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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 | |
22 | * makes for cleaner and more compact code. -TYT, 9/17/92 | |
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 | |
44 | * | |
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. | |
65 | * alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
66 | */ | |
67 | ||
68 | #include <linux/config.h> | |
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> | |
81 | #include <linux/console.h> | |
82 | #include <linux/timer.h> | |
83 | #include <linux/ctype.h> | |
84 | #include <linux/kd.h> | |
85 | #include <linux/mm.h> | |
86 | #include <linux/string.h> | |
87 | #include <linux/slab.h> | |
88 | #include <linux/poll.h> | |
89 | #include <linux/proc_fs.h> | |
90 | #include <linux/init.h> | |
91 | #include <linux/module.h> | |
92 | #include <linux/smp_lock.h> | |
93 | #include <linux/device.h> | |
94 | #include <linux/idr.h> | |
95 | #include <linux/wait.h> | |
96 | #include <linux/bitops.h> | |
b20f3ae5 | 97 | #include <linux/delay.h> |
1da177e4 LT |
98 | |
99 | #include <asm/uaccess.h> | |
100 | #include <asm/system.h> | |
101 | ||
102 | #include <linux/kbd_kern.h> | |
103 | #include <linux/vt_kern.h> | |
104 | #include <linux/selection.h> | |
105 | #include <linux/devfs_fs_kernel.h> | |
106 | ||
107 | #include <linux/kmod.h> | |
108 | ||
109 | #undef TTY_DEBUG_HANGUP | |
110 | ||
111 | #define TTY_PARANOIA_CHECK 1 | |
112 | #define CHECK_TTY_COUNT 1 | |
113 | ||
114 | struct termios tty_std_termios = { /* for the benefit of tty drivers */ | |
115 | .c_iflag = ICRNL | IXON, | |
116 | .c_oflag = OPOST | ONLCR, | |
117 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
118 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
119 | ECHOCTL | ECHOKE | IEXTEN, | |
120 | .c_cc = INIT_C_CC | |
121 | }; | |
122 | ||
123 | EXPORT_SYMBOL(tty_std_termios); | |
124 | ||
125 | /* This list gets poked at by procfs and various bits of boot up code. This | |
126 | could do with some rationalisation such as pulling the tty proc function | |
127 | into this file */ | |
128 | ||
129 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ | |
130 | ||
131 | /* Semaphore to protect creating and releasing a tty. This is shared with | |
132 | vt.c for deeply disgusting hack reasons */ | |
133 | DECLARE_MUTEX(tty_sem); | |
134 | ||
135 | #ifdef CONFIG_UNIX98_PTYS | |
136 | extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ | |
137 | extern int pty_limit; /* Config limit on Unix98 ptys */ | |
138 | static DEFINE_IDR(allocated_ptys); | |
139 | static DECLARE_MUTEX(allocated_ptys_lock); | |
140 | static int ptmx_open(struct inode *, struct file *); | |
141 | #endif | |
142 | ||
143 | extern void disable_early_printk(void); | |
144 | ||
145 | static void initialize_tty_struct(struct tty_struct *tty); | |
146 | ||
147 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); | |
148 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
149 | ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); | |
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 *); | |
153 | int tty_ioctl(struct inode * inode, struct file * file, | |
154 | unsigned int cmd, unsigned long arg); | |
155 | static int tty_fasync(int fd, struct file * filp, int on); | |
1da177e4 LT |
156 | static void release_mem(struct tty_struct *tty, int idx); |
157 | ||
158 | ||
159 | static struct tty_struct *alloc_tty_struct(void) | |
160 | { | |
161 | struct tty_struct *tty; | |
162 | ||
163 | tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL); | |
164 | if (tty) | |
165 | memset(tty, 0, sizeof(struct tty_struct)); | |
166 | return tty; | |
167 | } | |
168 | ||
33f0f88f AC |
169 | static void tty_buffer_free_all(struct tty_struct *); |
170 | ||
1da177e4 LT |
171 | static inline void free_tty_struct(struct tty_struct *tty) |
172 | { | |
173 | kfree(tty->write_buf); | |
33f0f88f | 174 | tty_buffer_free_all(tty); |
1da177e4 LT |
175 | kfree(tty); |
176 | } | |
177 | ||
178 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) | |
179 | ||
180 | char *tty_name(struct tty_struct *tty, char *buf) | |
181 | { | |
182 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
183 | strcpy(buf, "NULL tty"); | |
184 | else | |
185 | strcpy(buf, tty->name); | |
186 | return buf; | |
187 | } | |
188 | ||
189 | EXPORT_SYMBOL(tty_name); | |
190 | ||
d769a669 | 191 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
192 | const char *routine) |
193 | { | |
194 | #ifdef TTY_PARANOIA_CHECK | |
195 | if (!tty) { | |
196 | printk(KERN_WARNING | |
197 | "null TTY for (%d:%d) in %s\n", | |
198 | imajor(inode), iminor(inode), routine); | |
199 | return 1; | |
200 | } | |
201 | if (tty->magic != TTY_MAGIC) { | |
202 | printk(KERN_WARNING | |
203 | "bad magic number for tty struct (%d:%d) in %s\n", | |
204 | imajor(inode), iminor(inode), routine); | |
205 | return 1; | |
206 | } | |
207 | #endif | |
208 | return 0; | |
209 | } | |
210 | ||
211 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
212 | { | |
213 | #ifdef CHECK_TTY_COUNT | |
214 | struct list_head *p; | |
215 | int count = 0; | |
216 | ||
217 | file_list_lock(); | |
218 | list_for_each(p, &tty->tty_files) { | |
219 | count++; | |
220 | } | |
221 | file_list_unlock(); | |
222 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
223 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
224 | tty->link && tty->link->count) | |
225 | count++; | |
226 | if (tty->count != count) { | |
227 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
228 | "!= #fd's(%d) in %s\n", | |
229 | tty->name, tty->count, count, routine); | |
230 | return count; | |
231 | } | |
232 | #endif | |
233 | return 0; | |
234 | } | |
235 | ||
33f0f88f AC |
236 | /* |
237 | * Tty buffer allocation management | |
238 | */ | |
239 | ||
240 | static void tty_buffer_free_all(struct tty_struct *tty) | |
241 | { | |
242 | struct tty_buffer *thead; | |
243 | while((thead = tty->buf.head) != NULL) { | |
244 | tty->buf.head = thead->next; | |
245 | kfree(thead); | |
246 | } | |
247 | while((thead = tty->buf.free) != NULL) { | |
248 | tty->buf.free = thead->next; | |
249 | kfree(thead); | |
250 | } | |
251 | tty->buf.tail = NULL; | |
252 | } | |
253 | ||
254 | static void tty_buffer_init(struct tty_struct *tty) | |
255 | { | |
256 | tty->buf.head = NULL; | |
257 | tty->buf.tail = NULL; | |
258 | tty->buf.free = NULL; | |
259 | } | |
260 | ||
261 | static struct tty_buffer *tty_buffer_alloc(size_t size) | |
262 | { | |
263 | struct tty_buffer *p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); | |
264 | if(p == NULL) | |
265 | return NULL; | |
266 | p->used = 0; | |
267 | p->size = size; | |
268 | p->next = NULL; | |
269 | p->char_buf_ptr = (char *)(p->data); | |
270 | p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size; | |
271 | /* printk("Flip create %p\n", p); */ | |
272 | return p; | |
273 | } | |
274 | ||
275 | /* Must be called with the tty_read lock held. This needs to acquire strategy | |
276 | code to decide if we should kfree or relink a given expired buffer */ | |
277 | ||
278 | static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b) | |
279 | { | |
280 | /* Dumb strategy for now - should keep some stats */ | |
281 | /* printk("Flip dispose %p\n", b); */ | |
282 | if(b->size >= 512) | |
283 | kfree(b); | |
284 | else { | |
285 | b->next = tty->buf.free; | |
286 | tty->buf.free = b; | |
287 | } | |
288 | } | |
289 | ||
290 | static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size) | |
291 | { | |
292 | struct tty_buffer **tbh = &tty->buf.free; | |
293 | while((*tbh) != NULL) { | |
294 | struct tty_buffer *t = *tbh; | |
295 | if(t->size >= size) { | |
296 | *tbh = t->next; | |
297 | t->next = NULL; | |
298 | t->used = 0; | |
299 | /* DEBUG ONLY */ | |
300 | memset(t->data, '*', size); | |
301 | /* printk("Flip recycle %p\n", t); */ | |
302 | return t; | |
303 | } | |
304 | tbh = &((*tbh)->next); | |
305 | } | |
306 | /* Round the buffer size out */ | |
307 | size = (size + 0xFF) & ~ 0xFF; | |
308 | return tty_buffer_alloc(size); | |
309 | /* Should possibly check if this fails for the largest buffer we | |
310 | have queued and recycle that ? */ | |
311 | } | |
312 | ||
313 | int tty_buffer_request_room(struct tty_struct *tty, size_t size) | |
314 | { | |
607f4e38 | 315 | struct tty_buffer *b = tty->buf.tail, *n; |
33f0f88f AC |
316 | int left = 0; |
317 | ||
318 | /* OPTIMISATION: We could keep a per tty "zero" sized buffer to | |
319 | remove this conditional if its worth it. This would be invisible | |
320 | to the callers */ | |
321 | if(b != NULL) | |
322 | left = b->size - b->used; | |
323 | if(left >= size) | |
324 | return size; | |
325 | /* This is the slow path - looking for new buffers to use */ | |
326 | n = tty_buffer_find(tty, size); | |
327 | if(n == NULL) | |
328 | return left; | |
33f0f88f AC |
329 | if(b != NULL) |
330 | b->next = n; | |
331 | else | |
332 | tty->buf.head = n; | |
333 | tty->buf.tail = n; | |
334 | return size; | |
335 | } | |
336 | ||
337 | EXPORT_SYMBOL_GPL(tty_buffer_request_room); | |
338 | ||
339 | int tty_insert_flip_string(struct tty_struct *tty, unsigned char *chars, size_t size) | |
340 | { | |
341 | int copied = 0; | |
342 | do { | |
343 | int space = tty_buffer_request_room(tty, size - copied); | |
344 | struct tty_buffer *tb = tty->buf.tail; | |
345 | /* If there is no space then tb may be NULL */ | |
346 | if(unlikely(space == 0)) | |
347 | break; | |
348 | memcpy(tb->char_buf_ptr + tb->used, chars, space); | |
349 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); | |
350 | tb->used += space; | |
351 | copied += space; | |
352 | chars += space; | |
353 | /* printk("Flip insert %d.\n", space); */ | |
354 | } | |
355 | /* There is a small chance that we need to split the data over | |
356 | several buffers. If this is the case we must loop */ | |
357 | while (unlikely(size > copied)); | |
358 | return copied; | |
359 | } | |
360 | ||
361 | EXPORT_SYMBOL_GPL(tty_insert_flip_string); | |
362 | ||
363 | int tty_insert_flip_string_flags(struct tty_struct *tty, unsigned char *chars, char *flags, size_t size) | |
364 | { | |
365 | int copied = 0; | |
366 | do { | |
367 | int space = tty_buffer_request_room(tty, size - copied); | |
368 | struct tty_buffer *tb = tty->buf.tail; | |
369 | /* If there is no space then tb may be NULL */ | |
370 | if(unlikely(space == 0)) | |
371 | break; | |
372 | memcpy(tb->char_buf_ptr + tb->used, chars, space); | |
373 | memcpy(tb->flag_buf_ptr + tb->used, flags, space); | |
374 | tb->used += space; | |
375 | copied += space; | |
376 | chars += space; | |
377 | flags += space; | |
378 | } | |
379 | /* There is a small chance that we need to split the data over | |
380 | several buffers. If this is the case we must loop */ | |
381 | while (unlikely(size > copied)); | |
382 | return copied; | |
383 | } | |
384 | ||
385 | EXPORT_SYMBOL_GPL(tty_insert_flip_string_flags); | |
386 | ||
387 | ||
388 | /* | |
389 | * Prepare a block of space in the buffer for data. Returns the length | |
390 | * available and buffer pointer to the space which is now allocated and | |
391 | * accounted for as ready for normal characters. This is used for drivers | |
392 | * that need their own block copy routines into the buffer. There is no | |
393 | * guarantee the buffer is a DMA target! | |
394 | */ | |
395 | ||
396 | int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size) | |
397 | { | |
398 | int space = tty_buffer_request_room(tty, size); | |
399 | struct tty_buffer *tb = tty->buf.tail; | |
400 | *chars = tb->char_buf_ptr + tb->used; | |
401 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); | |
402 | tb->used += space; | |
403 | return space; | |
404 | } | |
405 | ||
406 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string); | |
407 | ||
408 | /* | |
409 | * Prepare a block of space in the buffer for data. Returns the length | |
410 | * available and buffer pointer to the space which is now allocated and | |
411 | * accounted for as ready for characters. This is used for drivers | |
412 | * that need their own block copy routines into the buffer. There is no | |
413 | * guarantee the buffer is a DMA target! | |
414 | */ | |
415 | ||
416 | int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size) | |
417 | { | |
418 | int space = tty_buffer_request_room(tty, size); | |
419 | struct tty_buffer *tb = tty->buf.tail; | |
420 | *chars = tb->char_buf_ptr + tb->used; | |
421 | *flags = tb->flag_buf_ptr + tb->used; | |
422 | tb->used += space; | |
423 | return space; | |
424 | } | |
425 | ||
426 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); | |
427 | ||
428 | ||
429 | ||
1da177e4 LT |
430 | /* |
431 | * This is probably overkill for real world processors but | |
432 | * they are not on hot paths so a little discipline won't do | |
433 | * any harm. | |
434 | */ | |
435 | ||
436 | static void tty_set_termios_ldisc(struct tty_struct *tty, int num) | |
437 | { | |
438 | down(&tty->termios_sem); | |
439 | tty->termios->c_line = num; | |
440 | up(&tty->termios_sem); | |
441 | } | |
442 | ||
443 | /* | |
444 | * This guards the refcounted line discipline lists. The lock | |
445 | * must be taken with irqs off because there are hangup path | |
446 | * callers who will do ldisc lookups and cannot sleep. | |
447 | */ | |
448 | ||
449 | static DEFINE_SPINLOCK(tty_ldisc_lock); | |
