drivers/char/vt_ioctl.c

   1 /*
   2  *  linux/drivers/char/vt_ioctl.c
   3  *
   4  *  Copyright (C) 1992 obz under the linux copyright
   5  *
   6  *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
   7  *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
   8  *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
   9  *  Some code moved for less code duplication - Andi Kleen - Mar 1997
  10  *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/types.h>
  15 #include <linux/errno.h>
  16 #include <linux/sched.h>
  17 #include <linux/tty.h>
  18 #include <linux/timer.h>
  19 #include <linux/kernel.h>
  20 #include <linux/kd.h>
  21 #include <linux/vt.h>
  22 #include <linux/string.h>
  23 #include <linux/slab.h>
  24 #include <linux/major.h>
  25 #include <linux/fs.h>
  26 #include <linux/console.h>
  27 #include <linux/signal.h>
  28 #include <linux/timex.h>
  29
  30 #include <asm/io.h>
  31 #include <asm/uaccess.h>
  32
  33 #include <linux/kbd_kern.h>
  34 #include <linux/vt_kern.h>
  35 #include <linux/kbd_diacr.h>
  36 #include <linux/selection.h>
  37
  38 static char vt_dont_switch;
  39 extern struct tty_driver *console_driver;
  40
  41 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
  42 #define VT_BUSY(i)      (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
  43
  44 /*
  45  * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  46  * experimentation and study of X386 SYSV handling.
  47  *
  48  * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  49  * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  50  * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  51  * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  52  * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  53  * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  54  * to the current console is done by the main ioctl code.
  55  */
  56
  57 #ifdef CONFIG_X86
  58 #include <linux/syscalls.h>
  59 #endif
  60
  61 static void complete_change_console(struct vc_data *vc);
  62
  63 /*
  64  * these are the valid i/o ports we're allowed to change. they map all the
  65  * video ports
  66  */
  67 #define GPFIRST 0x3b4
  68 #define GPLAST 0x3df
  69 #define GPNUM (GPLAST - GPFIRST + 1)
  70
  71 #define i (tmp.kb_index)
  72 #define s (tmp.kb_table)
  73 #define v (tmp.kb_value)
  74 static inline int
  75 do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
  76 {
  77         struct kbentry tmp;
  78         ushort *key_map, val, ov;
  79
  80         if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
  81                 return -EFAULT;
  82
  83         switch (cmd) {
  84         case KDGKBENT:
  85                 key_map = key_maps[s];
  86                 if (key_map) {
  87                     val = U(key_map[i]);
  88                     if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
  89                         val = K_HOLE;
  90                 } else
  91                     val = (i ? K_HOLE : K_NOSUCHMAP);
  92                 return put_user(val, &user_kbe->kb_value);
  93         case KDSKBENT:
  94                 if (!perm)
  95                         return -EPERM;
  96                 if (!i && v == K_NOSUCHMAP) {
  97                         /* disallocate map */
  98                         key_map = key_maps[s];
  99                         if (s && key_map) {
 100                             key_maps[s] = NULL;
 101                             if (key_map[0] == U(K_ALLOCATED)) {
 102                                         kfree(key_map);
 103                                         keymap_count--;
 104                             }
 105                         }
 106                         break;
 107                 }
 108
 109                 if (KTYP(v) < NR_TYPES) {
 110                     if (KVAL(v) > max_vals[KTYP(v)])
 111                                 return -EINVAL;
 112                 } else
 113                     if (kbd->kbdmode != VC_UNICODE)
 114                                 return -EINVAL;
 115
 116                 /* ++Geert: non-PC keyboards may generate keycode zero */
 117 #if !defined(__mc68000__) && !defined(__powerpc__)
 118                 /* assignment to entry 0 only tests validity of args */
 119                 if (!i)
 120                         break;
 121 #endif
 122
 123                 if (!(key_map = key_maps[s])) {
 124                         int j;
 125
 126                         if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
 127                             !capable(CAP_SYS_RESOURCE))
 128                                 return -EPERM;
 129
 130                         key_map = (ushort *) kmalloc(sizeof(plain_map),
 131                                                      GFP_KERNEL);
 132                         if (!key_map)
 133                                 return -ENOMEM;
 134                         key_maps[s] = key_map;
 135                         key_map[0] = U(K_ALLOCATED);
 136                         for (j = 1; j < NR_KEYS; j++)
 137                                 key_map[j] = U(K_HOLE);
 138                         keymap_count++;
 139                 }
 140                 ov = U(key_map[i]);
 141                 if (v == ov)
 142                         break;  /* nothing to do */
 143                 /*
 144                  * Attention Key.
