/* assemble.c code generation for the Netwide Assembler * * The Netwide Assembler is copyright (C) 1996 Simon Tatham and * Julian Hall. All rights reserved. The software is * redistributable under the licence given in the file "Licence" * distributed in the NASM archive. * * the actual codes (C syntax, i.e. octal): * \0 - terminates the code. (Unless it's a literal of course.) * \1, \2, \3 - that many literal bytes follow in the code stream * \4, \6 - the POP/PUSH (respectively) codes for CS, DS, ES, SS * (POP is never used for CS) depending on operand 0 * \5, \7 - the second byte of POP/PUSH codes for FS, GS, depending * on operand 0 * \10..\13 - a literal byte follows in the code stream, to be added * to the register value of operand 0..3 * \14..\17 - a signed byte immediate operand, from operand 0..3 * \20..\23 - a byte immediate operand, from operand 0..3 * \24..\27 - an unsigned byte immediate operand, from operand 0..3 * \30..\33 - a word immediate operand, from operand 0..3 * \34..\37 - select between \3[0-3] and \4[0-3] depending on 16/32 bit * assembly mode or the operand-size override on the operand * \40..\43 - a long immediate operand, from operand 0..3 * \44..\47 - select between \3[0-3], \4[0-3] and \5[4-7] * depending on assembly mode or the address-size override * on the operand. * \50..\53 - a byte relative operand, from operand 0..3 * \54..\57 - a qword immediate operand, from operand 0..3 * \60..\63 - a word relative operand, from operand 0..3 * \64..\67 - select between \6[0-3] and \7[0-3] depending on 16/32 bit * assembly mode or the operand-size override on the operand * \70..\73 - a long relative operand, from operand 0..3 * \74..\77 - a word constant, from the _segment_ part of operand 0..3 * \1ab - a ModRM, calculated on EA in operand a, with the spare * field the register value of operand b. * \140..\143 - an immediate word or signed byte for operand 0..3 * \144..\147 - or 2 (s-field) into next opcode byte if operand 0..3 * is a signed byte rather than a word. * \150..\153 - an immediate dword or signed byte for operand 0..3 * \154..\157 - or 2 (s-field) into next opcode byte if operand 0..3 * is a signed byte rather than a dword. * \160..\163 - this instruction uses DREX rather than REX, with the * OC0 field set to 0, and the dest field taken from * operand 0..3. * \164..\167 - this instruction uses DREX rather than REX, with the * OC0 field set to 1, and the dest field taken from * operand 0..3. * \170 - encodes the literal byte 0. (Some compilers don't take * kindly to a zero byte in the _middle_ of a compile time * string constant, so I had to put this hack in.) * \171 - placement of DREX suffix in the absence of an EA * \2ab - a ModRM, calculated on EA in operand a, with the spare * field equal to digit b. * \310 - indicates fixed 16-bit address size, i.e. optional 0x67. * \311 - indicates fixed 32-bit address size, i.e. optional 0x67. * \312 - (disassembler only) marker on LOOP, LOOPxx instructions. * \313 - indicates fixed 64-bit address size, 0x67 invalid. * \320 - indicates fixed 16-bit operand size, i.e. optional 0x66. * \321 - indicates fixed 32-bit operand size, i.e. optional 0x66. * \322 - indicates that this instruction is only valid when the * operand size is the default (instruction to disassembler, * generates no code in the assembler) * \323 - indicates fixed 64-bit operand size, REX on extensions only. * \324 - indicates 64-bit operand size requiring REX prefix. * \330 - a literal byte follows in the code stream, to be added * to the condition code value of the instruction. * \331 - instruction not valid with REP prefix. Hint for * disassembler only; for SSE instructions. * \332 - REP prefix (0xF2 byte) used as opcode extension. * \333 - REP prefix (0xF3 byte) used as opcode extension. * \334 - LOCK prefix used instead of REX.R * \335 - disassemble a rep (0xF3 byte) prefix as repe not rep. * \340 - reserve bytes of uninitialized storage. * Operand 0 had better be a segmentless constant. * \364 - operand-size prefix (0x66) not permitted * \365 - address-size prefix (0x67) not permitted * \366 - operand-size prefix (0x66) used as opcode extension * \367 - address-size prefix (0x67) used as opcode extension * \370,\371,\372 - match only if operand 0 meets byte jump criteria. * 370 is used for Jcc, 371 is used for JMP. * \373 - assemble 0x03 if bits==16, 0x05 if bits==32; * used for conditional jump over longer jump */ #include "compiler.h" #include #include #include #include "nasm.h" #include "nasmlib.h" #include "assemble.h" #include "insns.h" #include "preproc.h" #include "regflags.c" #include "regvals.c" typedef struct { int sib_present; /* is a SIB byte necessary? */ int bytes; /* # of bytes of offset needed */ int size; /* lazy - this is sib+bytes+1 */ uint8_t modrm, sib, rex, rip; /* the bytes themselves */ } ea; static uint32_t cpu; /* cpu level received from nasm.c */ static efunc errfunc; static struct ofmt *outfmt; static ListGen *list; static int32_t calcsize(int32_t, int32_t, int, insn *, const char *); static void gencode(int32_t, int32_t, int, insn *, const char *, int32_t); static int matches(const struct itemplate *, insn *, int bits); static int32_t regflag(const operand *); static int32_t regval(const operand *); static int rexflags(int, int32_t, int); static int op_rexflags(const operand *, int); static ea *process_ea(operand *, ea *, int, int, int32_t, int); static void add_asp(insn *, int); static int has_prefix(insn * ins, enum prefixes prefix) { int j; for (j = 0; j < ins->nprefix; j++) { if (ins->prefixes[j] == prefix) return 1; } return 0; } static void assert_no_prefix(insn * ins, enum prefixes prefix) { if (has_prefix(ins, prefix)) errfunc(ERR_NONFATAL, "invalid %s prefix", prefix_name(prefix)); } /* * This routine wrappers the real output format's output routine, * in order to