450 | static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); | |
bfb07599 | 451 | static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ |
1da177e4 LT |
452 | |
453 | int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) | |
454 | { | |
455 | unsigned long flags; | |
456 | int ret = 0; | |
457 | ||
458 | if (disc < N_TTY || disc >= NR_LDISCS) | |
459 | return -EINVAL; | |
460 | ||
461 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
bfb07599 AD |
462 | tty_ldiscs[disc] = *new_ldisc; |
463 | tty_ldiscs[disc].num = disc; | |
464 | tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; | |
465 | tty_ldiscs[disc].refcount = 0; | |
1da177e4 LT |
466 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
467 | ||
468 | return ret; | |
469 | } | |
1da177e4 LT |
470 | EXPORT_SYMBOL(tty_register_ldisc); |
471 | ||
bfb07599 AD |
472 | int tty_unregister_ldisc(int disc) |
473 | { | |
474 | unsigned long flags; | |
475 | int ret = 0; | |
476 | ||
477 | if (disc < N_TTY || disc >= NR_LDISCS) | |
478 | return -EINVAL; | |
479 | ||
480 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
481 | if (tty_ldiscs[disc].refcount) | |
482 | ret = -EBUSY; | |
483 | else | |
484 | tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; | |
485 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
486 | ||
487 | return ret; | |
488 | } | |
489 | EXPORT_SYMBOL(tty_unregister_ldisc); | |
490 | ||
1da177e4 LT |
491 | struct tty_ldisc *tty_ldisc_get(int disc) |
492 | { | |
493 | unsigned long flags; | |
494 | struct tty_ldisc *ld; | |
495 | ||
496 | if (disc < N_TTY || disc >= NR_LDISCS) | |
497 | return NULL; | |
498 | ||
499 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
500 | ||
501 | ld = &tty_ldiscs[disc]; | |
502 | /* Check the entry is defined */ | |
503 | if(ld->flags & LDISC_FLAG_DEFINED) | |
504 | { | |
505 | /* If the module is being unloaded we can't use it */ | |
506 | if (!try_module_get(ld->owner)) | |
507 | ld = NULL; | |
508 | else /* lock it */ | |
509 | ld->refcount++; | |
510 | } | |
511 | else | |
512 | ld = NULL; | |
513 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
514 | return ld; | |
515 | } | |
516 | ||
517 | EXPORT_SYMBOL_GPL(tty_ldisc_get); | |
518 | ||
519 | void tty_ldisc_put(int disc) | |
520 | { | |
521 | struct tty_ldisc *ld; | |
522 | unsigned long flags; | |
523 | ||
524 | if (disc < N_TTY || disc >= NR_LDISCS) | |
525 | BUG(); | |
526 | ||
527 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
528 | ld = &tty_ldiscs[disc]; | |
529 | if(ld->refcount == 0) | |
530 | BUG(); | |
531 | ld->refcount --; | |
532 | module_put(ld->owner); | |
533 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
534 | } | |
535 | ||
536 | EXPORT_SYMBOL_GPL(tty_ldisc_put); | |
537 | ||
538 | static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) | |
539 | { | |
540 | tty->ldisc = *ld; | |
541 | tty->ldisc.refcount = 0; | |
542 | } | |
543 | ||
544 | /** | |
545 | * tty_ldisc_try - internal helper | |
546 | * @tty: the tty | |
547 | * | |
548 | * Make a single attempt to grab and bump the refcount on | |
549 | * the tty ldisc. Return 0 on failure or 1 on success. This is | |
550 | * used to implement both the waiting and non waiting versions | |
551 | * of tty_ldisc_ref | |
552 | */ | |
553 | ||
554 | static int tty_ldisc_try(struct tty_struct *tty) | |
555 | { | |
556 | unsigned long flags; | |
557 | struct tty_ldisc *ld; | |
558 | int ret = 0; | |
559 | ||
560 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
561 | ld = &tty->ldisc; | |
562 | if(test_bit(TTY_LDISC, &tty->flags)) | |
563 | { | |
564 | ld->refcount++; | |
565 | ret = 1; | |
566 | } | |
567 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
568 | return ret; | |
569 | } | |
570 | ||
571 | /** | |
572 | * tty_ldisc_ref_wait - wait for the tty ldisc | |
573 | * @tty: tty device | |
574 | * | |
575 | * Dereference the line discipline for the terminal and take a | |
576 | * reference to it. If the line discipline is in flux then | |
577 | * wait patiently until it changes. | |
578 | * | |
579 | * Note: Must not be called from an IRQ/timer context. The caller | |
580 | * must also be careful not to hold other locks that will deadlock | |
581 | * against a discipline change, such as an existing ldisc reference | |
582 | * (which we check for) | |
583 | */ | |
584 | ||
585 | struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) | |
586 | { | |
587 | /* wait_event is a macro */ | |
588 | wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); | |
589 | if(tty->ldisc.refcount == 0) | |
590 | printk(KERN_ERR "tty_ldisc_ref_wait\n"); | |
591 | return &tty->ldisc; | |
592 | } | |
593 | ||
594 | EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); | |
595 | ||
596 | /** | |
597 | * tty_ldisc_ref - get the tty ldisc | |
598 | * @tty: tty device | |
599 | * | |
600 | * Dereference the line discipline for the terminal and take a | |
601 | * reference to it. If the line discipline is in flux then | |
602 | * return NULL. Can be called from IRQ and timer functions. | |
603 | */ | |
604 | ||
605 | struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) | |
606 | { | |
607 | if(tty_ldisc_try(tty)) | |
608 | return &tty->ldisc; | |
609 | return NULL; | |
610 | } | |
611 | ||
612 | EXPORT_SYMBOL_GPL(tty_ldisc_ref); | |
613 | ||
614 | /** | |
615 | * tty_ldisc_deref - free a tty ldisc reference | |
616 | * @ld: reference to free up | |
617 | * | |
618 | * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May | |
619 | * be called in IRQ context. | |
620 | */ | |
621 | ||
622 | void tty_ldisc_deref(struct tty_ldisc *ld) | |
623 | { | |
624 | unsigned long flags; | |
625 | ||
626 | if(ld == NULL) | |
627 | BUG(); | |
628 | ||
629 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
630 | if(ld->refcount == 0) | |
631 | printk(KERN_ERR "tty_ldisc_deref: no references.\n"); | |
632 | else | |
633 | ld->refcount--; | |
634 | if(ld->refcount == 0) | |
635 | wake_up(&tty_ldisc_wait); | |
636 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
637 | } | |
638 | ||
639 | EXPORT_SYMBOL_GPL(tty_ldisc_deref); | |
640 | ||
641 | /** | |
642 | * tty_ldisc_enable - allow ldisc use | |
643 | * @tty: terminal to activate ldisc on | |
644 | * | |
645 | * Set the TTY_LDISC flag when the line discipline can be called | |
646 | * again. Do neccessary wakeups for existing sleepers. | |
647 | * | |
648 | * Note: nobody should set this bit except via this function. Clearing | |
649 | * directly is allowed. | |
650 | */ | |
651 | ||
652 | static void tty_ldisc_enable(struct tty_struct *tty) | |
653 | { | |
654 | set_bit(TTY_LDISC, &tty->flags); | |
655 | wake_up(&tty_ldisc_wait); | |
656 | } | |
657 | ||
658 | /** | |
659 | * tty_set_ldisc - set line discipline | |
660 | * @tty: the terminal to set | |
661 | * @ldisc: the line discipline | |
662 | * | |
663 | * Set the discipline of a tty line. Must be called from a process | |
664 | * context. | |
665 | */ | |
666 | ||
667 | static int tty_set_ldisc(struct tty_struct *tty, int ldisc) | |
668 | { | |
ff55fe20 JB |
669 | int retval = 0; |
670 | struct tty_ldisc o_ldisc; | |
1da177e4 LT |
671 | char buf[64]; |
672 | int work; | |
673 | unsigned long flags; | |
674 | struct tty_ldisc *ld; | |
ff55fe20 | 675 | struct tty_struct *o_tty; |
1da177e4 LT |
676 | |
677 | if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) | |
678 | return -EINVAL; | |
679 | ||
680 | restart: | |
681 | ||
1da177e4 LT |
682 | ld = tty_ldisc_get(ldisc); |
683 | /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ | |
684 | /* Cyrus Durgin <cider@speakeasy.org> */ | |
685 | if (ld == NULL) { | |
686 | request_module("tty-ldisc-%d", ldisc); | |
687 | ld = tty_ldisc_get(ldisc); | |
688 | } | |
689 | if (ld == NULL) | |
690 | return -EINVAL; | |
691 | ||
33f0f88f AC |
692 | /* |
693 | * No more input please, we are switching. The new ldisc | |
694 | * will update this value in the ldisc open function | |
695 | */ | |
696 | ||
697 | tty->receive_room = 0; | |
698 | ||
699 | /* | |
700 | * Problem: What do we do if this blocks ? | |
701 | */ | |
702 | ||
1da177e4 LT |
703 | tty_wait_until_sent(tty, 0); |
704 | ||
ff55fe20 JB |
705 | if (tty->ldisc.num == ldisc) { |
706 | tty_ldisc_put(ldisc); | |
707 | return 0; | |
708 | } | |
709 | ||
710 | o_ldisc = tty->ldisc; | |
711 | o_tty = tty->link; | |
712 | ||
1da177e4 LT |
713 | /* |
714 | * Make sure we don't change while someone holds a | |
715 | * reference to the line discipline. The TTY_LDISC bit | |
716 | * prevents anyone taking a reference once it is clear. | |
717 | * We need the lock to avoid racing reference takers. | |
718 | */ | |
ff55fe20 | 719 | |
1da177e4 | 720 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
ff55fe20 JB |
721 | if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) { |
722 | if(tty->ldisc.refcount) { | |
723 | /* Free the new ldisc we grabbed. Must drop the lock | |
724 | first. */ | |
725 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
726 | tty_ldisc_put(ldisc); | |
727 | /* | |
728 | * There are several reasons we may be busy, including | |
729 | * random momentary I/O traffic. We must therefore | |
730 | * retry. We could distinguish between blocking ops | |
731 | * and retries if we made tty_ldisc_wait() smarter. That | |
732 | * is up for discussion. | |
733 | */ | |
734 | if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) | |
735 | return -ERESTARTSYS; | |
736 | goto restart; | |
737 | } | |
738 | if(o_tty && o_tty->ldisc.refcount) { | |
739 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
740 | tty_ldisc_put(ldisc); | |
741 | if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0) | |
742 | return -ERESTARTSYS; | |
743 | goto restart; | |
744 | } | |
745 | } | |
746 | ||
747 | /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */ | |
748 | ||
749 | if (!test_bit(TTY_LDISC, &tty->flags)) { | |
1da177e4 LT |
750 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
751 | tty_ldisc_put(ldisc); | |
ff55fe20 JB |
752 | ld = tty_ldisc_ref_wait(tty); |
753 | tty_ldisc_deref(ld); | |
1da177e4 LT |
754 | goto restart; |
755 | } | |
ff55fe20 JB |
756 | |
757 | clear_bit(TTY_LDISC, &tty->flags); | |
1da177e4 | 758 | clear_bit(TTY_DONT_FLIP, &tty->flags); |
ff55fe20 JB |
759 | if (o_tty) { |
760 | clear_bit(TTY_LDISC, &o_tty->flags); | |
761 | clear_bit(TTY_DONT_FLIP, &o_tty->flags); | |
762 | } | |
1da177e4 | 763 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
ff55fe20 | 764 | |
1da177e4 LT |
765 | /* |
766 | * From this point on we know nobody has an ldisc | |
767 | * usage reference, nor can they obtain one until | |
768 | * we say so later on. | |
769 | */ | |
ff55fe20 | 770 | |
33f0f88f | 771 | work = cancel_delayed_work(&tty->buf.work); |
1da177e4 | 772 | /* |
33f0f88f | 773 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
1da177e4 LT |
774 | */ |
775 | ||
776 | flush_scheduled_work(); | |
777 | /* Shutdown the current discipline. */ | |
778 | if (tty->ldisc.close) | |
779 | (tty->ldisc.close)(tty); | |
780 | ||
781 | /* Now set up the new line discipline. */ | |
782 | tty_ldisc_assign(tty, ld); | |
783 | tty_set_termios_ldisc(tty, ldisc); | |
784 | if (tty->ldisc.open) | |
785 | retval = (tty->ldisc.open)(tty); | |
786 | if (retval < 0) { | |
787 | tty_ldisc_put(ldisc); | |
788 | /* There is an outstanding reference here so this is safe */ | |
789 | tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num)); | |
790 | tty_set_termios_ldisc(tty, tty->ldisc.num); | |
791 | if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { | |
792 | tty_ldisc_put(o_ldisc.num); | |
793 | /* This driver is always present */ | |
794 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); | |
795 | tty_set_termios_ldisc(tty, N_TTY); | |
796 | if (tty->ldisc.open) { | |
797 | int r = tty->ldisc.open(tty); | |
798 | ||
799 | if (r < 0) | |
800 | panic("Couldn't open N_TTY ldisc for " | |
801 | "%s --- error %d.", | |
802 | tty_name(tty, buf), r); | |
803 | } | |
804 | } | |
805 | } | |
806 | /* At this point we hold a reference to the new ldisc and a | |
807 | a reference to the old ldisc. If we ended up flipping back | |
808 | to the existing ldisc we have two references to it */ | |
809 | ||
810 | if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc) | |
811 | tty->driver->set_ldisc(tty); | |
812 | ||
813 | tty_ldisc_put(o_ldisc.num); | |
814 | ||
815 | /* | |
816 | * Allow ldisc referencing to occur as soon as the driver | |
817 | * ldisc callback completes. | |
818 | */ | |
819 | ||
820 | tty_ldisc_enable(tty); | |
ff55fe20 JB |
821 | if (o_tty) |
822 | tty_ldisc_enable(o_tty); | |
1da177e4 LT |
823 | |
824 | /* Restart it in case no characters kick it off. Safe if | |
825 | already running */ | |
ff55fe20 | 826 | if (work) |
33f0f88f | 827 | schedule_delayed_work(&tty->buf.work, 1); |
1da177e4 LT |
828 | return retval; |
829 | } | |
830 | ||
831 | /* | |
832 | * This routine returns a tty driver structure, given a device number | |
833 | */ | |
834 | static struct tty_driver *get_tty_driver(dev_t device, int *index) | |
835 | { | |
836 | struct tty_driver *p; | |
837 | ||
838 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
839 | dev_t base = MKDEV(p->major, p->minor_start); | |
840 | if (device < base || device >= base + p->num) | |
841 | continue; | |
842 | *index = device - base; | |
843 | return p; | |
844 | } | |
845 | return NULL; | |
846 | } | |
847 | ||
848 | /* | |
