Handle illegal instructions (#43)

src/test-sample/test.cpp

@@ -234,7 +234,7 @@ bool test_exceptions()
 	}
 }
 
-void throw_native_exception()
+void throw_access_violation()
 {
 	if (do_the_task)
 	{
@@ -242,19 +242,55 @@ void throw_native_exception()
 	}
 }
 
-bool test_native_exceptions()
+bool test_access_violation_exception()
 {
 	__try
 	{
-		throw_native_exception();
+		throw_access_violation();
 		return false;
 	}
 	__except (EXCEPTION_EXECUTE_HANDLER)
 	{
-		return true;
+		return GetExceptionCode() == STATUS_ACCESS_VIOLATION;
 	}
 }
 
+bool test_ud2_exception(void* address)
+{
+	__try
+	{
+		static_cast<void(*)()>(address)();
+		return false;
+	}
+	__except (EXCEPTION_EXECUTE_HANDLER)
+	{
+		return GetExceptionCode() == STATUS_ILLEGAL_INSTRUCTION;
+	}
+}
+
+bool test_illegal_instruction_exception()
+{
+	const auto address = VirtualAlloc(nullptr, 0x1000, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
+	if (!address)
+	{
+		return false;
+	}
+
+	memcpy(address, "\x0F\x0B", 2); // ud2
+
+	const auto res = test_ud2_exception(address);
+
+	VirtualFree(address, 0x1000, MEM_RELEASE);
+
+	return res;
+}
+
+bool test_native_exceptions()
+{
+	return test_access_violation_exception()
+		&& test_illegal_instruction_exception();
+}
+
 void print_time()
 {
 	const auto epoch_time = std::chrono::system_clock::now().time_since_epoch();

src/windows-emulator/windows_emulator.cpp

@@ -425,6 +425,27 @@ namespace
 		dispatch_exception_pointers(emu, dispatcher, pointers);
 	}
 
+	void dispatch_illegal_instruction_violation(x64_emulator& emu, const uint64_t dispatcher)
+	{
+		CONTEXT ctx{};
+		ctx.ContextFlags = CONTEXT_ALL;
+		context_frame::save(emu, ctx);
+
+		EXCEPTION_RECORD record{};
+		memset(&record, 0, sizeof(record));
+		record.ExceptionCode = static_cast<DWORD>(STATUS_ILLEGAL_INSTRUCTION);
+		record.ExceptionFlags = 0;
+		record.ExceptionRecord = nullptr;
+		record.ExceptionAddress = reinterpret_cast<void*>(emu.read_instruction_pointer());
+		record.NumberParameters = 0;
+
+		EXCEPTION_POINTERS pointers{};
+		pointers.ContextRecord = &ctx;
+		pointers.ExceptionRecord = &record;
+
+		dispatch_exception_pointers(emu, dispatcher, pointers);
+	}
+
 	void perform_context_switch_work(windows_emulator& win_emu)
 	{
 		auto& devices = win_emu.process().devices;
@@ -462,7 +483,7 @@ namespace
 
 		if (active_thread)
 		{
-			win_emu.logger.print(color::green, "Performing thread switch...\n");
+			win_emu.logger.print(color::dark_gray, "Performing thread switch...\n");
 			active_thread->save(emu);
 		}
 
@@ -812,11 +833,18 @@ void windows_emulator::setup_hooks()
 	{
 		const auto ip = this->emu().read_instruction_pointer();
 		printf("Invalid instruction at: 0x%llX\n", ip);
+
 		return instruction_hook_continuation::skip_instruction;
 	});
 
 	this->emu().hook_interrupt([&](const int interrupt)
 	{
+		if (interrupt == 6)
+		{
+			dispatch_illegal_instruction_violation(this->emu(), this->process().ki_user_exception_dispatcher);
+			return;
+		}
+
 		const auto rip = this->emu().read_instruction_pointer();
 		printf("Interrupt: %i 0x%llX\n", interrupt, rip);