/* ----------------------------------------------------------------------------- * resolve_gpr64() - 64bit General Purpose Register-Selection. * ----------------------------------------------------------------------------- */ static enum ud_type resolve_gpr64(struct ud* u, enum ud_operand_code gpr_op) { if (gpr_op >= OP_rAXr8 && gpr_op <= OP_rDIr15) gpr_op = (gpr_op - OP_rAXr8) | (REX_B(u->pfx_rex) << 3); else gpr_op = (gpr_op - OP_rAX); if (u->opr_mode == 16) return gpr_op + UD_R_AX; if (u->dis_mode == 32 || (u->opr_mode == 32 && ! (REX_W(u->pfx_rex) || u->default64))) { return gpr_op + UD_R_EAX; } return gpr_op + UD_R_RAX; }
/* ----------------------------------------------------------------------------- * decode_operands() - Disassembles Operands. * ----------------------------------------------------------------------------- */ static int decode_operand(struct ud *u, struct ud_operand *operand, enum ud_operand_code type, unsigned int size) { switch (type) { case OP_A : decode_a(u, operand); break; case OP_MR: if (MODRM_MOD(modrm(u)) == 3) { decode_modrm_rm(u, operand, T_GPR, size == SZ_DY ? SZ_MDQ : SZ_V); } else if (size == SZ_WV) { decode_modrm_rm( u, operand, T_GPR, SZ_W); } else if (size == SZ_BV) { decode_modrm_rm( u, operand, T_GPR, SZ_B); } else if (size == SZ_DY) { decode_modrm_rm( u, operand, T_GPR, SZ_D); } else { assert(!"unexpected size"); } break; case OP_M: if (MODRM_MOD(modrm(u)) == 3) { u->error = 1; } /* intended fall through */ case OP_E: decode_modrm_rm(u, operand, T_GPR, size); break; break; case OP_G: decode_modrm_reg(u, operand, T_GPR, size); break; case OP_I: decode_imm(u, size, operand); break; case OP_I1: operand->type = UD_OP_CONST; operand->lval.udword = 1; break; case OP_PR: if (MODRM_MOD(modrm(u)) != 3) { u->error = 1; } decode_modrm_rm(u, operand, T_MMX, size); break; case OP_P: decode_modrm_reg(u, operand, T_MMX, size); break; case OP_VR: if (MODRM_MOD(modrm(u)) != 3) { u->error = 1; } /* intended fall through */ case OP_W: decode_modrm_rm(u, operand, T_XMM, size); break; case OP_V: decode_modrm_reg(u, operand, T_XMM, size); break; case OP_S: decode_modrm_reg(u, operand, T_SEG, size); break; case OP_AL: case OP_CL: case OP_DL: case OP_BL: case OP_AH: case OP_CH: case OP_DH: case OP_BH: operand->type = UD_OP_REG; operand->base = UD_R_AL + (type - OP_AL); operand->size = 8; break; case OP_DX: operand->type = UD_OP_REG; operand->base = UD_R_DX; operand->size = 16; break; case OP_O: decode_o(u, size, operand); break; case OP_rAXr8: case OP_rCXr9: case OP_rDXr10: case OP_rBXr11: case OP_rSPr12: case OP_rBPr13: case OP_rSIr14: case OP_rDIr15: case OP_rAX: case OP_rCX: case OP_rDX: case OP_rBX: case OP_rSP: case OP_rBP: case OP_rSI: case OP_rDI: operand->type = UD_OP_REG; operand->base = resolve_gpr64(u, type, &operand->size); break; case OP_ALr8b: case OP_CLr9b: case OP_DLr10b: case OP_BLr11b: case OP_AHr12b: case OP_CHr13b: case OP_DHr14b: case OP_BHr15b: { ud_type_t gpr = (type - OP_ALr8b) + UD_R_AL + (REX_B(u->pfx_rex) << 3); if (UD_R_AH <= gpr && u->pfx_rex) { gpr = gpr + 4; } operand->type = UD_OP_REG; operand->base = gpr; break; } case OP_eAX: case OP_eCX: case OP_eDX: case OP_eBX: case OP_eSP: case OP_eBP: case OP_eSI: case OP_eDI: operand->type = UD_OP_REG; operand->base = resolve_gpr32(u, type); operand->size = u->opr_mode == 16 ? 