dlls/krnl386.exe16/wowthunk.c

   1 /*
   2  * Win32 WOW Generic Thunk API
   3  *
   4  * Copyright 1999 Ulrich Weigand
   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <stdarg.h>
  26 #include <errno.h>
  27
  28 #include "wine/winbase16.h"
  29 #include "windef.h"
  30 #include "winbase.h"
  31 #include "winerror.h"
  32 #include "wownt32.h"
  33 #include "excpt.h"
  34 #include "winternl.h"
  35 #include "kernel16_private.h"
  36 #include "wine/exception.h"
  37 #include "wine/debug.h"
  38
  39 WINE_DEFAULT_DEBUG_CHANNEL(thunk);
  40 WINE_DECLARE_DEBUG_CHANNEL(relay);
  41 WINE_DECLARE_DEBUG_CHANNEL(snoop);
  42
  43 /* symbols exported from relay16.s */
  44 extern DWORD WINAPI wine_call_to_16( FARPROC16 target, DWORD cbArgs, PEXCEPTION_HANDLER handler );
  45 extern void WINAPI wine_call_to_16_regs( CONTEXT *context, DWORD cbArgs, PEXCEPTION_HANDLER handler );
  46 extern void __wine_call_to_16_ret(void);
  47 extern void CALL32_CBClient_Ret(void);
  48 extern void CALL32_CBClientEx_Ret(void);
  49 extern void DPMI_PendingEventCheck(void);
  50 extern void DPMI_PendingEventCheck_Cleanup(void);
  51 extern void DPMI_PendingEventCheck_Return(void);
  52 extern BYTE __wine_call16_start[];
  53 extern BYTE __wine_call16_end[];
  54
  55 extern void RELAY16_InitDebugLists(void);
  56
  57 static SEGPTR call16_ret_addr;  /* segptr to __wine_call_to_16_ret routine */
  58
  59 static WORD  dpmi_checker_selector;
  60 static DWORD dpmi_checker_offset_call;
  61 static DWORD dpmi_checker_offset_cleanup;
  62 static DWORD dpmi_checker_offset_return;
  63
  64 /***********************************************************************
  65  *           WOWTHUNK_Init
  66  */
  67 BOOL WOWTHUNK_Init(void)
  68 {
  69     /* allocate the code selector for CallTo16 routines */
  70     LDT_ENTRY entry;
  71     WORD codesel = wine_ldt_alloc_entries(1);
  72
  73     if (!codesel) return FALSE;
  74     wine_ldt_set_base( &entry, __wine_call16_start );
  75     wine_ldt_set_limit( &entry, (BYTE *)(&CallTo16_TebSelector + 1) - __wine_call16_start - 1 );
  76     wine_ldt_set_flags( &entry, WINE_LDT_FLAGS_CODE | WINE_LDT_FLAGS_32BIT );
  77     wine_ldt_set_entry( codesel, &entry );
  78
  79       /* Patch the return addresses for CallTo16 routines */
  80
  81     CallTo16_DataSelector = wine_get_ds();
  82     call16_ret_addr = MAKESEGPTR( codesel, (BYTE *)__wine_call_to_16_ret - __wine_call16_start );
  83     CALL32_CBClient_RetAddr =
  84         MAKESEGPTR( codesel, (BYTE *)CALL32_CBClient_Ret - __wine_call16_start );
  85     CALL32_CBClientEx_RetAddr =
  86         MAKESEGPTR( codesel, (BYTE *)CALL32_CBClientEx_Ret - __wine_call16_start );
  87
  88     /* Prepare selector and offsets for DPMI event checking. */
  89     dpmi_checker_selector = codesel;
  90     dpmi_checker_offset_call = (BYTE *)DPMI_PendingEventCheck - __wine_call16_start;
  91     dpmi_checker_offset_cleanup = (BYTE *)DPMI_PendingEventCheck_Cleanup - __wine_call16_start;
  92     dpmi_checker_offset_return = (BYTE *)DPMI_PendingEventCheck_Return - __wine_call16_start;
  93
  94     if (TRACE_ON(relay) || TRACE_ON(snoop)) RELAY16_InitDebugLists();
  95
  96     return TRUE;
  97 }
  98
  99
 100 /*************************************************************
 101  *            fix_selector
 102  *
 103  * Fix a selector load that caused an exception if it's in the
 104  * 16-bit relay code.