 145                  */
 146                 if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
 147                         return -EPERM;
 148                 key_map[i] = U(v);
 149                 if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
 150                         compute_shiftstate();
 151                 break;
 152         }
 153         return 0;
 154 }
 155 #undef i
 156 #undef s
 157 #undef v
 158
 159 static inline int
 160 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
 161 {
 162         struct kbkeycode tmp;
 163         int kc = 0;
 164
 165         if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
 166                 return -EFAULT;
 167         switch (cmd) {
 168         case KDGETKEYCODE:
 169                 kc = getkeycode(tmp.scancode);
 170                 if (kc >= 0)
 171                         kc = put_user(kc, &user_kbkc->keycode);
 172                 break;
 173         case KDSETKEYCODE:
 174                 if (!perm)
 175                         return -EPERM;
 176                 kc = setkeycode(tmp.scancode, tmp.keycode);
 177                 break;
 178         }
 179         return kc;
 180 }
 181
 182 static inline int
 183 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
 184 {
 185         struct kbsentry *kbs;
 186         char *p;
 187         u_char *q;
 188         u_char __user *up;
 189         int sz;
 190         int delta;
 191         char *first_free, *fj, *fnw;
 192         int i, j, k;
 193         int ret;
 194
 195         kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
 196         if (!kbs) {
 197                 ret = -ENOMEM;
 198                 goto reterr;
 199         }
 200
 201         /* we mostly copy too much here (512bytes), but who cares ;) */
 202         if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
 203                 ret = -EFAULT;
 204                 goto reterr;
 205         }
 206         kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
 207         i = kbs->kb_func;
 208
 209         switch (cmd) {
 210         case KDGKBSENT:
 211                 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
 212                                                   a struct member */
 213                 up = user_kdgkb->kb_string;
 214                 p = func_table[i];
 215                 if(p)
 216                         for ( ; *p && sz; p++, sz--)
 217                                 if (put_user(*p, up++)) {
 218                                         ret = -EFAULT;
 219                                         goto reterr;
 220                                 }
 221                 if (put_user('\0', up)) {
 222                         ret = -EFAULT;
 223                         goto reterr;
 224                 }
 225                 kfree(kbs);
 226                 return ((p && *p) ? -EOVERFLOW : 0);
 227         case KDSKBSENT:
 228                 if (!perm) {
 229                         ret = -EPERM;
 230                         goto reterr;
 231                 }
 232
 233                 q = func_table[i];
 234                 first_free = funcbufptr + (funcbufsize - funcbufleft);
 235                 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
 236                         ;
 237                 if (j < MAX_NR_FUNC)
 238                         fj = func_table[j];
 239                 else
 240                         fj = first_free;
 241
 242                 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
 243                 if (delta <= funcbufleft) {     /* it fits in current buf */
 244                     if (j < MAX_NR_FUNC) {
 245                         memmove(fj + delta, fj, first_free - fj);
 246                         for (k = j; k < MAX_NR_FUNC; k++)
 247                             if (func_table[k])
 248                                 func_table[k] += delta;
 249                     }
 250                     if (!q)
 251                       func_table[i] = fj;
 252                     funcbufleft -= delta;
 253                 } else {                        /* allocate a larger buffer */
 254                     sz = 256;
 255                     while (sz < funcbufsize - funcbufleft + delta)
 256                       sz <<= 1;
 257                     fnw = (char *) kmalloc(sz, GFP_KERNEL);
 258                     if(!fnw) {
 259                       ret = -ENOMEM;
 260                       goto reterr;
 261                     }
 262
 263                     if (!q)
 264                       func_table[i] = fj;
 265                     if (fj > funcbufptr)
 266                         memmove(fnw, funcbufptr, fj - funcbufptr);
 267                     for (k = 0; k < j; k++)
 268                       if (func_table[k])
 269                         func_table[k] = fnw + (func_table[k] - funcbufptr);
 270
 271                     if (first_free > fj) {
 272                         memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
 273                         for (k = j; k < MAX_NR_FUNC; k++)
 274                           if (func_table[k])
 275                             func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
 276                     }
 277                     if (funcbufptr != func_buf)
 278                       kfree(funcbufptr);
 279                     funcbufptr = fnw;
 280                     funcbufleft = funcbufleft - delta + sz - funcbufsize;
 281                     funcbufsize = sz;
 282                 }
 283                 strcpy(func_table[i], kbs->kb_string);
 284                 break;
 285         }
 286         ret = 0;
 287 reterr:
 288         kfree(kbs);
 289         return ret;
 290 }
 291
 292 static inline int
 293 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 294 {
 295         struct consolefontdesc cfdarg;
 296         int i;
 297
 298         if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
 299                 return -EFAULT;
 300
 301         switch (cmd) {
 302         case PIO_FONTX:
 303                 if (!perm)
 304                         return -EPERM;
 305                 op->op = KD_FONT_OP_SET;
 306                 op->flags = KD_FONT_FLAG_OLD;
