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         if (!capable(CAP_SYS_TTY_CONFIG))
  84                 perm = 0;
  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         if (!capable(CAP_SYS_TTY_CONFIG))
 199                 perm = 0;
 200
 201         kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
 202         if (!kbs) {
 203                 ret = -ENOMEM;
 204                 goto reterr;
 205         }
 206
 207         /* we mostly copy too much here (512bytes), but who cares ;) */
 208         if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
 209                 ret = -EFAULT;
 210                 goto reterr;
 211         }
 212         kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
 213         i = kbs->kb_func;
 214
 215         switch (cmd) {
 216         case KDGKBSENT:
 217                 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
 218                                                   a struct member */
 219                 up = user_kdgkb->kb_string;
 220                 p = func_table[i];
 221                 if(p)
 222                         for ( ; *p && sz; p++, sz--)
 223                                 if (put_user(*p, up++)) {
 224                                         ret = -EFAULT;
 225                                         goto reterr;
 226                                 }
 227                 if (put_user('\0', up)) {
 228                         ret = -EFAULT;
 229                         goto reterr;
 230                 }
 231                 kfree(kbs);
 232                 return ((p && *p) ? -EOVERFLOW : 0);
 233         case KDSKBSENT:
 234                 if (!perm) {
 235                         ret = -EPERM;
 236                         goto reterr;
 237                 }
 238
 239                 q = func_table[i];
 240                 first_free = funcbufptr + (funcbufsize - funcbufleft);
 241                 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
 242                         ;
 243                 if (j < MAX_NR_FUNC)
 244                         fj = func_table[j];
 245                 else
 246                         fj = first_free;
 247
 248                 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
 249                 if (delta <= funcbufleft) {     /* it fits in current buf */
 250                     if (j < MAX_NR_FUNC) {
 251                         memmove(fj + delta, fj, first_free - fj);
 252                         for (k = j; k < MAX_NR_FUNC; k++)
 253                             if (func_table[k])
 254                                 func_table[k] += delta;
 255                     }
 256                     if (!q)
 257                       func_table[i] = fj;
 258                     funcbufleft -= delta;
 259                 } else {                        /* allocate a larger buffer */
 260                     sz = 256;
 261                     while (sz < funcbufsize - funcbufleft + delta)
 262                       sz <<= 1;
 263                     fnw = (char *) kmalloc(sz, GFP_KERNEL);
 264                     if(!fnw) {
 265                       ret = -ENOMEM;
 266                       goto reterr;
 267                     }
 268
 269                     if (!q)
 270                       func_table[i] = fj;
 271                     if (fj > funcbufptr)
 272                         memmove(fnw, funcbufptr, fj - funcbufptr);
 273                     for (k = 0; k < j; k++)
 274                       if (func_table[k])
 275                         func_table[k] = fnw + (func_table[k] - funcbufptr);
 276
 277                     if (first_free > fj) {
 278                         memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
 279                         for (k = j; k < MAX_NR_FUNC; k++)
 280                           if (func_table[k])
 281                             func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
 282                     }
 283                     if (funcbufptr != func_buf)
 284                       kfree(funcbufptr);
 285                     funcbufptr = fnw;
 286                     funcbufleft = funcbufleft - delta + sz - funcbufsize;
 287                     funcbufsize = sz;
 288                 }
 289                 strcpy(func_table[i], kbs->kb_string);
 290                 break;
 291         }
 292         ret = 0;
 293 reterr:
 294         kfree(kbs);
 295         return ret;
 296 }
 297
 298 static inline int
 299 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 300 {
 301         struct consolefontdesc cfdarg;
 302         int i;
 303
 304         if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
 305                 return -EFAULT;
 306
 307         switch (cmd) {
 308         case PIO_FONTX:
 309                 if (!perm)
 310                         return -EPERM;
 311                 op->op = KD_FONT_OP_SET;
 312                 op->flags = KD_FONT_FLAG_OLD;
 313                 op->width = 8;
 314                 op->height = cfdarg.charheight;
 315                 op->charcount = cfdarg.charcount;
 316                 op->data = cfdarg.chardata;
 317                 return con_font_op(vc_cons[fg_console].d, op);
 318         case GIO_FONTX: {
 319                 op->op = KD_FONT_OP_GET;
 320                 op->flags = KD_FONT_FLAG_OLD;
 321                 op->width = 8;
 322                 op->height = cfdarg.charheight;
 323                 op->charcount = cfdarg.charcount;
 324                 op->data = cfdarg.chardata;
 325                 i = con_font_op(vc_cons[fg_console].d, op);
 326                 if (i)
 327                         return i;
 328                 cfdarg.charheight = op->height;
 329                 cfdarg.charcount = op->charcount;
 330                 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 331                         return -EFAULT;
 332                 return 0;
 333                 }
 334         }
 335         return -EINVAL;
 336 }
 337
 338 static inline int
 339 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 340 {
 341         struct unimapdesc tmp;
 342
 343         if (copy_from_user(&tmp, user_ud, sizeof tmp))
 344                 return -EFAULT;
 345         if (tmp.entries)
 346                 if (!access_ok(VERIFY_WRITE, tmp.entries,
 347                                 tmp.entry_ct*sizeof(struct unipair)))
 348                         return -EFAULT;
 349         switch (cmd) {
 350         case PIO_UNIMAP:
 351                 if (!perm)
 352                         return -EPERM;
 353                 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 354         case GIO_UNIMAP:
 355                 if (!perm && fg_console != vc->vc_num)
 356                         return -EPERM;
 357                 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 358         }
 359         return 0;
 360 }
 361
 362 /*
 363  * We handle the console-specific ioctl's here.  We allow the
 364  * capability to modify any console, not just the fg_console.
