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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 void initialize_tty_struct(struct tty_struct *tty); |
140 | ||
141 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); | |
142 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
143 | ssize_t redirected_tty_write(struct file *, const char __user *, |
144 | size_t, loff_t *); | |
1da177e4 LT |
145 | static unsigned int tty_poll(struct file *, poll_table *); |
146 | static int tty_open(struct inode *, struct file *); | |
147 | static int tty_release(struct inode *, struct file *); | |
04f378b1 | 148 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 149 | #ifdef CONFIG_COMPAT |
37bdfb07 | 150 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
151 | unsigned long arg); |
152 | #else | |
153 | #define tty_compat_ioctl NULL | |
154 | #endif | |
37bdfb07 | 155 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 156 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 157 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 158 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 159 | |
af9b897e AC |
160 | /** |
161 | * alloc_tty_struct - allocate a tty object | |
162 | * | |
163 | * Return a new empty tty structure. The data fields have not | |
164 | * been initialized in any way but has been zeroed | |
165 | * | |
166 | * Locking: none | |
af9b897e | 167 | */ |
1da177e4 LT |
168 | |
169 | static struct tty_struct *alloc_tty_struct(void) | |
170 | { | |
1266b1e1 | 171 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
172 | } |
173 | ||
af9b897e AC |
174 | /** |
175 | * free_tty_struct - free a disused tty | |
176 | * @tty: tty struct to free | |
177 | * | |
178 | * Free the write buffers, tty queue and tty memory itself. | |
179 | * | |
180 | * Locking: none. Must be called after tty is definitely unused | |
181 | */ | |
182 | ||
1da177e4 LT |
183 | static inline void free_tty_struct(struct tty_struct *tty) |
184 | { | |
185 | kfree(tty->write_buf); | |
33f0f88f | 186 | tty_buffer_free_all(tty); |
1da177e4 LT |
187 | kfree(tty); |
188 | } | |
189 | ||
190 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) | |
191 | ||
af9b897e AC |
192 | /** |
193 | * tty_name - return tty naming | |
194 | * @tty: tty structure | |
195 | * @buf: buffer for output | |
196 | * | |
197 | * Convert a tty structure into a name. The name reflects the kernel | |
198 | * naming policy and if udev is in use may not reflect user space | |
199 | * | |
200 | * Locking: none | |
201 | */ | |
202 | ||
1da177e4 LT |
203 | char *tty_name(struct tty_struct *tty, char *buf) |
204 | { | |
205 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
206 | strcpy(buf, "NULL tty"); | |
207 | else | |
208 | strcpy(buf, tty->name); | |
209 | return buf; | |
210 | } | |
211 | ||
212 | EXPORT_SYMBOL(tty_name); | |
213 | ||
d769a669 | 214 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
215 | const char *routine) |
216 | { | |
217 | #ifdef TTY_PARANOIA_CHECK | |
218 | if (!tty) { | |
219 | printk(KERN_WARNING | |
220 | "null TTY for (%d:%d) in %s\n", | |
221 | imajor(inode), iminor(inode), routine); | |
222 | return 1; | |
223 | } | |
224 | if (tty->magic != TTY_MAGIC) { | |
225 | printk(KERN_WARNING | |
226 | "bad magic number for tty struct (%d:%d) in %s\n", | |
227 | imajor(inode), iminor(inode), routine); | |
228 | return 1; | |
229 | } | |
230 | #endif | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
235 | { | |
236 | #ifdef CHECK_TTY_COUNT | |
237 | struct list_head *p; | |
238 | int count = 0; | |
37bdfb07 | 239 | |
1da177e4 LT |
240 | file_list_lock(); |
241 | list_for_each(p, &tty->tty_files) { | |
242 | count++; | |
243 | } | |
244 | file_list_unlock(); | |
245 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
246 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
247 | tty->link && tty->link->count) | |
248 | count++; | |
249 | if (tty->count != count) { | |
250 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
251 | "!= #fd's(%d) in %s\n", | |
252 | tty->name, tty->count, count, routine); | |
253 | return count; | |
24ec839c | 254 | } |
1da177e4 LT |
255 | #endif |
256 | return 0; | |
257 | } | |
258 | ||
af9b897e AC |
259 | /** |
260 | * get_tty_driver - find device of a tty | |
261 | * @dev_t: device identifier | |
262 | * @index: returns the index of the tty | |
263 | * | |
264 | * This routine returns a tty driver structure, given a device number | |
265 | * and also passes back the index number. | |
266 | * | |
267 | * Locking: caller must hold tty_mutex | |
1da177e4 | 268 | */ |
af9b897e | 269 | |
1da177e4 LT |
270 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
271 | { | |
272 | struct tty_driver *p; | |
273 | ||
274 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
275 | dev_t base = MKDEV(p->major, p->minor_start); | |
276 | if (device < base || device >= base + p->num) | |
277 | continue; | |
278 | *index = device - base; | |
279 | return p; | |
280 | } | |
281 | return NULL; | |
282 | } | |
283 | ||
f2d937f3 JW |
284 | #ifdef CONFIG_CONSOLE_POLL |
285 | ||
286 | /** | |
287 | * tty_find_polling_driver - find device of a polled tty | |
288 | * @name: name string to match | |
289 | * @line: pointer to resulting tty line nr | |
290 | * | |
291 | * This routine returns a tty driver structure, given a name | |
292 | * and the condition that the tty driver is capable of polled | |
293 | * operation. | |
294 | */ | |
295 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
296 | { | |
297 | struct tty_driver *p, *res = NULL; | |
298 | int tty_line = 0; | |
0dca0fd2 | 299 | int len; |
f2d937f3 JW |
300 | char *str; |
301 | ||
0dca0fd2 JW |
302 | for (str = name; *str; str++) |
303 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
304 | break; | |
305 | if (!*str) | |
306 | return NULL; | |
307 | ||
308 | len = str - name; | |
309 | tty_line = simple_strtoul(str, &str, 10); | |
310 | ||
f2d937f3 JW |
311 | mutex_lock(&tty_mutex); |
312 | /* Search through the tty devices to look for a match */ | |
313 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
314 | if (strncmp(name, p->name, len) != 0) |
315 | continue; | |
f2d937f3 JW |
316 | if (*str == ',') |
317 | str++; | |
318 | if (*str == '\0') | |
8da56309 | 319 | str = NULL; |
f2d937f3 | 320 | |
f34d7a5b AC |
321 | if (tty_line >= 0 && tty_line <= p->num && p->ops && |
322 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) { | |
f2d937f3 JW |
323 | res = p; |
324 | *line = tty_line; | |
325 | break; | |
326 | } | |
327 | } | |
328 | mutex_unlock(&tty_mutex); | |
329 | ||
330 | return res; | |
331 | } | |
332 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
333 | #endif | |
334 | ||
af9b897e AC |
335 | /** |
336 | * tty_check_change - check for POSIX terminal changes | |
337 | * @tty: tty to check | |
338 | * | |
339 | * If we try to write to, or set the state of, a terminal and we're | |
340 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
341 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
342 | * | |
978e595f | 343 | * Locking: ctrl_lock |
1da177e4 | 344 | */ |
af9b897e | 345 | |
37bdfb07 | 346 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 347 | { |
47f86834 AC |
348 | unsigned long flags; |
349 | int ret = 0; | |
350 | ||
1da177e4 LT |
351 | if (current->signal->tty != tty) |
352 | return 0; | |
47f86834 AC |
353 | |
354 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
355 | ||
ab521dc0 EB |
356 | if (!tty->pgrp) { |
357 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 358 | goto out_unlock; |
1da177e4 | 359 | } |
ab521dc0 | 360 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
361 | goto out_unlock; |
362 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 363 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
364 | goto out; |
365 | if (is_current_pgrp_orphaned()) { | |
366 | ret = -EIO; | |
367 | goto out; | |
368 | } | |
040b6362 ON |
369 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
370 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
371 | ret = -ERESTARTSYS; |
372 | out: | |
9ffee4cb AM |
373 | return ret; |
374 | out_unlock: | |
47f86834 AC |
375 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
376 | return ret; | |
1da177e4 LT |
377 | } |
378 | ||
379 | EXPORT_SYMBOL(tty_check_change); | |
380 | ||
37bdfb07 | 381 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
382 | size_t count, loff_t *ppos) |
383 | { | |
384 | return 0; | |
385 | } | |
386 | ||
37bdfb07 | 387 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
388 | size_t count, loff_t *ppos) |
389 | { | |
390 | return -EIO; | |
391 | } | |
392 | ||
393 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 394 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
395 | { |
396 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
397 | } | |
398 | ||
04f378b1 AC |
399 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
400 | unsigned long arg) | |
38ad2ed0 PF |
401 | { |
402 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
403 | } | |
404 | ||
37bdfb07 | 405 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 406 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
407 | { |
408 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
409 | } | |
410 | ||
62322d25 | 411 | static const struct file_operations tty_fops = { |
1da177e4 LT |
412 | .llseek = no_llseek, |
413 | .read = tty_read, | |
414 | .write = tty_write, | |
415 | .poll = tty_poll, | |
04f378b1 | 416 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 417 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
418 | .open = tty_open, |
419 | .release = tty_release, | |
420 | .fasync = tty_fasync, | |
421 | }; | |
422 | ||
62322d25 | 423 | static const struct file_operations console_fops = { |
1da177e4 LT |
424 | .llseek = no_llseek, |
425 | .read = tty_read, | |
426 | .write = redirected_tty_write, | |
427 | .poll = tty_poll, | |
04f378b1 | 428 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 429 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
430 | .open = tty_open, |
431 | .release = tty_release, | |
432 | .fasync = tty_fasync, | |
433 | }; | |
434 | ||
62322d25 | 435 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
436 | .llseek = no_llseek, |
437 | .read = hung_up_tty_read, | |
438 | .write = hung_up_tty_write, | |
439 | .poll = hung_up_tty_poll, | |
04f378b1 | 440 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 441 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
442 | .release = tty_release, |
443 | }; | |
444 | ||
445 | static DEFINE_SPINLOCK(redirect_lock); | |
446 | static struct file *redirect; | |
447 | ||
448 | /** | |
449 | * tty_wakeup - request more data | |
450 | * @tty: terminal | |
451 | * | |
452 | * Internal and external helper for wakeups of tty. This function | |
453 | * informs the line discipline if present that the driver is ready | |
454 | * to receive more output data. | |
455 | */ | |
37bdfb07 | 456 | |
1da177e4 LT |
457 | void tty_wakeup(struct tty_struct *tty) |
458 | { | |
459 | struct tty_ldisc *ld; | |
37bdfb07 | 460 | |
1da177e4 LT |
461 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
462 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 463 | if (ld) { |
a352def2 AC |
464 | if (ld->ops->write_wakeup) |
465 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
466 | tty_ldisc_deref(ld); |
467 | } | |
468 | } | |
469 | wake_up_interruptible(&tty->write_wait); | |
470 | } | |
471 | ||
472 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
473 | ||
474 | /** | |
475 | * tty_ldisc_flush - flush line discipline queue | |
476 | * @tty: tty | |
477 | * | |
478 | * Flush the line discipline queue (if any) for this tty. If there | |
479 | * is no line discipline active this is a no-op. | |
480 | */ | |
37bdfb07 | 481 | |
1da177e4 LT |
482 | void tty_ldisc_flush(struct tty_struct *tty) |
483 | { | |
484 | struct tty_ldisc *ld = tty_ldisc_ref(tty); | |
37bdfb07 | 485 | if (ld) { |
a352def2 AC |
486 | if (ld->ops->flush_buffer) |
487 | ld->ops->flush_buffer(tty); | |
1da177e4 LT |
488 | tty_ldisc_deref(ld); |
489 | } | |
c5c34d48 | 490 | tty_buffer_flush(tty); |
1da177e4 LT |
491 | } |
492 | ||
493 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); | |
edc6afc5 AC |
494 | |
495 | /** | |
496 | * tty_reset_termios - reset terminal state | |
497 | * @tty: tty to reset | |
498 | * | |
499 | * Restore a terminal to the driver default state | |
500 | */ | |
501 | ||
502 | static void tty_reset_termios(struct tty_struct *tty) | |
503 | { | |
504 | mutex_lock(&tty->termios_mutex); | |
505 | *tty->termios = tty->driver->init_termios; | |
506 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
507 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
508 | mutex_unlock(&tty->termios_mutex); | |
509 | } | |
37bdfb07 | 510 | |
af9b897e AC |
511 | /** |
512 | * do_tty_hangup - actual handler for hangup events | |
65f27f38 | 513 | * @work: tty device |
af9b897e | 514 | * |
1bad879a | 515 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
516 | * synchronous but doesn't hold any locks, so we need to make sure we |
517 | * have the appropriate locks for what we're doing. | |
518 | * | |
519 | * The hangup event clears any pending redirections onto the hung up | |
520 | * device. It ensures future writes will error and it does the needed | |
521 | * line discipline hangup and signal delivery. The tty object itself | |
522 | * remains intact. | |
523 | * | |
524 | * Locking: | |
525 | * BKL | |
24ec839c PZ |
526 | * redirect lock for undoing redirection |
527 | * file list lock for manipulating list of ttys | |
528 | * tty_ldisc_lock from called functions | |
529 | * termios_mutex resetting termios data | |
530 | * tasklist_lock to walk task list for hangup event | |
531 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 532 | */ |
65f27f38 | 533 | static void do_tty_hangup(struct work_struct *work) |
1da177e4 | 534 | { |