pass a copy of the data off to the listing file * generator at the same time. */ static void out(int32_t offset, int32_t segto, const void *data, uint32_t type, int32_t segment, int32_t wrt) { static int32_t lineno = 0; /* static!!! */ static char *lnfname = NULL; if ((type & OUT_TYPMASK) == OUT_ADDRESS) { if (segment != NO_SEG || wrt != NO_SEG) { /* * This address is relocated. We must write it as * OUT_ADDRESS, so there's no work to be done here. */ list->output(offset, data, type); } else { uint8_t p[8], *q = p; /* * This is a non-relocated address, and we're going to * convert it into RAWDATA format. */ if ((type & OUT_SIZMASK) == 4) { WRITELONG(q, *(int32_t *)data); list->output(offset, p, OUT_RAWDATA + 4); } else if ((type & OUT_SIZMASK) == 8) { WRITEDLONG(q, *(int64_t *)data); list->output(offset, p, OUT_RAWDATA + 8); } else { WRITESHORT(q, *(int32_t *)data); list->output(offset, p, OUT_RAWDATA + 2); } } } else if ((type & OUT_TYPMASK) == OUT_RAWDATA) { list->output(offset, data, type); } else if ((type & OUT_TYPMASK) == OUT_RESERVE) { list->output(offset, NULL, type); } else if ((type & OUT_TYPMASK) == OUT_REL2ADR || (type & OUT_TYPMASK) == OUT_REL4ADR) { list->output(offset, data, type); } /* * this call to src_get determines when we call the * debug-format-specific "linenum" function * it updates lineno and lnfname to the current values * returning 0 if "same as last time", -2 if lnfname * changed, and the amount by which lineno changed, * if it did. thus, these variables must be static */ if (src_get(&lineno, &lnfname)) { outfmt->current_dfmt->linenum(lnfname, lineno, segto); } outfmt->output(segto, data, type, segment, wrt); } static int jmp_match(int32_t segment, int32_t offset, int bits, insn * ins, const char *code) { int32_t isize; uint8_t c = code[0]; if (c != 0370 && c != 0371) return 0; if (ins->oprs[0].opflags & OPFLAG_FORWARD) { if ((optimizing < 0 || (ins->oprs[0].type & STRICT)) && c == 0370) return 1; else return (pass0 == 0); /* match a forward reference */ } isize = calcsize(segment, offset, bits, ins, code); if (ins->oprs[0].segment != segment) return 0; isize = ins->oprs[0].offset - offset - isize; /* isize is now the delta */ if (isize >= -128L && isize <= 127L) return 1; /* it is byte size */ return 0; } int32_t assemble(int32_t segment, int32_t offset, int bits, uint32_t cp, insn * instruction, struct ofmt *output, efunc error, ListGen * listgen) { const struct itemplate *temp; int j; int size_prob; int32_t insn_end; int32_t itimes; int32_t start = offset; int32_t wsize = 0; /* size for DB etc. */ errfunc = error; /* to pass to other functions */ cpu = cp; outfmt = output; /* likewise */ list = listgen; /* and again */ switch (instruction->opcode) { case -1: return 0; case I_DB: wsize = 1; break; case I_DW: wsize = 2; break; case I_DD: wsize = 4; break; case I_DQ: wsize = 8; break; case I_DT: wsize = 10; break; case I_DO: wsize = 16; break; default: break; } if (wsize) { extop *e; int32_t t = instruction->times; if (t < 0) errfunc(ERR_PANIC, "instruction->times < 0 (%ld) in assemble()", t); while (t--) { /* repeat TIMES times */ for (e = instruction->eops; e; e = e->next) { if (e->type == EOT_DB_NUMBER) { if (wsize == 1) { if (e->segment != NO_SEG) errfunc(ERR_NONFATAL, "one-byte relocation attempted"); else { uint8_t out_byte = e->offset; out(offset, segment, &out_byte, OUT_RAWDATA + 1, NO_SEG, NO_SEG); } } else if (wsize > 8) { errfunc(ERR_NONFATAL, "integer supplied to a DT or DO" " instruction"); } else out(offset, segment, &e->offset, OUT_ADDRESS + wsize, e->segment, e->wrt); offset += wsize; } else if (e->type == EOT_DB_STRING) { int align; out(offset, segment, e->stringval, OUT_RAWDATA + e->stringlen, NO_SEG, NO_SEG); align = e->stringlen % wsize; if (align) { align = wsize - align; out(offset, segment, "\0\0\0\0\0\0\0\0", OUT_RAWDATA + align, NO_SEG, NO_SEG); } offset += e->stringlen + align; } } if (t > 0 && t == instruction->times - 1) { /* * Dummy call to list->output to give the offset to the * listing module. */ list->output(offset, NULL, OUT_RAWDATA); list->uplevel(LIST_TIMES); } } if (instruction->times > 1) list->downlevel(LIST_TIMES); return offset - start; } if (instruction->opcode == I_INCBIN) { static char fname[FILENAME_MAX]; FILE *fp; int32_t len; char *prefix = "", *combine; char **pPrevPath = NULL; len = FILENAME_MAX - 1; if (len > instruction->eops->stringlen) len = instruction->eops->stringlen; strncpy(fname, instruction->eops->stringval, len); fname[len] = '\0'; while (1) { /* added by alexfru: 'incbin' uses include paths */ combine = nasm_malloc(strlen(prefix) + len + 1); strcpy(combine, prefix); strcat(combine, fname); if ((fp = fopen(combine, "rb")) != NULL) { nasm_free(combine); break; } nasm_free(combine); pPrevPath = pp_get_include_path_ptr(pPrevPath); if (pPrevPath == NULL) break; prefix = *pPrevPath; } if (fp == NULL) error(ERR_NONFATAL, "`incbin': unable to open file `%s'", fname); else if (fseek(fp, 0L, SEEK_END) < 0) error(ERR_NONFATAL, "`incbin': unable to seek on file `%s'", fname); else { static char buf[2048]; int32_t t = instruction->times; int32_t base = 0; len = ftell(fp); if (instruction->eops->next) { base = instruction->eops->next->offset; len -= base; if (instruction->eops->next->next && len > instruction->eops->next->next->offset) len = instruction->eops->next->next->offset; } /* * Dummy call to list->output to give the offset to the * listing module. */ list->output(offset, NULL, OUT_RAWDATA); list->uplevel(LIST_INCBIN); while (t--) { int32_t l; fseek(fp, base, SEEK_SET); l = len; while (l > 0) { int32_t m = fread(buf, 1, (l > (int32_t) sizeof(buf) ? (int32_t) sizeof(buf) : l), fp); if (!m) { /* * This shouldn't happen unless the file * actually changes while we are reading * it. */ error(ERR_NONFATAL, "`incbin': unexpected EOF while" " reading file `%s'", fname); t = 0; /* Try to exit cleanly */ break; } out(offset, segment, buf, OUT_RAWDATA + m, NO_SEG, NO_SEG); l -= m; } } list->downlevel(LIST_INCBIN); if (instruction->times > 1) { /* * Dummy call to list->output to give the offset to the * listing module. */ list->output(offset, NULL, OUT_RAWDATA); list->uplevel(LIST_TIMES); list->downlevel(LIST_TIMES); } fclose(fp); return instruction->times * len; } return 0; /* if we're here, there's an error */ } /* Check to see if we need an address-size prefix */ add_asp(instruction, bits); size_prob = false; for (temp = nasm_instructions[instruction->opcode]; temp->opcode != -1; temp++){ int m = matches(temp, instruction, bits); if (m == 99) m += jmp_match(segment, offset, bits, instruction, temp->code); if (m == 100) { /* matches! */ const char *codes = temp->code; int32_t insn_size = calcsize(segment, offset, bits, instruction, codes); itimes = instruction->times; if (insn_size < 0) /* shouldn't be, on pass two */ error(ERR_PANIC, "errors made it through from pass one"); else while (itimes--) { for (j = 0; j < instruction->nprefix; j++) { uint8_t c = 0; switch (instruction->prefixes[j]) { case P_LOCK: c = 0xF0; break; case P_REPNE: case P_REPNZ: c = 0xF2; break; case P_REPE: case P_REPZ: case P_REP: c = 0xF3; break; case R_CS: if (bits == 64) { error(ERR_WARNING, "cs segment base ignored in 64-bit mode"); } c = 0x2E; break; case R_DS: if (bits == 64) { error(ERR_WARNING, "ds segment base ignored in 64-bit mode"); } c = 0x3E; break; case R_ES: if (bits == 64) { error(ERR_WARNING, "es segment base ignored in 64-bit mode"); } c = 0x26; break; case R_FS: c = 0x64; break; case R_GS: c = 0x65; break; case R_SS: if (bits == 64) { error(ERR_WARNING, "ss segment base ignored in 64-bit mode"); } c = 0x36; break; case R_SEGR6: case R_SEGR7: error(ERR_NONFATAL, "segr6 and segr7 cannot be used as prefixes"); break; case P_A16: if (bits == 64) { error(ERR_NONFATAL, "16-bit addressing is not supported " "in 64-bit mode"); break; } if (bits != 16) c = 0x67; break; case P_A32: if (bits != 32) c = 0x67; break; case P_O16: if (bits != 16) c = 0x66; break; case P_O32: if (bits == 16) c = 0x66; break; default: error(ERR_PANIC, "invalid instruction prefix"); } if (c != 0) { out(offset, segment, &c, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; } } insn_end = offset + insn_size; gencode(segment, offset, bits, instruction, codes, insn_end); offset += insn_size; if (itimes > 0 && itimes == instruction->times - 1) { /* * Dummy call to list->output to give the offset to the * listing module. */ list->output(offset, NULL, OUT_RAWDATA); list->uplevel(LIST_TIMES); } } if (instruction->times > 1) list->downlevel(LIST_TIMES); return offset - start; } else if (m > 0 && m > size_prob) { size_prob = m; } // temp++; } if (temp->opcode == -1) { /* didn't match any instruction */ switch (size_prob) { case 1: error(ERR_NONFATAL, "operation size not specified"); break; case 2: error(ERR_NONFATAL, "mismatch in operand sizes"); break; case 3: error(ERR_NONFATAL, "no instruction for this cpu level"); break; case 4: error(ERR_NONFATAL, "instruction not supported in 64-bit mode"); break; default: error(ERR_NONFATAL, "invalid combination of opcode and operands"); break; } } return 0; } int32_t insn_size(int32_t segment, int32_t offset, int bits, uint32_t cp, insn * instruction, efunc error) { const struct itemplate *temp; errfunc = error; /* to pass to other functions */ cpu = cp; if (instruction->opcode == -1) return 0; if (instruction->opcode == I_DB || instruction->opcode == I_DW || instruction->opcode == I_DD || instruction->opcode == I_DQ || instruction->opcode == I_DT || instruction->opcode == I_DO) { extop *e; int32_t isize, osize, wsize = 0; /* placate gcc */ isize = 0; switch (instruction->opcode) { case I_DB: wsize = 1; break; case I_DW: wsize = 2; break; case I_DD: wsize = 4; break; case I_DQ: wsize = 8; break; case I_DT: wsize = 10; break; case I_DO: wsize = 16; break; default: break; } for (e = instruction->eops; e; e = e->next) { int32_t align; osize = 0; if (e->type == EOT_DB_NUMBER) osize = 1; else if (e->type == EOT_DB_STRING) osize = e->stringlen; align = (-osize) % wsize; if (align < 0) align += wsize; isize += osize + align; } return isize * instruction->times; } if (instruction->opcode == I_INCBIN) { char fname[FILENAME_MAX]; FILE *fp; int32_t len; char *prefix = "", *combine; char **pPrevPath = NULL; len = FILENAME_MAX - 1; if (len > instruction->eops->stringlen) len = instruction->eops->stringlen; strncpy(fname, instruction->eops->stringval, len); fname[len] = '\0'; while (1) { /* added by alexfru: 'incbin' uses include paths */ combine = nasm_malloc(strlen(prefix) + len + 1); strcpy(combine, prefix); strcat(combine, fname); if ((fp = fopen(combine, "rb")) != NULL) { nasm_free(combine); break; } nasm_free(combine); pPrevPath = pp_get_include_path_ptr(pPrevPath); if (pPrevPath == NULL) break; prefix = *pPrevPath; } if (fp == NULL) error(ERR_NONFATAL, "`incbin': unable to open file `%s'", fname); else if (fseek(fp, 0L, SEEK_END) < 0) error(ERR_NONFATAL, "`incbin': unable to seek on file `%s'", fname); else { len = ftell(fp); fclose(fp); if (instruction->eops->next) { len -= instruction->eops->next->offset; if (instruction->eops->next->next && len > instruction->eops->next->next->offset) { len = instruction->eops->next->next->offset; } } return instruction->times * len; } return 0; /* if we're here, there's an error */ } /* Check to see if we need an address-size prefix */ add_asp(instruction, bits); for (temp = nasm_instructions[instruction->opcode]; temp->opcode != -1; temp++) { int m = matches(temp, instruction, bits); if (m == 99) m += jmp_match(segment, offset, bits, instruction, temp->code); if (m == 100) { /* we've matched an instruction. */ int32_t isize; const char *codes = temp->code; int j; isize = calcsize(segment, offset, bits, instruction, codes); if (isize < 0) return -1; for (j = 0; j < instruction->nprefix; j++) { switch (instruction->prefixes[j]) { case P_A16: if (bits != 16) isize++; break; case P_A32: if (bits != 32) isize++; break; case P_O16: if (bits != 16) isize++; break; case P_O32: if (bits == 16) isize++; break; default: isize++; break; } } return isize * instruction->times; } } return -1; /* didn't match any instruction */ } /* check that opn[op] is a signed byte of size 16 or 32, and return the signed value*/ static int is_sbyte(insn * ins, int op, int size) { int32_t v; int ret; ret = !