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
  28 #include <asm/io.h>
  29 #include <asm/uaccess.h>
  30
  31 #include <linux/kbd_kern.h>
  32 #include <linux/vt_kern.h>
  33 #include <linux/kbd_diacr.h>
  34 #include <linux/selection.h>
  35
  36 char vt_dont_switch;
  37 extern struct tty_driver *console_driver;
  38
  39 #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count)
  40 #define VT_BUSY(i)      (VT_IS_IN_USE(i) || i == fg_console || i == sel_cons)
  41
  42 /*
  43  * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
  44  * experimentation and study of X386 SYSV handling.
  45  *
  46  * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
  47  * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
  48  * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
  49  * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
  50  * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
  51  * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
  52  * to the current console is done by the main ioctl code.
  53  */
  54
  55 struct vt_struct *vt_cons[MAX_NR_CONSOLES];
  56
  57 /* Keyboard type: Default is KB_101, but can be set by machine
  58  * specific code.
  59  */
  60 unsigned char keyboard_type = KB_101;
  61
  62 #ifdef CONFIG_X86
  63 #include <linux/syscalls.h>
  64 #endif
  65
  66 /*
  67  * these are the valid i/o ports we're allowed to change. they map all the
  68  * video ports
  69  */
  70 #define GPFIRST 0x3b4
  71 #define GPLAST 0x3df
  72 #define GPNUM (GPLAST - GPFIRST + 1)
  73
  74 #define i (tmp.kb_index)
  75 #define s (tmp.kb_table)
  76 #define v (tmp.kb_value)
  77 static inline int
  78 do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
  79 {
  80         struct kbentry tmp;
  81         ushort *key_map, val, ov;
  82
  83         if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
  84                 return -EFAULT;
  85
  86         switch (cmd) {
  87         case KDGKBENT:
  88                 key_map = key_maps[s];
  89                 if (key_map) {
  90                     val = U(key_map[i]);
  91                     if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
  92                         val = K_HOLE;
  93                 } else
  94                     val = (i ? K_HOLE : K_NOSUCHMAP);
  95                 return put_user(val, &user_kbe->kb_value);
  96         case KDSKBENT:
  97                 if (!perm)
  98                         return -EPERM;
  99                 if (!i && v == K_NOSUCHMAP) {
 100                         /* disallocate map */
 101                         key_map = key_maps[s];
 102                         if (s && key_map) {
 103                             key_maps[s] = NULL;
 104                             if (key_map[0] == U(K_ALLOCATED)) {
 105                                         kfree(key_map);
 106                                         keymap_count--;
 107                             }
 108                         }
 109                         break;
 110                 }
 111
 112                 if (KTYP(v) < NR_TYPES) {
 113                     if (KVAL(v) > max_vals[KTYP(v)])
 114                                 return -EINVAL;
 115                 } else
 116                     if (kbd->kbdmode != VC_UNICODE)
 117                                 return -EINVAL;
 118
 119                 /* ++Geert: non-PC keyboards may generate keycode zero */
 120 #if !defined(__mc68000__) && !defined(__powerpc__)
 121                 /* assignment to entry 0 only tests validity of args */
 122                 if (!i)
 123                         break;
 124 #endif
 125
 126                 if (!(key_map = key_maps[s])) {
 127                         int j;
 128
 129                         if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
 130                             !capable(CAP_SYS_RESOURCE))
 131                                 return -EPERM;
 132
 133                         key_map = (ushort *) kmalloc(sizeof(plain_map),
 134                                                      GFP_KERNEL);
 135                         if (!key_map)
 136                                 return -ENOMEM;
 137                         key_maps[s] = key_map;
 138                         key_map[0] = U(K_ALLOCATED);
 139                         for (j = 1; j < NR_KEYS; j++)
 140                                 key_map[j] = U(K_HOLE);
 141                         keymap_count++;
 142                 }
 143                 ov = U(key_map[i]);
 144                 if (v == ov)
 145                         break;  /* nothing to do */
 146                 /*
 147                  * Attention Key.