65f27f38 DH |
535 | struct tty_struct *tty = |
536 | container_of(work, struct tty_struct, hangup_work); | |
37bdfb07 | 537 | struct file *cons_filp = NULL; |
1da177e4 LT |
538 | struct file *filp, *f = NULL; |
539 | struct task_struct *p; | |
540 | struct tty_ldisc *ld; | |
541 | int closecount = 0, n; | |
47f86834 | 542 | unsigned long flags; |
9c9f4ded | 543 | int refs = 0; |
1da177e4 LT |
544 | |
545 | if (!tty) | |
546 | return; | |
547 | ||
548 | /* inuse_filps is protected by the single kernel lock */ | |
549 | lock_kernel(); | |
550 | ||
551 | spin_lock(&redirect_lock); | |
552 | if (redirect && redirect->private_data == tty) { | |
553 | f = redirect; | |
554 | redirect = NULL; | |
555 | } | |
556 | spin_unlock(&redirect_lock); | |
37bdfb07 | 557 | |
1da177e4 LT |
558 | check_tty_count(tty, "do_tty_hangup"); |
559 | file_list_lock(); | |
560 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ | |
2f512016 | 561 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
1da177e4 LT |
562 | if (filp->f_op->write == redirected_tty_write) |
563 | cons_filp = filp; | |
564 | if (filp->f_op->write != tty_write) | |
565 | continue; | |
566 | closecount++; | |
567 | tty_fasync(-1, filp, 0); /* can't block */ | |
568 | filp->f_op = &hung_up_tty_fops; | |
569 | } | |
570 | file_list_unlock(); | |
37bdfb07 AC |
571 | /* |
572 | * FIXME! What are the locking issues here? This may me overdoing | |
573 | * things... This question is especially important now that we've | |
574 | * removed the irqlock. | |
575 | */ | |
1da177e4 | 576 | ld = tty_ldisc_ref(tty); |
37bdfb07 AC |
577 | if (ld != NULL) { |
578 | /* We may have no line discipline at this point */ | |
a352def2 AC |
579 | if (ld->ops->flush_buffer) |
580 | ld->ops->flush_buffer(tty); | |
f34d7a5b | 581 | tty_driver_flush_buffer(tty); |
1da177e4 | 582 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && |
a352def2 AC |
583 | ld->ops->write_wakeup) |
584 | ld->ops->write_wakeup(tty); | |
585 | if (ld->ops->hangup) | |
586 | ld->ops->hangup(tty); | |
1da177e4 | 587 | } |
37bdfb07 AC |
588 | /* |
589 | * FIXME: Once we trust the LDISC code better we can wait here for | |
590 | * ldisc completion and fix the driver call race | |
591 | */ | |
1da177e4 LT |
592 | wake_up_interruptible(&tty->write_wait); |
593 | wake_up_interruptible(&tty->read_wait); | |
1da177e4 LT |
594 | /* |
595 | * Shutdown the current line discipline, and reset it to | |
596 | * N_TTY. | |
597 | */ | |
598 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
edc6afc5 | 599 | tty_reset_termios(tty); |
1da177e4 LT |
600 | /* Defer ldisc switch */ |
601 | /* tty_deferred_ldisc_switch(N_TTY); | |
37bdfb07 | 602 | |
1da177e4 LT |
603 | This should get done automatically when the port closes and |
604 | tty_release is called */ | |
37bdfb07 | 605 | |
1da177e4 | 606 | read_lock(&tasklist_lock); |
ab521dc0 EB |
607 | if (tty->session) { |
608 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 609 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 610 | if (p->signal->tty == tty) { |
1da177e4 | 611 | p->signal->tty = NULL; |
9c9f4ded AC |
612 | /* We defer the dereferences outside fo |
613 | the tasklist lock */ | |
614 | refs++; | |
615 | } | |
24ec839c PZ |
616 | if (!p->signal->leader) { |
617 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 618 | continue; |
24ec839c PZ |
619 | } |
620 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
621 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 622 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 623 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
624 | if (tty->pgrp) |
625 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 626 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 627 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 628 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
629 | } |
630 | read_unlock(&tasklist_lock); | |
631 | ||
47f86834 | 632 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 | 633 | tty->flags = 0; |
d9c1e9a8 EB |
634 | put_pid(tty->session); |
635 | put_pid(tty->pgrp); | |
ab521dc0 EB |
636 | tty->session = NULL; |
637 | tty->pgrp = NULL; | |
1da177e4 | 638 | tty->ctrl_status = 0; |
47f86834 AC |
639 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
640 | ||
9c9f4ded AC |
641 | /* Account for the p->signal references we killed */ |
642 | while (refs--) | |
643 | tty_kref_put(tty); | |
644 | ||
1da177e4 | 645 | /* |
37bdfb07 AC |
646 | * If one of the devices matches a console pointer, we |
647 | * cannot just call hangup() because that will cause | |
648 | * tty->count and state->count to go out of sync. | |
649 | * So we just call close() the right number of times. | |
1da177e4 LT |
650 | */ |
651 | if (cons_filp) { | |
f34d7a5b | 652 | if (tty->ops->close) |
1da177e4 | 653 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
654 | tty->ops->close(tty, cons_filp); |
655 | } else if (tty->ops->hangup) | |
656 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
657 | /* |
658 | * We don't want to have driver/ldisc interactions beyond | |
659 | * the ones we did here. The driver layer expects no | |
660 | * calls after ->hangup() from the ldisc side. However we | |
661 | * can't yet guarantee all that. | |
662 | */ | |
1da177e4 LT |
663 | set_bit(TTY_HUPPED, &tty->flags); |
664 | if (ld) { | |
665 | tty_ldisc_enable(tty); | |
666 | tty_ldisc_deref(ld); | |
667 | } | |
668 | unlock_kernel(); | |
669 | if (f) | |
670 | fput(f); | |
671 | } | |
672 | ||
af9b897e AC |
673 | /** |
674 | * tty_hangup - trigger a hangup event | |
675 | * @tty: tty to hangup | |
676 | * | |
677 | * A carrier loss (virtual or otherwise) has occurred on this like | |
678 | * schedule a hangup sequence to run after this event. | |
679 | */ | |
680 | ||
37bdfb07 | 681 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
682 | { |
683 | #ifdef TTY_DEBUG_HANGUP | |
684 | char buf[64]; | |
1da177e4 LT |
685 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
686 | #endif | |
687 | schedule_work(&tty->hangup_work); | |
688 | } | |
689 | ||
690 | EXPORT_SYMBOL(tty_hangup); | |
691 | ||
af9b897e AC |
692 | /** |
693 | * tty_vhangup - process vhangup | |
694 | * @tty: tty to hangup | |
695 | * | |
696 | * The user has asked via system call for the terminal to be hung up. | |
697 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 698 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
699 | */ |
700 | ||
37bdfb07 | 701 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
702 | { |
703 | #ifdef TTY_DEBUG_HANGUP | |
704 | char buf[64]; | |
705 | ||
706 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
707 | #endif | |
65f27f38 | 708 | do_tty_hangup(&tty->hangup_work); |
1da177e4 | 709 | } |
37bdfb07 | 710 | |
1da177e4 LT |
711 | EXPORT_SYMBOL(tty_vhangup); |
712 | ||
2cb5998b AC |
713 | /** |
714 | * tty_vhangup_self - process vhangup for own ctty | |
715 | * | |
716 | * Perform a vhangup on the current controlling tty | |
717 | */ | |
718 | ||
719 | void tty_vhangup_self(void) | |
720 | { | |
721 | struct tty_struct *tty; | |
722 | ||
2cb5998b AC |
723 | tty = get_current_tty(); |
724 | if (tty) { | |
725 | tty_vhangup(tty); | |
726 | tty_kref_put(tty); | |
727 | } | |
2cb5998b AC |
728 | } |
729 | ||
af9b897e AC |
730 | /** |
731 | * tty_hung_up_p - was tty hung up | |
732 | * @filp: file pointer of tty | |
733 | * | |
734 | * Return true if the tty has been subject to a vhangup or a carrier | |
735 | * loss | |
736 | */ | |
737 | ||
37bdfb07 | 738 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
739 | { |
740 | return (filp->f_op == &hung_up_tty_fops); | |
741 | } | |
742 | ||
743 | EXPORT_SYMBOL(tty_hung_up_p); | |
744 | ||
ab521dc0 | 745 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
746 | { |
747 | struct task_struct *p; | |
ab521dc0 | 748 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 749 | proc_clear_tty(p); |
ab521dc0 | 750 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
751 | } |
752 | ||
af9b897e AC |
753 | /** |
754 | * disassociate_ctty - disconnect controlling tty | |
755 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 756 | * |
af9b897e AC |
757 | * This function is typically called only by the session leader, when |
758 | * it wants to disassociate itself from its controlling tty. | |
759 | * | |
760 | * It performs the following functions: | |
1da177e4 LT |
761 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
762 | * (2) Clears the tty from being controlling the session | |
763 | * (3) Clears the controlling tty for all processes in the | |
764 | * session group. | |
765 | * | |
af9b897e AC |
766 | * The argument on_exit is set to 1 if called when a process is |
767 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
768 | * | |
24ec839c | 769 | * Locking: |
af9b897e | 770 | * BKL is taken for hysterical raisins |
24ec839c PZ |
771 | * tty_mutex is taken to protect tty |
772 | * ->siglock is taken to protect ->signal/->sighand | |
773 | * tasklist_lock is taken to walk process list for sessions | |
774 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 775 | */ |
af9b897e | 776 | |
1da177e4 LT |
777 | void disassociate_ctty(int on_exit) |
778 | { | |
779 | struct tty_struct *tty; | |
ab521dc0 | 780 | struct pid *tty_pgrp = NULL; |
1da177e4 | 781 | |
1da177e4 | 782 | |
24ec839c | 783 | tty = get_current_tty(); |
1da177e4 | 784 | if (tty) { |
ab521dc0 | 785 | tty_pgrp = get_pid(tty->pgrp); |
452a00d2 | 786 | lock_kernel(); |
1da177e4 LT |
787 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
788 | tty_vhangup(tty); | |
04f378b1 | 789 | unlock_kernel(); |
452a00d2 | 790 | tty_kref_put(tty); |
680a9671 | 791 | } else if (on_exit) { |
ab521dc0 | 792 | struct pid *old_pgrp; |
680a9671 EB |
793 | spin_lock_irq(¤t->sighand->siglock); |
794 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 795 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 796 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 797 | if (old_pgrp) { |
ab521dc0 EB |
798 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
799 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
800 | put_pid(old_pgrp); | |
1da177e4 | 801 | } |
1da177e4 LT |
802 | return; |
803 | } | |
ab521dc0 EB |
804 | if (tty_pgrp) { |
805 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
1da177e4 | 806 | if (!on_exit) |
ab521dc0 EB |
807 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); |
808 | put_pid(tty_pgrp); | |
1da177e4 LT |
809 | } |
810 | ||
24ec839c | 811 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 812 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 813 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
814 | spin_unlock_irq(¤t->sighand->siglock); |
815 | ||
24ec839c PZ |
816 | tty = get_current_tty(); |
817 | if (tty) { | |
47f86834 AC |
818 | unsigned long flags; |
819 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
820 | put_pid(tty->session); |
821 | put_pid(tty->pgrp); | |
822 | tty->session = NULL; | |
823 | tty->pgrp = NULL; | |
47f86834 | 824 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 825 | tty_kref_put(tty); |
24ec839c PZ |
826 | } else { |
827 | #ifdef TTY_DEBUG_HANGUP | |
828 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
829 | " = NULL", tty); | |
830 | #endif | |
831 | } | |
1da177e4 LT |
832 | |
833 | /* Now clear signal->tty under the lock */ | |
834 | read_lock(&tasklist_lock); | |
ab521dc0 | 835 | session_clear_tty(task_session(current)); |
1da177e4 | 836 | read_unlock(&tasklist_lock); |
1da177e4 LT |
837 | } |
838 | ||
98a27ba4 EB |
839 | /** |
840 | * | |
841 | * no_tty - Ensure the current process does not have a controlling tty | |
842 | */ | |
843 | void no_tty(void) | |
844 | { | |
845 | struct task_struct *tsk = current; | |
04f378b1 | 846 | lock_kernel(); |
98a27ba4 EB |
847 | if (tsk->signal->leader) |
848 | disassociate_ctty(0); | |
04f378b1 | 849 | unlock_kernel(); |
98a27ba4 EB |
850 | proc_clear_tty(tsk); |
851 | } | |
852 | ||
af9b897e AC |
853 | |
854 | /** | |
beb7dd86 | 855 | * stop_tty - propagate flow control |
af9b897e AC |
856 | * @tty: tty to stop |
857 | * | |
858 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 859 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
860 | * on an already stopped device and will not re-call the driver |
861 | * method. | |
862 | * | |
863 | * This functionality is used by both the line disciplines for | |
864 | * halting incoming flow and by the driver. It may therefore be | |
865 | * called from any context, may be under the tty atomic_write_lock | |
866 | * but not always. | |
867 | * | |
868 | * Locking: | |
04f378b1 | 869 | * Uses the tty control lock internally |
af9b897e AC |
870 | */ |
871 | ||
1da177e4 LT |
872 | void stop_tty(struct tty_struct *tty) |
873 | { | |
04f378b1 AC |
874 | unsigned long flags; |
875 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
876 | if (tty->stopped) { | |
877 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 878 | return; |
04f378b1 | 879 | } |
1da177e4 LT |
880 | tty->stopped = 1; |
881 | if (tty->link && tty->link->packet) { | |
882 | tty->ctrl_status &= ~TIOCPKT_START; | |
883 | tty->ctrl_status |= TIOCPKT_STOP; | |
884 | wake_up_interruptible(&tty->link->read_wait); | |
885 | } | |
04f378b1 | 886 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
887 | if (tty->ops->stop) |
888 | (tty->ops->stop)(tty); | |
1da177e4 LT |
889 | } |
890 | ||
891 | EXPORT_SYMBOL(stop_tty); | |
892 | ||
af9b897e | 893 | /** |
beb7dd86 | 894 | * start_tty - propagate flow control |
af9b897e AC |
895 | * @tty: tty to start |
896 | * | |
897 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 898 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
899 | * is the tty was previous stopped and is being started then the |
900 | * driver start method is invoked and the line discipline woken. | |
901 | * | |
902 | * Locking: | |
04f378b1 | 903 | * ctrl_lock |
af9b897e AC |
904 | */ |
905 | ||
