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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "disassembler_x86.h"
#include <iostream>
#include "logging.h"
#include "stringprintf.h"
#include "thread.h"
namespace art {
namespace x86 {
DisassemblerX86::DisassemblerX86() {
}
void DisassemblerX86::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
size_t length = 0;
for (const uint8_t* cur = begin; cur < end; cur += length) {
length = DumpInstruction(os, cur);
}
}
static const char* gReg8Names[] = { "al", "cl", "dl", "bl", "ah", "ch", "dh", "bh" };
static const char* gReg16Names[] = { "ax", "cx", "dx", "bx", "sp", "bp", "di", "si" };
static const char* gReg32Names[] = { "eax", "ecx", "edx", "ebx", "esp", "ebp", "edi", "esi" };
static void DumpReg0(std::ostream& os, uint8_t /*rex*/, size_t reg,
bool byte_operand, uint8_t size_override) {
DCHECK_LT(reg, 8u);
// TODO: combine rex into size
size_t size = byte_operand ? 1 : (size_override == 0x66 ? 2 : 4);
switch (size) {
case 1: os << gReg8Names[reg]; break;
case 2: os << gReg16Names[reg]; break;
case 4: os << gReg32Names[reg]; break;
default: LOG(FATAL) << "unexpected size " << size;
}
}
enum RegFile { GPR, MMX, SSE };
static void DumpReg(std::ostream& os, uint8_t rex, uint8_t reg,
bool byte_operand, uint8_t size_override, RegFile reg_file) {
size_t reg_num = reg; // TODO: combine with REX.R on 64bit
if (reg_file == GPR) {
DumpReg0(os, rex, reg_num, byte_operand, size_override);
} else if (reg_file == SSE) {
os << "xmm" << reg_num;
} else {
os << "mm" << reg_num;
}
}
static void DumpBaseReg(std::ostream& os, uint8_t rex, uint8_t reg) {
size_t reg_num = reg; // TODO: combine with REX.B on 64bit
DumpReg0(os, rex, reg_num, false, 0);
}
static void DumpIndexReg(std::ostream& os, uint8_t rex, uint8_t reg) {
int reg_num = reg; // TODO: combine with REX.X on 64bit
DumpReg0(os, rex, reg_num, false, 0);
}
enum SegmentPrefix {
kCs = 0x2e,
kSs = 0x36,
kDs = 0x3e,
kEs = 0x26,
kFs = 0x64,
kGs = 0x65,
};
static void DumpSegmentOverride(std::ostream& os, uint8_t segment_prefix) {
switch (segment_prefix) {
case kCs: os << "cs:"; break;
case kSs: os << "ss:"; break;
case kDs: os << "ds:"; break;
case kEs: os << "es:"; break;
case kFs: os << "fs:"; break;
case kGs: os << "gs:"; break;
default: break;
}
}
size_t DisassemblerX86::DumpInstruction(std::ostream& os, const uint8_t* instr) {
const uint8_t* begin_instr = instr;
bool have_prefixes = true;
uint8_t prefix[4] = {0, 0, 0, 0};
const char** modrm_opcodes = NULL;
do {
switch (*instr) {
// Group 1 - lock and repeat prefixes:
case 0xF0:
case 0xF2:
case 0xF3:
prefix[0] = *instr;
break;
// Group 2 - segment override prefixes:
case kCs:
case kSs:
case kDs:
case kEs:
case kFs:
case kGs:
prefix[1] = *instr;
break;
// Group 3 - operand size override:
case 0x66:
prefix[2] = *instr;
break;
// Group 4 - address size override:
case 0x67:
prefix[3] = *instr;
break;
default:
have_prefixes = false;
break;
}
if (have_prefixes) {
instr++;
}
} while (have_prefixes);
uint8_t rex = (*instr >= 0x40 && *instr <= 0x4F) ? *instr : 0;
bool has_modrm = false;
bool reg_is_opcode = false;
size_t immediate_bytes = 0;
size_t branch_bytes = 0;
std::ostringstream opcode;
