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 "wingdi.h"
  31 #include "wine/winuser16.h"
  32 #include "excpt.h"
  33 #include "thread.h"
  34 #include "wine/debug.h"
  35 #include "kernel_private.h"
  36 #include "kernel16_private.h"
  37 #include "wine/exception.h"
  38
  39 WINE_DEFAULT_DEBUG_CHANNEL(int);
  40 WINE_DECLARE_DEBUG_CHANNEL(io);
  41
  42 /* macros to set parts of a DWORD */
  43 #define SET_LOWORD(dw,val)  ((dw) = ((dw) & 0xffff0000) | LOWORD(val))
  44 #define SET_LOBYTE(dw,val)  ((dw) = ((dw) & 0xffffff00) | LOBYTE(val))
  45 #define ADD_LOWORD(dw,val)  ((dw) = ((dw) & 0xffff0000) | LOWORD((DWORD)(dw)+(val)))
  46 #define ISV86(context)      ((context)->EFlags & 0x00020000)
  47
  48 static inline void add_stack( CONTEXT86 *context, int offset )
  49 {
  50     if (ISV86(context) || !IS_SELECTOR_32BIT(context->SegSs))
  51         ADD_LOWORD( context->Esp, offset );
  52     else
  53         context->Esp += offset;
  54 }
  55
  56 static inline void *make_ptr( CONTEXT86 *context, DWORD seg, DWORD off, int long_addr )
  57 {
  58     if (ISV86(context)) return (void *)((seg << 4) + LOWORD(off));
  59     if (wine_ldt_is_system(seg)) return (void *)off;
  60     if (!long_addr) off = LOWORD(off);
  61     return (char *) MapSL( MAKESEGPTR( seg, 0 ) ) + off;
  62 }
  63
  64 static inline void *get_stack( CONTEXT86 *context )
  65 {
  66     if (ISV86(context)) return (void *)((context->SegSs << 4) + LOWORD(context->Esp));
  67     return wine_ldt_get_ptr( context->SegSs, context->Esp );
  68 }
  69
  70 #include "pshpack1.h"
  71 struct idtr
  72 {
  73     WORD  limit;
  74     BYTE *base;
  75 };
  76 #include "poppack.h"
  77
  78 static LDT_ENTRY idt[256];
  79
  80 static inline struct idtr get_idtr(void)
  81 {
  82     struct idtr ret;
  83 #if defined(__i386__) && defined(__GNUC__)
  84     __asm__( "sidtl %0" : "=m" (ret) );
  85 #else
  86     ret.base = (BYTE *)idt;
  87     ret.limit = sizeof(idt) - 1;
  88 #endif
  89     return ret;
  90 }
  91
  92
  93 /***********************************************************************
  94  *           INSTR_ReplaceSelector
  95  *
  96  * Try to replace an invalid selector by a valid one.
  97  * The only selector where it is allowed to do "mov ax,40;mov es,ax"
  98  * is the so called 'bimodal' selector 0x40, which points to the BIOS
  99  * data segment. Used by (at least) Borland products (and programs compiled
 100  * using Borland products).
 101  *
 102  * See Undocumented Windows, Chapter 5, __0040.
 103  */
 104 static BOOL INSTR_ReplaceSelector( CONTEXT86 *context, WORD *sel )
 105 {
 106     if (*sel == 0x40)
 107     {
 108         static WORD sys_timer = 0;
 109         if (!sys_timer)
 110         {
 111             if (!winedos.BiosTick) load_winedos();
 112             if (winedos.BiosTick)
 113                 sys_timer = CreateSystemTimer( 55, winedos.BiosTick );
 114         }
 115         *sel = DOSMEM_BiosDataSeg;
 116         return TRUE;
 117     }
 118     return FALSE;  /* Can't replace selector, crashdump */
 119 }
 120
 121
 122 /* store an operand into a register */
 123 static void store_reg( CONTEXT86 *context, BYTE regmodrm, const BYTE *addr, int long_op )
 124 {
 125     switch((regmodrm >> 3) & 7)
 126     {
 127     case 0:
 128         if (long_op) context->Eax = *(const DWORD *)addr;
 129         else SET_LOWORD(context->Eax, *(const WORD *)addr);
 130         break;
 131     case 1:
 132         if (long_op) context->Ecx = *(const DWORD *)addr;
 133         else SET_LOWORD(context->Ecx, *(const WORD *)addr);
 134         break;
 135     case 2:
 136         if (long_op) context->Edx = *(const DWORD *)addr;
 137         else SET_LOWORD(context->Edx, *(const WORD *)addr);
 138         break;
 139     case 3:
 140         if (long_op) context->Ebx = *(const DWORD *)addr;
 141         else SET_LOWORD(context->Ebx, *(const WORD *)addr);
 142         break;
 143     case 4:
 144         if (long_op) context->Esp = *(const DWORD *)addr;
 145         else SET_LOWORD(context->Esp, *(const WORD *)addr);
 146         break;
 147     case 5:
 148         if (long_op) context->Ebp = *(const DWORD *)addr;
 149         else SET_LOWORD(context->Ebp, *(const WORD *)addr);
 150         break;
 151     case 6:
 152         if (long_op) context->Esi = *(const DWORD *)addr;
 153         else SET_LOWORD(context->Esi, *(const WORD *)addr);
 154         break;
 155     case 7:
 156         if (long_op) context->Edi = *(const DWORD *)addr;
 157         else SET_LOWORD(context->Edi, *(const WORD *)addr);
 158         break;
 159     }
 160 }
 161
 162 /***********************************************************************
 163  *           INSTR_GetOperandAddr
 164  *
 165  * Return the address of an instruction operand (from the mod/rm byte).
