]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/tty_io.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
9 | * or rs-channels. It also implements echoing, cooked mode etc. | |
10 | * | |
11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
12 | * | |
13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
14 | * tty_struct and tty_queue structures. Previously there was an array | |
15 | * of 256 tty_struct's which was statically allocated, and the | |
16 | * tty_queue structures were allocated at boot time. Both are now | |
17 | * dynamically allocated only when the tty is open. | |
18 | * | |
19 | * Also restructured routines so that there is more of a separation | |
20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
21 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
23 | * |
24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
25 | * which can be dynamically activated and de-activated by the line | |
26 | * discipline handling modules (like SLIP). | |
27 | * | |
28 | * NOTE: pay no attention to the line discipline code (yet); its | |
29 | * interface is still subject to change in this version... | |
30 | * -- TYT, 1/31/92 | |
31 | * | |
32 | * Added functionality to the OPOST tty handling. No delays, but all | |
33 | * other bits should be there. | |
34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
35 | * | |
36 | * Rewrote canonical mode and added more termios flags. | |
37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
38 | * | |
39 | * Reorganized FASYNC support so mouse code can share it. | |
40 | * -- ctm@ardi.com, 9Sep95 | |
41 | * | |
42 | * New TIOCLINUX variants added. | |
43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 44 | * |
1da177e4 LT |
45 | * Restrict vt switching via ioctl() |
46 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
47 | * | |
48 | * Move console and virtual terminal code to more appropriate files, | |
49 | * implement CONFIG_VT and generalize console device interface. | |
50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
51 | * | |
d81ed103 | 52 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
53 | * -- Bill Hawes <whawes@star.net>, June 97 |
54 | * | |
55 | * Added devfs support. | |
56 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
57 | * | |
58 | * Added support for a Unix98-style ptmx device. | |
59 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
60 | * | |
61 | * Reduced memory usage for older ARM systems | |
62 | * -- Russell King <rmk@arm.linux.org.uk> | |
63 | * | |
64 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
65 | * alloc_tty_struct() always uses kmalloc() |
66 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
67 | */ |
68 | ||
1da177e4 LT |
69 | #include <linux/types.h> |
70 | #include <linux/major.h> | |
71 | #include <linux/errno.h> | |
72 | #include <linux/signal.h> | |
73 | #include <linux/fcntl.h> | |
74 | #include <linux/sched.h> | |
75 | #include <linux/interrupt.h> | |
76 | #include <linux/tty.h> | |
77 | #include <linux/tty_driver.h> | |
78 | #include <linux/tty_flip.h> | |
79 | #include <linux/devpts_fs.h> | |
80 | #include <linux/file.h> | |
9f3acc31 | 81 | #include <linux/fdtable.h> |
1da177e4 LT |
82 | #include <linux/console.h> |
83 | #include <linux/timer.h> | |
84 | #include <linux/ctype.h> | |
85 | #include <linux/kd.h> | |
86 | #include <linux/mm.h> | |
87 | #include <linux/string.h> | |
88 | #include <linux/slab.h> | |
89 | #include <linux/poll.h> | |
90 | #include <linux/proc_fs.h> | |
91 | #include <linux/init.h> | |
92 | #include <linux/module.h> | |
93 | #include <linux/smp_lock.h> | |
94 | #include <linux/device.h> | |
1da177e4 LT |
95 | #include <linux/wait.h> |
96 | #include <linux/bitops.h> | |
b20f3ae5 | 97 | #include <linux/delay.h> |
a352def2 | 98 | #include <linux/seq_file.h> |
1da177e4 | 99 | |
a352def2 | 100 | #include <linux/uaccess.h> |
1da177e4 LT |
101 | #include <asm/system.h> |
102 | ||
103 | #include <linux/kbd_kern.h> | |
104 | #include <linux/vt_kern.h> | |
105 | #include <linux/selection.h> | |
1da177e4 LT |
106 | |
107 | #include <linux/kmod.h> | |
b488893a | 108 | #include <linux/nsproxy.h> |
1da177e4 LT |
109 | |
110 | #undef TTY_DEBUG_HANGUP | |
111 | ||
112 | #define TTY_PARANOIA_CHECK 1 | |
113 | #define CHECK_TTY_COUNT 1 | |
114 | ||
edc6afc5 | 115 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
116 | .c_iflag = ICRNL | IXON, |
117 | .c_oflag = OPOST | ONLCR, | |
118 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
119 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
120 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
121 | .c_cc = INIT_C_CC, |
122 | .c_ispeed = 38400, | |
123 | .c_ospeed = 38400 | |
1da177e4 LT |
124 | }; |
125 | ||
126 | EXPORT_SYMBOL(tty_std_termios); | |
127 | ||
128 | /* This list gets poked at by procfs and various bits of boot up code. This | |
129 | could do with some rationalisation such as pulling the tty proc function | |
130 | into this file */ | |
37bdfb07 | 131 | |
1da177e4 LT |
132 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
133 | ||
24ec839c | 134 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 135 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 136 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 137 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 138 | |
1da177e4 LT |
139 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
140 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
141 | ssize_t redirected_tty_write(struct file *, const char __user *, |
142 | size_t, loff_t *); | |
1da177e4 LT |
143 | static unsigned int tty_poll(struct file *, poll_table *); |
144 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 145 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 146 | #ifdef CONFIG_COMPAT |
37bdfb07 | 147 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
148 | unsigned long arg); |
149 | #else | |
150 | #define tty_compat_ioctl NULL | |
151 | #endif | |
37bdfb07 | 152 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 153 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 154 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 155 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 156 | |
af9b897e AC |
157 | /** |
158 | * alloc_tty_struct - allocate a tty object | |
159 | * | |
160 | * Return a new empty tty structure. The data fields have not | |
161 | * been initialized in any way but has been zeroed | |
162 | * | |
163 | * Locking: none | |
af9b897e | 164 | */ |
1da177e4 | 165 | |
bf970ee4 | 166 | struct tty_struct *alloc_tty_struct(void) |
1da177e4 | 167 | { |
1266b1e1 | 168 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
169 | } |
170 | ||
af9b897e AC |
171 | /** |
172 | * free_tty_struct - free a disused tty | |
173 | * @tty: tty struct to free | |
174 | * | |
175 | * Free the write buffers, tty queue and tty memory itself. | |
176 | * | |
177 | * Locking: none. Must be called after tty is definitely unused | |
178 | */ | |
179 | ||
bf970ee4 | 180 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 LT |
181 | { |
182 | kfree(tty->write_buf); | |
33f0f88f | 183 | tty_buffer_free_all(tty); |
1da177e4 LT |
184 | kfree(tty); |
185 | } | |
186 | ||
187 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) | |
188 | ||
af9b897e AC |
189 | /** |
190 | * tty_name - return tty naming | |
191 | * @tty: tty structure | |
192 | * @buf: buffer for output | |
193 | * | |
194 | * Convert a tty structure into a name. The name reflects the kernel | |
195 | * naming policy and if udev is in use may not reflect user space | |
196 | * | |
197 | * Locking: none | |
198 | */ | |
199 | ||
1da177e4 LT |
200 | char *tty_name(struct tty_struct *tty, char *buf) |
201 | { | |
202 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
203 | strcpy(buf, "NULL tty"); | |
204 | else | |
205 | strcpy(buf, tty->name); | |
206 | return buf; | |
207 | } | |
208 | ||
209 | EXPORT_SYMBOL(tty_name); | |
210 | ||
d769a669 | 211 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
212 | const char *routine) |
213 | { | |
214 | #ifdef TTY_PARANOIA_CHECK | |
215 | if (!tty) { | |
216 | printk(KERN_WARNING | |
217 | "null TTY for (%d:%d) in %s\n", | |
218 | imajor(inode), iminor(inode), routine); | |
219 | return 1; | |
220 | } | |
221 | if (tty->magic != TTY_MAGIC) { | |
222 | printk(KERN_WARNING | |
223 | "bad magic number for tty struct (%d:%d) in %s\n", | |
224 | imajor(inode), iminor(inode), routine); | |
225 | return 1; | |
226 | } | |
227 | #endif | |
228 | return 0; | |
229 | } | |
230 | ||
231 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
232 | { | |
233 | #ifdef CHECK_TTY_COUNT | |
234 | struct list_head *p; | |
235 | int count = 0; | |
37bdfb07 | 236 | |
1da177e4 LT |
237 | file_list_lock(); |
238 | list_for_each(p, &tty->tty_files) { | |
239 | count++; | |
240 | } | |
241 | file_list_unlock(); | |
242 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
243 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
244 | tty->link && tty->link->count) | |
245 | count++; | |
246 | if (tty->count != count) { | |
247 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
248 | "!= #fd's(%d) in %s\n", | |
249 | tty->name, tty->count, count, routine); | |
250 | return count; | |
24ec839c | 251 | } |
1da177e4 LT |
252 | #endif |
253 | return 0; | |
254 | } | |
255 | ||
af9b897e AC |
256 | /** |
257 | * get_tty_driver - find device of a tty | |
258 | * @dev_t: device identifier | |
259 | * @index: returns the index of the tty | |
260 | * | |
261 | * This routine returns a tty driver structure, given a device number | |
262 | * and also passes back the index number. | |
263 | * | |
264 | * Locking: caller must hold tty_mutex | |
1da177e4 | 265 | */ |
af9b897e | 266 | |
1da177e4 LT |
267 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
268 | { | |
269 | struct tty_driver *p; | |
270 | ||
271 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
272 | dev_t base = MKDEV(p->major, p->minor_start); | |
273 | if (device < base || device >= base + p->num) | |
274 | continue; | |
275 | *index = device - base; | |
7d7b93c1 | 276 | return tty_driver_kref_get(p); |
1da177e4 LT |
277 | } |
278 | return NULL; | |
279 | } | |
280 | ||
f2d937f3 JW |
281 | #ifdef CONFIG_CONSOLE_POLL |
282 | ||
283 | /** | |
284 | * tty_find_polling_driver - find device of a polled tty | |
285 | * @name: name string to match | |
286 | * @line: pointer to resulting tty line nr | |
287 | * | |
288 | * This routine returns a tty driver structure, given a name | |
289 | * and the condition that the tty driver is capable of polled | |
290 | * operation. | |
291 | */ | |
292 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
293 | { | |
294 | struct tty_driver *p, *res = NULL; | |
295 | int tty_line = 0; | |
0dca0fd2 | 296 | int len; |
5f0878ac | 297 | char *str, *stp; |
f2d937f3 | 298 | |
0dca0fd2 JW |
299 | for (str = name; *str; str++) |
300 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
301 | break; | |
302 | if (!*str) | |
303 | return NULL; | |
304 | ||
305 | len = str - name; | |
306 | tty_line = simple_strtoul(str, &str, 10); | |
307 | ||
f2d937f3 JW |
308 | mutex_lock(&tty_mutex); |
309 | /* Search through the tty devices to look for a match */ | |
310 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
311 | if (strncmp(name, p->name, len) != 0) |
312 | continue; | |
5f0878ac AC |
313 | stp = str; |
314 | if (*stp == ',') | |
315 | stp++; | |
316 | if (*stp == '\0') | |
317 | stp = NULL; | |
f2d937f3 | 318 | |
f34d7a5b | 319 | if (tty_line >= 0 && tty_line <= p->num && p->ops && |
5f0878ac | 320 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 321 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
322 | *line = tty_line; |
323 | break; | |
324 | } | |
325 | } | |
326 | mutex_unlock(&tty_mutex); | |
327 | ||
328 | return res; | |
329 | } | |
330 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
331 | #endif | |
332 | ||
af9b897e AC |
333 | /** |
334 | * tty_check_change - check for POSIX terminal changes | |
335 | * @tty: tty to check | |
336 | * | |
337 | * If we try to write to, or set the state of, a terminal and we're | |
338 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
339 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
340 | * | |
978e595f | 341 | * Locking: ctrl_lock |
1da177e4 | 342 | */ |
af9b897e | 343 | |
37bdfb07 | 344 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 345 | { |
47f86834 AC |
346 | unsigned long flags; |
347 | int ret = 0; | |
348 | ||
1da177e4 LT |
349 | if (current->signal->tty != tty) |
350 | return 0; | |
47f86834 AC |
351 | |
352 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
353 | ||
ab521dc0 EB |
354 | if (!tty->pgrp) { |
355 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 356 | goto out_unlock; |
1da177e4 | 357 | } |
ab521dc0 | 358 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
359 | goto out_unlock; |
360 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 361 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
362 | goto out; |
363 | if (is_current_pgrp_orphaned()) { | |
364 | ret = -EIO; | |
365 | goto out; | |
366 | } | |
040b6362 ON |
367 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
368 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
369 | ret = -ERESTARTSYS; |
370 | out: | |
9ffee4cb AM |
371 | return ret; |
372 | out_unlock: | |
47f86834 AC |
373 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
374 | return ret; | |
1da177e4 LT |
375 | } |
376 | ||
377 | EXPORT_SYMBOL(tty_check_change); | |
378 | ||
37bdfb07 | 379 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
380 | size_t count, loff_t *ppos) |
381 | { | |
382 | return 0; | |
383 | } | |
384 | ||
37bdfb07 | 385 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
386 | size_t count, loff_t *ppos) |
387 | { | |
388 | return -EIO; | |
389 | } | |
390 | ||
391 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 392 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
393 | { |
394 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
395 | } | |
396 | ||
04f378b1 AC |
397 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
398 | unsigned long arg) | |
38ad2ed0 PF |
399 | { |
400 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
401 | } | |
402 | ||
37bdfb07 | 403 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 404 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
405 | { |
406 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
407 | } | |
408 | ||
