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/types.h>
  14 #include <linux/errno.h>
  15 #include <linux/sched.h>
  16 #include <linux/tty.h>
  17 #include <linux/timer.h>
  18 #include <linux/kernel.h>
  19 #include <linux/kd.h>
  20 #include <linux/vt.h>
  21 #include <linux/string.h>
  22 #include <linux/slab.h>
  23 #include <linux/major.h>
  24 #include <linux/fs.h>
  25 #include <linux/console.h>
  26 #include <linux/signal.h>
  27 #include <linux/timex.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 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         if (!capable(CAP_SYS_TTY_CONFIG))
  83                 perm = 0;
  84
  85         switch (cmd) {
  86         case KDGKBENT:
  87                 key_map = key_maps[s];
  88                 if (key_map) {
  89                     val = U(key_map[i]);
  90                     if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
  91                         val = K_HOLE;
  92                 } else
  93                     val = (i ? K_HOLE : K_NOSUCHMAP);
  94                 return put_user(val, &user_kbe->kb_value);
  95         case KDSKBENT:
  96                 if (!perm)
  97                         return -EPERM;
  98                 if (!i && v == K_NOSUCHMAP) {
  99                         /* deallocate map */
 100                         key_map = key_maps[s];
 101                         if (s && key_map) {
 102                             key_maps[s] = NULL;
 103                             if (key_map[0] == U(K_ALLOCATED)) {
 104                                         kfree(key_map);
 105                                         keymap_count--;
 106                             }
 107                         }
 108                         break;
 109                 }
 110
 111                 if (KTYP(v) < NR_TYPES) {
 112                     if (KVAL(v) > max_vals[KTYP(v)])
 113                                 return -EINVAL;
 114                 } else
 115                     if (kbd->kbdmode != VC_UNICODE)
 116                                 return -EINVAL;
 117
 118                 /* ++Geert: non-PC keyboards may generate keycode zero */
 119 #if !defined(__mc68000__) && !defined(__powerpc__)
 120                 /* assignment to entry 0 only tests validity of args */
 121                 if (!i)
 122                         break;
 123 #endif
 124
 125                 if (!(key_map = key_maps[s])) {
 126                         int j;
 127
 128                         if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
 129                             !capable(CAP_SYS_RESOURCE))
 130                                 return -EPERM;
 131
 132                         key_map = kmalloc(sizeof(plain_map),
 133                                                      GFP_KERNEL);
 134                         if (!key_map)
 135                                 return -ENOMEM;
 136                         key_maps[s] = key_map;
 137                         key_map[0] = U(K_ALLOCATED);
 138                         for (j = 1; j < NR_KEYS; j++)
 139                                 key_map[j] = U(K_HOLE);
 140                         keymap_count++;
 141                 }
 142                 ov = U(key_map[i]);
 143                 if (v == ov)
 144                         break;  /* nothing to do */
 145                 /*
 146                  * Attention Key.
 147                  */
 148                 if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
 149                         return -EPERM;
 150                 key_map[i] = U(v);
 151                 if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
 152                         compute_shiftstate();
 153                 break;
 154         }
 155         return 0;
 156 }
 157 #undef i
 158 #undef s
 159 #undef v
 160
 161 static inline int
 162 do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
 163 {
 164         struct kbkeycode tmp;
 165         int kc = 0;
 166
 167         if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
 168                 return -EFAULT;
 169         switch (cmd) {
 170         case KDGETKEYCODE:
 171                 kc = getkeycode(tmp.scancode);
 172                 if (kc >= 0)
 173                         kc = put_user(kc, &user_kbkc->keycode);
 174                 break;
 175         case KDSETKEYCODE:
 176                 if (!perm)
 177                         return -EPERM;
 178                 kc = setkeycode(tmp.scancode, tmp.keycode);
 179                 break;
 180         }
 181         return kc;
 182 }
 183
 184 static inline int
 185 do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
 186 {
 187         struct kbsentry *kbs;
 188         char *p;
 189         u_char *q;
 190         u_char __user *up;
 191         int sz;
 192         int delta;
 193         char *first_free, *fj, *fnw;
 194         int i, j, k;
 195         int ret;
 196
 197         if (!capable(CAP_SYS_TTY_CONFIG))
 198                 perm = 0;
 199
 200         kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
 201         if (!kbs) {
 202                 ret = -ENOMEM;
 203                 goto reterr;
 204         }
 205
 206         /* we mostly copy too much here (512bytes), but who cares ;) */
 207         if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
