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 GetSelectorBase( WORD sel )
 321 {
 322     void *base = wine_ldt_copy.base[sel >> __AHSHIFT];
 323
 324     /* if base points into DOSMEM, assume we have to
 325      * return pointer into physical lower 1MB */
 326
 327     return DOSMEM_MapLinearToDos( base );
 328 }
 329
 330
 331 /***********************************************************************
 332  *             SetSelectorBase   (KERNEL.187)
 333  */
 334 WORD WINAPI SetSelectorBase( WORD sel, DWORD base )
 335 {
 336     LDT_ENTRY entry;
 337     wine_ldt_get_entry( sel, &entry );
 338     wine_ldt_set_base( &entry, DOSMEM_MapDosToLinear(base) );
 339     wine_ldt_set_entry( sel, &entry );
 340     return sel;
 341 }
 342
 343
 344 /***********************************************************************
 345  *           GetSelectorLimit   (KERNEL.188)
 346  */
 347 DWORD WINAPI GetSelectorLimit16( WORD sel )
 348 {
 349     return wine_ldt_copy.limit[sel >> __AHSHIFT];
 350 }
 351
 352
 353 /***********************************************************************
 354  *           SetSelectorLimit   (KERNEL.189)
 355  */
 356 WORD WINAPI SetSelectorLimit16( WORD sel, DWORD limit )
 357 {
 358     LDT_ENTRY entry;
 359     wine_ldt_get_entry( sel, &entry );
 360     wine_ldt_set_limit( &entry, limit );
 361     wine_ldt_set_entry( sel, &entry );
 362     return sel;
 363 }
 364
 365
 366 /***********************************************************************
 367  *           SelectorAccessRights   (KERNEL.196)
 368  */
 369 WORD WINAPI SelectorAccessRights16( WORD sel, WORD op, WORD val )
 370 {
 371     LDT_ENTRY entry;
 372     wine_ldt_get_entry( sel, &entry );
 373
 374     if (op == 0)  /* get */
 375     {
 376         return entry.HighWord.Bytes.Flags1 | ((entry.HighWord.Bytes.Flags2 << 8) & 0xf0);
 377     }
 378     else  /* set */
 379     {
 380         entry.HighWord.Bytes.Flags1 = LOBYTE(val) | 0xf0;
 381         entry.HighWord.Bytes.Flags2 = (entry.HighWord.Bytes.Flags2 & 0x0f) | (HIBYTE(val) & 0xf0);
 382         wine_ldt_set_entry( sel, &entry );
 383         return 0;
 384     }
 385 }
 386
 387
 388 /***********************************************************************
 389  *           IsBadCodePtr   (KERNEL.336)
 390  */
 391 BOOL16 WINAPI IsBadCodePtr16( SEGPTR lpfn )
 392 {
 393     WORD sel;
 394     LDT_ENTRY entry;
 395
 396     sel = SELECTOROF(lpfn);
 397     if (!sel) return TRUE;
 398     if (IS_SELECTOR_FREE(sel)) return TRUE;
 399     wine_ldt_get_entry( sel, &entry );
 400     /* check for code segment, ignoring conforming, read-only and accessed bits */
 401     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_CODE) & 0x18) return TRUE;
 402     if (OFFSETOF(lpfn) > wine_ldt_get_limit(&entry)) return TRUE;
 403     return FALSE;
 404 }
 405
 406
 407 /***********************************************************************
 408  *           IsBadStringPtr   (KERNEL.337)
 409  */
 410 BOOL16 WINAPI IsBadStringPtr16( SEGPTR ptr, UINT16 size )
 411 {
 412     WORD sel;
 413     LDT_ENTRY entry;
 414
 415     sel = SELECTOROF(ptr);
 416     if (!sel) return TRUE;
 417     if (IS_SELECTOR_FREE(sel)) return TRUE;
 418     wine_ldt_get_entry( sel, &entry );
 419     /* check for data or readable code segment */
 420     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 421     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 422     if (strlen(MapSL(ptr)) < size) size = strlen(MapSL(ptr)) + 1;
 423     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit(&entry))) return TRUE;
 424     return FALSE;
 425 }
 426
 427
 428 /***********************************************************************
 429  *           IsBadHugeReadPtr   (KERNEL.346)
 430  */
 431 BOOL16 WINAPI IsBadHugeReadPtr16( SEGPTR ptr, DWORD size )
 432 {
 433     WORD sel;
 434     LDT_ENTRY entry;
 435
 436     sel = SELECTOROF(ptr);
