dlls/kernel32/instr.c

   1 /*
   2  * Emulation of privileged instructions
   3  *
   4  * Copyright 1995 Alexandre Julliard
   5  * Copyright 2005 Ivan Leo Puoti
   6  * Copyright 2005 Laurent Pinchart
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 #include "config.h"
  24 #include "wine/port.h"
  25
  26 #include <stdarg.h>
  27
  28 #include "windef.h"
  29 #include "winbase.h"
  30 #include "winternl.h"
  31 #include "wine/winuser16.h"
  32 #include "excpt.h"
  33 #include "wine/debug.h"
  34 #include "kernel_private.h"
  35 #include "kernel16_private.h"
  36 #include "wine/exception.h"
  37
  38 WINE_DEFAULT_DEBUG_CHANNEL(int);
  39 WINE_DECLARE_DEBUG_CHANNEL(io);
  40
  41 /* macros to set parts of a DWORD */
  42 #define SET_LOWORD(dw,val)  ((dw) = ((dw) & 0xffff0000) | LOWORD(val))
  43 #define SET_LOBYTE(dw,val)  ((dw) = ((dw) & 0xffffff00) | LOBYTE(val))
  44 #define ADD_LOWORD(dw,val)  ((dw) = ((dw) & 0xffff0000) | LOWORD((DWORD)(dw)+(val)))
  45 #define ISV86(context)      ((context)->EFlags & 0x00020000)
  46
  47 static inline void add_stack( CONTEXT86 *context, int offset )
  48 {
  49     if (ISV86(context) || !IS_SELECTOR_32BIT(context->SegSs))
  50         ADD_LOWORD( context->Esp, offset );
  51     else
  52         context->Esp += offset;
  53 }
  54
  55 static inline void *make_ptr( CONTEXT86 *context, DWORD seg, DWORD off, int long_addr )
  56 {
  57     if (ISV86(context)) return (void *)((seg << 4) + LOWORD(off));
  58     if (wine_ldt_is_system(seg)) return (void *)off;
  59     if (!long_addr) off = LOWORD(off);
  60     return (char *) MapSL( MAKESEGPTR( seg, 0 ) ) + off;
  61 }
  62
  63 static inline void *get_stack( CONTEXT86 *context )
  64 {
  65     if (ISV86(context)) return (void *)((context->SegSs << 4) + LOWORD(context->Esp));
  66     return wine_ldt_get_ptr( context->SegSs, context->Esp );
  67 }
  68
  69 #include "pshpack1.h"
  70 struct idtr
  71 {
  72     WORD  limit;
  73     BYTE *base;
  74 };
  75 #include "poppack.h"
  76
  77 static LDT_ENTRY idt[256];
  78
  79 static inline struct idtr get_idtr(void)
  80 {
  81     struct idtr ret;
  82 #if defined(__i386__) && defined(__GNUC__)
  83     __asm__( "sidtl %0" : "=m" (ret) );
  84 #else
  85     ret.base = (BYTE *)idt;
  86     ret.limit = sizeof(idt) - 1;
  87 #endif
  88     return ret;
  89 }
  90
  91
  92 /***********************************************************************
  93  *           INSTR_ReplaceSelector
  94  *
  95  * Try to replace an invalid selector by a valid one.
  96  * The only selector where it is allowed to do "mov ax,40;mov es,ax"
  97  * is the so called 'bimodal' selector 0x40, which points to the BIOS
  98  * data segment. Used by (at least) Borland products (and programs compiled
  99  * using Borland products).
 100  *
 101  * See Undocumented Windows, Chapter 5, __0040.
