memory/selector.c

   1 /*
   2  * Selector manipulation functions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <string.h>
  25
  26 #include "winerror.h"
  27 #include "wine/winbase16.h"
  28 #include "miscemu.h"
  29 #include "selectors.h"
  30 #include "stackframe.h"
  31 #include "wine/server.h"
  32 #include "wine/debug.h"
  33 #include "toolhelp.h"
  34
  35 WINE_DEFAULT_DEBUG_CHANNEL(selector);
  36
  37 #define LDT_SIZE 8192
  38
  39 /* get the number of selectors needed to cover up to the selector limit */
  40 inline static WORD get_sel_count( WORD sel )
  41 {
  42     return (wine_ldt_copy.limit[sel >> __AHSHIFT] >> 16) + 1;
  43 }
  44
  45 static const LDT_ENTRY null_entry;  /* all-zeros, used to clear LDT entries */
  46
  47 /***********************************************************************
  48  *           SELECTOR_AllocArray
  49  *
  50  * Allocate a selector array without setting the LDT entries
  51  */
  52 static WORD SELECTOR_AllocArray( WORD count )
  53 {
  54     WORD i, sel, size = 0;
  55
  56     if (!count) return 0;
  57     for (i = FIRST_LDT_ENTRY_TO_ALLOC; i < LDT_SIZE; i++)
  58     {
  59         if (wine_ldt_copy.flags[i] & WINE_LDT_FLAGS_ALLOCATED) size = 0;
  60         else if (++size >= count) break;
  61     }
  62     if (i == LDT_SIZE) return 0;
  63     sel = i - size + 1;
  64
  65     /* mark selectors as allocated */
  66     for (i = 0; i < count; i++) wine_ldt_copy.flags[sel + i] |= WINE_LDT_FLAGS_ALLOCATED;
  67
  68     return (sel << __AHSHIFT) | 7;
  69 }
  70
  71
  72 /***********************************************************************
  73  *           AllocSelectorArray   (KERNEL.206)
  74  */
  75 WORD WINAPI AllocSelectorArray16( WORD count )
  76 {
  77     WORD i, sel = SELECTOR_AllocArray( count );
  78
  79     if (sel)
  80     {
  81         LDT_ENTRY entry;
  82         wine_ldt_set_base( &entry, 0 );
  83         wine_ldt_set_limit( &entry, 1 ); /* avoid 0 base and limit */
  84         wine_ldt_set_flags( &entry, WINE_LDT_FLAGS_DATA );
  85         for (i = 0; i < count; i++) wine_ldt_set_entry( sel + (i << __AHSHIFT), &entry );
  86     }
  87     return sel;
  88 }
  89
  90
  91 /***********************************************************************
  92  *           AllocSelector   (KERNEL.175)
  93  */
  94 WORD WINAPI AllocSelector16( WORD sel )
  95 {
  96     WORD newsel, count, i;
  97
  98     count = sel ? get_sel_count(sel) : 1;
  99     newsel = SELECTOR_AllocArray( count );
 100     TRACE("(%04x): returning %04x\n", sel, newsel );
 101     if (!newsel) return 0;
 102     if (!sel) return newsel;  /* nothing to copy */
 103     for (i = 0; i < count; i++)
 104     {
 105         LDT_ENTRY entry;
 106         wine_ldt_get_entry( sel + (i << __AHSHIFT), &entry );
 107         wine_ldt_set_entry( newsel + (i << __AHSHIFT), &entry );
 108     }
 109     return newsel;
 110 }
 111
 112
 113 /***********************************************************************
 114  *           FreeSelector   (KERNEL.176)
 115  */
 116 WORD WINAPI FreeSelector16( WORD sel )
 117 {
 118     if (IS_SELECTOR_FREE(sel)) return sel;  /* error */
 119
 120 #ifdef __i386__
 121     /* Check if we are freeing current %fs or %gs selector */
 122     if (!((wine_get_fs() ^ sel) & ~3))
 123     {
 124         WARN("Freeing %%fs selector (%04x), not good.\n", wine_get_fs() );
 125         wine_set_fs( 0 );
 126     }
 127     if (!((wine_get_gs() ^ sel) & ~3)) wine_set_gs( 0 );
 128 #endif  /* __i386__ */
 129
 130     wine_ldt_set_entry( sel, &null_entry );
 131     wine_ldt_copy.flags[sel >> __AHSHIFT] &= ~WINE_LDT_FLAGS_ALLOCATED;
 132     return 0;
 133 }
 134
 135
 136 /***********************************************************************
 137  *           SELECTOR_FreeFs
 138  *
 139  * Free the current %fs selector.
