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1/*
2 * Provide access to virtual console memory.
3 * /dev/vcs0: the screen as it is being viewed right now (possibly scrolled)
4 * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
5 * [minor: N]
6 *
7 * /dev/vcsaN: idem, but including attributes, and prefixed with
8 * the 4 bytes lines,columns,x,y (as screendump used to give).
9 * Attribute/character pair is in native endianity.
10 * [minor: N+128]
11 *
12 * This replaces screendump and part of selection, so that the system
13 * administrator can control access using file system permissions.
14 *
15 * aeb@cwi.nl - efter Friedas begravelse - 950211
16 *
17 * machek@k332.feld.cvut.cz - modified not to send characters to wrong console
18 * - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
19 * - making it shorter - scr_readw are macros which expand in PRETTY long code
20 */
21
22#include <linux/kernel.h>
23#include <linux/major.h>
24#include <linux/errno.h>
25#include <linux/tty.h>
26#include <linux/interrupt.h>
27#include <linux/mm.h>
28#include <linux/init.h>
29#include <linux/vt_kern.h>
30#include <linux/selection.h>
31#include <linux/kbd_kern.h>
32#include <linux/console.h>
33#include <linux/device.h>
34#include <linux/sched.h>
35#include <linux/fs.h>
36#include <linux/poll.h>
37#include <linux/signal.h>
38#include <linux/slab.h>
39#include <linux/notifier.h>
40
41#include <asm/uaccess.h>
42#include <asm/byteorder.h>
43#include <asm/unaligned.h>
44
45#undef attr
46#undef org
47#undef addr
48#define HEADER_SIZE 4
49
50#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
51
52struct vcs_poll_data {
53 struct notifier_block notifier;
54 unsigned int cons_num;
55 bool seen_last_update;
56 wait_queue_head_t waitq;
57 struct fasync_struct *fasync;
58};
59
60static int
61vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
62{
63 struct vt_notifier_param *param = _param;
64 struct vc_data *vc = param->vc;
65 struct vcs_poll_data *poll =
66 container_of(nb, struct vcs_poll_data, notifier);
67 int currcons = poll->cons_num;
68
69 if (code != VT_UPDATE)
70 return NOTIFY_DONE;
71
72 if (currcons == 0)
73 currcons = fg_console;
74 else
75 currcons--;
76 if (currcons != vc->vc_num)
77 return NOTIFY_DONE;
78
79 poll->seen_last_update = false;
80 wake_up_interruptible(&poll->waitq);
81 kill_fasync(&poll->fasync, SIGIO, POLL_IN);
82 return NOTIFY_OK;
83}
84
85static void
86vcs_poll_data_free(struct vcs_poll_data *poll)
87{
88 unregister_vt_notifier(&poll->notifier);
89 kfree(poll);
90}
91
92static struct vcs_poll_data *
93vcs_poll_data_get(struct file *file)
94{
95 struct vcs_poll_data *poll = file->private_data;
96
97 if (poll)
98 return poll;
99
100 poll = kzalloc(sizeof(*poll), GFP_KERNEL);
101 if (!poll)
102 return NULL;
103 poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127;
104 init_waitqueue_head(&poll->waitq);
105 poll->notifier.notifier_call = vcs_notifier;
106 if (register_vt_notifier(&poll->notifier) != 0) {
107 kfree(poll);
108 return NULL;
109 }
110
111 /*
112 * This code may be called either through ->poll() or ->fasync().
113 * If we have two threads using the same file descriptor, they could
114 * both enter this function, both notice that the structure hasn't
115 * been allocated yet and go ahead allocating it in parallel, but
116 * only one of them must survive and be shared otherwise we'd leak
117 * memory with a dangling notifier callback.
118 */
119 spin_lock(&file->f_lock);
120 if (!file->private_data) {
121 file->private_data = poll;
122 } else {
123 /* someone else raced ahead of us */
124 vcs_poll_data_free(poll);
125 poll = file->private_data;
126 }
127 spin_unlock(&file->f_lock);
128
129 return poll;
130}
131
132/*
133 * Returns VC for inode.
134 * Must be called with console_lock.
135 */
136static struct vc_data*
137vcs_vc(struct inode *inode, int *viewed)
138{
139 unsigned int currcons = iminor(inode) & 127;
140
141 WARN_CONSOLE_UNLOCKED();
142
143 if (currcons == 0) {
144 currcons = fg_console;
145 if (viewed)
146 *viewed = 1;
147 } else {
148 currcons--;
149 if (viewed)
150 *viewed = 0;
151 }
152 return vc_cons[currcons].d;
153}
154
155/*
156 * Returns size for VC carried by inode.