 102  */
 103 static BOOL INSTR_ReplaceSelector( CONTEXT86 *context, WORD *sel )
 104 {
 105     if (*sel == 0x40)
 106     {
 107         static WORD sys_timer = 0;
 108         if (!sys_timer)
 109         {
 110             if (!winedos.BiosTick) load_winedos();
 111             if (winedos.BiosTick)
 112                 sys_timer = CreateSystemTimer( 55, winedos.BiosTick );
 113         }
 114         *sel = DOSMEM_BiosDataSeg;
 115         return TRUE;
 116     }
 117     return FALSE;  /* Can't replace selector, crashdump */
 118 }
 119
 120
 121 /* store an operand into a register */
 122 static void store_reg( CONTEXT86 *context, BYTE regmodrm, const BYTE *addr, int long_op )
 123 {
 124     switch((regmodrm >> 3) & 7)
 125     {
 126     case 0:
 127         if (long_op) context->Eax = *(const DWORD *)addr;
 128         else SET_LOWORD(context->Eax, *(const WORD *)addr);
 129         break;
 130     case 1:
 131         if (long_op) context->Ecx = *(const DWORD *)addr;
 132         else SET_LOWORD(context->Ecx, *(const WORD *)addr);
 133         break;
 134     case 2:
 135         if (long_op) context->Edx = *(const DWORD *)addr;
 136         else SET_LOWORD(context->Edx, *(const WORD *)addr);
 137         break;
 138     case 3:
 139         if (long_op) context->Ebx = *(const DWORD *)addr;
 140         else SET_LOWORD(context->Ebx, *(const WORD *)addr);
 141         break;
 142     case 4:
 143         if (long_op) context->Esp = *(const DWORD *)addr;
 144         else SET_LOWORD(context->Esp, *(const WORD *)addr);
 145         break;
 146     case 5:
 147         if (long_op) context->Ebp = *(const DWORD *)addr;
 148         else SET_LOWORD(context->Ebp, *(const WORD *)addr);
 149         break;
 150     case 6:
 151         if (long_op) context->Esi = *(const DWORD *)addr;
 152         else SET_LOWORD(context->Esi, *(const WORD *)addr);
 153         break;
 154     case 7:
 155         if (long_op) context->Edi = *(const DWORD *)addr;
 156         else SET_LOWORD(context->Edi, *(const WORD *)addr);
 157         break;
 158     }
 159 }
 160
 161 /***********************************************************************
 162  *           INSTR_GetOperandAddr
 163  *
 164  * Return the address of an instruction operand (from the mod/rm byte).
 165  */
 166 static BYTE *INSTR_GetOperandAddr( CONTEXT86 *context, BYTE *instr,
 167                                    int long_addr, int segprefix, int *len )
 168 {
 169     int mod, rm, base = 0, index = 0, ss = 0, seg = 0, off;
 170     LDT_ENTRY entry;
 171
 172 #define GET_VAL(val,type) \
 173     { *val = *(type *)instr; instr += sizeof(type); *len += sizeof(type); }
 174
 175     *len = 0;
 176     GET_VAL( &mod, BYTE );
 177     rm = mod & 7;
 178     mod >>= 6;
 179
 180     if (mod == 3)
 181     {
 182         switch(rm)
 183         {
 184         case 0: return (BYTE *)&context->Eax;
 185         case 1: return (BYTE *)&context->Ecx;
 186         case 2: return (BYTE *)&context->Edx;
 187         case 3: return (BYTE *)&context->Ebx;
 188         case 4: return (BYTE *)&context->Esp;
 189         case 5: return (BYTE *)&context->Ebp;
 190         case 6: return (BYTE *)&context->Esi;
 191         case 7: return (BYTE *)&context->Edi;
 192         }
 193     }
 194
 195     if (long_addr)
 196     {
 197         if (rm == 4)
 198         {
 199             BYTE sib;
 200             GET_VAL( &sib, BYTE );
 201             rm = sib & 7;
 202             ss = sib >> 6;
 203             switch(sib >> 3)
 204             {
 205             case 0: index = context->Eax; break;
 206             case 1: index = context->Ecx; break;
 207             case 2: index = context->Edx; break;
 208             case 3: index = context->Ebx; break;
 209             case 4: index = 0; break;
 210             case 5: index = context->Ebp; break;
 211             case 6: index = context->Esi; break;
 212             case 7: index = context->Edi; break;
 213             }
 214         }
 215
 216         switch(rm)
 217         {
 218         case 0: base = context->Eax; seg = context->SegDs; break;
 219         case 1: base = context->Ecx; seg = context->SegDs; break;
 220         case 2: base = context->Edx; seg = context->SegDs; break;
 221         case 3: base = context->Ebx; seg = context->SegDs; break;
 222         case 4: base = context->Esp; seg = context->SegSs; break;
 223         case 5: base = context->Ebp; seg = context->SegSs; break;
 224         case 6: base = context->Esi; seg = context->SegDs; break;
 225         case 7: base = context->Edi; seg = context->SegDs; break;
 226         }
 227         switch (mod)
 228         {
 229         case 0:
