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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/tty_io.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
9 | * or rs-channels. It also implements echoing, cooked mode etc. | |
10 | * | |
11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
12 | * | |
13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
14 | * tty_struct and tty_queue structures. Previously there was an array | |
15 | * of 256 tty_struct's which was statically allocated, and the | |
16 | * tty_queue structures were allocated at boot time. Both are now | |
17 | * dynamically allocated only when the tty is open. | |
18 | * | |
19 | * Also restructured routines so that there is more of a separation | |
20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
21 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
23 | * |
24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
25 | * which can be dynamically activated and de-activated by the line | |
26 | * discipline handling modules (like SLIP). | |
27 | * | |
28 | * NOTE: pay no attention to the line discipline code (yet); its | |
29 | * interface is still subject to change in this version... | |
30 | * -- TYT, 1/31/92 | |
31 | * | |
32 | * Added functionality to the OPOST tty handling. No delays, but all | |
33 | * other bits should be there. | |
34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
35 | * | |
36 | * Rewrote canonical mode and added more termios flags. | |
37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
38 | * | |
39 | * Reorganized FASYNC support so mouse code can share it. | |
40 | * -- ctm@ardi.com, 9Sep95 | |
41 | * | |
42 | * New TIOCLINUX variants added. | |
43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 44 | * |
1da177e4 LT |
45 | * Restrict vt switching via ioctl() |
46 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
47 | * | |
48 | * Move console and virtual terminal code to more appropriate files, | |
49 | * implement CONFIG_VT and generalize console device interface. | |
50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
51 | * | |
52 | * Rewrote init_dev and release_dev to eliminate races. | |
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 LT |
138 | |
139 | #ifdef CONFIG_UNIX98_PTYS | |
140 | extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ | |
1da177e4 LT |
141 | static int ptmx_open(struct inode *, struct file *); |
142 | #endif | |
143 | ||
1da177e4 LT |
144 | static void initialize_tty_struct(struct tty_struct *tty); |
145 | ||
146 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); | |
147 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
148 | ssize_t redirected_tty_write(struct file *, const char __user *, |
149 | size_t, loff_t *); | |
1da177e4 LT |
150 | static unsigned int tty_poll(struct file *, poll_table *); |
151 | static int tty_open(struct inode *, struct file *); | |
152 | static int tty_release(struct inode *, struct file *); | |
04f378b1 | 153 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 154 | #ifdef CONFIG_COMPAT |
37bdfb07 | 155 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
156 | unsigned long arg); |
157 | #else | |
158 | #define tty_compat_ioctl NULL | |
159 | #endif | |
37bdfb07 | 160 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 161 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 162 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 163 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 164 | |
af9b897e AC |
165 | /** |
166 | * alloc_tty_struct - allocate a tty object | |
167 | * | |
168 | * Return a new empty tty structure. The data fields have not | |
169 | * been initialized in any way but has been zeroed | |
170 | * | |
171 | * Locking: none | |
af9b897e | 172 | */ |
1da177e4 LT |
173 | |
174 | static struct tty_struct *alloc_tty_struct(void) | |
175 | { | |
1266b1e1 | 176 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
177 | } |
178 | ||
af9b897e AC |
179 | /** |
180 | * free_tty_struct - free a disused tty | |
181 | * @tty: tty struct to free | |
182 | * | |
183 | * Free the write buffers, tty queue and tty memory itself. | |
184 | * | |
185 | * Locking: none. Must be called after tty is definitely unused | |
186 | */ | |
187 | ||
1da177e4 LT |
188 | static inline void free_tty_struct(struct tty_struct *tty) |
189 | { | |
190 | kfree(tty->write_buf); | |
33f0f88f | 191 | tty_buffer_free_all(tty); |
1da177e4 LT |
192 | kfree(tty); |
193 | } | |
194 | ||
195 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) | |
196 | ||
af9b897e AC |
197 | /** |
198 | * tty_name - return tty naming | |
199 | * @tty: tty structure | |
200 | * @buf: buffer for output | |
201 | * | |
202 | * Convert a tty structure into a name. The name reflects the kernel | |
203 | * naming policy and if udev is in use may not reflect user space | |
204 | * | |
205 | * Locking: none | |
206 | */ | |
207 | ||
1da177e4 LT |
208 | char *tty_name(struct tty_struct *tty, char *buf) |
209 | { | |
210 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
211 | strcpy(buf, "NULL tty"); | |
212 | else | |
213 | strcpy(buf, tty->name); | |
214 | return buf; | |
215 | } | |
216 | ||
217 | EXPORT_SYMBOL(tty_name); | |
218 | ||
d769a669 | 219 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
220 | const char *routine) |
221 | { | |
222 | #ifdef TTY_PARANOIA_CHECK | |
223 | if (!tty) { | |
224 | printk(KERN_WARNING | |
225 | "null TTY for (%d:%d) in %s\n", | |
226 | imajor(inode), iminor(inode), routine); | |
227 | return 1; | |
228 | } | |
229 | if (tty->magic != TTY_MAGIC) { | |
230 | printk(KERN_WARNING | |
231 | "bad magic number for tty struct (%d:%d) in %s\n", | |
232 | imajor(inode), iminor(inode), routine); | |
233 | return 1; | |
234 | } | |
235 | #endif | |
236 | return 0; | |
237 | } | |
238 | ||
239 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
240 | { | |
241 | #ifdef CHECK_TTY_COUNT | |
242 | struct list_head *p; | |
243 | int count = 0; | |
37bdfb07 | 244 | |
1da177e4 LT |
245 | file_list_lock(); |
246 | list_for_each(p, &tty->tty_files) { | |
247 | count++; | |
248 | } | |
249 | file_list_unlock(); | |
250 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
251 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
252 | tty->link && tty->link->count) | |
253 | count++; | |
254 | if (tty->count != count) { | |
255 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
256 | "!= #fd's(%d) in %s\n", | |
257 | tty->name, tty->count, count, routine); | |
258 | return count; | |
24ec839c | 259 | } |
1da177e4 LT |
260 | #endif |
261 | return 0; | |
262 | } | |
263 | ||
af9b897e AC |
264 | /** |
265 | * get_tty_driver - find device of a tty | |
266 | * @dev_t: device identifier | |
267 | * @index: returns the index of the tty | |
268 | * | |
269 | * This routine returns a tty driver structure, given a device number | |
270 | * and also passes back the index number. | |
271 | * | |
272 | * Locking: caller must hold tty_mutex | |
1da177e4 | 273 | */ |
af9b897e | 274 | |
1da177e4 LT |
275 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
276 | { | |
277 | struct tty_driver *p; | |
278 | ||
279 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
280 | dev_t base = MKDEV(p->major, p->minor_start); | |
281 | if (device < base || device >= base + p->num) | |
282 | continue; | |
283 | *index = device - base; | |
284 | return p; | |
285 | } | |
286 | return NULL; | |
287 | } | |
288 | ||
f2d937f3 JW |
289 | #ifdef CONFIG_CONSOLE_POLL |
290 | ||
291 | /** | |
292 | * tty_find_polling_driver - find device of a polled tty | |
293 | * @name: name string to match | |
294 | * @line: pointer to resulting tty line nr | |
295 | * | |
296 | * This routine returns a tty driver structure, given a name | |
297 | * and the condition that the tty driver is capable of polled | |
298 | * operation. | |
299 | */ | |
300 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
301 | { | |
302 | struct tty_driver *p, *res = NULL; | |
303 | int tty_line = 0; | |
0dca0fd2 | 304 | int len; |
f2d937f3 JW |
305 | char *str; |
306 | ||
0dca0fd2 JW |
307 | for (str = name; *str; str++) |
308 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
309 | break; | |
310 | if (!*str) | |
311 | return NULL; | |
312 | ||
313 | len = str - name; | |
314 | tty_line = simple_strtoul(str, &str, 10); | |
315 | ||
f2d937f3 JW |
316 | mutex_lock(&tty_mutex); |
317 | /* Search through the tty devices to look for a match */ | |
318 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
319 | if (strncmp(name, p->name, len) != 0) |
320 | continue; | |
f2d937f3 JW |
321 | if (*str == ',') |
322 | str++; | |
323 | if (*str == '\0') | |
8da56309 | 324 | str = NULL; |
f2d937f3 | 325 | |
f34d7a5b AC |
326 | if (tty_line >= 0 && tty_line <= p->num && p->ops && |
327 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) { | |
f2d937f3 JW |
328 | res = p; |
329 | *line = tty_line; | |
330 | break; | |
331 | } | |
332 | } | |
333 | mutex_unlock(&tty_mutex); | |
334 | ||
335 | return res; | |
336 | } | |
337 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
338 | #endif | |
339 | ||
af9b897e AC |
340 | /** |
341 | * tty_check_change - check for POSIX terminal changes | |
342 | * @tty: tty to check | |
343 | * | |
344 | * If we try to write to, or set the state of, a terminal and we're | |
345 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
346 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
347 | * | |
978e595f | 348 | * Locking: ctrl_lock |
1da177e4 | 349 | */ |
af9b897e | 350 | |
37bdfb07 | 351 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 352 | { |
47f86834 AC |
353 | unsigned long flags; |
354 | int ret = 0; | |
355 | ||
1da177e4 LT |
356 | if (current->signal->tty != tty) |
357 | return 0; | |
47f86834 AC |
358 | |
359 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
360 | ||
ab521dc0 EB |
361 | if (!tty->pgrp) { |
362 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 363 | goto out_unlock; |
1da177e4 | 364 | } |
ab521dc0 | 365 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
366 | goto out_unlock; |
367 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 368 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
369 | goto out; |
370 | if (is_current_pgrp_orphaned()) { | |
371 | ret = -EIO; | |
372 | goto out; | |
373 | } | |
040b6362 ON |
374 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
375 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
376 | ret = -ERESTARTSYS; |
377 | out: | |
9ffee4cb AM |
378 | return ret; |
379 | out_unlock: | |
47f86834 AC |
380 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
381 | return ret; | |
1da177e4 LT |
382 | } |
383 | ||
384 | EXPORT_SYMBOL(tty_check_change); | |
385 | ||
37bdfb07 | 386 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
387 | size_t count, loff_t *ppos) |
388 | { | |
389 | return 0; | |
390 | } | |
391 | ||
37bdfb07 | 392 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
393 | size_t count, loff_t *ppos) |
394 | { | |
395 | return -EIO; | |
396 | } | |
397 | ||
398 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 399 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
400 | { |
401 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
402 | } | |
403 | ||
04f378b1 AC |
404 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
405 | unsigned long arg) | |
38ad2ed0 PF |
406 | { |
407 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
408 | } | |
409 | ||
37bdfb07 | 410 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 411 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
412 | { |
413 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
414 | } | |
415 | ||
62322d25 | 416 | static const struct file_operations tty_fops = { |
1da177e4 LT |
417 | .llseek = no_llseek, |
418 | .read = tty_read, | |
419 | .write = tty_write, | |
420 | .poll = tty_poll, | |
04f378b1 | 421 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 422 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
423 | .open = tty_open, |
424 | .release = tty_release, | |
425 | .fasync = tty_fasync, | |
426 | }; | |
427 | ||
428 | #ifdef CONFIG_UNIX98_PTYS | |
62322d25 | 429 | static const struct file_operations ptmx_fops = { |
1da177e4 LT |
430 | .llseek = no_llseek, |
431 | .read = tty_read, | |
432 | .write = tty_write, | |
433 | .poll = tty_poll, | |
04f378b1 | 434 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 435 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
436 | .open = ptmx_open, |
437 | .release = tty_release, | |
438 | .fasync = tty_fasync, | |
439 | }; | |
440 | #endif | |
441 | ||
62322d25 | 442 | static const struct file_operations console_fops = { |
1da177e4 LT |
443 | .llseek = no_llseek, |
444 | .read = tty_read, | |
445 | .write = redirected_tty_write, | |
446 | .poll = tty_poll, | |
04f378b1 | 447 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 448 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
449 | .open = tty_open, |
450 | .release = tty_release, | |
451 | .fasync = tty_fasync, | |
452 | }; | |
453 | ||
62322d25 | 454 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
455 | .llseek = no_llseek, |
456 | .read = hung_up_tty_read, | |
457 | .write = hung_up_tty_write, | |
458 | .poll = hung_up_tty_poll, | |
04f378b1 | 459 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 460 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
461 | .release = tty_release, |
462 | }; | |
463 | ||
464 | static DEFINE_SPINLOCK(redirect_lock); | |
465 | static struct file *redirect; | |
466 | ||
467 | /** | |
468 | * tty_wakeup - request more data | |
469 | * @tty: terminal | |
470 | * | |
471 | * Internal and external helper for wakeups of tty. This function | |
472 | * informs the line discipline if present that the driver is ready | |
473 | * to receive more output data. | |
474 | */ | |
37bdfb07 | 475 | |
1da177e4 LT |
476 | void tty_wakeup(struct tty_struct *tty) |
477 | { | |
478 | struct tty_ldisc *ld; | |
37bdfb07 | 479 | |
1da177e4 LT |
480 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
481 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 482 | if (ld) { |
a352def2 AC |
483 | if (ld->ops->write_wakeup) |
484 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
485 | tty_ldisc_deref(ld); |
486 | } | |
487 | } | |
488 | wake_up_interruptible(&tty->write_wait); | |
489 | } | |
490 | ||
491 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