 437     if (!sel) return TRUE;
 438     if (IS_SELECTOR_FREE(sel)) return TRUE;
 439     wine_ldt_get_entry( sel, &entry );
 440     /* check for data or readable code segment */
 441     if (!(entry.HighWord.Bits.Type & 0x10)) return TRUE;  /* system descriptor */
 442     if ((entry.HighWord.Bits.Type & 0x0a) == 0x08) return TRUE;  /* non-readable code segment */
 443     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 444     return FALSE;
 445 }
 446
 447
 448 /***********************************************************************
 449  *           IsBadHugeWritePtr   (KERNEL.347)
 450  */
 451 BOOL16 WINAPI IsBadHugeWritePtr16( SEGPTR ptr, DWORD size )
 452 {
 453     WORD sel;
 454     LDT_ENTRY entry;
 455
 456     sel = SELECTOROF(ptr);
 457     if (!sel) return TRUE;
 458     if (IS_SELECTOR_FREE(sel)) return TRUE;
 459     wine_ldt_get_entry( sel, &entry );
 460     /* check for writeable data segment, ignoring expand-down and accessed flags */
 461     if ((entry.HighWord.Bits.Type ^ WINE_LDT_FLAGS_DATA) & ~5) return TRUE;
 462     if (size && (OFFSETOF(ptr) + size - 1 > wine_ldt_get_limit( &entry ))) return TRUE;
 463     return FALSE;
 464 }
 465
 466 /***********************************************************************
 467  *           IsBadReadPtr   (KERNEL.334)
 468  */
 469 BOOL16 WINAPI IsBadReadPtr16( SEGPTR ptr, UINT16 size )
 470 {
 471     return IsBadHugeReadPtr16( ptr, size );
 472 }
 473
 474
 475 /***********************************************************************
 476  *           IsBadWritePtr   (KERNEL.335)
 477  */
 478 BOOL16 WINAPI IsBadWritePtr16( SEGPTR ptr, UINT16 size )
 479 {
 480     return IsBadHugeWritePtr16( ptr, size );
 481 }
 482
 483
 484 /***********************************************************************
 485  *           IsBadFlatReadWritePtr   (KERNEL.627)
 486  */
 487 BOOL16 WINAPI IsBadFlatReadWritePtr16( SEGPTR ptr, DWORD size, BOOL16 bWrite )
 488 {
 489     return bWrite? IsBadHugeWritePtr16( ptr, size )
 490                  : IsBadHugeReadPtr16( ptr, size );
 491 }
 492
 493
 494 /***********************************************************************
 495  *           MemoryRead   (TOOLHELP.78)
 496  */
 497 DWORD WINAPI MemoryRead16( WORD sel, DWORD offset, void *buffer, DWORD count )
 498 {
 499     WORD index = sel >> __AHSHIFT;
 500
 501     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 502     if (offset > wine_ldt_copy.limit[index]) return 0;
 503     if (offset + count > wine_ldt_copy.limit[index] + 1)
 504         count = wine_ldt_copy.limit[index] + 1 - offset;
 505     memcpy( buffer, (char *)wine_ldt_copy.base[index] + offset, count );
 506     return count;
 507 }
 508
 509
 510 /***********************************************************************
 511  *           MemoryWrite   (TOOLHELP.79)
 512  */
 513 DWORD WINAPI MemoryWrite16( WORD sel, DWORD offset, void *buffer, DWORD count )
 514 {
 515     WORD index = sel >> __AHSHIFT;
 516
 517     if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)) return 0;
 518     if (offset > wine_ldt_copy.limit[index]) return 0;
 519     if (offset + count > wine_ldt_copy.limit[index] + 1)
 520         count = wine_ldt_copy.limit[index] + 1 - offset;
 521     memcpy( (char *)wine_ldt_copy.base[index] + offset, buffer, count );
 522     return count;
 523 }
 524
 525 /************************************* Win95 pointer mapping functions *
 526  *
 527  */
 528
 529 struct mapls_entry
 530 {
 531     struct mapls_entry *next;
 532     void               *addr;   /* linear address */
 533     int                 count;  /* ref count */
 534     WORD                sel;    /* selector */
 535 };
 536
 537 static struct mapls_entry *first_entry;
 538
 539
 540 /***********************************************************************
 541  *           MapLS   (KERNEL32.@)
 542  *           MapLS   (KERNEL.358)
 543  *
 544  * Maps linear pointer to segmented.