 230             if (rm == 5)  /* special case: ds:(disp32) */
 231             {
 232                 GET_VAL( &base, DWORD );
 233                 seg = context->SegDs;
 234             }
 235             break;
 236
 237         case 1:  /* 8-bit disp */
 238             GET_VAL( &off, BYTE );
 239             base += (signed char)off;
 240             break;
 241
 242         case 2:  /* 32-bit disp */
 243             GET_VAL( &off, DWORD );
 244             base += (signed long)off;
 245             break;
 246         }
 247     }
 248     else  /* short address */
 249     {
 250         switch(rm)
 251         {
 252         case 0:  /* ds:(bx,si) */
 253             base = LOWORD(context->Ebx) + LOWORD(context->Esi);
 254             seg  = context->SegDs;
 255             break;
 256         case 1:  /* ds:(bx,di) */
 257             base = LOWORD(context->Ebx) + LOWORD(context->Edi);
 258             seg  = context->SegDs;
 259             break;
 260         case 2:  /* ss:(bp,si) */
 261             base = LOWORD(context->Ebp) + LOWORD(context->Esi);
 262             seg  = context->SegSs;
 263             break;
 264         case 3:  /* ss:(bp,di) */
 265             base = LOWORD(context->Ebp) + LOWORD(context->Edi);
 266             seg  = context->SegSs;
 267             break;
 268         case 4:  /* ds:(si) */
 269             base = LOWORD(context->Esi);
 270             seg  = context->SegDs;
 271             break;
 272         case 5:  /* ds:(di) */
 273             base = LOWORD(context->Edi);
 274             seg  = context->SegDs;
 275             break;
 276         case 6:  /* ss:(bp) */
 277             base = LOWORD(context->Ebp);
 278             seg  = context->SegSs;
 279             break;
 280         case 7:  /* ds:(bx) */
 281             base = LOWORD(context->Ebx);
 282             seg  = context->SegDs;
 283             break;
 284         }
 285
 286         switch(mod)
 287         {
 288         case 0:
 289             if (rm == 6)  /* special case: ds:(disp16) */
 290             {
 291                 GET_VAL( &base, WORD );
 292                 seg  = context->SegDs;
 293             }
 294             break;
 295
 296         case 1:  /* 8-bit disp */
 297             GET_VAL( &off, BYTE );
 298             base += (signed char)off;
 299             break;
 300
 301         case 2:  /* 16-bit disp */
 302             GET_VAL( &off, WORD );
 303             base += (signed short)off;
 304             break;
 305         }
 306         base &= 0xffff;
 307     }
 308     if (segprefix != -1) seg = segprefix;
 309
 310     /* Make sure the segment and offset are valid */
 311     if (wine_ldt_is_system(seg)) return (BYTE *)(base + (index << ss));
 312     if ((seg & 7) != 7) return NULL;
 313     wine_ldt_get_entry( seg, &entry );
 314     if (wine_ldt_is_empty( &entry )) return NULL;
 315     if (wine_ldt_get_limit(&entry) < (base + (index << ss))) return NULL;
 316     return (BYTE *)wine_ldt_get_base(&entry) + base + (index << ss);
 317 #undef GET_VAL
 318 }
 319
 320
 321 /***********************************************************************
 322  *           INSTR_EmulateLDS
 323  *
 324  * Emulate the LDS (and LES,LFS,etc.) instruction.
 325  */
 326 static BOOL INSTR_EmulateLDS( CONTEXT86 *context, BYTE *instr, int long_op,
 327                               int long_addr, int segprefix, int *len )
 328 {
 329     WORD seg;
 330     BYTE *regmodrm = instr + 1 + (*instr == 0x0f);
 331     BYTE *addr = INSTR_GetOperandAddr( context, regmodrm,
 332                                        long_addr, segprefix, len );
 333     if (!addr)
 334         return FALSE;  /* Unable to emulate it */
 335     seg = *(WORD *)(addr + (long_op ? 4 : 2));
 336
 337     if (!INSTR_ReplaceSelector( context, &seg ))
 338         return FALSE;  /* Unable to emulate it */
 339
 340     /* Now store the offset in the correct register */
 341
 342     store_reg( context, *regmodrm, addr, long_op );
 343
 344     /* Store the correct segment in the segment register */
 345
 346     switch(*instr)
 347     {
 348     case 0xc4: context->SegEs = seg; break;  /* les */
 349     case 0xc5: context->SegDs = seg; break;  /* lds */
 350     case 0x0f: switch(instr[1])
 351                {
 352                case 0xb2: context->SegSs = seg; break;  /* lss */
 353                case 0xb4: context->SegFs = seg; break;  /* lfs */
 354                case 0xb5: context->SegGs = seg; break;  /* lgs */
 355                }
 356                break;
 357     }
 358
 359     /* Add the opcode size to the total length */
 360
 361     *len += 1 + (*instr == 0x0f);
 362     return TRUE;
