203 | * this is just advisory information but for the Linux console it | |
2204 | * actually has driver level meaning and triggers a VC resize. | |
2205 | * | |
2206 | * Locking: | |
25985edc | 2207 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2208 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2209 | * then calls into the default method. | |
2210 | */ | |
2211 | ||
fc6f6238 | 2212 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2213 | { |
2214 | struct winsize tmp_ws; | |
2215 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2216 | return -EFAULT; | |
2217 | ||
2218 | if (tty->ops->resize) | |
fc6f6238 | 2219 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2220 | else |
fc6f6238 | 2221 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2222 | } |
2223 | ||
af9b897e AC |
2224 | /** |
2225 | * tioccons - allow admin to move logical console | |
2226 | * @file: the file to become console | |
2227 | * | |
25985edc | 2228 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2229 | * |
2230 | * Locking: uses redirect_lock to guard the redirect information | |
2231 | */ | |
2232 | ||
1da177e4 LT |
2233 | static int tioccons(struct file *file) |
2234 | { | |
2235 | if (!capable(CAP_SYS_ADMIN)) | |
2236 | return -EPERM; | |
2237 | if (file->f_op->write == redirected_tty_write) { | |
2238 | struct file *f; | |
2239 | spin_lock(&redirect_lock); | |
2240 | f = redirect; | |
2241 | redirect = NULL; | |
2242 | spin_unlock(&redirect_lock); | |
2243 | if (f) | |
2244 | fput(f); | |
2245 | return 0; | |
2246 | } | |
2247 | spin_lock(&redirect_lock); | |
2248 | if (redirect) { | |
2249 | spin_unlock(&redirect_lock); | |
2250 | return -EBUSY; | |
2251 | } | |
2252 | get_file(file); | |
2253 | redirect = file; | |
2254 | spin_unlock(&redirect_lock); | |
2255 | return 0; | |
2256 | } | |
2257 | ||
af9b897e AC |
2258 | /** |
2259 | * fionbio - non blocking ioctl | |
2260 | * @file: file to set blocking value | |
2261 | * @p: user parameter | |
2262 | * | |
2263 | * Historical tty interfaces had a blocking control ioctl before | |
2264 | * the generic functionality existed. This piece of history is preserved | |
2265 | * in the expected tty API of posix OS's. | |
2266 | * | |
6146b9af | 2267 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2268 | */ |
1da177e4 LT |
2269 | |
2270 | static int fionbio(struct file *file, int __user *p) | |
2271 | { | |
2272 | int nonblock; | |
2273 | ||
2274 | if (get_user(nonblock, p)) | |
2275 | return -EFAULT; | |
2276 | ||
db1dd4d3 | 2277 | spin_lock(&file->f_lock); |
1da177e4 LT |
2278 | if (nonblock) |
2279 | file->f_flags |= O_NONBLOCK; | |
2280 | else | |
2281 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2282 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2283 | return 0; |
2284 | } | |
2285 | ||
af9b897e AC |
2286 | /** |
2287 | * tiocsctty - set controlling tty | |
2288 | * @tty: tty structure | |
2289 | * @arg: user argument | |
2290 | * | |
2291 | * This ioctl is used to manage job control. It permits a session | |
2292 | * leader to set this tty as the controlling tty for the session. | |
2293 | * | |
2294 | * Locking: | |
28298232 | 2295 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2296 | * Takes tasklist_lock internally to walk sessions |
2297 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2298 | */ |
2299 | ||
1da177e4 LT |
2300 | static int tiocsctty(struct tty_struct *tty, int arg) |
2301 | { | |
24ec839c | 2302 | int ret = 0; |
ab521dc0 | 2303 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2304 | return ret; |
2305 | ||
2306 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2307 | /* |
2308 | * The process must be a session leader and | |
2309 | * not have a controlling tty already. | |
2310 | */ | |
24ec839c PZ |
2311 | if (!current->signal->leader || current->signal->tty) { |
2312 | ret = -EPERM; | |
2313 | goto unlock; | |
2314 | } | |
2315 | ||
ab521dc0 | 2316 | if (tty->session) { |
1da177e4 LT |
2317 | /* |
2318 | * This tty is already the controlling | |
2319 | * tty for another session group! | |
2320 | */ | |
37bdfb07 | 2321 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2322 | /* |
2323 | * Steal it away | |
2324 | */ | |
1da177e4 | 2325 | read_lock(&tasklist_lock); |
24ec839c | 2326 | session_clear_tty(tty->session); |
1da177e4 | 2327 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2328 | } else { |
2329 | ret = -EPERM; | |
2330 | goto unlock; | |
2331 | } | |
1da177e4 | 2332 | } |
24ec839c PZ |
2333 | proc_set_tty(current, tty); |
2334 | unlock: | |
28298232 | 2335 | mutex_unlock(&tty_mutex); |
24ec839c | 2336 | return ret; |
1da177e4 LT |
2337 | } |
2338 | ||
5d0fdf1e AC |
2339 | /** |
2340 | * tty_get_pgrp - return a ref counted pgrp pid | |
2341 | * @tty: tty to read | |
2342 | * | |
2343 | * Returns a refcounted instance of the pid struct for the process | |
2344 | * group controlling the tty. | |
2345 | */ | |
2346 | ||
2347 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2348 | { | |
2349 | unsigned long flags; | |
2350 | struct pid *pgrp; | |
2351 | ||
2352 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2353 | pgrp = get_pid(tty->pgrp); | |
2354 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2355 | ||
2356 | return pgrp; | |
2357 | } | |
2358 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2359 | ||
af9b897e AC |
2360 | /** |
2361 | * tiocgpgrp - get process group | |
2362 | * @tty: tty passed by user | |
