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); |
89c8d91e | 190 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
191 | kfree(tty); |
192 | } | |
193 | ||
d996b62a NP |
194 | static inline struct tty_struct *file_tty(struct file *file) |
195 | { | |
196 | return ((struct tty_file_private *)file->private_data)->tty; | |
197 | } | |
198 | ||
fa90e1c9 | 199 | int tty_alloc_file(struct file *file) |
d996b62a NP |
200 | { |
201 | struct tty_file_private *priv; | |
202 | ||
f573bd17 PE |
203 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
204 | if (!priv) | |
205 | return -ENOMEM; | |
d996b62a | 206 | |
fa90e1c9 JS |
207 | file->private_data = priv; |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
212 | /* Associate a new file with the tty structure */ | |
213 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
214 | { | |
215 | struct tty_file_private *priv = file->private_data; | |
216 | ||
d996b62a NP |
217 | priv->tty = tty; |
218 | priv->file = file; | |
d996b62a NP |
219 | |
220 | spin_lock(&tty_files_lock); | |
221 | list_add(&priv->list, &tty->tty_files); | |
222 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 223 | } |
f573bd17 | 224 | |
fa90e1c9 JS |
225 | /** |
226 | * tty_free_file - free file->private_data | |
227 | * | |
228 | * This shall be used only for fail path handling when tty_add_file was not | |
229 | * called yet. | |
230 | */ | |
231 | void tty_free_file(struct file *file) | |
232 | { | |
233 | struct tty_file_private *priv = file->private_data; | |
234 | ||
235 | file->private_data = NULL; | |
236 | kfree(priv); | |
d996b62a NP |
237 | } |
238 | ||
239 | /* Delete file from its tty */ | |
240 | void tty_del_file(struct file *file) | |
241 | { | |
242 | struct tty_file_private *priv = file->private_data; | |
243 | ||
244 | spin_lock(&tty_files_lock); | |
245 | list_del(&priv->list); | |
246 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 247 | tty_free_file(file); |
d996b62a NP |
248 | } |
249 | ||
250 | ||
1da177e4 LT |
251 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
252 | ||
af9b897e AC |
253 | /** |
254 | * tty_name - return tty naming | |
255 | * @tty: tty structure | |
256 | * @buf: buffer for output | |
257 | * | |
258 | * Convert a tty structure into a name. The name reflects the kernel | |
259 | * naming policy and if udev is in use may not reflect user space | |
260 | * | |
261 | * Locking: none | |
262 | */ | |
263 | ||
1da177e4 LT |
264 | char *tty_name(struct tty_struct *tty, char *buf) |
265 | { | |
266 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
267 | strcpy(buf, "NULL tty"); | |
268 | else | |
269 | strcpy(buf, tty->name); | |
270 | return buf; | |
271 | } | |
272 | ||
273 | EXPORT_SYMBOL(tty_name); | |
274 | ||
d769a669 | 275 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
276 | const char *routine) |
277 | { | |
278 | #ifdef TTY_PARANOIA_CHECK | |
279 | if (!tty) { | |
280 | printk(KERN_WARNING | |
281 | "null TTY for (%d:%d) in %s\n", | |
282 | imajor(inode), iminor(inode), routine); | |
283 | return 1; | |
284 | } | |
285 | if (tty->magic != TTY_MAGIC) { | |
286 | printk(KERN_WARNING | |
287 | "bad magic number for tty struct (%d:%d) in %s\n", | |
288 | imajor(inode), iminor(inode), routine); | |
289 | return 1; | |
290 | } | |
291 | #endif | |
292 | return 0; | |
293 | } | |
294 | ||
295 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
296 | { | |
297 | #ifdef CHECK_TTY_COUNT | |
298 | struct list_head *p; | |
299 | int count = 0; | |
37bdfb07 | 300 | |
ee2ffa0d | 301 | spin_lock(&tty_files_lock); |
1da177e4 LT |
302 | list_for_each(p, &tty->tty_files) { |
303 | count++; | |
304 | } | |
ee2ffa0d | 305 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
306 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
307 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
308 | tty->link && tty->link->count) | |
309 | count++; | |
310 | if (tty->count != count) { | |
311 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
312 | "!= #fd's(%d) in %s\n", | |
313 | tty->name, tty->count, count, routine); | |
314 | return count; | |
24ec839c | 315 | } |
1da177e4 LT |
316 | #endif |
317 | return 0; | |
318 | } | |
319 | ||
af9b897e AC |
320 | /** |
321 | * get_tty_driver - find device of a tty | |
322 | * @dev_t: device identifier | |
323 | * @index: returns the index of the tty | |
324 | * | |
325 | * This routine returns a tty driver structure, given a device number | |
326 | * and also passes back the index number. | |
327 | * | |
328 | * Locking: caller must hold tty_mutex | |
1da177e4 | 329 | */ |
af9b897e | 330 | |
1da177e4 LT |
331 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
332 | { | |
333 | struct tty_driver *p; | |
334 | ||
335 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
336 | dev_t base = MKDEV(p->major, p->minor_start); | |
337 | if (device < base || device >= base + p->num) | |
338 | continue; | |
339 | *index = device - base; | |
7d7b93c1 | 340 | return tty_driver_kref_get(p); |
1da177e4 LT |
341 | } |
342 | return NULL; | |
343 | } | |
344 | ||
f2d937f3 JW |
345 | #ifdef CONFIG_CONSOLE_POLL |
346 | ||
347 | /** | |
348 | * tty_find_polling_driver - find device of a polled tty | |
349 | * @name: name string to match | |
350 | * @line: pointer to resulting tty line nr | |
351 | * | |
352 | * This routine returns a tty driver structure, given a name | |
353 | * and the condition that the tty driver is capable of polled | |
354 | * operation. | |
355 | */ | |
356 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
357 | { | |
358 | struct tty_driver *p, *res = NULL; | |
359 | int tty_line = 0; | |
0dca0fd2 | 360 | int len; |
5f0878ac | 361 | char *str, *stp; |
f2d937f3 | 362 | |
0dca0fd2 JW |
363 | for (str = name; *str; str++) |
364 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
365 | break; | |
366 | if (!*str) | |
367 | return NULL; | |
368 | ||
369 | len = str - name; | |
370 | tty_line = simple_strtoul(str, &str, 10); | |
371 | ||
f2d937f3 JW |
372 | mutex_lock(&tty_mutex); |
373 | /* Search through the tty devices to look for a match */ | |
374 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
375 | if (strncmp(name, p->name, len) != 0) |
376 | continue; | |
5f0878ac AC |
377 | stp = str; |
378 | if (*stp == ',') | |
379 | stp++; | |
380 | if (*stp == '\0') | |
381 | stp = NULL; | |
f2d937f3 | 382 | |
6eb68d6f | 383 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 384 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 385 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
386 | *line = tty_line; |
387 | break; | |
388 | } | |
389 | } | |
390 | mutex_unlock(&tty_mutex); | |
391 | ||
392 | return res; | |
393 | } | |
394 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
395 | #endif | |
396 | ||
af9b897e AC |
397 | /** |
398 | * tty_check_change - check for POSIX terminal changes | |
399 | * @tty: tty to check | |
400 | * | |
401 | * If we try to write to, or set the state of, a terminal and we're | |
402 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
403 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
404 | * | |
978e595f | 405 | * Locking: ctrl_lock |
1da177e4 | 406 | */ |
af9b897e | 407 | |
37bdfb07 | 408 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 409 | { |
47f86834 AC |
410 | unsigned long flags; |
411 | int ret = 0; | |
412 | ||
1da177e4 LT |
413 | if (current->signal->tty != tty) |
414 | return 0; | |
47f86834 AC |
415 | |
416 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
417 | ||
ab521dc0 EB |
418 | if (!tty->pgrp) { |
419 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 420 | goto out_unlock; |
1da177e4 | 421 | } |
ab521dc0 | 422 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
423 | goto out_unlock; |
424 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 425 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
426 | goto out; |
427 | if (is_current_pgrp_orphaned()) { | |
428 | ret = -EIO; | |
429 | goto out; | |
430 | } | |
040b6362 ON |
431 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
432 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
433 | ret = -ERESTARTSYS; |
434 | out: | |
9ffee4cb AM |
435 | return ret; |
436 | out_unlock: | |
47f86834 AC |
437 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
438 | return ret; | |
1da177e4 LT |
439 | } |
440 | ||
441 | EXPORT_SYMBOL(tty_check_change); | |
442 | ||
37bdfb07 | 443 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
444 | size_t count, loff_t *ppos) |
445 | { | |
446 | return 0; | |
447 | } | |
448 | ||
37bdfb07 | 449 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
450 | size_t count, loff_t *ppos) |
451 | { | |
452 | return -EIO; | |
453 | } | |
454 | ||
455 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 456 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
457 | { |
458 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
459 | } | |
460 | ||
04f378b1 AC |
461 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
462 | unsigned long arg) | |
38ad2ed0 PF |
463 | { |
464 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
465 | } | |
466 | ||
37bdfb07 | 467 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 468 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
469 | { |
470 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
471 | } | |
472 | ||
62322d25 | 473 | static const struct file_operations tty_fops = { |
1da177e4 LT |
474 | .llseek = no_llseek, |
475 | .read = tty_read, | |
476 | .write = tty_write, | |
477 | .poll = tty_poll, | |
04f378b1 | 478 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 479 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
480 | .open = tty_open, |
481 | .release = tty_release, | |
482 | .fasync = tty_fasync, | |
483 | }; | |
484 | ||
62322d25 | 485 | static const struct file_operations console_fops = { |
1da177e4 LT |
486 | .llseek = no_llseek, |
487 | .read = tty_read, | |
488 | .write = redirected_tty_write, | |
489 | .poll = tty_poll, | |
04f378b1 | 490 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 491 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
492 | .open = tty_open, |
493 | .release = tty_release, | |
494 | .fasync = tty_fasync, | |
495 | }; | |
496 | ||
62322d25 | 497 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
498 | .llseek = no_llseek, |
499 | .read = hung_up_tty_read, | |
500 | .write = hung_up_tty_write, | |
501 | .poll = hung_up_tty_poll, | |
04f378b1 | 502 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 503 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
504 | .release = tty_release, |
505 | }; | |
506 | ||
507 | static DEFINE_SPINLOCK(redirect_lock); | |
508 | static struct file *redirect; | |
509 | ||
510 | /** | |
511 | * tty_wakeup - request more data | |
512 | * @tty: terminal | |
513 | * | |
514 | * Internal and external helper for wakeups of tty. This function | |
515 | * informs the line discipline if present that the driver is ready | |
516 | * to receive more output data. | |
517 | */ | |
37bdfb07 | 518 | |
1da177e4 LT |
519 | void tty_wakeup(struct tty_struct *tty) |
520 | { | |
521 | struct tty_ldisc *ld; | |
37bdfb07 | 522 | |
1da177e4 LT |
523 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
524 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 525 | if (ld) { |
a352def2 AC |
526 | if (ld->ops->write_wakeup) |
527 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
528 | tty_ldisc_deref(ld); |
529 | } | |
530 | } | |
4b19449d | 531 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
532 | } |
533 | ||
534 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
535 | ||
af9b897e | 536 | /** |
11dbf203 | 537 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 538 | * @work: tty device |
af9b897e | 539 | * |
1bad879a | 540 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
541 | * synchronous but doesn't hold any locks, so we need to make sure we |
542 | * have the appropriate locks for what we're doing. | |
543 | * | |
544 | * The hangup event clears any pending redirections onto the hung up | |
545 | * device. It ensures future writes will error and it does the needed | |
546 | * line discipline hangup and signal delivery. The tty object itself | |
547 | * remains intact. | |
548 | * | |
549 | * Locking: | |
ec79d605 | 550 | * BTM |
24ec839c PZ |
551 | * redirect lock for undoing redirection |
552 | * file list lock for manipulating list of ttys | |
553 | * tty_ldisc_lock from called functions | |
554 | * termios_mutex resetting termios data | |
555 | * tasklist_lock to walk task list for hangup event | |
556 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 557 | */ |
11dbf203 | 558 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 559 | { |
37bdfb07 | 560 | struct file *cons_filp = NULL; |
1da177e4 LT |
561 | struct file *filp, *f = NULL; |
562 | struct task_struct *p; | |
d996b62a | 563 | struct tty_file_private *priv; |
1da177e4 | 564 | int closecount = 0, n; |
47f86834 | 565 | unsigned long flags; |
9c9f4ded | 566 | int refs = 0; |
1da177e4 LT |
567 | |
568 | if (!tty) | |
569 | return; | |
570 | ||
1da177e4 LT |
571 | |
572 | spin_lock(&redirect_lock); | |
d996b62a | 573 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
574 | f = redirect; |
575 | redirect = NULL; | |
576 | } | |
577 | spin_unlock(&redirect_lock); | |
37bdfb07 | 578 | |
89c8d91e | 579 | tty_lock(tty); |
11dbf203 | 580 | |
acfa747b JS |
581 | /* some functions below drop BTM, so we need this bit */ |
582 | set_bit(TTY_HUPPING, &tty->flags); | |
583 | ||
ec79d605 AB |
584 | /* inuse_filps is protected by the single tty lock, |
585 | this really needs to change if we want to flush the | |
586 | workqueue with the lock held */ | |
11dbf203 | 587 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 588 | |
ee2ffa0d | 589 | spin_lock(&tty_files_lock); |
1da177e4 | 590 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
591 | list_for_each_entry(priv, &tty->tty_files, list) { |
592 | filp = priv->file; | |
1da177e4 LT |
593 | if (filp->f_op->write == redirected_tty_write) |
594 | cons_filp = filp; | |
595 | if (filp->f_op->write != tty_write) | |
596 | continue; | |
597 | closecount++; | |
ec79d605 | 598 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
599 | filp->f_op = &hung_up_tty_fops; |
600 | } | |
ee2ffa0d | 601 | spin_unlock(&tty_files_lock); |
37bdfb07 | 602 | |
acfa747b JS |
603 | /* |
604 | * it drops BTM and thus races with reopen | |
605 | * we protect the race by TTY_HUPPING | |
606 | */ | |
c65c9bc3 | 607 | tty_ldisc_hangup(tty); |
37bdfb07 | 608 | |
1da177e4 | 609 | read_lock(&tasklist_lock); |
ab521dc0 EB |
610 | if (tty->session) { |
611 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 612 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 613 | if (p->signal->tty == tty) { |
1da177e4 | 614 | p->signal->tty = NULL; |
9c9f4ded AC |
615 | /* We defer the dereferences outside fo |
616 | the tasklist lock */ | |
617 | refs++; | |
618 | } | |
24ec839c PZ |
619 | if (!p->signal->leader) { |
620 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 621 | continue; |
24ec839c PZ |