 363 }
 364
 365 /***********************************************************************
 366  *           INSTR_inport
 367  *
 368  * input on an I/O port
 369  */
 370 static DWORD INSTR_inport( WORD port, int size, CONTEXT86 *context )
 371 {
 372     DWORD res = ~0U;
 373
 374     if (!winedos.inport) load_winedos();
 375     if (winedos.inport) res = winedos.inport( port, size );
 376
 377     if (TRACE_ON(io))
 378     {
 379         switch(size)
 380         {
 381         case 1:
 382             TRACE_(io)( "0x%x < %02x @ %04x:%04x\n", port, LOBYTE(res),
 383                      (WORD)context->SegCs, LOWORD(context->Eip));
 384             break;
 385         case 2:
 386             TRACE_(io)( "0x%x < %04x @ %04x:%04x\n", port, LOWORD(res),
 387                      (WORD)context->SegCs, LOWORD(context->Eip));
 388             break;
 389         case 4:
 390             TRACE_(io)( "0x%x < %08x @ %04x:%04x\n", port, res,
 391                      (WORD)context->SegCs, LOWORD(context->Eip));
 392             break;
 393         }
 394     }
 395     return res;
 396 }
 397
 398
 399 /***********************************************************************
 400  *           INSTR_outport
 401  *
 402  * output on an I/O port
 403  */
 404 static void INSTR_outport( WORD port, int size, DWORD val, CONTEXT86 *context )
 405 {
 406     if (!winedos.outport) load_winedos();
 407     if (winedos.outport) winedos.outport( port, size, val );
 408
 409     if (TRACE_ON(io))
 410     {
 411         switch(size)
 412         {
 413         case 1:
 414             TRACE_(io)("0x%x > %02x @ %04x:%04x\n", port, LOBYTE(val),
 415                     (WORD)context->SegCs, LOWORD(context->Eip));
 416             break;
 417         case 2:
 418             TRACE_(io)("0x%x > %04x @ %04x:%04x\n", port, LOWORD(val),
 419                     (WORD)context->SegCs, LOWORD(context->Eip));
 420             break;
 421         case 4:
 422             TRACE_(io)("0x%x > %08x @ %04x:%04x\n", port, val,
 423                     (WORD)context->SegCs, LOWORD(context->Eip));
 424             break;
 425         }
 426     }
 427 }
 428
 429
 430 /***********************************************************************
 431  *           __wine_emulate_instruction
 432  *
 433  * Emulate a privileged instruction.
 434  * Returns exception continuation status.
 435  */
 436 DWORD __wine_emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT86 *context )
 437 {
 438     int prefix, segprefix, prefixlen, len, repX, long_op, long_addr;
 439     BYTE *instr;
 440
 441     long_op = long_addr = (!ISV86(context) && IS_SELECTOR_32BIT(context->SegCs));
 442     instr = make_ptr( context, context->SegCs, context->Eip, TRUE );
 443     if (!instr) return ExceptionContinueSearch;
 444
 445     /* First handle any possible prefix */
 446
 447     segprefix = -1;  /* no prefix */
 448     prefix = 1;
 449     repX = 0;
 450     prefixlen = 0;
 451     while(prefix)
 452     {
 453         switch(*instr)
 454         {
 455         case 0x2e:
 456             segprefix = context->SegCs;
 457             break;
 458         case 0x36:
 459             segprefix = context->SegSs;
 460             break;
 461         case 0x3e:
 462             segprefix = context->SegDs;
 463             break;
 464         case 0x26:
 465             segprefix = context->SegEs;
 466             break;
 467         case 0x64:
 468             segprefix = context->SegFs;
 469             break;
 470         case 0x65:
 471             segprefix = context->SegGs;
 472             break;
 473         case 0x66:
 474             long_op = !long_op;  /* opcode size prefix */
 475             break;
 476         case 0x67:
 477             long_addr = !long_addr;  /* addr size prefix */
 478             break;
 479         case 0xf0:  /* lock */
 480             break;
 481         case 0xf2:  /* repne */
 482             repX = 1;
 483             break;
 484         case 0xf3:  /* repe */
 485             repX = 2;
 486             break;
 487         default:
 488             prefix = 0;  /* no more prefixes */
 489             break;
 490         }
 491         if (prefix)
 492         {
 493             instr++;
 494             prefixlen++;
 495         }
 496     }
 497
 498     /* Now look at the actual instruction */
 499
 500     switch(*instr)
 501     {
 502         case 0x07: /* pop es */
 503         case 0x17: /* pop ss */
 504         case 0x1f: /* pop ds */
 505             {
 506                 WORD seg = *(WORD *)get_stack( context );
 507                 if (INSTR_ReplaceSelector( context, &seg ))
 508                 {