849 | * If we try to write to, or set the state of, a terminal and we're | |
850 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
851 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
852 | */ | |
853 | int tty_check_change(struct tty_struct * tty) | |
854 | { | |
855 | if (current->signal->tty != tty) | |
856 | return 0; | |
857 | if (tty->pgrp <= 0) { | |
858 | printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n"); | |
859 | return 0; | |
860 | } | |
861 | if (process_group(current) == tty->pgrp) | |
862 | return 0; | |
863 | if (is_ignored(SIGTTOU)) | |
864 | return 0; | |
865 | if (is_orphaned_pgrp(process_group(current))) | |
866 | return -EIO; | |
867 | (void) kill_pg(process_group(current), SIGTTOU, 1); | |
868 | return -ERESTARTSYS; | |
869 | } | |
870 | ||
871 | EXPORT_SYMBOL(tty_check_change); | |
872 | ||
873 | static ssize_t hung_up_tty_read(struct file * file, char __user * buf, | |
874 | size_t count, loff_t *ppos) | |
875 | { | |
876 | return 0; | |
877 | } | |
878 | ||
879 | static ssize_t hung_up_tty_write(struct file * file, const char __user * buf, | |
880 | size_t count, loff_t *ppos) | |
881 | { | |
882 | return -EIO; | |
883 | } | |
884 | ||
885 | /* No kernel lock held - none needed ;) */ | |
886 | static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait) | |
887 | { | |
888 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
889 | } | |
890 | ||
891 | static int hung_up_tty_ioctl(struct inode * inode, struct file * file, | |
892 | unsigned int cmd, unsigned long arg) | |
893 | { | |
894 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
895 | } | |
896 | ||
897 | static struct file_operations tty_fops = { | |
898 | .llseek = no_llseek, | |
899 | .read = tty_read, | |
900 | .write = tty_write, | |
901 | .poll = tty_poll, | |
902 | .ioctl = tty_ioctl, | |
903 | .open = tty_open, | |
904 | .release = tty_release, | |
905 | .fasync = tty_fasync, | |
906 | }; | |
907 | ||
908 | #ifdef CONFIG_UNIX98_PTYS | |
909 | static struct file_operations ptmx_fops = { | |
910 | .llseek = no_llseek, | |
911 | .read = tty_read, | |
912 | .write = tty_write, | |
913 | .poll = tty_poll, | |
914 | .ioctl = tty_ioctl, | |
915 | .open = ptmx_open, | |
916 | .release = tty_release, | |
917 | .fasync = tty_fasync, | |
918 | }; | |
919 | #endif | |
920 | ||
921 | static struct file_operations console_fops = { | |
922 | .llseek = no_llseek, | |
923 | .read = tty_read, | |
924 | .write = redirected_tty_write, | |
925 | .poll = tty_poll, | |
926 | .ioctl = tty_ioctl, | |
927 | .open = tty_open, | |
928 | .release = tty_release, | |
929 | .fasync = tty_fasync, | |
930 | }; | |
931 | ||
932 | static struct file_operations hung_up_tty_fops = { | |
933 | .llseek = no_llseek, | |
934 | .read = hung_up_tty_read, | |
935 | .write = hung_up_tty_write, | |
936 | .poll = hung_up_tty_poll, | |
937 | .ioctl = hung_up_tty_ioctl, | |
938 | .release = tty_release, | |
939 | }; | |
940 | ||
941 | static DEFINE_SPINLOCK(redirect_lock); | |
942 | static struct file *redirect; | |
943 | ||
944 | /** | |
945 | * tty_wakeup - request more data | |
946 | * @tty: terminal | |
947 | * | |
948 | * Internal and external helper for wakeups of tty. This function | |
949 | * informs the line discipline if present that the driver is ready | |
950 | * to receive more output data. | |
951 | */ | |
952 | ||
953 | void tty_wakeup(struct tty_struct *tty) | |
954 | { | |
955 | struct tty_ldisc *ld; | |
956 | ||
957 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { | |
958 | ld = tty_ldisc_ref(tty); | |
959 | if(ld) { | |
960 | if(ld->write_wakeup) | |
961 | ld->write_wakeup(tty); | |
962 | tty_ldisc_deref(ld); | |
963 | } | |
964 | } | |
965 | wake_up_interruptible(&tty->write_wait); | |
966 | } | |
967 | ||
968 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
969 | ||
970 | /** | |
971 | * tty_ldisc_flush - flush line discipline queue | |
972 | * @tty: tty | |
973 | * | |
974 | * Flush the line discipline queue (if any) for this tty. If there | |
975 | * is no line discipline active this is a no-op. | |
976 | */ | |
977 | ||
978 | void tty_ldisc_flush(struct tty_struct *tty) | |
979 | { | |
980 | struct tty_ldisc *ld = tty_ldisc_ref(tty); | |
981 | if(ld) { | |
982 | if(ld->flush_buffer) | |
983 | ld->flush_buffer(tty); | |
984 | tty_ldisc_deref(ld); | |
985 | } | |
986 | } | |
987 | ||
988 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); | |
989 | ||
990 | /* | |
991 | * This can be called by the "eventd" kernel thread. That is process synchronous, | |
992 | * but doesn't hold any locks, so we need to make sure we have the appropriate | |
993 | * locks for what we're doing.. | |
994 | */ | |
995 | static void do_tty_hangup(void *data) | |
996 | { | |
997 | struct tty_struct *tty = (struct tty_struct *) data; | |
998 | struct file * cons_filp = NULL; | |
999 | struct file *filp, *f = NULL; | |
1000 | struct task_struct *p; | |
1001 | struct tty_ldisc *ld; | |
1002 | int closecount = 0, n; | |
1003 | ||
1004 | if (!tty) | |
1005 | return; | |
1006 | ||
1007 | /* inuse_filps is protected by the single kernel lock */ | |
1008 | lock_kernel(); | |
1009 | ||
1010 | spin_lock(&redirect_lock); | |
1011 | if (redirect && redirect->private_data == tty) { | |
1012 | f = redirect; | |
1013 | redirect = NULL; | |
1014 | } | |
1015 | spin_unlock(&redirect_lock); | |
1016 | ||
1017 | check_tty_count(tty, "do_tty_hangup"); | |
1018 | file_list_lock(); | |
1019 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ | |
2f512016 | 1020 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
1da177e4 LT |
1021 | if (filp->f_op->write == redirected_tty_write) |
1022 | cons_filp = filp; | |
1023 | if (filp->f_op->write != tty_write) | |
1024 | continue; | |
1025 | closecount++; | |
1026 | tty_fasync(-1, filp, 0); /* can't block */ | |
1027 | filp->f_op = &hung_up_tty_fops; | |
1028 | } | |
1029 | file_list_unlock(); | |
1030 | ||
1031 | /* FIXME! What are the locking issues here? This may me overdoing things.. | |
1032 | * this question is especially important now that we've removed the irqlock. */ | |
1033 | ||
1034 | ld = tty_ldisc_ref(tty); | |
1035 | if(ld != NULL) /* We may have no line discipline at this point */ | |
1036 | { | |
1037 | if (ld->flush_buffer) | |
1038 | ld->flush_buffer(tty); | |
1039 | if (tty->driver->flush_buffer) | |
1040 | tty->driver->flush_buffer(tty); | |
1041 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && | |
1042 | ld->write_wakeup) | |
1043 | ld->write_wakeup(tty); | |
1044 | if (ld->hangup) | |
1045 | ld->hangup(tty); | |
1046 | } | |
1047 | ||
1048 | /* FIXME: Once we trust the LDISC code better we can wait here for | |
1049 | ldisc completion and fix the driver call race */ | |
1050 | ||
1051 | wake_up_interruptible(&tty->write_wait); | |
1052 | wake_up_interruptible(&tty->read_wait); | |
1053 | ||
1054 | /* | |
1055 | * Shutdown the current line discipline, and reset it to | |
1056 | * N_TTY. | |
1057 | */ | |
1058 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1059 | { | |
1060 | down(&tty->termios_sem); | |
1061 | *tty->termios = tty->driver->init_termios; | |
1062 | up(&tty->termios_sem); | |
1063 | } | |
1064 | ||
1065 | /* Defer ldisc switch */ | |
1066 | /* tty_deferred_ldisc_switch(N_TTY); | |
1067 | ||
1068 | This should get done automatically when the port closes and | |
1069 | tty_release is called */ | |
1070 | ||
1071 | read_lock(&tasklist_lock); | |
1072 | if (tty->session > 0) { | |
1073 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { | |
1074 | if (p->signal->tty == tty) | |
1075 | p->signal->tty = NULL; | |
1076 | if (!p->signal->leader) | |
1077 | continue; | |
1078 | send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
1079 | send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
1080 | if (tty->pgrp > 0) | |
1081 | p->signal->tty_old_pgrp = tty->pgrp; | |
1082 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); | |
1083 | } | |
1084 | read_unlock(&tasklist_lock); | |
1085 | ||
1086 | tty->flags = 0; | |
1087 | tty->session = 0; | |
1088 | tty->pgrp = -1; | |
1089 | tty->ctrl_status = 0; | |
1090 | /* | |
1091 | * If one of the devices matches a console pointer, we | |
1092 | * cannot just call hangup() because that will cause | |
1093 | * tty->count and state->count to go out of sync. | |
1094 | * So we just call close() the right number of times. | |
1095 | */ | |
1096 | if (cons_filp) { | |
1097 | if (tty->driver->close) | |
1098 | for (n = 0; n < closecount; n++) | |
1099 | tty->driver->close(tty, cons_filp); | |
1100 | } else if (tty->driver->hangup) | |
1101 | (tty->driver->hangup)(tty); | |
1102 | ||
1103 | /* We don't want to have driver/ldisc interactions beyond | |
1104 | the ones we did here. The driver layer expects no | |
1105 | calls after ->hangup() from the ldisc side. However we | |
1106 | can't yet guarantee all that */ | |
1107 | ||
1108 | set_bit(TTY_HUPPED, &tty->flags); | |
1109 | if (ld) { | |
1110 | tty_ldisc_enable(tty); | |
1111 | tty_ldisc_deref(ld); | |
1112 | } | |
1113 | unlock_kernel(); | |
1114 | if (f) | |
1115 | fput(f); | |
1116 | } | |
1117 | ||
1118 | void tty_hangup(struct tty_struct * tty) | |
1119 | { | |
1120 | #ifdef TTY_DEBUG_HANGUP | |
1121 | char buf[64]; | |
1122 | ||
1123 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); | |
1124 | #endif | |
1125 | schedule_work(&tty->hangup_work); | |
1126 | } | |
1127 | ||
1128 | EXPORT_SYMBOL(tty_hangup); | |
1129 | ||
1130 | void tty_vhangup(struct tty_struct * tty) | |
1131 | { | |
1132 | #ifdef TTY_DEBUG_HANGUP | |
1133 | char buf[64]; | |
1134 | ||
1135 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
1136 | #endif | |
1137 | do_tty_hangup((void *) tty); | |
1138 | } | |
1139 | EXPORT_SYMBOL(tty_vhangup); | |
1140 | ||
1141 | int tty_hung_up_p(struct file * filp) | |
1142 | { | |
1143 | return (filp->f_op == &hung_up_tty_fops); | |
1144 | } | |
1145 | ||
1146 | EXPORT_SYMBOL(tty_hung_up_p); | |
1147 | ||
1148 | /* | |
1149 | * This function is typically called only by the session leader, when | |
1150 | * it wants to disassociate itself from its controlling tty. | |
1151 | * | |
1152 | * It performs the following functions: | |
1153 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group | |
1154 | * (2) Clears the tty from being controlling the session | |
1155 | * (3) Clears the controlling tty for all processes in the | |
1156 | * session group. | |
1157 | * | |
1158 | * The argument on_exit is set to 1 if called when a process is | |
1159 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
1160 | */ | |
1161 | void disassociate_ctty(int on_exit) | |
1162 | { | |
1163 | struct tty_struct *tty; | |
1164 | struct task_struct *p; | |
1165 | int tty_pgrp = -1; | |
1166 | ||
1167 | lock_kernel(); | |
1168 | ||
1169 | down(&tty_sem); | |
1170 | tty = current->signal->tty; | |
1171 | if (tty) { | |
1172 | tty_pgrp = tty->pgrp; | |
1173 | up(&tty_sem); | |
1174 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) | |
1175 | tty_vhangup(tty); | |
1176 | } else { | |
1177 | if (current->signal->tty_old_pgrp) { | |
1178 | kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit); | |
1179 | kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit); | |
1180 | } | |
1181 | up(&tty_sem); | |
1182 | unlock_kernel(); | |
1183 | return; | |
1184 | } | |
1185 | if (tty_pgrp > 0) { | |
1186 | kill_pg(tty_pgrp, SIGHUP, on_exit); | |
1187 | if (!on_exit) | |
1188 | kill_pg(tty_pgrp, SIGCONT, on_exit); | |
1189 | } | |
1190 | ||
1191 | /* Must lock changes to tty_old_pgrp */ | |
1192 | down(&tty_sem); | |
1193 | current->signal->tty_old_pgrp = 0; | |
1194 | tty->session = 0; | |
1195 | tty->pgrp = -1; | |
1196 | ||
1197 | /* Now clear signal->tty under the lock */ | |
1198 | read_lock(&tasklist_lock); | |
1199 | do_each_task_pid(current->signal->session, PIDTYPE_SID, p) { | |
1200 | p->signal->tty = NULL; | |
1201 | } while_each_task_pid(current->signal->session, PIDTYPE_SID, p); | |
1202 | read_unlock(&tasklist_lock); | |
1203 | up(&tty_sem); | |
1204 | unlock_kernel(); | |
1205 | } | |
1206 | ||
1207 | void stop_tty(struct tty_struct *tty) | |
1208 | { | |
1209 | if (tty->stopped) | |
1210 | return; | |
1211 | tty->stopped = 1; | |
1212 | if (tty->link && tty->link->packet) { | |
1213 | tty->ctrl_status &= ~TIOCPKT_START; | |
1214 | tty->ctrl_status |= TIOCPKT_STOP; | |
1215 | wake_up_interruptible(&tty->link->read_wait); | |
1216 | } | |
1217 | if (tty->driver->stop) | |
1218 | (tty->driver->stop)(tty); | |
1219 | } | |
1220 | ||
1221 | EXPORT_SYMBOL(stop_tty); | |
1222 | ||
1223 | void start_tty(struct tty_struct *tty) | |
1224 | { | |
1225 | if (!tty->stopped || tty->flow_stopped) | |
1226 | return; | |
1227 | tty->stopped = 0; | |
1228 | if (tty->link && tty->link->packet) { | |
1229 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
1230 | tty->ctrl_status |= TIOCPKT_START; | |
1231 | wake_up_interruptible(&tty->link->read_wait); | |
1232 | } | |
1233 | if (tty->driver->start) | |
1234 | (tty->driver->start)(tty); | |
1235 | ||
1236 | /* If we have a running line discipline it may need kicking */ | |
1237 | tty_wakeup(tty); | |
1238 | wake_up_interruptible(&tty->write_wait); | |
1239 | } | |
1240 | ||
1241 | EXPORT_SYMBOL(start_tty); | |
1242 | ||
1243 | static ssize_t tty_read(struct file * file, char __user * buf, size_t count, | |
1244 | loff_t *ppos) | |
1245 | { | |
1246 | int i; | |
1247 | struct tty_struct * tty; | |