 545  */
 546 SEGPTR WINAPI MapLS( LPCVOID ptr )
 547 {
 548     struct mapls_entry *entry, *free = NULL;
 549     void *base;
 550     SEGPTR ret = 0;
 551
 552     if (!HIWORD(ptr)) return (SEGPTR)ptr;
 553
 554     base = (char *)ptr - ((unsigned int)ptr & 0x7fff);
 555     HeapLock( GetProcessHeap() );
 556     for (entry = first_entry; entry; entry = entry->next)
 557     {
 558         if (entry->addr == base) break;
 559         if (!entry->count) free = entry;
 560     }
 561
 562     if (!entry)
 563     {
 564         if (!free)  /* no free entry found, create a new one */
 565         {
 566             if (!(free = HeapAlloc( GetProcessHeap(), 0, sizeof(*free) ))) goto done;
 567             if (!(free->sel = SELECTOR_AllocBlock( base, 0x10000, WINE_LDT_FLAGS_DATA )))
 568             {
 569                 HeapFree( GetProcessHeap(), 0, free );
 570                 goto done;
 571             }
 572             free->count = 0;
 573             free->next = first_entry;
 574             first_entry = free;
 575         }
 576         SetSelectorBase( free->sel, (DWORD)base );
 577         free->addr = base;
 578         entry = free;
 579     }
 580     entry->count++;
 581     ret = MAKESEGPTR( entry->sel, (char *)ptr - (char *)entry->addr );
 582  done:
 583     HeapUnlock( GetProcessHeap() );
 584     return ret;
 585 }
 586
 587 /***********************************************************************
 588  *           UnMapLS   (KERNEL32.@)
 589  *           UnMapLS   (KERNEL.359)
 590  *
 591  * Free mapped selector.
 592  */
 593 void WINAPI UnMapLS( SEGPTR sptr )
 594 {
 595     struct mapls_entry *entry;
 596     WORD sel = SELECTOROF(sptr);
 597
 598     if (sel)
 599     {
 600         HeapLock( GetProcessHeap() );
 601         for (entry = first_entry; entry; entry = entry->next) if (entry->sel == sel) break;
 602         if (entry && entry->count > 0) entry->count--;
 603         HeapUnlock( GetProcessHeap() );
 604     }
 605 }
 606
 607 /***********************************************************************
 608  *           MapSL   (KERNEL32.@)
 609  *           MapSL   (KERNEL.357)
 610  *
 611  * Maps fixed segmented pointer to linear.
 612  */
 613 LPVOID WINAPI MapSL( SEGPTR sptr )
 614 {
 615     return (char *)wine_ldt_copy.base[SELECTOROF(sptr) >> __AHSHIFT] + OFFSETOF(sptr);
 616 }
 617
 618 /***********************************************************************
 619  *           MapSLFix   (KERNEL32.@)
 620  *
 621  * FIXME: MapSLFix and UnMapSLFixArray should probably prevent
 622  * unexpected linear address change when GlobalCompact() shuffles
 623  * moveable blocks.