(ins->forw_ref && ins->oprs[op].opflags) && /* dead in the water on forward reference or External */ optimizing >= 0 && !(ins->oprs[op].type & STRICT) && ins->oprs[op].wrt == NO_SEG && ins->oprs[op].segment == NO_SEG; v = ins->oprs[op].offset; if (size == 16) v = (int16_t)v; /* sign extend if 16 bits */ return ret && v >= -128L && v <= 127L; } static int32_t calcsize(int32_t segment, int32_t offset, int bits, insn * ins, const char *codes) { int32_t length = 0; uint8_t c; int rex_mask = ~0; ins->rex = 0; /* Ensure REX is reset */ (void)segment; /* Don't warn that this parameter is unused */ (void)offset; /* Don't warn that this parameter is unused */ while (*codes) switch (c = *codes++) { case 01: case 02: case 03: codes += c, length += c; break; case 04: case 05: case 06: case 07: length++; break; case 010: case 011: case 012: case 013: ins->rex |= op_rexflags(&ins->oprs[c - 010], REX_B|REX_H|REX_P|REX_W); codes++, length++; break; case 014: case 015: case 016: case 017: length++; break; case 020: case 021: case 022: case 023: length++; break; case 024: case 025: case 026: case 027: length++; break; case 030: case 031: case 032: case 033: length += 2; break; case 034: case 035: case 036: case 037: if (ins->oprs[c - 034].type & (BITS16 | BITS32 | BITS64)) length += (ins->oprs[c - 034].type & BITS16) ? 2 : 4; else length += (bits == 16) ? 2 : 4; break; case 040: case 041: case 042: case 043: length += 4; break; case 044: case 045: case 046: case 047: length += ((ins->oprs[c - 044].addr_size ? ins->oprs[c - 044].addr_size : bits) >> 3); break; case 050: case 051: case 052: case 053: length++; break; case 054: case 055: case 056: case 057: length += 8; /* MOV reg64/imm */ break; case 060: case 061: case 062: case 063: length += 2; break; case 064: case 065: case 066: case 067: if (ins->oprs[c - 064].type & (BITS16 | BITS32 | BITS64)) length += (ins->oprs[c - 064].type & BITS16) ? 2 : 4; else length += (bits == 16) ? 2 : 4; break; case 070: case 071: case 072: case 073: length += 4; break; case 074: case 075: case 076: case 077: length += 2; break; case 0140: case 0141: case 0142: case 0143: length += is_sbyte(ins, c - 0140, 16) ? 1 : 2; break; case 0144: case 0145: case 0146: case 0147: codes += 2; length++; break; case 0150: case 0151: case 0152: case 0153: length += is_sbyte(ins, c - 0150, 32) ? 1 : 4; break; case 0154: case 0155: case 0156: case 0157: codes += 2; length++; break; case 0160: case 0161: case 0162: case 0163: length++; ins->rex |= REX_D; ins->drexdst = regval(&ins->oprs[c & 3]); break; case 0164: case 0165: case 0166: case 0167: length++; ins->rex |= REX_D|REX_OC; ins->drexdst = regval(&ins->oprs[c & 3]); break; case 0170: length++; break; case 0171: break; case 0300: case 0301: case 0302: case 0303: break; case 0310: if (bits == 64) return -1; length += (bits != 16) && !has_prefix(ins,P_A16); break; case 0311: length += (bits != 32) && !has_prefix(ins,P_A32); break; case 0312: break; case 0313: if (bits != 64 || has_prefix(ins,P_A16) || has_prefix(ins,P_A32)) return -1; break; case 0320: length += (bits != 16); break; case 0321: length += (bits == 16); break; case 0322: break; case 0323: rex_mask &= ~REX_W; break; case 0324: ins->rex |= REX_W; break; case 0330: codes++, length++; break; case 0331: break; case 0332: case 0333: length++; break; case 0334: assert_no_prefix(ins, P_LOCK); ins->rex |= REX_L; break; case 0335: break; case 0340: case 0341: case 0342: if (ins->oprs[0].segment != NO_SEG) errfunc(ERR_NONFATAL, "attempt to reserve non-constant" " quantity of BSS space"); else length += ins->oprs[0].offset << (c - 0340); break; case 0364: case 0365: break; case 0366: case 0367: length++; break; case 0370: case 0371: case 0372: break; case 0373: length++; break; default: /* can't do it by 'case' statements */ if (c >= 0100 && c <= 0277) { /* it's an EA */ ea ea_data; int rfield; int32_t rflags; ea_data.rex = 0; /* Ensure ea.REX is initially 0 */ if (c <= 0177) { /* pick rfield from operand b */ rflags = regflag(&ins->oprs[c & 7]); rfield = regvals[ins->oprs[c & 7].basereg]; } else { rflags = 0; rfield = c & 7; } if (!process_ea (&ins->oprs[(c >> 3) & 7], &ea_data, bits, rfield, rflags, ins->forw_ref)) { errfunc(ERR_NONFATAL, "invalid effective address"); return -1; } else { ins->rex |= ea_data.rex; length += ea_data.size; } } else errfunc(ERR_PANIC, "internal instruction table corrupt" ": instruction code 0x%02X given", c); } ins->rex &= rex_mask; if (ins->rex & REX_D) { if (ins->rex & REX_H) { errfunc(ERR_NONFATAL, "cannot use high register in drex instruction"); return -1; } if (bits != 64 && ((ins->rex & (REX_W|REX_X|REX_B)) || ins->drexdst > 7)) { errfunc(ERR_NONFATAL, "invalid operands in non-64-bit mode"); return -1; } length++; } else if (ins->rex & REX_REAL) { if (ins->rex & REX_H) { errfunc(ERR_NONFATAL, "cannot use high register in rex instruction"); return -1; } else if (bits == 64 || ((ins->rex & REX_L) && !(ins->rex & (REX_P|REX_W|REX_X|REX_B)) && cpu >= IF_X86_64)) { length++; } else { errfunc(ERR_NONFATAL, "invalid operands in non-64-bit mode"); return -1; } } return length; } #define EMIT_REX() \ if (!