 105  */
 106 static BOOL fix_selector( CONTEXT *context )
 107 {
 108     WORD *stack;
 109     BYTE *instr = (BYTE *)context->Eip;
 110
 111     if (instr < __wine_call16_start || instr >= __wine_call16_end) return FALSE;
 112
 113     /* skip prefixes */
 114     while (*instr == 0x66 || *instr == 0x67) instr++;
 115
 116     switch(instr[0])
 117     {
 118     case 0x07: /* pop es */
 119     case 0x17: /* pop ss */
 120     case 0x1f: /* pop ds */
 121         break;
 122     case 0x0f: /* extended instruction */
 123         switch(instr[1])
 124         {
 125         case 0xa1: /* pop fs */
 126         case 0xa9: /* pop gs */
 127             break;
 128         default:
 129             return FALSE;
 130         }
 131         break;
 132     default:
 133         return FALSE;
 134     }
 135     stack = wine_ldt_get_ptr( context->SegSs, context->Esp );
 136     TRACE( "fixing up selector %x for pop instruction\n", *stack );
 137     *stack = 0;
 138     return TRUE;
 139 }
 140
 141
 142 /*************************************************************
 143  *            insert_event_check
 144  *
 145  * Make resuming the context check for pending DPMI events
 146  * before the original context is restored. This is required
 147  * because DPMI events are asynchronous, they are blocked while
 148  * Wine 32-bit code is being executed and we want to prevent
 149  * a race when returning back to 16-bit or 32-bit DPMI context.
 150  */
 151 static void insert_event_check( CONTEXT *context )
 152 {
 153     char *stack = wine_ldt_get_ptr( context->SegSs, context->Esp );
 154
 155     /* don't do event check while in system code */
 156     if (wine_ldt_is_system(context->SegCs))
 157         return;
 158
 159     if(context->SegCs == dpmi_checker_selector &&
 160        context->Eip   >= dpmi_checker_offset_call &&
 161        context->Eip   <= dpmi_checker_offset_cleanup)
 162     {
 163         /*
 164          * Nested call. Stack will be preserved.
 165          */
 166     }
 167     else if(context->SegCs == dpmi_checker_selector &&
 168             context->Eip   == dpmi_checker_offset_return)
 169     {
 170         /*
 171          * Nested call. We have just finished popping the fs
 172          * register, lets put it back into stack.
 173          */
 174
 175         stack -= sizeof(WORD);
 176         *(WORD*)stack = context->SegFs;
 177
 178         context->Esp -= 2;
 179     }
 180     else
 181     {
 182         /*
 183          * Call is not nested.
 184          * Push modified registers into stack.
 185          * These will be popped by the assembler stub.
 186          */
 187
 188         stack -= sizeof(DWORD);
 189         *(DWORD*)stack = context->EFlags;
 190
 191         stack -= sizeof(DWORD);
 192         *(DWORD*)stack = context->SegCs;
 193
 194         stack -= sizeof(DWORD);
 195         *(DWORD*)stack = context->Eip;
 196
 197         stack -= sizeof(WORD);
 198         *(WORD*)stack = context->SegFs;
 199
 200         context->Esp  -= 14;
 201     }
 202
 203     /*
 204      * Modify the context so that we jump into assembler stub.
 205      * TEB access is made easier by providing the stub
 206      * with the correct fs register value.
