Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/tty_io.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
9 | * or rs-channels. It also implements echoing, cooked mode etc. | |
10 | * | |
11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
12 | * | |
13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
14 | * tty_struct and tty_queue structures. Previously there was an array | |
15 | * of 256 tty_struct's which was statically allocated, and the | |
16 | * tty_queue structures were allocated at boot time. Both are now | |
17 | * dynamically allocated only when the tty is open. | |
18 | * | |
19 | * Also restructured routines so that there is more of a separation | |
20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
21 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
23 | * |
24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
25 | * which can be dynamically activated and de-activated by the line | |
26 | * discipline handling modules (like SLIP). | |
27 | * | |
28 | * NOTE: pay no attention to the line discipline code (yet); its | |
29 | * interface is still subject to change in this version... | |
30 | * -- TYT, 1/31/92 | |
31 | * | |
32 | * Added functionality to the OPOST tty handling. No delays, but all | |
33 | * other bits should be there. | |
34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
35 | * | |
36 | * Rewrote canonical mode and added more termios flags. | |
37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
38 | * | |
39 | * Reorganized FASYNC support so mouse code can share it. | |
40 | * -- ctm@ardi.com, 9Sep95 | |
41 | * | |
42 | * New TIOCLINUX variants added. | |
43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 44 | * |
1da177e4 LT |
45 | * Restrict vt switching via ioctl() |
46 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
47 | * | |
48 | * Move console and virtual terminal code to more appropriate files, | |
49 | * implement CONFIG_VT and generalize console device interface. | |
50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
51 | * | |
d81ed103 | 52 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
53 | * -- Bill Hawes <whawes@star.net>, June 97 |
54 | * | |
55 | * Added devfs support. | |
56 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
57 | * | |
58 | * Added support for a Unix98-style ptmx device. | |
59 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
60 | * | |
61 | * Reduced memory usage for older ARM systems | |
62 | * -- Russell King <rmk@arm.linux.org.uk> | |
63 | * | |
64 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
65 | * alloc_tty_struct() always uses kmalloc() |
66 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
67 | */ |
68 | ||
1da177e4 LT |
69 | #include <linux/types.h> |
70 | #include <linux/major.h> | |
71 | #include <linux/errno.h> | |
72 | #include <linux/signal.h> | |
73 | #include <linux/fcntl.h> | |
74 | #include <linux/sched.h> | |
75 | #include <linux/interrupt.h> | |
76 | #include <linux/tty.h> | |
77 | #include <linux/tty_driver.h> | |
78 | #include <linux/tty_flip.h> | |
79 | #include <linux/devpts_fs.h> | |
80 | #include <linux/file.h> | |
9f3acc31 | 81 | #include <linux/fdtable.h> |
1da177e4 LT |
82 | #include <linux/console.h> |
83 | #include <linux/timer.h> | |
84 | #include <linux/ctype.h> | |
85 | #include <linux/kd.h> | |
86 | #include <linux/mm.h> | |
87 | #include <linux/string.h> | |
88 | #include <linux/slab.h> | |
89 | #include <linux/poll.h> | |
90 | #include <linux/proc_fs.h> | |
91 | #include <linux/init.h> | |
92 | #include <linux/module.h> | |
93 | #include <linux/smp_lock.h> | |
94 | #include <linux/device.h> | |
1da177e4 LT |
95 | #include <linux/wait.h> |
96 | #include <linux/bitops.h> | |
b20f3ae5 | 97 | #include <linux/delay.h> |
a352def2 | 98 | #include <linux/seq_file.h> |
1da177e4 | 99 | |
a352def2 | 100 | #include <linux/uaccess.h> |
1da177e4 LT |
101 | #include <asm/system.h> |
102 | ||
103 | #include <linux/kbd_kern.h> | |
104 | #include <linux/vt_kern.h> | |
105 | #include <linux/selection.h> | |
1da177e4 LT |
106 | |
107 | #include <linux/kmod.h> | |
b488893a | 108 | #include <linux/nsproxy.h> |
1da177e4 LT |
109 | |
110 | #undef TTY_DEBUG_HANGUP | |
111 | ||
112 | #define TTY_PARANOIA_CHECK 1 | |
113 | #define CHECK_TTY_COUNT 1 | |
114 | ||
edc6afc5 | 115 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
116 | .c_iflag = ICRNL | IXON, |
117 | .c_oflag = OPOST | ONLCR, | |
118 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
119 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
120 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
121 | .c_cc = INIT_C_CC, |
122 | .c_ispeed = 38400, | |
123 | .c_ospeed = 38400 | |
1da177e4 LT |
124 | }; |
125 | ||
126 | EXPORT_SYMBOL(tty_std_termios); | |
127 | ||
128 | /* This list gets poked at by procfs and various bits of boot up code. This | |
129 | could do with some rationalisation such as pulling the tty proc function | |
130 | into this file */ | |
37bdfb07 | 131 | |
1da177e4 LT |
132 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
133 | ||
24ec839c | 134 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 135 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 136 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 137 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 138 | |
1da177e4 LT |
139 | static 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; | |
7d7b93c1 | 279 | return tty_driver_kref_get(p); |
1da177e4 LT |
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)) { | |
7d7b93c1 | 323 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
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 | 1191 | /** |
8b0a88d5 | 1192 | * tty_line_name - generate name for a tty |
af9b897e AC |
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 | ||
99f1fe18 AC |
1207 | /** |
1208 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1209 | * @driver: the driver for the tty | |
1210 | * @idx: the minor number | |
23499705 | 1211 | * |
99f1fe18 | 1212 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1213 | * |
99f1fe18 AC |
1214 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1215 | * be held until the 'fast-open' is also done. Will change once we | |
1216 | * have refcounting in the driver and per driver locking | |
23499705 | 1217 | */ |
99f1fe18 | 1218 | struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx) |
23499705 SB |
1219 | { |
1220 | struct tty_struct *tty; | |
1221 | ||
99f1fe18 AC |
1222 | if (driver->ops->lookup) |
1223 | return driver->ops->lookup(driver, idx); | |
23499705 | 1224 | |
8b0a88d5 | 1225 | tty = driver->ttys[idx]; |
23499705 SB |
1226 | return tty; |
1227 | } | |
1228 | ||
99f1fe18 | 1229 | /** |
8b0a88d5 AC |
1230 | * tty_driver_install_tty() - install a tty entry in the driver |
1231 | * @driver: the driver for the tty | |
1232 | * @tty: the tty | |
1233 | * | |
1234 | * Install a tty object into the driver tables. The tty->index field | |
1235 | * will be set by the time this is called. | |
1236 | * | |
1237 | * Locking: tty_mutex for now | |
1238 | */ | |
1239 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1240 | struct tty_struct *tty) | |
1241 | { | |
1242 | if (driver->ops->install) | |
1243 | return driver->ops->install(driver, tty); | |
1244 | driver->ttys[tty->index] = tty; | |
1245 | return 0; | |
1246 | } | |
1247 | ||
1248 | /** | |
1249 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1250 | * @driver: the driver for the tty | |
1251 | * @idx: the minor number | |
1252 | * | |
1253 | * Remvoe a tty object from the driver tables. The tty->index field | |
1254 | * will be set by the time this is called. | |
1255 | * | |
1256 | * Locking: tty_mutex for now | |
1257 | */ | |
1258 | static void tty_driver_remove_tty(struct tty_driver *driver, | |
1259 | struct tty_struct *tty) | |
1260 | { | |
1261 | if (driver->ops->remove) | |
1262 | driver->ops->remove(driver, tty); | |
1263 | else | |
1264 | driver->ttys[tty->index] = NULL; | |
1265 | } | |
1266 | ||
1267 | /* | |
1268 | * tty_reopen() - fast re-open of an open tty | |
1269 | * @tty - the tty to open | |
23499705 | 1270 | * |
99f1fe18 | 1271 | * Return 0 on success, -errno on error. |
23499705 | 1272 | * |
99f1fe18 AC |
1273 | * Locking: tty_mutex must be held from the time the tty was found |
1274 | * till this open completes. | |
23499705 | 1275 | */ |
99f1fe18 | 1276 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1277 | { |
1278 | struct tty_driver *driver = tty->driver; | |
1279 | ||
1280 | if (test_bit(TTY_CLOSING, &tty->flags)) | |
1281 | return -EIO; | |
1282 | ||
1283 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1284 | driver->subtype == PTY_TYPE_MASTER) { | |
1285 | /* | |
1286 | * special case for PTY masters: only one open permitted, | |
1287 | * and the slave side open count is incremented as well. | |
1288 | */ | |
1289 | if (tty->count) | |
1290 | return -EIO; | |
1291 | ||
1292 | tty->link->count++; | |
1293 | } | |
1294 | tty->count++; | |
1295 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1296 | ||
99f1fe18 | 1297 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
23499705 SB |
1298 | |
1299 | return 0; | |
1300 | } | |
1301 | ||
af9b897e | 1302 | /** |
d81ed103 | 1303 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1304 | * @driver: tty driver we are opening a device on |
1305 | * @idx: device index | |
15582d36 AC |
1306 | * @ret_tty: returned tty structure |
1307 | * @first_ok: ok to open a new device (used by ptmx) | |
af9b897e AC |
1308 | * |
1309 | * Prepare a tty device. This may not be a "new" clean device but | |
1310 | * could also be an active device. The pty drivers require special | |
1311 | * handling because of this. | |
1312 | * | |
1313 | * Locking: | |
1314 | * The function is called under the tty_mutex, which | |
1315 | * protects us from the tty struct or driver itself going away. | |
1316 | * | |
1317 | * On exit the tty device has the line discipline attached and | |
1318 | * a reference count of 1. If a pair was created for pty/tty use | |
1319 | * and the other was a pty master then it too has a reference count of 1. | |
1320 | * | |