(ins->rex & REX_D) && (ins->rex & REX_REAL) && (bits == 64)) { \ ins->rex = (ins->rex & REX_REAL)|REX_P; \ out(offset, segment, &ins->rex, OUT_RAWDATA+1, NO_SEG, NO_SEG); \ ins->rex = 0; \ offset += 1; \ } static void gencode(int32_t segment, int32_t offset, int bits, insn * ins, const char *codes, int32_t insn_end) { static char condval[] = { /* conditional opcodes */ 0x7, 0x3, 0x2, 0x6, 0x2, 0x4, 0xF, 0xD, 0xC, 0xE, 0x6, 0x2, 0x3, 0x7, 0x3, 0x5, 0xE, 0xC, 0xD, 0xF, 0x1, 0xB, 0x9, 0x5, 0x0, 0xA, 0xA, 0xB, 0x8, 0x4 }; uint8_t c; uint8_t bytes[4]; int32_t size; int64_t data; while (*codes) switch (c = *codes++) { case 01: case 02: case 03: EMIT_REX(); out(offset, segment, codes, OUT_RAWDATA + c, NO_SEG, NO_SEG); codes += c; offset += c; break; case 04: case 06: switch (ins->oprs[0].basereg) { case R_CS: bytes[0] = 0x0E + (c == 0x04 ? 1 : 0); break; case R_DS: bytes[0] = 0x1E + (c == 0x04 ? 1 : 0); break; case R_ES: bytes[0] = 0x06 + (c == 0x04 ? 1 : 0); break; case R_SS: bytes[0] = 0x16 + (c == 0x04 ? 1 : 0); break; default: errfunc(ERR_PANIC, "bizarre 8086 segment register received"); } out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; break; case 05: case 07: switch (ins->oprs[0].basereg) { case R_FS: bytes[0] = 0xA0 + (c == 0x05 ? 1 : 0); break; case R_GS: bytes[0] = 0xA8 + (c == 0x05 ? 1 : 0); break; default: errfunc(ERR_PANIC, "bizarre 386 segment register received"); } out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; break; case 010: case 011: case 012: case 013: EMIT_REX(); bytes[0] = *codes++ + ((regval(&ins->oprs[c - 010])) & 7); out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 014: case 015: case 016: case 017: if (ins->oprs[c - 014].offset < -128 || ins->oprs[c - 014].offset > 127) { errfunc(ERR_WARNING, "signed byte value exceeds bounds"); } if (ins->oprs[c - 014].segment != NO_SEG) { data = ins->oprs[c - 014].offset; out(offset, segment, &data, OUT_ADDRESS + 1, ins->oprs[c - 014].segment, ins->oprs[c - 014].wrt); } else { bytes[0] = ins->oprs[c - 014].offset; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); } offset += 1; break; case 020: case 021: case 022: case 023: if (ins->oprs[c - 020].offset < -256 || ins->oprs[c - 020].offset > 255) { errfunc(ERR_WARNING, "byte value exceeds bounds"); } if (ins->oprs[c - 020].segment != NO_SEG) { data = ins->oprs[c - 020].offset; out(offset, segment, &data, OUT_ADDRESS + 1, ins->oprs[c - 020].segment, ins->oprs[c - 020].wrt); } else { bytes[0] = ins->oprs[c - 020].offset; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); } offset += 1; break; case 024: case 025: case 026: case 027: if (ins->oprs[c - 024].offset < 0 || ins->oprs[c - 024].offset > 255) errfunc(ERR_WARNING, "unsigned byte value exceeds bounds"); if (ins->oprs[c - 024].segment != NO_SEG) { data = ins->oprs[c - 024].offset; out(offset, segment, &data, OUT_ADDRESS + 1, ins->oprs[c - 024].segment, ins->oprs[c - 024].wrt); } else { bytes[0] = ins->oprs[c - 024].offset; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); } offset += 1; break; case 030: case 031: case 032: case 033: if (ins->oprs[c - 030].segment == NO_SEG && ins->oprs[c - 030].wrt == NO_SEG && (ins->oprs[c - 030].offset < -65536L || ins->oprs[c - 030].offset > 65535L)) { errfunc(ERR_WARNING, "word value exceeds bounds"); } data = ins->oprs[c - 030].offset; out(offset, segment, &data, OUT_ADDRESS + 2, ins->oprs[c - 030].segment, ins->oprs[c - 030].wrt); offset += 2; break; case 034: case 035: case 036: case 037: if (ins->oprs[c - 034].type & (BITS16 | BITS32)) size = (ins->oprs[c - 034].type & BITS16) ? 2 : 4; else size = (bits == 16) ? 2 : 4; data = ins->oprs[c - 034].offset; if (size == 2 && (data < -65536L || data > 65535L)) errfunc(ERR_WARNING, "word value exceeds bounds"); out(offset, segment, &data, OUT_ADDRESS + size, ins->oprs[c - 034].segment, ins->oprs[c - 034].wrt); offset += size; break; case 040: case 041: case 042: case 043: data = ins->oprs[c - 040].offset; out(offset, segment, &data, OUT_ADDRESS + 4, ins->oprs[c - 040].segment, ins->oprs[c - 040].wrt); offset += 4; break; case 044: case 045: case 046: case 047: data = ins->oprs[c - 044].offset; size = ((ins->oprs[c - 044].addr_size ? ins->oprs[c - 044].addr_size : bits) >> 3); if (size == 2 && (data < -65536L || data > 65535L)) errfunc(ERR_WARNING, "word value exceeds bounds"); out(offset, segment, &data, OUT_ADDRESS + size, ins->oprs[c - 044].segment, ins->oprs[c - 044].wrt); offset += size; break; case 050: case 051: case 052: case 053: if (ins->oprs[c - 050].segment != segment) errfunc(ERR_NONFATAL, "short relative jump outside segment"); data = ins->oprs[c - 050].offset - insn_end; if (data > 127 || data < -128) errfunc(ERR_NONFATAL, "short jump is out of range"); bytes[0] = data; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 054: case 055: case 056: case 057: data = (int64_t)ins->oprs[c - 054].offset; out(offset, segment, &data, OUT_ADDRESS + 8, ins->oprs[c - 054].segment, ins->oprs[c - 054].wrt); offset += 8; break; case 060: case 061: case 062: case 063: if (ins->oprs[c - 060].segment != segment) { data = ins->oprs[c - 060].offset; out(offset, segment, &data, OUT_REL2ADR + insn_end - offset, ins->oprs[c - 060].segment, ins->oprs[c - 060].wrt); } else { data = ins->oprs[c - 060].offset - insn_end; out(offset, segment, &data, OUT_ADDRESS + 2, NO_SEG, NO_SEG); } offset += 2; break; case 064: case 065: case 066: case 067: if (ins->oprs[c - 064].type & (BITS16 | BITS32 | BITS64)) size = (ins->oprs[c - 064].type & BITS16) ? 2 : 4; else size = (bits == 16) ? 