/** @file * * VBox disassembler: * Main */ /* * Copyright (C) 2006-2007 Sun Microsystems, Inc. * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 USA or visit http://www.sun.com if you need * additional information or have any questions. */ /******************************************************************************* * Header Files * *******************************************************************************/ #ifdef USING_VISUAL_STUDIO # include #endif #include #include #include #include #include #include "DisasmInternal.h" #include "DisasmTables.h" /** * Disassembles a code block. * * @returns VBox error code * @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode * set correctly. * @param pvCodeBlock Pointer to the strunction to disassemble. * @param cbMax Maximum number of bytes to disassemble. * @param pcbSize Where to store the size of the instruction. * NULL is allowed. * * * @todo Define output callback. * @todo Using signed integers as sizes is a bit odd. There are still * some GCC warnings about mixing signed and unsigend integers. * @todo Need to extend this interface to include a code address so we * can dissassemble GC code. Perhaps a new function is better... * @remark cbMax isn't respected as a boundry. DISInstr() will read beyond cbMax. * This means *pcbSize >= cbMax sometimes. */ DISDECL(int) DISBlock(PDISCPUSTATE pCpu, RTUINTPTR pvCodeBlock, unsigned cbMax, unsigned *pSize) { unsigned i = 0; char szOutput[256]; while (i < cbMax) { unsigned cbInstr; int rc = DISInstr(pCpu, pvCodeBlock + i, 0, &cbInstr, szOutput); if (VBOX_FAILURE(rc)) return rc; i += cbInstr; } if (pSize) *pSize = i; return true; } /** * Disassembles one instruction * * @returns VBox error code * @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode * set correctly. * @param pu8Instruction Pointer to the strunction to disassemble. * @param u32EipOffset Offset to add to instruction address to get the real virtual address * @param pcbSize Where to store the size of the instruction. * NULL is allowed. * @param pszOutput Storage for disassembled instruction * * @todo Define output callback. */ DISDECL(int) DISInstr(PDISCPUSTATE pCpu, RTUINTPTR pu8Instruction, unsigned u32EipOffset, unsigned *pcbSize, char *pszOutput) { return DISInstrEx(pCpu, pu8Instruction, u32EipOffset, pcbSize, pszOutput, OPTYPE_ALL); } /** * Disassembles one instruction; only fully disassembly an instruction if it matches the filter criteria * * @returns VBox error code * @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode * set correctly. * @param pu8Instruction Pointer to the strunction to disassemble. * @param u32EipOffset Offset to add to instruction address to get the real virtual address * @param pcbSize Where to store the size of the instruction. * NULL is allowed. * @param pszOutput Storage for disassembled instruction * @param uFilter Instruction type filter * * @todo Define output callback. */ DISDECL(int) DISInstrEx(PDISCPUSTATE pCpu, RTUINTPTR pu8Instruction, unsigned u32EipOffset, unsigned *pcbSize, char *pszOutput, unsigned uFilter) { unsigned i = 0, prefixbytes; unsigned idx, inc; #ifdef __L4ENV__ jmp_buf jumpbuffer; #endif //reset instruction settings pCpu->prefix = PREFIX_NONE; pCpu->prefix_seg = 0; pCpu->addrmode = pCpu->mode; pCpu->opmode = pCpu->mode; pCpu->ModRM = 0; pCpu->SIB = 0; pCpu->lastprefix = 0; pCpu->param1.parval = 0; pCpu->param2.parval = 0; pCpu->param3.parval = 0; pCpu->param1.szParam[0] = 0; pCpu->param2.szParam[0] = 0; pCpu->param3.szParam[0] = 0; pCpu->param1.size = 0; pCpu->param2.size = 0; pCpu->param3.size = 0; pCpu->param1.flags = 0; pCpu->param2.flags = 0; pCpu->param3.flags = 0; pCpu->uFilter = uFilter; pCpu->pfnDisasmFnTable = pfnFullDisasm; if (pszOutput) *pszOutput = '\0'; prefixbytes = 0; #ifndef __L4ENV__ /* Unfortunately, we have no exception handling in l4env */ try #else pCpu->pJumpBuffer = &jumpbuffer; if (setjmp(jumpbuffer) == 0) #endif { while(1) { uint8_t codebyte = DISReadByte(pCpu, pu8Instruction+i); uint8_t opcode = g_aOneByteMapX86[codebyte].opcode; /* Hardcoded assumption about OP_* values!! */ if (opcode <= OP_LOCK) { pCpu->lastprefix = opcode; switch(opcode) { case OP_INVALID: #if 0 //defined (DEBUG_Sander) AssertMsgFailed(("Invalid opcode!!\n")); #endif return VERR_DIS_INVALID_OPCODE; // segment override prefix byte case OP_SEG: pCpu->prefix_seg = g_aOneByteMapX86[codebyte].param1 - OP_PARM_REG_SEG_START; pCpu->prefix |= PREFIX_SEG; i += sizeof(uint8_t); prefixbytes++; continue; //fetch the next byte // lock prefix byte case OP_LOCK: pCpu->prefix |= PREFIX_LOCK; i += sizeof(uint8_t); prefixbytes++; continue; //fetch the next byte // address size override prefix byte case OP_ADRSIZE: pCpu->prefix |= PREFIX_ADDRSIZE; if(pCpu->mode == CPUMODE_16BIT) pCpu->addrmode = CPUMODE_32BIT; else pCpu->addrmode = CPUMODE_16BIT; i += sizeof(uint8_t); prefixbytes++; continue; //fetch the next byte // operand size override prefix byte case OP_OPSIZE: pCpu->prefix |= PREFIX_OPSIZE; if(pCpu->mode == CPUMODE_16BIT) pCpu->opmode = CPUMODE_32BIT; else pCpu->opmode = CPUMODE_16BIT; i += sizeof(uint8_t); prefixbytes++; continue; //fetch the next byte // rep