1da177e4 | 1321 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1322 | * failed open. The new code protects the open with a mutex, so it's |
1323 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1324 | * relaxed for the (most common) case of reopening a tty. |
1325 | */ | |
af9b897e | 1326 | |
d81ed103 | 1327 | int tty_init_dev(struct tty_driver *driver, int idx, |
15582d36 | 1328 | struct tty_struct **ret_tty, int first_ok) |
1da177e4 LT |
1329 | { |
1330 | struct tty_struct *tty, *o_tty; | |
edc6afc5 AC |
1331 | struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; |
1332 | struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; | |
af9b897e | 1333 | int retval = 0; |
1da177e4 LT |
1334 | |
1335 | /* check whether we're reopening an existing tty */ | |
99f1fe18 | 1336 | tty = tty_driver_lookup_tty(driver, idx); |
23499705 SB |
1337 | if (IS_ERR(tty)) { |
1338 | retval = PTR_ERR(tty); | |
1339 | goto end_init; | |
1340 | } | |
1341 | ||
1342 | if (tty) { | |
99f1fe18 | 1343 | retval = tty_reopen(tty); |
23499705 SB |
1344 | if (retval) |
1345 | return retval; | |
1346 | *ret_tty = tty; | |
1347 | return 0; | |
1da177e4 | 1348 | } |
1da177e4 | 1349 | |
23499705 | 1350 | /* Check if pty master is being opened multiple times */ |
15582d36 AC |
1351 | if (driver->subtype == PTY_TYPE_MASTER && |
1352 | (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { | |
1353 | retval = -EIO; | |
1354 | goto end_init; | |
1355 | } | |
1da177e4 LT |
1356 | /* |
1357 | * First time open is complex, especially for PTY devices. | |
1358 | * This code guarantees that either everything succeeds and the | |
1359 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1360 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1361 | * and locked termios may be retained.) |
1362 | */ | |
1363 | ||
1364 | if (!try_module_get(driver->owner)) { | |
1365 | retval = -ENODEV; | |
1366 | goto end_init; | |
1367 | } | |
1368 | ||
1369 | o_tty = NULL; | |
1370 | tp = o_tp = NULL; | |
1371 | ltp = o_ltp = NULL; | |
1372 | ||
1373 | tty = alloc_tty_struct(); | |
37bdfb07 | 1374 | if (!tty) |
1da177e4 LT |
1375 | goto fail_no_mem; |
1376 | initialize_tty_struct(tty); | |
1377 | tty->driver = driver; | |
f34d7a5b | 1378 | tty->ops = driver->ops; |
1da177e4 LT |
1379 | tty->index = idx; |
1380 | tty_line_name(driver, idx, tty->name); | |
1381 | ||
1382 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1383 | tp_loc = &tty->termios; | |
1384 | ltp_loc = &tty->termios_locked; | |
1385 | } else { | |
1386 | tp_loc = &driver->termios[idx]; | |
1387 | ltp_loc = &driver->termios_locked[idx]; | |
1388 | } | |
1389 | ||
1390 | if (!*tp_loc) { | |
abcb1ff3 | 1391 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1392 | if (!tp) |
1393 | goto free_mem_out; | |
1394 | *tp = driver->init_termios; | |
1395 | } | |
1396 | ||
1397 | if (!*ltp_loc) { | |
506eb99a | 1398 | ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1399 | if (!ltp) |
1400 | goto free_mem_out; | |
1da177e4 LT |
1401 | } |
1402 | ||
1403 | if (driver->type == TTY_DRIVER_TYPE_PTY) { | |
1404 | o_tty = alloc_tty_struct(); | |
1405 | if (!o_tty) | |
1406 | goto free_mem_out; | |
6f967f78 AC |
1407 | if (!try_module_get(driver->other->owner)) { |
1408 | /* This cannot in fact currently happen */ | |
1409 | free_tty_struct(o_tty); | |
1410 | o_tty = NULL; | |
1411 | goto free_mem_out; | |
1412 | } | |
1da177e4 LT |
1413 | initialize_tty_struct(o_tty); |
1414 | o_tty->driver = driver->other; | |
f34d7a5b | 1415 | o_tty->ops = driver->ops; |
1da177e4 LT |
1416 | o_tty->index = idx; |
1417 | tty_line_name(driver->other, idx, o_tty->name); | |
1418 | ||
1419 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1420 | o_tp_loc = &o_tty->termios; | |
1421 | o_ltp_loc = &o_tty->termios_locked; | |
1422 | } else { | |
1423 | o_tp_loc = &driver->other->termios[idx]; | |
1424 | o_ltp_loc = &driver->other->termios_locked[idx]; | |
1425 | } | |
1426 | ||
1427 | if (!*o_tp_loc) { | |
abcb1ff3 | 1428 | o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1429 | if (!o_tp) |
1430 | goto free_mem_out; | |
1431 | *o_tp = driver->other->init_termios; | |
1432 | } | |
1433 | ||
1434 | if (!*o_ltp_loc) { | |
506eb99a | 1435 | o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1436 | if (!o_ltp) |
1437 | goto free_mem_out; | |
1da177e4 LT |
1438 | } |
1439 | ||
1440 | /* | |
1441 | * Everything allocated ... set up the o_tty structure. | |
1442 | */ | |
37bdfb07 | 1443 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) |
1da177e4 | 1444 | driver->other->ttys[idx] = o_tty; |
1da177e4 LT |
1445 | if (!*o_tp_loc) |
1446 | *o_tp_loc = o_tp; | |
1447 | if (!*o_ltp_loc) | |
1448 | *o_ltp_loc = o_ltp; | |
1449 | o_tty->termios = *o_tp_loc; | |
1450 | o_tty->termios_locked = *o_ltp_loc; | |
7d7b93c1 | 1451 | tty_driver_kref_get(driver->other); |
1da177e4 LT |
1452 | if (driver->subtype == PTY_TYPE_MASTER) |
1453 | o_tty->count++; | |
1454 | ||
1455 | /* Establish the links in both directions */ | |
1456 | tty->link = o_tty; | |
1457 | o_tty->link = tty; | |
1458 | } | |
1459 | ||
37bdfb07 | 1460 | /* |
1da177e4 | 1461 | * All structures have been allocated, so now we install them. |
d5698c28 | 1462 | * Failures after this point use release_tty to clean up, so |
1da177e4 LT |
1463 | * there's no need to null out the local pointers. |
1464 | */ | |
37bdfb07 | 1465 | |
1da177e4 LT |
1466 | if (!*tp_loc) |
1467 | *tp_loc = tp; | |
1468 | if (!*ltp_loc) | |
1469 | *ltp_loc = ltp; | |
1470 | tty->termios = *tp_loc; | |
1471 | tty->termios_locked = *ltp_loc; | |
edc6afc5 AC |
1472 | /* Compatibility until drivers always set this */ |
1473 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1474 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
7d7b93c1 | 1475 | tty_driver_kref_get(driver); |
1da177e4 LT |
1476 | tty->count++; |
1477 | ||
8b0a88d5 AC |
1478 | if (tty_driver_install_tty(driver, tty) < 0) |
1479 | goto release_mem_out; | |
1480 | ||
37bdfb07 | 1481 | /* |
1da177e4 | 1482 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1483 | * If we fail here just call release_tty to clean up. No need |
1484 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 LT |
1485 | */ |
1486 | ||
01e1abb2 AC |
1487 | retval = tty_ldisc_setup(tty, o_tty); |
1488 | ||
1489 | if (retval) | |
1490 | goto release_mem_out; | |
37bdfb07 | 1491 | |
99f1fe18 | 1492 | *ret_tty = tty; |
70522e12 | 1493 | /* All paths come through here to release the mutex */ |
1da177e4 LT |
1494 | end_init: |
1495 | return retval; | |
1496 | ||
1497 | /* Release locally allocated memory ... nothing placed in slots */ | |
1498 | free_mem_out: | |
735d5661 | 1499 | kfree(o_tp); |
6f967f78 AC |
1500 | if (o_tty) { |
1501 | module_put(o_tty->driver->owner); | |
1da177e4 | 1502 | free_tty_struct(o_tty); |
6f967f78 | 1503 | } |
735d5661 JJ |
1504 | kfree(ltp); |
1505 | kfree(tp); | |
1da177e4 LT |
1506 | free_tty_struct(tty); |
1507 | ||
1508 | fail_no_mem: | |
1509 | module_put(driver->owner); | |
1510 | retval = -ENOMEM; | |
1511 | goto end_init; | |
1512 | ||
d5698c28 | 1513 | /* call the tty release_tty routine to clean out this slot */ |
1da177e4 | 1514 | release_mem_out: |
4050914f | 1515 | if (printk_ratelimit()) |
d81ed103 | 1516 | printk(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1517 | "clearing slot %d\n", idx); |
d5698c28 | 1518 | release_tty(tty, idx); |
1da177e4 LT |
1519 | goto end_init; |
1520 | } | |
1521 | ||
feebed65 AC |
1522 | void tty_free_termios(struct tty_struct *tty) |
1523 | { | |
1524 | struct ktermios *tp; | |
1525 | int idx = tty->index; | |
1526 | /* Kill this flag and push into drivers for locking etc */ | |
1527 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1528 | /* FIXME: Locking on ->termios array */ | |
1529 | tp = tty->termios; | |
1530 | tty->driver->termios[idx] = NULL; | |
1531 | kfree(tp); | |
1532 | ||
1533 | tp = tty->termios_locked; | |
1534 | tty->driver->termios_locked[idx] = NULL; | |
1535 | kfree(tp); | |
1536 | } | |
1537 | } | |
1538 | EXPORT_SYMBOL(tty_free_termios); | |
1539 | ||
1540 | void tty_shutdown(struct tty_struct *tty) | |
1541 | { | |
8b0a88d5 | 1542 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1543 | tty_free_termios(tty); |
1544 | } | |
1545 | EXPORT_SYMBOL(tty_shutdown); | |
1546 | ||
af9b897e | 1547 | /** |
d5698c28 | 1548 | * release_one_tty - release tty structure memory |
9c9f4ded | 1549 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1550 | * |
1551 | * Releases memory associated with a tty structure, and clears out the | |
1552 | * driver table slots. This function is called when a device is no longer | |
1553 | * in use. It also gets called when setup of a device fails. | |
1554 | * | |
1555 | * Locking: | |
1556 | * tty_mutex - sometimes only | |
1557 | * takes the file list lock internally when working on the list | |
1558 | * of ttys that the driver keeps. | |
1da177e4 | 1559 | */ |
9c9f4ded | 1560 | static void release_one_tty(struct kref *kref) |
1da177e4 | 1561 | { |
9c9f4ded | 1562 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); |
6f967f78 | 1563 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1564 | |
feebed65 AC |
1565 | if (tty->ops->shutdown) |
1566 | tty->ops->shutdown(tty); | |
1567 | else | |
1568 | tty_shutdown(tty); | |
1da177e4 | 1569 | tty->magic = 0; |
7d7b93c1 | 1570 | tty_driver_kref_put(driver); |
6f967f78 | 1571 | module_put(driver->owner); |
d5698c28 | 1572 | |
1da177e4 LT |
1573 | file_list_lock(); |
1574 | list_del_init(&tty->tty_files); | |
1575 | file_list_unlock(); | |
d5698c28 | 1576 | |
1da177e4 LT |
1577 | free_tty_struct(tty); |
1578 | } | |
1579 | ||
9c9f4ded AC |
1580 | /** |
1581 | * tty_kref_put - release a tty kref | |
1582 | * @tty: tty device | |
1583 | * | |
1584 | * Release a reference to a tty device and if need be let the kref | |
1585 | * layer destruct the object for us | |
1586 | */ | |
1587 | ||
1588 | void tty_kref_put(struct tty_struct *tty) | |
1589 | { | |
1590 | if (tty) | |
1591 | kref_put(&tty->kref, release_one_tty); | |
1592 | } | |
1593 | EXPORT_SYMBOL(tty_kref_put); | |
1594 | ||
d5698c28 CH |
1595 | /** |
1596 | * release_tty - release tty structure memory | |