 140  */
 141 void SELECTOR_FreeFs(void)
 142 {
 143     WORD fs = wine_get_fs();
 144     if (fs)
 145     {
 146         wine_ldt_copy.flags[fs >> __AHSHIFT] &= ~WINE_LDT_FLAGS_ALLOCATED;
 147         wine_set_fs(0);
 148         wine_ldt_set_entry( fs, &null_entry );
 149     }
 150 }
 151
 152
 153 /***********************************************************************
 154  *           SELECTOR_SetEntries
 155  *
 156  * Set the LDT entries for an array of selectors.
 157  */
 158 static void SELECTOR_SetEntries( WORD sel, const void *base, DWORD size, unsigned char flags )
 159 {
 160     LDT_ENTRY entry;
 161     WORD i, count;
 162
 163     wine_ldt_set_base( &entry, base );
 164     wine_ldt_set_limit( &entry, size - 1 );
 165     wine_ldt_set_flags( &entry, flags );
 166     count = (size + 0xffff) / 0x10000;
 167     for (i = 0; i < count; i++)
 168     {
 169         wine_ldt_set_entry( sel + (i << __AHSHIFT), &entry );
 170         wine_ldt_set_base( &entry, (char*)wine_ldt_get_base(&entry) + 0x10000);
 171         /* yep, Windows sets limit like that, not 64K sel units */
 172         wine_ldt_set_limit( &entry, wine_ldt_get_limit(&entry) - 0x10000 );
 173     }
 174 }
 175
 176
 177 /***********************************************************************
 178  *           SELECTOR_AllocBlock
 179  *
 180  * Allocate selectors for a block of linear memory.
 181  */
 182 WORD SELECTOR_AllocBlock( const void *base, DWORD size, unsigned char flags )
 183 {
 184     WORD sel, count;
 185
 186     if (!size) return 0;
 187     count = (size + 0xffff) / 0x10000;
 188     sel = SELECTOR_AllocArray( count );
 189     if (sel) SELECTOR_SetEntries( sel, base, size, flags );
 190     return sel;
 191 }
 192
 193
 194 /***********************************************************************
 195  *           SELECTOR_FreeBlock
 196  *
 197  * Free a block of selectors.
 198  */
 199 void SELECTOR_FreeBlock( WORD sel )
 200 {
 201     WORD i, count = get_sel_count( sel );
 202
 203     TRACE("(%04x,%d)\n", sel, count );
 204     for (i = 0; i < count; i++) FreeSelector16( sel + (i << __AHSHIFT) );
 205 }
 206
 207
 208 /***********************************************************************
 209  *           SELECTOR_ReallocBlock
 210  *
 211  * Change the size of a block of selectors.
 212  */
 213 WORD SELECTOR_ReallocBlock( WORD sel, const void *base, DWORD size )
 214 {
 215     LDT_ENTRY entry;
 216     WORD i, oldcount, newcount;
 217
 218     if (!size) size = 1;
 219     oldcount = get_sel_count( sel );
 220     newcount = (size + 0xffff) >> 16;
 221     wine_ldt_get_entry( sel, &entry );
 222
 223     if (oldcount < newcount)  /* We need to add selectors */
 224     {
 225         WORD index = sel >> __AHSHIFT;
 226           /* Check if the next selectors are free */
 227         if (index + newcount > LDT_SIZE) i = oldcount;
 228         else
 229             for (i = oldcount; i < newcount; i++)
 230                 if (wine_ldt_copy.flags[index+i] & WINE_LDT_FLAGS_ALLOCATED) break;
 231
 232         if (i < newcount)  /* they are not free */
 233         {
 234             SELECTOR_FreeBlock( sel );
 235             sel = SELECTOR_AllocArray( newcount );
 236         }
 237         else  /* mark the selectors as allocated */
 238         {
 239             for (i = oldcount; i < newcount; i++)
 240                 wine_ldt_copy.flags[index+i] |= WINE_LDT_FLAGS_ALLOCATED;
 241         }
 242     }
 243     else if (oldcount > newcount) /* We need to remove selectors */
 244     {
