Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Provide access to virtual console memory.
4 : * /dev/vcs: the screen as it is being viewed right now (possibly scrolled)
5 : * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
6 : * [minor: N]
7 : *
8 : * /dev/vcsaN: idem, but including attributes, and prefixed with
9 : * the 4 bytes lines,columns,x,y (as screendump used to give).
10 : * Attribute/character pair is in native endianity.
11 : * [minor: N+128]
12 : *
13 : * /dev/vcsuN: similar to /dev/vcsaN but using 4-byte unicode values
14 : * instead of 1-byte screen glyph values.
15 : * [minor: N+64]
16 : *
17 : * /dev/vcsuaN: same idea as /dev/vcsaN for unicode (not yet implemented).
18 : *
19 : * This replaces screendump and part of selection, so that the system
20 : * administrator can control access using file system permissions.
21 : *
22 : * [email protected] - efter Friedas begravelse - 950211
23 : *
24 : * [email protected] - modified not to send characters to wrong console
25 : * - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
26 : * - making it shorter - scr_readw are macros which expand in PRETTY long code
27 : */
28 :
29 : #include <linux/kernel.h>
30 : #include <linux/major.h>
31 : #include <linux/errno.h>
32 : #include <linux/export.h>
33 : #include <linux/tty.h>
34 : #include <linux/interrupt.h>
35 : #include <linux/mm.h>
36 : #include <linux/init.h>
37 : #include <linux/vt_kern.h>
38 : #include <linux/selection.h>
39 : #include <linux/kbd_kern.h>
40 : #include <linux/console.h>
41 : #include <linux/device.h>
42 : #include <linux/sched.h>
43 : #include <linux/fs.h>
44 : #include <linux/poll.h>
45 : #include <linux/signal.h>
46 : #include <linux/slab.h>
47 : #include <linux/notifier.h>
48 :
49 : #include <linux/uaccess.h>
50 : #include <asm/byteorder.h>
51 : #include <linux/unaligned.h>
52 :
53 : #define HEADER_SIZE 4u
54 : #define CON_BUF_SIZE (IS_ENABLED(CONFIG_BASE_SMALL) ? 256 : PAGE_SIZE)
55 :
56 : /*
57 : * Our minor space:
58 : *
59 : * 0 ... 63 glyph mode without attributes
60 : * 64 ... 127 unicode mode without attributes
61 : * 128 ... 191 glyph mode with attributes
62 : * 192 ... 255 unused (reserved for unicode with attributes)
63 : *
64 : * This relies on MAX_NR_CONSOLES being <= 63, meaning 63 actual consoles
65 : * with minors 0, 64, 128 and 192 being proxies for the foreground console.
66 : */
67 : #if MAX_NR_CONSOLES > 63
68 : #warning "/dev/vcs* devices may not accommodate more than 63 consoles"
69 : #endif
70 :
71 : #define console(inode) (iminor(inode) & 63)
72 : #define use_unicode(inode) (iminor(inode) & 64)
73 : #define use_attributes(inode) (iminor(inode) & 128)
74 :
75 :
76 : struct vcs_poll_data {
77 : struct notifier_block notifier;
78 : unsigned int cons_num;
79 : int event;
80 : wait_queue_head_t waitq;
81 : struct fasync_struct *fasync;
82 : };
83 :
84 : static int
85 0 : vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
86 : {
87 0 : struct vt_notifier_param *param = _param;
88 0 : struct vc_data *vc = param->vc;
89 0 : struct vcs_poll_data *poll =
90 0 : container_of(nb, struct vcs_poll_data, notifier);
91 0 : int currcons = poll->cons_num;
92 0 : int fa_band;
93 :
94 0 : switch (code) {
95 : case VT_UPDATE:
