Merge pull request #1496 from janvorli/fix-exception-memleak

Fix memory leak from managed exceptions

5 files changed, 68 insertions, 24 deletions

diff --git a/src/pal/inc/pal.h b/src/pal/inc/pal.h
index 5d8e56e0ef..43fc0694f5 100644
--- a/src/pal/inc/pal.h
+++ b/src/pal/inc/pal.h
@@ -6364,6 +6364,25 @@ public:
         ExceptionRecord = *pExceptionRecord;
         ContextRecord = *pContextRecord;
     }
+
+    PAL_SEHException()
+    {
+    }    
+
+    PAL_SEHException(const PAL_SEHException& ex)
+    {
+        *this = ex;
+    }    
+
+    PAL_SEHException& operator=(const PAL_SEHException& ex)
+    {
+        ExceptionPointers.ExceptionRecord = &ExceptionRecord;
+        ExceptionPointers.ContextRecord = &ContextRecord;
+        ExceptionRecord = ex.ExceptionRecord;
+        ContextRecord = ex.ContextRecord;
+
+        return *this;
+    }    
 };
 
 typedef VOID (PALAPI *PHARDWARE_EXCEPTION_HANDLER)(PAL_SEHException* ex);
diff --git a/src/pal/src/thread/thread.cpp b/src/pal/src/thread/thread.cpp
index 2c7b2388a8..33dbfbc914 100644
--- a/src/pal/src/thread/thread.cpp
+++ b/src/pal/src/thread/thread.cpp
@@ -2446,6 +2446,9 @@ PAL_GetStackBase()
     status = pthread_attr_getstack(&attr, &stackAddr, &stackSize);
     _ASSERT_MSG(status == 0, "pthread_attr_getstack call failed");
 
+    status = pthread_attr_destroy(&attr);
+    _ASSERT_MSG(status == 0, "pthread_attr_destroy call failed");
+
     return (void*)((size_t)stackAddr + stackSize);
 #endif
 }
@@ -2480,6 +2483,9 @@ PAL_GetStackLimit()
 
     status = pthread_attr_getstack(&attr, &stackAddr, &stackSize);
     _ASSERT_MSG(status == 0, "pthread_attr_getstack call failed");
+
+    status = pthread_attr_destroy(&attr);
+    _ASSERT_MSG(status == 0, "pthread_attr_destroy call failed");
     
     return stackAddr;
 #endif
diff --git a/src/vm/amd64/unixasmhelpers.S b/src/vm/amd64/unixasmhelpers.S
index e3f4adc259..ccf552367c 100644
--- a/src/vm/amd64/unixasmhelpers.S
+++ b/src/vm/amd64/unixasmhelpers.S
@@ -291,7 +291,7 @@ LEAF_END SinglecastDelegateInvokeStub, _TEXT
 // from the passed in context and finally sets the RSP to that frame and sets the return
 // address to the target frame's RIP.
 //
-// EXTERN_C void StartUnwindingNativeFrames(CONTEXT* context);
+// EXTERN_C void StartUnwindingNativeFrames(CONTEXT* context, PAL_SEHException* ex);
 LEAF_ENTRY StartUnwindingNativeFrames, _TEXT
         // Save the RBP to the stack so that the unwind can work at the instruction after
         // loading the RBP from the context, but before loading the RSP from the context.
@@ -316,6 +316,8 @@ LEAF_ENTRY StartUnwindingNativeFrames, _TEXT
         // Store return address to the stack
         push_register rax
         push_nonvol_reg rbp
-        call    EXTERNAL_C_FUNC(__cxa_rethrow)
+        // The PAL_SEHException pointer
+        mov     rdi, rsi 
+        call    EXTERNAL_C_FUNC(ThrowExceptionHelper)
 LEAF_END StartUnwindingNativeFrames, _TEXT
 