 509                     switch(*instr)
 510                     {
 511                     case 0x07: context->SegEs = seg; break;
 512                     case 0x17: context->SegSs = seg; break;
 513                     case 0x1f: context->SegDs = seg; break;
 514                     }
 515                     add_stack(context, long_op ? 4 : 2);
 516                     context->Eip += prefixlen + 1;
 517                     return ExceptionContinueExecution;
 518                 }
 519             }
 520             break;  /* Unable to emulate it */
 521
 522         case 0x0f: /* extended instruction */
 523             switch(instr[1])
 524             {
 525             case 0x22: /* mov eax, crX */
 526                 switch (instr[2])
 527                 {
 528                 case 0xc0:
 529                         ERR("mov eax,cr0 at 0x%08x, EAX=0x%08x\n",
 530                             context->Eip,context->Eax );
 531                         context->Eip += prefixlen+3;
 532                         return ExceptionContinueExecution;
 533                 default:
 534                         break; /*fallthrough to bad instruction handling */
 535                 }
 536                 break; /*fallthrough to bad instruction handling */
 537             case 0x20: /* mov crX, eax */
 538                 switch (instr[2])
 539                 {
 540                 case 0xe0: /* mov cr4, eax */
 541                     /* CR4 register . See linux/arch/i386/mm/init.c, X86_CR4_ defs
 542                      * bit 0: VME       Virtual Mode Exception ?
 543                      * bit 1: PVI       Protected mode Virtual Interrupt
 544                      * bit 2: TSD       Timestamp disable
 545                      * bit 3: DE        Debugging extensions
 546                      * bit 4: PSE       Page size extensions
 547                      * bit 5: PAE   Physical address extension
 548                      * bit 6: MCE       Machine check enable
 549                      * bit 7: PGE   Enable global pages
 550                      * bit 8: PCE       Enable performance counters at IPL3
 551                      */
 552                     ERR("mov cr4,eax at 0x%08x\n",context->Eip);
 553                     context->Eax = 0;
 554                     context->Eip += prefixlen+3;
 555                     return ExceptionContinueExecution;
 556                 case 0xc0: /* mov cr0, eax */
 557                     ERR("mov cr0,eax at 0x%08x\n",context->Eip);
 558                     context->Eax = 0x10; /* FIXME: set more bits ? */
 559                     context->Eip += prefixlen+3;
 560                     return ExceptionContinueExecution;
 561                 default: /* fallthrough to illegal instruction */
 562                     break;
 563                 }
 564                 /* fallthrough to illegal instruction */
 565                 break;
 566             case 0x21: /* mov drX, eax */
 567                 switch (instr[2])
 568                 {
 569                 case 0xc8: /* mov dr1, eax */
 570                     TRACE("mov dr1,eax at 0x%08x\n",context->Eip);
 571                     context->Eax = context->Dr1;
 572                     context->Eip += prefixlen+3;
 573                     return ExceptionContinueExecution;
 574                 case 0xf8: /* mov dr7, eax */
 575                     TRACE("mov dr7,eax at 0x%08x\n",context->Eip);
 576                     context->Eax = 0x400;
 577                     context->Eip += prefixlen+3;
 578                     return ExceptionContinueExecution;
 579                 }
 580                 ERR("Unsupported DR register, eip+2 is %02x\n", instr[2]);
 581                 /* fallthrough to illegal instruction */
 582                 break;
 583             case 0x23: /* mov eax drX */
 584                 switch (instr[2])
 585                 {
 586                 case 0xc8: /* mov eax, dr1 */
 587                     context->Dr1 = context->Eax;
 588                     context->Eip += prefixlen+3;
 589                     return ExceptionContinueExecution;
 590                 }
 591                 ERR("Unsupported DR register, eip+2 is %02x\n", instr[2]);
 592                 /* fallthrough to illegal instruction */
 593                 break;
 594             case 0xa1: /* pop fs */
 595                 {
 596                     WORD seg = *(WORD *)get_stack( context );
 597                     if (INSTR_ReplaceSelector( context, &seg ))
 598                     {
 599                         context->SegFs = seg;
 600                         add_stack(context, long_op ? 4 : 2);
 601                         context->Eip += prefixlen + 2;