96 0 : fa_band = POLL_PRI;
97 0 : break;
98 : case VT_DEALLOCATE:
99 0 : fa_band = POLL_HUP;
100 0 : break;
101 : default:
102 0 : return NOTIFY_DONE;
103 : }
104 :
105 0 : if (currcons == 0)
106 0 : currcons = fg_console;
107 : else
108 0 : currcons--;
109 0 : if (currcons != vc->vc_num)
110 0 : return NOTIFY_DONE;
111 :
112 0 : poll->event = code;
113 0 : wake_up_interruptible(&poll->waitq);
114 0 : kill_fasync(&poll->fasync, SIGIO, fa_band);
115 0 : return NOTIFY_OK;
116 0 : }
117 :
118 : static void
119 0 : vcs_poll_data_free(struct vcs_poll_data *poll)
120 : {
121 0 : unregister_vt_notifier(&poll->notifier);
122 0 : kfree(poll);
123 0 : }
124 :
125 : static struct vcs_poll_data *
126 0 : vcs_poll_data_get(struct file *file)
127 : {
128 0 : struct vcs_poll_data *poll = file->private_data, *kill = NULL;
129 :
130 0 : if (poll)
131 0 : return poll;
132 :
133 0 : poll = kzalloc(sizeof(*poll), GFP_KERNEL);
134 0 : if (!poll)
135 0 : return NULL;
136 0 : poll->cons_num = console(file_inode(file));
137 0 : init_waitqueue_head(&poll->waitq);
138 0 : poll->notifier.notifier_call = vcs_notifier;
139 : /*
140 : * In order not to lose any update event, we must pretend one might
141 : * have occurred before we have a chance to register our notifier.
142 : * This is also how user space has come to detect which kernels
143 : * support POLLPRI on /dev/vcs* devices i.e. using poll() with
144 : * POLLPRI and a zero timeout.
145 : */
146 0 : poll->event = VT_UPDATE;
147 :
148 0 : if (register_vt_notifier(&poll->notifier) != 0) {
149 0 : kfree(poll);
150 0 : return NULL;
151 : }
152 :
153 : /*
154 : * This code may be called either through ->poll() or ->fasync().
155 : * If we have two threads using the same file descriptor, they could
156 : * both enter this function, both notice that the structure hasn't
157 : * been allocated yet and go ahead allocating it in parallel, but
158 : * only one of them must survive and be shared otherwise we'd leak
159 : * memory with a dangling notifier callback.
160 : */
161 0 : spin_lock(&file->f_lock);
162 0 : if (!file->private_data) {
163 0 : file->private_data = poll;
164 0 : } else {
165 : /* someone else raced ahead of us */
166 0 : kill = poll;
167 0 : poll = file->private_data;
168 : }
169 0 : spin_unlock(&file->f_lock);
170 0 : if (kill)
171 0 : vcs_poll_data_free(kill);
172 :
173 0 : return poll;
174 0 : }
175 :
176 : /**
177 : * vcs_vc - return VC for @inode
178 : * @inode: inode for which to return a VC
179 : * @viewed: returns whether this console is currently foreground (viewed)
180 : *
181 : * Must be called with console_lock.
182 : */
183 0 : static struct vc_data *vcs_vc(struct inode *inode, bool *viewed)
184 : {
185 0 : unsigned int currcons = console(inode);
186 :
187 0 : WARN_CONSOLE_UNLOCKED();
188 :
189 0 : if (currcons == 0) {
190 0 : currcons = fg_console;
191 0 : if (viewed)
192 0 : *viewed = true;
193 0 : } else {
194 0 : currcons--;
195 0 : if (viewed)
196 0 : *viewed = false;
197 : }
198 0 : return vc_cons[currcons].d;
199 0 : }
200 :
201 : /**
202 : * vcs_size - return size for a VC in @vc
203 : * @vc: which VC
204 : * @attr: does it use attributes?
205 : * @unicode: is it unicode?
206 : *
207 : * Must be called with console_lock.
