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 | { |
dc6802a7 DC |
184 | if (!tty) |
185 | return; | |
30004ac9 DES |
186 | if (tty->dev) |
187 | put_device(tty->dev); | |
1da177e4 | 188 | kfree(tty->write_buf); |
33f0f88f | 189 | tty_buffer_free_all(tty); |
1da177e4 LT |
190 | kfree(tty); |
191 | } | |
192 | ||
d996b62a NP |
193 | static inline struct tty_struct *file_tty(struct file *file) |
194 | { | |
195 | return ((struct tty_file_private *)file->private_data)->tty; | |
196 | } | |
197 | ||
fa90e1c9 | 198 | int tty_alloc_file(struct file *file) |
d996b62a NP |
199 | { |
200 | struct tty_file_private *priv; | |
201 | ||
f573bd17 PE |
202 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
203 | if (!priv) | |
204 | return -ENOMEM; | |
d996b62a | 205 | |
fa90e1c9 JS |
206 | file->private_data = priv; |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | /* Associate a new file with the tty structure */ | |
212 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
213 | { | |
214 | struct tty_file_private *priv = file->private_data; | |
215 | ||
d996b62a NP |
216 | priv->tty = tty; |
217 | priv->file = file; | |
d996b62a NP |
218 | |
219 | spin_lock(&tty_files_lock); | |
220 | list_add(&priv->list, &tty->tty_files); | |
221 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 222 | } |
f573bd17 | 223 | |
fa90e1c9 JS |
224 | /** |
225 | * tty_free_file - free file->private_data | |
226 | * | |
227 | * This shall be used only for fail path handling when tty_add_file was not | |
228 | * called yet. | |
229 | */ | |
230 | void tty_free_file(struct file *file) | |
231 | { | |
232 | struct tty_file_private *priv = file->private_data; | |
233 | ||
234 | file->private_data = NULL; | |
235 | kfree(priv); | |
d996b62a NP |
236 | } |
237 | ||
238 | /* Delete file from its tty */ | |
239 | void tty_del_file(struct file *file) | |
240 | { | |
241 | struct tty_file_private *priv = file->private_data; | |
242 | ||
243 | spin_lock(&tty_files_lock); | |
244 | list_del(&priv->list); | |
245 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 246 | tty_free_file(file); |
d996b62a NP |
247 | } |
248 | ||
249 | ||
1da177e4 LT |
250 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
251 | ||
af9b897e AC |
252 | /** |
253 | * tty_name - return tty naming | |
254 | * @tty: tty structure | |
255 | * @buf: buffer for output | |
256 | * | |
257 | * Convert a tty structure into a name. The name reflects the kernel | |
258 | * naming policy and if udev is in use may not reflect user space | |
259 | * | |
260 | * Locking: none | |
261 | */ | |
262 | ||
1da177e4 LT |
263 | char *tty_name(struct tty_struct *tty, char *buf) |
264 | { | |
265 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
266 | strcpy(buf, "NULL tty"); | |
267 | else | |
268 | strcpy(buf, tty->name); | |
269 | return buf; | |
270 | } | |
271 | ||
272 | EXPORT_SYMBOL(tty_name); | |
273 | ||
d769a669 | 274 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
275 | const char *routine) |
276 | { | |
277 | #ifdef TTY_PARANOIA_CHECK | |
278 | if (!tty) { | |
279 | printk(KERN_WARNING | |
280 | "null TTY for (%d:%d) in %s\n", | |
281 | imajor(inode), iminor(inode), routine); | |
282 | return 1; | |
283 | } | |
284 | if (tty->magic != TTY_MAGIC) { | |
285 | printk(KERN_WARNING | |
286 | "bad magic number for tty struct (%d:%d) in %s\n", | |
287 | imajor(inode), iminor(inode), routine); | |
288 | return 1; | |
289 | } | |
290 | #endif | |
291 | return 0; | |
292 | } | |
293 | ||
294 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
295 | { | |
296 | #ifdef CHECK_TTY_COUNT | |
297 | struct list_head *p; | |
298 | int count = 0; | |
37bdfb07 | 299 | |
ee2ffa0d | 300 | spin_lock(&tty_files_lock); |
1da177e4 LT |
301 | list_for_each(p, &tty->tty_files) { |
302 | count++; | |
303 | } | |
ee2ffa0d | 304 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
305 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
306 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
307 | tty->link && tty->link->count) | |
308 | count++; | |
309 | if (tty->count != count) { | |
310 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
311 | "!= #fd's(%d) in %s\n", | |
312 | tty->name, tty->count, count, routine); | |
313 | return count; | |
24ec839c | 314 | } |
1da177e4 LT |
315 | #endif |
316 | return 0; | |
317 | } | |
318 | ||
af9b897e AC |
319 | /** |
320 | * get_tty_driver - find device of a tty | |
321 | * @dev_t: device identifier | |
322 | * @index: returns the index of the tty | |
323 | * | |
324 | * This routine returns a tty driver structure, given a device number | |
325 | * and also passes back the index number. | |
326 | * | |
327 | * Locking: caller must hold tty_mutex | |
1da177e4 | 328 | */ |
af9b897e | 329 | |
1da177e4 LT |
330 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
331 | { | |
332 | struct tty_driver *p; | |
333 | ||
334 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
335 | dev_t base = MKDEV(p->major, p->minor_start); | |
336 | if (device < base || device >= base + p->num) | |
337 | continue; | |
338 | *index = device - base; | |
7d7b93c1 | 339 | return tty_driver_kref_get(p); |
1da177e4 LT |
340 | } |
341 | return NULL; | |
342 | } | |
343 | ||
f2d937f3 JW |
344 | #ifdef CONFIG_CONSOLE_POLL |
345 | ||
346 | /** | |
347 | * tty_find_polling_driver - find device of a polled tty | |
348 | * @name: name string to match | |
349 | * @line: pointer to resulting tty line nr | |
350 | * | |
351 | * This routine returns a tty driver structure, given a name | |
352 | * and the condition that the tty driver is capable of polled | |
353 | * operation. | |
354 | */ | |
355 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
356 | { | |
357 | struct tty_driver *p, *res = NULL; | |
358 | int tty_line = 0; | |
0dca0fd2 | 359 | int len; |
5f0878ac | 360 | char *str, *stp; |
f2d937f3 | 361 | |
0dca0fd2 JW |
362 | for (str = name; *str; str++) |
363 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
364 | break; | |
365 | if (!*str) | |
366 | return NULL; | |
367 | ||
368 | len = str - name; | |
369 | tty_line = simple_strtoul(str, &str, 10); | |
370 | ||
f2d937f3 JW |
371 | mutex_lock(&tty_mutex); |
372 | /* Search through the tty devices to look for a match */ | |
373 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
374 | if (strncmp(name, p->name, len) != 0) |
375 | continue; | |
5f0878ac AC |
376 | stp = str; |
377 | if (*stp == ',') | |
378 | stp++; | |
379 | if (*stp == '\0') | |
380 | stp = NULL; | |
f2d937f3 | 381 | |
6eb68d6f | 382 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 383 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 384 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
385 | *line = tty_line; |
386 | break; | |
387 | } | |
388 | } | |
389 | mutex_unlock(&tty_mutex); | |
390 | ||
391 | return res; | |
392 | } | |
393 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
394 | #endif | |
395 | ||
af9b897e AC |
396 | /** |
397 | * tty_check_change - check for POSIX terminal changes | |
398 | * @tty: tty to check | |
399 | * | |
400 | * If we try to write to, or set the state of, a terminal and we're | |
401 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
402 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
403 | * | |
978e595f | 404 | * Locking: ctrl_lock |
1da177e4 | 405 | */ |
af9b897e | 406 | |
37bdfb07 | 407 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 408 | { |
47f86834 AC |
409 | unsigned long flags; |
410 | int ret = 0; | |
411 | ||
1da177e4 LT |
412 | if (current->signal->tty != tty) |
413 | return 0; | |
47f86834 AC |
414 | |
415 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
416 | ||
ab521dc0 EB |
417 | if (!tty->pgrp) { |
418 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 419 | goto out_unlock; |
1da177e4 | 420 | } |
ab521dc0 | 421 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
422 | goto out_unlock; |
423 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 424 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
425 | goto out; |
426 | if (is_current_pgrp_orphaned()) { | |
427 | ret = -EIO; | |
428 | goto out; | |
429 | } | |
040b6362 ON |
430 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
431 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
432 | ret = -ERESTARTSYS; |
433 | out: | |
9ffee4cb AM |
434 | return ret; |
435 | out_unlock: | |
47f86834 AC |
436 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
437 | return ret; | |
1da177e4 LT |
438 | } |
439 | ||
440 | EXPORT_SYMBOL(tty_check_change); | |
441 | ||
37bdfb07 | 442 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
443 | size_t count, loff_t *ppos) |
444 | { | |
445 | return 0; | |
446 | } | |
447 | ||
37bdfb07 | 448 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
449 | size_t count, loff_t *ppos) |
450 | { | |
451 | return -EIO; | |
452 | } | |
453 | ||
454 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 455 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
456 | { |
457 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
458 | } | |
459 | ||
04f378b1 AC |
460 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
461 | unsigned long arg) | |
38ad2ed0 PF |
462 | { |
463 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
464 | } | |
465 | ||
37bdfb07 | 466 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 467 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
468 | { |
469 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
470 | } | |
471 | ||
62322d25 | 472 | static const struct file_operations tty_fops = { |
1da177e4 LT |
473 | .llseek = no_llseek, |
474 | .read = tty_read, | |
475 | .write = tty_write, | |
476 | .poll = tty_poll, | |
04f378b1 | 477 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 478 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
479 | .open = tty_open, |
480 | .release = tty_release, | |
481 | .fasync = tty_fasync, | |
482 | }; | |
483 | ||
62322d25 | 484 | static const struct file_operations console_fops = { |
1da177e4 LT |
485 | .llseek = no_llseek, |
486 | .read = tty_read, | |
487 | .write = redirected_tty_write, | |
488 | .poll = tty_poll, | |
04f378b1 | 489 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 490 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
491 | .open = tty_open, |
492 | .release = tty_release, | |
493 | .fasync = tty_fasync, | |
494 | }; | |
495 | ||
62322d25 | 496 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
497 | .llseek = no_llseek, |
498 | .read = hung_up_tty_read, | |
499 | .write = hung_up_tty_write, | |
500 | .poll = hung_up_tty_poll, | |
04f378b1 | 501 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 502 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
503 | .release = tty_release, |
504 | }; | |
505 | ||
506 | static DEFINE_SPINLOCK(redirect_lock); | |
507 | static struct file *redirect; | |
508 | ||
509 | /** | |
510 | * tty_wakeup - request more data | |
511 | * @tty: terminal | |
512 | * | |
513 | * Internal and external helper for wakeups of tty. This function | |
514 | * informs the line discipline if present that the driver is ready | |
515 | * to receive more output data. | |
516 | */ | |
37bdfb07 | 517 | |
1da177e4 LT |
518 | void tty_wakeup(struct tty_struct *tty) |
519 | { | |
520 | struct tty_ldisc *ld; | |
37bdfb07 | 521 | |
1da177e4 LT |
522 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
523 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 524 | if (ld) { |
a352def2 AC |
525 | if (ld->ops->write_wakeup) |
526 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
527 | tty_ldisc_deref(ld); |
528 | } | |
529 | } | |
4b19449d | 530 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
531 | } |
532 | ||
533 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
534 | ||
af9b897e | 535 | /** |
11dbf203 | 536 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 537 | * @work: tty device |
af9b897e | 538 | * |
1bad879a | 539 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
540 | * synchronous but doesn't hold any locks, so we need to make sure we |
541 | * have the appropriate locks for what we're doing. | |
542 | * | |
543 | * The hangup event clears any pending redirections onto the hung up | |
544 | * device. It ensures future writes will error and it does the needed | |
545 | * line discipline hangup and signal delivery. The tty object itself | |
546 | * remains intact. | |
547 | * | |
548 | * Locking: | |
ec79d605 | 549 | * BTM |
24ec839c PZ |
550 | * redirect lock for undoing redirection |
551 | * file list lock for manipulating list of ttys | |
552 | * tty_ldisc_lock from called functions | |
553 | * termios_mutex resetting termios data | |
554 | * tasklist_lock to walk task list for hangup event | |
555 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 556 | */ |
11dbf203 | 557 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 558 | { |
37bdfb07 | 559 | struct file *cons_filp = NULL; |
1da177e4 LT |
560 | struct file *filp, *f = NULL; |
561 | struct task_struct *p; | |
d996b62a | 562 | struct tty_file_private *priv; |
1da177e4 | 563 | int closecount = 0, n; |
47f86834 | 564 | unsigned long flags; |
9c9f4ded | 565 | int refs = 0; |
1da177e4 LT |
566 | |
567 | if (!tty) | |
568 | return; | |
569 | ||
1da177e4 LT |
570 | |
571 | spin_lock(&redirect_lock); | |
d996b62a | 572 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
573 | f = redirect; |
574 | redirect = NULL; | |
575 | } | |
576 | spin_unlock(&redirect_lock); | |
37bdfb07 | 577 | |
6d31a88c | 578 | tty_lock(); |
11dbf203 | 579 | |
acfa747b JS |
580 | /* some functions below drop BTM, so we need this bit */ |
581 | set_bit(TTY_HUPPING, &tty->flags); | |
582 | ||
ec79d605 AB |
583 | /* inuse_filps is protected by the single tty lock, |
584 | this really needs to change if we want to flush the | |
585 | workqueue with the lock held */ | |
11dbf203 | 586 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 587 | |