 166  */
 167 static BYTE *INSTR_GetOperandAddr( CONTEXT86 *context, BYTE *instr,
 168                                    int long_addr, int segprefix, int *len )
 169 {
 170     int mod, rm, base = 0, index = 0, ss = 0, seg = 0, off;
 171     LDT_ENTRY entry;
 172
 173 #define GET_VAL(val,type) \
 174     { *val = *(type *)instr; instr += sizeof(type); *len += sizeof(type); }
 175
 176     *len = 0;
 177     GET_VAL( &mod, BYTE );
 178     rm = mod & 7;
 179     mod >>= 6;
 180
 181     if (mod == 3)
 182     {
 183         switch(rm)
 184         {
 185         case 0: return (BYTE *)&context->Eax;
 186         case 1: return (BYTE *)&context->Ecx;
 187         case 2: return (BYTE *)&context->Edx;
 188         case 3: return (BYTE *)&context->Ebx;
 189         case 4: return (BYTE *)&context->Esp;
 190         case 5: return (BYTE *)&context->Ebp;
 191         case 6: return (BYTE *)&context->Esi;
 192         case 7: return (BYTE *)&context->Edi;
 193         }
 194     }
 195
 196     if (long_addr)
 197     {
 198         if (rm == 4)
 199         {
 200             BYTE sib;
 201             GET_VAL( &sib, BYTE );
 202             rm = sib & 7;
 203             ss = sib >> 6;
 204             switch(sib >> 3)
 205             {
 206             case 0: index = context->Eax; break;
 207             case 1: index = context->Ecx; break;
 208             case 2: index = context->Edx; break;
 209             case 3: index = context->Ebx; break;
 210             case 4: index = 0; break;
 211             case 5: index = context->Ebp; break;
 212             case 6: index = context->Esi; break;
 213             case 7: index = context->Edi; break;
 214             }
 215         }
 216
 217         switch(rm)
 218         {
 219         case 0: base = context->Eax; seg = context->SegDs; break;
 220         case 1: base = context->Ecx; seg = context->SegDs; break;
 221         case 2: base = context->Edx; seg = context->SegDs; break;
 222         case 3: base = context->Ebx; seg = context->SegDs; break;
 223         case 4: base = context->Esp; seg = context->SegSs; break;
 224         case 5: base = context->Ebp; seg = context->SegSs; break;
 225         case 6: base = context->Esi; seg = context->SegDs; break;
 226         case 7: base = context->Edi; seg = context->SegDs; break;
 227         }
 228         switch (mod)
 229         {
 230         case 0:
 231             if (rm == 5)  /* special case: ds:(disp32) */
 232             {
 233                 GET_VAL( &base, DWORD );
 234                 seg = context->SegDs;
 235             }
 236             break;
 237
 238         case 1:  /* 8-bit disp */
 239             GET_VAL( &off, BYTE );
 240             base += (signed char)off;
 241             break;
 242
 243         case 2:  /* 32-bit disp */
 244             GET_VAL( &off, DWORD );
 245             base += (signed long)off;
 246             break;
 247         }
 248     }
 249     else  /* short address */
 250     {
 251         switch(rm)
 252         {
 253         case 0:  /* ds:(bx,si) */
 254             base = LOWORD(context->Ebx) + LOWORD(context->Esi);
 255             seg  = context->SegDs;
 256             break;
 257         case 1:  /* ds:(bx,di) */
 258             base = LOWORD(context->Ebx) + LOWORD(context->Edi);
 259             seg  = context->SegDs;
 260             break;
 261         case 2:  /* ss:(bp,si) */
 262             base = LOWORD(context->Ebp) + LOWORD(context->Esi);
 263             seg  = context->SegSs;
 264             break;
 265         case 3:  /* ss:(bp,di) */
 266             base = LOWORD(context->Ebp) + LOWORD(context->Edi);
 267             seg  = context->SegSs;
 268             break;
 269         case 4:  /* ds:(si) */
 270             base = LOWORD(context->Esi);
 271             seg  = context->SegDs;
 272             break;
 273         case 5:  /* ds:(di) */
 274             base = LOWORD(context->Edi);
 275             seg  = context->SegDs;
 276             break;
 277         case 6:  /* ss:(bp) */
 278             base = LOWORD(context->Ebp);
 279             seg  = context->SegSs;
 280             break;
 281         case 7:  /* ds:(bx) */
 282             base = LOWORD(context->Ebx);
 283             seg  = context->SegDs;
 284             break;
 285         }
 286
 287         switch(mod)
 288         {
 289         case 0:
 290             if (rm == 6)  /* special case: ds:(disp16) */
 291             {
 292                 GET_VAL( &base, WORD );