1da177e4 LT |
906 | void start_tty(struct tty_struct *tty) |
907 | { | |
04f378b1 AC |
908 | unsigned long flags; |
909 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
910 | if (!tty->stopped || tty->flow_stopped) { | |
911 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 912 | return; |
04f378b1 | 913 | } |
1da177e4 LT |
914 | tty->stopped = 0; |
915 | if (tty->link && tty->link->packet) { | |
916 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
917 | tty->ctrl_status |= TIOCPKT_START; | |
918 | wake_up_interruptible(&tty->link->read_wait); | |
919 | } | |
04f378b1 | 920 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
921 | if (tty->ops->start) |
922 | (tty->ops->start)(tty); | |
1da177e4 LT |
923 | /* If we have a running line discipline it may need kicking */ |
924 | tty_wakeup(tty); | |
1da177e4 LT |
925 | } |
926 | ||
927 | EXPORT_SYMBOL(start_tty); | |
928 | ||
af9b897e AC |
929 | /** |
930 | * tty_read - read method for tty device files | |
931 | * @file: pointer to tty file | |
932 | * @buf: user buffer | |
933 | * @count: size of user buffer | |
934 | * @ppos: unused | |
935 | * | |
936 | * Perform the read system call function on this terminal device. Checks | |
937 | * for hung up devices before calling the line discipline method. | |
938 | * | |
939 | * Locking: | |
47f86834 AC |
940 | * Locks the line discipline internally while needed. Multiple |
941 | * read calls may be outstanding in parallel. | |
af9b897e AC |
942 | */ |
943 | ||
37bdfb07 | 944 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
945 | loff_t *ppos) |
946 | { | |
947 | int i; | |
37bdfb07 | 948 | struct tty_struct *tty; |
1da177e4 LT |
949 | struct inode *inode; |
950 | struct tty_ldisc *ld; | |
951 | ||
952 | tty = (struct tty_struct *)file->private_data; | |
a7113a96 | 953 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
954 | if (tty_paranoia_check(tty, inode, "tty_read")) |
955 | return -EIO; | |
956 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
957 | return -EIO; | |
958 | ||
959 | /* We want to wait for the line discipline to sort out in this | |
960 | situation */ | |
961 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
962 | if (ld->ops->read) |
963 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
964 | else |
965 | i = -EIO; | |
966 | tty_ldisc_deref(ld); | |
1da177e4 LT |
967 | if (i > 0) |
968 | inode->i_atime = current_fs_time(inode->i_sb); | |
969 | return i; | |
970 | } | |
971 | ||
9c1729db AC |
972 | void tty_write_unlock(struct tty_struct *tty) |
973 | { | |
974 | mutex_unlock(&tty->atomic_write_lock); | |
975 | wake_up_interruptible(&tty->write_wait); | |
976 | } | |
977 | ||
978 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
979 | { | |
980 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
981 | if (ndelay) | |
982 | return -EAGAIN; | |
983 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
984 | return -ERESTARTSYS; | |
985 | } | |
986 | return 0; | |
987 | } | |
988 | ||
1da177e4 LT |
989 | /* |
990 | * Split writes up in sane blocksizes to avoid | |
991 | * denial-of-service type attacks | |
992 | */ | |
993 | static inline ssize_t do_tty_write( | |
994 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
995 | struct tty_struct *tty, | |
996 | struct file *file, | |
997 | const char __user *buf, | |
998 | size_t count) | |
999 | { | |
9c1729db | 1000 | ssize_t ret, written = 0; |
1da177e4 | 1001 | unsigned int chunk; |
37bdfb07 | 1002 | |
9c1729db AC |
1003 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1004 | if (ret < 0) | |
1005 | return ret; | |
1da177e4 LT |
1006 | |
1007 | /* | |
1008 | * We chunk up writes into a temporary buffer. This | |
1009 | * simplifies low-level drivers immensely, since they | |
1010 | * don't have locking issues and user mode accesses. | |
1011 | * | |
1012 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1013 | * big chunk-size.. | |
1014 | * | |
1015 | * The default chunk-size is 2kB, because the NTTY | |
1016 | * layer has problems with bigger chunks. It will | |
1017 | * claim to be able to handle more characters than | |
1018 | * it actually does. | |
af9b897e AC |
1019 | * |
1020 | * FIXME: This can probably go away now except that 64K chunks | |
1021 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1022 | */ |
1023 | chunk = 2048; | |
1024 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1025 | chunk = 65536; | |
1026 | if (count < chunk) | |
1027 | chunk = count; | |
1028 | ||
70522e12 | 1029 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 LT |
1030 | if (tty->write_cnt < chunk) { |
1031 | unsigned char *buf; | |
1032 | ||
1033 | if (chunk < 1024) | |
1034 | chunk = 1024; | |
1035 | ||
1036 | buf = kmalloc(chunk, GFP_KERNEL); | |
1037 | if (!buf) { | |
9c1729db AC |
1038 | ret = -ENOMEM; |
1039 | goto out; | |
1da177e4 LT |
1040 | } |
1041 | kfree(tty->write_buf); | |
1042 | tty->write_cnt = chunk; | |
1043 | tty->write_buf = buf; | |
1044 | } | |
1045 | ||
1046 | /* Do the write .. */ | |
1047 | for (;;) { | |
1048 | size_t size = count; | |
1049 | if (size > chunk) | |
1050 | size = chunk; | |
1051 | ret = -EFAULT; | |
1052 | if (copy_from_user(tty->write_buf, buf, size)) | |
1053 | break; | |
1da177e4 | 1054 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1055 | if (ret <= 0) |
1056 | break; | |
1057 | written += ret; | |
1058 | buf += ret; | |
1059 | count -= ret; | |
1060 | if (!count) | |
1061 | break; | |
1062 | ret = -ERESTARTSYS; | |
1063 | if (signal_pending(current)) | |
1064 | break; | |
1065 | cond_resched(); | |
1066 | } | |
1067 | if (written) { | |
a7113a96 | 1068 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1069 | inode->i_mtime = current_fs_time(inode->i_sb); |
1070 | ret = written; | |
1071 | } | |
9c1729db AC |
1072 | out: |
1073 | tty_write_unlock(tty); | |
1da177e4 LT |
1074 | return ret; |
1075 | } | |
1076 | ||
95f9bfc6 AC |
1077 | /** |
1078 | * tty_write_message - write a message to a certain tty, not just the console. | |
1079 | * @tty: the destination tty_struct | |
1080 | * @msg: the message to write | |
1081 | * | |
1082 | * This is used for messages that need to be redirected to a specific tty. | |
1083 | * We don't put it into the syslog queue right now maybe in the future if | |
1084 | * really needed. | |
1085 | * | |
1086 | * We must still hold the BKL and test the CLOSING flag for the moment. | |
1087 | */ | |
1088 | ||
1089 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1090 | { | |
1091 | lock_kernel(); | |
1092 | if (tty) { | |
1093 | mutex_lock(&tty->atomic_write_lock); | |
1094 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) | |
1095 | tty->ops->write(tty, msg, strlen(msg)); | |
1096 | tty_write_unlock(tty); | |
1097 | } | |
1098 | unlock_kernel(); | |
1099 | return; | |
1100 | } | |
1101 | ||
1da177e4 | 1102 | |
af9b897e AC |
1103 | /** |
1104 | * tty_write - write method for tty device file | |
1105 | * @file: tty file pointer | |
1106 | * @buf: user data to write | |
1107 | * @count: bytes to write | |
1108 | * @ppos: unused | |
1109 | * | |
1110 | * Write data to a tty device via the line discipline. | |
1111 | * | |
1112 | * Locking: | |
1113 | * Locks the line discipline as required | |
1114 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1115 | * and are then processed in chunks to the device. The line discipline | |
1116 | * write method will not be involked in parallel for each device | |
1117 | * The line discipline write method is called under the big | |
1118 | * kernel lock for historical reasons. New code should not rely on this. | |
1119 | */ | |
1120 | ||
37bdfb07 AC |
1121 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1122 | size_t count, loff_t *ppos) | |
1da177e4 | 1123 | { |
37bdfb07 | 1124 | struct tty_struct *tty; |
a7113a96 | 1125 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1126 | ssize_t ret; |
1127 | struct tty_ldisc *ld; | |
37bdfb07 | 1128 | |
1da177e4 LT |
1129 | tty = (struct tty_struct *)file->private_data; |
1130 | if (tty_paranoia_check(tty, inode, "tty_write")) | |
1131 | return -EIO; | |
f34d7a5b | 1132 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1133 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1134 | return -EIO; | |
f34d7a5b AC |
1135 | /* Short term debug to catch buggy drivers */ |
1136 | if (tty->ops->write_room == NULL) | |
1137 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1138 | tty->driver->name); | |
37bdfb07 | 1139 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1140 | if (!ld->ops->write) |
1da177e4 LT |
1141 | ret = -EIO; |
1142 | else | |
a352def2 | 1143 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1144 | tty_ldisc_deref(ld); |
1145 | return ret; | |
1146 | } | |
1147 | ||
37bdfb07 AC |
1148 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1149 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1150 | { |
1151 | struct file *p = NULL; | |
1152 | ||
1153 | spin_lock(&redirect_lock); | |
1154 | if (redirect) { | |
1155 | get_file(redirect); | |
1156 | p = redirect; | |
1157 | } | |
1158 | spin_unlock(&redirect_lock); | |
1159 | ||
1160 | if (p) { | |
1161 | ssize_t res; | |
1162 | res = vfs_write(p, buf, count, &p->f_pos); | |
1163 | fput(p); | |
1164 | return res; | |
1165 | } | |
1da177e4 LT |
1166 | return tty_write(file, buf, count, ppos); |
1167 | } | |
1168 | ||
1169 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1170 | ||
af9b897e AC |
1171 | /** |
1172 | * pty_line_name - generate name for a pty | |
1173 | * @driver: the tty driver in use | |
1174 | * @index: the minor number | |
1175 | * @p: output buffer of at least 6 bytes | |
1176 | * | |
1177 | * Generate a name from a driver reference and write it to the output | |
1178 | * buffer. | |
1179 | * | |
1180 | * Locking: None | |
1181 | */ | |
1182 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1183 | { |
1184 | int i = index + driver->name_base; | |
1185 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1186 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1187 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1188 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1189 | } |
1190 | ||
af9b897e AC |
1191 | /** |
1192 | * pty_line_name - generate name for a tty | |
1193 | * @driver: the tty driver in use | |
1194 | * @index: the minor number | |
1195 | * @p: output buffer of at least 7 bytes | |
1196 | * | |
1197 | * Generate a name from a driver reference and write it to the output | |
1198 | * buffer. | |
1199 | * | |
1200 | * Locking: None | |
1201 | */ | |
1202 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1203 | { |
1204 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1205 | } | |
1206 | ||
af9b897e | 1207 | /** |
d81ed103 | 1208 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1209 | * @driver: tty driver we are opening a device on |
1210 | * @idx: device index | |
15582d36 AC |
1211 | * @ret_tty: returned tty structure |
1212 | * @first_ok: ok to open a new device (used by ptmx) | |
af9b897e AC |
1213 | * |
1214 | * Prepare a tty device. This may not be a "new" clean device but | |
1215 | * could also be an active device. The pty drivers require special | |
1216 | * handling because of this. | |
1217 | * | |
1218 | * Locking: | |
1219 | * The function is called under the tty_mutex, which | |
1220 | * protects us from the tty struct or driver itself going away. | |
1221 | * | |
1222 | * On exit the tty device has the line discipline attached and | |
1223 | * a reference count of 1. If a pair was created for pty/tty use | |
1224 | * and the other was a pty master then it too has a reference count of 1. | |
1225 | * | |
1da177e4 | 1226 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1227 | * failed open. The new code protects the open with a mutex, so it's |
1228 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1229 | * relaxed for the (most common) case of reopening a tty. |
1230 | */ | |
af9b897e | 1231 | |
d81ed103 | 1232 | int tty_init_dev(struct tty_driver *driver, int idx, |
15582d36 | 1233 | struct tty_struct **ret_tty, int first_ok) |
1da177e4 LT |
1234 | { |
1235 | struct tty_struct *tty, *o_tty; | |
edc6afc5 AC |
1236 | struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; |
1237 | struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; | |
af9b897e | 1238 | int retval = 0; |
1da177e4 LT |
1239 | |
1240 | /* check whether we're reopening an existing tty */ | |
1241 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1242 | tty = devpts_get_tty(idx); | |
5a39e8c6 ASRF |
1243 | /* |
1244 | * If we don't have a tty here on a slave open, it's because | |
1245 | * the master already started the close process and there's | |
1246 | * no relation between devpts file and tty anymore. | |
1247 | */ | |
1248 | if (!tty && driver->subtype == PTY_TYPE_SLAVE) { | |
1249 | retval = -EIO; | |
1250 | goto end_init; | |
1251 | } | |
1252 | /* | |
d81ed103 AC |
1253 | * It's safe from now on because tty_init_dev() is called with |
1254 | * tty_mutex held and tty_release_dev() won't change tty->count | |
5a39e8c6 ASRF |
1255 | * or tty->flags without having to grab tty_mutex |
1256 | */ | |
1da177e4 LT |
1257 | if (tty && driver->subtype == PTY_TYPE_MASTER) |
1258 | tty = tty->link; | |
1259 | } else { | |
1260 | tty = driver->ttys[idx]; | |
1261 | } | |
1262 | if (tty) goto fast_track; | |
1263 | ||
15582d36 AC |
1264 | if (driver->subtype == PTY_TYPE_MASTER && |
1265 | (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { | |
1266 | retval = -EIO; | |
1267 | goto end_init; | |
1268 | } | |
1da177e4 LT |
1269 | /* |
1270 | * First time open is complex, especially for PTY devices. | |
1271 | * This code guarantees that either everything succeeds and the | |
1272 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1273 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1274 | * and locked termios may be retained.) |
1275 | */ | |
1276 | ||