 207      */
 208
 209     context->SegCs = dpmi_checker_selector;
 210     context->Eip   = dpmi_checker_offset_call;
 211     context->SegFs = wine_get_fs();
 212 }
 213
 214
 215 /*************************************************************
 216  *            call16_handler
 217  *
 218  * Handler for exceptions occurring in 16-bit code.
 219  */
 220 static DWORD call16_handler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_RECORD *frame,
 221                              CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **pdispatcher )
 222 {
 223     if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 224     {
 225         /* unwinding: restore the stack pointer in the TEB, and leave the Win16 mutex */
 226         STACK32FRAME *frame32 = (STACK32FRAME *)((char *)frame - offsetof(STACK32FRAME,frame));
 227         NtCurrentTeb()->WOW32Reserved = (void *)frame32->frame16;
 228         _LeaveWin16Lock();
 229     }
 230     else if (record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
 231              record->ExceptionCode == EXCEPTION_PRIV_INSTRUCTION)
 232     {
 233         if (wine_ldt_is_system(context->SegCs))
 234         {
 235             if (fix_selector( context )) return ExceptionContinueExecution;
 236         }
 237         else
 238         {
 239             SEGPTR gpHandler;
 240             DWORD ret = __wine_emulate_instruction( record, context );
 241
 242             /*
 243              * Insert check for pending DPMI events. Note that this
 244              * check must be inserted after instructions have been
 245              * emulated because the instruction emulation requires
 246              * original CS:IP and the emulation may change TEB.dpmi_vif.
 247              */
 248             if(get_vm86_teb_info()->dpmi_vif)
 249                 insert_event_check( context );
 250
 251             if (ret != ExceptionContinueSearch) return ret;
 252
 253             /* check for Win16 __GP handler */
 254             if ((gpHandler = HasGPHandler16( MAKESEGPTR( context->SegCs, context->Eip ) )))
 255             {
 256                 WORD *stack = wine_ldt_get_ptr( context->SegSs, context->Esp );
 257                 *--stack = context->SegCs;
 258                 *--stack = context->Eip;
 259
 260                 if (!IS_SELECTOR_32BIT(context->SegSs))
 261                     context->Esp = MAKELONG( LOWORD(context->Esp - 2*sizeof(WORD)),
 262                                              HIWORD(context->Esp) );
 263                 else
 264                     context->Esp -= 2*sizeof(WORD);
 265
 266                 context->SegCs = SELECTOROF( gpHandler );
 267                 context->Eip   = OFFSETOF( gpHandler );
 268                 return ExceptionContinueExecution;
 269             }
 270         }
 271     }
 272     else if (record->ExceptionCode == EXCEPTION_VM86_STI)
 273     {
 274         insert_event_check( context );
 275     }
 276     return ExceptionContinueSearch;
 277 }
 278
 279
 280 /*************************************************************
 281  *            vm86_handler
 282  *
 283  * Handler for exceptions occurring in vm86 code.
 284  */
 285 static DWORD vm86_handler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_RECORD *frame,
 286                            CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **pdispatcher )
 287 {
 288     if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 289         return ExceptionContinueSearch;
 290
 291     if (record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
 292         record->ExceptionCode == EXCEPTION_PRIV_INSTRUCTION)
 293     {
 294         return __wine_emulate_instruction( record, context );
 295     }
 296
 297     return ExceptionContinueSearch;
 298 }
 299
 300
 301 /*
 302  *  32-bit WOW routines (in WOW32, but actually forwarded to KERNEL32)
 303  */
 304
 305 /**********************************************************************
 306  *           K32WOWGetDescriptor        (KERNEL32.70)
 307  */
 308 BOOL WINAPI K32WOWGetDescriptor( SEGPTR segptr, LPLDT_ENTRY ldtent )
 309 {
 310     return GetThreadSelectorEntry( GetCurrentThread(),
 311                                    segptr >> 16, ldtent );
 312 }
 313
 314 /**********************************************************************
 315  *           K32WOWGetVDMPointer        (KERNEL32.56)
 316  */
 317 LPVOID WINAPI K32WOWGetVDMPointer( DWORD vp, DWORD dwBytes, BOOL fProtectedMode )
 318 {
 319     /* FIXME: add size check too */
 320
 321     if ( fProtectedMode )
 322         return MapSL( vp );
 323     else
 324         return DOSMEM_MapRealToLinear( vp );
 325 }
 326
 327 /**********************************************************************
 328  *           K32WOWGetVDMPointerFix     (KERNEL32.68)
 329  */
 330 LPVOID WINAPI K32WOWGetVDMPointerFix( DWORD vp, DWORD dwBytes, BOOL fProtectedMode )
 331 {
 332     /*
 333      * Hmmm. According to the docu, we should call:
 334      *
 335      *          GlobalFix16( SELECTOROF(vp) );
 336      *
 337      * But this is unnecessary under Wine, as we never move global
 338      * memory segments in linear memory anyway.
