Merge pull request #28 from RadWolfie/fix-pr-1341

Restore Cxbx's emu exception (SEH) while keep LLE exception handler (VEH)

src/CxbxKrnl/CxbxKrnl.cpp

@@ -188,18 +188,14 @@ void SetupPerTitleKeys()
 
 void CxbxLaunchXbe(void(*Entry)())
 {
-#ifdef USE_SEH
 	__try
 	{
-#endif // USE_SEH
 		Entry();
-#ifdef USE_SEH
 	}
 	__except (EmuException(GetExceptionInformation()))
 	{
 		EmuWarning("Problem with ExceptionFilter");
 	}
-#endif // USE_SEH
 }
 
 // Entry point address XOR keys per Xbe type (Retail, Debug or Chihiro) :

src/CxbxKrnl/Emu.cpp

@@ -196,7 +196,7 @@ bool EmuExceptionBreakpointAsk(LPEXCEPTION_POINTERS e)
 	}
 
 	return false;
-}
+}
 
 void EmuExceptionNonBreakpointUnhandledShow(LPEXCEPTION_POINTERS e)
 {
@@ -226,10 +226,33 @@ bool IsXboxCodeAddress(xbaddr addr)
 	// Note : Not IS_USER_ADDRESS(), that would include host DLL code
 }
 
+void genericException(EXCEPTION_POINTERS *e) {
+	// Try to report this exception to the debugger, which may allow handling of this exception
+	if (CxbxDebugger::CanReport()) {
+		bool DebuggerHandled = false;
+		CxbxDebugger::ReportAndHandleException(e->ExceptionRecord, DebuggerHandled);
+		if (!DebuggerHandled) {
+			// Kill the process immediately without the Cxbx notifier
+			EmuExceptionExitProcess();
+		}
+
+		// Bypass exception
+	}
+	else {
+		// notify user
+		EmuExceptionNonBreakpointUnhandledShow(e);
+	}
+}
+
+static thread_local bool bOverrideException;
+
 bool IsRdtscInstruction(xbaddr addr);
 ULONGLONG CxbxRdTsc(bool xbox);
-bool TryHandleException(EXCEPTION_POINTERS *e)
+bool lleTryHandleException(EXCEPTION_POINTERS *e)
 {
+	// Initalize local thread variable
+	bOverrideException = false;
+
 	// Only handle exceptions which originate from Xbox code
 	if (!IsXboxCodeAddress(e->ContextRecord->Eip)) {
 		return false;
@@ -253,8 +276,8 @@ bool TryHandleException(EXCEPTION_POINTERS *e)
 			}
 			break;
 		case STATUS_BREAKPOINT:
-			// Let user choose between continue or break
-			return EmuExceptionBreakpointAsk(e);
+			// Pass breakpoint down to EmuException since VEH doesn't have call stack viewable.
+			return false;
 		default:
 			// Skip past CxbxDebugger-specific exceptions thrown when an unsupported was attached (ie Visual Studio)
 			if (CxbxDebugger::IsDebuggerException(e->ExceptionRecord->ExceptionCode)) {
@@ -267,33 +290,58 @@ bool TryHandleException(EXCEPTION_POINTERS *e)
 	if (EmuX86_DecodeException(e)) {
 		// We're allowed to continue :
 		return true;
-	}
+	}
 
-	// Try to Report this exception to the debugger, which may allow handling of this exception
-	if (CxbxDebugger::CanReport()) {
-		bool DebuggerHandled = false;
-		CxbxDebugger::ReportAndHandleException(e->ExceptionRecord, DebuggerHandled);
-		if (DebuggerHandled) {
-			// Bypass exception
-			return false;
-		}
-
-		// Kill the process immediately without the Cxbx notifier
-		EmuExceptionExitProcess();
-	}
-	else {
-		// notify user
-		EmuExceptionNonBreakpointUnhandledShow(e);
-	}
+	genericException(e);
+
+	// We do not need EmuException to handle it again.
+	bOverrideException = true;
 
 	// Unhandled exception :
 	return false;
 }
 
-LONG NTAPI EmuException(EXCEPTION_POINTERS *e)
+// Only for LLE emulation coding (to help performance a little bit better)
+LONG NTAPI lleException(EXCEPTION_POINTERS *e)
 {
 	g_bEmuException = true;
-	LONG result = TryHandleException(e) ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_CONTINUE_SEARCH;
+	LONG result = lleTryHandleException(e) ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_CONTINUE_SEARCH;
+	g_bEmuException = false;
+	return result;
+}
+
+// Only for Cxbx emulation coding (to catch all of last resort exception may occur.)
+bool EmuTryHandleException(EXCEPTION_POINTERS *e)
+{
+
+	// Check if lle exception is already called first before emu exception.
+	if (bOverrideException) {
+		return false;
+	}
+
+	if (e->ExceptionRecord->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) {
+		switch (e->ExceptionRecord->ExceptionCode) {
+		case STATUS_BREAKPOINT:
+			// Let user choose between continue or break
+			return EmuExceptionBreakpointAsk(e);
+		default:
+			// Skip past CxbxDebugger-specific exceptions thrown when an unsupported was attached (ie Visual Studio)
+			if (CxbxDebugger::IsDebuggerException(e->ExceptionRecord->ExceptionCode)) {
+				return true;
+			}
+		}
+	}
+
+	genericException(e);
+
+	// Unhandled exception :
+	return false;
+}
+
+int EmuException(EXCEPTION_POINTERS *e)
+{
+	g_bEmuException = true;
+	LONG result = EmuTryHandleException(e) ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_CONTINUE_SEARCH;
 	g_bEmuException = false;
 	return result;
 }

src/CxbxKrnl/Emu.h

@@ -48,7 +48,8 @@ inline void NTAPI EmuWarning(const char *szWarningMessage, ...) { }
 #endif
 
