Files
test-repo/decode.h
Alexis Engelke 8063cb7401 Decode additional segment prefixes
This is mainly needed to handle the new control flow enforcement
extensions, making 3E a "notrack" prefix for indirect calls and jumps.

This is not (yet) modeled, and requires additional information on the
order of the prefixes, as 3E_66 (16-bit in ds segment) has a different
meaning than 66_3E (16-bit notrack). Before implementing this, an
analysis of the performance impact when decoding more prefix information
is probably required to avoid degrading overall performance for very few
and (as of now) seldomly used corner cases.
2018-12-31 13:23:42 +01:00

157 lines
2.9 KiB
C

#ifndef ARMX86_DECODE_H
#define ARMX86_DECODE_H
#include <stddef.h>
#include <stdint.h>
#if defined(ARCH_X86_64) && __SIZEOF_POINTER__ < 8
#error "Decoding x86-64 requires a 64-bit architecture"
#endif
#ifndef ssize_t
#define ssize_t intptr_t
#endif
#define DECODE_TABLE_MNEMONICS
#define MNEMONIC(name,value) IT_ ## name = value,
enum
{
#include <decode-table.inc>
};
#undef DECODE_TABLE_MNEMONICS
#undef MNEMONIC
enum RegIndex {
RI_AL = 0,
RI_CL,
RI_DL,
RI_BL,
RI_AH,
RI_CH,
RI_DH,
RI_BH,
RI_AX = 0,
RI_CX,
RI_DX,
RI_BX,
RI_SP,
RI_BP,
RI_SI,
RI_DI,
#if defined(ARCH_X86_64)
RI_R8,
RI_R9,
RI_R10,
RI_R11,
RI_R12,
RI_R13,
RI_R14,
RI_R15,
#endif
// EIP cannot be encoded in Protected/Compatibility Mode
#if defined(ARCH_X86_64)
RI_IP = 0x10,
#endif
RI_ES = 0,
RI_CS,
RI_SS,
RI_DS,
RI_FS,
RI_GS,
};
typedef uint8_t Reg;
#define reg_index(reg) (reg)
#define reg_is_none(reg) ((reg) == REG_NONE)
#define REG_NONE (0x3f)
enum PrefixSet
{
PREFIX_SEG_FS = 1 << 0,
PREFIX_SEG_GS = 1 << 1,
PREFIX_SEG_CS = 1 << 12,
PREFIX_SEG_DS = 1 << 17,
PREFIX_SEG_ES = 1 << 18,
PREFIX_OPSZ = 1 << 2,
PREFIX_ADDRSZ = 1 << 3,
PREFIX_LOCK = 1 << 4,
PREFIX_REPNZ = 1 << 5,
PREFIX_REP = 1 << 6,
#if defined(ARCH_X86_64)
PREFIX_REX = 1 << 7,
PREFIX_REXB = 1 << 8,
PREFIX_REXX = 1 << 9,
PREFIX_REXR = 1 << 10,
PREFIX_REXW = 1 << 11,
#endif
PREFIX_ESC_NONE = 0 << 13,
PREFIX_ESC_0F = 1 << 13,
PREFIX_ESC_0F38 = 2 << 13,
PREFIX_ESC_0F3A = 3 << 13,
PREFIX_ESC_MASK = 3 << 13,
PREFIX_VEX = 1 << 15,
PREFIX_VEXL = 1 << 16,
};
typedef enum PrefixSet PrefixSet;
enum OperandType
{
OT_NONE = 0,
OT_REG = 1,
OT_IMM = 2,
OT_MEM = 3,
};
struct Operand
{
uint8_t type : 2;
uint8_t reg : 6;
uint8_t size;
};
struct Instr
{
uint16_t type;
struct Operand operands[4];
uint8_t segment : 3;
uint8_t width : 5;
/**
* Encoded as 1 << (scale - 1) **or** no scaled register at all if zero.
**/
uint8_t scale : 3;
uint8_t sreg : 5;
PrefixSet prefixes;
size_t immediate;
intptr_t disp;
uintptr_t address;
uint32_t size : 4;
};
typedef struct Instr Instr;
#define INSTR_SEGMENT(instr) ((instr)->segment)
#define INSTR_WIDTH(instr) ((instr)->width)
#define INSTR_HAS_REP(instr) ((instr)->prefixes & PREFIX_REP)
#define INSTR_HAS_REPNZ(instr) ((instr)->prefixes & PREFIX_REPNZ)
#define INSTR_HAS_LOCK(instr) ((instr)->prefixes & PREFIX_LOCK)
#define INSTR_HAS_ADDRSZ(instr) ((instr)->prefixes & PREFIX_ADDRSZ)
#if defined(ARCH_X86_64)
#define INSTR_HAS_REX(instr) ((instr)->prefixes & PREFIX_REX)
#endif
int decode(const uint8_t* buffer, int len, Instr* out_instr);
void instr_format(const Instr* instr, char buffer[128]);
void instr_print(const Instr* instr) __attribute__((deprecated));
#endif