and repne are not really prefixes, but we'll treat them as such case OP_REPE: pCpu->prefix |= PREFIX_REP; i += sizeof(uint8_t); prefixbytes += sizeof(uint8_t); continue; //fetch the next byte case OP_REPNE: pCpu->prefix |= PREFIX_REPNE; i += sizeof(uint8_t); prefixbytes += sizeof(uint8_t); continue; //fetch the next byte } } idx = i; i += sizeof(uint8_t); //first opcode byte pCpu->opcode = codebyte; /* Prefix byte(s) is/are part of the instruction. */ pCpu->opaddr = pu8Instruction + idx + u32EipOffset - prefixbytes; inc = ParseInstruction(pu8Instruction + i, &g_aOneByteMapX86[pCpu->opcode], pCpu); pCpu->opsize = prefixbytes + inc + sizeof(uint8_t); if(pszOutput) { disasmSprintf(pszOutput, pu8Instruction+i-1-prefixbytes, pCpu, &pCpu->param1, &pCpu->param2, &pCpu->param3); } i += inc; prefixbytes = 0; break; } } #ifndef __L4ENV__ catch(...) #else else /* setjmp has returned a non-zero value: an exception occured */ #endif { if (pcbSize) *pcbSize = 0; return VERR_DIS_GEN_FAILURE; } if (pcbSize) *pcbSize = i; return VINF_SUCCESS; } //***************************************************************************** //***************************************************************************** char *DbgBytesToString(PDISCPUSTATE pCpu, RTUINTPTR pBytes, int size, char *pszOutput) { char szByte[4]; int len = strlen(pszOutput); int i; for(i = len; i < 40; i++) { strcat(pszOutput, " "); } strcat(pszOutput, " ["); for(i = 0; i < size; i++) { RTStrPrintf(szByte, sizeof(szByte), "%02X ", DISReadByte(pCpu, pBytes+i)); RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, szByte); } len = strlen(pszOutput); pszOutput[len - 1] = 0; //cut off last space strcat(pszOutput, "]"); return pszOutput; } //***************************************************************************** //***************************************************************************** void disasmSprintf(char *pszOutput, RTUINTPTR pu8Instruction, PDISCPUSTATE pCpu, OP_PARAMETER *pParam1, OP_PARAMETER *pParam2, OP_PARAMETER *pParam3) { const char *lpszFormat = pCpu->pszOpcode; int param = 1; RTStrPrintf(pszOutput, 64, "%08X: ", (unsigned)pCpu->opaddr); if(pCpu->prefix & PREFIX_LOCK) { RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "lock "); } if(pCpu->prefix & PREFIX_REP) { RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "rep(e) "); } else if(pCpu->prefix & PREFIX_REPNE) { RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "repne "); } if(!strcmp("Invalid Opcode", lpszFormat)) { RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "Invalid Opcode [%02X][%02X]", DISReadByte(pCpu, pu8Instruction), DISReadByte(pCpu, pu8Instruction+1) ); } else while(*lpszFormat) { switch(*lpszFormat) { case '%': switch(*(lpszFormat+1)) { case 'J': //Relative jump offset { int32_t disp; AssertMsg(param == 1, ("Invalid branch parameter nr")); if(pParam1->flags & USE_IMMEDIATE8_REL) { disp = (int32_t)(char)pParam1->parval; } else if(pParam1->flags & USE_IMMEDIATE16_REL) { disp = (int32_t)(uint16_t)pParam1->parval; } else if(pParam1->flags & USE_IMMEDIATE32_REL) { disp = (int32_t)pParam1->parval; } else { AssertMsgFailed(("Oops!\n")); return; } uint32_t addr = (uint32_t)(pCpu->opaddr + pCpu->opsize) + disp; RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "[%08X]", addr); } //no break; case 'A': //direct address case 'C': //control register case 'D': //debug register case 'E': //ModRM specifies parameter case 'F': //Eflags register case 'G': //ModRM selects general register case 'I': //Immediate data case 'M': //ModRM may only refer to memory case 'O': //No ModRM byte case 'P': //ModRM byte selects MMX register case 'Q': //ModRM byte selects MMX register or memory address case 'R': //ModRM byte may only refer to a general register case 'S': //ModRM byte selects a segment register case 'T': //ModRM byte selects a test register case 'V': //ModRM byte selects an XMM/SSE register case 'W': //ModRM byte selects an XMM/SSE register or a memory address case 'X': //DS:SI case 'Y': //ES:DI switch(param) { case 1: RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam1->szParam); break; case 2: RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam2->szParam); break; case 3: RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam3->szParam); break; } break; case 'e': //register based on operand size (e.g. %eAX) if(pCpu->opmode == CPUMODE_32BIT) { RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "E"); } RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "%c%c", lpszFormat[2], lpszFormat[3]); break; default: AssertMsgFailed(("Oops!\n")); break; } //Go to the next parameter in the format string while(*lpszFormat && *lpszFormat != ',') lpszFormat++; if(*lpszFormat == ',') lpszFormat--; break; case ',': param++; //no break default: RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "%c", *lpszFormat); break; } if(*lpszFormat) lpszFormat++; } DbgBytesToString(pCpu, pu8Instruction, pCpu->opsize, pszOutput); RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "\n"); } //***************************************************************************** //*****************************************************************************