25985edc | 2363 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2364 | * @p: returned pid |
2365 | * | |
2366 | * Obtain the process group of the tty. If there is no process group | |
2367 | * return an error. | |
2368 | * | |
24ec839c | 2369 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2370 | */ |
2371 | ||
1da177e4 LT |
2372 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2373 | { | |
5d0fdf1e AC |
2374 | struct pid *pid; |
2375 | int ret; | |
1da177e4 LT |
2376 | /* |
2377 | * (tty == real_tty) is a cheap way of | |
2378 | * testing if the tty is NOT a master pty. | |
2379 | */ | |
2380 | if (tty == real_tty && current->signal->tty != real_tty) | |
2381 | return -ENOTTY; | |
5d0fdf1e AC |
2382 | pid = tty_get_pgrp(real_tty); |
2383 | ret = put_user(pid_vnr(pid), p); | |
2384 | put_pid(pid); | |
2385 | return ret; | |
1da177e4 LT |
2386 | } |
2387 | ||
af9b897e AC |
2388 | /** |
2389 | * tiocspgrp - attempt to set process group | |
2390 | * @tty: tty passed by user | |
2391 | * @real_tty: tty side device matching tty passed by user | |
2392 | * @p: pid pointer | |
2393 | * | |
2394 | * Set the process group of the tty to the session passed. Only | |
2395 | * permitted where the tty session is our session. | |
2396 | * | |
47f86834 | 2397 | * Locking: RCU, ctrl lock |
af9b897e AC |
2398 | */ |
2399 | ||
1da177e4 LT |
2400 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2401 | { | |
04a2e6a5 EB |
2402 | struct pid *pgrp; |
2403 | pid_t pgrp_nr; | |
1da177e4 | 2404 | int retval = tty_check_change(real_tty); |
47f86834 | 2405 | unsigned long flags; |
1da177e4 LT |
2406 | |
2407 | if (retval == -EIO) | |
2408 | return -ENOTTY; | |
2409 | if (retval) | |
2410 | return retval; | |
2411 | if (!current->signal->tty || | |
2412 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2413 | (real_tty->session != task_session(current))) |
1da177e4 | 2414 | return -ENOTTY; |
04a2e6a5 | 2415 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2416 | return -EFAULT; |
04a2e6a5 | 2417 | if (pgrp_nr < 0) |
1da177e4 | 2418 | return -EINVAL; |
04a2e6a5 | 2419 | rcu_read_lock(); |
b488893a | 2420 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2421 | retval = -ESRCH; |
2422 | if (!pgrp) | |
2423 | goto out_unlock; | |
2424 | retval = -EPERM; | |
2425 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2426 | goto out_unlock; | |
2427 | retval = 0; | |
47f86834 | 2428 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2429 | put_pid(real_tty->pgrp); |
2430 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2431 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2432 | out_unlock: |
2433 | rcu_read_unlock(); | |
2434 | return retval; | |
1da177e4 LT |
2435 | } |
2436 | ||
af9b897e AC |
2437 | /** |
2438 | * tiocgsid - get session id | |
2439 | * @tty: tty passed by user | |
25985edc | 2440 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2441 | * @p: pointer to returned session id |
2442 | * | |
2443 | * Obtain the session id of the tty. If there is no session | |
2444 | * return an error. | |
2445 | * | |
24ec839c | 2446 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2447 | */ |
2448 | ||
1da177e4 LT |
2449 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2450 | { | |
2451 | /* | |
2452 | * (tty == real_tty) is a cheap way of | |
2453 | * testing if the tty is NOT a master pty. | |
2454 | */ | |
2455 | if (tty == real_tty && current->signal->tty != real_tty) | |
2456 | return -ENOTTY; | |
ab521dc0 | 2457 | if (!real_tty->session) |
1da177e4 | 2458 | return -ENOTTY; |
b488893a | 2459 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2460 | } |
2461 | ||
af9b897e AC |
2462 | /** |
2463 | * tiocsetd - set line discipline | |
2464 | * @tty: tty device | |
2465 | * @p: pointer to user data | |
2466 | * | |
2467 | * Set the line discipline according to user request. | |
2468 | * | |
2469 | * Locking: see tty_set_ldisc, this function is just a helper | |
2470 | */ | |
2471 | ||
1da177e4 LT |
2472 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2473 | { | |
2474 | int ldisc; | |
04f378b1 | 2475 | int ret; |
1da177e4 LT |
2476 | |
2477 | if (get_user(ldisc, p)) | |
2478 | return -EFAULT; | |
04f378b1 | 2479 | |
04f378b1 | 2480 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2481 | |
2482 | return ret; | |
1da177e4 LT |
2483 | } |
2484 | ||
af9b897e AC |
2485 | /** |
2486 | * send_break - performed time break | |
2487 | * @tty: device to break on | |
2488 | * @duration: timeout in mS | |
2489 | * | |
2490 | * Perform a timed break on hardware that lacks its own driver level | |
2491 | * timed break functionality. | |
2492 | * | |
2493 | * Locking: | |
28298232 | 2494 | * atomic_write_lock serializes |
af9b897e | 2495 | * |
af9b897e AC |
2496 | */ |
2497 | ||
b20f3ae5 | 2498 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2499 | { |
9e98966c AC |
2500 | int retval; |
2501 | ||
2502 | if (tty->ops->break_ctl == NULL) | |
2503 | return 0; | |
2504 | ||
2505 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2506 | retval = tty->ops->break_ctl(tty, duration); | |
2507 | else { | |
2508 | /* Do the work ourselves */ | |
2509 | if (tty_write_lock(tty, 0) < 0) | |
2510 | return -EINTR; | |
2511 | retval = tty->ops->break_ctl(tty, -1); | |
2512 | if (retval) | |
2513 | goto out; | |
2514 | if (!signal_pending(current)) | |
2515 | msleep_interruptible(duration); | |
2516 | retval = tty->ops->break_ctl(tty, 0); | |