2 : 4; if (ins->oprs[c - 064].segment != segment) { int32_t reltype = (size == 2 ? OUT_REL2ADR : OUT_REL4ADR); data = ins->oprs[c - 064].offset; out(offset, segment, &data, reltype + insn_end - offset, ins->oprs[c - 064].segment, ins->oprs[c - 064].wrt); } else { data = ins->oprs[c - 064].offset - insn_end; out(offset, segment, &data, OUT_ADDRESS + size, NO_SEG, NO_SEG); } offset += size; break; case 070: case 071: case 072: case 073: if (ins->oprs[c - 070].segment != segment) { data = ins->oprs[c - 070].offset; out(offset, segment, &data, OUT_REL4ADR + insn_end - offset, ins->oprs[c - 070].segment, ins->oprs[c - 070].wrt); } else { data = ins->oprs[c - 070].offset - insn_end; out(offset, segment, &data, OUT_ADDRESS + 4, NO_SEG, NO_SEG); } offset += 4; break; case 074: case 075: case 076: case 077: if (ins->oprs[c - 074].segment == NO_SEG) errfunc(ERR_NONFATAL, "value referenced by FAR is not" " relocatable"); data = 0L; out(offset, segment, &data, OUT_ADDRESS + 2, outfmt->segbase(1 + ins->oprs[c - 074].segment), ins->oprs[c - 074].wrt); offset += 2; break; case 0140: case 0141: case 0142: case 0143: data = ins->oprs[c - 0140].offset; if (is_sbyte(ins, c - 0140, 16)) { bytes[0] = data; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; } else { if (ins->oprs[c - 0140].segment == NO_SEG && ins->oprs[c - 0140].wrt == NO_SEG && (data < -65536L || data > 65535L)) { errfunc(ERR_WARNING, "word value exceeds bounds"); } out(offset, segment, &data, OUT_ADDRESS + 2, ins->oprs[c - 0140].segment, ins->oprs[c - 0140].wrt); offset += 2; } break; case 0144: case 0145: case 0146: case 0147: EMIT_REX(); codes++; bytes[0] = *codes++; if (is_sbyte(ins, c - 0144, 16)) bytes[0] |= 2; /* s-bit */ out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; break; case 0150: case 0151: case 0152: case 0153: data = ins->oprs[c - 0150].offset; if (is_sbyte(ins, c - 0150, 32)) { bytes[0] = data; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; } else { out(offset, segment, &data, OUT_ADDRESS + 4, ins->oprs[c - 0150].segment, ins->oprs[c - 0150].wrt); offset += 4; } break; case 0154: case 0155: case 0156: case 0157: EMIT_REX(); codes++; bytes[0] = *codes++; if (is_sbyte(ins, c - 0154, 32)) bytes[0] |= 2; /* s-bit */ out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; break; case 0160: case 0161: case 0162: case 0163: case 0164: case 0165: case 0166: case 0167: break; case 0170: EMIT_REX(); bytes[0] = 0; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 0171: bytes[0] = (ins->drexdst << 4) | (ins->rex & REX_OC ? 0x08 : 0) | (ins->rex & (REX_R|REX_X|REX_B)); ins->rex = 0; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset++; break; case 0300: case 0301: case 0302: case 0303: break; case 0310: if (bits == 32 && !has_prefix(ins,P_A16)) { *bytes = 0x67; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; } else offset += 0; break; case 0311: if (bits != 32 && !has_prefix(ins,P_A32)) { *bytes = 0x67; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; } else offset += 0; break; case 0312: break; case 0313: ins->rex = 0; break; case 0320: if (bits != 16) { *bytes = 0x66; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; } else offset += 0; break; case 0321: if (bits == 16) { *bytes = 0x66; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; } else offset += 0; break; case 0322: case 0323: break; case 0324: ins->rex |= REX_W; break; case 0330: *bytes = *codes++ ^ condval[ins->condition]; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 0331: break; case 0332: case 0333: *bytes = c - 0332 + 0xF2; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 0334: if (ins->rex & REX_R) { *bytes = 0xF0; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; } ins->rex &= ~(REX_L|REX_R); break; case 0335: break; case 0340: case 0341: case 0342: if (ins->oprs[0].segment != NO_SEG) errfunc(ERR_PANIC, "non-constant BSS size in pass two"); else { int32_t size = ins->oprs[0].offset << (c - 0340); if (size > 0) out(offset, segment, NULL, OUT_RESERVE + size, NO_SEG, NO_SEG); offset += size; } break; case 0364: case 0365: break; case 0366: case 0367: *bytes = c - 0366 + 0x66; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; case 0370: case 0371: case 0372: break; case 0373: *bytes = bits == 16 ? 3 : 5; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); offset += 1; break; default: /* can't do it by 'case' statements */ if (c >= 0100 && c <= 0277) { /* it's an EA */ ea ea_data; int rfield; int32_t rflags; uint8_t *p; int32_t s; if (c <= 0177) { /* pick rfield from operand b */ rflags = regflag(&ins->oprs[c & 7]); rfield = regvals[ins->oprs[c & 7].basereg]; } else { /* rfield is constant */ rflags = 0; rfield = c & 7; } if (!process_ea (&ins->oprs[(c >> 3) & 7], &ea_data, bits, rfield, rflags, ins->forw_ref)) { errfunc(ERR_NONFATAL, "invalid effective address"); } p = bytes; *p++ = ea_data.modrm; if (ea_data.sib_present) *p++ = ea_data.sib; /* DREX suffixes come between the SIB and the displacement */ if (ins->rex & REX_D) { *p++ = (ins->drexdst << 4) | (ins->rex & REX_OC ? 0x08 : 0) | (ins->rex & (REX_R|REX_X|REX_B)); ins->rex = 0; } s = p - bytes; out(offset, segment, bytes, OUT_RAWDATA + s, NO_SEG, NO_SEG); switch (ea_data.bytes) { case 0: break; case 1: if (ins->oprs[(c >> 3) & 7].segment != NO_SEG) { data = ins->oprs[(c >> 3) & 7].offset; out(offset, segment, &data, OUT_ADDRESS + 1, ins->oprs[(c >> 3) & 7].segment, ins->oprs[(c >> 3) & 7].wrt); } else { *bytes = ins->oprs[(c >> 3) & 7].offset; out(offset, segment, bytes, OUT_RAWDATA + 1, NO_SEG, NO_SEG); } s++; break; case 8: case 2: case 4: data = ins->oprs[(c >> 3) & 7].offset; out(offset, segment, &data, (ea_data.rip ? OUT_REL4ADR : OUT_ADDRESS) + ea_data.bytes, ins->oprs[(c >> 3) & 7].segment, ins->oprs[(c >> 3) & 7].wrt); s += ea_data.bytes; break; } offset += s; } else errfunc(ERR_PANIC, "internal instruction table corrupt" ": instruction code 0x%02X given", c); } } static int32_t regflag(const operand * o) { if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) { errfunc(ERR_PANIC, "invalid operand passed to regflag()"); } return reg_flags[o->basereg]; } static int32_t regval(const operand * o) { if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) { errfunc(ERR_PANIC, "invalid operand passed to regval()"); } return regvals[o->basereg]; } static int op_rexflags(const operand * o, int mask) { int32_t flags; int val; if (o->basereg < EXPR_REG_START || o->basereg >= REG_ENUM_LIMIT) { errfunc(ERR_PANIC, "invalid operand passed to op_rexflags()"); } flags = reg_flags[o->basereg]; val = regvals[o->basereg]; return rexflags(val, flags, mask); } static int rexflags(int val, int32_t flags, int mask) { int rex = 0; if (val >= 8) rex |= REX_B|REX_X|REX_R; if (flags & BITS64) rex |= REX_W; if (!