 602                         return ExceptionContinueExecution;
 603                     }
 604                 }
 605                 break;
 606             case 0xa9: /* pop gs */
 607                 {
 608                     WORD seg = *(WORD *)get_stack( context );
 609                     if (INSTR_ReplaceSelector( context, &seg ))
 610                     {
 611                         context->SegGs = seg;
 612                         add_stack(context, long_op ? 4 : 2);
 613                         context->Eip += prefixlen + 2;
 614                         return ExceptionContinueExecution;
 615                     }
 616                 }
 617                 break;
 618             case 0xb2: /* lss addr,reg */
 619             case 0xb4: /* lfs addr,reg */
 620             case 0xb5: /* lgs addr,reg */
 621                 if (INSTR_EmulateLDS( context, instr, long_op,
 622                                       long_addr, segprefix, &len ))
 623                 {
 624                     context->Eip += prefixlen + len;
 625                     return ExceptionContinueExecution;
 626                 }
 627                 break;
 628             }
 629             break;  /* Unable to emulate it */
 630
 631         case 0x6c: /* insb     */
 632         case 0x6d: /* insw/d   */
 633         case 0x6e: /* outsb    */
 634         case 0x6f: /* outsw/d  */
 635             {
 636               int typ = *instr;  /* Just in case it's overwritten.  */
 637               int outp = (typ >= 0x6e);
 638               unsigned long count = repX ?
 639                           (long_addr ? context->Ecx : LOWORD(context->Ecx)) : 1;
 640               int opsize = (typ & 1) ? (long_op ? 4 : 2) : 1;
 641               int step = (context->EFlags & 0x400) ? -opsize : +opsize;
 642               int seg = outp ? context->SegDs : context->SegEs;  /* FIXME: is this right? */
 643
 644               if (outp)
 645                 /* FIXME: Check segment is readable.  */
 646                 (void)0;
 647               else
 648                 /* FIXME: Check segment is writable.  */
 649                 (void)0;
 650
 651               if (repX)
 652               {
 653                 if (long_addr) context->Ecx = 0;
 654                 else SET_LOWORD(context->Ecx,0);
 655               }
 656
 657               while (count-- > 0)
 658                 {
 659                   void *data;
 660                   WORD dx = LOWORD(context->Edx);
 661                   if (outp)
 662                   {
 663                       data = make_ptr( context, seg, context->Esi, long_addr );
 664                       if (long_addr) context->Esi += step;
 665                       else ADD_LOWORD(context->Esi,step);
 666                   }
 667                   else
 668                   {
 669                       data = make_ptr( context, seg, context->Edi, long_addr );
 670                       if (long_addr) context->Edi += step;
 671                       else ADD_LOWORD(context->Edi,step);
 672                   }
 673
 674                   switch (typ)
 675                   {
 676                     case 0x6c:
 677                       *(BYTE *)data = INSTR_inport( dx, 1, context );
 678                       break;
 679                     case 0x6d:
 680                       if (long_op)
 681                           *(DWORD *)data = INSTR_inport( dx, 4, context );
 682                       else
 683                           *(WORD *)data = INSTR_inport( dx, 2, context );
 684                       break;
 685                     case 0x6e:
 686                         INSTR_outport( dx, 1, *(BYTE *)data, context );
 687                         break;
 688                     case 0x6f:
 689                         if (long_op)
 690                             INSTR_outport( dx, 4, *(DWORD *)data, context );
 691                         else
 692                             INSTR_outport( dx, 2, *(WORD *)data, context );
 693                         break;
 694                     }
 695                 }
 696               context->Eip += prefixlen + 1;
 697             }
 698             return ExceptionContinueExecution;
 699
 700         case 0x8b: /* mov Ev, Gv */
 701             {
 702                 BYTE *addr = INSTR_GetOperandAddr(context, instr + 1, long_addr,
 703                                                   segprefix, &len);
 704                 struct idtr idtr = get_idtr();
 705                 unsigned int offset = addr - idtr.base;
 706
 707                 if (offset <= idtr.limit + 1 - (long_op ? 4 : 2))
 708                 {