16 : 32; break; case OP_ES: case OP_CS: case OP_DS: case OP_SS: case OP_FS: case OP_GS: /* in 64bits mode, only fs and gs are allowed */ if (u->dis_mode == 64) { if (type != OP_FS && type != OP_GS) { u->error= 1; } } operand->type = UD_OP_REG; operand->base = (type - OP_ES) + UD_R_ES; operand->size = 16; break; case OP_J : decode_imm(u, size, operand); operand->type = UD_OP_JIMM; break ; case OP_Q: decode_modrm_rm(u, operand, T_MMX, size); break; case OP_R : decode_modrm_rm(u, operand, T_GPR, size); break; case OP_C: decode_modrm_reg(u, operand, T_CRG, size); break; case OP_D: decode_modrm_reg(u, operand, T_DBG, size); break; case OP_I3 : operand->type = UD_OP_CONST; operand->lval.sbyte = 3; break; case OP_ST0: case OP_ST1: case OP_ST2: case OP_ST3: case OP_ST4: case OP_ST5: case OP_ST6: case OP_ST7: operand->type = UD_OP_REG; operand->base = (type - OP_ST0) + UD_R_ST0; operand->size = 0; break; case OP_AX: operand->type = UD_OP_REG; operand->base = UD_R_AX; operand->size = 16; break; default : operand->type = UD_NONE; break; } return 0; }
/* * decode_modrm_rm * * Decodes rm field of mod/rm byte * */ static void decode_modrm_rm(struct ud *u, struct ud_operand *op, unsigned char type, unsigned int size) { unsigned char mod, rm, reg; /* get mod, r/m and reg fields */ mod = MODRM_MOD(modrm(u)); rm = (REX_B(u->pfx_rex) << 3) | MODRM_RM(modrm(u)); reg = (REX_R(u->pfx_rex) << 3) | MODRM_REG(modrm(u)); op->size = resolve_operand_size(u, size); /* * If mod is 11b, then the modrm.rm specifies a register. * */ if (mod == 3) { op->type = UD_OP_REG; if (type == T_GPR) { op->base = decode_gpr(u, op->size, rm); } else { op->base = resolve_reg(u, type, (REX_B(u->pfx_rex) << 3) | (rm & 7)); } return; } /* * !11 => Memory Address */ op->type = UD_OP_MEM; if (u->adr_mode == 64) { op->base = UD_R_RAX + rm; if (mod == 1) { op->offset = 8; } else if (mod == 2) { op->offset = 32; } else if (mod == 0 && (rm & 7) == 5) { op->base = UD_R_RIP; op->offset = 32; } else { op->offset = 0; } /* * Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_RAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_RAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); /* special conditions for base reference */ if (op->index == UD_R_RSP) { op->index = UD_NONE; op->scale = UD_NONE; } if (op->base == UD_R_RBP || op->base == UD_R_R13) { if (mod == 0) { op->base = UD_NONE; } if (mod == 1) { op->offset = 8; } else { op->offset = 32; } } } } else if (u->adr_mode == 32) { op->base = UD_R_EAX + rm; if (mod == 1) { op->offset = 8; } else if (mod == 2) { op->offset = 32; } else if (mod == 0 && rm == 5) { op->base = UD_NONE; op->offset = 32; } else { op->offset = 0; } /* Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_EAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_EAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); if (op->index == UD_R_ESP) { op->index = UD_NONE; op->scale = UD_NONE; } /* special condition for base reference */ if (op->base == UD_R_EBP) { if (mod == 0) { op->base = UD_NONE; } if (mod == 1) { op->offset = 8; } else { op->offset = 32; } } } } else { const unsigned int bases[] = { UD_R_BX, UD_R_BX, UD_R_BP, UD_R_BP, UD_R_SI, UD_R_DI, UD_R_BP, UD_R_BX }; const unsigned int indices[] = { UD_R_SI, UD_R_DI, UD_R_SI, UD_R_DI, UD_NONE, UD_NONE, UD_NONE, UD_NONE }; op->base = bases[rm & 7]; op->index = indices[rm & 7]; if (mod == 0 && rm == 6) { op->offset= 16; op->base = UD_NONE; } else if (mod == 1) { op->offset = 8; } else if (mod == 2) { op->offset = 16; } } /* * extract offset, if any */ switch (op->offset) { case 8 : op->lval.ubyte = inp_uint8(u); break; case 16: op->lval.uword = inp_uint16(u); break; case 32: op->lval.udword = inp_uint32(u); break; case 64: op->lval.uqword = inp_uint64(u); break; default: break; } }