492 | ||
493 | /** | |
494 | * tty_ldisc_flush - flush line discipline queue | |
495 | * @tty: tty | |
496 | * | |
497 | * Flush the line discipline queue (if any) for this tty. If there | |
498 | * is no line discipline active this is a no-op. | |
499 | */ | |
37bdfb07 | 500 | |
1da177e4 LT |
501 | void tty_ldisc_flush(struct tty_struct *tty) |
502 | { | |
503 | struct tty_ldisc *ld = tty_ldisc_ref(tty); | |
37bdfb07 | 504 | if (ld) { |
a352def2 AC |
505 | if (ld->ops->flush_buffer) |
506 | ld->ops->flush_buffer(tty); | |
1da177e4 LT |
507 | tty_ldisc_deref(ld); |
508 | } | |
c5c34d48 | 509 | tty_buffer_flush(tty); |
1da177e4 LT |
510 | } |
511 | ||
512 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); | |
edc6afc5 AC |
513 | |
514 | /** | |
515 | * tty_reset_termios - reset terminal state | |
516 | * @tty: tty to reset | |
517 | * | |
518 | * Restore a terminal to the driver default state | |
519 | */ | |
520 | ||
521 | static void tty_reset_termios(struct tty_struct *tty) | |
522 | { | |
523 | mutex_lock(&tty->termios_mutex); | |
524 | *tty->termios = tty->driver->init_termios; | |
525 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
526 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
527 | mutex_unlock(&tty->termios_mutex); | |
528 | } | |
37bdfb07 | 529 | |
af9b897e AC |
530 | /** |
531 | * do_tty_hangup - actual handler for hangup events | |
65f27f38 | 532 | * @work: tty device |
af9b897e | 533 | * |
1bad879a | 534 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
535 | * synchronous but doesn't hold any locks, so we need to make sure we |
536 | * have the appropriate locks for what we're doing. | |
537 | * | |
538 | * The hangup event clears any pending redirections onto the hung up | |
539 | * device. It ensures future writes will error and it does the needed | |
540 | * line discipline hangup and signal delivery. The tty object itself | |
541 | * remains intact. | |
542 | * | |
543 | * Locking: | |
544 | * BKL | |
24ec839c PZ |
545 | * redirect lock for undoing redirection |
546 | * file list lock for manipulating list of ttys | |
547 | * tty_ldisc_lock from called functions | |
548 | * termios_mutex resetting termios data | |
549 | * tasklist_lock to walk task list for hangup event | |
550 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 551 | */ |
65f27f38 | 552 | static void do_tty_hangup(struct work_struct *work) |
1da177e4 | 553 | { |
65f27f38 DH |
554 | struct tty_struct *tty = |
555 | container_of(work, struct tty_struct, hangup_work); | |
37bdfb07 | 556 | struct file *cons_filp = NULL; |
1da177e4 LT |
557 | struct file *filp, *f = NULL; |
558 | struct task_struct *p; | |
559 | struct tty_ldisc *ld; | |
560 | int closecount = 0, n; | |
47f86834 | 561 | unsigned long flags; |
9c9f4ded | 562 | int refs = 0; |
1da177e4 LT |
563 | |
564 | if (!tty) | |
565 | return; | |
566 | ||
567 | /* inuse_filps is protected by the single kernel lock */ | |
568 | lock_kernel(); | |
569 | ||
570 | spin_lock(&redirect_lock); | |
571 | if (redirect && redirect->private_data == tty) { | |
572 | f = redirect; | |
573 | redirect = NULL; | |
574 | } | |
575 | spin_unlock(&redirect_lock); | |
37bdfb07 | 576 | |
1da177e4 LT |
577 | check_tty_count(tty, "do_tty_hangup"); |
578 | file_list_lock(); | |
579 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ | |
2f512016 | 580 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
1da177e4 LT |
581 | if (filp->f_op->write == redirected_tty_write) |
582 | cons_filp = filp; | |
583 | if (filp->f_op->write != tty_write) | |
584 | continue; | |
585 | closecount++; | |
586 | tty_fasync(-1, filp, 0); /* can't block */ | |
587 | filp->f_op = &hung_up_tty_fops; | |
588 | } | |
589 | file_list_unlock(); | |
37bdfb07 AC |
590 | /* |
591 | * FIXME! What are the locking issues here? This may me overdoing | |
592 | * things... This question is especially important now that we've | |
593 | * removed the irqlock. | |
594 | */ | |
1da177e4 | 595 | ld = tty_ldisc_ref(tty); |
37bdfb07 AC |
596 | if (ld != NULL) { |
597 | /* We may have no line discipline at this point */ | |
a352def2 AC |
598 | if (ld->ops->flush_buffer) |
599 | ld->ops->flush_buffer(tty); | |
f34d7a5b | 600 | tty_driver_flush_buffer(tty); |
1da177e4 | 601 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && |
a352def2 AC |
602 | ld->ops->write_wakeup) |
603 | ld->ops->write_wakeup(tty); | |
604 | if (ld->ops->hangup) | |
605 | ld->ops->hangup(tty); | |
1da177e4 | 606 | } |
37bdfb07 AC |
607 | /* |
608 | * FIXME: Once we trust the LDISC code better we can wait here for | |
609 | * ldisc completion and fix the driver call race | |
610 | */ | |
1da177e4 LT |
611 | wake_up_interruptible(&tty->write_wait); |
612 | wake_up_interruptible(&tty->read_wait); | |
1da177e4 LT |
613 | /* |
614 | * Shutdown the current line discipline, and reset it to | |
615 | * N_TTY. | |
616 | */ | |
617 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
edc6afc5 | 618 | tty_reset_termios(tty); |
1da177e4 LT |
619 | /* Defer ldisc switch */ |
620 | /* tty_deferred_ldisc_switch(N_TTY); | |
37bdfb07 | 621 | |
1da177e4 LT |
622 | This should get done automatically when the port closes and |
623 | tty_release is called */ | |
37bdfb07 | 624 | |
1da177e4 | 625 | read_lock(&tasklist_lock); |
ab521dc0 EB |
626 | if (tty->session) { |
627 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 628 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 629 | if (p->signal->tty == tty) { |
1da177e4 | 630 | p->signal->tty = NULL; |
9c9f4ded AC |
631 | /* We defer the dereferences outside fo |
632 | the tasklist lock */ | |
633 | refs++; | |
634 | } | |
24ec839c PZ |
635 | if (!p->signal->leader) { |
636 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 637 | continue; |
24ec839c PZ |
638 | } |
639 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
640 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 641 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 642 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
643 | if (tty->pgrp) |
644 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 645 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 646 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 647 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
648 | } |
649 | read_unlock(&tasklist_lock); | |
650 | ||
47f86834 | 651 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 | 652 | tty->flags = 0; |
d9c1e9a8 EB |
653 | put_pid(tty->session); |
654 | put_pid(tty->pgrp); | |
ab521dc0 EB |
655 | tty->session = NULL; |
656 | tty->pgrp = NULL; | |
1da177e4 | 657 | tty->ctrl_status = 0; |
47f86834 AC |
658 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
659 | ||
9c9f4ded AC |
660 | /* Account for the p->signal references we killed */ |
661 | while (refs--) | |
662 | tty_kref_put(tty); | |
663 | ||
1da177e4 | 664 | /* |
37bdfb07 AC |
665 | * If one of the devices matches a console pointer, we |
666 | * cannot just call hangup() because that will cause | |
667 | * tty->count and state->count to go out of sync. | |
668 | * So we just call close() the right number of times. | |
1da177e4 LT |
669 | */ |
670 | if (cons_filp) { | |
f34d7a5b | 671 | if (tty->ops->close) |
1da177e4 | 672 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
673 | tty->ops->close(tty, cons_filp); |
674 | } else if (tty->ops->hangup) | |
675 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
676 | /* |
677 | * We don't want to have driver/ldisc interactions beyond | |
678 | * the ones we did here. The driver layer expects no | |
679 | * calls after ->hangup() from the ldisc side. However we | |
680 | * can't yet guarantee all that. | |
681 | */ | |
1da177e4 LT |
682 | set_bit(TTY_HUPPED, &tty->flags); |
683 | if (ld) { | |
684 | tty_ldisc_enable(tty); | |
685 | tty_ldisc_deref(ld); | |
686 | } | |
687 | unlock_kernel(); | |
688 | if (f) | |
689 | fput(f); | |
690 | } | |
691 | ||
af9b897e AC |
692 | /** |
693 | * tty_hangup - trigger a hangup event | |
694 | * @tty: tty to hangup | |
695 | * | |
696 | * A carrier loss (virtual or otherwise) has occurred on this like | |
697 | * schedule a hangup sequence to run after this event. | |
698 | */ | |
699 | ||
37bdfb07 | 700 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
701 | { |
702 | #ifdef TTY_DEBUG_HANGUP | |
703 | char buf[64]; | |
1da177e4 LT |
704 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
705 | #endif | |
706 | schedule_work(&tty->hangup_work); | |
707 | } | |
708 | ||
709 | EXPORT_SYMBOL(tty_hangup); | |
710 | ||
af9b897e AC |
711 | /** |
712 | * tty_vhangup - process vhangup | |
713 | * @tty: tty to hangup | |
714 | * | |
715 | * The user has asked via system call for the terminal to be hung up. | |
716 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 717 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
718 | */ |
719 | ||
37bdfb07 | 720 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
721 | { |
722 | #ifdef TTY_DEBUG_HANGUP | |
723 | char buf[64]; | |
724 | ||
725 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
726 | #endif | |
65f27f38 | 727 | do_tty_hangup(&tty->hangup_work); |
1da177e4 | 728 | } |
37bdfb07 | 729 | |
1da177e4 LT |
730 | EXPORT_SYMBOL(tty_vhangup); |
731 | ||
af9b897e AC |
732 | /** |
733 | * tty_hung_up_p - was tty hung up | |
734 | * @filp: file pointer of tty | |
735 | * | |
736 | * Return true if the tty has been subject to a vhangup or a carrier | |
737 | * loss | |
738 | */ | |
739 | ||
37bdfb07 | 740 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
741 | { |
742 | return (filp->f_op == &hung_up_tty_fops); | |
743 | } | |
744 | ||
745 | EXPORT_SYMBOL(tty_hung_up_p); | |
746 | ||
ab521dc0 | 747 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
748 | { |
749 | struct task_struct *p; | |
ab521dc0 | 750 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 751 | proc_clear_tty(p); |
ab521dc0 | 752 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
753 | } |
754 | ||
af9b897e AC |
755 | /** |
756 | * disassociate_ctty - disconnect controlling tty | |
757 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 758 | * |
af9b897e AC |
759 | * This function is typically called only by the session leader, when |
760 | * it wants to disassociate itself from its controlling tty. | |
761 | * | |
762 | * It performs the following functions: | |
1da177e4 LT |
763 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
764 | * (2) Clears the tty from being controlling the session | |
765 | * (3) Clears the controlling tty for all processes in the | |
766 | * session group. | |
767 | * | |
af9b897e AC |
768 | * The argument on_exit is set to 1 if called when a process is |
769 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
770 | * | |
24ec839c | 771 | * Locking: |
af9b897e | 772 | * BKL is taken for hysterical raisins |
24ec839c PZ |
773 | * tty_mutex is taken to protect tty |
774 | * ->siglock is taken to protect ->signal/->sighand | |
775 | * tasklist_lock is taken to walk process list for sessions | |
776 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 777 | */ |
af9b897e | 778 | |
1da177e4 LT |
779 | void disassociate_ctty(int on_exit) |
780 | { | |
781 | struct tty_struct *tty; | |
ab521dc0 | 782 | struct pid *tty_pgrp = NULL; |
1da177e4 | 783 | |
1da177e4 | 784 | |
70522e12 | 785 | mutex_lock(&tty_mutex); |
24ec839c | 786 | tty = get_current_tty(); |
1da177e4 | 787 | if (tty) { |
ab521dc0 | 788 | tty_pgrp = get_pid(tty->pgrp); |
04f378b1 | 789 | lock_kernel(); |
000b9151 | 790 | mutex_unlock(&tty_mutex); |
24ec839c | 791 | /* XXX: here we race, there is nothing protecting tty */ |
1da177e4 LT |
792 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
793 | tty_vhangup(tty); | |
04f378b1 | 794 | unlock_kernel(); |
680a9671 | 795 | } else if (on_exit) { |
ab521dc0 | 796 | struct pid *old_pgrp; |
680a9671 EB |
797 | spin_lock_irq(¤t->sighand->siglock); |
798 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 799 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 800 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 801 | if (old_pgrp) { |
ab521dc0 EB |
802 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
803 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
804 | put_pid(old_pgrp); | |
1da177e4 | 805 | } |
70522e12 | 806 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
807 | return; |
808 | } | |
ab521dc0 EB |
809 | if (tty_pgrp) { |
810 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
1da177e4 | 811 | if (!on_exit) |
ab521dc0 EB |
812 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); |
813 | put_pid(tty_pgrp); | |
1da177e4 LT |
814 | } |
815 | ||
24ec839c | 816 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 817 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 818 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
819 | spin_unlock_irq(¤t->sighand->siglock); |
820 | ||
821 | mutex_lock(&tty_mutex); | |
822 | /* It is possible that do_tty_hangup has free'd this tty */ | |
823 | tty = get_current_tty(); | |
824 | if (tty) { | |
47f86834 AC |
825 | unsigned long flags; |
826 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
827 | put_pid(tty->session); |
828 | put_pid(tty->pgrp); | |
829 | tty->session = NULL; | |
830 | tty->pgrp = NULL; | |
47f86834 | 831 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c PZ |
832 | } else { |
833 | #ifdef TTY_DEBUG_HANGUP | |
834 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
835 | " = NULL", tty); | |
836 | #endif | |
837 | } | |
838 | mutex_unlock(&tty_mutex); | |
1da177e4 LT |
839 | |
840 | /* Now clear signal->tty under the lock */ | |
841 | read_lock(&tasklist_lock); | |
ab521dc0 | 842 | session_clear_tty(task_session(current)); |
1da177e4 | 843 | read_unlock(&tasklist_lock); |
1da177e4 LT |
844 | } |
845 | ||
98a27ba4 EB |
846 | /** |
847 | * | |
848 | * no_tty - Ensure the current process does not have a controlling tty | |
849 | */ | |
850 | void no_tty(void) | |
851 | { | |
852 | struct task_struct *tsk = current; | |
04f378b1 | 853 | lock_kernel(); |
98a27ba4 EB |
854 | if (tsk->signal->leader) |
855 | disassociate_ctty(0); | |
04f378b1 | 856 | unlock_kernel(); |
98a27ba4 EB |
857 | proc_clear_tty(tsk); |
858 | } | |
859 | ||
af9b897e AC |
860 | |
861 | /** | |
beb7dd86 | 862 | * stop_tty - propagate flow control |
af9b897e AC |
863 | * @tty: tty to stop |
864 | * | |