 148                  */
 149                 if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
 150                         return -EPERM;
 151                 key_map[i] = U(v);
 152                 if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
 153                         compute_shiftstate();
 154                 break;
 155         }
 156         return 0;
 157 }
 158 #undef i
 159 #undef s
 160 #undef v
 161
 162 static inline int
 163 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
 164 {
 165         struct kbkeycode tmp;
 166         int kc = 0;
 167
 168         if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
 169                 return -EFAULT;
 170         switch (cmd) {
 171         case KDGETKEYCODE:
 172                 kc = getkeycode(tmp.scancode);
 173                 if (kc >= 0)
 174                         kc = put_user(kc, &user_kbkc->keycode);
 175                 break;
 176         case KDSETKEYCODE:
 177                 if (!perm)
 178                         return -EPERM;
 179                 kc = setkeycode(tmp.scancode, tmp.keycode);
 180                 break;
 181         }
 182         return kc;
 183 }
 184
 185 static inline int
 186 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
 187 {
 188         struct kbsentry *kbs;
 189         char *p;
 190         u_char *q;
 191         u_char __user *up;
 192         int sz;
 193         int delta;
 194         char *first_free, *fj, *fnw;
 195         int i, j, k;
 196         int ret;
 197
 198         kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
 199         if (!kbs) {
 200                 ret = -ENOMEM;
 201                 goto reterr;
 202         }
 203
 204         /* we mostly copy too much here (512bytes), but who cares ;) */
 205         if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
 206                 ret = -EFAULT;
 207                 goto reterr;
 208         }
 209         kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
 210         i = kbs->kb_func;
 211
 212         switch (cmd) {
 213         case KDGKBSENT:
 214                 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
 215                                                   a struct member */
 216                 up = user_kdgkb->kb_string;
 217                 p = func_table[i];
 218                 if(p)
 219                         for ( ; *p && sz; p++, sz--)
 220                                 if (put_user(*p, up++)) {
 221                                         ret = -EFAULT;
 222                                         goto reterr;
 223                                 }
 224                 if (put_user('\0', up)) {
 225                         ret = -EFAULT;
 226                         goto reterr;
 227                 }
 228                 kfree(kbs);
 229                 return ((p && *p) ? -EOVERFLOW : 0);
 230         case KDSKBSENT:
 231                 if (!perm) {
 232                         ret = -EPERM;
 233                         goto reterr;
 234                 }
 235
 236                 q = func_table[i];
 237                 first_free = funcbufptr + (funcbufsize - funcbufleft);
 238                 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
 239                         ;
 240                 if (j < MAX_NR_FUNC)
 241                         fj = func_table[j];
 242                 else
 243                         fj = first_free;
 244
 245                 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
 246                 if (delta <= funcbufleft) {     /* it fits in current buf */
 247                     if (j < MAX_NR_FUNC) {
 248                         memmove(fj + delta, fj, first_free - fj);
 249                         for (k = j; k < MAX_NR_FUNC; k++)
 250                             if (func_table[k])
 251                                 func_table[k] += delta;
 252                     }
 253                     if (!q)
 254                       func_table[i] = fj;
 255                     funcbufleft -= delta;
 256                 } else {                        /* allocate a larger buffer */
 257                     sz = 256;
 258                     while (sz < funcbufsize - funcbufleft + delta)
 259                       sz <<= 1;
 260                     fnw = (char *) kmalloc(sz, GFP_KERNEL);
 261                     if(!fnw) {
 262                       ret = -ENOMEM;
 263                       goto reterr;
 264                     }
 265
 266                     if (!q)
 267                       func_table[i] = fj;
 268                     if (fj > funcbufptr)
 269                         memmove(fnw, funcbufptr, fj - funcbufptr);
 270                     for (k = 0; k < j; k++)
 271                       if (func_table[k])
 272                         func_table[k] = fnw + (func_table[k] - funcbufptr);
 273
 274                     if (first_free > fj) {
 275                         memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
 276                         for (k = j; k < MAX_NR_FUNC; k++)
 277                           if (func_table[k])
 278                             func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
 279                     }
 280                     if (funcbufptr != func_buf)
 281                       kfree(funcbufptr);
 282                     funcbufptr = fnw;
 283                     funcbufleft = funcbufleft - delta + sz - funcbufsize;
 284                     funcbufsize = sz;
 285                 }
 286                 strcpy(func_table[i], kbs->kb_string);
 287                 break;
 288         }
 289         ret = 0;
 290 reterr:
 291         kfree(kbs);
 292         return ret;
 293 }
 294
 295 static inline int
 296 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 297 {
 298         struct consolefontdesc cfdarg;
 299         int i;
 300
 301         if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
 302                 return -EFAULT;
 303
 304         switch (cmd) {
 305         case PIO_FONTX:
 306                 if (!perm)
 307                         return -EPERM;
 308                 op->op = KD_FONT_OP_SET;
 309                 op->flags = KD_FONT_FLAG_OLD;
 310                 op->width = 8;
 311                 op->height = cfdarg.charheight;
 312                 op->charcount = cfdarg.charcount;
 313                 op->data = cfdarg.chardata;
 314                 return con_font_op(fg_console, op);
 315         case GIO_FONTX: {
 316                 op->op = KD_FONT_OP_GET;
 317                 op->flags = KD_FONT_FLAG_OLD;
 318                 op->width = 8;
 319                 op->height = cfdarg.charheight;
 320                 op->charcount = cfdarg.charcount;
 321                 op->data = cfdarg.chardata;
 322                 i = con_font_op(fg_console, op);
 323                 if (i)
 324                         return i;
 325                 cfdarg.charheight = op->height;
 326                 cfdarg.charcount = op->charcount;
 327                 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 328                         return -EFAULT;
 329                 return 0;
 330                 }
 331         }
 332         return -EINVAL;
 333 }
 334
 335 static inline int
 336 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, unsigned int console)
 337 {
 338         struct unimapdesc tmp;
 339         int i = 0;
 340
 341         if (copy_from_user(&tmp, user_ud, sizeof tmp))
 342                 return -EFAULT;
 343         if (tmp.entries) {
 344                 i = verify_area(VERIFY_WRITE, tmp.entries,
 345                                                 tmp.entry_ct*sizeof(struct unipair));
 346                 if (i) return i;
 347         }
 348         switch (cmd) {
 349         case PIO_UNIMAP:
 350                 if (!perm)
 351                         return -EPERM;
 352                 return con_set_unimap(console, tmp.entry_ct, tmp.entries);
 353         case GIO_UNIMAP:
 354                 if (!perm && fg_console != console)
 355                         return -EPERM;
 356                 return con_get_unimap(console, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 357         }
 358         return 0;
 359 }
 360
 361 /*
 362  * We handle the console-specific ioctl's here.  We allow the
 363  * capability to modify any console, not just the fg_console.