1248 | struct inode *inode; | |
1249 | struct tty_ldisc *ld; | |
1250 | ||
1251 | tty = (struct tty_struct *)file->private_data; | |
1252 | inode = file->f_dentry->d_inode; | |
1253 | if (tty_paranoia_check(tty, inode, "tty_read")) | |
1254 | return -EIO; | |
1255 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1256 | return -EIO; | |
1257 | ||
1258 | /* We want to wait for the line discipline to sort out in this | |
1259 | situation */ | |
1260 | ld = tty_ldisc_ref_wait(tty); | |
1261 | lock_kernel(); | |
1262 | if (ld->read) | |
1263 | i = (ld->read)(tty,file,buf,count); | |
1264 | else | |
1265 | i = -EIO; | |
1266 | tty_ldisc_deref(ld); | |
1267 | unlock_kernel(); | |
1268 | if (i > 0) | |
1269 | inode->i_atime = current_fs_time(inode->i_sb); | |
1270 | return i; | |
1271 | } | |
1272 | ||
1273 | /* | |
1274 | * Split writes up in sane blocksizes to avoid | |
1275 | * denial-of-service type attacks | |
1276 | */ | |
1277 | static inline ssize_t do_tty_write( | |
1278 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1279 | struct tty_struct *tty, | |
1280 | struct file *file, | |
1281 | const char __user *buf, | |
1282 | size_t count) | |
1283 | { | |
1284 | ssize_t ret = 0, written = 0; | |
1285 | unsigned int chunk; | |
1286 | ||
1287 | if (down_interruptible(&tty->atomic_write)) { | |
1288 | return -ERESTARTSYS; | |
1289 | } | |
1290 | ||
1291 | /* | |
1292 | * We chunk up writes into a temporary buffer. This | |
1293 | * simplifies low-level drivers immensely, since they | |
1294 | * don't have locking issues and user mode accesses. | |
1295 | * | |
1296 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1297 | * big chunk-size.. | |
1298 | * | |
1299 | * The default chunk-size is 2kB, because the NTTY | |
1300 | * layer has problems with bigger chunks. It will | |
1301 | * claim to be able to handle more characters than | |
1302 | * it actually does. | |
1303 | */ | |
1304 | chunk = 2048; | |
1305 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1306 | chunk = 65536; | |
1307 | if (count < chunk) | |
1308 | chunk = count; | |
1309 | ||
1310 | /* write_buf/write_cnt is protected by the atomic_write semaphore */ | |
1311 | if (tty->write_cnt < chunk) { | |
1312 | unsigned char *buf; | |
1313 | ||
1314 | if (chunk < 1024) | |
1315 | chunk = 1024; | |
1316 | ||
1317 | buf = kmalloc(chunk, GFP_KERNEL); | |
1318 | if (!buf) { | |
1319 | up(&tty->atomic_write); | |
1320 | return -ENOMEM; | |
1321 | } | |
1322 | kfree(tty->write_buf); | |
1323 | tty->write_cnt = chunk; | |
1324 | tty->write_buf = buf; | |
1325 | } | |
1326 | ||
1327 | /* Do the write .. */ | |
1328 | for (;;) { | |
1329 | size_t size = count; | |
1330 | if (size > chunk) | |
1331 | size = chunk; | |
1332 | ret = -EFAULT; | |
1333 | if (copy_from_user(tty->write_buf, buf, size)) | |
1334 | break; | |
1335 | lock_kernel(); | |
1336 | ret = write(tty, file, tty->write_buf, size); | |
1337 | unlock_kernel(); | |
1338 | if (ret <= 0) | |
1339 | break; | |
1340 | written += ret; | |
1341 | buf += ret; | |
1342 | count -= ret; | |
1343 | if (!count) | |
1344 | break; | |
1345 | ret = -ERESTARTSYS; | |
1346 | if (signal_pending(current)) | |
1347 | break; | |
1348 | cond_resched(); | |
1349 | } | |
1350 | if (written) { | |
1351 | struct inode *inode = file->f_dentry->d_inode; | |
1352 | inode->i_mtime = current_fs_time(inode->i_sb); | |
1353 | ret = written; | |
1354 | } | |
1355 | up(&tty->atomic_write); | |
1356 | return ret; | |
1357 | } | |
1358 | ||
1359 | ||
1360 | static ssize_t tty_write(struct file * file, const char __user * buf, size_t count, | |
1361 | loff_t *ppos) | |
1362 | { | |
1363 | struct tty_struct * tty; | |
1364 | struct inode *inode = file->f_dentry->d_inode; | |
1365 | ssize_t ret; | |
1366 | struct tty_ldisc *ld; | |
1367 | ||
1368 | tty = (struct tty_struct *)file->private_data; | |
1369 | if (tty_paranoia_check(tty, inode, "tty_write")) | |
1370 | return -EIO; | |
1371 | if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1372 | return -EIO; | |
1373 | ||
1374 | ld = tty_ldisc_ref_wait(tty); | |
1375 | if (!ld->write) | |
1376 | ret = -EIO; | |
1377 | else | |
1378 | ret = do_tty_write(ld->write, tty, file, buf, count); | |
1379 | tty_ldisc_deref(ld); | |
1380 | return ret; | |
1381 | } | |
1382 | ||
1383 | ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count, | |
1384 | loff_t *ppos) | |
1385 | { | |
1386 | struct file *p = NULL; | |
1387 | ||
1388 | spin_lock(&redirect_lock); | |
1389 | if (redirect) { | |
1390 | get_file(redirect); | |
1391 | p = redirect; | |
1392 | } | |
1393 | spin_unlock(&redirect_lock); | |
1394 | ||
1395 | if (p) { | |
1396 | ssize_t res; | |
1397 | res = vfs_write(p, buf, count, &p->f_pos); | |
1398 | fput(p); | |
1399 | return res; | |
1400 | } | |
1401 | ||
1402 | return tty_write(file, buf, count, ppos); | |
1403 | } | |
1404 | ||
1405 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1406 | ||
1407 | static inline void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1408 | { | |
1409 | int i = index + driver->name_base; | |
1410 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1411 | sprintf(p, "%s%c%x", | |
1412 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, | |
1413 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1414 | } | |
1415 | ||
1416 | static inline void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1417 | { | |
1418 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1419 | } | |
1420 | ||
1421 | /* | |
1422 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a | |
1423 | * failed open. The new code protects the open with a semaphore, so it's | |
1424 | * really quite straightforward. The semaphore locking can probably be | |
1425 | * relaxed for the (most common) case of reopening a tty. | |
1426 | */ | |
1427 | static int init_dev(struct tty_driver *driver, int idx, | |
1428 | struct tty_struct **ret_tty) | |
1429 | { | |
1430 | struct tty_struct *tty, *o_tty; | |
1431 | struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; | |
1432 | struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; | |
1433 | int retval=0; | |
1434 | ||
1435 | /* check whether we're reopening an existing tty */ | |
1436 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1437 | tty = devpts_get_tty(idx); | |
1438 | if (tty && driver->subtype == PTY_TYPE_MASTER) | |
1439 | tty = tty->link; | |
1440 | } else { | |
1441 | tty = driver->ttys[idx]; | |
1442 | } | |
1443 | if (tty) goto fast_track; | |
1444 | ||
1445 | /* | |
1446 | * First time open is complex, especially for PTY devices. | |
1447 | * This code guarantees that either everything succeeds and the | |
1448 | * TTY is ready for operation, or else the table slots are vacated | |
1449 | * and the allocated memory released. (Except that the termios | |
1450 | * and locked termios may be retained.) | |
1451 | */ | |
1452 | ||
1453 | if (!try_module_get(driver->owner)) { | |
1454 | retval = -ENODEV; | |
1455 | goto end_init; | |
1456 | } | |
1457 | ||
1458 | o_tty = NULL; | |
1459 | tp = o_tp = NULL; | |
1460 | ltp = o_ltp = NULL; | |
1461 | ||
1462 | tty = alloc_tty_struct(); | |
1463 | if(!tty) | |
1464 | goto fail_no_mem; | |
1465 | initialize_tty_struct(tty); | |
1466 | tty->driver = driver; | |
1467 | tty->index = idx; | |
1468 | tty_line_name(driver, idx, tty->name); | |
1469 | ||
1470 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1471 | tp_loc = &tty->termios; | |
1472 | ltp_loc = &tty->termios_locked; | |
1473 | } else { | |
1474 | tp_loc = &driver->termios[idx]; | |
1475 | ltp_loc = &driver->termios_locked[idx]; | |
1476 | } | |
1477 | ||
1478 | if (!*tp_loc) { | |
1479 | tp = (struct termios *) kmalloc(sizeof(struct termios), | |
1480 | GFP_KERNEL); | |
1481 | if (!tp) | |
1482 | goto free_mem_out; | |
1483 | *tp = driver->init_termios; | |
1484 | } | |
1485 | ||
1486 | if (!*ltp_loc) { | |
1487 | ltp = (struct termios *) kmalloc(sizeof(struct termios), | |
1488 | GFP_KERNEL); | |
1489 | if (!ltp) | |
1490 | goto free_mem_out; | |
1491 | memset(ltp, 0, sizeof(struct termios)); | |
1492 | } | |
1493 | ||
1494 | if (driver->type == TTY_DRIVER_TYPE_PTY) { | |
1495 | o_tty = alloc_tty_struct(); | |
1496 | if (!o_tty) | |
1497 | goto free_mem_out; | |
1498 | initialize_tty_struct(o_tty); | |
1499 | o_tty->driver = driver->other; | |
1500 | o_tty->index = idx; | |
1501 | tty_line_name(driver->other, idx, o_tty->name); | |
1502 | ||
1503 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { | |
1504 | o_tp_loc = &o_tty->termios; | |
1505 | o_ltp_loc = &o_tty->termios_locked; | |
1506 | } else { | |
1507 | o_tp_loc = &driver->other->termios[idx]; | |
1508 | o_ltp_loc = &driver->other->termios_locked[idx]; | |
1509 | } | |
1510 | ||
1511 | if (!*o_tp_loc) { | |
1512 | o_tp = (struct termios *) | |
1513 | kmalloc(sizeof(struct termios), GFP_KERNEL); | |
1514 | if (!o_tp) | |
1515 | goto free_mem_out; | |
1516 | *o_tp = driver->other->init_termios; | |
1517 | } | |
1518 | ||
1519 | if (!*o_ltp_loc) { | |
1520 | o_ltp = (struct termios *) | |
1521 | kmalloc(sizeof(struct termios), GFP_KERNEL); | |
1522 | if (!o_ltp) | |
1523 | goto free_mem_out; | |
1524 | memset(o_ltp, 0, sizeof(struct termios)); | |
1525 | } | |
1526 | ||
1527 | /* | |
1528 | * Everything allocated ... set up the o_tty structure. | |
1529 | */ | |
1530 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1531 | driver->other->ttys[idx] = o_tty; | |
1532 | } | |
1533 | if (!*o_tp_loc) | |
1534 | *o_tp_loc = o_tp; | |
1535 | if (!*o_ltp_loc) | |
1536 | *o_ltp_loc = o_ltp; | |
1537 | o_tty->termios = *o_tp_loc; | |
1538 | o_tty->termios_locked = *o_ltp_loc; | |
1539 | driver->other->refcount++; | |
1540 | if (driver->subtype == PTY_TYPE_MASTER) | |
1541 | o_tty->count++; | |
1542 | ||
1543 | /* Establish the links in both directions */ | |
1544 | tty->link = o_tty; | |
1545 | o_tty->link = tty; | |
1546 | } | |
1547 | ||
1548 | /* | |
1549 | * All structures have been allocated, so now we install them. | |
1550 | * Failures after this point use release_mem to clean up, so | |
1551 | * there's no need to null out the local pointers. | |
1552 | */ | |
1553 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1554 | driver->ttys[idx] = tty; | |
1555 | } | |
1556 | ||
1557 | if (!*tp_loc) | |
1558 | *tp_loc = tp; | |
1559 | if (!*ltp_loc) | |
1560 | *ltp_loc = ltp; | |
1561 | tty->termios = *tp_loc; | |
1562 | tty->termios_locked = *ltp_loc; | |
1563 | driver->refcount++; | |
1564 | tty->count++; | |
1565 | ||
1566 | /* | |
1567 | * Structures all installed ... call the ldisc open routines. | |
1568 | * If we fail here just call release_mem to clean up. No need | |
1569 | * to decrement the use counts, as release_mem doesn't care. | |
1570 | */ | |
1571 | ||
1572 | if (tty->ldisc.open) { | |
1573 | retval = (tty->ldisc.open)(tty); | |
1574 | if (retval) | |
1575 | goto release_mem_out; | |
1576 | } | |
1577 | if (o_tty && o_tty->ldisc.open) { | |
1578 | retval = (o_tty->ldisc.open)(o_tty); | |
1579 | if (retval) { | |
1580 | if (tty->ldisc.close) | |
1581 | (tty->ldisc.close)(tty); | |
1582 | goto release_mem_out; | |
1583 | } | |
1584 | tty_ldisc_enable(o_tty); | |
1585 | } | |
1586 | tty_ldisc_enable(tty); | |
1587 | goto success; | |
1588 | ||
1589 | /* | |
1590 | * This fast open can be used if the tty is already open. | |
1591 | * No memory is allocated, and the only failures are from | |
1592 | * attempting to open a closing tty or attempting multiple | |
1593 | * opens on a pty master. | |
1594 | */ | |
1595 | fast_track: | |
1596 | if (test_bit(TTY_CLOSING, &tty->flags)) { | |
1597 | retval = -EIO; | |
1598 | goto end_init; | |
1599 | } | |
1600 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1601 | driver->subtype == PTY_TYPE_MASTER) { | |
1602 | /* | |
1603 | * special case for PTY masters: only one open permitted, | |
1604 | * and the slave side open count is incremented as well. | |
1605 | */ | |
1606 | if (tty->count) { | |
1607 | retval = -EIO; | |
1608 | goto end_init; | |
1609 | } | |
1610 | tty->link->count++; | |
1611 | } | |
1612 | tty->count++; | |
1613 | tty->driver = driver; /* N.B. why do this every time?? */ | |
1614 | ||
1615 | /* FIXME */ | |
1616 | if(!test_bit(TTY_LDISC, &tty->flags)) | |
1617 | printk(KERN_ERR "init_dev but no ldisc\n"); | |
1618 | success: | |
1619 | *ret_tty = tty; | |
1620 | ||
1621 | /* All paths come through here to release the semaphore */ | |
1622 | end_init: | |
1623 | return retval; | |
1624 | ||
1625 | /* Release locally allocated memory ... nothing placed in slots */ | |
1626 | free_mem_out: | |
735d5661 | 1627 | kfree(o_tp); |
1da177e4 LT |
1628 | if (o_tty) |
1629 | free_tty_struct(o_tty); | |
735d5661 JJ |
1630 | kfree(ltp); |
1631 | kfree(tp); | |
1da177e4 LT |
1632 | free_tty_struct(tty); |
1633 | ||
1634 | fail_no_mem: | |
1635 | module_put(driver->owner); | |
1636 | retval = -ENOMEM; | |
1637 | goto end_init; | |
1638 | ||
1639 | /* call the tty release_mem routine to clean out this slot */ | |
1640 | release_mem_out: | |
1641 | printk(KERN_INFO "init_dev: ldisc open failed, " | |
1642 | "clearing slot %d\n", idx); | |
1643 | release_mem(tty, idx); | |
1644 | goto end_init; | |
1645 | } | |
1646 | ||
1647 | /* | |
1648 | * Releases memory associated with a tty structure, and clears out the | |
1649 | * driver table slots. | |
1650 | */ | |
1651 | static void release_mem(struct tty_struct *tty, int idx) | |
1652 | { | |