 208                 ret = -EFAULT;
 209                 goto reterr;
 210         }
 211         kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
 212         i = kbs->kb_func;
 213
 214         switch (cmd) {
 215         case KDGKBSENT:
 216                 sz = sizeof(kbs->kb_string) - 1; /* sz should have been
 217                                                   a struct member */
 218                 up = user_kdgkb->kb_string;
 219                 p = func_table[i];
 220                 if(p)
 221                         for ( ; *p && sz; p++, sz--)
 222                                 if (put_user(*p, up++)) {
 223                                         ret = -EFAULT;
 224                                         goto reterr;
 225                                 }
 226                 if (put_user('\0', up)) {
 227                         ret = -EFAULT;
 228                         goto reterr;
 229                 }
 230                 kfree(kbs);
 231                 return ((p && *p) ? -EOVERFLOW : 0);
 232         case KDSKBSENT:
 233                 if (!perm) {
 234                         ret = -EPERM;
 235                         goto reterr;
 236                 }
 237
 238                 q = func_table[i];
 239                 first_free = funcbufptr + (funcbufsize - funcbufleft);
 240                 for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++)
 241                         ;
 242                 if (j < MAX_NR_FUNC)
 243                         fj = func_table[j];
 244                 else
 245                         fj = first_free;
 246
 247                 delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
 248                 if (delta <= funcbufleft) {     /* it fits in current buf */
 249                     if (j < MAX_NR_FUNC) {
 250                         memmove(fj + delta, fj, first_free - fj);
 251                         for (k = j; k < MAX_NR_FUNC; k++)
 252                             if (func_table[k])
 253                                 func_table[k] += delta;
 254                     }
 255                     if (!q)
 256                       func_table[i] = fj;
 257                     funcbufleft -= delta;
 258                 } else {                        /* allocate a larger buffer */
 259                     sz = 256;
 260                     while (sz < funcbufsize - funcbufleft + delta)
 261                       sz <<= 1;
 262                     fnw = kmalloc(sz, GFP_KERNEL);
 263                     if(!fnw) {
 264                       ret = -ENOMEM;
 265                       goto reterr;
 266                     }
 267
 268                     if (!q)
 269                       func_table[i] = fj;
 270                     if (fj > funcbufptr)
 271                         memmove(fnw, funcbufptr, fj - funcbufptr);
 272                     for (k = 0; k < j; k++)
 273                       if (func_table[k])
 274                         func_table[k] = fnw + (func_table[k] - funcbufptr);
 275
 276                     if (first_free > fj) {
 277                         memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
 278                         for (k = j; k < MAX_NR_FUNC; k++)
 279                           if (func_table[k])
 280                             func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
 281                     }
 282                     if (funcbufptr != func_buf)
 283                       kfree(funcbufptr);
 284                     funcbufptr = fnw;
 285                     funcbufleft = funcbufleft - delta + sz - funcbufsize;
 286                     funcbufsize = sz;
 287                 }
 288                 strcpy(func_table[i], kbs->kb_string);
 289                 break;
 290         }
 291         ret = 0;
 292 reterr:
 293         kfree(kbs);
 294         return ret;
 295 }
 296
 297 static inline int
 298 do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
 299 {
 300         struct consolefontdesc cfdarg;
 301         int i;
 302
 303         if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc)))
 304                 return -EFAULT;
 305
 306         switch (cmd) {
 307         case PIO_FONTX:
 308                 if (!perm)
 309                         return -EPERM;
 310                 op->op = KD_FONT_OP_SET;
 311                 op->flags = KD_FONT_FLAG_OLD;
 312                 op->width = 8;
 313                 op->height = cfdarg.charheight;
 314                 op->charcount = cfdarg.charcount;
 315                 op->data = cfdarg.chardata;
 316                 return con_font_op(vc_cons[fg_console].d, op);
 317         case GIO_FONTX: {
 318                 op->op = KD_FONT_OP_GET;
 319                 op->flags = KD_FONT_FLAG_OLD;
 320                 op->width = 8;
 321                 op->height = cfdarg.charheight;
 322                 op->charcount = cfdarg.charcount;
 323                 op->data = cfdarg.chardata;
 324                 i = con_font_op(vc_cons[fg_console].d, op);
 325                 if (i)
 326                         return i;
 327                 cfdarg.charheight = op->height;
 328                 cfdarg.charcount = op->charcount;
 329                 if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