622 | } |
623 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
624 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 625 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 626 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
627 | if (tty->pgrp) |
628 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 629 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 630 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 631 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
632 | } |
633 | read_unlock(&tasklist_lock); | |
634 | ||
47f86834 | 635 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
636 | clear_bit(TTY_THROTTLED, &tty->flags); |
637 | clear_bit(TTY_PUSH, &tty->flags); | |
638 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
639 | put_pid(tty->session); |
640 | put_pid(tty->pgrp); | |
ab521dc0 EB |
641 | tty->session = NULL; |
642 | tty->pgrp = NULL; | |
1da177e4 | 643 | tty->ctrl_status = 0; |
47f86834 AC |
644 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
645 | ||
9c9f4ded AC |
646 | /* Account for the p->signal references we killed */ |
647 | while (refs--) | |
648 | tty_kref_put(tty); | |
649 | ||
1da177e4 | 650 | /* |
37bdfb07 AC |
651 | * If one of the devices matches a console pointer, we |
652 | * cannot just call hangup() because that will cause | |
653 | * tty->count and state->count to go out of sync. | |
654 | * So we just call close() the right number of times. | |
1da177e4 LT |
655 | */ |
656 | if (cons_filp) { | |
f34d7a5b | 657 | if (tty->ops->close) |
1da177e4 | 658 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
659 | tty->ops->close(tty, cons_filp); |
660 | } else if (tty->ops->hangup) | |
661 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
662 | /* |
663 | * We don't want to have driver/ldisc interactions beyond | |
664 | * the ones we did here. The driver layer expects no | |
665 | * calls after ->hangup() from the ldisc side. However we | |
666 | * can't yet guarantee all that. | |
667 | */ | |
1da177e4 | 668 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 669 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 670 | tty_ldisc_enable(tty); |
11dbf203 | 671 | |
89c8d91e | 672 | tty_unlock(tty); |
11dbf203 | 673 | |
1da177e4 LT |
674 | if (f) |
675 | fput(f); | |
676 | } | |
677 | ||
ddcd9fb6 AB |
678 | static void do_tty_hangup(struct work_struct *work) |
679 | { | |
680 | struct tty_struct *tty = | |
681 | container_of(work, struct tty_struct, hangup_work); | |
682 | ||
11dbf203 | 683 | __tty_hangup(tty); |
ddcd9fb6 AB |
684 | } |
685 | ||
af9b897e AC |
686 | /** |
687 | * tty_hangup - trigger a hangup event | |
688 | * @tty: tty to hangup | |
689 | * | |
690 | * A carrier loss (virtual or otherwise) has occurred on this like | |
691 | * schedule a hangup sequence to run after this event. | |
692 | */ | |
693 | ||
37bdfb07 | 694 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
695 | { |
696 | #ifdef TTY_DEBUG_HANGUP | |
697 | char buf[64]; | |
1da177e4 LT |
698 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
699 | #endif | |
700 | schedule_work(&tty->hangup_work); | |
701 | } | |
702 | ||
703 | EXPORT_SYMBOL(tty_hangup); | |
704 | ||
af9b897e AC |
705 | /** |
706 | * tty_vhangup - process vhangup | |
707 | * @tty: tty to hangup | |
708 | * | |
709 | * The user has asked via system call for the terminal to be hung up. | |
710 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 711 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
712 | */ |
713 | ||
37bdfb07 | 714 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
715 | { |
716 | #ifdef TTY_DEBUG_HANGUP | |
717 | char buf[64]; | |
718 | ||
719 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
720 | #endif | |
11dbf203 | 721 | __tty_hangup(tty); |
1da177e4 | 722 | } |
37bdfb07 | 723 | |
1da177e4 LT |
724 | EXPORT_SYMBOL(tty_vhangup); |
725 | ||
11dbf203 | 726 | |
2cb5998b AC |
727 | /** |
728 | * tty_vhangup_self - process vhangup for own ctty | |
729 | * | |
730 | * Perform a vhangup on the current controlling tty | |
731 | */ | |
732 | ||
733 | void tty_vhangup_self(void) | |
734 | { | |
735 | struct tty_struct *tty; | |
736 | ||
2cb5998b AC |
737 | tty = get_current_tty(); |
738 | if (tty) { | |
739 | tty_vhangup(tty); | |
740 | tty_kref_put(tty); | |
741 | } | |
2cb5998b AC |
742 | } |
743 | ||
af9b897e AC |
744 | /** |
745 | * tty_hung_up_p - was tty hung up | |
746 | * @filp: file pointer of tty | |
747 | * | |
748 | * Return true if the tty has been subject to a vhangup or a carrier | |
749 | * loss | |
750 | */ | |
751 | ||
37bdfb07 | 752 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
753 | { |
754 | return (filp->f_op == &hung_up_tty_fops); | |
755 | } | |
756 | ||
757 | EXPORT_SYMBOL(tty_hung_up_p); | |
758 | ||
ab521dc0 | 759 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
760 | { |
761 | struct task_struct *p; | |
ab521dc0 | 762 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 763 | proc_clear_tty(p); |
ab521dc0 | 764 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
765 | } |
766 | ||
af9b897e AC |
767 | /** |
768 | * disassociate_ctty - disconnect controlling tty | |
769 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 770 | * |
af9b897e AC |
771 | * This function is typically called only by the session leader, when |
772 | * it wants to disassociate itself from its controlling tty. | |
773 | * | |
774 | * It performs the following functions: | |
1da177e4 LT |
775 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
776 | * (2) Clears the tty from being controlling the session | |
777 | * (3) Clears the controlling tty for all processes in the | |
778 | * session group. | |
779 | * | |
af9b897e AC |
780 | * The argument on_exit is set to 1 if called when a process is |
781 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
782 | * | |
24ec839c | 783 | * Locking: |
ec79d605 AB |
784 | * BTM is taken for hysterical raisins, and held when |
785 | * called from no_tty(). | |
24ec839c PZ |
786 | * tty_mutex is taken to protect tty |
787 | * ->siglock is taken to protect ->signal/->sighand | |
788 | * tasklist_lock is taken to walk process list for sessions | |
789 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 790 | */ |
af9b897e | 791 | |
1da177e4 LT |
792 | void disassociate_ctty(int on_exit) |
793 | { | |
794 | struct tty_struct *tty; | |
1da177e4 | 795 | |
5ec93d11 AC |
796 | if (!current->signal->leader) |
797 | return; | |
1da177e4 | 798 | |
24ec839c | 799 | tty = get_current_tty(); |
1da177e4 | 800 | if (tty) { |
1411dc4a | 801 | struct pid *tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 802 | if (on_exit) { |
ddcd9fb6 | 803 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 804 | tty_vhangup(tty); |
ddcd9fb6 | 805 | } |
452a00d2 | 806 | tty_kref_put(tty); |
1411dc4a JS |
807 | if (tty_pgrp) { |
808 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
809 | if (!on_exit) | |
810 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
811 | put_pid(tty_pgrp); | |
812 | } | |
680a9671 | 813 | } else if (on_exit) { |
ab521dc0 | 814 | struct pid *old_pgrp; |
680a9671 EB |
815 | spin_lock_irq(¤t->sighand->siglock); |
816 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 817 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 818 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 819 | if (old_pgrp) { |
ab521dc0 EB |
820 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
821 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
822 | put_pid(old_pgrp); | |
1da177e4 | 823 | } |
1da177e4 LT |
824 | return; |
825 | } | |
1da177e4 | 826 | |
24ec839c | 827 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 828 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 829 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
830 | spin_unlock_irq(¤t->sighand->siglock); |
831 | ||
24ec839c PZ |
832 | tty = get_current_tty(); |
833 | if (tty) { | |
47f86834 AC |
834 | unsigned long flags; |
835 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
836 | put_pid(tty->session); |
837 | put_pid(tty->pgrp); | |
838 | tty->session = NULL; | |
839 | tty->pgrp = NULL; | |
47f86834 | 840 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 841 | tty_kref_put(tty); |
24ec839c PZ |
842 | } else { |
843 | #ifdef TTY_DEBUG_HANGUP | |
844 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
845 | " = NULL", tty); | |
846 | #endif | |
847 | } | |
1da177e4 LT |
848 | |
849 | /* Now clear signal->tty under the lock */ | |
850 | read_lock(&tasklist_lock); | |
ab521dc0 | 851 | session_clear_tty(task_session(current)); |
1da177e4 | 852 | read_unlock(&tasklist_lock); |
1da177e4 LT |
853 | } |
854 | ||
98a27ba4 EB |
855 | /** |
856 | * | |
857 | * no_tty - Ensure the current process does not have a controlling tty | |
858 | */ | |
859 | void no_tty(void) | |
860 | { | |
3af502b9 AC |
861 | /* FIXME: Review locking here. The tty_lock never covered any race |
862 | between a new association and proc_clear_tty but possible we need | |
863 | to protect against this anyway */ | |
98a27ba4 | 864 | struct task_struct *tsk = current; |
5ec93d11 | 865 | disassociate_ctty(0); |
98a27ba4 EB |
866 | proc_clear_tty(tsk); |
867 | } | |
868 | ||
af9b897e AC |
869 | |
870 | /** | |
beb7dd86 | 871 | * stop_tty - propagate flow control |
af9b897e AC |
872 | * @tty: tty to stop |
873 | * | |
874 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 875 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
876 | * on an already stopped device and will not re-call the driver |
877 | * method. | |
878 | * | |
879 | * This functionality is used by both the line disciplines for | |
880 | * halting incoming flow and by the driver. It may therefore be | |
881 | * called from any context, may be under the tty atomic_write_lock | |
882 | * but not always. | |
883 | * | |
884 | * Locking: | |
04f378b1 | 885 | * Uses the tty control lock internally |
af9b897e AC |
886 | */ |
887 | ||
1da177e4 LT |
888 | void stop_tty(struct tty_struct *tty) |
889 | { | |
04f378b1 AC |
890 | unsigned long flags; |
891 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
892 | if (tty->stopped) { | |
893 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 894 | return; |
04f378b1 | 895 | } |
1da177e4 LT |
896 | tty->stopped = 1; |
897 | if (tty->link && tty->link->packet) { | |
898 | tty->ctrl_status &= ~TIOCPKT_START; | |
899 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 900 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 901 | } |
04f378b1 | 902 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
903 | if (tty->ops->stop) |
904 | (tty->ops->stop)(tty); | |
1da177e4 LT |
905 | } |
906 | ||
907 | EXPORT_SYMBOL(stop_tty); | |
908 | ||
af9b897e | 909 | /** |
beb7dd86 | 910 | * start_tty - propagate flow control |
af9b897e AC |
911 | * @tty: tty to start |
912 | * | |
913 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 914 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
915 | * is the tty was previous stopped and is being started then the |
916 | * driver start method is invoked and the line discipline woken. | |
917 | * | |
918 | * Locking: | |
04f378b1 | 919 | * ctrl_lock |
af9b897e AC |
920 | */ |
921 | ||
1da177e4 LT |
922 | void start_tty(struct tty_struct *tty) |
923 | { | |
04f378b1 AC |
924 | unsigned long flags; |
925 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
926 | if (!tty->stopped || tty->flow_stopped) { | |
927 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 928 | return; |
04f378b1 | 929 | } |
1da177e4 LT |
930 | tty->stopped = 0; |
931 | if (tty->link && tty->link->packet) { | |
932 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
933 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 934 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 935 | } |
04f378b1 | 936 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
937 | if (tty->ops->start) |
938 | (tty->ops->start)(tty); | |
1da177e4 LT |
939 | /* If we have a running line discipline it may need kicking */ |
940 | tty_wakeup(tty); | |
1da177e4 LT |
941 | } |
942 | ||
943 | EXPORT_SYMBOL(start_tty); | |
944 | ||
af9b897e AC |
945 | /** |
946 | * tty_read - read method for tty device files | |
947 | * @file: pointer to tty file | |
948 | * @buf: user buffer | |
949 | * @count: size of user buffer | |
950 | * @ppos: unused | |
951 | * | |
952 | * Perform the read system call function on this terminal device. Checks | |
953 | * for hung up devices before calling the line discipline method. | |
954 | * | |
955 | * Locking: | |
47f86834 AC |
956 | * Locks the line discipline internally while needed. Multiple |
957 | * read calls may be outstanding in parallel. | |
af9b897e AC |
958 | */ |
959 | ||
37bdfb07 | 960 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
961 | loff_t *ppos) |
962 | { | |
963 | int i; | |
d996b62a NP |
964 | struct inode *inode = file->f_path.dentry->d_inode; |
965 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
966 | struct tty_ldisc *ld; |
967 | ||
1da177e4 LT |
968 | if (tty_paranoia_check(tty, inode, "tty_read")) |
969 | return -EIO; | |
970 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
971 | return -EIO; | |
972 | ||
973 | /* We want to wait for the line discipline to sort out in this | |
974 | situation */ | |
975 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
976 | if (ld->ops->read) |
977 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
978 | else |
979 | i = -EIO; | |
980 | tty_ldisc_deref(ld); | |
1da177e4 LT |
981 | if (i > 0) |
982 | inode->i_atime = current_fs_time(inode->i_sb); | |
983 | return i; | |
984 | } | |
985 | ||
9c1729db | 986 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 987 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
988 | { |
989 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 990 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
991 | } |
992 | ||
993 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 994 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
995 | { |
996 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
997 | if (ndelay) | |
998 | return -EAGAIN; | |
999 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1000 | return -ERESTARTSYS; | |
1001 | } | |
1002 | return 0; | |
1003 | } | |
1004 | ||
1da177e4 LT |
1005 | /* |
1006 | * Split writes up in sane blocksizes to avoid | |
1007 | * denial-of-service type attacks | |
1008 | */ | |
1009 | static inline ssize_t do_tty_write( | |
1010 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1011 | struct tty_struct *tty, | |
1012 | struct file *file, | |
1013 | const char __user *buf, | |
1014 | size_t count) | |
1015 | { | |
9c1729db | 1016 | ssize_t ret, written = 0; |
1da177e4 | 1017 | unsigned int chunk; |
37bdfb07 | 1018 | |
9c1729db AC |
1019 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1020 | if (ret < 0) | |
1021 | return ret; | |
1da177e4 LT |
1022 | |
1023 | /* | |
1024 | * We chunk up writes into a temporary buffer. This | |
1025 | * simplifies low-level drivers immensely, since they | |
1026 | * don't have locking issues and user mode accesses. | |
