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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/Utils.h"
/* ============================================================================================== */
/* Exported functions */
/* ============================================================================================== */
/* ---------------------------------------------------------------------------------------------- */
/* Address calculation */
/* ---------------------------------------------------------------------------------------------- */
// Signed integer overflow is expected behavior in this function, for wrapping around the
// instruction pointer on jumps right at the end of the address space.
ZYAN_NO_SANITIZE("signed-integer-overflow")
ZyanStatus ZydisCalcAbsoluteAddress(const ZydisDecodedInstruction* instruction,
const ZydisDecodedOperand* operand, ZyanU64 runtime_address, ZyanU64* result_address)
{
if (!instruction || !operand || !result_address)
{
return ZYAN_STATUS_INVALID_ARGUMENT;
}
switch (operand->type)
{
case ZYDIS_OPERAND_TYPE_MEMORY:
if (!operand->mem.disp.has_displacement)
{
return ZYAN_STATUS_INVALID_ARGUMENT;
}
if (operand->mem.base == ZYDIS_REGISTER_EIP)
{
*result_address = ((ZyanU32)runtime_address + instruction->length +
(ZyanU32)operand->mem.disp.value);
return ZYAN_STATUS_SUCCESS;
}
if (operand->mem.base == ZYDIS_REGISTER_RIP)
{
*result_address = (ZyanU64)(runtime_address + instruction->length +
operand->mem.disp.value);
return ZYAN_STATUS_SUCCESS;
}
if ((operand->mem.base == ZYDIS_REGISTER_NONE) &&
(operand->mem.index == ZYDIS_REGISTER_NONE))
{
switch (instruction->address_width)
{
case 16:
*result_address = (ZyanU64)operand->mem.disp.value & 0x000000000000FFFF;
return ZYAN_STATUS_SUCCESS;
case 32:
*result_address = (ZyanU64)operand->mem.disp.value & 0x00000000FFFFFFFF;
return ZYAN_STATUS_SUCCESS;
case 64:
*result_address = (ZyanU64)operand->mem.disp.value;
return ZYAN_STATUS_SUCCESS;
default:
return ZYAN_STATUS_INVALID_ARGUMENT;
}
}
break;
case ZYDIS_OPERAND_TYPE_IMMEDIATE:
if (operand->imm.is_signed && operand->imm.is_relative)
{
*result_address = (ZyanU64)((ZyanI64)runtime_address + instruction->length +
operand->imm.value.s);
switch (instruction->machine_mode)
{
case ZYDIS_MACHINE_MODE_LONG_COMPAT_16:
case ZYDIS_MACHINE_MODE_LEGACY_16:
case ZYDIS_MACHINE_MODE_REAL_16:
case ZYDIS_MACHINE_MODE_LONG_COMPAT_32:
case ZYDIS_MACHINE_MODE_LEGACY_32:
// `XBEGIN` is a special case as it doesn't truncate computed address
// This behavior is documented by Intel (SDM Vol. 2C):
// Use of the 16-bit operand size does not cause this address to be truncated to
// 16 bits, unlike a near jump to a relative offset.
if ((instruction->operand_width == 16) &&
(instruction->mnemonic != ZYDIS_MNEMONIC_XBEGIN))
{
*result_address &= 0xFFFF;
}
break;
case ZYDIS_MACHINE_MODE_LONG_64:
break;
default:
return ZYAN_STATUS_INVALID_ARGUMENT;
}
return ZYAN_STATUS_SUCCESS;
}
break;
default:
break;
}
return ZYAN_STATUS_INVALID_ARGUMENT;
}
ZyanStatus ZydisCalcAbsoluteAddressEx(const ZydisDecodedInstruction* instruction,
const ZydisDecodedOperand* operand, ZyanU64 runtime_address,
const ZydisRegisterContext* register_context, ZyanU64* result_address)
{
// TODO: Test this with AGEN/MIB operands
// TODO: Add support for Gather/Scatter instructions
if (!instruction || !operand || !register_context || !result_address)
{
return ZYAN_STATUS_INVALID_ARGUMENT;
}
if ((operand->type != ZYDIS_OPERAND_TYPE_MEMORY) ||
((operand->mem.base == ZYDIS_REGISTER_NONE) &&
(operand->mem.index == ZYDIS_REGISTER_NONE)) ||
(operand->mem.base == ZYDIS_REGISTER_EIP) ||
(operand->mem.base == ZYDIS_REGISTER_RIP))
{
return ZydisCalcAbsoluteAddress(instruction, operand, runtime_address, result_address);
}
ZyanU64 value = operand->mem.disp.value;
if (operand->mem.base)
{
value += register_context->values[operand->mem.base];
}
if (operand->mem.index)
{
value += register_context->values[operand->mem.index] * operand->mem.scale;
}
switch (instruction->address_width)
{
case 16:
*result_address = value & 0x000000000000FFFF;
return ZYAN_STATUS_SUCCESS;
case 32:
*result_address = value & 0x00000000FFFFFFFF;
return ZYAN_STATUS_SUCCESS;
case 64:
*result_address = value;
return ZYAN_STATUS_SUCCESS;
default:
return ZYAN_STATUS_INVALID_ARGUMENT;
}
}
/* ============================================================================================== */