157 * Must be called with console_lock.
158 */
159static int
160vcs_size(struct inode *inode)
161{
162 int size;
163 int minor = iminor(inode);
164 struct vc_data *vc;
165
166 WARN_CONSOLE_UNLOCKED();
167
168 vc = vcs_vc(inode, NULL);
169 if (!vc)
170 return -ENXIO;
171
172 size = vc->vc_rows * vc->vc_cols;
173
174 if (minor & 128)
175 size = 2*size + HEADER_SIZE;
176 return size;
177}
178
179static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
180{
181 int size;
182
183 console_lock();
184 size = vcs_size(file->f_path.dentry->d_inode);
185 console_unlock();
186 if (size < 0)
187 return size;
188 switch (orig) {
189 default:
190 return -EINVAL;
191 case 2:
192 offset += size;
193 break;
194 case 1:
195 offset += file->f_pos;
196 case 0:
197 break;
198 }
199 if (offset < 0 || offset > size) {
200 return -EINVAL;
201 }
202 file->f_pos = offset;
203 return file->f_pos;
204}
205
206
207static ssize_t
208vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
209{
210 struct inode *inode = file->f_path.dentry->d_inode;
211 unsigned int currcons = iminor(inode);
212 struct vc_data *vc;
213 struct vcs_poll_data *poll;
214 long pos;
215 long attr, read;
216 int col, maxcol, viewed;
217 unsigned short *org = NULL;
218 ssize_t ret;
219 char *con_buf;
220
221 con_buf = (char *) __get_free_page(GFP_KERNEL);
222 if (!con_buf)
223 return -ENOMEM;
224
225 pos = *ppos;
226
227 /* Select the proper current console and verify
228 * sanity of the situation under the console lock.
229 */
230 console_lock();
231
232 attr = (currcons & 128);
233 ret = -ENXIO;
234 vc = vcs_vc(inode, &viewed);
235 if (!vc)
236 goto unlock_out;
237
238 ret = -EINVAL;
239 if (pos < 0)
240 goto unlock_out;
241 poll = file->private_data;
242 if (count && poll)
243 poll->seen_last_update = true;
244 read = 0;
245 ret = 0;
246 while (count) {
247 char *con_buf0, *con_buf_start;
248 long this_round, size;
249 ssize_t orig_count;
250 long p = pos;
251
252 /* Check whether we are above size each round,
253 * as copy_to_user at the end of this loop
254 * could sleep.
255 */
256 size = vcs_size(inode);
257 if (size < 0) {
258 if (read)
259 break;
260 ret = size;
261 goto unlock_out;
262 }
263 if (pos >= size)
264 break;
265 if (count > size - pos)
266 count = size - pos;
267
268 this_round = count;
269 if (this_round > CON_BUF_SIZE)
270 this_round = CON_BUF_SIZE;
271
272 /* Perform the whole read into the local con_buf.
273 * Then we can drop the console spinlock and safely
274 * attempt to move it to userspace.
275 */
276
277 con_buf_start = con_buf0 = con_buf;
278 orig_count = this_round;
279 maxcol = vc->vc_cols;
280 if (!attr) {
281 org = screen_pos(vc, p, viewed);
282 col = p % maxcol;
283 p += maxcol - col;
284 while (this_round-- > 0) {
285 *con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff);
286 if (++col == maxcol) {
287 org = screen_pos(vc, p, viewed);
288 col = 0;
289 p += maxcol;
290 }
291 }
292 } else {
293 if (p < HEADER_SIZE) {
294 size_t tmp_count;
295
296 con_buf0[0] = (char)vc->vc_rows;
297 con_buf0[1] = (char)vc->vc_cols;
298 getconsxy(vc, con_buf0 + 2);
299
300 con_buf_start += p;
301 this_round += p;
302 if (this_round > CON_BUF_SIZE) {
303 this_round = CON_BUF_SIZE;
304 orig_count = this_round - p;
305 }
306
307 tmp_count = HEADER_SIZE;
308 if (tmp_count > this_round)
309 tmp_count = this_round;
310
311 /* Advance state pointers and move on. */
312 this_round -= tmp_count;
313 p = HEADER_SIZE;
314 con_buf0 = con_buf + HEADER_SIZE;
315 /* If this_round >= 0, then p is even... */
316 } else if (p & 1) {
317 /* Skip first byte for output if start address is odd
318 * Update region sizes up/down depending on free
319 * space in buffer.
