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