1027 | * | |
1028 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1029 | * big chunk-size.. | |
1030 | * | |
1031 | * The default chunk-size is 2kB, because the NTTY | |
1032 | * layer has problems with bigger chunks. It will | |
1033 | * claim to be able to handle more characters than | |
1034 | * it actually does. | |
af9b897e AC |
1035 | * |
1036 | * FIXME: This can probably go away now except that 64K chunks | |
1037 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1038 | */ |
1039 | chunk = 2048; | |
1040 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1041 | chunk = 65536; | |
1042 | if (count < chunk) | |
1043 | chunk = count; | |
1044 | ||
70522e12 | 1045 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1046 | if (tty->write_cnt < chunk) { |
402fda92 | 1047 | unsigned char *buf_chunk; |
1da177e4 LT |
1048 | |
1049 | if (chunk < 1024) | |
1050 | chunk = 1024; | |
1051 | ||
402fda92 JW |
1052 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1053 | if (!buf_chunk) { | |
9c1729db AC |
1054 | ret = -ENOMEM; |
1055 | goto out; | |
1da177e4 LT |
1056 | } |
1057 | kfree(tty->write_buf); | |
1058 | tty->write_cnt = chunk; | |
402fda92 | 1059 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1060 | } |
1061 | ||
1062 | /* Do the write .. */ | |
1063 | for (;;) { | |
1064 | size_t size = count; | |
1065 | if (size > chunk) | |
1066 | size = chunk; | |
1067 | ret = -EFAULT; | |
1068 | if (copy_from_user(tty->write_buf, buf, size)) | |
1069 | break; | |
1da177e4 | 1070 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1071 | if (ret <= 0) |
1072 | break; | |
1073 | written += ret; | |
1074 | buf += ret; | |
1075 | count -= ret; | |
1076 | if (!count) | |
1077 | break; | |
1078 | ret = -ERESTARTSYS; | |
1079 | if (signal_pending(current)) | |
1080 | break; | |
1081 | cond_resched(); | |
1082 | } | |
1083 | if (written) { | |
a7113a96 | 1084 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1085 | inode->i_mtime = current_fs_time(inode->i_sb); |
1086 | ret = written; | |
1087 | } | |
9c1729db AC |
1088 | out: |
1089 | tty_write_unlock(tty); | |
1da177e4 LT |
1090 | return ret; |
1091 | } | |
1092 | ||
95f9bfc6 AC |
1093 | /** |
1094 | * tty_write_message - write a message to a certain tty, not just the console. | |
1095 | * @tty: the destination tty_struct | |
1096 | * @msg: the message to write | |
1097 | * | |
1098 | * This is used for messages that need to be redirected to a specific tty. | |
1099 | * We don't put it into the syslog queue right now maybe in the future if | |
1100 | * really needed. | |
1101 | * | |
ec79d605 | 1102 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1103 | */ |
1104 | ||
1105 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1106 | { | |
95f9bfc6 AC |
1107 | if (tty) { |
1108 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1109 | tty_lock(tty); |
eeb89d91 | 1110 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
89c8d91e | 1111 | tty_unlock(tty); |
95f9bfc6 | 1112 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1113 | } else |
89c8d91e | 1114 | tty_unlock(tty); |
95f9bfc6 AC |
1115 | tty_write_unlock(tty); |
1116 | } | |
95f9bfc6 AC |
1117 | return; |
1118 | } | |
1119 | ||
1da177e4 | 1120 | |
af9b897e AC |
1121 | /** |
1122 | * tty_write - write method for tty device file | |
1123 | * @file: tty file pointer | |
1124 | * @buf: user data to write | |
1125 | * @count: bytes to write | |
1126 | * @ppos: unused | |
1127 | * | |
1128 | * Write data to a tty device via the line discipline. | |
1129 | * | |
1130 | * Locking: | |
1131 | * Locks the line discipline as required | |
1132 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1133 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1134 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1135 | */ |
1136 | ||
37bdfb07 AC |
1137 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1138 | size_t count, loff_t *ppos) | |
1da177e4 | 1139 | { |
a7113a96 | 1140 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1141 | struct tty_struct *tty = file_tty(file); |
1142 | struct tty_ldisc *ld; | |
1da177e4 | 1143 | ssize_t ret; |
37bdfb07 | 1144 | |
1da177e4 LT |
1145 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1146 | return -EIO; | |
f34d7a5b | 1147 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1148 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1149 | return -EIO; | |
f34d7a5b AC |
1150 | /* Short term debug to catch buggy drivers */ |
1151 | if (tty->ops->write_room == NULL) | |
1152 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1153 | tty->driver->name); | |
37bdfb07 | 1154 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1155 | if (!ld->ops->write) |
1da177e4 LT |
1156 | ret = -EIO; |
1157 | else | |
a352def2 | 1158 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1159 | tty_ldisc_deref(ld); |
1160 | return ret; | |
1161 | } | |
1162 | ||
37bdfb07 AC |
1163 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1164 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1165 | { |
1166 | struct file *p = NULL; | |
1167 | ||
1168 | spin_lock(&redirect_lock); | |
1169 | if (redirect) { | |
1170 | get_file(redirect); | |
1171 | p = redirect; | |
1172 | } | |
1173 | spin_unlock(&redirect_lock); | |
1174 | ||
1175 | if (p) { | |
1176 | ssize_t res; | |
1177 | res = vfs_write(p, buf, count, &p->f_pos); | |
1178 | fput(p); | |
1179 | return res; | |
1180 | } | |
1da177e4 LT |
1181 | return tty_write(file, buf, count, ppos); |
1182 | } | |
1183 | ||
1184 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1185 | ||
af9b897e AC |
1186 | /** |
1187 | * pty_line_name - generate name for a pty | |
1188 | * @driver: the tty driver in use | |
1189 | * @index: the minor number | |
1190 | * @p: output buffer of at least 6 bytes | |
1191 | * | |
1192 | * Generate a name from a driver reference and write it to the output | |
1193 | * buffer. | |
1194 | * | |
1195 | * Locking: None | |
1196 | */ | |
1197 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1198 | { |
1199 | int i = index + driver->name_base; | |
1200 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1201 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1202 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1203 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1204 | } |
1205 | ||
af9b897e | 1206 | /** |
8b0a88d5 | 1207 | * tty_line_name - generate name for a tty |
af9b897e AC |
1208 | * @driver: the tty driver in use |
1209 | * @index: the minor number | |
1210 | * @p: output buffer of at least 7 bytes | |
1211 | * | |
1212 | * Generate a name from a driver reference and write it to the output | |
1213 | * buffer. | |
1214 | * | |
1215 | * Locking: None | |
1216 | */ | |
1217 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 | 1218 | { |
0019b408 JS |
1219 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
1220 | strcpy(p, driver->name); | |
1221 | else | |
1222 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1da177e4 LT |
1223 | } |
1224 | ||
99f1fe18 AC |
1225 | /** |
1226 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1227 | * @driver: the driver for the tty | |
1228 | * @idx: the minor number | |
23499705 | 1229 | * |
99f1fe18 | 1230 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1231 | * |
99f1fe18 AC |
1232 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1233 | * be held until the 'fast-open' is also done. Will change once we | |
1234 | * have refcounting in the driver and per driver locking | |
23499705 | 1235 | */ |
a47d545f | 1236 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1237 | struct inode *inode, int idx) |
23499705 | 1238 | { |
99f1fe18 | 1239 | if (driver->ops->lookup) |
15f1a633 | 1240 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1241 | |
d4834267 | 1242 | return driver->ttys[idx]; |
23499705 SB |
1243 | } |
1244 | ||
bf970ee4 AC |
1245 | /** |
1246 | * tty_init_termios - helper for termios setup | |
1247 | * @tty: the tty to set up | |
1248 | * | |
1249 | * Initialise the termios structures for this tty. Thus runs under | |
1250 | * the tty_mutex currently so we can be relaxed about ordering. | |
1251 | */ | |
1252 | ||
1253 | int tty_init_termios(struct tty_struct *tty) | |
1254 | { | |
fe6e29fd | 1255 | struct ktermios *tp; |
bf970ee4 AC |
1256 | int idx = tty->index; |
1257 | ||
36b3c070 AC |
1258 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1259 | tty->termios = tty->driver->init_termios; | |
1260 | else { | |
1261 | /* Check for lazy saved data */ | |
1262 | tp = tty->driver->termios[idx]; | |
1263 | if (tp != NULL) | |
1264 | tty->termios = *tp; | |
1265 | else | |
1266 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1267 | } |
bf970ee4 | 1268 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1269 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1270 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
1271 | return 0; |
1272 | } | |
fe1ae7fd | 1273 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1274 | |
66d450e8 JS |
1275 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1276 | { | |
1277 | int ret = tty_init_termios(tty); | |
1278 | if (ret) | |
1279 | return ret; | |
1280 | ||
1281 | tty_driver_kref_get(driver); | |
1282 | tty->count++; | |
1283 | driver->ttys[tty->index] = tty; | |
1284 | return 0; | |
1285 | } | |
1286 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1287 | ||
99f1fe18 | 1288 | /** |
8b0a88d5 AC |
1289 | * tty_driver_install_tty() - install a tty entry in the driver |
1290 | * @driver: the driver for the tty | |
1291 | * @tty: the tty | |
1292 | * | |
1293 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1294 | * will be set by the time this is called. This method is responsible |
1295 | * for ensuring any need additional structures are allocated and | |
1296 | * configured. | |
8b0a88d5 AC |
1297 | * |
1298 | * Locking: tty_mutex for now | |
1299 | */ | |
1300 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1301 | struct tty_struct *tty) | |
1302 | { | |
66d450e8 JS |
1303 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1304 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1305 | } |
1306 | ||
1307 | /** | |
1308 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1309 | * @driver: the driver for the tty | |
1310 | * @idx: the minor number | |
1311 | * | |
1312 | * Remvoe a tty object from the driver tables. The tty->index field | |
1313 | * will be set by the time this is called. | |
1314 | * | |
1315 | * Locking: tty_mutex for now | |
1316 | */ | |
24d406a6 | 1317 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1318 | { |
1319 | if (driver->ops->remove) | |
1320 | driver->ops->remove(driver, tty); | |
1321 | else | |
1322 | driver->ttys[tty->index] = NULL; | |
1323 | } | |
1324 | ||
1325 | /* | |
1326 | * tty_reopen() - fast re-open of an open tty | |
1327 | * @tty - the tty to open | |
23499705 | 1328 | * |
99f1fe18 | 1329 | * Return 0 on success, -errno on error. |
23499705 | 1330 | * |
99f1fe18 AC |
1331 | * Locking: tty_mutex must be held from the time the tty was found |
1332 | * till this open completes. | |
23499705 | 1333 | */ |
99f1fe18 | 1334 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1335 | { |
1336 | struct tty_driver *driver = tty->driver; | |
1337 | ||
e2efafbf | 1338 | if (test_bit(TTY_CLOSING, &tty->flags) || |
acfa747b | 1339 | test_bit(TTY_HUPPING, &tty->flags) || |
e2efafbf | 1340 | test_bit(TTY_LDISC_CHANGING, &tty->flags)) |
23499705 SB |
1341 | return -EIO; |
1342 | ||
1343 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1344 | driver->subtype == PTY_TYPE_MASTER) { | |
1345 | /* | |
1346 | * special case for PTY masters: only one open permitted, | |
1347 | * and the slave side open count is incremented as well. | |
1348 | */ | |
1349 | if (tty->count) | |
1350 | return -EIO; | |
1351 | ||
1352 | tty->link->count++; | |
1353 | } | |
1354 | tty->count++; | |
23499705 | 1355 | |
1aa4bed8 | 1356 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1357 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1358 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1359 | |
1360 | return 0; | |
1361 | } | |
1362 | ||
af9b897e | 1363 | /** |
d81ed103 | 1364 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1365 | * @driver: tty driver we are opening a device on |
1366 | * @idx: device index | |
15582d36 | 1367 | * @ret_tty: returned tty structure |
af9b897e AC |
1368 | * |
1369 | * Prepare a tty device. This may not be a "new" clean device but | |
1370 | * could also be an active device. The pty drivers require special | |
1371 | * handling because of this. | |
1372 | * | |
1373 | * Locking: | |
1374 | * The function is called under the tty_mutex, which | |
1375 | * protects us from the tty struct or driver itself going away. | |
1376 | * | |
1377 | * On exit the tty device has the line discipline attached and | |
1378 | * a reference count of 1. If a pair was created for pty/tty use | |
1379 | * and the other was a pty master then it too has a reference count of 1. | |
1380 | * | |
1da177e4 | 1381 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1382 | * failed open. The new code protects the open with a mutex, so it's |
1383 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1384 | * relaxed for the (most common) case of reopening a tty. |
1385 | */ | |
af9b897e | 1386 | |
593a27c4 | 1387 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1388 | { |
bf970ee4 | 1389 | struct tty_struct *tty; |
73ec06fc | 1390 | int retval; |
1da177e4 | 1391 | |
1da177e4 LT |
1392 | /* |
1393 | * First time open is complex, especially for PTY devices. | |
1394 | * This code guarantees that either everything succeeds and the | |
1395 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1396 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1397 | * and locked termios may be retained.) |
1398 | */ | |
1399 | ||
73ec06fc AC |
1400 | if (!try_module_get(driver->owner)) |
1401 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1402 | |
1da177e4 | 1403 | tty = alloc_tty_struct(); |
d5543503 JS |
1404 | if (!tty) { |
1405 | retval = -ENOMEM; | |
1406 | goto err_module_put; | |
1407 | } | |
bf970ee4 | 1408 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1409 | |
89c8d91e | 1410 | tty_lock(tty); |
73ec06fc | 1411 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1412 | if (retval < 0) |
a9dccddb | 1413 | goto err_deinit_tty; |
8b0a88d5 | 1414 | |
04831dc1 JS |
1415 | if (!tty->port) |
1416 | tty->port = driver->ports[idx]; | |
1417 | ||
5d4121c0 JS |
1418 | WARN_RATELIMIT(!tty->port, |
1419 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1420 | __func__, tty->driver->name); | |
1421 | ||
37bdfb07 | 1422 | /* |
1da177e4 | 1423 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1424 | * If we fail here just call release_tty to clean up. No need |
1425 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1426 | */ |
bf970ee4 | 1427 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1428 | if (retval) |
d5543503 | 1429 | goto err_release_tty; |
89c8d91e | 1430 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1431 | return tty; |