1277 | if (!try_module_get(driver->owner)) { | |
1278 | retval = -ENODEV; | |
1279 | goto end_init; | |
1280 | } | |
1281 | ||
1282 | o_tty = NULL; | |
1283 | tp = o_tp = NULL; | |
1284 | ltp = o_ltp = NULL; | |
1285 | ||
1286 | tty = alloc_tty_struct(); | |
37bdfb07 | 1287 | if (!tty) |
1da177e4 LT |
1288 | goto fail_no_mem; |
1289 | initialize_tty_struct(tty); | |
1290 | tty->driver = driver; | |
f34d7a5b | 1291 | tty->ops = driver->ops; |
1da177e4 LT |
1292 | tty->index = idx; |
1293 | tty_line_name(driver, idx, tty->name); | |
1294 | ||
1295 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1296 | tp_loc = &tty->termios; | |
1297 | ltp_loc = &tty->termios_locked; | |
1298 | } else { | |
1299 | tp_loc = &driver->termios[idx]; | |
1300 | ltp_loc = &driver->termios_locked[idx]; | |
1301 | } | |
1302 | ||
1303 | if (!*tp_loc) { | |
abcb1ff3 | 1304 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1305 | if (!tp) |
1306 | goto free_mem_out; | |
1307 | *tp = driver->init_termios; | |
1308 | } | |
1309 | ||
1310 | if (!*ltp_loc) { | |
506eb99a | 1311 | ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1312 | if (!ltp) |
1313 | goto free_mem_out; | |
1da177e4 LT |
1314 | } |
1315 | ||
1316 | if (driver->type == TTY_DRIVER_TYPE_PTY) { | |
1317 | o_tty = alloc_tty_struct(); | |
1318 | if (!o_tty) | |
1319 | goto free_mem_out; | |
6f967f78 AC |
1320 | if (!try_module_get(driver->other->owner)) { |
1321 | /* This cannot in fact currently happen */ | |
1322 | free_tty_struct(o_tty); | |
1323 | o_tty = NULL; | |
1324 | goto free_mem_out; | |
1325 | } | |
1da177e4 LT |
1326 | initialize_tty_struct(o_tty); |
1327 | o_tty->driver = driver->other; | |
f34d7a5b | 1328 | o_tty->ops = driver->ops; |
1da177e4 LT |
1329 | o_tty->index = idx; |
1330 | tty_line_name(driver->other, idx, o_tty->name); | |
1331 | ||
1332 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1333 | o_tp_loc = &o_tty->termios; | |
1334 | o_ltp_loc = &o_tty->termios_locked; | |
1335 | } else { | |
1336 | o_tp_loc = &driver->other->termios[idx]; | |
1337 | o_ltp_loc = &driver->other->termios_locked[idx]; | |
1338 | } | |
1339 | ||
1340 | if (!*o_tp_loc) { | |
abcb1ff3 | 1341 | o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1342 | if (!o_tp) |
1343 | goto free_mem_out; | |
1344 | *o_tp = driver->other->init_termios; | |
1345 | } | |
1346 | ||
1347 | if (!*o_ltp_loc) { | |
506eb99a | 1348 | o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1349 | if (!o_ltp) |
1350 | goto free_mem_out; | |
1da177e4 LT |
1351 | } |
1352 | ||
1353 | /* | |
1354 | * Everything allocated ... set up the o_tty structure. | |
1355 | */ | |
37bdfb07 | 1356 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) |
1da177e4 | 1357 | driver->other->ttys[idx] = o_tty; |
1da177e4 LT |
1358 | if (!*o_tp_loc) |
1359 | *o_tp_loc = o_tp; | |
1360 | if (!*o_ltp_loc) | |
1361 | *o_ltp_loc = o_ltp; | |
1362 | o_tty->termios = *o_tp_loc; | |
1363 | o_tty->termios_locked = *o_ltp_loc; | |
1364 | driver->other->refcount++; | |
1365 | if (driver->subtype == PTY_TYPE_MASTER) | |
1366 | o_tty->count++; | |
1367 | ||
1368 | /* Establish the links in both directions */ | |
1369 | tty->link = o_tty; | |
1370 | o_tty->link = tty; | |
1371 | } | |
1372 | ||
37bdfb07 | 1373 | /* |
1da177e4 | 1374 | * All structures have been allocated, so now we install them. |
d5698c28 | 1375 | * Failures after this point use release_tty to clean up, so |
1da177e4 LT |
1376 | * there's no need to null out the local pointers. |
1377 | */ | |
37bdfb07 | 1378 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) |
1da177e4 | 1379 | driver->ttys[idx] = tty; |
37bdfb07 | 1380 | |
1da177e4 LT |
1381 | if (!*tp_loc) |
1382 | *tp_loc = tp; | |
1383 | if (!*ltp_loc) | |
1384 | *ltp_loc = ltp; | |
1385 | tty->termios = *tp_loc; | |
1386 | tty->termios_locked = *ltp_loc; | |
edc6afc5 AC |
1387 | /* Compatibility until drivers always set this */ |
1388 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1389 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1da177e4 LT |
1390 | driver->refcount++; |
1391 | tty->count++; | |
1392 | ||
37bdfb07 | 1393 | /* |
1da177e4 | 1394 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1395 | * If we fail here just call release_tty to clean up. No need |
1396 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 LT |
1397 | */ |
1398 | ||
01e1abb2 AC |
1399 | retval = tty_ldisc_setup(tty, o_tty); |
1400 | ||
1401 | if (retval) | |
1402 | goto release_mem_out; | |
15582d36 | 1403 | goto success; |
1da177e4 LT |
1404 | |
1405 | /* | |
1406 | * This fast open can be used if the tty is already open. | |
1407 | * No memory is allocated, and the only failures are from | |
1408 | * attempting to open a closing tty or attempting multiple | |
1409 | * opens on a pty master. | |
1410 | */ | |
1411 | fast_track: | |
1412 | if (test_bit(TTY_CLOSING, &tty->flags)) { | |
1413 | retval = -EIO; | |
1414 | goto end_init; | |
1415 | } | |
1416 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1417 | driver->subtype == PTY_TYPE_MASTER) { | |
1418 | /* | |
37bdfb07 | 1419 | * special case for PTY masters: only one open permitted, |
1da177e4 LT |
1420 | * and the slave side open count is incremented as well. |
1421 | */ | |
1422 | if (tty->count) { | |
1423 | retval = -EIO; | |
1424 | goto end_init; | |
1425 | } | |
1426 | tty->link->count++; | |
1427 | } | |
1428 | tty->count++; | |
1429 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1430 | ||
1431 | /* FIXME */ | |
37bdfb07 | 1432 | if (!test_bit(TTY_LDISC, &tty->flags)) |
d81ed103 | 1433 | printk(KERN_ERR "tty_init_dev but no ldisc\n"); |
1da177e4 LT |
1434 | success: |
1435 | *ret_tty = tty; | |
37bdfb07 | 1436 | |
70522e12 | 1437 | /* All paths come through here to release the mutex */ |
1da177e4 LT |
1438 | end_init: |
1439 | return retval; | |
1440 | ||
1441 | /* Release locally allocated memory ... nothing placed in slots */ | |
1442 | free_mem_out: | |
735d5661 | 1443 | kfree(o_tp); |
6f967f78 AC |
1444 | if (o_tty) { |
1445 | module_put(o_tty->driver->owner); | |
1da177e4 | 1446 | free_tty_struct(o_tty); |
6f967f78 | 1447 | } |
735d5661 JJ |
1448 | kfree(ltp); |
1449 | kfree(tp); | |
1da177e4 LT |
1450 | free_tty_struct(tty); |
1451 | ||
1452 | fail_no_mem: | |
1453 | module_put(driver->owner); | |
1454 | retval = -ENOMEM; | |
1455 | goto end_init; | |
1456 | ||
d5698c28 | 1457 | /* call the tty release_tty routine to clean out this slot */ |
1da177e4 | 1458 | release_mem_out: |
4050914f | 1459 | if (printk_ratelimit()) |
d81ed103 | 1460 | printk(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1461 | "clearing slot %d\n", idx); |
d5698c28 | 1462 | release_tty(tty, idx); |
1da177e4 LT |
1463 | goto end_init; |
1464 | } | |
1465 | ||
feebed65 AC |
1466 | void tty_free_termios(struct tty_struct *tty) |
1467 | { | |
1468 | struct ktermios *tp; | |
1469 | int idx = tty->index; | |
1470 | /* Kill this flag and push into drivers for locking etc */ | |
1471 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1472 | /* FIXME: Locking on ->termios array */ | |
1473 | tp = tty->termios; | |
1474 | tty->driver->termios[idx] = NULL; | |
1475 | kfree(tp); | |
1476 | ||
1477 | tp = tty->termios_locked; | |
1478 | tty->driver->termios_locked[idx] = NULL; | |
1479 | kfree(tp); | |
1480 | } | |
1481 | } | |
1482 | EXPORT_SYMBOL(tty_free_termios); | |
1483 | ||
1484 | void tty_shutdown(struct tty_struct *tty) | |
1485 | { | |
1486 | tty->driver->ttys[tty->index] = NULL; | |
1487 | tty_free_termios(tty); | |
1488 | } | |
1489 | EXPORT_SYMBOL(tty_shutdown); | |
1490 | ||
af9b897e | 1491 | /** |
d5698c28 | 1492 | * release_one_tty - release tty structure memory |
9c9f4ded | 1493 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1494 | * |
1495 | * Releases memory associated with a tty structure, and clears out the | |
1496 | * driver table slots. This function is called when a device is no longer | |
1497 | * in use. It also gets called when setup of a device fails. | |
1498 | * | |
1499 | * Locking: | |
1500 | * tty_mutex - sometimes only | |
1501 | * takes the file list lock internally when working on the list | |
1502 | * of ttys that the driver keeps. | |
1da177e4 | 1503 | */ |
9c9f4ded | 1504 | static void release_one_tty(struct kref *kref) |
1da177e4 | 1505 | { |
9c9f4ded | 1506 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); |
6f967f78 | 1507 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1508 | |
feebed65 AC |
1509 | if (tty->ops->shutdown) |
1510 | tty->ops->shutdown(tty); | |
1511 | else | |
1512 | tty_shutdown(tty); | |
1da177e4 | 1513 | tty->magic = 0; |
9c9f4ded | 1514 | /* FIXME: locking on tty->driver->refcount */ |
1da177e4 | 1515 | tty->driver->refcount--; |
6f967f78 | 1516 | module_put(driver->owner); |
d5698c28 | 1517 | |
1da177e4 LT |
1518 | file_list_lock(); |
1519 | list_del_init(&tty->tty_files); | |
1520 | file_list_unlock(); | |
d5698c28 | 1521 | |
1da177e4 LT |
1522 | free_tty_struct(tty); |
1523 | } | |
1524 | ||
9c9f4ded AC |
1525 | /** |
1526 | * tty_kref_put - release a tty kref | |
1527 | * @tty: tty device | |
1528 | * | |
1529 | * Release a reference to a tty device and if need be let the kref | |
1530 | * layer destruct the object for us | |
1531 | */ | |
1532 | ||
1533 | void tty_kref_put(struct tty_struct *tty) | |
1534 | { | |
1535 | if (tty) | |
1536 | kref_put(&tty->kref, release_one_tty); | |
1537 | } | |
1538 | EXPORT_SYMBOL(tty_kref_put); | |
1539 | ||
d5698c28 CH |
1540 | /** |
1541 | * release_tty - release tty structure memory | |
1542 | * | |
1543 | * Release both @tty and a possible linked partner (think pty pair), | |
1544 | * and decrement the refcount of the backing module. | |
1545 | * | |
1546 | * Locking: | |
1547 | * tty_mutex - sometimes only | |
1548 | * takes the file list lock internally when working on the list | |
1549 | * of ttys that the driver keeps. | |
1550 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1551 | * |
d5698c28 CH |
1552 | */ |
1553 | static void release_tty(struct tty_struct *tty, int idx) | |
1554 | { | |
9c9f4ded AC |
1555 | /* This should always be true but check for the moment */ |
1556 | WARN_ON(tty->index != idx); | |
1557 | ||
d5698c28 | 1558 | if (tty->link) |
9c9f4ded AC |
1559 | tty_kref_put(tty->link); |
1560 | tty_kref_put(tty); | |
d5698c28 CH |
1561 | } |
1562 | ||
1da177e4 LT |
1563 | /* |
1564 | * Even releasing the tty structures is a tricky business.. We have | |
1565 | * to be very careful that the structures are all released at the | |
1566 | * same time, as interrupts might otherwise get the wrong pointers. | |
1567 | * | |
1568 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1569 | * lead to double frees or releasing memory still in use. | |
1570 | */ | |
d81ed103 | 1571 | void tty_release_dev(struct file *filp) |
1da177e4 LT |
1572 | { |
1573 | struct tty_struct *tty, *o_tty; | |
1574 | int pty_master, tty_closing, o_tty_closing, do_sleep; | |
14a6283e | 1575 | int devpts; |
1da177e4 LT |
1576 | int idx; |
1577 | char buf[64]; | |
37bdfb07 | 1578 | |
1da177e4 | 1579 | tty = (struct tty_struct *)filp->private_data; |
37bdfb07 | 1580 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, |
d81ed103 | 1581 | "tty_release_dev")) |
1da177e4 LT |
1582 | return; |
1583 | ||
d81ed103 | 1584 | check_tty_count(tty, "tty_release_dev"); |
1da177e4 LT |
1585 | |
1586 | tty_fasync(-1, filp, 0); | |
1587 | ||
1588 | idx = tty->index; | |
1589 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1590 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1591 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1592 | o_tty = tty->link; |
1593 | ||
1594 | #ifdef TTY_PARANOIA_CHECK | |
1595 | if (idx < 0 || idx >= tty->driver->num) { | |
d81ed103 | 1596 | printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " |
1da177e4 LT |
1597 | "free (%s)\n", tty->name); |
1598 | return; | |
1599 | } | |
1600 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1601 | if (tty != tty->driver->ttys[idx]) { | |
d81ed103 | 1602 | printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " |
1da177e4 LT |
1603 | "for (%s)\n", idx, tty->name); |
1604 | return; | |
1605 | } | |
1606 | if (tty->termios != tty->driver->termios[idx]) { | |
d81ed103 | 1607 | printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " |
1da177e4 LT |
1608 | "for (%s)\n", |
1609 | idx, tty->name); | |
1610 | return; | |
1611 | } | |
1612 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { | |
d81ed103 | 1613 | printk(KERN_DEBUG "tty_release_dev: driver.termios_locked[%d] not " |
1da177e4 LT |
1614 | "termios_locked for (%s)\n", |
1615 | idx, tty->name); | |
1616 | return; | |
1617 | } | |
1618 | } | |
1619 | #endif | |
1620 | ||
1621 | #ifdef TTY_DEBUG_HANGUP | |
d81ed103 | 1622 | printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", |
1da177e4 LT |
1623 | tty_name(tty, buf), tty->count); |
1624 | #endif | |
1625 | ||
1626 | #ifdef TTY_PARANOIA_CHECK | |
1627 | if (tty->driver->other && | |
1628 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1629 | if (o_tty != tty->driver->other->ttys[idx]) { | |
d81ed103 | 1630 | printk(KERN_DEBUG "tty_release_dev: other->table[%d] " |
1da177e4 LT |
1631 | "not o_tty for (%s)\n", |
1632 | idx, tty->name); | |
1633 | return; | |
1634 | } | |
1635 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
d81ed103 | 1636 | printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " |
1da177e4 LT |
1637 | "not o_termios for (%s)\n", |
1638 | idx, tty->name); | |
1639 | return; | |
1640 | } | |
37bdfb07 | 1641 | if (o_tty->termios_locked != |
1da177e4 | 1642 | tty->driver->other->termios_locked[idx]) { |
d81ed103 | 1643 | printk(KERN_DEBUG "tty_release_dev: other->termios_locked[" |
1da177e4 LT |
1644 | "%d] not o_termios_locked for (%s)\n", |
1645 | idx, tty->name); | |
1646 | return; | |
1647 | } | |
1648 | if (o_tty->link != tty) { | |
d81ed103 | 1649 | printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); |