 330                         return -EFAULT;
 331                 return 0;
 332                 }
 333         }
 334         return -EINVAL;
 335 }
 336
 337 static inline int
 338 do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
 339 {
 340         struct unimapdesc tmp;
 341
 342         if (copy_from_user(&tmp, user_ud, sizeof tmp))
 343                 return -EFAULT;
 344         if (tmp.entries)
 345                 if (!access_ok(VERIFY_WRITE, tmp.entries,
 346                                 tmp.entry_ct*sizeof(struct unipair)))
 347                         return -EFAULT;
 348         switch (cmd) {
 349         case PIO_UNIMAP:
 350                 if (!perm)
 351                         return -EPERM;
 352                 return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
 353         case GIO_UNIMAP:
 354                 if (!perm && fg_console != vc->vc_num)
 355                         return -EPERM;
 356                 return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
 357         }
 358         return 0;
 359 }
 360
 361 /*
 362  * We handle the console-specific ioctl's here.  We allow the
 363  * capability to modify any console, not just the fg_console.
 364  */
 365 int vt_ioctl(struct tty_struct *tty, struct file * file,
 366              unsigned int cmd, unsigned long arg)
 367 {
 368         struct vc_data *vc = (struct vc_data *)tty->driver_data;
 369         struct console_font_op op;      /* used in multiple places here */
 370         struct kbd_struct * kbd;
 371         unsigned int console;
 372         unsigned char ucval;
 373         void __user *up = (void __user *)arg;
 374         int i, perm;
 375
 376         console = vc->vc_num;
 377
 378         if (!vc_cons_allocated(console))        /* impossible? */
 379                 return -ENOIOCTLCMD;
 380
 381         /*
 382          * To have permissions to do most of the vt ioctls, we either have
 383          * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
 384          */
 385         perm = 0;
 386         if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
 387                 perm = 1;
 388
 389         kbd = kbd_table + console;
 390         switch (cmd) {
 391         case KIOCSOUND:
 392                 if (!perm)
 393                         return -EPERM;
 394                 if (arg)
 395                         arg = CLOCK_TICK_RATE / arg;
 396                 kd_mksound(arg, 0);
 397                 return 0;
 398
 399         case KDMKTONE:
 400                 if (!perm)
 401                         return -EPERM;
 402         {
 403                 unsigned int ticks, count;
 404
 405                 /*
 406                  * Generate the tone for the appropriate number of ticks.
 407                  * If the time is zero, turn off sound ourselves.
 408                  */
 409                 ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
 410                 count = ticks ? (arg & 0xffff) : 0;
 411                 if (count)
 412                         count = CLOCK_TICK_RATE / count;
 413                 kd_mksound(count, ticks);
 414                 return 0;
 415         }
 416
 417         case KDGKBTYPE:
 418                 /*
 419                  * this is naive.
 420                  */
 421                 ucval = KB_101;
 422                 goto setchar;
 423
 424                 /*
 425                  * These cannot be implemented on any machine that implements
 426                  * ioperm() in user level (such as Alpha PCs) or not at all.
 427                  *
 428                  * XXX: you should never use these, just call ioperm directly..
 429                  */
 430 #ifdef CONFIG_X86
 431         case KDADDIO:
 432         case KDDELIO:
 433                 /*
 434                  * KDADDIO and KDDELIO may be able to add ports beyond what
 435                  * we reject here, but to be safe...
 436                  */
 437                 if (arg < GPFIRST || arg > GPLAST)
 438                         return -EINVAL;
 439                 return sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
 440
 441         case KDENABIO:
 442         case KDDISABIO:
 443                 return sys_ioperm(GPFIRST, GPNUM,
 444                                   (cmd == KDENABIO)) ? -ENXIO : 0;
 445 #endif
 446
 447         /* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
 448
 449         case KDKBDREP:
 450         {
 451                 struct kbd_repeat kbrep;
 452                 int err;
 453
 454                 if (!capable(CAP_SYS_TTY_CONFIG))
 455                         return -EPERM;
 456
 457                 if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat)))
 458                         return -EFAULT;
 459                 err = kbd_rate(&kbrep);
 460                 if (err)
 461                         return err;
 462                 if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
 463                         return -EFAULT;
 464                 return 0;
 465         }
 466
 467         case KDSETMODE:
 468                 /*
 469                  * currently, setting the mode from KD_TEXT to KD_GRAPHICS
 470                  * doesn't do a whole lot. i'm not sure if it should do any
 471                  * restoration of modes or what...