865 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 866 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
867 | * on an already stopped device and will not re-call the driver |
868 | * method. | |
869 | * | |
870 | * This functionality is used by both the line disciplines for | |
871 | * halting incoming flow and by the driver. It may therefore be | |
872 | * called from any context, may be under the tty atomic_write_lock | |
873 | * but not always. | |
874 | * | |
875 | * Locking: | |
04f378b1 | 876 | * Uses the tty control lock internally |
af9b897e AC |
877 | */ |
878 | ||
1da177e4 LT |
879 | void stop_tty(struct tty_struct *tty) |
880 | { | |
04f378b1 AC |
881 | unsigned long flags; |
882 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
883 | if (tty->stopped) { | |
884 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 885 | return; |
04f378b1 | 886 | } |
1da177e4 LT |
887 | tty->stopped = 1; |
888 | if (tty->link && tty->link->packet) { | |
889 | tty->ctrl_status &= ~TIOCPKT_START; | |
890 | tty->ctrl_status |= TIOCPKT_STOP; | |
891 | wake_up_interruptible(&tty->link->read_wait); | |
892 | } | |
04f378b1 | 893 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
894 | if (tty->ops->stop) |
895 | (tty->ops->stop)(tty); | |
1da177e4 LT |
896 | } |
897 | ||
898 | EXPORT_SYMBOL(stop_tty); | |
899 | ||
af9b897e | 900 | /** |
beb7dd86 | 901 | * start_tty - propagate flow control |
af9b897e AC |
902 | * @tty: tty to start |
903 | * | |
904 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 905 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
906 | * is the tty was previous stopped and is being started then the |
907 | * driver start method is invoked and the line discipline woken. | |
908 | * | |
909 | * Locking: | |
04f378b1 | 910 | * ctrl_lock |
af9b897e AC |
911 | */ |
912 | ||
1da177e4 LT |
913 | void start_tty(struct tty_struct *tty) |
914 | { | |
04f378b1 AC |
915 | unsigned long flags; |
916 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
917 | if (!tty->stopped || tty->flow_stopped) { | |
918 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 919 | return; |
04f378b1 | 920 | } |
1da177e4 LT |
921 | tty->stopped = 0; |
922 | if (tty->link && tty->link->packet) { | |
923 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
924 | tty->ctrl_status |= TIOCPKT_START; | |
925 | wake_up_interruptible(&tty->link->read_wait); | |
926 | } | |
04f378b1 | 927 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
928 | if (tty->ops->start) |
929 | (tty->ops->start)(tty); | |
1da177e4 LT |
930 | /* If we have a running line discipline it may need kicking */ |
931 | tty_wakeup(tty); | |
1da177e4 LT |
932 | } |
933 | ||
934 | EXPORT_SYMBOL(start_tty); | |
935 | ||
af9b897e AC |
936 | /** |
937 | * tty_read - read method for tty device files | |
938 | * @file: pointer to tty file | |
939 | * @buf: user buffer | |
940 | * @count: size of user buffer | |
941 | * @ppos: unused | |
942 | * | |
943 | * Perform the read system call function on this terminal device. Checks | |
944 | * for hung up devices before calling the line discipline method. | |
945 | * | |
946 | * Locking: | |
47f86834 AC |
947 | * Locks the line discipline internally while needed. Multiple |
948 | * read calls may be outstanding in parallel. | |
af9b897e AC |
949 | */ |
950 | ||
37bdfb07 | 951 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
952 | loff_t *ppos) |
953 | { | |
954 | int i; | |
37bdfb07 | 955 | struct tty_struct *tty; |
1da177e4 LT |
956 | struct inode *inode; |
957 | struct tty_ldisc *ld; | |
958 | ||
959 | tty = (struct tty_struct *)file->private_data; | |
a7113a96 | 960 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
961 | if (tty_paranoia_check(tty, inode, "tty_read")) |
962 | return -EIO; | |
963 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
964 | return -EIO; | |
965 | ||
966 | /* We want to wait for the line discipline to sort out in this | |
967 | situation */ | |
968 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
969 | if (ld->ops->read) |
970 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
971 | else |
972 | i = -EIO; | |
973 | tty_ldisc_deref(ld); | |
1da177e4 LT |
974 | if (i > 0) |
975 | inode->i_atime = current_fs_time(inode->i_sb); | |
976 | return i; | |
977 | } | |
978 | ||
9c1729db AC |
979 | void tty_write_unlock(struct tty_struct *tty) |
980 | { | |
981 | mutex_unlock(&tty->atomic_write_lock); | |
982 | wake_up_interruptible(&tty->write_wait); | |
983 | } | |
984 | ||
985 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
986 | { | |
987 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
988 | if (ndelay) | |
989 | return -EAGAIN; | |
990 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
991 | return -ERESTARTSYS; | |
992 | } | |
993 | return 0; | |
994 | } | |
995 | ||
1da177e4 LT |
996 | /* |
997 | * Split writes up in sane blocksizes to avoid | |
998 | * denial-of-service type attacks | |
999 | */ | |
1000 | static inline ssize_t do_tty_write( | |
1001 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1002 | struct tty_struct *tty, | |
1003 | struct file *file, | |
1004 | const char __user *buf, | |
1005 | size_t count) | |
1006 | { | |
9c1729db | 1007 | ssize_t ret, written = 0; |
1da177e4 | 1008 | unsigned int chunk; |
37bdfb07 | 1009 | |
9c1729db AC |
1010 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1011 | if (ret < 0) | |
1012 | return ret; | |
1da177e4 LT |
1013 | |
1014 | /* | |
1015 | * We chunk up writes into a temporary buffer. This | |
1016 | * simplifies low-level drivers immensely, since they | |
1017 | * don't have locking issues and user mode accesses. | |
1018 | * | |
1019 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1020 | * big chunk-size.. | |
1021 | * | |
1022 | * The default chunk-size is 2kB, because the NTTY | |
1023 | * layer has problems with bigger chunks. It will | |
1024 | * claim to be able to handle more characters than | |
1025 | * it actually does. | |
af9b897e AC |
1026 | * |
1027 | * FIXME: This can probably go away now except that 64K chunks | |
1028 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1029 | */ |
1030 | chunk = 2048; | |
1031 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1032 | chunk = 65536; | |
1033 | if (count < chunk) | |
1034 | chunk = count; | |
1035 | ||
70522e12 | 1036 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 LT |
1037 | if (tty->write_cnt < chunk) { |
1038 | unsigned char *buf; | |
1039 | ||
1040 | if (chunk < 1024) | |
1041 | chunk = 1024; | |
1042 | ||
1043 | buf = kmalloc(chunk, GFP_KERNEL); | |
1044 | if (!buf) { | |
9c1729db AC |
1045 | ret = -ENOMEM; |
1046 | goto out; | |
1da177e4 LT |
1047 | } |
1048 | kfree(tty->write_buf); | |
1049 | tty->write_cnt = chunk; | |
1050 | tty->write_buf = buf; | |
1051 | } | |
1052 | ||
1053 | /* Do the write .. */ | |
1054 | for (;;) { | |
1055 | size_t size = count; | |
1056 | if (size > chunk) | |
1057 | size = chunk; | |
1058 | ret = -EFAULT; | |
1059 | if (copy_from_user(tty->write_buf, buf, size)) | |
1060 | break; | |
1da177e4 | 1061 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1062 | if (ret <= 0) |
1063 | break; | |
1064 | written += ret; | |
1065 | buf += ret; | |
1066 | count -= ret; | |
1067 | if (!count) | |
1068 | break; | |
1069 | ret = -ERESTARTSYS; | |
1070 | if (signal_pending(current)) | |
1071 | break; | |
1072 | cond_resched(); | |
1073 | } | |
1074 | if (written) { | |
a7113a96 | 1075 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1076 | inode->i_mtime = current_fs_time(inode->i_sb); |
1077 | ret = written; | |
1078 | } | |
9c1729db AC |
1079 | out: |
1080 | tty_write_unlock(tty); | |
1da177e4 LT |
1081 | return ret; |
1082 | } | |
1083 | ||
1084 | ||
af9b897e AC |
1085 | /** |
1086 | * tty_write - write method for tty device file | |
1087 | * @file: tty file pointer | |
1088 | * @buf: user data to write | |
1089 | * @count: bytes to write | |
1090 | * @ppos: unused | |
1091 | * | |
1092 | * Write data to a tty device via the line discipline. | |
1093 | * | |
1094 | * Locking: | |
1095 | * Locks the line discipline as required | |
1096 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1097 | * and are then processed in chunks to the device. The line discipline | |
1098 | * write method will not be involked in parallel for each device | |
1099 | * The line discipline write method is called under the big | |
1100 | * kernel lock for historical reasons. New code should not rely on this. | |
1101 | */ | |
1102 | ||
37bdfb07 AC |
1103 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1104 | size_t count, loff_t *ppos) | |
1da177e4 | 1105 | { |
37bdfb07 | 1106 | struct tty_struct *tty; |
a7113a96 | 1107 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1108 | ssize_t ret; |
1109 | struct tty_ldisc *ld; | |
37bdfb07 | 1110 | |
1da177e4 LT |
1111 | tty = (struct tty_struct *)file->private_data; |
1112 | if (tty_paranoia_check(tty, inode, "tty_write")) | |
1113 | return -EIO; | |
f34d7a5b | 1114 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1115 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1116 | return -EIO; | |
f34d7a5b AC |
1117 | /* Short term debug to catch buggy drivers */ |
1118 | if (tty->ops->write_room == NULL) | |
1119 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1120 | tty->driver->name); | |
37bdfb07 | 1121 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1122 | if (!ld->ops->write) |
1da177e4 LT |
1123 | ret = -EIO; |
1124 | else | |
a352def2 | 1125 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1126 | tty_ldisc_deref(ld); |
1127 | return ret; | |
1128 | } | |
1129 | ||
37bdfb07 AC |
1130 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1131 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1132 | { |
1133 | struct file *p = NULL; | |
1134 | ||
1135 | spin_lock(&redirect_lock); | |
1136 | if (redirect) { | |
1137 | get_file(redirect); | |
1138 | p = redirect; | |
1139 | } | |
1140 | spin_unlock(&redirect_lock); | |
1141 | ||
1142 | if (p) { | |
1143 | ssize_t res; | |
1144 | res = vfs_write(p, buf, count, &p->f_pos); | |
1145 | fput(p); | |
1146 | return res; | |
1147 | } | |
1da177e4 LT |
1148 | return tty_write(file, buf, count, ppos); |
1149 | } | |
1150 | ||
1151 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1152 | ||
af9b897e AC |
1153 | /** |
1154 | * pty_line_name - generate name for a pty | |
1155 | * @driver: the tty driver in use | |
1156 | * @index: the minor number | |
1157 | * @p: output buffer of at least 6 bytes | |
1158 | * | |
1159 | * Generate a name from a driver reference and write it to the output | |
1160 | * buffer. | |
1161 | * | |
1162 | * Locking: None | |
1163 | */ | |
1164 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1165 | { |
1166 | int i = index + driver->name_base; | |
1167 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1168 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1169 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1170 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1171 | } |
1172 | ||
af9b897e AC |
1173 | /** |
1174 | * pty_line_name - generate name for a tty | |
1175 | * @driver: the tty driver in use | |
1176 | * @index: the minor number | |
1177 | * @p: output buffer of at least 7 bytes | |
1178 | * | |
1179 | * Generate a name from a driver reference and write it to the output | |
1180 | * buffer. | |
1181 | * | |
1182 | * Locking: None | |
1183 | */ | |
1184 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1185 | { |
1186 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1187 | } | |
1188 | ||
af9b897e AC |
1189 | /** |
1190 | * init_dev - initialise a tty device | |
1191 | * @driver: tty driver we are opening a device on | |
1192 | * @idx: device index | |
1193 | * @tty: returned tty structure | |
1194 | * | |
1195 | * Prepare a tty device. This may not be a "new" clean device but | |
1196 | * could also be an active device. The pty drivers require special | |
1197 | * handling because of this. | |
1198 | * | |
1199 | * Locking: | |
1200 | * The function is called under the tty_mutex, which | |
1201 | * protects us from the tty struct or driver itself going away. | |
1202 | * | |
1203 | * On exit the tty device has the line discipline attached and | |
1204 | * a reference count of 1. If a pair was created for pty/tty use | |
1205 | * and the other was a pty master then it too has a reference count of 1. | |
1206 | * | |
1da177e4 | 1207 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1208 | * failed open. The new code protects the open with a mutex, so it's |
1209 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1210 | * relaxed for the (most common) case of reopening a tty. |
1211 | */ | |
af9b897e | 1212 | |
1da177e4 LT |
1213 | static int init_dev(struct tty_driver *driver, int idx, |
1214 | struct tty_struct **ret_tty) | |
1215 | { | |
1216 | struct tty_struct *tty, *o_tty; | |
edc6afc5 AC |
1217 | struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc; |
1218 | struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; | |
af9b897e | 1219 | int retval = 0; |
1da177e4 LT |
1220 | |
1221 | /* check whether we're reopening an existing tty */ | |
1222 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1223 | tty = devpts_get_tty(idx); | |
5a39e8c6 ASRF |
1224 | /* |
1225 | * If we don't have a tty here on a slave open, it's because | |
1226 | * the master already started the close process and there's | |
1227 | * no relation between devpts file and tty anymore. | |
1228 | */ | |
1229 | if (!tty && driver->subtype == PTY_TYPE_SLAVE) { | |
1230 | retval = -EIO; | |
1231 | goto end_init; | |
1232 | } | |
1233 | /* | |
1234 | * It's safe from now on because init_dev() is called with | |
1235 | * tty_mutex held and release_dev() won't change tty->count | |
1236 | * or tty->flags without having to grab tty_mutex | |
1237 | */ | |
1da177e4 LT |
1238 | if (tty && driver->subtype == PTY_TYPE_MASTER) |
1239 | tty = tty->link; | |
1240 | } else { | |
1241 | tty = driver->ttys[idx]; | |
1242 | } | |
1243 | if (tty) goto fast_track; | |
1244 | ||
1245 | /* | |
1246 | * First time open is complex, especially for PTY devices. | |
1247 | * This code guarantees that either everything succeeds and the | |
1248 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1249 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1250 | * and locked termios may be retained.) |
1251 | */ | |
1252 | ||
1253 | if (!try_module_get(driver->owner)) { | |