 364  */
 365 int vt_ioctl(struct tty_struct *tty, struct file * file,
 366              unsigned int cmd, unsigned long arg)
 367 {
 368         struct vt_struct *vt = (struct vt_struct *)tty->driver_data;
 369         struct vc_data *vc = vc_cons[vt->vc_num].d;
 370         struct console_font_op op;      /* used in multiple places here */
 371         struct kbd_struct * kbd;
 372         unsigned int console;
 373         unsigned char ucval;
 374         void __user *up = (void __user *)arg;
 375         int i, perm;
 376
 377         console = vt->vc_num;
 378
 379         if (!vc_cons_allocated(console))        /* impossible? */
 380                 return -ENOIOCTLCMD;
 381
 382         /*
 383          * To have permissions to do most of the vt ioctls, we either have
 384          * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 385          */
 386         perm = 0;
 387         if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 388                 perm = 1;
 389
 390         kbd = kbd_table + console;
 391         switch (cmd) {
 392         case KIOCSOUND:
 393                 if (!perm)
 394                         return -EPERM;
 395                 if (arg)
 396                         arg = 1193182 / arg;
 397                 kd_mksound(arg, 0);
 398                 return 0;
 399
 400         case KDMKTONE:
 401                 if (!perm)
 402                         return -EPERM;
 403         {
 404                 unsigned int ticks, count;
 405
 406                 /*
 407                  * Generate the tone for the appropriate number of ticks.
 408                  * If the time is zero, turn off sound ourselves.
 409                  */
 410                 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
 411                 count = ticks ? (arg & 0xffff) : 0;
 412                 if (count)
 413                         count = 1193182 / count;
 414                 kd_mksound(count, ticks);
 415                 return 0;
 416         }
 417
 418         case KDGKBTYPE:
 419                 /*
 420                  * this is naive.
 421                  */
 422                 ucval = keyboard_type;
 423                 goto setchar;
 424
 425                 /*
 426                  * These cannot be implemented on any machine that implements
 427                  * ioperm() in user level (such as Alpha PCs) or not at all.
 428                  *
 429                  * XXX: you should never use these, just call ioperm directly..
 430                  */
 431 #ifdef CONFIG_X86
 432         case KDADDIO:
 433         case KDDELIO:
 434                 /*
 435                  * KDADDIO and KDDELIO may be able to add ports beyond what
 436                  * we reject here, but to be safe...
 437                  */
 438                 if (arg < GPFIRST || arg > GPLAST)
 439                         return -EINVAL;
 440                 return sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 441
 442         case KDENABIO:
 443         case KDDISABIO:
 444                 return sys_ioperm(GPFIRST, GPNUM,
 445                                   (cmd == KDENABIO)) ? -ENXIO : 0;
 446 #endif
 447
 448         /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 449
 450         case KDKBDREP:
 451         {
 452                 struct kbd_repeat kbrep;
 453                 int err;
 454
 455                 if (!capable(CAP_SYS_TTY_CONFIG))
 456                         return -EPERM;
 457
 458                 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
 459                         return -EFAULT;
 460                 err = kbd_rate(&kbrep);
 461                 if (err)
 462                         return err;
 463                 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 464                         return -EFAULT;
 465                 return 0;
 466         }
 467
 468         case KDSETMODE:
 469                 /*
 470                  * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 471                  * doesn't do a whole lot. i'm not sure if it should do any
 472                  * restoration of modes or what...
