Patch extrq (#943)

* Use a singleton for instruction decoding

* Use singleton class

* Patch `EXTRQ`

* Fixup signal context functions

* Update CMakeLists.txt

---------

Co-authored-by: georgemoralis <giorgosmrls@gmail.com>

src/common/decoder.cpp

@@ -2,18 +2,18 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <fmt/format.h>
-#include "common/disassembler.h"
+#include "common/decoder.h"
 
 namespace Common {
 
-Disassembler::Disassembler() {
+DecoderImpl::DecoderImpl() {
     ZydisDecoderInit(&m_decoder, ZYDIS_MACHINE_MODE_LONG_64, ZYDIS_STACK_WIDTH_64);
     ZydisFormatterInit(&m_formatter, ZYDIS_FORMATTER_STYLE_INTEL);
 }
 
-Disassembler::~Disassembler() = default;
+DecoderImpl::~DecoderImpl() = default;
 
-void Disassembler::printInstruction(void* code, u64 address) {
+void DecoderImpl::printInstruction(void* code, u64 address) {
     ZydisDecodedInstruction instruction;
     ZydisDecodedOperand operands[ZYDIS_MAX_OPERAND_COUNT_VISIBLE];
     ZyanStatus status =
@@ -25,8 +25,8 @@ void Disassembler::printInstruction(void* code, u64 address) {
     }
 }
 
-void Disassembler::printInst(ZydisDecodedInstruction& inst, ZydisDecodedOperand* operands,
-                             u64 address) {
+void DecoderImpl::printInst(ZydisDecodedInstruction& inst, ZydisDecodedOperand* operands,
+                            u64 address) {
     const int bufLen = 256;
     char szBuffer[bufLen];
     ZydisFormatterFormatInstruction(&m_formatter, &inst, operands, inst.operand_count_visible,
@@ -34,4 +34,9 @@ void Disassembler::printInst(ZydisDecodedInstruction& inst, ZydisDecodedOperand*
     fmt::print("instruction: {}\n", szBuffer);
 }
 
+ZyanStatus DecoderImpl::decodeInstruction(ZydisDecodedInstruction& inst,
+                                          ZydisDecodedOperand* operands, void* data, u64 size) {
+    return ZydisDecoderDecodeFull(&m_decoder, data, size, &inst, operands);
+}
+
 } // namespace Common

src/common/decoder.h

@@ -4,21 +4,26 @@
 #pragma once
 
 #include <Zydis/Zydis.h>
+#include "common/singleton.h"
 #include "common/types.h"
 
 namespace Common {
 
-class Disassembler {
+class DecoderImpl {
 public:
-    Disassembler();
-    ~Disassembler();
+    DecoderImpl();
+    ~DecoderImpl();
 
     void printInst(ZydisDecodedInstruction& inst, ZydisDecodedOperand* operands, u64 address);
     void printInstruction(void* code, u64 address);
+    ZyanStatus decodeInstruction(ZydisDecodedInstruction& inst, ZydisDecodedOperand* operands,
+                                 void* data, u64 size = 15);
 
 private:
     ZydisDecoder m_decoder;
     ZydisFormatter m_formatter;
 };
 
+using Decoder = Common::Singleton<DecoderImpl>;
+
 } // namespace Common

src/common/signal_context.cpp

@@ -0,0 +1,92 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "common/arch.h"
+#include "common/assert.h"
+#include "common/signal_context.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/ucontext.h>
+#endif
+
+namespace Common {
+
+void* GetXmmPointer(void* ctx, u8 index) {
+#if defined(_WIN32)
+#define CASE(index)                                                                                \
+    case index:                                                                                    \
+        return (void*)(&((EXCEPTION_POINTERS*)ctx)->ContextRecord->Xmm##index.Low)
+#elif defined(__APPLE__)
+#define CASE(index)                                                                                \
+    case index:                                                                                    \
+        return (void*)(&((ucontext_t*)ctx)->uc_mcontext->__fs.__fpu_xmm##index);
+#else
+#define CASE(index)                                                                                \
+    case index:                                                                                    \
+        return (void*)(&((ucontext_t*)ctx)->uc_mcontext.fpregs->_xmm[index].element[0])
+#endif
+    switch (index) {
+        CASE(0);
+        CASE(1);
+        CASE(2);
+        CASE(3);
+        CASE(4);
+        CASE(5);
+        CASE(6);
+        CASE(7);
+        CASE(8);
+        CASE(9);
+        CASE(10);
+        CASE(11);
+        CASE(12);
+        CASE(13);
+        CASE(14);
+        CASE(15);
+    default: {
+        UNREACHABLE_MSG("Invalid XMM register index: {}", index);
+        return nullptr;
+    }
+    }
+#undef CASE
+}
+
+void* GetRip(void* ctx) {
+#if defined(_WIN32)
+    return (void*)((EXCEPTION_POINTERS*)ctx)->ContextRecord->Rip;
+#elif defined(__APPLE__)
+    return (void*)((ucontext_t*)ctx)->uc_mcontext->__ss.__rip;
+#else
+    return (void*)((ucontext_t*)ctx)->uc_mcontext.gregs[REG_RIP];
+#endif
+}
+
+void IncrementRip(void* ctx, u64 length) {
+#if defined(_WIN32)
+    ((EXCEPTION_POINTERS*)ctx)->ContextRecord->Rip += length;
+#elif defined(__APPLE__)
+    ((ucontext_t*)ctx)->uc_mcontext->__ss.__rip += length;
+#else
+    ((ucontext_t*)ctx)->uc_mcontext.gregs[REG_RIP] += length;
+#endif
+}
+
+bool IsWriteError(void* ctx) {
+#if defined(_WIN32)
+    return ((EXCEPTION_POINTERS*)ctx)->ExceptionRecord->ExceptionInformation[0] == 1;
+#elif defined(__APPLE__)
+#if defined(ARCH_X86_64)
+    return ((ucontext_t*)ctx)->uc_mcontext->__es.__err & 0x2;
+#elif defined(ARCH_ARM64)
+    return ((ucontext_t*)ctx)->uc_mcontext->__es.__esr & 0x40;
+#endif
+#else
+#if defined(ARCH_X86_64)
+    return ((ucontext_t*)ctx)->uc_mcontext.gregs[REG_ERR] & 0x2;
+#else
+#error "Unsupported architecture"
+#endif
+#endif
+}
+} // namespace Common

src/common/signal_context.h

@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/types.h"
+
+namespace Common {
+
+void* GetXmmPointer(void* ctx, u8 index);
+
+void* GetRip(void* ctx);
+
+void IncrementRip(void* ctx, u64 length);
+
+bool IsWriteError(void* ctx);
+
+} // namespace Common