 307                 op->width = 8;
 308                 op->height = cfdarg.charheight;
 309                 op->charcount = cfdarg.charcount;
 310                 op->data = cfdarg.chardata;
 311                 return con_font_op(vc_cons[fg_console].d, op);
 312         case GIO_FONTX: {
 313                 op->op = KD_FONT_OP_GET;
 314                 op->flags = KD_FONT_FLAG_OLD;
 315                 op->width = 8;
 316                 op->height = cfdarg.charheight;
 317                 op->charcount = cfdarg.charcount;
 318                 op->data = cfdarg.chardata;
 319                 i = con_font_op(vc_cons[fg_console].d, op);
 320                 if (i)
 321                         return i;
 322                 cfdarg.charheight = op->height;
 323                 cfdarg.charcount = op->charcount;
 324                 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 325                         return -EFAULT;
 326                 return 0;
 327                 }
 328         }
 329         return -EINVAL;
 330 }
 331
 332 static inline int
 333 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 334 {
 335         struct unimapdesc tmp;
 336
 337         if (copy_from_user(&tmp, user_ud, sizeof tmp))
 338                 return -EFAULT;
 339         if (tmp.entries)
 340                 if (!access_ok(VERIFY_WRITE, tmp.entries,
 341                                 tmp.entry_ct*sizeof(struct unipair)))
 342                         return -EFAULT;
 343         switch (cmd) {
 344         case PIO_UNIMAP:
 345                 if (!perm)
 346                         return -EPERM;
 347                 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 348         case GIO_UNIMAP:
 349                 if (!perm && fg_console != vc->vc_num)
 350                         return -EPERM;
 351                 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 352         }
 353         return 0;
 354 }
 355
 356 /*
 357  * We handle the console-specific ioctl's here.  We allow the
 358  * capability to modify any console, not just the fg_console.
 359  */
 360 int vt_ioctl(struct tty_struct *tty, struct file * file,
 361              unsigned int cmd, unsigned long arg)
 362 {
 363         struct vc_data *vc = (struct vc_data *)tty->driver_data;
 364         struct console_font_op op;      /* used in multiple places here */
 365         struct kbd_struct * kbd;
 366         unsigned int console;
 367         unsigned char ucval;
 368         void __user *up = (void __user *)arg;
 369         int i, perm;
 370
 371         console = vc->vc_num;
 372
 373         if (!vc_cons_allocated(console))        /* impossible? */
 374                 return -ENOIOCTLCMD;
 375
 376         /*
 377          * To have permissions to do most of the vt ioctls, we either have
 378          * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 379          */
 380         perm = 0;
 381         if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 382                 perm = 1;
 383
 384         kbd = kbd_table + console;
 385         switch (cmd) {
 386         case KIOCSOUND:
 387                 if (!perm)
 388                         return -EPERM;
 389                 if (arg)
 390                         arg = CLOCK_TICK_RATE / arg;
 391                 kd_mksound(arg, 0);
 392                 return 0;
 393
 394         case KDMKTONE:
 395                 if (!perm)
 396                         return -EPERM;
 397         {
 398                 unsigned int ticks, count;
 399
 400                 /*
 401                  * Generate the tone for the appropriate number of ticks.
 402                  * If the time is zero, turn off sound ourselves.
 403                  */
 404                 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
 405                 count = ticks ? (arg & 0xffff) : 0;
 406                 if (count)
 407                         count = CLOCK_TICK_RATE / count;
 408                 kd_mksound(count, ticks);
 409                 return 0;
 410         }
 411
 412         case KDGKBTYPE:
 413                 /*
 414                  * this is naive.
 415                  */
 416                 ucval = KB_101;
 417                 goto setchar;
 418
 419                 /*
 420                  * These cannot be implemented on any machine that implements
 421                  * ioperm() in user level (such as Alpha PCs) or not at all.
 422                  *
 423                  * XXX: you should never use these, just call ioperm directly..
 424                  */
 425 #ifdef CONFIG_X86
 426         case KDADDIO:
 427         case KDDELIO:
 428                 /*
 429                  * KDADDIO and KDDELIO may be able to add ports beyond what
 430                  * we reject here, but to be safe...
 431                  */
 432                 if (arg < GPFIRST || arg > GPLAST)
 433                         return -EINVAL;
 434                 return sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 435
 436         case KDENABIO:
 437         case KDDISABIO:
 438                 return sys_ioperm(GPFIRST, GPNUM,
 439                                   (cmd == KDENABIO)) ? -ENXIO : 0;
 440 #endif
 441
 442         /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 443
 444         case KDKBDREP:
 445         {
 446                 struct kbd_repeat kbrep;
 447                 int err;
 448
 449                 if (!capable(CAP_SYS_TTY_CONFIG))
 450                         return -EPERM;
 451
 452                 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
 453                         return -EFAULT;
 454                 err = kbd_rate(&kbrep);
 455                 if (err)
 456                         return err;
 457                 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 458                         return -EFAULT;
 459                 return 0;
 460         }
 461
 462         case KDSETMODE:
 463                 /*
 464                  * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 465                  * doesn't do a whole lot. i'm not sure if it should do any
 466                  * restoration of modes or what...