1653 | struct tty_struct *o_tty; | |
1654 | struct termios *tp; | |
1655 | int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; | |
1656 | ||
1657 | if ((o_tty = tty->link) != NULL) { | |
1658 | if (!devpts) | |
1659 | o_tty->driver->ttys[idx] = NULL; | |
1660 | if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1661 | tp = o_tty->termios; | |
1662 | if (!devpts) | |
1663 | o_tty->driver->termios[idx] = NULL; | |
1664 | kfree(tp); | |
1665 | ||
1666 | tp = o_tty->termios_locked; | |
1667 | if (!devpts) | |
1668 | o_tty->driver->termios_locked[idx] = NULL; | |
1669 | kfree(tp); | |
1670 | } | |
1671 | o_tty->magic = 0; | |
1672 | o_tty->driver->refcount--; | |
1673 | file_list_lock(); | |
1674 | list_del_init(&o_tty->tty_files); | |
1675 | file_list_unlock(); | |
1676 | free_tty_struct(o_tty); | |
1677 | } | |
1678 | ||
1679 | if (!devpts) | |
1680 | tty->driver->ttys[idx] = NULL; | |
1681 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1682 | tp = tty->termios; | |
1683 | if (!devpts) | |
1684 | tty->driver->termios[idx] = NULL; | |
1685 | kfree(tp); | |
1686 | ||
1687 | tp = tty->termios_locked; | |
1688 | if (!devpts) | |
1689 | tty->driver->termios_locked[idx] = NULL; | |
1690 | kfree(tp); | |
1691 | } | |
1692 | ||
1693 | tty->magic = 0; | |
1694 | tty->driver->refcount--; | |
1695 | file_list_lock(); | |
1696 | list_del_init(&tty->tty_files); | |
1697 | file_list_unlock(); | |
1698 | module_put(tty->driver->owner); | |
1699 | free_tty_struct(tty); | |
1700 | } | |
1701 | ||
1702 | /* | |
1703 | * Even releasing the tty structures is a tricky business.. We have | |
1704 | * to be very careful that the structures are all released at the | |
1705 | * same time, as interrupts might otherwise get the wrong pointers. | |
1706 | * | |
1707 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1708 | * lead to double frees or releasing memory still in use. | |
1709 | */ | |
1710 | static void release_dev(struct file * filp) | |
1711 | { | |
1712 | struct tty_struct *tty, *o_tty; | |
1713 | int pty_master, tty_closing, o_tty_closing, do_sleep; | |
1714 | int devpts_master, devpts; | |
1715 | int idx; | |
1716 | char buf[64]; | |
1717 | unsigned long flags; | |
1718 | ||
1719 | tty = (struct tty_struct *)filp->private_data; | |
1720 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev")) | |
1721 | return; | |
1722 | ||
1723 | check_tty_count(tty, "release_dev"); | |
1724 | ||
1725 | tty_fasync(-1, filp, 0); | |
1726 | ||
1727 | idx = tty->index; | |
1728 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1729 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1730 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
1731 | devpts_master = pty_master && devpts; | |
1732 | o_tty = tty->link; | |
1733 | ||
1734 | #ifdef TTY_PARANOIA_CHECK | |
1735 | if (idx < 0 || idx >= tty->driver->num) { | |
1736 | printk(KERN_DEBUG "release_dev: bad idx when trying to " | |
1737 | "free (%s)\n", tty->name); | |
1738 | return; | |
1739 | } | |
1740 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1741 | if (tty != tty->driver->ttys[idx]) { | |
1742 | printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " | |
1743 | "for (%s)\n", idx, tty->name); | |
1744 | return; | |
1745 | } | |
1746 | if (tty->termios != tty->driver->termios[idx]) { | |
1747 | printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " | |
1748 | "for (%s)\n", | |
1749 | idx, tty->name); | |
1750 | return; | |
1751 | } | |
1752 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { | |
1753 | printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " | |
1754 | "termios_locked for (%s)\n", | |
1755 | idx, tty->name); | |
1756 | return; | |
1757 | } | |
1758 | } | |
1759 | #endif | |
1760 | ||
1761 | #ifdef TTY_DEBUG_HANGUP | |
1762 | printk(KERN_DEBUG "release_dev of %s (tty count=%d)...", | |
1763 | tty_name(tty, buf), tty->count); | |
1764 | #endif | |
1765 | ||
1766 | #ifdef TTY_PARANOIA_CHECK | |
1767 | if (tty->driver->other && | |
1768 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
1769 | if (o_tty != tty->driver->other->ttys[idx]) { | |
1770 | printk(KERN_DEBUG "release_dev: other->table[%d] " | |
1771 | "not o_tty for (%s)\n", | |
1772 | idx, tty->name); | |
1773 | return; | |
1774 | } | |
1775 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
1776 | printk(KERN_DEBUG "release_dev: other->termios[%d] " | |
1777 | "not o_termios for (%s)\n", | |
1778 | idx, tty->name); | |
1779 | return; | |
1780 | } | |
1781 | if (o_tty->termios_locked != | |
1782 | tty->driver->other->termios_locked[idx]) { | |
1783 | printk(KERN_DEBUG "release_dev: other->termios_locked[" | |
1784 | "%d] not o_termios_locked for (%s)\n", | |
1785 | idx, tty->name); | |
1786 | return; | |
1787 | } | |
1788 | if (o_tty->link != tty) { | |
1789 | printk(KERN_DEBUG "release_dev: bad pty pointers\n"); | |
1790 | return; | |
1791 | } | |
1792 | } | |
1793 | #endif | |
1794 | if (tty->driver->close) | |
1795 | tty->driver->close(tty, filp); | |
1796 | ||
1797 | /* | |
1798 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1799 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1800 | * wait queues and kick everyone out _before_ actually starting to | |
1801 | * close. This ensures that we won't block while releasing the tty | |
1802 | * structure. | |
1803 | * | |
1804 | * The test for the o_tty closing is necessary, since the master and | |
1805 | * slave sides may close in any order. If the slave side closes out | |
1806 | * first, its count will be one, since the master side holds an open. | |
1807 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1808 | * so we do it now. | |
1809 | * | |
1810 | * Note that it's possible for the tty to be opened again while we're | |
1811 | * flushing out waiters. By recalculating the closing flags before | |
1812 | * each iteration we avoid any problems. | |
1813 | */ | |
1814 | while (1) { | |
1815 | /* Guard against races with tty->count changes elsewhere and | |
1816 | opens on /dev/tty */ | |
1817 | ||
1818 | down(&tty_sem); | |
1819 | tty_closing = tty->count <= 1; | |
1820 | o_tty_closing = o_tty && | |
1821 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1822 | up(&tty_sem); | |
1823 | do_sleep = 0; | |
1824 | ||
1825 | if (tty_closing) { | |
1826 | if (waitqueue_active(&tty->read_wait)) { | |
1827 | wake_up(&tty->read_wait); | |
1828 | do_sleep++; | |
1829 | } | |
1830 | if (waitqueue_active(&tty->write_wait)) { | |
1831 | wake_up(&tty->write_wait); | |
1832 | do_sleep++; | |
1833 | } | |
1834 | } | |
1835 | if (o_tty_closing) { | |
1836 | if (waitqueue_active(&o_tty->read_wait)) { | |
1837 | wake_up(&o_tty->read_wait); | |
1838 | do_sleep++; | |
1839 | } | |
1840 | if (waitqueue_active(&o_tty->write_wait)) { | |
1841 | wake_up(&o_tty->write_wait); | |
1842 | do_sleep++; | |
1843 | } | |
1844 | } | |
1845 | if (!do_sleep) | |
1846 | break; | |
1847 | ||
1848 | printk(KERN_WARNING "release_dev: %s: read/write wait queue " | |
1849 | "active!\n", tty_name(tty, buf)); | |
1850 | schedule(); | |
1851 | } | |
1852 | ||
1853 | /* | |
1854 | * The closing flags are now consistent with the open counts on | |
1855 | * both sides, and we've completed the last operation that could | |
1856 | * block, so it's safe to proceed with closing. | |
1857 | */ | |
1858 | ||
1859 | down(&tty_sem); | |
1860 | if (pty_master) { | |
1861 | if (--o_tty->count < 0) { | |
1862 | printk(KERN_WARNING "release_dev: bad pty slave count " | |
1863 | "(%d) for %s\n", | |
1864 | o_tty->count, tty_name(o_tty, buf)); | |
1865 | o_tty->count = 0; | |
1866 | } | |
1867 | } | |
1868 | if (--tty->count < 0) { | |
1869 | printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n", | |
1870 | tty->count, tty_name(tty, buf)); | |
1871 | tty->count = 0; | |
1872 | } | |
1873 | up(&tty_sem); | |
1874 | ||
1875 | /* | |
1876 | * We've decremented tty->count, so we need to remove this file | |
1877 | * descriptor off the tty->tty_files list; this serves two | |
1878 | * purposes: | |
1879 | * - check_tty_count sees the correct number of file descriptors | |
1880 | * associated with this tty. | |
1881 | * - do_tty_hangup no longer sees this file descriptor as | |
1882 | * something that needs to be handled for hangups. | |
1883 | */ | |
1884 | file_kill(filp); | |
1885 | filp->private_data = NULL; | |
1886 | ||
1887 | /* | |
1888 | * Perform some housekeeping before deciding whether to return. | |
1889 | * | |
1890 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1891 | * case of a pty we may have to wait around for the other side | |
1892 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1893 | */ | |
1894 | if(tty_closing) | |
1895 | set_bit(TTY_CLOSING, &tty->flags); | |
1896 | if(o_tty_closing) | |
1897 | set_bit(TTY_CLOSING, &o_tty->flags); | |
1898 | ||
1899 | /* | |
1900 | * If _either_ side is closing, make sure there aren't any | |
1901 | * processes that still think tty or o_tty is their controlling | |
1902 | * tty. | |
1903 | */ | |
1904 | if (tty_closing || o_tty_closing) { | |
1905 | struct task_struct *p; | |
1906 | ||
1907 | read_lock(&tasklist_lock); | |
1908 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { | |
1909 | p->signal->tty = NULL; | |
1910 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); | |
1911 | if (o_tty) | |
1912 | do_each_task_pid(o_tty->session, PIDTYPE_SID, p) { | |
1913 | p->signal->tty = NULL; | |
1914 | } while_each_task_pid(o_tty->session, PIDTYPE_SID, p); | |
1915 | read_unlock(&tasklist_lock); | |
1916 | } | |
1917 | ||
1918 | /* check whether both sides are closing ... */ | |
1919 | if (!tty_closing || (o_tty && !o_tty_closing)) | |
1920 | return; | |
1921 | ||
1922 | #ifdef TTY_DEBUG_HANGUP | |
1923 | printk(KERN_DEBUG "freeing tty structure..."); | |
1924 | #endif | |
1925 | /* | |
1926 | * Prevent flush_to_ldisc() from rescheduling the work for later. Then | |
1927 | * kill any delayed work. As this is the final close it does not | |
1928 | * race with the set_ldisc code path. | |
1929 | */ | |
1930 | clear_bit(TTY_LDISC, &tty->flags); | |
1931 | clear_bit(TTY_DONT_FLIP, &tty->flags); | |
33f0f88f | 1932 | cancel_delayed_work(&tty->buf.work); |
1da177e4 LT |
1933 | |
1934 | /* | |
33f0f88f | 1935 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
1da177e4 LT |
1936 | */ |
1937 | ||
1938 | flush_scheduled_work(); | |
1939 | ||
1940 | /* | |
1941 | * Wait for any short term users (we know they are just driver | |
1942 | * side waiters as the file is closing so user count on the file | |
1943 | * side is zero. | |
1944 | */ | |
1945 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
1946 | while(tty->ldisc.refcount) | |
1947 | { | |
1948 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
1949 | wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0); | |
1950 | spin_lock_irqsave(&tty_ldisc_lock, flags); | |
1951 | } | |
1952 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); | |
1953 | /* | |
1954 | * Shutdown the current line discipline, and reset it to N_TTY. | |
1955 | * N.B. why reset ldisc when we're releasing the memory?? | |
1956 | * | |
1957 | * FIXME: this MUST get fixed for the new reflocking | |
1958 | */ | |
1959 | if (tty->ldisc.close) | |
1960 | (tty->ldisc.close)(tty); | |
1961 | tty_ldisc_put(tty->ldisc.num); | |
1962 | ||
1963 | /* | |
1964 | * Switch the line discipline back | |
1965 | */ | |
1966 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); | |
1967 | tty_set_termios_ldisc(tty,N_TTY); | |
1968 | if (o_tty) { | |
1969 | /* FIXME: could o_tty be in setldisc here ? */ | |
1970 | clear_bit(TTY_LDISC, &o_tty->flags); | |
1971 | if (o_tty->ldisc.close) | |
1972 | (o_tty->ldisc.close)(o_tty); | |
1973 | tty_ldisc_put(o_tty->ldisc.num); | |
1974 | tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY)); | |
1975 | tty_set_termios_ldisc(o_tty,N_TTY); | |
1976 | } | |
1977 | /* | |
1978 | * The release_mem function takes care of the details of clearing | |
1979 | * the slots and preserving the termios structure. | |
1980 | */ | |
1981 | release_mem(tty, idx); | |
1982 | ||
1983 | #ifdef CONFIG_UNIX98_PTYS | |
1984 | /* Make this pty number available for reallocation */ | |
1985 | if (devpts) { | |
1986 | down(&allocated_ptys_lock); | |
1987 | idr_remove(&allocated_ptys, idx); | |
1988 | up(&allocated_ptys_lock); | |
1989 | } | |
1990 | #endif | |
1991 | ||
1992 | } | |
1993 | ||
1994 | /* | |
1995 | * tty_open and tty_release keep up the tty count that contains the | |
1996 | * number of opens done on a tty. We cannot use the inode-count, as | |
1997 | * different inodes might point to the same tty. | |
1998 | * | |
1999 | * Open-counting is needed for pty masters, as well as for keeping | |
2000 | * track of serial lines: DTR is dropped when the last close happens. | |
2001 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
2002 | * | |
2003 | * The termios state of a pty is reset on first open so that | |
2004 | * settings don't persist across reuse. | |
2005 | */ | |
2006 | static int tty_open(struct inode * inode, struct file * filp) | |
2007 | { | |
2008 | struct tty_struct *tty; | |
2009 | int noctty, retval; | |
2010 | struct tty_driver *driver; | |
2011 | int index; | |
2012 | dev_t device = inode->i_rdev; | |
2013 | unsigned short saved_flags = filp->f_flags; | |
2014 | ||
2015 | nonseekable_open(inode, filp); | |
2016 | ||
2017 | retry_open: | |
2018 | noctty = filp->f_flags & O_NOCTTY; | |
