externals: Update zydis to 4.0.0

Merge commit '6fa8d51479e9a5542c67bec715a1f68e7ed057ba'

externals/zydis/tools/ZydisFuzzReEncoding.c

@@ -0,0 +1,89 @@
+/***************************************************************************************************
+
+  Zyan Disassembler Library (Zydis)
+
+  Original Author : Mappa
+
+ * 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.
+
+***************************************************************************************************/
+
+/**
+ * @file
+ *
+ * This file implements fuzz target for re-encoding. Fuzzer input is passed to decoder first and if
+ * it decodes as a valid instruction `ZydisEncoderDecodedInstructionToEncoderRequest` is used to
+ * create encoder request which gets passed to the encoder.
+ */
+
+#include "ZydisFuzzShared.h"
+
+/* ============================================================================================== */
+/* Enums and types                                                                                */
+/* ============================================================================================== */
+
+/**
+ * Structure for fuzzing decoder inputs.
+ */
+typedef struct ZydisFuzzControlBlock_
+{
+    ZydisMachineMode machine_mode;
+    ZydisStackWidth stack_width;
+} ZydisFuzzControlBlock;
+
+/* ============================================================================================== */
+/* Fuzz target                                                                                    */
+/* ============================================================================================== */
+
+ZYAN_NO_SANITIZE("enum")
+int ZydisFuzzTarget(ZydisStreamRead read_fn, void *stream_ctx)
+{
+    ZydisFuzzControlBlock control_block;
+    if (read_fn(
+        stream_ctx, (ZyanU8 *)&control_block, sizeof(control_block)) != sizeof(control_block))
+    {
+        ZYDIS_MAYBE_FPUTS("Not enough bytes to fuzz\n", ZYAN_STDERR);
+        return EXIT_SUCCESS;
+    }
+
+    ZydisDecoder decoder;
+    if (!ZYAN_SUCCESS(ZydisDecoderInit(&decoder, control_block.machine_mode,
+        control_block.stack_width)))
+    {
+        ZYDIS_MAYBE_FPUTS("Failed to initialize decoder\n", ZYAN_STDERR);
+        return EXIT_FAILURE;
+    }
+
+    ZyanU8 buffer[32];
+    ZyanUSize input_len = read_fn(stream_ctx, buffer, sizeof(buffer));
+
+    ZydisDecodedInstruction insn1;
+    ZydisDecodedOperand operands1[ZYDIS_MAX_OPERAND_COUNT];
+    ZyanStatus status = ZydisDecoderDecodeFull(&decoder, buffer, input_len, &insn1, operands1);
+    if (!ZYAN_SUCCESS(status))
+    {
+        return EXIT_FAILURE;
+    }
+
+    ZydisReEncodeInstruction(&decoder, &insn1, operands1, insn1.operand_count_visible, buffer);
+
+    return EXIT_SUCCESS;
+}
+
+/* ============================================================================================== */