1597 | * | |
1598 | * Release both @tty and a possible linked partner (think pty pair), | |
1599 | * and decrement the refcount of the backing module. | |
1600 | * | |
1601 | * Locking: | |
1602 | * tty_mutex - sometimes only | |
1603 | * takes the file list lock internally when working on the list | |
1604 | * of ttys that the driver keeps. | |
1605 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1606 | * |
d5698c28 CH |
1607 | */ |
1608 | static void release_tty(struct tty_struct *tty, int idx) | |
1609 | { | |
9c9f4ded AC |
1610 | /* This should always be true but check for the moment */ |
1611 | WARN_ON(tty->index != idx); | |
1612 | ||
d5698c28 | 1613 | if (tty->link) |
9c9f4ded AC |
1614 | tty_kref_put(tty->link); |
1615 | tty_kref_put(tty); | |
d5698c28 CH |
1616 | } |
1617 | ||
1da177e4 LT |
1618 | /* |
1619 | * Even releasing the tty structures is a tricky business.. We have | |
1620 | * to be very careful that the structures are all released at the | |
1621 | * same time, as interrupts might otherwise get the wrong pointers. | |
1622 | * | |
1623 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1624 | * lead to double frees or releasing memory still in use. | |
1625 | */ | |
d81ed103 | 1626 | void tty_release_dev(struct file *filp) |
1da177e4 LT |
1627 | { |
1628 | struct tty_struct *tty, *o_tty; | |
1629 | int pty_master, tty_closing, o_tty_closing, do_sleep; | |
14a6283e | 1630 | int devpts; |
1da177e4 LT |
1631 | int idx; |
1632 | char buf[64]; | |
37bdfb07 | 1633 | |
1da177e4 | 1634 | tty = (struct tty_struct *)filp->private_data; |
37bdfb07 | 1635 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, |
d81ed103 | 1636 | "tty_release_dev")) |
1da177e4 LT |
1637 | return; |
1638 | ||
d81ed103 | 1639 | check_tty_count(tty, "tty_release_dev"); |
1da177e4 LT |
1640 | |
1641 | tty_fasync(-1, filp, 0); | |
1642 | ||
1643 | idx = tty->index; | |
1644 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1645 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1646 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1647 | o_tty = tty->link; |
1648 | ||
1649 | #ifdef TTY_PARANOIA_CHECK | |
1650 | if (idx < 0 || idx >= tty->driver->num) { | |
d81ed103 | 1651 | printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " |
1da177e4 LT |
1652 | "free (%s)\n", tty->name); |
1653 | return; | |
1654 | } | |
8b0a88d5 | 1655 | if (!devpts) { |
1da177e4 | 1656 | if (tty != tty->driver->ttys[idx]) { |
d81ed103 | 1657 | printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " |
1da177e4 LT |
1658 | "for (%s)\n", idx, tty->name); |
1659 | return; | |
1660 | } | |
1661 | if (tty->termios != tty->driver->termios[idx]) { | |
d81ed103 | 1662 | printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " |
1da177e4 LT |
1663 | "for (%s)\n", |
1664 | idx, tty->name); | |
1665 | return; | |
1666 | } | |
1667 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { | |
d81ed103 | 1668 | printk(KERN_DEBUG "tty_release_dev: driver.termios_locked[%d] not " |
1da177e4 LT |
1669 | "termios_locked for (%s)\n", |
1670 | idx, tty->name); | |
1671 | return; | |
1672 | } | |
1673 | } | |
1674 | #endif | |
1675 | ||
1676 | #ifdef TTY_DEBUG_HANGUP | |
d81ed103 | 1677 | printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", |
1da177e4 LT |
1678 | tty_name(tty, buf), tty->count); |
1679 | #endif | |
1680 | ||
1681 | #ifdef TTY_PARANOIA_CHECK | |
1682 | if (tty->driver->other && | |
1683 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1684 | if (o_tty != tty->driver->other->ttys[idx]) { | |
d81ed103 | 1685 | printk(KERN_DEBUG "tty_release_dev: other->table[%d] " |
1da177e4 LT |
1686 | "not o_tty for (%s)\n", |
1687 | idx, tty->name); | |
1688 | return; | |
1689 | } | |
1690 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
d81ed103 | 1691 | printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " |
1da177e4 LT |
1692 | "not o_termios for (%s)\n", |
1693 | idx, tty->name); | |
1694 | return; | |
1695 | } | |
37bdfb07 | 1696 | if (o_tty->termios_locked != |
1da177e4 | 1697 | tty->driver->other->termios_locked[idx]) { |
d81ed103 | 1698 | printk(KERN_DEBUG "tty_release_dev: other->termios_locked[" |
1da177e4 LT |
1699 | "%d] not o_termios_locked for (%s)\n", |
1700 | idx, tty->name); | |
1701 | return; | |
1702 | } | |
1703 | if (o_tty->link != tty) { | |
d81ed103 | 1704 | printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); |
1da177e4 LT |
1705 | return; |
1706 | } | |
1707 | } | |
1708 | #endif | |
f34d7a5b AC |
1709 | if (tty->ops->close) |
1710 | tty->ops->close(tty, filp); | |
1da177e4 LT |
1711 | |
1712 | /* | |
1713 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1714 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1715 | * wait queues and kick everyone out _before_ actually starting to | |
1716 | * close. This ensures that we won't block while releasing the tty | |
1717 | * structure. | |
1718 | * | |
1719 | * The test for the o_tty closing is necessary, since the master and | |
1720 | * slave sides may close in any order. If the slave side closes out | |
1721 | * first, its count will be one, since the master side holds an open. | |
1722 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1723 | * so we do it now. | |
1724 | * | |
1725 | * Note that it's possible for the tty to be opened again while we're | |
1726 | * flushing out waiters. By recalculating the closing flags before | |
1727 | * each iteration we avoid any problems. | |
1728 | */ | |
1729 | while (1) { | |
1730 | /* Guard against races with tty->count changes elsewhere and | |
1731 | opens on /dev/tty */ | |
37bdfb07 | 1732 | |
70522e12 | 1733 | mutex_lock(&tty_mutex); |
1da177e4 LT |
1734 | tty_closing = tty->count <= 1; |
1735 | o_tty_closing = o_tty && | |
1736 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1737 | do_sleep = 0; |
1738 | ||
1739 | if (tty_closing) { | |
1740 | if (waitqueue_active(&tty->read_wait)) { | |
1741 | wake_up(&tty->read_wait); | |
1742 | do_sleep++; | |
1743 | } | |
1744 | if (waitqueue_active(&tty->write_wait)) { | |
1745 | wake_up(&tty->write_wait); | |
1746 | do_sleep++; | |
1747 | } | |
1748 | } | |
1749 | if (o_tty_closing) { | |
1750 | if (waitqueue_active(&o_tty->read_wait)) { | |
1751 | wake_up(&o_tty->read_wait); | |
1752 | do_sleep++; | |
1753 | } | |
1754 | if (waitqueue_active(&o_tty->write_wait)) { | |
1755 | wake_up(&o_tty->write_wait); | |
1756 | do_sleep++; | |
1757 | } | |
1758 | } | |
1759 | if (!do_sleep) | |
1760 | break; | |
1761 | ||
d81ed103 | 1762 | printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " |
1da177e4 | 1763 | "active!\n", tty_name(tty, buf)); |
70522e12 | 1764 | mutex_unlock(&tty_mutex); |
1da177e4 | 1765 | schedule(); |
37bdfb07 | 1766 | } |
1da177e4 LT |
1767 | |
1768 | /* | |
37bdfb07 AC |
1769 | * The closing flags are now consistent with the open counts on |
1770 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1771 | * block, so it's safe to proceed with closing. |
1772 | */ | |
1da177e4 LT |
1773 | if (pty_master) { |
1774 | if (--o_tty->count < 0) { | |
d81ed103 | 1775 | printk(KERN_WARNING "tty_release_dev: bad pty slave count " |
1da177e4 LT |
1776 | "(%d) for %s\n", |
1777 | o_tty->count, tty_name(o_tty, buf)); | |
1778 | o_tty->count = 0; | |
1779 | } | |
1780 | } | |
1781 | if (--tty->count < 0) { | |
d81ed103 | 1782 | printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", |
1da177e4 LT |
1783 | tty->count, tty_name(tty, buf)); |
1784 | tty->count = 0; | |
1785 | } | |
37bdfb07 | 1786 | |
1da177e4 LT |
1787 | /* |
1788 | * We've decremented tty->count, so we need to remove this file | |
1789 | * descriptor off the tty->tty_files list; this serves two | |
1790 | * purposes: | |
1791 | * - check_tty_count sees the correct number of file descriptors | |
1792 | * associated with this tty. | |
1793 | * - do_tty_hangup no longer sees this file descriptor as | |
1794 | * something that needs to be handled for hangups. | |
1795 | */ | |
1796 | file_kill(filp); | |
1797 | filp->private_data = NULL; | |
1798 | ||
1799 | /* | |
1800 | * Perform some housekeeping before deciding whether to return. | |
1801 | * | |
1802 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1803 | * case of a pty we may have to wait around for the other side | |
1804 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1805 | */ | |
37bdfb07 | 1806 | if (tty_closing) |
1da177e4 | 1807 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1808 | if (o_tty_closing) |
1da177e4 LT |
1809 | set_bit(TTY_CLOSING, &o_tty->flags); |
1810 | ||
1811 | /* | |
1812 | * If _either_ side is closing, make sure there aren't any | |
1813 | * processes that still think tty or o_tty is their controlling | |
1814 | * tty. | |
1815 | */ | |
1816 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1817 | read_lock(&tasklist_lock); |
24ec839c | 1818 | session_clear_tty(tty->session); |
1da177e4 | 1819 | if (o_tty) |
24ec839c | 1820 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1821 | read_unlock(&tasklist_lock); |
1822 | } | |
1823 | ||
70522e12 | 1824 | mutex_unlock(&tty_mutex); |
da965822 | 1825 | |
1da177e4 LT |
1826 | /* check whether both sides are closing ... */ |
1827 | if (!tty_closing || (o_tty && !o_tty_closing)) | |
1828 | return; | |
37bdfb07 | 1829 | |
1da177e4 LT |
1830 | #ifdef TTY_DEBUG_HANGUP |
1831 | printk(KERN_DEBUG "freeing tty structure..."); | |
1832 | #endif | |
1833 | /* | |
01e1abb2 | 1834 | * Ask the line discipline code to release its structures |
1da177e4 | 1835 | */ |
01e1abb2 | 1836 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1837 | /* |
d5698c28 | 1838 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1839 | * the slots and preserving the termios structure. |
1840 | */ | |
d5698c28 | 1841 | release_tty(tty, idx); |
1da177e4 | 1842 | |
1da177e4 | 1843 | /* Make this pty number available for reallocation */ |
718a9163 SB |
1844 | if (devpts) |
1845 | devpts_kill_index(idx); | |
1da177e4 LT |
1846 | } |
1847 | ||
af9b897e | 1848 | /** |
15582d36 | 1849 | * __tty_open - open a tty device |
af9b897e AC |
1850 | * @inode: inode of device file |
1851 | * @filp: file pointer to tty | |
1da177e4 | 1852 | * |
af9b897e AC |
