further refine the exception handler

FlashpointProject · Jul 17, 2022 · a372d9f · a372d9f
1 parent 58bf659
commit a372d9f
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Showing 21 changed files with 18 additions and 13 deletions.
diff --git a/Debug/FlashpointProxy.dll b/Debug/FlashpointProxy.dll
diff --git a/Debug/FlashpointProxy.ilk b/Debug/FlashpointProxy.ilk
diff --git a/Debug/FlashpointProxy.pdb b/Debug/FlashpointProxy.pdb
diff --git a/FlashpointProxy/Debug/FlashpointProxy.log b/FlashpointProxy/Debug/FlashpointProxy.log
@@ -4,8 +4,8 @@
   main.cpp
   shared.cpp
   Generating Code...
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(89): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(98): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(94): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(103): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
 FlashpointProxy.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/SAFESEH' specification
      Creating library C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Debug\FlashpointProxy.lib and object C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Debug\FlashpointProxy.exp
   FlashpointProxy.vcxproj -> C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Debug\FlashpointProxy.dll
diff --git a/FlashpointProxy/Debug/FlashpointProxy.obj b/FlashpointProxy/Debug/FlashpointProxy.obj
diff --git a/FlashpointProxy/Debug/main.obj b/FlashpointProxy/Debug/main.obj
diff --git a/FlashpointProxy/Debug/safeseh.obj b/FlashpointProxy/Debug/safeseh.obj
diff --git a/FlashpointProxy/Debug/shared.obj b/FlashpointProxy/Debug/shared.obj
diff --git a/FlashpointProxy/Debug/vc141.idb b/FlashpointProxy/Debug/vc141.idb
diff --git a/FlashpointProxy/Debug/vc141.pdb b/FlashpointProxy/Debug/vc141.pdb
diff --git a/FlashpointProxy/Release/FlashpointProxy.log b/FlashpointProxy/Release/FlashpointProxy.log
@@ -5,10 +5,10 @@
   shared.cpp
      Creating library C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Release\FlashpointProxy.lib and object C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Release\FlashpointProxy.exp
   Generating code
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(89): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(98): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(89): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
-c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(98): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(94): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(103): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(94): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
+c:\users\anthony\documents\visual studio 2017\projects\flashpointproxy\flashpointproxy\shared.cpp(103): warning C4733: Inline asm assigning to 'FS:0': handler not registered as safe handler
   All 393 functions were compiled because no usable IPDB/IOBJ from previous compilation was found.
   Finished generating code
   FlashpointProxy.vcxproj -> C:\Users\Anthony\Documents\Visual Studio 2017\Projects\FlashpointProxy\Release\FlashpointProxy.dll
diff --git a/FlashpointProxy/Release/FlashpointProxy.obj b/FlashpointProxy/Release/FlashpointProxy.obj
diff --git a/FlashpointProxy/Release/main.obj b/FlashpointProxy/Release/main.obj
diff --git a/FlashpointProxy/Release/safeseh.obj b/FlashpointProxy/Release/safeseh.obj
diff --git a/FlashpointProxy/Release/shared.obj b/FlashpointProxy/Release/shared.obj
diff --git a/FlashpointProxy/Release/vc141.pdb b/FlashpointProxy/Release/vc141.pdb
diff --git a/FlashpointProxy/shared.cpp b/FlashpointProxy/shared.cpp
@@ -57,15 +57,20 @@ extern "C" EXCEPTION_DISPOSITION __cdecl _except_handler(struct _EXCEPTION_RECOR
 		return ExceptionContinueSearch;
 	}
 
+	if (!EstablisherFrame) {
+		return ExceptionContinueSearch;
+	}
+
+	DWORD record = *(PDWORD)EstablisherFrame;
+
 	// set the new thread context to the one passed in as an argument
 	*ContextRecord = *(PCONTEXT)ExceptionRecord->ExceptionInformation[0];
 
 	__asm {
 		// remove our EXCEPTION_REGISTRATION record
-		mov eax, [EstablisherFrame] // get establisher frame
-		mov eax, [eax] // get pointer to previous record
-		mov ecx, fs:[0] // get address of current handler
-		mov [ecx], eax // set pointer to previous record in the current handler
+		mov eax, record // address of previous record
+		mov ecx, fs:[0] // address of current record
+		mov [ecx], eax // set pointer to previous record at address of current record
 	}
 	return ExceptionContinueExecution;
 }
@@ -76,16 +81,16 @@ void setCurrentThreadContext(CONTEXT &context) {
 	// intended Windows function for this purpose, 64-bit only :(
 	RtlRestoreContext(&context, NULL);
 	#else
+	ULONG_PTR setCurrentThreadContextArguments[SET_CURRENT_THREAD_CONTEXT_NUMBER_OF_ARGUMENTS] = { (ULONG_PTR)&context };
+
 	// use SEH to set the current thread's context
 	DWORD handler = (DWORD)_except_handler_safeseh;
 
 	// pass the new thread context as an argument
-	ULONG_PTR setCurrentThreadContextArguments[SET_CURRENT_THREAD_CONTEXT_NUMBER_OF_ARGUMENTS] = { (ULONG_PTR)&context };
-
 	__asm {
 		// build EXCEPTION_REGISTRATION record
 		push handler // address of handler function
-		push fs:[0] // address of previous handler
+		push fs:[0] // address of previous record
 		mov fs:[0], esp // install new EXCEPTION_REGISTRATION
 	}
 

diff --git a/Release/FlashpointProxy.dll b/Release/FlashpointProxy.dll
diff --git a/Release/FlashpointProxy.iobj b/Release/FlashpointProxy.iobj
diff --git a/Release/FlashpointProxy.ipdb b/Release/FlashpointProxy.ipdb
diff --git a/Release/FlashpointProxy.pdb b/Release/FlashpointProxy.pdb