1da177e4 | 1432 | |
a9dccddb | 1433 | err_deinit_tty: |
89c8d91e | 1434 | tty_unlock(tty); |
a9dccddb | 1435 | deinitialize_tty_struct(tty); |
d5543503 JS |
1436 | free_tty_struct(tty); |
1437 | err_module_put: | |
1da177e4 | 1438 | module_put(driver->owner); |
d5543503 | 1439 | return ERR_PTR(retval); |
1da177e4 | 1440 | |
d5698c28 | 1441 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1442 | err_release_tty: |
89c8d91e | 1443 | tty_unlock(tty); |
5a3c6b25 | 1444 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1445 | "clearing slot %d\n", idx); |
d5698c28 | 1446 | release_tty(tty, idx); |
73ec06fc | 1447 | return ERR_PTR(retval); |
1da177e4 LT |
1448 | } |
1449 | ||
feebed65 AC |
1450 | void tty_free_termios(struct tty_struct *tty) |
1451 | { | |
1452 | struct ktermios *tp; | |
1453 | int idx = tty->index; | |
36b3c070 AC |
1454 | |
1455 | /* If the port is going to reset then it has no termios to save */ | |
1456 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1457 | return; | |
1458 | ||
1459 | /* Stash the termios data */ | |
1460 | tp = tty->driver->termios[idx]; | |
1461 | if (tp == NULL) { | |
1462 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1463 | if (tp == NULL) { | |
1464 | pr_warn("tty: no memory to save termios state.\n"); | |
1465 | return; | |
1466 | } | |
4ac5d705 | 1467 | tty->driver->termios[idx] = tp; |
feebed65 | 1468 | } |
36b3c070 | 1469 | *tp = tty->termios; |
feebed65 AC |
1470 | } |
1471 | EXPORT_SYMBOL(tty_free_termios); | |
1472 | ||
feebed65 | 1473 | |
af9b897e | 1474 | /** |
d5698c28 | 1475 | * release_one_tty - release tty structure memory |
9c9f4ded | 1476 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1477 | * |
1478 | * Releases memory associated with a tty structure, and clears out the | |
1479 | * driver table slots. This function is called when a device is no longer | |
1480 | * in use. It also gets called when setup of a device fails. | |
1481 | * | |
1482 | * Locking: | |
af9b897e AC |
1483 | * takes the file list lock internally when working on the list |
1484 | * of ttys that the driver keeps. | |
b50989dc AC |
1485 | * |
1486 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1487 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1488 | */ |
b50989dc | 1489 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1490 | { |
b50989dc AC |
1491 | struct tty_struct *tty = |
1492 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1493 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1494 | |
f278a2f7 DY |
1495 | if (tty->ops->cleanup) |
1496 | tty->ops->cleanup(tty); | |
1497 | ||
1da177e4 | 1498 | tty->magic = 0; |
7d7b93c1 | 1499 | tty_driver_kref_put(driver); |
6f967f78 | 1500 | module_put(driver->owner); |
d5698c28 | 1501 | |
ee2ffa0d | 1502 | spin_lock(&tty_files_lock); |
1da177e4 | 1503 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1504 | spin_unlock(&tty_files_lock); |
d5698c28 | 1505 | |
6da8d866 ON |
1506 | put_pid(tty->pgrp); |
1507 | put_pid(tty->session); | |
1da177e4 LT |
1508 | free_tty_struct(tty); |
1509 | } | |
1510 | ||
b50989dc AC |
1511 | static void queue_release_one_tty(struct kref *kref) |
1512 | { | |
1513 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1514 | |
b50989dc AC |
1515 | /* The hangup queue is now free so we can reuse it rather than |
1516 | waste a chunk of memory for each port */ | |
1517 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1518 | schedule_work(&tty->hangup_work); | |
1519 | } | |
1520 | ||
9c9f4ded AC |
1521 | /** |
1522 | * tty_kref_put - release a tty kref | |
1523 | * @tty: tty device | |
1524 | * | |
1525 | * Release a reference to a tty device and if need be let the kref | |
1526 | * layer destruct the object for us | |
1527 | */ | |
1528 | ||
1529 | void tty_kref_put(struct tty_struct *tty) | |
1530 | { | |
1531 | if (tty) | |
b50989dc | 1532 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1533 | } |
1534 | EXPORT_SYMBOL(tty_kref_put); | |
1535 | ||
d5698c28 CH |
1536 | /** |
1537 | * release_tty - release tty structure memory | |
1538 | * | |
1539 | * Release both @tty and a possible linked partner (think pty pair), | |
1540 | * and decrement the refcount of the backing module. | |
1541 | * | |
1542 | * Locking: | |
d155255a | 1543 | * tty_mutex |
d5698c28 CH |
1544 | * takes the file list lock internally when working on the list |
1545 | * of ttys that the driver keeps. | |
9c9f4ded | 1546 | * |
d5698c28 CH |
1547 | */ |
1548 | static void release_tty(struct tty_struct *tty, int idx) | |
1549 | { | |
9c9f4ded AC |
1550 | /* This should always be true but check for the moment */ |
1551 | WARN_ON(tty->index != idx); | |
d155255a | 1552 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1553 | if (tty->ops->shutdown) |
1554 | tty->ops->shutdown(tty); | |
1555 | tty_free_termios(tty); | |
1556 | tty_driver_remove_tty(tty->driver, tty); | |
1557 | ||
d5698c28 | 1558 | if (tty->link) |
9c9f4ded AC |
1559 | tty_kref_put(tty->link); |
1560 | tty_kref_put(tty); | |
d5698c28 CH |
1561 | } |
1562 | ||
955787ca JS |
1563 | /** |
1564 | * tty_release_checks - check a tty before real release | |
1565 | * @tty: tty to check | |
1566 | * @o_tty: link of @tty (if any) | |
1567 | * @idx: index of the tty | |
1568 | * | |
1569 | * Performs some paranoid checking before true release of the @tty. | |
1570 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1571 | */ | |
1572 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1573 | int idx) | |
1574 | { | |
1575 | #ifdef TTY_PARANOIA_CHECK | |
1576 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1577 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1578 | __func__, tty->name); | |
955787ca JS |
1579 | return -1; |
1580 | } | |
1581 | ||
1582 | /* not much to check for devpts */ | |
1583 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1584 | return 0; | |
1585 | ||
1586 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1587 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1588 | __func__, idx, tty->name); | |
955787ca JS |
1589 | return -1; |
1590 | } | |
955787ca JS |
1591 | if (tty->driver->other) { |
1592 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1593 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1594 | __func__, idx, tty->name); | |
955787ca JS |
1595 | return -1; |
1596 | } | |
955787ca | 1597 | if (o_tty->link != tty) { |
9de44bd6 | 1598 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1599 | return -1; |
1600 | } | |
1601 | } | |
1602 | #endif | |
1603 | return 0; | |
1604 | } | |
1605 | ||
eeb89d91 AC |
1606 | /** |
1607 | * tty_release - vfs callback for close | |
1608 | * @inode: inode of tty | |
1609 | * @filp: file pointer for handle to tty | |
1610 | * | |
1611 | * Called the last time each file handle is closed that references | |
1612 | * this tty. There may however be several such references. | |
1613 | * | |
1614 | * Locking: | |
1615 | * Takes bkl. See tty_release_dev | |
1616 | * | |
1da177e4 LT |
1617 | * Even releasing the tty structures is a tricky business.. We have |
1618 | * to be very careful that the structures are all released at the | |
1619 | * same time, as interrupts might otherwise get the wrong pointers. | |
1620 | * | |
1621 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1622 | * lead to double frees or releasing memory still in use. | |
1623 | */ | |
eeb89d91 AC |
1624 | |
1625 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1626 | { |
d996b62a NP |
1627 | struct tty_struct *tty = file_tty(filp); |
1628 | struct tty_struct *o_tty; | |
1da177e4 | 1629 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1630 | int devpts; |
1da177e4 LT |
1631 | int idx; |
1632 | char buf[64]; | |
37bdfb07 | 1633 | |
9de44bd6 | 1634 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1635 | return 0; |
1da177e4 | 1636 | |
89c8d91e | 1637 | tty_lock(tty); |
9de44bd6 | 1638 | check_tty_count(tty, __func__); |
1da177e4 | 1639 | |
ec79d605 | 1640 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1641 | |
1642 | idx = tty->index; | |
1643 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1644 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1645 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
89c8d91e | 1646 | /* Review: parallel close */ |
1da177e4 LT |
1647 | o_tty = tty->link; |
1648 | ||
955787ca | 1649 | if (tty_release_checks(tty, o_tty, idx)) { |
89c8d91e | 1650 | tty_unlock(tty); |
eeb89d91 | 1651 | return 0; |
1da177e4 | 1652 | } |
1da177e4 LT |
1653 | |
1654 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1655 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1656 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1657 | #endif |
1658 | ||
f34d7a5b AC |
1659 | if (tty->ops->close) |
1660 | tty->ops->close(tty, filp); | |
1da177e4 | 1661 | |
89c8d91e | 1662 | tty_unlock(tty); |
1da177e4 LT |
1663 | /* |
1664 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1665 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1666 | * wait queues and kick everyone out _before_ actually starting to | |
1667 | * close. This ensures that we won't block while releasing the tty | |
1668 | * structure. | |
1669 | * | |
1670 | * The test for the o_tty closing is necessary, since the master and | |
1671 | * slave sides may close in any order. If the slave side closes out | |
1672 | * first, its count will be one, since the master side holds an open. | |
1673 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1674 | * so we do it now. | |
1675 | * | |
1676 | * Note that it's possible for the tty to be opened again while we're | |
1677 | * flushing out waiters. By recalculating the closing flags before | |
1678 | * each iteration we avoid any problems. | |
1679 | */ | |
1680 | while (1) { | |
1681 | /* Guard against races with tty->count changes elsewhere and | |
1682 | opens on /dev/tty */ | |
37bdfb07 | 1683 | |
70522e12 | 1684 | mutex_lock(&tty_mutex); |
89c8d91e | 1685 | tty_lock_pair(tty, o_tty); |
1da177e4 LT |
1686 | tty_closing = tty->count <= 1; |
1687 | o_tty_closing = o_tty && | |
1688 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1689 | do_sleep = 0; |
1690 | ||
1691 | if (tty_closing) { | |
1692 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1693 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1694 | do_sleep++; |
1695 | } | |
1696 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1697 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1698 | do_sleep++; |
1699 | } | |
1700 | } | |
1701 | if (o_tty_closing) { | |
1702 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1703 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1704 | do_sleep++; |
1705 | } | |
1706 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1707 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1708 | do_sleep++; |
1709 | } | |
1710 | } | |
1711 | if (!do_sleep) | |
1712 | break; | |
1713 | ||
9de44bd6 JS |
1714 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1715 | __func__, tty_name(tty, buf)); | |
89c8d91e | 1716 | tty_unlock_pair(tty, o_tty); |
70522e12 | 1717 | mutex_unlock(&tty_mutex); |
1da177e4 | 1718 | schedule(); |
37bdfb07 | 1719 | } |
1da177e4 LT |
1720 | |
1721 | /* | |
37bdfb07 AC |
1722 | * The closing flags are now consistent with the open counts on |
1723 | * both sides, and we've completed the last operation that could | |
1da177e4 | 1724 | * block, so it's safe to proceed with closing. |
d155255a AC |
1725 | * |
1726 | * We must *not* drop the tty_mutex until we ensure that a further | |
1727 | * entry into tty_open can not pick up this tty. | |
1da177e4 | 1728 | */ |
1da177e4 LT |
1729 | if (pty_master) { |
1730 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1731 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1732 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1733 | o_tty->count = 0; |
1734 | } | |
1735 | } | |
1736 | if (--tty->count < 0) { | |
9de44bd6 JS |
1737 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1738 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1739 | tty->count = 0; |
1740 | } | |
37bdfb07 | 1741 | |
1da177e4 LT |
1742 | /* |
1743 | * We've decremented tty->count, so we need to remove this file | |
1744 | * descriptor off the tty->tty_files list; this serves two | |
1745 | * purposes: | |
1746 | * - check_tty_count sees the correct number of file descriptors | |
1747 | * associated with this tty. | |
1748 | * - do_tty_hangup no longer sees this file descriptor as | |
1749 | * something that needs to be handled for hangups. | |
1750 | */ | |
d996b62a | 1751 | tty_del_file(filp); |
1da177e4 LT |
1752 | |
1753 | /* | |
1754 | * Perform some housekeeping before deciding whether to return. | |
1755 | * | |
1756 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1757 | * case of a pty we may have to wait around for the other side | |
1758 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1759 | */ | |
37bdfb07 | 1760 | if (tty_closing) |
1da177e4 | 1761 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1762 | if (o_tty_closing) |
1da177e4 LT |
1763 | set_bit(TTY_CLOSING, &o_tty->flags); |
1764 | ||
1765 | /* | |
1766 | * If _either_ side is closing, make sure there aren't any | |
1767 | * processes that still think tty or o_tty is their controlling | |
1768 | * tty. | |
1769 | */ | |
1770 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1771 | read_lock(&tasklist_lock); |
24ec839c | 1772 | session_clear_tty(tty->session); |
1da177e4 | 1773 | if (o_tty) |
24ec839c | 1774 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1775 | read_unlock(&tasklist_lock); |
1776 | } | |
1777 | ||
70522e12 | 1778 | mutex_unlock(&tty_mutex); |
89c8d91e | 1779 | tty_unlock_pair(tty, o_tty); |
d155255a AC |
1780 | /* At this point the TTY_CLOSING flag should ensure a dead tty |
1781 | cannot be re-opened by a racing opener */ | |
da965822 | 1782 | |
1da177e4 | 1783 | /* check whether both sides are closing ... */ |
d155255a | 1784 | if (!tty_closing || (o_tty && !o_tty_closing)) |
eeb89d91 | 1785 | return 0; |
37bdfb07 | 1786 | |
1da177e4 | 1787 | #ifdef TTY_DEBUG_HANGUP |
9de44bd6 | 1788 | printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__); |
1da177e4 LT |
1789 | #endif |
1790 | /* | |
01e1abb2 | 1791 | * Ask the line discipline code to release its structures |
1da177e4 | 1792 | */ |
01e1abb2 | 1793 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1794 | /* |
d5698c28 | 1795 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1796 | * the slots and preserving the termios structure. The tty_unlock_pair |
1797 | * should be safe as we keep a kref while the tty is locked (so the | |
1798 | * unlock never unlocks a freed tty). | |
1da177e4 | 1799 | */ |
d155255a | 1800 | mutex_lock(&tty_mutex); |
d5698c28 | 1801 | release_tty(tty, idx); |
d155255a | 1802 | mutex_unlock(&tty_mutex); |
1da177e4 | 1803 | |
1da177e4 | 1804 | /* Make this pty number available for reallocation */ |
718a9163 | 1805 | if (devpts) |
15f1a633 | 1806 | devpts_kill_index(inode, idx); |
eeb89d91 | 1807 | return 0; |
1da177e4 LT |
1808 | } |
1809 | ||
b82154ac JS |
1810 | /** |