1853 | * tty_open and tty_release keep up the tty count that contains the |
1854 | * number of opens done on a tty. We cannot use the inode-count, as | |
1855 | * different inodes might point to the same tty. | |
1da177e4 | 1856 | * |
af9b897e AC |
1857 | * Open-counting is needed for pty masters, as well as for keeping |
1858 | * track of serial lines: DTR is dropped when the last close happens. | |
1859 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1860 | * | |
1861 | * The termios state of a pty is reset on first open so that | |
1862 | * settings don't persist across reuse. | |
1863 | * | |
d81ed103 | 1864 | * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. |
24ec839c PZ |
1865 | * tty->count should protect the rest. |
1866 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1867 | */ |
af9b897e | 1868 | |
39d95b9d | 1869 | static int __tty_open(struct inode *inode, struct file *filp) |
1da177e4 LT |
1870 | { |
1871 | struct tty_struct *tty; | |
1872 | int noctty, retval; | |
1873 | struct tty_driver *driver; | |
1874 | int index; | |
1875 | dev_t device = inode->i_rdev; | |
1876 | unsigned short saved_flags = filp->f_flags; | |
1877 | ||
1878 | nonseekable_open(inode, filp); | |
37bdfb07 | 1879 | |
1da177e4 LT |
1880 | retry_open: |
1881 | noctty = filp->f_flags & O_NOCTTY; | |
1882 | index = -1; | |
1883 | retval = 0; | |
37bdfb07 | 1884 | |
70522e12 | 1885 | mutex_lock(&tty_mutex); |
1da177e4 | 1886 | |
37bdfb07 | 1887 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1888 | tty = get_current_tty(); |
1889 | if (!tty) { | |
70522e12 | 1890 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1891 | return -ENXIO; |
1892 | } | |
7d7b93c1 | 1893 | driver = tty_driver_kref_get(tty->driver); |
24ec839c | 1894 | index = tty->index; |
1da177e4 LT |
1895 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1896 | /* noctty = 1; */ | |
452a00d2 AC |
1897 | /* FIXME: Should we take a driver reference ? */ |
1898 | tty_kref_put(tty); | |
1da177e4 LT |
1899 | goto got_driver; |
1900 | } | |
1901 | #ifdef CONFIG_VT | |
37bdfb07 | 1902 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 | 1903 | extern struct tty_driver *console_driver; |
7d7b93c1 | 1904 | driver = tty_driver_kref_get(console_driver); |
1da177e4 LT |
1905 | index = fg_console; |
1906 | noctty = 1; | |
1907 | goto got_driver; | |
1908 | } | |
1909 | #endif | |
37bdfb07 | 1910 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
7d7b93c1 | 1911 | driver = tty_driver_kref_get(console_device(&index)); |
1da177e4 LT |
1912 | if (driver) { |
1913 | /* Don't let /dev/console block */ | |
1914 | filp->f_flags |= O_NONBLOCK; | |
1915 | noctty = 1; | |
1916 | goto got_driver; | |
1917 | } | |
70522e12 | 1918 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1919 | return -ENODEV; |
1920 | } | |
1921 | ||
1922 | driver = get_tty_driver(device, &index); | |
1923 | if (!driver) { | |
70522e12 | 1924 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1925 | return -ENODEV; |
1926 | } | |
1927 | got_driver: | |
d81ed103 | 1928 | retval = tty_init_dev(driver, index, &tty, 0); |
70522e12 | 1929 | mutex_unlock(&tty_mutex); |
7d7b93c1 | 1930 | tty_driver_kref_put(driver); |
1da177e4 LT |
1931 | if (retval) |
1932 | return retval; | |
1933 | ||
1934 | filp->private_data = tty; | |
1935 | file_move(filp, &tty->tty_files); | |
1936 | check_tty_count(tty, "tty_open"); | |
1937 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1938 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1939 | noctty = 1; | |
1940 | #ifdef TTY_DEBUG_HANGUP | |
1941 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1942 | #endif | |
1943 | if (!retval) { | |
f34d7a5b AC |
1944 | if (tty->ops->open) |
1945 | retval = tty->ops->open(tty, filp); | |
1da177e4 LT |
1946 | else |
1947 | retval = -ENODEV; | |
1948 | } | |
1949 | filp->f_flags = saved_flags; | |
1950 | ||
37bdfb07 AC |
1951 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1952 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1953 | retval = -EBUSY; |
1954 | ||
1955 | if (retval) { | |
1956 | #ifdef TTY_DEBUG_HANGUP | |
1957 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1958 | tty->name); | |
1959 | #endif | |
d81ed103 | 1960 | tty_release_dev(filp); |
1da177e4 LT |
1961 | if (retval != -ERESTARTSYS) |
1962 | return retval; | |
1963 | if (signal_pending(current)) | |
1964 | return retval; | |
1965 | schedule(); | |
1966 | /* | |
1967 | * Need to reset f_op in case a hangup happened. | |
1968 | */ | |
1969 | if (filp->f_op == &hung_up_tty_fops) | |
1970 | filp->f_op = &tty_fops; | |
1971 | goto retry_open; | |
1972 | } | |
24ec839c PZ |
1973 | |
1974 | mutex_lock(&tty_mutex); | |
1975 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
1976 | if (!noctty && |
1977 | current->signal->leader && | |
1978 | !current->signal->tty && | |
ab521dc0 | 1979 | tty->session == NULL) |
2a65f1d9 | 1980 | __proc_set_tty(current, tty); |
24ec839c PZ |
1981 | spin_unlock_irq(¤t->sighand->siglock); |
1982 | mutex_unlock(&tty_mutex); | |
1da177e4 LT |
1983 | return 0; |
1984 | } | |
1985 | ||
39d95b9d JC |
1986 | /* BKL pushdown: scary code avoidance wrapper */ |
1987 | static int tty_open(struct inode *inode, struct file *filp) | |
1988 | { | |
1989 | int ret; | |
1990 | ||
1991 | lock_kernel(); | |
1992 | ret = __tty_open(inode, filp); | |
1993 | unlock_kernel(); | |
1994 | return ret; | |
1995 | } | |
1996 | ||
1997 | ||
1998 | ||
1da177e4 | 1999 | |
af9b897e AC |
2000 | /** |
2001 | * tty_release - vfs callback for close | |
2002 | * @inode: inode of tty | |
2003 | * @filp: file pointer for handle to tty | |
2004 | * | |
2005 | * Called the last time each file handle is closed that references | |
2006 | * this tty. There may however be several such references. | |
2007 | * | |
2008 | * Locking: | |
d81ed103 | 2009 | * Takes bkl. See tty_release_dev |
af9b897e AC |
2010 | */ |
2011 | ||
37bdfb07 | 2012 | static int tty_release(struct inode *inode, struct file *filp) |
1da177e4 LT |
2013 | { |
2014 | lock_kernel(); | |
d81ed103 | 2015 | tty_release_dev(filp); |
1da177e4 LT |
2016 | unlock_kernel(); |
2017 | return 0; | |
2018 | } | |
2019 | ||
af9b897e AC |
2020 | /** |
2021 | * tty_poll - check tty status | |
2022 | * @filp: file being polled | |
2023 | * @wait: poll wait structures to update | |
2024 | * | |
2025 | * Call the line discipline polling method to obtain the poll | |
2026 | * status of the device. | |
2027 | * | |
2028 | * Locking: locks called line discipline but ldisc poll method | |
2029 | * may be re-entered freely by other callers. | |
2030 | */ | |
2031 | ||
37bdfb07 | 2032 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2033 | { |
37bdfb07 | 2034 | struct tty_struct *tty; |
1da177e4 LT |
2035 | struct tty_ldisc *ld; |
2036 | int ret = 0; | |
2037 | ||
2038 | tty = (struct tty_struct *)filp->private_data; | |
a7113a96 | 2039 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2040 | return 0; |
37bdfb07 | 2041 | |
1da177e4 | 2042 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2043 | if (ld->ops->poll) |
2044 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2045 | tty_ldisc_deref(ld); |
2046 | return ret; | |
2047 | } | |
2048 | ||
37bdfb07 | 2049 | static int tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2050 | { |
37bdfb07 | 2051 | struct tty_struct *tty; |
47f86834 | 2052 | unsigned long flags; |
5d1e3230 | 2053 | int retval = 0; |
1da177e4 | 2054 | |
5d1e3230 | 2055 | lock_kernel(); |
1da177e4 | 2056 | tty = (struct tty_struct *)filp->private_data; |
a7113a96 | 2057 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2058 | goto out; |
37bdfb07 | 2059 | |
1da177e4 LT |
2060 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2061 | if (retval <= 0) | |
5d1e3230 | 2062 | goto out; |
1da177e4 LT |
2063 | |
2064 | if (on) { | |
ab521dc0 EB |
2065 | enum pid_type type; |
2066 | struct pid *pid; | |
1da177e4 LT |
2067 | if (!waitqueue_active(&tty->read_wait)) |
2068 | tty->minimum_to_wake = 1; | |
47f86834 | 2069 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2070 | if (tty->pgrp) { |
2071 | pid = tty->pgrp; | |
2072 | type = PIDTYPE_PGID; | |
2073 | } else { | |
2074 | pid = task_pid(current); | |
2075 | type = PIDTYPE_PID; | |
2076 | } | |
47f86834 | 2077 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
ab521dc0 | 2078 | retval = __f_setown(filp, pid, type, 0); |
1da177e4 | 2079 | if (retval) |
5d1e3230 | 2080 | goto out; |
1da177e4 LT |
2081 | } else { |
2082 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2083 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2084 | } | |
5d1e3230 JC |
2085 | retval = 0; |
2086 | out: | |
2087 | unlock_kernel(); | |
2088 | return retval; | |
1da177e4 LT |
2089 | } |
2090 | ||
af9b897e AC |
2091 | /** |
2092 | * tiocsti - fake input character | |
2093 | * @tty: tty to fake input into | |
2094 | * @p: pointer to character | |
2095 | * | |
3a4fa0a2 | 2096 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2097 | * input management. |
2098 | * | |
2099 | * FIXME: does not honour flow control ?? | |
2100 | * | |
2101 | * Locking: | |
2102 | * Called functions take tty_ldisc_lock | |
2103 | * current->signal->tty check is safe without locks | |
28298232 AC |
2104 | * |
2105 | * FIXME: may race normal receive processing | |
af9b897e AC |
2106 | */ |
2107 | ||
1da177e4 LT |
2108 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2109 | { | |
2110 | char ch, mbz = 0; | |
2111 | struct tty_ldisc *ld; | |
37bdfb07 | 2112 | |
1da177e4 LT |
2113 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2114 | return -EPERM; | |
2115 | if (get_user(ch, p)) | |
2116 | return -EFAULT; | |
2117 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 2118 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2119 | tty_ldisc_deref(ld); |
2120 | return 0; | |
2121 | } | |
2122 | ||
af9b897e AC |
2123 | /** |
2124 | * tiocgwinsz - implement window query ioctl | |
2125 | * @tty; tty | |
2126 | * @arg: user buffer for result | |
2127 | * | |
808a0d38 | 2128 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2129 | * |
24ec839c | 2130 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2131 | * is consistent. |