ee2ffa0d | 588 | spin_lock(&tty_files_lock); |
1da177e4 | 589 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
590 | list_for_each_entry(priv, &tty->tty_files, list) { |
591 | filp = priv->file; | |
1da177e4 LT |
592 | if (filp->f_op->write == redirected_tty_write) |
593 | cons_filp = filp; | |
594 | if (filp->f_op->write != tty_write) | |
595 | continue; | |
596 | closecount++; | |
ec79d605 | 597 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
598 | filp->f_op = &hung_up_tty_fops; |
599 | } | |
ee2ffa0d | 600 | spin_unlock(&tty_files_lock); |
37bdfb07 | 601 | |
acfa747b JS |
602 | /* |
603 | * it drops BTM and thus races with reopen | |
604 | * we protect the race by TTY_HUPPING | |
605 | */ | |
c65c9bc3 | 606 | tty_ldisc_hangup(tty); |
37bdfb07 | 607 | |
1da177e4 | 608 | read_lock(&tasklist_lock); |
ab521dc0 EB |
609 | if (tty->session) { |
610 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 611 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 612 | if (p->signal->tty == tty) { |
1da177e4 | 613 | p->signal->tty = NULL; |
9c9f4ded AC |
614 | /* We defer the dereferences outside fo |
615 | the tasklist lock */ | |
616 | refs++; | |
617 | } | |
24ec839c PZ |
618 | if (!p->signal->leader) { |
619 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 620 | continue; |
24ec839c PZ |
621 | } |
622 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
623 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 624 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 625 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
626 | if (tty->pgrp) |
627 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 628 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 629 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 630 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
631 | } |
632 | read_unlock(&tasklist_lock); | |
633 | ||
47f86834 | 634 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
635 | clear_bit(TTY_THROTTLED, &tty->flags); |
636 | clear_bit(TTY_PUSH, &tty->flags); | |
637 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
638 | put_pid(tty->session); |
639 | put_pid(tty->pgrp); | |
ab521dc0 EB |
640 | tty->session = NULL; |
641 | tty->pgrp = NULL; | |
1da177e4 | 642 | tty->ctrl_status = 0; |
47f86834 AC |
643 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
644 | ||
9c9f4ded AC |
645 | /* Account for the p->signal references we killed */ |
646 | while (refs--) | |
647 | tty_kref_put(tty); | |
648 | ||
1da177e4 | 649 | /* |
37bdfb07 AC |
650 | * If one of the devices matches a console pointer, we |
651 | * cannot just call hangup() because that will cause | |
652 | * tty->count and state->count to go out of sync. | |
653 | * So we just call close() the right number of times. | |
1da177e4 LT |
654 | */ |
655 | if (cons_filp) { | |
f34d7a5b | 656 | if (tty->ops->close) |
1da177e4 | 657 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
658 | tty->ops->close(tty, cons_filp); |
659 | } else if (tty->ops->hangup) | |
660 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
661 | /* |
662 | * We don't want to have driver/ldisc interactions beyond | |
663 | * the ones we did here. The driver layer expects no | |
664 | * calls after ->hangup() from the ldisc side. However we | |
665 | * can't yet guarantee all that. | |
666 | */ | |
1da177e4 | 667 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 668 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 669 | tty_ldisc_enable(tty); |
11dbf203 | 670 | |
6d31a88c | 671 | tty_unlock(); |
11dbf203 | 672 | |
1da177e4 LT |
673 | if (f) |
674 | fput(f); | |
675 | } | |
676 | ||
ddcd9fb6 AB |
677 | static void do_tty_hangup(struct work_struct *work) |
678 | { | |
679 | struct tty_struct *tty = | |
680 | container_of(work, struct tty_struct, hangup_work); | |
681 | ||
11dbf203 | 682 | __tty_hangup(tty); |
ddcd9fb6 AB |
683 | } |
684 | ||
af9b897e AC |
685 | /** |
686 | * tty_hangup - trigger a hangup event | |
687 | * @tty: tty to hangup | |
688 | * | |
689 | * A carrier loss (virtual or otherwise) has occurred on this like | |
690 | * schedule a hangup sequence to run after this event. | |
691 | */ | |
692 | ||
37bdfb07 | 693 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
694 | { |
695 | #ifdef TTY_DEBUG_HANGUP | |
696 | char buf[64]; | |
1da177e4 LT |
697 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
698 | #endif | |
699 | schedule_work(&tty->hangup_work); | |
700 | } | |
701 | ||
702 | EXPORT_SYMBOL(tty_hangup); | |
703 | ||
af9b897e AC |
704 | /** |
705 | * tty_vhangup - process vhangup | |
706 | * @tty: tty to hangup | |
707 | * | |
708 | * The user has asked via system call for the terminal to be hung up. | |
709 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 710 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
711 | */ |
712 | ||
37bdfb07 | 713 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
714 | { |
715 | #ifdef TTY_DEBUG_HANGUP | |
716 | char buf[64]; | |
717 | ||
718 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
719 | #endif | |
11dbf203 | 720 | __tty_hangup(tty); |
1da177e4 | 721 | } |
37bdfb07 | 722 | |
1da177e4 LT |
723 | EXPORT_SYMBOL(tty_vhangup); |
724 | ||
11dbf203 | 725 | |
2cb5998b AC |
726 | /** |
727 | * tty_vhangup_self - process vhangup for own ctty | |
728 | * | |
729 | * Perform a vhangup on the current controlling tty | |
730 | */ | |
731 | ||
732 | void tty_vhangup_self(void) | |
733 | { | |
734 | struct tty_struct *tty; | |
735 | ||
2cb5998b AC |
736 | tty = get_current_tty(); |
737 | if (tty) { | |
738 | tty_vhangup(tty); | |
739 | tty_kref_put(tty); | |
740 | } | |
2cb5998b AC |
741 | } |
742 | ||
af9b897e AC |
743 | /** |
744 | * tty_hung_up_p - was tty hung up | |
745 | * @filp: file pointer of tty | |
746 | * | |
747 | * Return true if the tty has been subject to a vhangup or a carrier | |
748 | * loss | |
749 | */ | |
750 | ||
37bdfb07 | 751 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
752 | { |
753 | return (filp->f_op == &hung_up_tty_fops); | |
754 | } | |
755 | ||
756 | EXPORT_SYMBOL(tty_hung_up_p); | |
757 | ||
ab521dc0 | 758 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
759 | { |
760 | struct task_struct *p; | |
ab521dc0 | 761 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 762 | proc_clear_tty(p); |
ab521dc0 | 763 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
764 | } |
765 | ||
af9b897e AC |
766 | /** |
767 | * disassociate_ctty - disconnect controlling tty | |
768 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 769 | * |
af9b897e AC |
770 | * This function is typically called only by the session leader, when |
771 | * it wants to disassociate itself from its controlling tty. | |
772 | * | |
773 | * It performs the following functions: | |
1da177e4 LT |
774 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
775 | * (2) Clears the tty from being controlling the session | |
776 | * (3) Clears the controlling tty for all processes in the | |
777 | * session group. | |
778 | * | |
af9b897e AC |
779 | * The argument on_exit is set to 1 if called when a process is |
780 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
781 | * | |
24ec839c | 782 | * Locking: |
ec79d605 AB |
783 | * BTM is taken for hysterical raisins, and held when |
784 | * called from no_tty(). | |
24ec839c PZ |
785 | * tty_mutex is taken to protect tty |
786 | * ->siglock is taken to protect ->signal/->sighand | |
787 | * tasklist_lock is taken to walk process list for sessions | |
788 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 789 | */ |
af9b897e | 790 | |
1da177e4 LT |
791 | void disassociate_ctty(int on_exit) |
792 | { | |
793 | struct tty_struct *tty; | |
1da177e4 | 794 | |
5ec93d11 AC |
795 | if (!current->signal->leader) |
796 | return; | |
1da177e4 | 797 | |
24ec839c | 798 | tty = get_current_tty(); |
1da177e4 | 799 | if (tty) { |
1411dc4a | 800 | struct pid *tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 801 | if (on_exit) { |
ddcd9fb6 | 802 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 803 | tty_vhangup(tty); |
ddcd9fb6 | 804 | } |
452a00d2 | 805 | tty_kref_put(tty); |
1411dc4a JS |
806 | if (tty_pgrp) { |
807 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
808 | if (!on_exit) | |
809 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
810 | put_pid(tty_pgrp); | |
811 | } | |
680a9671 | 812 | } else if (on_exit) { |
ab521dc0 | 813 | struct pid *old_pgrp; |
680a9671 EB |
814 | spin_lock_irq(¤t->sighand->siglock); |
815 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 816 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 817 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 818 | if (old_pgrp) { |
ab521dc0 EB |
819 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
820 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
821 | put_pid(old_pgrp); | |
1da177e4 | 822 | } |
1da177e4 LT |
823 | return; |
824 | } | |
1da177e4 | 825 | |
24ec839c | 826 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 827 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 828 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
829 | spin_unlock_irq(¤t->sighand->siglock); |
830 | ||
24ec839c PZ |
831 | tty = get_current_tty(); |
832 | if (tty) { | |
47f86834 AC |
833 | unsigned long flags; |
834 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
835 | put_pid(tty->session); |
836 | put_pid(tty->pgrp); | |
837 | tty->session = NULL; | |
838 | tty->pgrp = NULL; | |
47f86834 | 839 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 840 | tty_kref_put(tty); |
24ec839c PZ |
841 | } else { |
842 | #ifdef TTY_DEBUG_HANGUP | |
843 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
844 | " = NULL", tty); | |
845 | #endif | |
846 | } | |
1da177e4 LT |
847 | |
848 | /* Now clear signal->tty under the lock */ | |
849 | read_lock(&tasklist_lock); | |
ab521dc0 | 850 | session_clear_tty(task_session(current)); |
1da177e4 | 851 | read_unlock(&tasklist_lock); |
1da177e4 LT |
852 | } |
853 | ||
98a27ba4 EB |
854 | /** |
855 | * | |
856 | * no_tty - Ensure the current process does not have a controlling tty | |
857 | */ | |
858 | void no_tty(void) | |
859 | { | |
3af502b9 AC |
860 | /* FIXME: Review locking here. The tty_lock never covered any race |
861 | between a new association and proc_clear_tty but possible we need | |
862 | to protect against this anyway */ | |
98a27ba4 | 863 | struct task_struct *tsk = current; |
5ec93d11 | 864 | disassociate_ctty(0); |
98a27ba4 EB |
865 | proc_clear_tty(tsk); |
866 | } | |
867 | ||
af9b897e AC |
868 | |
869 | /** | |
beb7dd86 | 870 | * stop_tty - propagate flow control |
af9b897e AC |
871 | * @tty: tty to stop |
872 | * | |
873 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 874 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
875 | * on an already stopped device and will not re-call the driver |
876 | * method. | |
877 | * | |
878 | * This functionality is used by both the line disciplines for | |
879 | * halting incoming flow and by the driver. It may therefore be | |
880 | * called from any context, may be under the tty atomic_write_lock | |
881 | * but not always. | |
882 | * | |
883 | * Locking: | |
04f378b1 | 884 | * Uses the tty control lock internally |
af9b897e AC |
885 | */ |
886 | ||
1da177e4 LT |
887 | void stop_tty(struct tty_struct *tty) |
888 | { | |
04f378b1 AC |
889 | unsigned long flags; |
890 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
891 | if (tty->stopped) { | |
892 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 893 | return; |
04f378b1 | 894 | } |
1da177e4 LT |
895 | tty->stopped = 1; |
896 | if (tty->link && tty->link->packet) { | |
897 | tty->ctrl_status &= ~TIOCPKT_START; | |
898 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 899 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 900 | } |
04f378b1 | 901 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
902 | if (tty->ops->stop) |
903 | (tty->ops->stop)(tty); | |
1da177e4 LT |
904 | } |
905 | ||
906 | EXPORT_SYMBOL(stop_tty); | |
907 | ||
af9b897e | 908 | /** |
beb7dd86 | 909 | * start_tty - propagate flow control |
af9b897e AC |
910 | * @tty: tty to start |
911 | * | |
912 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 913 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
914 | * is the tty was previous stopped and is being started then the |
915 | * driver start method is invoked and the line discipline woken. | |
916 | * | |
917 | * Locking: | |
04f378b1 | 918 | * ctrl_lock |
af9b897e AC |
919 | */ |
920 | ||
1da177e4 LT |
921 | void start_tty(struct tty_struct *tty) |
922 | { | |
04f378b1 AC |
923 | unsigned long flags; |
924 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
925 | if (!tty->stopped || tty->flow_stopped) { | |
926 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 927 | return; |
04f378b1 | 928 | } |
1da177e4 LT |
929 | tty->stopped = 0; |
930 | if (tty->link && tty->link->packet) { | |
931 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
932 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 933 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 934 | } |
04f378b1 | 935 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
936 | if (tty->ops->start) |
937 | (tty->ops->start)(tty); | |
1da177e4 LT |
938 | /* If we have a running line discipline it may need kicking */ |
939 | tty_wakeup(tty); | |
1da177e4 LT |
940 | } |
941 | ||
942 | EXPORT_SYMBOL(start_tty); | |
943 | ||
af9b897e AC |
944 | /** |
945 | * tty_read - read method for tty device files | |
946 | * @file: pointer to tty file | |
947 | * @buf: user buffer | |
948 | * @count: size of user buffer | |
949 | * @ppos: unused | |
950 | * | |
951 | * Perform the read system call function on this terminal device. Checks | |
952 | * for hung up devices before calling the line discipline method. | |
953 | * | |
954 | * Locking: | |
47f86834 AC |
955 | * Locks the line discipline internally while needed. Multiple |
956 | * read calls may be outstanding in parallel. | |