1811 | * tty_open_current_tty - get tty of current task for open | |
1812 | * @device: device number | |
1813 | * @filp: file pointer to tty | |
1814 | * @return: tty of the current task iff @device is /dev/tty | |
1815 | * | |
1816 | * We cannot return driver and index like for the other nodes because | |
1817 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1818 | * |
1819 | * We need to move to returning a refcounted object from all the lookup | |
1820 | * paths including this one. | |
b82154ac JS |
1821 | */ |
1822 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1823 | { | |
1824 | struct tty_struct *tty; | |
1825 | ||
1826 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1827 | return NULL; | |
1828 | ||
1829 | tty = get_current_tty(); | |
1830 | if (!tty) | |
1831 | return ERR_PTR(-ENXIO); | |
1832 | ||
1833 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1834 | /* noctty = 1; */ | |
1835 | tty_kref_put(tty); | |
1836 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1837 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1838 | return tty; |
1839 | } | |
1840 | ||
5b5e7040 JS |
1841 | /** |
1842 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1843 | * @device: device number | |
1844 | * @filp: file pointer to tty | |
1845 | * @noctty: set if the device should not become a controlling tty | |
1846 | * @index: index for the device in the @return driver | |
1847 | * @return: driver for this inode (with increased refcount) | |
1848 | * | |
1849 | * If @return is not erroneous, the caller is responsible to decrement the | |
1850 | * refcount by tty_driver_kref_put. | |
1851 | * | |
1852 | * Locking: tty_mutex protects get_tty_driver | |
1853 | */ | |
1854 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1855 | int *noctty, int *index) | |
1856 | { | |
1857 | struct tty_driver *driver; | |
1858 | ||
2cd0050c | 1859 | switch (device) { |
5b5e7040 | 1860 | #ifdef CONFIG_VT |
2cd0050c | 1861 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1862 | extern struct tty_driver *console_driver; |
1863 | driver = tty_driver_kref_get(console_driver); | |
1864 | *index = fg_console; | |
1865 | *noctty = 1; | |
2cd0050c | 1866 | break; |
5b5e7040 JS |
1867 | } |
1868 | #endif | |
2cd0050c | 1869 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1870 | struct tty_driver *console_driver = console_device(index); |
1871 | if (console_driver) { | |
1872 | driver = tty_driver_kref_get(console_driver); | |
1873 | if (driver) { | |
1874 | /* Don't let /dev/console block */ | |
1875 | filp->f_flags |= O_NONBLOCK; | |
1876 | *noctty = 1; | |
2cd0050c | 1877 | break; |
5b5e7040 JS |
1878 | } |
1879 | } | |
1880 | return ERR_PTR(-ENODEV); | |
1881 | } | |
2cd0050c JS |
1882 | default: |
1883 | driver = get_tty_driver(device, index); | |
1884 | if (!driver) | |
1885 | return ERR_PTR(-ENODEV); | |
1886 | break; | |
1887 | } | |
5b5e7040 JS |
1888 | return driver; |
1889 | } | |
1890 | ||
af9b897e | 1891 | /** |
eeb89d91 | 1892 | * tty_open - open a tty device |
af9b897e AC |
1893 | * @inode: inode of device file |
1894 | * @filp: file pointer to tty | |
1da177e4 | 1895 | * |
af9b897e AC |
1896 | * tty_open and tty_release keep up the tty count that contains the |
1897 | * number of opens done on a tty. We cannot use the inode-count, as | |
1898 | * different inodes might point to the same tty. | |
1da177e4 | 1899 | * |
af9b897e AC |
1900 | * Open-counting is needed for pty masters, as well as for keeping |
1901 | * track of serial lines: DTR is dropped when the last close happens. | |
1902 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1903 | * | |
1904 | * The termios state of a pty is reset on first open so that | |
1905 | * settings don't persist across reuse. | |
1906 | * | |
5b5e7040 | 1907 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1908 | * tty->count should protect the rest. |
1909 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
1910 | * |
1911 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
1912 | * tty_mutex | |
1da177e4 | 1913 | */ |
af9b897e | 1914 | |
eeb89d91 | 1915 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1916 | { |
b82154ac | 1917 | struct tty_struct *tty; |
1da177e4 | 1918 | int noctty, retval; |
b82154ac | 1919 | struct tty_driver *driver = NULL; |
1da177e4 LT |
1920 | int index; |
1921 | dev_t device = inode->i_rdev; | |
846c151a | 1922 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1923 | |
1924 | nonseekable_open(inode, filp); | |
37bdfb07 | 1925 | |
1da177e4 | 1926 | retry_open: |
fa90e1c9 JS |
1927 | retval = tty_alloc_file(filp); |
1928 | if (retval) | |
1929 | return -ENOMEM; | |
1930 | ||
1da177e4 LT |
1931 | noctty = filp->f_flags & O_NOCTTY; |
1932 | index = -1; | |
1933 | retval = 0; | |
37bdfb07 | 1934 | |
70522e12 | 1935 | mutex_lock(&tty_mutex); |
89c8d91e | 1936 | /* This is protected by the tty_mutex */ |
b82154ac JS |
1937 | tty = tty_open_current_tty(device, filp); |
1938 | if (IS_ERR(tty)) { | |
ba5db448 JS |
1939 | retval = PTR_ERR(tty); |
1940 | goto err_unlock; | |
5b5e7040 JS |
1941 | } else if (!tty) { |
1942 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
1943 | if (IS_ERR(driver)) { | |
ba5db448 JS |
1944 | retval = PTR_ERR(driver); |
1945 | goto err_unlock; | |
1da177e4 | 1946 | } |
1da177e4 | 1947 | |
4a2b5fdd | 1948 | /* check whether we're reopening an existing tty */ |
15f1a633 | 1949 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 1950 | if (IS_ERR(tty)) { |
ba5db448 JS |
1951 | retval = PTR_ERR(tty); |
1952 | goto err_unlock; | |
808ffa3d | 1953 | } |
4a2b5fdd SB |
1954 | } |
1955 | ||
1956 | if (tty) { | |
89c8d91e | 1957 | tty_lock(tty); |
4a2b5fdd | 1958 | retval = tty_reopen(tty); |
89c8d91e AC |
1959 | if (retval < 0) { |
1960 | tty_unlock(tty); | |
4a2b5fdd | 1961 | tty = ERR_PTR(retval); |
89c8d91e AC |
1962 | } |
1963 | } else /* Returns with the tty_lock held for now */ | |
593a27c4 | 1964 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 1965 | |
70522e12 | 1966 | mutex_unlock(&tty_mutex); |
b82154ac JS |
1967 | if (driver) |
1968 | tty_driver_kref_put(driver); | |
eeb89d91 | 1969 | if (IS_ERR(tty)) { |
ba5db448 JS |
1970 | retval = PTR_ERR(tty); |
1971 | goto err_file; | |
eeb89d91 | 1972 | } |
1da177e4 | 1973 | |
fa90e1c9 | 1974 | tty_add_file(tty, filp); |
d996b62a | 1975 | |
9de44bd6 | 1976 | check_tty_count(tty, __func__); |
1da177e4 LT |
1977 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1978 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1979 | noctty = 1; | |
1980 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 1981 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 1982 | #endif |
909bc774 HRK |
1983 | if (tty->ops->open) |
1984 | retval = tty->ops->open(tty, filp); | |
1985 | else | |
1986 | retval = -ENODEV; | |
1da177e4 LT |
1987 | filp->f_flags = saved_flags; |
1988 | ||
37bdfb07 AC |
1989 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1990 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1991 | retval = -EBUSY; |
1992 | ||
1993 | if (retval) { | |
1994 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1995 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
1996 | retval, tty->name); | |
1da177e4 | 1997 | #endif |
89c8d91e | 1998 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 1999 | tty_release(inode, filp); |
64ba3dc3 | 2000 | if (retval != -ERESTARTSYS) |
1da177e4 | 2001 | return retval; |
64ba3dc3 AB |
2002 | |
2003 | if (signal_pending(current)) | |
1da177e4 | 2004 | return retval; |
64ba3dc3 | 2005 | |
1da177e4 LT |
2006 | schedule(); |
2007 | /* | |
2008 | * Need to reset f_op in case a hangup happened. | |
2009 | */ | |
2010 | if (filp->f_op == &hung_up_tty_fops) | |
2011 | filp->f_op = &tty_fops; | |
2012 | goto retry_open; | |
2013 | } | |
89c8d91e | 2014 | tty_unlock(tty); |
eeb89d91 | 2015 | |
24ec839c PZ |
2016 | |
2017 | mutex_lock(&tty_mutex); | |
89c8d91e | 2018 | tty_lock(tty); |
24ec839c | 2019 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2020 | if (!noctty && |
2021 | current->signal->leader && | |
2022 | !current->signal->tty && | |
ab521dc0 | 2023 | tty->session == NULL) |
2a65f1d9 | 2024 | __proc_set_tty(current, tty); |
24ec839c | 2025 | spin_unlock_irq(¤t->sighand->siglock); |
89c8d91e | 2026 | tty_unlock(tty); |
24ec839c | 2027 | mutex_unlock(&tty_mutex); |
1da177e4 | 2028 | return 0; |
ba5db448 | 2029 | err_unlock: |
ba5db448 JS |
2030 | mutex_unlock(&tty_mutex); |
2031 | /* after locks to avoid deadlock */ | |
2032 | if (!IS_ERR_OR_NULL(driver)) | |
2033 | tty_driver_kref_put(driver); | |
2034 | err_file: | |
2035 | tty_free_file(filp); | |
2036 | return retval; | |
1da177e4 LT |
2037 | } |
2038 | ||
39d95b9d JC |
2039 | |
2040 | ||
af9b897e AC |
2041 | /** |
2042 | * tty_poll - check tty status | |
2043 | * @filp: file being polled | |
2044 | * @wait: poll wait structures to update | |
2045 | * | |
2046 | * Call the line discipline polling method to obtain the poll | |
2047 | * status of the device. | |
2048 | * | |
2049 | * Locking: locks called line discipline but ldisc poll method | |
2050 | * may be re-entered freely by other callers. | |
2051 | */ | |
2052 | ||
37bdfb07 | 2053 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2054 | { |
d996b62a | 2055 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2056 | struct tty_ldisc *ld; |
2057 | int ret = 0; | |
2058 | ||
a7113a96 | 2059 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2060 | return 0; |
37bdfb07 | 2061 | |
1da177e4 | 2062 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2063 | if (ld->ops->poll) |
2064 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2065 | tty_ldisc_deref(ld); |
2066 | return ret; | |
2067 | } | |
2068 | ||
ec79d605 | 2069 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2070 | { |
d996b62a | 2071 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2072 | unsigned long flags; |
5d1e3230 | 2073 | int retval = 0; |
1da177e4 | 2074 | |
a7113a96 | 2075 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2076 | goto out; |
37bdfb07 | 2077 | |
1da177e4 LT |
2078 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2079 | if (retval <= 0) | |
5d1e3230 | 2080 | goto out; |
1da177e4 LT |
2081 | |
2082 | if (on) { | |
ab521dc0 EB |
2083 | enum pid_type type; |
2084 | struct pid *pid; | |
1da177e4 LT |
2085 | if (!waitqueue_active(&tty->read_wait)) |
2086 | tty->minimum_to_wake = 1; | |
47f86834 | 2087 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2088 | if (tty->pgrp) { |
2089 | pid = tty->pgrp; | |
2090 | type = PIDTYPE_PGID; | |
2091 | } else { | |
2092 | pid = task_pid(current); | |
2093 | type = PIDTYPE_PID; | |
2094 | } | |
80e1e823 | 2095 | get_pid(pid); |
70362511 | 2096 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2097 | retval = __f_setown(filp, pid, type, 0); |
2098 | put_pid(pid); | |
1da177e4 | 2099 | if (retval) |
5d1e3230 | 2100 | goto out; |
1da177e4 LT |
2101 | } else { |
2102 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2103 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2104 | } | |
5d1e3230 JC |
2105 | retval = 0; |
2106 | out: | |
ec79d605 AB |
2107 | return retval; |
2108 | } | |
2109 | ||
2110 | static int tty_fasync(int fd, struct file *filp, int on) | |
2111 | { | |
89c8d91e | 2112 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2113 | int retval; |
89c8d91e AC |
2114 | |
2115 | tty_lock(tty); | |
ec79d605 | 2116 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2117 | tty_unlock(tty); |
2118 | ||
5d1e3230 | 2119 | return retval; |
1da177e4 LT |
2120 | } |
2121 | ||
af9b897e AC |
2122 | /** |
2123 | * tiocsti - fake input character | |
2124 | * @tty: tty to fake input into | |
2125 | * @p: pointer to character | |
2126 | * | |
3a4fa0a2 | 2127 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2128 | * input management. |
2129 | * | |
2130 | * FIXME: does not honour flow control ?? | |
2131 | * | |
2132 | * Locking: | |
2133 | * Called functions take tty_ldisc_lock | |
2134 | * current->signal->tty check is safe without locks | |
28298232 AC |
2135 | * |
2136 | * FIXME: may race normal receive processing | |
af9b897e AC |
2137 | */ |
2138 | ||
1da177e4 LT |
2139 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2140 | { | |
2141 | char ch, mbz = 0; | |
2142 | struct tty_ldisc *ld; | |
37bdfb07 | 2143 | |
1da177e4 LT |
2144 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2145 | return -EPERM; | |
2146 | if (get_user(ch, p)) | |
2147 | return -EFAULT; | |
1e641743 | 2148 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2149 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2150 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2151 | tty_ldisc_deref(ld); |
2152 | return 0; | |
2153 | } | |
2154 | ||
af9b897e AC |
2155 | /** |
2156 | * tiocgwinsz - implement window query ioctl | |
2157 | * @tty; tty | |
2158 | * @arg: user buffer for result | |
2159 | * | |
808a0d38 | 2160 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2161 | * |
24ec839c | 2162 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2163 | * is consistent. |
af9b897e AC |
2164 | */ |
2165 | ||
37bdfb07 | 2166 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2167 | { |
808a0d38 AC |
2168 | int err; |
2169 | ||
5785c95b | 2170 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2171 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2172 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2173 | |
2174 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2175 | } |
2176 | ||
af9b897e | 2177 | /** |
8c9a9dd0 AC |
2178 | * tty_do_resize - resize event |
2179 | * @tty: tty being resized | |
8c9a9dd0 AC |
2180 | * @rows: rows (character) |
2181 | * @cols: cols (character) | |
2182 | * | |
3ad2f3fb | 2183 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2184 | * peform a terminal resize correctly |
af9b897e AC |
2185 | */ |
2186 | ||
fc6f6238 | 2187 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2188 | { |
fc6f6238 | 2189 | struct pid *pgrp; |
47f86834 | 2190 | unsigned long flags; |
1da177e4 | 2191 | |
fc6f6238 AC |
2192 | /* Lock the tty */ |
2193 | mutex_lock(&tty->termios_mutex); | |
2194 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2195 | goto done; |
47f86834 AC |
2196 | /* Get the PID values and reference them so we can |
2197 | avoid holding the tty ctrl lock while sending signals */ | |
2198 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2199 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2200 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2201 | ||
2202 | if (pgrp) | |
2203 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2204 | put_pid(pgrp); |
47f86834 | 2205 | |
8c9a9dd0 | 2206 | tty->winsize = *ws; |
ca9bda00 | 2207 | done: |
fc6f6238 | 2208 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2209 | return 0; |
2210 | } | |
2211 | ||
8c9a9dd0 AC |
2212 | /** |
2213 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2214 | * @tty; tty side of tty |
8c9a9dd0 AC |
2215 | * @arg: user buffer for result |
2216 | * | |
2217 | * Copies the user idea of the window size to the kernel. Traditionally | |
