Changeset 287510 in webkit for trunk/Source/JavaScriptCore/disassembler/X86Disassembler.cpp

Timestamp:

Jan 2, 2022, 12:20:28 AM (3 years ago)

Author:

[email protected]

Message:

[JSC] Replace UDIS86 with Zydis
​https://bugs.webkit.org/show_bug.cgi?id=234765

Reviewed by Michael Saboff.

Source/JavaScriptCore:

UDIS86 is not updated from 2014. Since it is missing relatively new SIMD opcodes,
we cannot disassemble these opcodes when implementing Wasm SIMD.
This patch replaces UDIS86 with Zydis, which is actively developed and used in
SpiderMonkey too. It is under MIT license.

This patch imports Zydis v3.2.1.

1. Import header and C files of Zydis and Zycore in a flattened manner.
2. Add directory names to the files (e.g. Zydis/Decoder.c => ZydisDecoder.c) to make it easy to build in JSC build.
3. Replace header includes from #include <Zydis/XXX.h> to #include "ZydisXXX.h".
4. Fix compile errors with our stricter compiler flags.
5. Remove Zycore API files and ZycoreArgParse.[hc] since they are not used.

We didn't add files to Sources.txt since unified builds do not support C files currently.

Source/WTF:

• wtf/PlatformEnable.h:

File:

• trunk/Source/JavaScriptCore/disassembler/X86Disassembler.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/disassembler/X86Disassembler.cpp

@@ -27 +27 @@
 #include "Disassembler.h"
 
-#if ENABLE(UDIS86)
+#if ENABLE(ZYDIS)
 
 #include "MacroAssemblerCodeRef.h"
-#include "UDis86Disassembler.h"
+#include "Zydis.h"
 
 namespace JSC {
@@ -36 +36 @@
 bool tryToDisassemble(const MacroAssemblerCodePtr<DisassemblyPtrTag>& codePtr, size_t size, const char* prefix, PrintStream& out)
 {
-    return tryToDisassembleWithUDis86(codePtr, size, prefix, out);
+    ZydisDecoder decoder;
+    ZydisDecoderInit(&decoder, ZYDIS_MACHINE_MODE_LONG_64, ZYDIS_ADDRESS_WIDTH_64);
+
+    ZydisFormatter formatter;
+    ZydisFormatterInit(&formatter, ZYDIS_FORMATTER_STYLE_ATT);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_FORCE_SIZE, ZYAN_TRUE);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_HEX_UPPERCASE, ZYAN_FALSE);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_ADDR_PADDING_ABSOLUTE, ZYDIS_PADDING_DISABLED);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_ADDR_PADDING_RELATIVE, ZYDIS_PADDING_DISABLED);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_DISP_PADDING, ZYDIS_PADDING_DISABLED);
+    ZydisFormatterSetProperty(&formatter, ZYDIS_FORMATTER_PROP_IMM_PADDING, ZYDIS_PADDING_DISABLED);
+
+    const auto* data = codePtr.dataLocation<unsigned char*>();
+    ZyanUSize offset = 0;
+    ZydisDecodedInstruction instruction;
+    char formatted[1024];
+    while (ZYAN_SUCCESS(ZydisDecoderDecodeBuffer(&decoder, data + offset, size - offset, &instruction))) {
+        if (ZYAN_SUCCESS(ZydisFormatterFormatInstruction(&formatter, &instruction, formatted, sizeof(formatted), bitwise_cast<unsigned long long>(data + offset))))
+            out.printf("%s%#16llx: %s\n", prefix, static_cast<unsigned long long>(bitwise_cast<uintptr_t>(data + offset)), formatted);
+        else
+            out.printf("%s%#16llx: failed-to-format\n", prefix, static_cast<unsigned long long>(bitwise_cast<uintptr_t>(data + offset)));
+        offset += instruction.length;
+    }
+
+    return true;
 }
 
 } // namespace JSC
 
-#endif // ENABLE(UDIS86)
+#endif // ENABLE(ZYDIS)