 472                  *
 473                  * XXX It should at least call into the driver, fbdev's definitely
 474                  * need to restore their engine state. --BenH
 475                  */
 476                 if (!perm)
 477                         return -EPERM;
 478                 switch (arg) {
 479                 case KD_GRAPHICS:
 480                         break;
 481                 case KD_TEXT0:
 482                 case KD_TEXT1:
 483                         arg = KD_TEXT;
 484                 case KD_TEXT:
 485                         break;
 486                 default:
 487                         return -EINVAL;
 488                 }
 489                 if (vc->vc_mode == (unsigned char) arg)
 490                         return 0;
 491                 vc->vc_mode = (unsigned char) arg;
 492                 if (console != fg_console)
 493                         return 0;
 494                 /*
 495                  * explicitly blank/unblank the screen if switching modes
 496                  */
 497                 acquire_console_sem();
 498                 if (arg == KD_TEXT)
 499                         do_unblank_screen(1);
 500                 else
 501                         do_blank_screen(1);
 502                 release_console_sem();
 503                 return 0;
 504
 505         case KDGETMODE:
 506                 ucval = vc->vc_mode;
 507                 goto setint;
 508
 509         case KDMAPDISP:
 510         case KDUNMAPDISP:
 511                 /*
 512                  * these work like a combination of mmap and KDENABIO.
 513                  * this could be easily finished.
 514                  */
 515                 return -EINVAL;
 516
 517         case KDSKBMODE:
 518                 if (!perm)
 519                         return -EPERM;
 520                 switch(arg) {
 521                   case K_RAW:
 522                         kbd->kbdmode = VC_RAW;
 523                         break;
 524                   case K_MEDIUMRAW:
 525                         kbd->kbdmode = VC_MEDIUMRAW;
 526                         break;
 527                   case K_XLATE:
 528                         kbd->kbdmode = VC_XLATE;
 529                         compute_shiftstate();
 530                         break;
 531                   case K_UNICODE:
 532                         kbd->kbdmode = VC_UNICODE;
 533                         compute_shiftstate();
 534                         break;
 535                   default:
 536                         return -EINVAL;
 537                 }
 538                 tty_ldisc_flush(tty);
 539                 return 0;
 540
 541         case KDGKBMODE:
 542                 ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
 543                                  (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
 544                                  (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
 545                                  K_XLATE);
 546                 goto setint;
 547
 548         /* this could be folded into KDSKBMODE, but for compatibility
 549            reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
 550         case KDSKBMETA:
 551                 switch(arg) {
 552                   case K_METABIT:
 553                         clr_vc_kbd_mode(kbd, VC_META);
 554                         break;
 555                   case K_ESCPREFIX:
 556                         set_vc_kbd_mode(kbd, VC_META);
 557                         break;
 558                   default:
 559                         return -EINVAL;
 560                 }
 561                 return 0;
 562
 563         case KDGKBMETA:
 564                 ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
 565         setint:
 566                 return put_user(ucval, (int __user *)arg);
 567
 568         case KDGETKEYCODE:
 569         case KDSETKEYCODE:
 570                 if(!capable(CAP_SYS_TTY_CONFIG))
 571                         perm=0;
 572                 return do_kbkeycode_ioctl(cmd, up, perm);
 573
 574         case KDGKBENT:
 575         case KDSKBENT:
 576                 return do_kdsk_ioctl(cmd, up, perm, kbd);
 577
 578         case KDGKBSENT:
 579         case KDSKBSENT:
 580                 return do_kdgkb_ioctl(cmd, up, perm);
 581
 582         case KDGKBDIACR:
 583         {
 584                 struct kbdiacrs __user *a = up;
 585
 586                 if (put_user(accent_table_size, &a->kb_cnt))
 587                         return -EFAULT;
 588                 if (copy_to_user(a->kbdiacr, accent_table, accent_table_size*sizeof(struct kbdiacr)))
 589                         return -EFAULT;
 590                 return 0;
 591         }
 592
 593         case KDSKBDIACR:
 594         {
 595                 struct kbdiacrs __user *a = up;
 596                 unsigned int ct;
 597
 598                 if (!perm)