 365  */
 366 int vt_ioctl(struct tty_struct *tty, struct file * file,
 367              unsigned int cmd, unsigned long arg)
 368 {
 369         struct vc_data *vc = (struct vc_data *)tty->driver_data;
 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 = vc->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 = CLOCK_TICK_RATE / 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 = CLOCK_TICK_RATE / count;
 414                 kd_mksound(count, ticks);
 415                 return 0;
 416         }
 417
 418         case KDGKBTYPE:
 419                 /*
 420                  * this is naive.
 421                  */
 422                 ucval = KB_101;
 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 (vc->vc_mode == (unsigned char) arg)
 491                         return 0;
 492                 vc->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 = vc->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 (!valid_signal(arg) || arg < 1 || 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                 vc->vt_mode = tmp;
 671                 /* the frsig is ignored, so we set it to 0 */
 672                 vc->vt_mode.frsig = 0;
 673                 vc->vt_pid = current->pid;
 674                 /* no switch is required -- saw@shade.msu.ru */
 675                 vc->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, &vc->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 (vc->vt_mode.mode != VT_PROCESS)
 765                         return -EINVAL;
 766
 767                 /*
 768                  * Switching-from response
 769                  */
 770                 if (vc->vt_newvt >= 0) {
 771                         if (arg == 0)
 772                                 /*
 773                                  * Switch disallowed, so forget we were trying
 774                                  * to do it.
 775                                  */
 776                                 vc->vt_newvt = -1;
 777
 778                         else {
 779                                 /*
 780                                  * The current vt has been released, so
 781                                  * complete the switch.
 782                                  */
 783                                 int newvt;
 784                                 acquire_console_sem();
 785                                 newvt = vc->vt_newvt;
 786                                 vc->vt_newvt = -1;
 787                                 i = vc_allocate(newvt);
 788                                 if (i) {
 789                                         release_console_sem();
 790                                         return i;
 791                                 }
 792                                 /*
 793                                  * When we actually do the console switch,
 794                                  * make sure we are atomic with respect to
 795                                  * other console switches..