320 */
321 con_buf_start++;
322 if (this_round < CON_BUF_SIZE)
323 this_round++;
324 else
325 orig_count--;
326 }
327 if (this_round > 0) {
328 unsigned short *tmp_buf = (unsigned short *)con_buf0;
329
330 p -= HEADER_SIZE;
331 p /= 2;
332 col = p % maxcol;
333
334 org = screen_pos(vc, p, viewed);
335 p += maxcol - col;
336
337 /* Buffer has even length, so we can always copy
338 * character + attribute. We do not copy last byte
339 * to userspace if this_round is odd.
340 */
341 this_round = (this_round + 1) >> 1;
342
343 while (this_round) {
344 *tmp_buf++ = vcs_scr_readw(vc, org++);
345 this_round --;
346 if (++col == maxcol) {
347 org = screen_pos(vc, p, viewed);
348 col = 0;
349 p += maxcol;
350 }
351 }
352 }
353 }
354
355 /* Finally, release the console semaphore while we push
356 * all the data to userspace from our temporary buffer.
357 *
358 * AKPM: Even though it's a semaphore, we should drop it because
359 * the pagefault handling code may want to call printk().
360 */
361
362 console_unlock();
363 ret = copy_to_user(buf, con_buf_start, orig_count);
364 console_lock();
365
366 if (ret) {
367 read += (orig_count - ret);
368 ret = -EFAULT;
369 break;
370 }
371 buf += orig_count;
372 pos += orig_count;
373 read += orig_count;
374 count -= orig_count;
375 }
376 *ppos += read;
377 if (read)
378 ret = read;
379unlock_out:
380 console_unlock();
381 free_page((unsigned long) con_buf);
382 return ret;
383}
384
385static ssize_t
386vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
387{
388 struct inode *inode = file->f_path.dentry->d_inode;
389 unsigned int currcons = iminor(inode);
390 struct vc_data *vc;
391 long pos;
392 long attr, size, written;
393 char *con_buf0;
394 int col, maxcol, viewed;
395 u16 *org0 = NULL, *org = NULL;
396 size_t ret;
397 char *con_buf;
398
399 con_buf = (char *) __get_free_page(GFP_KERNEL);
400 if (!con_buf)
401 return -ENOMEM;
402
403 pos = *ppos;
404
405 /* Select the proper current console and verify
406 * sanity of the situation under the console lock.
407 */
408 console_lock();
409
410 attr = (currcons & 128);
411 ret = -ENXIO;
412 vc = vcs_vc(inode, &viewed);
413 if (!vc)
414 goto unlock_out;
415
416 size = vcs_size(inode);
417 ret = -EINVAL;
418 if (pos < 0 || pos > size)
419 goto unlock_out;
420 if (count > size - pos)
421 count = size - pos;
422 written = 0;
423 while (count) {
424 long this_round = count;
425 size_t orig_count;
426 long p;
427
428 if (this_round > CON_BUF_SIZE)
429 this_round = CON_BUF_SIZE;
430
431 /* Temporarily drop the console lock so that we can read
432 * in the write data from userspace safely.
433 */
434 console_unlock();
435 ret = copy_from_user(con_buf, buf, this_round);
436 console_lock();
437
438 if (ret) {
439 this_round -= ret;
440 if (!this_round) {
441 /* Abort loop if no data were copied. Otherwise
442 * fail with -EFAULT.
443 */
444 if (written)
445 break;
446 ret = -EFAULT;
447 goto unlock_out;
448 }
449 }
450
451 /* The vcs_size might have changed while we slept to grab
452 * the user buffer, so recheck.
453 * Return data written up to now on failure.
454 */
455 size = vcs_size(inode);
456 if (size < 0) {
457 if (written)
458 break;
459 ret = size;
460 goto unlock_out;
461 }
462 if (pos >= size)
463 break;
464 if (this_round > size - pos)
465 this_round = size - pos;
466
467 /* OK, now actually push the write to the console
468 * under the lock using the local kernel buffer.
