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Diffstat (limited to 'vere/ext/nasm/disasm/disasm.c')
-rw-r--r-- | vere/ext/nasm/disasm/disasm.c | 1762 |
1 files changed, 1762 insertions, 0 deletions
diff --git a/vere/ext/nasm/disasm/disasm.c b/vere/ext/nasm/disasm/disasm.c new file mode 100644 index 0000000..ac2dc97 --- /dev/null +++ b/vere/ext/nasm/disasm/disasm.c @@ -0,0 +1,1762 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 1996-2022 The NASM Authors - All Rights Reserved + * See the file AUTHORS included with the NASM distribution for + * the specific copyright holders. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following + * conditions are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * ----------------------------------------------------------------------- */ + +/* + * disasm.c where all the _work_ gets done in the Netwide Disassembler + */ + +#include "compiler.h" + + +#include "nasm.h" +#include "disasm.h" +#include "sync.h" +#include "insns.h" +#include "tables.h" +#include "regdis.h" +#include "disp8.h" + +#define fetch_safe(_start, _ptr, _size, _need, _op) \ + do { \ + if (((_ptr) - (_start)) >= ((_size) - (_need))) \ + _op; \ + } while (0) + +#define fetch_or_return(_start, _ptr, _size, _need) \ + fetch_safe(_start, _ptr, _size, _need, return 0) + +/* + * Flags that go into the `segment' field of `insn' structures + * during disassembly. + */ +#define SEG_RELATIVE 1 +#define SEG_32BIT 2 +#define SEG_RMREG 4 +#define SEG_DISP8 8 +#define SEG_DISP16 16 +#define SEG_DISP32 32 +#define SEG_NODISP 64 +#define SEG_SIGNED 128 +#define SEG_64BIT 256 + +/* + * Prefix information + */ +struct prefix_info { + uint8_t osize; /* Operand size */ + uint8_t asize; /* Address size */ + uint8_t osp; /* Operand size prefix present */ + uint8_t asp; /* Address size prefix present */ + uint8_t rep; /* Rep prefix present */ + uint8_t seg; /* Segment override prefix present */ + uint8_t wait; /* WAIT "prefix" present */ + uint8_t lock; /* Lock prefix present */ + uint8_t vex[3]; /* VEX prefix present */ + uint8_t vex_c; /* VEX "class" (VEX, XOP, ...) */ + uint8_t vex_m; /* VEX.M field */ + uint8_t vex_v; + uint8_t vex_lp; /* VEX.LP fields */ + uint32_t rex; /* REX prefix present */ + uint8_t evex[3]; /* EVEX prefix present */ +}; + +#define getu8(x) (*(uint8_t *)(x)) +#if X86_MEMORY +/* Littleendian CPU which can handle unaligned references */ +#define getu16(x) (*(uint16_t *)(x)) +#define getu32(x) (*(uint32_t *)(x)) +#define getu64(x) (*(uint64_t *)(x)) +#else +static uint16_t getu16(uint8_t *data) +{ + return (uint16_t)data[0] + ((uint16_t)data[1] << 8); +} +static uint32_t getu32(uint8_t *data) +{ + return (uint32_t)getu16(data) + ((uint32_t)getu16(data+2) << 16); +} +static uint64_t getu64(uint8_t *data) +{ + return (uint64_t)getu32(data) + ((uint64_t)getu32(data+4) << 32); +} +#endif + +#define gets8(x) ((int8_t)getu8(x)) +#define gets16(x) ((int16_t)getu16(x)) +#define gets32(x) ((int32_t)getu32(x)) +#define gets64(x) ((int64_t)getu64(x)) + +/* Important: regval must already have been adjusted for rex extensions */ +static enum reg_enum whichreg(opflags_t regflags, int regval, int rex) +{ + size_t i; + + static const struct { + opflags_t flags; + enum reg_enum reg; + } specific_registers[] = { + {REG_AL, R_AL}, + {REG_AX, R_AX}, + {REG_EAX, R_EAX}, + {REG_RAX, R_RAX}, + {REG_DL, R_DL}, + {REG_DX, R_DX}, + {REG_EDX, R_EDX}, + {REG_RDX, R_RDX}, + {REG_CL, R_CL}, + {REG_CX, R_CX}, + {REG_ECX, R_ECX}, + {REG_RCX, R_RCX}, + {FPU0, R_ST0}, + {XMM0, R_XMM0}, + {YMM0, R_YMM0}, + {ZMM0, R_ZMM0}, + {REG_ES, R_ES}, + {REG_CS, R_CS}, + {REG_SS, R_SS}, + {REG_DS, R_DS}, + {REG_FS, R_FS}, + {REG_GS, R_GS}, + {OPMASK0, R_K0}, + }; + + if (!(regflags & (REGISTER|REGMEM))) + return 0; /* Registers not permissible?! */ + + regflags |= REGISTER; + + for (i = 0; i < ARRAY_SIZE(specific_registers); i++) + if (!(specific_registers[i].flags & ~regflags)) + return specific_registers[i].reg; + + /* All the entries below look up regval in an 16-entry array */ + if (regval < 0 || regval > (rex & REX_EV ? 31 : 15)) + return 0; + +#define GET_REGISTER(__array, __index) \ + ((size_t)(__index) < (size_t)ARRAY_SIZE(__array) ? __array[(__index)] : 0) + + if (!(REG8 & ~regflags)) { + if (rex & (REX_P|REX_NH)) + return GET_REGISTER(nasm_rd_reg8_rex, regval); + else + return GET_REGISTER(nasm_rd_reg8, regval); + } + if (!(REG16 & ~regflags)) + return GET_REGISTER(nasm_rd_reg16, regval); + if (!(REG32 & ~regflags)) + return GET_REGISTER(nasm_rd_reg32, regval); + if (!(REG64 & ~regflags)) + return GET_REGISTER(nasm_rd_reg64, regval); + if (!(REG_SREG & ~regflags)) + return GET_REGISTER(nasm_rd_sreg, regval & 7); /* Ignore REX */ + if (!(REG_CREG & ~regflags)) + return GET_REGISTER(nasm_rd_creg, regval); + if (!(REG_DREG & ~regflags)) + return GET_REGISTER(nasm_rd_dreg, regval); + if (!