 339      *
 340      * (I'm not so sure what we are *supposed* to do if
 341      *  fProtectedMode is TRUE, anyway ...)
 342      */
 343
 344     return K32WOWGetVDMPointer( vp, dwBytes, fProtectedMode );
 345 }
 346
 347 /**********************************************************************
 348  *           K32WOWGetVDMPointerUnfix   (KERNEL32.69)
 349  */
 350 VOID WINAPI K32WOWGetVDMPointerUnfix( DWORD vp )
 351 {
 352     /*
 353      * See above why we don't call:
 354      *
 355      * GlobalUnfix16( SELECTOROF(vp) );
 356      *
 357      */
 358 }
 359
 360 /**********************************************************************
 361  *           K32WOWGlobalAlloc16        (KERNEL32.59)
 362  */
 363 WORD WINAPI K32WOWGlobalAlloc16( WORD wFlags, DWORD cb )
 364 {
 365     return (WORD)GlobalAlloc16( wFlags, cb );
 366 }
 367
 368 /**********************************************************************
 369  *           K32WOWGlobalFree16         (KERNEL32.62)
 370  */
 371 WORD WINAPI K32WOWGlobalFree16( WORD hMem )
 372 {
 373     return (WORD)GlobalFree16( (HGLOBAL16)hMem );
 374 }
 375
 376 /**********************************************************************
 377  *           K32WOWGlobalUnlock16       (KERNEL32.61)
 378  */
 379 BOOL WINAPI K32WOWGlobalUnlock16( WORD hMem )
 380 {
 381     return (BOOL)GlobalUnlock16( (HGLOBAL16)hMem );
 382 }
 383
 384 /**********************************************************************
 385  *           K32WOWGlobalAllocLock16    (KERNEL32.63)
 386  */
 387 DWORD WINAPI K32WOWGlobalAllocLock16( WORD wFlags, DWORD cb, WORD *phMem )
 388 {
 389     WORD hMem = K32WOWGlobalAlloc16( wFlags, cb );
 390     if (phMem) *phMem = hMem;
 391
 392     return K32WOWGlobalLock16( hMem );
 393 }
 394
 395 /**********************************************************************
 396  *           K32WOWGlobalLockSize16     (KERNEL32.65)
 397  */
 398 DWORD WINAPI K32WOWGlobalLockSize16( WORD hMem, PDWORD pcb )
 399 {
 400     if ( pcb )
 401         *pcb = GlobalSize16( (HGLOBAL16)hMem );
 402
 403     return K32WOWGlobalLock16( hMem );
 404 }
 405
 406 /**********************************************************************
 407  *           K32WOWGlobalUnlockFree16   (KERNEL32.64)
 408  */
 409 WORD WINAPI K32WOWGlobalUnlockFree16( DWORD vpMem )
 410 {
 411     if ( !K32WOWGlobalUnlock16( HIWORD(vpMem) ) )
 412         return FALSE;
 413
 414     return K32WOWGlobalFree16( HIWORD(vpMem) );
 415 }
 416
 417
 418 /**********************************************************************
 419  *           K32WOWYield16              (KERNEL32.66)
 420  */
 421 VOID WINAPI K32WOWYield16( void )
 422 {
 423     /*
 424      * This does the right thing for both Win16 and Win32 tasks.
