drivers/tty/vt/vc_screen.c

   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  * aeb@cwi.nl - efter Friedas begravelse - 950211
  23  *
  24  * machek@k332.feld.cvut.cz - 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 <asm/unaligned.h>
  52
  53 #undef attr
  54 #undef org
  55 #undef addr
  56 #define HEADER_SIZE     4
  57
  58 #define CON_BUF_SIZE (CONFIG_BASE_SMALL ? 256 : PAGE_SIZE)
  59
  60 /*
  61  * Our minor space:
  62  *
  63  *   0 ... 63   glyph mode without attributes
  64  *  64 ... 127  unicode mode without attributes
  65  * 128 ... 191  glyph mode with attributes
  66  * 192 ... 255  unused (reserved for unicode with attributes)
  67  *
  68  * This relies on MAX_NR_CONSOLES being  <= 63, meaning 63 actual consoles
  69  * with minors 0, 64, 128 and 192 being proxies for the foreground console.
  70  */
  71 #if MAX_NR_CONSOLES > 63
  72 #warning "/dev/vcs* devices may not accommodate more than 63 consoles"
  73 #endif
  74
  75 #define console(inode)          (iminor(inode) & 63)
  76 #define use_unicode(inode)      (iminor(inode) & 64)
  77 #define use_attributes(inode)   (iminor(inode) & 128)
  78
  79
  80 struct vcs_poll_data {
  81         struct notifier_block notifier;
  82         unsigned int cons_num;
  83         int event;
  84         wait_queue_head_t waitq;
  85         struct fasync_struct *fasync;
  86 };
  87
  88 static int
  89 vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
  90 {
  91         struct vt_notifier_param *param = _param;
  92         struct vc_data *vc = param->vc;
  93         struct vcs_poll_data *poll =
  94                 container_of(nb, struct vcs_poll_data, notifier);
  95         int currcons = poll->cons_num;
  96         int fa_band;
  97
  98         switch (code) {
  99         case VT_UPDATE:
 100                 fa_band = POLL_PRI;
 101                 break;
 102         case VT_DEALLOCATE:
 103                 fa_band = POLL_HUP;
 104                 break;
 105         default:
 106                 return NOTIFY_DONE;
 107         }
 108
 109         if (currcons == 0)
 110                 currcons = fg_console;
 111         else
 112                 currcons--;
 113         if (currcons != vc->vc_num)
 114                 return NOTIFY_DONE;
 115
 116         poll->event = code;
 117         wake_up_interruptible(&poll->waitq);
 118         kill_fasync(&poll->fasync, SIGIO, fa_band);
 119         return NOTIFY_OK;
 120 }
 121
 122 static void
 123 vcs_poll_data_free(struct vcs_poll_data *poll)
 124 {
 125         unregister_vt_notifier(&poll->notifier);
 126         kfree(poll);
 127 }
 128
 129 static struct vcs_poll_data *
 130 vcs_poll_data_get(struct file *file)
 131 {
 132         struct vcs_poll_data *poll = file->private_data, *kill = NULL;
 133
 134         if (poll)
 135                 return poll;
 136
 137         poll = kzalloc(sizeof(*poll), GFP_KERNEL);
 138         if (!poll)
 139                 return NULL;
 140         poll->cons_num = console(file_inode(file));
 141         init_waitqueue_head(&poll->waitq);
 142         poll->notifier.notifier_call = vcs_notifier;
 143         /*
 144          * In order not to lose any update event, we must pretend one might
 145          * have occurred before we have a chance to register our notifier.
 146          * This is also how user space has come to detect which kernels
 147          * support POLLPRI on /dev/vcs* devices i.e. using poll() with
 148          * POLLPRI and a zero timeout.
 149          */
 150         poll->event = VT_UPDATE;
 151
 152         if (register_vt_notifier(&poll->notifier) != 0) {
 153                 kfree(poll);
 154                 return NULL;
 155         }
 156
 157         /*
 158          * This code may be called either through ->poll() or ->fasync().