(REG_TREG & ~regflags)) { + if (regval > 7) + return 0; /* TR registers are ill-defined with rex */ + return GET_REGISTER(nasm_rd_treg, regval); + } + if (!(FPUREG & ~regflags)) + return GET_REGISTER(nasm_rd_fpureg, regval & 7); /* Ignore REX */ + if (!(MMXREG & ~regflags)) + return GET_REGISTER(nasm_rd_mmxreg, regval & 7); /* Ignore REX */ + if (!(XMMREG & ~regflags)) + return GET_REGISTER(nasm_rd_xmmreg, regval); + if (!(YMMREG & ~regflags)) + return GET_REGISTER(nasm_rd_ymmreg, regval); + if (!(ZMMREG & ~regflags)) + return GET_REGISTER(nasm_rd_zmmreg, regval); + if (!(OPMASKREG & ~regflags)) + return GET_REGISTER(nasm_rd_opmaskreg, regval); + if (!(BNDREG & ~regflags)) + return GET_REGISTER(nasm_rd_bndreg, regval); + if (!(TMMREG & ~regflags)) + return GET_REGISTER(nasm_rd_tmmreg, regval); + +#undef GET_REGISTER + return 0; +} + +static uint32_t append_evex_reg_deco(char *buf, uint32_t num, + decoflags_t deco, uint8_t *evex) +{ + const char * const er_names[] = {"rn-sae", "rd-sae", "ru-sae", "rz-sae"}; + uint32_t num_chars = 0; + + if ((deco & MASK) && (evex[2] & EVEX_P2AAA)) { + enum reg_enum opmasknum = nasm_rd_opmaskreg[evex[2] & EVEX_P2AAA]; + const char * regname = nasm_reg_names[opmasknum - EXPR_REG_START]; + + num_chars += snprintf(buf + num_chars, num - num_chars, + "{%s}", regname); + + if ((deco & Z) && (evex[2] & EVEX_P2Z)) { + num_chars += snprintf(buf + num_chars, num - num_chars, + "{z}"); + } + } + + if (evex[2] & EVEX_P2B) { + if (deco & ER) { + uint8_t er_type = (evex[2] & EVEX_P2LL) >> 5; + num_chars += snprintf(buf + num_chars, num - num_chars, + ",{%s}", er_names[er_type]); + } else if (deco & SAE) { + num_chars += snprintf(buf + num_chars, num - num_chars, + ",{sae}"); + } + } + + return num_chars; +} + +static uint32_t append_evex_mem_deco(char *buf, uint32_t num, opflags_t type, + decoflags_t deco, uint8_t *evex) +{ + uint32_t num_chars = 0; + + if ((evex[2] & EVEX_P2B) && (deco & BRDCAST_MASK)) { + decoflags_t deco_brsize = deco & BRSIZE_MASK; + opflags_t template_opsize = brsize_to_size(deco_brsize); + unsigned int br_num = (type & SIZE_MASK) / BITS128 * + BITS64 / template_opsize * 2; + + num_chars += snprintf(buf + num_chars, num - num_chars, + "{1to%d}", br_num); + } + + if ((deco & MASK) && (evex[2] & EVEX_P2AAA)) { + enum reg_enum opmasknum = nasm_rd_opmaskreg[evex[2] & EVEX_P2AAA]; + const char * regname = nasm_reg_names[opmasknum - EXPR_REG_START]; + + num_chars += snprintf(buf + num_chars, num - num_chars, + "{%s}", regname); + + if ((deco & Z) && (evex[2] & EVEX_P2Z)) { + num_chars += snprintf(buf + num_chars, num - num_chars, + "{z}"); + } + } + + + return num_chars; +} + +/* + * Process an effective address (ModRM) specification. + */ +static uint8_t *do_ea(uint8_t *data, int modrm, int asize, + int segsize, enum ea_type type, + operand *op, insn *ins) +{ + int mod, rm, scale, index, base; + int rex; + uint8_t *evex; + uint8_t sib = 0; + bool is_evex = !!(ins->rex & REX_EV); + + mod = (modrm >> 6) & 03; + rm = modrm & 07; + + if (mod != 3 && asize != 16 && rm == 4) + sib = *data++; + + rex = ins->rex; + evex = ins->evex_p; + + if (mod == 3) { /* pure register version */ + op->basereg = rm+(rex & REX_B ? 8 : 0); + op->segment |= SEG_RMREG; + if (is_evex && segsize == 64) { + op->basereg += (evex[0] & EVEX_P0X ? 0 : 16); + } + return data; + } + + op->disp_size = 0; + op->eaflags = 0; + + if (asize == 16) { + /* + * <mod> specifies the displacement size (none, byte or + * word), and <rm> specifies the register combination. + * Exception: mod=0,rm=6 does not specify [BP] as one might + * expect, but instead specifies [disp16]. + */ + + if (type != EA_SCALAR) + return NULL; + + op->indexreg = op->basereg = -1; + op->scale = 1; /* always, in 16 bits */ + switch (rm) { + case 0: + op->basereg = R_BX; + op->indexreg = R_SI; + break; + case 1: + op->basereg = R_BX; + op->indexreg = R_DI; + break; + case 2: + op->basereg = R_BP; + op->indexreg = R_SI; + break; + case 3: + op->basereg = R_BP; + op->indexreg = R_DI; + break; + case 4: + op->basereg = R_SI; + break; + case 5: + op->basereg = R_DI; + break; + case 6: + op->basereg = R_BP; + break; + case 7: + op->basereg = R_BX; + break; + } + if (rm == 6 && mod == 0) { /* special case */ + op->basereg = -1; + if (segsize != 16) + op->disp_size = 16; + mod = 2; /* fake disp16 */ + } + switch (mod) { + case 0: + op->segment |= SEG_NODISP; + break; + case 1: + op->segment |= SEG_DISP8; + if (ins->evex_tuple != 0) { + op->offset = gets8(data) * get_disp8N(ins); + } else { + op->offset = gets8(data); + } + data++; + break; + case 2: + op->segment |= SEG_DISP16; + op->offset = *data++; + op->offset |= ((unsigned)*data++) << 8; + break; + } + return data; + } else { + /* + * Once again, <mod> specifies displacement size (this time + * none, byte or *dword*), while <rm> specifies the base + * register. Again, [EBP] is missing, replaced by a pure + * disp32 (this time that's mod=0,rm=*5*) in 32-bit mode, + * and RIP-relative addressing in 64-bit mode. + * + * However, rm=4 + * indicates not a single base register, but instead the + * presence of a SIB byte... + */ + int a64 = asize == 64; + + op->indexreg = -1; + + if (a64) + op->basereg = nasm_rd_reg64[rm | ((rex & REX_B) ? 