af9b897e AC |
957 | */ |
958 | ||
37bdfb07 | 959 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
960 | loff_t *ppos) |
961 | { | |
962 | int i; | |
d996b62a NP |
963 | struct inode *inode = file->f_path.dentry->d_inode; |
964 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
965 | struct tty_ldisc *ld; |
966 | ||
1da177e4 LT |
967 | if (tty_paranoia_check(tty, inode, "tty_read")) |
968 | return -EIO; | |
969 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
970 | return -EIO; | |
971 | ||
972 | /* We want to wait for the line discipline to sort out in this | |
973 | situation */ | |
974 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
975 | if (ld->ops->read) |
976 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
977 | else |
978 | i = -EIO; | |
979 | tty_ldisc_deref(ld); | |
1da177e4 LT |
980 | if (i > 0) |
981 | inode->i_atime = current_fs_time(inode->i_sb); | |
982 | return i; | |
983 | } | |
984 | ||
9c1729db | 985 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 986 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
987 | { |
988 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 989 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
990 | } |
991 | ||
992 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 993 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
994 | { |
995 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
996 | if (ndelay) | |
997 | return -EAGAIN; | |
998 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
999 | return -ERESTARTSYS; | |
1000 | } | |
1001 | return 0; | |
1002 | } | |
1003 | ||
1da177e4 LT |
1004 | /* |
1005 | * Split writes up in sane blocksizes to avoid | |
1006 | * denial-of-service type attacks | |
1007 | */ | |
1008 | static inline ssize_t do_tty_write( | |
1009 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1010 | struct tty_struct *tty, | |
1011 | struct file *file, | |
1012 | const char __user *buf, | |
1013 | size_t count) | |
1014 | { | |
9c1729db | 1015 | ssize_t ret, written = 0; |
1da177e4 | 1016 | unsigned int chunk; |
37bdfb07 | 1017 | |
9c1729db AC |
1018 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1019 | if (ret < 0) | |
1020 | return ret; | |
1da177e4 LT |
1021 | |
1022 | /* | |
1023 | * We chunk up writes into a temporary buffer. This | |
1024 | * simplifies low-level drivers immensely, since they | |
1025 | * don't have locking issues and user mode accesses. | |
1026 | * | |
1027 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1028 | * big chunk-size.. | |
1029 | * | |
1030 | * The default chunk-size is 2kB, because the NTTY | |
1031 | * layer has problems with bigger chunks. It will | |
1032 | * claim to be able to handle more characters than | |
1033 | * it actually does. | |
af9b897e AC |
1034 | * |
1035 | * FIXME: This can probably go away now except that 64K chunks | |
1036 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1037 | */ |
1038 | chunk = 2048; | |
1039 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1040 | chunk = 65536; | |
1041 | if (count < chunk) | |
1042 | chunk = count; | |
1043 | ||
70522e12 | 1044 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1045 | if (tty->write_cnt < chunk) { |
402fda92 | 1046 | unsigned char *buf_chunk; |
1da177e4 LT |
1047 | |
1048 | if (chunk < 1024) | |
1049 | chunk = 1024; | |
1050 | ||
402fda92 JW |
1051 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1052 | if (!buf_chunk) { | |
9c1729db AC |
1053 | ret = -ENOMEM; |
1054 | goto out; | |
1da177e4 LT |
1055 | } |
1056 | kfree(tty->write_buf); | |
1057 | tty->write_cnt = chunk; | |
402fda92 | 1058 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1059 | } |
1060 | ||
1061 | /* Do the write .. */ | |
1062 | for (;;) { | |
1063 | size_t size = count; | |
1064 | if (size > chunk) | |
1065 | size = chunk; | |
1066 | ret = -EFAULT; | |
1067 | if (copy_from_user(tty->write_buf, buf, size)) | |
1068 | break; | |
1da177e4 | 1069 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1070 | if (ret <= 0) |
1071 | break; | |
1072 | written += ret; | |
1073 | buf += ret; | |
1074 | count -= ret; | |
1075 | if (!count) | |
1076 | break; | |
1077 | ret = -ERESTARTSYS; | |
1078 | if (signal_pending(current)) | |
1079 | break; | |
1080 | cond_resched(); | |
1081 | } | |
1082 | if (written) { | |
a7113a96 | 1083 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1084 | inode->i_mtime = current_fs_time(inode->i_sb); |
1085 | ret = written; | |
1086 | } | |
9c1729db AC |
1087 | out: |
1088 | tty_write_unlock(tty); | |
1da177e4 LT |
1089 | return ret; |
1090 | } | |
1091 | ||
95f9bfc6 AC |
1092 | /** |
1093 | * tty_write_message - write a message to a certain tty, not just the console. | |
1094 | * @tty: the destination tty_struct | |
1095 | * @msg: the message to write | |
1096 | * | |
1097 | * This is used for messages that need to be redirected to a specific tty. | |
1098 | * We don't put it into the syslog queue right now maybe in the future if | |
1099 | * really needed. | |
1100 | * | |
ec79d605 | 1101 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1102 | */ |
1103 | ||
1104 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1105 | { | |
95f9bfc6 AC |
1106 | if (tty) { |
1107 | mutex_lock(&tty->atomic_write_lock); | |
6d31a88c | 1108 | tty_lock(); |
eeb89d91 | 1109 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
6d31a88c | 1110 | tty_unlock(); |
95f9bfc6 | 1111 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1112 | } else |
6d31a88c | 1113 | tty_unlock(); |
95f9bfc6 AC |
1114 | tty_write_unlock(tty); |
1115 | } | |
95f9bfc6 AC |
1116 | return; |
1117 | } | |
1118 | ||
1da177e4 | 1119 | |
af9b897e AC |
1120 | /** |
1121 | * tty_write - write method for tty device file | |
1122 | * @file: tty file pointer | |
1123 | * @buf: user data to write | |
1124 | * @count: bytes to write | |
1125 | * @ppos: unused | |
1126 | * | |
1127 | * Write data to a tty device via the line discipline. | |
1128 | * | |
1129 | * Locking: | |
1130 | * Locks the line discipline as required | |
1131 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1132 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1133 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1134 | */ |
1135 | ||
37bdfb07 AC |
1136 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1137 | size_t count, loff_t *ppos) | |
1da177e4 | 1138 | { |
a7113a96 | 1139 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1140 | struct tty_struct *tty = file_tty(file); |
1141 | struct tty_ldisc *ld; | |
1da177e4 | 1142 | ssize_t ret; |
37bdfb07 | 1143 | |
1da177e4 LT |
1144 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1145 | return -EIO; | |
f34d7a5b | 1146 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1147 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1148 | return -EIO; | |
f34d7a5b AC |
1149 | /* Short term debug to catch buggy drivers */ |
1150 | if (tty->ops->write_room == NULL) | |
1151 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1152 | tty->driver->name); | |
37bdfb07 | 1153 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1154 | if (!ld->ops->write) |
1da177e4 LT |
1155 | ret = -EIO; |
1156 | else | |
a352def2 | 1157 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1158 | tty_ldisc_deref(ld); |
1159 | return ret; | |
1160 | } | |
1161 | ||
37bdfb07 AC |
1162 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1163 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1164 | { |
1165 | struct file *p = NULL; | |
1166 | ||
1167 | spin_lock(&redirect_lock); | |
1168 | if (redirect) { | |
1169 | get_file(redirect); | |
1170 | p = redirect; | |
1171 | } | |
1172 | spin_unlock(&redirect_lock); | |
1173 | ||
1174 | if (p) { | |
1175 | ssize_t res; | |
1176 | res = vfs_write(p, buf, count, &p->f_pos); | |
1177 | fput(p); | |
1178 | return res; | |
1179 | } | |
1da177e4 LT |
1180 | return tty_write(file, buf, count, ppos); |
1181 | } | |
1182 | ||
1183 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1184 | ||
af9b897e AC |
1185 | /** |
1186 | * pty_line_name - generate name for a pty | |
1187 | * @driver: the tty driver in use | |
1188 | * @index: the minor number | |
1189 | * @p: output buffer of at least 6 bytes | |
1190 | * | |
1191 | * Generate a name from a driver reference and write it to the output | |
1192 | * buffer. | |
1193 | * | |
1194 | * Locking: None | |
1195 | */ | |
1196 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1197 | { |
1198 | int i = index + driver->name_base; | |
1199 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1200 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1201 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1202 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1203 | } |
1204 | ||
af9b897e | 1205 | /** |
8b0a88d5 | 1206 | * tty_line_name - generate name for a tty |
af9b897e AC |
1207 | * @driver: the tty driver in use |
1208 | * @index: the minor number | |
1209 | * @p: output buffer of at least 7 bytes | |
1210 | * | |
1211 | * Generate a name from a driver reference and write it to the output | |
1212 | * buffer. | |
1213 | * | |
1214 | * Locking: None | |
1215 | */ | |
1216 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1217 | { |
1218 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1219 | } | |
1220 | ||
99f1fe18 AC |
1221 | /** |
1222 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1223 | * @driver: the driver for the tty | |
1224 | * @idx: the minor number | |
23499705 | 1225 | * |
99f1fe18 | 1226 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1227 | * |
99f1fe18 AC |
1228 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1229 | * be held until the 'fast-open' is also done. Will change once we | |
1230 | * have refcounting in the driver and per driver locking | |
23499705 | 1231 | */ |
a47d545f | 1232 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1233 | struct inode *inode, int idx) |
23499705 | 1234 | { |
99f1fe18 | 1235 | if (driver->ops->lookup) |
15f1a633 | 1236 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1237 | |
d4834267 | 1238 | return driver->ttys[idx]; |
23499705 SB |
1239 | } |
1240 | ||
bf970ee4 AC |
1241 | /** |
1242 | * tty_init_termios - helper for termios setup | |
1243 | * @tty: the tty to set up | |
1244 | * | |
1245 | * Initialise the termios structures for this tty. Thus runs under | |
1246 | * the tty_mutex currently so we can be relaxed about ordering. | |
1247 | */ | |
1248 | ||
1249 | int tty_init_termios(struct tty_struct *tty) | |
1250 | { | |
fe6e29fd | 1251 | struct ktermios *tp; |
bf970ee4 AC |
1252 | int idx = tty->index; |
1253 | ||
36b3c070 AC |
1254 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1255 | tty->termios = tty->driver->init_termios; | |
1256 | else { | |
1257 | /* Check for lazy saved data */ | |
1258 | tp = tty->driver->termios[idx]; | |
1259 | if (tp != NULL) | |
1260 | tty->termios = *tp; | |
1261 | else | |
1262 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1263 | } |
bf970ee4 | 1264 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1265 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1266 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
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; | |
36b3c070 AC |
1442 | |
1443 | /* If the port is going to reset then it has no termios to save */ | |
1444 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1445 | return; | |
1446 | ||
1447 | /* Stash the termios data */ | |
1448 | tp = tty->driver->termios[idx]; | |
1449 | if (tp == NULL) { | |
1450 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1451 | if (tp == NULL) { | |
1452 | pr_warn("tty: no memory to save termios state.\n"); | |
1453 | return; | |
1454 | } | |
4ac5d705 | 1455 | tty->driver->termios[idx] = tp; |
feebed65 | 1456 | } |
36b3c070 | 1457 | *tp = tty->termios; |
feebed65 AC |
1458 | } |
1459 | EXPORT_SYMBOL(tty_free_termios); | |
1460 | ||
feebed65 | 1461 | |
af9b897e | 1462 | /** |
d5698c28 | 1463 | * release_one_tty - release tty structure memory |
9c9f4ded | 1464 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1465 | * |
1466 | * Releases memory associated with a tty structure, and clears out the | |
1467 | * driver table slots. This function is called when a device is no longer | |
1468 | * in use. It also gets called when setup of a device fails. | |
1469 | * | |
1470 | * Locking: | |
af9b897e AC |
1471 | * takes the file list lock internally when working on the list |
1472 | * of ttys that the driver keeps. | |
b50989dc AC |
1473 | * |
1474 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1475 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1476 | */ |
b50989dc | 1477 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1478 | { |
b50989dc AC |
1479 | struct tty_struct *tty = |
1480 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1481 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1482 | |
f278a2f7 DY |
1483 | if (tty->ops->cleanup) |
1484 | tty->ops->cleanup(tty); | |
1485 | ||
1da177e4 | 1486 | tty->magic = 0; |
7d7b93c1 | 1487 | tty_driver_kref_put(driver); |
6f967f78 | 1488 | module_put(driver->owner); |
d5698c28 | 1489 | |
ee2ffa0d | 1490 | spin_lock(&tty_files_lock); |
1da177e4 | 1491 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1492 | spin_unlock(&tty_files_lock); |
d5698c28 | 1493 | |
6da8d866 ON |
1494 | put_pid(tty->pgrp); |
1495 | put_pid(tty->session); | |
1da177e4 LT |
1496 | free_tty_struct(tty); |
1497 | } | |
1498 | ||
b50989dc AC |
1499 | static void queue_release_one_tty(struct kref *kref) |
1500 | { | |
1501 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1502 | |
b50989dc AC |
1503 | /* The hangup queue is now free so we can reuse it rather than |
1504 | waste a chunk of memory for each port */ | |
1505 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1506 | schedule_work(&tty->hangup_work); | |
1507 | } | |
1508 | ||
9c9f4ded AC |
1509 | /** |
1510 | * tty_kref_put - release a tty kref | |