 425      * More or less, at least :-/
 426      */
 427     Yield16();
 428 }
 429
 430 /**********************************************************************
 431  *           K32WOWDirectedYield16       (KERNEL32.67)
 432  */
 433 VOID WINAPI K32WOWDirectedYield16( WORD htask16 )
 434 {
 435     /*
 436      * Argh.  Our scheduler doesn't like DirectedYield by Win32
 437      * tasks at all.  So we do hope that this routine is indeed
 438      * only ever called by Win16 tasks that have thunked up ...
 439      */
 440     DirectedYield16( (HTASK16)htask16 );
 441 }
 442
 443
 444 /***********************************************************************
 445  *           K32WOWHandle32              (KERNEL32.57)
 446  */
 447 HANDLE WINAPI K32WOWHandle32( WORD handle, WOW_HANDLE_TYPE type )
 448 {
 449     switch ( type )
 450     {
 451     case WOW_TYPE_HWND:
 452     case WOW_TYPE_HMENU:
 453     case WOW_TYPE_HDWP:
 454     case WOW_TYPE_HDROP:
 455     case WOW_TYPE_HDC:
 456     case WOW_TYPE_HFONT:
 457     case WOW_TYPE_HRGN:
 458     case WOW_TYPE_HBITMAP:
 459     case WOW_TYPE_HBRUSH:
 460     case WOW_TYPE_HPALETTE:
 461     case WOW_TYPE_HPEN:
 462     case WOW_TYPE_HACCEL:
 463         return (HANDLE)(ULONG_PTR)handle;
 464
 465     case WOW_TYPE_HMETAFILE:
 466         FIXME( "conversion of metafile handles not supported yet\n" );
 467         return (HANDLE)(ULONG_PTR)handle;
 468
 469     case WOW_TYPE_HTASK:
 470         return ((TDB *)GlobalLock16(handle))->teb->ClientId.UniqueThread;
 471
 472     case WOW_TYPE_FULLHWND:
 473         FIXME( "conversion of full window handles not supported yet\n" );
 474         return (HANDLE)(ULONG_PTR)handle;
 475
 476     default:
 477         ERR( "handle 0x%04x of unknown type %d\n", handle, type );
 478         return (HANDLE)(ULONG_PTR)handle;
 479     }
 480 }
 481
 482 /***********************************************************************
 483  *           K32WOWHandle16              (KERNEL32.58)
 484  */
 485 WORD WINAPI K32WOWHandle16( HANDLE handle, WOW_HANDLE_TYPE type )
 486 {
 487     switch ( type )
 488     {
 489     case WOW_TYPE_HWND:
 490     case WOW_TYPE_HMENU:
 491     case WOW_TYPE_HDWP:
 492     case WOW_TYPE_HDROP:
 493     case WOW_TYPE_HDC:
 494     case WOW_TYPE_HFONT:
 495     case WOW_TYPE_HRGN:
 496     case WOW_TYPE_HBITMAP:
 497     case WOW_TYPE_HBRUSH:
 498     case WOW_TYPE_HPALETTE:
 499     case WOW_TYPE_HPEN:
 500     case WOW_TYPE_HACCEL:
 501     case WOW_TYPE_FULLHWND:
 502         if ( HIWORD(handle ) )
 503                 ERR( "handle %p of type %d has non-zero HIWORD\n", handle, type );
 504         return LOWORD(handle);
 505
 506     case WOW_TYPE_HMETAFILE:
 507         FIXME( "conversion of metafile handles not supported yet\n" );
 508         return LOWORD(handle);
 509
 510     case WOW_TYPE_HTASK:
 511         return TASK_GetTaskFromThread( (DWORD)handle );
 512
 513     default:
 514         ERR( "handle %p of unknown type %d\n", handle, type );
 515         return LOWORD(handle);
 516     }
 517 }
 518
 519 /**********************************************************************
 520  *           K32WOWCallback16Ex         (KERNEL32.55)
 521  */
 522 BOOL WINAPI K32WOWCallback16Ex( DWORD vpfn16, DWORD dwFlags,
 523                                 DWORD cbArgs, LPVOID pArgs, LPDWORD pdwRetCode )
 524 {
 525     /*
 526      * Arguments must be prepared in the correct order by the caller
 527      * (both for PASCAL and CDECL calling convention), so we simply
 528      * copy them to the 16-bit stack ...