 // exception handler
-extern LONG NTAPI EmuException(EXCEPTION_POINTERS *e);
+extern LONG NTAPI lleException(EXCEPTION_POINTERS *e);
+int EmuException(EXCEPTION_POINTERS *e);
 
 // print call stack trace
 #ifdef _DEBUG

src/CxbxKrnl/EmuKrnlKe.cpp

@@ -161,21 +161,17 @@ DWORD ExecuteDpcQueue()
 		// Set DpcRoutineActive to support KeIsExecutingDpc:
 		KeGetCurrentPrcb()->DpcRoutineActive = TRUE; // Experimental
 		DbgPrintf("KRNL: Global DpcQueue, calling DPC at 0x%.8X\n", pkdpc->DeferredRoutine);
-#ifdef USE_SEH
 		__try {
-#endif // USE_SEH
 			// Call the Deferred Procedure  :
 			pkdpc->DeferredRoutine(
 				pkdpc,
 				pkdpc->DeferredContext,
 				pkdpc->SystemArgument1,
 				pkdpc->SystemArgument2);
-#ifdef USE_SEH
 		} __except (EmuException(GetExceptionInformation()))
 		{
 			EmuWarning("Problem with ExceptionFilter!");
 		}
-#endif // USE_SEH
 
 		KeGetCurrentPrcb()->DpcRoutineActive = FALSE; // Experimental
 	}
@@ -209,20 +205,17 @@ DWORD ExecuteDpcQueue()
 				break; // while
 
 			DbgPrintf("KRNL: Global TimerQueue, calling DPC at 0x%.8X\n", pkdpc->DeferredRoutine);
-#ifdef USE_SEH
+
 			__try {
-#endif // USE_SEH
 				pkdpc->DeferredRoutine(
 					pkdpc,
 					pkdpc->DeferredContext,
 					pkdpc->SystemArgument1,
 					pkdpc->SystemArgument2);
-#ifdef USE_SEH
 			} __except (EmuException(GetExceptionInformation()))
 			{
 				EmuWarning("Problem with ExceptionFilter!");
 			}
-#endif // USE_SEH
 		}
 	}
 

src/CxbxKrnl/EmuKrnlPs.cpp

@@ -167,10 +167,8 @@ static unsigned int WINAPI PCSTProxy
 	}
 
 	// use the special calling convention
-#ifdef USE_SEH
 	__try
 	{
-#endif // USE_SEH
 		// Given the non-standard calling convention (requiring
 		// the first argument in ebp+4) we need the below __asm.
 		//
@@ -187,14 +185,11 @@ static unsigned int WINAPI PCSTProxy
 			lea         ebp, [esp - 4]
 			jmp near    esi
 		}
-
-#ifdef USE_SEH
 	}
 	__except (EmuException(GetExceptionInformation()))
 	{
 		EmuWarning("Problem with ExceptionFilter!");
 	}
-#endif // USE_SEH
 
 callComplete:
 
@@ -212,19 +207,15 @@ void PspSystemThreadStartup
 	IN PVOID StartContext
 )
 {
-#ifdef USE_SEH
 	__try
 	{
-#endif // USE_SEH
 		(StartRoutine)(StartContext);
-#ifdef USE_SEH
 	}
 	__except (EmuException(GetExceptionInformation()))
 	// TODO : Call PspUnhandledExceptionInSystemThread(GetExceptionInformation())
 	{
 		EmuWarning("Problem with ExceptionFilter!"); // TODO : Disable?
 	}
-#endif // USE_SEH
 
 	xboxkrnl::PsTerminateSystemThread(STATUS_SUCCESS);
 }

src/CxbxKrnl/EmuX86.cpp

@@ -1131,8 +1131,8 @@ opcode_error:
 void EmuX86_Init()
 {
 	DbgPrintf("X86 : Initializing distorm version %d\n", distorm_version());
-#ifndef USE_SEH // implies VEH
-	AddVectoredExceptionHandler(/*FirstHandler=*/ULONG(true), EmuException);
-#endif // !USE_SEG
+
+	AddVectoredExceptionHandler(/*FirstHandler=*/ULONG(true), lleException);
+
 	EmuX86_InitContextRecordOffsetByRegisterType();
 }

src/CxbxKrnl/EmuXapi.cpp

@@ -1390,19 +1390,15 @@ typedef struct {
 
 void WINAPI EmuFiberStartup(fiber_context_t* context)
 {
-#ifdef USE_SEH
 	__try
 	{
-#endif //USE_SEH
 		LPFIBER_START_ROUTINE pfStartRoutine = (LPFIBER_START_ROUTINE)context->lpStartRoutine;
 		pfStartRoutine(context->lpParameter);
-#ifdef USE_SEH
 	}
 	__except (EmuException(GetExceptionInformation()))
 	{
 		EmuWarning("Problem with ExceptionFilter");
 	}
-#endif //USE_SEH
 }
 
 // ******************************************************************