2218 | * this is just advisory information but for the Linux console it | |
2219 | * actually has driver level meaning and triggers a VC resize. | |
2220 | * | |
2221 | * Locking: | |
25985edc | 2222 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2223 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2224 | * then calls into the default method. | |
2225 | */ | |
2226 | ||
fc6f6238 | 2227 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2228 | { |
2229 | struct winsize tmp_ws; | |
2230 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2231 | return -EFAULT; | |
2232 | ||
2233 | if (tty->ops->resize) | |
fc6f6238 | 2234 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2235 | else |
fc6f6238 | 2236 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2237 | } |
2238 | ||
af9b897e AC |
2239 | /** |
2240 | * tioccons - allow admin to move logical console | |
2241 | * @file: the file to become console | |
2242 | * | |
25985edc | 2243 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2244 | * |
2245 | * Locking: uses redirect_lock to guard the redirect information | |
2246 | */ | |
2247 | ||
1da177e4 LT |
2248 | static int tioccons(struct file *file) |
2249 | { | |
2250 | if (!capable(CAP_SYS_ADMIN)) | |
2251 | return -EPERM; | |
2252 | if (file->f_op->write == redirected_tty_write) { | |
2253 | struct file *f; | |
2254 | spin_lock(&redirect_lock); | |
2255 | f = redirect; | |
2256 | redirect = NULL; | |
2257 | spin_unlock(&redirect_lock); | |
2258 | if (f) | |
2259 | fput(f); | |
2260 | return 0; | |
2261 | } | |
2262 | spin_lock(&redirect_lock); | |
2263 | if (redirect) { | |
2264 | spin_unlock(&redirect_lock); | |
2265 | return -EBUSY; | |
2266 | } | |
2267 | get_file(file); | |
2268 | redirect = file; | |
2269 | spin_unlock(&redirect_lock); | |
2270 | return 0; | |
2271 | } | |
2272 | ||
af9b897e AC |
2273 | /** |
2274 | * fionbio - non blocking ioctl | |
2275 | * @file: file to set blocking value | |
2276 | * @p: user parameter | |
2277 | * | |
2278 | * Historical tty interfaces had a blocking control ioctl before | |
2279 | * the generic functionality existed. This piece of history is preserved | |
2280 | * in the expected tty API of posix OS's. | |
2281 | * | |
6146b9af | 2282 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2283 | */ |
1da177e4 LT |
2284 | |
2285 | static int fionbio(struct file *file, int __user *p) | |
2286 | { | |
2287 | int nonblock; | |
2288 | ||
2289 | if (get_user(nonblock, p)) | |
2290 | return -EFAULT; | |
2291 | ||
db1dd4d3 | 2292 | spin_lock(&file->f_lock); |
1da177e4 LT |
2293 | if (nonblock) |
2294 | file->f_flags |= O_NONBLOCK; | |
2295 | else | |
2296 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2297 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2298 | return 0; |
2299 | } | |
2300 | ||
af9b897e AC |
2301 | /** |
2302 | * tiocsctty - set controlling tty | |
2303 | * @tty: tty structure | |
2304 | * @arg: user argument | |
2305 | * | |
2306 | * This ioctl is used to manage job control. It permits a session | |
2307 | * leader to set this tty as the controlling tty for the session. | |
2308 | * | |
2309 | * Locking: | |
28298232 | 2310 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2311 | * Takes tasklist_lock internally to walk sessions |
2312 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2313 | */ |
2314 | ||
1da177e4 LT |
2315 | static int tiocsctty(struct tty_struct *tty, int arg) |
2316 | { | |
24ec839c | 2317 | int ret = 0; |
ab521dc0 | 2318 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2319 | return ret; |
2320 | ||
2321 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2322 | /* |
2323 | * The process must be a session leader and | |
2324 | * not have a controlling tty already. | |
2325 | */ | |
24ec839c PZ |
2326 | if (!current->signal->leader || current->signal->tty) { |
2327 | ret = -EPERM; | |
2328 | goto unlock; | |
2329 | } | |
2330 | ||
ab521dc0 | 2331 | if (tty->session) { |
1da177e4 LT |
2332 | /* |
2333 | * This tty is already the controlling | |
2334 | * tty for another session group! | |
2335 | */ | |
37bdfb07 | 2336 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2337 | /* |
2338 | * Steal it away | |
2339 | */ | |
1da177e4 | 2340 | read_lock(&tasklist_lock); |
24ec839c | 2341 | session_clear_tty(tty->session); |
1da177e4 | 2342 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2343 | } else { |
2344 | ret = -EPERM; | |
2345 | goto unlock; | |
2346 | } | |
1da177e4 | 2347 | } |
24ec839c PZ |
2348 | proc_set_tty(current, tty); |
2349 | unlock: | |
28298232 | 2350 | mutex_unlock(&tty_mutex); |
24ec839c | 2351 | return ret; |
1da177e4 LT |
2352 | } |
2353 | ||
5d0fdf1e AC |
2354 | /** |
2355 | * tty_get_pgrp - return a ref counted pgrp pid | |
2356 | * @tty: tty to read | |
2357 | * | |
2358 | * Returns a refcounted instance of the pid struct for the process | |
2359 | * group controlling the tty. | |
2360 | */ | |
2361 | ||
2362 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2363 | { | |
2364 | unsigned long flags; | |
2365 | struct pid *pgrp; | |
2366 | ||
2367 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2368 | pgrp = get_pid(tty->pgrp); | |
2369 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2370 | ||
2371 | return pgrp; | |
2372 | } | |
2373 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2374 | ||
af9b897e AC |
2375 | /** |
2376 | * tiocgpgrp - get process group | |
2377 | * @tty: tty passed by user | |
25985edc | 2378 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2379 | * @p: returned pid |
2380 | * | |
2381 | * Obtain the process group of the tty. If there is no process group | |
2382 | * return an error. | |
2383 | * | |
24ec839c | 2384 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2385 | */ |
2386 | ||
1da177e4 LT |
2387 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2388 | { | |
5d0fdf1e AC |
2389 | struct pid *pid; |
2390 | int ret; | |
1da177e4 LT |
2391 | /* |
2392 | * (tty == real_tty) is a cheap way of | |
2393 | * testing if the tty is NOT a master pty. | |
2394 | */ | |
2395 | if (tty == real_tty && current->signal->tty != real_tty) | |
2396 | return -ENOTTY; | |
5d0fdf1e AC |
2397 | pid = tty_get_pgrp(real_tty); |
2398 | ret = put_user(pid_vnr(pid), p); | |
2399 | put_pid(pid); | |
2400 | return ret; | |
1da177e4 LT |
2401 | } |
2402 | ||
af9b897e AC |
2403 | /** |
2404 | * tiocspgrp - attempt to set process group | |
2405 | * @tty: tty passed by user | |
2406 | * @real_tty: tty side device matching tty passed by user | |
2407 | * @p: pid pointer | |
2408 | * | |
2409 | * Set the process group of the tty to the session passed. Only | |
2410 | * permitted where the tty session is our session. | |
2411 | * | |
47f86834 | 2412 | * Locking: RCU, ctrl lock |
af9b897e AC |
2413 | */ |
2414 | ||
1da177e4 LT |
2415 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2416 | { | |
04a2e6a5 EB |
2417 | struct pid *pgrp; |
2418 | pid_t pgrp_nr; | |
1da177e4 | 2419 | int retval = tty_check_change(real_tty); |
47f86834 | 2420 | unsigned long flags; |
1da177e4 LT |
2421 | |
2422 | if (retval == -EIO) | |
2423 | return -ENOTTY; | |
2424 | if (retval) | |
2425 | return retval; | |
2426 | if (!current->signal->tty || | |
2427 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2428 | (real_tty->session != task_session(current))) |
1da177e4 | 2429 | return -ENOTTY; |
04a2e6a5 | 2430 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2431 | return -EFAULT; |
04a2e6a5 | 2432 | if (pgrp_nr < 0) |
1da177e4 | 2433 | return -EINVAL; |
04a2e6a5 | 2434 | rcu_read_lock(); |
b488893a | 2435 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2436 | retval = -ESRCH; |
2437 | if (!pgrp) | |
2438 | goto out_unlock; | |
2439 | retval = -EPERM; | |
2440 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2441 | goto out_unlock; | |
2442 | retval = 0; | |
47f86834 | 2443 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2444 | put_pid(real_tty->pgrp); |
2445 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2446 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2447 | out_unlock: |
2448 | rcu_read_unlock(); | |
2449 | return retval; | |
1da177e4 LT |
2450 | } |
2451 | ||
af9b897e AC |
2452 | /** |
2453 | * tiocgsid - get session id | |
2454 | * @tty: tty passed by user | |
25985edc | 2455 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2456 | * @p: pointer to returned session id |
2457 | * | |
2458 | * Obtain the session id of the tty. If there is no session | |
2459 | * return an error. | |
2460 | * | |
24ec839c | 2461 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2462 | */ |
2463 | ||
1da177e4 LT |
2464 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2465 | { | |
2466 | /* | |
2467 | * (tty == real_tty) is a cheap way of | |
2468 | * testing if the tty is NOT a master pty. | |
2469 | */ | |
2470 | if (tty == real_tty && current->signal->tty != real_tty) | |
2471 | return -ENOTTY; | |
ab521dc0 | 2472 | if (!real_tty->session) |
1da177e4 | 2473 | return -ENOTTY; |
b488893a | 2474 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2475 | } |
2476 | ||
af9b897e AC |
2477 | /** |
2478 | * tiocsetd - set line discipline | |
2479 | * @tty: tty device | |
2480 | * @p: pointer to user data | |
2481 | * | |
2482 | * Set the line discipline according to user request. | |
2483 | * | |
2484 | * Locking: see tty_set_ldisc, this function is just a helper | |
2485 | */ | |
2486 | ||
1da177e4 LT |
2487 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2488 | { | |
2489 | int ldisc; | |
04f378b1 | 2490 | int ret; |
1da177e4 LT |
2491 | |
2492 | if (get_user(ldisc, p)) | |
2493 | return -EFAULT; | |
04f378b1 | 2494 | |
04f378b1 | 2495 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2496 | |
2497 | return ret; | |
1da177e4 LT |
2498 | } |
2499 | ||
af9b897e AC |
2500 | /** |
2501 | * send_break - performed time break | |
2502 | * @tty: device to break on | |
2503 | * @duration: timeout in mS | |
2504 | * | |
2505 | * Perform a timed break on hardware that lacks its own driver level | |
2506 | * timed break functionality. | |
2507 | * | |
2508 | * Locking: | |
28298232 | 2509 | * atomic_write_lock serializes |
af9b897e | 2510 | * |
af9b897e AC |
2511 | */ |
2512 | ||
b20f3ae5 | 2513 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2514 | { |
9e98966c AC |
2515 | int retval; |
2516 | ||
2517 | if (tty->ops->break_ctl == NULL) | |
2518 | return 0; | |
2519 | ||
2520 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2521 | retval = tty->ops->break_ctl(tty, duration); | |
2522 | else { | |
2523 | /* Do the work ourselves */ | |
2524 | if (tty_write_lock(tty, 0) < 0) | |
2525 | return -EINTR; | |
2526 | retval = tty->ops->break_ctl(tty, -1); | |
2527 | if (retval) | |
2528 | goto out; | |
2529 | if (!signal_pending(current)) | |
2530 | msleep_interruptible(duration); | |
2531 | retval = tty->ops->break_ctl(tty, 0); | |
2532 | out: | |
2533 | tty_write_unlock(tty); | |
2534 | if (signal_pending(current)) | |
2535 | retval = -EINTR; | |
2536 | } | |
2537 | return retval; | |
1da177e4 LT |
2538 | } |
2539 | ||
af9b897e | 2540 | /** |
f34d7a5b | 2541 | * tty_tiocmget - get modem status |
af9b897e AC |
2542 | * @tty: tty device |
2543 | * @file: user file pointer | |
2544 | * @p: pointer to result | |
2545 | * | |
2546 | * Obtain the modem status bits from the tty driver if the feature | |
2547 | * is supported. Return -EINVAL if it is not available. | |
2548 | * | |
2549 | * Locking: none (up to the driver) | |
2550 | */ | |
2551 | ||
60b33c13 | 2552 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2553 | { |
2554 | int retval = -EINVAL; | |
2555 | ||
f34d7a5b | 2556 | if (tty->ops->tiocmget) { |
60b33c13 | 2557 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2558 | |
2559 | if (retval >= 0) | |
2560 | retval = put_user(retval, p); | |
2561 | } | |
2562 | return retval; | |
2563 | } | |
2564 | ||
af9b897e | 2565 | /** |
f34d7a5b | 2566 | * tty_tiocmset - set modem status |
af9b897e | 2567 | * @tty: tty device |
af9b897e AC |
2568 | * @cmd: command - clear bits, set bits or set all |
2569 | * @p: pointer to desired bits | |
2570 | * | |
2571 | * Set the modem status bits from the tty driver if the feature | |
2572 | * is supported. Return -EINVAL if it is not available. | |
2573 | * | |
2574 | * Locking: none (up to the driver) | |
2575 | */ | |
2576 | ||
20b9d177 | 2577 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2578 | unsigned __user *p) |
2579 | { | |
ae677517 AC |
2580 | int retval; |
2581 | unsigned int set, clear, val; | |
1da177e4 | 2582 | |
ae677517 AC |
2583 | if (tty->ops->tiocmset == NULL) |
2584 | return -EINVAL; | |
1da177e4 | 2585 | |
ae677517 AC |
2586 | retval = get_user(val, p); |
2587 | if (retval) | |
2588 | return retval; | |
2589 | set = clear = 0; | |
2590 | switch (cmd) { | |
2591 | case TIOCMBIS: | |
2592 | set = val; | |
2593 | break; | |
2594 | case TIOCMBIC: | |
2595 | clear = val; | |
2596 | break; | |
2597 | case TIOCMSET: | |
2598 | set = val; | |
2599 | clear = ~val; | |
2600 | break; | |
2601 | } | |
2602 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2603 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2604 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2605 | } |
2606 | ||
d281da7f AC |
2607 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2608 | { | |
2609 | int retval = -EINVAL; | |
2610 | struct serial_icounter_struct icount; | |
2611 | memset(&icount, 0, sizeof(icount)); | |
2612 | if (tty->ops->get_icount) | |
2613 | retval = tty->ops->get_icount(tty, &icount); | |
2614 | if (retval != 0) | |
2615 | return retval; | |
2616 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2617 | return -EFAULT; | |
2618 | return 0; | |
2619 | } | |
2620 | ||
e8b70e7d AC |
2621 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2622 | { | |
2623 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2624 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2625 | tty = tty->link; | |
2626 | return tty; | |
2627 | } | |
2628 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2629 | ||
2630 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2631 | { | |
2632 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2633 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2634 | return tty; | |
2635 | return tty->link; | |
2636 | } | |
2637 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2638 | ||
1da177e4 LT |
2639 | /* |
2640 | * Split this up, as gcc can choke on it otherwise.. | |
2641 | */ | |
04f378b1 | 2642 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2643 | { |
d996b62a NP |
2644 | struct tty_struct *tty = file_tty(file); |
2645 | struct tty_struct *real_tty; | |
1da177e4 LT |
2646 | void __user *p = (void __user *)arg; |
2647 | int retval; | |
2648 | struct tty_ldisc *ld; | |
04f378b1 | 2649 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2650 | |
1da177e4 LT |
2651 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2652 | return -EINVAL; | |
2653 | ||
e8b70e7d | 2654 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2655 | |
2656 | /* | |
2657 | * Factor out some common prep work | |