 529      */
 530     char *stack = (char *)CURRENT_STACK16 - cbArgs;
 531
 532     memcpy( stack, pArgs, cbArgs );
 533
 534     if (dwFlags & (WCB16_REGS|WCB16_REGS_LONG))
 535     {
 536         CONTEXT *context = (CONTEXT *)pdwRetCode;
 537
 538         if (TRACE_ON(relay))
 539         {
 540             DWORD count = cbArgs / sizeof(WORD);
 541             WORD * wstack = (WORD *)stack;
 542
 543             DPRINTF("%04x:CallTo16(func=%04x:%04x,ds=%04x",
 544                     GetCurrentThreadId(),
 545                     context->SegCs, LOWORD(context->Eip), context->SegDs );
 546             while (count) DPRINTF( ",%04x", wstack[--count] );
 547             DPRINTF(") ss:sp=%04x:%04x",
 548                     SELECTOROF(NtCurrentTeb()->WOW32Reserved), OFFSETOF(NtCurrentTeb()->WOW32Reserved) );
 549             DPRINTF(" ax=%04x bx=%04x cx=%04x dx=%04x si=%04x di=%04x bp=%04x es=%04x fs=%04x\n",
 550                     (WORD)context->Eax, (WORD)context->Ebx, (WORD)context->Ecx,
 551                     (WORD)context->Edx, (WORD)context->Esi, (WORD)context->Edi,
 552                     (WORD)context->Ebp, (WORD)context->SegEs, (WORD)context->SegFs );
 553             SYSLEVEL_CheckNotLevel( 2 );
 554         }
 555
 556         if (context->EFlags & 0x00020000)  /* v86 mode */
 557         {
 558             EXCEPTION_REGISTRATION_RECORD frame;
 559             frame.Handler = vm86_handler;
 560             errno = 0;
 561             __wine_push_frame( &frame );
 562             __wine_enter_vm86( context );
 563             __wine_pop_frame( &frame );
 564             if (errno != 0)  /* enter_vm86 will fall with ENOSYS on x64 kernels */
 565             {
 566                 WARN("__wine_enter_vm86 failed (errno=%d)\n", errno);
 567                 if (errno == ENOSYS)
 568                     SetLastError(ERROR_NOT_SUPPORTED);
 569                 else
 570                     SetLastError(ERROR_GEN_FAILURE);
 571                 return FALSE;
 572             }
 573         }
 574         else
 575         {
 576             /* push return address */
 577             if (dwFlags & WCB16_REGS_LONG)
 578             {
 579                 stack -= sizeof(DWORD);
 580                 *((DWORD *)stack) = HIWORD(call16_ret_addr);
 581                 stack -= sizeof(DWORD);
 582                 *((DWORD *)stack) = LOWORD(call16_ret_addr);
 583                 cbArgs += 2 * sizeof(DWORD);
 584             }
 585             else
 586             {
 587                 stack -= sizeof(SEGPTR);
 588                 *((SEGPTR *)stack) = call16_ret_addr;
 589                 cbArgs += sizeof(SEGPTR);
 590             }
 591
 592             /*
 593              * Start call by checking for pending events.
 594              * Note that wine_call_to_16_regs overwrites context stack
 595              * pointer so we may modify it here without a problem.