 624  */
 625
 626 LPVOID WINAPI MapSLFix( SEGPTR sptr )
 627 {
 628     return MapSL(sptr);
 629 }
 630
 631 /***********************************************************************
 632  *           UnMapSLFixArray   (KERNEL32.@)
 633  */
 634
 635 void WINAPI UnMapSLFixArray( SEGPTR sptr[], INT length, CONTEXT86 *context )
 636 {
 637     /* Must not change EAX, hence defined as 'register' function */
 638 }
 639
 640 /***********************************************************************
 641  *           GetThreadSelectorEntry   (KERNEL32.@)
 642  */
 643 BOOL WINAPI GetThreadSelectorEntry( HANDLE hthread, DWORD sel, LPLDT_ENTRY ldtent)
 644 {
 645 #ifdef __i386__
 646     BOOL ret;
 647
 648     if (!(sel & 4))  /* GDT selector */
 649     {
 650         sel &= ~3;  /* ignore RPL */
 651         if (!sel)  /* null selector */
 652         {
 653             memset( ldtent, 0, sizeof(*ldtent) );
 654             return TRUE;
 655         }
 656         ldtent->BaseLow                   = 0;
 657         ldtent->HighWord.Bits.BaseMid     = 0;
 658         ldtent->HighWord.Bits.BaseHi      = 0;
 659         ldtent->LimitLow                  = 0xffff;
 660         ldtent->HighWord.Bits.LimitHi     = 0xf;
 661         ldtent->HighWord.Bits.Dpl         = 3;
 662         ldtent->HighWord.Bits.Sys         = 0;
 663         ldtent->HighWord.Bits.Pres        = 1;
 664         ldtent->HighWord.Bits.Granularity = 1;
 665         ldtent->HighWord.Bits.Default_Big = 1;
 666         ldtent->HighWord.Bits.Type        = 0x12;
 667         /* it has to be one of the system GDT selectors */
 668         if (sel == (wine_get_ds() & ~3)) return TRUE;
 669         if (sel == (wine_get_ss() & ~3)) return TRUE;
 670         if (sel == (wine_get_cs() & ~3))
 671         {
 672             ldtent->HighWord.Bits.Type |= 8;  /* code segment */
 673             return TRUE;
 674         }
 675         SetLastError( ERROR_NOACCESS );
 676         return FALSE;
 677     }
 678
 679     SERVER_START_REQ( get_selector_entry )
 680     {
 681         req->handle = hthread;
 682         req->entry = sel >> __AHSHIFT;
 683         if ((ret = !wine_server_call_err( req )))
 684         {
 685             if (!(reply->flags & WINE_LDT_FLAGS_ALLOCATED))
 686             {
 687                 SetLastError( ERROR_MR_MID_NOT_FOUND );  /* sic */
 688                 ret = FALSE;
 689             }
 690             else
 691             {
 692                 wine_ldt_set_base( ldtent, (void *)reply->base );
 693                 wine_ldt_set_limit( ldtent, reply->limit );
 694                 wine_ldt_set_flags( ldtent, reply->flags );
 695             }
 696         }
 697     }
 698     SERVER_END_REQ;
 699     return ret;
 700 #else
 701     SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
 702     return FALSE;
 703 #endif
 704 }
 705
 706
 707 /**********************************************************************
 708  *              SMapLS*         (KERNEL32)
 709  * These functions map linear pointers at [EBP+xxx] to segmented pointers
 710  * and return them.
 711  * Win95 uses some kind of alias structs, which it stores in [EBP+x] to
 712  * unravel them at SUnMapLS. We just store the segmented pointer there.