af9b897e AC |
2132 | */ |
2133 | ||
37bdfb07 | 2134 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2135 | { |
808a0d38 AC |
2136 | int err; |
2137 | ||
5785c95b | 2138 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2139 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2140 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2141 | |
2142 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2143 | } |
2144 | ||
af9b897e | 2145 | /** |
8c9a9dd0 AC |
2146 | * tty_do_resize - resize event |
2147 | * @tty: tty being resized | |
a152db71 | 2148 | * @real_tty: real tty (not the same as tty if using a pty/tty pair) |
8c9a9dd0 AC |
2149 | * @rows: rows (character) |
2150 | * @cols: cols (character) | |
2151 | * | |
2152 | * Update the termios variables and send the neccessary signals to | |
2153 | * peform a terminal resize correctly | |
af9b897e AC |
2154 | */ |
2155 | ||
8c9a9dd0 AC |
2156 | int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, |
2157 | struct winsize *ws) | |
1da177e4 | 2158 | { |
47f86834 AC |
2159 | struct pid *pgrp, *rpgrp; |
2160 | unsigned long flags; | |
1da177e4 | 2161 | |
a152db71 AC |
2162 | /* For a PTY we need to lock the tty side */ |
2163 | mutex_lock(&real_tty->termios_mutex); | |
f4d2a6c2 | 2164 | if (!memcmp(ws, &real_tty->winsize, sizeof(*ws))) |
ca9bda00 | 2165 | goto done; |
47f86834 AC |
2166 | /* Get the PID values and reference them so we can |
2167 | avoid holding the tty ctrl lock while sending signals */ | |
2168 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2169 | pgrp = get_pid(tty->pgrp); | |
2170 | rpgrp = get_pid(real_tty->pgrp); | |
2171 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2172 | ||
2173 | if (pgrp) | |
2174 | kill_pgrp(pgrp, SIGWINCH, 1); | |
2175 | if (rpgrp != pgrp && rpgrp) | |
2176 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
2177 | ||
2178 | put_pid(pgrp); | |
2179 | put_pid(rpgrp); | |
2180 | ||
8c9a9dd0 AC |
2181 | tty->winsize = *ws; |
2182 | real_tty->winsize = *ws; | |
ca9bda00 | 2183 | done: |
a152db71 | 2184 | mutex_unlock(&real_tty->termios_mutex); |
1da177e4 LT |
2185 | return 0; |
2186 | } | |
2187 | ||
8c9a9dd0 AC |
2188 | /** |
2189 | * tiocswinsz - implement window size set ioctl | |
2190 | * @tty; tty | |
2191 | * @arg: user buffer for result | |
2192 | * | |
2193 | * Copies the user idea of the window size to the kernel. Traditionally | |
2194 | * this is just advisory information but for the Linux console it | |
2195 | * actually has driver level meaning and triggers a VC resize. | |
2196 | * | |
2197 | * Locking: | |
2198 | * Driver dependant. The default do_resize method takes the | |
2199 | * tty termios mutex and ctrl_lock. The console takes its own lock | |
2200 | * then calls into the default method. | |
2201 | */ | |
2202 | ||
2203 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, | |
2204 | struct winsize __user *arg) | |
2205 | { | |
2206 | struct winsize tmp_ws; | |
2207 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2208 | return -EFAULT; | |
2209 | ||
2210 | if (tty->ops->resize) | |
2211 | return tty->ops->resize(tty, real_tty, &tmp_ws); | |
2212 | else | |
2213 | return tty_do_resize(tty, real_tty, &tmp_ws); | |
2214 | } | |
2215 | ||
af9b897e AC |
2216 | /** |
2217 | * tioccons - allow admin to move logical console | |
2218 | * @file: the file to become console | |
2219 | * | |
2220 | * Allow the adminstrator to move the redirected console device | |
2221 | * | |
2222 | * Locking: uses redirect_lock to guard the redirect information | |
2223 | */ | |
2224 | ||
1da177e4 LT |
2225 | static int tioccons(struct file *file) |
2226 | { | |
2227 | if (!capable(CAP_SYS_ADMIN)) | |
2228 | return -EPERM; | |
2229 | if (file->f_op->write == redirected_tty_write) { | |
2230 | struct file *f; | |
2231 | spin_lock(&redirect_lock); | |
2232 | f = redirect; | |
2233 | redirect = NULL; | |
2234 | spin_unlock(&redirect_lock); | |
2235 | if (f) | |
2236 | fput(f); | |
2237 | return 0; | |
2238 | } | |
2239 | spin_lock(&redirect_lock); | |
2240 | if (redirect) { | |
2241 | spin_unlock(&redirect_lock); | |
2242 | return -EBUSY; | |
2243 | } | |
2244 | get_file(file); | |
2245 | redirect = file; | |
2246 | spin_unlock(&redirect_lock); | |
2247 | return 0; | |
2248 | } | |
2249 | ||
af9b897e AC |
2250 | /** |
2251 | * fionbio - non blocking ioctl | |
2252 | * @file: file to set blocking value | |
2253 | * @p: user parameter | |
2254 | * | |
2255 | * Historical tty interfaces had a blocking control ioctl before | |
2256 | * the generic functionality existed. This piece of history is preserved | |
2257 | * in the expected tty API of posix OS's. | |
2258 | * | |
2259 | * Locking: none, the open fle handle ensures it won't go away. | |
2260 | */ | |
1da177e4 LT |
2261 | |
2262 | static int fionbio(struct file *file, int __user *p) | |
2263 | { | |
2264 | int nonblock; | |
2265 | ||
2266 | if (get_user(nonblock, p)) | |
2267 | return -EFAULT; | |
2268 | ||
04f378b1 AC |
2269 | /* file->f_flags is still BKL protected in the fs layer - vomit */ |
2270 | lock_kernel(); | |
1da177e4 LT |
2271 | if (nonblock) |
2272 | file->f_flags |= O_NONBLOCK; | |
2273 | else | |
2274 | file->f_flags &= ~O_NONBLOCK; | |
04f378b1 | 2275 | unlock_kernel(); |
1da177e4 LT |
2276 | return 0; |
2277 | } | |
2278 | ||
af9b897e AC |
2279 | /** |
2280 | * tiocsctty - set controlling tty | |
2281 | * @tty: tty structure | |
2282 | * @arg: user argument | |
2283 | * | |
2284 | * This ioctl is used to manage job control. It permits a session | |
2285 | * leader to set this tty as the controlling tty for the session. | |
2286 | * | |
2287 | * Locking: | |
28298232 | 2288 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2289 | * Takes tasklist_lock internally to walk sessions |
2290 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2291 | */ |
2292 | ||
1da177e4 LT |
2293 | static int tiocsctty(struct tty_struct *tty, int arg) |
2294 | { | |
24ec839c | 2295 | int ret = 0; |
ab521dc0 | 2296 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2297 | return ret; |
2298 | ||
2299 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2300 | /* |
2301 | * The process must be a session leader and | |
2302 | * not have a controlling tty already. | |
2303 | */ | |
24ec839c PZ |
2304 | if (!current->signal->leader || current->signal->tty) { |
2305 | ret = -EPERM; | |
2306 | goto unlock; | |
2307 | } | |
2308 | ||
ab521dc0 | 2309 | if (tty->session) { |
1da177e4 LT |
2310 | /* |
2311 | * This tty is already the controlling | |
2312 | * tty for another session group! | |
2313 | */ | |
37bdfb07 | 2314 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2315 | /* |
2316 | * Steal it away | |
2317 | */ | |
1da177e4 | 2318 | read_lock(&tasklist_lock); |
24ec839c | 2319 | session_clear_tty(tty->session); |
1da177e4 | 2320 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2321 | } else { |
2322 | ret = -EPERM; | |
2323 | goto unlock; | |
2324 | } | |
1da177e4 | 2325 | } |
24ec839c PZ |
2326 | proc_set_tty(current, tty); |
2327 | unlock: | |
28298232 | 2328 | mutex_unlock(&tty_mutex); |
24ec839c | 2329 | return ret; |
1da177e4 LT |
2330 | } |
2331 | ||
5d0fdf1e AC |
2332 | /** |
2333 | * tty_get_pgrp - return a ref counted pgrp pid | |
2334 | * @tty: tty to read | |
2335 | * | |
2336 | * Returns a refcounted instance of the pid struct for the process | |
2337 | * group controlling the tty. | |
2338 | */ | |
2339 | ||
2340 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2341 | { | |
2342 | unsigned long flags; | |
2343 | struct pid *pgrp; | |
2344 | ||
2345 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2346 | pgrp = get_pid(tty->pgrp); | |
2347 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2348 | ||
2349 | return pgrp; | |
2350 | } | |
2351 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2352 | ||
af9b897e AC |
2353 | /** |
2354 | * tiocgpgrp - get process group | |
2355 | * @tty: tty passed by user | |
2356 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2357 | * @p: returned pid | |
2358 | * | |
2359 | * Obtain the process group of the tty. If there is no process group | |
2360 | * return an error. | |
2361 | * | |
24ec839c | 2362 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2363 | */ |
2364 | ||
1da177e4 LT |
2365 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2366 | { | |
5d0fdf1e AC |
2367 | struct pid *pid; |
2368 | int ret; | |
1da177e4 LT |
2369 | /* |
2370 | * (tty == real_tty) is a cheap way of | |
2371 | * testing if the tty is NOT a master pty. | |
2372 | */ | |
2373 | if (tty == real_tty && current->signal->tty != real_tty) | |
2374 | return -ENOTTY; | |
5d0fdf1e AC |
2375 | pid = tty_get_pgrp(real_tty); |
2376 | ret = put_user(pid_vnr(pid), p); | |
2377 | put_pid(pid); | |
2378 | return ret; | |
1da177e4 LT |
2379 | } |
2380 | ||
af9b897e AC |
2381 | /** |
2382 | * tiocspgrp - attempt to set process group | |
2383 | * @tty: tty passed by user | |
2384 | * @real_tty: tty side device matching tty passed by user | |
2385 | * @p: pid pointer | |
2386 | * | |
2387 | * Set the process group of the tty to the session passed. Only | |
2388 | * permitted where the tty session is our session. | |
2389 | * | |
47f86834 | 2390 | * Locking: RCU, ctrl lock |
af9b897e AC |
2391 | */ |
2392 | ||
1da177e4 LT |
2393 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2394 | { | |
04a2e6a5 EB |
2395 | struct pid *pgrp; |
2396 | pid_t pgrp_nr; | |
1da177e4 | 2397 | int retval = tty_check_change(real_tty); |
47f86834 | 2398 | unsigned long flags; |
1da177e4 LT |
2399 | |
2400 | if (retval == -EIO) | |
2401 | return -ENOTTY; | |
2402 | if (retval) | |
2403 | return retval; | |
2404 | if (!current->signal->tty || | |
2405 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2406 | (real_tty->session != task_session(current))) |
1da177e4 | 2407 | return -ENOTTY; |
04a2e6a5 | 2408 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2409 | return -EFAULT; |
04a2e6a5 | 2410 | if (pgrp_nr < 0) |
1da177e4 | 2411 | return -EINVAL; |
04a2e6a5 | 2412 | rcu_read_lock(); |
b488893a | 2413 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2414 | retval = -ESRCH; |
2415 | if (!pgrp) | |