bool store = false; // stores to memory (ie rm is on the left)
bool load = false; // loads from memory (ie rm is on the right)
bool byte_operand = false;
bool ax = false; // implicit use of ax
bool reg_in_opcode = false; // low 3-bits of opcode encode register parameter
RegFile src_reg_file = GPR;
RegFile dst_reg_file = GPR;
switch (*instr) {
#define DISASSEMBLER_ENTRY(opname, \
rm8_r8, rm32_r32, \
r8_rm8, r32_rm32, \
ax8_i8, ax32_i32) \
case rm8_r8: opcode << #opname; store = true; has_modrm = true; byte_operand = true; break; \
case rm32_r32: opcode << #opname; store = true; has_modrm = true; break; \
case r8_rm8: opcode << #opname; load = true; has_modrm = true; byte_operand = true; break; \
case r32_rm32: opcode << #opname; load = true; has_modrm = true; break; \
case ax8_i8: opcode << #opname; ax = true; immediate_bytes = 1; byte_operand = true; break; \
case ax32_i32: opcode << #opname; ax = true; immediate_bytes = 4; break;
DISASSEMBLER_ENTRY(add,
0x00 /* RegMem8/Reg8 */, 0x01 /* RegMem32/Reg32 */,
0x02 /* Reg8/RegMem8 */, 0x03 /* Reg32/RegMem32 */,
0x04 /* Rax8/imm8 opcode */, 0x05 /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(or,
0x08 /* RegMem8/Reg8 */, 0x09 /* RegMem32/Reg32 */,
0x0A /* Reg8/RegMem8 */, 0x0B /* Reg32/RegMem32 */,
0x0C /* Rax8/imm8 opcode */, 0x0D /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(adc,
0x10 /* RegMem8/Reg8 */, 0x11 /* RegMem32/Reg32 */,
0x12 /* Reg8/RegMem8 */, 0x13 /* Reg32/RegMem32 */,
0x14 /* Rax8/imm8 opcode */, 0x15 /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(sbb,
0x18 /* RegMem8/Reg8 */, 0x19 /* RegMem32/Reg32 */,
0x1A /* Reg8/RegMem8 */, 0x1B /* Reg32/RegMem32 */,
0x1C /* Rax8/imm8 opcode */, 0x1D /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(and,
0x20 /* RegMem8/Reg8 */, 0x21 /* RegMem32/Reg32 */,
0x22 /* Reg8/RegMem8 */, 0x23 /* Reg32/RegMem32 */,
0x24 /* Rax8/imm8 opcode */, 0x25 /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(sub,
0x28 /* RegMem8/Reg8 */, 0x29 /* RegMem32/Reg32 */,
0x2A /* Reg8/RegMem8 */, 0x2B /* Reg32/RegMem32 */,
0x2C /* Rax8/imm8 opcode */, 0x2D /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(xor,
0x30 /* RegMem8/Reg8 */, 0x31 /* RegMem32/Reg32 */,
0x32 /* Reg8/RegMem8 */, 0x33 /* Reg32/RegMem32 */,
0x34 /* Rax8/imm8 opcode */, 0x35 /* Rax32/imm32 */)
DISASSEMBLER_ENTRY(cmp,
0x38 /* RegMem8/Reg8 */, 0x39 /* RegMem32/Reg32 */,
0x3A /* Reg8/RegMem8 */, 0x3B /* Reg32/RegMem32 */,
0x3C /* Rax8/imm8 opcode */, 0x3D /* Rax32/imm32 */)
#undef DISASSEMBLER_ENTRY
case 0x50: case 0x51: case 0x52: case 0x53: case 0x54: case 0x55: case 0x56: case 0x57:
opcode << "push";
reg_in_opcode = true;
break;
case 0x58: case 0x59: case 0x5A: case 0x5B: case 0x5C: case 0x5D: case 0x5E: case 0x5F:
opcode << "pop";
reg_in_opcode = true;
break;
case 0x68: opcode << "push"; immediate_bytes = 4; break;
case 0x6A: opcode << "push"; immediate_bytes = 1; break;
case 0x70: case 0x71: case 0x72: case 0x73: case 0x74: case 0x75: case 0x76: case 0x77:
case 0x78: case 0x79: case 0x7A: case 0x7B: case 0x7C: case 0x7D: case 0x7E: case 0x7F:
static const char* condition_codes[] =
{"o", "no", "b/nae/c", "nb/ae/nc", "z/eq", "nz/ne", "be/na", "nbe/a",