 159          * If we have two threads using the same file descriptor, they could
 160          * both enter this function, both notice that the structure hasn't
 161          * been allocated yet and go ahead allocating it in parallel, but
 162          * only one of them must survive and be shared otherwise we'd leak
 163          * memory with a dangling notifier callback.
 164          */
 165         spin_lock(&file->f_lock);
 166         if (!file->private_data) {
 167                 file->private_data = poll;
 168         } else {
 169                 /* someone else raced ahead of us */
 170                 kill = poll;
 171                 poll = file->private_data;
 172         }
 173         spin_unlock(&file->f_lock);
 174         if (kill)
 175                 vcs_poll_data_free(kill);
 176
 177         return poll;
 178 }
 179
 180 /**
 181  * vcs_vc -- return VC for @inode
 182  * @inode: inode for which to return a VC
 183  * @viewed: returns whether this console is currently foreground (viewed)
 184  *
 185  * Must be called with console_lock.
 186  */
 187 static struct vc_data *vcs_vc(struct inode *inode, bool *viewed)
 188 {
 189         unsigned int currcons = console(inode);
 190
 191         WARN_CONSOLE_UNLOCKED();
 192
 193         if (currcons == 0) {
 194                 currcons = fg_console;
 195                 if (viewed)
 196                         *viewed = true;
 197         } else {
 198                 currcons--;
 199                 if (viewed)
 200                         *viewed = false;
 201         }
 202         return vc_cons[currcons].d;
 203 }
 204
 205 /**
 206  * vcs_size -- return size for a VC in @vc
 207  * @vc: which VC
 208  * @attr: does it use attributes?
 209  * @unicode: is it unicode?
 210  *
 211  * Must be called with console_lock.
 212  */
 213 static int vcs_size(const struct vc_data *vc, bool attr, bool unicode)
 214 {
 215         int size;
 216
 217         WARN_CONSOLE_UNLOCKED();
 218
 219         size = vc->vc_rows * vc->vc_cols;
 220
 221         if (attr) {
 222                 if (unicode)
 223                         return -EOPNOTSUPP;
 224
 225                 size = 2 * size + HEADER_SIZE;
 226         } else if (unicode)
 227                 size *= 4;
 228
 229         return size;
 230 }
 231
 232 static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
 233 {
 234         struct inode *inode = file_inode(file);
 235         struct vc_data *vc;
 236         int size;
 237
 238         console_lock();
 239         vc = vcs_vc(inode, NULL);
 240         if (!vc) {
 241                 console_unlock();
 242                 return -ENXIO;
 243         }
 244
 245         size = vcs_size(vc, use_attributes(inode), use_unicode(inode));
 246         console_unlock();
 247         if (size < 0)
 248                 return size;
 249         return fixed_size_llseek(file, offset, orig, size);
 250 }
 251
 252
 253 static ssize_t
 254 vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 255 {
 256         struct inode *inode = file_inode(file);
 257         struct vc_data *vc;
 258         struct vcs_poll_data *poll;
 259         long pos, read;
 260         int attr, uni_mode, row, col, maxcol;
 261         unsigned short *org = NULL;
 262         ssize_t ret;
 263         char *con_buf;
 264         bool viewed;
 265
 266         con_buf = (char *) __get_free_page(GFP_KERNEL);
 267         if (!con_buf)
 268                 return -ENOMEM;
 269
 270         pos = *ppos;
 271
 272         /* Select the proper current console and verify
 273          * sanity of the situation under the console lock.
 274          */
 275         console_lock();
 276
 277         uni_mode = use_unicode(inode);
 278         attr = use_attributes(inode);
 279         ret = -ENXIO;
 280         vc = vcs_vc(inode, &viewed);
 281         if (!vc)
 282                 goto unlock_out;
 283
 284         ret = -EINVAL;
 285         if (pos < 0)
 286                 goto unlock_out;
 287         /* we enforce 32-bit alignment for pos and count in unicode mode */
 288         if (uni_mode && (pos | count) & 3)
 289                 goto unlock_out;
 290
 291         poll = file->private_data;
 292         if (count && poll)
 293                 poll->event = 0;
 294         read = 0;
 295         ret = 0;
 296         while (count) {
 297                 char *con_buf0, *con_buf_start;
 298                 long this_round, size;
 299                 ssize_t orig_count;
 300                 long p = pos;
 301
 302                 /* Check whether we are above size each round,
 303                  * as copy_to_user at the end of this loop
 304                  * could sleep.