2517 | out: | |
2518 | tty_write_unlock(tty); | |
2519 | if (signal_pending(current)) | |
2520 | retval = -EINTR; | |
2521 | } | |
2522 | return retval; | |
1da177e4 LT |
2523 | } |
2524 | ||
af9b897e | 2525 | /** |
f34d7a5b | 2526 | * tty_tiocmget - get modem status |
af9b897e AC |
2527 | * @tty: tty device |
2528 | * @file: user file pointer | |
2529 | * @p: pointer to result | |
2530 | * | |
2531 | * Obtain the modem status bits from the tty driver if the feature | |
2532 | * is supported. Return -EINVAL if it is not available. | |
2533 | * | |
2534 | * Locking: none (up to the driver) | |
2535 | */ | |
2536 | ||
60b33c13 | 2537 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2538 | { |
2539 | int retval = -EINVAL; | |
2540 | ||
f34d7a5b | 2541 | if (tty->ops->tiocmget) { |
60b33c13 | 2542 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2543 | |
2544 | if (retval >= 0) | |
2545 | retval = put_user(retval, p); | |
2546 | } | |
2547 | return retval; | |
2548 | } | |
2549 | ||
af9b897e | 2550 | /** |
f34d7a5b | 2551 | * tty_tiocmset - set modem status |
af9b897e | 2552 | * @tty: tty device |
af9b897e AC |
2553 | * @cmd: command - clear bits, set bits or set all |
2554 | * @p: pointer to desired bits | |
2555 | * | |
2556 | * Set the modem status bits from the tty driver if the feature | |
2557 | * is supported. Return -EINVAL if it is not available. | |
2558 | * | |
2559 | * Locking: none (up to the driver) | |
2560 | */ | |
2561 | ||
20b9d177 | 2562 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2563 | unsigned __user *p) |
2564 | { | |
ae677517 AC |
2565 | int retval; |
2566 | unsigned int set, clear, val; | |
1da177e4 | 2567 | |
ae677517 AC |
2568 | if (tty->ops->tiocmset == NULL) |
2569 | return -EINVAL; | |
1da177e4 | 2570 | |
ae677517 AC |
2571 | retval = get_user(val, p); |
2572 | if (retval) | |
2573 | return retval; | |
2574 | set = clear = 0; | |
2575 | switch (cmd) { | |
2576 | case TIOCMBIS: | |
2577 | set = val; | |
2578 | break; | |
2579 | case TIOCMBIC: | |
2580 | clear = val; | |
2581 | break; | |
2582 | case TIOCMSET: | |
2583 | set = val; | |
2584 | clear = ~val; | |
2585 | break; | |
2586 | } | |
2587 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2588 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2589 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2590 | } |
2591 | ||
d281da7f AC |
2592 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2593 | { | |
2594 | int retval = -EINVAL; | |
2595 | struct serial_icounter_struct icount; | |
2596 | memset(&icount, 0, sizeof(icount)); | |
2597 | if (tty->ops->get_icount) | |
2598 | retval = tty->ops->get_icount(tty, &icount); | |
2599 | if (retval != 0) | |
2600 | return retval; | |
2601 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2602 | return -EFAULT; | |
2603 | return 0; | |
2604 | } | |
2605 | ||
e8b70e7d AC |
2606 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2607 | { | |
2608 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2609 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2610 | tty = tty->link; | |
2611 | return tty; | |
2612 | } | |
2613 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2614 | ||
2615 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2616 | { | |
2617 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2618 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2619 | return tty; | |
2620 | return tty->link; | |
2621 | } | |
2622 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2623 | ||
1da177e4 LT |
2624 | /* |
2625 | * Split this up, as gcc can choke on it otherwise.. | |
2626 | */ | |
04f378b1 | 2627 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2628 | { |
d996b62a NP |
2629 | struct tty_struct *tty = file_tty(file); |
2630 | struct tty_struct *real_tty; | |
1da177e4 LT |
2631 | void __user *p = (void __user *)arg; |
2632 | int retval; | |
2633 | struct tty_ldisc *ld; | |
04f378b1 | 2634 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2635 | |
1da177e4 LT |
2636 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2637 | return -EINVAL; | |
2638 | ||
e8b70e7d | 2639 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2640 | |
2641 | /* | |
2642 | * Factor out some common prep work | |
2643 | */ | |
2644 | switch (cmd) { | |
2645 | case TIOCSETD: | |
2646 | case TIOCSBRK: | |
2647 | case TIOCCBRK: | |
2648 | case TCSBRK: | |
37bdfb07 | 2649 | case TCSBRKP: |
1da177e4 LT |
2650 | retval = tty_check_change(tty); |
2651 | if (retval) | |
2652 | return retval; | |
2653 | if (cmd != TIOCCBRK) { | |
2654 | tty_wait_until_sent(tty, 0); | |
2655 | if (signal_pending(current)) | |
2656 | return -EINTR; | |
2657 | } | |
2658 | break; | |
2659 | } | |
2660 | ||
9e98966c AC |
2661 | /* |
2662 | * Now do the stuff. | |
2663 | */ | |
1da177e4 | 2664 | switch (cmd) { |
37bdfb07 AC |
2665 | case TIOCSTI: |
2666 | return tiocsti(tty, p); | |
2667 | case TIOCGWINSZ: | |
8f520021 | 2668 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2669 | case TIOCSWINSZ: |
fc6f6238 | 2670 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2671 | case TIOCCONS: |
2672 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2673 | case FIONBIO: | |
2674 | return fionbio(file, p); | |
2675 | case TIOCEXCL: | |
2676 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2677 | return 0; | |
2678 | case TIOCNXCL: | |
2679 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2680 | return 0; | |