1da177e4 LT |
1650 | return; |
1651 | } | |
1652 | } | |
1653 | #endif | |
f34d7a5b AC |
1654 | if (tty->ops->close) |
1655 | tty->ops->close(tty, filp); | |
1da177e4 LT |
1656 | |
1657 | /* | |
1658 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1659 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1660 | * wait queues and kick everyone out _before_ actually starting to | |
1661 | * close. This ensures that we won't block while releasing the tty | |
1662 | * structure. | |
1663 | * | |
1664 | * The test for the o_tty closing is necessary, since the master and | |
1665 | * slave sides may close in any order. If the slave side closes out | |
1666 | * first, its count will be one, since the master side holds an open. | |
1667 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1668 | * so we do it now. | |
1669 | * | |
1670 | * Note that it's possible for the tty to be opened again while we're | |
1671 | * flushing out waiters. By recalculating the closing flags before | |
1672 | * each iteration we avoid any problems. | |
1673 | */ | |
1674 | while (1) { | |
1675 | /* Guard against races with tty->count changes elsewhere and | |
1676 | opens on /dev/tty */ | |
37bdfb07 | 1677 | |
70522e12 | 1678 | mutex_lock(&tty_mutex); |
1da177e4 LT |
1679 | tty_closing = tty->count <= 1; |
1680 | o_tty_closing = o_tty && | |
1681 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1682 | do_sleep = 0; |
1683 | ||
1684 | if (tty_closing) { | |
1685 | if (waitqueue_active(&tty->read_wait)) { | |
1686 | wake_up(&tty->read_wait); | |
1687 | do_sleep++; | |
1688 | } | |
1689 | if (waitqueue_active(&tty->write_wait)) { | |
1690 | wake_up(&tty->write_wait); | |
1691 | do_sleep++; | |
1692 | } | |
1693 | } | |
1694 | if (o_tty_closing) { | |
1695 | if (waitqueue_active(&o_tty->read_wait)) { | |
1696 | wake_up(&o_tty->read_wait); | |
1697 | do_sleep++; | |
1698 | } | |
1699 | if (waitqueue_active(&o_tty->write_wait)) { | |
1700 | wake_up(&o_tty->write_wait); | |
1701 | do_sleep++; | |
1702 | } | |
1703 | } | |
1704 | if (!do_sleep) | |
1705 | break; | |
1706 | ||
d81ed103 | 1707 | printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " |
1da177e4 | 1708 | "active!\n", tty_name(tty, buf)); |
70522e12 | 1709 | mutex_unlock(&tty_mutex); |
1da177e4 | 1710 | schedule(); |
37bdfb07 | 1711 | } |
1da177e4 LT |
1712 | |
1713 | /* | |
37bdfb07 AC |
1714 | * The closing flags are now consistent with the open counts on |
1715 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1716 | * block, so it's safe to proceed with closing. |
1717 | */ | |
1da177e4 LT |
1718 | if (pty_master) { |
1719 | if (--o_tty->count < 0) { | |
d81ed103 | 1720 | printk(KERN_WARNING "tty_release_dev: bad pty slave count " |
1da177e4 LT |
1721 | "(%d) for %s\n", |
1722 | o_tty->count, tty_name(o_tty, buf)); | |
1723 | o_tty->count = 0; | |
1724 | } | |
1725 | } | |
1726 | if (--tty->count < 0) { | |
d81ed103 | 1727 | printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", |
1da177e4 LT |
1728 | tty->count, tty_name(tty, buf)); |
1729 | tty->count = 0; | |
1730 | } | |
37bdfb07 | 1731 | |
1da177e4 LT |
1732 | /* |
1733 | * We've decremented tty->count, so we need to remove this file | |
1734 | * descriptor off the tty->tty_files list; this serves two | |
1735 | * purposes: | |
1736 | * - check_tty_count sees the correct number of file descriptors | |
1737 | * associated with this tty. | |
1738 | * - do_tty_hangup no longer sees this file descriptor as | |
1739 | * something that needs to be handled for hangups. | |
1740 | */ | |
1741 | file_kill(filp); | |
1742 | filp->private_data = NULL; | |
1743 | ||
1744 | /* | |
1745 | * Perform some housekeeping before deciding whether to return. | |
1746 | * | |
1747 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1748 | * case of a pty we may have to wait around for the other side | |
1749 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1750 | */ | |
37bdfb07 | 1751 | if (tty_closing) |
1da177e4 | 1752 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1753 | if (o_tty_closing) |
1da177e4 LT |
1754 | set_bit(TTY_CLOSING, &o_tty->flags); |
1755 | ||
1756 | /* | |
1757 | * If _either_ side is closing, make sure there aren't any | |
1758 | * processes that still think tty or o_tty is their controlling | |
1759 | * tty. | |
1760 | */ | |
1761 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1762 | read_lock(&tasklist_lock); |
24ec839c | 1763 | session_clear_tty(tty->session); |
1da177e4 | 1764 | if (o_tty) |
24ec839c | 1765 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1766 | read_unlock(&tasklist_lock); |
1767 | } | |
1768 | ||
70522e12 | 1769 | mutex_unlock(&tty_mutex); |
da965822 | 1770 | |
1da177e4 LT |
1771 | /* check whether both sides are closing ... */ |
1772 | if (!tty_closing || (o_tty && !o_tty_closing)) | |
1773 | return; | |
37bdfb07 | 1774 | |
1da177e4 LT |
1775 | #ifdef TTY_DEBUG_HANGUP |
1776 | printk(KERN_DEBUG "freeing tty structure..."); | |
1777 | #endif | |
1778 | /* | |
01e1abb2 | 1779 | * Ask the line discipline code to release its structures |
1da177e4 | 1780 | */ |
01e1abb2 | 1781 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1782 | /* |
d5698c28 | 1783 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1784 | * the slots and preserving the termios structure. |
1785 | */ | |
d5698c28 | 1786 | release_tty(tty, idx); |
1da177e4 | 1787 | |
1da177e4 | 1788 | /* Make this pty number available for reallocation */ |
718a9163 SB |
1789 | if (devpts) |
1790 | devpts_kill_index(idx); | |
1da177e4 LT |
1791 | } |
1792 | ||
af9b897e | 1793 | /** |
15582d36 | 1794 | * __tty_open - open a tty device |
af9b897e AC |
1795 | * @inode: inode of device file |
1796 | * @filp: file pointer to tty | |
1da177e4 | 1797 | * |
af9b897e AC |
1798 | * tty_open and tty_release keep up the tty count that contains the |
1799 | * number of opens done on a tty. We cannot use the inode-count, as | |
1800 | * different inodes might point to the same tty. | |
1da177e4 | 1801 | * |
af9b897e AC |
1802 | * Open-counting is needed for pty masters, as well as for keeping |
1803 | * track of serial lines: DTR is dropped when the last close happens. | |
1804 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1805 | * | |
1806 | * The termios state of a pty is reset on first open so that | |
1807 | * settings don't persist across reuse. | |
1808 | * | |
d81ed103 | 1809 | * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. |
24ec839c PZ |
1810 | * tty->count should protect the rest. |
1811 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1812 | */ |
af9b897e | 1813 | |
39d95b9d | 1814 | static int __tty_open(struct inode *inode, struct file *filp) |
1da177e4 LT |
1815 | { |
1816 | struct tty_struct *tty; | |
1817 | int noctty, retval; | |
1818 | struct tty_driver *driver; | |
1819 | int index; | |
1820 | dev_t device = inode->i_rdev; | |
1821 | unsigned short saved_flags = filp->f_flags; | |
1822 | ||
1823 | nonseekable_open(inode, filp); | |
37bdfb07 | 1824 | |
1da177e4 LT |
1825 | retry_open: |
1826 | noctty = filp->f_flags & O_NOCTTY; | |
1827 | index = -1; | |
1828 | retval = 0; | |
37bdfb07 | 1829 | |
70522e12 | 1830 | mutex_lock(&tty_mutex); |
1da177e4 | 1831 | |
37bdfb07 | 1832 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1833 | tty = get_current_tty(); |
1834 | if (!tty) { | |
70522e12 | 1835 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1836 | return -ENXIO; |
1837 | } | |
24ec839c PZ |
1838 | driver = tty->driver; |
1839 | index = tty->index; | |
1da177e4 LT |
1840 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1841 | /* noctty = 1; */ | |
452a00d2 AC |
1842 | /* FIXME: Should we take a driver reference ? */ |
1843 | tty_kref_put(tty); | |
1da177e4 LT |
1844 | goto got_driver; |
1845 | } | |
1846 | #ifdef CONFIG_VT | |
37bdfb07 | 1847 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 LT |
1848 | extern struct tty_driver *console_driver; |
1849 | driver = console_driver; | |
1850 | index = fg_console; | |
1851 | noctty = 1; | |
1852 | goto got_driver; | |
1853 | } | |
1854 | #endif | |
37bdfb07 | 1855 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
1da177e4 LT |
1856 | driver = console_device(&index); |
1857 | if (driver) { | |
1858 | /* Don't let /dev/console block */ | |
1859 | filp->f_flags |= O_NONBLOCK; | |
1860 | noctty = 1; | |
1861 | goto got_driver; | |
1862 | } | |
70522e12 | 1863 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1864 | return -ENODEV; |
1865 | } | |
1866 | ||
1867 | driver = get_tty_driver(device, &index); | |
1868 | if (!driver) { | |
70522e12 | 1869 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1870 | return -ENODEV; |
1871 | } | |
1872 | got_driver: | |
d81ed103 | 1873 | retval = tty_init_dev(driver, index, &tty, 0); |
70522e12 | 1874 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1875 | if (retval) |
1876 | return retval; | |
1877 | ||
1878 | filp->private_data = tty; | |
1879 | file_move(filp, &tty->tty_files); | |
1880 | check_tty_count(tty, "tty_open"); | |
1881 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1882 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1883 | noctty = 1; | |
1884 | #ifdef TTY_DEBUG_HANGUP | |
1885 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1886 | #endif | |
1887 | if (!retval) { | |
f34d7a5b AC |
1888 | if (tty->ops->open) |
1889 | retval = tty->ops->open(tty, filp); | |
1da177e4 LT |
1890 | else |
1891 | retval = -ENODEV; | |
1892 | } | |
1893 | filp->f_flags = saved_flags; | |
1894 | ||
37bdfb07 AC |
1895 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1896 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1897 | retval = -EBUSY; |
1898 | ||
1899 | if (retval) { | |
1900 | #ifdef TTY_DEBUG_HANGUP | |
1901 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1902 | tty->name); | |
1903 | #endif | |
d81ed103 | 1904 | tty_release_dev(filp); |
1da177e4 LT |
1905 | if (retval != -ERESTARTSYS) |
1906 | return retval; | |
1907 | if (signal_pending(current)) | |
1908 | return retval; | |
1909 | schedule(); | |
1910 | /* | |
1911 | * Need to reset f_op in case a hangup happened. | |
1912 | */ | |
1913 | if (filp->f_op == &hung_up_tty_fops) | |
1914 | filp->f_op = &tty_fops; | |
1915 | goto retry_open; | |
1916 | } | |
24ec839c PZ |
1917 | |
1918 | mutex_lock(&tty_mutex); | |
1919 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
1920 | if (!noctty && |
1921 | current->signal->leader && | |
1922 | !current->signal->tty && | |
ab521dc0 | 1923 | tty->session == NULL) |
2a65f1d9 | 1924 | __proc_set_tty(current, tty); |
24ec839c PZ |
1925 | spin_unlock_irq(¤t->sighand->siglock); |
1926 | mutex_unlock(&tty_mutex); | |
1da177e4 LT |
1927 | return 0; |
1928 | } | |
1929 | ||
39d95b9d JC |
1930 | /* BKL pushdown: scary code avoidance wrapper */ |
1931 | static int tty_open(struct inode *inode, struct file *filp) | |
1932 | { | |
1933 | int ret; | |
1934 | ||
1935 | lock_kernel(); | |
1936 | ret = __tty_open(inode, filp); | |
1937 | unlock_kernel(); | |
1938 | return ret; | |
1939 | } | |
1940 | ||
1941 | ||
1942 | ||
1da177e4 | 1943 | |
af9b897e AC |
1944 | /** |
1945 | * tty_release - vfs callback for close | |
1946 | * @inode: inode of tty | |
1947 | * @filp: file pointer for handle to tty | |
1948 | * | |
1949 | * Called the last time each file handle is closed that references | |
1950 | * this tty. There may however be several such references. | |
1951 | * | |
1952 | * Locking: | |
d81ed103 | 1953 | * Takes bkl. See tty_release_dev |
af9b897e AC |
1954 | */ |
1955 | ||
37bdfb07 | 1956 | static int tty_release(struct inode *inode, struct file *filp) |
1da177e4 LT |
1957 | { |
1958 | lock_kernel(); | |
d81ed103 | 1959 | tty_release_dev(filp); |
1da177e4 LT |
1960 | unlock_kernel(); |
1961 | return 0; | |
1962 | } | |
1963 | ||
af9b897e AC |
1964 | /** |
1965 | * tty_poll - check tty status | |
1966 | * @filp: file being polled | |
1967 | * @wait: poll wait structures to update | |
1968 | * | |
1969 | * Call the line discipline polling method to obtain the poll | |
1970 | * status of the device. | |
1971 | * | |
1972 | * Locking: locks called line discipline but ldisc poll method | |
1973 | * may be re-entered freely by other callers. | |
1974 | */ | |
1975 | ||
37bdfb07 | 1976 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 1977 | { |
37bdfb07 | 1978 | struct tty_struct *tty; |
1da177e4 LT |
1979 | struct tty_ldisc *ld; |
1980 | int ret = 0; | |
1981 | ||
1982 | tty = (struct tty_struct *)filp->private_data; | |
a7113a96 | 1983 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 1984 | return 0; |
37bdfb07 | 1985 | |
1da177e4 | 1986 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
1987 | if (ld->ops->poll) |
1988 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
1989 | tty_ldisc_deref(ld); |
1990 | return ret; | |
1991 | } | |
1992 | ||
37bdfb07 | 1993 | static int tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 1994 | { |
37bdfb07 | 1995 | struct tty_struct *tty; |
47f86834 | 1996 | unsigned long flags; |
5d1e3230 | 1997 | int retval = 0; |
1da177e4 | 1998 | |
5d1e3230 | 1999 | lock_kernel(); |
1da177e4 | 2000 | tty = (struct tty_struct *)filp->private_data; |
a7113a96 | 2001 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2002 | goto out; |
37bdfb07 | 2003 | |
1da177e4 LT |
2004 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2005 | if (retval <= 0) | |
5d1e3230 | 2006 | goto out; |
1da177e4 LT |
2007 | |
2008 | if (on) { | |
ab521dc0 EB |
2009 | enum pid_type type; |
2010 | struct pid *pid; | |
1da177e4 LT |
2011 | if (!waitqueue_active(&tty->read_wait)) |
2012 | tty->minimum_to_wake = 1; | |
47f86834 | 2013 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2014 | if (tty->pgrp) { |
2015 | pid = tty->pgrp; | |
2016 | type = PIDTYPE_PGID; | |
2017 | } else { | |
2018 | pid = task_pid(current); | |
2019 | type = PIDTYPE_PID; | |
2020 | } | |