2658 | */ | |
2659 | switch (cmd) { | |
2660 | case TIOCSETD: | |
2661 | case TIOCSBRK: | |
2662 | case TIOCCBRK: | |
2663 | case TCSBRK: | |
37bdfb07 | 2664 | case TCSBRKP: |
1da177e4 LT |
2665 | retval = tty_check_change(tty); |
2666 | if (retval) | |
2667 | return retval; | |
2668 | if (cmd != TIOCCBRK) { | |
2669 | tty_wait_until_sent(tty, 0); | |
2670 | if (signal_pending(current)) | |
2671 | return -EINTR; | |
2672 | } | |
2673 | break; | |
2674 | } | |
2675 | ||
9e98966c AC |
2676 | /* |
2677 | * Now do the stuff. | |
2678 | */ | |
1da177e4 | 2679 | switch (cmd) { |
37bdfb07 AC |
2680 | case TIOCSTI: |
2681 | return tiocsti(tty, p); | |
2682 | case TIOCGWINSZ: | |
8f520021 | 2683 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2684 | case TIOCSWINSZ: |
fc6f6238 | 2685 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2686 | case TIOCCONS: |
2687 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2688 | case FIONBIO: | |
2689 | return fionbio(file, p); | |
2690 | case TIOCEXCL: | |
2691 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2692 | return 0; | |
2693 | case TIOCNXCL: | |
2694 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2695 | return 0; | |
2696 | case TIOCNOTTY: | |
2697 | if (current->signal->tty != tty) | |
2698 | return -ENOTTY; | |
2699 | no_tty(); | |
2700 | return 0; | |
2701 | case TIOCSCTTY: | |
2702 | return tiocsctty(tty, arg); | |
2703 | case TIOCGPGRP: | |
2704 | return tiocgpgrp(tty, real_tty, p); | |
2705 | case TIOCSPGRP: | |
2706 | return tiocspgrp(tty, real_tty, p); | |
2707 | case TIOCGSID: | |
2708 | return tiocgsid(tty, real_tty, p); | |
2709 | case TIOCGETD: | |
c65c9bc3 | 2710 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2711 | case TIOCSETD: |
2712 | return tiocsetd(tty, p); | |
3c95c985 KS |
2713 | case TIOCVHANGUP: |
2714 | if (!capable(CAP_SYS_ADMIN)) | |
2715 | return -EPERM; | |
2716 | tty_vhangup(tty); | |
2717 | return 0; | |
b7b8de08 WF |
2718 | case TIOCGDEV: |
2719 | { | |
2720 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2721 | return put_user(ret, (unsigned int __user *)p); | |
2722 | } | |
37bdfb07 AC |
2723 | /* |
2724 | * Break handling | |
2725 | */ | |
2726 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2727 | if (tty->ops->break_ctl) |
9e98966c | 2728 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2729 | return 0; |
37bdfb07 | 2730 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2731 | if (tty->ops->break_ctl) |
9e98966c | 2732 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2733 | return 0; |
2734 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2735 | /* non-zero arg means wait for all output data | |
2736 | * to be sent (performed above) but don't send break. | |
2737 | * This is used by the tcdrain() termios function. | |
2738 | */ | |
2739 | if (!arg) | |
2740 | return send_break(tty, 250); | |
2741 | return 0; | |
2742 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2743 | return send_break(tty, arg ? arg*100 : 250); | |
2744 | ||
2745 | case TIOCMGET: | |
60b33c13 | 2746 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2747 | case TIOCMSET: |
2748 | case TIOCMBIC: | |
2749 | case TIOCMBIS: | |
20b9d177 | 2750 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2751 | case TIOCGICOUNT: |
2752 | retval = tty_tiocgicount(tty, p); | |
2753 | /* For the moment allow fall through to the old method */ | |
2754 | if (retval != -EINVAL) | |
2755 | return retval; | |
2756 | break; | |
37bdfb07 AC |
2757 | case TCFLSH: |
2758 | switch (arg) { | |
2759 | case TCIFLUSH: | |
2760 | case TCIOFLUSH: | |
2761 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2762 | tty_buffer_flush(tty); | |
c5c34d48 | 2763 | break; |
37bdfb07 AC |
2764 | } |
2765 | break; | |
1da177e4 | 2766 | } |
f34d7a5b | 2767 | if (tty->ops->ioctl) { |
6caa76b7 | 2768 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2769 | if (retval != -ENOIOCTLCMD) |
2770 | return retval; | |
2771 | } | |
2772 | ld = tty_ldisc_ref_wait(tty); | |
2773 | retval = -EINVAL; | |
a352def2 AC |
2774 | if (ld->ops->ioctl) { |
2775 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2776 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2777 | retval = -ENOTTY; |
1da177e4 LT |
2778 | } |
2779 | tty_ldisc_deref(ld); | |
2780 | return retval; | |
2781 | } | |
2782 | ||
e10cc1df | 2783 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2784 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2785 | unsigned long arg) |
2786 | { | |
2787 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2788 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2789 | struct tty_ldisc *ld; |
2790 | int retval = -ENOIOCTLCMD; | |
2791 | ||
2792 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2793 | return -EINVAL; | |
2794 | ||
f34d7a5b | 2795 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2796 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2797 | if (retval != -ENOIOCTLCMD) |
2798 | return retval; | |
2799 | } | |
2800 | ||
2801 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2802 | if (ld->ops->compat_ioctl) |
2803 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2804 | else |
2805 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2806 | tty_ldisc_deref(ld); |
2807 | ||
2808 | return retval; | |
2809 | } | |
2810 | #endif | |
1da177e4 LT |
2811 | |
2812 | /* | |
2813 | * This implements the "Secure Attention Key" --- the idea is to | |
2814 | * prevent trojan horses by killing all processes associated with this | |
2815 | * tty when the user hits the "Secure Attention Key". Required for | |
2816 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2817 | * |
1da177e4 LT |
2818 | * This code could be nicer; ideally it should send a HUP, wait a few |
2819 | * seconds, then send a INT, and then a KILL signal. But you then | |
2820 | * have to coordinate with the init process, since all processes associated | |
2821 | * with the current tty must be dead before the new getty is allowed | |
2822 | * to spawn. | |
2823 | * | |
2824 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2825 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2826 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2827 | * | |
2828 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2829 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2830 | */ | |
8b6312f4 | 2831 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2832 | { |
2833 | #ifdef TTY_SOFT_SAK | |
2834 | tty_hangup(tty); | |
2835 | #else | |
652486fb | 2836 | struct task_struct *g, *p; |
ab521dc0 | 2837 | struct pid *session; |
1da177e4 LT |
2838 | int i; |
2839 | struct file *filp; | |
badf1662 | 2840 | struct fdtable *fdt; |
37bdfb07 | 2841 | |
1da177e4 LT |
2842 | if (!tty) |
2843 | return; | |
24ec839c | 2844 | session = tty->session; |
37bdfb07 | 2845 | |
b3f13deb | 2846 | tty_ldisc_flush(tty); |
1da177e4 | 2847 | |
f34d7a5b | 2848 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2849 | |
1da177e4 | 2850 | read_lock(&tasklist_lock); |
652486fb | 2851 | /* Kill the entire session */ |
ab521dc0 | 2852 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2853 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2854 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2855 | task_pid_nr(p), p->comm); |
652486fb | 2856 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2857 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2858 | /* Now kill any processes that happen to have the |
2859 | * tty open. | |
2860 | */ | |
2861 | do_each_thread(g, p) { | |
2862 | if (p->signal->tty == tty) { | |
1da177e4 | 2863 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2864 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2865 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2866 | send_sig(SIGKILL, p, 1); |
2867 | continue; | |
2868 | } | |
2869 | task_lock(p); | |
2870 | if (p->files) { | |
ca99c1da DS |
2871 | /* |
2872 | * We don't take a ref to the file, so we must | |
2873 | * hold ->file_lock instead. | |
2874 | */ | |
2875 | spin_lock(&p->files->file_lock); | |
badf1662 | 2876 | fdt = files_fdtable(p->files); |
37bdfb07 | 2877 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2878 | filp = fcheck_files(p->files, i); |
2879 | if (!filp) | |
2880 | continue; | |
2881 | if (filp->f_op->read == tty_read && | |
d996b62a | 2882 | file_tty(filp) == tty) { |
1da177e4 LT |
2883 | printk(KERN_NOTICE "SAK: killed process %d" |
2884 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2885 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2886 | force_sig(SIGKILL, p); |
1da177e4 LT |
2887 | break; |
2888 | } | |
2889 | } | |
ca99c1da | 2890 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2891 | } |
2892 | task_unlock(p); | |
652486fb | 2893 | } while_each_thread(g, p); |
1da177e4 LT |
2894 | read_unlock(&tasklist_lock); |
2895 | #endif | |
2896 | } | |
2897 | ||
8b6312f4 EB |
2898 | static void do_SAK_work(struct work_struct *work) |
2899 | { | |
2900 | struct tty_struct *tty = | |
2901 | container_of(work, struct tty_struct, SAK_work); | |
2902 | __do_SAK(tty); | |
2903 | } | |
2904 | ||
1da177e4 LT |
2905 | /* |
2906 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2907 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2908 | * the values which we write to it will be identical to the values which it | |
2909 | * already has. --akpm | |
2910 | */ | |
2911 | void do_SAK(struct tty_struct *tty) | |
2912 | { | |
2913 | if (!tty) | |
2914 | return; | |
1da177e4 LT |
2915 | schedule_work(&tty->SAK_work); |
2916 | } | |
2917 | ||
2918 | EXPORT_SYMBOL(do_SAK); | |
2919 | ||
30004ac9 DES |
2920 | static int dev_match_devt(struct device *dev, void *data) |
2921 | { | |
2922 | dev_t *devt = data; | |
2923 | return dev->devt == *devt; | |
2924 | } | |
2925 | ||
2926 | /* Must put_device() after it's unused! */ | |
2927 | static struct device *tty_get_device(struct tty_struct *tty) | |
2928 | { | |
2929 | dev_t devt = tty_devnum(tty); | |
2930 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2931 | } | |
2932 | ||
2933 | ||
af9b897e AC |
2934 | /** |
2935 | * initialize_tty_struct | |
2936 | * @tty: tty to initialize | |
2937 | * | |
2938 | * This subroutine initializes a tty structure that has been newly | |
2939 | * allocated. | |
2940 | * | |
2941 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2942 | */ |
af9b897e | 2943 | |
bf970ee4 AC |
2944 | void initialize_tty_struct(struct tty_struct *tty, |
2945 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2946 | { |
2947 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2948 | kref_init(&tty->kref); |
1da177e4 | 2949 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2950 | tty_ldisc_init(tty); |
ab521dc0 EB |
2951 | tty->session = NULL; |
2952 | tty->pgrp = NULL; | |
1da177e4 | 2953 | tty->overrun_time = jiffies; |
33f0f88f | 2954 | tty_buffer_init(tty); |
89c8d91e | 2955 | mutex_init(&tty->legacy_mutex); |
5785c95b | 2956 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2957 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2958 | init_waitqueue_head(&tty->write_wait); |
2959 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2960 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2961 | mutex_init(&tty->atomic_read_lock); |
2962 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2963 | mutex_init(&tty->output_lock); |
2964 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2965 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2966 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2967 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2968 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2969 | |
2970 | tty->driver = driver; | |
2971 | tty->ops = driver->ops; | |
2972 | tty->index = idx; | |
2973 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2974 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2975 | } |
2976 | ||
6716671d JS |
2977 | /** |
2978 | * deinitialize_tty_struct | |
2979 | * @tty: tty to deinitialize | |
2980 | * | |
2981 | * This subroutine deinitializes a tty structure that has been newly | |
2982 | * allocated but tty_release cannot be called on that yet. | |
2983 | * | |
2984 | * Locking: none - tty in question must not be exposed at this point | |
2985 | */ | |
2986 | void deinitialize_tty_struct(struct tty_struct *tty) | |
2987 | { | |
2988 | tty_ldisc_deinit(tty); | |
2989 | } | |
2990 | ||
f34d7a5b AC |
2991 | /** |
2992 | * tty_put_char - write one character to a tty | |
2993 | * @tty: tty | |
2994 | * @ch: character | |
2995 | * | |
2996 | * Write one byte to the tty using the provided put_char method | |
2997 | * if present. Returns the number of characters successfully output. | |
2998 | * | |
2999 | * Note: the specific put_char operation in the driver layer may go | |
3000 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3001 | */ |
af9b897e | 3002 | |
f34d7a5b | 3003 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3004 | { |
f34d7a5b AC |
3005 | if (tty->ops->put_char) |
3006 | return tty->ops->put_char(tty, ch); | |
3007 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3008 | } |
f34d7a5b AC |
3009 | EXPORT_SYMBOL_GPL(tty_put_char); |
3010 | ||
d81ed103 | 3011 | struct class *tty_class; |
1da177e4 | 3012 | |
7e73eca6 JS |
3013 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3014 | unsigned int index, unsigned int count) | |
3015 | { | |
3016 | /* init here, since reused cdevs cause crashes */ | |
3017 | cdev_init(&driver->cdevs[index], &tty_fops); | |
3018 | driver->cdevs[index].owner = driver->owner; | |
3019 | return cdev_add(&driver->cdevs[index], dev, count); | |
3020 | } | |
3021 | ||
1da177e4 | 3022 | /** |
af9b897e AC |
3023 | * tty_register_device - register a tty device |
3024 | * @driver: the tty driver that describes the tty device | |
3025 | * @index: the index in the tty driver for this tty device | |
3026 | * @device: a struct device that is associated with this tty device. | |
3027 | * This field is optional, if there is no known struct device | |
3028 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3029 | * |
01107d34 GKH |
3030 | * Returns a pointer to the struct device for this tty device |
3031 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3032 | * |
af9b897e AC |
3033 | * This call is required to be made to register an individual tty device |
3034 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3035 | * that bit is not set, this function should not be called by a tty | |
3036 | * driver. | |
3037 | * | |
3038 | * Locking: ?? | |
1da177e4 | 3039 | */ |
af9b897e | 3040 | |
01107d34 GKH |
3041 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3042 | struct device *device) | |
1da177e4 | 3043 | { |
7e73eca6 | 3044 | struct device *ret; |
1da177e4 LT |
3045 | char name[64]; |
3046 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
7e73eca6 | 3047 | bool cdev = false; |
1da177e4 LT |
3048 | |
3049 | if (index >= driver->num) { | |
3050 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3051 | " (%d).\n", index); | |
1cdcb6b4 | 3052 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3053 | } |