208 : */
209 0 : static int vcs_size(const struct vc_data *vc, bool attr, bool unicode)
210 : {
211 0 : int size;
212 :
213 0 : WARN_CONSOLE_UNLOCKED();
214 :
215 0 : size = vc->vc_rows * vc->vc_cols;
216 :
217 0 : if (attr) {
218 0 : if (unicode)
219 0 : return -EOPNOTSUPP;
220 :
221 0 : size = 2 * size + HEADER_SIZE;
222 0 : } else if (unicode)
223 0 : size *= 4;
224 :
225 0 : return size;
226 0 : }
227 :
228 0 : static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
229 : {
230 0 : struct inode *inode = file_inode(file);
231 0 : struct vc_data *vc;
232 0 : int size;
233 :
234 0 : console_lock();
235 0 : vc = vcs_vc(inode, NULL);
236 0 : if (!vc) {
237 0 : console_unlock();
238 0 : return -ENXIO;
239 : }
240 :
241 0 : size = vcs_size(vc, use_attributes(inode), use_unicode(inode));
242 0 : console_unlock();
243 0 : if (size < 0)
244 0 : return size;
245 0 : return fixed_size_llseek(file, offset, orig, size);
246 0 : }
247 :
248 0 : static int vcs_read_buf_uni(struct vc_data *vc, char *con_buf,
249 : unsigned int pos, unsigned int count, bool viewed)
250 : {
251 0 : unsigned int nr, row, col, maxcol = vc->vc_cols;
252 0 : int ret;
253 :
254 0 : ret = vc_uniscr_check(vc);
255 0 : if (ret)
256 0 : return ret;
257 :
258 0 : pos /= 4;
259 0 : row = pos / maxcol;
260 0 : col = pos % maxcol;
261 0 : nr = maxcol - col;
262 0 : do {
263 0 : if (nr > count / 4)
264 0 : nr = count / 4;
265 0 : vc_uniscr_copy_line(vc, con_buf, viewed, row, col, nr);
266 0 : con_buf += nr * 4;
267 0 : count -= nr * 4;
268 0 : row++;
269 0 : col = 0;
270 0 : nr = maxcol;
271 0 : } while (count);
272 :
273 0 : return 0;
274 0 : }
275 :
276 0 : static void vcs_read_buf_noattr(const struct vc_data *vc, char *con_buf,
277 : unsigned int pos, unsigned int count, bool viewed)
278 : {
279 0 : u16 *org;
280 0 : unsigned int col, maxcol = vc->vc_cols;
281 :
282 0 : org = screen_pos(vc, pos, viewed);
283 0 : col = pos % maxcol;
284 0 : pos += maxcol - col;
285 :
286 0 : while (count-- > 0) {
287 0 : *con_buf++ = (vcs_scr_readw(vc, org++) & 0xff);
288 0 : if (++col == maxcol) {
289 0 : org = screen_pos(vc, pos, viewed);
290 0 : col = 0;
291 0 : pos += maxcol;
292 0 : }
293 : }
294 0 : }
295 :
296 0 : static unsigned int vcs_read_buf(const struct vc_data *vc, char *con_buf,
297 : unsigned int pos, unsigned int count, bool viewed,
298 : unsigned int *skip)
299 : {
300 0 : u16 *org, *con_buf16;
301 0 : unsigned int col, maxcol = vc->vc_cols;
302 0 : unsigned int filled = count;
303 :
304 0 : if (pos < HEADER_SIZE) {
305 : /* clamp header values if they don't fit */
306 0 : con_buf[0] = min(vc->vc_rows, 0xFFu);
307 0 : con_buf[1] = min(vc->vc_cols, 0xFFu);
308 0 : getconsxy(vc, con_buf + 2);
309 :
310 0 : *skip += pos;
311 0 : count += pos;
312 0 : if (count > CON_BUF_SIZE) {
313 0 : count = CON_BUF_SIZE;
314 0 : filled = count - pos;
315 0 : }
316 :
317 : /* Advance state pointers and move on. */
318 0 : count -= min(HEADER_SIZE, count);
319 0 : pos = HEADER_SIZE;
320 0 : con_buf += HEADER_SIZE;
321 : /* If count >= 0, then pos is even... */
322 0 : } else if (pos & 1) {
323 : /*
324 : * Skip first byte for output if start address is odd. Update
325 : * region sizes up/down depending on free space in buffer.
326 : */
327 0 : (*skip)++;
328 0 : if (count < CON_BUF_SIZE)
329 0 : count++;
330 : else
331 0 : filled--;
332 0 : }
333 :
334 0 : if (!count)
335 0 : return filled;
336 :
337 0 : pos -= HEADER_SIZE;
338 0 : pos /= 2;
339 0 : col = pos % maxcol;
340 :
341 0 : org = screen_pos(vc, pos, viewed);
342 0 : pos += maxcol - col;
343 :
344 : /*
345 : * Buffer has even length, so we can always copy character + attribute.