1511 | * @tty: tty device | |
1512 | * | |
1513 | * Release a reference to a tty device and if need be let the kref | |
1514 | * layer destruct the object for us | |
1515 | */ | |
1516 | ||
1517 | void tty_kref_put(struct tty_struct *tty) | |
1518 | { | |
1519 | if (tty) | |
b50989dc | 1520 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1521 | } |
1522 | EXPORT_SYMBOL(tty_kref_put); | |
1523 | ||
d5698c28 CH |
1524 | /** |
1525 | * release_tty - release tty structure memory | |
1526 | * | |
1527 | * Release both @tty and a possible linked partner (think pty pair), | |
1528 | * and decrement the refcount of the backing module. | |
1529 | * | |
1530 | * Locking: | |
d155255a | 1531 | * tty_mutex |
d5698c28 CH |
1532 | * takes the file list lock internally when working on the list |
1533 | * of ttys that the driver keeps. | |
9c9f4ded | 1534 | * |
d5698c28 CH |
1535 | */ |
1536 | static void release_tty(struct tty_struct *tty, int idx) | |
1537 | { | |
9c9f4ded AC |
1538 | /* This should always be true but check for the moment */ |
1539 | WARN_ON(tty->index != idx); | |
d155255a | 1540 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1541 | if (tty->ops->shutdown) |
1542 | tty->ops->shutdown(tty); | |
1543 | tty_free_termios(tty); | |
1544 | tty_driver_remove_tty(tty->driver, tty); | |
1545 | ||
d5698c28 | 1546 | if (tty->link) |
9c9f4ded AC |
1547 | tty_kref_put(tty->link); |
1548 | tty_kref_put(tty); | |
d5698c28 CH |
1549 | } |
1550 | ||
955787ca JS |
1551 | /** |
1552 | * tty_release_checks - check a tty before real release | |
1553 | * @tty: tty to check | |
1554 | * @o_tty: link of @tty (if any) | |
1555 | * @idx: index of the tty | |
1556 | * | |
1557 | * Performs some paranoid checking before true release of the @tty. | |
1558 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1559 | */ | |
1560 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1561 | int idx) | |
1562 | { | |
1563 | #ifdef TTY_PARANOIA_CHECK | |
1564 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1565 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1566 | __func__, tty->name); | |
955787ca JS |
1567 | return -1; |
1568 | } | |
1569 | ||
1570 | /* not much to check for devpts */ | |
1571 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1572 | return 0; | |
1573 | ||
1574 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1575 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1576 | __func__, idx, tty->name); | |
955787ca JS |
1577 | return -1; |
1578 | } | |
955787ca JS |
1579 | if (tty->driver->other) { |
1580 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1581 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1582 | __func__, idx, tty->name); | |
955787ca JS |
1583 | return -1; |
1584 | } | |
955787ca | 1585 | if (o_tty->link != tty) { |
9de44bd6 | 1586 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1587 | return -1; |
1588 | } | |
1589 | } | |
1590 | #endif | |
1591 | return 0; | |
1592 | } | |
1593 | ||
eeb89d91 AC |
1594 | /** |
1595 | * tty_release - vfs callback for close | |
1596 | * @inode: inode of tty | |
1597 | * @filp: file pointer for handle to tty | |
1598 | * | |
1599 | * Called the last time each file handle is closed that references | |
1600 | * this tty. There may however be several such references. | |
1601 | * | |
1602 | * Locking: | |
1603 | * Takes bkl. See tty_release_dev | |
1604 | * | |
1da177e4 LT |
1605 | * Even releasing the tty structures is a tricky business.. We have |
1606 | * to be very careful that the structures are all released at the | |
1607 | * same time, as interrupts might otherwise get the wrong pointers. | |
1608 | * | |
1609 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1610 | * lead to double frees or releasing memory still in use. | |
1611 | */ | |
eeb89d91 AC |
1612 | |
1613 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1614 | { |
d996b62a NP |
1615 | struct tty_struct *tty = file_tty(filp); |
1616 | struct tty_struct *o_tty; | |
1da177e4 | 1617 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1618 | int devpts; |
1da177e4 LT |
1619 | int idx; |
1620 | char buf[64]; | |
37bdfb07 | 1621 | |
9de44bd6 | 1622 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1623 | return 0; |
1da177e4 | 1624 | |
6d31a88c | 1625 | tty_lock(); |
9de44bd6 | 1626 | check_tty_count(tty, __func__); |
1da177e4 | 1627 | |
ec79d605 | 1628 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1629 | |
1630 | idx = tty->index; | |
1631 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1632 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1633 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1634 | o_tty = tty->link; |
1635 | ||
955787ca | 1636 | if (tty_release_checks(tty, o_tty, idx)) { |
6d31a88c | 1637 | tty_unlock(); |
eeb89d91 | 1638 | return 0; |
1da177e4 | 1639 | } |
1da177e4 LT |
1640 | |
1641 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1642 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1643 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1644 | #endif |
1645 | ||
f34d7a5b AC |
1646 | if (tty->ops->close) |
1647 | tty->ops->close(tty, filp); | |
1da177e4 | 1648 | |
6d31a88c | 1649 | tty_unlock(); |
1da177e4 LT |
1650 | /* |
1651 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1652 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1653 | * wait queues and kick everyone out _before_ actually starting to | |
1654 | * close. This ensures that we won't block while releasing the tty | |
1655 | * structure. | |
1656 | * | |
1657 | * The test for the o_tty closing is necessary, since the master and | |
1658 | * slave sides may close in any order. If the slave side closes out | |
1659 | * first, its count will be one, since the master side holds an open. | |
1660 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1661 | * so we do it now. | |
1662 | * | |
1663 | * Note that it's possible for the tty to be opened again while we're | |
1664 | * flushing out waiters. By recalculating the closing flags before | |
1665 | * each iteration we avoid any problems. | |
1666 | */ | |
1667 | while (1) { | |
1668 | /* Guard against races with tty->count changes elsewhere and | |
1669 | opens on /dev/tty */ | |
37bdfb07 | 1670 | |
70522e12 | 1671 | mutex_lock(&tty_mutex); |
6d31a88c | 1672 | tty_lock(); |
1da177e4 LT |
1673 | tty_closing = tty->count <= 1; |
1674 | o_tty_closing = o_tty && | |
1675 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1676 | do_sleep = 0; |
1677 | ||
1678 | if (tty_closing) { | |
1679 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1680 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1681 | do_sleep++; |
1682 | } | |
1683 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1684 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1685 | do_sleep++; |
1686 | } | |
1687 | } | |
1688 | if (o_tty_closing) { | |
1689 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1690 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1691 | do_sleep++; |
1692 | } | |
1693 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1694 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1695 | do_sleep++; |
1696 | } | |
1697 | } | |
1698 | if (!do_sleep) | |
1699 | break; | |
1700 | ||
9de44bd6 JS |
1701 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1702 | __func__, tty_name(tty, buf)); | |
6d31a88c | 1703 | tty_unlock(); |
70522e12 | 1704 | mutex_unlock(&tty_mutex); |
1da177e4 | 1705 | schedule(); |
37bdfb07 | 1706 | } |
1da177e4 LT |
1707 | |
1708 | /* | |
37bdfb07 AC |
1709 | * The closing flags are now consistent with the open counts on |
1710 | * both sides, and we've completed the last operation that could | |
1da177e4 | 1711 | * block, so it's safe to proceed with closing. |
d155255a AC |
1712 | * |
1713 | * We must *not* drop the tty_mutex until we ensure that a further | |
1714 | * entry into tty_open can not pick up this tty. | |
1da177e4 | 1715 | */ |
1da177e4 LT |
1716 | if (pty_master) { |
1717 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1718 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1719 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1720 | o_tty->count = 0; |
1721 | } | |
1722 | } | |
1723 | if (--tty->count < 0) { | |
9de44bd6 JS |
1724 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1725 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1726 | tty->count = 0; |
1727 | } | |
37bdfb07 | 1728 | |
1da177e4 LT |
1729 | /* |
1730 | * We've decremented tty->count, so we need to remove this file | |
1731 | * descriptor off the tty->tty_files list; this serves two | |
1732 | * purposes: | |
1733 | * - check_tty_count sees the correct number of file descriptors | |
1734 | * associated with this tty. | |
1735 | * - do_tty_hangup no longer sees this file descriptor as | |
1736 | * something that needs to be handled for hangups. | |
1737 | */ | |
d996b62a | 1738 | tty_del_file(filp); |
1da177e4 LT |
1739 | |
1740 | /* | |
1741 | * Perform some housekeeping before deciding whether to return. | |
1742 | * | |
1743 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1744 | * case of a pty we may have to wait around for the other side | |
1745 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1746 | */ | |
37bdfb07 | 1747 | if (tty_closing) |
1da177e4 | 1748 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1749 | if (o_tty_closing) |
1da177e4 LT |
1750 | set_bit(TTY_CLOSING, &o_tty->flags); |
1751 | ||
1752 | /* | |
1753 | * If _either_ side is closing, make sure there aren't any | |
1754 | * processes that still think tty or o_tty is their controlling | |
1755 | * tty. | |
1756 | */ | |
1757 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1758 | read_lock(&tasklist_lock); |
24ec839c | 1759 | session_clear_tty(tty->session); |
1da177e4 | 1760 | if (o_tty) |
24ec839c | 1761 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1762 | read_unlock(&tasklist_lock); |
1763 | } | |
1764 | ||
70522e12 | 1765 | mutex_unlock(&tty_mutex); |
d155255a AC |
1766 | tty_unlock(); |
1767 | /* At this point the TTY_CLOSING flag should ensure a dead tty | |
1768 | cannot be re-opened by a racing opener */ | |
da965822 | 1769 | |
1da177e4 | 1770 | /* check whether both sides are closing ... */ |
d155255a | 1771 | if (!tty_closing || (o_tty && !o_tty_closing)) |
eeb89d91 | 1772 | return 0; |
37bdfb07 | 1773 | |
1da177e4 | 1774 | #ifdef TTY_DEBUG_HANGUP |
9de44bd6 | 1775 | printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__); |
1da177e4 LT |
1776 | #endif |
1777 | /* | |
01e1abb2 | 1778 | * Ask the line discipline code to release its structures |
1da177e4 | 1779 | */ |
01e1abb2 | 1780 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1781 | /* |
d5698c28 | 1782 | * The release_tty function takes care of the details of clearing |
6d31a88c | 1783 | * the slots and preserving the termios structure. |
1da177e4 | 1784 | */ |
d155255a | 1785 | mutex_lock(&tty_mutex); |
d5698c28 | 1786 | release_tty(tty, idx); |
d155255a | 1787 | mutex_unlock(&tty_mutex); |
1da177e4 | 1788 | |
1da177e4 | 1789 | /* Make this pty number available for reallocation */ |
718a9163 | 1790 | if (devpts) |
15f1a633 | 1791 | devpts_kill_index(inode, idx); |
d155255a | 1792 | |
eeb89d91 | 1793 | return 0; |
1da177e4 LT |
1794 | } |
1795 | ||
b82154ac JS |
1796 | /** |
1797 | * tty_open_current_tty - get tty of current task for open | |
1798 | * @device: device number | |
1799 | * @filp: file pointer to tty | |
1800 | * @return: tty of the current task iff @device is /dev/tty | |
1801 | * | |
1802 | * We cannot return driver and index like for the other nodes because | |
1803 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1804 | * |
1805 | * We need to move to returning a refcounted object from all the lookup | |
1806 | * paths including this one. | |
b82154ac JS |
1807 | */ |
1808 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1809 | { | |
1810 | struct tty_struct *tty; | |
1811 | ||
1812 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1813 | return NULL; | |
1814 | ||
1815 | tty = get_current_tty(); | |
1816 | if (!tty) | |
1817 | return ERR_PTR(-ENXIO); | |
1818 | ||
1819 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1820 | /* noctty = 1; */ | |
1821 | tty_kref_put(tty); | |
1822 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1823 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1824 | return tty; |
1825 | } | |
1826 | ||
5b5e7040 JS |
1827 | /** |
1828 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1829 | * @device: device number | |
1830 | * @filp: file pointer to tty | |
1831 | * @noctty: set if the device should not become a controlling tty | |
1832 | * @index: index for the device in the @return driver | |
1833 | * @return: driver for this inode (with increased refcount) | |
1834 | * | |
1835 | * If @return is not erroneous, the caller is responsible to decrement the | |
1836 | * refcount by tty_driver_kref_put. | |
1837 | * | |
1838 | * Locking: tty_mutex protects get_tty_driver | |
1839 | */ | |
1840 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1841 | int *noctty, int *index) | |
1842 | { | |
1843 | struct tty_driver *driver; | |
1844 | ||
2cd0050c | 1845 | switch (device) { |
5b5e7040 | 1846 | #ifdef CONFIG_VT |
2cd0050c | 1847 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1848 | extern struct tty_driver *console_driver; |
1849 | driver = tty_driver_kref_get(console_driver); | |
1850 | *index = fg_console; | |
1851 | *noctty = 1; | |
2cd0050c | 1852 | break; |
5b5e7040 JS |
1853 | } |
1854 | #endif | |
2cd0050c | 1855 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1856 | struct tty_driver *console_driver = console_device(index); |
1857 | if (console_driver) { | |
1858 | driver = tty_driver_kref_get(console_driver); | |
1859 | if (driver) { | |
1860 | /* Don't let /dev/console block */ | |
1861 | filp->f_flags |= O_NONBLOCK; | |
1862 | *noctty = 1; | |
2cd0050c | 1863 | break; |
5b5e7040 JS |
1864 | } |