"s", "ns", "p/pe", "np/po", "l/nge", "nl/ge", "le/ng", "nle/g"
};
opcode << "j" << condition_codes[*instr & 0xF];
branch_bytes = 1;
break;
case 0x88: opcode << "mov"; store = true; has_modrm = true; byte_operand = true; break;
case 0x89: opcode << "mov"; store = true; has_modrm = true; break;
case 0x8A: opcode << "mov"; load = true; has_modrm = true; byte_operand = true; break;
case 0x8B: opcode << "mov"; load = true; has_modrm = true; break;
case 0x0F: // 2 byte extended opcode
instr++;
switch (*instr) {
case 0x10: case 0x11:
if (prefix[0] == 0xF2) {
opcode << "movsd";
} else if (prefix[0] == 0xF3) {
opcode << "movss";
} else if (prefix[2] == 0x66) {
opcode << "movupd";
} else {
opcode << "movups";
}
has_modrm = true;
src_reg_file = dst_reg_file = SSE;
load = *instr == 0x10;
store = !load;
break;
case 0x38: // 3 byte extended opcode
opcode << StringPrintf("unknown opcode '0F 38 %02X'", *instr);
break;
case 0x3A: // 3 byte extended opcode
opcode << StringPrintf("unknown opcode '0F 3A %02X'", *instr);
break;
case 0x50: case 0x51: case 0x52: case 0x53: case 0x54: case 0x55: case 0x56: case 0x57:
case 0x58: case 0x59: case 0x5C: case 0x5D: case 0x5E: case 0x5F: {
switch (*instr) {
case 0x50: opcode << "movmsk"; break;
case 0x51: opcode << "sqrt"; break;
case 0x52: opcode << "rsqrt"; break;
case 0x53: opcode << "rcp"; break;
case 0x54: opcode << "and"; break;
case 0x55: opcode << "andn"; break;
case 0x56: opcode << "or"; break;
case 0x57: opcode << "xor"; break;
case 0x58: opcode << "add"; break;
case 0x59: opcode << "mul"; break;
case 0x5C: opcode << "sub"; break;
case 0x5D: opcode << "min"; break;
case 0x5E: opcode << "div"; break;
case 0x5F: opcode << "max"; break;
default: LOG(FATAL) << "Unreachable";
}
if (prefix[2] == 0x66) {
opcode << "pd";
prefix[2] = 0; // clear prefix now its served its purpose as part of the opcode
} else if (prefix[0] == 0xF2) {
opcode << "sd";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else if (prefix[0] == 0xF3) {
opcode << "ss";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else {
opcode << "ps";
}
load = true;
has_modrm = true;
src_reg_file = dst_reg_file = SSE;
break;
}
case 0x5A:
if (prefix[2] == 0x66) {
opcode << "cvtpd2ps";
prefix[2] = 0; // clear prefix now its served its purpose as part of the opcode
} else if (prefix[0] == 0xF2) {
opcode << "cvtsd2ss";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else if (prefix[0] == 0xF3) {
opcode << "cvtss2sd";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else {
opcode << "cvtps2pd";
}
load = true;
has_modrm = true;
src_reg_file = dst_reg_file = SSE;
break;
case 0x5B:
if (prefix[2] == 0x66) {
opcode << "cvtps2dq";
prefix[2] = 0; // clear prefix now its served its purpose as part of the opcode
} else if (prefix[0] == 0xF2) {
opcode << "bad opcode F2 0F 5B";
} else if (prefix[0] == 0xF3) {
opcode << "cvttps2dq";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else {
opcode << "cvtdq2ps";
}
load = true;
has_modrm = true;
src_reg_file = dst_reg_file = SSE;
break;
case 0x6E:
if (prefix[2] == 0x66) {
dst_reg_file = SSE;
opcode << "movq";
prefix[2] = 0; // clear prefix now its served its purpose as part of the opcode
} else {
dst_reg_file = MMX;
