Fix Thread::SetProfilerFilterContext usage (dotnet#52607)

Add holder to catch exceptions and clear context. Issue: dotnet#47895
fnerdman · May 11, 2021 · acdc536 · acdc536
1 parent b306268
commit acdc536
Showing 1 changed file with 23 additions and 8 deletions.
diff --git a/src/coreclr/debug/daccess/dacimpl.h b/src/coreclr/debug/daccess/dacimpl.h
@@ -1989,7 +1989,6 @@ class DacStackReferenceWalker : public DefaultCOMImpl<ISOSStackRefEnum, IID_ISOS
         return &pData[mCurr->count++];
     }
 
-
     template <class IntType, class StructType>
     IntType WalkStack(IntType count, StructType refs[], promote_func promote, GCEnumCallback enumFunc)
     {
@@ -2001,15 +2000,36 @@ class DacStackReferenceWalker : public DefaultCOMImpl<ISOSStackRefEnum, IID_ISOS
         _ASSERTE(mCurr == NULL);
         _ASSERTE(mHead.next == NULL);
 
-        bool clearProfilerFilterContext = false;
+        class ProfilerFilterContextHolder
+        {
+            Thread* m_pThread;
+
+        public:
+            ProfilerFilterContextHolder() : m_pThread(NULL)
+            {
+            }
+
+            void Activate(Thread* pThread)
+            {
+                m_pThread = pThread;
+            }
+
+            ~ProfilerFilterContextHolder()
+            {
+                if (m_pThread != NULL)
+                    m_pThread->SetProfilerFilterContext(NULL);
+            }
+        };
+
+        ProfilerFilterContextHolder contextHolder;
         T_CONTEXT ctx;
 
         // Get the current thread's context and set that as the filter context
         if (mThread->GetFilterContext() == NULL && mThread->GetProfilerFilterContext() == NULL)
         {
             mDac->m_pTarget->GetThreadContext(mThread->GetOSThreadId(), CONTEXT_FULL, sizeof(ctx), (BYTE*)&ctx);
             mThread->SetProfilerFilterContext(&ctx);
-            clearProfilerFilterContext = true;
+            contextHolder.Activate(mThread);
         }
 
         // Setup GCCONTEXT structs for the stackwalk.
@@ -2036,11 +2056,6 @@ class DacStackReferenceWalker : public DefaultCOMImpl<ISOSStackRefEnum, IID_ISOS
         mEnumerated = true;
         mThread->StackWalkFrames(DacStackReferenceWalker::Callback, &gcctx, flagsStackWalk);
 
-        if (clearProfilerFilterContext)
-        {
-            mThread->SetProfilerFilterContext(NULL);
-        }
-
         // We have filled the user's array as much as we could.  If there's more data than
         // could fit, mHead.Next will contain a linked list of refs to enumerate.
         mCurr = mHead.next;