memory/selector.c

   1 /*
   2  * Selector manipulation functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <string.h>
  10
  11 #include "winerror.h"
  12 #include "wine/winbase16.h"
  13 #include "miscemu.h"
  14 #include "selectors.h"
  15 #include "stackframe.h"
  16 #include "wine/server.h"
  17 #include "debugtools.h"
  18 #include "toolhelp.h"
  19
  20 DEFAULT_DEBUG_CHANNEL(selector);
  21
  22 #define LDT_SIZE 8192
  23
  24 /* get the number of selectors needed to cover up to the selector limit */
  25 inline static WORD get_sel_count( WORD sel )
  26 {
  27     return (wine_ldt_copy.limit[sel >> __AHSHIFT] >> 16) + 1;
  28 }
  29
  30 static const LDT_ENTRY null_entry;  /* all-zeros, used to clear LDT entries */
  31
  32 /***********************************************************************
  33  *           SELECTOR_AllocArray
  34  *
  35  * Allocate a selector array without setting the LDT entries
  36  */
  37 static WORD SELECTOR_AllocArray( WORD count )
  38 {
  39     WORD i, sel, size = 0;
  40
  41     if (!count) return 0;
  42     for (i = FIRST_LDT_ENTRY_TO_ALLOC; i < LDT_SIZE; i++)
  43     {
  44         if (wine_ldt_copy.flags[i] & WINE_LDT_FLAGS_ALLOCATED) size = 0;
  45         else if (++size >= count) break;
  46     }
  47     if (i == LDT_SIZE) return 0;
  48     sel = i - size + 1;
  49
  50     /* mark selectors as allocated */
  51     for (i = 0; i < count; i++) wine_ldt_copy.flags[sel + i] |= WINE_LDT_FLAGS_ALLOCATED;
  52
  53     return (sel << __AHSHIFT) | 7;
  54 }
  55
  56
  57 /***********************************************************************
  58  *           AllocSelectorArray   (KERNEL.206)
  59  */
  60 WORD WINAPI AllocSelectorArray16( WORD count )
  61 {
  62     WORD i, sel = SELECTOR_AllocArray( count );
  63
  64     if (sel)
  65     {
  66         LDT_ENTRY entry;
  67         wine_ldt_set_base( &entry, 0 );
  68         wine_ldt_set_limit( &entry, 1 ); /* avoid 0 base and limit */
  69         wine_ldt_set_flags( &entry, WINE_LDT_FLAGS_DATA );
  70         for (i = 0; i < count; i++) wine_ldt_set_entry( sel + (i << __AHSHIFT), &entry );
  71     }
  72     return sel;
  73 }
  74
  75
  76 /***********************************************************************
  77  *           AllocSelector   (KERNEL.175)
  78  */
  79 WORD WINAPI AllocSelector16( WORD sel )
  80 {
  81     WORD newsel, count, i;
  82
  83     count = sel ? get_sel_count(sel) : 1;
  84     newsel = SELECTOR_AllocArray( count );
  85     TRACE("(%04x): returning %04x\n", sel, newsel );
  86     if (!newsel) return 0;
  87     if (!sel) return newsel;  /* nothing to copy */
  88     for (i = 0; i < count; i++)
  89     {
  90         LDT_ENTRY entry;
  91         wine_ldt_get_entry( sel + (i << __AHSHIFT), &entry );
  92         wine_ldt_set_entry( newsel + (i << __AHSHIFT), &entry );
  93     }
  94     return newsel;
  95 }
  96
  97
  98 /***********************************************************************
  99  *           FreeSelector   (KERNEL.176)
 100  */
 101 WORD WINAPI FreeSelector16( WORD sel )
 102 {
 103     if (IS_SELECTOR_FREE(sel)) return sel;  /* error */
 104
 105 #ifdef __i386__
 106     /* Check if we are freeing current %fs or %gs selector */
 107     if (!((__get_fs() ^ sel) & ~7))
 108     {
 109         WARN("Freeing %%fs selector (%04x), not good.\n", __get_fs() );
 110         __set_fs( 0 );
 111     }
 112     if (!((__get_gs() ^ sel) & ~7)) __set_gs( 0 );
 113 #endif  /* __i386__ */
 114
 115     wine_ldt_set_entry( sel, &null_entry );
 116     wine_ldt_copy.flags[sel >> __AHSHIFT] &= ~WINE_LDT_FLAGS_ALLOCATED;
 117     return 0;
 118 }
 119
 120
 121 /***********************************************************************
 122  *           SELECTOR_FreeFs
 123  *
 124  * Free the current %fs selector.