 467                  *
 468                  * XXX It should at least call into the driver, fbdev's definitely
 469                  * need to restore their engine state. --BenH
 470                  */
 471                 if (!perm)
 472                         return -EPERM;
 473                 switch (arg) {
 474                 case KD_GRAPHICS:
 475                         break;
 476                 case KD_TEXT0:
 477                 case KD_TEXT1:
 478                         arg = KD_TEXT;
 479                 case KD_TEXT:
 480                         break;
 481                 default:
 482                         return -EINVAL;
 483                 }
 484                 if (vc->vc_mode == (unsigned char) arg)
 485                         return 0;
 486                 vc->vc_mode = (unsigned char) arg;
 487                 if (console != fg_console)
 488                         return 0;
 489                 /*
 490                  * explicitly blank/unblank the screen if switching modes
 491                  */
 492                 acquire_console_sem();
 493                 if (arg == KD_TEXT)
 494                         do_unblank_screen(1);
 495                 else
 496                         do_blank_screen(1);
 497                 release_console_sem();
 498                 return 0;
 499
 500         case KDGETMODE:
 501                 ucval = vc->vc_mode;
 502                 goto setint;
 503
 504         case KDMAPDISP:
 505         case KDUNMAPDISP:
 506                 /*
 507                  * these work like a combination of mmap and KDENABIO.
 508                  * this could be easily finished.
 509                  */
 510                 return -EINVAL;
 511
 512         case KDSKBMODE:
 513                 if (!perm)
 514                         return -EPERM;
 515                 switch(arg) {
 516                   case K_RAW:
 517                         kbd->kbdmode = VC_RAW;
 518                         break;
 519                   case K_MEDIUMRAW:
 520                         kbd->kbdmode = VC_MEDIUMRAW;
 521                         break;
 522                   case K_XLATE:
 523                         kbd->kbdmode = VC_XLATE;
 524                         compute_shiftstate();
 525                         break;
 526                   case K_UNICODE:
 527                         kbd->kbdmode = VC_UNICODE;
 528                         compute_shiftstate();
 529                         break;
 530                   default:
 531                         return -EINVAL;
 532                 }
 533                 tty_ldisc_flush(tty);
 534                 return 0;
 535
 536         case KDGKBMODE:
 537                 ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
 538                                  (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
 539                                  (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
 540                                  K_XLATE);
 541                 goto setint;
 542
 543         /* this could be folded into KDSKBMODE, but for compatibility
 544            reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 545         case KDSKBMETA:
 546                 switch(arg) {
 547                   case K_METABIT:
 548                         clr_vc_kbd_mode(kbd, VC_META);
 549                         break;
 550                   case K_ESCPREFIX:
 551                         set_vc_kbd_mode(kbd, VC_META);
 552                         break;
 553                   default:
 554                         return -EINVAL;
 555                 }
 556                 return 0;
 557
 558         case KDGKBMETA:
 559                 ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
 560         setint:
 561                 return put_user(ucval, (int __user *)arg);
 562
 563         case KDGETKEYCODE:
 564         case KDSETKEYCODE:
 565                 if(!capable(CAP_SYS_TTY_CONFIG))
 566                         perm=0;
 567                 return do_kbkeycode_ioctl(cmd, up, perm);
 568
 569         case KDGKBENT:
 570         case KDSKBENT:
 571                 return do_kdsk_ioctl(cmd, up, perm, kbd);
 572
 573         case KDGKBSENT:
 574         case KDSKBSENT:
 575                 return do_kdgkb_ioctl(cmd, up, perm);
 576
 577         case KDGKBDIACR:
 578         {
 579                 struct kbdiacrs __user *a = up;
 580
 581                 if (put_user(accent_table_size, &a->kb_cnt))
 582                         return -EFAULT;
 583                 if (copy_to_user(a->kbdiacr, accent_table, accent_table_size*sizeof(struct kbdiacr)))
 584                         return -EFAULT;
 585                 return 0;
 586         }
 587
 588         case KDSKBDIACR:
 589         {
 590                 struct kbdiacrs __user *a = up;
 591                 unsigned int ct;
 592
 593                 if (!perm)
 594                         return -EPERM;
 595                 if (get_user(ct,&a->kb_cnt))
 596                         return -EFAULT;
 597                 if (ct >= MAX_DIACR)
 598                         return -EINVAL;
 599                 accent_table_size = ct;
 600                 if (copy_from_user(accent_table, a->kbdiacr, ct*sizeof(struct kbdiacr)))
 601                         return -EFAULT;
 602                 return 0;
 603         }
 604
 605         /* the ioctls below read/set the flags usually shown in the leds */
 606         /* don't use them - they will go away without warning */
 607         case KDGKBLED:
 608                 ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
 609                 goto setchar;
 610
 611         case KDSKBLED:
 612                 if (!perm)
 613                         return -EPERM;
 614                 if (arg & ~0x77)
 615                         return -EINVAL;
 616                 kbd->ledflagstate = (arg & 7);
 617                 kbd->default_ledflagstate = ((arg >> 4) & 7);
 618                 set_leds();
 619                 return 0;
 620
 621         /* the ioctls below only set the lights, not the functions */
 622         /* for those, see KDGKBLED and KDSKBLED above */
 623         case KDGETLED:
 624                 ucval = getledstate();
 625         setchar:
 626                 return put_user(ucval, (char __user *)arg);
 627
 628         case KDSETLED:
 629                 if (!perm)
 630                   return -EPERM;
 631                 setledstate(kbd, arg);
 632                 return 0;
 633
 634         /*
 635          * A process can indicate its willingness to accept signals
 636          * generated by pressing an appropriate key combination.