 305                  */
 306                 size = vcs_size(vc, attr, uni_mode);
 307                 if (size < 0) {
 308                         if (read)
 309                                 break;
 310                         ret = size;
 311                         goto unlock_out;
 312                 }
 313                 if (pos >= size)
 314                         break;
 315                 if (count > size - pos)
 316                         count = size - pos;
 317
 318                 this_round = count;
 319                 if (this_round > CON_BUF_SIZE)
 320                         this_round = CON_BUF_SIZE;
 321
 322                 /* Perform the whole read into the local con_buf.
 323                  * Then we can drop the console spinlock and safely
 324                  * attempt to move it to userspace.
 325                  */
 326
 327                 con_buf_start = con_buf0 = con_buf;
 328                 orig_count = this_round;
 329                 maxcol = vc->vc_cols;
 330                 if (uni_mode) {
 331                         unsigned int nr;
 332
 333                         ret = vc_uniscr_check(vc);
 334                         if (ret)
 335                                 break;
 336                         p /= 4;
 337                         row = p / vc->vc_cols;
 338                         col = p % maxcol;
 339                         nr = maxcol - col;
 340                         do {
 341                                 if (nr > this_round/4)
 342                                         nr = this_round/4;
 343                                 vc_uniscr_copy_line(vc, con_buf0, viewed,
 344                                                     row, col, nr);
 345                                 con_buf0 += nr * 4;
 346                                 this_round -= nr * 4;
 347                                 row++;
 348                                 col = 0;
 349                                 nr = maxcol;
 350                         } while (this_round);
 351                 } else if (!attr) {
 352                         org = screen_pos(vc, p, viewed);
 353                         col = p % maxcol;
 354                         p += maxcol - col;
 355                         while (this_round-- > 0) {
 356                                 *con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff);
 357                                 if (++col == maxcol) {
 358                                         org = screen_pos(vc, p, viewed);
 359                                         col = 0;
 360                                         p += maxcol;
 361                                 }
 362                         }
 363                 } else {
 364                         if (p < HEADER_SIZE) {
 365                                 size_t tmp_count;
 366
 367                                 /* clamp header values if they don't fit */
 368                                 con_buf0[0] = min(vc->vc_rows, 0xFFu);
 369                                 con_buf0[1] = min(vc->vc_cols, 0xFFu);
 370                                 getconsxy(vc, con_buf0 + 2);
 371
 372                                 con_buf_start += p;
 373                                 this_round += p;
 374                                 if (this_round > CON_BUF_SIZE) {
 375                                         this_round = CON_BUF_SIZE;
 376                                         orig_count = this_round - p;
 377                                 }
 378
 379                                 tmp_count = HEADER_SIZE;
 380                                 if (tmp_count > this_round)
 381                                         tmp_count = this_round;
 382
 383                                 /* Advance state pointers and move on. */
 384                                 this_round -= tmp_count;
 385                                 p = HEADER_SIZE;
 386                                 con_buf0 = con_buf + HEADER_SIZE;
 387                                 /* If this_round >= 0, then p is even... */
 388                         } else if (p & 1) {
 389                                 /* Skip first byte for output if start address is odd
 390                                  * Update region sizes up/down depending on free
 391                                  * space in buffer.
 392                                  */
 393                                 con_buf_start++;
 394                                 if (this_round < CON_BUF_SIZE)
 395                                         this_round++;
 396                                 else
 397                                         orig_count--;
 398                         }
 399                         if (this_round > 0) {
 400                                 unsigned short *tmp_buf = (unsigned short *)con_buf0;
 401
 402                                 p -= HEADER_SIZE;
 403                                 p /= 2;
 404                                 col = p % maxcol;
 405
 406                                 org = screen_pos(vc, p, viewed);
 407                                 p += maxcol - col;
 408
 409                                 /* Buffer has even length, so we can always copy
 410                                  * character + attribute. We do not copy last byte
 411                                  * to userspace if this_round is odd.