1254 | retval = -ENODEV; | |
1255 | goto end_init; | |
1256 | } | |
1257 | ||
1258 | o_tty = NULL; | |
1259 | tp = o_tp = NULL; | |
1260 | ltp = o_ltp = NULL; | |
1261 | ||
1262 | tty = alloc_tty_struct(); | |
37bdfb07 | 1263 | if (!tty) |
1da177e4 LT |
1264 | goto fail_no_mem; |
1265 | initialize_tty_struct(tty); | |
1266 | tty->driver = driver; | |
f34d7a5b | 1267 | tty->ops = driver->ops; |
1da177e4 LT |
1268 | tty->index = idx; |
1269 | tty_line_name(driver, idx, tty->name); | |
1270 | ||
1271 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1272 | tp_loc = &tty->termios; | |
1273 | ltp_loc = &tty->termios_locked; | |
1274 | } else { | |
1275 | tp_loc = &driver->termios[idx]; | |
1276 | ltp_loc = &driver->termios_locked[idx]; | |
1277 | } | |
1278 | ||
1279 | if (!*tp_loc) { | |
abcb1ff3 | 1280 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1281 | if (!tp) |
1282 | goto free_mem_out; | |
1283 | *tp = driver->init_termios; | |
1284 | } | |
1285 | ||
1286 | if (!*ltp_loc) { | |
506eb99a | 1287 | ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1288 | if (!ltp) |
1289 | goto free_mem_out; | |
1da177e4 LT |
1290 | } |
1291 | ||
1292 | if (driver->type == TTY_DRIVER_TYPE_PTY) { | |
1293 | o_tty = alloc_tty_struct(); | |
1294 | if (!o_tty) | |
1295 | goto free_mem_out; | |
6f967f78 AC |
1296 | if (!try_module_get(driver->other->owner)) { |
1297 | /* This cannot in fact currently happen */ | |
1298 | free_tty_struct(o_tty); | |
1299 | o_tty = NULL; | |
1300 | goto free_mem_out; | |
1301 | } | |
1da177e4 LT |
1302 | initialize_tty_struct(o_tty); |
1303 | o_tty->driver = driver->other; | |
f34d7a5b | 1304 | o_tty->ops = driver->ops; |
1da177e4 LT |
1305 | o_tty->index = idx; |
1306 | tty_line_name(driver->other, idx, o_tty->name); | |
1307 | ||
1308 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1309 | o_tp_loc = &o_tty->termios; | |
1310 | o_ltp_loc = &o_tty->termios_locked; | |
1311 | } else { | |
1312 | o_tp_loc = &driver->other->termios[idx]; | |
1313 | o_ltp_loc = &driver->other->termios_locked[idx]; | |
1314 | } | |
1315 | ||
1316 | if (!*o_tp_loc) { | |
abcb1ff3 | 1317 | o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1318 | if (!o_tp) |
1319 | goto free_mem_out; | |
1320 | *o_tp = driver->other->init_termios; | |
1321 | } | |
1322 | ||
1323 | if (!*o_ltp_loc) { | |
506eb99a | 1324 | o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); |
1da177e4 LT |
1325 | if (!o_ltp) |
1326 | goto free_mem_out; | |
1da177e4 LT |
1327 | } |
1328 | ||
1329 | /* | |
1330 | * Everything allocated ... set up the o_tty structure. | |
1331 | */ | |
37bdfb07 | 1332 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) |
1da177e4 | 1333 | driver->other->ttys[idx] = o_tty; |
1da177e4 LT |
1334 | if (!*o_tp_loc) |
1335 | *o_tp_loc = o_tp; | |
1336 | if (!*o_ltp_loc) | |
1337 | *o_ltp_loc = o_ltp; | |
1338 | o_tty->termios = *o_tp_loc; | |
1339 | o_tty->termios_locked = *o_ltp_loc; | |
1340 | driver->other->refcount++; | |
1341 | if (driver->subtype == PTY_TYPE_MASTER) | |
1342 | o_tty->count++; | |
1343 | ||
1344 | /* Establish the links in both directions */ | |
1345 | tty->link = o_tty; | |
1346 | o_tty->link = tty; | |
1347 | } | |
1348 | ||
37bdfb07 | 1349 | /* |
1da177e4 | 1350 | * All structures have been allocated, so now we install them. |
d5698c28 | 1351 | * Failures after this point use release_tty to clean up, so |
1da177e4 LT |
1352 | * there's no need to null out the local pointers. |
1353 | */ | |
37bdfb07 | 1354 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) |
1da177e4 | 1355 | driver->ttys[idx] = tty; |
37bdfb07 | 1356 | |
1da177e4 LT |
1357 | if (!*tp_loc) |
1358 | *tp_loc = tp; | |
1359 | if (!*ltp_loc) | |
1360 | *ltp_loc = ltp; | |
1361 | tty->termios = *tp_loc; | |
1362 | tty->termios_locked = *ltp_loc; | |
edc6afc5 AC |
1363 | /* Compatibility until drivers always set this */ |
1364 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1365 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1da177e4 LT |
1366 | driver->refcount++; |
1367 | tty->count++; | |
1368 | ||
37bdfb07 | 1369 | /* |
1da177e4 | 1370 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1371 | * If we fail here just call release_tty to clean up. No need |
1372 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 LT |
1373 | */ |
1374 | ||
01e1abb2 AC |
1375 | retval = tty_ldisc_setup(tty, o_tty); |
1376 | ||
1377 | if (retval) | |
1378 | goto release_mem_out; | |
1379 | goto success; | |
1da177e4 LT |
1380 | |
1381 | /* | |
1382 | * This fast open can be used if the tty is already open. | |
1383 | * No memory is allocated, and the only failures are from | |
1384 | * attempting to open a closing tty or attempting multiple | |
1385 | * opens on a pty master. | |
1386 | */ | |
1387 | fast_track: | |
1388 | if (test_bit(TTY_CLOSING, &tty->flags)) { | |
1389 | retval = -EIO; | |
1390 | goto end_init; | |
1391 | } | |
1392 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1393 | driver->subtype == PTY_TYPE_MASTER) { | |
1394 | /* | |
37bdfb07 | 1395 | * special case for PTY masters: only one open permitted, |
1da177e4 LT |
1396 | * and the slave side open count is incremented as well. |
1397 | */ | |
1398 | if (tty->count) { | |
1399 | retval = -EIO; | |
1400 | goto end_init; | |
1401 | } | |
1402 | tty->link->count++; | |
1403 | } | |
1404 | tty->count++; | |
1405 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1406 | ||
1407 | /* FIXME */ | |
37bdfb07 | 1408 | if (!test_bit(TTY_LDISC, &tty->flags)) |
1da177e4 LT |
1409 | printk(KERN_ERR "init_dev but no ldisc\n"); |
1410 | success: | |
1411 | *ret_tty = tty; | |
37bdfb07 | 1412 | |
70522e12 | 1413 | /* All paths come through here to release the mutex */ |
1da177e4 LT |
1414 | end_init: |
1415 | return retval; | |
1416 | ||
1417 | /* Release locally allocated memory ... nothing placed in slots */ | |
1418 | free_mem_out: | |
735d5661 | 1419 | kfree(o_tp); |
6f967f78 AC |
1420 | if (o_tty) { |
1421 | module_put(o_tty->driver->owner); | |
1da177e4 | 1422 | free_tty_struct(o_tty); |
6f967f78 | 1423 | } |
735d5661 JJ |
1424 | kfree(ltp); |
1425 | kfree(tp); | |
1da177e4 LT |
1426 | free_tty_struct(tty); |
1427 | ||
1428 | fail_no_mem: | |
1429 | module_put(driver->owner); | |
1430 | retval = -ENOMEM; | |
1431 | goto end_init; | |
1432 | ||
d5698c28 | 1433 | /* call the tty release_tty routine to clean out this slot */ |
1da177e4 | 1434 | release_mem_out: |
4050914f AM |
1435 | if (printk_ratelimit()) |
1436 | printk(KERN_INFO "init_dev: ldisc open failed, " | |
1437 | "clearing slot %d\n", idx); | |
d5698c28 | 1438 | release_tty(tty, idx); |
1da177e4 LT |
1439 | goto end_init; |
1440 | } | |
1441 | ||
af9b897e | 1442 | /** |
d5698c28 | 1443 | * release_one_tty - release tty structure memory |
9c9f4ded | 1444 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1445 | * |
1446 | * Releases memory associated with a tty structure, and clears out the | |
1447 | * driver table slots. This function is called when a device is no longer | |
1448 | * in use. It also gets called when setup of a device fails. | |
1449 | * | |
1450 | * Locking: | |
1451 | * tty_mutex - sometimes only | |
1452 | * takes the file list lock internally when working on the list | |
1453 | * of ttys that the driver keeps. | |
1da177e4 | 1454 | */ |
9c9f4ded | 1455 | static void release_one_tty(struct kref *kref) |
1da177e4 | 1456 | { |
9c9f4ded | 1457 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); |
6f967f78 | 1458 | struct tty_driver *driver = tty->driver; |
1da177e4 | 1459 | int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; |
d5698c28 | 1460 | struct ktermios *tp; |
9c9f4ded | 1461 | int idx = tty->index; |
1da177e4 LT |
1462 | |
1463 | if (!devpts) | |
1464 | tty->driver->ttys[idx] = NULL; | |
d5698c28 | 1465 | |
1da177e4 | 1466 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
9c9f4ded | 1467 | /* FIXME: Locking on ->termios array */ |
1da177e4 LT |
1468 | tp = tty->termios; |
1469 | if (!devpts) | |
1470 | tty->driver->termios[idx] = NULL; | |
1471 | kfree(tp); | |
1472 | ||
1473 | tp = tty->termios_locked; | |
1474 | if (!devpts) | |
1475 | tty->driver->termios_locked[idx] = NULL; | |
1476 | kfree(tp); | |
1477 | } | |
1478 | ||
d5698c28 | 1479 | |
1da177e4 | 1480 | tty->magic = 0; |
9c9f4ded | 1481 | /* FIXME: locking on tty->driver->refcount */ |
1da177e4 | 1482 | tty->driver->refcount--; |
6f967f78 | 1483 | module_put(driver->owner); |
d5698c28 | 1484 | |
1da177e4 LT |
1485 | file_list_lock(); |
1486 | list_del_init(&tty->tty_files); | |
1487 | file_list_unlock(); | |
d5698c28 | 1488 | |
1da177e4 LT |
1489 | free_tty_struct(tty); |
1490 | } | |
1491 | ||
9c9f4ded AC |
1492 | /** |
1493 | * tty_kref_put - release a tty kref | |
1494 | * @tty: tty device | |
1495 | * | |
1496 | * Release a reference to a tty device and if need be let the kref | |
1497 | * layer destruct the object for us | |
1498 | */ | |
1499 | ||
1500 | void tty_kref_put(struct tty_struct *tty) | |
1501 | { | |
1502 | if (tty) | |
1503 | kref_put(&tty->kref, release_one_tty); | |
1504 | } | |
1505 | EXPORT_SYMBOL(tty_kref_put); | |
1506 | ||
d5698c28 CH |
1507 | /** |
1508 | * release_tty - release tty structure memory | |
1509 | * | |
1510 | * Release both @tty and a possible linked partner (think pty pair), | |
1511 | * and decrement the refcount of the backing module. | |
1512 | * | |
1513 | * Locking: | |
1514 | * tty_mutex - sometimes only | |
1515 | * takes the file list lock internally when working on the list | |
1516 | * of ttys that the driver keeps. | |
1517 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1518 | * |
d5698c28 CH |
1519 | */ |
1520 | static void release_tty(struct tty_struct *tty, int idx) | |
1521 | { | |
9c9f4ded AC |
1522 | /* This should always be true but check for the moment */ |
1523 | WARN_ON(tty->index != idx); | |
1524 | ||
d5698c28 | 1525 | if (tty->link) |
9c9f4ded AC |
1526 | tty_kref_put(tty->link); |
1527 | tty_kref_put(tty); | |
d5698c28 CH |
1528 | } |
1529 | ||
1da177e4 LT |
1530 | /* |
1531 | * Even releasing the tty structures is a tricky business.. We have | |
1532 | * to be very careful that the structures are all released at the | |
1533 | * same time, as interrupts might otherwise get the wrong pointers. | |
1534 | * | |
1535 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1536 | * lead to double frees or releasing memory still in use. | |
1537 | */ | |
37bdfb07 | 1538 | static void release_dev(struct file *filp) |
1da177e4 LT |
1539 | { |
1540 | struct tty_struct *tty, *o_tty; | |
1541 | int pty_master, tty_closing, o_tty_closing, do_sleep; | |
14a6283e | 1542 | int devpts; |
1da177e4 LT |
1543 | int idx; |
1544 | char buf[64]; | |
37bdfb07 | 1545 | |
1da177e4 | 1546 | tty = (struct tty_struct *)filp->private_data; |
37bdfb07 AC |
1547 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, |
1548 | "release_dev")) | |
1da177e4 LT |
1549 | return; |
1550 | ||
1551 | check_tty_count(tty, "release_dev"); | |
1552 | ||
1553 | tty_fasync(-1, filp, 0); | |
1554 | ||
1555 | idx = tty->index; | |
1556 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1557 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1558 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1da177e4 LT |
1559 | o_tty = tty->link; |
1560 | ||
1561 | #ifdef TTY_PARANOIA_CHECK | |
1562 | if (idx < 0 || idx >= tty->driver->num) { | |
1563 | printk(KERN_DEBUG "release_dev: bad idx when trying to " | |
1564 | "free (%s)\n", tty->name); | |
1565 | return; | |
1566 | } | |
1567 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1568 | if (tty != tty->driver->ttys[idx]) { | |
1569 | printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " | |
1570 | "for (%s)\n", idx, tty->name); | |
1571 | return; | |
1572 | } | |
1573 | if (tty->termios != tty->driver->termios[idx]) { | |
1574 | printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " | |
1575 | "for (%s)\n", | |
1576 | idx, tty->name); | |
1577 | return; | |
1578 | } | |
1579 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { | |
1580 | printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " | |
1581 | "termios_locked for (%s)\n", | |
1582 | idx, tty->name); | |
1583 | return; | |
1584 | } | |
1585 | } | |
1586 | #endif | |
1587 | ||
1588 | #ifdef TTY_DEBUG_HANGUP | |
1589 | printk(KERN_DEBUG "release_dev of %s (tty count=%d)...", | |
1590 | tty_name(tty, buf), tty->count); | |
1591 | #endif | |
1592 | ||
1593 | #ifdef TTY_PARANOIA_CHECK | |
1594 | if (tty->driver->other && | |
1595 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1596 | if (o_tty != tty->driver->other->ttys[idx]) { | |
1597 | printk(KERN_DEBUG "release_dev: other->table[%d] " | |
1598 | "not o_tty for (%s)\n", | |
1599 | idx, tty->name); | |
1600 | return; | |
1601 | } | |
1602 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
1603 | printk(KERN_DEBUG "release_dev: other->termios[%d] " | |
1604 | "not o_termios for (%s)\n", | |
1605 | idx, tty->name); | |
1606 | return; | |
1607 | } | |
37bdfb07 | 1608 | if (o_tty->termios_locked != |
1da177e4 LT |
1609 | tty->driver->other->termios_locked[idx]) { |
1610 | printk(KERN_DEBUG "release_dev: other->termios_locked[" | |
1611 | "%d] not o_termios_locked for (%s)\n", | |
1612 | idx, tty->name); | |
1613 | return; | |
1614 | } | |
1615 | if (o_tty->link != tty) { | |
1616 | printk(KERN_DEBUG "release_dev: bad pty pointers\n"); | |
1617 | return; | |
1618 | } | |
1619 | } | |
1620 | #endif | |
f34d7a5b AC |
1621 | if (tty->ops->close) |
1622 | tty->ops->close(tty, filp); | |
1da177e4 LT |
1623 | |
1624 | /* | |
1625 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1626 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1627 | * wait queues and kick everyone out _before_ actually starting to | |
1628 | * close. This ensures that we won't block while releasing the tty | |
1629 | * structure. | |
1630 | * | |
1631 | * The test for the o_tty closing is necessary, since the master and | |
1632 | * slave sides may close in any order. If the slave side closes out | |
1633 | * first, its count will be one, since the master side holds an open. | |
1634 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1635 | * so we do it now. | |
1636 | * | |
1637 | * Note that it's possible for the tty to be opened again while we're | |
1638 | * flushing out waiters. By recalculating the closing flags before | |
