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