 125  */
 126 void SELECTOR_FreeFs(void)
 127 {
 128     WORD fs = __get_fs();
 129     if (fs)
 130     {
 131         wine_ldt_copy.flags[fs >> __AHSHIFT] &= ~WINE_LDT_FLAGS_ALLOCATED;
 132         __set_fs(0);
 133         wine_ldt_set_entry( fs, &null_entry );
 134     }
 135 }
 136
 137
 138 /***********************************************************************
 139  *           SELECTOR_SetEntries
 140  *
 141  * Set the LDT entries for an array of selectors.
 142  */
 143 static void SELECTOR_SetEntries( WORD sel, const void *base, DWORD size, unsigned char flags )
 144 {
 145     LDT_ENTRY entry;
 146     WORD i, count;
 147
 148     wine_ldt_set_base( &entry, base );
 149     wine_ldt_set_limit( &entry, size - 1 );
 150     wine_ldt_set_flags( &entry, flags );
 151     /* Make sure base and limit are not 0 together if the size is not 0 */
 152     if (!base && size == 1) wine_ldt_set_limit( &entry, 1 );
 153     count = (size + 0xffff) / 0x10000;
 154     for (i = 0; i < count; i++)
 155     {
 156         wine_ldt_set_entry( sel + (i << __AHSHIFT), &entry );
 157         wine_ldt_set_base( &entry, wine_ldt_get_base(&entry) + 0x10000 );
 158         wine_ldt_set_limit( &entry, wine_ldt_get_limit(&entry) - 0x10000 );
 159     }
 160 }
 161
 162
 163 /***********************************************************************
 164  *           SELECTOR_AllocBlock
 165  *
 166  * Allocate selectors for a block of linear memory.
 167  */
 168 WORD SELECTOR_AllocBlock( const void *base, DWORD size, unsigned char flags )
 169 {
 170     WORD sel, count;
 171
 172     if (!size) return 0;
 173     count = (size + 0xffff) / 0x10000;
 174     sel = SELECTOR_AllocArray( count );
 175     if (sel) SELECTOR_SetEntries( sel, base, size, flags );
 176     return sel;
 177 }
 178
 179
 180 /***********************************************************************
 181  *           SELECTOR_FreeBlock
 182  *
 183  * Free a block of selectors.
 184  */
 185 void SELECTOR_FreeBlock( WORD sel )
 186 {
 187     WORD i, count = get_sel_count( sel );
 188
 189     TRACE("(%04x,%d)\n", sel, count );
 190     for (i = 0; i < count; i++) FreeSelector16( sel + (i << __AHSHIFT) );
 191 }
 192
 193
 194 /***********************************************************************
 195  *           SELECTOR_ReallocBlock
 196  *
 197  * Change the size of a block of selectors.
 198  */
 199 WORD SELECTOR_ReallocBlock( WORD sel, const void *base, DWORD size )
 200 {
 201     LDT_ENTRY entry;
 202     WORD i, oldcount, newcount;
 203
 204     if (!size) size = 1;
 205     oldcount = get_sel_count( sel );
 206     newcount = (size + 0xffff) >> 16;
 207     wine_ldt_get_entry( sel, &entry );
 208
 209     if (oldcount < newcount)  /* We need to add selectors */
 210     {
 211         WORD index = sel >> __AHSHIFT;
 212           /* Check if the next selectors are free */
 213         if (index + newcount > LDT_SIZE) i = oldcount;
 214         else
 215             for (i = oldcount; i < newcount; i++)
 216                 if (wine_ldt_copy.flags[index+i] & WINE_LDT_FLAGS_ALLOCATED) break;
 217
 218         if (i < newcount)  /* they are not free */
 219         {
 220             SELECTOR_FreeBlock( sel );
 221             sel = SELECTOR_AllocArray( newcount );
 222         }
 223         else  /* mark the selectors as allocated */
 224         {
 225             for (i = oldcount; i < newcount; i++)
 226                 wine_ldt_copy.flags[index+i] |= WINE_LDT_FLAGS_ALLOCATED;
 227         }
 228     }
 229     else if (oldcount > newcount) /* We need to remove selectors */