2681 | case TIOCNOTTY: | |
2682 | if (current->signal->tty != tty) | |
2683 | return -ENOTTY; | |
2684 | no_tty(); | |
2685 | return 0; | |
2686 | case TIOCSCTTY: | |
2687 | return tiocsctty(tty, arg); | |
2688 | case TIOCGPGRP: | |
2689 | return tiocgpgrp(tty, real_tty, p); | |
2690 | case TIOCSPGRP: | |
2691 | return tiocspgrp(tty, real_tty, p); | |
2692 | case TIOCGSID: | |
2693 | return tiocgsid(tty, real_tty, p); | |
2694 | case TIOCGETD: | |
c65c9bc3 | 2695 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2696 | case TIOCSETD: |
2697 | return tiocsetd(tty, p); | |
3c95c985 KS |
2698 | case TIOCVHANGUP: |
2699 | if (!capable(CAP_SYS_ADMIN)) | |
2700 | return -EPERM; | |
2701 | tty_vhangup(tty); | |
2702 | return 0; | |
b7b8de08 WF |
2703 | case TIOCGDEV: |
2704 | { | |
2705 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2706 | return put_user(ret, (unsigned int __user *)p); | |
2707 | } | |
37bdfb07 AC |
2708 | /* |
2709 | * Break handling | |
2710 | */ | |
2711 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2712 | if (tty->ops->break_ctl) |
9e98966c | 2713 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2714 | return 0; |
37bdfb07 | 2715 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2716 | if (tty->ops->break_ctl) |
9e98966c | 2717 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2718 | return 0; |
2719 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2720 | /* non-zero arg means wait for all output data | |
2721 | * to be sent (performed above) but don't send break. | |
2722 | * This is used by the tcdrain() termios function. | |
2723 | */ | |
2724 | if (!arg) | |
2725 | return send_break(tty, 250); | |
2726 | return 0; | |
2727 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2728 | return send_break(tty, arg ? arg*100 : 250); | |
2729 | ||
2730 | case TIOCMGET: | |
60b33c13 | 2731 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2732 | case TIOCMSET: |
2733 | case TIOCMBIC: | |
2734 | case TIOCMBIS: | |
20b9d177 | 2735 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2736 | case TIOCGICOUNT: |
2737 | retval = tty_tiocgicount(tty, p); | |
2738 | /* For the moment allow fall through to the old method */ | |
2739 | if (retval != -EINVAL) | |
2740 | return retval; | |
2741 | break; | |
37bdfb07 AC |
2742 | case TCFLSH: |
2743 | switch (arg) { | |
2744 | case TCIFLUSH: | |
2745 | case TCIOFLUSH: | |
2746 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2747 | tty_buffer_flush(tty); | |
c5c34d48 | 2748 | break; |
37bdfb07 AC |
2749 | } |
2750 | break; | |
1da177e4 | 2751 | } |
f34d7a5b | 2752 | if (tty->ops->ioctl) { |
6caa76b7 | 2753 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2754 | if (retval != -ENOIOCTLCMD) |
2755 | return retval; | |
2756 | } | |
2757 | ld = tty_ldisc_ref_wait(tty); | |
2758 | retval = -EINVAL; | |
a352def2 AC |
2759 | if (ld->ops->ioctl) { |
2760 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2761 | if (retval == -ENOIOCTLCMD) |
2762 | retval = -EINVAL; | |
2763 | } | |
2764 | tty_ldisc_deref(ld); | |
2765 | return retval; | |
2766 | } | |
2767 | ||
e10cc1df | 2768 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2769 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2770 | unsigned long arg) |
2771 | { | |
2772 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2773 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2774 | struct tty_ldisc *ld; |
2775 | int retval = -ENOIOCTLCMD; | |
2776 | ||
2777 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2778 | return -EINVAL; | |
2779 | ||
f34d7a5b | 2780 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2781 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2782 | if (retval != -ENOIOCTLCMD) |
2783 | return retval; | |
2784 | } | |
2785 | ||
2786 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2787 | if (ld->ops->compat_ioctl) |
2788 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2789 | else |
2790 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2791 | tty_ldisc_deref(ld); |
2792 | ||
2793 | return retval; | |
2794 | } | |
2795 | #endif | |
1da177e4 LT |
2796 | |
2797 | /* | |
2798 | * This implements the "Secure Attention Key" --- the idea is to | |
2799 | * prevent trojan horses by killing all processes associated with this | |
2800 | * tty when the user hits the "Secure Attention Key". Required for | |
2801 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2802 | * |
1da177e4 LT |
2803 | * This code could be nicer; ideally it should send a HUP, wait a few |
2804 | * seconds, then send a INT, and then a KILL signal. But you then | |
2805 | * have to coordinate with the init process, since all processes associated | |
2806 | * with the current tty must be dead before the new getty is allowed | |
2807 | * to spawn. | |
2808 | * | |
2809 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2810 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2811 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2812 | * | |
2813 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2814 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2815 | */ | |
8b6312f4 | 2816 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2817 | { |
2818 | #ifdef TTY_SOFT_SAK | |
2819 | tty_hangup(tty); | |
2820 | #else | |
652486fb | 2821 | struct task_struct *g, *p; |
ab521dc0 | 2822 | struct pid *session; |
1da177e4 LT |
2823 | int i; |
2824 | struct file *filp; | |
badf1662 | 2825 | struct fdtable *fdt; |