47f86834 | 2021 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
ab521dc0 | 2022 | retval = __f_setown(filp, pid, type, 0); |
1da177e4 | 2023 | if (retval) |
5d1e3230 | 2024 | goto out; |
1da177e4 LT |
2025 | } else { |
2026 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2027 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2028 | } | |
5d1e3230 JC |
2029 | retval = 0; |
2030 | out: | |
2031 | unlock_kernel(); | |
2032 | return retval; | |
1da177e4 LT |
2033 | } |
2034 | ||
af9b897e AC |
2035 | /** |
2036 | * tiocsti - fake input character | |
2037 | * @tty: tty to fake input into | |
2038 | * @p: pointer to character | |
2039 | * | |
3a4fa0a2 | 2040 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2041 | * input management. |
2042 | * | |
2043 | * FIXME: does not honour flow control ?? | |
2044 | * | |
2045 | * Locking: | |
2046 | * Called functions take tty_ldisc_lock | |
2047 | * current->signal->tty check is safe without locks | |
28298232 AC |
2048 | * |
2049 | * FIXME: may race normal receive processing | |
af9b897e AC |
2050 | */ |
2051 | ||
1da177e4 LT |
2052 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2053 | { | |
2054 | char ch, mbz = 0; | |
2055 | struct tty_ldisc *ld; | |
37bdfb07 | 2056 | |
1da177e4 LT |
2057 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2058 | return -EPERM; | |
2059 | if (get_user(ch, p)) | |
2060 | return -EFAULT; | |
2061 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 2062 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2063 | tty_ldisc_deref(ld); |
2064 | return 0; | |
2065 | } | |
2066 | ||
af9b897e AC |
2067 | /** |
2068 | * tiocgwinsz - implement window query ioctl | |
2069 | * @tty; tty | |
2070 | * @arg: user buffer for result | |
2071 | * | |
808a0d38 | 2072 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2073 | * |
24ec839c | 2074 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2075 | * is consistent. |
af9b897e AC |
2076 | */ |
2077 | ||
37bdfb07 | 2078 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2079 | { |
808a0d38 AC |
2080 | int err; |
2081 | ||
5785c95b | 2082 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2083 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2084 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2085 | |
2086 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2087 | } |
2088 | ||
af9b897e | 2089 | /** |
8c9a9dd0 AC |
2090 | * tty_do_resize - resize event |
2091 | * @tty: tty being resized | |
a152db71 | 2092 | * @real_tty: real tty (not the same as tty if using a pty/tty pair) |
8c9a9dd0 AC |
2093 | * @rows: rows (character) |
2094 | * @cols: cols (character) | |
2095 | * | |
2096 | * Update the termios variables and send the neccessary signals to | |
2097 | * peform a terminal resize correctly | |
af9b897e AC |
2098 | */ |
2099 | ||
8c9a9dd0 AC |
2100 | int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, |
2101 | struct winsize *ws) | |
1da177e4 | 2102 | { |
47f86834 AC |
2103 | struct pid *pgrp, *rpgrp; |
2104 | unsigned long flags; | |
1da177e4 | 2105 | |
a152db71 AC |
2106 | /* For a PTY we need to lock the tty side */ |
2107 | mutex_lock(&real_tty->termios_mutex); | |
f4d2a6c2 | 2108 | if (!memcmp(ws, &real_tty->winsize, sizeof(*ws))) |
ca9bda00 | 2109 | goto done; |
47f86834 AC |
2110 | /* Get the PID values and reference them so we can |
2111 | avoid holding the tty ctrl lock while sending signals */ | |
2112 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2113 | pgrp = get_pid(tty->pgrp); | |
2114 | rpgrp = get_pid(real_tty->pgrp); | |
2115 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2116 | ||
2117 | if (pgrp) | |
2118 | kill_pgrp(pgrp, SIGWINCH, 1); | |
2119 | if (rpgrp != pgrp && rpgrp) | |
2120 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
2121 | ||
2122 | put_pid(pgrp); | |
2123 | put_pid(rpgrp); | |
2124 | ||
8c9a9dd0 AC |
2125 | tty->winsize = *ws; |
2126 | real_tty->winsize = *ws; | |
ca9bda00 | 2127 | done: |
a152db71 | 2128 | mutex_unlock(&real_tty->termios_mutex); |
1da177e4 LT |
2129 | return 0; |
2130 | } | |
2131 | ||
8c9a9dd0 AC |
2132 | /** |
2133 | * tiocswinsz - implement window size set ioctl | |
2134 | * @tty; tty | |
2135 | * @arg: user buffer for result | |
2136 | * | |
2137 | * Copies the user idea of the window size to the kernel. Traditionally | |
2138 | * this is just advisory information but for the Linux console it | |
2139 | * actually has driver level meaning and triggers a VC resize. | |
2140 | * | |
2141 | * Locking: | |
2142 | * Driver dependant. The default do_resize method takes the | |
2143 | * tty termios mutex and ctrl_lock. The console takes its own lock | |
2144 | * then calls into the default method. | |
2145 | */ | |
2146 | ||
2147 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, | |
2148 | struct winsize __user *arg) | |
2149 | { | |
2150 | struct winsize tmp_ws; | |
2151 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2152 | return -EFAULT; | |
2153 | ||
2154 | if (tty->ops->resize) | |
2155 | return tty->ops->resize(tty, real_tty, &tmp_ws); | |
2156 | else | |
2157 | return tty_do_resize(tty, real_tty, &tmp_ws); | |
2158 | } | |
2159 | ||
af9b897e AC |
2160 | /** |
2161 | * tioccons - allow admin to move logical console | |
2162 | * @file: the file to become console | |
2163 | * | |
2164 | * Allow the adminstrator to move the redirected console device | |
2165 | * | |
2166 | * Locking: uses redirect_lock to guard the redirect information | |
2167 | */ | |
2168 | ||
1da177e4 LT |
2169 | static int tioccons(struct file *file) |
2170 | { | |
2171 | if (!capable(CAP_SYS_ADMIN)) | |
2172 | return -EPERM; | |
2173 | if (file->f_op->write == redirected_tty_write) { | |
2174 | struct file *f; | |
2175 | spin_lock(&redirect_lock); | |
2176 | f = redirect; | |
2177 | redirect = NULL; | |
2178 | spin_unlock(&redirect_lock); | |
2179 | if (f) | |
2180 | fput(f); | |
2181 | return 0; | |
2182 | } | |
2183 | spin_lock(&redirect_lock); | |
2184 | if (redirect) { | |
2185 | spin_unlock(&redirect_lock); | |
2186 | return -EBUSY; | |
2187 | } | |
2188 | get_file(file); | |
2189 | redirect = file; | |
2190 | spin_unlock(&redirect_lock); | |
2191 | return 0; | |
2192 | } | |
2193 | ||
af9b897e AC |
2194 | /** |
2195 | * fionbio - non blocking ioctl | |
2196 | * @file: file to set blocking value | |
2197 | * @p: user parameter | |
2198 | * | |
2199 | * Historical tty interfaces had a blocking control ioctl before | |
2200 | * the generic functionality existed. This piece of history is preserved | |
2201 | * in the expected tty API of posix OS's. | |
2202 | * | |
2203 | * Locking: none, the open fle handle ensures it won't go away. | |
2204 | */ | |
1da177e4 LT |
2205 | |
2206 | static int fionbio(struct file *file, int __user *p) | |
2207 | { | |
2208 | int nonblock; | |
2209 | ||
2210 | if (get_user(nonblock, p)) | |
2211 | return -EFAULT; | |
2212 | ||
04f378b1 AC |
2213 | /* file->f_flags is still BKL protected in the fs layer - vomit */ |
2214 | lock_kernel(); | |
1da177e4 LT |
2215 | if (nonblock) |
2216 | file->f_flags |= O_NONBLOCK; | |
2217 | else | |
2218 | file->f_flags &= ~O_NONBLOCK; | |
04f378b1 | 2219 | unlock_kernel(); |
1da177e4 LT |
2220 | return 0; |
2221 | } | |
2222 | ||
af9b897e AC |
2223 | /** |
2224 | * tiocsctty - set controlling tty | |
2225 | * @tty: tty structure | |
2226 | * @arg: user argument | |
2227 | * | |
2228 | * This ioctl is used to manage job control. It permits a session | |
2229 | * leader to set this tty as the controlling tty for the session. | |
2230 | * | |
2231 | * Locking: | |
28298232 | 2232 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2233 | * Takes tasklist_lock internally to walk sessions |
2234 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2235 | */ |
2236 | ||
1da177e4 LT |
2237 | static int tiocsctty(struct tty_struct *tty, int arg) |
2238 | { | |
24ec839c | 2239 | int ret = 0; |
ab521dc0 | 2240 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2241 | return ret; |
2242 | ||
2243 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2244 | /* |
2245 | * The process must be a session leader and | |
2246 | * not have a controlling tty already. | |
2247 | */ | |
24ec839c PZ |
2248 | if (!current->signal->leader || current->signal->tty) { |
2249 | ret = -EPERM; | |
2250 | goto unlock; | |
2251 | } | |
2252 | ||
ab521dc0 | 2253 | if (tty->session) { |
1da177e4 LT |
2254 | /* |
2255 | * This tty is already the controlling | |
2256 | * tty for another session group! | |
2257 | */ | |
37bdfb07 | 2258 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2259 | /* |
2260 | * Steal it away | |
2261 | */ | |
1da177e4 | 2262 | read_lock(&tasklist_lock); |
24ec839c | 2263 | session_clear_tty(tty->session); |
1da177e4 | 2264 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2265 | } else { |
2266 | ret = -EPERM; | |
2267 | goto unlock; | |
2268 | } | |
1da177e4 | 2269 | } |
24ec839c PZ |
2270 | proc_set_tty(current, tty); |
2271 | unlock: | |
28298232 | 2272 | mutex_unlock(&tty_mutex); |
24ec839c | 2273 | return ret; |
1da177e4 LT |
2274 | } |
2275 | ||
5d0fdf1e AC |
2276 | /** |
2277 | * tty_get_pgrp - return a ref counted pgrp pid | |
2278 | * @tty: tty to read | |
2279 | * | |
2280 | * Returns a refcounted instance of the pid struct for the process | |
2281 | * group controlling the tty. | |
2282 | */ | |
2283 | ||
2284 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2285 | { | |
2286 | unsigned long flags; | |
2287 | struct pid *pgrp; | |
2288 | ||
2289 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2290 | pgrp = get_pid(tty->pgrp); | |
2291 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2292 | ||
2293 | return pgrp; | |
2294 | } | |
2295 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2296 | ||
af9b897e AC |
2297 | /** |
2298 | * tiocgpgrp - get process group | |
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: returned pid | |
2302 | * | |
2303 | * Obtain the process group of the tty. If there is no process group | |
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 tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2310 | { | |
5d0fdf1e AC |
2311 | struct pid *pid; |
2312 | int ret; | |
1da177e4 LT |
2313 | /* |
2314 | * (tty == real_tty) is a cheap way of | |
2315 | * testing if the tty is NOT a master pty. | |
2316 | */ | |
2317 | if (tty == real_tty && current->signal->tty != real_tty) | |
2318 | return -ENOTTY; | |
5d0fdf1e AC |
2319 | pid = tty_get_pgrp(real_tty); |
2320 | ret = put_user(pid_vnr(pid), p); | |
2321 | put_pid(pid); | |
2322 | return ret; | |
1da177e4 LT |
2323 | } |
2324 | ||
af9b897e AC |
2325 | /** |
2326 | * tiocspgrp - attempt to set process group | |
2327 | * @tty: tty passed by user | |
2328 | * @real_tty: tty side device matching tty passed by user | |
2329 | * @p: pid pointer | |
2330 | * | |
2331 | * Set the process group of the tty to the session passed. Only | |
2332 | * permitted where the tty session is our session. | |
2333 | * | |
47f86834 | 2334 | * Locking: RCU, ctrl lock |
af9b897e AC |
2335 | */ |
2336 | ||
1da177e4 LT |
2337 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2338 | { | |
04a2e6a5 EB |
2339 | struct pid *pgrp; |
2340 | pid_t pgrp_nr; | |
1da177e4 | 2341 | int retval = tty_check_change(real_tty); |
47f86834 | 2342 | unsigned long flags; |
1da177e4 LT |
2343 | |
2344 | if (retval == -EIO) | |
2345 | return -ENOTTY; | |
2346 | if (retval) | |
2347 | return retval; | |
2348 | if (!current->signal->tty || | |
2349 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2350 | (real_tty->session != task_session(current))) |
1da177e4 | 2351 | return -ENOTTY; |
04a2e6a5 | 2352 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2353 | return -EFAULT; |
04a2e6a5 | 2354 | if (pgrp_nr < 0) |
1da177e4 | 2355 | return -EINVAL; |
04a2e6a5 | 2356 | rcu_read_lock(); |
b488893a | 2357 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2358 | retval = -ESRCH; |
2359 | if (!pgrp) | |
2360 | goto out_unlock; | |
2361 | retval = -EPERM; | |
2362 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2363 | goto out_unlock; | |
2364 | retval = 0; | |
47f86834 | 2365 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2366 | put_pid(real_tty->pgrp); |
2367 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2368 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2369 | out_unlock: |
2370 | rcu_read_unlock(); | |
2371 | return retval; | |
1da177e4 LT |
2372 | } |
2373 | ||
af9b897e AC |
2374 | /** |
2375 | * tiocgsid - get session id | |
2376 | * @tty: tty passed by user | |
2377 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2378 | * @p: pointer to returned session id | |
2379 | * | |
2380 | * Obtain the session id of the tty. If there is no session | |
2381 | * return an error. | |
2382 | * | |
24ec839c | 2383 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2384 | */ |
2385 | ||
1da177e4 LT |
2386 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2387 | { | |
2388 | /* | |
2389 | * (tty == real_tty) is a cheap way of | |
2390 | * testing if the tty is NOT a master pty. | |
2391 | */ | |
2392 | if (tty == real_tty && current->signal->tty != real_tty) | |
2393 | return -ENOTTY; | |
ab521dc0 | 2394 | if (!real_tty->session) |
1da177e4 | 2395 | return -ENOTTY; |
b488893a | 2396 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2397 | } |
2398 | ||
af9b897e AC |
2399 | /** |
2400 | * tiocsetd - set line discipline | |
2401 | * @tty: tty device | |
2402 | * @p: pointer to user data | |
2403 | * | |
2404 | * Set the line discipline according to user request. | |
2405 | * | |
2406 | * Locking: see tty_set_ldisc, this function is just a helper | |
2407 | */ | |
2408 | ||
1da177e4 LT |
2409 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2410 | { | |
2411 | int ldisc; | |
04f378b1 | 2412 | int ret; |
1da177e4 LT |
2413 | |
2414 | if (get_user(ldisc, p)) | |
2415 | return -EFAULT; | |
04f378b1 AC |
2416 | |
2417 | lock_kernel(); | |