/* ----------------------------------------------------------------------------- * decode_operands() - Disassembles Operands. * ----------------------------------------------------------------------------- */ static int decode_operand(struct ud *u, struct ud_operand *operand, enum ud_operand_code type, unsigned int size) { operand->_oprcode = type; switch (type) { case OP_A : decode_a(u, operand); break; case OP_MR: decode_modrm_rm(u, operand, REGCLASS_GPR, MODRM_MOD(modrm(u)) == 3 ? Mx_reg_size(size) : Mx_mem_size(size)); break; case OP_F: u->br_far = 1; /* intended fall through */ case OP_M: if (MODRM_MOD(modrm(u)) == 3) { UDERR(u, "expected modrm.mod != 3\n"); } /* intended fall through */ case OP_E: decode_modrm_rm(u, operand, REGCLASS_GPR, size); break; case OP_G: decode_modrm_reg(u, operand, REGCLASS_GPR, size); break; case OP_sI: case OP_I: decode_imm(u, size, operand); break; case OP_I1: operand->type = UD_OP_CONST; operand->lval.udword = 1; break; case OP_N: if (MODRM_MOD(modrm(u)) != 3) { UDERR(u, "expected modrm.mod == 3\n"); } /* intended fall through */ case OP_Q: decode_modrm_rm(u, operand, REGCLASS_MMX, size); break; case OP_P: decode_modrm_reg(u, operand, REGCLASS_MMX, size); break; case OP_U: if (MODRM_MOD(modrm(u)) != 3) { UDERR(u, "expected modrm.mod == 3\n"); } /* intended fall through */ case OP_W: decode_modrm_rm(u, operand, REGCLASS_XMM, size); break; case OP_V: decode_modrm_reg(u, operand, REGCLASS_XMM, size); break; case OP_MU: decode_modrm_rm(u, operand, REGCLASS_XMM, MODRM_MOD(modrm(u)) == 3 ? Mx_reg_size(size) : Mx_mem_size(size)); break; case OP_S: decode_modrm_reg(u, operand, REGCLASS_SEG, size); break; case OP_O: decode_moffset(u, size, operand); break; case OP_R0: case OP_R1: case OP_R2: case OP_R3: case OP_R4: case OP_R5: case OP_R6: case OP_R7: decode_reg(u, operand, REGCLASS_GPR, (REX_B(u->pfx_rex) << 3) | (type - OP_R0), size); break; case OP_AL: case OP_AX: case OP_eAX: case OP_rAX: decode_reg(u, operand, REGCLASS_GPR, 0, size); break; case OP_CL: case OP_CX: case OP_eCX: decode_reg(u, operand, REGCLASS_GPR, 1, size); break; case OP_DL: case OP_DX: case OP_eDX: decode_reg(u, operand, REGCLASS_GPR, 2, size); break; case OP_ES: case OP_CS: case OP_DS: case OP_SS: case OP_FS: case OP_GS: /* in 64bits mode, only fs and gs are allowed */ if (u->dis_mode == 64) { if (type != OP_FS && type != OP_GS) { UDERR(u, "invalid segment register in 64bits\n"); } } operand->type = UD_OP_REG; operand->base = (type - OP_ES) + UD_R_ES; operand->size = 16; break; case OP_J : decode_imm(u, size, operand); operand->type = UD_OP_JIMM; break ; case OP_R : if (MODRM_MOD(modrm(u)) != 3) { UDERR(u, "expected modrm.mod == 3\n"); } decode_modrm_rm(u, operand, REGCLASS_GPR, size); break; case OP_C: decode_modrm_reg(u, operand, REGCLASS_CR, size); break; case OP_D: decode_modrm_reg(u, operand, REGCLASS_DB, size); break; case OP_I3 : operand->type = UD_OP_CONST; operand->lval.sbyte = 3; break; case OP_ST0: case OP_ST1: case OP_ST2: case OP_ST3: case OP_ST4: case OP_ST5: case OP_ST6: case OP_ST7: operand->type = UD_OP_REG; operand->base = (type - OP_ST0) + UD_R_ST0; operand->size = 80; break; default : break; } return 0; }