1639 | * each iteration we avoid any problems. | |
1640 | */ | |
1641 | while (1) { | |
1642 | /* Guard against races with tty->count changes elsewhere and | |
1643 | opens on /dev/tty */ | |
37bdfb07 | 1644 | |
70522e12 | 1645 | mutex_lock(&tty_mutex); |
1da177e4 LT |
1646 | tty_closing = tty->count <= 1; |
1647 | o_tty_closing = o_tty && | |
1648 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1649 | do_sleep = 0; |
1650 | ||
1651 | if (tty_closing) { | |
1652 | if (waitqueue_active(&tty->read_wait)) { | |
1653 | wake_up(&tty->read_wait); | |
1654 | do_sleep++; | |
1655 | } | |
1656 | if (waitqueue_active(&tty->write_wait)) { | |
1657 | wake_up(&tty->write_wait); | |
1658 | do_sleep++; | |
1659 | } | |
1660 | } | |
1661 | if (o_tty_closing) { | |
1662 | if (waitqueue_active(&o_tty->read_wait)) { | |
1663 | wake_up(&o_tty->read_wait); | |
1664 | do_sleep++; | |
1665 | } | |
1666 | if (waitqueue_active(&o_tty->write_wait)) { | |
1667 | wake_up(&o_tty->write_wait); | |
1668 | do_sleep++; | |
1669 | } | |
1670 | } | |
1671 | if (!do_sleep) | |
1672 | break; | |
1673 | ||
1674 | printk(KERN_WARNING "release_dev: %s: read/write wait queue " | |
1675 | "active!\n", tty_name(tty, buf)); | |
70522e12 | 1676 | mutex_unlock(&tty_mutex); |
1da177e4 | 1677 | schedule(); |
37bdfb07 | 1678 | } |
1da177e4 LT |
1679 | |
1680 | /* | |
37bdfb07 AC |
1681 | * The closing flags are now consistent with the open counts on |
1682 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1683 | * block, so it's safe to proceed with closing. |
1684 | */ | |
1da177e4 LT |
1685 | if (pty_master) { |
1686 | if (--o_tty->count < 0) { | |
1687 | printk(KERN_WARNING "release_dev: bad pty slave count " | |
1688 | "(%d) for %s\n", | |
1689 | o_tty->count, tty_name(o_tty, buf)); | |
1690 | o_tty->count = 0; | |
1691 | } | |
1692 | } | |
1693 | if (--tty->count < 0) { | |
1694 | printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n", | |
1695 | tty->count, tty_name(tty, buf)); | |
1696 | tty->count = 0; | |
1697 | } | |
37bdfb07 | 1698 | |
1da177e4 LT |
1699 | /* |
1700 | * We've decremented tty->count, so we need to remove this file | |
1701 | * descriptor off the tty->tty_files list; this serves two | |
1702 | * purposes: | |
1703 | * - check_tty_count sees the correct number of file descriptors | |
1704 | * associated with this tty. | |
1705 | * - do_tty_hangup no longer sees this file descriptor as | |
1706 | * something that needs to be handled for hangups. | |
1707 | */ | |
1708 | file_kill(filp); | |
1709 | filp->private_data = NULL; | |
1710 | ||
1711 | /* | |
1712 | * Perform some housekeeping before deciding whether to return. | |
1713 | * | |
1714 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1715 | * case of a pty we may have to wait around for the other side | |
1716 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1717 | */ | |
37bdfb07 | 1718 | if (tty_closing) |
1da177e4 | 1719 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1720 | if (o_tty_closing) |
1da177e4 LT |
1721 | set_bit(TTY_CLOSING, &o_tty->flags); |
1722 | ||
1723 | /* | |
1724 | * If _either_ side is closing, make sure there aren't any | |
1725 | * processes that still think tty or o_tty is their controlling | |
1726 | * tty. | |
1727 | */ | |
1728 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1729 | read_lock(&tasklist_lock); |
24ec839c | 1730 | session_clear_tty(tty->session); |
1da177e4 | 1731 | if (o_tty) |
24ec839c | 1732 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1733 | read_unlock(&tasklist_lock); |
1734 | } | |
1735 | ||
70522e12 | 1736 | mutex_unlock(&tty_mutex); |
da965822 | 1737 | |
1da177e4 LT |
1738 | /* check whether both sides are closing ... */ |
1739 | if (!tty_closing || (o_tty && !o_tty_closing)) | |
1740 | return; | |
37bdfb07 | 1741 | |
1da177e4 LT |
1742 | #ifdef TTY_DEBUG_HANGUP |
1743 | printk(KERN_DEBUG "freeing tty structure..."); | |
1744 | #endif | |
1745 | /* | |
01e1abb2 | 1746 | * Ask the line discipline code to release its structures |
1da177e4 | 1747 | */ |
01e1abb2 | 1748 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1749 | /* |
d5698c28 | 1750 | * The release_tty function takes care of the details of clearing |
1da177e4 LT |
1751 | * the slots and preserving the termios structure. |
1752 | */ | |
d5698c28 | 1753 | release_tty(tty, idx); |
1da177e4 | 1754 | |
1da177e4 | 1755 | /* Make this pty number available for reallocation */ |
718a9163 SB |
1756 | if (devpts) |
1757 | devpts_kill_index(idx); | |
1da177e4 LT |
1758 | } |
1759 | ||
af9b897e AC |
1760 | /** |
1761 | * tty_open - open a tty device | |
1762 | * @inode: inode of device file | |
1763 | * @filp: file pointer to tty | |
1da177e4 | 1764 | * |
af9b897e AC |
1765 | * tty_open and tty_release keep up the tty count that contains the |
1766 | * number of opens done on a tty. We cannot use the inode-count, as | |
1767 | * different inodes might point to the same tty. | |
1da177e4 | 1768 | * |
af9b897e AC |
1769 | * Open-counting is needed for pty masters, as well as for keeping |
1770 | * track of serial lines: DTR is dropped when the last close happens. | |
1771 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1772 | * | |
1773 | * The termios state of a pty is reset on first open so that | |
1774 | * settings don't persist across reuse. | |
1775 | * | |
24ec839c PZ |
1776 | * Locking: tty_mutex protects tty, get_tty_driver and init_dev work. |
1777 | * tty->count should protect the rest. | |
1778 | * ->siglock protects ->signal/->sighand | |
1da177e4 | 1779 | */ |
af9b897e | 1780 | |
39d95b9d | 1781 | static int __tty_open(struct inode *inode, struct file *filp) |
1da177e4 LT |
1782 | { |
1783 | struct tty_struct *tty; | |
1784 | int noctty, retval; | |
1785 | struct tty_driver *driver; | |
1786 | int index; | |
1787 | dev_t device = inode->i_rdev; | |
1788 | unsigned short saved_flags = filp->f_flags; | |
1789 | ||
1790 | nonseekable_open(inode, filp); | |
37bdfb07 | 1791 | |
1da177e4 LT |
1792 | retry_open: |
1793 | noctty = filp->f_flags & O_NOCTTY; | |
1794 | index = -1; | |
1795 | retval = 0; | |
37bdfb07 | 1796 | |
70522e12 | 1797 | mutex_lock(&tty_mutex); |
1da177e4 | 1798 | |
37bdfb07 | 1799 | if (device == MKDEV(TTYAUX_MAJOR, 0)) { |
24ec839c PZ |
1800 | tty = get_current_tty(); |
1801 | if (!tty) { | |
70522e12 | 1802 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1803 | return -ENXIO; |
1804 | } | |
24ec839c PZ |
1805 | driver = tty->driver; |
1806 | index = tty->index; | |
1da177e4 LT |
1807 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1808 | /* noctty = 1; */ | |
1809 | goto got_driver; | |
1810 | } | |
1811 | #ifdef CONFIG_VT | |
37bdfb07 | 1812 | if (device == MKDEV(TTY_MAJOR, 0)) { |
1da177e4 LT |
1813 | extern struct tty_driver *console_driver; |
1814 | driver = console_driver; | |
1815 | index = fg_console; | |
1816 | noctty = 1; | |
1817 | goto got_driver; | |
1818 | } | |
1819 | #endif | |
37bdfb07 | 1820 | if (device == MKDEV(TTYAUX_MAJOR, 1)) { |
1da177e4 LT |
1821 | driver = console_device(&index); |
1822 | if (driver) { | |
1823 | /* Don't let /dev/console block */ | |
1824 | filp->f_flags |= O_NONBLOCK; | |
1825 | noctty = 1; | |
1826 | goto got_driver; | |
1827 | } | |
70522e12 | 1828 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1829 | return -ENODEV; |
1830 | } | |
1831 | ||
1832 | driver = get_tty_driver(device, &index); | |
1833 | if (!driver) { | |
70522e12 | 1834 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1835 | return -ENODEV; |
1836 | } | |
1837 | got_driver: | |
1838 | retval = init_dev(driver, index, &tty); | |
70522e12 | 1839 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
1840 | if (retval) |
1841 | return retval; | |
1842 | ||
1843 | filp->private_data = tty; | |
1844 | file_move(filp, &tty->tty_files); | |
1845 | check_tty_count(tty, "tty_open"); | |
1846 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1847 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1848 | noctty = 1; | |
1849 | #ifdef TTY_DEBUG_HANGUP | |
1850 | printk(KERN_DEBUG "opening %s...", tty->name); | |
1851 | #endif | |
1852 | if (!retval) { | |
f34d7a5b AC |
1853 | if (tty->ops->open) |
1854 | retval = tty->ops->open(tty, filp); | |
1da177e4 LT |
1855 | else |
1856 | retval = -ENODEV; | |
1857 | } | |
1858 | filp->f_flags = saved_flags; | |
1859 | ||
37bdfb07 AC |
1860 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1861 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1862 | retval = -EBUSY; |
1863 | ||
1864 | if (retval) { | |
1865 | #ifdef TTY_DEBUG_HANGUP | |
1866 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
1867 | tty->name); | |
1868 | #endif | |
1869 | release_dev(filp); | |
1870 | if (retval != -ERESTARTSYS) | |
1871 | return retval; | |
1872 | if (signal_pending(current)) | |
1873 | return retval; | |
1874 | schedule(); | |
1875 | /* | |
1876 | * Need to reset f_op in case a hangup happened. | |
1877 | */ | |
1878 | if (filp->f_op == &hung_up_tty_fops) | |
1879 | filp->f_op = &tty_fops; | |
1880 | goto retry_open; | |
1881 | } | |
24ec839c PZ |
1882 | |
1883 | mutex_lock(&tty_mutex); | |
1884 | spin_lock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
1885 | if (!noctty && |
1886 | current->signal->leader && | |
1887 | !current->signal->tty && | |
ab521dc0 | 1888 | tty->session == NULL) |
2a65f1d9 | 1889 | __proc_set_tty(current, tty); |
24ec839c PZ |
1890 | spin_unlock_irq(¤t->sighand->siglock); |
1891 | mutex_unlock(&tty_mutex); | |
1da177e4 LT |
1892 | return 0; |
1893 | } | |
1894 | ||
39d95b9d JC |
1895 | /* BKL pushdown: scary code avoidance wrapper */ |
1896 | static int tty_open(struct inode *inode, struct file *filp) | |
1897 | { | |
1898 | int ret; | |
1899 | ||
1900 | lock_kernel(); | |
1901 | ret = __tty_open(inode, filp); | |
1902 | unlock_kernel(); | |
1903 | return ret; | |
1904 | } | |
1905 | ||
1906 | ||
1907 | ||
1da177e4 | 1908 | #ifdef CONFIG_UNIX98_PTYS |
af9b897e AC |
1909 | /** |
1910 | * ptmx_open - open a unix 98 pty master | |
1911 | * @inode: inode of device file | |
1912 | * @filp: file pointer to tty | |
1913 | * | |
1914 | * Allocate a unix98 pty master device from the ptmx driver. | |
1915 | * | |
1916 | * Locking: tty_mutex protects theinit_dev work. tty->count should | |
37bdfb07 | 1917 | * protect the rest. |
af9b897e AC |
1918 | * allocated_ptys_lock handles the list of free pty numbers |
1919 | */ | |
1920 | ||
39d95b9d | 1921 | static int __ptmx_open(struct inode *inode, struct file *filp) |
1da177e4 LT |
1922 | { |
1923 | struct tty_struct *tty; | |
1924 | int retval; | |
1925 | int index; | |
1da177e4 LT |
1926 | |
1927 | nonseekable_open(inode, filp); | |
1928 | ||
1929 | /* find a device that is not in use. */ | |
718a9163 SB |
1930 | index = devpts_new_index(); |
1931 | if (index < 0) | |
1932 | return index; | |
1da177e4 | 1933 | |
70522e12 | 1934 | mutex_lock(&tty_mutex); |
1da177e4 | 1935 | retval = init_dev(ptm_driver, index, &tty); |
70522e12 | 1936 | mutex_unlock(&tty_mutex); |
37bdfb07 | 1937 | |
1da177e4 LT |
1938 | if (retval) |
1939 | goto out; | |
1940 | ||
1941 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
1942 | filp->private_data = tty; | |
1943 | file_move(filp, &tty->tty_files); | |
1944 | ||
4f8f9d66 SB |
1945 | retval = devpts_pty_new(tty->link); |
1946 | if (retval) | |
1da177e4 LT |
1947 | goto out1; |
1948 | ||
86a96538 | 1949 | check_tty_count(tty, "ptmx_open"); |
f34d7a5b | 1950 | retval = ptm_driver->ops->open(tty, filp); |
41126226 | 1951 | if (!retval) |
1da177e4 LT |
1952 | return 0; |
1953 | out1: | |
1954 | release_dev(filp); | |
9453a5ad | 1955 | return retval; |
1da177e4 | 1956 | out: |
718a9163 | 1957 | devpts_kill_index(index); |
1da177e4 LT |
1958 | return retval; |
1959 | } | |
39d95b9d JC |
1960 | |
1961 | static int ptmx_open(struct inode *inode, struct file *filp) | |
1962 | { | |
1963 | int ret; | |
1964 | ||
1965 | lock_kernel(); | |
1966 | ret = __ptmx_open(inode, filp); | |
1967 | unlock_kernel(); | |
1968 | return ret; | |
1969 | } | |
1da177e4 LT |
1970 | #endif |
1971 | ||
af9b897e AC |
1972 | /** |
1973 | * tty_release - vfs callback for close | |
1974 | * @inode: inode of tty | |
1975 | * @filp: file pointer for handle to tty | |
1976 | * | |
1977 | * Called the last time each file handle is closed that references | |
1978 | * this tty. There may however be several such references. | |
1979 | * | |
1980 | * Locking: | |
1981 | * Takes bkl. See release_dev | |
1982 | */ | |
1983 | ||
37bdfb07 | 1984 | static int tty_release(struct inode *inode, struct file *filp) |
1da177e4 LT |
1985 | { |
1986 | lock_kernel(); | |
1987 | release_dev(filp); | |
1988 | unlock_kernel(); | |
1989 | return 0; | |
1990 | } | |
1991 | ||
af9b897e AC |
1992 | /** |
1993 | * tty_poll - check tty status | |
1994 | * @filp: file being polled | |
1995 | * @wait: poll wait structures to update | |
1996 | * | |
1997 | * Call the line discipline polling method to obtain the poll | |
1998 | * status of the device. | |
1999 | * | |
2000 | * Locking: locks called line discipline but ldisc poll method | |
2001 | * may be re-entered freely by other callers. | |
2002 | */ | |
2003 | ||
37bdfb07 | 2004 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2005 | { |
37bdfb07 | 2006 | struct tty_struct *tty; |
1da177e4 LT |
2007 | struct tty_ldisc *ld; |
2008 | int ret = 0; | |
2009 | ||
2010 | tty = (struct tty_struct *)filp->private_data; | |
a7113a96 | 2011 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2012 | return 0; |
37bdfb07 | 2013 | |
1da177e4 | 2014 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2015 | if (ld->ops->poll) |
2016 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2017 | tty_ldisc_deref(ld); |
2018 | return ret; | |
2019 | } | |
2020 | ||
37bdfb07 | 2021 | static int tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2022 | { |
37bdfb07 | 2023 | struct tty_struct *tty; |
47f86834 | 2024 | unsigned long flags; |
5d1e3230 | 2025 | int retval = 0; |
1da177e4 | 2026 | |
5d1e3230 | 2027 | lock_kernel(); |
1da177e4 | 2028 | tty = (struct tty_struct *)filp->private_data; |
a7113a96 | 2029 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2030 | goto out; |
37bdfb07 | 2031 | |
1da177e4 LT |
2032 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2033 | if (retval <= 0) | |
5d1e3230 | 2034 | goto out; |
1da177e4 LT |
2035 | |
2036 | if (on) { | |
ab521dc0 EB |
2037 | enum pid_type type; |