opcode << "movd";
}
load = true;
has_modrm = true;
break;
case 0x6F:
if (prefix[2] == 0x66) {
dst_reg_file = SSE;
opcode << "movdqa";
} else if (prefix[0] == 0xF3) {
dst_reg_file = SSE;
opcode << "movdqu";
prefix[0] = 0; // clear prefix now its served its purpose as part of the opcode
} else {
dst_reg_file = MMX;
opcode << "movq";
}
load = true;
has_modrm = true;
break;
case 0x80: case 0x81: case 0x82: case 0x83: case 0x84: case 0x85: case 0x86: case 0x87:
case 0x88: case 0x89: case 0x8A: case 0x8B: case 0x8C: case 0x8D: case 0x8E: case 0x8F:
opcode << "j" << condition_codes[*instr & 0xF];
branch_bytes = 4;
break;
case 0x90: case 0x91: case 0x92: case 0x93: case 0x94: case 0x95: case 0x96: case 0x97:
case 0x98: case 0x99: case 0x9A: case 0x9B: case 0x9C: case 0x9D: case 0x9E: case 0x9F:
opcode << "set" << condition_codes[*instr & 0xF];
modrm_opcodes = NULL;
reg_is_opcode = true;
has_modrm = true;
store = true;
break;
case 0xB6: opcode << "movzxb"; has_modrm = true; load = true; break;
case 0xB7: opcode << "movzxw"; has_modrm = true; load = true; break;
default:
opcode << StringPrintf("unknown opcode '0F %02X'", *instr);
break;
}
break;
case 0x80: case 0x81: case 0x82: case 0x83:
static const char* x80_opcodes[] = {"add", "or", "adc", "sbb", "and", "sub", "xor", "cmp"};
modrm_opcodes = x80_opcodes;
has_modrm = true;
reg_is_opcode = true;
store = true;
byte_operand = (*instr & 1) == 0;
immediate_bytes = *instr == 0x81 ? 4 : 1;
break;
case 0x8D:
opcode << "lea";
has_modrm = true;
load = true;
break;
case 0xB0: case 0xB1: case 0xB2: case 0xB3: case 0xB4: case 0xB5: case 0xB6: case 0xB7:
opcode << "mov";
immediate_bytes = 1;
reg_in_opcode = true;
break;
case 0xB8: case 0xB9: case 0xBA: case 0xBB: case 0xBC: case 0xBD: case 0xBE: case 0xBF:
opcode << "mov";
immediate_bytes = 4;
reg_in_opcode = true;
break;
case 0xC0: case 0xC1:
case 0xD0: case 0xD1:
static const char* shift_opcodes[] =
{"rol", "ror", "rcl", "rcr", "shl", "shr", "unknown-shift", "sar"};
modrm_opcodes = shift_opcodes;
has_modrm = true;
reg_is_opcode = true;
store = true;
immediate_bytes = ((*instr & 0xf0) == 0xc0) ? 1 : 0;
byte_operand = *instr == 0xC0;
break;
case 0xC3: opcode << "ret"; break;
case 0xC7:
static const char* c7_opcodes[] = {"mov", "unknown-c7", "unknown-c7", "unknown-c7", "unknown-c7", "unknown-c7", "unknown-c7", "unknown-c7"};
modrm_opcodes = c7_opcodes;
store = true;
immediate_bytes = 4;
has_modrm = true;
reg_is_opcode = true;
break;
case 0xCC: opcode << "int 3"; break;
case 0xE8: opcode << "call"; branch_bytes = 4; break;
case 0xE9: opcode << "jmp"; branch_bytes = 4; break;
case 0xEB: opcode << "jmp"; branch_bytes = 1; break;
case 0xF6: case 0xF7:
static const char* f7_opcodes[] = {"test", "unknown-f7", "not", "neg", "mul edx:eax, eax *", "imul edx:eax, eax *", "div edx:eax, edx:eax /", "idiv edx:eax, edx:eax /"};
modrm_opcodes = f7_opcodes;
has_modrm = true;
reg_is_opcode = true;
store = true;
immediate_bytes = ((instr[1] & 0x38) == 0) ? 1 : 0;
break;
case 0xFF:
static const char* ff_opcodes[] = {"inc", "dec", "call", "call", "jmp", "jmp", "push", "unknown-ff"};
modrm_opcodes = ff_opcodes;
has_modrm = true;
reg_is_opcode = true;
load = true;
break;