 599                         return -EPERM;
 600                 if (get_user(ct,&a->kb_cnt))
 601                         return -EFAULT;
 602                 if (ct >= MAX_DIACR)
 603                         return -EINVAL;
 604                 accent_table_size = ct;
 605                 if (copy_from_user(accent_table, a->kbdiacr, ct*sizeof(struct kbdiacr)))
 606                         return -EFAULT;
 607                 return 0;
 608         }
 609
 610         /* the ioctls below read/set the flags usually shown in the leds */
 611         /* don't use them - they will go away without warning */
 612         case KDGKBLED:
 613                 ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
 614                 goto setchar;
 615
 616         case KDSKBLED:
 617                 if (!perm)
 618                         return -EPERM;
 619                 if (arg & ~0x77)
 620                         return -EINVAL;
 621                 kbd->ledflagstate = (arg & 7);
 622                 kbd->default_ledflagstate = ((arg >> 4) & 7);
 623                 set_leds();
 624                 return 0;
 625
 626         /* the ioctls below only set the lights, not the functions */
 627         /* for those, see KDGKBLED and KDSKBLED above */
 628         case KDGETLED:
 629                 ucval = getledstate();
 630         setchar:
 631                 return put_user(ucval, (char __user *)arg);
 632
 633         case KDSETLED:
 634                 if (!perm)
 635                   return -EPERM;
 636                 setledstate(kbd, arg);
 637                 return 0;
 638
 639         /*
 640          * A process can indicate its willingness to accept signals
 641          * generated by pressing an appropriate key combination.
 642          * Thus, one can have a daemon that e.g. spawns a new console
 643          * upon a keypress and then changes to it.
 644          * See also the kbrequest field of inittab(5).
 645          */
 646         case KDSIGACCEPT:
 647         {
 648                 if (!perm || !capable(CAP_KILL))
 649                   return -EPERM;
 650                 if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 651                   return -EINVAL;
 652
 653                 spin_lock_irq(&vt_spawn_con.lock);
 654                 put_pid(vt_spawn_con.pid);
 655                 vt_spawn_con.pid = get_pid(task_pid(current));
 656                 vt_spawn_con.sig = arg;
 657                 spin_unlock_irq(&vt_spawn_con.lock);
 658                 return 0;
 659         }
 660
 661         case VT_SETMODE:
 662         {
 663                 struct vt_mode tmp;
 664
 665                 if (!perm)
 666                         return -EPERM;
 667                 if (copy_from_user(&tmp, up, sizeof(struct vt_mode)))
 668                         return -EFAULT;
 669                 if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS)
 670                         return -EINVAL;
 671                 acquire_console_sem();
 672                 vc->vt_mode = tmp;
 673                 /* the frsig is ignored, so we set it to 0 */
 674                 vc->vt_mode.frsig = 0;
 675                 put_pid(vc->vt_pid);
 676                 vc->vt_pid = get_pid(task_pid(current));
 677                 /* no switch is required -- saw@shade.msu.ru */
 678                 vc->vt_newvt = -1;
 679                 release_console_sem();
 680                 return 0;
 681         }
 682
 683         case VT_GETMODE:
 684         {
 685                 struct vt_mode tmp;
 686                 int rc;
 687
 688                 acquire_console_sem();
 689                 memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
 690                 release_console_sem();
 691
 692                 rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
 693                 return rc ? -EFAULT : 0;
 694         }
 695
 696         /*
 697          * Returns global vt state. Note that VT 0 is always open, since
 698          * it's an alias for the current VT, and people can't use it here.
 699          * We cannot return state for more than 16 VTs, since v_state is short.
 700          */
 701         case VT_GETSTATE:
 702         {
 703                 struct vt_stat __user *vtstat = up;
 704                 unsigned short state, mask;
 705
 706                 if (put_user(fg_console + 1, &vtstat->v_active))
 707                         return -EFAULT;
 708                 state = 1;      /* /dev/tty0 is always open */
 709                 for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask; ++i, mask <<= 1)
 710                         if (VT_IS_IN_USE(i))
 711                                 state |= mask;
 712                 return put_user(state, &vtstat->v_state);
 713         }
 714
 715         /*
 716          * Returns the first available (non-opened) console.