8 : 0)]; + else + op->basereg = nasm_rd_reg32[rm | ((rex & REX_B) ? 8 : 0)]; + + if (rm == 5 && mod == 0) { + if (segsize == 64) { + op->eaflags |= EAF_REL; + op->segment |= SEG_RELATIVE; + } + + if (asize != 64) + op->disp_size = asize; + + op->basereg = -1; + mod = 2; /* fake disp32 */ + } + + + if (rm == 4) { /* process SIB */ + uint8_t vsib_hi = 0; + scale = (sib >> 6) & 03; + index = (sib >> 3) & 07; + base = sib & 07; + + op->scale = 1 << scale; + + if (segsize == 64) { + vsib_hi = (rex & REX_X ? 8 : 0) | + (evex[2] & EVEX_P2VP ? 0 : 16); + } + + if (type == EA_XMMVSIB) + op->indexreg = nasm_rd_xmmreg[index | vsib_hi]; + else if (type == EA_YMMVSIB) + op->indexreg = nasm_rd_ymmreg[index | vsib_hi]; + else if (type == EA_ZMMVSIB) + op->indexreg = nasm_rd_zmmreg[index | vsib_hi]; + else if (index == 4 && !(rex & REX_X)) + op->indexreg = -1; /* ESP/RSP cannot be an index */ + else if (a64) + op->indexreg = nasm_rd_reg64[index | ((rex & REX_X) ? 8 : 0)]; + else + op->indexreg = nasm_rd_reg32[index | ((rex & REX_X) ? 8 : 0)]; + + if (base == 5 && mod == 0) { + op->basereg = -1; + mod = 2; /* Fake disp32 */ + } else if (a64) + op->basereg = nasm_rd_reg64[base | ((rex & REX_B) ? 8 : 0)]; + else + op->basereg = nasm_rd_reg32[base | ((rex & REX_B) ? 8 : 0)]; + + if (segsize == 16) + op->disp_size = 32; + } else if (type != EA_SCALAR) { + /* Can't have VSIB without SIB */ + return NULL; + } + + switch (mod) { + case 0: + op->segment |= SEG_NODISP; + break; + case 1: + op->segment |= SEG_DISP8; + if (ins->evex_tuple != 0) { + op->offset = gets8(data) * get_disp8N(ins); + } else { + op->offset = gets8(data); + } + data++; + break; + case 2: + op->segment |= SEG_DISP32; + op->offset = gets32(data); + data += 4; + break; + } + return data; + } +} + +/* + * Determine whether the instruction template in t corresponds to the data + * stream in data. Return the number of bytes matched if so. + */ +#define case4(x) case (x): case (x)+1: case (x)+2: case (x)+3 + +static int matches(const struct itemplate *t, uint8_t *data, + const struct prefix_info *prefix, int segsize, insn *ins) +{ + uint8_t *r = (uint8_t *)(t->code); + uint8_t *origdata = data; + bool a_used = false, o_used = false; + enum prefixes drep = 0; + enum prefixes dwait = 0; + uint8_t lock = prefix->lock; + int osize = prefix->osize; + int asize = prefix->asize; + int i, c; + int op1, op2; + struct operand *opx, *opy; + uint8_t opex = 0; + bool vex_ok = false; + int regmask = (segsize == 64) ? 15 : 7; + enum ea_type eat = EA_SCALAR; + + for (i = 0; i < MAX_OPERANDS; i++) { + ins->oprs[i].segment = ins->oprs[i].disp_size = + (segsize == 64 ? SEG_64BIT : segsize == 32 ? SEG_32BIT : 0); + } + ins->evex_tuple = 0; + ins->rex = prefix->rex; + memset(ins->prefixes, 0, sizeof ins->prefixes); + + if (itemp_has(t, (segsize == 64 ? IF_NOLONG : IF_LONG))) + return 0; + + if (prefix->rep == 0xF2) + drep = (itemp_has(t, IF_BND) ? P_BND : P_REPNE); + else if (prefix->rep == 0xF3) + drep = P_REP; + + dwait = prefix->wait ? P_WAIT : 0; + + while ((c = *r++) != 0) { + op1 = (c & 3) + ((opex & 1) << 2); + op2 = ((c >> 3) & 3) + ((opex & 2) << 1); + opx = &ins->oprs[op1]; + opy = &ins->oprs[op2]; + opex = 0; + + switch (c) { + case 01: + case 02: + case 03: + case 04: + while (c--) + if (*r++ != *data++) + return 0; + break; + + case 05: + case 06: + case 07: + opex = c; + break; + + case4(010): + { + int t = *r++, d = *data++; + if (d < t || d > t + 7) + return 0; + else { + opx->basereg = (d-t)+ + (ins->rex & REX_B ? 8 : 0); + opx->segment |= SEG_RMREG; + } + break; + } + + case4(014): + /* this is an separate index reg position of MIB operand (ICC) */ + /* Disassembler uses NASM's split EA form only */ + break; + + case4(0274): + opx->offset = (int8_t)*data++; + opx->segment |= SEG_SIGNED; + break; + + case4(020): + opx->offset = *data++; + break; + + case4(024): + opx->offset = *data++; + break; + + case4(030): + opx->offset = getu16(data); + data += 2; + break; + + case4(034): + if (osize == 32) { + opx->offset = getu32(data); + data += 4; + } else { + opx->offset = getu16(data); + data += 2; + } + if (segsize != asize) + opx->disp_size = asize; + break; + + case4(040): + opx->offset = getu32(data); + data += 4; + break; + + case4(0254): + opx->offset = gets32(data); + data += 4; + break; + + case4(044): + switch (asize) { + case 16: + opx->offset = getu16(data); + data += 2; + if (segsize != 