346 : * We do not copy last byte to userspace if count is odd.
347 : */
348 0 : count = (count + 1) / 2;
349 0 : con_buf16 = (u16 *)con_buf;
350 :
351 0 : while (count) {
352 0 : *con_buf16++ = vcs_scr_readw(vc, org++);
353 0 : count--;
354 0 : if (++col == maxcol) {
355 0 : org = screen_pos(vc, pos, viewed);
356 0 : col = 0;
357 0 : pos += maxcol;
358 0 : }
359 : }
360 :
361 0 : return filled;
362 0 : }
363 :
364 : static ssize_t
365 0 : vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
366 : {
367 0 : struct inode *inode = file_inode(file);
368 0 : struct vc_data *vc;
369 0 : struct vcs_poll_data *poll;
370 0 : unsigned int read;
371 0 : ssize_t ret;
372 0 : char *con_buf;
373 0 : loff_t pos;
374 0 : bool viewed, attr, uni_mode;
375 :
376 0 : con_buf = (char *) __get_free_page(GFP_KERNEL);
377 0 : if (!con_buf)
378 0 : return -ENOMEM;
379 :
380 0 : pos = *ppos;
381 :
382 : /* Select the proper current console and verify
383 : * sanity of the situation under the console lock.
384 : */
385 0 : console_lock();
386 :
387 0 : uni_mode = use_unicode(inode);
388 0 : attr = use_attributes(inode);
389 :
390 0 : ret = -EINVAL;
391 0 : if (pos < 0)
392 0 : goto unlock_out;
393 : /* we enforce 32-bit alignment for pos and count in unicode mode */
394 0 : if (uni_mode && (pos | count) & 3)
395 0 : goto unlock_out;
396 :
397 0 : poll = file->private_data;
398 0 : if (count && poll)
399 0 : poll->event = 0;
400 0 : read = 0;
401 0 : ret = 0;
402 0 : while (count) {
403 0 : unsigned int this_round, skip = 0;
404 0 : int size;
405 :
406 0 : vc = vcs_vc(inode, &viewed);
407 0 : if (!vc) {
408 0 : ret = -ENXIO;
409 0 : break;
410 : }
411 :
412 : /* Check whether we are above size each round,
413 : * as copy_to_user at the end of this loop
414 : * could sleep.
415 : */
416 0 : size = vcs_size(vc, attr, uni_mode);
417 0 : if (size < 0) {
418 0 : ret = size;
419 0 : break;
420 : }
421 0 : if (pos >= size)
422 0 : break;
423 0 : if (count > size - pos)
424 0 : count = size - pos;
425 :
426 0 : this_round = count;
427 0 : if (this_round > CON_BUF_SIZE)
428 0 : this_round = CON_BUF_SIZE;
429 :
430 : /* Perform the whole read into the local con_buf.
431 : * Then we can drop the console spinlock and safely
432 : * attempt to move it to userspace.
433 : */
434 :
435 0 : if (uni_mode) {
436 0 : ret = vcs_read_buf_uni(vc, con_buf, pos, this_round,
437 0 : viewed);
438 0 : if (ret)
439 0 : break;
440 0 : } else if (!attr) {
441 0 : vcs_read_buf_noattr(vc, con_buf, pos, this_round,
442 0 : viewed);
443 0 : } else {
444 0 : this_round = vcs_read_buf(vc, con_buf, pos, this_round,
445 0 : viewed, &skip);
446 : }
447 :
448 : /* Finally, release the console semaphore while we push
449 : * all the data to userspace from our temporary buffer.
450 : *
451 : * AKPM: Even though it's a semaphore, we should drop it because
452 : * the pagefault handling code may want to call printk().
