Remove preventing EH and entering EE at shutdown

src/coreclr/vm/ceemain.cpp

@@ -1332,9 +1332,6 @@ void STDMETHODCALLTYPE EEShutDownHelper(BOOL fIsDllUnloading)
                 // Shutdown finalizer before we suspend all background threads. Otherwise we
                 // never get to finalize anything.
 
-                // No longer process exceptions
-                g_fNoExceptions = true;
-
                 // <TODO>@TODO: This does things which shouldn't occur in part 2.  Namely,
                 // calling managed dll main callbacks (AppDomain::SignalProcessDetach), and
                 // RemoveAppDomainFromIPC.

src/coreclr/vm/crst.h

@@ -103,7 +103,6 @@ extern DWORD g_fEEShutDown;
 #endif
 // Total count of Crst lock  of the type (Shutdown) that are currently in use
 extern Volatile<LONG> g_ShutdownCrstUsageCount;
-extern Volatile<LONG> g_fForbidEnterEE;
 
 // The CRST.
 class CrstBase

src/coreclr/vm/eepolicy.cpp

@@ -41,8 +41,6 @@ void SafeExitProcess(UINT exitCode, ShutdownCompleteAction sca = SCA_ExitProcess
     // other DLLs call Release() on us in their detach [dangerous!], etc.
     GCX_PREEMP_NO_DTOR();
 
-    InterlockedExchange((LONG*)&g_fForbidEnterEE, TRUE);
-
     // Note that for free and retail builds StressLog must also be enabled
     if (g_pConfig && g_pConfig->StressLog())
     {
@@ -59,13 +57,6 @@ void SafeExitProcess(UINT exitCode, ShutdownCompleteAction sca = SCA_ExitProcess
         }
     }
 
-    // Turn off exception processing, because if some other random DLL has a
-    //  fault in DLL_PROCESS_DETACH, we could get called for exception handling.
-    //  Since we've turned off part of the runtime, we can't, for instance,
-    //  properly execute the GC that handling an exception might trigger.
-    g_fNoExceptions = true;
-    LOG((LF_EH, LL_INFO10, "SafeExitProcess: turning off exceptions\n"));
-
     if (sca == SCA_TerminateProcessWhenShutdownComplete)
     {
         // disabled because if we fault in this code path we will trigger our Watson code

src/coreclr/vm/excep.cpp

@@ -4585,13 +4585,6 @@ LONG InternalUnhandledExceptionFilter_Worker(
     STRESS_LOG2(LF_EH, LL_INFO10, "In InternalUnhandledExceptionFilter_Worker, Exception = %x, sp = %p\n",
                                     pExceptionInfo->ExceptionRecord->ExceptionCode, GetCurrentSP());
 
-    // If we can't enter the EE, done.
-    if (g_fForbidEnterEE)
-    {
-        LOG((LF_EH, LL_INFO100, "InternalUnhandledExceptionFilter_Worker: g_fForbidEnterEE is TRUE\n"));
-        return EXCEPTION_CONTINUE_SEARCH;
-    }
-
     // We don't do anything when this is called from an unmanaged thread.
     Thread *pThread = GetThreadNULLOk();
 
@@ -4623,18 +4616,6 @@ LONG InternalUnhandledExceptionFilter_Worker(
     }
 #endif
 
-    // This shouldn't be possible, but MSVC re-installs us... for now, just bail if this happens.
-    if (g_fNoExceptions)
-    {
-        return EXCEPTION_CONTINUE_SEARCH;
-    }
-
-    // Are we looking at a stack overflow here?
-    if ((pThread !=  NULL) && !pThread->DetermineIfGuardPagePresent())
-    {
-        g_fForbidEnterEE = true;
-    }
-
 #ifdef DEBUGGING_SUPPORTED
 
     // Mark that this exception has gone unhandled. At the moment only the debugger will
@@ -5533,8 +5514,6 @@ static LONG ThreadBaseExceptionFilter_Worker(PEXCEPTION_POINTERS pExceptionInfo,
     ThreadBaseExceptionFilterParam *pParam = (ThreadBaseExceptionFilterParam *) pvParam;
     UnhandledExceptionLocation location = pParam->location;
 
-    _ASSERTE(!g_fNoExceptions);
-
     Thread* pThread = GetThread();
 
 #ifdef _DEBUG
@@ -6737,14 +6716,6 @@ VEH_ACTION WINAPI CLRVectoredExceptionHandlerPhase3(PEXCEPTION_POINTERS pExcepti
 