 245         SELECTOR_FreeBlock( sel + (newcount << __AHSHIFT) );
 246     }
 247     if (sel) SELECTOR_SetEntries( sel, base, size, wine_ldt_get_flags(&entry) );
 248     return sel;
 249 }
 250
 251
 252 /***********************************************************************
 253  *           PrestoChangoSelector   (KERNEL.177)
 254  */
 255 WORD WINAPI PrestoChangoSelector16( WORD selSrc, WORD selDst )
 256 {
 257     LDT_ENTRY entry;
 258     wine_ldt_get_entry( selSrc, &entry );
 259     /* toggle the executable bit */
 260     entry.HighWord.Bits.Type ^= (WINE_LDT_FLAGS_CODE ^ WINE_LDT_FLAGS_DATA);
 261     wine_ldt_set_entry( selDst, &entry );
 262     return selDst;
 263 }
 264
 265
 266 /***********************************************************************
 267  *           AllocCStoDSAlias   (KERNEL.170)
 268  *           AllocAlias         (KERNEL.172)
 269  */
 270 WORD WINAPI AllocCStoDSAlias16( WORD sel )
 271 {
 272     WORD newsel;
 273     LDT_ENTRY entry;
 274
 275     newsel = SELECTOR_AllocArray( 1 );
 276     TRACE("(%04x): returning %04x\n",
 277                       sel, newsel );
 278     if (!newsel) return 0;
 279     wine_ldt_get_entry( sel, &entry );
 280     entry.HighWord.Bits.Type = WINE_LDT_FLAGS_DATA;
 281     wine_ldt_set_entry( newsel, &entry );
 282     return newsel;
 283 }
 284
 285
 286 /***********************************************************************
 287  *           AllocDStoCSAlias   (KERNEL.171)
 288  */
 289 WORD WINAPI AllocDStoCSAlias16( WORD sel )
 290 {
 291     WORD newsel;
 292     LDT_ENTRY entry;
 293
 294     newsel = SELECTOR_AllocArray( 1 );
 295     TRACE("(%04x): returning %04x\n",
 296                       sel, newsel );
 297     if (!newsel) return 0;
 298     wine_ldt_get_entry( sel, &entry );
 299     entry.HighWord.Bits.Type = WINE_LDT_FLAGS_CODE;
 300     wine_ldt_set_entry( newsel, &entry );
 301     return newsel;
 302 }
 303
 304
 305 /***********************************************************************
 306  *           LongPtrAdd   (KERNEL.180)
 307  */
 308 void WINAPI LongPtrAdd16( DWORD ptr, DWORD add )
 309 {
 310     LDT_ENTRY entry;
 311     wine_ldt_get_entry( SELECTOROF(ptr), &entry );
 312     wine_ldt_set_base( &entry, (char *)wine_ldt_get_base(&entry) + add );
 313     wine_ldt_set_entry( SELECTOROF(ptr), &entry );
 314 }
 315
 316
 317 /***********************************************************************
 318  *           GetSelectorBase   (KERNEL.186)
 319  */
 320 DWORD WINAPI WIN16_GetSelectorBase( WORD sel )
 321 {
 322     /*
 323      * Note: For Win32s processes, the whole linear address space is
 324      *       shifted by 0x10000 relative to the OS linear address space.
 325      *       See the comment in msdos/vxd.c.
 326      */
 327
 328     DWORD base = GetSelectorBase( sel );
 329     return W32S_WINE2APP( base );
 330 }
 331 DWORD WINAPI GetSelectorBase( WORD sel )
 332 {
 333     void *base = wine_ldt_copy.base[sel >> __AHSHIFT];
 334
 335     /* if base points into DOSMEM, assume we have to
 336      * return pointer into physical lower 1MB */
 337
 338     return DOSMEM_MapLinearToDos( base );
 339 }
 340
 341
 342 /***********************************************************************
 343  *           SetSelectorBase   (KERNEL.187)
 344  */
 345 DWORD WINAPI WIN16_SetSelectorBase( WORD sel, DWORD base )
 346 {
 347     /*
 348      * Note: For Win32s processes, the whole linear address space is
 349      *       shifted by 0x10000 relative to the OS linear address space.
 350      *       See the comment in msdos/vxd.c.