 596              */
 597             if (get_vm86_teb_info()->dpmi_vif)
 598             {
 599                 context->SegSs = wine_get_ds();
 600                 context->Esp   = (DWORD)stack;
 601                 insert_event_check( context );
 602                 cbArgs += (DWORD)stack - context->Esp;
 603             }
 604
 605             _EnterWin16Lock();
 606             wine_call_to_16_regs( context, cbArgs, call16_handler );
 607             _LeaveWin16Lock();
 608         }
 609
 610         if (TRACE_ON(relay))
 611         {
 612             DPRINTF("%04x:RetFrom16() ss:sp=%04x:%04x ",
 613                     GetCurrentThreadId(), SELECTOROF(NtCurrentTeb()->WOW32Reserved),
 614                     OFFSETOF(NtCurrentTeb()->WOW32Reserved));
 615             DPRINTF(" ax=%04x bx=%04x cx=%04x dx=%04x bp=%04x sp=%04x\n",
 616                     (WORD)context->Eax, (WORD)context->Ebx, (WORD)context->Ecx,
 617                     (WORD)context->Edx, (WORD)context->Ebp, (WORD)context->Esp );
 618             SYSLEVEL_CheckNotLevel( 2 );
 619         }
 620     }
 621     else
 622     {
 623         DWORD ret;
 624
 625         if (TRACE_ON(relay))
 626         {
 627             DWORD count = cbArgs / sizeof(WORD);
 628             WORD * wstack = (WORD *)stack;
 629
 630             DPRINTF("%04x:CallTo16(func=%04x:%04x,ds=%04x",
 631                     GetCurrentThreadId(), HIWORD(vpfn16), LOWORD(vpfn16),
 632                     SELECTOROF(NtCurrentTeb()->WOW32Reserved) );
 633             while (count) DPRINTF( ",%04x", wstack[--count] );
 634             DPRINTF(") ss:sp=%04x:%04x\n",
 635                     SELECTOROF(NtCurrentTeb()->WOW32Reserved), OFFSETOF(NtCurrentTeb()->WOW32Reserved) );
 636             SYSLEVEL_CheckNotLevel( 2 );
 637         }
 638
 639         /* push return address */
 640         stack -= sizeof(SEGPTR);
 641         *((SEGPTR *)stack) = call16_ret_addr;
 642         cbArgs += sizeof(SEGPTR);
 643
 644         /*
 645          * Actually, we should take care whether the called routine cleans up
 646          * its stack or not.  Fortunately, our wine_call_to_16 core doesn't rely on
 647          * the callee to do so; after the routine has returned, the 16-bit
 648          * stack pointer is always reset to the position it had before.
 649          */
 650         _EnterWin16Lock();
 651         ret = wine_call_to_16( (FARPROC16)vpfn16, cbArgs, call16_handler );
 652         if (pdwRetCode) *pdwRetCode = ret;
 653         _LeaveWin16Lock();
 654
 655         if (TRACE_ON(relay))
 656         {
 657             DPRINTF("%04x:RetFrom16() ss:sp=%04x:%04x retval=%08x\n",
 658                     GetCurrentThreadId(), SELECTOROF(NtCurrentTeb()->WOW32Reserved),
 659                     OFFSETOF(NtCurrentTeb()->WOW32Reserved), ret);
 660             SYSLEVEL_CheckNotLevel( 2 );
 661         }
 662     }
 663
 664     return TRUE;  /* success */
 665 }
 666
 667 /**********************************************************************
 668  *           K32WOWCallback16            (KERNEL32.54)
 669  */
 670 DWORD WINAPI K32WOWCallback16( DWORD vpfn16, DWORD dwParam )
 671 {
 672     DWORD ret;
 673
 674     if ( !K32WOWCallback16Ex( vpfn16, WCB16_PASCAL,
 675                            sizeof(DWORD), &dwParam, &ret ) )
 676         ret = 0L;
 677
 678     return ret;
 679 }