 230     {
 231         SELECTOR_FreeBlock( sel + (newcount << __AHSHIFT) );
 232     }
 233     if (sel) SELECTOR_SetEntries( sel, base, size, wine_ldt_get_flags(&entry) );
 234     return sel;
 235 }
 236
 237
 238 /***********************************************************************
 239  *           PrestoChangoSelector   (KERNEL.177)
 240  */
 241 WORD WINAPI PrestoChangoSelector16( WORD selSrc, WORD selDst )
 242 {
 243     LDT_ENTRY entry;
 244     wine_ldt_get_entry( selSrc, &entry );
 245     /* toggle the executable bit */
 246     entry.HighWord.Bits.Type ^= (WINE_LDT_FLAGS_CODE ^ WINE_LDT_FLAGS_DATA);
 247     wine_ldt_set_entry( selDst, &entry );
 248     return selDst;
 249 }
 250
 251
 252 /***********************************************************************
 253  *           AllocCStoDSAlias   (KERNEL.170)
 254  *           AllocAlias         (KERNEL.172)
 255  */
 256 WORD WINAPI AllocCStoDSAlias16( WORD sel )
 257 {
 258     WORD newsel;
 259     LDT_ENTRY entry;
 260
 261     newsel = SELECTOR_AllocArray( 1 );
 262     TRACE("(%04x): returning %04x\n",
 263                       sel, newsel );
 264     if (!newsel) return 0;
 265     wine_ldt_get_entry( sel, &entry );
 266     entry.HighWord.Bits.Type = WINE_LDT_FLAGS_DATA;
 267     wine_ldt_set_entry( newsel, &entry );
 268     return newsel;
 269 }
 270
 271
 272 /***********************************************************************
 273  *           AllocDStoCSAlias   (KERNEL.171)
 274  */
 275 WORD WINAPI AllocDStoCSAlias16( WORD sel )
 276 {
 277     WORD newsel;
 278     LDT_ENTRY entry;
 279
 280     newsel = SELECTOR_AllocArray( 1 );
 281     TRACE("(%04x): returning %04x\n",
 282                       sel, newsel );
 283     if (!newsel) return 0;
 284     wine_ldt_get_entry( sel, &entry );
 285     entry.HighWord.Bits.Type = WINE_LDT_FLAGS_CODE;
 286     wine_ldt_set_entry( newsel, &entry );
 287     return newsel;
 288 }
 289
 290
 291 /***********************************************************************
 292  *           LongPtrAdd   (KERNEL.180)
 293  */
 294 void WINAPI LongPtrAdd16( DWORD ptr, DWORD add )
 295 {
 296     LDT_ENTRY entry;
 297     wine_ldt_get_entry( SELECTOROF(ptr), &entry );
 298     wine_ldt_set_base( &entry, (char *)wine_ldt_get_base(&entry) + add );
 299     wine_ldt_set_entry( SELECTOROF(ptr), &entry );
 300 }
 301
 302
 303 /***********************************************************************
 304  *           GetSelectorBase   (KERNEL.186)
 305  */
 306 DWORD WINAPI WIN16_GetSelectorBase( WORD sel )
 307 {
 308     /*
 309      * Note: For Win32s processes, the whole linear address space is
 310      *       shifted by 0x10000 relative to the OS linear address space.
 311      *       See the comment in msdos/vxd.c.
 312      */
 313
 314     DWORD base = GetSelectorBase( sel );
 315     return W32S_WINE2APP( base );
 316 }
 317 DWORD WINAPI GetSelectorBase( WORD sel )
 318 {
 319     void *base = wine_ldt_copy.base[sel >> __AHSHIFT];
 320
 321     /* if base points into DOSMEM, assume we have to
 322      * return pointer into physical lower 1MB */
 323
 324     return DOSMEM_MapLinearToDos( base );
 325 }
 326
 327
 328 /***********************************************************************
 329  *           SetSelectorBase   (KERNEL.187)
 330  */
 331 DWORD WINAPI WIN16_SetSelectorBase( WORD sel, DWORD base )
 332 {
 333     /*
 334      * Note: For Win32s processes, the whole linear address space is
 335      *       shifted by 0x10000 relative to the OS linear address space.
 336      *       See the comment in msdos/vxd.c.