453 : */
454 :
455 0 : console_unlock();
456 0 : ret = copy_to_user(buf, con_buf + skip, this_round);
457 0 : console_lock();
458 :
459 0 : if (ret) {
460 0 : read += this_round - ret;
461 0 : ret = -EFAULT;
462 0 : break;
463 : }
464 0 : buf += this_round;
465 0 : pos += this_round;
466 0 : read += this_round;
467 0 : count -= this_round;
468 0 : }
469 0 : *ppos += read;
470 0 : if (read)
471 0 : ret = read;
472 : unlock_out:
473 0 : console_unlock();
474 0 : free_page((unsigned long) con_buf);
475 0 : return ret;
476 0 : }
477 :
478 0 : static u16 *vcs_write_buf_noattr(struct vc_data *vc, const char *con_buf,
479 : unsigned int pos, unsigned int count, bool viewed, u16 **org0)
480 : {
481 0 : u16 *org;
482 0 : unsigned int col, maxcol = vc->vc_cols;
483 :
484 0 : *org0 = org = screen_pos(vc, pos, viewed);
485 0 : col = pos % maxcol;
486 0 : pos += maxcol - col;
487 :
488 0 : while (count > 0) {
489 0 : unsigned char c = *con_buf++;
490 :
491 0 : count--;
492 0 : vcs_scr_writew(vc,
493 0 : (vcs_scr_readw(vc, org) & 0xff00) | c, org);
494 0 : org++;
495 0 : if (++col == maxcol) {
496 0 : org = screen_pos(vc, pos, viewed);
497 0 : col = 0;
498 0 : pos += maxcol;
499 0 : }
500 0 : }
501 :
502 0 : return org;
503 0 : }
504 :
505 : /*
506 : * Compilers (gcc 10) are unable to optimize the swap in cpu_to_le16. So do it
507 : * the poor man way.
508 : */
509 0 : static inline u16 vc_compile_le16(u8 hi, u8 lo)
510 : {
511 : #ifdef __BIG_ENDIAN
512 : return (lo << 8u) | hi;
513 : #else
514 0 : return (hi << 8u) | lo;
515 : #endif
516 : }
517 :
518 0 : static u16 *vcs_write_buf(struct vc_data *vc, const char *con_buf,
519 : unsigned int pos, unsigned int count, bool viewed, u16 **org0)
520 : {
521 0 : u16 *org;
522 0 : unsigned int col, maxcol = vc->vc_cols;
523 0 : unsigned char c;
524 :
525 : /* header */
526 0 : if (pos < HEADER_SIZE) {
527 0 : char header[HEADER_SIZE];
528 :
529 0 : getconsxy(vc, header + 2);
530 0 : while (pos < HEADER_SIZE && count > 0) {
531 0 : count--;
532 0 : header[pos++] = *con_buf++;
533 : }
534 0 : if (!viewed)
535 0 : putconsxy(vc, header + 2);
536 0 : }
537 :
538 0 : if (!count)
539 0 : return NULL;
540 :
541 0 : pos -= HEADER_SIZE;
542 0 : col = (pos/2) % maxcol;
543 :
544 0 : *org0 = org = screen_pos(vc, pos/2, viewed);
545 :
546 : /* odd pos -- the first single character */
547 0 : if (pos & 1) {
548 0 : count--;
549 0 : c = *con_buf++;
550 0 : vcs_scr_writew(vc, vc_compile_le16(c, vcs_scr_readw(vc, org)),
551 0 : org);
552 0 : org++;
553 0 : pos++;
554 0 : if (++col == maxcol) {
555 0 : org = screen_pos(vc, pos/2, viewed);
556 0 : col = 0;
557 0 : }
558 0 : }
559 :
560 0 : pos /= 2;
561 0 : pos += maxcol - col;
562 :
563 : /* even pos -- handle attr+character pairs */
564 0 : while (count > 1) {
565 0 : unsigned short w;
566 :
567 0 : w = get_unaligned(((unsigned short *)con_buf));
568 0 : vcs_scr_writew(vc, w, org++);
569 0 : con_buf += 2;
570 0 : count -= 2;
571 0 : if (++col == maxcol) {
572 0 : org = screen_pos(vc, pos, viewed);
573 0 : col = 0;
574 0 : pos += maxcol;
575 0 : }
576 0 : }
577 :
578 0 : if (!count)
579 0 : return org;
580 :
581 : /* odd pos -- the remaining character */
582 0 : c = *con_buf++;
583 0 : vcs_scr_writew(vc, vc_compile_le16(vcs_scr_readw(vc, org) >> 8, c),
584 0 : org);
585 :
586 0 : return org;
587 0 : }
588 :
589 : static ssize_t
590 0 : vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
591 : {
592 0 : struct inode *inode = file_inode(file);
593 0 : struct vc_data *vc;
594 0 : char *con_buf;
595 0 : u16 *org0, *org;
596 0 : unsigned int written;
597 0 : int size;
598 0 : ssize_t ret;
599 0 : loff_t pos;
600 0 : bool viewed, attr;
601 :
602 0 : if (use_unicode(inode))
603 0 : return -EOPNOTSUPP;
604 :
605 0 : con_buf = (char *) __get_free_page(GFP_KERNEL);
606 0 : if (!con_buf)
607 0 : return -ENOMEM;
608 :
609 0 : pos = *ppos;
610 :
611 : /* Select the proper current console and verify
612 : * sanity of the situation under the console lock.