diff --git a/src/vm/exceptionhandling.cpp b/src/vm/exceptionhandling.cpp
index 5d5f3e61c0..982c3e06d5 100644
--- a/src/vm/exceptionhandling.cpp
+++ b/src/vm/exceptionhandling.cpp
@@ -3631,7 +3631,7 @@ ExceptionTracker* ExceptionTracker::GetOrCreateTracker(
             fIsRethrow = true;
         }
         else
-        if (pTracker->m_ptrs.ExceptionRecord != pExceptionRecord)
+        if ((pTracker->m_ptrs.ExceptionRecord != pExceptionRecord) && !fIsInterleavedHandling)
         {
             EH_LOG((LL_INFO100, ">>NEW exception (exception records do not match)\n"));
             fCreateNewTracker = true;
@@ -4396,7 +4396,8 @@ bool IsSpInStackLimits(ULONG64 sp, ULONG64 stackLowAddress, ULONG64 stackHighAdd
 //
 // Arguments:
 //      context - context at which to start the native unwinding
-extern "C" void StartUnwindingNativeFrames(CONTEXT* context);
+//      ex      - pointer to the exception to use to unwind the native frames
+extern "C" void StartUnwindingNativeFrames(CONTEXT* context, PAL_SEHException* ex);
 
 //---------------------------------------------------------------------------------------
 //
@@ -4678,7 +4679,7 @@ VOID DECLSPEC_NORETURN UnwindManagedExceptionPass1(PAL_SEHException& ex)
 
             // Now we need to unwind the native frames until we reach managed frames again or the exception is
             // handled in the native code.
-            StartUnwindingNativeFrames(&frameContext);
+            StartUnwindingNativeFrames(&frameContext, &ex);
             UNREACHABLE();
         }
 
@@ -4688,16 +4689,35 @@ VOID DECLSPEC_NORETURN UnwindManagedExceptionPass1(PAL_SEHException& ex)
     EEPOLICY_HANDLE_FATAL_ERROR(COR_E_EXECUTIONENGINE);
 }
 
+//---------------------------------------------------------------------------------------
+//
+// Helper function to throw the passed in exception.
+// It is called from the assembler function StartUnwindingNativeFrames 
+// Arguments:
+//
+//      ex - the exception to throw.
+//
+extern "C"
+void ThrowExceptionHelper(PAL_SEHException* ex)
+{
+    throw *ex;
+}
+
 VOID DECLSPEC_NORETURN DispatchManagedException(PAL_SEHException& ex)
 {
-    try
-    {
-        UnwindManagedExceptionPass1(ex);
-    }
-    catch (PAL_SEHException& ex)
+    do
     {
-        DispatchManagedException(ex);
+        try
+        {
+            UnwindManagedExceptionPass1(ex);
+            UNREACHABLE();
+        }
+        catch (PAL_SEHException& ex2)
+        {
+            ex = ex2;
+        }
     }
+    while (true);
 }
 
 #ifdef _AMD64_
@@ -5064,17 +5084,7 @@ VOID PALAPI HandleHardwareException(PAL_SEHException* ex)
             }
 #endif //_AMD64_
 
-            // We throw the exception and catch it right away so that in case the DispatchManagedException
-            // needs to cross managed to native stack frames boundary, there is an exception that can
-            // be rethrow in the StartUnwindingNativeFrames.
-            try
-            {
-                throw *ex;
-            }
-            catch (PAL_SEHException& ex2)
-            {
-                DispatchManagedException(ex2);
-            }
+            DispatchManagedException(*ex);
             UNREACHABLE();
         }
     }
diff --git a/src/vm/exceptmacros.h b/src/vm/exceptmacros.h
index e712f217e7..3c426fd3bd 100644
--- a/src/vm/exceptmacros.h
+++ b/src/vm/exceptmacros.h
@@ -323,14 +323,21 @@ VOID DECLSPEC_NORETURN UnwindAndContinueRethrowHelperAfterCatch(Frame* pEntryFra
 VOID DECLSPEC_NORETURN DispatchManagedException(PAL_SEHException& ex);
 
 #define INSTALL_MANAGED_EXCEPTION_DISPATCHER        \
-        try { \
+        PAL_SEHException exCopy;                    \
+        bool hasCaughtException = false;            \
+        try {
 
 #define UNINSTALL_MANAGED_EXCEPTION_DISPATCHER      \
         }                                           \
         catch (PAL_SEHException& ex)                \
         {                                           \
-            DispatchManagedException(ex);           \
+            exCopy = ex;                            \
+            hasCaughtException = true;              \
         }                                           \
+        if (hasCaughtException)                     \
+        {                                           \
+            DispatchManagedException(exCopy);       \
+        }
 
 #else