 713  */
 714 static void
 715 x_SMapLS_IP_EBP_x(CONTEXT86 *context,int argoff) {
 716     DWORD       val,ptr;
 717
 718     val =*(DWORD*)(context->Ebp + argoff);
 719     if (val<0x10000) {
 720         ptr=val;
 721         *(DWORD*)(context->Ebp + argoff) = 0;
 722     } else {
 723         ptr = MapLS((LPVOID)val);
 724         *(DWORD*)(context->Ebp + argoff) = ptr;
 725     }
 726     context->Eax = ptr;
 727 }
 728
 729 /***********************************************************************
 730  *              SMapLS_IP_EBP_8 (KERNEL32.@)
 731  */
 732 void WINAPI SMapLS_IP_EBP_8 (CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context, 8);}
 733
 734 /***********************************************************************
 735  *              SMapLS_IP_EBP_12 (KERNEL32.@)
 736  */
 737 void WINAPI SMapLS_IP_EBP_12(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,12);}
 738
 739 /***********************************************************************
 740  *              SMapLS_IP_EBP_16 (KERNEL32.@)
 741  */
 742 void WINAPI SMapLS_IP_EBP_16(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,16);}
 743
 744 /***********************************************************************
 745  *              SMapLS_IP_EBP_20 (KERNEL32.@)
 746  */
 747 void WINAPI SMapLS_IP_EBP_20(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,20);}
 748
 749 /***********************************************************************
 750  *              SMapLS_IP_EBP_24 (KERNEL32.@)
 751  */
 752 void WINAPI SMapLS_IP_EBP_24(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,24);}
 753
 754 /***********************************************************************
 755  *              SMapLS_IP_EBP_28 (KERNEL32.@)
 756  */
 757 void WINAPI SMapLS_IP_EBP_28(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,28);}
 758
 759 /***********************************************************************
 760  *              SMapLS_IP_EBP_32 (KERNEL32.@)
 761  */
 762 void WINAPI SMapLS_IP_EBP_32(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,32);}
 763
 764 /***********************************************************************
 765  *              SMapLS_IP_EBP_36 (KERNEL32.@)
 766  */
 767 void WINAPI SMapLS_IP_EBP_36(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,36);}
 768
 769 /***********************************************************************
 770  *              SMapLS_IP_EBP_40 (KERNEL32.@)
 771  */
 772 void WINAPI SMapLS_IP_EBP_40(CONTEXT86 *context) {x_SMapLS_IP_EBP_x(context,40);}
 773
 774 /***********************************************************************
 775  *              SMapLS (KERNEL32.@)
 776  */
 777 void WINAPI SMapLS( CONTEXT86 *context )
 778 {
 779     if (HIWORD(context->Eax))
 780     {
 781         context->Eax = MapLS( (LPVOID)context->Eax );
 782         context->Edx = context->Eax;
 783     } else {
 784         context->Edx = 0;
 785     }
 786 }
 787
 788 /***********************************************************************
 789  *              SUnMapLS (KERNEL32.@)
 790  */
 791
 792 void WINAPI SUnMapLS( CONTEXT86 *context )
 793 {
 794     if (HIWORD(context->Eax)) UnMapLS( (SEGPTR)context->Eax );
 795 }
 796
 797 inline static void x_SUnMapLS_IP_EBP_x(CONTEXT86 *context,int argoff)
 798 {
 799     SEGPTR *ptr = (SEGPTR *)(context->Ebp + argoff);
 800     if (*ptr)
 801     {
 802         UnMapLS( *ptr );
 803         *ptr = 0;
 804     }
 805 }
 806
 807 /***********************************************************************
 808  *              SUnMapLS_IP_EBP_8 (KERNEL32.@)
 809  */
 810 void WINAPI SUnMapLS_IP_EBP_8 (CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context, 8); }
 811
 812 /***********************************************************************