2416 | goto out_unlock; | |
2417 | retval = -EPERM; | |
2418 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2419 | goto out_unlock; | |
2420 | retval = 0; | |
47f86834 | 2421 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2422 | put_pid(real_tty->pgrp); |
2423 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2424 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2425 | out_unlock: |
2426 | rcu_read_unlock(); | |
2427 | return retval; | |
1da177e4 LT |
2428 | } |
2429 | ||
af9b897e AC |
2430 | /** |
2431 | * tiocgsid - get session id | |
2432 | * @tty: tty passed by user | |
2433 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2434 | * @p: pointer to returned session id | |
2435 | * | |
2436 | * Obtain the session id of the tty. If there is no session | |
2437 | * return an error. | |
2438 | * | |
24ec839c | 2439 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2440 | */ |
2441 | ||
1da177e4 LT |
2442 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2443 | { | |
2444 | /* | |
2445 | * (tty == real_tty) is a cheap way of | |
2446 | * testing if the tty is NOT a master pty. | |
2447 | */ | |
2448 | if (tty == real_tty && current->signal->tty != real_tty) | |
2449 | return -ENOTTY; | |
ab521dc0 | 2450 | if (!real_tty->session) |
1da177e4 | 2451 | return -ENOTTY; |
b488893a | 2452 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2453 | } |
2454 | ||
af9b897e AC |
2455 | /** |
2456 | * tiocsetd - set line discipline | |
2457 | * @tty: tty device | |
2458 | * @p: pointer to user data | |
2459 | * | |
2460 | * Set the line discipline according to user request. | |
2461 | * | |
2462 | * Locking: see tty_set_ldisc, this function is just a helper | |
2463 | */ | |
2464 | ||
1da177e4 LT |
2465 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2466 | { | |
2467 | int ldisc; | |
04f378b1 | 2468 | int ret; |
1da177e4 LT |
2469 | |
2470 | if (get_user(ldisc, p)) | |
2471 | return -EFAULT; | |
04f378b1 AC |
2472 | |
2473 | lock_kernel(); | |
2474 | ret = tty_set_ldisc(tty, ldisc); | |
2475 | unlock_kernel(); | |
2476 | ||
2477 | return ret; | |
1da177e4 LT |
2478 | } |
2479 | ||
af9b897e AC |
2480 | /** |
2481 | * send_break - performed time break | |
2482 | * @tty: device to break on | |
2483 | * @duration: timeout in mS | |
2484 | * | |
2485 | * Perform a timed break on hardware that lacks its own driver level | |
2486 | * timed break functionality. | |
2487 | * | |
2488 | * Locking: | |
28298232 | 2489 | * atomic_write_lock serializes |
af9b897e | 2490 | * |
af9b897e AC |
2491 | */ |
2492 | ||
b20f3ae5 | 2493 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2494 | { |
9e98966c AC |
2495 | int retval; |
2496 | ||
2497 | if (tty->ops->break_ctl == NULL) | |
2498 | return 0; | |
2499 | ||
2500 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2501 | retval = tty->ops->break_ctl(tty, duration); | |
2502 | else { | |
2503 | /* Do the work ourselves */ | |
2504 | if (tty_write_lock(tty, 0) < 0) | |
2505 | return -EINTR; | |
2506 | retval = tty->ops->break_ctl(tty, -1); | |
2507 | if (retval) | |
2508 | goto out; | |
2509 | if (!signal_pending(current)) | |
2510 | msleep_interruptible(duration); | |
2511 | retval = tty->ops->break_ctl(tty, 0); | |
2512 | out: | |
2513 | tty_write_unlock(tty); | |
2514 | if (signal_pending(current)) | |
2515 | retval = -EINTR; | |
2516 | } | |
2517 | return retval; | |
1da177e4 LT |
2518 | } |
2519 | ||
af9b897e | 2520 | /** |
f34d7a5b | 2521 | * tty_tiocmget - get modem status |
af9b897e AC |
2522 | * @tty: tty device |
2523 | * @file: user file pointer | |
2524 | * @p: pointer to result | |
2525 | * | |
2526 | * Obtain the modem status bits from the tty driver if the feature | |
2527 | * is supported. Return -EINVAL if it is not available. | |
2528 | * | |
2529 | * Locking: none (up to the driver) | |
2530 | */ | |
2531 | ||
2532 | static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) | |
1da177e4 LT |
2533 | { |
2534 | int retval = -EINVAL; | |
2535 | ||
f34d7a5b AC |
2536 | if (tty->ops->tiocmget) { |
2537 | retval = tty->ops->tiocmget(tty, file); | |
1da177e4 LT |
2538 | |
2539 | if (retval >= 0) | |
2540 | retval = put_user(retval, p); | |
2541 | } | |
2542 | return retval; | |
2543 | } | |
2544 | ||
af9b897e | 2545 | /** |
f34d7a5b | 2546 | * tty_tiocmset - set modem status |
af9b897e AC |
2547 | * @tty: tty device |
2548 | * @file: user file pointer | |
2549 | * @cmd: command - clear bits, set bits or set all | |
2550 | * @p: pointer to desired bits | |
2551 | * | |
2552 | * Set the modem status bits from the tty driver if the feature | |
2553 | * is supported. Return -EINVAL if it is not available. | |
2554 | * | |
2555 | * Locking: none (up to the driver) | |
2556 | */ | |
2557 | ||
2558 | static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, | |
1da177e4 LT |
2559 | unsigned __user *p) |
2560 | { | |
ae677517 AC |
2561 | int retval; |
2562 | unsigned int set, clear, val; | |
1da177e4 | 2563 | |
ae677517 AC |
2564 | if (tty->ops->tiocmset == NULL) |
2565 | return -EINVAL; | |
1da177e4 | 2566 | |
ae677517 AC |
2567 | retval = get_user(val, p); |
2568 | if (retval) | |
2569 | return retval; | |
2570 | set = clear = 0; | |
2571 | switch (cmd) { | |
2572 | case TIOCMBIS: | |
2573 | set = val; | |
2574 | break; | |
2575 | case TIOCMBIC: | |
2576 | clear = val; | |
2577 | break; | |
2578 | case TIOCMSET: | |
2579 | set = val; | |
2580 | clear = ~val; | |
2581 | break; | |
2582 | } | |
2583 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2584 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2585 | return tty->ops->tiocmset(tty, file, set, clear); | |
1da177e4 LT |
2586 | } |
2587 | ||
2588 | /* | |
2589 | * Split this up, as gcc can choke on it otherwise.. | |
2590 | */ | |
04f378b1 | 2591 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
2592 | { |
2593 | struct tty_struct *tty, *real_tty; | |
2594 | void __user *p = (void __user *)arg; | |
2595 | int retval; | |
2596 | struct tty_ldisc *ld; | |
04f378b1 | 2597 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2598 | |
1da177e4 LT |
2599 | tty = (struct tty_struct *)file->private_data; |
2600 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2601 | return -EINVAL; | |
2602 | ||
2603 | real_tty = tty; | |
2604 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2605 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2606 | real_tty = tty->link; | |
2607 | ||
1da177e4 LT |
2608 | |
2609 | /* | |
2610 | * Factor out some common prep work | |
2611 | */ | |
2612 | switch (cmd) { | |
2613 | case TIOCSETD: | |
2614 | case TIOCSBRK: | |
2615 | case TIOCCBRK: | |
2616 | case TCSBRK: | |
37bdfb07 | 2617 | case TCSBRKP: |
1da177e4 LT |
2618 | retval = tty_check_change(tty); |
2619 | if (retval) | |
2620 | return retval; | |
2621 | if (cmd != TIOCCBRK) { | |
2622 | tty_wait_until_sent(tty, 0); | |
2623 | if (signal_pending(current)) | |
2624 | return -EINTR; | |
2625 | } | |
2626 | break; | |
2627 | } | |
2628 | ||
9e98966c AC |
2629 | /* |
2630 | * Now do the stuff. | |
2631 | */ | |
1da177e4 | 2632 | switch (cmd) { |
37bdfb07 AC |
2633 | case TIOCSTI: |
2634 | return tiocsti(tty, p); | |
2635 | case TIOCGWINSZ: | |
8f520021 | 2636 | return tiocgwinsz(real_tty, p); |
37bdfb07 AC |
2637 | case TIOCSWINSZ: |
2638 | return tiocswinsz(tty, real_tty, p); | |
2639 | case TIOCCONS: | |
2640 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2641 | case FIONBIO: | |
2642 | return fionbio(file, p); | |
2643 | case TIOCEXCL: | |
2644 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2645 | return 0; | |
2646 | case TIOCNXCL: | |
2647 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2648 | return 0; | |
2649 | case TIOCNOTTY: | |
2650 | if (current->signal->tty != tty) | |
2651 | return -ENOTTY; | |
2652 | no_tty(); | |
2653 | return 0; | |
2654 | case TIOCSCTTY: | |
2655 | return tiocsctty(tty, arg); | |
2656 | case TIOCGPGRP: | |
2657 | return tiocgpgrp(tty, real_tty, p); | |
2658 | case TIOCSPGRP: | |
2659 | return tiocspgrp(tty, real_tty, p); | |
2660 | case TIOCGSID: | |
2661 | return tiocgsid(tty, real_tty, p); | |
2662 | case TIOCGETD: | |
a352def2 | 2663 | return put_user(tty->ldisc.ops->num, (int __user *)p); |
37bdfb07 AC |
2664 | case TIOCSETD: |
2665 | return tiocsetd(tty, p); | |
37bdfb07 AC |
2666 | /* |
2667 | * Break handling | |
2668 | */ | |
2669 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2670 | if (tty->ops->break_ctl) |
9e98966c | 2671 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2672 | return 0; |
37bdfb07 | 2673 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2674 | if (tty->ops->break_ctl) |
9e98966c | 2675 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2676 | return 0; |
2677 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2678 | /* non-zero arg means wait for all output data | |
2679 | * to be sent (performed above) but don't send break. | |
2680 | * This is used by the tcdrain() termios function. | |
2681 | */ | |
2682 | if (!arg) | |
2683 | return send_break(tty, 250); | |
2684 | return 0; | |
2685 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2686 | return send_break(tty, arg ? arg*100 : 250); | |
2687 | ||
2688 | case TIOCMGET: | |
2689 | return tty_tiocmget(tty, file, p); | |
2690 | case TIOCMSET: | |
2691 | case TIOCMBIC: | |
2692 | case TIOCMBIS: | |
2693 | return tty_tiocmset(tty, file, cmd, p); | |
2694 | case TCFLSH: | |
2695 | switch (arg) { | |
2696 | case TCIFLUSH: | |
2697 | case TCIOFLUSH: | |
2698 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2699 | tty_buffer_flush(tty); | |
c5c34d48 | 2700 | break; |
37bdfb07 AC |
2701 | } |
2702 | break; | |
1da177e4 | 2703 | } |
f34d7a5b AC |
2704 | if (tty->ops->ioctl) { |
2705 | retval = (tty->ops->ioctl)(tty, file, cmd, arg); | |
1da177e4 LT |
2706 | if (retval != -ENOIOCTLCMD) |
2707 | return retval; | |
2708 | } | |
2709 | ld = tty_ldisc_ref_wait(tty); | |
2710 | retval = -EINVAL; | |
a352def2 AC |
2711 | if (ld->ops->ioctl) { |
2712 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2713 | if (retval == -ENOIOCTLCMD) |
2714 | retval = -EINVAL; | |
2715 | } | |
2716 | tty_ldisc_deref(ld); | |
2717 | return retval; | |