 351      */
 352
 353     SetSelectorBase( sel, W32S_APP2WINE( base ) );
 354     return sel;
 355 }
 356 WORD WINAPI SetSelectorBase( WORD sel, DWORD base )
 357 {
 358     LDT_ENTRY entry;
 359     wine_ldt_get_entry( sel, &entry );
 360     wine_ldt_set_base( &entry, DOSMEM_MapDosToLinear(base) );
 361     wine_ldt_set_entry( sel, &entry );
 362     return sel;
 363 }
 364
 365
 366 /***********************************************************************
 367  *           GetSelectorLimit   (KERNEL.188)
 368  */
 369 DWORD WINAPI GetSelectorLimit16( WORD sel )
 370 {
 371     return wine_ldt_copy.limit[sel >> __AHSHIFT];
 372 }
 373
 374
 375 /***********************************************************************
 376  *           SetSelectorLimit   (KERNEL.189)
 377  */
 378 WORD WINAPI SetSelectorLimit16( WORD sel, DWORD limit )
 379 {
 380     LDT_ENTRY entry;
 381     wine_ldt_get_entry( sel, &entry );
 382     wine_ldt_set_limit( &entry, limit );
 383     wine_ldt_set_entry( sel, &entry );
 384     return sel;
 385 }
 386
 387
 388 /***********************************************************************
 389  *           SelectorAccessRights   (KERNEL.196)
 390  */
 391 WORD WINAPI SelectorAccessRights16( WORD sel, WORD op, WORD val )
 392 {
 393     LDT_ENTRY entry;
 394     wine_ldt_get_entry( sel, &entry );
 395
 396     if (op == 0)  /* get */
 397     {
 398         return entry.HighWord.Bytes.Flags1 | ((entry.HighWord.Bytes.Flags2 << 8) & 0xf0);
 399     }
 400     else  /* set */
 401     {
 402         entry.HighWord.Bytes.Flags1 = LOBYTE(val) | 0xf0;
 403         entry.HighWord.Bytes.Flags2 = (entry.HighWord.Bytes.Flags2 & 0x0f) | (HIBYTE(val) & 0xf0);
 404         wine_ldt_set_entry( sel, &entry );
 405         return 0;
 406     }
 407 }
 408
 409
 410 /***********************************************************************
 411  *           IsBadCodePtr   (KERNEL.336)
 412  */
 413 BOOL16 WINAPI IsBadCodePtr16( SEGPTR lpfn )
 414 {
 415     WORD sel;
 416     LDT_ENTRY entry;
 417
 418     sel = SELECTOROF(lpfn);
 419     if (!sel) return TRUE;
 420     if (IS_SELECTOR_FREE(sel)) return TRUE;
 421     wine_ldt_get_entry( sel, &entry );
 422     /* check for code segment, ignoring conforming, read-only and accessed bits */
 423     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_CODE) & 0x18) return TRUE;
 424     if (OFFSETOF(lpfn) > wine_ldt_get_limit(&entry)) return TRUE;
 425     return FALSE;
 426 }
 427
 428
 429 /***********************************************************************
 430  *           IsBadStringPtr   (KERNEL.337)
 431  */
 432 BOOL16 WINAPI IsBadStringPtr16( SEGPTR ptr, UINT16 size )
 433 {
 434     WORD sel;
 435     LDT_ENTRY entry;
 436
 437     sel = SELECTOROF(ptr);
 438     if (!sel) return TRUE;
 439     if (IS_SELECTOR_FREE(sel)) return TRUE;
 440     wine_ldt_get_entry( sel, &entry );
 441     /* check for data or readable code segment */
 442     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 443     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 444     if (strlen(MapSL(ptr)) < size) size = strlen(MapSL(ptr)) + 1;
 445     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit(&entry))) return TRUE;
 446     return FALSE;
 447 }
 448
 449
 450 /***********************************************************************
 451  *           IsBadHugeReadPtr   (KERNEL.346)
 452  */
 453 BOOL16 WINAPI IsBadHugeReadPtr16( SEGPTR ptr, DWORD size )
 454 {
 455     WORD sel;
 456     LDT_ENTRY entry;
 457
 458     sel = SELECTOROF(ptr);
 459     if (!sel) return TRUE;
 460     if (IS_SELECTOR_FREE(sel)) return TRUE;
 461     wine_ldt_get_entry( sel, &entry );
 462     /* check for data or readable code segment */
 463     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 464     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 465     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 466     return FALSE;
 467 }
 468
 469
 470 /***********************************************************************
 471  *           IsBadHugeWritePtr   (KERNEL.347)
 472  */
 473 BOOL16 WINAPI IsBadHugeWritePtr16( SEGPTR ptr, DWORD size )
 474 {
 475     WORD sel;
 476     LDT_ENTRY entry;
 477
 478     sel = SELECTOROF(ptr);
 479     if (!sel) return TRUE;
 480     if (IS_SELECTOR_FREE(sel)) return TRUE;
 481     wine_ldt_get_entry( sel, &entry );
 482     /* check for writeable data segment, ignoring expand-down and accessed flags */