16) + opx->disp_size = 16; + break; + case 32: + opx->offset = getu32(data); + data += 4; + if (segsize == 16) + opx->disp_size = 32; + break; + case 64: + opx->offset = getu64(data); + opx->disp_size = 64; + data += 8; + break; + } + break; + + case4(050): + opx->offset = gets8(data++); + opx->segment |= SEG_RELATIVE; + break; + + case4(054): + opx->offset = getu64(data); + data += 8; + break; + + case4(060): + opx->offset = gets16(data); + data += 2; + opx->segment |= SEG_RELATIVE; + opx->segment &= ~SEG_32BIT; + break; + + case4(064): /* rel */ + opx->segment |= SEG_RELATIVE; + /* In long mode rel is always 32 bits, sign extended. */ + if (segsize == 64 || osize == 32) { + opx->offset = gets32(data); + data += 4; + if (segsize != 64) + opx->segment |= SEG_32BIT; + opx->type = (opx->type & ~SIZE_MASK) + | (segsize == 64 ? BITS64 : BITS32); + } else { + opx->offset = gets16(data); + data += 2; + opx->segment &= ~SEG_32BIT; + opx->type = (opx->type & ~SIZE_MASK) | BITS16; + } + break; + + case4(070): + opx->offset = gets32(data); + data += 4; + opx->segment |= SEG_32BIT | SEG_RELATIVE; + break; + + case4(0100): + case4(0110): + case4(0120): + case4(0130): + { + int modrm = *data++; + opx->segment |= SEG_RMREG; + data = do_ea(data, modrm, asize, segsize, eat, opy, ins); + if (!data) + return 0; + opx->basereg = ((modrm >> 3) & 7) + (ins->rex & REX_R ? 8 : 0); + if ((ins->rex & REX_EV) && (segsize == 64)) + opx->basereg += (ins->evex_p[0] & EVEX_P0RP ? 0 : 16); + break; + } + + case 0171: + { + uint8_t t = *r++; + uint8_t d = *data++; + if ((d ^ t) & ~070) { + return 0; + } else { + op2 = (op2 & ~3) | ((t >> 3) & 3); + opy = &ins->oprs[op2]; + opy->basereg = ((d >> 3) & 7) + + (ins->rex & REX_R ? 8 : 0); + opy->segment |= SEG_RMREG; + } + break; + } + + case 0172: + { + uint8_t ximm = *data++; + c = *r++; + ins->oprs[c >> 3].basereg = (ximm >> 4) & regmask; + ins->oprs[c >> 3].segment |= SEG_RMREG; + ins->oprs[c & 7].offset = ximm & 15; + } + break; + + case 0173: + { + uint8_t ximm = *data++; + c = *r++; + + if ((c ^ ximm) & 15) + return 0; + + ins->oprs[c >> 4].basereg = (ximm >> 4) & regmask; + ins->oprs[c >> 4].segment |= SEG_RMREG; + } + break; + + case4(0174): + { + uint8_t ximm = *data++; + + opx->basereg = (ximm >> 4) & regmask; + opx->segment |= SEG_RMREG; + } + break; + + case4(0200): + case4(0204): + case4(0210): + case4(0214): + case4(0220): + case4(0224): + case4(0230): + case4(0234): + { + int modrm = *data++; + if (((modrm >> 3) & 07) != (c & 07)) + return 0; /* spare field doesn't match up */ + data = do_ea(data, modrm, asize, segsize, eat, opy, ins); + if (!data) + return 0; + break; + } + + case4(0240): + case 0250: + { + uint8_t evexm = *r++; + uint8_t evexwlp = *r++; + uint8_t modrm, valid_mask; + ins->evex_tuple = *r++ - 0300; + modrm = *(origdata + 1); + + ins->rex |= REX_EV; + if ((prefix->rex & (REX_EV|REX_V|REX_P)) != REX_EV) + return 0; + + if ((evexm & 0x1f) != prefix->vex_m) + return 0; + + switch (evexwlp & 060) { + case 000: + if (prefix->rex & REX_W) + return 0; + break; + case 020: + if (!(prefix->rex & REX_W)) + return 0; + ins->rex |= REX_W; + break; + case 040: /* VEX.W is a don't care */ + ins->rex &= ~REX_W; + break; + case 060: + break; + } + + /* If EVEX.b is set with reg-reg op, + * EVEX.L'L contains embedded rounding control info + */ + if ((prefix->evex[2] & EVEX_P2B) && ((modrm >> 6) == 3)) { + valid_mask = 0x3; /* prefix only */ + } else { + valid_mask = 0xf; /* vector length and prefix */ + } + if ((evexwlp ^ prefix->vex_lp) & valid_mask) + return 0; + + if (c == 0250) { + if ((prefix->vex_v != 0) || + (!(prefix->evex[2] & EVEX_P2VP) && + ((eat < EA_XMMVSIB) || (eat > EA_ZMMVSIB)))) + return 0; + } else { + opx->segment |= SEG_RMREG; + opx->basereg = ((~prefix->evex[2] & EVEX_P2VP) << (4 - 3) ) | + prefix->vex_v; + } + vex_ok = true; + memcpy(ins->evex_p, prefix->evex, 3); + break; + } + + case4(0260): + case 0270: + { + int vexm = *r++; + int vexwlp = *r++; + + ins->rex |= REX_V; + if ((prefix->rex & (REX_V|REX_P)) != REX_V) + return 0; + + if ((vexm & 0x1f) != prefix->vex_m) + return 0; + + switch (vexwlp & 060) { + case 000: + if (prefix->rex & REX_W) + return 0; + break; + case 020: + if (!(prefix->rex & REX_W)) + return 0; + ins->rex &= ~REX_W; + break; + case 040: /* VEX.W is a don't care */ + ins->rex &= ~REX_W; + break; + case 060: + break; + } + + /* The 010 bit of vexwlp is set if VEX.L is ignored */ + if ((vexwlp ^ prefix->vex_lp) & ((vexwlp & 010) ? 