2718 | } | |
2719 | ||
e10cc1df | 2720 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2721 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2722 | unsigned long arg) |
2723 | { | |
2724 | struct inode *inode = file->f_dentry->d_inode; | |
2725 | struct tty_struct *tty = file->private_data; | |
2726 | struct tty_ldisc *ld; | |
2727 | int retval = -ENOIOCTLCMD; | |
2728 | ||
2729 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2730 | return -EINVAL; | |
2731 | ||
f34d7a5b AC |
2732 | if (tty->ops->compat_ioctl) { |
2733 | retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg); | |
e10cc1df PF |
2734 | if (retval != -ENOIOCTLCMD) |
2735 | return retval; | |
2736 | } | |
2737 | ||
2738 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2739 | if (ld->ops->compat_ioctl) |
2740 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
e10cc1df PF |
2741 | tty_ldisc_deref(ld); |
2742 | ||
2743 | return retval; | |
2744 | } | |
2745 | #endif | |
1da177e4 LT |
2746 | |
2747 | /* | |
2748 | * This implements the "Secure Attention Key" --- the idea is to | |
2749 | * prevent trojan horses by killing all processes associated with this | |
2750 | * tty when the user hits the "Secure Attention Key". Required for | |
2751 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2752 | * |
1da177e4 LT |
2753 | * This code could be nicer; ideally it should send a HUP, wait a few |
2754 | * seconds, then send a INT, and then a KILL signal. But you then | |
2755 | * have to coordinate with the init process, since all processes associated | |
2756 | * with the current tty must be dead before the new getty is allowed | |
2757 | * to spawn. | |
2758 | * | |
2759 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2760 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2761 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2762 | * | |
2763 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2764 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2765 | */ | |
8b6312f4 | 2766 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2767 | { |
2768 | #ifdef TTY_SOFT_SAK | |
2769 | tty_hangup(tty); | |
2770 | #else | |
652486fb | 2771 | struct task_struct *g, *p; |
ab521dc0 | 2772 | struct pid *session; |
1da177e4 LT |
2773 | int i; |
2774 | struct file *filp; | |
badf1662 | 2775 | struct fdtable *fdt; |
37bdfb07 | 2776 | |
1da177e4 LT |
2777 | if (!tty) |
2778 | return; | |
24ec839c | 2779 | session = tty->session; |
37bdfb07 | 2780 | |
b3f13deb | 2781 | tty_ldisc_flush(tty); |
1da177e4 | 2782 | |
f34d7a5b | 2783 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2784 | |
1da177e4 | 2785 | read_lock(&tasklist_lock); |
652486fb | 2786 | /* Kill the entire session */ |
ab521dc0 | 2787 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2788 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2789 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2790 | task_pid_nr(p), p->comm); |
652486fb | 2791 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2792 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2793 | /* Now kill any processes that happen to have the |
2794 | * tty open. | |
2795 | */ | |
2796 | do_each_thread(g, p) { | |
2797 | if (p->signal->tty == tty) { | |
1da177e4 | 2798 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2799 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2800 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2801 | send_sig(SIGKILL, p, 1); |
2802 | continue; | |
2803 | } | |
2804 | task_lock(p); | |
2805 | if (p->files) { | |
ca99c1da DS |
2806 | /* |
2807 | * We don't take a ref to the file, so we must | |
2808 | * hold ->file_lock instead. | |
2809 | */ | |
2810 | spin_lock(&p->files->file_lock); | |
badf1662 | 2811 | fdt = files_fdtable(p->files); |
37bdfb07 | 2812 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2813 | filp = fcheck_files(p->files, i); |
2814 | if (!filp) | |
2815 | continue; | |
2816 | if (filp->f_op->read == tty_read && | |
2817 | filp->private_data == tty) { | |
2818 | printk(KERN_NOTICE "SAK: killed process %d" | |
2819 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2820 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2821 | force_sig(SIGKILL, p); |
1da177e4 LT |
2822 | break; |
2823 | } | |
2824 | } | |
ca99c1da | 2825 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2826 | } |
2827 | task_unlock(p); | |
652486fb | 2828 | } while_each_thread(g, p); |
1da177e4 LT |
2829 | read_unlock(&tasklist_lock); |
2830 | #endif | |
2831 | } | |
2832 | ||
8b6312f4 EB |
2833 | static void do_SAK_work(struct work_struct *work) |
2834 | { | |
2835 | struct tty_struct *tty = | |
2836 | container_of(work, struct tty_struct, SAK_work); | |
2837 | __do_SAK(tty); | |
2838 | } | |
2839 | ||
1da177e4 LT |
2840 | /* |
2841 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2842 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2843 | * the values which we write to it will be identical to the values which it | |
2844 | * already has. --akpm | |
2845 | */ | |
2846 | void do_SAK(struct tty_struct *tty) | |
2847 | { | |
2848 | if (!tty) | |
2849 | return; | |
1da177e4 LT |
2850 | schedule_work(&tty->SAK_work); |
2851 | } | |
2852 | ||
2853 | EXPORT_SYMBOL(do_SAK); | |
2854 | ||
af9b897e AC |
2855 | /** |
2856 | * initialize_tty_struct | |
2857 | * @tty: tty to initialize | |
2858 | * | |
2859 | * This subroutine initializes a tty structure that has been newly | |
2860 | * allocated. | |
2861 | * | |
2862 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2863 | */ |
af9b897e | 2864 | |
1da177e4 LT |
2865 | static void initialize_tty_struct(struct tty_struct *tty) |
2866 | { | |
2867 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2868 | kref_init(&tty->kref); |
1da177e4 | 2869 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2870 | tty_ldisc_init(tty); |
ab521dc0 EB |
2871 | tty->session = NULL; |
2872 | tty->pgrp = NULL; | |
1da177e4 | 2873 | tty->overrun_time = jiffies; |
33f0f88f AC |
2874 | tty->buf.head = tty->buf.tail = NULL; |
2875 | tty_buffer_init(tty); | |
5785c95b | 2876 | mutex_init(&tty->termios_mutex); |
1da177e4 LT |
2877 | init_waitqueue_head(&tty->write_wait); |
2878 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2879 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2880 | mutex_init(&tty->atomic_read_lock); |
2881 | mutex_init(&tty->atomic_write_lock); | |
1da177e4 | 2882 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2883 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2884 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2885 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
1da177e4 LT |
2886 | } |
2887 | ||
f34d7a5b AC |
2888 | /** |
2889 | * tty_put_char - write one character to a tty | |
2890 | * @tty: tty | |
2891 | * @ch: character | |
2892 | * | |
2893 | * Write one byte to the tty using the provided put_char method | |
2894 | * if present. Returns the number of characters successfully output. | |
2895 | * | |
2896 | * Note: the specific put_char operation in the driver layer may go | |
2897 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2898 | */ |
af9b897e | 2899 | |
f34d7a5b | 2900 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2901 | { |
f34d7a5b AC |
2902 | if (tty->ops->put_char) |
2903 | return tty->ops->put_char(tty, ch); | |
2904 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 2905 | } |
f34d7a5b AC |
2906 | EXPORT_SYMBOL_GPL(tty_put_char); |
2907 | ||
d81ed103 | 2908 | struct class *tty_class; |
1da177e4 LT |
2909 | |
2910 | /** | |
af9b897e AC |
2911 | * tty_register_device - register a tty device |
2912 | * @driver: the tty driver that describes the tty device | |
2913 | * @index: the index in the tty driver for this tty device | |
2914 | * @device: a struct device that is associated with this tty device. | |
2915 | * This field is optional, if there is no known struct device | |
2916 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2917 | * |
01107d34 GKH |
2918 | * Returns a pointer to the struct device for this tty device |
2919 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2920 | * |
af9b897e AC |
2921 | * This call is required to be made to register an individual tty device |
2922 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2923 | * that bit is not set, this function should not be called by a tty | |
2924 | * driver. | |
2925 | * | |
2926 | * Locking: ?? | |
1da177e4 | 2927 | */ |
af9b897e | 2928 | |
01107d34 GKH |
2929 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2930 | struct device *device) | |
1da177e4 LT |
2931 | { |
2932 | char name[64]; | |
2933 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2934 | ||
2935 | if (index >= driver->num) { | |
2936 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2937 | " (%d).\n", index); | |
1cdcb6b4 | 2938 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2939 | } |
2940 | ||
1da177e4 LT |
2941 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2942 | pty_line_name(driver, index, name); | |
2943 | else | |
2944 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2945 | |
47aa5793 | 2946 | return device_create_drvdata(tty_class, device, dev, NULL, name); |
1da177e4 | 2947 | } |
7d7b93c1 | 2948 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
2949 | |
2950 | /** | |
af9b897e AC |
2951 | * tty_unregister_device - unregister a tty device |
2952 | * @driver: the tty driver that describes the tty device | |
2953 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2954 | * |
af9b897e AC |
2955 | * If a tty device is registered with a call to tty_register_device() then |
2956 | * this function must be called when the tty device is gone. | |
2957 | * | |
2958 | * Locking: ?? | |
1da177e4 | 2959 | */ |
af9b897e | 2960 | |
1da177e4 LT |
2961 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2962 | { | |
37bdfb07 AC |
2963 | device_destroy(tty_class, |
2964 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 2965 | } |
1da177e4 LT |
2966 | EXPORT_SYMBOL(tty_unregister_device); |
2967 | ||
2968 | struct tty_driver *alloc_tty_driver(int lines) | |
2969 | { | |
2970 | struct tty_driver *driver; | |
2971 | ||