 637          * Thus, one can have a daemon that e.g. spawns a new console
 638          * upon a keypress and then changes to it.
 639          * See also the kbrequest field of inittab(5).
 640          */
 641         case KDSIGACCEPT:
 642         {
 643                 extern int spawnpid, spawnsig;
 644                 if (!perm || !capable(CAP_KILL))
 645                   return -EPERM;
 646                 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 647                   return -EINVAL;
 648                 spawnpid = current->pid;
 649                 spawnsig = arg;
 650                 return 0;
 651         }
 652
 653         case VT_SETMODE:
 654         {
 655                 struct vt_mode tmp;
 656
 657                 if (!perm)
 658                         return -EPERM;
 659                 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
 660                         return -EFAULT;
 661                 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
 662                         return -EINVAL;
 663                 acquire_console_sem();
 664                 vc->vt_mode = tmp;
 665                 /* the frsig is ignored, so we set it to 0 */
 666                 vc->vt_mode.frsig = 0;
 667                 vc->vt_pid = current->pid;
 668                 /* no switch is required -- saw@shade.msu.ru */
 669                 vc->vt_newvt = -1;
 670                 release_console_sem();
 671                 return 0;
 672         }
 673
 674         case VT_GETMODE:
 675         {
 676                 struct vt_mode tmp;
 677                 int rc;
 678
 679                 acquire_console_sem();
 680                 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 681                 release_console_sem();
 682
 683                 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 684                 return rc ? -EFAULT : 0;
 685         }
 686
 687         /*
 688          * Returns global vt state. Note that VT 0 is always open, since
 689          * it's an alias for the current VT, and people can't use it here.
 690          * We cannot return state for more than 16 VTs, since v_state is short.
 691          */
 692         case VT_GETSTATE:
 693         {
 694                 struct vt_stat __user *vtstat = up;
 695                 unsigned short state, mask;
 696
 697                 if (put_user(fg_console + 1, &vtstat->v_active))
 698                         return -EFAULT;
 699                 state = 1;      /* /dev/tty0 is always open */
 700                 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1)
 701                         if (VT_IS_IN_USE(i))
 702                                 state |= mask;
 703                 return put_user(state, &vtstat->v_state);
 704         }
 705
 706         /*
 707          * Returns the first available (non-opened) console.
 708          */
 709         case VT_OPENQRY:
 710                 for (i = 0; i < MAX_NR_CONSOLES; ++i)
 711                         if (! VT_IS_IN_USE(i))
 712                                 break;
 713                 ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
 714                 goto setint;
 715
 716         /*
 717          * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 718          * with num >= 1 (switches to vt 0, our console, are not allowed, just
 719          * to preserve sanity).
 720          */
 721         case VT_ACTIVATE:
 722                 if (!perm)
 723                         return -EPERM;
 724                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 725                         return -ENXIO;
 726                 arg--;
 727                 acquire_console_sem();
 728                 i = vc_allocate(arg);
 729                 release_console_sem();
 730                 if (i)
 731                         return i;
 732                 set_console(arg);
 733                 return 0;
 734
 735         /*
 736          * wait until the specified VT has been activated
 737          */
 738         case VT_WAITACTIVE:
 739                 if (!perm)
 740                         return -EPERM;
 741                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 742                         return -ENXIO;
 743                 return vt_waitactive(arg-1);
 744
 745         /*
 746          * If a vt is under process control, the kernel will not switch to it
 747          * immediately, but postpone the operation until the process calls this
 748          * ioctl, allowing the switch to complete.
 749          *
 750          * According to the X sources this is the behavior:
 751          *      0:      pending switch-from not OK
 752          *      1:      pending switch-from OK
 753          *      2:      completed switch-to OK
 754          */
 755         case VT_RELDISP:
 756                 if (!perm)
 757                         return -EPERM;
 758                 if (vc->vt_mode.mode != VT_PROCESS)
 759                         return -EINVAL;
 760
 761                 /*
 762                  * Switching-from response
 763                  */
 764                 if (vc->vt_newvt >= 0) {
 765                         if (arg == 0)
 766                                 /*
 767                                  * Switch disallowed, so forget we were trying
 768                                  * to do it.