 709                     idt[1].LimitLow = 0x100; /* FIXME */
 710                     idt[2].LimitLow = 0x11E; /* FIXME */
 711                     idt[3].LimitLow = 0x500; /* FIXME */
 712                     store_reg( context, instr[1], (BYTE *)&idt + offset, long_op );
 713                     context->Eip += prefixlen + len + 1;
 714                     return ExceptionContinueExecution;
 715                 }
 716             }
 717             break;  /* Unable to emulate it */
 718
 719         case 0x8e: /* mov XX,segment_reg */
 720             {
 721                 WORD seg;
 722                 BYTE *addr = INSTR_GetOperandAddr(context, instr + 1,
 723                                                   long_addr, segprefix, &len );
 724                 if (!addr)
 725                     break;  /* Unable to emulate it */
 726                 seg = *(WORD *)addr;
 727                 if (!INSTR_ReplaceSelector( context, &seg ))
 728                     break;  /* Unable to emulate it */
 729
 730                 switch((instr[1] >> 3) & 7)
 731                 {
 732                 case 0:
 733                     context->SegEs = seg;
 734                     context->Eip += prefixlen + len + 1;
 735                     return ExceptionContinueExecution;
 736                 case 1:  /* cs */
 737                     break;
 738                 case 2:
 739                     context->SegSs = seg;
 740                     context->Eip += prefixlen + len + 1;
 741                     return ExceptionContinueExecution;
 742                 case 3:
 743                     context->SegDs = seg;
 744                     context->Eip += prefixlen + len + 1;
 745                     return ExceptionContinueExecution;
 746                 case 4:
 747                     context->SegFs = seg;
 748                     context->Eip += prefixlen + len + 1;
 749                     return ExceptionContinueExecution;
 750                 case 5:
 751                     context->SegGs = seg;
 752                     context->Eip += prefixlen + len + 1;
 753                     return ExceptionContinueExecution;
 754                 case 6:  /* unused */
 755                 case 7:  /* unused */
 756                     break;
 757                 }
 758             }
 759             break;  /* Unable to emulate it */
 760
 761         case 0xc4: /* les addr,reg */
 762         case 0xc5: /* lds addr,reg */
 763             if (INSTR_EmulateLDS( context, instr, long_op,
 764                                   long_addr, segprefix, &len ))
 765             {
 766                 context->Eip += prefixlen + len;
 767                 return ExceptionContinueExecution;
 768             }
 769             break;  /* Unable to emulate it */
 770
 771         case 0xcd: /* int <XX> */
 772             if (!winedos.EmulateInterruptPM) load_winedos();
 773             if (winedos.EmulateInterruptPM)
 774             {
 775                 context->Eip += prefixlen + 2;
 776                 if (winedos.EmulateInterruptPM( context, instr[1] )) return ExceptionContinueExecution;
 777                 context->Eip -= prefixlen + 2;  /* restore eip */
 778             }
 779             break;  /* Unable to emulate it */
 780
 781         case 0xcf: /* iret */
 782             if (wine_ldt_is_system(context->SegCs)) break;  /* don't emulate it in 32-bit code */
 783             if (long_op)
 784             {
 785                 DWORD *stack = get_stack( context );
 786                 context->Eip = *stack++;
 787                 context->SegCs  = *stack++;
 788                 context->EFlags = *stack;
 789                 add_stack(context, 3*sizeof(DWORD));  /* Pop the return address and flags */
 790             }
 791             else
 792             {
 793                 WORD *stack = get_stack( context );
 794                 context->Eip = *stack++;
 795                 context->SegCs  = *stack++;
 796                 SET_LOWORD(context->EFlags,*stack);
 797                 add_stack(context, 3*sizeof(WORD));  /* Pop the return address and flags */
 798             }
 799             return ExceptionContinueExecution;
 800
 801         case 0xe4: /* inb al,XX */
 802             SET_LOBYTE(context->Eax,INSTR_inport( instr[1], 1, context ));
 803             context->Eip += prefixlen + 2;
 804             return ExceptionContinueExecution;
 805
 806         case 0xe5: /* in (e)ax,XX */
 807             if (long_op)
 808                 context->Eax = INSTR_inport( instr[1], 4, context );
 809             else
 810                 SET_LOWORD(context->Eax, INSTR_inport( instr[1], 2, context ));