 717          */
 718         case VT_OPENQRY:
 719                 for (i = 0; i < MAX_NR_CONSOLES; ++i)
 720                         if (! VT_IS_IN_USE(i))
 721                                 break;
 722                 ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
 723                 goto setint;
 724
 725         /*
 726          * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
 727          * with num >= 1 (switches to vt 0, our console, are not allowed, just
 728          * to preserve sanity).
 729          */
 730         case VT_ACTIVATE:
 731                 if (!perm)
 732                         return -EPERM;
 733                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 734                         return -ENXIO;
 735                 arg--;
 736                 acquire_console_sem();
 737                 i = vc_allocate(arg);
 738                 release_console_sem();
 739                 if (i)
 740                         return i;
 741                 set_console(arg);
 742                 return 0;
 743
 744         /*
 745          * wait until the specified VT has been activated
 746          */
 747         case VT_WAITACTIVE:
 748                 if (!perm)
 749                         return -EPERM;
 750                 if (arg == 0 || arg > MAX_NR_CONSOLES)
 751                         return -ENXIO;
 752                 return vt_waitactive(arg-1);
 753
 754         /*
 755          * If a vt is under process control, the kernel will not switch to it
 756          * immediately, but postpone the operation until the process calls this
 757          * ioctl, allowing the switch to complete.
 758          *
 759          * According to the X sources this is the behavior:
 760          *      0:      pending switch-from not OK
 761          *      1:      pending switch-from OK
 762          *      2:      completed switch-to OK
 763          */
 764         case VT_RELDISP:
 765                 if (!perm)
 766                         return -EPERM;
 767                 if (vc->vt_mode.mode != VT_PROCESS)
 768                         return -EINVAL;
 769
 770                 /*
 771                  * Switching-from response
 772                  */
 773                 if (vc->vt_newvt >= 0) {
 774                         if (arg == 0)
 775                                 /*
 776                                  * Switch disallowed, so forget we were trying
 777                                  * to do it.
 778                                  */
 779                                 vc->vt_newvt = -1;
 780
 781                         else {
 782                                 /*
 783                                  * The current vt has been released, so
 784                                  * complete the switch.
 785                                  */
 786                                 int newvt;
 787                                 acquire_console_sem();
 788                                 newvt = vc->vt_newvt;
 789                                 vc->vt_newvt = -1;
 790                                 i = vc_allocate(newvt);
 791                                 if (i) {
 792                                         release_console_sem();
 793                                         return i;
 794                                 }
 795                                 /*
 796                                  * When we actually do the console switch,
 797                                  * make sure we are atomic with respect to
 798                                  * other console switches..
 799                                  */
 800                                 complete_change_console(vc_cons[newvt].d);
 801                                 release_console_sem();
 802                         }
 803                 }
 804
 805                 /*
 806                  * Switched-to response
 807                  */
 808                 else
 809                 {
 810                         /*
 811                          * If it's just an ACK, ignore it
 812                          */
 813                         if (arg != VT_ACKACQ)
 814                                 return -EINVAL;
 815                 }
 816
 817                 return 0;
 818
 819          /*
 820           * Disallocate memory associated to VT (but leave VT1)
 821           */
 822          case VT_DISALLOCATE:
 823                 if (arg > MAX_NR_CONSOLES)
 824                         return -ENXIO;
 825                 if (arg == 0) {
 826                     /* deallocate all unused consoles, but leave 0 */
 827                         acquire_console_sem();
 828                         for (i=1; i<MAX_NR_CONSOLES; i++)
 829                                 if (! VT_BUSY(i))
 830                                         vc_deallocate(i);
 831                         release_console_sem();
 832                 } else {
 833                         /* deallocate a single console, if possible */
 834                         arg--;
 835                         if (VT_BUSY(arg))
 836                                 return -EBUSY;
 837                         if (arg) {                            /* leave 0 */
 838                                 acquire_console_sem();
 839                                 vc_deallocate(arg);
 840                                 release_console_sem();
 841                         }
 842                 }
 843                 return 0;
 844
 845         case VT_RESIZE:
 846         {
 847                 struct vt_sizes __user *vtsizes = up;
 848                 ushort ll,cc;
 849                 if (!perm)
 850                         return -EPERM;
 851                 if (get_user(ll, &vtsizes->v_rows) ||
 852                     get_user(cc, &vtsizes->v_cols))
 853                         return -EFAULT;
 854                 for (i = 0; i < MAX_NR_CONSOLES; i++)
 855                         vc_lock_resize(vc_cons[i].d, cc, ll);
 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         case VT_GETHIFONTMASK:
1016                 return put_user(vc->vc_hi_font_mask, (unsigned short __user *)arg);
1017         default:
1018                 return -ENOIOCTLCMD;
1019         }
1020 }
1021
1022 /*
1023  * Sometimes we want to wait until a particular VT has been activated. We
1024  * do it in a very simple manner. Everybody waits on a single queue and
1025  * get woken up at once. Those that are satisfied go on with their business,
1026  * while those not ready go back to sleep. Seems overkill to add a wait
1027  * to each vt just for this - usually this does nothing!