2019 | index = -1; | |
2020 | retval = 0; | |
2021 | ||
2022 | down(&tty_sem); | |
2023 | ||
2024 | if (device == MKDEV(TTYAUX_MAJOR,0)) { | |
2025 | if (!current->signal->tty) { | |
2026 | up(&tty_sem); | |
2027 | return -ENXIO; | |
2028 | } | |
2029 | driver = current->signal->tty->driver; | |
2030 | index = current->signal->tty->index; | |
2031 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
2032 | /* noctty = 1; */ | |
2033 | goto got_driver; | |
2034 | } | |
2035 | #ifdef CONFIG_VT | |
2036 | if (device == MKDEV(TTY_MAJOR,0)) { | |
2037 | extern struct tty_driver *console_driver; | |
2038 | driver = console_driver; | |
2039 | index = fg_console; | |
2040 | noctty = 1; | |
2041 | goto got_driver; | |
2042 | } | |
2043 | #endif | |
2044 | if (device == MKDEV(TTYAUX_MAJOR,1)) { | |
2045 | driver = console_device(&index); | |
2046 | if (driver) { | |
2047 | /* Don't let /dev/console block */ | |
2048 | filp->f_flags |= O_NONBLOCK; | |
2049 | noctty = 1; | |
2050 | goto got_driver; | |
2051 | } | |
2052 | up(&tty_sem); | |
2053 | return -ENODEV; | |
2054 | } | |
2055 | ||
2056 | driver = get_tty_driver(device, &index); | |
2057 | if (!driver) { | |
2058 | up(&tty_sem); | |
2059 | return -ENODEV; | |
2060 | } | |
2061 | got_driver: | |
2062 | retval = init_dev(driver, index, &tty); | |
2063 | up(&tty_sem); | |
2064 | if (retval) | |
2065 | return retval; | |
2066 | ||
2067 | filp->private_data = tty; | |
2068 | file_move(filp, &tty->tty_files); | |
2069 | check_tty_count(tty, "tty_open"); | |
2070 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2071 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2072 | noctty = 1; | |
2073 | #ifdef TTY_DEBUG_HANGUP | |
2074 | printk(KERN_DEBUG "opening %s...", tty->name); | |
2075 | #endif | |
2076 | if (!retval) { | |
2077 | if (tty->driver->open) | |
2078 | retval = tty->driver->open(tty, filp); | |
2079 | else | |
2080 | retval = -ENODEV; | |
2081 | } | |
2082 | filp->f_flags = saved_flags; | |
2083 | ||
2084 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) | |
2085 | retval = -EBUSY; | |
2086 | ||
2087 | if (retval) { | |
2088 | #ifdef TTY_DEBUG_HANGUP | |
2089 | printk(KERN_DEBUG "error %d in opening %s...", retval, | |
2090 | tty->name); | |
2091 | #endif | |
2092 | release_dev(filp); | |
2093 | if (retval != -ERESTARTSYS) | |
2094 | return retval; | |
2095 | if (signal_pending(current)) | |
2096 | return retval; | |
2097 | schedule(); | |
2098 | /* | |
2099 | * Need to reset f_op in case a hangup happened. | |
2100 | */ | |
2101 | if (filp->f_op == &hung_up_tty_fops) | |
2102 | filp->f_op = &tty_fops; | |
2103 | goto retry_open; | |
2104 | } | |
2105 | if (!noctty && | |
2106 | current->signal->leader && | |
2107 | !current->signal->tty && | |
2108 | tty->session == 0) { | |
2109 | task_lock(current); | |
2110 | current->signal->tty = tty; | |
2111 | task_unlock(current); | |
2112 | current->signal->tty_old_pgrp = 0; | |
2113 | tty->session = current->signal->session; | |
2114 | tty->pgrp = process_group(current); | |
2115 | } | |
2116 | return 0; | |
2117 | } | |
2118 | ||
2119 | #ifdef CONFIG_UNIX98_PTYS | |
2120 | static int ptmx_open(struct inode * inode, struct file * filp) | |
2121 | { | |
2122 | struct tty_struct *tty; | |
2123 | int retval; | |
2124 | int index; | |
2125 | int idr_ret; | |
2126 | ||
2127 | nonseekable_open(inode, filp); | |
2128 | ||
2129 | /* find a device that is not in use. */ | |
2130 | down(&allocated_ptys_lock); | |
2131 | if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { | |
2132 | up(&allocated_ptys_lock); | |
2133 | return -ENOMEM; | |
2134 | } | |
2135 | idr_ret = idr_get_new(&allocated_ptys, NULL, &index); | |
2136 | if (idr_ret < 0) { | |
2137 | up(&allocated_ptys_lock); | |
2138 | if (idr_ret == -EAGAIN) | |
2139 | return -ENOMEM; | |
2140 | return -EIO; | |
2141 | } | |
2142 | if (index >= pty_limit) { | |
2143 | idr_remove(&allocated_ptys, index); | |
2144 | up(&allocated_ptys_lock); | |
2145 | return -EIO; | |
2146 | } | |
2147 | up(&allocated_ptys_lock); | |
2148 | ||
2149 | down(&tty_sem); | |
2150 | retval = init_dev(ptm_driver, index, &tty); | |
2151 | up(&tty_sem); | |
2152 | ||
2153 | if (retval) | |
2154 | goto out; | |
2155 | ||
2156 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
2157 | filp->private_data = tty; | |
2158 | file_move(filp, &tty->tty_files); | |
2159 | ||
2160 | retval = -ENOMEM; | |
2161 | if (devpts_pty_new(tty->link)) | |
2162 | goto out1; | |
2163 | ||
2164 | check_tty_count(tty, "tty_open"); | |
2165 | retval = ptm_driver->open(tty, filp); | |
2166 | if (!retval) | |
2167 | return 0; | |
2168 | out1: | |
2169 | release_dev(filp); | |
2170 | out: | |
2171 | down(&allocated_ptys_lock); | |
2172 | idr_remove(&allocated_ptys, index); | |
2173 | up(&allocated_ptys_lock); | |
2174 | return retval; | |
2175 | } | |
2176 | #endif | |
2177 | ||
2178 | static int tty_release(struct inode * inode, struct file * filp) | |
2179 | { | |
2180 | lock_kernel(); | |
2181 | release_dev(filp); | |
2182 | unlock_kernel(); | |
2183 | return 0; | |
2184 | } | |
2185 | ||
2186 | /* No kernel lock held - fine */ | |
2187 | static unsigned int tty_poll(struct file * filp, poll_table * wait) | |
2188 | { | |
2189 | struct tty_struct * tty; | |
2190 | struct tty_ldisc *ld; | |
2191 | int ret = 0; | |
2192 | ||
2193 | tty = (struct tty_struct *)filp->private_data; | |
2194 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll")) | |
2195 | return 0; | |
2196 | ||
2197 | ld = tty_ldisc_ref_wait(tty); | |
2198 | if (ld->poll) | |
2199 | ret = (ld->poll)(tty, filp, wait); | |
2200 | tty_ldisc_deref(ld); | |
2201 | return ret; | |
2202 | } | |
2203 | ||
2204 | static int tty_fasync(int fd, struct file * filp, int on) | |
2205 | { | |
2206 | struct tty_struct * tty; | |
2207 | int retval; | |
2208 | ||
2209 | tty = (struct tty_struct *)filp->private_data; | |
2210 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync")) | |
2211 | return 0; | |
2212 | ||
2213 | retval = fasync_helper(fd, filp, on, &tty->fasync); | |
2214 | if (retval <= 0) | |
2215 | return retval; | |
2216 | ||
2217 | if (on) { | |
2218 | if (!waitqueue_active(&tty->read_wait)) | |
2219 | tty->minimum_to_wake = 1; | |
2220 | retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0); | |
2221 | if (retval) | |
2222 | return retval; | |
2223 | } else { | |
2224 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2225 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2226 | } | |
2227 | return 0; | |
2228 | } | |
2229 | ||
2230 | static int tiocsti(struct tty_struct *tty, char __user *p) | |
2231 | { | |
2232 | char ch, mbz = 0; | |
2233 | struct tty_ldisc *ld; | |
2234 | ||
2235 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) | |
2236 | return -EPERM; | |
2237 | if (get_user(ch, p)) | |
2238 | return -EFAULT; | |
2239 | ld = tty_ldisc_ref_wait(tty); | |
2240 | ld->receive_buf(tty, &ch, &mbz, 1); | |
2241 | tty_ldisc_deref(ld); | |
2242 | return 0; | |
2243 | } | |
2244 | ||
2245 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) | |
2246 | { | |
2247 | if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) | |
2248 | return -EFAULT; | |
2249 | return 0; | |
2250 | } | |
2251 | ||
2252 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, | |
2253 | struct winsize __user * arg) | |
2254 | { | |
2255 | struct winsize tmp_ws; | |
2256 | ||
2257 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2258 | return -EFAULT; | |
2259 | if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) | |
2260 | return 0; | |
2261 | #ifdef CONFIG_VT | |
2262 | if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { | |
2263 | int rc; | |
2264 | ||
2265 | acquire_console_sem(); | |
2266 | rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row); | |
2267 | release_console_sem(); | |
2268 | if (rc) | |
2269 | return -ENXIO; | |
2270 | } | |
2271 | #endif | |
2272 | if (tty->pgrp > 0) | |
2273 | kill_pg(tty->pgrp, SIGWINCH, 1); | |
2274 | if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) | |
2275 | kill_pg(real_tty->pgrp, SIGWINCH, 1); | |
2276 | tty->winsize = tmp_ws; | |
2277 | real_tty->winsize = tmp_ws; | |
2278 | return 0; | |
2279 | } | |
2280 | ||
2281 | static int tioccons(struct file *file) | |
2282 | { | |
2283 | if (!capable(CAP_SYS_ADMIN)) | |
2284 | return -EPERM; | |
2285 | if (file->f_op->write == redirected_tty_write) { | |
2286 | struct file *f; | |
2287 | spin_lock(&redirect_lock); | |
2288 | f = redirect; | |
2289 | redirect = NULL; | |
2290 | spin_unlock(&redirect_lock); | |
2291 | if (f) | |
2292 | fput(f); | |
2293 | return 0; | |
2294 | } | |
2295 | spin_lock(&redirect_lock); | |
2296 | if (redirect) { | |
2297 | spin_unlock(&redirect_lock); | |
2298 | return -EBUSY; | |
2299 | } | |
2300 | get_file(file); | |
2301 | redirect = file; | |
2302 | spin_unlock(&redirect_lock); | |
2303 | return 0; | |
2304 | } | |
2305 | ||
2306 | ||
2307 | static int fionbio(struct file *file, int __user *p) | |
2308 | { | |
2309 | int nonblock; | |
2310 | ||
2311 | if (get_user(nonblock, p)) | |
2312 | return -EFAULT; | |
2313 | ||
2314 | if (nonblock) | |
2315 | file->f_flags |= O_NONBLOCK; | |
2316 | else | |
2317 | file->f_flags &= ~O_NONBLOCK; | |
2318 | return 0; | |
2319 | } | |
2320 | ||
2321 | static int tiocsctty(struct tty_struct *tty, int arg) | |
2322 | { | |
2323 | task_t *p; | |
2324 | ||
2325 | if (current->signal->leader && | |
2326 | (current->signal->session == tty->session)) | |
2327 | return 0; | |
2328 | /* | |
2329 | * The process must be a session leader and | |
2330 | * not have a controlling tty already. | |
2331 | */ | |
2332 | if (!current->signal->leader || current->signal->tty) | |
2333 | return -EPERM; | |
2334 | if (tty->session > 0) { | |
2335 | /* | |
2336 | * This tty is already the controlling | |
2337 | * tty for another session group! | |
2338 | */ | |
2339 | if ((arg == 1) && capable(CAP_SYS_ADMIN)) { | |
2340 | /* | |
2341 | * Steal it away | |
2342 | */ | |
2343 | ||
2344 | read_lock(&tasklist_lock); | |
2345 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { | |
2346 | p->signal->tty = NULL; | |
2347 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); | |
2348 | read_unlock(&tasklist_lock); | |
2349 | } else | |
2350 | return -EPERM; | |
2351 | } | |
2352 | task_lock(current); | |
2353 | current->signal->tty = tty; | |
2354 | task_unlock(current); | |
2355 | current->signal->tty_old_pgrp = 0; | |
2356 | tty->session = current->signal->session; | |
2357 | tty->pgrp = process_group(current); | |
2358 | return 0; | |
2359 | } | |
2360 | ||
2361 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
2362 | { | |
2363 | /* | |
2364 | * (tty == real_tty) is a cheap way of | |
2365 | * testing if the tty is NOT a master pty. | |
2366 | */ | |
2367 | if (tty == real_tty && current->signal->tty != real_tty) | |
2368 | return -ENOTTY; | |
2369 | return put_user(real_tty->pgrp, p); | |
2370 | } | |
2371 | ||
2372 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
2373 | { | |
2374 | pid_t pgrp; | |
2375 | int retval = tty_check_change(real_tty); | |
2376 | ||
2377 | if (retval == -EIO) | |
2378 | return -ENOTTY; | |
2379 | if (retval) | |
2380 | return retval; | |
2381 | if (!current->signal->tty || | |
2382 | (current->signal->tty != real_tty) || | |
2383 | (real_tty->session != current->signal->session)) | |
2384 | return -ENOTTY; | |
2385 | if (get_user(pgrp, p)) | |
2386 | return -EFAULT; | |
2387 | if (pgrp < 0) | |
2388 | return -EINVAL; | |
2389 | if (session_of_pgrp(pgrp) != current->signal->session) | |
2390 | return -EPERM; | |
2391 | real_tty->pgrp = pgrp; | |
2392 | return 0; | |
2393 | } | |
2394 | ||
2395 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
2396 | { | |
2397 | /* | |
2398 | * (tty == real_tty) is a cheap way of | |
2399 | * testing if the tty is NOT a master pty. | |
2400 | */ | |
2401 | if (tty == real_tty && current->signal->tty != real_tty) | |
2402 | return -ENOTTY; | |
2403 | if (real_tty->session <= 0) | |
2404 | return -ENOTTY; | |
2405 | return put_user(real_tty->session, p); | |
2406 | } | |
2407 | ||
2408 | static int tiocsetd(struct tty_struct *tty, int __user *p) | |
2409 | { | |
2410 | int ldisc; | |
2411 | ||
2412 | if (get_user(ldisc, p)) | |
2413 | return -EFAULT; | |
2414 | return tty_set_ldisc(tty, ldisc); | |
2415 | } | |
2416 | ||
b20f3ae5 | 2417 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 LT |
2418 | { |
2419 | tty->driver->break_ctl(tty, -1); | |
2420 | if (!signal_pending(current)) { | |
b20f3ae5 | 2421 | msleep_interruptible(duration); |
1da177e4 LT |
2422 | } |
2423 | tty->driver->break_ctl(tty, 0); | |
2424 | if (signal_pending(current)) | |
2425 | return -EINTR; | |
2426 | return 0; | |
2427 | } | |
2428 | ||
2429 | static int | |
2430 | tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) | |
2431 | { | |
2432 | int retval = -EINVAL; | |
2433 | ||
2434 | if (tty->driver->tiocmget) { | |
2435 | retval = tty->driver->tiocmget(tty, file); | |
2436 | ||
2437 | if (retval >= 0) | |
2438 | retval = put_user(retval, p); | |
2439 | } | |
2440 | return retval; | |
2441 | } | |
2442 | ||
2443 | static int | |
2444 | tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, | |
2445 | unsigned __user *p) | |
2446 | { | |
2447 | int retval = -EINVAL; | |
2448 | ||
2449 | if (tty->driver->tiocmset) { | |
2450 | unsigned int set, clear, val; | |
2451 | ||
2452 | retval = get_user(val, p); | |