506eb99a | 2972 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 2973 | if (driver) { |
7d7b93c1 | 2974 | kref_init(&driver->kref); |
1da177e4 LT |
2975 | driver->magic = TTY_DRIVER_MAGIC; |
2976 | driver->num = lines; | |
2977 | /* later we'll move allocation of tables here */ | |
2978 | } | |
2979 | return driver; | |
2980 | } | |
7d7b93c1 | 2981 | EXPORT_SYMBOL(alloc_tty_driver); |
1da177e4 | 2982 | |
7d7b93c1 | 2983 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 2984 | { |
7d7b93c1 AC |
2985 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
2986 | int i; | |
2987 | struct ktermios *tp; | |
2988 | void *p; | |
2989 | ||
2990 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
2991 | /* | |
2992 | * Free the termios and termios_locked structures because | |
2993 | * we don't want to get memory leaks when modular tty | |
2994 | * drivers are removed from the kernel. | |
2995 | */ | |
2996 | for (i = 0; i < driver->num; i++) { | |
2997 | tp = driver->termios[i]; | |
2998 | if (tp) { | |
2999 | driver->termios[i] = NULL; | |
3000 | kfree(tp); | |
3001 | } | |
3002 | tp = driver->termios_locked[i]; | |
3003 | if (tp) { | |
3004 | driver->termios_locked[i] = NULL; | |
3005 | kfree(tp); | |
3006 | } | |
3007 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) | |
3008 | tty_unregister_device(driver, i); | |
3009 | } | |
3010 | p = driver->ttys; | |
3011 | proc_tty_unregister_driver(driver); | |
3012 | driver->ttys = NULL; | |
3013 | driver->termios = driver->termios_locked = NULL; | |
3014 | kfree(p); | |
3015 | cdev_del(&driver->cdev); | |
3016 | } | |
1da177e4 LT |
3017 | kfree(driver); |
3018 | } | |
3019 | ||
7d7b93c1 AC |
3020 | void tty_driver_kref_put(struct tty_driver *driver) |
3021 | { | |
3022 | kref_put(&driver->kref, destruct_tty_driver); | |
3023 | } | |
3024 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3025 | ||
b68e31d0 JD |
3026 | void tty_set_operations(struct tty_driver *driver, |
3027 | const struct tty_operations *op) | |
1da177e4 | 3028 | { |
f34d7a5b AC |
3029 | driver->ops = op; |
3030 | }; | |
7d7b93c1 | 3031 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3032 | |
7d7b93c1 AC |
3033 | void put_tty_driver(struct tty_driver *d) |
3034 | { | |
3035 | tty_driver_kref_put(d); | |
3036 | } | |
1da177e4 | 3037 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3038 | |
3039 | /* | |
3040 | * Called by a tty driver to register itself. | |
3041 | */ | |
3042 | int tty_register_driver(struct tty_driver *driver) | |
3043 | { | |
3044 | int error; | |
37bdfb07 | 3045 | int i; |
1da177e4 LT |
3046 | dev_t dev; |
3047 | void **p = NULL; | |
3048 | ||
543691a6 AW |
3049 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
3050 | p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); | |
1da177e4 LT |
3051 | if (!p) |
3052 | return -ENOMEM; | |
1da177e4 LT |
3053 | } |
3054 | ||
3055 | if (!driver->major) { | |
37bdfb07 AC |
3056 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3057 | driver->num, driver->name); | |
1da177e4 LT |
3058 | if (!error) { |
3059 | driver->major = MAJOR(dev); | |
3060 | driver->minor_start = MINOR(dev); | |
3061 | } | |
3062 | } else { | |
3063 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3064 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
3065 | } |
3066 | if (error < 0) { | |
3067 | kfree(p); | |
3068 | return error; | |
3069 | } | |
3070 | ||
3071 | if (p) { | |
3072 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3073 | driver->termios = (struct ktermios **)(p + driver->num); |
37bdfb07 AC |
3074 | driver->termios_locked = (struct ktermios **) |
3075 | (p + driver->num * 2); | |
1da177e4 LT |
3076 | } else { |
3077 | driver->ttys = NULL; | |
3078 | driver->termios = NULL; | |
3079 | driver->termios_locked = NULL; | |
3080 | } | |
3081 | ||
3082 | cdev_init(&driver->cdev, &tty_fops); | |
3083 | driver->cdev.owner = driver->owner; | |
3084 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3085 | if (error) { | |
1da177e4 LT |
3086 | unregister_chrdev_region(dev, driver->num); |
3087 | driver->ttys = NULL; | |
3088 | driver->termios = driver->termios_locked = NULL; | |
3089 | kfree(p); | |
3090 | return error; | |
3091 | } | |
3092 | ||
ca509f69 | 3093 | mutex_lock(&tty_mutex); |
1da177e4 | 3094 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3095 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3096 | |
3097 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
3098 | for (i = 0; i < driver->num; i++) | |
1da177e4 LT |
3099 | tty_register_device(driver, i, NULL); |
3100 | } | |
3101 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3102 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 LT |
3103 | return 0; |
3104 | } | |
3105 | ||
3106 | EXPORT_SYMBOL(tty_register_driver); | |
3107 | ||
3108 | /* | |
3109 | * Called by a tty driver to unregister itself. | |
3110 | */ | |
3111 | int tty_unregister_driver(struct tty_driver *driver) | |
3112 | { | |
7d7b93c1 AC |
3113 | #if 0 |
3114 | /* FIXME */ | |
1da177e4 LT |
3115 | if (driver->refcount) |
3116 | return -EBUSY; | |
7d7b93c1 | 3117 | #endif |
1da177e4 LT |
3118 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3119 | driver->num); | |
ca509f69 | 3120 | mutex_lock(&tty_mutex); |
1da177e4 | 3121 | list_del(&driver->tty_drivers); |
ca509f69 | 3122 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3123 | return 0; |
3124 | } | |
7d7b93c1 | 3125 | |
1da177e4 LT |
3126 | EXPORT_SYMBOL(tty_unregister_driver); |
3127 | ||
24ec839c PZ |
3128 | dev_t tty_devnum(struct tty_struct *tty) |
3129 | { | |
3130 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3131 | } | |
3132 | EXPORT_SYMBOL(tty_devnum); | |
3133 | ||
3134 | void proc_clear_tty(struct task_struct *p) | |
3135 | { | |
9c9f4ded | 3136 | struct tty_struct *tty; |
24ec839c | 3137 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 3138 | tty = p->signal->tty; |
24ec839c PZ |
3139 | p->signal->tty = NULL; |
3140 | spin_unlock_irq(&p->sighand->siglock); | |
9c9f4ded | 3141 | tty_kref_put(tty); |
24ec839c | 3142 | } |
24ec839c | 3143 | |
47f86834 AC |
3144 | /* Called under the sighand lock */ |
3145 | ||
2a65f1d9 | 3146 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3147 | { |
3148 | if (tty) { | |
47f86834 AC |
3149 | unsigned long flags; |
3150 | /* We should not have a session or pgrp to put here but.... */ | |
3151 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3152 | put_pid(tty->session); |
3153 | put_pid(tty->pgrp); | |
ab521dc0 | 3154 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3155 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3156 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3157 | if (tsk->signal->tty) { |
3158 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3159 | tty_kref_put(tsk->signal->tty); | |
3160 | } | |
24ec839c | 3161 | } |
2a65f1d9 | 3162 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3163 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3164 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3165 | } |
3166 | ||
98a27ba4 | 3167 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3168 | { |
3169 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3170 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3171 | spin_unlock_irq(&tsk->sighand->siglock); |
3172 | } | |
3173 | ||
3174 | struct tty_struct *get_current_tty(void) | |
3175 | { | |
3176 | struct tty_struct *tty; | |
934e6ebf AC |
3177 | unsigned long flags; |
3178 | ||
3179 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3180 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3181 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3182 | return tty; |
3183 | } | |
a311f743 | 3184 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3185 | |
d81ed103 AC |
3186 | void tty_default_fops(struct file_operations *fops) |
3187 | { | |
3188 | *fops = tty_fops; | |
3189 | } | |
3190 | ||
1da177e4 LT |
3191 | /* |
3192 | * Initialize the console device. This is called *early*, so | |
3193 | * we can't necessarily depend on lots of kernel help here. | |
3194 | * Just do some early initializations, and do the complex setup | |
3195 | * later. | |
3196 | */ | |
3197 | void __init console_init(void) | |
3198 | { | |
3199 | initcall_t *call; | |
3200 | ||
3201 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3202 | tty_ldisc_begin(); |
1da177e4 LT |
3203 | |
3204 | /* | |
37bdfb07 | 3205 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3206 | * inform about problems etc.. |
3207 | */ | |
1da177e4 LT |
3208 | call = __con_initcall_start; |
3209 | while (call < __con_initcall_end) { | |
3210 | (*call)(); | |
3211 | call++; | |
3212 | } | |
3213 | } | |
3214 | ||
1da177e4 LT |
3215 | static int __init tty_class_init(void) |
3216 | { | |
7fe845d1 | 3217 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3218 | if (IS_ERR(tty_class)) |
3219 | return PTR_ERR(tty_class); | |
3220 | return 0; | |
3221 | } | |
3222 | ||
3223 | postcore_initcall(tty_class_init); | |
3224 | ||
3225 | /* 3/2004 jmc: why do these devices exist? */ | |
3226 | ||
3227 | static struct cdev tty_cdev, console_cdev; | |
1da177e4 LT |
3228 | |
3229 | /* | |
3230 | * Ok, now we can initialize the rest of the tty devices and can count | |
3231 | * on memory allocations, interrupts etc.. | |
3232 | */ | |
3233 | static int __init tty_init(void) | |
3234 | { | |
3235 | cdev_init(&tty_cdev, &tty_fops); | |
3236 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3237 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3238 | panic("Couldn't register /dev/tty driver\n"); | |
d81ed103 | 3239 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, |
47aa5793 | 3240 | "tty"); |
1da177e4 LT |
3241 | |
3242 | cdev_init(&console_cdev, &console_fops); | |
3243 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3244 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3245 | panic("Couldn't register /dev/console driver\n"); | |
d81ed103 | 3246 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3247 | "console"); |
1da177e4 | 3248 | |
1da177e4 | 3249 | #ifdef CONFIG_VT |
d81ed103 | 3250 | vty_init(&console_fops); |
1da177e4 LT |
3251 | #endif |
3252 | return 0; | |
3253 | } | |
3254 | module_init(tty_init); |