/* * decode_modrm_rm * * Decodes rm field of mod/rm byte * */ static void decode_modrm_rm(struct ud *u, struct ud_operand *op, unsigned char type, /* register type */ unsigned int size) /* operand size */ { size_t offset = 0; unsigned char mod, rm; /* get mod, r/m and reg fields */ mod = MODRM_MOD(modrm(u)); rm = (REX_B(u->pfx_rex) << 3) | MODRM_RM(modrm(u)); /* * If mod is 11b, then the modrm.rm specifies a register. * */ if (mod == 3) { decode_reg(u, op, type, rm, size); return; } /* * !11b => Memory Address */ op->type = UD_OP_MEM; op->size = resolve_operand_size(u, size); if (u->adr_mode == 64) { op->base = UD_R_RAX + rm; if (mod == 1) { offset = 8; } else if (mod == 2) { offset = 32; } else if (mod == 0 && (rm & 7) == 5) { op->base = UD_R_RIP; offset = 32; } else { offset = 0; } /* * Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_RAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_RAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); /* special conditions for base reference */ if (op->index == UD_R_RSP) { op->index = UD_NONE; op->scale = UD_NONE; } if (op->base == UD_R_RBP || op->base == UD_R_R13) { if (mod == 0) { op->base = UD_NONE; } if (mod == 1) { offset = 8; } else { offset = 32; } } } } else if (u->adr_mode == 32) { op->base = UD_R_EAX + rm; if (mod == 1) { offset = 8; } else if (mod == 2) { offset = 32; } else if (mod == 0 && rm == 5) { op->base = UD_NONE; offset = 32; } else { offset = 0; } /* Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_EAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_EAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); if (op->index == UD_R_ESP) { op->index = UD_NONE; op->scale = UD_NONE; } /* special condition for base reference */ if (op->base == UD_R_EBP) { if (mod == 0) { op->base = UD_NONE; } if (mod == 1) { offset = 8; } else { offset = 32; } } } } else { const unsigned int bases[] = { UD_R_BX, UD_R_BX, UD_R_BP, UD_R_BP, UD_R_SI, UD_R_DI, UD_R_BP, UD_R_BX }; const unsigned int indices[] = { UD_R_SI, UD_R_DI, UD_R_SI, UD_R_DI, UD_NONE, UD_NONE, UD_NONE, UD_NONE }; op->base = bases[rm & 7]; op->index = indices[rm & 7]; if (mod == 0 && rm == 6) { offset = 16; op->base = UD_NONE; } else if (mod == 1) { offset = 8; } else if (mod == 2) { offset = 16; } } if (offset) { decode_mem_disp(u, offset, op); } }
/* ----------------------------------------------------------------------------- * disasm_operands() - Disassembles Operands. * ----------------------------------------------------------------------------- */ static int disasm_operands(register struct ud* u) { /* mopXt = map entry, operand X, type; */ enum ud_operand_code mop1t = u->itab_entry->operand1.type; enum ud_operand_code mop2t = u->itab_entry->operand2.type; enum ud_operand_code mop3t = u->itab_entry->operand3.type; /* mopXs = map entry, operand X, size */ unsigned int mop1s = u->itab_entry->operand1.size; unsigned int mop2s = u->itab_entry->operand2.size; unsigned int mop3s = u->itab_entry->operand3.size; /* iop = instruction operand */ register struct ud_operand* iop = u->operand; switch(mop1t) { case OP_A : decode_a(u, &(iop[0])); break; /* M[b] ... */ case OP_M : if (MODRM_MOD(inp_peek(u)) == 3) u->error= 1; /* E, G/P/V/I/CL/1/S */ case OP_E : if (mop2t == OP_G) { decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_GPR); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); else if (mop3t == OP_CL) { iop[2].type = UD_OP_REG; iop[2].base = UD_R_CL; iop[2].size = 8; } } else if (mop2t == OP_P) decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_MMX); else if (mop2t == OP_V) decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_XMM); else