37bdfb07 | 2826 | |
1da177e4 LT |
2827 | if (!tty) |
2828 | return; | |
24ec839c | 2829 | session = tty->session; |
37bdfb07 | 2830 | |
b3f13deb | 2831 | tty_ldisc_flush(tty); |
1da177e4 | 2832 | |
f34d7a5b | 2833 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2834 | |
1da177e4 | 2835 | read_lock(&tasklist_lock); |
652486fb | 2836 | /* Kill the entire session */ |
ab521dc0 | 2837 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2838 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2839 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2840 | task_pid_nr(p), p->comm); |
652486fb | 2841 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2842 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2843 | /* Now kill any processes that happen to have the |
2844 | * tty open. | |
2845 | */ | |
2846 | do_each_thread(g, p) { | |
2847 | if (p->signal->tty == tty) { | |
1da177e4 | 2848 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2849 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2850 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2851 | send_sig(SIGKILL, p, 1); |
2852 | continue; | |
2853 | } | |
2854 | task_lock(p); | |
2855 | if (p->files) { | |
ca99c1da DS |
2856 | /* |
2857 | * We don't take a ref to the file, so we must | |
2858 | * hold ->file_lock instead. | |
2859 | */ | |
2860 | spin_lock(&p->files->file_lock); | |
badf1662 | 2861 | fdt = files_fdtable(p->files); |
37bdfb07 | 2862 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2863 | filp = fcheck_files(p->files, i); |
2864 | if (!filp) | |
2865 | continue; | |
2866 | if (filp->f_op->read == tty_read && | |
d996b62a | 2867 | file_tty(filp) == tty) { |
1da177e4 LT |
2868 | printk(KERN_NOTICE "SAK: killed process %d" |
2869 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2870 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2871 | force_sig(SIGKILL, p); |
1da177e4 LT |
2872 | break; |
2873 | } | |
2874 | } | |
ca99c1da | 2875 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2876 | } |
2877 | task_unlock(p); | |
652486fb | 2878 | } while_each_thread(g, p); |
1da177e4 LT |
2879 | read_unlock(&tasklist_lock); |
2880 | #endif | |
2881 | } | |
2882 | ||
8b6312f4 EB |
2883 | static void do_SAK_work(struct work_struct *work) |
2884 | { | |
2885 | struct tty_struct *tty = | |
2886 | container_of(work, struct tty_struct, SAK_work); | |
2887 | __do_SAK(tty); | |
2888 | } | |
2889 | ||
1da177e4 LT |
2890 | /* |
2891 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2892 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2893 | * the values which we write to it will be identical to the values which it | |
2894 | * already has. --akpm | |
2895 | */ | |
2896 | void do_SAK(struct tty_struct *tty) | |
2897 | { | |
2898 | if (!tty) | |
2899 | return; | |
1da177e4 LT |
2900 | schedule_work(&tty->SAK_work); |
2901 | } | |
2902 | ||
2903 | EXPORT_SYMBOL(do_SAK); | |
2904 | ||
30004ac9 DES |
2905 | static int dev_match_devt(struct device *dev, void *data) |
2906 | { | |
2907 | dev_t *devt = data; | |
2908 | return dev->devt == *devt; | |
2909 | } | |
2910 | ||
2911 | /* Must put_device() after it's unused! */ | |
2912 | static struct device *tty_get_device(struct tty_struct *tty) | |
2913 | { | |
2914 | dev_t devt = tty_devnum(tty); | |
2915 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2916 | } | |
2917 | ||
2918 | ||
af9b897e AC |
2919 | /** |
2920 | * initialize_tty_struct | |
2921 | * @tty: tty to initialize | |
2922 | * | |
2923 | * This subroutine initializes a tty structure that has been newly | |
2924 | * allocated. | |
2925 | * | |
2926 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2927 | */ |
af9b897e | 2928 | |
bf970ee4 AC |
2929 | void initialize_tty_struct(struct tty_struct *tty, |
2930 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2931 | { |
2932 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2933 | kref_init(&tty->kref); |
1da177e4 | 2934 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2935 | tty_ldisc_init(tty); |
ab521dc0 EB |
2936 | tty->session = NULL; |
2937 | tty->pgrp = NULL; | |
1da177e4 | 2938 | tty->overrun_time = jiffies; |
33f0f88f | 2939 | tty_buffer_init(tty); |
5785c95b | 2940 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2941 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2942 | init_waitqueue_head(&tty->write_wait); |
2943 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2944 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2945 | mutex_init(&tty->atomic_read_lock); |
2946 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2947 | mutex_init(&tty->output_lock); |
2948 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2949 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2950 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2951 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2952 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2953 | |
2954 | tty->driver = driver; | |
2955 | tty->ops = driver->ops; | |
2956 | tty->index = idx; | |
2957 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2958 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2959 | } |
2960 | ||
6716671d JS |
2961 | /** |
2962 | * deinitialize_tty_struct | |
2963 | * @tty: tty to deinitialize | |
2964 | * | |
2965 | * This subroutine deinitializes a tty structure that has been newly | |
2966 | * allocated but tty_release cannot be called on that yet. | |
2967 | * | |