default:
opcode << StringPrintf("unknown opcode '%02X'", *instr);
break;
}
std::ostringstream args;
if (reg_in_opcode) {
DCHECK(!has_modrm);
DumpReg(args, rex, *instr & 0x7, false, prefix[2], GPR);
}
instr++;
uint32_t address_bits = 0;
if (has_modrm) {
uint8_t modrm = *instr;
instr++;
uint8_t mod = modrm >> 6;
uint8_t reg_or_opcode = (modrm >> 3) & 7;
uint8_t rm = modrm & 7;
std::ostringstream address;
if (mod == 0 && rm == 5) { // fixed address
address_bits = *reinterpret_cast<const uint32_t*>(instr);
address << StringPrintf("[0x%x]", address_bits);
instr += 4;
} else if (rm == 4 && mod != 3) { // SIB
uint8_t sib = *instr;
instr++;
uint8_t ss = (sib >> 6) & 3;
uint8_t index = (sib >> 3) & 7;
uint8_t base = sib & 7;
address << "[";
if (base != 5 || mod != 0) {
DumpBaseReg(address, rex, base);
if (index != 4) {
address << " + ";
}
}
if (index != 4) {
DumpIndexReg(address, rex, index);
if (ss != 0) {
address << StringPrintf(" * %d", 1 << ss);
}
}
if (mod == 1) {
address << StringPrintf(" + %d", *reinterpret_cast<const int8_t*>(instr));
instr++;
} else if (mod == 2) {
address << StringPrintf(" + %d", *reinterpret_cast<const int32_t*>(instr));
instr += 4;
}
address << "]";
} else {
if (mod == 3) {
DumpReg(address, rex, rm, byte_operand, prefix[2], load ? src_reg_file : dst_reg_file);
} else {
address << "[";
DumpBaseReg(address, rex, rm);
if (mod == 1) {
address << StringPrintf(" + %d", *reinterpret_cast<const int8_t*>(instr));
instr++;
} else if (mod == 2) {
address << StringPrintf(" + %d", *reinterpret_cast<const int32_t*>(instr));
instr += 4;
}
address << "]";
}
}
if (reg_is_opcode && modrm_opcodes != NULL) {
opcode << modrm_opcodes[reg_or_opcode];
}
if (load) {
if (!reg_is_opcode) {
DumpReg(args, rex, reg_or_opcode, byte_operand, prefix[2], dst_reg_file);
args << ", ";
}
DumpSegmentOverride(args, prefix[1]);
args << address.str();
} else {
DCHECK(store);
DumpSegmentOverride(args, prefix[1]);
args << address.str();
if (!reg_is_opcode) {
args << ", ";
DumpReg(args, rex, reg_or_opcode, byte_operand, prefix[2], src_reg_file);
}
}
}
if (ax) {
DumpReg(args, rex, 0 /* EAX */, byte_operand, prefix[2], GPR);
}
if (immediate_bytes > 0) {
if (has_modrm || reg_in_opcode || ax) {
args << ", ";
}
if (immediate_bytes == 1) {
args << StringPrintf("%d", *reinterpret_cast<const int8_t*>(instr));
instr++;
} else {
CHECK_EQ(immediate_bytes, 4u);
args << StringPrintf("%d", *reinterpret_cast<const int32_t*>(instr));
instr += 4;
}
} else if (branch_bytes > 0) {
DCHECK(!has_modrm);
int32_t displacement;
if (branch_bytes == 1) {
displacement = *reinterpret_cast<const int8_t*>(instr);
instr++;
} else {
CHECK_EQ(branch_bytes, 4u);
displacement = *reinterpret_cast<const int32_t*>(instr);
instr += 4;
}
args << StringPrintf("%+d (%p)", displacement, instr + displacement);
}
if (prefix[1] == kFs) {
args << " ; ";
Thread::DumpThreadOffset(args, address_bits, 4);
}
std::stringstream hex;
for (size_t i = 0; begin_instr + i < instr; ++i) {
hex << StringPrintf("%02X", begin_instr[i]);
}
os << StringPrintf("\t\t\t%p: %22s \t%-7s ", begin_instr, hex.str().c_str(), opcode.str().c_str()) << args.str() << '\n';
return instr - begin_instr;
}
} // namespace x86
} // namespace art