1865 | } | |
1866 | return ERR_PTR(-ENODEV); | |
1867 | } | |
2cd0050c JS |
1868 | default: |
1869 | driver = get_tty_driver(device, index); | |
1870 | if (!driver) | |
1871 | return ERR_PTR(-ENODEV); | |
1872 | break; | |
1873 | } | |
5b5e7040 JS |
1874 | return driver; |
1875 | } | |
1876 | ||
af9b897e | 1877 | /** |
eeb89d91 | 1878 | * tty_open - open a tty device |
af9b897e AC |
1879 | * @inode: inode of device file |
1880 | * @filp: file pointer to tty | |
1da177e4 | 1881 | * |
af9b897e AC |
1882 | * tty_open and tty_release keep up the tty count that contains the |
1883 | * number of opens done on a tty. We cannot use the inode-count, as | |
1884 | * different inodes might point to the same tty. | |
1da177e4 | 1885 | * |
af9b897e AC |
1886 | * Open-counting is needed for pty masters, as well as for keeping |
1887 | * track of serial lines: DTR is dropped when the last close happens. | |
1888 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1889 | * | |
1890 | * The termios state of a pty is reset on first open so that | |
1891 | * settings don't persist across reuse. | |
1892 | * | |
5b5e7040 | 1893 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1894 | * tty->count should protect the rest. |
1895 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1896 | */ |
af9b897e | 1897 | |
eeb89d91 | 1898 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1899 | { |
b82154ac | 1900 | struct tty_struct *tty; |
1da177e4 | 1901 | int noctty, retval; |
b82154ac | 1902 | struct tty_driver *driver = NULL; |
1da177e4 LT |
1903 | int index; |
1904 | dev_t device = inode->i_rdev; | |
846c151a | 1905 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1906 | |
1907 | nonseekable_open(inode, filp); | |
37bdfb07 | 1908 | |
1da177e4 | 1909 | retry_open: |
fa90e1c9 JS |
1910 | retval = tty_alloc_file(filp); |
1911 | if (retval) | |
1912 | return -ENOMEM; | |
1913 | ||
1da177e4 LT |
1914 | noctty = filp->f_flags & O_NOCTTY; |
1915 | index = -1; | |
1916 | retval = 0; | |
37bdfb07 | 1917 | |
70522e12 | 1918 | mutex_lock(&tty_mutex); |
6d31a88c AC |
1919 | tty_lock(); |
1920 | ||
b82154ac JS |
1921 | tty = tty_open_current_tty(device, filp); |
1922 | if (IS_ERR(tty)) { | |
ba5db448 JS |
1923 | retval = PTR_ERR(tty); |
1924 | goto err_unlock; | |
5b5e7040 JS |
1925 | } else if (!tty) { |
1926 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
1927 | if (IS_ERR(driver)) { | |
ba5db448 JS |
1928 | retval = PTR_ERR(driver); |
1929 | goto err_unlock; | |
1da177e4 | 1930 | } |
1da177e4 | 1931 | |
4a2b5fdd | 1932 | /* check whether we're reopening an existing tty */ |
15f1a633 | 1933 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 1934 | if (IS_ERR(tty)) { |
ba5db448 JS |
1935 | retval = PTR_ERR(tty); |
1936 | goto err_unlock; | |
808ffa3d | 1937 | } |
4a2b5fdd SB |
1938 | } |
1939 | ||
1940 | if (tty) { | |
1941 | retval = tty_reopen(tty); | |
6d31a88c | 1942 | if (retval) |
4a2b5fdd | 1943 | tty = ERR_PTR(retval); |
6d31a88c | 1944 | } else |
593a27c4 | 1945 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 1946 | |
70522e12 | 1947 | mutex_unlock(&tty_mutex); |
b82154ac JS |
1948 | if (driver) |
1949 | tty_driver_kref_put(driver); | |
eeb89d91 | 1950 | if (IS_ERR(tty)) { |
6d31a88c | 1951 | tty_unlock(); |
ba5db448 JS |
1952 | retval = PTR_ERR(tty); |
1953 | goto err_file; | |
eeb89d91 | 1954 | } |
1da177e4 | 1955 | |
fa90e1c9 | 1956 | tty_add_file(tty, filp); |
d996b62a | 1957 | |
9de44bd6 | 1958 | check_tty_count(tty, __func__); |
1da177e4 LT |
1959 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1960 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1961 | noctty = 1; | |
1962 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 1963 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 1964 | #endif |
909bc774 HRK |
1965 | if (tty->ops->open) |
1966 | retval = tty->ops->open(tty, filp); | |
1967 | else | |
1968 | retval = -ENODEV; | |
1da177e4 LT |
1969 | filp->f_flags = saved_flags; |
1970 | ||
37bdfb07 AC |
1971 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1972 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1973 | retval = -EBUSY; |
1974 | ||
1975 | if (retval) { | |
1976 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1977 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
1978 | retval, tty->name); | |
1da177e4 | 1979 | #endif |
6d31a88c | 1980 | tty_unlock(); /* need to call tty_release without BTM */ |
eeb89d91 | 1981 | tty_release(inode, filp); |
64ba3dc3 | 1982 | if (retval != -ERESTARTSYS) |
1da177e4 | 1983 | return retval; |
64ba3dc3 AB |
1984 | |
1985 | if (signal_pending(current)) | |
1da177e4 | 1986 | return retval; |
64ba3dc3 | 1987 | |
1da177e4 LT |
1988 | schedule(); |
1989 | /* | |
1990 | * Need to reset f_op in case a hangup happened. | |
1991 | */ | |
6d31a88c | 1992 | tty_lock(); |
1da177e4 LT |
1993 | if (filp->f_op == &hung_up_tty_fops) |
1994 | filp->f_op = &tty_fops; | |
6d31a88c | 1995 | tty_unlock(); |
1da177e4 LT |
1996 | goto retry_open; |
1997 | } | |
6d31a88c | 1998 | tty_unlock(); |
eeb89d91 | 1999 | |
24ec839c PZ |
2000 | |
2001 | mutex_lock(&tty_mutex); | |
6d31a88c | 2002 | tty_lock(); |
24ec839c | 2003 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2004 | if (!noctty && |
2005 | current->signal->leader && | |
2006 | !current->signal->tty && | |
ab521dc0 | 2007 | tty->session == NULL) |
2a65f1d9 | 2008 | __proc_set_tty(current, tty); |
24ec839c | 2009 | spin_unlock_irq(¤t->sighand->siglock); |
6d31a88c | 2010 | tty_unlock(); |
24ec839c | 2011 | mutex_unlock(&tty_mutex); |
1da177e4 | 2012 | return 0; |
ba5db448 | 2013 | err_unlock: |
6d31a88c | 2014 | tty_unlock(); |
ba5db448 JS |
2015 | mutex_unlock(&tty_mutex); |
2016 | /* after locks to avoid deadlock */ | |
2017 | if (!IS_ERR_OR_NULL(driver)) | |
2018 | tty_driver_kref_put(driver); | |
2019 | err_file: | |
2020 | tty_free_file(filp); | |
2021 | return retval; | |
1da177e4 LT |
2022 | } |
2023 | ||
39d95b9d JC |
2024 | |
2025 | ||
af9b897e AC |
2026 | /** |
2027 | * tty_poll - check tty status | |
2028 | * @filp: file being polled | |
2029 | * @wait: poll wait structures to update | |
2030 | * | |
2031 | * Call the line discipline polling method to obtain the poll | |
2032 | * status of the device. | |
2033 | * | |
2034 | * Locking: locks called line discipline but ldisc poll method | |
2035 | * may be re-entered freely by other callers. | |
2036 | */ | |
2037 | ||
37bdfb07 | 2038 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2039 | { |
d996b62a | 2040 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2041 | struct tty_ldisc *ld; |
2042 | int ret = 0; | |
2043 | ||
a7113a96 | 2044 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2045 | return 0; |
37bdfb07 | 2046 | |
1da177e4 | 2047 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2048 | if (ld->ops->poll) |
2049 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2050 | tty_ldisc_deref(ld); |
2051 | return ret; | |
2052 | } | |
2053 | ||
ec79d605 | 2054 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2055 | { |
d996b62a | 2056 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2057 | unsigned long flags; |
5d1e3230 | 2058 | int retval = 0; |
1da177e4 | 2059 | |
a7113a96 | 2060 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2061 | goto out; |
37bdfb07 | 2062 | |
1da177e4 LT |
2063 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2064 | if (retval <= 0) | |
5d1e3230 | 2065 | goto out; |
1da177e4 LT |
2066 | |
2067 | if (on) { | |
ab521dc0 EB |
2068 | enum pid_type type; |
2069 | struct pid *pid; | |
1da177e4 LT |
2070 | if (!waitqueue_active(&tty->read_wait)) |
2071 | tty->minimum_to_wake = 1; | |
47f86834 | 2072 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2073 | if (tty->pgrp) { |
2074 | pid = tty->pgrp; | |
2075 | type = PIDTYPE_PGID; | |
2076 | } else { | |
2077 | pid = task_pid(current); | |
2078 | type = PIDTYPE_PID; | |
2079 | } | |
80e1e823 | 2080 | get_pid(pid); |
70362511 | 2081 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2082 | retval = __f_setown(filp, pid, type, 0); |
2083 | put_pid(pid); | |
1da177e4 | 2084 | if (retval) |
5d1e3230 | 2085 | goto out; |
1da177e4 LT |
2086 | } else { |
2087 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2088 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2089 | } | |
5d1e3230 JC |
2090 | retval = 0; |
2091 | out: | |
ec79d605 AB |
2092 | return retval; |
2093 | } | |
2094 | ||
2095 | static int tty_fasync(int fd, struct file *filp, int on) | |
2096 | { | |
2097 | int retval; | |
6d31a88c | 2098 | tty_lock(); |
ec79d605 | 2099 | retval = __tty_fasync(fd, filp, on); |
6d31a88c | 2100 | tty_unlock(); |
5d1e3230 | 2101 | return retval; |
1da177e4 LT |
2102 | } |
2103 | ||
af9b897e AC |
2104 | /** |
2105 | * tiocsti - fake input character | |
2106 | * @tty: tty to fake input into | |
2107 | * @p: pointer to character | |
2108 | * | |
3a4fa0a2 | 2109 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2110 | * input management. |
2111 | * | |
2112 | * FIXME: does not honour flow control ?? | |
2113 | * | |
2114 | * Locking: | |
2115 | * Called functions take tty_ldisc_lock | |
2116 | * current->signal->tty check is safe without locks | |
28298232 AC |
2117 | * |
2118 | * FIXME: may race normal receive processing | |
af9b897e AC |
2119 | */ |
2120 | ||
1da177e4 LT |
2121 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2122 | { | |
2123 | char ch, mbz = 0; | |
2124 | struct tty_ldisc *ld; | |
37bdfb07 | 2125 | |
1da177e4 LT |
2126 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2127 | return -EPERM; | |
2128 | if (get_user(ch, p)) | |
2129 | return -EFAULT; | |
1e641743 | 2130 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2131 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2132 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2133 | tty_ldisc_deref(ld); |
2134 | return 0; | |
2135 | } | |
2136 | ||
af9b897e AC |
2137 | /** |
2138 | * tiocgwinsz - implement window query ioctl | |
2139 | * @tty; tty | |
2140 | * @arg: user buffer for result | |
2141 | * | |
808a0d38 | 2142 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2143 | * |
24ec839c | 2144 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2145 | * is consistent. |
af9b897e AC |
2146 | */ |
2147 | ||
37bdfb07 | 2148 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2149 | { |
808a0d38 AC |
2150 | int err; |
2151 | ||
5785c95b | 2152 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2153 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2154 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2155 | |
2156 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2157 | } |
2158 | ||
af9b897e | 2159 | /** |
8c9a9dd0 AC |
2160 | * tty_do_resize - resize event |
2161 | * @tty: tty being resized | |
8c9a9dd0 AC |
2162 | * @rows: rows (character) |
2163 | * @cols: cols (character) | |
2164 | * | |
3ad2f3fb | 2165 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2166 | * peform a terminal resize correctly |
af9b897e AC |
2167 | */ |
2168 | ||
fc6f6238 | 2169 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2170 | { |
fc6f6238 | 2171 | struct pid *pgrp; |
47f86834 | 2172 | unsigned long flags; |
1da177e4 | 2173 | |
fc6f6238 AC |
2174 | /* Lock the tty */ |
2175 | mutex_lock(&tty->termios_mutex); | |
2176 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2177 | goto done; |
47f86834 AC |
2178 | /* Get the PID values and reference them so we can |
2179 | avoid holding the tty ctrl lock while sending signals */ | |
2180 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2181 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2182 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2183 | ||
2184 | if (pgrp) | |
2185 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2186 | put_pid(pgrp); |
47f86834 | 2187 | |
8c9a9dd0 | 2188 | tty->winsize = *ws; |
ca9bda00 | 2189 | done: |
fc6f6238 | 2190 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2191 | return 0; |
2192 | } | |
2193 | ||
8c9a9dd0 AC |
2194 | /** |
2195 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2196 | * @tty; tty side of tty |
8c9a9dd0 AC |
2197 | * @arg: user buffer for result |
2198 | * | |
2199 | * Copies the user idea of the window size to the kernel. Traditionally | |
2200 | * this is just advisory information but for the Linux console it | |
2201 | * actually has driver level meaning and triggers a VC resize. | |
2202 | * | |
2203 | * Locking: | |
25985edc | 2204 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2205 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2206 | * then calls into the default method. | |
2207 | */ | |
2208 | ||
fc6f6238 | 2209 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2210 | { |
2211 | struct winsize tmp_ws; | |
2212 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2213 | return -EFAULT; | |
2214 | ||
2215 | if (tty->ops->resize) | |
fc6f6238 | 2216 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2217 | else |
fc6f6238 | 2218 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2219 | } |
2220 | ||
af9b897e AC |
2221 | /** |
2222 | * tioccons - allow admin to move logical console | |
2223 | * @file: the file to become console | |
2224 | * | |
25985edc | 2225 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2226 | * |
2227 | * Locking: uses redirect_lock to guard the redirect information | |
2228 | */ | |
2229 | ||
1da177e4 LT |
2230 | static int tioccons(struct file *file) |
2231 | { | |
2232 | if (!capable(CAP_SYS_ADMIN)) | |
2233 | return -EPERM; | |
2234 | if (file->f_op->write == redirected_tty_write) { | |
2235 | struct file *f; | |
2236 | spin_lock(&redirect_lock); | |
2237 | f = redirect; | |
2238 | redirect = NULL; | |
2239 | spin_unlock(&redirect_lock); | |
2240 | if (f) | |
2241 | fput(f); | |
2242 | return 0; | |
2243 | } | |
2244 | spin_lock(&redirect_lock); | |
2245 | if (redirect) { | |
2246 | spin_unlock(&redirect_lock); | |
2247 | return -EBUSY; | |
2248 | } | |