613 : */
614 0 : console_lock();
615 :
616 0 : attr = use_attributes(inode);
617 0 : ret = -ENXIO;
618 0 : vc = vcs_vc(inode, &viewed);
619 0 : if (!vc)
620 0 : goto unlock_out;
621 :
622 0 : size = vcs_size(vc, attr, false);
623 0 : if (size < 0) {
624 0 : ret = size;
625 0 : goto unlock_out;
626 : }
627 0 : ret = -EINVAL;
628 0 : if (pos < 0 || pos > size)
629 0 : goto unlock_out;
630 0 : if (count > size - pos)
631 0 : count = size - pos;
632 0 : written = 0;
633 0 : while (count) {
634 0 : unsigned int this_round = count;
635 :
636 0 : if (this_round > CON_BUF_SIZE)
637 0 : this_round = CON_BUF_SIZE;
638 :
639 : /* Temporarily drop the console lock so that we can read
640 : * in the write data from userspace safely.
641 : */
642 0 : console_unlock();
643 0 : ret = copy_from_user(con_buf, buf, this_round);
644 0 : console_lock();
645 :
646 0 : if (ret) {
647 0 : this_round -= ret;
648 0 : if (!this_round) {
649 : /* Abort loop if no data were copied. Otherwise
650 : * fail with -EFAULT.
651 : */
652 0 : if (written)
653 0 : break;
654 0 : ret = -EFAULT;
655 0 : goto unlock_out;
656 : }
657 0 : }
658 :
659 : /* The vc might have been freed or vcs_size might have changed
660 : * while we slept to grab the user buffer, so recheck.
661 : * Return data written up to now on failure.
662 : */
663 0 : vc = vcs_vc(inode, &viewed);
664 0 : if (!vc) {
665 0 : if (written)
666 0 : break;
667 0 : ret = -ENXIO;
668 0 : goto unlock_out;
669 : }
670 0 : size = vcs_size(vc, attr, false);
671 0 : if (size < 0) {
672 0 : if (written)
673 0 : break;
674 0 : ret = size;
675 0 : goto unlock_out;
676 : }
677 0 : if (pos >= size)
678 0 : break;
679 0 : if (this_round > size - pos)
680 0 : this_round = size - pos;
681 :
682 : /* OK, now actually push the write to the console
683 : * under the lock using the local kernel buffer.