 473                  *
 474                  * XXX It should at least call into the driver, fbdev's definitely
 475                  * need to restore their engine state. --BenH
 476                  */
 477                 if (!perm)
 478                         return -EPERM;
 479                 switch (arg) {
 480                 case KD_GRAPHICS:
 481                         break;
 482                 case KD_TEXT0:
 483                 case KD_TEXT1:
 484                         arg = KD_TEXT;
 485                 case KD_TEXT:
 486                         break;
 487                 default:
 488                         return -EINVAL;
 489                 }
 490                 if (vt_cons[console]->vc_mode == (unsigned char) arg)
 491                         return 0;
 492                 vt_cons[console]->vc_mode = (unsigned char) arg;
 493                 if (console != fg_console)
 494                         return 0;
 495                 /*
 496                  * explicitly blank/unblank the screen if switching modes
 497                  */
 498                 acquire_console_sem();
 499                 if (arg == KD_TEXT)
 500                         do_unblank_screen(1);
 501                 else
 502                         do_blank_screen(1);
 503                 release_console_sem();
 504                 return 0;
 505
 506         case KDGETMODE:
 507                 ucval = vt_cons[console]->vc_mode;
 508                 goto setint;
 509
 510         case KDMAPDISP:
 511         case KDUNMAPDISP:
 512                 /*
 513                  * these work like a combination of mmap and KDENABIO.
 514                  * this could be easily finished.
 515                  */
 516                 return -EINVAL;
 517
 518         case KDSKBMODE:
 519                 if (!perm)
 520                         return -EPERM;
 521                 switch(arg) {
 522                   case K_RAW:
 523                         kbd->kbdmode = VC_RAW;
 524                         break;
 525                   case K_MEDIUMRAW:
 526                         kbd->kbdmode = VC_MEDIUMRAW;
 527                         break;
 528                   case K_XLATE:
 529                         kbd->kbdmode = VC_XLATE;
 530                         compute_shiftstate();
 531                         break;
 532                   case K_UNICODE:
 533                         kbd->kbdmode = VC_UNICODE;
 534                         compute_shiftstate();
 535                         break;
 536                   default:
 537                         return -EINVAL;
 538                 }
 539                 tty_ldisc_flush(tty);
 540                 return 0;
 541
 542         case KDGKBMODE:
 543                 ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
 544                                  (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
 545                                  (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
 546                                  K_XLATE);
 547                 goto setint;
 548
 549         /* this could be folded into KDSKBMODE, but for compatibility
 550            reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 551         case KDSKBMETA:
 552                 switch(arg) {
 553                   case K_METABIT:
 554                         clr_vc_kbd_mode(kbd, VC_META);
 555                         break;
 556                   case K_ESCPREFIX:
 557                         set_vc_kbd_mode(kbd, VC_META);
 558                         break;
 559                   default:
 560                         return -EINVAL;
 561                 }
 562                 return 0;
 563
 564         case KDGKBMETA:
 565                 ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
 566         setint:
 567                 return put_user(ucval, (int __user *)arg);
 568
 569         case KDGETKEYCODE:
 570         case KDSETKEYCODE:
 571                 if(!capable(CAP_SYS_TTY_CONFIG))
 572                         perm=0;
 573                 return do_kbkeycode_ioctl(cmd, up, perm);
 574
 575         case KDGKBENT:
 576         case KDSKBENT:
 577                 return do_kdsk_ioctl(cmd, up, perm, kbd);
 578
 579         case KDGKBSENT:
 580         case KDSKBSENT:
 581                 return do_kdgkb_ioctl(cmd, up, perm);
 582
 583         case KDGKBDIACR:
 584         {
 585                 struct kbdiacrs __user *a = up;
 586
 587                 if (put_user(accent_table_size, &a->kb_cnt))
 588                         return -EFAULT;
 589                 if (copy_to_user(a->kbdiacr, accent_table, accent_table_size*sizeof(struct kbdiacr)))
 590                         return -EFAULT;
 591                 return 0;
 592         }
 593
 594         case KDSKBDIACR:
 595         {
 596                 struct kbdiacrs __user *a = up;
 597                 unsigned int ct;
 598
 599                 if (!perm)
 600                         return -EPERM;
 601                 if (get_user(ct,&a->kb_cnt))
 602                         return -EFAULT;
 603                 if (ct >= MAX_DIACR)
 604                         return -EINVAL;
 605                 accent_table_size = ct;
 606                 if (copy_from_user(accent_table, a->kbdiacr, ct*sizeof(struct kbdiacr)))
 607                         return -EFAULT;
 608                 return 0;
 609         }
 610
 611         /* the ioctls below read/set the flags usually shown in the leds */
 612         /* don't use them - they will go away without warning */
 613         case KDGKBLED:
 614                 ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
 615                 goto setchar;
 616
 617         case KDSKBLED:
 618                 if (!perm)
 619                         return -EPERM;
 620                 if (arg & ~0x77)
 621                         return -EINVAL;
 622                 kbd->ledflagstate = (arg & 7);
 623                 kbd->default_ledflagstate = ((arg >> 4) & 7);
 624                 set_leds();
 625                 return 0;
 626
 627         /* the ioctls below only set the lights, not the functions */
 628         /* for those, see KDGKBLED and KDSKBLED above */
 629         case KDGETLED:
 630                 ucval = getledstate();
 631         setchar:
 632                 return put_user(ucval, (char __user *)arg);
 633
 634         case KDSETLED:
 635                 if (!perm)
 636                   return -EPERM;
 637                 setledstate(kbd, arg);
 638                 return 0;
 639
 640         /*
 641          * A process can indicate its willingness to accept signals
 642          * generated by pressing an appropriate key combination.
