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Fix unhandled exception reporting corner cases #118450

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Merged
jkotas merged 2 commits into from
Aug 8, 2025
Merged

Fix unhandled exception reporting corner cases #118450

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77cd9fe
Fix unhandled exception reporting corner cases
janvorli Jul 23, 2025
f0222ca
Ensure AppDomain.CurrentDomain.UnhandledException occurs before finally
janvorli Aug 7, 2025
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58 changes: 25 additions & 33 deletions src/coreclr/vm/exceptionhandling.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -579,32 +579,21 @@ ProcessCLRException(IN PEXCEPTION_RECORD pExceptionRecord,
}
#endif

if (pThread->HasThreadStateNC(Thread::TSNC_UnhandledException2ndPass) && !(pExceptionRecord->ExceptionFlags & EXCEPTION_UNWINDING))
{
// We are in the 1st pass of exception handling, but the thread mark says that it has already executed 2nd pass
// of unhandled exception handling. That means that some external native code on top of the stack has caught the
// exception that runtime considered to be unhandled, and a new native exception was thrown on the current thread.
// We need to reset the flags below so that we no longer block exception handling for the managed frames.
pThread->ResetThreadStateNC(Thread::TSNC_UnhandledException2ndPass);
pThread->ResetThreadStateNC(Thread::TSNC_ProcessedUnhandledException);
}

// Also skip all frames when processing unhandled exceptions. That allows them to reach the host app
// level and let 3rd party the chance to handle them.
if (pThread->HasThreadStateNC(Thread::TSNC_ProcessedUnhandledException))
if (pThread->HasThreadStateNC(Thread::TSNC_SkipManagedPersonalityRoutine))
{
if (pExceptionRecord->ExceptionFlags & EXCEPTION_UNWINDING)
{
if (!pThread->HasThreadStateNC(Thread::TSNC_UnhandledException2ndPass))
// The 3rd argument passes to PopExplicitFrame is normally the parent SP to correctly handle InlinedCallFrame embbeded
// in parent managed frame. But at this point there are no further managed frames are on the stack, so we can pass NULL.
// Also don't pop the GC frames, their destructor will pop them as the exception propagates.
// NOTE: this needs to be popped in the 2nd pass to ensure that crash dumps and Watson get the dump with these still
// present.
ExInfo *pExInfo = (ExInfo*)pThread->GetExceptionState()->GetCurrentExceptionTracker();
if (pExInfo != NULL)
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{
pThread->SetThreadStateNC(Thread::TSNC_UnhandledException2ndPass);
GCX_COOP();
// The 3rd argument passes to PopExplicitFrame is normally the parent SP to correctly handle InlinedCallFrame embbeded
// in parent managed frame. But at this point there are no further managed frames are on the stack, so we can pass NULL.
// Also don't pop the GC frames, their destructor will pop them as the exception propagates.
// NOTE: this needs to be popped in the 2nd pass to ensure that crash dumps and Watson get the dump with these still
// present.
ExInfo *pExInfo = (ExInfo*)pThread->GetExceptionState()->GetCurrentExceptionTracker();
void *sp = (void*)GetRegdisplaySP(pExInfo->m_frameIter.m_crawl.GetRegisterSet());
PopExplicitFrames(pThread, sp, NULL /* targetCallerSp */, false /* popGCFrames */);
ExInfo::PopExInfos(pThread, sp);
Expand Down Expand Up @@ -3757,7 +3746,10 @@ extern "C" CLR_BOOL QCALLTYPE SfiInit(StackFrameIterator* pThis, CONTEXT* pStack
Thread* pThread = GET_THREAD();
ExInfo* pExInfo = (ExInfo*)pThread->GetExceptionState()->GetCurrentExceptionTracker();

pThread->ResetThreadStateNC(Thread::TSNC_ProcessedUnhandledException);
if (pExInfo->m_passNumber == 1)
{
pThread->ResetThreadStateNC(Thread::TSNC_SkipManagedPersonalityRoutine);
}

BEGIN_QCALL;