2249 | get_file(file); | |
2250 | redirect = file; | |
2251 | spin_unlock(&redirect_lock); | |
2252 | return 0; | |
2253 | } | |
2254 | ||
af9b897e AC |
2255 | /** |
2256 | * fionbio - non blocking ioctl | |
2257 | * @file: file to set blocking value | |
2258 | * @p: user parameter | |
2259 | * | |
2260 | * Historical tty interfaces had a blocking control ioctl before | |
2261 | * the generic functionality existed. This piece of history is preserved | |
2262 | * in the expected tty API of posix OS's. | |
2263 | * | |
6146b9af | 2264 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2265 | */ |
1da177e4 LT |
2266 | |
2267 | static int fionbio(struct file *file, int __user *p) | |
2268 | { | |
2269 | int nonblock; | |
2270 | ||
2271 | if (get_user(nonblock, p)) | |
2272 | return -EFAULT; | |
2273 | ||
db1dd4d3 | 2274 | spin_lock(&file->f_lock); |
1da177e4 LT |
2275 | if (nonblock) |
2276 | file->f_flags |= O_NONBLOCK; | |
2277 | else | |
2278 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2279 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2280 | return 0; |
2281 | } | |
2282 | ||
af9b897e AC |
2283 | /** |
2284 | * tiocsctty - set controlling tty | |
2285 | * @tty: tty structure | |
2286 | * @arg: user argument | |
2287 | * | |
2288 | * This ioctl is used to manage job control. It permits a session | |
2289 | * leader to set this tty as the controlling tty for the session. | |
2290 | * | |
2291 | * Locking: | |
28298232 | 2292 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2293 | * Takes tasklist_lock internally to walk sessions |
2294 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2295 | */ |
2296 | ||
1da177e4 LT |
2297 | static int tiocsctty(struct tty_struct *tty, int arg) |
2298 | { | |
24ec839c | 2299 | int ret = 0; |
ab521dc0 | 2300 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2301 | return ret; |
2302 | ||
2303 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2304 | /* |
2305 | * The process must be a session leader and | |
2306 | * not have a controlling tty already. | |
2307 | */ | |
24ec839c PZ |
2308 | if (!current->signal->leader || current->signal->tty) { |
2309 | ret = -EPERM; | |
2310 | goto unlock; | |
2311 | } | |
2312 | ||
ab521dc0 | 2313 | if (tty->session) { |
1da177e4 LT |
2314 | /* |
2315 | * This tty is already the controlling | |
2316 | * tty for another session group! | |
2317 | */ | |
37bdfb07 | 2318 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2319 | /* |
2320 | * Steal it away | |
2321 | */ | |
1da177e4 | 2322 | read_lock(&tasklist_lock); |
24ec839c | 2323 | session_clear_tty(tty->session); |
1da177e4 | 2324 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2325 | } else { |
2326 | ret = -EPERM; | |
2327 | goto unlock; | |
2328 | } | |
1da177e4 | 2329 | } |
24ec839c PZ |
2330 | proc_set_tty(current, tty); |
2331 | unlock: | |
28298232 | 2332 | mutex_unlock(&tty_mutex); |
24ec839c | 2333 | return ret; |
1da177e4 LT |
2334 | } |
2335 | ||
5d0fdf1e AC |
2336 | /** |
2337 | * tty_get_pgrp - return a ref counted pgrp pid | |
2338 | * @tty: tty to read | |
2339 | * | |
2340 | * Returns a refcounted instance of the pid struct for the process | |
2341 | * group controlling the tty. | |
2342 | */ | |
2343 | ||
2344 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2345 | { | |
2346 | unsigned long flags; | |
2347 | struct pid *pgrp; | |
2348 | ||
2349 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2350 | pgrp = get_pid(tty->pgrp); | |
2351 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2352 | ||
2353 | return pgrp; | |
2354 | } | |
2355 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2356 | ||
af9b897e AC |
2357 | /** |
2358 | * tiocgpgrp - get process group | |
2359 | * @tty: tty passed by user | |
25985edc | 2360 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2361 | * @p: returned pid |
2362 | * | |
2363 | * Obtain the process group of the tty. If there is no process group | |
2364 | * return an error. | |
2365 | * | |
24ec839c | 2366 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2367 | */ |
2368 | ||
1da177e4 LT |
2369 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2370 | { | |
5d0fdf1e AC |
2371 | struct pid *pid; |
2372 | int ret; | |
1da177e4 LT |
2373 | /* |
2374 | * (tty == real_tty) is a cheap way of | |
2375 | * testing if the tty is NOT a master pty. | |
2376 | */ | |
2377 | if (tty == real_tty && current->signal->tty != real_tty) | |
2378 | return -ENOTTY; | |
5d0fdf1e AC |
2379 | pid = tty_get_pgrp(real_tty); |
2380 | ret = put_user(pid_vnr(pid), p); | |
2381 | put_pid(pid); | |
2382 | return ret; | |
1da177e4 LT |
2383 | } |
2384 | ||
af9b897e AC |
2385 | /** |
2386 | * tiocspgrp - attempt to set process group | |
2387 | * @tty: tty passed by user | |
2388 | * @real_tty: tty side device matching tty passed by user | |
2389 | * @p: pid pointer | |
2390 | * | |
2391 | * Set the process group of the tty to the session passed. Only | |
2392 | * permitted where the tty session is our session. | |
2393 | * | |
47f86834 | 2394 | * Locking: RCU, ctrl lock |
af9b897e AC |
2395 | */ |
2396 | ||
1da177e4 LT |
2397 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2398 | { | |
04a2e6a5 EB |
2399 | struct pid *pgrp; |
2400 | pid_t pgrp_nr; | |
1da177e4 | 2401 | int retval = tty_check_change(real_tty); |
47f86834 | 2402 | unsigned long flags; |
1da177e4 LT |
2403 | |
2404 | if (retval == -EIO) | |
2405 | return -ENOTTY; | |
2406 | if (retval) | |
2407 | return retval; | |
2408 | if (!current->signal->tty || | |
2409 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2410 | (real_tty->session != task_session(current))) |
1da177e4 | 2411 | return -ENOTTY; |
04a2e6a5 | 2412 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2413 | return -EFAULT; |
04a2e6a5 | 2414 | if (pgrp_nr < 0) |
1da177e4 | 2415 | return -EINVAL; |
04a2e6a5 | 2416 | rcu_read_lock(); |
b488893a | 2417 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2418 | retval = -ESRCH; |
2419 | if (!pgrp) | |
2420 | goto out_unlock; | |
2421 | retval = -EPERM; | |
2422 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2423 | goto out_unlock; | |
2424 | retval = 0; | |
47f86834 | 2425 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2426 | put_pid(real_tty->pgrp); |
2427 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2428 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2429 | out_unlock: |
2430 | rcu_read_unlock(); | |
2431 | return retval; | |
1da177e4 LT |
2432 | } |
2433 | ||
af9b897e AC |
2434 | /** |
2435 | * tiocgsid - get session id | |
2436 | * @tty: tty passed by user | |
25985edc | 2437 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2438 | * @p: pointer to returned session id |
2439 | * | |
2440 | * Obtain the session id of the tty. If there is no session | |
2441 | * return an error. | |
2442 | * | |
24ec839c | 2443 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2444 | */ |
2445 | ||
1da177e4 LT |
2446 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2447 | { | |
2448 | /* | |
2449 | * (tty == real_tty) is a cheap way of | |
2450 | * testing if the tty is NOT a master pty. | |
2451 | */ | |
2452 | if (tty == real_tty && current->signal->tty != real_tty) | |
2453 | return -ENOTTY; | |
ab521dc0 | 2454 | if (!real_tty->session) |
1da177e4 | 2455 | return -ENOTTY; |
b488893a | 2456 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2457 | } |
2458 | ||
af9b897e AC |
2459 | /** |
2460 | * tiocsetd - set line discipline | |
2461 | * @tty: tty device | |
2462 | * @p: pointer to user data | |
2463 | * | |
2464 | * Set the line discipline according to user request. | |
2465 | * | |
2466 | * Locking: see tty_set_ldisc, this function is just a helper | |
2467 | */ | |
2468 | ||
1da177e4 LT |
2469 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2470 | { | |
2471 | int ldisc; | |
04f378b1 | 2472 | int ret; |
1da177e4 LT |
2473 | |
2474 | if (get_user(ldisc, p)) | |
2475 | return -EFAULT; | |
04f378b1 | 2476 | |
04f378b1 | 2477 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2478 | |
2479 | return ret; | |
1da177e4 LT |
2480 | } |
2481 | ||
af9b897e AC |
2482 | /** |
2483 | * send_break - performed time break | |
2484 | * @tty: device to break on | |
2485 | * @duration: timeout in mS | |
2486 | * | |
2487 | * Perform a timed break on hardware that lacks its own driver level | |
2488 | * timed break functionality. | |
2489 | * | |
2490 | * Locking: | |
28298232 | 2491 | * atomic_write_lock serializes |
af9b897e | 2492 | * |
af9b897e AC |
2493 | */ |
2494 | ||
b20f3ae5 | 2495 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2496 | { |
9e98966c AC |
2497 | int retval; |
2498 | ||
2499 | if (tty->ops->break_ctl == NULL) | |
2500 | return 0; | |
2501 | ||
2502 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2503 | retval = tty->ops->break_ctl(tty, duration); | |
2504 | else { | |
2505 | /* Do the work ourselves */ | |
2506 | if (tty_write_lock(tty, 0) < 0) | |
2507 | return -EINTR; | |
2508 | retval = tty->ops->break_ctl(tty, -1); | |
2509 | if (retval) | |
2510 | goto out; | |
2511 | if (!signal_pending(current)) | |
2512 | msleep_interruptible(duration); | |
2513 | retval = tty->ops->break_ctl(tty, 0); | |
2514 | out: | |
2515 | tty_write_unlock(tty); | |
2516 | if (signal_pending(current)) | |
2517 | retval = -EINTR; | |
2518 | } | |
2519 | return retval; | |
1da177e4 LT |
2520 | } |
2521 | ||
af9b897e | 2522 | /** |
f34d7a5b | 2523 | * tty_tiocmget - get modem status |
af9b897e AC |
2524 | * @tty: tty device |
2525 | * @file: user file pointer | |
2526 | * @p: pointer to result | |
2527 | * | |
2528 | * Obtain the modem status bits from the tty driver if the feature | |
2529 | * is supported. Return -EINVAL if it is not available. | |
2530 | * | |
2531 | * Locking: none (up to the driver) | |
2532 | */ | |
2533 | ||
60b33c13 | 2534 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2535 | { |
2536 | int retval = -EINVAL; | |
2537 | ||
f34d7a5b | 2538 | if (tty->ops->tiocmget) { |
60b33c13 | 2539 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2540 | |
2541 | if (retval >= 0) | |
2542 | retval = put_user(retval, p); | |
2543 | } | |
2544 | return retval; | |
2545 | } | |
2546 | ||
af9b897e | 2547 | /** |
f34d7a5b | 2548 | * tty_tiocmset - set modem status |
af9b897e | 2549 | * @tty: tty device |
af9b897e AC |
2550 | * @cmd: command - clear bits, set bits or set all |
2551 | * @p: pointer to desired bits | |
2552 | * | |
2553 | * Set the modem status bits from the tty driver if the feature | |
2554 | * is supported. Return -EINVAL if it is not available. | |
2555 | * | |
2556 | * Locking: none (up to the driver) | |
2557 | */ | |
2558 | ||
20b9d177 | 2559 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2560 | unsigned __user *p) |
2561 | { | |
ae677517 AC |
2562 | int retval; |
2563 | unsigned int set, clear, val; | |
1da177e4 | 2564 | |
ae677517 AC |
2565 | if (tty->ops->tiocmset == NULL) |
2566 | return -EINVAL; | |
1da177e4 | 2567 | |
ae677517 AC |
2568 | retval = get_user(val, p); |
2569 | if (retval) | |
2570 | return retval; | |
2571 | set = clear = 0; | |
2572 | switch (cmd) { | |
2573 | case TIOCMBIS: | |
2574 | set = val; | |
2575 | break; | |
2576 | case TIOCMBIC: | |
2577 | clear = val; | |
2578 | break; | |
2579 | case TIOCMSET: | |
2580 | set = val; | |
2581 | clear = ~val; | |
2582 | break; | |
2583 | } | |
2584 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2585 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2586 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2587 | } |
2588 | ||
d281da7f AC |
2589 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2590 | { | |
2591 | int retval = -EINVAL; | |
2592 | struct serial_icounter_struct icount; | |
2593 | memset(&icount, 0, sizeof(icount)); | |
2594 | if (tty->ops->get_icount) | |
2595 | retval = tty->ops->get_icount(tty, &icount); | |
2596 | if (retval != 0) | |
2597 | return retval; | |
2598 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2599 | return -EFAULT; | |
2600 | return 0; | |
2601 | } | |
2602 | ||
e8b70e7d AC |
2603 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2604 | { | |
2605 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2606 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2607 | tty = tty->link; | |
2608 | return tty; | |
2609 | } | |
2610 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2611 | ||
2612 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2613 | { | |
2614 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2615 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2616 | return tty; | |
2617 | return tty->link; | |
2618 | } | |
2619 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2620 | ||
1da177e4 LT |
2621 | /* |
2622 | * Split this up, as gcc can choke on it otherwise.. | |
2623 | */ | |
04f378b1 | 2624 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2625 | { |
d996b62a NP |
2626 | struct tty_struct *tty = file_tty(file); |
2627 | struct tty_struct *real_tty; | |
1da177e4 LT |
2628 | void __user *p = (void __user *)arg; |
2629 | int retval; | |
2630 | struct tty_ldisc *ld; | |
04f378b1 | 2631 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2632 | |
1da177e4 LT |
2633 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2634 | return -EINVAL; | |
2635 | ||
e8b70e7d | 2636 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2637 | |
2638 | /* | |
2639 | * Factor out some common prep work | |
2640 | */ | |
2641 | switch (cmd) { | |
2642 | case TIOCSETD: | |
2643 | case TIOCSBRK: | |
2644 | case TIOCCBRK: | |
2645 | case TCSBRK: | |
37bdfb07 | 2646 | case TCSBRKP: |
1da177e4 LT |
2647 | retval = tty_check_change(tty); |
2648 | if (retval) | |
2649 | return retval; | |
2650 | if (cmd != TIOCCBRK) { | |
2651 | tty_wait_until_sent(tty, 0); | |
2652 | if (signal_pending(current)) | |
2653 | return -EINTR; | |
2654 | } | |
2655 | break; | |
2656 | } | |
2657 | ||
9e98966c AC |
2658 | /* |
2659 | * Now do the stuff. | |