62322d25 | 409 | static const struct file_operations tty_fops = { |
1da177e4 LT |
410 | .llseek = no_llseek, |
411 | .read = tty_read, | |
412 | .write = tty_write, | |
413 | .poll = tty_poll, | |
04f378b1 | 414 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 415 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
416 | .open = tty_open, |
417 | .release = tty_release, | |
418 | .fasync = tty_fasync, | |
419 | }; | |
420 | ||
62322d25 | 421 | static const struct file_operations console_fops = { |
1da177e4 LT |
422 | .llseek = no_llseek, |
423 | .read = tty_read, | |
424 | .write = redirected_tty_write, | |
425 | .poll = tty_poll, | |
04f378b1 | 426 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 427 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
428 | .open = tty_open, |
429 | .release = tty_release, | |
430 | .fasync = tty_fasync, | |
431 | }; | |
432 | ||
62322d25 | 433 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
434 | .llseek = no_llseek, |
435 | .read = hung_up_tty_read, | |
436 | .write = hung_up_tty_write, | |
437 | .poll = hung_up_tty_poll, | |
04f378b1 | 438 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 439 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
440 | .release = tty_release, |
441 | }; | |
442 | ||
443 | static DEFINE_SPINLOCK(redirect_lock); | |
444 | static struct file *redirect; | |
445 | ||
446 | /** | |
447 | * tty_wakeup - request more data | |
448 | * @tty: terminal | |
449 | * | |
450 | * Internal and external helper for wakeups of tty. This function | |
451 | * informs the line discipline if present that the driver is ready | |
452 | * to receive more output data. | |
453 | */ | |
37bdfb07 | 454 | |
1da177e4 LT |
455 | void tty_wakeup(struct tty_struct *tty) |
456 | { | |
457 | struct tty_ldisc *ld; | |
37bdfb07 | 458 | |
1da177e4 LT |
459 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
460 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 461 | if (ld) { |
a352def2 AC |
462 | if (ld->ops->write_wakeup) |
463 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
464 | tty_ldisc_deref(ld); |
465 | } | |
466 | } | |
4b19449d | 467 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
468 | } |
469 | ||
470 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
471 | ||
af9b897e AC |
472 | /** |
473 | * do_tty_hangup - actual handler for hangup events | |
65f27f38 | 474 | * @work: tty device |
af9b897e | 475 | * |
1bad879a | 476 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
477 | * synchronous but doesn't hold any locks, so we need to make sure we |
478 | * have the appropriate locks for what we're doing. | |
479 | * | |
480 | * The hangup event clears any pending redirections onto the hung up | |
481 | * device. It ensures future writes will error and it does the needed | |
482 | * line discipline hangup and signal delivery. The tty object itself | |
483 | * remains intact. | |
484 | * | |
485 | * Locking: | |
486 | * BKL | |
24ec839c PZ |
487 | * redirect lock for undoing redirection |
488 | * file list lock for manipulating list of ttys | |
489 | * tty_ldisc_lock from called functions | |
490 | * termios_mutex resetting termios data | |
491 | * tasklist_lock to walk task list for hangup event | |
492 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 493 | */ |
65f27f38 | 494 | static void do_tty_hangup(struct work_struct *work) |
1da177e4 | 495 | { |
65f27f38 DH |
496 | struct tty_struct *tty = |
497 | container_of(work, struct tty_struct, hangup_work); | |
37bdfb07 | 498 | struct file *cons_filp = NULL; |
1da177e4 LT |
499 | struct file *filp, *f = NULL; |
500 | struct task_struct *p; | |
1da177e4 | 501 | int closecount = 0, n; |
47f86834 | 502 | unsigned long flags; |
9c9f4ded | 503 | int refs = 0; |
1da177e4 LT |
504 | |
505 | if (!tty) | |
506 | return; | |
507 | ||
1da177e4 LT |
508 | |
509 | spin_lock(&redirect_lock); | |
510 | if (redirect && redirect->private_data == tty) { | |
511 | f = redirect; | |
512 | redirect = NULL; | |
513 | } | |
514 | spin_unlock(&redirect_lock); | |
37bdfb07 | 515 | |
38c70b27 AC |
516 | /* inuse_filps is protected by the single kernel lock */ |
517 | lock_kernel(); | |
1da177e4 | 518 | check_tty_count(tty, "do_tty_hangup"); |
36ba782e | 519 | |
1da177e4 LT |
520 | file_list_lock(); |
521 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ | |
2f512016 | 522 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
1da177e4 LT |
523 | if (filp->f_op->write == redirected_tty_write) |
524 | cons_filp = filp; | |
525 | if (filp->f_op->write != tty_write) | |
526 | continue; | |
527 | closecount++; | |
528 | tty_fasync(-1, filp, 0); /* can't block */ | |
529 | filp->f_op = &hung_up_tty_fops; | |
530 | } | |
531 | file_list_unlock(); | |
37bdfb07 | 532 | |
c65c9bc3 | 533 | tty_ldisc_hangup(tty); |
37bdfb07 | 534 | |
1da177e4 | 535 | read_lock(&tasklist_lock); |
ab521dc0 EB |
536 | if (tty->session) { |
537 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 538 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 539 | if (p->signal->tty == tty) { |
1da177e4 | 540 | p->signal->tty = NULL; |
9c9f4ded AC |
541 | /* We defer the dereferences outside fo |
542 | the tasklist lock */ | |
543 | refs++; | |
544 | } | |
24ec839c PZ |
545 | if (!p->signal->leader) { |
546 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 547 | continue; |
24ec839c PZ |
548 | } |
549 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
550 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 551 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 552 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
553 | if (tty->pgrp) |
554 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 555 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 556 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 557 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
558 | } |
559 | read_unlock(&tasklist_lock); | |
560 | ||
47f86834 | 561 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
562 | clear_bit(TTY_THROTTLED, &tty->flags); |
563 | clear_bit(TTY_PUSH, &tty->flags); | |
564 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
565 | put_pid(tty->session); |
566 | put_pid(tty->pgrp); | |
ab521dc0 EB |
567 | tty->session = NULL; |
568 | tty->pgrp = NULL; | |
1da177e4 | 569 | tty->ctrl_status = 0; |
c65c9bc3 | 570 | set_bit(TTY_HUPPED, &tty->flags); |
47f86834 AC |
571 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
572 | ||
9c9f4ded AC |
573 | /* Account for the p->signal references we killed */ |
574 | while (refs--) | |
575 | tty_kref_put(tty); | |
576 | ||
1da177e4 | 577 | /* |
37bdfb07 AC |
578 | * If one of the devices matches a console pointer, we |
579 | * cannot just call hangup() because that will cause | |
580 | * tty->count and state->count to go out of sync. | |
581 | * So we just call close() the right number of times. | |
1da177e4 LT |
582 | */ |
583 | if (cons_filp) { | |
f34d7a5b | 584 | if (tty->ops->close) |
1da177e4 | 585 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
586 | tty->ops->close(tty, cons_filp); |
587 | } else if (tty->ops->hangup) | |
588 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
589 | /* |
590 | * We don't want to have driver/ldisc interactions beyond | |
591 | * the ones we did here. The driver layer expects no | |
592 | * calls after ->hangup() from the ldisc side. However we | |
593 | * can't yet guarantee all that. | |
594 | */ | |
1da177e4 | 595 | set_bit(TTY_HUPPED, &tty->flags); |
c65c9bc3 | 596 | tty_ldisc_enable(tty); |
1da177e4 LT |
597 | unlock_kernel(); |
598 | if (f) | |
599 | fput(f); | |
600 | } | |
601 | ||
af9b897e AC |
602 | /** |
603 | * tty_hangup - trigger a hangup event | |
604 | * @tty: tty to hangup | |
605 | * | |
606 | * A carrier loss (virtual or otherwise) has occurred on this like | |
607 | * schedule a hangup sequence to run after this event. | |
608 | */ | |
609 | ||
37bdfb07 | 610 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
611 | { |
612 | #ifdef TTY_DEBUG_HANGUP | |
613 | char buf[64]; | |
1da177e4 LT |
614 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
615 | #endif | |
616 | schedule_work(&tty->hangup_work); | |
617 | } | |
618 | ||
619 | EXPORT_SYMBOL(tty_hangup); | |
620 | ||
af9b897e AC |
621 | /** |
622 | * tty_vhangup - process vhangup | |
623 | * @tty: tty to hangup | |
624 | * | |
625 | * The user has asked via system call for the terminal to be hung up. | |
626 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 627 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
628 | */ |
629 | ||
37bdfb07 | 630 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
631 | { |
632 | #ifdef TTY_DEBUG_HANGUP | |
633 | char buf[64]; | |
634 | ||
635 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
636 | #endif | |
65f27f38 | 637 | do_tty_hangup(&tty->hangup_work); |
1da177e4 | 638 | } |
37bdfb07 | 639 | |
1da177e4 LT |
640 | EXPORT_SYMBOL(tty_vhangup); |
641 | ||
2cb5998b AC |
642 | /** |
643 | * tty_vhangup_self - process vhangup for own ctty | |
644 | * | |
645 | * Perform a vhangup on the current controlling tty | |
646 | */ | |
647 | ||
648 | void tty_vhangup_self(void) | |
649 | { | |
650 | struct tty_struct *tty; | |
651 | ||
2cb5998b AC |
652 | tty = get_current_tty(); |
653 | if (tty) { | |
654 | tty_vhangup(tty); | |
655 | tty_kref_put(tty); | |
656 | } | |
2cb5998b AC |
657 | } |
658 | ||
af9b897e AC |
659 | /** |
660 | * tty_hung_up_p - was tty hung up | |
661 | * @filp: file pointer of tty | |
662 | * | |
663 | * Return true if the tty has been subject to a vhangup or a carrier | |
664 | * loss | |
665 | */ | |
666 | ||
37bdfb07 | 667 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
668 | { |
669 | return (filp->f_op == &hung_up_tty_fops); | |
670 | } | |
671 | ||
672 | EXPORT_SYMBOL(tty_hung_up_p); | |
673 | ||
ab521dc0 | 674 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
675 | { |
676 | struct task_struct *p; | |
ab521dc0 | 677 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 678 | proc_clear_tty(p); |
ab521dc0 | 679 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
680 | } |
681 | ||
af9b897e AC |
682 | /** |
683 | * disassociate_ctty - disconnect controlling tty | |
684 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 685 | * |
af9b897e AC |
686 | * This function is typically called only by the session leader, when |
687 | * it wants to disassociate itself from its controlling tty. | |
688 | * | |
689 | * It performs the following functions: | |
1da177e4 LT |
690 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
691 | * (2) Clears the tty from being controlling the session | |
692 | * (3) Clears the controlling tty for all processes in the | |
693 | * session group. | |
694 | * | |
af9b897e AC |
695 | * The argument on_exit is set to 1 if called when a process is |
696 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
697 | * | |
24ec839c | 698 | * Locking: |
af9b897e | 699 | * BKL is taken for hysterical raisins |
24ec839c PZ |
700 | * tty_mutex is taken to protect tty |
701 | * ->siglock is taken to protect ->signal/->sighand | |
702 | * tasklist_lock is taken to walk process list for sessions | |
703 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 704 | */ |
af9b897e | 705 | |
1da177e4 LT |
706 | void disassociate_ctty(int on_exit) |
707 | { | |
708 | struct tty_struct *tty; | |
ab521dc0 | 709 | struct pid *tty_pgrp = NULL; |
1da177e4 | 710 | |
5ec93d11 AC |
711 | if (!current->signal->leader) |
712 | return; | |
1da177e4 | 713 | |
24ec839c | 714 | tty = get_current_tty(); |
1da177e4 | 715 | if (tty) { |
ab521dc0 | 716 | tty_pgrp = get_pid(tty->pgrp); |
452a00d2 | 717 | lock_kernel(); |
1da177e4 LT |
718 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
719 | tty_vhangup(tty); | |
04f378b1 | 720 | unlock_kernel(); |
452a00d2 | 721 | tty_kref_put(tty); |
680a9671 | 722 | } else if (on_exit) { |
ab521dc0 | 723 | struct pid *old_pgrp; |
680a9671 EB |
724 | spin_lock_irq(¤t->sighand->siglock); |
725 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 726 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 727 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 728 | if (old_pgrp) { |
ab521dc0 EB |
729 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
730 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
731 | put_pid(old_pgrp); | |
1da177e4 | 732 | } |
1da177e4 LT |
733 | return; |
734 | } | |
ab521dc0 EB |
735 | if (tty_pgrp) { |
736 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
1da177e4 | 737 | if (!on_exit) |
ab521dc0 EB |
738 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); |
739 | put_pid(tty_pgrp); | |
1da177e4 LT |
740 | } |
741 | ||
24ec839c | 742 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 743 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 744 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
745 | spin_unlock_irq(¤t->sighand->siglock); |
746 | ||
24ec839c PZ |
747 | tty = get_current_tty(); |
748 | if (tty) { | |
47f86834 AC |
749 | unsigned long flags; |
750 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
751 | put_pid(tty->session); |
752 | put_pid(tty->pgrp); | |
753 | tty->session = NULL; | |
754 | tty->pgrp = NULL; | |
47f86834 | 755 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 756 | tty_kref_put(tty); |
24ec839c PZ |
757 | } else { |
758 | #ifdef TTY_DEBUG_HANGUP | |
759 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
760 | " = NULL", tty); | |
761 | #endif | |
762 | } | |
1da177e4 LT |
763 | |
764 | /* Now clear signal->tty under the lock */ | |
765 | read_lock(&tasklist_lock); | |
ab521dc0 | 766 | session_clear_tty(task_session(current)); |
1da177e4 | 767 | read_unlock(&tasklist_lock); |
1da177e4 LT |
768 | } |
769 | ||
98a27ba4 EB |
770 | /** |
771 | * | |
772 | * no_tty - Ensure the current process does not have a controlling tty | |
773 | */ | |
774 | void no_tty(void) | |
775 | { | |
776 | struct task_struct *tsk = current; | |
04f378b1 | 777 | lock_kernel(); |
5ec93d11 | 778 | disassociate_ctty(0); |
04f378b1 | 779 | unlock_kernel(); |
98a27ba4 EB |
780 | proc_clear_tty(tsk); |
781 | } | |
782 | ||
af9b897e AC |
783 | |
784 | /** | |
beb7dd86 | 785 | * stop_tty - propagate flow control |
af9b897e AC |
786 | * @tty: tty to stop |
787 | * | |
788 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 789 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
790 | * on an already stopped device and will not re-call the driver |
791 | * method. | |
792 | * | |
793 | * This functionality is used by both the line disciplines for | |