 643          * Thus, one can have a daemon that e.g. spawns a new console
 644          * upon a keypress and then changes to it.
 645          * See also the kbrequest field of inittab(5).
 646          */
 647         case KDSIGACCEPT:
 648         {
 649                 extern int spawnpid, spawnsig;
 650                 if (!perm || !capable(CAP_KILL))
 651                   return -EPERM;
 652                 if (arg < 1 || arg > _NSIG || arg == SIGKILL)
 653                   return -EINVAL;
 654                 spawnpid = current->pid;
 655                 spawnsig = arg;
 656                 return 0;
 657         }
 658
 659         case VT_SETMODE:
 660         {
 661                 struct vt_mode tmp;
 662
 663                 if (!perm)
 664                         return -EPERM;
 665                 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
 666                         return -EFAULT;
 667                 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
 668                         return -EINVAL;
 669                 acquire_console_sem();
 670                 vt_cons[console]->vt_mode = tmp;
 671                 /* the frsig is ignored, so we set it to 0 */
 672                 vt_cons[console]->vt_mode.frsig = 0;
 673                 vt_cons[console]->vt_pid = current->pid;
 674                 /* no switch is required -- saw@shade.msu.ru */
 675                 vt_cons[console]->vt_newvt = -1;
 676                 release_console_sem();
 677                 return 0;
 678         }
 679
 680         case VT_GETMODE:
 681         {
 682                 struct vt_mode tmp;
 683                 int rc;
 684
 685                 acquire_console_sem();
 686                 memcpy(&tmp, &vt_cons[console]->vt_mode, sizeof(struct vt_mode));
 687                 release_console_sem();
 688
 689                 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 690                 return rc ? -EFAULT : 0;
 691         }
 692
 693         /*
 694          * Returns global vt state. Note that VT 0 is always open, since
 695          * it's an alias for the current VT, and people can't use it here.
 696          * We cannot return state for more than 16 VTs, since v_state is short.
 697          */
 698         case VT_GETSTATE:
 699         {
 700                 struct vt_stat __user *vtstat = up;
 701                 unsigned short state, mask;
 702
 703                 if (put_user(fg_console + 1, &vtstat->v_active))
 704                         return -EFAULT;
 705                 state = 1;      /* /dev/tty0 is always open */
 706                 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1)
 707                         if (VT_IS_IN_USE(i))
 708                                 state |= mask;
 709                 return put_user(state, &vtstat->v_state);
 710         }
 711
 712         /*
 713          * Returns the first available (non-opened) console.
 714          */
 715         case VT_OPENQRY:
 716                 for (i = 0; i < MAX_NR_CONSOLES; ++i)
 717                         if (! VT_IS_IN_USE(i))
 718                                 break;
 719                 ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
 720                 goto setint;
 721
 722         /*
 723          * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 724          * with num >= 1 (switches to vt 0, our console, are not allowed, just
 725          * to preserve sanity).
 726          */
 727         case VT_ACTIVATE:
 728                 if (!perm)
 729                         return -EPERM;
 730                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 731                         return -ENXIO;
 732                 arg--;
 733                 acquire_console_sem();
 734                 i = vc_allocate(arg);
 735                 release_console_sem();
 736                 if (i)
 737                         return i;
 738                 set_console(arg);
 739                 return 0;
 740
 741         /*
 742          * wait until the specified VT has been activated
 743          */
 744         case VT_WAITACTIVE:
 745                 if (!perm)
 746                         return -EPERM;
 747                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 748                         return -ENXIO;
 749                 return vt_waitactive(arg-1);
 750
 751         /*
 752          * If a vt is under process control, the kernel will not switch to it
 753          * immediately, but postpone the operation until the process calls this
 754          * ioctl, allowing the switch to complete.
 755          *
 756          * According to the X sources this is the behavior:
 757          *      0:      pending switch-from not OK
 758          *      1:      pending switch-from OK
 759          *      2:      completed switch-to OK
 760          */
 761         case VT_RELDISP:
 762                 if (!perm)
 763                         return -EPERM;
 764                 if (vt_cons[console]->vt_mode.mode != VT_PROCESS)
 765                         return -EINVAL;
 766
 767                 /*
 768                  * Switching-from response
 769                  */
 770                 if (vt_cons[console]->vt_newvt >= 0)
 771                 {
 772                         if (arg == 0)
 773                                 /*
 774                                  * Switch disallowed, so forget we were trying
 775                                  * to do it.
 776                                  */
 777                                 vt_cons[console]->vt_newvt = -1;
 778
 779                         else
 780                         {
 781                                 /*
 782                                  * The current vt has been released, so
 783                                  * complete the switch.