2968 | * Locking: none - tty in question must not be exposed at this point | |
2969 | */ | |
2970 | void deinitialize_tty_struct(struct tty_struct *tty) | |
2971 | { | |
2972 | tty_ldisc_deinit(tty); | |
2973 | } | |
2974 | ||
f34d7a5b AC |
2975 | /** |
2976 | * tty_put_char - write one character to a tty | |
2977 | * @tty: tty | |
2978 | * @ch: character | |
2979 | * | |
2980 | * Write one byte to the tty using the provided put_char method | |
2981 | * if present. Returns the number of characters successfully output. | |
2982 | * | |
2983 | * Note: the specific put_char operation in the driver layer may go | |
2984 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2985 | */ |
af9b897e | 2986 | |
f34d7a5b | 2987 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2988 | { |
f34d7a5b AC |
2989 | if (tty->ops->put_char) |
2990 | return tty->ops->put_char(tty, ch); | |
2991 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2992 | } |
f34d7a5b AC |
2993 | EXPORT_SYMBOL_GPL(tty_put_char); |
2994 | ||
d81ed103 | 2995 | struct class *tty_class; |
1da177e4 LT |
2996 | |
2997 | /** | |
af9b897e AC |
2998 | * tty_register_device - register a tty device |
2999 | * @driver: the tty driver that describes the tty device | |
3000 | * @index: the index in the tty driver for this tty device | |
3001 | * @device: a struct device that is associated with this tty device. | |
3002 | * This field is optional, if there is no known struct device | |
3003 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3004 | * |
01107d34 GKH |
3005 | * Returns a pointer to the struct device for this tty device |
3006 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3007 | * |
af9b897e AC |
3008 | * This call is required to be made to register an individual tty device |
3009 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3010 | * that bit is not set, this function should not be called by a tty | |
3011 | * driver. | |
3012 | * | |
3013 | * Locking: ?? | |
1da177e4 | 3014 | */ |
af9b897e | 3015 | |
01107d34 GKH |
3016 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3017 | struct device *device) | |
1da177e4 LT |
3018 | { |
3019 | char name[64]; | |
3020 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
3021 | ||
3022 | if (index >= driver->num) { | |
3023 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3024 | " (%d).\n", index); | |
1cdcb6b4 | 3025 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3026 | } |
3027 | ||
1da177e4 LT |
3028 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3029 | pty_line_name(driver, index, name); | |
3030 | else | |
3031 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3032 | |
03457cd4 | 3033 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 3034 | } |
7d7b93c1 | 3035 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
3036 | |
3037 | /** | |
af9b897e AC |
3038 | * tty_unregister_device - unregister a tty device |
3039 | * @driver: the tty driver that describes the tty device | |
3040 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3041 | * |
af9b897e AC |
3042 | * If a tty device is registered with a call to tty_register_device() then |
3043 | * this function must be called when the tty device is gone. | |
3044 | * | |
3045 | * Locking: ?? | |
1da177e4 | 3046 | */ |
af9b897e | 3047 | |
1da177e4 LT |
3048 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3049 | { | |
37bdfb07 AC |
3050 | device_destroy(tty_class, |
3051 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 3052 | } |
1da177e4 LT |
3053 | EXPORT_SYMBOL(tty_unregister_device); |
3054 | ||
1a54a76d | 3055 | struct tty_driver *__alloc_tty_driver(int lines, struct module *owner) |
1da177e4 LT |
3056 | { |
3057 | struct tty_driver *driver; | |
3058 | ||
506eb99a | 3059 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 3060 | if (driver) { |
7d7b93c1 | 3061 | kref_init(&driver->kref); |
1da177e4 LT |
3062 | driver->magic = TTY_DRIVER_MAGIC; |
3063 | driver->num = lines; | |
1a54a76d | 3064 | driver->owner = owner; |
1da177e4 LT |
3065 | /* later we'll move allocation of tables here */ |
3066 | } | |
3067 | return driver; | |
3068 | } | |
1a54a76d | 3069 | EXPORT_SYMBOL(__alloc_tty_driver); |
1da177e4 | 3070 | |
7d7b93c1 | 3071 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3072 | { |
7d7b93c1 AC |
3073 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3074 | int i; | |
3075 | struct ktermios *tp; | |
3076 | void *p; | |
3077 | ||
3078 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3079 | /* | |
3080 | * Free the termios and termios_locked structures because | |
3081 | * we don't want to get memory leaks when modular tty | |
3082 | * drivers are removed from the kernel. | |
3083 | */ | |
3084 | for (i = 0; i < driver->num; i++) { | |
3085 | tp = driver->termios[i]; | |
3086 | if (tp) { | |
3087 | driver->termios[i] = NULL; | |
3088 | kfree(tp); | |
3089 | } | |
7d7b93c1 AC |
3090 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3091 | tty_unregister_device(driver, i); | |
3092 | } | |
3093 | p = driver->ttys; | |
3094 | proc_tty_unregister_driver(driver); | |
3095 | driver->ttys = NULL; | |
fe6e29fd | 3096 | driver->termios = NULL; |
7d7b93c1 AC |
3097 | kfree(p); |
3098 | cdev_del(&driver->cdev); | |
3099 | } | |
04831dc1 | 3100 | kfree(driver->ports); |
1da177e4 LT |
3101 | kfree(driver); |
3102 | } | |
3103 | ||
7d7b93c1 AC |
3104 | void tty_driver_kref_put(struct tty_driver *driver) |
3105 | { | |
3106 | kref_put(&driver->kref, destruct_tty_driver); | |