(REG_HIGH & ~flags)) /* AH, CH, DH, BH */ rex |= REX_H; else if (!(REG8 & ~flags) && val >= 4) /* SPL, BPL, SIL, DIL */ rex |= REX_P; return rex & mask; } static int matches(const struct itemplate *itemp, insn * instruction, int bits) { int i, size[MAX_OPERANDS], asize, oprs, ret; ret = 100; /* * Check the opcode */ if (itemp->opcode != instruction->opcode) return 0; /* * Count the operands */ if (itemp->operands != instruction->operands) return 0; /* * Check that no spurious colons or TOs are present */ for (i = 0; i < itemp->operands; i++) if (instruction->oprs[i].type & ~itemp->opd[i] & (COLON | TO)) return 0; /* * Check that the operand flags all match up */ for (i = 0; i < itemp->operands; i++) { if (itemp->opd[i] & SAME_AS) { int j = itemp->opd[i] & ~SAME_AS; if (instruction->oprs[i].type != instruction->oprs[j].type || instruction->oprs[i].basereg != instruction->oprs[j].basereg) return 0; } else if (itemp->opd[i] & ~instruction->oprs[i].type || ((itemp->opd[i] & SIZE_MASK) && ((itemp->opd[i] ^ instruction->oprs[i].type) & SIZE_MASK))) { if ((itemp->opd[i] & ~instruction->oprs[i].type & ~SIZE_MASK) || (instruction->oprs[i].type & SIZE_MASK)) return 0; else return 1; } } /* * Check operand sizes */ if (itemp->flags & IF_ARMASK) { memset(size, 0, sizeof size); switch (itemp->flags & IF_ARMASK) { case IF_AR0: i = 0; break; case IF_AR1: i = 1; break; case IF_AR2: i = 2; break; case IF_AR3: i = 3; break; default: break; /* Shouldn't happen */ } switch (itemp->flags & IF_SMASK) { case IF_SB: size[i] = BITS8; break; case IF_SW: size[i] = BITS16; break; case IF_SD: size[i] = BITS32; break; case IF_SQ: size[i] = BITS64; break; case IF_SO: size[i] = BITS128; break; default: break; } } else { asize = 0; switch (itemp->flags & IF_SMASK) { case IF_SB: asize = BITS8; oprs = itemp->operands; break; case IF_SW: asize = BITS16; oprs = itemp->operands; break; case IF_SD: asize = BITS32; oprs = itemp->operands; break; case IF_SQ: asize = BITS64; oprs = itemp->operands; break; case IF_SO: asize = BITS128; oprs = itemp->operands; break; default: break; } for (i = 0; i < MAX_OPERANDS; i++) size[i] = asize; } if (itemp->flags & (IF_SM | IF_SM2)) { oprs = (itemp->flags & IF_SM2 ? 2 : itemp->operands); asize = 0; for (i = 0; i < oprs; i++) { if ((asize = itemp->opd[i] & SIZE_MASK) != 0) { int j; for (j = 0; j < oprs; j++) size[j] = asize; break; } } } else { oprs = itemp->operands; } for (i = 0; i < itemp->operands; i++) { if (!(itemp->opd[i] & SIZE_MASK) && (instruction->oprs[i].type & SIZE_MASK & ~size[i])) return 2; } /* * Check template is okay at the set cpu level */ if (((itemp->flags & IF_PLEVEL) > cpu)) return 3; /* * Check if instruction is available in long mode */ if ((itemp->flags & IF_NOLONG) && (bits == 64)) return 4; /* * Check if special handling needed for Jumps */ if ((uint8_t)(itemp->code[0]) >= 0370) return 99; return ret; } static ea *process_ea(operand * input, ea * output, int addrbits, int rfield, int32_t rflags, int forw_ref) { output->rip = false; /* REX flags for the rfield operand */ output->rex |= rexflags(rfield, rflags, REX_R|REX_P|REX_W|REX_H); if (!(REGISTER & ~input->type)) { /* register direct */ int i; int32_t f; if (input->basereg < EXPR_REG_START /* Verify as Register */ || input->basereg >= REG_ENUM_LIMIT) return NULL; f = regflag(input); i = regvals[input->basereg]; if (REG_EA & ~f) return NULL; /* Invalid EA register */ output->rex |= op_rexflags(input, REX_B|REX_P|REX_W|REX_H); output->sib_present = false; /* no SIB necessary */ output->bytes = 0; /* no offset necessary either */ output->modrm = 0xC0 | ((rfield & 7) << 3) | (i & 7); } else { /* it's a memory reference */ if (input->basereg == -1 && (input->indexreg == -1 || input->scale == 0)) { /* it's a pure offset */ if (input->addr_size) addrbits = input->addr_size; if (globalbits == 64 && (~input->type & IP_REL)) { int scale, index, base; output->sib_present = true; scale = 0; index = 4; base = 5; output->sib = (scale << 6) | (index << 3) | base; output->bytes = 4; output->modrm = 4 | ((rfield & 7) << 3); output->rip = false; } else { output->sib_present = false; output->bytes = (addrbits != 16 ? 4 : 2); output->modrm = (addrbits != 16 ? 5 : 6) | ((rfield & 7) << 3); output->rip = globalbits == 64; } } else { /* it's an indirection */ int i = input->indexreg, b = input->basereg, s = input->scale; int32_t o = input->offset, seg = input->segment; int hb = input->hintbase, ht = input->hinttype; int t; int it, bt; int32_t ix, bx; /* register flags */ if (s == 0) i = -1; /* make this easy, at least */ if (i >= EXPR_REG_START && i < REG_ENUM_LIMIT) { it = regvals[i]; ix = reg_flags[i]; } else { it = -1; ix = 0; } if (b != -1 && b >= EXPR_REG_START && b < REG_ENUM_LIMIT) { bt = regvals[b]; bx = reg_flags[b]; } else { bt = -1; bx = 0; } /* check for a 32/64-bit memory reference... */ if ((ix|bx) & (BITS32|BITS64)) { /* it must be a 32/64-bit memory reference. Firstly we have * to check that all registers involved are type E/Rxx. */ int32_t sok = BITS32|BITS64; if (it != -1) { if (!(REG64 & ~ix) || !(REG32 & ~ix)) sok &= ix; else return NULL; } if (bt != -1) { if (REG_GPR & ~bx) return NULL; /* Invalid register */ if (~sok & bx & SIZE_MASK) return NULL; /* Invalid size */ sok &= ~bx; } /* While we're here, ensure the user didn't specify WORD. */ if (input->addr_size == 16 || (input->addr_size == 32 && !