 784                                  */
 785                                 int newvt;
 786                                 acquire_console_sem();
 787                                 newvt = vt_cons[console]->vt_newvt;
 788                                 vt_cons[console]->vt_newvt = -1;
 789                                 i = vc_allocate(newvt);
 790                                 if (i) {
 791                                         release_console_sem();
 792                                         return i;
 793                                 }
 794                                 /*
 795                                  * When we actually do the console switch,
 796                                  * make sure we are atomic with respect to
 797                                  * other console switches..
 798                                  */
 799                                 complete_change_console(newvt);
 800                                 release_console_sem();
 801                         }
 802                 }
 803
 804                 /*
 805                  * Switched-to response
 806                  */
 807                 else
 808                 {
 809                         /*
 810                          * If it's just an ACK, ignore it
 811                          */
 812                         if (arg != VT_ACKACQ)
 813                                 return -EINVAL;
 814                 }
 815
 816                 return 0;
 817
 818          /*
 819           * Disallocate memory associated to VT (but leave VT1)
 820           */
 821          case VT_DISALLOCATE:
 822                 if (arg > MAX_NR_CONSOLES)
 823                         return -ENXIO;
 824                 if (arg == 0) {
 825                     /* disallocate all unused consoles, but leave 0 */
 826                         acquire_console_sem();
 827                         for (i=1; i<MAX_NR_CONSOLES; i++)
 828                                 if (! VT_BUSY(i))
 829                                         vc_disallocate(i);
 830                         release_console_sem();
 831                 } else {
 832                         /* disallocate a single console, if possible */
 833                         arg--;
 834                         if (VT_BUSY(arg))
 835                                 return -EBUSY;
 836                         if (arg) {                            /* leave 0 */
 837                                 acquire_console_sem();
 838                                 vc_disallocate(arg);
 839                                 release_console_sem();
 840                         }
 841                 }
 842                 return 0;
 843
 844         case VT_RESIZE:
 845         {
 846                 struct vt_sizes __user *vtsizes = up;
 847                 ushort ll,cc;
 848                 if (!perm)
 849                         return -EPERM;
 850                 if (get_user(ll, &vtsizes->v_rows) ||
 851                     get_user(cc, &vtsizes->v_cols))
 852                         return -EFAULT;
 853                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 854                         acquire_console_sem();
 855                         vc_resize(i, cc, ll);
 856                         release_console_sem();
 857                 }
 858                 return 0;
 859         }
 860
 861         case VT_RESIZEX:
 862         {
 863                 struct vt_consize __user *vtconsize = up;
 864                 ushort ll,cc,vlin,clin,vcol,ccol;
 865                 if (!perm)
 866                         return -EPERM;
 867                 if (verify_area(VERIFY_READ, vtconsize,
 868                                 sizeof(struct vt_consize)))
 869                         return -EFAULT;
 870                 __get_user(ll, &vtconsize->v_rows);
 871                 __get_user(cc, &vtconsize->v_cols);
 872                 __get_user(vlin, &vtconsize->v_vlin);
 873                 __get_user(clin, &vtconsize->v_clin);
 874                 __get_user(vcol, &vtconsize->v_vcol);
 875                 __get_user(ccol, &vtconsize->v_ccol);
 876                 vlin = vlin ? vlin : vc->vc_scan_lines;
 877                 if (clin) {
 878                         if (ll) {
 879                                 if (ll != vlin/clin)
 880                                         return -EINVAL; /* Parameters don't add up */
 881                         } else
 882                                 ll = vlin/clin;
 883                 }
 884                 if (vcol && ccol) {
 885                         if (cc) {
 886                                 if (cc != vcol/ccol)
 887                                         return -EINVAL;
 888                         } else
 889                                 cc = vcol/ccol;
 890                 }
 891
 892                 if (clin > 32)
 893                         return -EINVAL;
 894
 895                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 896                         if (!vc_cons[i].d)
 897                                 continue;
 898                         acquire_console_sem();
 899                         if (vlin)
 900                                 vc_cons[i].d->vc_scan_lines = vlin;
 901                         if (clin)
 902                                 vc_cons[i].d->vc_font.height = clin;
 903                         vc_resize(i, cc, ll);
 904                         release_console_sem();
 905                 }
 906                 return 0;
 907         }
 908
 909         case PIO_FONT: {
 910                 if (!perm)
 911                         return -EPERM;
 912                 op.op = KD_FONT_OP_SET;
 913                 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
 914                 op.width = 8;
 915                 op.height = 0;
 916                 op.charcount = 256;
 917                 op.data = up;