3107 | } | |
3108 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3109 | ||
b68e31d0 JD |
3110 | void tty_set_operations(struct tty_driver *driver, |
3111 | const struct tty_operations *op) | |
1da177e4 | 3112 | { |
f34d7a5b AC |
3113 | driver->ops = op; |
3114 | }; | |
7d7b93c1 | 3115 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3116 | |
7d7b93c1 AC |
3117 | void put_tty_driver(struct tty_driver *d) |
3118 | { | |
3119 | tty_driver_kref_put(d); | |
3120 | } | |
1da177e4 | 3121 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3122 | |
3123 | /* | |
3124 | * Called by a tty driver to register itself. | |
3125 | */ | |
3126 | int tty_register_driver(struct tty_driver *driver) | |
3127 | { | |
3128 | int error; | |
37bdfb07 | 3129 | int i; |
1da177e4 LT |
3130 | dev_t dev; |
3131 | void **p = NULL; | |
b670bde0 | 3132 | struct device *d; |
1da177e4 | 3133 | |
543691a6 | 3134 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 3135 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
3136 | if (!p) |
3137 | return -ENOMEM; | |
1da177e4 | 3138 | } |
04831dc1 JS |
3139 | /* |
3140 | * There is too many lines in PTY and we won't need the array there | |
3141 | * since it has an ->install hook where it assigns ports properly. | |
3142 | */ | |
3143 | if (driver->type != TTY_DRIVER_TYPE_PTY) { | |
3144 | driver->ports = kcalloc(driver->num, sizeof(struct tty_port *), | |
3145 | GFP_KERNEL); | |
3146 | if (!driver->ports) { | |
3147 | error = -ENOMEM; | |
3148 | goto err_free_p; | |
3149 | } | |
3150 | } | |
1da177e4 LT |
3151 | |
3152 | if (!driver->major) { | |
37bdfb07 AC |
3153 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3154 | driver->num, driver->name); | |
1da177e4 LT |
3155 | if (!error) { |
3156 | driver->major = MAJOR(dev); | |
3157 | driver->minor_start = MINOR(dev); | |
3158 | } | |
3159 | } else { | |
3160 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3161 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3162 | } |
9bb8a3d4 JS |
3163 | if (error < 0) |
3164 | goto err_free_p; | |
1da177e4 LT |
3165 | |
3166 | if (p) { | |
3167 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3168 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
3169 | } else { |
3170 | driver->ttys = NULL; | |
3171 | driver->termios = NULL; | |
1da177e4 LT |
3172 | } |
3173 | ||
3174 | cdev_init(&driver->cdev, &tty_fops); | |
3175 | driver->cdev.owner = driver->owner; | |
3176 | error = cdev_add(&driver->cdev, dev, driver->num); | |
9bb8a3d4 JS |
3177 | if (error) |
3178 | goto err_unreg_char; | |
1da177e4 | 3179 | |
ca509f69 | 3180 | mutex_lock(&tty_mutex); |
1da177e4 | 3181 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3182 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3183 | |
3184 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3185 | for (i = 0; i < driver->num; i++) { |
3186 | d = tty_register_device(driver, i, NULL); | |
3187 | if (IS_ERR(d)) { | |
3188 | error = PTR_ERR(d); | |
3189 | goto err; | |
3190 | } | |
3191 | } | |
1da177e4 LT |
3192 | } |
3193 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3194 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3195 | return 0; |
b670bde0 VK |
3196 | |
3197 | err: | |
3198 | for (i--; i >= 0; i--) | |
3199 | tty_unregister_device(driver, i); | |
3200 | ||
3201 | mutex_lock(&tty_mutex); | |
3202 | list_del(&driver->tty_drivers); | |
3203 | mutex_unlock(&tty_mutex); | |
3204 | ||
9bb8a3d4 | 3205 | err_unreg_char: |
b670bde0 VK |
3206 | unregister_chrdev_region(dev, driver->num); |
3207 | driver->ttys = NULL; | |
3208 | driver->termios = NULL; | |
04831dc1 | 3209 | err_free_p: /* destruct_tty_driver will free driver->ports */ |
b670bde0 VK |
3210 | kfree(p); |
3211 | return error; | |
1da177e4 | 3212 | } |
1da177e4 LT |
3213 | EXPORT_SYMBOL(tty_register_driver); |
3214 | ||
3215 | /* | |
3216 | * Called by a tty driver to unregister itself. | |
3217 | */ | |
3218 | int tty_unregister_driver(struct tty_driver *driver) | |
3219 | { | |
7d7b93c1 AC |
3220 | #if 0 |
3221 | /* FIXME */ | |
1da177e4 LT |
3222 | if (driver->refcount) |
3223 | return -EBUSY; | |
7d7b93c1 | 3224 | #endif |
1da177e4 LT |
3225 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3226 | driver->num); | |
ca509f69 | 3227 | mutex_lock(&tty_mutex); |
1da177e4 | 3228 | list_del(&driver->tty_drivers); |
ca509f69 | 3229 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3230 | return 0; |
3231 | } | |
7d7b93c1 | 3232 | |
1da177e4 LT |
3233 | EXPORT_SYMBOL(tty_unregister_driver); |
3234 | ||
24ec839c PZ |
3235 | dev_t tty_devnum(struct tty_struct *tty) |
3236 | { | |
3237 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3238 | } | |
3239 | EXPORT_SYMBOL(tty_devnum); | |
3240 | ||
3241 | void proc_clear_tty(struct task_struct *p) | |
3242 | { | |
7c3b1dcf | 3243 | unsigned long flags; |
9c9f4ded | 3244 | struct tty_struct *tty; |
7c3b1dcf | 3245 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3246 | tty = p->signal->tty; |
24ec839c | 3247 | p->signal->tty = NULL; |
7c3b1dcf | 3248 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3249 | tty_kref_put(tty); |
24ec839c | 3250 | } |
24ec839c | 3251 | |
47f86834 AC |
3252 | /* Called under the sighand lock */ |
3253 | ||
2a65f1d9 | 3254 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3255 | { |
3256 | if (tty) { | |
47f86834 AC |
3257 | unsigned long flags; |
3258 | /* We should not have a session or pgrp to put here but.... */ | |