794 | * halting incoming flow and by the driver. It may therefore be | |
795 | * called from any context, may be under the tty atomic_write_lock | |
796 | * but not always. | |
797 | * | |
798 | * Locking: | |
04f378b1 | 799 | * Uses the tty control lock internally |
af9b897e AC |
800 | */ |
801 | ||
1da177e4 LT |
802 | void stop_tty(struct tty_struct *tty) |
803 | { | |
04f378b1 AC |
804 | unsigned long flags; |
805 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
806 | if (tty->stopped) { | |
807 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 808 | return; |
04f378b1 | 809 | } |
1da177e4 LT |
810 | tty->stopped = 1; |
811 | if (tty->link && tty->link->packet) { | |
812 | tty->ctrl_status &= ~TIOCPKT_START; | |
813 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 814 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 815 | } |
04f378b1 | 816 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
817 | if (tty->ops->stop) |
818 | (tty->ops->stop)(tty); | |
1da177e4 LT |
819 | } |
820 | ||
821 | EXPORT_SYMBOL(stop_tty); | |
822 | ||
af9b897e | 823 | /** |
beb7dd86 | 824 | * start_tty - propagate flow control |
af9b897e AC |
825 | * @tty: tty to start |
826 | * | |
827 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 828 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
829 | * is the tty was previous stopped and is being started then the |
830 | * driver start method is invoked and the line discipline woken. | |
831 | * | |
832 | * Locking: | |
04f378b1 | 833 | * ctrl_lock |
af9b897e AC |
834 | */ |
835 | ||
1da177e4 LT |
836 | void start_tty(struct tty_struct *tty) |
837 | { | |
04f378b1 AC |
838 | unsigned long flags; |
839 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
840 | if (!tty->stopped || tty->flow_stopped) { | |
841 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 842 | return; |
04f378b1 | 843 | } |
1da177e4 LT |
844 | tty->stopped = 0; |
845 | if (tty->link && tty->link->packet) { | |
846 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
847 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 848 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 849 | } |
04f378b1 | 850 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
851 | if (tty->ops->start) |
852 | (tty->ops->start)(tty); | |
1da177e4 LT |
853 | /* If we have a running line discipline it may need kicking */ |
854 | tty_wakeup(tty); | |
1da177e4 LT |
855 | } |
856 | ||
857 | EXPORT_SYMBOL(start_tty); | |
858 | ||
af9b897e AC |
859 | /** |
860 | * tty_read - read method for tty device files | |
861 | * @file: pointer to tty file | |
862 | * @buf: user buffer | |
863 | * @count: size of user buffer | |
864 | * @ppos: unused | |
865 | * | |
866 | * Perform the read system call function on this terminal device. Checks | |
867 | * for hung up devices before calling the line discipline method. | |
868 | * | |
869 | * Locking: | |
47f86834 AC |
870 | * Locks the line discipline internally while needed. Multiple |
871 | * read calls may be outstanding in parallel. | |
af9b897e AC |
872 | */ |
873 | ||
37bdfb07 | 874 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
875 | loff_t *ppos) |
876 | { | |
877 | int i; | |
37bdfb07 | 878 | struct tty_struct *tty; |
1da177e4 LT |
879 | struct inode *inode; |
880 | struct tty_ldisc *ld; | |
881 | ||
882 | tty = (struct tty_struct *)file->private_data; | |
a7113a96 | 883 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
884 | if (tty_paranoia_check(tty, inode, "tty_read")) |
885 | return -EIO; | |
886 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
887 | return -EIO; | |
888 | ||
889 | /* We want to wait for the line discipline to sort out in this | |
890 | situation */ | |
891 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
892 | if (ld->ops->read) |
893 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
894 | else |
895 | i = -EIO; | |
896 | tty_ldisc_deref(ld); | |
1da177e4 LT |
897 | if (i > 0) |
898 | inode->i_atime = current_fs_time(inode->i_sb); | |
899 | return i; | |
900 | } | |
901 | ||
9c1729db AC |
902 | void tty_write_unlock(struct tty_struct *tty) |
903 | { | |
904 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 905 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
906 | } |
907 | ||
908 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
909 | { | |
910 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
911 | if (ndelay) | |
912 | return -EAGAIN; | |
913 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
914 | return -ERESTARTSYS; | |
915 | } | |
916 | return 0; | |
917 | } | |
918 | ||
1da177e4 LT |
919 | /* |
920 | * Split writes up in sane blocksizes to avoid | |
921 | * denial-of-service type attacks | |
922 | */ | |
923 | static inline ssize_t do_tty_write( | |
924 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
925 | struct tty_struct *tty, | |
926 | struct file *file, | |
927 | const char __user *buf, | |
928 | size_t count) | |
929 | { | |
9c1729db | 930 | ssize_t ret, written = 0; |
1da177e4 | 931 | unsigned int chunk; |
37bdfb07 | 932 | |
9c1729db AC |
933 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
934 | if (ret < 0) | |
935 | return ret; | |
1da177e4 LT |
936 | |
937 | /* | |
938 | * We chunk up writes into a temporary buffer. This | |
939 | * simplifies low-level drivers immensely, since they | |
940 | * don't have locking issues and user mode accesses. | |
941 | * | |
942 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
943 | * big chunk-size.. | |
944 | * | |
945 | * The default chunk-size is 2kB, because the NTTY | |
946 | * layer has problems with bigger chunks. It will | |
947 | * claim to be able to handle more characters than | |
948 | * it actually does. | |
af9b897e AC |
949 | * |
950 | * FIXME: This can probably go away now except that 64K chunks | |
951 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
952 | */ |
953 | chunk = 2048; | |
954 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
955 | chunk = 65536; | |
956 | if (count < chunk) | |
957 | chunk = count; | |
958 | ||
70522e12 | 959 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 960 | if (tty->write_cnt < chunk) { |
402fda92 | 961 | unsigned char *buf_chunk; |
1da177e4 LT |
962 | |
963 | if (chunk < 1024) | |
964 | chunk = 1024; | |
965 | ||
402fda92 JW |
966 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
967 | if (!buf_chunk) { | |
9c1729db AC |
968 | ret = -ENOMEM; |
969 | goto out; | |
1da177e4 LT |
970 | } |
971 | kfree(tty->write_buf); | |
972 | tty->write_cnt = chunk; | |
402fda92 | 973 | tty->write_buf = buf_chunk; |
1da177e4 LT |
974 | } |
975 | ||
976 | /* Do the write .. */ | |
977 | for (;;) { | |
978 | size_t size = count; | |
979 | if (size > chunk) | |
980 | size = chunk; | |
981 | ret = -EFAULT; | |
982 | if (copy_from_user(tty->write_buf, buf, size)) | |
983 | break; | |
1da177e4 | 984 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
985 | if (ret <= 0) |
986 | break; | |
987 | written += ret; | |
988 | buf += ret; | |
989 | count -= ret; | |
990 | if (!count) | |
991 | break; | |
992 | ret = -ERESTARTSYS; | |
993 | if (signal_pending(current)) | |
994 | break; | |
995 | cond_resched(); | |
996 | } | |
997 | if (written) { | |
a7113a96 | 998 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
999 | inode->i_mtime = current_fs_time(inode->i_sb); |
1000 | ret = written; | |
1001 | } | |
9c1729db AC |
1002 | out: |
1003 | tty_write_unlock(tty); | |
1da177e4 LT |
1004 | return ret; |
1005 | } | |
1006 | ||
95f9bfc6 AC |
1007 | /** |
1008 | * tty_write_message - write a message to a certain tty, not just the console. | |
1009 | * @tty: the destination tty_struct | |
1010 | * @msg: the message to write | |
1011 | * | |
1012 | * This is used for messages that need to be redirected to a specific tty. | |
1013 | * We don't put it into the syslog queue right now maybe in the future if | |
1014 | * really needed. | |
1015 | * | |
1016 | * We must still hold the BKL and test the CLOSING flag for the moment. | |
1017 | */ | |
1018 | ||
1019 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1020 | { | |
95f9bfc6 AC |
1021 | if (tty) { |
1022 | mutex_lock(&tty->atomic_write_lock); | |
eeb89d91 AC |
1023 | lock_kernel(); |
1024 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { | |
1025 | unlock_kernel(); | |
95f9bfc6 | 1026 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 AC |
1027 | } else |
1028 | unlock_kernel(); | |
95f9bfc6 AC |
1029 | tty_write_unlock(tty); |
1030 | } | |
95f9bfc6 AC |
1031 | return; |
1032 | } | |
1033 | ||
1da177e4 | 1034 | |
af9b897e AC |
1035 | /** |
1036 | * tty_write - write method for tty device file | |
1037 | * @file: tty file pointer | |
1038 | * @buf: user data to write | |
1039 | * @count: bytes to write | |
1040 | * @ppos: unused | |
1041 | * | |
1042 | * Write data to a tty device via the line discipline. | |
1043 | * | |
1044 | * Locking: | |
1045 | * Locks the line discipline as required | |
1046 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1047 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1048 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1049 | */ |
1050 | ||
37bdfb07 AC |
1051 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1052 | size_t count, loff_t *ppos) | |
1da177e4 | 1053 | { |
37bdfb07 | 1054 | struct tty_struct *tty; |
a7113a96 | 1055 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1056 | ssize_t ret; |
1057 | struct tty_ldisc *ld; | |
37bdfb07 | 1058 | |
1da177e4 LT |
1059 | tty = (struct tty_struct *)file->private_data; |
1060 | if (tty_paranoia_check(tty, inode, "tty_write")) | |
1061 | return -EIO; | |
f34d7a5b | 1062 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1063 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1064 | return -EIO; | |
f34d7a5b AC |
1065 | /* Short term debug to catch buggy drivers */ |
1066 | if (tty->ops->write_room == NULL) | |
1067 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1068 | tty->driver->name); | |
37bdfb07 | 1069 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1070 | if (!ld->ops->write) |
1da177e4 LT |
1071 | ret = -EIO; |
1072 | else | |
a352def2 | 1073 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1074 | tty_ldisc_deref(ld); |
1075 | return ret; | |
1076 | } | |
1077 | ||
37bdfb07 AC |
1078 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1079 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1080 | { |
1081 | struct file *p = NULL; | |
1082 | ||
1083 | spin_lock(&redirect_lock); | |
1084 | if (redirect) { | |
1085 | get_file(redirect); | |
1086 | p = redirect; | |
1087 | } | |
1088 | spin_unlock(&redirect_lock); | |
1089 | ||
1090 | if (p) { | |
1091 | ssize_t res; | |
1092 | res = vfs_write(p, buf, count, &p->f_pos); | |
1093 | fput(p); | |
1094 | return res; | |
1095 | } | |
1da177e4 LT |
1096 | return tty_write(file, buf, count, ppos); |
1097 | } | |
1098 | ||
1099 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1100 | ||
af9b897e AC |
1101 | /** |
1102 | * pty_line_name - generate name for a pty | |
1103 | * @driver: the tty driver in use | |
1104 | * @index: the minor number | |
1105 | * @p: output buffer of at least 6 bytes | |
1106 | * | |
1107 | * Generate a name from a driver reference and write it to the output | |
1108 | * buffer. | |
1109 | * | |
1110 | * Locking: None | |
1111 | */ | |
1112 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1113 | { |
1114 | int i = index + driver->name_base; | |
1115 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1116 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1117 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1118 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1119 | } |
1120 | ||
af9b897e | 1121 | /** |
8b0a88d5 | 1122 | * tty_line_name - generate name for a tty |
af9b897e AC |
1123 | * @driver: the tty driver in use |
1124 | * @index: the minor number | |
1125 | * @p: output buffer of at least 7 bytes | |
1126 | * | |
1127 | * Generate a name from a driver reference and write it to the output | |
1128 | * buffer. | |
1129 | * | |
1130 | * Locking: None | |
1131 | */ | |
1132 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1133 | { |
1134 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1135 | } | |
1136 | ||
99f1fe18 AC |
1137 | /** |
1138 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1139 | * @driver: the driver for the tty | |
1140 | * @idx: the minor number | |
23499705 | 1141 | * |
99f1fe18 | 1142 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1143 | * |
99f1fe18 AC |
1144 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1145 | * be held until the 'fast-open' is also done. Will change once we | |
1146 | * have refcounting in the driver and per driver locking | |
23499705 | 1147 | */ |
a47d545f | 1148 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1149 | struct inode *inode, int idx) |
23499705 SB |
1150 | { |
1151 | struct tty_struct *tty; | |
1152 | ||
99f1fe18 | 1153 | if (driver->ops->lookup) |
15f1a633 | 1154 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1155 | |
8b0a88d5 | 1156 | tty = driver->ttys[idx]; |
23499705 SB |
1157 | return tty; |
1158 | } | |
1159 | ||
bf970ee4 AC |
1160 | /** |
1161 | * tty_init_termios - helper for termios setup | |
1162 | * @tty: the tty to set up | |
1163 | * | |
1164 | * Initialise the termios structures for this tty. Thus runs under | |
1165 | * the tty_mutex currently so we can be relaxed about ordering. | |
1166 | */ | |
1167 | ||
1168 | int tty_init_termios(struct tty_struct *tty) | |
1169 | { | |
fe6e29fd | 1170 | struct ktermios *tp; |
bf970ee4 AC |
1171 | int idx = tty->index; |
1172 | ||
1173 | tp = tty->driver->termios[idx]; | |
bf970ee4 | 1174 | if (tp == NULL) { |
fe6e29fd AC |
1175 | tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
1176 | if (tp == NULL) | |
bf970ee4 | 1177 | return -ENOMEM; |
bf970ee4 AC |
1178 | memcpy(tp, &tty->driver->init_termios, |
1179 | sizeof(struct ktermios)); | |
1180 | tty->driver->termios[idx] = tp; | |
bf970ee4 AC |
1181 | } |
1182 | tty->termios = tp; | |
fe6e29fd | 1183 | tty->termios_locked = tp + 1; |
bf970ee4 AC |
1184 | |
1185 | /* Compatibility until drivers always set this */ | |
1186 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1187 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1188 | return 0; | |
1189 | } | |
fe1ae7fd | 1190 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1191 | |
99f1fe18 | 1192 | /** |
8b0a88d5 AC |
1193 | * tty_driver_install_tty() - install a tty entry in the driver |