 483     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_DATA) & ~5) return TRUE;
 484     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 485     return FALSE;
 486 }
 487
 488 /***********************************************************************
 489  *           IsBadReadPtr   (KERNEL.334)
 490  */
 491 BOOL16 WINAPI IsBadReadPtr16( SEGPTR ptr, UINT16 size )
 492 {
 493     return IsBadHugeReadPtr16( ptr, size );
 494 }
 495
 496
 497 /***********************************************************************
 498  *           IsBadWritePtr   (KERNEL.335)
 499  */
 500 BOOL16 WINAPI IsBadWritePtr16( SEGPTR ptr, UINT16 size )
 501 {
 502     return IsBadHugeWritePtr16( ptr, size );
 503 }
 504
 505
 506 /***********************************************************************
 507  *           IsBadFlatReadWritePtr   (KERNEL.627)
 508  */
 509 BOOL16 WINAPI IsBadFlatReadWritePtr16( SEGPTR ptr, DWORD size, BOOL16 bWrite )
 510 {
 511     return bWrite? IsBadHugeWritePtr16( ptr, size )
 512                  : IsBadHugeReadPtr16( ptr, size );
 513 }
 514
 515
 516 /***********************************************************************
 517  *           MemoryRead   (TOOLHELP.78)
 518  */
 519 DWORD WINAPI MemoryRead16( WORD sel, DWORD offset, void *buffer, DWORD count )
 520 {
 521     WORD index = sel >> __AHSHIFT;
 522
 523     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 524     if (offset > wine_ldt_copy.limit[index]) return 0;
 525     if (offset + count > wine_ldt_copy.limit[index] + 1)
 526         count = wine_ldt_copy.limit[index] + 1 - offset;
 527     memcpy( buffer, (char *)wine_ldt_copy.base[index] + offset, count );
 528     return count;
 529 }
 530
 531
 532 /***********************************************************************
 533  *           MemoryWrite   (TOOLHELP.79)
 534  */
 535 DWORD WINAPI MemoryWrite16( WORD sel, DWORD offset, void *buffer, DWORD count )
 536 {
 537     WORD index = sel >> __AHSHIFT;
 538
 539     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 540     if (offset > wine_ldt_copy.limit[index]) return 0;
 541     if (offset + count > wine_ldt_copy.limit[index] + 1)
 542         count = wine_ldt_copy.limit[index] + 1 - offset;
 543     memcpy( (char *)wine_ldt_copy.base[index] + offset, buffer, count );
 544     return count;
 545 }
 546
 547 /************************************* Win95 pointer mapping functions *
 548  *
 549  */
 550
 551 struct mapls_entry
 552 {
 553     struct mapls_entry *next;
 554     void               *addr;   /* linear address */
 555     int                 count;  /* ref count */
 556     WORD                sel;    /* selector */
 557 };
 558
 559 static struct mapls_entry *first_entry;
 560
 561
 562 /***********************************************************************
 563  *           MapLS   (KERNEL32.@)
 564  *           MapLS   (KERNEL.358)
 565  *
 566  * Maps linear pointer to segmented.
 567  */
 568 SEGPTR WINAPI MapLS( LPCVOID ptr )
 569 {
 570     struct mapls_entry *entry, *free = NULL;
 571     void *base;
 572     SEGPTR ret = 0;
 573
 574     if (!HIWORD(ptr)) return (SEGPTR)ptr;
 575
 576     base = (char *)ptr - ((unsigned int)ptr & 0x7fff);
 577     HeapLock( GetProcessHeap() );
 578     for (entry = first_entry; entry; entry = entry->next)
 579     {
 580         if (entry->addr == base) break;
 581         if (!entry->count) free = entry;
 582     }
 583
 584     if (!entry)
 585     {
 586         if (!free)  /* no free entry found, create a new one */
 587         {
 588             if (!(free = HeapAlloc( GetProcessHeap(), 0, sizeof(*free) ))) goto done;
 589             if (!(free->sel = SELECTOR_AllocBlock( base, 0x10000, WINE_LDT_FLAGS_DATA )))
 590             {
 591                 HeapFree( GetProcessHeap(), 0, free );
 592                 goto done;
 593             }
 594             free->count = 0;
 595             free->next = first_entry;
 596             first_entry = free;
 597         }
 598         SetSelectorBase( free->sel, (DWORD)base );
 599         free->addr = base;
 600         entry = free;
 601     }
 602     entry->count++;
 603     ret = MAKESEGPTR( entry->sel, (char *)ptr - (char *)entry->addr );
 604  done:
 605     HeapUnlock( GetProcessHeap() );
 606     return ret;
 607 }
 608
 609 /***********************************************************************
 610  *           UnMapLS   (KERNEL32.@)
 611  *           UnMapLS   (KERNEL.359)
 612  *
 613  * Free mapped selector.