469 */
470
471 con_buf0 = con_buf;
472 orig_count = this_round;
473 maxcol = vc->vc_cols;
474 p = pos;
475 if (!attr) {
476 org0 = org = screen_pos(vc, p, viewed);
477 col = p % maxcol;
478 p += maxcol - col;
479
480 while (this_round > 0) {
481 unsigned char c = *con_buf0++;
482
483 this_round--;
484 vcs_scr_writew(vc,
485 (vcs_scr_readw(vc, org) & 0xff00) | c, org);
486 org++;
487 if (++col == maxcol) {
488 org = screen_pos(vc, p, viewed);
489 col = 0;
490 p += maxcol;
491 }
492 }
493 } else {
494 if (p < HEADER_SIZE) {
495 char header[HEADER_SIZE];
496
497 getconsxy(vc, header + 2);
498 while (p < HEADER_SIZE && this_round > 0) {
499 this_round--;
500 header[p++] = *con_buf0++;
501 }
502 if (!viewed)
503 putconsxy(vc, header + 2);
504 }
505 p -= HEADER_SIZE;
506 col = (p/2) % maxcol;
507 if (this_round > 0) {
508 org0 = org = screen_pos(vc, p/2, viewed);
509 if ((p & 1) && this_round > 0) {
510 char c;
511
512 this_round--;
513 c = *con_buf0++;
514#ifdef __BIG_ENDIAN
515 vcs_scr_writew(vc, c |
516 (vcs_scr_readw(vc, org) & 0xff00), org);
517#else
518 vcs_scr_writew(vc, (c << 8) |
519 (vcs_scr_readw(vc, org) & 0xff), org);
520#endif
521 org++;
522 p++;
523 if (++col == maxcol) {
524 org = screen_pos(vc, p/2, viewed);
525 col = 0;
526 }
527 }
528 p /= 2;
529 p += maxcol - col;
530 }
531 while (this_round > 1) {
532 unsigned short w;
533
534 w = get_unaligned(((unsigned short *)con_buf0));
535 vcs_scr_writew(vc, w, org++);
536 con_buf0 += 2;
537 this_round -= 2;
538 if (++col == maxcol) {
539 org = screen_pos(vc, p, viewed);
540 col = 0;
541 p += maxcol;
542 }
543 }
544 if (this_round > 0) {
545 unsigned char c;
546
547 c = *con_buf0++;
548#ifdef __BIG_ENDIAN
549 vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org);
550#else
551 vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org);
552#endif
553 }
554 }
555 count -= orig_count;
556 written += orig_count;
557 buf += orig_count;
558 pos += orig_count;
559 if (org0)
560 update_region(vc, (unsigned long)(org0), org - org0);
561 }
562 *ppos += written;
563 ret = written;
564 if (written)
565 vcs_scr_updated(vc);
566
567unlock_out:
568 console_unlock();
569 free_page((unsigned long) con_buf);
570 return ret;
571}
572
573static unsigned int
574vcs_poll(struct file *file, poll_table *wait)
575{
576 struct vcs_poll_data *poll = vcs_poll_data_get(file);
577 int ret = DEFAULT_POLLMASK|POLLERR|POLLPRI;
578
579 if (poll) {
580 poll_wait(file, &poll->waitq, wait);
581 if (poll->seen_last_update)
582 ret = DEFAULT_POLLMASK;
583 }
584 return ret;
585}
586
587static int
588vcs_fasync(int fd, struct file *file, int on)
589{
590 struct vcs_poll_data *poll = file->private_data;
591
592 if (!poll) {
593 /* don't allocate anything if all we want is disable fasync */
594 if (!on)
595 return 0;
596 poll = vcs_poll_data_get(file);
597 if (!poll)
598 return -ENOMEM;
599 }
600
601 return fasync_helper(fd, file, on, &poll->fasync);
602}
603
604static int
605vcs_open(struct inode *inode, struct file *filp)
606{
607 unsigned int currcons = iminor(inode) & 127;
608 int ret = 0;
609
610 tty_lock();
611 if(currcons && !vc_cons_allocated(currcons-1))
612 ret = -ENXIO;
613 tty_unlock();
614 return ret;
615}
616
617static int vcs_release(struct inode *inode, struct file *file)
618{
619 struct vcs_poll_data *poll = file->private_data;
620
621 if (poll)
622 vcs_poll_data_free(poll);
623 return 0;
624}
625
626static const struct file_operations vcs_fops = {
627 .llseek = vcs_lseek,
628 .read = vcs_read,
629 .write = vcs_write,
630 .poll = vcs_poll,
631 .fasync = vcs_fasync,
632 .open = vcs_open,
633 .release = vcs_release,
634};
635
636static struct class *vc_class;
637
638void vcs_make_sysfs(int index)
639{
640 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
641 "vcs%u", index + 1);
642 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
643 "vcsa%u", index + 1);
644}
645
646void vcs_remove_sysfs(int index)
647{
648 device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
649 device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
650}
651
652int __init vcs_init(void)
653{
654 unsigned int i;
655
656 if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
657 panic("unable to get major %d for vcs device", VCS_MAJOR);
658 vc_class = class_create(THIS_MODULE, "vc");
659
660 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
661 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
662 for (i = 0; i < MIN_NR_CONSOLES; i++)
663 vcs_make_sysfs(i);
664 return 0;
665}
1/*
2 * Provide access to virtual console memory.