 VEH_ACTION WINAPI CLRVectoredExceptionHandler(PEXCEPTION_POINTERS pExceptionInfo)
 {
-    // It is not safe to execute code inside VM after we shutdown EE.  One example is DisablePreemptiveGC
-    // will block forever.
-    if (g_fForbidEnterEE)
-    {
-        return VEH_CONTINUE_SEARCH;
-    }
-
-
     //
     // DO NOT USE CONTRACTS HERE AS THIS ROUTINE MAY NEVER RETURN.  You can use
     // static contracts, but currently this is all WRAPPER_NO_CONTRACT.
@@ -7434,12 +7405,6 @@ LONG WINAPI CLRVectoredExceptionHandlerShim(PEXCEPTION_POINTERS pExceptionInfo)
     // WARNING WARNING WARNING WARNING WARNING WARNING WARNING
     //
 
-    // If exceptions (or runtime) have been disabled, then simply return.
-    if (g_fForbidEnterEE || g_fNoExceptions)
-    {
-        return EXCEPTION_CONTINUE_SEARCH;
-    }
-
 #ifdef FEATURE_EH_FUNCLETS
     pExceptionInfo->ContextRecord->ContextFlags |= CONTEXT_EXCEPTION_ACTIVE;
 #endif // FEATURE_EH_FUNCLETS

src/coreclr/vm/i386/excepx86.cpp

@@ -1571,9 +1571,6 @@ EXCEPTION_HANDLER_IMPL(COMPlusFrameHandler)
 
     _ASSERTE((pContext == NULL) || ((pContext->ContextFlags & CONTEXT_CONTROL) == CONTEXT_CONTROL));
 
-    if (g_fNoExceptions)
-        return ExceptionContinueSearch; // No EH during EE shutdown.
-
     // Check if the exception represents a GCStress Marker. If it does,
     // we shouldnt record its entry in the TLS as such exceptions are
     // continuable and can confuse the VM to treat them as CSE,

src/coreclr/vm/runtimecallablewrapper.cpp

@@ -1790,7 +1790,7 @@ void RCW::Cleanup()
 
         // Remove the memory pressure caused by this RCW (if present)
         // If we're in a shutdown situation, we can ignore the memory pressure.
-        if ((GetThread()->m_StateNC & Thread::TSNC_UnsafeSkipEnterCooperative) == 0 && !g_fForbidEnterEE)
+        if ((GetThread()->m_StateNC & Thread::TSNC_UnsafeSkipEnterCooperative) == 0)
             RemoveMemoryPressure();
     }
 

src/coreclr/vm/stdinterfaces_wrapper.cpp

@@ -52,7 +52,7 @@ namespace
         LIMITED_METHOD_CONTRACT;
         // If we are finalizing all alive objects, or after this stage, we do not allow
         // a thread to enter EE.
-        return !((g_fEEShutDown & ShutDown_Finalize2) || g_fForbidEnterEE);
+        return !(g_fEEShutDown & ShutDown_Finalize2);
     }
 }
 

src/coreclr/vm/threads.cpp

@@ -7767,7 +7767,7 @@ OBJECTREF Thread::GetCulture(BOOL bUICulture)
 
     // This is the case when we're building CoreLib and haven't yet created
     // the system assembly.
-    if (SystemDomain::System()->SystemAssembly()==NULL || g_fForbidEnterEE) {
+    if (SystemDomain::System()->SystemAssembly()==NULL) {
         return NULL;
     }
 

src/coreclr/vm/vars.cpp

@@ -194,9 +194,7 @@ GVAL_IMPL(SIZE_T, g_runtimeVirtualSize);
 
 #ifndef DACCESS_COMPILE
 
-Volatile<LONG> g_fForbidEnterEE = false;
 bool g_fManagedAttach = false;
-bool g_fNoExceptions = false;
 
 DWORD g_FinalizerWaiterStatus = 0;
 

src/coreclr/vm/vars.hpp

@@ -480,13 +480,11 @@ EXTERN BOOL g_fComStarted;
 GVAL_DECL(DWORD, g_fEEShutDown);
 EXTERN DWORD g_fFastExitProcess;
 EXTERN BOOL g_fFatalErrorOccurredOnGCThread;
-EXTERN Volatile<LONG> g_fForbidEnterEE;
 GVAL_DECL(bool, g_fProcessDetach);
 #ifdef FEATURE_METADATA_UPDATER
 GVAL_DECL(bool, g_metadataUpdatesApplied);
 #endif
 EXTERN bool g_fManagedAttach;
-EXTERN bool g_fNoExceptions;
 
 // Indicates whether we're executing shut down as a result of DllMain
 // (DLL_PROCESS_DETACH). See comments at code:EEShutDown for details.