if (mop2t == OP_S) decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_SEG); else { decode_modrm(u, &(iop[0]), mop1s, T_GPR, NULL, 0, T_NONE); if (mop2t == OP_CL) { iop[1].type = UD_OP_REG; iop[1].base = UD_R_CL; iop[1].size = 8; } else if (mop2t == OP_I1) { iop[1].type = UD_OP_CONST; u->operand[1].lval.udword = 1; } else if (mop2t == OP_I) { decode_imm(u, mop2s, &(iop[1])); } } break; /* G, E/PR[,I]/VR */ case OP_G : if (mop2t == OP_M) { if (MODRM_MOD(inp_peek(u)) == 3) u->error= 1; decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_GPR); } else if (mop2t == OP_E) { decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_GPR); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); } else if (mop2t == OP_PR) { decode_modrm(u, &(iop[1]), mop2s, T_MMX, &(iop[0]), mop1s, T_GPR); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); } else if (mop2t == OP_VR) { if (MODRM_MOD(inp_peek(u)) != 3) u->error = 1; decode_modrm(u, &(iop[1]), mop2s, T_XMM, &(iop[0]), mop1s, T_GPR); } else if (mop2t == OP_W) decode_modrm(u, &(iop[1]), mop2s, T_XMM, &(iop[0]), mop1s, T_GPR); break; /* AL..BH, I/O/DX */ case OP_AL : case OP_CL : case OP_DL : case OP_BL : case OP_AH : case OP_CH : case OP_DH : case OP_BH : iop[0].type = UD_OP_REG; iop[0].base = UD_R_AL + (mop1t - OP_AL); iop[0].size = 8; if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); else if (mop2t == OP_DX) { iop[1].type = UD_OP_REG; iop[1].base = UD_R_DX; iop[1].size = 16; } else if (mop2t == OP_O) decode_o(u, mop2s, &(iop[1])); break; /* rAX[r8]..rDI[r15], I/rAX..rDI/O */ case OP_rAXr8 : case OP_rCXr9 : case OP_rDXr10 : case OP_rBXr11 : case OP_rSPr12: case OP_rBPr13: case OP_rSIr14 : case OP_rDIr15 : case OP_rAX : case OP_rCX : case OP_rDX : case OP_rBX : case OP_rSP : case OP_rBP : case OP_rSI : case OP_rDI : iop[0].type = UD_OP_REG; iop[0].base = resolve_gpr64(u, mop1t); if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); else if (mop2t >= OP_rAX && mop2t <= OP_rDI) { iop[1].type = UD_OP_REG; iop[1].base = resolve_gpr64(u, mop2t); } else if (mop2t == OP_O) { decode_o(u, mop2s, &(iop[1])); iop[0].size = (uint8_t)resolve_operand_size(u, mop2s); } break; /* AL[r8b]..BH[r15b], I */ case OP_ALr8b : case OP_CLr9b : case OP_DLr10b : case OP_BLr11b : case OP_AHr12b: case OP_CHr13b: case OP_DHr14b : case OP_BHr15b : { ud_type_t gpr = (mop1t - OP_ALr8b) + UD_R_AL + (REX_B(u->pfx_rex) << 3); if (UD_R_AH <= gpr && u->pfx_rex) gpr = gpr + 4; iop[0].type = UD_OP_REG; iop[0].base = gpr; if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); break; } /* eAX..eDX, DX/I */ case OP_eAX : case OP_eCX : case OP_eDX : case OP_eBX : case OP_eSP : case OP_eBP : case OP_eSI : case OP_eDI : iop[0].type = UD_OP_REG; iop[0].base = resolve_gpr32(u, mop1t); if (mop2t == OP_DX) { iop[1].type = UD_OP_REG; iop[1].base = UD_R_DX; iop[1].size = 16; } else if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); break; /* ES..GS */ case OP_ES : case OP_CS : case OP_DS : case OP_SS : case OP_FS : case OP_GS : /* in 64bits mode, only fs and gs are allowed */ if (u->dis_mode == 64) if (mop1t != OP_FS && mop1t != OP_GS) u->error= 1; iop[0].type = UD_OP_REG; iop[0].base = (mop1t - OP_ES) + UD_R_ES; iop[0].size = 16; break; /* J */ case OP_J : decode_imm(u, mop1s, &(iop[0])); iop[0].type = UD_OP_JIMM; break ; /* PR, I */ case OP_PR: if (MODRM_MOD(inp_peek(u)) != 3) u->error = 1; decode_modrm(u, &(iop[0]), mop1s, T_MMX, NULL, 0, T_NONE); if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); break; /* VR, I */ case OP_VR: if (MODRM_MOD(inp_peek(u)) != 3) u->error = 1; decode_modrm(u, &(iop[0]), mop1s, T_XMM, NULL, 0, T_NONE); if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); break; /* P, Q[,I]/W/E[,I],VR */ case OP_P : if (mop2t == OP_Q) { decode_modrm(u, &(iop[1]), mop2s, T_MMX, &(iop[0]), mop1s, T_MMX); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); } else if (mop2t == OP_W) { decode_modrm(u, &(iop[1]), mop2s, T_XMM, &(iop[0]), mop1s, T_MMX); } else if (mop2t == OP_VR) { if (MODRM_MOD(inp_peek(u)) != 3) u->error = 1; decode_modrm(u, &(iop[1]), mop2s, T_XMM, &(iop[0]), mop1s, T_MMX); } else if (mop2t == OP_E) { decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_MMX); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); } break; /* R, C/D */ case OP_R : if (mop2t == OP_C) decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_CRG); else if (mop2t == OP_D) decode_modrm(u, &(iop[0]), mop1s, T_GPR, &(iop[1]), mop2s, T_DBG); break; /* C, R */ case OP_C : decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_CRG); break; /* D, R */ case OP_D : decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_DBG); break; /* Q, P */ case OP_Q : decode_modrm(u, &(iop[0]), mop1s, T_MMX, &(iop[1]), mop2s, T_MMX); break; /* S, E */ case OP_S : decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_SEG); break; /* W, V */ case OP_W : decode_modrm(u, &(iop[0]), mop1s, T_XMM, &(iop[1]), mop2s, T_XMM); break; /* V, W[,I]/Q/M/E */ case OP_V : if (mop2t == OP_W) { /* special cases for movlps and movhps */ if (MODRM_MOD(inp_peek(u)) == 3) { if (u->mnemonic == UD_Imovlps) u->mnemonic = UD_Imovhlps; else if (u->mnemonic == UD_Imovhps) u->mnemonic = UD_Imovlhps; } decode_modrm(u, &(iop[1]), mop2s, T_XMM, &(iop[0]), mop1s, T_XMM); if (mop3t == OP_I) decode_imm(u, mop3s, &(iop[2])); } else if (mop2t == OP_Q) decode_modrm(u, &(iop[1]), mop2s, T_MMX, &(iop[0]), mop1s, T_XMM); else if (mop2t == OP_M) { if (MODRM_MOD(inp_peek(u)) == 3) u->error= 1; decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_XMM); } else if (mop2t == OP_E) { decode_modrm(u, &(iop[1]), mop2s, T_GPR, &(iop[0]), mop1s, T_XMM); } else if (mop2t == OP_PR) { decode_modrm(u, &(iop[1]), mop2s, T_MMX, &(iop[0]), mop1s, T_XMM); } break; /* DX, eAX/AL */ case OP_DX : iop[0].type = UD_OP_REG; iop[0].base = UD_R_DX; iop[0].size = 16; if (mop2t == OP_eAX) { iop[1].type = UD_OP_REG; iop[1].base = resolve_gpr32(u, mop2t); } else if (mop2t == OP_AL) { iop[1].type = UD_OP_REG; iop[1].base = UD_R_AL; iop[1].size = 8; } break; /* I, I/AL/eAX */ case OP_I : decode_imm(u, mop1s, &(iop[0])); if (mop2t == OP_I) decode_imm(u, mop2s, &(iop[1])); else if (mop2t == OP_AL) { iop[1].type = UD_OP_REG; iop[1].base = UD_R_AL; iop[1].size = 16; } else if (mop2t == OP_eAX) { iop[1].type = UD_OP_REG; iop[1].base = resolve_gpr32(u, mop2t); } break; /* O, AL/eAX */ case OP_O : decode_o(u, mop1s, &(iop[0])); iop[1].type = UD_OP_REG; iop[1].size = (uint8_t)resolve_operand_size(u, mop1s); if (mop2t == OP_AL) iop[1].base = UD_R_AL; else if (mop2t == OP_eAX) iop[1].base = resolve_gpr32(u, mop2t); else if (mop2t == OP_rAX) iop[1].base = resolve_gpr64(u, mop2t); break; /* 3 */ case OP_I3 : iop[0].type = UD_OP_CONST; iop[0].lval.sbyte = 3; break; /* ST(n), ST(n) */ case OP_ST0 : case OP_ST1 : case OP_ST2 : case OP_ST3 : case OP_ST4 : case OP_ST5 : case OP_ST6 : case OP_ST7 : iop[0].type = UD_OP_REG; iop[0].base = (mop1t-OP_ST0) + UD_R_ST0; iop[0].size = 0; if (mop2t >= OP_ST0 && mop2t <= OP_ST7) { iop[1].type = UD_OP_REG; iop[1].base = (mop2t-OP_ST0) + UD_R_ST0; iop[1].size = 0; } break; /* AX */ case OP_AX: iop[0].type = UD_OP_REG; iop[0].base = UD_R_AX; iop[0].size = 16; break; /* none */ default : iop[0].type = iop[1].type = iop[2].type = UD_NONE; } return 0; }