3 * /dev/vcs0: the screen as it is being viewed right now (possibly scrolled)
4 * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
5 * [minor: N]
6 *
7 * /dev/vcsaN: idem, but including attributes, and prefixed with
8 * the 4 bytes lines,columns,x,y (as screendump used to give).
9 * Attribute/character pair is in native endianity.
10 * [minor: N+128]
11 *
12 * This replaces screendump and part of selection, so that the system
13 * administrator can control access using file system permissions.
14 *
15 * aeb@cwi.nl - efter Friedas begravelse - 950211
16 *
17 * machek@k332.feld.cvut.cz - modified not to send characters to wrong console
18 * - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
19 * - making it shorter - scr_readw are macros which expand in PRETTY long code
20 */
21
22#include <linux/kernel.h>
23#include <linux/major.h>
24#include <linux/errno.h>
25#include <linux/export.h>
26#include <linux/tty.h>
27#include <linux/interrupt.h>
28#include <linux/mm.h>
29#include <linux/init.h>
30#include <linux/vt_kern.h>
31#include <linux/selection.h>
32#include <linux/kbd_kern.h>
33#include <linux/console.h>
34#include <linux/device.h>
35#include <linux/sched.h>
36#include <linux/fs.h>
37#include <linux/poll.h>
38#include <linux/signal.h>
39#include <linux/slab.h>
40#include <linux/notifier.h>
41
42#include <asm/uaccess.h>
43#include <asm/byteorder.h>
44#include <asm/unaligned.h>
45
46#undef attr
47#undef org
48#undef addr
49#define HEADER_SIZE 4
50
51#define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
52
53struct vcs_poll_data {
54 struct notifier_block notifier;
55 unsigned int cons_num;
56 bool seen_last_update;
57 wait_queue_head_t waitq;
58 struct fasync_struct *fasync;
59};
60
61static int
62vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
63{
64 struct vt_notifier_param *param = _param;
65 struct vc_data *vc = param->vc;
66 struct vcs_poll_data *poll =
67 container_of(nb, struct vcs_poll_data, notifier);
68 int currcons = poll->cons_num;
69
70 if (code != VT_UPDATE)
71 return NOTIFY_DONE;
72
73 if (currcons == 0)
74 currcons = fg_console;
75 else
76 currcons--;
77 if (currcons != vc->vc_num)
78 return NOTIFY_DONE;
79
80 poll->seen_last_update = false;
81 wake_up_interruptible(&poll->waitq);
82 kill_fasync(&poll->fasync, SIGIO, POLL_IN);
83 return NOTIFY_OK;
84}
85
86static void
87vcs_poll_data_free(struct vcs_poll_data *poll)
88{
89 unregister_vt_notifier(&poll->notifier);
90 kfree(poll);
91}
92
93static struct vcs_poll_data *
94vcs_poll_data_get(struct file *file)
95{
96 struct vcs_poll_data *poll = file->private_data;
97
98 if (poll)
99 return poll;
100
101 poll = kzalloc(sizeof(*poll), GFP_KERNEL);
102 if (!poll)
103 return NULL;
104 poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127;
105 init_waitqueue_head(&poll->waitq);
106 poll->notifier.notifier_call = vcs_notifier;
107 if (register_vt_notifier(&poll->notifier) != 0) {
108 kfree(poll);
109 return NULL;
110 }
111
112 /*
113 * This code may be called either through ->poll() or ->fasync().
114 * If we have two threads using the same file descriptor, they could
115 * both enter this function, both notice that the structure hasn't
116 * been allocated yet and go ahead allocating it in parallel, but
117 * only one of them must survive and be shared otherwise we'd leak
118 * memory with a dangling notifier callback.
119 */
120 spin_lock(&file->f_lock);
121 if (!file->private_data) {
122 file->private_data = poll;
123 } else {
124 /* someone else raced ahead of us */
125 vcs_poll_data_free(poll);
126 poll = file->private_data;
127 }
128 spin_unlock(&file->f_lock);
129
130 return poll;
131}
132
133/*
134 * Returns VC for inode.
135 * Must be called with console_lock.
136 */
137static struct vc_data*
138vcs_vc(struct inode *inode, int *viewed)
139{
140 unsigned int currcons = iminor(inode) & 127;
141
142 WARN_CONSOLE_UNLOCKED();
143
144 if (currcons == 0) {
145 currcons = fg_console;
146 if (viewed)
147 *viewed = 1;
148 } else {
149 currcons--;
150 if (viewed)
151 *viewed = 0;
152 }
153 return vc_cons[currcons].d;
154}
155
156/*
157 * Returns size for VC carried by inode.
