dep: Add Zydis

dep/zydis/src/Utils.c

@@ -0,0 +1,171 @@
+/***************************************************************************************************
+
+  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 <Zycore/LibC.h>
+#include <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;
+    }
+}
+
+/* ============================================================================================== */