Expand Down Expand Up @@ -3872,14 +3864,13 @@ extern "C" CLR_BOOL QCALLTYPE SfiInit(StackFrameIterator* pThis, CONTEXT* pStack
}
else
{
// There are no managed frames on the stack
EH_LOG((LL_INFO100, "SfiInit: No more managed frames found on stack\n"));
// There are no managed frames on the stack, fail fast and report unhandled exception
LONG disposition = InternalUnhandledExceptionFilter_Worker((EXCEPTION_POINTERS *)&pExInfo->m_ptrs);
#ifdef HOST_WINDOWS
CreateCrashDumpIfEnabled(/* fSOException */ FALSE);
GetThread()->SetThreadStateNC(Thread::TSNC_ProcessedUnhandledException);
GetThread()->SetThreadStateNC(Thread::TSNC_SkipManagedPersonalityRoutine);
RaiseException(pExInfo->m_ExceptionCode, EXCEPTION_NONCONTINUABLE, pExInfo->m_ptrs.ExceptionRecord->NumberParameters, pExInfo->m_ptrs.ExceptionRecord->ExceptionInformation);
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#else
LONG disposition = InternalUnhandledExceptionFilter_Worker((EXCEPTION_POINTERS *)&pExInfo->m_ptrs);
CrashDumpAndTerminateProcess(pExInfo->m_ExceptionCode);
#endif
}
Expand Down Expand Up @@ -3970,6 +3961,7 @@ extern "C" CLR_BOOL QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollid

if (isPropagatingToNativeCode)
{
// Propagating through Reverse pinvoke
#ifdef HOST_UNIX
void* callbackCxt = NULL;
Interop::ManagedToNativeExceptionCallback callback = Interop::GetPropagatingExceptionCallback(
Expand All @@ -3983,13 +3975,14 @@ extern "C" CLR_BOOL QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollid
pTopExInfo->m_propagateExceptionContext = callbackCxt;
}
else
#endif // HOST_UNIX
{
isPropagatingToExternalNativeCode = true;
}
#endif // HOST_UNIX
}
else
{
// Propagating to CallDescrWorkerInternal, filter funclet or CallEHFunclet.
if (IsCallDescrWorkerInternalReturnAddress(GetIP(pThis->m_crawl.GetRegisterSet()->pCurrentContext)))
{
EH_LOG((LL_INFO100, "SfiNext: the native frame is CallDescrWorkerInternal"));
Expand All @@ -4000,10 +3993,6 @@ extern "C" CLR_BOOL QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollid
EH_LOG((LL_INFO100, "SfiNext: current frame is filter funclet"));
isPropagatingToNativeCode = TRUE;
}
else
{
isPropagatingToExternalNativeCode = true;
}
}

if (isPropagatingToNativeCode)
Expand All @@ -4024,18 +4013,21 @@ extern "C" CLR_BOOL QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollid

if (isNotHandledByRuntime && IsExceptionFromManagedCode(pTopExInfo->m_ptrs.ExceptionRecord))
{
EH_LOG((LL_INFO100, "SfiNext (pass %d): no more managed frames on the stack, the exception is unhandled", pTopExInfo->m_passNumber));
EH_LOG((LL_INFO100, "SfiNext (pass %d): no more managed frames on the stack, the exception is not handled by the runtime\n", pTopExInfo->m_passNumber));
if (pTopExInfo->m_passNumber == 1)
{
LONG disposition = InternalUnhandledExceptionFilter_Worker((EXCEPTION_POINTERS *)&pTopExInfo->m_ptrs);
#ifdef HOST_WINDOWS
CreateCrashDumpIfEnabled(/* fSOException */ FALSE);
if (!isPropagatingToExternalNativeCode)
#endif
{
LONG disposition = InternalUnhandledExceptionFilter_Worker((EXCEPTION_POINTERS *)&pTopExInfo->m_ptrs);
GetThread()->SetThreadStateNC(Thread::TSNC_ProcessedUnhandledException);
}
}
else
{
#ifdef HOST_WINDOWS
GetThread()->SetThreadStateNC(Thread::TSNC_ProcessedUnhandledException);
GetThread()->SetThreadStateNC(Thread::TSNC_SkipManagedPersonalityRoutine);
RaiseException(pTopExInfo->m_ExceptionCode, EXCEPTION_NONCONTINUABLE, pTopExInfo->m_ptrs.ExceptionRecord->NumberParameters, pTopExInfo->m_ptrs.ExceptionRecord->ExceptionInformation);
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#else
CrashDumpAndTerminateProcess(pTopExInfo->m_ExceptionCode);
Expand Down
2 changes: 1 addition & 1 deletion src/coreclr/vm/threads.h
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Original file line number Diff line number Diff line change
Expand Up @@ -642,7 +642,7 @@ class Thread
// effort.
//
// Once we are completely independent of the OS UEF, we could remove this.
TSNC_UnhandledException2ndPass = 0x02000000, // The unhandled exception propagation is in the 2nd pass
TSNC_SkipManagedPersonalityRoutine = 0x02000000, // Ignore the ProcessCLRException calls when propagating exception to external native code
TSNC_DebuggerSleepWaitJoin = 0x04000000, // Indicates to the debugger that this thread is in a sleep wait or join state
// This almost mirrors the TS_Interruptible state however that flag can change
// during GC-preemptive mode whereas this one cannot.
Expand Down