158 * Must be called with console_lock.
159 */
160static int
161vcs_size(struct inode *inode)
162{
163 int size;
164 int minor = iminor(inode);
165 struct vc_data *vc;
166
167 WARN_CONSOLE_UNLOCKED();
168
169 vc = vcs_vc(inode, NULL);
170 if (!vc)
171 return -ENXIO;
172
173 size = vc->vc_rows * vc->vc_cols;
174
175 if (minor & 128)
176 size = 2*size + HEADER_SIZE;
177 return size;
178}
179
180static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
181{
182 int size;
183
184 console_lock();
185 size = vcs_size(file->f_path.dentry->d_inode);
186 console_unlock();
187 if (size < 0)
188 return size;
189 switch (orig) {
190 default:
191 return -EINVAL;
192 case 2:
193 offset += size;
194 break;
195 case 1:
196 offset += file->f_pos;
197 case 0:
198 break;
199 }
200 if (offset < 0 || offset > size) {
201 return -EINVAL;
202 }
203 file->f_pos = offset;
204 return file->f_pos;
205}
206
207
208static ssize_t
209vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
210{
211 struct inode *inode = file->f_path.dentry->d_inode;
212 unsigned int currcons = iminor(inode);
213 struct vc_data *vc;
214 struct vcs_poll_data *poll;
215 long pos;
216 long attr, read;
217 int col, maxcol, viewed;
218 unsigned short *org = NULL;
219 ssize_t ret;
220 char *con_buf;
221
222 con_buf = (char *) __get_free_page(GFP_KERNEL);
223 if (!con_buf)
224 return -ENOMEM;
225
226 pos = *ppos;
227
228 /* Select the proper current console and verify
229 * sanity of the situation under the console lock.
230 */
231 console_lock();
232
233 attr = (currcons & 128);
234 ret = -ENXIO;
235 vc = vcs_vc(inode, &viewed);
236 if (!vc)
237 goto unlock_out;
238
239 ret = -EINVAL;
240 if (pos < 0)
241 goto unlock_out;
242 poll = file->private_data;
243 if (count && poll)
244 poll->seen_last_update = true;
245 read = 0;
246 ret = 0;
247 while (count) {
248 char *con_buf0, *con_buf_start;
249 long this_round, size;
250 ssize_t orig_count;
251 long p = pos;
252
253 /* Check whether we are above size each round,
254 * as copy_to_user at the end of this loop
255 * could sleep.
256 */
257 size = vcs_size(inode);
258 if (size < 0) {
259 if (read)
260 break;
261 ret = size;
262 goto unlock_out;
263 }
264 if (pos >= size)
265 break;
266 if (count > size - pos)
267 count = size - pos;
268
269 this_round = count;
270 if (this_round > CON_BUF_SIZE)
271 this_round = CON_BUF_SIZE;
272
273 /* Perform the whole read into the local con_buf.
274 * Then we can drop the console spinlock and safely
275 * attempt to move it to userspace.
276 */
277
278 con_buf_start = con_buf0 = con_buf;
279 orig_count = this_round;
280 maxcol = vc->vc_cols;
281 if (!attr) {
282 org = screen_pos(vc, p, viewed);
283 col = p % maxcol;
284 p += maxcol - col;
285 while (this_round-- > 0) {
286 *con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff);
287 if (++col == maxcol) {
288 org = screen_pos(vc, p, viewed);
289 col = 0;
290 p += maxcol;
291 }
292 }
293 } else {
294 if (p < HEADER_SIZE) {
295 size_t tmp_count;
296
297 con_buf0[0] = (char)vc->vc_rows;
298 con_buf0[1] = (char)vc->vc_cols;
299 getconsxy(vc, con_buf0 + 2);
300
301 con_buf_start += p;
302 this_round += p;
303 if (this_round > CON_BUF_SIZE) {
304 this_round = CON_BUF_SIZE;
305 orig_count = this_round - p;
306 }
307
308 tmp_count = HEADER_SIZE;
309 if (tmp_count > this_round)
310 tmp_count = this_round;
311
312 /* Advance state pointers and move on. */
313 this_round -= tmp_count;
314 p = HEADER_SIZE;
315 con_buf0 = con_buf + HEADER_SIZE;
316 /* If this_round >= 0, then p is even... */
317 } else if (p & 1) {
318 /* Skip first byte for output if start address is odd
319 * Update region sizes up/down depending on free
320 * space in buffer.