 293                 seg  = context->SegDs;
 294             }
 295             break;
 296
 297         case 1:  /* 8-bit disp */
 298             GET_VAL( &off, BYTE );
 299             base += (signed char)off;
 300             break;
 301
 302         case 2:  /* 16-bit disp */
 303             GET_VAL( &off, WORD );
 304             base += (signed short)off;
 305             break;
 306         }
 307         base &= 0xffff;
 308     }
 309     if (segprefix != -1) seg = segprefix;
 310
 311     /* Make sure the segment and offset are valid */
 312     if (wine_ldt_is_system(seg)) return (BYTE *)(base + (index << ss));
 313     if ((seg & 7) != 7) return NULL;
 314     wine_ldt_get_entry( seg, &entry );
 315     if (wine_ldt_is_empty( &entry )) return NULL;
 316     if (wine_ldt_get_limit(&entry) < (base + (index << ss))) return NULL;
 317     return (BYTE *)wine_ldt_get_base(&entry) + base + (index << ss);
 318 #undef GET_VAL
 319 }
 320
 321
 322 /***********************************************************************
 323  *           INSTR_EmulateLDS
 324  *
 325  * Emulate the LDS (and LES,LFS,etc.) instruction.
 326  */
 327 static BOOL INSTR_EmulateLDS( CONTEXT86 *context, BYTE *instr, int long_op,
 328                               int long_addr, int segprefix, int *len )
 329 {
 330     WORD seg;
 331     BYTE *regmodrm = instr + 1 + (*instr == 0x0f);
 332     BYTE *addr = INSTR_GetOperandAddr( context, regmodrm,
 333                                        long_addr, segprefix, len );
 334     if (!addr)
 335         return FALSE;  /* Unable to emulate it */
 336     seg = *(WORD *)(addr + (long_op ? 4 : 2));
 337
 338     if (!INSTR_ReplaceSelector( context, &seg ))
 339         return FALSE;  /* Unable to emulate it */
 340
 341     /* Now store the offset in the correct register */
 342
 343     store_reg( context, *regmodrm, addr, long_op );
 344
 345     /* Store the correct segment in the segment register */
 346
 347     switch(*instr)
 348     {
 349     case 0xc4: context->SegEs = seg; break;  /* les */
 350     case 0xc5: context->SegDs = seg; break;  /* lds */
 351     case 0x0f: switch(instr[1])
 352                {
 353                case 0xb2: context->SegSs = seg; break;  /* lss */
 354                case 0xb4: context->SegFs = seg; break;  /* lfs */
 355                case 0xb5: context->SegGs = seg; break;  /* lgs */
 356                }
 357                break;
 358     }
 359
 360     /* Add the opcode size to the total length */
 361
 362     *len += 1 + (*instr == 0x0f);
 363     return TRUE;
 364 }
 365
 366 /***********************************************************************
 367  *           INSTR_inport
 368  *
 369  * input on an I/O port
 370  */
 371 static DWORD INSTR_inport( WORD port, int size, CONTEXT86 *context )
 372 {
 373     DWORD res = ~0U;
 374
 375     if (!winedos.inport) load_winedos();
 376     if (winedos.inport) res = winedos.inport( port, size );
 377
 378     if (TRACE_ON(io))
 379     {
 380         switch(size)
 381         {
 382         case 1:
 383             TRACE_(io)( "0x%x < %02x @ %04x:%04x\n", port, LOBYTE(res),
 384                      (WORD)context->SegCs, LOWORD(context->Eip));
 385             break;
 386         case 2:
 387             TRACE_(io)( "0x%x < %04x @ %04x:%04x\n", port, LOWORD(res),
 388                      (WORD)context->SegCs, LOWORD(context->Eip));
 389             break;
 390         case 4:
 391             TRACE_(io)( "0x%x < %08x @ %04x:%04x\n", port, res,
 392                      (WORD)context->SegCs, LOWORD(context->Eip));
 393             break;
 394         }
 395     }
 396     return res;
 397 }
 398
 399
 400 /***********************************************************************
 401  *           INSTR_outport
 402  *
 403  * output on an I/O port
 404  */
 405 static void INSTR_outport( WORD port, int size, DWORD val, CONTEXT86 *context )
 406 {
 407     if (!winedos.outport) load_winedos();
 408     if (winedos.outport) winedos.outport( port, size, val );
 409
 410     if (TRACE_ON(io))
 411     {
 412         switch(size)
 413         {
 414         case 1:
 415             TRACE_(io)("0x%x > %02x @ %04x:%04x\n", port, LOBYTE(val),
 416                     (WORD)context->SegCs, LOWORD(context->Eip));
 417             break;
 418         case 2:
 419             TRACE_(io)("0x%x > %04x @ %04x:%04x\n", port, LOWORD(val),
 420                     (WORD)context->SegCs, LOWORD(context->Eip));
 421             break;