 337      */
 338
 339     SetSelectorBase( sel, W32S_APP2WINE( base ) );
 340     return sel;
 341 }
 342 WORD WINAPI SetSelectorBase( WORD sel, DWORD base )
 343 {
 344     LDT_ENTRY entry;
 345     wine_ldt_get_entry( sel, &entry );
 346     wine_ldt_set_base( &entry, DOSMEM_MapDosToLinear(base) );
 347     wine_ldt_set_entry( sel, &entry );
 348     return sel;
 349 }
 350
 351
 352 /***********************************************************************
 353  *           GetSelectorLimit   (KERNEL.188)
 354  */
 355 DWORD WINAPI GetSelectorLimit16( WORD sel )
 356 {
 357     return wine_ldt_copy.limit[sel >> __AHSHIFT];
 358 }
 359
 360
 361 /***********************************************************************
 362  *           SetSelectorLimit   (KERNEL.189)
 363  */
 364 WORD WINAPI SetSelectorLimit16( WORD sel, DWORD limit )
 365 {
 366     LDT_ENTRY entry;
 367     wine_ldt_get_entry( sel, &entry );
 368     wine_ldt_set_limit( &entry, limit );
 369     wine_ldt_set_entry( sel, &entry );
 370     return sel;
 371 }
 372
 373
 374 /***********************************************************************
 375  *           SelectorAccessRights   (KERNEL.196)
 376  */
 377 WORD WINAPI SelectorAccessRights16( WORD sel, WORD op, WORD val )
 378 {
 379     LDT_ENTRY entry;
 380     wine_ldt_get_entry( sel, &entry );
 381
 382     if (op == 0)  /* get */
 383     {
 384         return entry.HighWord.Bytes.Flags1 | ((entry.HighWord.Bytes.Flags2 << 8) & 0xf0);
 385     }
 386     else  /* set */
 387     {
 388         entry.HighWord.Bytes.Flags1 = LOBYTE(val) | 0xf0;
 389         entry.HighWord.Bytes.Flags2 = (entry.HighWord.Bytes.Flags2 & 0x0f) | (HIBYTE(val) & 0xf0);
 390         wine_ldt_set_entry( sel, &entry );
 391         return 0;
 392     }
 393 }
 394
 395
 396 /***********************************************************************
 397  *           IsBadCodePtr   (KERNEL.336)
 398  */
 399 BOOL16 WINAPI IsBadCodePtr16( SEGPTR lpfn )
 400 {
 401     WORD sel;
 402     LDT_ENTRY entry;
 403
 404     sel = SELECTOROF(lpfn);
 405     if (!sel) return TRUE;
 406     if (IS_SELECTOR_FREE(sel)) return TRUE;
 407     wine_ldt_get_entry( sel, &entry );
 408     /* check for code segment, ignoring conforming, read-only and accessed bits */
 409     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_CODE) & 0x18) return TRUE;
 410     if (OFFSETOF(lpfn) > wine_ldt_get_limit(&entry)) return TRUE;
 411     return FALSE;
 412 }
 413
 414
 415 /***********************************************************************
 416  *           IsBadStringPtr   (KERNEL.337)
 417  */
 418 BOOL16 WINAPI IsBadStringPtr16( SEGPTR ptr, UINT16 size )
 419 {
 420     WORD sel;
 421     LDT_ENTRY entry;
 422
 423     sel = SELECTOROF(ptr);
 424     if (!sel) return TRUE;
 425     if (IS_SELECTOR_FREE(sel)) return TRUE;
 426     wine_ldt_get_entry( sel, &entry );
 427     /* check for data or readable code segment */
 428     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 429     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 430     if (strlen(MapSL(ptr)) < size) size = strlen(MapSL(ptr)) + 1;
 431     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit(&entry))) return TRUE;
 432     return FALSE;
 433 }
 434
 435
 436 /***********************************************************************
 437  *           IsBadHugeReadPtr   (KERNEL.346)
 438  */
 439 BOOL16 WINAPI IsBadHugeReadPtr16( SEGPTR ptr, DWORD size )
 440 {
 441     WORD sel;
 442     LDT_ENTRY entry;
 443
 444     sel = SELECTOROF(ptr);
 445     if (!sel) return TRUE;
 446     if (IS_SELECTOR_FREE(sel)) return TRUE;
 447     wine_ldt_get_entry( sel, &entry );
 448     /* check for data or readable code segment */
 449     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 450     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 451     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 452     return FALSE;
 453 }
 454
 455
 456 /***********************************************************************
 457  *           IsBadHugeWritePtr   (KERNEL.347)
 458  */
 459 BOOL16 WINAPI IsBadHugeWritePtr16( SEGPTR ptr, DWORD size )
 460 {
 461     WORD sel;
 462     LDT_ENTRY entry;
 463
 464     sel = SELECTOROF(ptr);
 465     if (!sel) return TRUE;
 466     if (IS_SELECTOR_FREE(sel)) return TRUE;
 467     wine_ldt_get_entry( sel, &entry );
 468     /* check for writeable data segment, ignoring expand-down and accessed flags */