321 */
322 con_buf_start++;
323 if (this_round < CON_BUF_SIZE)
324 this_round++;
325 else
326 orig_count--;
327 }
328 if (this_round > 0) {
329 unsigned short *tmp_buf = (unsigned short *)con_buf0;
330
331 p -= HEADER_SIZE;
332 p /= 2;
333 col = p % maxcol;
334
335 org = screen_pos(vc, p, viewed);
336 p += maxcol - col;
337
338 /* Buffer has even length, so we can always copy
339 * character + attribute. We do not copy last byte
340 * to userspace if this_round is odd.
341 */
342 this_round = (this_round + 1) >> 1;
343
344 while (this_round) {
345 *tmp_buf++ = vcs_scr_readw(vc, org++);
346 this_round --;
347 if (++col == maxcol) {
348 org = screen_pos(vc, p, viewed);
349 col = 0;
350 p += maxcol;
351 }
352 }
353 }
354 }
355
356 /* Finally, release the console semaphore while we push
357 * all the data to userspace from our temporary buffer.
358 *
359 * AKPM: Even though it's a semaphore, we should drop it because
360 * the pagefault handling code may want to call printk().
361 */
362
363 console_unlock();
364 ret = copy_to_user(buf, con_buf_start, orig_count);
365 console_lock();
366
367 if (ret) {
368 read += (orig_count - ret);
369 ret = -EFAULT;
370 break;
371 }
372 buf += orig_count;
373 pos += orig_count;
374 read += orig_count;
375 count -= orig_count;
376 }
377 *ppos += read;
378 if (read)
379 ret = read;
380unlock_out:
381 console_unlock();
382 free_page((unsigned long) con_buf);
383 return ret;
384}
385
386static ssize_t
387vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
388{
389 struct inode *inode = file->f_path.dentry->d_inode;
390 unsigned int currcons = iminor(inode);
391 struct vc_data *vc;
392 long pos;
393 long attr, size, written;
394 char *con_buf0;
395 int col, maxcol, viewed;
396 u16 *org0 = NULL, *org = NULL;
397 size_t ret;
398 char *con_buf;
399
400 con_buf = (char *) __get_free_page(GFP_KERNEL);
401 if (!con_buf)
402 return -ENOMEM;
403
404 pos = *ppos;
405
406 /* Select the proper current console and verify
407 * sanity of the situation under the console lock.
408 */
409 console_lock();
410
411 attr = (currcons & 128);
412 ret = -ENXIO;
413 vc = vcs_vc(inode, &viewed);
414 if (!vc)
415 goto unlock_out;
416
417 size = vcs_size(inode);
418 ret = -EINVAL;
419 if (pos < 0 || pos > size)
420 goto unlock_out;
421 if (count > size - pos)
422 count = size - pos;
423 written = 0;
424 while (count) {
425 long this_round = count;
426 size_t orig_count;
427 long p;
428
429 if (this_round > CON_BUF_SIZE)
430 this_round = CON_BUF_SIZE;
431
432 /* Temporarily drop the console lock so that we can read
433 * in the write data from userspace safely.
434 */
435 console_unlock();
436 ret = copy_from_user(con_buf, buf, this_round);
437 console_lock();
438
439 if (ret) {
440 this_round -= ret;
441 if (!this_round) {
442 /* Abort loop if no data were copied. Otherwise
443 * fail with -EFAULT.
444 */
445 if (written)
446 break;
447 ret = -EFAULT;
448 goto unlock_out;
449 }
450 }
451
452 /* The vcs_size might have changed while we slept to grab
453 * the user buffer, so recheck.
454 * Return data written up to now on failure.
455 */
456 size = vcs_size(inode);
457 if (size < 0) {
458 if (written)
459 break;
460 ret = size;
461 goto unlock_out;
462 }
463 if (pos >= size)
464 break;
465 if (this_round > size - pos)
466 this_round = size - pos;
467
468 /* OK, now actually push the write to the console
469 * under the lock using the local kernel buffer.