 422         case 4:
 423             TRACE_(io)("0x%x > %08x @ %04x:%04x\n", port, val,
 424                     (WORD)context->SegCs, LOWORD(context->Eip));
 425             break;
 426         }
 427     }
 428 }
 429
 430
 431 /***********************************************************************
 432  *           INSTR_EmulateInstruction
 433  *
 434  * Emulate a privileged instruction.
 435  * Returns exception continuation status.
 436  */
 437 DWORD INSTR_EmulateInstruction( EXCEPTION_RECORD *rec, CONTEXT86 *context )
 438 {
 439     int prefix, segprefix, prefixlen, len, repX, long_op, long_addr;
 440     BYTE *instr;
 441
 442     long_op = long_addr = (!ISV86(context) && IS_SELECTOR_32BIT(context->SegCs));
 443     instr = make_ptr( context, context->SegCs, context->Eip, TRUE );
 444     if (!instr) return ExceptionContinueSearch;
 445
 446     /* First handle any possible prefix */
 447
 448     segprefix = -1;  /* no prefix */
 449     prefix = 1;
 450     repX = 0;
 451     prefixlen = 0;
 452     while(prefix)
 453     {
 454         switch(*instr)
 455         {
 456         case 0x2e:
 457             segprefix = context->SegCs;
 458             break;
 459         case 0x36:
 460             segprefix = context->SegSs;
 461             break;
 462         case 0x3e:
 463             segprefix = context->SegDs;
 464             break;
 465         case 0x26:
 466             segprefix = context->SegEs;
 467             break;
 468         case 0x64:
 469             segprefix = context->SegFs;
 470             break;
 471         case 0x65:
 472             segprefix = context->SegGs;
 473             break;
 474         case 0x66:
 475             long_op = !long_op;  /* opcode size prefix */
 476             break;
 477         case 0x67:
 478             long_addr = !long_addr;  /* addr size prefix */
 479             break;
 480         case 0xf0:  /* lock */
 481             break;
 482         case 0xf2:  /* repne */
 483             repX = 1;
 484             break;
 485         case 0xf3:  /* repe */
 486             repX = 2;
 487             break;
 488         default:
 489             prefix = 0;  /* no more prefixes */
 490             break;
 491         }
 492         if (prefix)
 493         {
 494             instr++;
 495             prefixlen++;
 496         }
 497     }
 498
 499     /* Now look at the actual instruction */
 500
 501     switch(*instr)
 502     {
 503         case 0x07: /* pop es */
 504         case 0x17: /* pop ss */
 505         case 0x1f: /* pop ds */
 506             {
 507                 WORD seg = *(WORD *)get_stack( context );
 508                 if (INSTR_ReplaceSelector( context, &seg ))
 509                 {
 510                     switch(*instr)
 511                     {
 512                     case 0x07: context->SegEs = seg; break;
 513                     case 0x17: context->SegSs = seg; break;
 514                     case 0x1f: context->SegDs = seg; break;
 515                     }
 516                     add_stack(context, long_op ? 4 : 2);
 517                     context->Eip += prefixlen + 1;
 518                     return ExceptionContinueExecution;
 519                 }
 520             }
 521             break;  /* Unable to emulate it */
 522
 523         case 0x0f: /* extended instruction */
 524             switch(instr[1])
 525             {
 526             case 0x22: /* mov eax, crX */
 527                 switch (instr[2])
 528                 {
 529                 case 0xc0:
 530                         ERR("mov eax,cr0 at 0x%08x, EAX=0x%08x\n",
 531                             context->Eip,context->Eax );
 532                         context->Eip += prefixlen+3;
 533                         return ExceptionContinueExecution;
 534                 default:
 535                         break; /*fallthrough to bad instruction handling */
 536                 }
 537                 break; /*fallthrough to bad instruction handling */
 538             case 0x20: /* mov crX, eax */
 539                 switch (instr[2])
 540                 {
 541                 case 0xe0: /* mov cr4, eax */
 542                     /* CR4 register . See linux/arch/i386/mm/init.c, X86_CR4_ defs
 543                      * bit 0: VME       Virtual Mode Exception ?
 544                      * bit 1: PVI       Protected mode Virtual Interrupt
 545                      * bit 2: TSD       Timestamp disable
 546                      * bit 3: DE        Debugging extensions