2453 | if (retval) | |
2454 | return retval; | |
2455 | ||
2456 | set = clear = 0; | |
2457 | switch (cmd) { | |
2458 | case TIOCMBIS: | |
2459 | set = val; | |
2460 | break; | |
2461 | case TIOCMBIC: | |
2462 | clear = val; | |
2463 | break; | |
2464 | case TIOCMSET: | |
2465 | set = val; | |
2466 | clear = ~val; | |
2467 | break; | |
2468 | } | |
2469 | ||
2470 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2471 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2472 | ||
2473 | retval = tty->driver->tiocmset(tty, file, set, clear); | |
2474 | } | |
2475 | return retval; | |
2476 | } | |
2477 | ||
2478 | /* | |
2479 | * Split this up, as gcc can choke on it otherwise.. | |
2480 | */ | |
2481 | int tty_ioctl(struct inode * inode, struct file * file, | |
2482 | unsigned int cmd, unsigned long arg) | |
2483 | { | |
2484 | struct tty_struct *tty, *real_tty; | |
2485 | void __user *p = (void __user *)arg; | |
2486 | int retval; | |
2487 | struct tty_ldisc *ld; | |
2488 | ||
2489 | tty = (struct tty_struct *)file->private_data; | |
2490 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2491 | return -EINVAL; | |
2492 | ||
2493 | real_tty = tty; | |
2494 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2495 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2496 | real_tty = tty->link; | |
2497 | ||
2498 | /* | |
2499 | * Break handling by driver | |
2500 | */ | |
2501 | if (!tty->driver->break_ctl) { | |
2502 | switch(cmd) { | |
2503 | case TIOCSBRK: | |
2504 | case TIOCCBRK: | |
2505 | if (tty->driver->ioctl) | |
2506 | return tty->driver->ioctl(tty, file, cmd, arg); | |
2507 | return -EINVAL; | |
2508 | ||
2509 | /* These two ioctl's always return success; even if */ | |
2510 | /* the driver doesn't support them. */ | |
2511 | case TCSBRK: | |
2512 | case TCSBRKP: | |
2513 | if (!tty->driver->ioctl) | |
2514 | return 0; | |
2515 | retval = tty->driver->ioctl(tty, file, cmd, arg); | |
2516 | if (retval == -ENOIOCTLCMD) | |
2517 | retval = 0; | |
2518 | return retval; | |
2519 | } | |
2520 | } | |
2521 | ||
2522 | /* | |
2523 | * Factor out some common prep work | |
2524 | */ | |
2525 | switch (cmd) { | |
2526 | case TIOCSETD: | |
2527 | case TIOCSBRK: | |
2528 | case TIOCCBRK: | |
2529 | case TCSBRK: | |
2530 | case TCSBRKP: | |
2531 | retval = tty_check_change(tty); | |
2532 | if (retval) | |
2533 | return retval; | |
2534 | if (cmd != TIOCCBRK) { | |
2535 | tty_wait_until_sent(tty, 0); | |
2536 | if (signal_pending(current)) | |
2537 | return -EINTR; | |
2538 | } | |
2539 | break; | |
2540 | } | |
2541 | ||
2542 | switch (cmd) { | |
2543 | case TIOCSTI: | |
2544 | return tiocsti(tty, p); | |
2545 | case TIOCGWINSZ: | |
2546 | return tiocgwinsz(tty, p); | |
2547 | case TIOCSWINSZ: | |
2548 | return tiocswinsz(tty, real_tty, p); | |
2549 | case TIOCCONS: | |
2550 | return real_tty!=tty ? -EINVAL : tioccons(file); | |
2551 | case FIONBIO: | |
2552 | return fionbio(file, p); | |
2553 | case TIOCEXCL: | |
2554 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2555 | return 0; | |
2556 | case TIOCNXCL: | |
2557 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2558 | return 0; | |
2559 | case TIOCNOTTY: | |
2560 | if (current->signal->tty != tty) | |
2561 | return -ENOTTY; | |
2562 | if (current->signal->leader) | |
2563 | disassociate_ctty(0); | |
2564 | task_lock(current); | |
2565 | current->signal->tty = NULL; | |
2566 | task_unlock(current); | |
2567 | return 0; | |
2568 | case TIOCSCTTY: | |
2569 | return tiocsctty(tty, arg); | |
2570 | case TIOCGPGRP: | |
2571 | return tiocgpgrp(tty, real_tty, p); | |
2572 | case TIOCSPGRP: | |
2573 | return tiocspgrp(tty, real_tty, p); | |
2574 | case TIOCGSID: | |
2575 | return tiocgsid(tty, real_tty, p); | |
2576 | case TIOCGETD: | |
2577 | /* FIXME: check this is ok */ | |
2578 | return put_user(tty->ldisc.num, (int __user *)p); | |
2579 | case TIOCSETD: | |
2580 | return tiocsetd(tty, p); | |
2581 | #ifdef CONFIG_VT | |
2582 | case TIOCLINUX: | |
2583 | return tioclinux(tty, arg); | |
2584 | #endif | |
2585 | /* | |
2586 | * Break handling | |
2587 | */ | |
2588 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
2589 | tty->driver->break_ctl(tty, -1); | |
2590 | return 0; | |
2591 | ||
2592 | case TIOCCBRK: /* Turn break off, unconditionally */ | |
2593 | tty->driver->break_ctl(tty, 0); | |
2594 | return 0; | |
2595 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2596 | /* | |
2597 | * XXX is the above comment correct, or the | |
2598 | * code below correct? Is this ioctl used at | |
2599 | * all by anyone? | |
2600 | */ | |
2601 | if (!arg) | |
b20f3ae5 | 2602 | return send_break(tty, 250); |
1da177e4 LT |
2603 | return 0; |
2604 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
b20f3ae5 | 2605 | return send_break(tty, arg ? arg*100 : 250); |
1da177e4 LT |
2606 | |
2607 | case TIOCMGET: | |
2608 | return tty_tiocmget(tty, file, p); | |
2609 | ||
2610 | case TIOCMSET: | |
2611 | case TIOCMBIC: | |
2612 | case TIOCMBIS: | |
2613 | return tty_tiocmset(tty, file, cmd, p); | |
2614 | } | |
2615 | if (tty->driver->ioctl) { | |
2616 | retval = (tty->driver->ioctl)(tty, file, cmd, arg); | |
2617 | if (retval != -ENOIOCTLCMD) | |
2618 | return retval; | |
2619 | } | |
2620 | ld = tty_ldisc_ref_wait(tty); | |
2621 | retval = -EINVAL; | |
2622 | if (ld->ioctl) { | |
2623 | retval = ld->ioctl(tty, file, cmd, arg); | |
2624 | if (retval == -ENOIOCTLCMD) | |
2625 | retval = -EINVAL; | |
2626 | } | |
2627 | tty_ldisc_deref(ld); | |
2628 | return retval; | |
2629 | } | |
2630 | ||
2631 | ||
2632 | /* | |
2633 | * This implements the "Secure Attention Key" --- the idea is to | |
2634 | * prevent trojan horses by killing all processes associated with this | |
2635 | * tty when the user hits the "Secure Attention Key". Required for | |
2636 | * super-paranoid applications --- see the Orange Book for more details. | |
2637 | * | |
2638 | * This code could be nicer; ideally it should send a HUP, wait a few | |
2639 | * seconds, then send a INT, and then a KILL signal. But you then | |
2640 | * have to coordinate with the init process, since all processes associated | |
2641 | * with the current tty must be dead before the new getty is allowed | |
2642 | * to spawn. | |
2643 | * | |
2644 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2645 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2646 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2647 | * | |
2648 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2649 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2650 | */ | |
2651 | static void __do_SAK(void *arg) | |
2652 | { | |
2653 | #ifdef TTY_SOFT_SAK | |
2654 | tty_hangup(tty); | |
2655 | #else | |
2656 | struct tty_struct *tty = arg; | |
2657 | struct task_struct *p; | |
2658 | int session; | |
2659 | int i; | |
2660 | struct file *filp; | |
2661 | struct tty_ldisc *disc; | |
badf1662 | 2662 | struct fdtable *fdt; |
1da177e4 LT |
2663 | |
2664 | if (!tty) | |
2665 | return; | |
2666 | session = tty->session; | |
2667 | ||
2668 | /* We don't want an ldisc switch during this */ | |
2669 | disc = tty_ldisc_ref(tty); | |
2670 | if (disc && disc->flush_buffer) | |
2671 | disc->flush_buffer(tty); | |
2672 | tty_ldisc_deref(disc); | |
2673 | ||
2674 | if (tty->driver->flush_buffer) | |
2675 | tty->driver->flush_buffer(tty); | |
2676 | ||
2677 | read_lock(&tasklist_lock); | |
2678 | do_each_task_pid(session, PIDTYPE_SID, p) { | |
2679 | if (p->signal->tty == tty || session > 0) { | |
2680 | printk(KERN_NOTICE "SAK: killed process %d" | |
2681 | " (%s): p->signal->session==tty->session\n", | |
2682 | p->pid, p->comm); | |
2683 | send_sig(SIGKILL, p, 1); | |
2684 | continue; | |
2685 | } | |
2686 | task_lock(p); | |
2687 | if (p->files) { | |
b835996f | 2688 | rcu_read_lock(); |
badf1662 DS |
2689 | fdt = files_fdtable(p->files); |
2690 | for (i=0; i < fdt->max_fds; i++) { | |
1da177e4 LT |
2691 | filp = fcheck_files(p->files, i); |
2692 | if (!filp) | |
2693 | continue; | |
2694 | if (filp->f_op->read == tty_read && | |
2695 | filp->private_data == tty) { | |
2696 | printk(KERN_NOTICE "SAK: killed process %d" | |
2697 | " (%s): fd#%d opened to the tty\n", | |
2698 | p->pid, p->comm, i); | |
2699 | send_sig(SIGKILL, p, 1); | |
2700 | break; | |
2701 | } | |
2702 | } | |
b835996f | 2703 | rcu_read_unlock(); |
1da177e4 LT |
2704 | } |
2705 | task_unlock(p); | |
2706 | } while_each_task_pid(session, PIDTYPE_SID, p); | |
2707 | read_unlock(&tasklist_lock); | |
2708 | #endif | |
2709 | } | |
2710 | ||
2711 | /* | |
2712 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2713 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2714 | * the values which we write to it will be identical to the values which it | |
2715 | * already has. --akpm | |
2716 | */ | |
2717 | void do_SAK(struct tty_struct *tty) | |
2718 | { | |
2719 | if (!tty) | |
2720 | return; | |
2721 | PREPARE_WORK(&tty->SAK_work, __do_SAK, tty); | |
2722 | schedule_work(&tty->SAK_work); | |
2723 | } | |
2724 | ||
2725 | EXPORT_SYMBOL(do_SAK); | |
2726 | ||
2727 | /* | |
2728 | * This routine is called out of the software interrupt to flush data | |
33f0f88f | 2729 | * from the buffer chain to the line discipline. |
1da177e4 LT |
2730 | */ |
2731 | ||
2732 | static void flush_to_ldisc(void *private_) | |
2733 | { | |
2734 | struct tty_struct *tty = (struct tty_struct *) private_; | |
1da177e4 LT |
2735 | unsigned long flags; |
2736 | struct tty_ldisc *disc; | |
33f0f88f | 2737 | struct tty_buffer *tbuf; |
1da177e4 LT |
2738 | |
2739 | disc = tty_ldisc_ref(tty); | |
2740 | if (disc == NULL) /* !TTY_LDISC */ | |
2741 | return; | |
2742 | ||
2743 | if (test_bit(TTY_DONT_FLIP, &tty->flags)) { | |
2744 | /* | |
2745 | * Do it after the next timer tick: | |
2746 | */ | |
33f0f88f | 2747 | schedule_delayed_work(&tty->buf.work, 1); |
1da177e4 LT |
2748 | goto out; |
2749 | } | |
2750 | spin_lock_irqsave(&tty->read_lock, flags); | |
33f0f88f AC |
2751 | while((tbuf = tty->buf.head) != NULL) { |
2752 | tty->buf.head = tbuf->next; | |
607f4e38 PF |
2753 | if (tty->buf.head == NULL) |
2754 | tty->buf.tail = NULL; | |
33f0f88f AC |
2755 | spin_unlock_irqrestore(&tty->read_lock, flags); |
2756 | /* printk("Process buffer %p for %d\n", tbuf, tbuf->used); */ | |
2757 | disc->receive_buf(tty, tbuf->char_buf_ptr, | |
2758 | tbuf->flag_buf_ptr, | |
2759 | tbuf->used); | |
2760 | spin_lock_irqsave(&tty->read_lock, flags); | |
2761 | tty_buffer_free(tty, tbuf); | |
2762 | } | |
1da177e4 | 2763 | spin_unlock_irqrestore(&tty->read_lock, flags); |
1da177e4 LT |
2764 | out: |
2765 | tty_ldisc_deref(disc); | |
2766 | } | |
2767 | ||
2768 | /* | |
2769 | * Routine which returns the baud rate of the tty | |
2770 | * | |
2771 | * Note that the baud_table needs to be kept in sync with the | |
2772 | * include/asm/termbits.h file. | |
2773 | */ | |
2774 | static int baud_table[] = { | |
2775 | 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, | |
2776 | 9600, 19200, 38400, 57600, 115200, 230400, 460800, | |
2777 | #ifdef __sparc__ | |
2778 | 76800, 153600, 307200, 614400, 921600 | |
2779 | #else | |
2780 | 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, | |
2781 | 2500000, 3000000, 3500000, 4000000 | |
2782 | #endif | |
2783 | }; | |
2784 | ||
2785 | static int n_baud_table = ARRAY_SIZE(baud_table); | |
2786 | ||
2787 | /** | |
2788 | * tty_termios_baud_rate | |
2789 | * @termios: termios structure | |
2790 | * | |
2791 | * Convert termios baud rate data into a speed. This should be called | |
2792 | * with the termios lock held if this termios is a terminal termios | |
2793 | * structure. May change the termios data. | |
2794 | */ | |
2795 | ||
2796 | int tty_termios_baud_rate(struct termios *termios) | |
2797 | { | |
2798 | unsigned int cbaud; | |
2799 | ||
2800 | cbaud = termios->c_cflag & CBAUD; | |
2801 | ||
2802 | if (cbaud & CBAUDEX) { | |
2803 | cbaud &= ~CBAUDEX; | |
2804 | ||
2805 | if (cbaud < 1 || cbaud + 15 > n_baud_table) | |
2806 | termios->c_cflag &= ~CBAUDEX; | |
2807 | else | |
2808 | cbaud += 15; | |
2809 | } | |
2810 | return baud_table[cbaud]; | |
2811 | } | |
2812 | ||
2813 | EXPORT_SYMBOL(tty_termios_baud_rate); | |
2814 | ||
2815 | /** | |
2816 | * tty_get_baud_rate - get tty bit rates | |
2817 | * @tty: tty to query | |
2818 | * | |
2819 | * Returns the baud rate as an integer for this terminal. The | |
2820 | * termios lock must be held by the caller and the terminal bit | |
2821 | * flags may be updated. | |
2822 | */ | |
2823 | ||
2824 | int tty_get_baud_rate(struct tty_struct *tty) | |
2825 | { | |
2826 | int baud = tty_termios_baud_rate(tty->termios); | |
2827 | ||
2828 | if (baud == 38400 && tty->alt_speed) { | |
2829 | if (!tty->warned) { | |
2830 | printk(KERN_WARNING "Use of setserial/setrocket to " | |
2831 | "set SPD_* flags is deprecated\n"); | |
2832 | tty->warned = 1; | |
2833 | } | |
2834 | baud = tty->alt_speed; | |
2835 | } | |
2836 | ||
2837 | return baud; | |
2838 | } | |
2839 | ||
2840 | EXPORT_SYMBOL(tty_get_baud_rate); | |
2841 | ||
2842 | /** | |
2843 | * tty_flip_buffer_push - terminal | |
2844 | * @tty: tty to push | |
2845 | * | |
2846 | * Queue a push of the terminal flip buffers to the line discipline. This | |
2847 | * function must not be called from IRQ context if tty->low_latency is set. | |
2848 | * | |
2849 | * In the event of the queue being busy for flipping the work will be | |
2850 | * held off and retried later. | |