 614  */
 615 void WINAPI UnMapLS( SEGPTR sptr )
 616 {
 617     struct mapls_entry *entry;
 618     WORD sel = SELECTOROF(sptr);
 619
 620     if (sel)
 621     {
 622         HeapLock( GetProcessHeap() );
 623         for (entry = first_entry; entry; entry = entry->next) if (entry->sel == sel) break;
 624         if (entry && entry->count > 0) entry->count--;
 625         HeapUnlock( GetProcessHeap() );
 626     }
 627 }
 628
 629 /***********************************************************************
 630  *           MapSL   (KERNEL32.@)
 631  *           MapSL   (KERNEL.357)
 632  *
 633  * Maps fixed segmented pointer to linear.
 634  */
 635 LPVOID WINAPI MapSL( SEGPTR sptr )
 636 {
 637     return (char *)wine_ldt_copy.base[SELECTOROF(sptr) >> __AHSHIFT] + OFFSETOF(sptr);
 638 }
 639
 640 /***********************************************************************
 641  *           MapSLFix   (KERNEL32.@)
 642  *
 643  * FIXME: MapSLFix and UnMapSLFixArray should probably prevent
 644  * unexpected linear address change when GlobalCompact() shuffles
 645  * moveable blocks.
 646  */
 647
 648 LPVOID WINAPI MapSLFix( SEGPTR sptr )
 649 {
 650     return MapSL(sptr);
 651 }
 652
 653 /***********************************************************************
 654  *           UnMapSLFixArray   (KERNEL32.@)
 655  */
 656
 657 void WINAPI UnMapSLFixArray( SEGPTR sptr[], INT length, CONTEXT86 *context )
 658 {
 659     /* Must not change EAX, hence defined as 'register' function */
 660 }
 661
 662 /***********************************************************************
 663  *           GetThreadSelectorEntry   (KERNEL32.@)
 664  */
 665 BOOL WINAPI GetThreadSelectorEntry( HANDLE hthread, DWORD sel, LPLDT_ENTRY ldtent)
 666 {
 667 #ifdef __i386__
 668     BOOL ret;
 669
 670     if (!(sel & 4))  /* GDT selector */
 671     {
 672         sel &= ~3;  /* ignore RPL */
 673         if (!sel)  /* null selector */
 674         {
 675             memset( ldtent, 0, sizeof(*ldtent) );
 676             return TRUE;
 677         }
 678         ldtent->BaseLow                   = 0;
 679         ldtent->HighWord.Bits.BaseMid     = 0;
 680         ldtent->HighWord.Bits.BaseHi      = 0;
 681         ldtent->LimitLow                  = 0xffff;
 682         ldtent->HighWord.Bits.LimitHi     = 0xf;
 683         ldtent->HighWord.Bits.Dpl         = 3;
 684         ldtent->HighWord.Bits.Sys         = 0;
 685         ldtent->HighWord.Bits.Pres        = 1;
 686         ldtent->HighWord.Bits.Granularity = 1;
 687         ldtent->HighWord.Bits.Default_Big = 1;
 688         ldtent->HighWord.Bits.Type        = 0x12;
 689         /* it has to be one of the system GDT selectors */
 690         if (sel == (wine_get_ds() & ~3)) return TRUE;
 691         if (sel == (wine_get_ss() & ~3)) return TRUE;
 692         if (sel == (wine_get_cs() & ~3))
 693         {
 694             ldtent->HighWord.Bits.Type |= 8;  /* code segment */
 695             return TRUE;
 696         }
 697         SetLastError( ERROR_NOACCESS );
 698         return FALSE;
 699     }
 700
 701     SERVER_START_REQ( get_selector_entry )
 702     {
 703         req->handle = hthread;
 704         req->entry = sel >> __AHSHIFT;
 705         if ((ret = !wine_server_call_err( req )))
 706         {
 707             if (!(reply->flags & WINE_LDT_FLAGS_ALLOCATED))
 708             {
 709                 SetLastError( ERROR_MR_MID_NOT_FOUND );  /* sic */
 710                 ret = FALSE;
 711             }
 712             else
 713             {
 714                 wine_ldt_set_base( ldtent, (void *)reply->base );
 715                 wine_ldt_set_limit( ldtent, reply->limit );
 716                 wine_ldt_set_flags( ldtent, reply->flags );
 717             }
 718         }
 719     }
 720     SERVER_END_REQ;
 721     return ret;
 722 #else
 723     SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
 724     return FALSE;
 725 #endif
 726 }
 727
 728
 729 /**********************************************************************
 730  *              SMapLS*         (KERNEL32)
 731  * These functions map linear pointers at [EBP+xxx] to segmented pointers
 732  * and return them.