03 : 07)) + return 0; + + if (c == 0270) { + if (prefix->vex_v != 0) + return 0; + } else { + opx->segment |= SEG_RMREG; + opx->basereg = prefix->vex_v; + } + vex_ok = true; + break; + } + + case 0271: + if (prefix->rep == 0xF3) + drep = P_XRELEASE; + break; + + case 0272: + if (prefix->rep == 0xF2) + drep = P_XACQUIRE; + else if (prefix->rep == 0xF3) + drep = P_XRELEASE; + break; + + case 0273: + if (prefix->lock == 0xF0) { + if (prefix->rep == 0xF2) + drep = P_XACQUIRE; + else if (prefix->rep == 0xF3) + drep = P_XRELEASE; + } + break; + + case 0310: + if (asize != 16) + return 0; + else + a_used = true; + break; + + case 0311: + if (asize != 32) + return 0; + else + a_used = true; + break; + + case 0312: + if (asize != segsize) + return 0; + else + a_used = true; + break; + + case 0313: + if (asize != 64) + return 0; + else + a_used = true; + break; + + case 0314: + if (prefix->rex & REX_B) + return 0; + break; + + case 0315: + if (prefix->rex & REX_X) + return 0; + break; + + case 0316: + if (prefix->rex & REX_R) + return 0; + break; + + case 0317: + if (prefix->rex & REX_W) + return 0; + break; + + case 0320: + if (osize != 16) + return 0; + else + o_used = true; + break; + + case 0321: + if (osize != 32) + return 0; + else + o_used = true; + break; + + case 0322: + if (osize != (segsize == 16 ? 16 : 32)) + return 0; + else + o_used = true; + break; + + case 0323: + ins->rex |= REX_W; /* 64-bit only instruction */ + osize = 64; + o_used = true; + break; + + case 0324: + if (osize != 64) + return 0; + o_used = true; + break; + + case 0325: + ins->rex |= REX_NH; + break; + + case 0326: + if (prefix->rep == 0xF3) + return 0; + break; + + case 0331: + if (prefix->rep) + return 0; + break; + + case 0332: + if (prefix->rep != 0xF2) + return 0; + drep = 0; + break; + + case 0333: + if (prefix->rep != 0xF3) + return 0; + drep = 0; + break; + + case 0334: + if (lock) { + ins->rex |= REX_R; + lock = 0; + } + break; + + case 0335: + if (drep == P_REP) + drep = P_REPE; + break; + + case 0336: + case 0337: + break; + + case 0340: + return 0; + + case 0341: + if (prefix->wait != 0x9B) + return 0; + dwait = 0; + break; + + case 0360: + if (prefix->osp || prefix->rep) + return 0; + break; + + case 0361: + if (!prefix->osp || prefix->rep) + return 0; + o_used = true; + break; + + case 0364: + if (prefix->osp) + return 0; + break; + + case 0365: + if (prefix->asp) + return 0; + break; + + case 0366: + if (!prefix->osp) + return 0; + o_used = true; + break; + + case 0367: + if (!prefix->asp) + return 0; + a_used = true; + break; + + case 0370: + case 0371: + break; + + case 0374: + eat = EA_XMMVSIB; + break; + + case 0375: + eat = EA_YMMVSIB; + break; + + case 0376: + eat = EA_ZMMVSIB; + break; + + default: + return 0; /* Unknown code */ + } + } + + if (!vex_ok && (ins->rex & (REX_V | REX_EV))) + return 0; + + /* REX cannot be combined with VEX */ + if ((ins->rex & REX_V) && (prefix->rex & REX_P)) + return 0; + + /* + * Check for unused rep or a/o prefixes. + */ + for (i = 0; i < t->operands; i++) { + if (ins->oprs[i].segment != SEG_RMREG) + a_used = true; + } + + if (lock) { + if (ins->prefixes[PPS_LOCK]) + return 0; + ins->prefixes[PPS_LOCK] = P_LOCK; + } + if (drep) { + if (ins->prefixes[PPS_REP]) + return 0; + ins->prefixes[PPS_REP] = drep; + } + ins->prefixes[PPS_WAIT] = dwait; + if (!o_used) { + if (osize != ((segsize == 16) ? 16 : 32)) { + enum prefixes pfx = 0; + + switch (osize) { + case 16: + pfx = P_O16; + break; + case 32: + pfx = P_O32; + break; + case 64: + pfx = P_O64; + break; + } + + if (ins->prefixes[PPS_OSIZE]) + return 0; + ins->prefixes[PPS_OSIZE] = pfx; + } + } + if (!a_used && asize != segsize) { + if (ins->prefixes[PPS_ASIZE]) + return 0; + ins->prefixes[PPS_ASIZE] = asize == 16 ? P_A16 : P_A32; + } + + /* Fix: check for redundant REX prefixes */ + + return data - origdata; +} + +int32_t disasm(uint8_t *data, int32_t data_size, char *output, int outbufsize, int segsize, + int64_t offset, int autosync, iflag_t *prefer) +{ + const struct itemplate * const *p, * const *best_p; + const struct disasm_index *ix; + uint8_t *dp; + int length, best_length = 0; + char *segover; + int i, slen, colon, n; + uint8_t *origdata; + int works; + insn tmp_ins, ins; + iflag_t goodness, best; + int best_pref; + struct prefix_info prefix; + bool end_prefix; + bool is_evex; + + memset(&ins, 0, sizeof ins); + + /* + * Scan for prefixes. + */ + memset(&prefix, 0, sizeof prefix); + prefix.asize = segsize; + prefix.osize = (segsize == 64) ? 32 : segsize; + segover = NULL; + origdata = data; + + ix = itable; + + end_prefix = false; + while (!end_prefix) { + switch (*data) { + case 0xF2: + case 0xF3: + fetch_or_return(origdata, data, data_size, 1); + prefix.rep = *data++; + break; + + case 0x9B: + fetch_or_return(origdata, data, data_size, 1); + prefix.wait = *data++; + break; + + case 0xF0: + fetch_or_return(origdata, data, data_size, 1); + prefix.lock = *data++; + break; + + case 0x2E: + fetch_or_return(origdata, data, data_size, 1); + segover = "cs", prefix.seg = *data++; + break; + case 0x36: + fetch_or_return(origdata, data, data_size, 1); + segover = "ss", prefix.seg = *data++; + break; + case 0x3E: + fetch_or_return(origdata, data, data_size, 1); + segover = "ds", prefix.seg = *data++; + break; + case 0x26: + fetch_or_return(origdata, data, data_size, 1); + segover = "es", prefix.seg = *data++; + break; + case 0x64: + fetch_or_return(origdata, data, data_size, 1); + segover = "fs", prefix.seg = *data++; + break; + case 0x65: + fetch_or_return(origdata, data, data_size, 1); + segover = "gs", prefix.seg = *data++; + break; + + case 0x66: + fetch_or_return(origdata, data, data_size, 1); + prefix.osize = (segsize == 16) ? 