 412                                  */
 413                                 this_round = (this_round + 1) >> 1;
 414
 415                                 while (this_round) {
 416                                         *tmp_buf++ = vcs_scr_readw(vc, org++);
 417                                         this_round --;
 418                                         if (++col == maxcol) {
 419                                                 org = screen_pos(vc, p, viewed);
 420                                                 col = 0;
 421                                                 p += maxcol;
 422                                         }
 423                                 }
 424                         }
 425                 }
 426
 427                 /* Finally, release the console semaphore while we push
 428                  * all the data to userspace from our temporary buffer.
 429                  *
 430                  * AKPM: Even though it's a semaphore, we should drop it because
 431                  * the pagefault handling code may want to call printk().
 432                  */
 433
 434                 console_unlock();
 435                 ret = copy_to_user(buf, con_buf_start, orig_count);
 436                 console_lock();
 437
 438                 if (ret) {
 439                         read += (orig_count - ret);
 440                         ret = -EFAULT;
 441                         break;
 442                 }
 443                 buf += orig_count;
 444                 pos += orig_count;
 445                 read += orig_count;
 446                 count -= orig_count;
 447         }
 448         *ppos += read;
 449         if (read)
 450                 ret = read;
 451 unlock_out:
 452         console_unlock();
 453         free_page((unsigned long) con_buf);
 454         return ret;
 455 }
 456
 457 static u16 *vcs_write_buf_noattr(struct vc_data *vc, const char *con_buf,
 458                 unsigned int pos, unsigned int count, bool viewed, u16 **org0)
 459 {
 460         u16 *org;
 461         unsigned int col, maxcol = vc->vc_cols;
 462
 463         *org0 = org = screen_pos(vc, pos, viewed);
 464         col = pos % maxcol;
 465         pos += maxcol - col;
 466
 467         while (count > 0) {
 468                 unsigned char c = *con_buf++;
 469
 470                 count--;
 471                 vcs_scr_writew(vc,
 472                                (vcs_scr_readw(vc, org) & 0xff00) | c, org);
 473                 org++;
 474                 if (++col == maxcol) {
 475                         org = screen_pos(vc, pos, viewed);
 476                         col = 0;
 477                         pos += maxcol;
 478                 }
 479         }
 480
 481         return org;
 482 }
 483
 484 static u16 *vcs_write_buf(struct vc_data *vc, const char *con_buf,
 485                 unsigned int pos, unsigned int count, bool viewed, u16 **org0)
 486 {
 487         u16 *org;
 488         unsigned int col, maxcol = vc->vc_cols;
 489         unsigned char c;
 490
 491         /* header */
 492         if (pos < HEADER_SIZE) {
 493                 char header[HEADER_SIZE];
 494
 495                 getconsxy(vc, header + 2);
 496                 while (pos < HEADER_SIZE && count > 0) {
 497                         count--;
 498                         header[pos++] = *con_buf++;
 499                 }
 500                 if (!viewed)
 501                         putconsxy(vc, header + 2);
 502         }
 503
 504         if (!count)
 505                 return NULL;
 506
 507         pos -= HEADER_SIZE;
 508         col = (pos/2) % maxcol;
 509
 510         *org0 = org = screen_pos(vc, pos/2, viewed);
 511
 512         /* odd pos -- the first single character */
 513         if (pos & 1) {
 514                 count--;
 515                 c = *con_buf++;
 516 #ifdef __BIG_ENDIAN
 517                 vcs_scr_writew(vc, c |
 518                      (vcs_scr_readw(vc, org) & 0xff00), org);
 519 #else
 520                 vcs_scr_writew(vc, (c << 8) |
 521                      (vcs_scr_readw(vc, org) & 0xff), org);
 522 #endif
 523                 org++;
 524                 pos++;
 525                 if (++col == maxcol) {
 526                         org = screen_pos(vc, pos/2, viewed);
 527                         col = 0;