 796                                  */
 797                                 complete_change_console(vc_cons[newvt].d);
 798                                 release_console_sem();
 799                         }
 800                 }
 801
 802                 /*
 803                  * Switched-to response
 804                  */
 805                 else
 806                 {
 807                         /*
 808                          * If it's just an ACK, ignore it
 809                          */
 810                         if (arg != VT_ACKACQ)
 811                                 return -EINVAL;
 812                 }
 813
 814                 return 0;
 815
 816          /*
 817           * Disallocate memory associated to VT (but leave VT1)
 818           */
 819          case VT_DISALLOCATE:
 820                 if (arg > MAX_NR_CONSOLES)
 821                         return -ENXIO;
 822                 if (arg == 0) {
 823                     /* disallocate all unused consoles, but leave 0 */
 824                         acquire_console_sem();
 825                         for (i=1; i<MAX_NR_CONSOLES; i++)
 826                                 if (! VT_BUSY(i))
 827                                         vc_disallocate(i);
 828                         release_console_sem();
 829                 } else {
 830                         /* disallocate a single console, if possible */
 831                         arg--;
 832                         if (VT_BUSY(arg))
 833                                 return -EBUSY;
 834                         if (arg) {                            /* leave 0 */
 835                                 acquire_console_sem();
 836                                 vc_disallocate(arg);
 837                                 release_console_sem();
 838                         }
 839                 }
 840                 return 0;
 841
 842         case VT_RESIZE:
 843         {
 844                 struct vt_sizes __user *vtsizes = up;
 845                 ushort ll,cc;
 846                 if (!perm)
 847                         return -EPERM;
 848                 if (get_user(ll, &vtsizes->v_rows) ||
 849                     get_user(cc, &vtsizes->v_cols))
 850                         return -EFAULT;
 851                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 852                         acquire_console_sem();
 853                         vc_resize(vc_cons[i].d, cc, ll);
 854                         release_console_sem();
 855                 }
 856                 return 0;
 857         }
 858
 859         case VT_RESIZEX:
 860         {
 861                 struct vt_consize __user *vtconsize = up;
 862                 ushort ll,cc,vlin,clin,vcol,ccol;
 863                 if (!perm)
 864                         return -EPERM;
 865                 if (!access_ok(VERIFY_READ, vtconsize,
 866                                 sizeof(struct vt_consize)))
 867                         return -EFAULT;
 868                 __get_user(ll, &vtconsize->v_rows);
 869                 __get_user(cc, &vtconsize->v_cols);
 870                 __get_user(vlin, &vtconsize->v_vlin);
 871                 __get_user(clin, &vtconsize->v_clin);
 872                 __get_user(vcol, &vtconsize->v_vcol);
 873                 __get_user(ccol, &vtconsize->v_ccol);
 874                 vlin = vlin ? vlin : vc->vc_scan_lines;
 875                 if (clin) {
 876                         if (ll) {
 877                                 if (ll != vlin/clin)
 878                                         return -EINVAL; /* Parameters don't add up */
 879                         } else
 880                                 ll = vlin/clin;
 881                 }
 882                 if (vcol && ccol) {
 883                         if (cc) {
 884                                 if (cc != vcol/ccol)
 885                                         return -EINVAL;
 886                         } else
 887                                 cc = vcol/ccol;
 888                 }
 889
 890                 if (clin > 32)
 891                         return -EINVAL;
 892
 893                 for (i = 0; i < MAX_NR_CONSOLES; i++) {
 894                         if (!vc_cons[i].d)
 895                                 continue;
 896                         acquire_console_sem();
 897                         if (vlin)
 898                                 vc_cons[i].d->vc_scan_lines = vlin;
 899                         if (clin)
 900                                 vc_cons[i].d->vc_font.height = clin;
 901                         vc_resize(vc_cons[i].d, cc, ll);
 902                         release_console_sem();
 903                 }
 904                 return 0;
 905         }
 906
 907         case PIO_FONT: {
 908                 if (!perm)
 909                         return -EPERM;
 910                 op.op = KD_FONT_OP_SET;
 911                 op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC; /* Compatibility */
 912                 op.width = 8;
 913                 op.height = 0;
 914                 op.charcount = 256;
 915                 op.data = up;
 916                 return con_font_op(vc_cons[fg_console].d, &op);
 917         }
 918
 919         case GIO_FONT: {
 920                 op.op = KD_FONT_OP_GET;
 921                 op.flags = KD_FONT_FLAG_OLD;
 922                 op.width = 8;
 923                 op.height = 32;
 924                 op.charcount = 256;