32 : 16; + prefix.osp = *data++; + break; + case 0x67: + fetch_or_return(origdata, data, data_size, 1); + prefix.asize = (segsize == 32) ? 16 : 32; + prefix.asp = *data++; + break; + + case 0xC4: + case 0xC5: + if (segsize == 64 || (data[1] & 0xc0) == 0xc0) { + fetch_or_return(origdata, data, data_size, 2); + prefix.vex[0] = *data++; + prefix.vex[1] = *data++; + + prefix.rex = REX_V; + prefix.vex_c = RV_VEX; + + if (prefix.vex[0] == 0xc4) { + fetch_or_return(origdata, data, data_size, 1); + prefix.vex[2] = *data++; + prefix.rex |= (~prefix.vex[1] >> 5) & 7; /* REX_RXB */ + prefix.rex |= (prefix.vex[2] >> (7-3)) & REX_W; + prefix.vex_m = prefix.vex[1] & 0x1f; + prefix.vex_v = (~prefix.vex[2] >> 3) & 15; + prefix.vex_lp = prefix.vex[2] & 7; + } else { + prefix.rex |= (~prefix.vex[1] >> (7-2)) & REX_R; + prefix.vex_m = 1; + prefix.vex_v = (~prefix.vex[1] >> 3) & 15; + prefix.vex_lp = prefix.vex[1] & 7; + } + + ix = itable_vex[RV_VEX][prefix.vex_m][prefix.vex_lp & 3]; + } + end_prefix = true; + break; + + case 0x62: + { + if (segsize == 64 || ((data[1] & 0xc0) == 0xc0)) { + fetch_or_return(origdata, data, data_size, 4); + data++; /* 62h EVEX prefix */ + prefix.evex[0] = *data++; + prefix.evex[1] = *data++; + prefix.evex[2] = *data++; + + prefix.rex = REX_EV; + prefix.vex_c = RV_EVEX; + prefix.rex |= (~prefix.evex[0] >> 5) & 7; /* REX_RXB */ + prefix.rex |= (prefix.evex[1] >> (7-3)) & REX_W; + prefix.vex_m = prefix.evex[0] & EVEX_P0MM; + prefix.vex_v = (~prefix.evex[1] & EVEX_P1VVVV) >> 3; + prefix.vex_lp = ((prefix.evex[2] & EVEX_P2LL) >> (5-2)) | + (prefix.evex[1] & EVEX_P1PP); + + ix = itable_vex[prefix.vex_c][prefix.vex_m][prefix.vex_lp & 3]; + } + end_prefix = true; + break; + } + + case 0x8F: + if ((data[1] & 030) != 0 && + (segsize == 64 || (data[1] & 0xc0) == 0xc0)) { + fetch_or_return(origdata, data, data_size, 3); + prefix.vex[0] = *data++; + prefix.vex[1] = *data++; + prefix.vex[2] = *data++; + + prefix.rex = REX_V; + prefix.vex_c = RV_XOP; + + prefix.rex |= (~prefix.vex[1] >> 5) & 7; /* REX_RXB */ + prefix.rex |= (prefix.vex[2] >> (7-3)) & REX_W; + prefix.vex_m = prefix.vex[1] & 0x1f; + prefix.vex_v = (~prefix.vex[2] >> 3) & 15; + prefix.vex_lp = prefix.vex[2] & 7; + + ix = itable_vex[RV_XOP][prefix.vex_m][prefix.vex_lp & 3]; + } + end_prefix = true; + break; + + case REX_P + 0x0: + case REX_P + 0x1: + case REX_P + 0x2: + case REX_P + 0x3: + case REX_P + 0x4: + case REX_P + 0x5: + case REX_P + 0x6: + case REX_P + 0x7: + case REX_P + 0x8: + case REX_P + 0x9: + case REX_P + 0xA: + case REX_P + 0xB: + case REX_P + 0xC: + case REX_P + 0xD: + case REX_P + 0xE: + case REX_P + 0xF: + if (segsize == 64) { + fetch_or_return(origdata, data, data_size, 1); + prefix.rex = *data++; + if (prefix.rex & REX_W) + prefix.osize = 64; + } + end_prefix = true; + break; + + default: + end_prefix = true; + break; + } + } + + iflag_set_all(&best); /* Worst possible */ + best_p = NULL; + best_pref = INT_MAX; + + if (!ix) + return 0; /* No instruction table at all... */ + + dp = data; + fetch_or_return(origdata, dp, data_size, 1); + ix += *dp++; + while (ix->n == -1) { + fetch_or_return(origdata, dp, data_size, 1); + ix = (const struct disasm_index *)ix->p + *dp++; + } + + p = (const struct itemplate * const *)ix->p; + for (n = ix->n; n; n--, p++) { + if ((length = matches(*p, data, &prefix, segsize, &tmp_ins))) { + works = true; + /* + * Final check to make sure the types of r/m match up. + * XXX: Need to make sure this is actually correct. + */ + for (i = 0; i < (*p)->operands; i++) { + if ( + /* If it's a mem-only EA but we have a + register, die. */ + ((tmp_ins.oprs[i].segment & SEG_RMREG) && + is_class(MEMORY, (*p)->opd[i])) || + /* If it's a reg-only EA but we have a memory + ref, die. */ + (!(tmp_ins.oprs[i].segment & SEG_RMREG) && + !(REG_EA & ~(*p)->opd[i]) && + !