 528                 }
 529         }
 530
 531         pos /= 2;
 532         pos += maxcol - col;
 533
 534         /* even pos -- handle attr+character pairs */
 535         while (count > 1) {
 536                 unsigned short w;
 537
 538                 w = get_unaligned(((unsigned short *)con_buf));
 539                 vcs_scr_writew(vc, w, org++);
 540                 con_buf += 2;
 541                 count -= 2;
 542                 if (++col == maxcol) {
 543                         org = screen_pos(vc, pos, viewed);
 544                         col = 0;
 545                         pos += maxcol;
 546                 }
 547         }
 548
 549         if (!count)
 550                 return org;
 551
 552         /* odd pos -- the remaining character */
 553         c = *con_buf++;
 554 #ifdef __BIG_ENDIAN
 555         vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org);
 556 #else
 557         vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org);
 558 #endif
 559
 560         return org;
 561 }
 562
 563 static ssize_t
 564 vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 565 {
 566         struct inode *inode = file_inode(file);
 567         struct vc_data *vc;
 568         char *con_buf;
 569         u16 *org0, *org;
 570         unsigned int written;
 571         int size;
 572         ssize_t ret;
 573         loff_t pos;
 574         bool viewed, attr;
 575
 576         if (use_unicode(inode))
 577                 return -EOPNOTSUPP;
 578
 579         con_buf = (char *) __get_free_page(GFP_KERNEL);
 580         if (!con_buf)
 581                 return -ENOMEM;
 582
 583         pos = *ppos;
 584
 585         /* Select the proper current console and verify
 586          * sanity of the situation under the console lock.
 587          */
 588         console_lock();
 589
 590         attr = use_attributes(inode);
 591         ret = -ENXIO;
 592         vc = vcs_vc(inode, &viewed);
 593         if (!vc)
 594                 goto unlock_out;
 595
 596         size = vcs_size(vc, attr, false);
 597         if (size < 0) {
 598                 ret = size;
 599                 goto unlock_out;
 600         }
 601         ret = -EINVAL;
 602         if (pos < 0 || pos > size)
 603                 goto unlock_out;
 604         if (count > size - pos)
 605                 count = size - pos;
 606         written = 0;
 607         while (count) {
 608                 unsigned int this_round = count;
 609
 610                 if (this_round > CON_BUF_SIZE)
 611                         this_round = CON_BUF_SIZE;
 612
 613                 /* Temporarily drop the console lock so that we can read
 614                  * in the write data from userspace safely.
 615                  */
 616                 console_unlock();
 617                 ret = copy_from_user(con_buf, buf, this_round);
 618                 console_lock();
 619
 620                 if (ret) {
 621                         this_round -= ret;
 622                         if (!this_round) {
 623                                 /* Abort loop if no data were copied. Otherwise
 624                                  * fail with -EFAULT.
 625                                  */
 626                                 if (written)
 627                                         break;
 628                                 ret = -EFAULT;
 629                                 goto unlock_out;
 630                         }
 631                 }
 632
 633                 /* The vcs_size might have changed while we slept to grab
 634                  * the user buffer, so recheck.
 635                  * Return data written up to now on failure.
 636                  */
 637                 size = vcs_size(vc, attr, false);
 638                 if (size < 0) {
 639                         if (written)
 640                                 break;
 641                         ret = size;
 642                         goto unlock_out;
 643                 }
 644                 if (pos >= size)
 645                         break;
 646                 if (this_round > size - pos)
 647                         this_round = size - pos;
 648
 649                 /* OK, now actually push the write to the console
 650                  * under the lock using the local kernel buffer.