 469     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_DATA) & ~5) return TRUE;
 470     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 471     return FALSE;
 472 }
 473
 474 /***********************************************************************
 475  *           IsBadReadPtr   (KERNEL.334)
 476  */
 477 BOOL16 WINAPI IsBadReadPtr16( SEGPTR ptr, UINT16 size )
 478 {
 479     return IsBadHugeReadPtr16( ptr, size );
 480 }
 481
 482
 483 /***********************************************************************
 484  *           IsBadWritePtr   (KERNEL.335)
 485  */
 486 BOOL16 WINAPI IsBadWritePtr16( SEGPTR ptr, UINT16 size )
 487 {
 488     return IsBadHugeWritePtr16( ptr, size );
 489 }
 490
 491
 492 /***********************************************************************
 493  *           IsBadFlatReadWritePtr   (KERNEL.627)
 494  */
 495 BOOL16 WINAPI IsBadFlatReadWritePtr16( SEGPTR ptr, DWORD size, BOOL16 bWrite )
 496 {
 497     return bWrite? IsBadHugeWritePtr16( ptr, size )
 498                  : IsBadHugeReadPtr16( ptr, size );
 499 }
 500
 501
 502 /***********************************************************************
 503  *           MemoryRead   (TOOLHELP.78)
 504  */
 505 DWORD WINAPI MemoryRead16( WORD sel, DWORD offset, void *buffer, DWORD count )
 506 {
 507     WORD index = sel >> __AHSHIFT;
 508
 509     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 510     if (offset > wine_ldt_copy.limit[index]) return 0;
 511     if (offset + count > wine_ldt_copy.limit[index] + 1)
 512         count = wine_ldt_copy.limit[index] + 1 - offset;
 513     memcpy( buffer, (char *)wine_ldt_copy.base[index] + offset, count );
 514     return count;
 515 }
 516
 517
 518 /***********************************************************************
 519  *           MemoryWrite   (TOOLHELP.79)
 520  */
 521 DWORD WINAPI MemoryWrite16( WORD sel, DWORD offset, void *buffer, DWORD count )
 522 {
 523     WORD index = sel >> __AHSHIFT;
 524
 525     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 526     if (offset > wine_ldt_copy.limit[index]) return 0;
 527     if (offset + count > wine_ldt_copy.limit[index] + 1)
 528         count = wine_ldt_copy.limit[index] + 1 - offset;
 529     memcpy( (char *)wine_ldt_copy.base[index] + offset, buffer, count );
 530     return count;
 531 }
 532
 533 /************************************* Win95 pointer mapping functions *
 534  *
 535  */
 536
 537 struct mapls_entry
 538 {
 539     struct mapls_entry *next;
 540     void               *addr;   /* linear address */
 541     int                 count;  /* ref count */
 542     WORD                sel;    /* selector */
 543 };
 544
 545 static struct mapls_entry *first_entry;
 546
 547
 548 /***********************************************************************
 549  *           MapLS   (KERNEL32.@)
 550  *           MapLS   (KERNEL.358)
 551  *
 552  * Maps linear pointer to segmented.
 553  */
 554 SEGPTR WINAPI MapLS( LPCVOID ptr )
 555 {
 556     struct mapls_entry *entry, *free = NULL;
 557     void *base;
 558     SEGPTR ret = 0;
 559
 560     if (!HIWORD(ptr)) return (SEGPTR)ptr;
 561
 562     base = (char *)ptr - ((unsigned int)ptr & 0x7fff);
 563     HeapLock( GetProcessHeap() );
 564     for (entry = first_entry; entry; entry = entry->next)
 565     {
 566         if (entry->addr == base) break;
 567         if (!entry->count) free = entry;
 568     }
 569
 570     if (!entry)
 571     {
 572         if (!free)  /* no free entry found, create a new one */
 573         {
 574             if (!(free = HeapAlloc( GetProcessHeap(), 0, sizeof(*free) ))) goto done;
 575             if (!(free->sel = SELECTOR_AllocBlock( base, 0x10000, WINE_LDT_FLAGS_DATA )))
 576             {
 577                 HeapFree( GetProcessHeap(), 0, free );
 578                 goto done;
 579             }
 580             free->count = 0;
 581             free->next = first_entry;
 582             first_entry = free;
 583         }
 584         SetSelectorBase( free->sel, (DWORD)base );
 585         free->addr = base;
 586         entry = free;
 587     }
 588     entry->count++;
 589     ret = MAKESEGPTR( entry->sel, (char *)ptr - (char *)entry->addr );
 590  done:
 591     HeapUnlock( GetProcessHeap() );
 592     return ret;
 593 }
 594
 595 /***********************************************************************
 596  *           UnMapLS   (KERNEL32.@)
 597  *           UnMapLS   (KERNEL.359)
 598  *
 599  * Free mapped selector.