2418 | ret = tty_set_ldisc(tty, ldisc); | |
2419 | unlock_kernel(); | |
2420 | ||
2421 | return ret; | |
1da177e4 LT |
2422 | } |
2423 | ||
af9b897e AC |
2424 | /** |
2425 | * send_break - performed time break | |
2426 | * @tty: device to break on | |
2427 | * @duration: timeout in mS | |
2428 | * | |
2429 | * Perform a timed break on hardware that lacks its own driver level | |
2430 | * timed break functionality. | |
2431 | * | |
2432 | * Locking: | |
28298232 | 2433 | * atomic_write_lock serializes |
af9b897e | 2434 | * |
af9b897e AC |
2435 | */ |
2436 | ||
b20f3ae5 | 2437 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2438 | { |
9e98966c AC |
2439 | int retval; |
2440 | ||
2441 | if (tty->ops->break_ctl == NULL) | |
2442 | return 0; | |
2443 | ||
2444 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2445 | retval = tty->ops->break_ctl(tty, duration); | |
2446 | else { | |
2447 | /* Do the work ourselves */ | |
2448 | if (tty_write_lock(tty, 0) < 0) | |
2449 | return -EINTR; | |
2450 | retval = tty->ops->break_ctl(tty, -1); | |
2451 | if (retval) | |
2452 | goto out; | |
2453 | if (!signal_pending(current)) | |
2454 | msleep_interruptible(duration); | |
2455 | retval = tty->ops->break_ctl(tty, 0); | |
2456 | out: | |
2457 | tty_write_unlock(tty); | |
2458 | if (signal_pending(current)) | |
2459 | retval = -EINTR; | |
2460 | } | |
2461 | return retval; | |
1da177e4 LT |
2462 | } |
2463 | ||
af9b897e | 2464 | /** |
f34d7a5b | 2465 | * tty_tiocmget - get modem status |
af9b897e AC |
2466 | * @tty: tty device |
2467 | * @file: user file pointer | |
2468 | * @p: pointer to result | |
2469 | * | |
2470 | * Obtain the modem status bits from the tty driver if the feature | |
2471 | * is supported. Return -EINVAL if it is not available. | |
2472 | * | |
2473 | * Locking: none (up to the driver) | |
2474 | */ | |
2475 | ||
2476 | static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) | |
1da177e4 LT |
2477 | { |
2478 | int retval = -EINVAL; | |
2479 | ||
f34d7a5b AC |
2480 | if (tty->ops->tiocmget) { |
2481 | retval = tty->ops->tiocmget(tty, file); | |
1da177e4 LT |
2482 | |
2483 | if (retval >= 0) | |
2484 | retval = put_user(retval, p); | |
2485 | } | |
2486 | return retval; | |
2487 | } | |
2488 | ||
af9b897e | 2489 | /** |
f34d7a5b | 2490 | * tty_tiocmset - set modem status |
af9b897e AC |
2491 | * @tty: tty device |
2492 | * @file: user file pointer | |
2493 | * @cmd: command - clear bits, set bits or set all | |
2494 | * @p: pointer to desired bits | |
2495 | * | |
2496 | * Set the modem status bits from the tty driver if the feature | |
2497 | * is supported. Return -EINVAL if it is not available. | |
2498 | * | |
2499 | * Locking: none (up to the driver) | |
2500 | */ | |
2501 | ||
2502 | static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, | |
1da177e4 LT |
2503 | unsigned __user *p) |
2504 | { | |
ae677517 AC |
2505 | int retval; |
2506 | unsigned int set, clear, val; | |
1da177e4 | 2507 | |
ae677517 AC |
2508 | if (tty->ops->tiocmset == NULL) |
2509 | return -EINVAL; | |
1da177e4 | 2510 | |
ae677517 AC |
2511 | retval = get_user(val, p); |
2512 | if (retval) | |
2513 | return retval; | |
2514 | set = clear = 0; | |
2515 | switch (cmd) { | |
2516 | case TIOCMBIS: | |
2517 | set = val; | |
2518 | break; | |
2519 | case TIOCMBIC: | |
2520 | clear = val; | |
2521 | break; | |
2522 | case TIOCMSET: | |
2523 | set = val; | |
2524 | clear = ~val; | |
2525 | break; | |
2526 | } | |
2527 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2528 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2529 | return tty->ops->tiocmset(tty, file, set, clear); | |
1da177e4 LT |
2530 | } |
2531 | ||
2532 | /* | |
2533 | * Split this up, as gcc can choke on it otherwise.. | |
2534 | */ | |
04f378b1 | 2535 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
2536 | { |
2537 | struct tty_struct *tty, *real_tty; | |
2538 | void __user *p = (void __user *)arg; | |
2539 | int retval; | |
2540 | struct tty_ldisc *ld; | |
04f378b1 | 2541 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2542 | |
1da177e4 LT |
2543 | tty = (struct tty_struct *)file->private_data; |
2544 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2545 | return -EINVAL; | |
2546 | ||
2547 | real_tty = tty; | |
2548 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2549 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2550 | real_tty = tty->link; | |
2551 | ||
1da177e4 LT |
2552 | |
2553 | /* | |
2554 | * Factor out some common prep work | |
2555 | */ | |
2556 | switch (cmd) { | |
2557 | case TIOCSETD: | |
2558 | case TIOCSBRK: | |
2559 | case TIOCCBRK: | |
2560 | case TCSBRK: | |
37bdfb07 | 2561 | case TCSBRKP: |
1da177e4 LT |
2562 | retval = tty_check_change(tty); |
2563 | if (retval) | |
2564 | return retval; | |
2565 | if (cmd != TIOCCBRK) { | |
2566 | tty_wait_until_sent(tty, 0); | |
2567 | if (signal_pending(current)) | |
2568 | return -EINTR; | |
2569 | } | |
2570 | break; | |
2571 | } | |
2572 | ||
9e98966c AC |
2573 | /* |
2574 | * Now do the stuff. | |
2575 | */ | |
1da177e4 | 2576 | switch (cmd) { |
37bdfb07 AC |
2577 | case TIOCSTI: |
2578 | return tiocsti(tty, p); | |
2579 | case TIOCGWINSZ: | |
8f520021 | 2580 | return tiocgwinsz(real_tty, p); |
37bdfb07 AC |
2581 | case TIOCSWINSZ: |
2582 | return tiocswinsz(tty, real_tty, p); | |
2583 | case TIOCCONS: | |
2584 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2585 | case FIONBIO: | |
2586 | return fionbio(file, p); | |
2587 | case TIOCEXCL: | |
2588 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2589 | return 0; | |
2590 | case TIOCNXCL: | |
2591 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2592 | return 0; | |
2593 | case TIOCNOTTY: | |
2594 | if (current->signal->tty != tty) | |
2595 | return -ENOTTY; | |
2596 | no_tty(); | |
2597 | return 0; | |
2598 | case TIOCSCTTY: | |
2599 | return tiocsctty(tty, arg); | |
2600 | case TIOCGPGRP: | |
2601 | return tiocgpgrp(tty, real_tty, p); | |
2602 | case TIOCSPGRP: | |
2603 | return tiocspgrp(tty, real_tty, p); | |
2604 | case TIOCGSID: | |
2605 | return tiocgsid(tty, real_tty, p); | |
2606 | case TIOCGETD: | |
a352def2 | 2607 | return put_user(tty->ldisc.ops->num, (int __user *)p); |
37bdfb07 AC |
2608 | case TIOCSETD: |
2609 | return tiocsetd(tty, p); | |
37bdfb07 AC |
2610 | /* |
2611 | * Break handling | |
2612 | */ | |
2613 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2614 | if (tty->ops->break_ctl) |
9e98966c | 2615 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2616 | return 0; |
37bdfb07 | 2617 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2618 | if (tty->ops->break_ctl) |
9e98966c | 2619 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2620 | return 0; |
2621 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2622 | /* non-zero arg means wait for all output data | |
2623 | * to be sent (performed above) but don't send break. | |
2624 | * This is used by the tcdrain() termios function. | |
2625 | */ | |
2626 | if (!arg) | |
2627 | return send_break(tty, 250); | |
2628 | return 0; | |
2629 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2630 | return send_break(tty, arg ? arg*100 : 250); | |
2631 | ||
2632 | case TIOCMGET: | |
2633 | return tty_tiocmget(tty, file, p); | |
2634 | case TIOCMSET: | |
2635 | case TIOCMBIC: | |
2636 | case TIOCMBIS: | |
2637 | return tty_tiocmset(tty, file, cmd, p); | |
2638 | case TCFLSH: | |
2639 | switch (arg) { | |
2640 | case TCIFLUSH: | |
2641 | case TCIOFLUSH: | |
2642 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2643 | tty_buffer_flush(tty); | |
c5c34d48 | 2644 | break; |
37bdfb07 AC |
2645 | } |
2646 | break; | |
1da177e4 | 2647 | } |
f34d7a5b AC |
2648 | if (tty->ops->ioctl) { |
2649 | retval = (tty->ops->ioctl)(tty, file, cmd, arg); | |
1da177e4 LT |
2650 | if (retval != -ENOIOCTLCMD) |
2651 | return retval; | |
2652 | } | |
2653 | ld = tty_ldisc_ref_wait(tty); | |
2654 | retval = -EINVAL; | |
a352def2 AC |
2655 | if (ld->ops->ioctl) { |
2656 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2657 | if (retval == -ENOIOCTLCMD) |
2658 | retval = -EINVAL; | |
2659 | } | |
2660 | tty_ldisc_deref(ld); | |
2661 | return retval; | |
2662 | } | |
2663 | ||
e10cc1df | 2664 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2665 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2666 | unsigned long arg) |
2667 | { | |
2668 | struct inode *inode = file->f_dentry->d_inode; | |
2669 | struct tty_struct *tty = file->private_data; | |
2670 | struct tty_ldisc *ld; | |
2671 | int retval = -ENOIOCTLCMD; | |
2672 | ||
2673 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2674 | return -EINVAL; | |
2675 | ||
f34d7a5b AC |
2676 | if (tty->ops->compat_ioctl) { |
2677 | retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg); | |
e10cc1df PF |
2678 | if (retval != -ENOIOCTLCMD) |
2679 | return retval; | |
2680 | } | |
2681 | ||
2682 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2683 | if (ld->ops->compat_ioctl) |
2684 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
e10cc1df PF |
2685 | tty_ldisc_deref(ld); |
2686 | ||
2687 | return retval; | |
2688 | } | |
2689 | #endif | |
1da177e4 LT |
2690 | |
2691 | /* | |
2692 | * This implements the "Secure Attention Key" --- the idea is to | |
2693 | * prevent trojan horses by killing all processes associated with this | |
2694 | * tty when the user hits the "Secure Attention Key". Required for | |
2695 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2696 | * |
1da177e4 LT |
2697 | * This code could be nicer; ideally it should send a HUP, wait a few |
2698 | * seconds, then send a INT, and then a KILL signal. But you then | |
2699 | * have to coordinate with the init process, since all processes associated | |
2700 | * with the current tty must be dead before the new getty is allowed | |
2701 | * to spawn. | |
2702 | * | |
2703 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2704 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2705 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2706 | * | |
2707 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2708 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2709 | */ | |
8b6312f4 | 2710 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2711 | { |
2712 | #ifdef TTY_SOFT_SAK | |
2713 | tty_hangup(tty); | |
2714 | #else | |
652486fb | 2715 | struct task_struct *g, *p; |
ab521dc0 | 2716 | struct pid *session; |
1da177e4 LT |
2717 | int i; |
2718 | struct file *filp; | |
badf1662 | 2719 | struct fdtable *fdt; |
37bdfb07 | 2720 | |
1da177e4 LT |
2721 | if (!tty) |
2722 | return; | |
24ec839c | 2723 | session = tty->session; |
37bdfb07 | 2724 | |
b3f13deb | 2725 | tty_ldisc_flush(tty); |
1da177e4 | 2726 | |
f34d7a5b | 2727 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2728 | |
1da177e4 | 2729 | read_lock(&tasklist_lock); |
652486fb | 2730 | /* Kill the entire session */ |
ab521dc0 | 2731 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2732 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2733 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2734 | task_pid_nr(p), p->comm); |
652486fb | 2735 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2736 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2737 | /* Now kill any processes that happen to have the |
2738 | * tty open. | |
2739 | */ | |
2740 | do_each_thread(g, p) { | |
2741 | if (p->signal->tty == tty) { | |
1da177e4 | 2742 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2743 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2744 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2745 | send_sig(SIGKILL, p, 1); |
2746 | continue; | |
2747 | } | |
2748 | task_lock(p); | |
2749 | if (p->files) { | |
ca99c1da DS |
2750 | /* |
2751 | * We don't take a ref to the file, so we must | |
2752 | * hold ->file_lock instead. | |
2753 | */ | |
2754 | spin_lock(&p->files->file_lock); | |
badf1662 | 2755 | fdt = files_fdtable(p->files); |
37bdfb07 | 2756 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2757 | filp = fcheck_files(p->files, i); |
2758 | if (!filp) | |
2759 | continue; | |
2760 | if (filp->f_op->read == tty_read && | |
2761 | filp->private_data == tty) { | |
2762 | printk(KERN_NOTICE "SAK: killed process %d" | |
2763 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2764 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2765 | force_sig(SIGKILL, p); |
1da177e4 LT |
2766 | break; |
2767 | } | |
2768 | } | |
ca99c1da | 2769 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2770 | } |
2771 | task_unlock(p); | |
652486fb | 2772 | } while_each_thread(g, p); |
1da177e4 LT |
2773 | read_unlock(&tasklist_lock); |
2774 | #endif | |
2775 | } | |
2776 | ||
8b6312f4 EB |
2777 | static void do_SAK_work(struct work_struct *work) |
2778 | { | |
2779 | struct tty_struct *tty = | |
2780 | container_of(work, struct tty_struct, SAK_work); | |
2781 | __do_SAK(tty); | |
2782 | } | |
2783 | ||
1da177e4 LT |
2784 | /* |
2785 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2786 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2787 | * the values which we write to it will be identical to the values which it | |
2788 | * already has. --akpm | |
2789 | */ | |
2790 | void do_SAK(struct tty_struct *tty) | |
2791 | { | |
2792 | if (!tty) | |
2793 | return; | |
1da177e4 LT |
2794 | schedule_work(&tty->SAK_work); |
2795 | } | |
2796 | ||
2797 | EXPORT_SYMBOL(do_SAK); | |
2798 | ||
af9b897e AC |
2799 | /** |
2800 | * initialize_tty_struct | |
2801 | * @tty: tty to initialize | |
2802 | * | |
2803 | * This subroutine initializes a tty structure that has been newly | |
2804 | * allocated. | |
2805 | * | |
2806 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2807 | */ |
af9b897e | 2808 | |
1da177e4 LT |
2809 | static void initialize_tty_struct(struct tty_struct *tty) |
2810 | { | |
2811 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2812 | kref_init(&tty->kref); |