2038 | struct pid *pid; | |
1da177e4 LT |
2039 | if (!waitqueue_active(&tty->read_wait)) |
2040 | tty->minimum_to_wake = 1; | |
47f86834 | 2041 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2042 | if (tty->pgrp) { |
2043 | pid = tty->pgrp; | |
2044 | type = PIDTYPE_PGID; | |
2045 | } else { | |
2046 | pid = task_pid(current); | |
2047 | type = PIDTYPE_PID; | |
2048 | } | |
47f86834 | 2049 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
ab521dc0 | 2050 | retval = __f_setown(filp, pid, type, 0); |
1da177e4 | 2051 | if (retval) |
5d1e3230 | 2052 | goto out; |
1da177e4 LT |
2053 | } else { |
2054 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2055 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2056 | } | |
5d1e3230 JC |
2057 | retval = 0; |
2058 | out: | |
2059 | unlock_kernel(); | |
2060 | return retval; | |
1da177e4 LT |
2061 | } |
2062 | ||
af9b897e AC |
2063 | /** |
2064 | * tiocsti - fake input character | |
2065 | * @tty: tty to fake input into | |
2066 | * @p: pointer to character | |
2067 | * | |
3a4fa0a2 | 2068 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2069 | * input management. |
2070 | * | |
2071 | * FIXME: does not honour flow control ?? | |
2072 | * | |
2073 | * Locking: | |
2074 | * Called functions take tty_ldisc_lock | |
2075 | * current->signal->tty check is safe without locks | |
28298232 AC |
2076 | * |
2077 | * FIXME: may race normal receive processing | |
af9b897e AC |
2078 | */ |
2079 | ||
1da177e4 LT |
2080 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2081 | { | |
2082 | char ch, mbz = 0; | |
2083 | struct tty_ldisc *ld; | |
37bdfb07 | 2084 | |
1da177e4 LT |
2085 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2086 | return -EPERM; | |
2087 | if (get_user(ch, p)) | |
2088 | return -EFAULT; | |
2089 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 | 2090 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2091 | tty_ldisc_deref(ld); |
2092 | return 0; | |
2093 | } | |
2094 | ||
af9b897e AC |
2095 | /** |
2096 | * tiocgwinsz - implement window query ioctl | |
2097 | * @tty; tty | |
2098 | * @arg: user buffer for result | |
2099 | * | |
808a0d38 | 2100 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2101 | * |
24ec839c | 2102 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2103 | * is consistent. |
af9b897e AC |
2104 | */ |
2105 | ||
37bdfb07 | 2106 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2107 | { |
808a0d38 AC |
2108 | int err; |
2109 | ||
5785c95b | 2110 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2111 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2112 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2113 | |
2114 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2115 | } |
2116 | ||
af9b897e | 2117 | /** |
8c9a9dd0 AC |
2118 | * tty_do_resize - resize event |
2119 | * @tty: tty being resized | |
a152db71 | 2120 | * @real_tty: real tty (not the same as tty if using a pty/tty pair) |
8c9a9dd0 AC |
2121 | * @rows: rows (character) |
2122 | * @cols: cols (character) | |
2123 | * | |
2124 | * Update the termios variables and send the neccessary signals to | |
2125 | * peform a terminal resize correctly | |
af9b897e AC |
2126 | */ |
2127 | ||
8c9a9dd0 AC |
2128 | int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, |
2129 | struct winsize *ws) | |
1da177e4 | 2130 | { |
47f86834 AC |
2131 | struct pid *pgrp, *rpgrp; |
2132 | unsigned long flags; | |
1da177e4 | 2133 | |
a152db71 AC |
2134 | /* For a PTY we need to lock the tty side */ |
2135 | mutex_lock(&real_tty->termios_mutex); | |
8c9a9dd0 | 2136 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2137 | goto done; |
47f86834 AC |
2138 | /* Get the PID values and reference them so we can |
2139 | avoid holding the tty ctrl lock while sending signals */ | |
2140 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2141 | pgrp = get_pid(tty->pgrp); | |
2142 | rpgrp = get_pid(real_tty->pgrp); | |
2143 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2144 | ||
2145 | if (pgrp) | |
2146 | kill_pgrp(pgrp, SIGWINCH, 1); | |
2147 | if (rpgrp != pgrp && rpgrp) | |
2148 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
2149 | ||
2150 | put_pid(pgrp); | |
2151 | put_pid(rpgrp); | |
2152 | ||
8c9a9dd0 AC |
2153 | tty->winsize = *ws; |
2154 | real_tty->winsize = *ws; | |
ca9bda00 | 2155 | done: |
a152db71 | 2156 | mutex_unlock(&real_tty->termios_mutex); |
1da177e4 LT |
2157 | return 0; |
2158 | } | |
2159 | ||
8c9a9dd0 AC |
2160 | /** |
2161 | * tiocswinsz - implement window size set ioctl | |
2162 | * @tty; tty | |
2163 | * @arg: user buffer for result | |
2164 | * | |
2165 | * Copies the user idea of the window size to the kernel. Traditionally | |
2166 | * this is just advisory information but for the Linux console it | |
2167 | * actually has driver level meaning and triggers a VC resize. | |
2168 | * | |
2169 | * Locking: | |
2170 | * Driver dependant. The default do_resize method takes the | |
2171 | * tty termios mutex and ctrl_lock. The console takes its own lock | |
2172 | * then calls into the default method. | |
2173 | */ | |
2174 | ||
2175 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, | |
2176 | struct winsize __user *arg) | |
2177 | { | |
2178 | struct winsize tmp_ws; | |
2179 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2180 | return -EFAULT; | |
2181 | ||
2182 | if (tty->ops->resize) | |
2183 | return tty->ops->resize(tty, real_tty, &tmp_ws); | |
2184 | else | |
2185 | return tty_do_resize(tty, real_tty, &tmp_ws); | |
2186 | } | |
2187 | ||
af9b897e AC |
2188 | /** |
2189 | * tioccons - allow admin to move logical console | |
2190 | * @file: the file to become console | |
2191 | * | |
2192 | * Allow the adminstrator to move the redirected console device | |
2193 | * | |
2194 | * Locking: uses redirect_lock to guard the redirect information | |
2195 | */ | |
2196 | ||
1da177e4 LT |
2197 | static int tioccons(struct file *file) |
2198 | { | |
2199 | if (!capable(CAP_SYS_ADMIN)) | |
2200 | return -EPERM; | |
2201 | if (file->f_op->write == redirected_tty_write) { | |
2202 | struct file *f; | |
2203 | spin_lock(&redirect_lock); | |
2204 | f = redirect; | |
2205 | redirect = NULL; | |
2206 | spin_unlock(&redirect_lock); | |
2207 | if (f) | |
2208 | fput(f); | |
2209 | return 0; | |
2210 | } | |
2211 | spin_lock(&redirect_lock); | |
2212 | if (redirect) { | |
2213 | spin_unlock(&redirect_lock); | |
2214 | return -EBUSY; | |
2215 | } | |
2216 | get_file(file); | |
2217 | redirect = file; | |
2218 | spin_unlock(&redirect_lock); | |
2219 | return 0; | |
2220 | } | |
2221 | ||
af9b897e AC |
2222 | /** |
2223 | * fionbio - non blocking ioctl | |
2224 | * @file: file to set blocking value | |
2225 | * @p: user parameter | |
2226 | * | |
2227 | * Historical tty interfaces had a blocking control ioctl before | |
2228 | * the generic functionality existed. This piece of history is preserved | |
2229 | * in the expected tty API of posix OS's. | |
2230 | * | |
2231 | * Locking: none, the open fle handle ensures it won't go away. | |
2232 | */ | |
1da177e4 LT |
2233 | |
2234 | static int fionbio(struct file *file, int __user *p) | |
2235 | { | |
2236 | int nonblock; | |
2237 | ||
2238 | if (get_user(nonblock, p)) | |
2239 | return -EFAULT; | |
2240 | ||
04f378b1 AC |
2241 | /* file->f_flags is still BKL protected in the fs layer - vomit */ |
2242 | lock_kernel(); | |
1da177e4 LT |
2243 | if (nonblock) |
2244 | file->f_flags |= O_NONBLOCK; | |
2245 | else | |
2246 | file->f_flags &= ~O_NONBLOCK; | |
04f378b1 | 2247 | unlock_kernel(); |
1da177e4 LT |
2248 | return 0; |
2249 | } | |
2250 | ||
af9b897e AC |
2251 | /** |
2252 | * tiocsctty - set controlling tty | |
2253 | * @tty: tty structure | |
2254 | * @arg: user argument | |
2255 | * | |
2256 | * This ioctl is used to manage job control. It permits a session | |
2257 | * leader to set this tty as the controlling tty for the session. | |
2258 | * | |
2259 | * Locking: | |
28298232 | 2260 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2261 | * Takes tasklist_lock internally to walk sessions |
2262 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2263 | */ |
2264 | ||
1da177e4 LT |
2265 | static int tiocsctty(struct tty_struct *tty, int arg) |
2266 | { | |
24ec839c | 2267 | int ret = 0; |
ab521dc0 | 2268 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2269 | return ret; |
2270 | ||
2271 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2272 | /* |
2273 | * The process must be a session leader and | |
2274 | * not have a controlling tty already. | |
2275 | */ | |
24ec839c PZ |
2276 | if (!current->signal->leader || current->signal->tty) { |
2277 | ret = -EPERM; | |
2278 | goto unlock; | |
2279 | } | |
2280 | ||
ab521dc0 | 2281 | if (tty->session) { |
1da177e4 LT |
2282 | /* |
2283 | * This tty is already the controlling | |
2284 | * tty for another session group! | |
2285 | */ | |
37bdfb07 | 2286 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2287 | /* |
2288 | * Steal it away | |
2289 | */ | |
1da177e4 | 2290 | read_lock(&tasklist_lock); |
24ec839c | 2291 | session_clear_tty(tty->session); |
1da177e4 | 2292 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2293 | } else { |
2294 | ret = -EPERM; | |
2295 | goto unlock; | |
2296 | } | |
1da177e4 | 2297 | } |
24ec839c PZ |
2298 | proc_set_tty(current, tty); |
2299 | unlock: | |
28298232 | 2300 | mutex_unlock(&tty_mutex); |
24ec839c | 2301 | return ret; |
1da177e4 LT |
2302 | } |
2303 | ||
5d0fdf1e AC |
2304 | /** |
2305 | * tty_get_pgrp - return a ref counted pgrp pid | |
2306 | * @tty: tty to read | |
2307 | * | |
2308 | * Returns a refcounted instance of the pid struct for the process | |
2309 | * group controlling the tty. | |
2310 | */ | |
2311 | ||
2312 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2313 | { | |
2314 | unsigned long flags; | |
2315 | struct pid *pgrp; | |
2316 | ||
2317 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2318 | pgrp = get_pid(tty->pgrp); | |
2319 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2320 | ||
2321 | return pgrp; | |
2322 | } | |
2323 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2324 | ||
af9b897e AC |
2325 | /** |
2326 | * tiocgpgrp - get process group | |
2327 | * @tty: tty passed by user | |
2328 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2329 | * @p: returned pid | |
2330 | * | |
2331 | * Obtain the process group of the tty. If there is no process group | |
2332 | * return an error. | |
2333 | * | |
24ec839c | 2334 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2335 | */ |
2336 | ||
1da177e4 LT |
2337 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2338 | { | |
5d0fdf1e AC |
2339 | struct pid *pid; |
2340 | int ret; | |
1da177e4 LT |
2341 | /* |
2342 | * (tty == real_tty) is a cheap way of | |
2343 | * testing if the tty is NOT a master pty. | |
2344 | */ | |
2345 | if (tty == real_tty && current->signal->tty != real_tty) | |
2346 | return -ENOTTY; | |
5d0fdf1e AC |
2347 | pid = tty_get_pgrp(real_tty); |
2348 | ret = put_user(pid_vnr(pid), p); | |
2349 | put_pid(pid); | |
2350 | return ret; | |
1da177e4 LT |
2351 | } |
2352 | ||
af9b897e AC |
2353 | /** |
2354 | * tiocspgrp - attempt to set process group | |
2355 | * @tty: tty passed by user | |
2356 | * @real_tty: tty side device matching tty passed by user | |
2357 | * @p: pid pointer | |
2358 | * | |
2359 | * Set the process group of the tty to the session passed. Only | |
2360 | * permitted where the tty session is our session. | |
2361 | * | |
47f86834 | 2362 | * Locking: RCU, ctrl lock |
af9b897e AC |
2363 | */ |
2364 | ||
1da177e4 LT |
2365 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2366 | { | |
04a2e6a5 EB |
2367 | struct pid *pgrp; |
2368 | pid_t pgrp_nr; | |
1da177e4 | 2369 | int retval = tty_check_change(real_tty); |
47f86834 | 2370 | unsigned long flags; |
1da177e4 LT |
2371 | |
2372 | if (retval == -EIO) | |
2373 | return -ENOTTY; | |
2374 | if (retval) | |
2375 | return retval; | |
2376 | if (!current->signal->tty || | |
2377 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2378 | (real_tty->session != task_session(current))) |
1da177e4 | 2379 | return -ENOTTY; |
04a2e6a5 | 2380 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2381 | return -EFAULT; |
04a2e6a5 | 2382 | if (pgrp_nr < 0) |
1da177e4 | 2383 | return -EINVAL; |
04a2e6a5 | 2384 | rcu_read_lock(); |
b488893a | 2385 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2386 | retval = -ESRCH; |
2387 | if (!pgrp) | |
2388 | goto out_unlock; | |
2389 | retval = -EPERM; | |
2390 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2391 | goto out_unlock; | |
2392 | retval = 0; | |
47f86834 | 2393 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2394 | put_pid(real_tty->pgrp); |
2395 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2396 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2397 | out_unlock: |
2398 | rcu_read_unlock(); | |
2399 | return retval; | |
1da177e4 LT |
2400 | } |
2401 | ||
af9b897e AC |
2402 | /** |
2403 | * tiocgsid - get session id | |
2404 | * @tty: tty passed by user | |
2405 | * @real_tty: tty side of the tty pased by the user if a pty else the tty | |
2406 | * @p: pointer to returned session id | |
2407 | * | |
2408 | * Obtain the session id of the tty. If there is no session | |
2409 | * return an error. | |
2410 | * | |
24ec839c | 2411 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2412 | */ |
2413 | ||
1da177e4 LT |
2414 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2415 | { | |
2416 | /* | |
2417 | * (tty == real_tty) is a cheap way of | |
2418 | * testing if the tty is NOT a master pty. | |
2419 | */ | |
2420 | if (tty == real_tty && current->signal->tty != real_tty) | |
2421 | return -ENOTTY; | |
ab521dc0 | 2422 | if (!real_tty->session) |
1da177e4 | 2423 | return -ENOTTY; |
b488893a | 2424 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2425 | } |
2426 | ||
af9b897e AC |
2427 | /** |
2428 | * tiocsetd - set line discipline | |
2429 | * @tty: tty device | |
2430 | * @p: pointer to user data | |
2431 | * | |
2432 | * Set the line discipline according to user request. | |
2433 | * | |
2434 | * Locking: see tty_set_ldisc, this function is just a helper | |
2435 | */ | |
2436 | ||
1da177e4 LT |
2437 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2438 | { | |
2439 | int ldisc; | |
04f378b1 | 2440 | int ret; |
1da177e4 LT |
2441 | |