 547                      * bit 4: PSE       Page size extensions
 548                      * bit 5: PAE   Physical address extension
 549                      * bit 6: MCE       Machine check enable
 550                      * bit 7: PGE   Enable global pages
 551                      * bit 8: PCE       Enable performance counters at IPL3
 552                      */
 553                     ERR("mov cr4,eax at 0x%08x\n",context->Eip);
 554                     context->Eax = 0;
 555                     context->Eip += prefixlen+3;
 556                     return ExceptionContinueExecution;
 557                 case 0xc0: /* mov cr0, eax */
 558                     ERR("mov cr0,eax at 0x%08x\n",context->Eip);
 559                     context->Eax = 0x10; /* FIXME: set more bits ? */
 560                     context->Eip += prefixlen+3;
 561                     return ExceptionContinueExecution;
 562                 default: /* fallthrough to illegal instruction */
 563                     break;
 564                 }
 565                 /* fallthrough to illegal instruction */
 566                 break;
 567             case 0x21: /* mov drX, eax */
 568                 switch (instr[2])
 569                 {
 570                 case 0xc8: /* mov dr1, eax */
 571                     TRACE("mov dr1,eax at 0x%08x\n",context->Eip);
 572                     context->Eax = context->Dr1;
 573                     context->Eip += prefixlen+3;
 574                     return ExceptionContinueExecution;
 575                 case 0xf8: /* mov dr7, eax */
 576                     TRACE("mov dr7,eax at 0x%08x\n",context->Eip);
 577                     context->Eax = 0x400;
 578                     context->Eip += prefixlen+3;
 579                     return ExceptionContinueExecution;
 580                 }
 581                 ERR("Unsupported DR register, eip+2 is %02x\n", instr[2]);
 582                 /* fallthrough to illegal instruction */
 583                 break;
 584             case 0x23: /* mov eax drX */
 585                 switch (instr[2])
 586                 {
 587                 case 0xc8: /* mov eax, dr1 */
 588                     context->Dr1 = context->Eax;
 589                     context->Eip += prefixlen+3;
 590                     return ExceptionContinueExecution;
 591                 }
 592                 ERR("Unsupported DR register, eip+2 is %02x\n", instr[2]);
 593                 /* fallthrough to illegal instruction */
 594                 break;
 595             case 0xa1: /* pop fs */
 596                 {
 597                     WORD seg = *(WORD *)get_stack( context );
 598                     if (INSTR_ReplaceSelector( context, &seg ))
 599                     {
 600                         context->SegFs = seg;
 601                         add_stack(context, long_op ? 4 : 2);
 602                         context->Eip += prefixlen + 2;
 603                         return ExceptionContinueExecution;
 604                     }
 605                 }
 606                 break;
 607             case 0xa9: /* pop gs */
 608                 {
 609                     WORD seg = *(WORD *)get_stack( context );
 610                     if (INSTR_ReplaceSelector( context, &seg ))
 611                     {
 612                         context->SegGs = seg;
 613                         add_stack(context, long_op ? 4 : 2);
 614                         context->Eip += prefixlen + 2;
 615                         return ExceptionContinueExecution;
 616                     }
 617                 }
 618                 break;
 619             case 0xb2: /* lss addr,reg */
 620             case 0xb4: /* lfs addr,reg */
 621             case 0xb5: /* lgs addr,reg */
 622                 if (INSTR_EmulateLDS( context, instr, long_op,
 623                                       long_addr, segprefix, &len ))
 624                 {
 625                     context->Eip += prefixlen + len;
 626                     return ExceptionContinueExecution;
 627                 }
 628                 break;
 629             }
 630             break;  /* Unable to emulate it */
 631
 632         case 0x6c: /* insb     */
 633         case 0x6d: /* insw/d   */
 634         case 0x6e: /* outsb    */
 635         case 0x6f: /* outsw/d  */
 636             {
 637               int typ = *instr;  /* Just in case it's overwritten.  */
 638               int outp = (typ >= 0x6e);
 639               unsigned long count = repX ?