 733  * Win95 uses some kind of alias structs, which it stores in [EBP+x] to
 734  * unravel them at SUnMapLS. We just store the segmented pointer there.
 735  */
 736 static void
 737 x_SMapLS_IP_EBP_x(CONTEXT86 *context,int argoff) {
 738     DWORD       val,ptr;
 739
 740     val =*(DWORD*)(context->Ebp + argoff);
 741     if (val<0x10000) {
 742         ptr=val;
 743         *(DWORD*)(context->Ebp + argoff) = 0;
 744     } else {
 745         ptr = MapLS((LPVOID)val);
 746         *(DWORD*)(context->Ebp + argoff) = ptr;
 747     }
 748     context->Eax = ptr;
 749 }
 750
 751 /***********************************************************************
 752  *              SMapLS_IP_EBP_8 (KERNEL32.@)
 753  */
 754 void WINAPI SMapLS_IP_EBP_8 (CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context, 8);}
 755
 756 /***********************************************************************
 757  *              SMapLS_IP_EBP_12 (KERNEL32.@)
 758  */
 759 void WINAPI SMapLS_IP_EBP_12(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,12);}
 760
 761 /***********************************************************************
 762  *              SMapLS_IP_EBP_16 (KERNEL32.@)
 763  */
 764 void WINAPI SMapLS_IP_EBP_16(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,16);}
 765
 766 /***********************************************************************
 767  *              SMapLS_IP_EBP_20 (KERNEL32.@)
 768  */
 769 void WINAPI SMapLS_IP_EBP_20(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,20);}
 770
 771 /***********************************************************************
 772  *              SMapLS_IP_EBP_24 (KERNEL32.@)
 773  */
 774 void WINAPI SMapLS_IP_EBP_24(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,24);}
 775
 776 /***********************************************************************
 777  *              SMapLS_IP_EBP_28 (KERNEL32.@)
 778  */
 779 void WINAPI SMapLS_IP_EBP_28(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,28);}
 780
 781 /***********************************************************************
 782  *              SMapLS_IP_EBP_32 (KERNEL32.@)
 783  */
 784 void WINAPI SMapLS_IP_EBP_32(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,32);}
 785
 786 /***********************************************************************
 787  *              SMapLS_IP_EBP_36 (KERNEL32.@)
 788  */
 789 void WINAPI SMapLS_IP_EBP_36(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,36);}
 790
 791 /***********************************************************************
 792  *              SMapLS_IP_EBP_40 (KERNEL32.@)
 793  */
 794 void WINAPI SMapLS_IP_EBP_40(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,40);}
 795
 796 /***********************************************************************
 797  *              SMapLS (KERNEL32.@)
 798  */
 799 void WINAPI SMapLS( CONTEXT86 *context )
 800 {
 801     if (HIWORD(context->Eax))
 802     {
 803         context->Eax = MapLS( (LPVOID)context->Eax );
 804         context->Edx = context->Eax;
 805     } else {
 806         context->Edx = 0;
 807     }
 808 }
 809
 810 /***********************************************************************
 811  *              SUnMapLS (KERNEL32.@)
 812  */
 813
 814 void WINAPI SUnMapLS( CONTEXT86 *context )
 815 {
 816     if (HIWORD(context->Eax)) UnMapLS( (SEGPTR)context->Eax );
 817 }
 818
 819 inline static void x_SUnMapLS_IP_EBP_x(CONTEXT86 *context,int argoff)
 820 {
 821     SEGPTR *ptr = (SEGPTR *)(context->Ebp + argoff);
 822     if (*ptr)
 823     {
 824         UnMapLS( *ptr );
 825         *ptr = 0;
 826     }
 827 }
 828
 829 /***********************************************************************
 830  *              SUnMapLS_IP_EBP_8 (KERNEL32.@)
 831  */
 832 void WINAPI SUnMapLS_IP_EBP_8 (CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context, 8); }