 769                                  */
 770                                 vc->vt_newvt = -1;
 771
 772                         else {
 773                                 /*
 774                                  * The current vt has been released, so
 775                                  * complete the switch.
 776                                  */
 777                                 int newvt;
 778                                 acquire_console_sem();
 779                                 newvt = vc->vt_newvt;
 780                                 vc->vt_newvt = -1;
 781                                 i = vc_allocate(newvt);
 782                                 if (i) {
 783                                         release_console_sem();
 784                                         return i;
 785                                 }
 786                                 /*
 787                                  * When we actually do the console switch,
 788                                  * make sure we are atomic with respect to
 789                                  * other console switches..
 790                                  */
 791                                 complete_change_console(vc_cons[newvt].d);
 792                                 release_console_sem();
 793                         }
 794                 }
 795
 796                 /*
 797                  * Switched-to response
 798                  */
 799                 else
 800                 {
 801                         /*
 802                          * If it's just an ACK, ignore it
 803                          */
 804                         if (arg != VT_ACKACQ)
 805                                 return -EINVAL;
 806                 }
 807
 808                 return 0;
 809
 810          /*
 811           * Disallocate memory associated to VT (but leave VT1)
 812           */
 813          case VT_DISALLOCATE:
 814                 if (arg > MAX_NR_CONSOLES)
 815                         return -ENXIO;
 816                 if (arg == 0) {
 817                     /* disallocate all unused consoles, but leave 0 */
 818                         acquire_console_sem();
 819                         for (i=1; i<MAX_NR_CONSOLES; i++)
 820                                 if (! VT_BUSY(i))
 821                                         vc_disallocate(i);
 822                         release_console_sem();
 823                 } else {
 824                         /* disallocate a single console, if possible */
 825                         arg--;
 826                         if (VT_BUSY(arg))
 827                                 return -EBUSY;
 828                         if (arg) {                            /* leave 0 */
 829                                 acquire_console_sem();
 830                                 vc_disallocate(arg);
 831                                 release_console_sem();
 832                         }
 833                 }
 834                 return 0;
 835
 836         case VT_RESIZE:
 837         {
 838                 struct vt_sizes __user *vtsizes = up;
 839                 ushort ll,cc;
 840                 if (!perm)
 841                         return -EPERM;
 842                 if (get_user(ll, &vtsizes->v_rows) ||
 843                     get_user(cc, &vtsizes->v_cols))
 844                         return -EFAULT;
 845                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 846                         acquire_console_sem();
 847                         vc_resize(vc_cons[i].d, cc, ll);
 848                         release_console_sem();
 849                 }
 850                 return 0;
 851         }
 852
 853         case VT_RESIZEX:
 854         {
 855                 struct vt_consize __user *vtconsize = up;
 856                 ushort ll,cc,vlin,clin,vcol,ccol;
 857                 if (!perm)
 858                         return -EPERM;
 859                 if (!access_ok(VERIFY_READ, vtconsize,
 860                                 sizeof(struct vt_consize)))
 861                         return -EFAULT;
 862                 __get_user(ll, &vtconsize->v_rows);
 863                 __get_user(cc, &vtconsize->v_cols);
 864                 __get_user(vlin, &vtconsize->v_vlin);
 865                 __get_user(clin, &vtconsize->v_clin);
 866                 __get_user(vcol, &vtconsize->v_vcol);
 867                 __get_user(ccol, &vtconsize->v_ccol);
 868                 vlin = vlin ? vlin : vc->vc_scan_lines;
 869                 if (clin) {
 870                         if (ll) {
 871                                 if (ll != vlin/clin)
 872                                         return -EINVAL; /* Parameters don't add up */
 873                         } else
 874                                 ll = vlin/clin;
 875                 }
 876                 if (vcol && ccol) {
 877                         if (cc) {
 878                                 if (cc != vcol/ccol)
 879                                         return -EINVAL;
 880                         } else
 881                                 cc = vcol/ccol;
 882                 }
 883
 884                 if (clin > 32)
 885                         return -EINVAL;
 886
 887                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 888                         if (!vc_cons[i].d)
 889                                 continue;
 890                         acquire_console_sem();
 891                         if (vlin)
 892                                 vc_cons[i].d->vc_scan_lines = vlin;
 893                         if (clin)
 894                                 vc_cons[i].d->vc_font.height = clin;
 895                         vc_resize(vc_cons[i].d, cc, ll);
 896                         release_console_sem();
 897                 }
 898                 return 0;
 899         }
 900
 901         case PIO_FONT: {
 902                 if (!perm)
 903                         return -EPERM;
 904                 op.op = KD_FONT_OP_SET;