1da177e4 | 2813 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2814 | tty_ldisc_init(tty); |
ab521dc0 EB |
2815 | tty->session = NULL; |
2816 | tty->pgrp = NULL; | |
1da177e4 | 2817 | tty->overrun_time = jiffies; |
33f0f88f AC |
2818 | tty->buf.head = tty->buf.tail = NULL; |
2819 | tty_buffer_init(tty); | |
5785c95b | 2820 | mutex_init(&tty->termios_mutex); |
1da177e4 LT |
2821 | init_waitqueue_head(&tty->write_wait); |
2822 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2823 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2824 | mutex_init(&tty->atomic_read_lock); |
2825 | mutex_init(&tty->atomic_write_lock); | |
1da177e4 | 2826 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2827 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2828 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2829 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
1da177e4 LT |
2830 | } |
2831 | ||
f34d7a5b AC |
2832 | /** |
2833 | * tty_put_char - write one character to a tty | |
2834 | * @tty: tty | |
2835 | * @ch: character | |
2836 | * | |
2837 | * Write one byte to the tty using the provided put_char method | |
2838 | * if present. Returns the number of characters successfully output. | |
2839 | * | |
2840 | * Note: the specific put_char operation in the driver layer may go | |
2841 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2842 | */ |
af9b897e | 2843 | |
f34d7a5b | 2844 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2845 | { |
f34d7a5b AC |
2846 | if (tty->ops->put_char) |
2847 | return tty->ops->put_char(tty, ch); | |
2848 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 LT |
2849 | } |
2850 | ||
f34d7a5b AC |
2851 | EXPORT_SYMBOL_GPL(tty_put_char); |
2852 | ||
d81ed103 | 2853 | struct class *tty_class; |
1da177e4 LT |
2854 | |
2855 | /** | |
af9b897e AC |
2856 | * tty_register_device - register a tty device |
2857 | * @driver: the tty driver that describes the tty device | |
2858 | * @index: the index in the tty driver for this tty device | |
2859 | * @device: a struct device that is associated with this tty device. | |
2860 | * This field is optional, if there is no known struct device | |
2861 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2862 | * |
01107d34 GKH |
2863 | * Returns a pointer to the struct device for this tty device |
2864 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2865 | * |
af9b897e AC |
2866 | * This call is required to be made to register an individual tty device |
2867 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2868 | * that bit is not set, this function should not be called by a tty | |
2869 | * driver. | |
2870 | * | |
2871 | * Locking: ?? | |
1da177e4 | 2872 | */ |
af9b897e | 2873 | |
01107d34 GKH |
2874 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2875 | struct device *device) | |
1da177e4 LT |
2876 | { |
2877 | char name[64]; | |
2878 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2879 | ||
2880 | if (index >= driver->num) { | |
2881 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2882 | " (%d).\n", index); | |
1cdcb6b4 | 2883 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2884 | } |
2885 | ||
1da177e4 LT |
2886 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2887 | pty_line_name(driver, index, name); | |
2888 | else | |
2889 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2890 | |
47aa5793 | 2891 | return device_create_drvdata(tty_class, device, dev, NULL, name); |
1da177e4 LT |
2892 | } |
2893 | ||
2894 | /** | |
af9b897e AC |
2895 | * tty_unregister_device - unregister a tty device |
2896 | * @driver: the tty driver that describes the tty device | |
2897 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2898 | * |
af9b897e AC |
2899 | * If a tty device is registered with a call to tty_register_device() then |
2900 | * this function must be called when the tty device is gone. | |
2901 | * | |
2902 | * Locking: ?? | |
1da177e4 | 2903 | */ |
af9b897e | 2904 | |
1da177e4 LT |
2905 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2906 | { | |
37bdfb07 AC |
2907 | device_destroy(tty_class, |
2908 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 LT |
2909 | } |
2910 | ||
2911 | EXPORT_SYMBOL(tty_register_device); | |
2912 | EXPORT_SYMBOL(tty_unregister_device); | |
2913 | ||
2914 | struct tty_driver *alloc_tty_driver(int lines) | |
2915 | { | |
2916 | struct tty_driver *driver; | |
2917 | ||
506eb99a | 2918 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 2919 | if (driver) { |
1da177e4 LT |
2920 | driver->magic = TTY_DRIVER_MAGIC; |
2921 | driver->num = lines; | |
2922 | /* later we'll move allocation of tables here */ | |
2923 | } | |
2924 | return driver; | |
2925 | } | |
2926 | ||
2927 | void put_tty_driver(struct tty_driver *driver) | |
2928 | { | |
2929 | kfree(driver); | |
2930 | } | |
2931 | ||
b68e31d0 JD |
2932 | void tty_set_operations(struct tty_driver *driver, |
2933 | const struct tty_operations *op) | |
1da177e4 | 2934 | { |
f34d7a5b AC |
2935 | driver->ops = op; |
2936 | }; | |
1da177e4 LT |
2937 | |
2938 | EXPORT_SYMBOL(alloc_tty_driver); | |
2939 | EXPORT_SYMBOL(put_tty_driver); | |
2940 | EXPORT_SYMBOL(tty_set_operations); | |
2941 | ||
2942 | /* | |
2943 | * Called by a tty driver to register itself. | |
2944 | */ | |
2945 | int tty_register_driver(struct tty_driver *driver) | |
2946 | { | |
2947 | int error; | |
37bdfb07 | 2948 | int i; |
1da177e4 LT |
2949 | dev_t dev; |
2950 | void **p = NULL; | |
2951 | ||
2952 | if (driver->flags & TTY_DRIVER_INSTALLED) | |
2953 | return 0; | |
2954 | ||
543691a6 AW |
2955 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
2956 | p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); | |
1da177e4 LT |
2957 | if (!p) |
2958 | return -ENOMEM; | |
1da177e4 LT |
2959 | } |
2960 | ||
2961 | if (!driver->major) { | |
37bdfb07 AC |
2962 | error = alloc_chrdev_region(&dev, driver->minor_start, |
2963 | driver->num, driver->name); | |
1da177e4 LT |
2964 | if (!error) { |
2965 | driver->major = MAJOR(dev); | |
2966 | driver->minor_start = MINOR(dev); | |
2967 | } | |
2968 | } else { | |
2969 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 2970 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
2971 | } |
2972 | if (error < 0) { | |
2973 | kfree(p); | |
2974 | return error; | |
2975 | } | |
2976 | ||
2977 | if (p) { | |
2978 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 2979 | driver->termios = (struct ktermios **)(p + driver->num); |
37bdfb07 AC |
2980 | driver->termios_locked = (struct ktermios **) |
2981 | (p + driver->num * 2); | |
1da177e4 LT |
2982 | } else { |
2983 | driver->ttys = NULL; | |
2984 | driver->termios = NULL; | |
2985 | driver->termios_locked = NULL; | |
2986 | } | |
2987 | ||
2988 | cdev_init(&driver->cdev, &tty_fops); | |
2989 | driver->cdev.owner = driver->owner; | |
2990 | error = cdev_add(&driver->cdev, dev, driver->num); | |
2991 | if (error) { | |
1da177e4 LT |
2992 | unregister_chrdev_region(dev, driver->num); |
2993 | driver->ttys = NULL; | |
2994 | driver->termios = driver->termios_locked = NULL; | |
2995 | kfree(p); | |
2996 | return error; | |
2997 | } | |
2998 | ||
ca509f69 | 2999 | mutex_lock(&tty_mutex); |
1da177e4 | 3000 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3001 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3002 | |
3003 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
3004 | for (i = 0; i < driver->num; i++) | |
1da177e4 LT |
3005 | tty_register_device(driver, i, NULL); |
3006 | } | |
3007 | proc_tty_register_driver(driver); | |
3008 | return 0; | |
3009 | } | |
3010 | ||
3011 | EXPORT_SYMBOL(tty_register_driver); | |
3012 | ||
3013 | /* | |
3014 | * Called by a tty driver to unregister itself. | |
3015 | */ | |
3016 | int tty_unregister_driver(struct tty_driver *driver) | |
3017 | { | |
3018 | int i; | |
edc6afc5 | 3019 | struct ktermios *tp; |
1da177e4 LT |
3020 | void *p; |
3021 | ||
3022 | if (driver->refcount) | |
3023 | return -EBUSY; | |
3024 | ||
3025 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), | |
3026 | driver->num); | |
ca509f69 | 3027 | mutex_lock(&tty_mutex); |
1da177e4 | 3028 | list_del(&driver->tty_drivers); |
ca509f69 | 3029 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3030 | |
3031 | /* | |
3032 | * Free the termios and termios_locked structures because | |
3033 | * we don't want to get memory leaks when modular tty | |
3034 | * drivers are removed from the kernel. | |
3035 | */ | |
3036 | for (i = 0; i < driver->num; i++) { | |
3037 | tp = driver->termios[i]; | |
3038 | if (tp) { | |
3039 | driver->termios[i] = NULL; | |
3040 | kfree(tp); | |
3041 | } | |
3042 | tp = driver->termios_locked[i]; | |
3043 | if (tp) { | |
3044 | driver->termios_locked[i] = NULL; | |
3045 | kfree(tp); | |
3046 | } | |
331b8319 | 3047 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
1da177e4 LT |
3048 | tty_unregister_device(driver, i); |
3049 | } | |
3050 | p = driver->ttys; | |
3051 | proc_tty_unregister_driver(driver); | |
3052 | driver->ttys = NULL; | |
3053 | driver->termios = driver->termios_locked = NULL; | |
3054 | kfree(p); | |
3055 | cdev_del(&driver->cdev); | |
3056 | return 0; | |
3057 | } | |
1da177e4 LT |
3058 | EXPORT_SYMBOL(tty_unregister_driver); |
3059 | ||
24ec839c PZ |
3060 | dev_t tty_devnum(struct tty_struct *tty) |
3061 | { | |
3062 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3063 | } | |
3064 | EXPORT_SYMBOL(tty_devnum); | |
3065 | ||
3066 | void proc_clear_tty(struct task_struct *p) | |
3067 | { | |
9c9f4ded | 3068 | struct tty_struct *tty; |
24ec839c | 3069 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 3070 | tty = p->signal->tty; |
24ec839c PZ |
3071 | p->signal->tty = NULL; |
3072 | spin_unlock_irq(&p->sighand->siglock); | |
9c9f4ded | 3073 | tty_kref_put(tty); |
24ec839c | 3074 | } |
24ec839c | 3075 | |
47f86834 AC |
3076 | /* Called under the sighand lock */ |
3077 | ||
2a65f1d9 | 3078 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3079 | { |
3080 | if (tty) { | |
47f86834 AC |
3081 | unsigned long flags; |
3082 | /* We should not have a session or pgrp to put here but.... */ | |
3083 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3084 | put_pid(tty->session); |
3085 | put_pid(tty->pgrp); | |
ab521dc0 | 3086 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3087 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3088 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3089 | if (tsk->signal->tty) { |
3090 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3091 | tty_kref_put(tsk->signal->tty); | |
3092 | } | |
24ec839c | 3093 | } |
2a65f1d9 | 3094 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3095 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3096 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3097 | } |
3098 | ||
98a27ba4 | 3099 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3100 | { |
3101 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3102 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3103 | spin_unlock_irq(&tsk->sighand->siglock); |
3104 | } | |
3105 | ||
3106 | struct tty_struct *get_current_tty(void) | |
3107 | { | |
3108 | struct tty_struct *tty; | |
934e6ebf AC |
3109 | unsigned long flags; |
3110 | ||
3111 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3112 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3113 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3114 | return tty; |
3115 | } | |
a311f743 | 3116 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3117 | |
d81ed103 AC |
3118 | void tty_default_fops(struct file_operations *fops) |
3119 | { | |
3120 | *fops = tty_fops; | |
3121 | } | |
3122 | ||
1da177e4 LT |
3123 | /* |
3124 | * Initialize the console device. This is called *early*, so | |
3125 | * we can't necessarily depend on lots of kernel help here. | |
3126 | * Just do some early initializations, and do the complex setup | |
3127 | * later. | |
3128 | */ | |
3129 | void __init console_init(void) | |
3130 | { | |
3131 | initcall_t *call; | |
3132 | ||
3133 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3134 | tty_ldisc_begin(); |
1da177e4 LT |
3135 | |
3136 | /* | |
37bdfb07 | 3137 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3138 | * inform about problems etc.. |
3139 | */ | |
1da177e4 LT |
3140 | call = __con_initcall_start; |
3141 | while (call < __con_initcall_end) { | |
3142 | (*call)(); | |
3143 | call++; | |
3144 | } | |
3145 | } | |
3146 | ||
1da177e4 LT |
3147 | static int __init tty_class_init(void) |
3148 | { | |
7fe845d1 | 3149 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3150 | if (IS_ERR(tty_class)) |
3151 | return PTR_ERR(tty_class); | |
3152 | return 0; | |
3153 | } | |
3154 | ||
3155 | postcore_initcall(tty_class_init); | |
3156 | ||
3157 | /* 3/2004 jmc: why do these devices exist? */ | |
3158 | ||
3159 | static struct cdev tty_cdev, console_cdev; | |
1da177e4 LT |
3160 | |
3161 | /* | |
3162 | * Ok, now we can initialize the rest of the tty devices and can count | |
3163 | * on memory allocations, interrupts etc.. | |
3164 | */ | |
3165 | static int __init tty_init(void) | |
3166 | { | |
3167 | cdev_init(&tty_cdev, &tty_fops); | |
3168 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3169 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3170 | panic("Couldn't register /dev/tty driver\n"); | |
d81ed103 | 3171 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, |
47aa5793 | 3172 | "tty"); |
1da177e4 LT |
3173 | |
3174 | cdev_init(&console_cdev, &console_fops); | |
3175 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3176 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3177 | panic("Couldn't register /dev/console driver\n"); | |
d81ed103 | 3178 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3179 | "console"); |
1da177e4 | 3180 | |
1da177e4 | 3181 | #ifdef CONFIG_VT |
d81ed103 | 3182 | vty_init(&console_fops); |
1da177e4 LT |
3183 | #endif |
3184 | return 0; | |
3185 | } | |
3186 | module_init(tty_init); |