/* ----------------------------------------------------------------------------- * decode_modrm() - Decodes ModRM Byte * ----------------------------------------------------------------------------- */ static void decode_modrm(struct ud* u, struct ud_operand *op, unsigned int s, unsigned char rm_type, struct ud_operand *opreg, unsigned int reg_size, unsigned char reg_type) { unsigned char mod, rm, reg; inp_next(u); /* get mod, r/m and reg fields */ mod = MODRM_MOD(inp_curr(u)); rm = (REX_B(u->pfx_rex) << 3) | MODRM_RM(inp_curr(u)); reg = (REX_R(u->pfx_rex) << 3) | MODRM_REG(inp_curr(u)); op->size = (uint8_t) resolve_operand_size(u, s); /* if mod is 11b, then the UD_R_m specifies a gpr/mmx/sse/control/debug */ if (mod == 3) { op->type = UD_OP_REG; if (rm_type == T_GPR) op->base = decode_gpr(u, op->size, rm); else op->base = resolve_reg(u, rm_type, (REX_B(u->pfx_rex) << 3) | (rm&7)); } /* else its memory addressing */ else { op->type = UD_OP_MEM; /* 64bit addressing */ if (u->adr_mode == 64) { op->base = UD_R_RAX + rm; /* get offset type */ if (mod == 1) op->offset = 8; else if (mod == 2) op->offset = 32; else if (mod == 0 && (rm & 7) == 5) { op->base = UD_R_RIP; op->offset = 32; } else op->offset = 0; /* Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_RAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_RAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); /* special conditions for base reference */ if (op->index == UD_R_RSP) { op->index = UD_NONE; op->scale = UD_NONE; } if (op->base == UD_R_RBP || op->base == UD_R_R13) { if (mod == 0) op->base = UD_NONE; if (mod == 1) op->offset = 8; else op->offset = 32; } } } /* 32-Bit addressing mode */ else if (u->adr_mode == 32) { /* get base */ op->base = UD_R_EAX + rm; /* get offset type */ if (mod == 1) op->offset = 8; else if (mod == 2) op->offset = 32; else if (mod == 0 && rm == 5) { op->base = UD_NONE; op->offset = 32; } else op->offset = 0; /* Scale-Index-Base (SIB) */ if ((rm & 7) == 4) { inp_next(u); op->scale = (1 << SIB_S(inp_curr(u))) & ~1; op->index = UD_R_EAX + (SIB_I(inp_curr(u)) | (REX_X(u->pfx_rex) << 3)); op->base = UD_R_EAX + (SIB_B(inp_curr(u)) | (REX_B(u->pfx_rex) << 3)); if (op->index == UD_R_ESP) { op->index = UD_NONE; op->scale = UD_NONE; } /* special condition for base reference */ if (op->base == UD_R_EBP) { if (mod == 0) op->base = UD_NONE; if (mod == 1) op->offset = 8; else op->offset = 32; } } } /* 16bit addressing mode */ else { switch (rm) { case 0: op->base = UD_R_BX; op->index = UD_R_SI; break; case 1: op->base = UD_R_BX; op->index = UD_R_DI; break; case 2: op->base = UD_R_BP; op->index = UD_R_SI; break; case 3: op->base = UD_R_BP; op->index = UD_R_DI; break; case 4: op->base = UD_R_SI; break; case 5: op->base = UD_R_DI; break; case 6: op->base = UD_R_BP; break; case 7: op->base = UD_R_BX; break; } if (mod == 0 && rm == 6) { op->offset= 16; op->base = UD_NONE; } else if (mod == 1) op->offset = 8; else if (mod == 2) op->offset = 16; } } /* extract offset, if any */ switch(op->offset) { case 8 : op->lval.ubyte = inp_uint8(u); break; case 16: op->lval.uword = inp_uint16(u); break; case 32: op->lval.udword = inp_uint32(u); break; default: break; } /* resolve register encoded in reg field */ if (opreg) { opreg->type = UD_OP_REG; opreg->size = (uint8_t)resolve_operand_size(u, reg_size); if (reg_type == T_GPR) opreg->base = decode_gpr(u, opreg->size, reg); else opreg->base = resolve_reg(u, reg_type, reg); } }