 918                 return con_font_op(fg_console, &op);
 919         }
 920
 921         case GIO_FONT: {
 922                 op.op = KD_FONT_OP_GET;
 923                 op.flags = KD_FONT_FLAG_OLD;
 924                 op.width = 8;
 925                 op.height = 32;
 926                 op.charcount = 256;
 927                 op.data = up;
 928                 return con_font_op(fg_console, &op);
 929         }
 930
 931         case PIO_CMAP:
 932                 if (!perm)
 933                         return -EPERM;
 934                 return con_set_cmap(up);
 935
 936         case GIO_CMAP:
 937                 return con_get_cmap(up);
 938
 939         case PIO_FONTX:
 940         case GIO_FONTX:
 941                 return do_fontx_ioctl(cmd, up, perm, &op);
 942
 943         case PIO_FONTRESET:
 944         {
 945                 if (!perm)
 946                         return -EPERM;
 947
 948 #ifdef BROKEN_GRAPHICS_PROGRAMS
 949                 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 950                    font is not saved. */
 951                 return -ENOSYS;
 952 #else
 953                 {
 954                 op.op = KD_FONT_OP_SET_DEFAULT;
 955                 op.data = NULL;
 956                 i = con_font_op(fg_console, &op);
 957                 if (i) return i;
 958                 con_set_default_unimap(fg_console);
 959                 return 0;
 960                 }
 961 #endif
 962         }
 963
 964         case KDFONTOP: {
 965                 if (copy_from_user(&op, up, sizeof(op)))
 966                         return -EFAULT;
 967                 if (!perm && op.op != KD_FONT_OP_GET)
 968                         return -EPERM;
 969                 i = con_font_op(console, &op);
 970                 if (i) return i;
 971                 if (copy_to_user(up, &op, sizeof(op)))
 972                         return -EFAULT;
 973                 return 0;
 974         }
 975
 976         case PIO_SCRNMAP:
 977                 if (!perm)
 978                         return -EPERM;
 979                 return con_set_trans_old(up);
 980
 981         case GIO_SCRNMAP:
 982                 return con_get_trans_old(up);
 983
 984         case PIO_UNISCRNMAP:
 985                 if (!perm)
 986                         return -EPERM;
 987                 return con_set_trans_new(up);
 988
 989         case GIO_UNISCRNMAP:
 990                 return con_get_trans_new(up);
 991
 992         case PIO_UNIMAPCLR:
 993               { struct unimapinit ui;
 994                 if (!perm)
 995                         return -EPERM;
 996                 i = copy_from_user(&ui, up, sizeof(struct unimapinit));
 997                 if (i) return -EFAULT;
 998                 con_clear_unimap(console, &ui);
 999                 return 0;
1000               }
1001
1002         case PIO_UNIMAP:
1003         case GIO_UNIMAP:
1004                 return do_unimap_ioctl(cmd, up, perm, console);
1005
1006         case VT_LOCKSWITCH:
1007                 if (!capable(CAP_SYS_TTY_CONFIG))
1008                    return -EPERM;
1009                 vt_dont_switch = 1;
1010                 return 0;
1011         case VT_UNLOCKSWITCH:
1012                 if (!capable(CAP_SYS_TTY_CONFIG))
1013                    return -EPERM;
1014                 vt_dont_switch = 0;
1015                 return 0;
1016         default:
1017                 return -ENOIOCTLCMD;
1018         }
1019 }
1020
1021 /*
1022  * Sometimes we want to wait until a particular VT has been activated. We
1023  * do it in a very simple manner. Everybody waits on a single queue and
1024  * get woken up at once. Those that are satisfied go on with their business,
1025  * while those not ready go back to sleep. Seems overkill to add a wait
1026  * to each vt just for this - usually this does nothing!
1027  */
1028 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
1029
1030 /*
1031  * Sleeps until a vt is activated, or the task is interrupted. Returns
1032  * 0 if activation, -EINTR if interrupted.
1033  */
1034 int vt_waitactive(int vt)
1035 {
1036         int retval;
1037         DECLARE_WAITQUEUE(wait, current);
1038
1039         add_wait_queue(&vt_activate_queue, &wait);
1040         for (;;) {
1041                 set_current_state(TASK_INTERRUPTIBLE);
1042                 retval = 0;
1043                 if (vt == fg_console)
1044                         break;
1045                 retval = -EINTR;
1046                 if (signal_pending(current))
1047                         break;
1048                 schedule();
1049         }
1050         remove_wait_queue(&vt_activate_queue, &wait);
1051         current->state = TASK_RUNNING;
1052         return retval;
1053 }
1054
1055 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1056
1057 void reset_vc(unsigned int new_console)
1058 {
1059         vt_cons[new_console]->vc_mode = KD_TEXT;
1060         kbd_table[new_console].kbdmode = VC_XLATE;
1061         vt_cons[new_console]->vt_mode.mode = VT_AUTO;
1062         vt_cons[new_console]->vt_mode.waitv = 0;
1063         vt_cons[new_console]->vt_mode.relsig = 0;
1064         vt_cons[new_console]->vt_mode.acqsig = 0;
1065         vt_cons[new_console]->vt_mode.frsig = 0;
1066         vt_cons[new_console]->vt_pid = -1;
1067         vt_cons[new_console]->vt_newvt = -1;
1068         if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1069                 reset_palette(new_console) ;
1070 }
1071
1072 /*
1073  * Performs the back end of a vt switch
1074  */
1075 void complete_change_console(unsigned int new_console)
1076 {
1077         unsigned char old_vc_mode;
1078
1079         last_console = fg_console;
1080
1081         /*
1082          * If we're switching, we could be going from KD_GRAPHICS to
1083          * KD_TEXT mode or vice versa, which means we need to blank or
1084          * unblank the screen later.