 813  *              SUnMapLS_IP_EBP_12 (KERNEL32.@)
 814  */
 815 void WINAPI SUnMapLS_IP_EBP_12(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,12); }
 816
 817 /***********************************************************************
 818  *              SUnMapLS_IP_EBP_16 (KERNEL32.@)
 819  */
 820 void WINAPI SUnMapLS_IP_EBP_16(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,16); }
 821
 822 /***********************************************************************
 823  *              SUnMapLS_IP_EBP_20 (KERNEL32.@)
 824  */
 825 void WINAPI SUnMapLS_IP_EBP_20(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,20); }
 826
 827 /***********************************************************************
 828  *              SUnMapLS_IP_EBP_24 (KERNEL32.@)
 829  */
 830 void WINAPI SUnMapLS_IP_EBP_24(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,24); }
 831
 832 /***********************************************************************
 833  *              SUnMapLS_IP_EBP_28 (KERNEL32.@)
 834  */
 835 void WINAPI SUnMapLS_IP_EBP_28(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,28); }
 836
 837 /***********************************************************************
 838  *              SUnMapLS_IP_EBP_32 (KERNEL32.@)
 839  */
 840 void WINAPI SUnMapLS_IP_EBP_32(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,32); }
 841
 842 /***********************************************************************
 843  *              SUnMapLS_IP_EBP_36 (KERNEL32.@)
 844  */
 845 void WINAPI SUnMapLS_IP_EBP_36(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,36); }
 846
 847 /***********************************************************************
 848  *              SUnMapLS_IP_EBP_40 (KERNEL32.@)
 849  */
 850 void WINAPI SUnMapLS_IP_EBP_40(CONTEXT86 *context) { x_SUnMapLS_IP_EBP_x(context,40); }
 851
 852 /**********************************************************************
 853  *              AllocMappedBuffer       (KERNEL32.38)
 854  *
 855  * This is a undocumented KERNEL32 function that
 856  * SMapLS's a GlobalAlloc'ed buffer.
 857  *
 858  * Input:   EDI register: size of buffer to allocate
 859  * Output:  EDI register: pointer to buffer
 860  *
 861  * Note: The buffer is preceded by 8 bytes:
 862  *        ...
 863  *       edi+0   buffer
 864  *       edi-4   SEGPTR to buffer
 865  *       edi-8   some magic Win95 needs for SUnMapLS
 866  *               (we use it for the memory handle)
 867  *
 868  *       The SEGPTR is used by the caller!
 869  */
 870
 871 void WINAPI AllocMappedBuffer( CONTEXT86 *context )
 872 {
 873     HGLOBAL handle = GlobalAlloc(0, context->Edi + 8);
 874     DWORD *buffer = (DWORD *)GlobalLock(handle);
 875     SEGPTR ptr = 0;
 876
 877     if (buffer)
 878         if (!(ptr = MapLS(buffer + 2)))
 879         {
 880             GlobalUnlock(handle);
 881             GlobalFree(handle);
 882         }
 883
 884     if (!ptr)
 885         context->Eax = context->Edi = 0;
 886     else
 887     {
 888         buffer[0] = (DWORD)handle;
 889         buffer[1] = ptr;
 890
 891         context->Eax = (DWORD) ptr;
 892         context->Edi = (DWORD)(buffer + 2);
 893     }
 894 }
 895
 896 /**********************************************************************
 897  *              FreeMappedBuffer        (KERNEL32.39)
 898  *
 899  * Free a buffer allocated by AllocMappedBuffer
 900  *
 901  * Input: EDI register: pointer to buffer
 902  */
 903
 904 void WINAPI FreeMappedBuffer( CONTEXT86 *context )
 905 {
 906     if (context->Edi)
 907     {
 908         DWORD *buffer = (DWORD *)context->Edi - 2;
 909
 910         UnMapLS(buffer[1]);
 911
 912         GlobalUnlock((HGLOBAL)buffer[0]);
 913         GlobalFree((HGLOBAL)buffer[0]);
 914     }
 915 }