 905                 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
 906                 op.width = 8;
 907                 op.height = 0;
 908                 op.charcount = 256;
 909                 op.data = up;
 910                 return con_font_op(vc_cons[fg_console].d, &op);
 911         }
 912
 913         case GIO_FONT: {
 914                 op.op = KD_FONT_OP_GET;
 915                 op.flags = KD_FONT_FLAG_OLD;
 916                 op.width = 8;
 917                 op.height = 32;
 918                 op.charcount = 256;
 919                 op.data = up;
 920                 return con_font_op(vc_cons[fg_console].d, &op);
 921         }
 922
 923         case PIO_CMAP:
 924                 if (!perm)
 925                         return -EPERM;
 926                 return con_set_cmap(up);
 927
 928         case GIO_CMAP:
 929                 return con_get_cmap(up);
 930
 931         case PIO_FONTX:
 932         case GIO_FONTX:
 933                 return do_fontx_ioctl(cmd, up, perm, &op);
 934
 935         case PIO_FONTRESET:
 936         {
 937                 if (!perm)
 938                         return -EPERM;
 939
 940 #ifdef BROKEN_GRAPHICS_PROGRAMS
 941                 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 942                    font is not saved. */
 943                 return -ENOSYS;
 944 #else
 945                 {
 946                 op.op = KD_FONT_OP_SET_DEFAULT;
 947                 op.data = NULL;
 948                 i = con_font_op(vc_cons[fg_console].d, &op);
 949                 if (i)
 950                         return i;
 951                 con_set_default_unimap(vc_cons[fg_console].d);
 952                 return 0;
 953                 }
 954 #endif
 955         }
 956
 957         case KDFONTOP: {
 958                 if (copy_from_user(&op, up, sizeof(op)))
 959                         return -EFAULT;
 960                 if (!perm && op.op != KD_FONT_OP_GET)
 961                         return -EPERM;
 962                 i = con_font_op(vc, &op);
 963                 if (i) return i;
 964                 if (copy_to_user(up, &op, sizeof(op)))
 965                         return -EFAULT;
 966                 return 0;
 967         }
 968
 969         case PIO_SCRNMAP:
 970                 if (!perm)
 971                         return -EPERM;
 972                 return con_set_trans_old(up);
 973
 974         case GIO_SCRNMAP:
 975                 return con_get_trans_old(up);
 976
 977         case PIO_UNISCRNMAP:
 978                 if (!perm)
 979                         return -EPERM;
 980                 return con_set_trans_new(up);
 981
 982         case GIO_UNISCRNMAP:
 983                 return con_get_trans_new(up);
 984
 985         case PIO_UNIMAPCLR:
 986               { struct unimapinit ui;
 987                 if (!perm)
 988                         return -EPERM;
 989                 i = copy_from_user(&ui, up, sizeof(struct unimapinit));
 990                 if (i) return -EFAULT;
 991                 con_clear_unimap(vc, &ui);
 992                 return 0;
 993               }
 994
 995         case PIO_UNIMAP:
 996         case GIO_UNIMAP:
 997                 return do_unimap_ioctl(cmd, up, perm, vc);
 998
 999         case VT_LOCKSWITCH:
1000                 if (!capable(CAP_SYS_TTY_CONFIG))
1001                    return -EPERM;
1002                 vt_dont_switch = 1;
1003                 return 0;
1004         case VT_UNLOCKSWITCH:
1005                 if (!capable(CAP_SYS_TTY_CONFIG))
1006                    return -EPERM;
1007                 vt_dont_switch = 0;
1008                 return 0;
1009         default:
1010                 return -ENOIOCTLCMD;
1011         }
1012 }
1013
1014 /*
1015  * Sometimes we want to wait until a particular VT has been activated. We
1016  * do it in a very simple manner. Everybody waits on a single queue and
1017  * get woken up at once. Those that are satisfied go on with their business,
1018  * while those not ready go back to sleep. Seems overkill to add a wait
1019  * to each vt just for this - usually this does nothing!
1020  */
1021 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
1022
1023 /*
1024  * Sleeps until a vt is activated, or the task is interrupted. Returns
1025  * 0 if activation, -EINTR if interrupted.
1026  */
1027 int vt_waitactive(int vt)
1028 {
1029         int retval;
1030         DECLARE_WAITQUEUE(wait, current);
1031
1032         add_wait_queue(&vt_activate_queue, &wait);
1033         for (;;) {
1034                 set_current_state(TASK_INTERRUPTIBLE);
1035                 retval = 0;
1036                 if (vt == fg_console)
1037                         break;
1038                 retval = -EINTR;
1039                 if (signal_pending(current))
1040                         break;
1041                 schedule();
1042         }
1043         remove_wait_queue(&vt_activate_queue, &wait);
1044         current->state = TASK_RUNNING;
1045         return retval;
1046 }
1047
1048 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1049
1050 void reset_vc(struct vc_data *vc)
1051 {
1052         vc->vc_mode = KD_TEXT;
1053         kbd_table[vc->vc_num].kbdmode = VC_XLATE;
1054         vc->vt_mode.mode = VT_AUTO;
1055         vc->vt_mode.waitv = 0;
1056         vc->vt_mode.relsig = 0;
1057         vc->vt_mode.acqsig = 0;
1058         vc->vt_mode.frsig = 0;
1059         vc->vt_pid = -1;
1060         vc->vt_newvt = -1;
1061         if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1062                 reset_palette(vc);
1063 }
1064
1065 /*
1066  * Performs the back end of a vt switch
1067  */
1068 static void complete_change_console(struct vc_data *vc)
1069 {
1070         unsigned char old_vc_mode;
1071
1072         last_console = fg_console;
1073
1074         /*
1075          * If we're switching, we could be going from KD_GRAPHICS to
1076          * KD_TEXT mode or vice versa, which means we need to blank or
1077          * unblank the screen later.