 600  */
 601 void WINAPI UnMapLS( SEGPTR sptr )
 602 {
 603     struct mapls_entry *entry;
 604     WORD sel = SELECTOROF(sptr);
 605
 606     if (sel)
 607     {
 608         HeapLock( GetProcessHeap() );
 609         for (entry = first_entry; entry; entry = entry->next) if (entry->sel == sel) break;
 610         if (entry && entry->count > 0) entry->count--;
 611         HeapUnlock( GetProcessHeap() );
 612     }
 613 }
 614
 615 /***********************************************************************
 616  *           MapSL   (KERNEL32.@)
 617  *           MapSL   (KERNEL.357)
 618  *
 619  * Maps fixed segmented pointer to linear.
 620  */
 621 LPVOID WINAPI MapSL( SEGPTR sptr )
 622 {
 623     return (char *)wine_ldt_copy.base[SELECTOROF(sptr) >> __AHSHIFT] + OFFSETOF(sptr);
 624 }
 625
 626 /***********************************************************************
 627  *           MapSLFix   (KERNEL32.@)
 628  *
 629  * FIXME: MapSLFix and UnMapSLFixArray should probably prevent
 630  * unexpected linear address change when GlobalCompact() shuffles
 631  * moveable blocks.
 632  */
 633
 634 LPVOID WINAPI MapSLFix( SEGPTR sptr )
 635 {
 636     return MapSL(sptr);
 637 }
 638
 639 /***********************************************************************
 640  *           UnMapSLFixArray   (KERNEL32.@)
 641  */
 642
 643 void WINAPI UnMapSLFixArray( SEGPTR sptr[], INT length, CONTEXT86 *context )
 644 {
 645     /* Must not change EAX, hence defined as 'register' function */
 646 }
 647
 648 /***********************************************************************
 649  *           GetThreadSelectorEntry   (KERNEL32.@)
 650  */
 651 BOOL WINAPI GetThreadSelectorEntry( HANDLE hthread, DWORD sel, LPLDT_ENTRY ldtent)
 652 {
 653 #ifdef __i386__
 654     BOOL ret;
 655
 656     if (!(sel & 4))  /* GDT selector */
 657     {
 658         sel &= ~3;  /* ignore RPL */
 659         if (!sel)  /* null selector */
 660         {
 661             memset( ldtent, 0, sizeof(*ldtent) );
 662             return TRUE;
 663         }
 664         ldtent->BaseLow                   = 0;
 665         ldtent->HighWord.Bits.BaseMid     = 0;
 666         ldtent->HighWord.Bits.BaseHi      = 0;
 667         ldtent->LimitLow                  = 0xffff;
 668         ldtent->HighWord.Bits.LimitHi     = 0xf;
 669         ldtent->HighWord.Bits.Dpl         = 3;
 670         ldtent->HighWord.Bits.Sys         = 0;
 671         ldtent->HighWord.Bits.Pres        = 1;
 672         ldtent->HighWord.Bits.Granularity = 1;
 673         ldtent->HighWord.Bits.Default_Big = 1;
 674         ldtent->HighWord.Bits.Type        = 0x12;
 675         /* it has to be one of the system GDT selectors */
 676         if (sel == (__get_ds() & ~3)) return TRUE;
 677         if (sel == (__get_ss() & ~3)) return TRUE;
 678         if (sel == (__get_cs() & ~3))
 679         {
 680             ldtent->HighWord.Bits.Type |= 8;  /* code segment */
 681             return TRUE;
 682         }
 683         SetLastError( ERROR_NOACCESS );
 684         return FALSE;
 685     }
 686
 687     SERVER_START_REQ( get_selector_entry )
 688     {
 689         req->handle = hthread;
 690         req->entry = sel >> __AHSHIFT;
 691         if ((ret = !wine_server_call_err( req )))
 692         {
 693             if (!(reply->flags & WINE_LDT_FLAGS_ALLOCATED))
 694             {
 695                 SetLastError( ERROR_MR_MID_NOT_FOUND );  /* sic */
 696                 ret = FALSE;
 697             }
 698             else
 699             {
 700                 wine_ldt_set_base( ldtent, (void *)reply->base );
 701                 wine_ldt_set_limit( ldtent, reply->limit );
 702                 wine_ldt_set_flags( ldtent, reply->flags );
 703             }
 704         }
 705     }
 706     SERVER_END_REQ;
 707     return ret;
 708 #else
 709     SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
 710     return FALSE;
 711 #endif
 712 }
 713
 714
 715 /**********************************************************************
 716  *              SMapLS*         (KERNEL32)
 717  * These functions map linear pointers at [EBP+xxx] to segmented pointers
 718  * and return them.