(sok & BITS32)) || (input->addr_size == 64 && !(sok & BITS64))) return NULL; /* now reorganize base/index */ if (s == 1 && bt != it && bt != -1 && it != -1 && ((hb == b && ht == EAH_NOTBASE) || (hb == i && ht == EAH_MAKEBASE))) { /* swap if hints say so */ t = bt, bt = it, it = t; t = bx, bx = ix, ix = t; } if (bt == it) /* convert EAX+2*EAX to 3*EAX */ bt = -1, bx = 0, s++; if (bt == -1 && s == 1 && !(hb == it && ht == EAH_NOTBASE)) { /* make single reg base, unless hint */ bt = it, bx = ix, it = -1, ix = 0; } if (((s == 2 && it != REG_NUM_ESP && !(input->eaflags & EAF_TIMESTWO)) || s == 3 || s == 5 || s == 9) && bt == -1) bt = it, bx = ix, s--; /* convert 3*EAX to EAX+2*EAX */ if (it == -1 && (bt & 7) != REG_NUM_ESP && (input->eaflags & EAF_TIMESTWO)) it = bt, ix = bx, bt = -1, bx = 0, s = 1; /* convert [NOSPLIT EAX] to sib format with 0x0 displacement */ if (s == 1 && it == REG_NUM_ESP) { /* swap ESP into base if scale is 1 */ t = it, it = bt, bt = t; t = ix, ix = bx, bx = t; } if (it == REG_NUM_ESP || (s != 1 && s != 2 && s != 4 && s != 8 && it != -1)) return NULL; /* wrong, for various reasons */ output->rex |= rexflags(it, ix, REX_X); output->rex |= rexflags(bt, bx, REX_B); if (it == -1 && (bt & 7) != REG_NUM_ESP) { /* no SIB needed */ int mod, rm; if (bt == -1) { rm = 5; mod = 0; } else { rm = (bt & 7); if (rm != REG_NUM_EBP && o == 0 && seg == NO_SEG && !forw_ref && !(input->eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS))) mod = 0; else if (input->eaflags & EAF_BYTEOFFS || (o >= -128 && o <= 127 && seg == NO_SEG && !forw_ref && !(input->eaflags & EAF_WORDOFFS))) mod = 1; else mod = 2; } output->sib_present = false; output->bytes = (bt == -1 || mod == 2 ? 4 : mod); output->modrm = (mod << 6) | ((rfield & 7) << 3) | rm; } else { /* we need a SIB */ int mod, scale, index, base; if (it == -1) index = 4, s = 1; else index = (it & 7); switch (s) { case 1: scale = 0; break; case 2: scale = 1; break; case 4: scale = 2; break; case 8: scale = 3; break; default: /* then what the smeg is it? */ return NULL; /* panic */ } if (bt == -1) { base = 5; mod = 0; } else { base = (bt & 7); if (base != REG_NUM_EBP && o == 0 && seg == NO_SEG && !forw_ref && !(input->eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS))) mod = 0; else if (input->eaflags & EAF_BYTEOFFS || (o >= -128 && o <= 127 && seg == NO_SEG && !forw_ref && !(input->eaflags & EAF_WORDOFFS))) mod = 1; else mod = 2; } output->sib_present = true; output->bytes = (bt == -1 || mod == 2 ? 4 : mod); output->modrm = (mod << 6) | ((rfield & 7) << 3) | 4; output->sib = (scale << 6) | (index << 3) | base; } } else { /* it's 16-bit */ int mod, rm; /* check for 64-bit long mode */ if (addrbits == 64) return NULL; /* check all registers are BX, BP, SI or DI */ if ((b != -1 && b != R_BP && b != R_BX && b != R_SI && b != R_DI) || (i != -1 && i != R_BP && i != R_BX && i != R_SI && i != R_DI)) return NULL; /* ensure the user didn't specify DWORD/QWORD */ if (input->addr_size == 32 || input->addr_size == 64) return NULL; if (s != 1 && i != -1) return NULL; /* no can do, in 16-bit EA */ if (b == -1 && i != -1) { int tmp = b; b = i; i = tmp; } /* swap */ if ((b == R_SI || b == R_DI) && i != -1) { int tmp = b; b = i; i = tmp; } /* have BX/BP as base, SI/DI index */ if (b == i) return NULL; /* shouldn't ever happen, in theory */ if (i != -1 && b != -1 && (i == R_BP || i == R_BX || b == R_SI || b == R_DI)) return NULL; /* invalid combinations */ if (b == -1) /* pure offset: handled above */ return NULL; /* so if it gets to here, panic! */ rm = -1; if (i != -1) switch (i * 256 + b) { case R_SI * 256 + R_BX: rm = 0; break; case R_DI * 256 + R_BX: rm = 1; break; case R_SI * 256 + R_BP: rm = 2; break; case R_DI * 256 + R_BP: rm = 3; break; } else switch (b) { case R_SI: rm = 4; break; case R_DI: rm = 5; break; case R_BP: rm = 6; break; case R_BX: rm = 7; break; } if (rm == -1) /* can't happen, in theory */ return NULL; /* so panic if it does */ if (o == 0 && seg == NO_SEG && !forw_ref && rm != 6 && !(input->eaflags & (EAF_BYTEOFFS | EAF_WORDOFFS))) mod = 0; else if (input->eaflags & EAF_BYTEOFFS || (o >= -128 && o <= 127 && seg == NO_SEG && !forw_ref && !(input->eaflags & EAF_WORDOFFS))) mod = 1; else mod = 2; output->sib_present = false; /* no SIB - it's 16-bit */ output->bytes = mod; /* bytes of offset needed */ output->modrm = (mod << 6) | ((rfield & 7) << 3) | rm; } } } output->size = 1 + output->sib_present + output->bytes; return output; } static void add_asp(insn *instruction, int addrbits) { int j, valid; valid = (addrbits == 64) ? 64|32 : 32|16; for (j = 0; j < instruction->operands; j++) { if (!(MEMORY & ~instruction->oprs[j].type)) { int32_t i, b; /* Verify as Register */ if (instruction->oprs[j].indexreg < EXPR_REG_START || instruction->oprs[j].indexreg >= REG_ENUM_LIMIT) i = 0; else i = reg_flags[instruction->oprs[j].indexreg]; /* Verify as Register */ if (instruction->oprs[j].basereg < EXPR_REG_START || instruction->oprs[j].basereg >= REG_ENUM_LIMIT) b = 0; else b = reg_flags[instruction->oprs[j].basereg]; if (instruction->oprs[j].scale == 0) i = 0; if (!i && !b) { if (instruction->oprs[j].addr_size) valid &= instruction->oprs[j].addr_size; } else { if (!(REG16 & ~b)) valid &= 16; if (!(REG32 & ~b)) valid &= 32; if (!(REG64 & ~b)) valid &= 64; if (!(REG16 & ~i)) valid &= 16; if (!(REG32 & ~i)) valid &= 32; if (!(REG64 & ~i)) valid &= 64; } } } if (valid & addrbits) { /* Don't do anything */ } else if (valid & ((addrbits == 32) ? 16 : 32)) { /* Add an instruction size prefix */ enum prefixes pref = (addrbits == 32) ? P_A16 : P_A32; for (j = 0; j < instruction->nprefix; j++) { if (instruction->prefixes[j] == pref) return; /* Already there */ } instruction->prefixes[j] = pref; instruction->nprefix++; } else { /* Impossible... */ errfunc(ERR_NONFATAL, "impossible combination of address sizes"); } }