1085          */
1086         old_vc_mode = vt_cons[fg_console]->vc_mode;
1087         switch_screen(new_console);
1088
1089         /*
1090          * This can't appear below a successful kill_proc().  If it did,
1091          * then the *blank_screen operation could occur while X, having
1092          * received acqsig, is waking up on another processor.  This
1093          * condition can lead to overlapping accesses to the VGA range
1094          * and the framebuffer (causing system lockups).
1095          *
1096          * To account for this we duplicate this code below only if the
1097          * controlling process is gone and we've called reset_vc.
1098          */
1099         if (old_vc_mode != vt_cons[new_console]->vc_mode)
1100         {
1101                 if (vt_cons[new_console]->vc_mode == KD_TEXT)
1102                         do_unblank_screen(1);
1103                 else
1104                         do_blank_screen(1);
1105         }
1106
1107         /*
1108          * If this new console is under process control, send it a signal
1109          * telling it that it has acquired. Also check if it has died and
1110          * clean up (similar to logic employed in change_console())
1111          */
1112         if (vt_cons[new_console]->vt_mode.mode == VT_PROCESS)
1113         {
1114                 /*
1115                  * Send the signal as privileged - kill_proc() will
1116                  * tell us if the process has gone or something else
1117                  * is awry
1118                  */
1119                 if (kill_proc(vt_cons[new_console]->vt_pid,
1120                               vt_cons[new_console]->vt_mode.acqsig,
1121                               1) != 0)
1122                 {
1123                 /*
1124                  * The controlling process has died, so we revert back to
1125                  * normal operation. In this case, we'll also change back
1126                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1127                  * but it saves the agony when the X server dies and the screen
1128                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1129                  * this outside of VT_PROCESS but there is no single process
1130                  * to account for and tracking tty count may be undesirable.
1131                  */
1132                         reset_vc(new_console);
1133
1134                         if (old_vc_mode != vt_cons[new_console]->vc_mode)
1135                         {
1136                                 if (vt_cons[new_console]->vc_mode == KD_TEXT)
1137                                         do_unblank_screen(1);
1138                                 else
1139                                         do_blank_screen(1);
1140                         }
1141                 }
1142         }
1143
1144         /*
1145          * Wake anyone waiting for their VT to activate
1146          */
1147         vt_wake_waitactive();
1148         return;
1149 }
1150
1151 /*
1152  * Performs the front-end of a vt switch
1153  */
1154 void change_console(unsigned int new_console)
1155 {
1156         if ((new_console == fg_console) || (vt_dont_switch))
1157                 return;
1158         if (!vc_cons_allocated(new_console))
1159                 return;
1160
1161         /*
1162          * If this vt is in process mode, then we need to handshake with
1163          * that process before switching. Essentially, we store where that
1164          * vt wants to switch to and wait for it to tell us when it's done
1165          * (via VT_RELDISP ioctl).
1166          *
1167          * We also check to see if the controlling process still exists.
1168          * If it doesn't, we reset this vt to auto mode and continue.
1169          * This is a cheap way to track process control. The worst thing
1170          * that can happen is: we send a signal to a process, it dies, and
1171          * the switch gets "lost" waiting for a response; hopefully, the
1172          * user will try again, we'll detect the process is gone (unless
1173          * the user waits just the right amount of time :-) and revert the
1174          * vt to auto control.
1175          */
1176         if (vt_cons[fg_console]->vt_mode.mode == VT_PROCESS)
1177         {
1178                 /*
1179                  * Send the signal as privileged - kill_proc() will
1180                  * tell us if the process has gone or something else
1181                  * is awry
1182                  */
1183                 if (kill_proc(vt_cons[fg_console]->vt_pid,
1184                               vt_cons[fg_console]->vt_mode.relsig,
1185                               1) == 0)
1186                 {
1187                         /*
1188                          * It worked. Mark the vt to switch to and
1189                          * return. The process needs to send us a
1190                          * VT_RELDISP ioctl to complete the switch.
1191                          */
1192                         vt_cons[fg_console]->vt_newvt = new_console;
1193                         return;
1194                 }
1195
1196                 /*
1197                  * The controlling process has died, so we revert back to
1198                  * normal operation. In this case, we'll also change back
1199                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1200                  * but it saves the agony when the X server dies and the screen
1201                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1202                  * this outside of VT_PROCESS but there is no single process
1203                  * to account for and tracking tty count may be undesirable.
1204                  */
1205                 reset_vc(fg_console);
1206
1207                 /*
1208                  * Fall through to normal (VT_AUTO) handling of the switch...
1209                  */
1210         }
1211
1212         /*
1213          * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1214          */
1215         if (vt_cons[fg_console]->vc_mode == KD_GRAPHICS)
1216                 return;
1217
1218         complete_change_console(new_console);
1219 }