 833
 834 /***********************************************************************
 835  *              SUnMapLS_IP_EBP_12 (KERNEL32.@)
 836  */
 837 void WINAPI SUnMapLS_IP_EBP_12(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,12); }
 838
 839 /***********************************************************************
 840  *              SUnMapLS_IP_EBP_16 (KERNEL32.@)
 841  */
 842 void WINAPI SUnMapLS_IP_EBP_16(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,16); }
 843
 844 /***********************************************************************
 845  *              SUnMapLS_IP_EBP_20 (KERNEL32.@)
 846  */
 847 void WINAPI SUnMapLS_IP_EBP_20(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,20); }
 848
 849 /***********************************************************************
 850  *              SUnMapLS_IP_EBP_24 (KERNEL32.@)
 851  */
 852 void WINAPI SUnMapLS_IP_EBP_24(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,24); }
 853
 854 /***********************************************************************
 855  *              SUnMapLS_IP_EBP_28 (KERNEL32.@)
 856  */
 857 void WINAPI SUnMapLS_IP_EBP_28(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,28); }
 858
 859 /***********************************************************************
 860  *              SUnMapLS_IP_EBP_32 (KERNEL32.@)
 861  */
 862 void WINAPI SUnMapLS_IP_EBP_32(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,32); }
 863
 864 /***********************************************************************
 865  *              SUnMapLS_IP_EBP_36 (KERNEL32.@)
 866  */
 867 void WINAPI SUnMapLS_IP_EBP_36(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,36); }
 868
 869 /***********************************************************************
 870  *              SUnMapLS_IP_EBP_40 (KERNEL32.@)
 871  */
 872 void WINAPI SUnMapLS_IP_EBP_40(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,40); }
 873
 874 /**********************************************************************
 875  *              AllocMappedBuffer       (KERNEL32.38)
 876  *
 877  * This is a undocumented KERNEL32 function that
 878  * SMapLS's a GlobalAlloc'ed buffer.
 879  *
 880  * Input:   EDI register: size of buffer to allocate
 881  * Output:  EDI register: pointer to buffer
 882  *
 883  * Note: The buffer is preceded by 8 bytes:
 884  *        ...
 885  *       edi+0   buffer
 886  *       edi-4   SEGPTR to buffer
 887  *       edi-8   some magic Win95 needs for SUnMapLS
 888  *               (we use it for the memory handle)
 889  *
 890  *       The SEGPTR is used by the caller!
 891  */
 892
 893 void WINAPI AllocMappedBuffer( CONTEXT86 *context )
 894 {
 895     HGLOBAL handle = GlobalAlloc(0, context->Edi + 8);
 896     DWORD *buffer = (DWORD *)GlobalLock(handle);
 897     SEGPTR ptr = 0;
 898
 899     if (buffer)
 900         if (!(ptr = MapLS(buffer + 2)))
 901         {
 902             GlobalUnlock(handle);
 903             GlobalFree(handle);
 904         }
 905
 906     if (!ptr)
 907         context->Eax = context->Edi = 0;
 908     else
 909     {
 910         buffer[0] = (DWORD)handle;
 911         buffer[1] = ptr;
 912
 913         context->Eax = (DWORD) ptr;
 914         context->Edi = (DWORD)(buffer + 2);
 915     }
 916 }
 917
 918 /**********************************************************************
 919  *              FreeMappedBuffer        (KERNEL32.39)
 920  *
 921  * Free a buffer allocated by AllocMappedBuffer
 922  *
 923  * Input: EDI register: pointer to buffer
 924  */
 925
 926 void WINAPI FreeMappedBuffer( CONTEXT86 *context )
 927 {
 928     if (context->Edi)
 929     {
 930         DWORD *buffer = (DWORD *)context->Edi - 2;
 931
 932         UnMapLS(buffer[1]);
 933
 934         GlobalUnlock((HGLOBAL)buffer[0]);
 935         GlobalFree((HGLOBAL)buffer[0]);
 936     }
 937 }