/* Searches the instruction tables for the right entry. */ static int search_itab( struct ud * u ) { struct ud_itab_entry * e = NULL; enum ud_itab_index table; uint8_t peek; uint8_t did_peek = 0; uint8_t curr; uint8_t index; /* if in state of error, return */ if ( u->error ) return -1; /* get first byte of opcode. */ inp_next(u); if ( u->error ) return -1; curr = inp_curr(u); /* resolve xchg, nop, pause crazyness */ if ( 0x90 == curr ) { if ( !( u->dis_mode == 64 && REX_B( u->pfx_rex ) ) ) { if ( u->pfx_rep ) { u->pfx_rep = 0; e = & ie_pause; } else { e = & ie_nop; } goto found_entry; } } /* get top-level table */ if ( 0x0F == curr ) { table = ITAB__0F; curr = inp_next(u); if ( u->error ) return -1; /* 2byte opcodes can be modified by 0x66, F3, and F2 prefixes */ if ( 0x66 == u->pfx_insn ) { if ( ud_itab_list[ ITAB__PFX_SSE66__0F ][ curr ].mnemonic != UD_Iinvalid ) { table = ITAB__PFX_SSE66__0F; u->pfx_opr = 0; } } else if ( 0xF2 == u->pfx_insn ) { if ( ud_itab_list[ ITAB__PFX_SSEF2__0F ][ curr ].mnemonic != UD_Iinvalid ) { table = ITAB__PFX_SSEF2__0F; u->pfx_repne = 0; } } else if ( 0xF3 == u->pfx_insn ) { if ( ud_itab_list[ ITAB__PFX_SSEF3__0F ][ curr ].mnemonic != UD_Iinvalid ) { table = ITAB__PFX_SSEF3__0F; u->pfx_repe = 0; u->pfx_rep = 0; } } /* pick an instruction from the 1byte table */ } else { table = ITAB__1BYTE; } index = curr; search: e = & ud_itab_list[ table ][ index ]; /* if mnemonic constant is a standard instruction constant * our search is over. */ if ( e->mnemonic < UD_Id3vil ) { if ( e->mnemonic == UD_Iinvalid ) { if ( did_peek ) { inp_next( u ); if ( u->error ) return -1; } goto found_entry; } goto found_entry; } table = e->prefix; switch ( e->mnemonic ) { case UD_Igrp_reg: peek = inp_peek( u ); did_peek = 1; index = MODRM_REG( peek ); break; case UD_Igrp_mod: peek = inp_peek( u ); did_peek = 1; index = MODRM_MOD( peek ); if ( index == 3 ) index = ITAB__MOD_INDX__11; else index = ITAB__MOD_INDX__NOT_11; break; case UD_Igrp_rm: curr = inp_next( u ); did_peek = 0; if ( u->error ) return -1; index = MODRM_RM( curr ); break; case UD_Igrp_x87: curr = inp_next( u ); did_peek = 0; if ( u->error ) return -1; index = curr - 0xC0; break; case UD_Igrp_osize: if ( u->opr_mode == 64 ) index = ITAB__MODE_INDX__64; else if ( u->opr_mode == 32 ) index = ITAB__MODE_INDX__32; else index = ITAB__MODE_INDX__16; break; case UD_Igrp_asize: if ( u->adr_mode == 64 ) index = ITAB__MODE_INDX__64; else if ( u->adr_mode == 32 ) index = ITAB__MODE_INDX__32; else index = ITAB__MODE_INDX__16; break; case UD_Igrp_mode: if ( u->dis_mode == 64 ) index = ITAB__MODE_INDX__64; else if ( u->dis_mode == 32 ) index = ITAB__MODE_INDX__32; else index = ITAB__MODE_INDX__16; break; case UD_Igrp_vendor: if ( u->vendor == UD_VENDOR_INTEL ) index = ITAB__VENDOR_INDX__INTEL; else if ( u->vendor == UD_VENDOR_AMD ) index = ITAB__VENDOR_INDX__AMD; /* else */ /* assert( !"unrecognized vendor id" ); */ break; case UD_Id3vil: /* assert( !"invalid instruction mnemonic constant Id3vil" ); */ break; default: /* assert( !"invalid instruction mnemonic constant" ); */ break; } goto search; found_entry: u->itab_entry = e; u->mnemonic = u->itab_entry->mnemonic; return 0; }