2660 | */ | |
1da177e4 | 2661 | switch (cmd) { |
37bdfb07 AC |
2662 | case TIOCSTI: |
2663 | return tiocsti(tty, p); | |
2664 | case TIOCGWINSZ: | |
8f520021 | 2665 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2666 | case TIOCSWINSZ: |
fc6f6238 | 2667 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2668 | case TIOCCONS: |
2669 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2670 | case FIONBIO: | |
2671 | return fionbio(file, p); | |
2672 | case TIOCEXCL: | |
2673 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2674 | return 0; | |
2675 | case TIOCNXCL: | |
2676 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2677 | return 0; | |
2678 | case TIOCNOTTY: | |
2679 | if (current->signal->tty != tty) | |
2680 | return -ENOTTY; | |
2681 | no_tty(); | |
2682 | return 0; | |
2683 | case TIOCSCTTY: | |
2684 | return tiocsctty(tty, arg); | |
2685 | case TIOCGPGRP: | |
2686 | return tiocgpgrp(tty, real_tty, p); | |
2687 | case TIOCSPGRP: | |
2688 | return tiocspgrp(tty, real_tty, p); | |
2689 | case TIOCGSID: | |
2690 | return tiocgsid(tty, real_tty, p); | |
2691 | case TIOCGETD: | |
c65c9bc3 | 2692 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2693 | case TIOCSETD: |
2694 | return tiocsetd(tty, p); | |
3c95c985 KS |
2695 | case TIOCVHANGUP: |
2696 | if (!capable(CAP_SYS_ADMIN)) | |
2697 | return -EPERM; | |
2698 | tty_vhangup(tty); | |
2699 | return 0; | |
b7b8de08 WF |
2700 | case TIOCGDEV: |
2701 | { | |
2702 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2703 | return put_user(ret, (unsigned int __user *)p); | |
2704 | } | |
37bdfb07 AC |
2705 | /* |
2706 | * Break handling | |
2707 | */ | |
2708 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2709 | if (tty->ops->break_ctl) |
9e98966c | 2710 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2711 | return 0; |
37bdfb07 | 2712 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2713 | if (tty->ops->break_ctl) |
9e98966c | 2714 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2715 | return 0; |
2716 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2717 | /* non-zero arg means wait for all output data | |
2718 | * to be sent (performed above) but don't send break. | |
2719 | * This is used by the tcdrain() termios function. | |
2720 | */ | |
2721 | if (!arg) | |
2722 | return send_break(tty, 250); | |
2723 | return 0; | |
2724 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2725 | return send_break(tty, arg ? arg*100 : 250); | |
2726 | ||
2727 | case TIOCMGET: | |
60b33c13 | 2728 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2729 | case TIOCMSET: |
2730 | case TIOCMBIC: | |
2731 | case TIOCMBIS: | |
20b9d177 | 2732 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2733 | case TIOCGICOUNT: |
2734 | retval = tty_tiocgicount(tty, p); | |
2735 | /* For the moment allow fall through to the old method */ | |
2736 | if (retval != -EINVAL) | |
2737 | return retval; | |
2738 | break; | |
37bdfb07 AC |
2739 | case TCFLSH: |
2740 | switch (arg) { | |
2741 | case TCIFLUSH: | |
2742 | case TCIOFLUSH: | |
2743 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2744 | tty_buffer_flush(tty); | |
c5c34d48 | 2745 | break; |
37bdfb07 AC |
2746 | } |
2747 | break; | |
1da177e4 | 2748 | } |
f34d7a5b | 2749 | if (tty->ops->ioctl) { |
6caa76b7 | 2750 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2751 | if (retval != -ENOIOCTLCMD) |
2752 | return retval; | |
2753 | } | |
2754 | ld = tty_ldisc_ref_wait(tty); | |
2755 | retval = -EINVAL; | |
a352def2 AC |
2756 | if (ld->ops->ioctl) { |
2757 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2758 | if (retval == -ENOIOCTLCMD) |
2759 | retval = -EINVAL; | |
2760 | } | |
2761 | tty_ldisc_deref(ld); | |
2762 | return retval; | |
2763 | } | |
2764 | ||
e10cc1df | 2765 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2766 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2767 | unsigned long arg) |
2768 | { | |
2769 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2770 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2771 | struct tty_ldisc *ld; |
2772 | int retval = -ENOIOCTLCMD; | |
2773 | ||
2774 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2775 | return -EINVAL; | |
2776 | ||
f34d7a5b | 2777 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2778 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2779 | if (retval != -ENOIOCTLCMD) |
2780 | return retval; | |
2781 | } | |
2782 | ||
2783 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2784 | if (ld->ops->compat_ioctl) |
2785 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2786 | else |
2787 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2788 | tty_ldisc_deref(ld); |
2789 | ||
2790 | return retval; | |
2791 | } | |
2792 | #endif | |
1da177e4 LT |
2793 | |
2794 | /* | |
2795 | * This implements the "Secure Attention Key" --- the idea is to | |
2796 | * prevent trojan horses by killing all processes associated with this | |
2797 | * tty when the user hits the "Secure Attention Key". Required for | |
2798 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2799 | * |
1da177e4 LT |
2800 | * This code could be nicer; ideally it should send a HUP, wait a few |
2801 | * seconds, then send a INT, and then a KILL signal. But you then | |
2802 | * have to coordinate with the init process, since all processes associated | |
2803 | * with the current tty must be dead before the new getty is allowed | |
2804 | * to spawn. | |
2805 | * | |
2806 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2807 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2808 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2809 | * | |
2810 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2811 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2812 | */ | |
8b6312f4 | 2813 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2814 | { |
2815 | #ifdef TTY_SOFT_SAK | |
2816 | tty_hangup(tty); | |
2817 | #else | |
652486fb | 2818 | struct task_struct *g, *p; |
ab521dc0 | 2819 | struct pid *session; |
1da177e4 LT |
2820 | int i; |
2821 | struct file *filp; | |
badf1662 | 2822 | struct fdtable *fdt; |
37bdfb07 | 2823 | |
1da177e4 LT |
2824 | if (!tty) |
2825 | return; | |
24ec839c | 2826 | session = tty->session; |
37bdfb07 | 2827 | |
b3f13deb | 2828 | tty_ldisc_flush(tty); |
1da177e4 | 2829 | |
f34d7a5b | 2830 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2831 | |
1da177e4 | 2832 | read_lock(&tasklist_lock); |
652486fb | 2833 | /* Kill the entire session */ |
ab521dc0 | 2834 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2835 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2836 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2837 | task_pid_nr(p), p->comm); |
652486fb | 2838 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2839 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2840 | /* Now kill any processes that happen to have the |
2841 | * tty open. | |
2842 | */ | |
2843 | do_each_thread(g, p) { | |
2844 | if (p->signal->tty == tty) { | |
1da177e4 | 2845 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2846 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2847 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2848 | send_sig(SIGKILL, p, 1); |
2849 | continue; | |
2850 | } | |
2851 | task_lock(p); | |
2852 | if (p->files) { | |
ca99c1da DS |
2853 | /* |
2854 | * We don't take a ref to the file, so we must | |
2855 | * hold ->file_lock instead. | |
2856 | */ | |
2857 | spin_lock(&p->files->file_lock); | |
badf1662 | 2858 | fdt = files_fdtable(p->files); |
37bdfb07 | 2859 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2860 | filp = fcheck_files(p->files, i); |
2861 | if (!filp) | |
2862 | continue; | |
2863 | if (filp->f_op->read == tty_read && | |
d996b62a | 2864 | file_tty(filp) == tty) { |
1da177e4 LT |
2865 | printk(KERN_NOTICE "SAK: killed process %d" |
2866 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2867 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2868 | force_sig(SIGKILL, p); |
1da177e4 LT |
2869 | break; |
2870 | } | |
2871 | } | |
ca99c1da | 2872 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2873 | } |
2874 | task_unlock(p); | |
652486fb | 2875 | } while_each_thread(g, p); |
1da177e4 LT |
2876 | read_unlock(&tasklist_lock); |
2877 | #endif | |
2878 | } | |
2879 | ||
8b6312f4 EB |
2880 | static void do_SAK_work(struct work_struct *work) |
2881 | { | |
2882 | struct tty_struct *tty = | |
2883 | container_of(work, struct tty_struct, SAK_work); | |
2884 | __do_SAK(tty); | |
2885 | } | |
2886 | ||
1da177e4 LT |
2887 | /* |
2888 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2889 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2890 | * the values which we write to it will be identical to the values which it | |
2891 | * already has. --akpm | |
2892 | */ | |
2893 | void do_SAK(struct tty_struct *tty) | |
2894 | { | |
2895 | if (!tty) | |
2896 | return; | |
1da177e4 LT |
2897 | schedule_work(&tty->SAK_work); |
2898 | } | |
2899 | ||
2900 | EXPORT_SYMBOL(do_SAK); | |
2901 | ||
30004ac9 DES |
2902 | static int dev_match_devt(struct device *dev, void *data) |
2903 | { | |
2904 | dev_t *devt = data; | |
2905 | return dev->devt == *devt; | |
2906 | } | |
2907 | ||
2908 | /* Must put_device() after it's unused! */ | |
2909 | static struct device *tty_get_device(struct tty_struct *tty) | |
2910 | { | |
2911 | dev_t devt = tty_devnum(tty); | |
2912 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2913 | } | |
2914 | ||
2915 | ||
af9b897e AC |
2916 | /** |
2917 | * initialize_tty_struct | |
2918 | * @tty: tty to initialize | |
2919 | * | |
2920 | * This subroutine initializes a tty structure that has been newly | |
2921 | * allocated. | |
2922 | * | |
2923 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2924 | */ |
af9b897e | 2925 | |
bf970ee4 AC |
2926 | void initialize_tty_struct(struct tty_struct *tty, |
2927 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2928 | { |
2929 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2930 | kref_init(&tty->kref); |
1da177e4 | 2931 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2932 | tty_ldisc_init(tty); |
ab521dc0 EB |
2933 | tty->session = NULL; |
2934 | tty->pgrp = NULL; | |
1da177e4 | 2935 | tty->overrun_time = jiffies; |
33f0f88f | 2936 | tty_buffer_init(tty); |
5785c95b | 2937 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2938 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2939 | init_waitqueue_head(&tty->write_wait); |
2940 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2941 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2942 | mutex_init(&tty->atomic_read_lock); |
2943 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2944 | mutex_init(&tty->output_lock); |
2945 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2946 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2947 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2948 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2949 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2950 | |
2951 | tty->driver = driver; | |
2952 | tty->ops = driver->ops; | |
2953 | tty->index = idx; | |
2954 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2955 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2956 | } |
2957 | ||
6716671d JS |
2958 | /** |
2959 | * deinitialize_tty_struct | |
2960 | * @tty: tty to deinitialize | |
2961 | * | |
2962 | * This subroutine deinitializes a tty structure that has been newly | |
2963 | * allocated but tty_release cannot be called on that yet. | |
2964 | * | |
2965 | * Locking: none - tty in question must not be exposed at this point | |
2966 | */ | |
2967 | void deinitialize_tty_struct(struct tty_struct *tty) | |
2968 | { | |
2969 | tty_ldisc_deinit(tty); | |
2970 | } | |
2971 | ||
f34d7a5b AC |
2972 | /** |
2973 | * tty_put_char - write one character to a tty | |
2974 | * @tty: tty | |
2975 | * @ch: character | |
2976 | * | |
2977 | * Write one byte to the tty using the provided put_char method | |
2978 | * if present. Returns the number of characters successfully output. | |
2979 | * | |
2980 | * Note: the specific put_char operation in the driver layer may go | |
2981 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2982 | */ |
af9b897e | 2983 | |
f34d7a5b | 2984 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2985 | { |
f34d7a5b AC |
2986 | if (tty->ops->put_char) |
2987 | return tty->ops->put_char(tty, ch); | |
2988 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2989 | } |
f34d7a5b AC |
2990 | EXPORT_SYMBOL_GPL(tty_put_char); |
2991 | ||
d81ed103 | 2992 | struct class *tty_class; |
1da177e4 LT |
2993 | |
2994 | /** | |
af9b897e AC |
2995 | * tty_register_device - register a tty device |
2996 | * @driver: the tty driver that describes the tty device | |
2997 | * @index: the index in the tty driver for this tty device | |
2998 | * @device: a struct device that is associated with this tty device. | |
2999 | * This field is optional, if there is no known struct device | |
3000 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3001 | * |
01107d34 GKH |
3002 | * Returns a pointer to the struct device for this tty device |
3003 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3004 | * |
af9b897e AC |
3005 | * This call is required to be made to register an individual tty device |
3006 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3007 | * that bit is not set, this function should not be called by a tty | |
3008 | * driver. | |
3009 | * | |
3010 | * Locking: ?? | |
1da177e4 | 3011 | */ |
af9b897e | 3012 | |
01107d34 GKH |
3013 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3014 | struct device *device) | |
1da177e4 LT |
3015 | { |
3016 | char name[64]; | |
3017 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
3018 | ||
3019 | if (index >= driver->num) { | |
3020 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3021 | " (%d).\n", index); | |