1194 | * @driver: the driver for the tty | |
1195 | * @tty: the tty | |
1196 | * | |
1197 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1198 | * will be set by the time this is called. This method is responsible |
1199 | * for ensuring any need additional structures are allocated and | |
1200 | * configured. | |
8b0a88d5 AC |
1201 | * |
1202 | * Locking: tty_mutex for now | |
1203 | */ | |
1204 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1205 | struct tty_struct *tty) | |
1206 | { | |
bf970ee4 | 1207 | int idx = tty->index; |
eeb89d91 | 1208 | int ret; |
bf970ee4 | 1209 | |
eeb89d91 AC |
1210 | if (driver->ops->install) { |
1211 | lock_kernel(); | |
1212 | ret = driver->ops->install(driver, tty); | |
1213 | unlock_kernel(); | |
1214 | return ret; | |
1215 | } | |
bf970ee4 AC |
1216 | |
1217 | if (tty_init_termios(tty) == 0) { | |
eeb89d91 | 1218 | lock_kernel(); |
bf970ee4 AC |
1219 | tty_driver_kref_get(driver); |
1220 | tty->count++; | |
1221 | driver->ttys[idx] = tty; | |
eeb89d91 | 1222 | unlock_kernel(); |
bf970ee4 AC |
1223 | return 0; |
1224 | } | |
1225 | return -ENOMEM; | |
8b0a88d5 AC |
1226 | } |
1227 | ||
1228 | /** | |
1229 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1230 | * @driver: the driver for the tty | |
1231 | * @idx: the minor number | |
1232 | * | |
1233 | * Remvoe a tty object from the driver tables. The tty->index field | |
1234 | * will be set by the time this is called. | |
1235 | * | |
1236 | * Locking: tty_mutex for now | |
1237 | */ | |
1238 | static void tty_driver_remove_tty(struct tty_driver *driver, | |
1239 | struct tty_struct *tty) | |
1240 | { | |
1241 | if (driver->ops->remove) | |
1242 | driver->ops->remove(driver, tty); | |
1243 | else | |
1244 | driver->ttys[tty->index] = NULL; | |
1245 | } | |
1246 | ||
1247 | /* | |
1248 | * tty_reopen() - fast re-open of an open tty | |
1249 | * @tty - the tty to open | |
23499705 | 1250 | * |
99f1fe18 | 1251 | * Return 0 on success, -errno on error. |
23499705 | 1252 | * |
99f1fe18 AC |
1253 | * Locking: tty_mutex must be held from the time the tty was found |
1254 | * till this open completes. | |
23499705 | 1255 | */ |
99f1fe18 | 1256 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1257 | { |
1258 | struct tty_driver *driver = tty->driver; | |
1259 | ||
1260 | if (test_bit(TTY_CLOSING, &tty->flags)) | |
1261 | return -EIO; | |
1262 | ||
1263 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1264 | driver->subtype == PTY_TYPE_MASTER) { | |
1265 | /* | |
1266 | * special case for PTY masters: only one open permitted, | |
1267 | * and the slave side open count is incremented as well. | |
1268 | */ | |
1269 | if (tty->count) | |
1270 | return -EIO; | |
1271 | ||
1272 | tty->link->count++; | |
1273 | } | |
1274 | tty->count++; | |
1275 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1276 | ||
1aa4bed8 | 1277 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1278 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1279 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1280 | |
1281 | return 0; | |
1282 | } | |
1283 | ||
af9b897e | 1284 | /** |
d81ed103 | 1285 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1286 | * @driver: tty driver we are opening a device on |
1287 | * @idx: device index | |
15582d36 AC |
1288 | * @ret_tty: returned tty structure |
1289 | * @first_ok: ok to open a new device (used by ptmx) | |
af9b897e AC |
1290 | * |
1291 | * Prepare a tty device. This may not be a "new" clean device but | |
1292 | * could also be an active device. The pty drivers require special | |
1293 | * handling because of this. | |
1294 | * | |
1295 | * Locking: | |
1296 | * The function is called under the tty_mutex, which | |
1297 | * protects us from the tty struct or driver itself going away. | |
1298 | * | |
1299 | * On exit the tty device has the line discipline attached and | |
1300 | * a reference count of 1. If a pair was created for pty/tty use | |
1301 | * and the other was a pty master then it too has a reference count of 1. | |
1302 | * | |
1da177e4 | 1303 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1304 | * failed open. The new code protects the open with a mutex, so it's |
1305 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1306 | * relaxed for the (most common) case of reopening a tty. |
1307 | */ | |
af9b897e | 1308 | |
73ec06fc AC |
1309 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, |
1310 | int first_ok) | |
1da177e4 | 1311 | { |
bf970ee4 | 1312 | struct tty_struct *tty; |
73ec06fc | 1313 | int retval; |
1da177e4 | 1314 | |
eeb89d91 | 1315 | lock_kernel(); |
23499705 | 1316 | /* Check if pty master is being opened multiple times */ |
15582d36 | 1317 | if (driver->subtype == PTY_TYPE_MASTER && |
eeb89d91 AC |
1318 | (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { |
1319 | unlock_kernel(); | |
73ec06fc | 1320 | return ERR_PTR(-EIO); |
eeb89d91 AC |
1321 | } |
1322 | unlock_kernel(); | |
73ec06fc | 1323 | |
1da177e4 LT |
1324 | /* |
1325 | * First time open is complex, especially for PTY devices. | |
1326 | * This code guarantees that either everything succeeds and the | |
1327 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1328 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1329 | * and locked termios may be retained.) |
1330 | */ | |
1331 | ||
73ec06fc AC |
1332 | if (!try_module_get(driver->owner)) |
1333 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1334 | |
1da177e4 | 1335 | tty = alloc_tty_struct(); |
37bdfb07 | 1336 | if (!tty) |
1da177e4 | 1337 | goto fail_no_mem; |
bf970ee4 | 1338 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1339 | |
73ec06fc | 1340 | retval = tty_driver_install_tty(driver, tty); |
bf970ee4 AC |
1341 | if (retval < 0) { |
1342 | free_tty_struct(tty); | |
1343 | module_put(driver->owner); | |
1344 | return ERR_PTR(retval); | |
1345 | } | |
8b0a88d5 | 1346 | |
37bdfb07 | 1347 | /* |
1da177e4 | 1348 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1349 | * If we fail here just call release_tty to clean up. No need |
1350 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1351 | */ |
bf970ee4 | 1352 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 AC |
1353 | if (retval) |
1354 | goto release_mem_out; | |
73ec06fc | 1355 | return tty; |
1da177e4 | 1356 | |
1da177e4 LT |
1357 | fail_no_mem: |
1358 | module_put(driver->owner); | |
73ec06fc | 1359 | return ERR_PTR(-ENOMEM); |
1da177e4 | 1360 | |
d5698c28 | 1361 | /* call the tty release_tty routine to clean out this slot */ |
1da177e4 | 1362 | release_mem_out: |
4050914f | 1363 | if (printk_ratelimit()) |
d81ed103 | 1364 | printk(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1365 | "clearing slot %d\n", idx); |
eeb89d91 | 1366 | lock_kernel(); |
d5698c28 | 1367 | release_tty(tty, idx); |
eeb89d91 | 1368 | unlock_kernel(); |
73ec06fc | 1369 | return ERR_PTR(retval); |
1da177e4 LT |
1370 | } |
1371 | ||
feebed65 AC |
1372 | void tty_free_termios(struct tty_struct *tty) |
1373 | { | |
1374 | struct ktermios *tp; | |
1375 | int idx = tty->index; | |
1376 | /* Kill this flag and push into drivers for locking etc */ | |
1377 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1378 | /* FIXME: Locking on ->termios array */ | |
1379 | tp = tty->termios; | |
1380 | tty->driver->termios[idx] = NULL; | |
1381 | kfree(tp); | |
feebed65 AC |
1382 | } |
1383 | } | |
1384 | EXPORT_SYMBOL(tty_free_termios); | |
1385 | ||
1386 | void tty_shutdown(struct tty_struct *tty) | |
1387 | { | |
8b0a88d5 | 1388 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1389 | tty_free_termios(tty); |
1390 | } | |
1391 | EXPORT_SYMBOL(tty_shutdown); | |
1392 | ||
af9b897e | 1393 | /** |
d5698c28 | 1394 | * release_one_tty - release tty structure memory |
9c9f4ded | 1395 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1396 | * |
1397 | * Releases memory associated with a tty structure, and clears out the | |
1398 | * driver table slots. This function is called when a device is no longer | |
1399 | * in use. It also gets called when setup of a device fails. | |
1400 | * | |
1401 | * Locking: | |
1402 | * tty_mutex - sometimes only | |
1403 | * takes the file list lock internally when working on the list | |
1404 | * of ttys that the driver keeps. | |
b50989dc AC |
1405 | * |
1406 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1407 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1408 | */ |
b50989dc | 1409 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1410 | { |
b50989dc AC |
1411 | struct tty_struct *tty = |
1412 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1413 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1414 | |
f278a2f7 DY |
1415 | if (tty->ops->cleanup) |
1416 | tty->ops->cleanup(tty); | |
1417 | ||
1da177e4 | 1418 | tty->magic = 0; |
7d7b93c1 | 1419 | tty_driver_kref_put(driver); |
6f967f78 | 1420 | module_put(driver->owner); |
d5698c28 | 1421 | |
1da177e4 LT |
1422 | file_list_lock(); |
1423 | list_del_init(&tty->tty_files); | |
1424 | file_list_unlock(); | |
d5698c28 | 1425 | |
1da177e4 LT |
1426 | free_tty_struct(tty); |
1427 | } | |
1428 | ||
b50989dc AC |
1429 | static void queue_release_one_tty(struct kref *kref) |
1430 | { | |
1431 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 DY |
1432 | |
1433 | if (tty->ops->shutdown) | |
1434 | tty->ops->shutdown(tty); | |
1435 | else | |
1436 | tty_shutdown(tty); | |
1437 | ||
b50989dc AC |
1438 | /* The hangup queue is now free so we can reuse it rather than |
1439 | waste a chunk of memory for each port */ | |
1440 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1441 | schedule_work(&tty->hangup_work); | |
1442 | } | |
1443 | ||
9c9f4ded AC |
1444 | /** |
1445 | * tty_kref_put - release a tty kref | |
1446 | * @tty: tty device | |
1447 | * | |
1448 | * Release a reference to a tty device and if need be let the kref | |
1449 | * layer destruct the object for us | |
1450 | */ | |
1451 | ||
1452 | void tty_kref_put(struct tty_struct *tty) | |
1453 | { | |
1454 | if (tty) | |
b50989dc | 1455 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1456 | } |
1457 | EXPORT_SYMBOL(tty_kref_put); | |
1458 | ||
d5698c28 CH |
1459 | /** |
1460 | * release_tty - release tty structure memory | |
1461 | * | |
1462 | * Release both @tty and a possible linked partner (think pty pair), | |
1463 | * and decrement the refcount of the backing module. | |
1464 | * | |
1465 | * Locking: | |
1466 | * tty_mutex - sometimes only | |
1467 | * takes the file list lock internally when working on the list | |
1468 | * of ttys that the driver keeps. | |
1469 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1470 | * |
d5698c28 CH |
1471 | */ |
1472 | static void release_tty(struct tty_struct *tty, int idx) | |
1473 | { | |
9c9f4ded AC |
1474 | /* This should always be true but check for the moment */ |
1475 | WARN_ON(tty->index != idx); | |
1476 | ||
d5698c28 | 1477 | if (tty->link) |
9c9f4ded AC |
1478 | tty_kref_put(tty->link); |
1479 | tty_kref_put(tty); | |
d5698c28 CH |
1480 | } |
1481 | ||
eeb89d91 AC |
1482 | /** |
1483 | * tty_release - vfs callback for close | |
1484 | * @inode: inode of tty | |
1485 | * @filp: file pointer for handle to tty | |
1486 | * | |
1487 | * Called the last time each file handle is closed that references | |
1488 | * this tty. There may however be several such references. | |
1489 | * | |
1490 | * Locking: | |
1491 | * Takes bkl. See tty_release_dev | |
1492 | * | |
1da177e4 LT |
1493 | * Even releasing the tty structures is a tricky business.. We have |
1494 | * to be very careful that the structures are all released at the | |
1495 | * same time, as interrupts might otherwise get the wrong pointers. | |
1496 | * | |
1497 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1498 | * lead to double frees or releasing memory still in use. | |
1499 | */ | |
eeb89d91 AC |
1500 | |
1501 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 LT |
1502 | { |
1503 | struct tty_struct *tty, *o_tty; | |
1504 | int pty_master, tty_closing, o_tty_closing, do_sleep; | |
14a6283e | 1505 | int devpts; |
1da177e4 LT |
1506 | int idx; |
1507 | char buf[64]; | |
37bdfb07 | 1508 | |
1da177e4 | 1509 | tty = (struct tty_struct *)filp->private_data; |
15f1a633 | 1510 | if (tty_paranoia_check(tty, inode, "tty_release_dev")) |
eeb89d91 | 1511 | return 0; |
1da177e4 | 1512 | |
eeb89d91 | 1513 | lock_kernel(); |
d81ed103 | 1514 | check_tty_count(tty, "tty_release_dev"); |
1da177e4 LT |
1515 | |
1516 | tty_fasync(-1, filp, 0); | |
1517 | ||
1518 | idx = tty->index; | |
1519 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1520 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1521 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1522 | o_tty = tty->link; |
1523 | ||
1524 | #ifdef TTY_PARANOIA_CHECK | |
1525 | if (idx < 0 || idx >= tty->driver->num) { | |
d81ed103 | 1526 | printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " |
1da177e4 | 1527 | "free (%s)\n", tty->name); |
eeb89d91 AC |
1528 | unlock_kernel(); |
1529 | return 0; | |
1da177e4 | 1530 | } |
8b0a88d5 | 1531 | if (!devpts) { |
1da177e4 | 1532 | if (tty != tty->driver->ttys[idx]) { |
eeb89d91 | 1533 | unlock_kernel(); |
d81ed103 | 1534 | printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " |
1da177e4 | 1535 | "for (%s)\n", idx, tty->name); |
eeb89d91 | 1536 | return 0; |
1da177e4 LT |
1537 | } |
1538 | if (tty->termios != tty->driver->termios[idx]) { | |
eeb89d91 | 1539 | unlock_kernel(); |
d81ed103 | 1540 | printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " |
1da177e4 LT |
1541 | "for (%s)\n", |
1542 | idx, tty->name); | |
eeb89d91 | 1543 | return 0; |
1da177e4 | 1544 | } |
1da177e4 LT |
1545 | } |
1546 | #endif | |
1547 | ||
1548 | #ifdef TTY_DEBUG_HANGUP | |
d81ed103 | 1549 | printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", |
1da177e4 LT |
1550 | tty_name(tty, buf), tty->count); |
1551 | #endif | |
1552 | ||
1553 | #ifdef TTY_PARANOIA_CHECK | |
1554 | if (tty->driver->other && | |
1555 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1556 | if (o_tty != tty->driver->other->ttys[idx]) { | |
eeb89d91 | 1557 | unlock_kernel(); |
d81ed103 | 1558 | printk(KERN_DEBUG "tty_release_dev: other->table[%d] " |
1da177e4 LT |
1559 | "not o_tty for (%s)\n", |
1560 | idx, tty->name); | |
eeb89d91 | 1561 | return 0 ; |
1da177e4 LT |
1562 | } |
1563 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
eeb89d91 | 1564 | unlock_kernel(); |
d81ed103 | 1565 | printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " |
1da177e4 LT |
1566 | "not o_termios for (%s)\n", |
1567 | idx, tty->name); | |
eeb89d91 | 1568 | return 0; |
1da177e4 | 1569 | } |
1da177e4 | 1570 | if (o_tty->link != tty) { |
eeb89d91 | 1571 | unlock_kernel(); |
d81ed103 | 1572 | printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); |
eeb89d91 | 1573 | return 0; |
1da177e4 LT |
1574 | } |
1575 | } | |
1576 | #endif | |
f34d7a5b AC |
1577 | if (tty->ops->close) |
1578 | tty->ops->close(tty, filp); | |
1da177e4 | 1579 | |
eeb89d91 | 1580 | unlock_kernel(); |
1da177e4 LT |
1581 | /* |
1582 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1583 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1584 | * wait queues and kick everyone out _before_ actually starting to | |
1585 | * close. This ensures that we won't block while releasing the tty | |
1586 | * structure. | |
1587 | * | |
1588 | * The test for the o_tty closing is necessary, since the master and | |
1589 | * slave sides may close in any order. If the slave side closes out | |
1590 | * first, its count will be one, since the master side holds an open. | |
1591 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1592 | * so we do it now. | |
1593 | * | |
1594 | * Note that it's possible for the tty to be opened again while we're | |
1595 | * flushing out waiters. By recalculating the closing flags before | |
1596 | * each iteration we avoid any problems. | |
1597 | */ | |
1598 | while (1) { | |
1599 | /* Guard against races with tty->count changes elsewhere and | |
1600 | opens on /dev/tty */ | |
37bdfb07 | 1601 | |
70522e12 | 1602 | mutex_lock(&tty_mutex); |
eeb89d91 | 1603 | lock_kernel(); |
1da177e4 LT |
1604 | tty_closing = tty->count <= 1; |
1605 | o_tty_closing = o_tty && | |
1606 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1607 | do_sleep = 0; |
1608 | ||
1609 | if (tty_closing) { | |
1610 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1611 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1612 | do_sleep++; |
1613 | } | |
1614 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1615 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1616 | do_sleep++; |
1617 | } | |
1618 | } | |
1619 | if (o_tty_closing) { | |
1620 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1621 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1622 | do_sleep++; |
1623 | } | |
1624 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1625 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1626 | do_sleep++; |
1627 | } | |
1628 | } | |
1629 | if (!do_sleep) | |
1630 | break; | |
1631 | ||
d81ed103 | 1632 | printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " |
1da177e4 | 1633 | "active!\n", tty_name(tty, buf)); |
eeb89d91 | 1634 | unlock_kernel(); |
70522e12 | 1635 | mutex_unlock(&tty_mutex); |
1da177e4 | 1636 | schedule(); |
37bdfb07 | 1637 | } |
1da177e4 LT |
1638 | |
1639 | /* | |
37bdfb07 AC |
1640 | * The closing flags are now consistent with the open counts on |
1641 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1642 | * block, so it's safe to proceed with closing. |
1643 | */ | |
1da177e4 LT |
1644 | if (pty_master) { |
1645 | if (--o_tty->count < 0) { | |
d81ed103 | 1646 | printk(KERN_WARNING "tty_release_dev: bad pty slave count " |
1da177e4 LT |
1647 | "(%d) for %s\n", |
1648 | o_tty->count, tty_name(o_tty, buf)); | |
1649 | o_tty->count = 0; | |
1650 | } | |
1651 | } | |
1652 | if (--tty->count < 0) { | |
d81ed103 | 1653 | printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", |
1da177e4 LT |
1654 | tty->count, tty_name(tty, buf)); |
1655 | tty->count = 0; | |
1656 | } | |
37bdfb07 | 1657 | |
1da177e4 LT |
1658 | /* |
1659 | * We've decremented tty->count, so we need to remove this file | |
1660 | * descriptor off the tty->tty_files list; this serves two | |
1661 | * purposes: | |
1662 | * - check_tty_count sees the correct number of file descriptors | |
1663 | * associated with this tty. | |
1664 | * - do_tty_hangup no longer sees this file descriptor as | |
1665 | * something that needs to be handled for hangups. | |
1666 | */ | |
1667 | file_kill(filp); | |
1668 | filp->private_data = NULL; | |
1669 | ||
1670 | /* | |
1671 | * Perform some housekeeping before deciding whether to return. | |
1672 | * | |
1673 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1674 | * case of a pty we may have to wait around for the other side | |
1675 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1676 | */ | |
37bdfb07 | 1677 | if (tty_closing) |
1da177e4 | 1678 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1679 | if (o_tty_closing) |
1da177e4 LT |
1680 | set_bit(TTY_CLOSING, &o_tty->flags); |
1681 | ||
1682 | /* | |
1683 | * If _either_ side is closing, make sure there aren't any | |
1684 | * processes that still think tty or o_tty is their controlling | |
1685 | * tty. | |
1686 | */ | |
1687 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1688 | read_lock(&tasklist_lock); |
24ec839c | 1689 | session_clear_tty(tty->session); |
1da177e4 | 1690 | if (o_tty) |
24ec839c | 1691 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1692 | read_unlock(&tasklist_lock); |
1693 | } | |
1694 | ||
70522e12 | 1695 | mutex_unlock(&tty_mutex); |
da965822 | 1696 | |
1da177e4 | 1697 | /* check whether both sides are closing ... */ |
eeb89d91 AC |
1698 | if (!tty_closing || (o_tty && !o_tty_closing)) { |
1699 | unlock_kernel(); | |
1700 | return 0; | |
1701 | } | |
37bdfb07 | 1702 | |
1da177e4 LT |
1703 | #ifdef TTY_DEBUG_HANGUP |
1704 | printk(KERN_DEBUG "freeing tty structure..."); | |
1705 | #endif | |
1706 | /* | |
01e1abb2 | 1707 | * Ask the line discipline code to release its structures |
1da177e4 | 1708 | */ |
01e1abb2 | 1709 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1710 | /* |
d5698c28 | 1711 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1712 | * the slots and preserving the termios structure. |
1713 | */ | |
d5698c28 | 1714 | release_tty(tty, idx); |
1da177e4 | 1715 | |
1da177e4 | 1716 | /* Make this pty number available for reallocation */ |
718a9163 | 1717 | if (devpts) |
15f1a633 | 1718 | devpts_kill_index(inode, idx); |
eeb89d91 AC |
1719 | unlock_kernel(); |
1720 | return 0; | |
1da177e4 LT |
1721 | } |
1722 | ||
af9b897e | 1723 | /** |
eeb89d91 | 1724 | * tty_open - open a tty device |
af9b897e AC |
1725 | * @inode: inode of device file |
1726 | * @filp: file pointer to tty | |
1da177e4 | 1727 | * |
af9b897e AC |
1728 | * tty_open and tty_release keep up the tty count that contains the |
1729 | * number of opens done on a tty. We cannot use the inode-count, as | |
1730 | * different inodes might point to the same tty. | |
1da177e4 | 1731 | * |
af9b897e AC |
1732 | * Open-counting is needed for pty masters, as well as for keeping |
1733 | * track of serial lines: DTR is dropped when the last close happens. | |
1734 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1735 | * | |
1736 | * The termios state of a pty is reset on first open so that | |
1737 | * settings don't persist across reuse. | |
1738 | * | |
d81ed103 | 1739 | * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. |
24ec839c PZ |
1740 | * tty->count should protect the rest. |
1741 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1742 | */ |
af9b897e | 1743 | |
eeb89d91 | 1744 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1745 | { |
4a2b5fdd | 1746 | struct tty_struct *tty = NULL; |
1da177e4 LT |
1747 | int noctty, retval; |
1748 | struct tty_driver *driver; | |
1749 | int index; | |
1750 | dev_t device = inode->i_rdev; | |
846c151a | 1751 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1752 | |
1753 | nonseekable_open(inode, filp); | |
37bdfb07 | 1754 | |
1da177e4 LT |
1755 | retry_open: |
1756 | noctty = filp->f_flags & O_NOCTTY; | |
1757 | index = -1; | |
1758 | retval = 0; | |
37bdfb07 | 1759 | |
70522e12 | 1760 | mutex_lock(&tty_mutex); |
eeb89d91 | 1761 | lock_kernel(); |
1da177e4 | 1762 | |
37bdfb07 | 1763 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1764 | tty = get_current_tty(); |
1765 | if (!tty) { | |
eeb89d91 | 1766 | unlock_kernel(); |
70522e12 | 1767 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1768 | return -ENXIO; |
1769 | } | |
7d7b93c1 | 1770 | driver = tty_driver_kref_get(tty->driver); |
24ec839c | 1771 | index = tty->index; |
1da177e4 LT |
1772 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1773 | /* noctty = 1; */ | |
452a00d2 AC |
1774 | /* FIXME: Should we take a driver reference ? */ |
1775 | tty_kref_put(tty); | |
1da177e4 LT |
1776 | goto got_driver; |
1777 | } | |
1778 | #ifdef CONFIG_VT | |
37bdfb07 | 1779 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 | 1780 | extern struct tty_driver *console_driver; |
7d7b93c1 | 1781 | driver = tty_driver_kref_get(console_driver); |
1da177e4 LT |
1782 | index = fg_console; |
1783 | noctty = 1; | |
1784 | goto got_driver; | |
1785 | } | |
1786 | #endif | |
37bdfb07 | 1787 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
296fa7f6 WN |
1788 | struct tty_driver *console_driver = console_device(&index); |
1789 | if (console_driver) { | |
1790 | driver = tty_driver_kref_get(console_driver); | |
1791 | if (driver) { | |
1792 | /* Don't let /dev/console block */ | |
1793 | filp->f_flags |= O_NONBLOCK; | |
1794 | noctty = 1; | |
1795 | goto got_driver; | |
1796 | } | |
1da177e4 | 1797 | } |
eeb89d91 | 1798 | unlock_kernel(); |
70522e12 | 1799 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1800 | return -ENODEV; |
1801 | } | |
1802 | ||
1803 | driver = get_tty_driver(device, &index); | |
1804 | if (!driver) { | |
eeb89d91 | 1805 | unlock_kernel(); |
70522e12 | 1806 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1807 | return -ENODEV; |
1808 | } | |
1809 | got_driver: | |
4a2b5fdd SB |
1810 | if (!tty) { |
1811 | /* check whether we're reopening an existing tty */ | |
15f1a633 | 1812 | tty = tty_driver_lookup_tty(driver, inode, index); |
4a2b5fdd | 1813 | |
808ffa3d | 1814 | if (IS_ERR(tty)) { |
eeb89d91 | 1815 | unlock_kernel(); |
808ffa3d | 1816 | mutex_unlock(&tty_mutex); |
4a2b5fdd | 1817 | return PTR_ERR(tty); |
808ffa3d | 1818 | } |
4a2b5fdd SB |
1819 | } |
1820 | ||
1821 | if (tty) { | |
1822 | retval = tty_reopen(tty); | |
1823 | if (retval) | |
1824 | tty = ERR_PTR(retval); | |
1825 | } else | |
1826 | tty = tty_init_dev(driver, index, 0); | |
1827 | ||
70522e12 | 1828 | mutex_unlock(&tty_mutex); |
7d7b93c1 | 1829 | tty_driver_kref_put(driver); |
eeb89d91 AC |
1830 | if (IS_ERR(tty)) { |
1831 | unlock_kernel(); | |
73ec06fc | 1832 | return PTR_ERR(tty); |
eeb89d91 | 1833 | } |
1da177e4 LT |
1834 | |
1835 | filp->private_data = tty; | |
1836 | file_move(filp, &tty->tty_files); | |
1837 | check_tty_count(tty, "tty_open"); | |
1838 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1839 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1840 | noctty = 1; | |
1841 | #ifdef TTY_DEBUG_HANGUP | |
1842 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1843 | #endif | |
1844 | if (!retval) { | |
f34d7a5b AC |
1845 | if (tty->ops->open) |
1846 | retval = tty->ops->open(tty, filp); | |
1da177e4 LT |
1847 | else |
1848 | retval = -ENODEV; | |
1849 | } | |
1850 | filp->f_flags = saved_flags; | |
1851 | ||
37bdfb07 AC |
1852 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1853 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1854 | retval = -EBUSY; |
1855 | ||
1856 | if (retval) { | |
1857 | #ifdef TTY_DEBUG_HANGUP | |
1858 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1859 | tty->name); | |
1860 | #endif | |
eeb89d91 AC |
1861 | tty_release(inode, filp); |
1862 | if (retval != -ERESTARTSYS) { | |
1863 | unlock_kernel(); | |
1da177e4 | 1864 | return retval; |
eeb89d91 AC |
1865 | } |
1866 | if (signal_pending(current)) { | |
1867 | unlock_kernel(); | |
1da177e4 | 1868 | return retval; |
eeb89d91 | 1869 | } |
1da177e4 LT |
1870 | schedule(); |
1871 | /* | |
1872 | * Need to reset f_op in case a hangup happened. | |
1873 | */ | |
1874 | if (filp->f_op == &hung_up_tty_fops) | |
1875 | filp->f_op = &tty_fops; | |
1876 | goto retry_open; | |
1877 | } | |
eeb89d91 AC |
1878 | unlock_kernel(); |
1879 | ||
24ec839c PZ |
1880 | |
1881 | mutex_lock(&tty_mutex); | |
eeb89d91 | 1882 | lock_kernel(); |
24ec839c | 1883 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
1884 | if (!noctty && |
1885 | current->signal->leader && | |
1886 | !current->signal->tty && | |
ab521dc0 | 1887 | tty->session == NULL) |
2a65f1d9 | 1888 | __proc_set_tty(current, tty); |
24ec839c | 1889 | spin_unlock_irq(¤t->sighand->siglock); |
eeb89d91 | 1890 | unlock_kernel(); |
24ec839c | 1891 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1892 | return 0; |
1893 | } | |
1894 | ||
39d95b9d JC |
1895 | |
1896 | ||
af9b897e AC |
1897 | /** |
1898 | * tty_poll - check tty status | |
1899 | * @filp: file being polled | |
1900 | * @wait: poll wait structures to update | |
1901 | * | |
1902 | * Call the line discipline polling method to obtain the poll | |
1903 | * status of the device. | |
1904 | * | |
1905 | * Locking: locks called line discipline but ldisc poll method | |
1906 | * may be re-entered freely by other callers. | |
1907 | */ | |
1908 | ||
37bdfb07 | 1909 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 1910 | { |
37bdfb07 | 1911 | struct tty_struct *tty; |
1da177e4 LT |
1912 | struct tty_ldisc *ld; |
1913 | int ret = 0; | |
1914 | ||
1915 | tty = (struct tty_struct *)filp->private_data; | |
a7113a96 | 1916 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 1917 | return 0; |
37bdfb07 | 1918 | |
1da177e4 | 1919 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
1920 | if (ld->ops->poll) |
1921 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
1922 | tty_ldisc_deref(ld); |
1923 | return ret; | |
1924 | } | |
1925 | ||
37bdfb07 | 1926 | static int tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 1927 | { |
37bdfb07 | 1928 | struct tty_struct *tty; |
47f86834 | 1929 | unsigned long flags; |
5d1e3230 | 1930 | int retval = 0; |
1da177e4 | 1931 | |
5d1e3230 | 1932 | lock_kernel(); |
1da177e4 | 1933 | tty = (struct tty_struct *)filp->private_data; |
a7113a96 | 1934 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 1935 | goto out; |
37bdfb07 | 1936 | |
1da177e4 LT |
1937 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
1938 | if (retval <= 0) | |
5d1e3230 | 1939 | goto out; |
1da177e4 LT |
1940 | |
1941 | if (on) { | |
ab521dc0 EB |
1942 | enum pid_type type; |
1943 | struct pid *pid; | |
1da177e4 LT |
1944 | if (!waitqueue_active(&tty->read_wait)) |