 719  * Win95 uses some kind of alias structs, which it stores in [EBP+x] to
 720  * unravel them at SUnMapLS. We just store the segmented pointer there.
 721  */
 722 static void
 723 x_SMapLS_IP_EBP_x(CONTEXT86 *context,int argoff) {
 724     DWORD       val,ptr;
 725
 726     val =*(DWORD*)(context->Ebp + argoff);
 727     if (val<0x10000) {
 728         ptr=val;
 729         *(DWORD*)(context->Ebp + argoff) = 0;
 730     } else {
 731         ptr = MapLS((LPVOID)val);
 732         *(DWORD*)(context->Ebp + argoff) = ptr;
 733     }
 734     context->Eax = ptr;
 735 }
 736
 737 /***********************************************************************
 738  *              SMapLS_IP_EBP_8 (KERNEL32.@)
 739  */
 740 void WINAPI SMapLS_IP_EBP_8 (CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context, 8);}
 741
 742 /***********************************************************************
 743  *              SMapLS_IP_EBP_12 (KERNEL32.@)
 744  */
 745 void WINAPI SMapLS_IP_EBP_12(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,12);}
 746
 747 /***********************************************************************
 748  *              SMapLS_IP_EBP_16 (KERNEL32.@)
 749  */
 750 void WINAPI SMapLS_IP_EBP_16(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,16);}
 751
 752 /***********************************************************************
 753  *              SMapLS_IP_EBP_20 (KERNEL32.@)
 754  */
 755 void WINAPI SMapLS_IP_EBP_20(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,20);}
 756
 757 /***********************************************************************
 758  *              SMapLS_IP_EBP_24 (KERNEL32.@)
 759  */
 760 void WINAPI SMapLS_IP_EBP_24(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,24);}
 761
 762 /***********************************************************************
 763  *              SMapLS_IP_EBP_28 (KERNEL32.@)
 764  */
 765 void WINAPI SMapLS_IP_EBP_28(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,28);}
 766
 767 /***********************************************************************
 768  *              SMapLS_IP_EBP_32 (KERNEL32.@)
 769  */
 770 void WINAPI SMapLS_IP_EBP_32(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,32);}
 771
 772 /***********************************************************************
 773  *              SMapLS_IP_EBP_36 (KERNEL32.@)
 774  */
 775 void WINAPI SMapLS_IP_EBP_36(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,36);}
 776
 777 /***********************************************************************
 778  *              SMapLS_IP_EBP_40 (KERNEL32.@)
 779  */
 780 void WINAPI SMapLS_IP_EBP_40(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,40);}
 781
 782 /***********************************************************************
 783  *              SMapLS (KERNEL32.@)
 784  */
 785 void WINAPI SMapLS( CONTEXT86 *context )
 786 {
 787     if (HIWORD(context->Eax))
 788     {
 789         context->Eax = MapLS( (LPVOID)context->Eax );
 790         context->Edx = context->Eax;
 791     } else {
 792         context->Edx = 0;
 793     }
 794 }
 795
 796 /***********************************************************************
 797  *              SUnMapLS (KERNEL32.@)
 798  */
 799
 800 void WINAPI SUnMapLS( CONTEXT86 *context )
 801 {
 802     if (HIWORD(context->Eax)) UnMapLS( (SEGPTR)context->Eax );
 803 }
 804
 805 inline static void x_SUnMapLS_IP_EBP_x(CONTEXT86 *context,int argoff)
 806 {
 807     SEGPTR *ptr = (SEGPTR *)(context->Ebp + argoff);
 808     if (*ptr)
 809     {
 810         UnMapLS( *ptr );
 811         *ptr = 0;
 812     }
 813 }
 814
 815 /***********************************************************************
 816  *              SUnMapLS_IP_EBP_8 (KERNEL32.@)
 817  */
 818 void WINAPI SUnMapLS_IP_EBP_8 (CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context, 8); }
 819
 820 /***********************************************************************
 821  *              SUnMapLS_IP_EBP_12 (KERNEL32.@)
 822  */
 823 void WINAPI SUnMapLS_IP_EBP_12(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,12); }
 824