1028  */
1029 static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
1030
1031 /*
1032  * Sleeps until a vt is activated, or the task is interrupted. Returns
1033  * 0 if activation, -EINTR if interrupted.
1034  */
1035 int vt_waitactive(int vt)
1036 {
1037         int retval;
1038         DECLARE_WAITQUEUE(wait, current);
1039
1040         add_wait_queue(&vt_activate_queue, &wait);
1041         for (;;) {
1042                 retval = 0;
1043
1044                 /*
1045                  * Synchronize with redraw_screen(). By acquiring the console
1046                  * semaphore we make sure that the console switch is completed
1047                  * before we return. If we didn't wait for the semaphore, we
1048                  * could return at a point where fg_console has already been
1049                  * updated, but the console switch hasn't been completed.
1050                  */
1051                 acquire_console_sem();
1052                 set_current_state(TASK_INTERRUPTIBLE);
1053                 if (vt == fg_console) {
1054                         release_console_sem();
1055                         break;
1056                 }
1057                 release_console_sem();
1058                 retval = -EINTR;
1059                 if (signal_pending(current))
1060                         break;
1061                 schedule();
1062         }
1063         remove_wait_queue(&vt_activate_queue, &wait);
1064         current->state = TASK_RUNNING;
1065         return retval;
1066 }
1067
1068 #define vt_wake_waitactive() wake_up(&vt_activate_queue)
1069
1070 void reset_vc(struct vc_data *vc)
1071 {
1072         vc->vc_mode = KD_TEXT;
1073         kbd_table[vc->vc_num].kbdmode = VC_XLATE;
1074         vc->vt_mode.mode = VT_AUTO;
1075         vc->vt_mode.waitv = 0;
1076         vc->vt_mode.relsig = 0;
1077         vc->vt_mode.acqsig = 0;
1078         vc->vt_mode.frsig = 0;
1079         put_pid(vc->vt_pid);
1080         vc->vt_pid = NULL;
1081         vc->vt_newvt = -1;
1082         if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
1083                 reset_palette(vc);
1084 }
1085
1086 void vc_SAK(struct work_struct *work)
1087 {
1088         struct vc *vc_con =
1089                 container_of(work, struct vc, SAK_work);
1090         struct vc_data *vc;
1091         struct tty_struct *tty;
1092
1093         acquire_console_sem();
1094         vc = vc_con->d;
1095         if (vc) {
1096                 tty = vc->vc_tty;
1097                 /*
1098                  * SAK should also work in all raw modes and reset
1099                  * them properly.
1100                  */
1101                 if (tty)
1102                         __do_SAK(tty);
1103                 reset_vc(vc);
1104         }
1105         release_console_sem();
1106 }
1107
1108 /*
1109  * Performs the back end of a vt switch
1110  */
1111 static void complete_change_console(struct vc_data *vc)
1112 {
1113         unsigned char old_vc_mode;
1114
1115         last_console = fg_console;
1116
1117         /*
1118          * If we're switching, we could be going from KD_GRAPHICS to
1119          * KD_TEXT mode or vice versa, which means we need to blank or
1120          * unblank the screen later.