1945 | tty->minimum_to_wake = 1; | |
47f86834 | 1946 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
1947 | if (tty->pgrp) { |
1948 | pid = tty->pgrp; | |
1949 | type = PIDTYPE_PGID; | |
1950 | } else { | |
1951 | pid = task_pid(current); | |
1952 | type = PIDTYPE_PID; | |
1953 | } | |
1954 | retval = __f_setown(filp, pid, type, 0); | |
70362511 | 1955 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 | 1956 | if (retval) |
5d1e3230 | 1957 | goto out; |
1da177e4 LT |
1958 | } else { |
1959 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
1960 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
1961 | } | |
5d1e3230 JC |
1962 | retval = 0; |
1963 | out: | |
1964 | unlock_kernel(); | |
1965 | return retval; | |
1da177e4 LT |
1966 | } |
1967 | ||
af9b897e AC |
1968 | /** |
1969 | * tiocsti - fake input character | |
1970 | * @tty: tty to fake input into | |
1971 | * @p: pointer to character | |
1972 | * | |
3a4fa0a2 | 1973 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
1974 | * input management. |
1975 | * | |
1976 | * FIXME: does not honour flow control ?? | |
1977 | * | |
1978 | * Locking: | |
1979 | * Called functions take tty_ldisc_lock | |
1980 | * current->signal->tty check is safe without locks | |
28298232 AC |
1981 | * |
1982 | * FIXME: may race normal receive processing | |
af9b897e AC |
1983 | */ |
1984 | ||
1da177e4 LT |
1985 | static int tiocsti(struct tty_struct *tty, char __user *p) |
1986 | { | |
1987 | char ch, mbz = 0; | |
1988 | struct tty_ldisc *ld; | |
37bdfb07 | 1989 | |
1da177e4 LT |
1990 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
1991 | return -EPERM; | |
1992 | if (get_user(ch, p)) | |
1993 | return -EFAULT; | |
1e641743 | 1994 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 1995 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1996 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
1997 | tty_ldisc_deref(ld); |
1998 | return 0; | |
1999 | } | |
2000 | ||
af9b897e AC |
2001 | /** |
2002 | * tiocgwinsz - implement window query ioctl | |
2003 | * @tty; tty | |
2004 | * @arg: user buffer for result | |
2005 | * | |
808a0d38 | 2006 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2007 | * |
24ec839c | 2008 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2009 | * is consistent. |
af9b897e AC |
2010 | */ |
2011 | ||
37bdfb07 | 2012 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2013 | { |
808a0d38 AC |
2014 | int err; |
2015 | ||
5785c95b | 2016 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2017 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2018 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2019 | |
2020 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2021 | } |
2022 | ||
af9b897e | 2023 | /** |
8c9a9dd0 AC |
2024 | * tty_do_resize - resize event |
2025 | * @tty: tty being resized | |
8c9a9dd0 AC |
2026 | * @rows: rows (character) |
2027 | * @cols: cols (character) | |
2028 | * | |
3ad2f3fb | 2029 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2030 | * peform a terminal resize correctly |
af9b897e AC |
2031 | */ |
2032 | ||
fc6f6238 | 2033 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2034 | { |
fc6f6238 | 2035 | struct pid *pgrp; |
47f86834 | 2036 | unsigned long flags; |
1da177e4 | 2037 | |
fc6f6238 AC |
2038 | /* Lock the tty */ |
2039 | mutex_lock(&tty->termios_mutex); | |
2040 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2041 | goto done; |
47f86834 AC |
2042 | /* Get the PID values and reference them so we can |
2043 | avoid holding the tty ctrl lock while sending signals */ | |
2044 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2045 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2046 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2047 | ||
2048 | if (pgrp) | |
2049 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2050 | put_pid(pgrp); |
47f86834 | 2051 | |
8c9a9dd0 | 2052 | tty->winsize = *ws; |
ca9bda00 | 2053 | done: |
fc6f6238 | 2054 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2055 | return 0; |
2056 | } | |
2057 | ||
8c9a9dd0 AC |
2058 | /** |
2059 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2060 | * @tty; tty side of tty |
8c9a9dd0 AC |
2061 | * @arg: user buffer for result |
2062 | * | |
2063 | * Copies the user idea of the window size to the kernel. Traditionally | |
2064 | * this is just advisory information but for the Linux console it | |
2065 | * actually has driver level meaning and triggers a VC resize. | |
2066 | * | |
2067 | * Locking: | |
2068 | * Driver dependant. The default do_resize method takes the | |
2069 | * tty termios mutex and ctrl_lock. The console takes its own lock | |
2070 | * then calls into the default method. | |
2071 | */ | |
2072 | ||
fc6f6238 | 2073 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2074 | { |
2075 | struct winsize tmp_ws; | |
2076 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2077 | return -EFAULT; | |
2078 | ||
2079 | if (tty->ops->resize) | |
fc6f6238 | 2080 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2081 | else |
fc6f6238 | 2082 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2083 | } |
2084 | ||
af9b897e AC |
2085 | /** |
2086 | * tioccons - allow admin to move logical console | |
2087 | * @file: the file to become console | |
2088 | * | |
2089 | * Allow the adminstrator to move the redirected console device | |
2090 | * | |
2091 | * Locking: uses redirect_lock to guard the redirect information | |
2092 | */ | |
2093 | ||
1da177e4 LT |
2094 | static int tioccons(struct file *file) |
2095 | { | |
2096 | if (!capable(CAP_SYS_ADMIN)) | |
2097 | return -EPERM; | |
2098 | if (file->f_op->write == redirected_tty_write) { | |
2099 | struct file *f; | |
2100 | spin_lock(&redirect_lock); | |
2101 | f = redirect; | |
2102 | redirect = NULL; | |
2103 | spin_unlock(&redirect_lock); | |
2104 | if (f) | |
2105 | fput(f); | |
2106 | return 0; | |
2107 | } | |
2108 | spin_lock(&redirect_lock); | |
2109 | if (redirect) { | |
2110 | spin_unlock(&redirect_lock); | |
2111 | return -EBUSY; | |
2112 | } | |
2113 | get_file(file); | |
2114 | redirect = file; | |
2115 | spin_unlock(&redirect_lock); | |
2116 | return 0; | |
2117 | } | |
2118 | ||
af9b897e AC |
2119 | /** |
2120 | * fionbio - non blocking ioctl | |
2121 | * @file: file to set blocking value | |
2122 | * @p: user parameter | |
2123 | * | |
2124 | * Historical tty interfaces had a blocking control ioctl before | |
2125 | * the generic functionality existed. This piece of history is preserved | |
2126 | * in the expected tty API of posix OS's. | |
2127 | * | |
6146b9af | 2128 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2129 | */ |
1da177e4 LT |
2130 | |
2131 | static int fionbio(struct file *file, int __user *p) | |
2132 | { | |
2133 | int nonblock; | |
2134 | ||
2135 | if (get_user(nonblock, p)) | |
2136 | return -EFAULT; | |
2137 | ||
db1dd4d3 | 2138 | spin_lock(&file->f_lock); |
1da177e4 LT |
2139 | if (nonblock) |
2140 | file->f_flags |= O_NONBLOCK; | |
2141 | else | |
2142 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2143 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2144 | return 0; |
2145 | } | |
2146 | ||
af9b897e AC |
2147 | /** |
2148 | * tiocsctty - set controlling tty | |
2149 | * @tty: tty structure | |
2150 | * @arg: user argument | |
2151 | * | |
2152 | * This ioctl is used to manage job control. It permits a session | |
2153 | * leader to set this tty as the controlling tty for the session. | |
2154 | * | |
2155 | * Locking: | |
28298232 | 2156 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2157 | * Takes tasklist_lock internally to walk sessions |
2158 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2159 | */ |
2160 | ||
1da177e4 LT |
2161 | static int tiocsctty(struct tty_struct *tty, int arg) |
2162 | { | |
24ec839c | 2163 | int ret = 0; |
ab521dc0 | 2164 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2165 | return ret; |
2166 | ||
2167 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2168 | /* |
2169 | * The process must be a session leader and | |
2170 | * not have a controlling tty already. | |
2171 | */ | |
24ec839c PZ |
2172 | if (!current->signal->leader || current->signal->tty) { |
2173 | ret = -EPERM; | |
2174 | goto unlock; | |
2175 | } | |
2176 | ||
ab521dc0 | 2177 | if (tty->session) { |
1da177e4 LT |
2178 | /* |
2179 | * This tty is already the controlling | |
2180 | * tty for another session group! | |
2181 | */ | |
37bdfb07 | 2182 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2183 | /* |
2184 | * Steal it away | |
2185 | */ | |
1da177e4 | 2186 | read_lock(&tasklist_lock); |
24ec839c | 2187 | session_clear_tty(tty->session); |
1da177e4 | 2188 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2189 | } else { |
2190 | ret = -EPERM; | |
2191 | goto unlock; | |
2192 | } | |
1da177e4 | 2193 | } |
24ec839c PZ |
2194 | proc_set_tty(current, tty); |
2195 | unlock: | |
28298232 | 2196 | mutex_unlock(&tty_mutex); |
24ec839c | 2197 | return ret; |
1da177e4 LT |
2198 | } |
2199 | ||
5d0fdf1e AC |
2200 | /** |
2201 | * tty_get_pgrp - return a ref counted pgrp pid | |
2202 | * @tty: tty to read | |
2203 | * | |
2204 | * Returns a refcounted instance of the pid struct for the process | |
2205 | * group controlling the tty. | |
2206 | */ | |
2207 | ||
2208 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2209 | { | |
2210 | unsigned long flags; | |
2211 | struct pid *pgrp; | |
2212 | ||
2213 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2214 | pgrp = get_pid(tty->pgrp); | |
2215 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2216 | ||
2217 | return pgrp; | |
2218 | } | |
2219 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2220 | ||
af9b897e AC |
2221 | /** |
2222 | * tiocgpgrp - get process group | |
2223 | * @tty: tty passed by user | |
2224 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2225 | * @p: returned pid | |
2226 | * | |
2227 | * Obtain the process group of the tty. If there is no process group | |
2228 | * return an error. | |
2229 | * | |
24ec839c | 2230 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2231 | */ |
2232 | ||
1da177e4 LT |
2233 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2234 | { | |
5d0fdf1e AC |
2235 | struct pid *pid; |
2236 | int ret; | |
1da177e4 LT |
2237 | /* |
2238 | * (tty == real_tty) is a cheap way of | |
2239 | * testing if the tty is NOT a master pty. | |
2240 | */ | |
2241 | if (tty == real_tty && current->signal->tty != real_tty) | |
2242 | return -ENOTTY; | |
5d0fdf1e AC |
2243 | pid = tty_get_pgrp(real_tty); |
2244 | ret = put_user(pid_vnr(pid), p); | |
2245 | put_pid(pid); | |
2246 | return ret; | |
1da177e4 LT |
2247 | } |
2248 | ||
af9b897e AC |
2249 | /** |
2250 | * tiocspgrp - attempt to set process group | |
2251 | * @tty: tty passed by user | |
2252 | * @real_tty: tty side device matching tty passed by user | |
2253 | * @p: pid pointer | |
2254 | * | |
2255 | * Set the process group of the tty to the session passed. Only | |
2256 | * permitted where the tty session is our session. | |
2257 | * | |
47f86834 | 2258 | * Locking: RCU, ctrl lock |
af9b897e AC |
2259 | */ |
2260 | ||
1da177e4 LT |
2261 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2262 | { | |
04a2e6a5 EB |
2263 | struct pid *pgrp; |
2264 | pid_t pgrp_nr; | |
1da177e4 | 2265 | int retval = tty_check_change(real_tty); |
47f86834 | 2266 | unsigned long flags; |
1da177e4 LT |
2267 | |
2268 | if (retval == -EIO) | |
2269 | return -ENOTTY; | |
2270 | if (retval) | |
2271 | return retval; | |
2272 | if (!current->signal->tty || | |
2273 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2274 | (real_tty->session != task_session(current))) |
1da177e4 | 2275 | return -ENOTTY; |
04a2e6a5 | 2276 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2277 | return -EFAULT; |
04a2e6a5 | 2278 | if (pgrp_nr < 0) |
1da177e4 | 2279 | return -EINVAL; |
04a2e6a5 | 2280 | rcu_read_lock(); |
b488893a | 2281 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2282 | retval = -ESRCH; |
2283 | if (!pgrp) | |
2284 | goto out_unlock; | |
2285 | retval = -EPERM; | |
2286 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2287 | goto out_unlock; | |
2288 | retval = 0; | |
47f86834 | 2289 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2290 | put_pid(real_tty->pgrp); |
2291 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2292 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2293 | out_unlock: |
2294 | rcu_read_unlock(); | |
2295 | return retval; | |
1da177e4 LT |
2296 | } |
2297 | ||
af9b897e AC |
2298 | /** |
2299 | * tiocgsid - get session id | |
2300 | * @tty: tty passed by user | |
2301 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2302 | * @p: pointer to returned session id | |
2303 | * | |
2304 | * Obtain the session id of the tty. If there is no session | |
2305 | * return an error. | |
2306 | * | |
24ec839c | 2307 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2308 | */ |
2309 | ||
1da177e4 LT |
2310 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2311 | { | |
2312 | /* | |
2313 | * (tty == real_tty) is a cheap way of | |
2314 | * testing if the tty is NOT a master pty. | |
2315 | */ | |
2316 | if (tty == real_tty && current->signal->tty != real_tty) | |
2317 | return -ENOTTY; | |
ab521dc0 | 2318 | if (!real_tty->session) |
1da177e4 | 2319 | return -ENOTTY; |
b488893a | 2320 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2321 | } |
2322 | ||
af9b897e AC |
2323 | /** |
2324 | * tiocsetd - set line discipline | |
2325 | * @tty: tty device | |
2326 | * @p: pointer to user data | |
2327 | * | |
2328 | * Set the line discipline according to user request. | |
2329 | * | |
2330 | * Locking: see tty_set_ldisc, this function is just a helper | |
2331 | */ | |
2332 | ||
1da177e4 LT |
2333 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2334 | { | |
2335 | int ldisc; | |
04f378b1 | 2336 | int ret; |
1da177e4 LT |
2337 | |
2338 | if (get_user(ldisc, p)) | |
2339 | return -EFAULT; | |
04f378b1 | 2340 | |
04f378b1 | 2341 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2342 | |
2343 | return ret; | |
1da177e4 LT |
2344 | } |
2345 | ||
af9b897e AC |
2346 | /** |
2347 | * send_break - performed time break | |
2348 | * @tty: device to break on | |
2349 | * @duration: timeout in mS | |
2350 | * | |
2351 | * Perform a timed break on hardware that lacks its own driver level | |
2352 | * timed break functionality. | |
2353 | * | |
2354 | * Locking: | |
28298232 | 2355 | * atomic_write_lock serializes |