((*p)->opd[i] & REG_SMASK)) || + /* Register type mismatch (eg FS vs REG_DESS): + die. */ + ((((*p)->opd[i] & (REGISTER | FPUREG)) || + (tmp_ins.oprs[i].segment & SEG_RMREG)) && + !whichreg((*p)->opd[i], + tmp_ins.oprs[i].basereg, tmp_ins.rex)) + ) { + works = false; + break; + } + } + + /* + * Note: we always prefer instructions which incorporate + * prefixes in the instructions themselves. This is to allow + * e.g. PAUSE to be preferred to REP NOP, and deal with + * MMX/SSE instructions where prefixes are used to select + * between MMX and SSE register sets or outright opcode + * selection. + */ + if (works) { + int i, nprefix; + goodness = iflag_pfmask(*p); + goodness = iflag_xor(&goodness, prefer); + nprefix = 0; + for (i = 0; i < MAXPREFIX; i++) + if (tmp_ins.prefixes[i]) + nprefix++; + if (nprefix < best_pref || + (nprefix == best_pref && + iflag_cmp(&goodness, &best) < 0)) { + /* This is the best one found so far */ + best = goodness; + best_p = p; + best_pref = nprefix; + best_length = length; + ins = tmp_ins; + } + } + } + } + + if (!best_p) + return 0; /* no instruction was matched */ + + /* Pick the best match */ + p = best_p; + length = best_length; + + slen = 0; + + /* TODO: snprintf returns the value that the string would have if + * the buffer were long enough, and not the actual length of + * the returned string, so each instance of using the return + * value of snprintf should actually be checked to assure that + * the return value is "sane." Maybe a macro wrapper could + * be used for that purpose. + */ + for (i = 0; i < MAXPREFIX; i++) { + const char *prefix = prefix_name(ins.prefixes[i]); + if (prefix) + slen += snprintf(output+slen, outbufsize-slen, "%s ", prefix); + } + + i = (*p)->opcode; + slen += snprintf(output + slen, outbufsize - slen, "%s", + nasm_insn_names[i]); + + colon = false; + is_evex = !!(ins.rex & REX_EV); + length += data - origdata; /* fix up for prefixes */ + for (i = 0; i < (*p)->operands; i++) { + opflags_t t = (*p)->opd[i]; + decoflags_t deco = (*p)->deco[i]; + const operand *o = &ins.oprs[i]; + int64_t offs; + + output[slen++] = (colon ? ':' : i == 0 ? ' ' : ','); + + offs = o->offset; + if (o->segment & SEG_RELATIVE) { + offs += offset + length; + /* + * sort out wraparound + */ + if (!(o->segment & (SEG_32BIT|SEG_64BIT))) + offs &= 0xffff; + else if (segsize != 64) + offs &= 0xffffffff; + + /* + * add sync marker, if autosync is on + */ + if (autosync) + add_sync(offs, 0L); + } + + if (t & COLON) + colon = true; + else + colon = false; + + if ((t & (REGISTER | FPUREG)) || + (o->segment & SEG_RMREG)) { + enum reg_enum reg; + reg = whichreg(t, o->basereg, ins.rex); + if (t & TO) + slen += snprintf(output + slen, outbufsize - slen, "to "); + slen += snprintf(output + slen, outbufsize - slen, "%s", + nasm_reg_names[reg-EXPR_REG_START]); + if (t & REGSET_MASK) + slen += snprintf(output + slen, outbufsize - slen, "+%d", + (int)((t & REGSET_MASK) >> (REGSET_SHIFT-1))-1); + if (is_evex && deco) + slen += append_evex_reg_deco(output + slen, outbufsize - slen, + deco, ins.evex_p); + } else if (!(UNITY & ~t)) { + output[slen++] = '1'; + } else if (t & IMMEDIATE) { + if (t & BITS8) { + slen += + snprintf(output + slen, outbufsize - slen, "byte "); + if (o->segment & SEG_SIGNED) { + if (offs < 0) { + offs *= -1; + output[slen++] = '-'; + } else + output[slen++] = '+'; + } + } else if (t & BITS16) { + slen += + snprintf(output + slen, outbufsize - slen, "word "); + } else if (t & BITS32) { + slen += + snprintf(output + slen, outbufsize - slen, "dword "); + } else if (t & BITS64) { + slen += + snprintf(output + slen, outbufsize - slen, "qword "); + } else if (t & NEAR) { + slen += + snprintf(output + slen, outbufsize - slen, "near "); + } else if (t & SHORT) { + slen += + snprintf(output + slen, outbufsize - slen, "short "); + } + slen += + snprintf(output + slen, outbufsize - slen, "0x%"PRIx64"", + offs); + } else if (!(MEM_OFFS & ~t)) { + slen += + snprintf(output + slen, outbufsize - slen, + "[%s%s%s0x%"PRIx64"]", + (segover ? segover : ""), + (segover ? ":" : ""), + (o->disp_size == 64 ? "qword " : + o->disp_size == 32 ? "dword " : + o->disp_size == 16 ? "word " : ""), offs); + segover = NULL; + } else if (is_class(REGMEM, t)) { + int started = false; + if (t & BITS8) + slen += + snprintf(output + slen, outbufsize - slen, "byte "); + if (t & BITS16) + slen += + snprintf(output + slen, outbufsize - slen, "word "); + if (t & BITS32) + slen += + snprintf(output + slen, outbufsize - slen, "dword "); + if (t & BITS64) + slen += + snprintf(output + slen, outbufsize - slen, "qword "); + if (t & BITS80) + slen += + snprintf(output + slen, outbufsize - slen, "tword "); + if ((ins.evex_p[2] & EVEX_P2B) && (deco & BRDCAST_MASK)) { + /* when broadcasting, each element size should be used */ + if (deco & BR_BITS16) + slen += + snprintf(output + slen, outbufsize - slen, "word "); + else if (deco & BR_BITS32) + slen += + snprintf(output + slen, outbufsize - slen, "dword "); + else if (deco & BR_BITS64) + slen += + snprintf(output + slen, outbufsize - slen, "qword "); + } else { + if (t & BITS128) + slen += + snprintf(output + slen, outbufsize - slen, "oword "); + if (t & BITS256) + slen += + snprintf(output + slen, outbufsize - slen, "yword "); + if (t & BITS512) + slen += + snprintf(output + slen, outbufsize - slen, "zword "); + } + if (t & FAR) + slen += snprintf(output + slen, outbufsize - slen, "far "); + if (t & NEAR) + slen += + snprintf(output + slen, outbufsize - slen, "near "); + output[slen++] = '['; + if (o->disp_size) + slen += snprintf(output + slen, outbufsize - slen, "%s", + (o->disp_size == 64 ? "qword " : + o->disp_size == 32 ? "dword " : + o->disp_size == 16 ? "word " : + "")); + if (o->eaflags & EAF_REL) + slen += snprintf(output + slen, outbufsize - slen, "rel "); + if (segover) { + slen += + snprintf(output + slen, outbufsize - slen, "%s:", + segover); + segover = NULL; + } + if (o->basereg != -1) { + slen += snprintf(output + slen, outbufsize - slen, "%s", + nasm_reg_names[(o->basereg-EXPR_REG_START)]); + started = true; + } + if (o->indexreg != -1 && !itemp_has(*best_p, IF_MIB)) { + if (started) + output[slen++] = '+'; + slen += snprintf(output + slen, outbufsize - slen, "%s", + nasm_reg_names[(o->indexreg-EXPR_REG_START)]); + if (o->scale > 1) + slen += + snprintf(output + slen, outbufsize - slen, "*%d", + o->scale); + started = true; + } + + + if (o->segment & SEG_DISP8) { + if (is_evex) { + const char *prefix; + uint32_t offset = offs; + if ((int32_t)offset < 0) { + prefix = "-"; + offset = -offset; + } else { + prefix = "+"; + } + slen += + snprintf(output + slen, outbufsize - slen, "%s0x%"PRIx32"", + prefix, offset); + } else { + const char *prefix; + uint8_t offset = offs; + if ((int8_t)offset < 0) { + prefix = "-"; + offset = -offset; + } else { + prefix = "+"; + } + slen += + snprintf(output + slen, outbufsize - slen, "%s0x%"PRIx8"", + prefix, offset); + } + } else if (o->segment & SEG_DISP16) { + const char *prefix; + uint16_t offset = offs; + if ((int16_t)offset < 0 && started) { + offset = -offset; + prefix = "-"; + } else { + prefix = started ? "+" : ""; + } + slen += + snprintf(output + slen, outbufsize - slen, + "%s0x%"PRIx16"", prefix, offset); + } else if (o->segment & SEG_DISP32) { + if (prefix.asize == 64) { + const char *prefix; + uint64_t offset = offs; + if ((int32_t)offs < 0 && started) { + offset = -offset; + prefix = "-"; + } else { + prefix = started ? "+" : ""; + } + slen += + snprintf(output + slen, outbufsize - slen, + "%s0x%"PRIx64"", prefix, offset); + } else { + const char *prefix; + uint32_t offset = offs; + if ((int32_t) offset < 0 && started) { + offset = -offset; + prefix = "-"; + } else { + prefix = started ? "+" : ""; + } + slen += + snprintf(output + slen, outbufsize - slen, + "%s0x%"PRIx32"", prefix, offset); + } + } + + if (o->indexreg != -1 && itemp_has(*best_p, IF_MIB)) { + output[slen++] = ','; + slen += snprintf(output + slen, outbufsize - slen, "%s", + nasm_reg_names[(o->indexreg-EXPR_REG_START)]); + if (o->scale > 1) + slen += + snprintf(output + slen, outbufsize - slen, "*%d", + o->scale); + started = true; + } + + output[slen++] = ']'; + + if (is_evex && deco) + slen += append_evex_mem_deco(output + slen, outbufsize - slen, + t, deco, ins.evex_p); + } else { + slen += + snprintf(output + slen, outbufsize - slen, "<operand%d>", + i); + } + } + output[slen] = '\0'; + if (segover) { /* unused segment override */ + char *p = output; + int count = slen + 1; + while (count--) + p[count + 3] = p[count]; + strncpy(output, segover, 2); + output[2] = ' '; + } + return length; +} + +/* + * This is called when we don't have a complete instruction. If it + * is a standalone *single-byte* prefix show it as such, otherwise + * print it as a literal. + */ +int32_t eatbyte(uint8_t *data, char *output, int outbufsize, int segsize) +{ + uint8_t byte = *data; + const char *str = NULL; + + switch (byte) { + case 0xF2: + str = "repne"; + break; + case 0xF3: + str = "rep"; + break; + case 0x9B: + str = "wait"; + break; + case 0xF0: + str = "lock"; + break; + case 0x2E: + str = "cs"; + break; + case 0x36: + str = "ss"; + break; + case 0x3E: + str = "ds"; + break; + case 0x26: + str = "es"; + break; + case 0x64: + str = "fs"; + break; + case 0x65: + str = "gs"; + break; + case 0x66: + str = (segsize == 16) ? "o32" : "o16"; + break; + case 0x67: + str = (segsize == 32) ? "a16" : "a32"; + break; + case REX_P + 0x0: + case REX_P + 0x1: + case REX_P + 0x2: + case REX_P + 0x3: + case REX_P + 0x4: + case REX_P + 0x5: + case REX_P + 0x6: + case REX_P + 0x7: + case REX_P + 0x8: + case REX_P + 0x9: + case REX_P + 0xA: + case REX_P + 0xB: + case REX_P + 0xC: + case REX_P + 0xD: + case REX_P + 0xE: + case REX_P + 0xF: + if (segsize == 64) { + snprintf(output, outbufsize, "rex%s%s%s%s%s", + (byte == REX_P) ? "" : ".", + (byte & REX_W) ? "w" : "", + (byte & REX_R) ? "r" : "", + (byte & REX_X) ? "x" : "", + (byte & REX_B) ? "b" : ""); + break; + } + /* else fall through */ + default: + snprintf(output, outbufsize, "db 0x%02x", byte); + break; + } + + if (str) + snprintf(output, outbufsize, "%s", str); + + return 1; +} |