 925                 op.data = up;
 926                 return con_font_op(vc_cons[fg_console].d, &op);
 927         }
 928
 929         case PIO_CMAP:
 930                 if (!perm)
 931                         return -EPERM;
 932                 return con_set_cmap(up);
 933
 934         case GIO_CMAP:
 935                 return con_get_cmap(up);
 936
 937         case PIO_FONTX:
 938         case GIO_FONTX:
 939                 return do_fontx_ioctl(cmd, up, perm, &op);
 940
 941         case PIO_FONTRESET:
 942         {
 943                 if (!perm)
 944                         return -EPERM;
 945
 946 #ifdef BROKEN_GRAPHICS_PROGRAMS
 947                 /* With BROKEN_GRAPHICS_PROGRAMS defined, the default
 948                    font is not saved. */
 949                 return -ENOSYS;
 950 #else
 951                 {
 952                 op.op = KD_FONT_OP_SET_DEFAULT;
 953                 op.data = NULL;
 954                 i = con_font_op(vc_cons[fg_console].d, &op);
 955                 if (i)
 956                         return i;
 957                 con_set_default_unimap(vc_cons[fg_console].d);
 958                 return 0;
 959                 }
 960 #endif
 961         }
 962
 963         case KDFONTOP: {
 964                 if (copy_from_user(&op, up, sizeof(op)))
 965                         return -EFAULT;
 966                 if (!perm && op.op != KD_FONT_OP_GET)
 967                         return -EPERM;
 968                 i = con_font_op(vc, &op);
 969                 if (i) return i;
 970                 if (copy_to_user(up, &op, sizeof(op)))
 971                         return -EFAULT;
 972                 return 0;
 973         }
 974
 975         case PIO_SCRNMAP:
 976                 if (!perm)
 977                         return -EPERM;
 978                 return con_set_trans_old(up);
 979
 980         case GIO_SCRNMAP:
 981                 return con_get_trans_old(up);
 982
 983         case PIO_UNISCRNMAP:
 984                 if (!perm)
 985                         return -EPERM;
 986                 return con_set_trans_new(up);
 987
 988         case GIO_UNISCRNMAP:
 989                 return con_get_trans_new(up);
 990
 991         case PIO_UNIMAPCLR:
 992               { struct unimapinit ui;
 993                 if (!perm)
 994                         return -EPERM;
 995                 i = copy_from_user(&ui, up, sizeof(struct unimapinit));
 996                 if (i) return -EFAULT;
 997                 con_clear_unimap(vc, &ui);
 998                 return 0;
 999               }
1000
1001         case PIO_UNIMAP:
1002         case GIO_UNIMAP:
1003                 return do_unimap_ioctl(cmd, up, perm, vc);
1004
1005         case VT_LOCKSWITCH:
1006                 if (!capable(CAP_SYS_TTY_CONFIG))
1007                    return -EPERM;
1008                 vt_dont_switch = 1;
1009                 return 0;
1010         case VT_UNLOCKSWITCH:
1011                 if (!capable(CAP_SYS_TTY_CONFIG))
1012                    return -EPERM;
1013                 vt_dont_switch = 0;
1014                 return 0;
1015         default:
1016                 return -ENOIOCTLCMD;
1017         }
1018 }
1019
1020 /*
1021  * Sometimes we want to wait until a particular VT has been activated. We
1022  * do it in a very simple manner. Everybody waits on a single queue and
1023  * get woken up at once. Those that are satisfied go on with their business,
1024  * while those not ready go back to sleep. Seems overkill to add a wait
1025  * to each vt just for this - usually this does nothing!
1026  */
1027 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
1028
1029 /*
1030  * Sleeps until a vt is activated, or the task is interrupted. Returns
1031  * 0 if activation, -EINTR if interrupted.
1032  */
1033 int vt_waitactive(int vt)
1034 {
1035         int retval;
1036         DECLARE_WAITQUEUE(wait, current);
1037
1038         add_wait_queue(&vt_activate_queue, &wait);
1039         for (;;) {
1040                 set_current_state(TASK_INTERRUPTIBLE);
1041                 retval = 0;
1042                 if (vt == fg_console)
1043                         break;
1044                 retval = -EINTR;
1045                 if (signal_pending(current))
1046                         break;
1047                 schedule();
1048         }
1049         remove_wait_queue(&vt_activate_queue, &wait);
1050         current->state = TASK_RUNNING;
1051         return retval;
1052 }
1053
1054 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1055
1056 void reset_vc(struct vc_data *vc)
1057 {
1058         vc->vc_mode = KD_TEXT;
1059         kbd_table[vc->vc_num].kbdmode = VC_XLATE;
1060         vc->vt_mode.mode = VT_AUTO;
1061         vc->vt_mode.waitv = 0;
1062         vc->vt_mode.relsig = 0;
1063         vc->vt_mode.acqsig = 0;
1064         vc->vt_mode.frsig = 0;
1065         vc->vt_pid = -1;
1066         vc->vt_newvt = -1;
1067         if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1068                 reset_palette(vc);
1069 }
1070
1071 /*
1072  * Performs the back end of a vt switch
1073  */
1074 static void complete_change_console(struct vc_data *vc)
1075 {
1076         unsigned char old_vc_mode;
1077
1078         last_console = fg_console;
1079
1080         /*
1081          * If we're switching, we could be going from KD_GRAPHICS to
1082          * KD_TEXT mode or vice versa, which means we need to blank or
1083          * unblank the screen later.