af9b897e | 2356 | * |
af9b897e AC |
2357 | */ |
2358 | ||
b20f3ae5 | 2359 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2360 | { |
9e98966c AC |
2361 | int retval; |
2362 | ||
2363 | if (tty->ops->break_ctl == NULL) | |
2364 | return 0; | |
2365 | ||
2366 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2367 | retval = tty->ops->break_ctl(tty, duration); | |
2368 | else { | |
2369 | /* Do the work ourselves */ | |
2370 | if (tty_write_lock(tty, 0) < 0) | |
2371 | return -EINTR; | |
2372 | retval = tty->ops->break_ctl(tty, -1); | |
2373 | if (retval) | |
2374 | goto out; | |
2375 | if (!signal_pending(current)) | |
2376 | msleep_interruptible(duration); | |
2377 | retval = tty->ops->break_ctl(tty, 0); | |
2378 | out: | |
2379 | tty_write_unlock(tty); | |
2380 | if (signal_pending(current)) | |
2381 | retval = -EINTR; | |
2382 | } | |
2383 | return retval; | |
1da177e4 LT |
2384 | } |
2385 | ||
af9b897e | 2386 | /** |
f34d7a5b | 2387 | * tty_tiocmget - get modem status |
af9b897e AC |
2388 | * @tty: tty device |
2389 | * @file: user file pointer | |
2390 | * @p: pointer to result | |
2391 | * | |
2392 | * Obtain the modem status bits from the tty driver if the feature | |
2393 | * is supported. Return -EINVAL if it is not available. | |
2394 | * | |
2395 | * Locking: none (up to the driver) | |
2396 | */ | |
2397 | ||
2398 | static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) | |
1da177e4 LT |
2399 | { |
2400 | int retval = -EINVAL; | |
2401 | ||
f34d7a5b AC |
2402 | if (tty->ops->tiocmget) { |
2403 | retval = tty->ops->tiocmget(tty, file); | |
1da177e4 LT |
2404 | |
2405 | if (retval >= 0) | |
2406 | retval = put_user(retval, p); | |
2407 | } | |
2408 | return retval; | |
2409 | } | |
2410 | ||
af9b897e | 2411 | /** |
f34d7a5b | 2412 | * tty_tiocmset - set modem status |
af9b897e AC |
2413 | * @tty: tty device |
2414 | * @file: user file pointer | |
2415 | * @cmd: command - clear bits, set bits or set all | |
2416 | * @p: pointer to desired bits | |
2417 | * | |
2418 | * Set the modem status bits from the tty driver if the feature | |
2419 | * is supported. Return -EINVAL if it is not available. | |
2420 | * | |
2421 | * Locking: none (up to the driver) | |
2422 | */ | |
2423 | ||
2424 | static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, | |
1da177e4 LT |
2425 | unsigned __user *p) |
2426 | { | |
ae677517 AC |
2427 | int retval; |
2428 | unsigned int set, clear, val; | |
1da177e4 | 2429 | |
ae677517 AC |
2430 | if (tty->ops->tiocmset == NULL) |
2431 | return -EINVAL; | |
1da177e4 | 2432 | |
ae677517 AC |
2433 | retval = get_user(val, p); |
2434 | if (retval) | |
2435 | return retval; | |
2436 | set = clear = 0; | |
2437 | switch (cmd) { | |
2438 | case TIOCMBIS: | |
2439 | set = val; | |
2440 | break; | |
2441 | case TIOCMBIC: | |
2442 | clear = val; | |
2443 | break; | |
2444 | case TIOCMSET: | |
2445 | set = val; | |
2446 | clear = ~val; | |
2447 | break; | |
2448 | } | |
2449 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2450 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2451 | return tty->ops->tiocmset(tty, file, set, clear); | |
1da177e4 LT |
2452 | } |
2453 | ||
e8b70e7d AC |
2454 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2455 | { | |
2456 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2457 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2458 | tty = tty->link; | |
2459 | return tty; | |
2460 | } | |
2461 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2462 | ||
2463 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2464 | { | |
2465 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2466 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2467 | return tty; | |
2468 | return tty->link; | |
2469 | } | |
2470 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2471 | ||
1da177e4 LT |
2472 | /* |
2473 | * Split this up, as gcc can choke on it otherwise.. | |
2474 | */ | |
04f378b1 | 2475 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
2476 | { |
2477 | struct tty_struct *tty, *real_tty; | |
2478 | void __user *p = (void __user *)arg; | |
2479 | int retval; | |
2480 | struct tty_ldisc *ld; | |
04f378b1 | 2481 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2482 | |
1da177e4 LT |
2483 | tty = (struct tty_struct *)file->private_data; |
2484 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2485 | return -EINVAL; | |
2486 | ||
e8b70e7d | 2487 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2488 | |
2489 | /* | |
2490 | * Factor out some common prep work | |
2491 | */ | |
2492 | switch (cmd) { | |
2493 | case TIOCSETD: | |
2494 | case TIOCSBRK: | |
2495 | case TIOCCBRK: | |
2496 | case TCSBRK: | |
37bdfb07 | 2497 | case TCSBRKP: |
1da177e4 LT |
2498 | retval = tty_check_change(tty); |
2499 | if (retval) | |
2500 | return retval; | |
2501 | if (cmd != TIOCCBRK) { | |
2502 | tty_wait_until_sent(tty, 0); | |
2503 | if (signal_pending(current)) | |
2504 | return -EINTR; | |
2505 | } | |
2506 | break; | |
2507 | } | |
2508 | ||
9e98966c AC |
2509 | /* |
2510 | * Now do the stuff. | |
2511 | */ | |
1da177e4 | 2512 | switch (cmd) { |
37bdfb07 AC |
2513 | case TIOCSTI: |
2514 | return tiocsti(tty, p); | |
2515 | case TIOCGWINSZ: | |
8f520021 | 2516 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2517 | case TIOCSWINSZ: |
fc6f6238 | 2518 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2519 | case TIOCCONS: |
2520 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2521 | case FIONBIO: | |
2522 | return fionbio(file, p); | |
2523 | case TIOCEXCL: | |
2524 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2525 | return 0; | |
2526 | case TIOCNXCL: | |
2527 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2528 | return 0; | |
2529 | case TIOCNOTTY: | |
2530 | if (current->signal->tty != tty) | |
2531 | return -ENOTTY; | |
2532 | no_tty(); | |
2533 | return 0; | |
2534 | case TIOCSCTTY: | |
2535 | return tiocsctty(tty, arg); | |
2536 | case TIOCGPGRP: | |
2537 | return tiocgpgrp(tty, real_tty, p); | |
2538 | case TIOCSPGRP: | |
2539 | return tiocspgrp(tty, real_tty, p); | |
2540 | case TIOCGSID: | |
2541 | return tiocgsid(tty, real_tty, p); | |
2542 | case TIOCGETD: | |
c65c9bc3 | 2543 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2544 | case TIOCSETD: |
2545 | return tiocsetd(tty, p); | |
37bdfb07 AC |
2546 | /* |
2547 | * Break handling | |
2548 | */ | |
2549 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2550 | if (tty->ops->break_ctl) |
9e98966c | 2551 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2552 | return 0; |
37bdfb07 | 2553 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2554 | if (tty->ops->break_ctl) |
9e98966c | 2555 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2556 | return 0; |
2557 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2558 | /* non-zero arg means wait for all output data | |
2559 | * to be sent (performed above) but don't send break. | |
2560 | * This is used by the tcdrain() termios function. | |
2561 | */ | |
2562 | if (!arg) | |
2563 | return send_break(tty, 250); | |
2564 | return 0; | |
2565 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2566 | return send_break(tty, arg ? arg*100 : 250); | |
2567 | ||
2568 | case TIOCMGET: | |
2569 | return tty_tiocmget(tty, file, p); | |
2570 | case TIOCMSET: | |
2571 | case TIOCMBIC: | |
2572 | case TIOCMBIS: | |
2573 | return tty_tiocmset(tty, file, cmd, p); | |
2574 | case TCFLSH: | |
2575 | switch (arg) { | |
2576 | case TCIFLUSH: | |
2577 | case TCIOFLUSH: | |
2578 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2579 | tty_buffer_flush(tty); | |
c5c34d48 | 2580 | break; |
37bdfb07 AC |
2581 | } |
2582 | break; | |
1da177e4 | 2583 | } |
f34d7a5b AC |
2584 | if (tty->ops->ioctl) { |
2585 | retval = (tty->ops->ioctl)(tty, file, cmd, arg); | |
1da177e4 LT |
2586 | if (retval != -ENOIOCTLCMD) |
2587 | return retval; | |
2588 | } | |
2589 | ld = tty_ldisc_ref_wait(tty); | |
2590 | retval = -EINVAL; | |
a352def2 AC |
2591 | if (ld->ops->ioctl) { |
2592 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2593 | if (retval == -ENOIOCTLCMD) |
2594 | retval = -EINVAL; | |
2595 | } | |
2596 | tty_ldisc_deref(ld); | |
2597 | return retval; | |
2598 | } | |
2599 | ||
e10cc1df | 2600 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2601 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2602 | unsigned long arg) |
2603 | { | |
2604 | struct inode *inode = file->f_dentry->d_inode; | |
2605 | struct tty_struct *tty = file->private_data; | |
2606 | struct tty_ldisc *ld; | |
2607 | int retval = -ENOIOCTLCMD; | |
2608 | ||
2609 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2610 | return -EINVAL; | |
2611 | ||
f34d7a5b AC |
2612 | if (tty->ops->compat_ioctl) { |
2613 | retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg); | |
e10cc1df PF |
2614 | if (retval != -ENOIOCTLCMD) |
2615 | return retval; | |
2616 | } | |
2617 | ||
2618 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2619 | if (ld->ops->compat_ioctl) |
2620 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
e10cc1df PF |
2621 | tty_ldisc_deref(ld); |
2622 | ||
2623 | return retval; | |
2624 | } | |
2625 | #endif | |
1da177e4 LT |
2626 | |
2627 | /* | |
2628 | * This implements the "Secure Attention Key" --- the idea is to | |
2629 | * prevent trojan horses by killing all processes associated with this | |
2630 | * tty when the user hits the "Secure Attention Key". Required for | |
2631 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2632 | * |
1da177e4 LT |
2633 | * This code could be nicer; ideally it should send a HUP, wait a few |
2634 | * seconds, then send a INT, and then a KILL signal. But you then | |
2635 | * have to coordinate with the init process, since all processes associated | |
2636 | * with the current tty must be dead before the new getty is allowed | |
2637 | * to spawn. | |
2638 | * | |
2639 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2640 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2641 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2642 | * | |
2643 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2644 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2645 | */ | |
8b6312f4 | 2646 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2647 | { |
2648 | #ifdef TTY_SOFT_SAK | |
2649 | tty_hangup(tty); | |
2650 | #else | |
652486fb | 2651 | struct task_struct *g, *p; |
ab521dc0 | 2652 | struct pid *session; |
1da177e4 LT |
2653 | int i; |
2654 | struct file *filp; | |
badf1662 | 2655 | struct fdtable *fdt; |
37bdfb07 | 2656 | |
1da177e4 LT |
2657 | if (!tty) |
2658 | return; | |
24ec839c | 2659 | session = tty->session; |
37bdfb07 | 2660 | |
b3f13deb | 2661 | tty_ldisc_flush(tty); |
1da177e4 | 2662 | |
f34d7a5b | 2663 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2664 | |
1da177e4 | 2665 | read_lock(&tasklist_lock); |
652486fb | 2666 | /* Kill the entire session */ |
ab521dc0 | 2667 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2668 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2669 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2670 | task_pid_nr(p), p->comm); |
652486fb | 2671 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2672 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2673 | /* Now kill any processes that happen to have the |
2674 | * tty open. | |
2675 | */ | |
2676 | do_each_thread(g, p) { | |
2677 | if (p->signal->tty == tty) { | |
1da177e4 | 2678 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2679 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2680 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2681 | send_sig(SIGKILL, p, 1); |
2682 | continue; | |
2683 | } | |
2684 | task_lock(p); | |
2685 | if (p->files) { | |
ca99c1da DS |
2686 | /* |
2687 | * We don't take a ref to the file, so we must | |
2688 | * hold ->file_lock instead. | |
2689 | */ | |
2690 | spin_lock(&p->files->file_lock); | |
badf1662 | 2691 | fdt = files_fdtable(p->files); |
37bdfb07 | 2692 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2693 | filp = fcheck_files(p->files, i); |
2694 | if (!filp) | |
2695 | continue; | |
2696 | if (filp->f_op->read == tty_read && | |
2697 | filp->private_data == tty) { | |
2698 | printk(KERN_NOTICE "SAK: killed process %d" | |
2699 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2700 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2701 | force_sig(SIGKILL, p); |
1da177e4 LT |
2702 | break; |
2703 | } | |
2704 | } | |
ca99c1da | 2705 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2706 | } |
2707 | task_unlock(p); | |
652486fb | 2708 | } while_each_thread(g, p); |
1da177e4 LT |
2709 | read_unlock(&tasklist_lock); |
2710 | #endif | |
2711 | } | |
2712 | ||
8b6312f4 EB |
2713 | static void do_SAK_work(struct work_struct *work) |
2714 | { | |
2715 | struct tty_struct *tty = | |
2716 | container_of(work, struct tty_struct, SAK_work); | |
2717 | __do_SAK(tty); | |
2718 | } | |
2719 | ||
1da177e4 LT |
2720 | /* |
2721 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2722 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2723 | * the values which we write to it will be identical to the values which it | |
2724 | * already has. --akpm | |
2725 | */ | |
2726 | void do_SAK(struct tty_struct *tty) | |
2727 | { | |
2728 | if (!tty) | |
2729 | return; | |
1da177e4 LT |
2730 | schedule_work(&tty->SAK_work); |
2731 | } | |
2732 | ||
2733 | EXPORT_SYMBOL(do_SAK); | |
2734 | ||
af9b897e AC |
2735 | /** |
2736 | * initialize_tty_struct | |
2737 | * @tty: tty to initialize | |
2738 | * | |
2739 | * This subroutine initializes a tty structure that has been newly | |
2740 | * allocated. | |
2741 | * | |
2742 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2743 | */ |
af9b897e | 2744 | |
bf970ee4 AC |
2745 | void initialize_tty_struct(struct tty_struct *tty, |
2746 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2747 | { |
2748 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2749 | kref_init(&tty->kref); |
1da177e4 | 2750 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2751 | tty_ldisc_init(tty); |
ab521dc0 EB |
2752 | tty->session = NULL; |
2753 | tty->pgrp = NULL; | |
1da177e4 | 2754 | tty->overrun_time = jiffies; |
33f0f88f AC |
2755 | tty->buf.head = tty->buf.tail = NULL; |
2756 | tty_buffer_init(tty); | |
5785c95b | 2757 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2758 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2759 | init_waitqueue_head(&tty->write_wait); |