3259 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3260 | put_pid(tty->session); |
3261 | put_pid(tty->pgrp); | |
ab521dc0 | 3262 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3263 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3264 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3265 | if (tsk->signal->tty) { |
3266 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3267 | tty_kref_put(tsk->signal->tty); | |
3268 | } | |
24ec839c | 3269 | } |
2a65f1d9 | 3270 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3271 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3272 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3273 | } |
3274 | ||
98a27ba4 | 3275 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3276 | { |
3277 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3278 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3279 | spin_unlock_irq(&tsk->sighand->siglock); |
3280 | } | |
3281 | ||
3282 | struct tty_struct *get_current_tty(void) | |
3283 | { | |
3284 | struct tty_struct *tty; | |
934e6ebf AC |
3285 | unsigned long flags; |
3286 | ||
3287 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3288 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3289 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3290 | return tty; |
3291 | } | |
a311f743 | 3292 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3293 | |
d81ed103 AC |
3294 | void tty_default_fops(struct file_operations *fops) |
3295 | { | |
3296 | *fops = tty_fops; | |
3297 | } | |
3298 | ||
1da177e4 LT |
3299 | /* |
3300 | * Initialize the console device. This is called *early*, so | |
3301 | * we can't necessarily depend on lots of kernel help here. | |
3302 | * Just do some early initializations, and do the complex setup | |
3303 | * later. | |
3304 | */ | |
3305 | void __init console_init(void) | |
3306 | { | |
3307 | initcall_t *call; | |
3308 | ||
3309 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3310 | tty_ldisc_begin(); |
1da177e4 LT |
3311 | |
3312 | /* | |
37bdfb07 | 3313 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3314 | * inform about problems etc.. |
3315 | */ | |
1da177e4 LT |
3316 | call = __con_initcall_start; |
3317 | while (call < __con_initcall_end) { | |
3318 | (*call)(); | |
3319 | call++; | |
3320 | } | |
3321 | } | |
3322 | ||
2c9ede55 | 3323 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3324 | { |
3325 | if (!mode) | |
3326 | return NULL; | |
3327 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3328 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3329 | *mode = 0666; | |
3330 | return NULL; | |
3331 | } | |
3332 | ||
1da177e4 LT |
3333 | static int __init tty_class_init(void) |
3334 | { | |
7fe845d1 | 3335 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3336 | if (IS_ERR(tty_class)) |
3337 | return PTR_ERR(tty_class); | |
e454cea2 | 3338 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3339 | return 0; |
3340 | } | |
3341 | ||
3342 | postcore_initcall(tty_class_init); | |
3343 | ||
3344 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3345 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3346 | |
fbc92a34 KS |
3347 | static ssize_t show_cons_active(struct device *dev, |
3348 | struct device_attribute *attr, char *buf) | |
3349 | { | |
3350 | struct console *cs[16]; | |
3351 | int i = 0; | |
3352 | struct console *c; | |
3353 | ssize_t count = 0; | |
3354 | ||
ac751efa | 3355 | console_lock(); |
a2a6a822 | 3356 | for_each_console(c) { |
fbc92a34 KS |
3357 | if (!c->device) |
3358 | continue; | |
3359 | if (!c->write) | |
3360 | continue; | |
3361 | if ((c->flags & CON_ENABLED) == 0) | |
3362 | continue; | |
3363 | cs[i++] = c; | |
3364 | if (i >= ARRAY_SIZE(cs)) | |
3365 | break; | |
3366 | } | |
3367 | while (i--) | |
3368 | count += sprintf(buf + count, "%s%d%c", | |
3369 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3370 | console_unlock(); |
fbc92a34 KS |
3371 | |
3372 | return count; | |
3373 | } | |
3374 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3375 | ||
3376 | static struct device *consdev; | |
3377 | ||
3378 | void console_sysfs_notify(void) | |
3379 | { | |
3380 | if (consdev) | |
3381 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3382 | } | |
3383 | ||
1da177e4 LT |
3384 | /* |
3385 | * Ok, now we can initialize the rest of the tty devices and can count | |
3386 | * on memory allocations, interrupts etc.. | |
3387 | */ | |
31d1d48e | 3388 | int __init tty_init(void) |
1da177e4 LT |
3389 | { |
3390 | cdev_init(&tty_cdev, &tty_fops); | |
3391 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3392 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3393 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3394 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3395 | |
3396 | cdev_init(&console_cdev, &console_fops); | |
3397 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3398 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3399 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3400 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3401 | "console"); |
fbc92a34 KS |
3402 | if (IS_ERR(consdev)) |
3403 | consdev = NULL; | |
3404 | else | |
a2a6a822 | 3405 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3406 | |
1da177e4 | 3407 | #ifdef CONFIG_VT |
d81ed103 | 3408 | vty_init(&console_fops); |
1da177e4 LT |
3409 | #endif |
3410 | return 0; | |
3411 | } | |
31d1d48e | 3412 |