2851 | */ | |
2852 | ||
2853 | void tty_flip_buffer_push(struct tty_struct *tty) | |
2854 | { | |
2855 | if (tty->low_latency) | |
2856 | flush_to_ldisc((void *) tty); | |
2857 | else | |
33f0f88f | 2858 | schedule_delayed_work(&tty->buf.work, 1); |
1da177e4 LT |
2859 | } |
2860 | ||
2861 | EXPORT_SYMBOL(tty_flip_buffer_push); | |
2862 | ||
33f0f88f | 2863 | |
1da177e4 LT |
2864 | /* |
2865 | * This subroutine initializes a tty structure. | |
2866 | */ | |
2867 | static void initialize_tty_struct(struct tty_struct *tty) | |
2868 | { | |
2869 | memset(tty, 0, sizeof(struct tty_struct)); | |
2870 | tty->magic = TTY_MAGIC; | |
2871 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); | |
2872 | tty->pgrp = -1; | |
2873 | tty->overrun_time = jiffies; | |
33f0f88f AC |
2874 | tty->buf.head = tty->buf.tail = NULL; |
2875 | tty_buffer_init(tty); | |
2876 | INIT_WORK(&tty->buf.work, flush_to_ldisc, tty); | |
2877 | init_MUTEX(&tty->buf.pty_sem); | |
1da177e4 LT |
2878 | init_MUTEX(&tty->termios_sem); |
2879 | init_waitqueue_head(&tty->write_wait); | |
2880 | init_waitqueue_head(&tty->read_wait); | |
2881 | INIT_WORK(&tty->hangup_work, do_tty_hangup, tty); | |
2882 | sema_init(&tty->atomic_read, 1); | |
2883 | sema_init(&tty->atomic_write, 1); | |
2884 | spin_lock_init(&tty->read_lock); | |
2885 | INIT_LIST_HEAD(&tty->tty_files); | |
2886 | INIT_WORK(&tty->SAK_work, NULL, NULL); | |
2887 | } | |
2888 | ||
2889 | /* | |
2890 | * The default put_char routine if the driver did not define one. | |
2891 | */ | |
2892 | static void tty_default_put_char(struct tty_struct *tty, unsigned char ch) | |
2893 | { | |
2894 | tty->driver->write(tty, &ch, 1); | |
2895 | } | |
2896 | ||
7fe845d1 | 2897 | static struct class *tty_class; |
1da177e4 LT |
2898 | |
2899 | /** | |
2900 | * tty_register_device - register a tty device | |
2901 | * @driver: the tty driver that describes the tty device | |
2902 | * @index: the index in the tty driver for this tty device | |
2903 | * @device: a struct device that is associated with this tty device. | |
2904 | * This field is optional, if there is no known struct device for this | |
2905 | * tty device it can be set to NULL safely. | |
2906 | * | |
2907 | * This call is required to be made to register an individual tty device if | |
2908 | * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that | |
2909 | * bit is not set, this function should not be called. | |
2910 | */ | |
2911 | void tty_register_device(struct tty_driver *driver, unsigned index, | |
2912 | struct device *device) | |
2913 | { | |
2914 | char name[64]; | |
2915 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
2916 | ||
2917 | if (index >= driver->num) { | |
2918 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
2919 | " (%d).\n", index); | |
2920 | return; | |
2921 | } | |
2922 | ||
2923 | devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR, | |
2924 | "%s%d", driver->devfs_name, index + driver->name_base); | |
2925 | ||
2926 | if (driver->type == TTY_DRIVER_TYPE_PTY) | |
2927 | pty_line_name(driver, index, name); | |
2928 | else | |
2929 | tty_line_name(driver, index, name); | |
53f46542 | 2930 | class_device_create(tty_class, NULL, dev, device, "%s", name); |
1da177e4 LT |
2931 | } |
2932 | ||
2933 | /** | |
2934 | * tty_unregister_device - unregister a tty device | |
2935 | * @driver: the tty driver that describes the tty device | |
2936 | * @index: the index in the tty driver for this tty device | |
2937 | * | |
2938 | * If a tty device is registered with a call to tty_register_device() then | |
2939 | * this function must be made when the tty device is gone. | |
2940 | */ | |
2941 | void tty_unregister_device(struct tty_driver *driver, unsigned index) | |
2942 | { | |
2943 | devfs_remove("%s%d", driver->devfs_name, index + driver->name_base); | |
7fe845d1 | 2944 | class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); |
1da177e4 LT |
2945 | } |
2946 | ||
2947 | EXPORT_SYMBOL(tty_register_device); | |
2948 | EXPORT_SYMBOL(tty_unregister_device); | |
2949 | ||
2950 | struct tty_driver *alloc_tty_driver(int lines) | |
2951 | { | |
2952 | struct tty_driver *driver; | |
2953 | ||
2954 | driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL); | |
2955 | if (driver) { | |
2956 | memset(driver, 0, sizeof(struct tty_driver)); | |
2957 | driver->magic = TTY_DRIVER_MAGIC; | |
2958 | driver->num = lines; | |
2959 | /* later we'll move allocation of tables here */ | |
2960 | } | |
2961 | return driver; | |
2962 | } | |
2963 | ||
2964 | void put_tty_driver(struct tty_driver *driver) | |
2965 | { | |
2966 | kfree(driver); | |
2967 | } | |
2968 | ||
2969 | void tty_set_operations(struct tty_driver *driver, struct tty_operations *op) | |
2970 | { | |
2971 | driver->open = op->open; | |
2972 | driver->close = op->close; | |
2973 | driver->write = op->write; | |
2974 | driver->put_char = op->put_char; | |
2975 | driver->flush_chars = op->flush_chars; | |
2976 | driver->write_room = op->write_room; | |
2977 | driver->chars_in_buffer = op->chars_in_buffer; | |
2978 | driver->ioctl = op->ioctl; | |
2979 | driver->set_termios = op->set_termios; | |
2980 | driver->throttle = op->throttle; | |
2981 | driver->unthrottle = op->unthrottle; | |
2982 | driver->stop = op->stop; | |
2983 | driver->start = op->start; | |
2984 | driver->hangup = op->hangup; | |
2985 | driver->break_ctl = op->break_ctl; | |
2986 | driver->flush_buffer = op->flush_buffer; | |
2987 | driver->set_ldisc = op->set_ldisc; | |
2988 | driver->wait_until_sent = op->wait_until_sent; | |
2989 | driver->send_xchar = op->send_xchar; | |
2990 | driver->read_proc = op->read_proc; | |
2991 | driver->write_proc = op->write_proc; | |
2992 | driver->tiocmget = op->tiocmget; | |
2993 | driver->tiocmset = op->tiocmset; | |
2994 | } | |
2995 | ||
2996 | ||
2997 | EXPORT_SYMBOL(alloc_tty_driver); | |
2998 | EXPORT_SYMBOL(put_tty_driver); | |
2999 | EXPORT_SYMBOL(tty_set_operations); | |
3000 | ||
3001 | /* | |
3002 | * Called by a tty driver to register itself. | |
3003 | */ | |
3004 | int tty_register_driver(struct tty_driver *driver) | |
3005 | { | |
3006 | int error; | |
3007 | int i; | |
3008 | dev_t dev; | |
3009 | void **p = NULL; | |
3010 | ||
3011 | if (driver->flags & TTY_DRIVER_INSTALLED) | |
3012 | return 0; | |
3013 | ||
3014 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3015 | p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); | |
3016 | if (!p) | |
3017 | return -ENOMEM; | |
3018 | memset(p, 0, driver->num * 3 * sizeof(void *)); | |
3019 | } | |
3020 | ||
3021 | if (!driver->major) { | |
3022 | error = alloc_chrdev_region(&dev, driver->minor_start, driver->num, | |
3023 | (char*)driver->name); | |
3024 | if (!error) { | |
3025 | driver->major = MAJOR(dev); | |
3026 | driver->minor_start = MINOR(dev); | |
3027 | } | |
3028 | } else { | |
3029 | dev = MKDEV(driver->major, driver->minor_start); | |
3030 | error = register_chrdev_region(dev, driver->num, | |
3031 | (char*)driver->name); | |
3032 | } | |
3033 | if (error < 0) { | |
3034 | kfree(p); | |
3035 | return error; | |
3036 | } | |
3037 | ||
3038 | if (p) { | |
3039 | driver->ttys = (struct tty_struct **)p; | |
3040 | driver->termios = (struct termios **)(p + driver->num); | |
3041 | driver->termios_locked = (struct termios **)(p + driver->num * 2); | |
3042 | } else { | |
3043 | driver->ttys = NULL; | |
3044 | driver->termios = NULL; | |
3045 | driver->termios_locked = NULL; | |
3046 | } | |
3047 | ||
3048 | cdev_init(&driver->cdev, &tty_fops); | |
3049 | driver->cdev.owner = driver->owner; | |
3050 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3051 | if (error) { | |
3052 | cdev_del(&driver->cdev); | |
3053 | unregister_chrdev_region(dev, driver->num); | |
3054 | driver->ttys = NULL; | |
3055 | driver->termios = driver->termios_locked = NULL; | |
3056 | kfree(p); | |
3057 | return error; | |
3058 | } | |
3059 | ||
3060 | if (!driver->put_char) | |
3061 | driver->put_char = tty_default_put_char; | |
3062 | ||
3063 | list_add(&driver->tty_drivers, &tty_drivers); | |
3064 | ||
3065 | if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) { | |
3066 | for(i = 0; i < driver->num; i++) | |
3067 | tty_register_device(driver, i, NULL); | |
3068 | } | |
3069 | proc_tty_register_driver(driver); | |
3070 | return 0; | |
3071 | } | |
3072 | ||
3073 | EXPORT_SYMBOL(tty_register_driver); | |
3074 | ||
3075 | /* | |
3076 | * Called by a tty driver to unregister itself. | |
3077 | */ | |
3078 | int tty_unregister_driver(struct tty_driver *driver) | |
3079 | { | |
3080 | int i; | |
3081 | struct termios *tp; | |
3082 | void *p; | |
3083 | ||
3084 | if (driver->refcount) | |
3085 | return -EBUSY; | |
3086 | ||
3087 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), | |
3088 | driver->num); | |
3089 | ||
3090 | list_del(&driver->tty_drivers); | |
3091 | ||
3092 | /* | |
3093 | * Free the termios and termios_locked structures because | |
3094 | * we don't want to get memory leaks when modular tty | |
3095 | * drivers are removed from the kernel. | |
3096 | */ | |
3097 | for (i = 0; i < driver->num; i++) { | |
3098 | tp = driver->termios[i]; | |
3099 | if (tp) { | |
3100 | driver->termios[i] = NULL; | |
3101 | kfree(tp); | |
3102 | } | |
3103 | tp = driver->termios_locked[i]; | |
3104 | if (tp) { | |
3105 | driver->termios_locked[i] = NULL; | |
3106 | kfree(tp); | |
3107 | } | |
3108 | if (!(driver->flags & TTY_DRIVER_NO_DEVFS)) | |
3109 | tty_unregister_device(driver, i); | |
3110 | } | |
3111 | p = driver->ttys; | |
3112 | proc_tty_unregister_driver(driver); | |
3113 | driver->ttys = NULL; | |
3114 | driver->termios = driver->termios_locked = NULL; | |
3115 | kfree(p); | |
3116 | cdev_del(&driver->cdev); | |
3117 | return 0; | |
3118 | } | |
3119 | ||
3120 | EXPORT_SYMBOL(tty_unregister_driver); | |
3121 | ||
3122 | ||
3123 | /* | |
3124 | * Initialize the console device. This is called *early*, so | |
3125 | * we can't necessarily depend on lots of kernel help here. | |
3126 | * Just do some early initializations, and do the complex setup | |
3127 | * later. | |
3128 | */ | |
3129 | void __init console_init(void) | |
3130 | { | |
3131 | initcall_t *call; | |
3132 | ||
3133 | /* Setup the default TTY line discipline. */ | |
3134 | (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); | |
3135 | ||
3136 | /* | |
3137 | * set up the console device so that later boot sequences can | |
3138 | * inform about problems etc.. | |
3139 | */ | |
3140 | #ifdef CONFIG_EARLY_PRINTK | |
3141 | disable_early_printk(); | |
1da177e4 LT |
3142 | #endif |
3143 | call = __con_initcall_start; | |
3144 | while (call < __con_initcall_end) { | |
3145 | (*call)(); | |
3146 | call++; | |
3147 | } | |
3148 | } | |
3149 | ||
3150 | #ifdef CONFIG_VT | |
3151 | extern int vty_init(void); | |
3152 | #endif | |
3153 | ||
3154 | static int __init tty_class_init(void) | |
3155 | { | |
7fe845d1 | 3156 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3157 | if (IS_ERR(tty_class)) |
3158 | return PTR_ERR(tty_class); | |
3159 | return 0; | |
3160 | } | |
3161 | ||
3162 | postcore_initcall(tty_class_init); | |
3163 | ||
3164 | /* 3/2004 jmc: why do these devices exist? */ | |
3165 | ||
3166 | static struct cdev tty_cdev, console_cdev; | |
3167 | #ifdef CONFIG_UNIX98_PTYS | |
3168 | static struct cdev ptmx_cdev; | |
3169 | #endif | |
3170 | #ifdef CONFIG_VT | |
3171 | static struct cdev vc0_cdev; | |
3172 | #endif | |
3173 | ||
3174 | /* | |
3175 | * Ok, now we can initialize the rest of the tty devices and can count | |
3176 | * on memory allocations, interrupts etc.. | |
3177 | */ | |
3178 | static int __init tty_init(void) | |
3179 | { | |
3180 | cdev_init(&tty_cdev, &tty_fops); | |
3181 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3182 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3183 | panic("Couldn't register /dev/tty driver\n"); | |
3184 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty"); | |
53f46542 | 3185 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3186 | |
3187 | cdev_init(&console_cdev, &console_fops); | |
3188 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3189 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3190 | panic("Couldn't register /dev/console driver\n"); | |
3191 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console"); | |
53f46542 | 3192 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console"); |
1da177e4 LT |
3193 | |
3194 | #ifdef CONFIG_UNIX98_PTYS | |
3195 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
3196 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
3197 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
3198 | panic("Couldn't register /dev/ptmx driver\n"); | |
3199 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx"); | |
53f46542 | 3200 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
1da177e4 LT |
3201 | #endif |
3202 | ||
3203 | #ifdef CONFIG_VT | |
3204 | cdev_init(&vc0_cdev, &console_fops); | |
3205 | if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || | |
3206 | register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) | |
3207 | panic("Couldn't register /dev/tty0 driver\n"); | |
3208 | devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0"); | |
53f46542 | 3209 | class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); |
1da177e4 LT |
3210 | |
3211 | vty_init(); | |
3212 | #endif | |
3213 | return 0; | |
3214 | } | |
3215 | module_init(tty_init); |