 640                           (long_addr ? context->Ecx : LOWORD(context->Ecx)) : 1;
 641               int opsize = (typ & 1) ? (long_op ? 4 : 2) : 1;
 642               int step = (context->EFlags & 0x400) ? -opsize : +opsize;
 643               int seg = outp ? context->SegDs : context->SegEs;  /* FIXME: is this right? */
 644
 645               if (outp)
 646                 /* FIXME: Check segment is readable.  */
 647                 (void)0;
 648               else
 649                 /* FIXME: Check segment is writable.  */
 650                 (void)0;
 651
 652               if (repX)
 653               {
 654                 if (long_addr) context->Ecx = 0;
 655                 else SET_LOWORD(context->Ecx,0);
 656               }
 657
 658               while (count-- > 0)
 659                 {
 660                   void *data;
 661                   WORD dx = LOWORD(context->Edx);
 662                   if (outp)
 663                   {
 664                       data = make_ptr( context, seg, context->Esi, long_addr );
 665                       if (long_addr) context->Esi += step;
 666                       else ADD_LOWORD(context->Esi,step);
 667                   }
 668                   else
 669                   {
 670                       data = make_ptr( context, seg, context->Edi, long_addr );
 671                       if (long_addr) context->Edi += step;
 672                       else ADD_LOWORD(context->Edi,step);
 673                   }
 674
 675                   switch (typ)
 676                   {
 677                     case 0x6c:
 678                       *(BYTE *)data = INSTR_inport( dx, 1, context );
 679                       break;
 680                     case 0x6d:
 681                       if (long_op)
 682                           *(DWORD *)data = INSTR_inport( dx, 4, context );
 683                       else
 684                           *(WORD *)data = INSTR_inport( dx, 2, context );
 685                       break;
 686                     case 0x6e:
 687                         INSTR_outport( dx, 1, *(BYTE *)data, context );
 688                         break;
 689                     case 0x6f:
 690                         if (long_op)
 691                             INSTR_outport( dx, 4, *(DWORD *)data, context );
 692                         else
 693                             INSTR_outport( dx, 2, *(WORD *)data, context );
 694                         break;
 695                     }
 696                 }
 697               context->Eip += prefixlen + 1;
 698             }
 699             return ExceptionContinueExecution;
 700
 701         case 0x8b: /* mov Ev, Gv */
 702             {
 703                 BYTE *addr = INSTR_GetOperandAddr(context, instr + 1, long_addr,
 704                                                   segprefix, &len);
 705                 struct idtr idtr = get_idtr();
 706                 unsigned int offset = addr - idtr.base;
 707
 708                 if (offset <= idtr.limit + 1 - (long_op ? 4 : 2))
 709                 {
 710                     idt[1].LimitLow = 0x100; /* FIXME */
 711                     idt[2].LimitLow = 0x11E; /* FIXME */
 712                     idt[3].LimitLow = 0x500; /* FIXME */
 713                     store_reg( context, instr[1], (BYTE *)&idt + offset, long_op );
 714                     context->Eip += prefixlen + len + 1;
 715                     return ExceptionContinueExecution;
 716                 }
 717             }
 718             break;  /* Unable to emulate it */
 719
 720         case 0x8e: /* mov XX,segment_reg */
 721             {
 722                 WORD seg;
 723                 BYTE *addr = INSTR_GetOperandAddr(context, instr + 1,
 724                                                   long_addr, segprefix, &len );
 725                 if (!addr)
 726                     break;  /* Unable to emulate it */
 727                 seg = *(WORD *)addr;
 728                 if (!INSTR_ReplaceSelector( context, &seg ))
 729                     break;  /* Unable to emulate it */
 730
 731                 switch((instr[1] >> 3) & 7)
 732                 {