470 */
471
472 con_buf0 = con_buf;
473 orig_count = this_round;
474 maxcol = vc->vc_cols;
475 p = pos;
476 if (!attr) {
477 org0 = org = screen_pos(vc, p, viewed);
478 col = p % maxcol;
479 p += maxcol - col;
480
481 while (this_round > 0) {
482 unsigned char c = *con_buf0++;
483
484 this_round--;
485 vcs_scr_writew(vc,
486 (vcs_scr_readw(vc, org) & 0xff00) | c, org);
487 org++;
488 if (++col == maxcol) {
489 org = screen_pos(vc, p, viewed);
490 col = 0;
491 p += maxcol;
492 }
493 }
494 } else {
495 if (p < HEADER_SIZE) {
496 char header[HEADER_SIZE];
497
498 getconsxy(vc, header + 2);
499 while (p < HEADER_SIZE && this_round > 0) {
500 this_round--;
501 header[p++] = *con_buf0++;
502 }
503 if (!viewed)
504 putconsxy(vc, header + 2);
505 }
506 p -= HEADER_SIZE;
507 col = (p/2) % maxcol;
508 if (this_round > 0) {
509 org0 = org = screen_pos(vc, p/2, viewed);
510 if ((p & 1) && this_round > 0) {
511 char c;
512
513 this_round--;
514 c = *con_buf0++;
515#ifdef __BIG_ENDIAN
516 vcs_scr_writew(vc, c |
517 (vcs_scr_readw(vc, org) & 0xff00), org);
518#else
519 vcs_scr_writew(vc, (c << 8) |
520 (vcs_scr_readw(vc, org) & 0xff), org);
521#endif
522 org++;
523 p++;
524 if (++col == maxcol) {
525 org = screen_pos(vc, p/2, viewed);
526 col = 0;
527 }
528 }
529 p /= 2;
530 p += maxcol - col;
531 }
532 while (this_round > 1) {
533 unsigned short w;
534
535 w = get_unaligned(((unsigned short *)con_buf0));
536 vcs_scr_writew(vc, w, org++);
537 con_buf0 += 2;
538 this_round -= 2;
539 if (++col == maxcol) {
540 org = screen_pos(vc, p, viewed);
541 col = 0;
542 p += maxcol;
543 }
544 }
545 if (this_round > 0) {
546 unsigned char c;
547
548 c = *con_buf0++;
549#ifdef __BIG_ENDIAN
550 vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org);
551#else
552 vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org);
553#endif
554 }
555 }
556 count -= orig_count;
557 written += orig_count;
558 buf += orig_count;
559 pos += orig_count;
560 if (org0)
561 update_region(vc, (unsigned long)(org0), org - org0);
562 }
563 *ppos += written;
564 ret = written;
565 if (written)
566 vcs_scr_updated(vc);
567
568unlock_out:
569 console_unlock();
570 free_page((unsigned long) con_buf);
571 return ret;
572}
573
574static unsigned int
575vcs_poll(struct file *file, poll_table *wait)
576{
577 struct vcs_poll_data *poll = vcs_poll_data_get(file);
578 int ret = DEFAULT_POLLMASK|POLLERR|POLLPRI;
579
580 if (poll) {
581 poll_wait(file, &poll->waitq, wait);
582 if (poll->seen_last_update)
583 ret = DEFAULT_POLLMASK;
584 }
585 return ret;
586}
587
588static int
589vcs_fasync(int fd, struct file *file, int on)
590{
591 struct vcs_poll_data *poll = file->private_data;
592
593 if (!poll) {
594 /* don't allocate anything if all we want is disable fasync */
595 if (!on)
596 return 0;
597 poll = vcs_poll_data_get(file);
598 if (!poll)
599 return -ENOMEM;
600 }
601
602 return fasync_helper(fd, file, on, &poll->fasync);
603}
604
605static int
606vcs_open(struct inode *inode, struct file *filp)
607{
608 unsigned int currcons = iminor(inode) & 127;
609 int ret = 0;
610
611 console_lock();
612 if(currcons && !vc_cons_allocated(currcons-1))
613 ret = -ENXIO;
614 console_unlock();
615 return ret;
616}
617
618static int vcs_release(struct inode *inode, struct file *file)
619{
620 struct vcs_poll_data *poll = file->private_data;
621
622 if (poll)
623 vcs_poll_data_free(poll);
624 return 0;
625}
626
627static const struct file_operations vcs_fops = {
628 .llseek = vcs_lseek,
629 .read = vcs_read,
630 .write = vcs_write,
631 .poll = vcs_poll,
632 .fasync = vcs_fasync,
633 .open = vcs_open,
634 .release = vcs_release,
635};
636
637static struct class *vc_class;
638
639void vcs_make_sysfs(int index)
640{
641 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
642 "vcs%u", index + 1);
643 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
644 "vcsa%u", index + 1);
645}
646
647void vcs_remove_sysfs(int index)
648{
649 device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
650 device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
651}
652
653int __init vcs_init(void)
654{
655 unsigned int i;
656
657 if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
658 panic("unable to get major %d for vcs device", VCS_MAJOR);
659 vc_class = class_create(THIS_MODULE, "vc");
660
661 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
662 device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
663 for (i = 0; i < MIN_NR_CONSOLES; i++)
664 vcs_make_sysfs(i);
665 return 0;
666}