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/***************************************************************************************************
Zyan Disassembler Library (Zydis)
Original Author : Florian Bernd
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
***************************************************************************************************/
#include "zydis/Zycore/LibC.h"
#include "zydis/Zydis/Segment.h"
/* ============================================================================================== */
/* Exported functions */
/* ============================================================================================== */
ZyanStatus ZydisGetInstructionSegments(const ZydisDecodedInstruction* instruction,
ZydisInstructionSegments* segments)
{
if (!instruction || !segments)
{
return ZYAN_STATUS_INVALID_ARGUMENT;
}
ZYAN_MEMSET(segments, 0, sizeof(*segments));
// Legacy prefixes and `REX`
if (instruction->raw.prefix_count)
{
const ZyanU8 rex_offset = (instruction->attributes & ZYDIS_ATTRIB_HAS_REX) ? 1 : 0;
if (!rex_offset || (instruction->raw.prefix_count > 1))
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_PREFIXES;
segments->segments[segments->count ].offset = 0;
segments->segments[segments->count++].size =
instruction->raw.prefix_count - rex_offset;
}
if (rex_offset)
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_REX;
segments->segments[segments->count ].offset =
instruction->raw.prefix_count - rex_offset;
segments->segments[segments->count++].size = 1;
}
}
// Encoding prefixes
ZydisInstructionSegment segment_type = ZYDIS_INSTR_SEGMENT_NONE;
ZyanU8 segment_offset = 0;
ZyanU8 segment_size = 0;
switch (instruction->encoding)
{
case ZYDIS_INSTRUCTION_ENCODING_XOP:
segment_type = ZYDIS_INSTR_SEGMENT_XOP;
segment_offset = instruction->raw.xop.offset;
segment_size = 3;
break;
case ZYDIS_INSTRUCTION_ENCODING_VEX:
segment_type = ZYDIS_INSTR_SEGMENT_VEX;
segment_offset = instruction->raw.vex.offset;
segment_size = instruction->raw.vex.size;
break;
case ZYDIS_INSTRUCTION_ENCODING_EVEX:
segment_type = ZYDIS_INSTR_SEGMENT_EVEX;
segment_offset = instruction->raw.evex.offset;
segment_size = 4;
break;
case ZYDIS_INSTRUCTION_ENCODING_MVEX:
segment_type = ZYDIS_INSTR_SEGMENT_MVEX;
segment_offset = instruction->raw.mvex.offset;
segment_size = 4;
break;
default:
break;
}
if (segment_type)
{
segments->segments[segments->count ].type = segment_type;
segments->segments[segments->count ].offset = segment_offset;
segments->segments[segments->count++].size = segment_size;
}
// Opcode
segment_size = 1;
if ((instruction->encoding == ZYDIS_INSTRUCTION_ENCODING_LEGACY) ||
(instruction->encoding == ZYDIS_INSTRUCTION_ENCODING_3DNOW))
{
switch (instruction->opcode_map)
{
case ZYDIS_OPCODE_MAP_DEFAULT:
break;
case ZYDIS_OPCODE_MAP_0F:
ZYAN_FALLTHROUGH;
case ZYDIS_OPCODE_MAP_0F0F:
segment_size = 2;
break;
case ZYDIS_OPCODE_MAP_0F38:
ZYAN_FALLTHROUGH;
case ZYDIS_OPCODE_MAP_0F3A:
segment_size = 3;
break;
default:
ZYAN_UNREACHABLE;
}
}
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_OPCODE;
if (segments->count)
{
segments->segments[segments->count].offset =
segments->segments[segments->count - 1].offset +
segments->segments[segments->count - 1].size;
} else
{
segments->segments[segments->count].offset = 0;
}
segments->segments[segments->count++].size = segment_size;
// ModRM
if (instruction->attributes & ZYDIS_ATTRIB_HAS_MODRM)
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_MODRM;
segments->segments[segments->count ].offset = instruction->raw.modrm.offset;
segments->segments[segments->count++].size = 1;
}
// SIB
if (instruction->attributes & ZYDIS_ATTRIB_HAS_SIB)
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_SIB;
segments->segments[segments->count ].offset = instruction->raw.sib.offset;
segments->segments[segments->count++].size = 1;
}
// Displacement
if (instruction->raw.disp.size)
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_DISPLACEMENT;
segments->segments[segments->count ].offset = instruction->raw.disp.offset;
segments->segments[segments->count++].size = instruction->raw.disp.size / 8;
}
// Immediates
for (ZyanU8 i = 0; i < 2; ++i)
{
if (instruction->raw.imm[i].size)
{
segments->segments[segments->count ].type = ZYDIS_INSTR_SEGMENT_IMMEDIATE;
segments->segments[segments->count ].offset = instruction->raw.imm[i].offset;
segments->segments[segments->count++].size = instruction->raw.imm[i].size / 8;
}
}
if (instruction->encoding == ZYDIS_INSTRUCTION_ENCODING_3DNOW)
{
segments->segments[segments->count].type = ZYDIS_INSTR_SEGMENT_OPCODE;
segments->segments[segments->count].offset = instruction->length -1;
segments->segments[segments->count++].size = 1;
}
return ZYAN_STATUS_SUCCESS;
}
/* ---------------------------------------------------------------------------------------------- */
/* ============================================================================================== */