 733                 case 0:
 734                     context->SegEs = seg;
 735                     context->Eip += prefixlen + len + 1;
 736                     return ExceptionContinueExecution;
 737                 case 1:  /* cs */
 738                     break;
 739                 case 2:
 740                     context->SegSs = seg;
 741                     context->Eip += prefixlen + len + 1;
 742                     return ExceptionContinueExecution;
 743                 case 3:
 744                     context->SegDs = seg;
 745                     context->Eip += prefixlen + len + 1;
 746                     return ExceptionContinueExecution;
 747                 case 4:
 748                     context->SegFs = seg;
 749                     context->Eip += prefixlen + len + 1;
 750                     return ExceptionContinueExecution;
 751                 case 5:
 752                     context->SegGs = seg;
 753                     context->Eip += prefixlen + len + 1;
 754                     return ExceptionContinueExecution;
 755                 case 6:  /* unused */
 756                 case 7:  /* unused */
 757                     break;
 758                 }
 759             }
 760             break;  /* Unable to emulate it */
 761
 762         case 0xc4: /* les addr,reg */
 763         case 0xc5: /* lds addr,reg */
 764             if (INSTR_EmulateLDS( context, instr, long_op,
 765                                   long_addr, segprefix, &len ))
 766             {
 767                 context->Eip += prefixlen + len;
 768                 return ExceptionContinueExecution;
 769             }
 770             break;  /* Unable to emulate it */
 771
 772         case 0xcd: /* int <XX> */
 773             if (wine_ldt_is_system(context->SegCs)) break;  /* don't emulate it in 32-bit code */
 774             if (!winedos.EmulateInterruptPM) load_winedos();
 775             if (winedos.EmulateInterruptPM)
 776             {
 777                 context->Eip += prefixlen + 2;
 778                 winedos.EmulateInterruptPM( context, instr[1] );
 779                 return ExceptionContinueExecution;
 780             }
 781             break;  /* Unable to emulate it */
 782
 783         case 0xcf: /* iret */
 784             if (wine_ldt_is_system(context->SegCs)) break;  /* don't emulate it in 32-bit code */
 785             if (long_op)
 786             {
 787                 DWORD *stack = get_stack( context );
 788                 context->Eip = *stack++;
 789                 context->SegCs  = *stack++;
 790                 context->EFlags = *stack;
 791                 add_stack(context, 3*sizeof(DWORD));  /* Pop the return address and flags */
 792             }
 793             else
 794             {
 795                 WORD *stack = get_stack( context );
 796                 context->Eip = *stack++;
 797                 context->SegCs  = *stack++;
 798                 SET_LOWORD(context->EFlags,*stack);
 799                 add_stack(context, 3*sizeof(WORD));  /* Pop the return address and flags */
 800             }
 801             return ExceptionContinueExecution;
 802
 803         case 0xe4: /* inb al,XX */
 804             SET_LOBYTE(context->Eax,INSTR_inport( instr[1], 1, context ));
 805             context->Eip += prefixlen + 2;
 806             return ExceptionContinueExecution;
 807
 808         case 0xe5: /* in (e)ax,XX */
 809             if (long_op)
 810                 context->Eax = INSTR_inport( instr[1], 4, context );
 811             else
 812                 SET_LOWORD(context->Eax, INSTR_inport( instr[1], 2, context ));
 813             context->Eip += prefixlen + 2;
 814             return ExceptionContinueExecution;
 815
 816         case 0xe6: /* outb XX,al */
 817             INSTR_outport( instr[1], 1, LOBYTE(context->Eax), context );
 818             context->Eip += prefixlen + 2;
 819             return ExceptionContinueExecution;
 820
 821         case 0xe7: /* out XX,(e)ax */
 822             if (long_op)
 823                 INSTR_outport( instr[1], 4, context->Eax, context );
 824             else