2442 | if (get_user(ldisc, p)) | |
2443 | return -EFAULT; | |
04f378b1 AC |
2444 | |
2445 | lock_kernel(); | |
2446 | ret = tty_set_ldisc(tty, ldisc); | |
2447 | unlock_kernel(); | |
2448 | ||
2449 | return ret; | |
1da177e4 LT |
2450 | } |
2451 | ||
af9b897e AC |
2452 | /** |
2453 | * send_break - performed time break | |
2454 | * @tty: device to break on | |
2455 | * @duration: timeout in mS | |
2456 | * | |
2457 | * Perform a timed break on hardware that lacks its own driver level | |
2458 | * timed break functionality. | |
2459 | * | |
2460 | * Locking: | |
28298232 | 2461 | * atomic_write_lock serializes |
af9b897e | 2462 | * |
af9b897e AC |
2463 | */ |
2464 | ||
b20f3ae5 | 2465 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2466 | { |
9e98966c AC |
2467 | int retval; |
2468 | ||
2469 | if (tty->ops->break_ctl == NULL) | |
2470 | return 0; | |
2471 | ||
2472 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2473 | retval = tty->ops->break_ctl(tty, duration); | |
2474 | else { | |
2475 | /* Do the work ourselves */ | |
2476 | if (tty_write_lock(tty, 0) < 0) | |
2477 | return -EINTR; | |
2478 | retval = tty->ops->break_ctl(tty, -1); | |
2479 | if (retval) | |
2480 | goto out; | |
2481 | if (!signal_pending(current)) | |
2482 | msleep_interruptible(duration); | |
2483 | retval = tty->ops->break_ctl(tty, 0); | |
2484 | out: | |
2485 | tty_write_unlock(tty); | |
2486 | if (signal_pending(current)) | |
2487 | retval = -EINTR; | |
2488 | } | |
2489 | return retval; | |
1da177e4 LT |
2490 | } |
2491 | ||
af9b897e | 2492 | /** |
f34d7a5b | 2493 | * tty_tiocmget - get modem status |
af9b897e AC |
2494 | * @tty: tty device |
2495 | * @file: user file pointer | |
2496 | * @p: pointer to result | |
2497 | * | |
2498 | * Obtain the modem status bits from the tty driver if the feature | |
2499 | * is supported. Return -EINVAL if it is not available. | |
2500 | * | |
2501 | * Locking: none (up to the driver) | |
2502 | */ | |
2503 | ||
2504 | static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) | |
1da177e4 LT |
2505 | { |
2506 | int retval = -EINVAL; | |
2507 | ||
f34d7a5b AC |
2508 | if (tty->ops->tiocmget) { |
2509 | retval = tty->ops->tiocmget(tty, file); | |
1da177e4 LT |
2510 | |
2511 | if (retval >= 0) | |
2512 | retval = put_user(retval, p); | |
2513 | } | |
2514 | return retval; | |
2515 | } | |
2516 | ||
af9b897e | 2517 | /** |
f34d7a5b | 2518 | * tty_tiocmset - set modem status |
af9b897e AC |
2519 | * @tty: tty device |
2520 | * @file: user file pointer | |
2521 | * @cmd: command - clear bits, set bits or set all | |
2522 | * @p: pointer to desired bits | |
2523 | * | |
2524 | * Set the modem status bits from the tty driver if the feature | |
2525 | * is supported. Return -EINVAL if it is not available. | |
2526 | * | |
2527 | * Locking: none (up to the driver) | |
2528 | */ | |
2529 | ||
2530 | static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, | |
1da177e4 LT |
2531 | unsigned __user *p) |
2532 | { | |
ae677517 AC |
2533 | int retval; |
2534 | unsigned int set, clear, val; | |
1da177e4 | 2535 | |
ae677517 AC |
2536 | if (tty->ops->tiocmset == NULL) |
2537 | return -EINVAL; | |
1da177e4 | 2538 | |
ae677517 AC |
2539 | retval = get_user(val, p); |
2540 | if (retval) | |
2541 | return retval; | |
2542 | set = clear = 0; | |
2543 | switch (cmd) { | |
2544 | case TIOCMBIS: | |
2545 | set = val; | |
2546 | break; | |
2547 | case TIOCMBIC: | |
2548 | clear = val; | |
2549 | break; | |
2550 | case TIOCMSET: | |
2551 | set = val; | |
2552 | clear = ~val; | |
2553 | break; | |
2554 | } | |
2555 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2556 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2557 | return tty->ops->tiocmset(tty, file, set, clear); | |
1da177e4 LT |
2558 | } |
2559 | ||
2560 | /* | |
2561 | * Split this up, as gcc can choke on it otherwise.. | |
2562 | */ | |
04f378b1 | 2563 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
2564 | { |
2565 | struct tty_struct *tty, *real_tty; | |
2566 | void __user *p = (void __user *)arg; | |
2567 | int retval; | |
2568 | struct tty_ldisc *ld; | |
04f378b1 | 2569 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2570 | |
1da177e4 LT |
2571 | tty = (struct tty_struct *)file->private_data; |
2572 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2573 | return -EINVAL; | |
2574 | ||
2575 | real_tty = tty; | |
2576 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2577 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2578 | real_tty = tty->link; | |
2579 | ||
1da177e4 LT |
2580 | |
2581 | /* | |
2582 | * Factor out some common prep work | |
2583 | */ | |
2584 | switch (cmd) { | |
2585 | case TIOCSETD: | |
2586 | case TIOCSBRK: | |
2587 | case TIOCCBRK: | |
2588 | case TCSBRK: | |
37bdfb07 | 2589 | case TCSBRKP: |
1da177e4 LT |
2590 | retval = tty_check_change(tty); |
2591 | if (retval) | |
2592 | return retval; | |
2593 | if (cmd != TIOCCBRK) { | |
2594 | tty_wait_until_sent(tty, 0); | |
2595 | if (signal_pending(current)) | |
2596 | return -EINTR; | |
2597 | } | |
2598 | break; | |
2599 | } | |
2600 | ||
9e98966c AC |
2601 | /* |
2602 | * Now do the stuff. | |
2603 | */ | |
1da177e4 | 2604 | switch (cmd) { |
37bdfb07 AC |
2605 | case TIOCSTI: |
2606 | return tiocsti(tty, p); | |
2607 | case TIOCGWINSZ: | |
2608 | return tiocgwinsz(tty, p); | |
2609 | case TIOCSWINSZ: | |
2610 | return tiocswinsz(tty, real_tty, p); | |
2611 | case TIOCCONS: | |
2612 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2613 | case FIONBIO: | |
2614 | return fionbio(file, p); | |
2615 | case TIOCEXCL: | |
2616 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2617 | return 0; | |
2618 | case TIOCNXCL: | |
2619 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2620 | return 0; | |
2621 | case TIOCNOTTY: | |
2622 | if (current->signal->tty != tty) | |
2623 | return -ENOTTY; | |
2624 | no_tty(); | |
2625 | return 0; | |
2626 | case TIOCSCTTY: | |
2627 | return tiocsctty(tty, arg); | |
2628 | case TIOCGPGRP: | |
2629 | return tiocgpgrp(tty, real_tty, p); | |
2630 | case TIOCSPGRP: | |
2631 | return tiocspgrp(tty, real_tty, p); | |
2632 | case TIOCGSID: | |
2633 | return tiocgsid(tty, real_tty, p); | |
2634 | case TIOCGETD: | |
a352def2 | 2635 | return put_user(tty->ldisc.ops->num, (int __user *)p); |
37bdfb07 AC |
2636 | case TIOCSETD: |
2637 | return tiocsetd(tty, p); | |
37bdfb07 AC |
2638 | /* |
2639 | * Break handling | |
2640 | */ | |
2641 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2642 | if (tty->ops->break_ctl) |
9e98966c | 2643 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2644 | return 0; |
37bdfb07 | 2645 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2646 | if (tty->ops->break_ctl) |
9e98966c | 2647 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2648 | return 0; |
2649 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2650 | /* non-zero arg means wait for all output data | |
2651 | * to be sent (performed above) but don't send break. | |
2652 | * This is used by the tcdrain() termios function. | |
2653 | */ | |
2654 | if (!arg) | |
2655 | return send_break(tty, 250); | |
2656 | return 0; | |
2657 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2658 | return send_break(tty, arg ? arg*100 : 250); | |
2659 | ||
2660 | case TIOCMGET: | |
2661 | return tty_tiocmget(tty, file, p); | |
2662 | case TIOCMSET: | |
2663 | case TIOCMBIC: | |
2664 | case TIOCMBIS: | |
2665 | return tty_tiocmset(tty, file, cmd, p); | |
2666 | case TCFLSH: | |
2667 | switch (arg) { | |
2668 | case TCIFLUSH: | |
2669 | case TCIOFLUSH: | |
2670 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2671 | tty_buffer_flush(tty); | |
c5c34d48 | 2672 | break; |
37bdfb07 AC |
2673 | } |
2674 | break; | |
1da177e4 | 2675 | } |
f34d7a5b AC |
2676 | if (tty->ops->ioctl) { |
2677 | retval = (tty->ops->ioctl)(tty, file, cmd, arg); | |
1da177e4 LT |
2678 | if (retval != -ENOIOCTLCMD) |
2679 | return retval; | |
2680 | } | |
2681 | ld = tty_ldisc_ref_wait(tty); | |
2682 | retval = -EINVAL; | |
a352def2 AC |
2683 | if (ld->ops->ioctl) { |
2684 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2685 | if (retval == -ENOIOCTLCMD) |
2686 | retval = -EINVAL; | |
2687 | } | |
2688 | tty_ldisc_deref(ld); | |
2689 | return retval; | |
2690 | } | |
2691 | ||
e10cc1df | 2692 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2693 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2694 | unsigned long arg) |
2695 | { | |
2696 | struct inode *inode = file->f_dentry->d_inode; | |
2697 | struct tty_struct *tty = file->private_data; | |
2698 | struct tty_ldisc *ld; | |
2699 | int retval = -ENOIOCTLCMD; | |
2700 | ||
2701 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2702 | return -EINVAL; | |
2703 | ||
f34d7a5b AC |
2704 | if (tty->ops->compat_ioctl) { |
2705 | retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg); | |
e10cc1df PF |
2706 | if (retval != -ENOIOCTLCMD) |
2707 | return retval; | |
2708 | } | |
2709 | ||
2710 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2711 | if (ld->ops->compat_ioctl) |
2712 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
e10cc1df PF |
2713 | tty_ldisc_deref(ld); |
2714 | ||
2715 | return retval; | |
2716 | } | |
2717 | #endif | |
1da177e4 LT |
2718 | |
2719 | /* | |
2720 | * This implements the "Secure Attention Key" --- the idea is to | |
2721 | * prevent trojan horses by killing all processes associated with this | |
2722 | * tty when the user hits the "Secure Attention Key". Required for | |
2723 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2724 | * |
1da177e4 LT |
2725 | * This code could be nicer; ideally it should send a HUP, wait a few |
2726 | * seconds, then send a INT, and then a KILL signal. But you then | |
2727 | * have to coordinate with the init process, since all processes associated | |
2728 | * with the current tty must be dead before the new getty is allowed | |
2729 | * to spawn. | |
2730 | * | |
2731 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2732 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2733 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2734 | * | |
2735 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2736 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2737 | */ | |
8b6312f4 | 2738 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2739 | { |
2740 | #ifdef TTY_SOFT_SAK | |
2741 | tty_hangup(tty); | |
2742 | #else | |
652486fb | 2743 | struct task_struct *g, *p; |
ab521dc0 | 2744 | struct pid *session; |
1da177e4 LT |
2745 | int i; |
2746 | struct file *filp; | |
badf1662 | 2747 | struct fdtable *fdt; |
37bdfb07 | 2748 | |
1da177e4 LT |
2749 | if (!tty) |
2750 | return; | |
24ec839c | 2751 | session = tty->session; |
37bdfb07 | 2752 | |
b3f13deb | 2753 | tty_ldisc_flush(tty); |
1da177e4 | 2754 | |
f34d7a5b | 2755 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2756 | |
1da177e4 | 2757 | read_lock(&tasklist_lock); |
652486fb | 2758 | /* Kill the entire session */ |
ab521dc0 | 2759 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2760 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2761 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2762 | task_pid_nr(p), p->comm); |
652486fb | 2763 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2764 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2765 | /* Now kill any processes that happen to have the |
2766 | * tty open. | |
2767 | */ | |
2768 | do_each_thread(g, p) { | |
2769 | if (p->signal->tty == tty) { | |
1da177e4 | 2770 | printk(KERN_NOTICE "SAK: killed process %d" |
a47afb0f | 2771 | " (%s): task_session_nr(p)==tty->session\n", |
ba25f9dc | 2772 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2773 | send_sig(SIGKILL, p, 1); |
2774 | continue; | |
2775 | } | |
2776 | task_lock(p); | |
2777 | if (p->files) { | |
ca99c1da DS |
2778 | /* |
2779 | * We don't take a ref to the file, so we must | |
2780 | * hold ->file_lock instead. | |
2781 | */ | |
2782 | spin_lock(&p->files->file_lock); | |
badf1662 | 2783 | fdt = files_fdtable(p->files); |
37bdfb07 | 2784 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2785 | filp = fcheck_files(p->files, i); |
2786 | if (!filp) | |
2787 | continue; | |
2788 | if (filp->f_op->read == tty_read && | |
2789 | filp->private_data == tty) { | |
2790 | printk(KERN_NOTICE "SAK: killed process %d" | |
2791 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2792 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2793 | force_sig(SIGKILL, p); |
1da177e4 LT |
2794 | break; |
2795 | } | |
2796 | } | |
ca99c1da | 2797 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2798 | } |
2799 | task_unlock(p); | |
652486fb | 2800 | } while_each_thread(g, p); |
1da177e4 LT |
2801 | read_unlock(&tasklist_lock); |
2802 | #endif | |
2803 | } | |
2804 | ||
8b6312f4 EB |
2805 | static void do_SAK_work(struct work_struct *work) |
2806 | { | |
2807 | struct tty_struct *tty = | |
2808 | container_of(work, struct tty_struct, SAK_work); | |
2809 | __do_SAK(tty); | |
2810 | } | |
2811 | ||
1da177e4 LT |
2812 | /* |
2813 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2814 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2815 | * the values which we write to it will be identical to the values which it | |
2816 | * already has. --akpm | |
2817 | */ | |
2818 | void do_SAK(struct tty_struct *tty) | |
2819 | { | |
2820 | if (!tty) | |
2821 | return; | |
1da177e4 LT |
2822 | schedule_work(&tty->SAK_work); |
2823 | } | |
2824 | ||
2825 | EXPORT_SYMBOL(do_SAK); | |
2826 | ||
af9b897e AC |
2827 | /** |
2828 | * initialize_tty_struct | |
2829 | * @tty: tty to initialize | |
2830 | * | |
2831 | * This subroutine initializes a tty structure that has been newly | |
2832 | * allocated. | |
2833 | * | |
2834 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2835 | */ |
af9b897e | 2836 | |
1da177e4 LT |
2837 | static void initialize_tty_struct(struct tty_struct *tty) |
2838 | { | |
2839 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2840 | kref_init(&tty->kref); |
1da177e4 | 2841 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2842 | tty_ldisc_init(tty); |
ab521dc0 EB |
2843 | tty->session = NULL; |
2844 | tty->pgrp = NULL; | |
1da177e4 | 2845 | tty->overrun_time = jiffies; |
33f0f88f AC |
2846 | tty->buf.head = tty->buf.tail = NULL; |
2847 | tty_buffer_init(tty); | |
5785c95b | 2848 | mutex_init(&tty->termios_mutex); |
1da177e4 LT |
2849 | init_waitqueue_head(&tty->write_wait); |