684 : */
685 :
686 0 : if (attr)
687 0 : org = vcs_write_buf(vc, con_buf, pos, this_round,
688 0 : viewed, &org0);
689 : else
690 0 : org = vcs_write_buf_noattr(vc, con_buf, pos, this_round,
691 0 : viewed, &org0);
692 :
693 0 : count -= this_round;
694 0 : written += this_round;
695 0 : buf += this_round;
696 0 : pos += this_round;
697 0 : if (org)
698 0 : update_region(vc, (unsigned long)(org0), org - org0);
699 0 : }
700 0 : *ppos += written;
701 0 : ret = written;
702 0 : if (written)
703 0 : vcs_scr_updated(vc);
704 :
705 : unlock_out:
706 0 : console_unlock();
707 0 : free_page((unsigned long) con_buf);
708 0 : return ret;
709 0 : }
710 :
711 : static __poll_t
712 0 : vcs_poll(struct file *file, poll_table *wait)
713 : {
714 0 : struct vcs_poll_data *poll = vcs_poll_data_get(file);
715 0 : __poll_t ret = DEFAULT_POLLMASK|EPOLLERR;
716 :
717 0 : if (poll) {
718 0 : poll_wait(file, &poll->waitq, wait);
719 0 : switch (poll->event) {
720 : case VT_UPDATE:
721 0 : ret = DEFAULT_POLLMASK|EPOLLPRI;
722 0 : break;
723 : case VT_DEALLOCATE:
724 0 : ret = DEFAULT_POLLMASK|EPOLLHUP|EPOLLERR;
725 0 : break;
726 : case 0:
727 0 : ret = DEFAULT_POLLMASK;
728 0 : break;
729 : }
730 0 : }
731 0 : return ret;
732 0 : }
733 :
734 : static int
735 0 : vcs_fasync(int fd, struct file *file, int on)
736 : {
737 0 : struct vcs_poll_data *poll = file->private_data;
738 :
739 0 : if (!poll) {
740 : /* don't allocate anything if all we want is disable fasync */
741 0 : if (!on)
742 0 : return 0;
743 0 : poll = vcs_poll_data_get(file);
744 0 : if (!poll)
745 0 : return -ENOMEM;
746 0 : }
747 :
748 0 : return fasync_helper(fd, file, on, &poll->fasync);
749 0 : }
750 :
751 : static int
752 0 : vcs_open(struct inode *inode, struct file *filp)
753 : {
754 0 : unsigned int currcons = console(inode);
755 0 : bool attr = use_attributes(inode);
756 0 : bool uni_mode = use_unicode(inode);
757 0 : int ret = 0;
758 :
759 : /* we currently don't support attributes in unicode mode */
760 0 : if (attr && uni_mode)
761 0 : return -EOPNOTSUPP;
762 :
763 0 : console_lock();
764 0 : if(currcons && !vc_cons_allocated(currcons-1))
765 0 : ret = -ENXIO;
766 0 : console_unlock();
767 0 : return ret;
768 0 : }
769 :
770 0 : static int vcs_release(struct inode *inode, struct file *file)
771 : {
772 0 : struct vcs_poll_data *poll = file->private_data;
773 :
774 0 : if (poll)
775 0 : vcs_poll_data_free(poll);
776 0 : return 0;
777 0 : }
778 :
779 : static const struct file_operations vcs_fops = {
780 : .llseek = vcs_lseek,
781 : .read = vcs_read,
782 : .write = vcs_write,
783 : .poll = vcs_poll,
784 : .fasync = vcs_fasync,
785 : .open = vcs_open,
786 : .release = vcs_release,
787 : };
788 :
789 : static const struct class vc_class = {
790 : .name = "vc",
791 : };
792 :
793 0 : void vcs_make_sysfs(int index)
794 : {
795 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL, "vcs%u", index + 1);
796 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, index + 65), NULL, "vcsu%u", index + 1);
797 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL, "vcsa%u", index + 1);
798 0 : }
799 :
800 0 : void vcs_remove_sysfs(int index)
801 : {
802 0 : device_destroy(&vc_class, MKDEV(VCS_MAJOR, index + 1));
803 0 : device_destroy(&vc_class, MKDEV(VCS_MAJOR, index + 65));
804 0 : device_destroy(&vc_class, MKDEV(VCS_MAJOR, index + 129));
805 0 : }
806 :
807 0 : int __init vcs_init(void)
808 : {
809 0 : unsigned int i;
810 :
811 0 : if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
812 0 : panic("unable to get major %d for vcs device", VCS_MAJOR);
813 0 : if (class_register(&vc_class))
814 0 : panic("unable to create vc_class");
815 :
816 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
817 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, 64), NULL, "vcsu");
818 0 : device_create(&vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
819 0 : for (i = 0; i < MIN_NR_CONSOLES; i++)
820 0 : vcs_make_sysfs(i);
821 0 : return 0;
822 0 : }
|