 825                 INSTR_outport( instr[1], 2, LOWORD(context->Eax), context );
 826             context->Eip += prefixlen + 2;
 827             return ExceptionContinueExecution;
 828
 829         case 0xec: /* inb al,dx */
 830             SET_LOBYTE(context->Eax, INSTR_inport( LOWORD(context->Edx), 1, context ) );
 831             context->Eip += prefixlen + 1;
 832             return ExceptionContinueExecution;
 833
 834         case 0xed: /* in (e)ax,dx */
 835             if (long_op)
 836                 context->Eax = INSTR_inport( LOWORD(context->Edx), 4, context );
 837             else
 838                 SET_LOWORD(context->Eax, INSTR_inport( LOWORD(context->Edx), 2, context ));
 839             context->Eip += prefixlen + 1;
 840             return ExceptionContinueExecution;
 841
 842         case 0xee: /* outb dx,al */
 843             INSTR_outport( LOWORD(context->Edx), 1, LOBYTE(context->Eax), context );
 844             context->Eip += prefixlen + 1;
 845             return ExceptionContinueExecution;
 846
 847         case 0xef: /* out dx,(e)ax */
 848             if (long_op)
 849                 INSTR_outport( LOWORD(context->Edx), 4, context->Eax, context );
 850             else
 851                 INSTR_outport( LOWORD(context->Edx), 2, LOWORD(context->Eax), context );
 852             context->Eip += prefixlen + 1;
 853             return ExceptionContinueExecution;
 854
 855         case 0xfa: /* cli */
 856             NtCurrentTeb()->dpmi_vif = 0;
 857             context->Eip += prefixlen + 1;
 858             return ExceptionContinueExecution;
 859
 860         case 0xfb: /* sti */
 861             NtCurrentTeb()->dpmi_vif = 1;
 862             context->Eip += prefixlen + 1;
 863             if (NtCurrentTeb()->vm86_pending)
 864             {
 865                 NtCurrentTeb()->vm86_pending = 0;
 866                 rec->ExceptionCode = EXCEPTION_VM86_STI;
 867                 break; /* Handle the pending event. */
 868             }
 869             return ExceptionContinueExecution;
 870     }
 871     return ExceptionContinueSearch;  /* Unable to emulate it */
 872 }
 873
 874
 875 /***********************************************************************
 876  *           INSTR_vectored_handler
 877  *
 878  * Vectored exception handler used to emulate protected instructions
 879  * from 32-bit code.
 880  */
 881 LONG CALLBACK INSTR_vectored_handler( EXCEPTION_POINTERS *ptrs )
 882 {
 883     EXCEPTION_RECORD *record = ptrs->ExceptionRecord;
 884     CONTEXT86 *context = ptrs->ContextRecord;
 885
 886     if (wine_ldt_is_system(context->SegCs) &&
 887         (record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
 888          record->ExceptionCode == EXCEPTION_PRIV_INSTRUCTION))
 889     {
 890         if (INSTR_EmulateInstruction( record, context ) == ExceptionContinueExecution)
 891             return EXCEPTION_CONTINUE_EXECUTION;
 892     }
 893     return EXCEPTION_CONTINUE_SEARCH;
 894 }
 895
 896
 897 /***********************************************************************
 898  *           INSTR_CallBuiltinHandler
 899  */
 900 void INSTR_CallBuiltinHandler( CONTEXT86 *context, BYTE intnum )
 901 {
 902     if (!winedos.CallBuiltinHandler) load_winedos();
 903     if (winedos.CallBuiltinHandler) winedos.CallBuiltinHandler( context, intnum );
 904 }
 905
 906
 907 /***********************************************************************
 908  *           DOS3Call         (KERNEL.102)
 909  */
 910 void WINAPI DOS3Call( CONTEXT86 *context )
 911 {
 912     INSTR_CallBuiltinHandler( context, 0x21 );
 913 }
 914
 915
 916 /***********************************************************************
 917  *           NetBIOSCall      (KERNEL.103)
 918  */
 919 void WINAPI NetBIOSCall16( CONTEXT86 *context )
 920 {
 921     INSTR_CallBuiltinHandler( context, 0x5c );
 922 }
 923
 924
 925 /***********************************************************************
 926  *              GetSetKernelDOSProc (KERNEL.311)
 927  */
 928 FARPROC16 WINAPI GetSetKernelDOSProc16( FARPROC16 DosProc )
 929 {
 930     FIXME("(DosProc=%p): stub\n", DosProc);
 931     return NULL;
 932 }