2760 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2761 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2762 | mutex_init(&tty->atomic_read_lock); |
2763 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2764 | mutex_init(&tty->output_lock); |
2765 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2766 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2767 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2768 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2769 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2770 | |
2771 | tty->driver = driver; | |
2772 | tty->ops = driver->ops; | |
2773 | tty->index = idx; | |
2774 | tty_line_name(driver, idx, tty->name); | |
1da177e4 LT |
2775 | } |
2776 | ||
f34d7a5b AC |
2777 | /** |
2778 | * tty_put_char - write one character to a tty | |
2779 | * @tty: tty | |
2780 | * @ch: character | |
2781 | * | |
2782 | * Write one byte to the tty using the provided put_char method | |
2783 | * if present. Returns the number of characters successfully output. | |
2784 | * | |
2785 | * Note: the specific put_char operation in the driver layer may go | |
2786 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2787 | */ |
af9b897e | 2788 | |
f34d7a5b | 2789 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2790 | { |
f34d7a5b AC |
2791 | if (tty->ops->put_char) |
2792 | return tty->ops->put_char(tty, ch); | |
2793 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2794 | } |
f34d7a5b AC |
2795 | EXPORT_SYMBOL_GPL(tty_put_char); |
2796 | ||
d81ed103 | 2797 | struct class *tty_class; |
1da177e4 LT |
2798 | |
2799 | /** | |
af9b897e AC |
2800 | * tty_register_device - register a tty device |
2801 | * @driver: the tty driver that describes the tty device | |
2802 | * @index: the index in the tty driver for this tty device | |
2803 | * @device: a struct device that is associated with this tty device. | |
2804 | * This field is optional, if there is no known struct device | |
2805 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2806 | * |
01107d34 GKH |
2807 | * Returns a pointer to the struct device for this tty device |
2808 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2809 | * |
af9b897e AC |
2810 | * This call is required to be made to register an individual tty device |
2811 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2812 | * that bit is not set, this function should not be called by a tty | |
2813 | * driver. | |
2814 | * | |
2815 | * Locking: ?? | |
1da177e4 | 2816 | */ |
af9b897e | 2817 | |
01107d34 GKH |
2818 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2819 | struct device *device) | |
1da177e4 LT |
2820 | { |
2821 | char name[64]; | |
2822 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2823 | ||
2824 | if (index >= driver->num) { | |
2825 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2826 | " (%d).\n", index); | |
1cdcb6b4 | 2827 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2828 | } |
2829 | ||
1da177e4 LT |
2830 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2831 | pty_line_name(driver, index, name); | |
2832 | else | |
2833 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2834 | |
03457cd4 | 2835 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 2836 | } |
7d7b93c1 | 2837 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
2838 | |
2839 | /** | |
af9b897e AC |
2840 | * tty_unregister_device - unregister a tty device |
2841 | * @driver: the tty driver that describes the tty device | |
2842 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2843 | * |
af9b897e AC |
2844 | * If a tty device is registered with a call to tty_register_device() then |
2845 | * this function must be called when the tty device is gone. | |
2846 | * | |
2847 | * Locking: ?? | |
1da177e4 | 2848 | */ |
af9b897e | 2849 | |
1da177e4 LT |
2850 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2851 | { | |
37bdfb07 AC |
2852 | device_destroy(tty_class, |
2853 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 2854 | } |
1da177e4 LT |
2855 | EXPORT_SYMBOL(tty_unregister_device); |
2856 | ||
2857 | struct tty_driver *alloc_tty_driver(int lines) | |
2858 | { | |
2859 | struct tty_driver *driver; | |
2860 | ||
506eb99a | 2861 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 2862 | if (driver) { |
7d7b93c1 | 2863 | kref_init(&driver->kref); |
1da177e4 LT |
2864 | driver->magic = TTY_DRIVER_MAGIC; |
2865 | driver->num = lines; | |
2866 | /* later we'll move allocation of tables here */ | |
2867 | } | |
2868 | return driver; | |
2869 | } | |
7d7b93c1 | 2870 | EXPORT_SYMBOL(alloc_tty_driver); |
1da177e4 | 2871 | |
7d7b93c1 | 2872 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 2873 | { |
7d7b93c1 AC |
2874 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
2875 | int i; | |
2876 | struct ktermios *tp; | |
2877 | void *p; | |
2878 | ||
2879 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
2880 | /* | |
2881 | * Free the termios and termios_locked structures because | |
2882 | * we don't want to get memory leaks when modular tty | |
2883 | * drivers are removed from the kernel. | |
2884 | */ | |
2885 | for (i = 0; i < driver->num; i++) { | |
2886 | tp = driver->termios[i]; | |
2887 | if (tp) { | |
2888 | driver->termios[i] = NULL; | |
2889 | kfree(tp); | |
2890 | } | |
7d7b93c1 AC |
2891 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
2892 | tty_unregister_device(driver, i); | |
2893 | } | |
2894 | p = driver->ttys; | |
2895 | proc_tty_unregister_driver(driver); | |
2896 | driver->ttys = NULL; | |
fe6e29fd | 2897 | driver->termios = NULL; |
7d7b93c1 AC |
2898 | kfree(p); |
2899 | cdev_del(&driver->cdev); | |
2900 | } | |
1da177e4 LT |
2901 | kfree(driver); |
2902 | } | |
2903 | ||
7d7b93c1 AC |
2904 | void tty_driver_kref_put(struct tty_driver *driver) |
2905 | { | |
2906 | kref_put(&driver->kref, destruct_tty_driver); | |
2907 | } | |
2908 | EXPORT_SYMBOL(tty_driver_kref_put); | |
2909 | ||
b68e31d0 JD |
2910 | void tty_set_operations(struct tty_driver *driver, |
2911 | const struct tty_operations *op) | |
1da177e4 | 2912 | { |
f34d7a5b AC |
2913 | driver->ops = op; |
2914 | }; | |
7d7b93c1 | 2915 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 2916 | |
7d7b93c1 AC |
2917 | void put_tty_driver(struct tty_driver *d) |
2918 | { | |
2919 | tty_driver_kref_put(d); | |
2920 | } | |
1da177e4 | 2921 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
2922 | |
2923 | /* | |
2924 | * Called by a tty driver to register itself. | |
2925 | */ | |
2926 | int tty_register_driver(struct tty_driver *driver) | |
2927 | { | |
2928 | int error; | |
37bdfb07 | 2929 | int i; |
1da177e4 LT |
2930 | dev_t dev; |
2931 | void **p = NULL; | |
2932 | ||
543691a6 | 2933 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 2934 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
2935 | if (!p) |
2936 | return -ENOMEM; | |
1da177e4 LT |
2937 | } |
2938 | ||
2939 | if (!driver->major) { | |
37bdfb07 AC |
2940 | error = alloc_chrdev_region(&dev, driver->minor_start, |
2941 | driver->num, driver->name); | |
1da177e4 LT |
2942 | if (!error) { |
2943 | driver->major = MAJOR(dev); | |
2944 | driver->minor_start = MINOR(dev); | |
2945 | } | |
2946 | } else { | |
2947 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 2948 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
2949 | } |
2950 | if (error < 0) { | |
2951 | kfree(p); | |
2952 | return error; | |
2953 | } | |
2954 | ||
2955 | if (p) { | |
2956 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 2957 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
2958 | } else { |
2959 | driver->ttys = NULL; | |
2960 | driver->termios = NULL; | |
1da177e4 LT |
2961 | } |
2962 | ||
2963 | cdev_init(&driver->cdev, &tty_fops); | |
2964 | driver->cdev.owner = driver->owner; | |
2965 | error = cdev_add(&driver->cdev, dev, driver->num); | |
2966 | if (error) { | |
1da177e4 LT |
2967 | unregister_chrdev_region(dev, driver->num); |
2968 | driver->ttys = NULL; | |
fe6e29fd | 2969 | driver->termios = NULL; |
1da177e4 LT |
2970 | kfree(p); |
2971 | return error; | |
2972 | } | |
2973 | ||
ca509f69 | 2974 | mutex_lock(&tty_mutex); |
1da177e4 | 2975 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 2976 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
2977 | |
2978 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
2979 | for (i = 0; i < driver->num; i++) | |
1da177e4 LT |
2980 | tty_register_device(driver, i, NULL); |
2981 | } | |
2982 | proc_tty_register_driver(driver); | |
7d7b93c1 | 2983 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 LT |
2984 | return 0; |
2985 | } | |
2986 | ||
2987 | EXPORT_SYMBOL(tty_register_driver); | |
2988 | ||
2989 | /* | |
2990 | * Called by a tty driver to unregister itself. | |
2991 | */ | |
2992 | int tty_unregister_driver(struct tty_driver *driver) | |
2993 | { | |
7d7b93c1 AC |
2994 | #if 0 |
2995 | /* FIXME */ | |
1da177e4 LT |
2996 | if (driver->refcount) |
2997 | return -EBUSY; | |
7d7b93c1 | 2998 | #endif |
1da177e4 LT |
2999 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3000 | driver->num); | |
ca509f69 | 3001 | mutex_lock(&tty_mutex); |
1da177e4 | 3002 | list_del(&driver->tty_drivers); |
ca509f69 | 3003 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3004 | return 0; |
3005 | } | |
7d7b93c1 | 3006 | |
1da177e4 LT |
3007 | EXPORT_SYMBOL(tty_unregister_driver); |
3008 | ||
24ec839c PZ |
3009 | dev_t tty_devnum(struct tty_struct *tty) |
3010 | { | |
3011 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3012 | } | |
3013 | EXPORT_SYMBOL(tty_devnum); | |
3014 | ||
3015 | void proc_clear_tty(struct task_struct *p) | |
3016 | { | |
7c3b1dcf | 3017 | unsigned long flags; |
9c9f4ded | 3018 | struct tty_struct *tty; |
7c3b1dcf | 3019 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3020 | tty = p->signal->tty; |
24ec839c | 3021 | p->signal->tty = NULL; |
7c3b1dcf | 3022 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3023 | tty_kref_put(tty); |
24ec839c | 3024 | } |
24ec839c | 3025 | |
47f86834 AC |
3026 | /* Called under the sighand lock */ |
3027 | ||
2a65f1d9 | 3028 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3029 | { |
3030 | if (tty) { | |
47f86834 AC |
3031 | unsigned long flags; |
3032 | /* We should not have a session or pgrp to put here but.... */ | |
3033 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3034 | put_pid(tty->session); |
3035 | put_pid(tty->pgrp); | |
ab521dc0 | 3036 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3037 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3038 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3039 | if (tsk->signal->tty) { |
3040 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3041 | tty_kref_put(tsk->signal->tty); | |
3042 | } | |
24ec839c | 3043 | } |
2a65f1d9 | 3044 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3045 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3046 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3047 | } |
3048 | ||
98a27ba4 | 3049 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3050 | { |
3051 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3052 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3053 | spin_unlock_irq(&tsk->sighand->siglock); |
3054 | } | |
3055 | ||
3056 | struct tty_struct *get_current_tty(void) | |
3057 | { | |
3058 | struct tty_struct *tty; | |
934e6ebf AC |
3059 | unsigned long flags; |
3060 | ||
3061 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3062 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3063 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3064 | return tty; |
3065 | } | |
a311f743 | 3066 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3067 | |
d81ed103 AC |
3068 | void tty_default_fops(struct file_operations *fops) |
3069 | { | |
3070 | *fops = tty_fops; | |
3071 | } | |
3072 | ||
1da177e4 LT |
3073 | /* |
3074 | * Initialize the console device. This is called *early*, so | |
3075 | * we can't necessarily depend on lots of kernel help here. | |
3076 | * Just do some early initializations, and do the complex setup | |
3077 | * later. | |
3078 | */ | |
3079 | void __init console_init(void) | |
3080 | { | |
3081 | initcall_t *call; | |
3082 | ||
3083 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3084 | tty_ldisc_begin(); |
1da177e4 LT |
3085 | |
3086 | /* | |
37bdfb07 | 3087 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3088 | * inform about problems etc.. |
3089 | */ | |
1da177e4 LT |
3090 | call = __con_initcall_start; |
3091 | while (call < __con_initcall_end) { | |
3092 | (*call)(); | |
3093 | call++; | |
3094 | } | |
3095 | } | |
3096 | ||
e454cea2 KS |
3097 | static char *tty_devnode(struct device *dev, mode_t *mode) |
3098 | { | |
3099 | if (!mode) | |
3100 | return NULL; | |
3101 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3102 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3103 | *mode = 0666; | |
3104 | return NULL; | |
3105 | } | |
3106 | ||
1da177e4 LT |
3107 | static int __init tty_class_init(void) |
3108 | { | |
7fe845d1 | 3109 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3110 | if (IS_ERR(tty_class)) |
3111 | return PTR_ERR(tty_class); | |
e454cea2 | 3112 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3113 | return 0; |
3114 | } | |
3115 | ||
3116 | postcore_initcall(tty_class_init); | |
3117 | ||
3118 | /* 3/2004 jmc: why do these devices exist? */ | |
3119 | ||
3120 | static struct cdev tty_cdev, console_cdev; | |
1da177e4 LT |
3121 | |
3122 | /* | |
3123 | * Ok, now we can initialize the rest of the tty devices and can count | |
3124 | * on memory allocations, interrupts etc.. | |
3125 | */ | |
3126 | static int __init tty_init(void) | |
3127 | { | |
3128 | cdev_init(&tty_cdev, &tty_fops); | |
3129 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3130 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3131 | panic("Couldn't register /dev/tty driver\n"); | |
d81ed103 | 3132 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, |
47aa5793 | 3133 | "tty"); |
1da177e4 LT |
3134 | |
3135 | cdev_init(&console_cdev, &console_fops); | |
3136 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3137 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3138 | panic("Couldn't register /dev/console driver\n"); | |
d81ed103 | 3139 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3140 | "console"); |
1da177e4 | 3141 | |
1da177e4 | 3142 | #ifdef CONFIG_VT |
d81ed103 | 3143 | vty_init(&console_fops); |
1da177e4 LT |
3144 | #endif |
3145 | return 0; | |
3146 | } | |
3147 | module_init(tty_init); |