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