3054 | ||
1da177e4 LT |
3055 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3056 | pty_line_name(driver, index, name); | |
3057 | else | |
3058 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3059 | |
7e73eca6 JS |
3060 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
3061 | int error = tty_cdev_add(driver, dev, index, 1); | |
3062 | if (error) | |
3063 | return ERR_PTR(error); | |
3064 | cdev = true; | |
3065 | } | |
3066 | ||
3067 | ret = device_create(tty_class, device, dev, NULL, name); | |
3068 | if (IS_ERR(ret) && cdev) | |
3069 | cdev_del(&driver->cdevs[index]); | |
3070 | ||
3071 | return ret; | |
1da177e4 | 3072 | } |
7d7b93c1 | 3073 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
3074 | |
3075 | /** | |
af9b897e AC |
3076 | * tty_unregister_device - unregister a tty device |
3077 | * @driver: the tty driver that describes the tty device | |
3078 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3079 | * |
af9b897e AC |
3080 | * If a tty device is registered with a call to tty_register_device() then |
3081 | * this function must be called when the tty device is gone. | |
3082 | * | |
3083 | * Locking: ?? | |
1da177e4 | 3084 | */ |
af9b897e | 3085 | |
1da177e4 LT |
3086 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3087 | { | |
37bdfb07 AC |
3088 | device_destroy(tty_class, |
3089 | MKDEV(driver->major, driver->minor_start) + index); | |
7e73eca6 JS |
3090 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) |
3091 | cdev_del(&driver->cdevs[index]); | |
1da177e4 | 3092 | } |
1da177e4 LT |
3093 | EXPORT_SYMBOL(tty_unregister_device); |
3094 | ||
7f0bc6a6 JS |
3095 | /** |
3096 | * __tty_alloc_driver -- allocate tty driver | |
3097 | * @lines: count of lines this driver can handle at most | |
3098 | * @owner: module which is repsonsible for this driver | |
3099 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3100 | * | |
3101 | * This should not be called directly, some of the provided macros should be | |
3102 | * used instead. Use IS_ERR and friends on @retval. | |
3103 | */ | |
3104 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3105 | unsigned long flags) | |
1da177e4 LT |
3106 | { |
3107 | struct tty_driver *driver; | |
7e73eca6 | 3108 | unsigned int cdevs = 1; |
16a02081 | 3109 | int err; |
1da177e4 | 3110 | |
0019b408 | 3111 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3112 | return ERR_PTR(-EINVAL); |
3113 | ||
506eb99a | 3114 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3115 | if (!driver) |
3116 | return ERR_PTR(-ENOMEM); | |
3117 | ||
3118 | kref_init(&driver->kref); | |
3119 | driver->magic = TTY_DRIVER_MAGIC; | |
3120 | driver->num = lines; | |
3121 | driver->owner = owner; | |
3122 | driver->flags = flags; | |
16a02081 JS |
3123 | |
3124 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3125 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3126 | GFP_KERNEL); | |
3127 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3128 | GFP_KERNEL); | |
3129 | if (!driver->ttys || !driver->termios) { | |
3130 | err = -ENOMEM; | |
3131 | goto err_free_all; | |
3132 | } | |
3133 | } | |
3134 | ||
3135 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3136 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3137 | GFP_KERNEL); | |
3138 | if (!driver->ports) { | |
3139 | err = -ENOMEM; | |
3140 | goto err_free_all; | |
3141 | } | |
7e73eca6 JS |
3142 | cdevs = lines; |
3143 | } | |
3144 | ||
3145 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3146 | if (!driver->cdevs) { | |
3147 | err = -ENOMEM; | |
3148 | goto err_free_all; | |
16a02081 | 3149 | } |
7f0bc6a6 | 3150 | |
1da177e4 | 3151 | return driver; |
16a02081 JS |
3152 | err_free_all: |
3153 | kfree(driver->ports); | |
3154 | kfree(driver->ttys); | |
3155 | kfree(driver->termios); | |
3156 | kfree(driver); | |
3157 | return ERR_PTR(err); | |
1da177e4 | 3158 | } |
7f0bc6a6 | 3159 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3160 | |
7d7b93c1 | 3161 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3162 | { |
7d7b93c1 AC |
3163 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3164 | int i; | |
3165 | struct ktermios *tp; | |
7d7b93c1 AC |
3166 | |
3167 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3168 | /* | |
3169 | * Free the termios and termios_locked structures because | |
3170 | * we don't want to get memory leaks when modular tty | |
3171 | * drivers are removed from the kernel. | |
3172 | */ | |
3173 | for (i = 0; i < driver->num; i++) { | |
3174 | tp = driver->termios[i]; | |
3175 | if (tp) { | |
3176 | driver->termios[i] = NULL; | |
3177 | kfree(tp); | |
3178 | } | |
7d7b93c1 AC |
3179 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3180 | tty_unregister_device(driver, i); | |
3181 | } | |
7d7b93c1 | 3182 | proc_tty_unregister_driver(driver); |
7e73eca6 JS |
3183 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
3184 | cdev_del(&driver->cdevs[0]); | |
7d7b93c1 | 3185 | } |
7e73eca6 | 3186 | kfree(driver->cdevs); |
04831dc1 | 3187 | kfree(driver->ports); |
16a02081 JS |
3188 | kfree(driver->termios); |
3189 | kfree(driver->ttys); | |
1da177e4 LT |
3190 | kfree(driver); |
3191 | } | |
3192 | ||
7d7b93c1 AC |
3193 | void tty_driver_kref_put(struct tty_driver *driver) |
3194 | { | |
3195 | kref_put(&driver->kref, destruct_tty_driver); | |
3196 | } | |
3197 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3198 | ||
b68e31d0 JD |
3199 | void tty_set_operations(struct tty_driver *driver, |
3200 | const struct tty_operations *op) | |
1da177e4 | 3201 | { |
f34d7a5b AC |
3202 | driver->ops = op; |
3203 | }; | |
7d7b93c1 | 3204 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3205 | |
7d7b93c1 AC |
3206 | void put_tty_driver(struct tty_driver *d) |
3207 | { | |
3208 | tty_driver_kref_put(d); | |
3209 | } | |
1da177e4 | 3210 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3211 | |
3212 | /* | |
3213 | * Called by a tty driver to register itself. | |
3214 | */ | |
3215 | int tty_register_driver(struct tty_driver *driver) | |
3216 | { | |
3217 | int error; | |
37bdfb07 | 3218 | int i; |
1da177e4 | 3219 | dev_t dev; |
b670bde0 | 3220 | struct device *d; |
1da177e4 | 3221 | |
1da177e4 | 3222 | if (!driver->major) { |
37bdfb07 AC |
3223 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3224 | driver->num, driver->name); | |
1da177e4 LT |
3225 | if (!error) { |
3226 | driver->major = MAJOR(dev); | |
3227 | driver->minor_start = MINOR(dev); | |
3228 | } | |
3229 | } else { | |
3230 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3231 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3232 | } |
9bb8a3d4 | 3233 | if (error < 0) |
16a02081 | 3234 | goto err; |
1da177e4 | 3235 | |
7e73eca6 JS |
3236 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3237 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3238 | if (error) | |
3239 | goto err_unreg_char; | |
3240 | } | |
1da177e4 | 3241 | |
ca509f69 | 3242 | mutex_lock(&tty_mutex); |
1da177e4 | 3243 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3244 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3245 | |
3246 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3247 | for (i = 0; i < driver->num; i++) { |
3248 | d = tty_register_device(driver, i, NULL); | |
3249 | if (IS_ERR(d)) { | |
3250 | error = PTR_ERR(d); | |
16a02081 | 3251 | goto err_unreg_devs; |
b670bde0 VK |
3252 | } |
3253 | } | |
1da177e4 LT |
3254 | } |
3255 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3256 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3257 | return 0; |
b670bde0 | 3258 | |
16a02081 | 3259 | err_unreg_devs: |
b670bde0 VK |
3260 | for (i--; i >= 0; i--) |
3261 | tty_unregister_device(driver, i); | |
3262 | ||
3263 | mutex_lock(&tty_mutex); | |
3264 | list_del(&driver->tty_drivers); | |
3265 | mutex_unlock(&tty_mutex); | |
3266 | ||
9bb8a3d4 | 3267 | err_unreg_char: |
b670bde0 | 3268 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3269 | err: |
b670bde0 | 3270 | return error; |
1da177e4 | 3271 | } |
1da177e4 LT |
3272 | EXPORT_SYMBOL(tty_register_driver); |
3273 | ||
3274 | /* | |
3275 | * Called by a tty driver to unregister itself. | |
3276 | */ | |
3277 | int tty_unregister_driver(struct tty_driver *driver) | |
3278 | { | |
7d7b93c1 AC |
3279 | #if 0 |
3280 | /* FIXME */ | |
1da177e4 LT |
3281 | if (driver->refcount) |
3282 | return -EBUSY; | |
7d7b93c1 | 3283 | #endif |
1da177e4 LT |
3284 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3285 | driver->num); | |
ca509f69 | 3286 | mutex_lock(&tty_mutex); |
1da177e4 | 3287 | list_del(&driver->tty_drivers); |
ca509f69 | 3288 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3289 | return 0; |
3290 | } | |
7d7b93c1 | 3291 | |
1da177e4 LT |
3292 | EXPORT_SYMBOL(tty_unregister_driver); |
3293 | ||
24ec839c PZ |
3294 | dev_t tty_devnum(struct tty_struct *tty) |
3295 | { | |
3296 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3297 | } | |
3298 | EXPORT_SYMBOL(tty_devnum); | |
3299 | ||
3300 | void proc_clear_tty(struct task_struct *p) | |
3301 | { | |
7c3b1dcf | 3302 | unsigned long flags; |
9c9f4ded | 3303 | struct tty_struct *tty; |
7c3b1dcf | 3304 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3305 | tty = p->signal->tty; |
24ec839c | 3306 | p->signal->tty = NULL; |
7c3b1dcf | 3307 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3308 | tty_kref_put(tty); |
24ec839c | 3309 | } |
24ec839c | 3310 | |
47f86834 AC |
3311 | /* Called under the sighand lock */ |
3312 | ||
2a65f1d9 | 3313 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3314 | { |
3315 | if (tty) { | |
47f86834 AC |
3316 | unsigned long flags; |
3317 | /* We should not have a session or pgrp to put here but.... */ | |
3318 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3319 | put_pid(tty->session); |
3320 | put_pid(tty->pgrp); | |
ab521dc0 | 3321 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3322 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3323 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3324 | if (tsk->signal->tty) { |
3325 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3326 | tty_kref_put(tsk->signal->tty); | |
3327 | } | |
24ec839c | 3328 | } |
2a65f1d9 | 3329 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3330 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3331 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3332 | } |
3333 | ||
98a27ba4 | 3334 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3335 | { |
3336 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3337 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3338 | spin_unlock_irq(&tsk->sighand->siglock); |
3339 | } | |
3340 | ||
3341 | struct tty_struct *get_current_tty(void) | |
3342 | { | |
3343 | struct tty_struct *tty; | |
934e6ebf AC |
3344 | unsigned long flags; |
3345 | ||
3346 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3347 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3348 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3349 | return tty; |
3350 | } | |
a311f743 | 3351 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3352 | |
d81ed103 AC |
3353 | void tty_default_fops(struct file_operations *fops) |
3354 | { | |
3355 | *fops = tty_fops; | |
3356 | } | |
3357 | ||
1da177e4 LT |
3358 | /* |
3359 | * Initialize the console device. This is called *early*, so | |
3360 | * we can't necessarily depend on lots of kernel help here. | |
3361 | * Just do some early initializations, and do the complex setup | |
3362 | * later. | |
3363 | */ | |
3364 | void __init console_init(void) | |
3365 | { | |
3366 | initcall_t *call; | |
3367 | ||
3368 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3369 | tty_ldisc_begin(); |
1da177e4 LT |
3370 | |
3371 | /* | |
37bdfb07 | 3372 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3373 | * inform about problems etc.. |
3374 | */ | |
1da177e4 LT |
3375 | call = __con_initcall_start; |
3376 | while (call < __con_initcall_end) { | |
3377 | (*call)(); | |
3378 | call++; | |
3379 | } | |
3380 | } | |
3381 | ||
2c9ede55 | 3382 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3383 | { |
3384 | if (!mode) | |
3385 | return NULL; | |
3386 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3387 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3388 | *mode = 0666; | |
3389 | return NULL; | |
3390 | } | |
3391 | ||
1da177e4 LT |
3392 | static int __init tty_class_init(void) |
3393 | { | |
7fe845d1 | 3394 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3395 | if (IS_ERR(tty_class)) |
3396 | return PTR_ERR(tty_class); | |
e454cea2 | 3397 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3398 | return 0; |
3399 | } | |
3400 | ||
3401 | postcore_initcall(tty_class_init); | |
3402 | ||
3403 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3404 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3405 | |
fbc92a34 KS |
3406 | static ssize_t show_cons_active(struct device *dev, |
3407 | struct device_attribute *attr, char *buf) | |
3408 | { | |
3409 | struct console *cs[16]; | |
3410 | int i = 0; | |
3411 | struct console *c; | |
3412 | ssize_t count = 0; | |
3413 | ||
ac751efa | 3414 | console_lock(); |
a2a6a822 | 3415 | for_each_console(c) { |
fbc92a34 KS |
3416 | if (!c->device) |
3417 | continue; | |
3418 | if (!c->write) | |
3419 | continue; | |
3420 | if ((c->flags & CON_ENABLED) == 0) | |
3421 | continue; | |
3422 | cs[i++] = c; | |
3423 | if (i >= ARRAY_SIZE(cs)) | |
3424 | break; | |
3425 | } | |
3426 | while (i--) | |
3427 | count += sprintf(buf + count, "%s%d%c", | |
3428 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3429 | console_unlock(); |
fbc92a34 KS |
3430 | |
3431 | return count; | |
3432 | } | |
3433 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3434 | ||
3435 | static struct device *consdev; | |
3436 | ||
3437 | void console_sysfs_notify(void) | |
3438 | { | |
3439 | if (consdev) | |
3440 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3441 | } | |
3442 | ||
1da177e4 LT |
3443 | /* |
3444 | * Ok, now we can initialize the rest of the tty devices and can count | |
3445 | * on memory allocations, interrupts etc.. | |
3446 | */ | |
31d1d48e | 3447 | int __init tty_init(void) |
1da177e4 LT |
3448 | { |
3449 | cdev_init(&tty_cdev, &tty_fops); | |
3450 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3451 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3452 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3453 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3454 | |
3455 | cdev_init(&console_cdev, &console_fops); | |
3456 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3457 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3458 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3459 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3460 | "console"); |
fbc92a34 KS |
3461 | if (IS_ERR(consdev)) |
3462 | consdev = NULL; | |
3463 | else | |
a2a6a822 | 3464 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3465 | |
1da177e4 | 3466 | #ifdef CONFIG_VT |
d81ed103 | 3467 | vty_init(&console_fops); |
1da177e4 LT |
3468 | #endif |
3469 | return 0; | |
3470 | } | |
31d1d48e | 3471 |