1078          */
1079         old_vc_mode = vc_cons[fg_console].d->vc_mode;
1080         switch_screen(vc);
1081
1082         /*
1083          * This can't appear below a successful kill_proc().  If it did,
1084          * then the *blank_screen operation could occur while X, having
1085          * received acqsig, is waking up on another processor.  This
1086          * condition can lead to overlapping accesses to the VGA range
1087          * and the framebuffer (causing system lockups).
1088          *
1089          * To account for this we duplicate this code below only if the
1090          * controlling process is gone and we've called reset_vc.
1091          */
1092         if (old_vc_mode != vc->vc_mode) {
1093                 if (vc->vc_mode == KD_TEXT)
1094                         do_unblank_screen(1);
1095                 else
1096                         do_blank_screen(1);
1097         }
1098
1099         /*
1100          * If this new console is under process control, send it a signal
1101          * telling it that it has acquired. Also check if it has died and
1102          * clean up (similar to logic employed in change_console())
1103          */
1104         if (vc->vt_mode.mode == VT_PROCESS) {
1105                 /*
1106                  * Send the signal as privileged - kill_proc() will
1107                  * tell us if the process has gone or something else
1108                  * is awry
1109                  */
1110                 if (kill_proc(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1111                 /*
1112                  * The controlling process has died, so we revert back to
1113                  * normal operation. In this case, we'll also change back
1114                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1115                  * but it saves the agony when the X server dies and the screen
1116                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1117                  * this outside of VT_PROCESS but there is no single process
1118                  * to account for and tracking tty count may be undesirable.
1119                  */
1120                         reset_vc(vc);
1121
1122                         if (old_vc_mode != vc->vc_mode) {
1123                                 if (vc->vc_mode == KD_TEXT)
1124                                         do_unblank_screen(1);
1125                                 else
1126                                         do_blank_screen(1);
1127                         }
1128                 }
1129         }
1130
1131         /*
1132          * Wake anyone waiting for their VT to activate
1133          */
1134         vt_wake_waitactive();
1135         return;
1136 }
1137
1138 /*
1139  * Performs the front-end of a vt switch
1140  */
1141 void change_console(struct vc_data *new_vc)
1142 {
1143         struct vc_data *vc;
1144
1145         if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1146                 return;
1147
1148         /*
1149          * If this vt is in process mode, then we need to handshake with
1150          * that process before switching. Essentially, we store where that
1151          * vt wants to switch to and wait for it to tell us when it's done
1152          * (via VT_RELDISP ioctl).
1153          *
1154          * We also check to see if the controlling process still exists.
1155          * If it doesn't, we reset this vt to auto mode and continue.
1156          * This is a cheap way to track process control. The worst thing
1157          * that can happen is: we send a signal to a process, it dies, and
1158          * the switch gets "lost" waiting for a response; hopefully, the
1159          * user will try again, we'll detect the process is gone (unless
1160          * the user waits just the right amount of time :-) and revert the
1161          * vt to auto control.
1162          */
1163         vc = vc_cons[fg_console].d;
1164         if (vc->vt_mode.mode == VT_PROCESS) {
1165                 /*
1166                  * Send the signal as privileged - kill_proc() will
1167                  * tell us if the process has gone or something else
1168                  * is awry
1169                  */
1170                 if (kill_proc(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1171                         /*
1172                          * It worked. Mark the vt to switch to and
1173                          * return. The process needs to send us a
1174                          * VT_RELDISP ioctl to complete the switch.
1175                          */
1176                         vc->vt_newvt = new_vc->vc_num;
1177                         return;
1178                 }
1179
1180                 /*
1181                  * The controlling process has died, so we revert back to
1182                  * normal operation. In this case, we'll also change back
1183                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1184                  * but it saves the agony when the X server dies and the screen
1185                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1186                  * this outside of VT_PROCESS but there is no single process
1187                  * to account for and tracking tty count may be undesirable.
1188                  */
1189                 reset_vc(vc);
1190
1191                 /*
1192                  * Fall through to normal (VT_AUTO) handling of the switch...
1193                  */
1194         }
1195
1196         /*
1197          * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1198          */
1199         if (vc->vc_mode == KD_GRAPHICS)
1200                 return;
1201
1202         complete_change_console(new_vc);
1203 }