1cdcb6b4 | 3022 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3023 | } |
3024 | ||
1da177e4 LT |
3025 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3026 | pty_line_name(driver, index, name); | |
3027 | else | |
3028 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3029 | |
03457cd4 | 3030 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 3031 | } |
7d7b93c1 | 3032 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
3033 | |
3034 | /** | |
af9b897e AC |
3035 | * tty_unregister_device - unregister a tty device |
3036 | * @driver: the tty driver that describes the tty device | |
3037 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3038 | * |
af9b897e AC |
3039 | * If a tty device is registered with a call to tty_register_device() then |
3040 | * this function must be called when the tty device is gone. | |
3041 | * | |
3042 | * Locking: ?? | |
1da177e4 | 3043 | */ |
af9b897e | 3044 | |
1da177e4 LT |
3045 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3046 | { | |
37bdfb07 AC |
3047 | device_destroy(tty_class, |
3048 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 3049 | } |
1da177e4 LT |
3050 | EXPORT_SYMBOL(tty_unregister_device); |
3051 | ||
1a54a76d | 3052 | struct tty_driver *__alloc_tty_driver(int lines, struct module *owner) |
1da177e4 LT |
3053 | { |
3054 | struct tty_driver *driver; | |
3055 | ||
506eb99a | 3056 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 3057 | if (driver) { |
7d7b93c1 | 3058 | kref_init(&driver->kref); |
1da177e4 LT |
3059 | driver->magic = TTY_DRIVER_MAGIC; |
3060 | driver->num = lines; | |
1a54a76d | 3061 | driver->owner = owner; |
1da177e4 LT |
3062 | /* later we'll move allocation of tables here */ |
3063 | } | |
3064 | return driver; | |
3065 | } | |
1a54a76d | 3066 | EXPORT_SYMBOL(__alloc_tty_driver); |
1da177e4 | 3067 | |
7d7b93c1 | 3068 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3069 | { |
7d7b93c1 AC |
3070 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3071 | int i; | |
3072 | struct ktermios *tp; | |
3073 | void *p; | |
3074 | ||
3075 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3076 | /* | |
3077 | * Free the termios and termios_locked structures because | |
3078 | * we don't want to get memory leaks when modular tty | |
3079 | * drivers are removed from the kernel. | |
3080 | */ | |
3081 | for (i = 0; i < driver->num; i++) { | |
3082 | tp = driver->termios[i]; | |
3083 | if (tp) { | |
3084 | driver->termios[i] = NULL; | |
3085 | kfree(tp); | |
3086 | } | |
7d7b93c1 AC |
3087 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3088 | tty_unregister_device(driver, i); | |
3089 | } | |
3090 | p = driver->ttys; | |
3091 | proc_tty_unregister_driver(driver); | |
3092 | driver->ttys = NULL; | |
fe6e29fd | 3093 | driver->termios = NULL; |
7d7b93c1 AC |
3094 | kfree(p); |
3095 | cdev_del(&driver->cdev); | |
3096 | } | |
04831dc1 | 3097 | kfree(driver->ports); |
1da177e4 LT |
3098 | kfree(driver); |
3099 | } | |
3100 | ||
7d7b93c1 AC |
3101 | void tty_driver_kref_put(struct tty_driver *driver) |
3102 | { | |
3103 | kref_put(&driver->kref, destruct_tty_driver); | |
3104 | } | |
3105 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3106 | ||
b68e31d0 JD |
3107 | void tty_set_operations(struct tty_driver *driver, |
3108 | const struct tty_operations *op) | |
1da177e4 | 3109 | { |
f34d7a5b AC |
3110 | driver->ops = op; |
3111 | }; | |
7d7b93c1 | 3112 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3113 | |
7d7b93c1 AC |
3114 | void put_tty_driver(struct tty_driver *d) |
3115 | { | |
3116 | tty_driver_kref_put(d); | |
3117 | } | |
1da177e4 | 3118 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3119 | |
3120 | /* | |
3121 | * Called by a tty driver to register itself. | |
3122 | */ | |
3123 | int tty_register_driver(struct tty_driver *driver) | |
3124 | { | |
3125 | int error; | |
37bdfb07 | 3126 | int i; |
1da177e4 LT |
3127 | dev_t dev; |
3128 | void **p = NULL; | |
b670bde0 | 3129 | struct device *d; |
1da177e4 | 3130 | |
543691a6 | 3131 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 3132 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
3133 | if (!p) |
3134 | return -ENOMEM; | |
1da177e4 | 3135 | } |
04831dc1 JS |
3136 | /* |
3137 | * There is too many lines in PTY and we won't need the array there | |
3138 | * since it has an ->install hook where it assigns ports properly. | |
3139 | */ | |
3140 | if (driver->type != TTY_DRIVER_TYPE_PTY) { | |
3141 | driver->ports = kcalloc(driver->num, sizeof(struct tty_port *), | |
3142 | GFP_KERNEL); | |
3143 | if (!driver->ports) { | |
3144 | error = -ENOMEM; | |
3145 | goto err_free_p; | |
3146 | } | |
3147 | } | |
1da177e4 LT |
3148 | |
3149 | if (!driver->major) { | |
37bdfb07 AC |
3150 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3151 | driver->num, driver->name); | |
1da177e4 LT |
3152 | if (!error) { |
3153 | driver->major = MAJOR(dev); | |
3154 | driver->minor_start = MINOR(dev); | |
3155 | } | |
3156 | } else { | |
3157 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3158 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3159 | } |
9bb8a3d4 JS |
3160 | if (error < 0) |
3161 | goto err_free_p; | |
1da177e4 LT |
3162 | |
3163 | if (p) { | |
3164 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3165 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
3166 | } else { |
3167 | driver->ttys = NULL; | |
3168 | driver->termios = NULL; | |
1da177e4 LT |
3169 | } |
3170 | ||
3171 | cdev_init(&driver->cdev, &tty_fops); | |
3172 | driver->cdev.owner = driver->owner; | |
3173 | error = cdev_add(&driver->cdev, dev, driver->num); | |
9bb8a3d4 JS |
3174 | if (error) |
3175 | goto err_unreg_char; | |
1da177e4 | 3176 | |
ca509f69 | 3177 | mutex_lock(&tty_mutex); |
1da177e4 | 3178 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3179 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3180 | |
3181 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3182 | for (i = 0; i < driver->num; i++) { |
3183 | d = tty_register_device(driver, i, NULL); | |
3184 | if (IS_ERR(d)) { | |
3185 | error = PTR_ERR(d); | |
3186 | goto err; | |
3187 | } | |
3188 | } | |
1da177e4 LT |
3189 | } |
3190 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3191 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3192 | return 0; |
b670bde0 VK |
3193 | |
3194 | err: | |
3195 | for (i--; i >= 0; i--) | |
3196 | tty_unregister_device(driver, i); | |
3197 | ||
3198 | mutex_lock(&tty_mutex); | |
3199 | list_del(&driver->tty_drivers); | |
3200 | mutex_unlock(&tty_mutex); | |
3201 | ||
9bb8a3d4 | 3202 | err_unreg_char: |
b670bde0 VK |
3203 | unregister_chrdev_region(dev, driver->num); |
3204 | driver->ttys = NULL; | |
3205 | driver->termios = NULL; | |
04831dc1 | 3206 | err_free_p: /* destruct_tty_driver will free driver->ports */ |
b670bde0 VK |
3207 | kfree(p); |
3208 | return error; | |
1da177e4 | 3209 | } |
1da177e4 LT |
3210 | EXPORT_SYMBOL(tty_register_driver); |
3211 | ||
3212 | /* | |
3213 | * Called by a tty driver to unregister itself. | |
3214 | */ | |
3215 | int tty_unregister_driver(struct tty_driver *driver) | |
3216 | { | |
7d7b93c1 AC |
3217 | #if 0 |
3218 | /* FIXME */ | |
1da177e4 LT |
3219 | if (driver->refcount) |
3220 | return -EBUSY; | |
7d7b93c1 | 3221 | #endif |
1da177e4 LT |
3222 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3223 | driver->num); | |
ca509f69 | 3224 | mutex_lock(&tty_mutex); |
1da177e4 | 3225 | list_del(&driver->tty_drivers); |
ca509f69 | 3226 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3227 | return 0; |
3228 | } | |
7d7b93c1 | 3229 | |
1da177e4 LT |
3230 | EXPORT_SYMBOL(tty_unregister_driver); |
3231 | ||
24ec839c PZ |
3232 | dev_t tty_devnum(struct tty_struct *tty) |
3233 | { | |
3234 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3235 | } | |
3236 | EXPORT_SYMBOL(tty_devnum); | |
3237 | ||
3238 | void proc_clear_tty(struct task_struct *p) | |
3239 | { | |
7c3b1dcf | 3240 | unsigned long flags; |
9c9f4ded | 3241 | struct tty_struct *tty; |
7c3b1dcf | 3242 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3243 | tty = p->signal->tty; |
24ec839c | 3244 | p->signal->tty = NULL; |
7c3b1dcf | 3245 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3246 | tty_kref_put(tty); |
24ec839c | 3247 | } |
24ec839c | 3248 | |
47f86834 AC |
3249 | /* Called under the sighand lock */ |
3250 | ||
2a65f1d9 | 3251 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3252 | { |
3253 | if (tty) { | |
47f86834 AC |
3254 | unsigned long flags; |
3255 | /* We should not have a session or pgrp to put here but.... */ | |
3256 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3257 | put_pid(tty->session); |
3258 | put_pid(tty->pgrp); | |
ab521dc0 | 3259 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3260 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3261 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3262 | if (tsk->signal->tty) { |
3263 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3264 | tty_kref_put(tsk->signal->tty); | |
3265 | } | |
24ec839c | 3266 | } |
2a65f1d9 | 3267 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3268 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3269 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3270 | } |
3271 | ||
98a27ba4 | 3272 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3273 | { |
3274 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3275 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3276 | spin_unlock_irq(&tsk->sighand->siglock); |
3277 | } | |
3278 | ||
3279 | struct tty_struct *get_current_tty(void) | |
3280 | { | |
3281 | struct tty_struct *tty; | |
934e6ebf AC |
3282 | unsigned long flags; |
3283 | ||
3284 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3285 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3286 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3287 | return tty; |
3288 | } | |
a311f743 | 3289 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3290 | |
d81ed103 AC |
3291 | void tty_default_fops(struct file_operations *fops) |
3292 | { | |
3293 | *fops = tty_fops; | |
3294 | } | |
3295 | ||
1da177e4 LT |
3296 | /* |
3297 | * Initialize the console device. This is called *early*, so | |
3298 | * we can't necessarily depend on lots of kernel help here. | |
3299 | * Just do some early initializations, and do the complex setup | |
3300 | * later. | |
3301 | */ | |
3302 | void __init console_init(void) | |
3303 | { | |
3304 | initcall_t *call; | |
3305 | ||
3306 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3307 | tty_ldisc_begin(); |
1da177e4 LT |
3308 | |
3309 | /* | |
37bdfb07 | 3310 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3311 | * inform about problems etc.. |
3312 | */ | |
1da177e4 LT |
3313 | call = __con_initcall_start; |
3314 | while (call < __con_initcall_end) { | |
3315 | (*call)(); | |
3316 | call++; | |
3317 | } | |
3318 | } | |
3319 | ||
2c9ede55 | 3320 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3321 | { |
3322 | if (!mode) | |
3323 | return NULL; | |
3324 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3325 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3326 | *mode = 0666; | |
3327 | return NULL; | |
3328 | } | |
3329 | ||
1da177e4 LT |
3330 | static int __init tty_class_init(void) |
3331 | { | |
7fe845d1 | 3332 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3333 | if (IS_ERR(tty_class)) |
3334 | return PTR_ERR(tty_class); | |
e454cea2 | 3335 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3336 | return 0; |
3337 | } | |
3338 | ||
3339 | postcore_initcall(tty_class_init); | |
3340 | ||
3341 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3342 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3343 | |
fbc92a34 KS |
3344 | static ssize_t show_cons_active(struct device *dev, |
3345 | struct device_attribute *attr, char *buf) | |
3346 | { | |
3347 | struct console *cs[16]; | |
3348 | int i = 0; | |
3349 | struct console *c; | |
3350 | ssize_t count = 0; | |
3351 | ||
ac751efa | 3352 | console_lock(); |
a2a6a822 | 3353 | for_each_console(c) { |
fbc92a34 KS |
3354 | if (!c->device) |
3355 | continue; | |
3356 | if (!c->write) | |
3357 | continue; | |
3358 | if ((c->flags & CON_ENABLED) == 0) | |
3359 | continue; | |
3360 | cs[i++] = c; | |
3361 | if (i >= ARRAY_SIZE(cs)) | |
3362 | break; | |
3363 | } | |
3364 | while (i--) | |
3365 | count += sprintf(buf + count, "%s%d%c", | |
3366 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3367 | console_unlock(); |
fbc92a34 KS |
3368 | |
3369 | return count; | |
3370 | } | |
3371 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3372 | ||
3373 | static struct device *consdev; | |
3374 | ||
3375 | void console_sysfs_notify(void) | |
3376 | { | |
3377 | if (consdev) | |
3378 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3379 | } | |
3380 | ||
1da177e4 LT |
3381 | /* |
3382 | * Ok, now we can initialize the rest of the tty devices and can count | |
3383 | * on memory allocations, interrupts etc.. | |
3384 | */ | |
31d1d48e | 3385 | int __init tty_init(void) |
1da177e4 LT |
3386 | { |
3387 | cdev_init(&tty_cdev, &tty_fops); | |
3388 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3389 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3390 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3391 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3392 | |
3393 | cdev_init(&console_cdev, &console_fops); | |
3394 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3395 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3396 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3397 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3398 | "console"); |
fbc92a34 KS |
3399 | if (IS_ERR(consdev)) |
3400 | consdev = NULL; | |
3401 | else | |
a2a6a822 | 3402 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3403 | |
1da177e4 | 3404 | #ifdef CONFIG_VT |
d81ed103 | 3405 | vty_init(&console_fops); |
1da177e4 LT |
3406 | #endif |
3407 | return 0; | |
3408 | } | |
31d1d48e | 3409 |