 811             context->Eip += prefixlen + 2;
 812             return ExceptionContinueExecution;
 813
 814         case 0xe6: /* outb XX,al */
 815             INSTR_outport( instr[1], 1, LOBYTE(context->Eax), context );
 816             context->Eip += prefixlen + 2;
 817             return ExceptionContinueExecution;
 818
 819         case 0xe7: /* out XX,(e)ax */
 820             if (long_op)
 821                 INSTR_outport( instr[1], 4, context->Eax, context );
 822             else
 823                 INSTR_outport( instr[1], 2, LOWORD(context->Eax), context );
 824             context->Eip += prefixlen + 2;
 825             return ExceptionContinueExecution;
 826
 827         case 0xec: /* inb al,dx */
 828             SET_LOBYTE(context->Eax, INSTR_inport( LOWORD(context->Edx), 1, context ) );
 829             context->Eip += prefixlen + 1;
 830             return ExceptionContinueExecution;
 831
 832         case 0xed: /* in (e)ax,dx */
 833             if (long_op)
 834                 context->Eax = INSTR_inport( LOWORD(context->Edx), 4, context );
 835             else
 836                 SET_LOWORD(context->Eax, INSTR_inport( LOWORD(context->Edx), 2, context ));
 837             context->Eip += prefixlen + 1;
 838             return ExceptionContinueExecution;
 839
 840         case 0xee: /* outb dx,al */
 841             INSTR_outport( LOWORD(context->Edx), 1, LOBYTE(context->Eax), context );
 842             context->Eip += prefixlen + 1;
 843             return ExceptionContinueExecution;
 844
 845         case 0xef: /* out dx,(e)ax */
 846             if (long_op)
 847                 INSTR_outport( LOWORD(context->Edx), 4, context->Eax, context );
 848             else
 849                 INSTR_outport( LOWORD(context->Edx), 2, LOWORD(context->Eax), context );
 850             context->Eip += prefixlen + 1;
 851             return ExceptionContinueExecution;
 852
 853         case 0xfa: /* cli */
 854             get_vm86_teb_info()->dpmi_vif = 0;
 855             context->Eip += prefixlen + 1;
 856             return ExceptionContinueExecution;
 857
 858         case 0xfb: /* sti */
 859             get_vm86_teb_info()->dpmi_vif = 1;
 860             context->Eip += prefixlen + 1;
 861             if (get_vm86_teb_info()->vm86_pending)
 862             {
 863                 get_vm86_teb_info()->vm86_pending = 0;
 864                 rec->ExceptionCode = EXCEPTION_VM86_STI;
 865                 break; /* Handle the pending event. */
 866             }
 867             return ExceptionContinueExecution;
 868     }
 869     return ExceptionContinueSearch;  /* Unable to emulate it */
 870 }
 871
 872
 873 /***********************************************************************
 874  *           INSTR_vectored_handler
 875  *
 876  * Vectored exception handler used to emulate protected instructions
 877  * from 32-bit code.
 878  */
 879 LONG CALLBACK INSTR_vectored_handler( EXCEPTION_POINTERS *ptrs )
 880 {
 881     EXCEPTION_RECORD *record = ptrs->ExceptionRecord;
 882     CONTEXT86 *context = ptrs->ContextRecord;
 883
 884     if (wine_ldt_is_system(context->SegCs) &&
 885         (record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
 886          record->ExceptionCode == EXCEPTION_PRIV_INSTRUCTION))
 887     {
 888         if (__wine_emulate_instruction( record, context ) == ExceptionContinueExecution)
 889             return EXCEPTION_CONTINUE_EXECUTION;
 890     }
 891     return EXCEPTION_CONTINUE_SEARCH;
 892 }
 893
 894
 895 /***********************************************************************
 896  *           INSTR_CallBuiltinHandler
 897  */
 898 void INSTR_CallBuiltinHandler( CONTEXT86 *context, BYTE intnum )
 899 {
 900     if (!winedos.CallBuiltinHandler) load_winedos();
 901     if (winedos.CallBuiltinHandler) winedos.CallBuiltinHandler( context, intnum );
 902 }
 903
 904
 905 /***********************************************************************
 906  *           DOS3Call         (KERNEL.102)
 907  */
 908 void WINAPI DOS3Call( CONTEXT86 *context )
 909 {
 910     INSTR_CallBuiltinHandler( context, 0x21 );
 911 }
 912
 913
 914 /***********************************************************************
 915  *           NetBIOSCall      (KERNEL.103)
 916  */
 917 void WINAPI NetBIOSCall16( CONTEXT86 *context )
 918 {
 919     INSTR_CallBuiltinHandler( context, 0x5c );
 920 }
 921
 922
 923 /***********************************************************************
 924  *              GetSetKernelDOSProc (KERNEL.311)
 925  */
 926 FARPROC16 WINAPI GetSetKernelDOSProc16( FARPROC16 DosProc )
 927 {
 928     FIXME("(DosProc=%p): stub\n", DosProc);
 929     return NULL;
 930 }