 825 /***********************************************************************
 826  *              SUnMapLS_IP_EBP_16 (KERNEL32.@)
 827  */
 828 void WINAPI SUnMapLS_IP_EBP_16(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,16); }
 829
 830 /***********************************************************************
 831  *              SUnMapLS_IP_EBP_20 (KERNEL32.@)
 832  */
 833 void WINAPI SUnMapLS_IP_EBP_20(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,20); }
 834
 835 /***********************************************************************
 836  *              SUnMapLS_IP_EBP_24 (KERNEL32.@)
 837  */
 838 void WINAPI SUnMapLS_IP_EBP_24(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,24); }
 839
 840 /***********************************************************************
 841  *              SUnMapLS_IP_EBP_28 (KERNEL32.@)
 842  */
 843 void WINAPI SUnMapLS_IP_EBP_28(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,28); }
 844
 845 /***********************************************************************
 846  *              SUnMapLS_IP_EBP_32 (KERNEL32.@)
 847  */
 848 void WINAPI SUnMapLS_IP_EBP_32(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,32); }
 849
 850 /***********************************************************************
 851  *              SUnMapLS_IP_EBP_36 (KERNEL32.@)
 852  */
 853 void WINAPI SUnMapLS_IP_EBP_36(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,36); }
 854
 855 /***********************************************************************
 856  *              SUnMapLS_IP_EBP_40 (KERNEL32.@)
 857  */
 858 void WINAPI SUnMapLS_IP_EBP_40(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,40); }
 859
 860 /**********************************************************************
 861  *              AllocMappedBuffer       (KERNEL32.38)
 862  *
 863  * This is a undocumented KERNEL32 function that
 864  * SMapLS's a GlobalAlloc'ed buffer.
 865  *
 866  * Input:   EDI register: size of buffer to allocate
 867  * Output:  EDI register: pointer to buffer
 868  *
 869  * Note: The buffer is preceded by 8 bytes:
 870  *        ...
 871  *       edi+0   buffer
 872  *       edi-4   SEGPTR to buffer
 873  *       edi-8   some magic Win95 needs for SUnMapLS
 874  *               (we use it for the memory handle)
 875  *
 876  *       The SEGPTR is used by the caller!
 877  */
 878
 879 void WINAPI AllocMappedBuffer( CONTEXT86 *context )
 880 {
 881     HGLOBAL handle = GlobalAlloc(0, context->Edi + 8);
 882     DWORD *buffer = (DWORD *)GlobalLock(handle);
 883     SEGPTR ptr = 0;
 884
 885     if (buffer)
 886         if (!(ptr = MapLS(buffer + 2)))
 887         {
 888             GlobalUnlock(handle);
 889             GlobalFree(handle);
 890         }
 891
 892     if (!ptr)
 893         context->Eax = context->Edi = 0;
 894     else
 895     {
 896         buffer[0] = handle;
 897         buffer[1] = ptr;
 898
 899         context->Eax = (DWORD) ptr;
 900         context->Edi = (DWORD)(buffer + 2);
 901     }
 902 }
 903
 904 /**********************************************************************
 905  *              FreeMappedBuffer        (KERNEL32.39)
 906  *
 907  * Free a buffer allocated by AllocMappedBuffer
 908  *
 909  * Input: EDI register: pointer to buffer
 910  */
 911
 912 void WINAPI FreeMappedBuffer( CONTEXT86 *context )
 913 {
 914     if (context->Edi)
 915     {
 916         DWORD *buffer = (DWORD *)context->Edi - 2;
 917
 918         UnMapLS(buffer[1]);
 919
 920         GlobalUnlock(buffer[0]);
 921         GlobalFree(buffer[0]);
 922     }
 923 }
 924
 925 #ifdef __i386__
 926 __ASM_GLOBAL_FUNC( __get_cs, "movw %cs,%ax\n\tret" )
 927 __ASM_GLOBAL_FUNC( __get_ds, "movw %ds,%ax\n\tret" )
 928 __ASM_GLOBAL_FUNC( __get_es, "movw %es,%ax\n\tret" )
 929 __ASM_GLOBAL_FUNC( __get_fs, "movw %fs,%ax\n\tret" )
 930 __ASM_GLOBAL_FUNC( __get_gs, "movw %gs,%ax\n\tret" )
 931 __ASM_GLOBAL_FUNC( __get_ss, "movw %ss,%ax\n\tret" )
 932 __ASM_GLOBAL_FUNC( __set_fs, "movl 4(%esp),%eax\n\tmovw %ax,%fs\n\tret" )
 933 __ASM_GLOBAL_FUNC( __set_gs, "movl 4(%esp),%eax\n\tmovw %ax,%gs\n\tret" )
 934 #endif