1121          */
1122         old_vc_mode = vc_cons[fg_console].d->vc_mode;
1123         switch_screen(vc);
1124
1125         /*
1126          * This can't appear below a successful kill_pid().  If it did,
1127          * then the *blank_screen operation could occur while X, having
1128          * received acqsig, is waking up on another processor.  This
1129          * condition can lead to overlapping accesses to the VGA range
1130          * and the framebuffer (causing system lockups).
1131          *
1132          * To account for this we duplicate this code below only if the
1133          * controlling process is gone and we've called reset_vc.
1134          */
1135         if (old_vc_mode != vc->vc_mode) {
1136                 if (vc->vc_mode == KD_TEXT)
1137                         do_unblank_screen(1);
1138                 else
1139                         do_blank_screen(1);
1140         }
1141
1142         /*
1143          * If this new console is under process control, send it a signal
1144          * telling it that it has acquired. Also check if it has died and
1145          * clean up (similar to logic employed in change_console())
1146          */
1147         if (vc->vt_mode.mode == VT_PROCESS) {
1148                 /*
1149                  * Send the signal as privileged - kill_pid() will
1150                  * tell us if the process has gone or something else
1151                  * is awry
1152                  */
1153                 if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
1154                 /*
1155                  * The controlling process has died, so we revert back to
1156                  * normal operation. In this case, we'll also change back
1157                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1158                  * but it saves the agony when the X server dies and the screen
1159                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1160                  * this outside of VT_PROCESS but there is no single process
1161                  * to account for and tracking tty count may be undesirable.
1162                  */
1163                         reset_vc(vc);
1164
1165                         if (old_vc_mode != vc->vc_mode) {
1166                                 if (vc->vc_mode == KD_TEXT)
1167                                         do_unblank_screen(1);
1168                                 else
1169                                         do_blank_screen(1);
1170                         }
1171                 }
1172         }
1173
1174         /*
1175          * Wake anyone waiting for their VT to activate
1176          */
1177         vt_wake_waitactive();
1178         return;
1179 }
1180
1181 /*
1182  * Performs the front-end of a vt switch
1183  */
1184 void change_console(struct vc_data *new_vc)
1185 {
1186         struct vc_data *vc;
1187
1188         if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
1189                 return;
1190
1191         /*
1192          * If this vt is in process mode, then we need to handshake with
1193          * that process before switching. Essentially, we store where that
1194          * vt wants to switch to and wait for it to tell us when it's done
1195          * (via VT_RELDISP ioctl).
1196          *
1197          * We also check to see if the controlling process still exists.
1198          * If it doesn't, we reset this vt to auto mode and continue.
1199          * This is a cheap way to track process control. The worst thing
1200          * that can happen is: we send a signal to a process, it dies, and
1201          * the switch gets "lost" waiting for a response; hopefully, the
1202          * user will try again, we'll detect the process is gone (unless
1203          * the user waits just the right amount of time :-) and revert the
1204          * vt to auto control.
1205          */
1206         vc = vc_cons[fg_console].d;
1207         if (vc->vt_mode.mode == VT_PROCESS) {
1208                 /*
1209                  * Send the signal as privileged - kill_pid() will
1210                  * tell us if the process has gone or something else
1211                  * is awry
1212                  */
1213                 if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
1214                         /*
1215                          * It worked. Mark the vt to switch to and
1216                          * return. The process needs to send us a
1217                          * VT_RELDISP ioctl to complete the switch.
1218                          */
1219                         vc->vt_newvt = new_vc->vc_num;
1220                         return;
1221                 }
1222
1223                 /*
1224                  * The controlling process has died, so we revert back to
1225                  * normal operation. In this case, we'll also change back
1226                  * to KD_TEXT mode. I'm not sure if this is strictly correct
1227                  * but it saves the agony when the X server dies and the screen
1228                  * remains blanked due to KD_GRAPHICS! It would be nice to do
1229                  * this outside of VT_PROCESS but there is no single process
1230                  * to account for and tracking tty count may be undesirable.
1231                  */
1232                 reset_vc(vc);
1233
1234                 /*
1235                  * Fall through to normal (VT_AUTO) handling of the switch...
1236                  */
1237         }
1238
1239         /*
1240          * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
1241          */
1242         if (vc->vc_mode == KD_GRAPHICS)
1243                 return;
1244
1245         complete_change_console(new_vc);
1246 }