 651                  */
 652
 653                 if (attr)
 654                         org = vcs_write_buf(vc, con_buf, pos, this_round,
 655                                         viewed, &org0);
 656                 else
 657                         org = vcs_write_buf_noattr(vc, con_buf, pos, this_round,
 658                                         viewed, &org0);
 659
 660                 count -= this_round;
 661                 written += this_round;
 662                 buf += this_round;
 663                 pos += this_round;
 664                 if (org)
 665                         update_region(vc, (unsigned long)(org0), org - org0);
 666         }
 667         *ppos += written;
 668         ret = written;
 669         if (written)
 670                 vcs_scr_updated(vc);
 671
 672 unlock_out:
 673         console_unlock();
 674         free_page((unsigned long) con_buf);
 675         return ret;
 676 }
 677
 678 static __poll_t
 679 vcs_poll(struct file *file, poll_table *wait)
 680 {
 681         struct vcs_poll_data *poll = vcs_poll_data_get(file);
 682         __poll_t ret = DEFAULT_POLLMASK|EPOLLERR;
 683
 684         if (poll) {
 685                 poll_wait(file, &poll->waitq, wait);
 686                 switch (poll->event) {
 687                 case VT_UPDATE:
 688                         ret = DEFAULT_POLLMASK|EPOLLPRI;
 689                         break;
 690                 case VT_DEALLOCATE:
 691                         ret = DEFAULT_POLLMASK|EPOLLHUP|EPOLLERR;
 692                         break;
 693                 case 0:
 694                         ret = DEFAULT_POLLMASK;
 695                         break;
 696                 }
 697         }
 698         return ret;
 699 }
 700
 701 static int
 702 vcs_fasync(int fd, struct file *file, int on)
 703 {
 704         struct vcs_poll_data *poll = file->private_data;
 705
 706         if (!poll) {
 707                 /* don't allocate anything if all we want is disable fasync */
 708                 if (!on)
 709                         return 0;
 710                 poll = vcs_poll_data_get(file);
 711                 if (!poll)
 712                         return -ENOMEM;
 713         }
 714
 715         return fasync_helper(fd, file, on, &poll->fasync);
 716 }
 717
 718 static int
 719 vcs_open(struct inode *inode, struct file *filp)
 720 {
 721         unsigned int currcons = console(inode);
 722         bool attr = use_attributes(inode);
 723         bool uni_mode = use_unicode(inode);
 724         int ret = 0;
 725
 726         /* we currently don't support attributes in unicode mode */
 727         if (attr && uni_mode)
 728                 return -EOPNOTSUPP;
 729
 730         console_lock();
 731         if(currcons && !vc_cons_allocated(currcons-1))
 732                 ret = -ENXIO;
 733         console_unlock();
 734         return ret;
 735 }
 736
 737 static int vcs_release(struct inode *inode, struct file *file)
 738 {
 739         struct vcs_poll_data *poll = file->private_data;
 740
 741         if (poll)
 742                 vcs_poll_data_free(poll);
 743         return 0;
 744 }
 745
 746 static const struct file_operations vcs_fops = {
 747         .llseek         = vcs_lseek,
 748         .read           = vcs_read,
 749         .write          = vcs_write,
 750         .poll           = vcs_poll,
 751         .fasync         = vcs_fasync,
 752         .open           = vcs_open,
 753         .release        = vcs_release,
 754 };
 755
 756 static struct class *vc_class;
 757
 758 void vcs_make_sysfs(int index)
 759 {
 760         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
 761                       "vcs%u", index + 1);
 762         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 65), NULL,
 763                       "vcsu%u", index + 1);
 764         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
 765                       "vcsa%u", index + 1);
 766 }
 767
 768 void vcs_remove_sysfs(int index)
 769 {
 770         device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
 771         device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 65));
 772         device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
 773 }
 774
 775 int __init vcs_init(void)
 776 {
 777         unsigned int i;
 778
 779         if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
 780                 panic("unable to get major %d for vcs device", VCS_MAJOR);
 781         vc_class = class_create(THIS_MODULE, "vc");
 782
 783         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
 784         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 64), NULL, "vcsu");
 785         device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
 786         for (i = 0; i < MIN_NR_CONSOLES; i++)
 787                 vcs_make_sysfs(i);
 788         return 0;
 789 }