2850 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2851 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2852 | mutex_init(&tty->atomic_read_lock); |
2853 | mutex_init(&tty->atomic_write_lock); | |
1da177e4 | 2854 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2855 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2856 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2857 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
1da177e4 LT |
2858 | } |
2859 | ||
f34d7a5b AC |
2860 | /** |
2861 | * tty_put_char - write one character to a tty | |
2862 | * @tty: tty | |
2863 | * @ch: character | |
2864 | * | |
2865 | * Write one byte to the tty using the provided put_char method | |
2866 | * if present. Returns the number of characters successfully output. | |
2867 | * | |
2868 | * Note: the specific put_char operation in the driver layer may go | |
2869 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2870 | */ |
af9b897e | 2871 | |
f34d7a5b | 2872 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2873 | { |
f34d7a5b AC |
2874 | if (tty->ops->put_char) |
2875 | return tty->ops->put_char(tty, ch); | |
2876 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 LT |
2877 | } |
2878 | ||
f34d7a5b AC |
2879 | EXPORT_SYMBOL_GPL(tty_put_char); |
2880 | ||
7fe845d1 | 2881 | static struct class *tty_class; |
1da177e4 LT |
2882 | |
2883 | /** | |
af9b897e AC |
2884 | * tty_register_device - register a tty device |
2885 | * @driver: the tty driver that describes the tty device | |
2886 | * @index: the index in the tty driver for this tty device | |
2887 | * @device: a struct device that is associated with this tty device. | |
2888 | * This field is optional, if there is no known struct device | |
2889 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 2890 | * |
01107d34 GKH |
2891 | * Returns a pointer to the struct device for this tty device |
2892 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 2893 | * |
af9b897e AC |
2894 | * This call is required to be made to register an individual tty device |
2895 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
2896 | * that bit is not set, this function should not be called by a tty | |
2897 | * driver. | |
2898 | * | |
2899 | * Locking: ?? | |
1da177e4 | 2900 | */ |
af9b897e | 2901 | |
01107d34 GKH |
2902 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
2903 | struct device *device) | |
1da177e4 LT |
2904 | { |
2905 | char name[64]; | |
2906 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2907 | ||
2908 | if (index >= driver->num) { | |
2909 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2910 | " (%d).\n", index); | |
1cdcb6b4 | 2911 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
2912 | } |
2913 | ||
1da177e4 LT |
2914 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2915 | pty_line_name(driver, index, name); | |
2916 | else | |
2917 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 2918 | |
47aa5793 | 2919 | return device_create_drvdata(tty_class, device, dev, NULL, name); |
1da177e4 LT |
2920 | } |
2921 | ||
2922 | /** | |
af9b897e AC |
2923 | * tty_unregister_device - unregister a tty device |
2924 | * @driver: the tty driver that describes the tty device | |
2925 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 2926 | * |
af9b897e AC |
2927 | * If a tty device is registered with a call to tty_register_device() then |
2928 | * this function must be called when the tty device is gone. | |
2929 | * | |
2930 | * Locking: ?? | |
1da177e4 | 2931 | */ |
af9b897e | 2932 | |
1da177e4 LT |
2933 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2934 | { | |
37bdfb07 AC |
2935 | device_destroy(tty_class, |
2936 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 LT |
2937 | } |
2938 | ||
2939 | EXPORT_SYMBOL(tty_register_device); | |
2940 | EXPORT_SYMBOL(tty_unregister_device); | |
2941 | ||
2942 | struct tty_driver *alloc_tty_driver(int lines) | |
2943 | { | |
2944 | struct tty_driver *driver; | |
2945 | ||
506eb99a | 2946 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 2947 | if (driver) { |
1da177e4 LT |
2948 | driver->magic = TTY_DRIVER_MAGIC; |
2949 | driver->num = lines; | |
2950 | /* later we'll move allocation of tables here */ | |
2951 | } | |
2952 | return driver; | |
2953 | } | |
2954 | ||
2955 | void put_tty_driver(struct tty_driver *driver) | |
2956 | { | |
2957 | kfree(driver); | |
2958 | } | |
2959 | ||
b68e31d0 JD |
2960 | void tty_set_operations(struct tty_driver *driver, |
2961 | const struct tty_operations *op) | |
1da177e4 | 2962 | { |
f34d7a5b AC |
2963 | driver->ops = op; |
2964 | }; | |
1da177e4 LT |
2965 | |
2966 | EXPORT_SYMBOL(alloc_tty_driver); | |
2967 | EXPORT_SYMBOL(put_tty_driver); | |
2968 | EXPORT_SYMBOL(tty_set_operations); | |
2969 | ||
2970 | /* | |
2971 | * Called by a tty driver to register itself. | |
2972 | */ | |
2973 | int tty_register_driver(struct tty_driver *driver) | |
2974 | { | |
2975 | int error; | |
37bdfb07 | 2976 | int i; |
1da177e4 LT |
2977 | dev_t dev; |
2978 | void **p = NULL; | |
2979 | ||
2980 | if (driver->flags & TTY_DRIVER_INSTALLED) | |
2981 | return 0; | |
2982 | ||
543691a6 AW |
2983 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
2984 | p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); | |
1da177e4 LT |
2985 | if (!p) |
2986 | return -ENOMEM; | |
1da177e4 LT |
2987 | } |
2988 | ||
2989 | if (!driver->major) { | |
37bdfb07 AC |
2990 | error = alloc_chrdev_region(&dev, driver->minor_start, |
2991 | driver->num, driver->name); | |
1da177e4 LT |
2992 | if (!error) { |
2993 | driver->major = MAJOR(dev); | |
2994 | driver->minor_start = MINOR(dev); | |
2995 | } | |
2996 | } else { | |
2997 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 2998 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
2999 | } |
3000 | if (error < 0) { | |
3001 | kfree(p); | |
3002 | return error; | |
3003 | } | |
3004 | ||
3005 | if (p) { | |
3006 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3007 | driver->termios = (struct ktermios **)(p + driver->num); |
37bdfb07 AC |
3008 | driver->termios_locked = (struct ktermios **) |
3009 | (p + driver->num * 2); | |
1da177e4 LT |
3010 | } else { |
3011 | driver->ttys = NULL; | |
3012 | driver->termios = NULL; | |
3013 | driver->termios_locked = NULL; | |
3014 | } | |
3015 | ||
3016 | cdev_init(&driver->cdev, &tty_fops); | |
3017 | driver->cdev.owner = driver->owner; | |
3018 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3019 | if (error) { | |
1da177e4 LT |
3020 | unregister_chrdev_region(dev, driver->num); |
3021 | driver->ttys = NULL; | |
3022 | driver->termios = driver->termios_locked = NULL; | |
3023 | kfree(p); | |
3024 | return error; | |
3025 | } | |
3026 | ||
ca509f69 | 3027 | mutex_lock(&tty_mutex); |
1da177e4 | 3028 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3029 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3030 | |
3031 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
3032 | for (i = 0; i < driver->num; i++) | |
1da177e4 LT |
3033 | tty_register_device(driver, i, NULL); |
3034 | } | |
3035 | proc_tty_register_driver(driver); | |
3036 | return 0; | |
3037 | } | |
3038 | ||
3039 | EXPORT_SYMBOL(tty_register_driver); | |
3040 | ||
3041 | /* | |
3042 | * Called by a tty driver to unregister itself. | |
3043 | */ | |
3044 | int tty_unregister_driver(struct tty_driver *driver) | |
3045 | { | |
3046 | int i; | |
edc6afc5 | 3047 | struct ktermios *tp; |
1da177e4 LT |
3048 | void *p; |
3049 | ||
3050 | if (driver->refcount) | |
3051 | return -EBUSY; | |
3052 | ||
3053 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), | |
3054 | driver->num); | |
ca509f69 | 3055 | mutex_lock(&tty_mutex); |
1da177e4 | 3056 | list_del(&driver->tty_drivers); |
ca509f69 | 3057 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3058 | |
3059 | /* | |
3060 | * Free the termios and termios_locked structures because | |
3061 | * we don't want to get memory leaks when modular tty | |
3062 | * drivers are removed from the kernel. | |
3063 | */ | |
3064 | for (i = 0; i < driver->num; i++) { | |
3065 | tp = driver->termios[i]; | |
3066 | if (tp) { | |
3067 | driver->termios[i] = NULL; | |
3068 | kfree(tp); | |
3069 | } | |
3070 | tp = driver->termios_locked[i]; | |
3071 | if (tp) { | |
3072 | driver->termios_locked[i] = NULL; | |
3073 | kfree(tp); | |
3074 | } | |
331b8319 | 3075 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
1da177e4 LT |
3076 | tty_unregister_device(driver, i); |
3077 | } | |
3078 | p = driver->ttys; | |
3079 | proc_tty_unregister_driver(driver); | |
3080 | driver->ttys = NULL; | |
3081 | driver->termios = driver->termios_locked = NULL; | |
3082 | kfree(p); | |
3083 | cdev_del(&driver->cdev); | |
3084 | return 0; | |
3085 | } | |
1da177e4 LT |
3086 | EXPORT_SYMBOL(tty_unregister_driver); |
3087 | ||
24ec839c PZ |
3088 | dev_t tty_devnum(struct tty_struct *tty) |
3089 | { | |
3090 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3091 | } | |
3092 | EXPORT_SYMBOL(tty_devnum); | |
3093 | ||
3094 | void proc_clear_tty(struct task_struct *p) | |
3095 | { | |
9c9f4ded | 3096 | struct tty_struct *tty; |
24ec839c | 3097 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 3098 | tty = p->signal->tty; |
24ec839c PZ |
3099 | p->signal->tty = NULL; |
3100 | spin_unlock_irq(&p->sighand->siglock); | |
9c9f4ded | 3101 | tty_kref_put(tty); |
24ec839c | 3102 | } |
24ec839c | 3103 | |
47f86834 AC |
3104 | /* Called under the sighand lock */ |
3105 | ||
2a65f1d9 | 3106 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3107 | { |
3108 | if (tty) { | |
47f86834 AC |
3109 | unsigned long flags; |
3110 | /* We should not have a session or pgrp to put here but.... */ | |
3111 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3112 | put_pid(tty->session); |
3113 | put_pid(tty->pgrp); | |
ab521dc0 | 3114 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3115 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3116 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3117 | if (tsk->signal->tty) { |
3118 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3119 | tty_kref_put(tsk->signal->tty); | |
3120 | } | |
24ec839c | 3121 | } |
2a65f1d9 | 3122 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3123 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3124 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3125 | } |
3126 | ||
98a27ba4 | 3127 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3128 | { |
3129 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3130 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3131 | spin_unlock_irq(&tsk->sighand->siglock); |
3132 | } | |
3133 | ||
3134 | struct tty_struct *get_current_tty(void) | |
3135 | { | |
3136 | struct tty_struct *tty; | |
3137 | WARN_ON_ONCE(!mutex_is_locked(&tty_mutex)); | |
3138 | tty = current->signal->tty; | |
3139 | /* | |
3140 | * session->tty can be changed/cleared from under us, make sure we | |
3141 | * issue the load. The obtained pointer, when not NULL, is valid as | |
3142 | * long as we hold tty_mutex. | |
3143 | */ | |
3144 | barrier(); | |
3145 | return tty; | |
3146 | } | |
a311f743 | 3147 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 LT |
3148 | |
3149 | /* | |
3150 | * Initialize the console device. This is called *early*, so | |
3151 | * we can't necessarily depend on lots of kernel help here. | |
3152 | * Just do some early initializations, and do the complex setup | |
3153 | * later. | |
3154 | */ | |
3155 | void __init console_init(void) | |
3156 | { | |
3157 | initcall_t *call; | |
3158 | ||
3159 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3160 | tty_ldisc_begin(); |
1da177e4 LT |
3161 | |
3162 | /* | |
37bdfb07 | 3163 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3164 | * inform about problems etc.. |
3165 | */ | |
1da177e4 LT |
3166 | call = __con_initcall_start; |
3167 | while (call < __con_initcall_end) { | |
3168 | (*call)(); | |
3169 | call++; | |
3170 | } | |
3171 | } | |
3172 | ||
1da177e4 LT |
3173 | static int __init tty_class_init(void) |
3174 | { | |
7fe845d1 | 3175 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3176 | if (IS_ERR(tty_class)) |
3177 | return PTR_ERR(tty_class); | |
3178 | return 0; | |
3179 | } | |
3180 | ||
3181 | postcore_initcall(tty_class_init); | |
3182 | ||
3183 | /* 3/2004 jmc: why do these devices exist? */ | |
3184 | ||
3185 | static struct cdev tty_cdev, console_cdev; | |
3186 | #ifdef CONFIG_UNIX98_PTYS | |
3187 | static struct cdev ptmx_cdev; | |
3188 | #endif | |
3189 | #ifdef CONFIG_VT | |
3190 | static struct cdev vc0_cdev; | |
3191 | #endif | |
3192 | ||
3193 | /* | |
3194 | * Ok, now we can initialize the rest of the tty devices and can count | |
3195 | * on memory allocations, interrupts etc.. | |
3196 | */ | |
3197 | static int __init tty_init(void) | |
3198 | { | |
3199 | cdev_init(&tty_cdev, &tty_fops); | |
3200 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3201 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3202 | panic("Couldn't register /dev/tty driver\n"); | |
47aa5793 GKH |
3203 | device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, |
3204 | "tty"); | |
1da177e4 LT |
3205 | |
3206 | cdev_init(&console_cdev, &console_fops); | |
3207 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3208 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3209 | panic("Couldn't register /dev/console driver\n"); | |
47aa5793 GKH |
3210 | device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
3211 | "console"); | |
1da177e4 LT |
3212 | |
3213 | #ifdef CONFIG_UNIX98_PTYS | |
3214 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
3215 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
3216 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
3217 | panic("Couldn't register /dev/ptmx driver\n"); | |
47aa5793 | 3218 | device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
1da177e4 LT |
3219 | #endif |
3220 | ||
3221 | #ifdef CONFIG_VT | |
3222 | cdev_init(&vc0_cdev, &console_fops); | |
3223 | if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || | |
3224 | register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) | |
3225 | panic("Couldn't register /dev/tty0 driver\n"); | |
47aa5793 | 3226 | device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); |
1da177e4 LT |
3227 | |
3228 | vty_init(); | |
3229 | #endif | |
3230 | return 0; | |
3231 | } | |
3232 | module_init(tty_init); |