1084          */
1085         old_vc_mode = vc_cons[fg_console].d->vc_mode;
1086         switch_screen(vc);
1087
1088         /*
1089          * This can't appear below a successful kill_proc().  If it did,
1090          * then the *blank_screen operation could occur while X, having
1091          * received acqsig, is waking up on another processor.  This
1092          * condition can lead to overlapping accesses to the VGA range
1093          * and the framebuffer (causing system lockups).
1094          *
1095          * To account for this we duplicate this code below only if the
1096          * controlling process is gone and we've called reset_vc.
1097          */
1098         if (old_vc_mode != vc->vc_mode) {
1099                 if (vc->vc_mode == KD_TEXT)
1100                         do_unblank_screen(1);
1101                 else
1102                         do_blank_screen(1);
1103         }
1104
1105         /*
1106          * If this new console is under process control, send it a signal
1107          * telling it that it has acquired. Also check if it has died and
1108          * clean up (similar to logic employed in change_console())
1109          */
1110         if (vc->vt_mode.mode == VT_PROCESS) {
1111                 /*
1112                  * Send the signal as privileged - kill_proc() will
1113                  * tell us if the process has gone or something else
1114                  * is awry
1115                  */
1116                 if (kill_proc(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1117                 /*
1118                  * The controlling process has died, so we revert back to
1119                  * normal operation. In this case, we'll also change back
1120                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1121                  * but it saves the agony when the X server dies and the screen
1122                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1123                  * this outside of VT_PROCESS but there is no single process
1124                  * to account for and tracking tty count may be undesirable.
1125                  */
1126                         reset_vc(vc);
1127
1128                         if (old_vc_mode != vc->vc_mode) {
1129                                 if (vc->vc_mode == KD_TEXT)
1130                                         do_unblank_screen(1);
1131                                 else
1132                                         do_blank_screen(1);
1133                         }
1134                 }
1135         }
1136
1137         /*
1138          * Wake anyone waiting for their VT to activate
1139          */
1140         vt_wake_waitactive();
1141         return;
1142 }
1143
1144 /*
1145  * Performs the front-end of a vt switch
1146  */
1147 void change_console(struct vc_data *new_vc)
1148 {
1149         struct vc_data *vc;
1150
1151         if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1152                 return;
1153
1154         /*
1155          * If this vt is in process mode, then we need to handshake with
1156          * that process before switching. Essentially, we store where that
1157          * vt wants to switch to and wait for it to tell us when it's done
1158          * (via VT_RELDISP ioctl).
1159          *
1160          * We also check to see if the controlling process still exists.
1161          * If it doesn't, we reset this vt to auto mode and continue.
1162          * This is a cheap way to track process control. The worst thing
1163          * that can happen is: we send a signal to a process, it dies, and
1164          * the switch gets "lost" waiting for a response; hopefully, the
1165          * user will try again, we'll detect the process is gone (unless
1166          * the user waits just the right amount of time :-) and revert the
1167          * vt to auto control.
1168          */
1169         vc = vc_cons[fg_console].d;
1170         if (vc->vt_mode.mode == VT_PROCESS) {
1171                 /*
1172                  * Send the signal as privileged - kill_proc() will
1173                  * tell us if the process has gone or something else
1174                  * is awry
1175                  */
1176                 if (kill_proc(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1177                         /*
1178                          * It worked. Mark the vt to switch to and
1179                          * return. The process needs to send us a
1180                          * VT_RELDISP ioctl to complete the switch.
1181                          */
1182                         vc->vt_newvt = new_vc->vc_num;
1183                         return;
1184                 }
1185
1186                 /*
1187                  * The controlling process has died, so we revert back to
1188                  * normal operation. In this case, we'll also change back
1189                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1190                  * but it saves the agony when the X server dies and the screen
1191                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1192                  * this outside of VT_PROCESS but there is no single process
1193                  * to account for and tracking tty count may be undesirable.
1194                  */
1195                 reset_vc(vc);
1196
1197                 /*
1198                  * Fall through to normal (VT_AUTO) handling of the switch...
1199                  */
1200         }
1201
1202         /*
1203          * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1204          */
1205         if (vc->vc_mode == KD_GRAPHICS)
1206                 return;
1207
1208         complete_change_console(new_vc);
1209 }