NullReferenceException in AddUniversalDynamicSymbol when opening nettrace with invalid symbol ranges

[mdh1418]

Opening certain EventPipe .nettrace files containing universal trace format symbols crashes with a NullReferenceException during ETLX conversion.

Suspected root cause:
AddUniversalDynamicSymbol in TraceLog.cs passes the symbol size to ForAllUnresolvedCodeAddressesInRange using an (int) cast, while the downstream UniversalMapping uses a (long) cast:

perfview/src/TraceEvent/TraceLog.cs

Line 8546 in 46f2cfa

ForAllUnresolvedCodeAddressesInRange(process, data.StartAddress, (int)(data.EndAddress - data.StartAddress), true, delegate (ref CodeAddressInfo info)

perfview/src/TraceEvent/TraceLog.cs

Line 7134 in 46f2cfa

long newImageSize = (long)(endAddress - startAddress);

When a ProcessSymbol event has an invalid address range (e.g., StartAddress=0x0, EndAddress=0xFFFFFFFFFFFFFFFF), the (int) truncation produces -1, which wraps to 0xFFFFFFFFFFFFFFFF as a ulong — causing the loop to iterate over every code
address in the process. Meanwhile, UniversalMapping correctly interprets the (long) cast as negative, leaving imageSize at 0. The resulting zero-size module cannot be found by FindModuleAndIndexContainingAddress, leaving loadedModule null and
causing the NRE at loadedModule.ModuleID.

This was observed with nettrace files generated by one-collect's record-trace without root access on Linux, where /proc/kallsyms returns zeroed addresses, causing the kernel symbol startup_64 to be emitted as [0x0, 0xFFFFFFFFFFFFFFFF).

  Started: Opening with-rbp-chain-walk.nettrace
  Creating ETLX file C:\Users\mihw\AppData\Local\Temp\PerfView (4)\with-rbp-chain-walk_d0b9d067.etlx from \\wsl.localhost\Ubuntu-24.04\home\mihw\repo\mihw-notes\stack-investigation\traces\with-rbp-chain-walk.nettrace
  [Opening a log file of size 0 MB.]
  [ELAPSED  0 seconds.     READ    131,072 events.     TIMESTAMP       0ms.     WRITTEN    19MB.     ]
  [ELAPSED  1 seconds.     READ    262,144 events.     TIMESTAMP       0ms.     WRITTEN    39MB.     ]
  [ELAPSED  1 seconds.     READ    393,216 events.     TIMESTAMP       0ms.     WRITTEN    58MB.     ]
  [ELAPSED  1 seconds.     READ    524,288 events.     TIMESTAMP       0ms.     WRITTEN    77MB.     ]
  [ELAPSED  1 seconds.     READ    655,360 events.     TIMESTAMP       0ms.     WRITTEN    97MB.     ]
  [ELAPSED  2 seconds.     READ    786,432 events.     TIMESTAMP       0ms.     WRITTEN   116MB.     ]
  [ELAPSED  2 seconds.     READ    917,504 events.     TIMESTAMP       0ms.     WRITTEN   135MB.     ]
  [ELAPSED  2 seconds.     READ  1,048,576 events.     TIMESTAMP       0ms.     WRITTEN   155MB.     ]
  [ELAPSED  3 seconds.     READ  1,179,648 events.     TIMESTAMP       0ms.     WRITTEN   174MB.     ]
  [ELAPSED  3 seconds.     READ  1,310,720 events.     TIMESTAMP       0ms.     WRITTEN   193MB.     ]
  [ELAPSED  4 seconds.     READ  1,441,792 events.     TIMESTAMP       0ms.     WRITTEN   213MB.     ]
  [ELAPSED  4 seconds.     READ  1,572,864 events.     TIMESTAMP       0ms.     WRITTEN   232MB.     ]
  [ELAPSED  4 seconds.     READ  1,703,936 events.     TIMESTAMP       0ms.     WRITTEN   252MB.     ]
  [ELAPSED  5 seconds.     READ  1,835,008 events.     TIMESTAMP       0ms.     WRITTEN   271MB.     ]
  [ELAPSED  5 seconds.     READ  1,966,080 events.     TIMESTAMP       0ms.     WRITTEN   290MB.     ]
  [ELAPSED  5 seconds.     READ  2,097,152 events.     TIMESTAMP       0ms.     WRITTEN   310MB.     ]
  [ELAPSED  6 seconds.     READ  2,228,224 events.     TIMESTAMP       0ms.     WRITTEN   329MB.     ]
  WARNING: Events occurred > 10msec before process 12975 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12977 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12976 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12978 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12979 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12980 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12981 start at 0.000 msec
  WARNING: Events occurred > 10msec before process 12982 start at 0.000 msec
  Error: Exception EventPipe conversion: System.NullReferenceException: Object reference not set to an instance of an object.
     at Microsoft.Diagnostics.Tracing.Etlx.TraceCodeAddresses.<>c__DisplayClass33_0.<AddUniversalDynamicSymbol>b__0(CodeAddressInfo& info)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceCodeAddresses.ForAllUnresolvedCodeAddressesInRange(TraceProcess process, UInt64 start, Int64 length, Boolean considerResolved, ForAllCodeAddrAction body)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceCodeAddresses.AddUniversalDynamicSymbol(ProcessSymbolTraceData data, TraceProcess process)
     at Microsoft.Diagnostics.Tracing.SourceConverters.NettraceUniversalConverter.AfterProcess(TraceLog traceLog)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.CopyRawEvents(TraceEventDispatcher rawEvents, IStreamWriter writer)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.<>c__DisplayClass134_0.<FastSerialization.IFastSerializable.ToStream>b__0()
     at FastSerialization.DeferedRegion.Write(Serializer serializer, Action toStream)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.FastSerialization.IFastSerializable.ToStream(Serializer serializer)
     at FastSerialization.Serializer.WriteObjectData(IFastSerializable obj, Tags beginTag)
     at FastSerialization.Serializer.WriteObjectRef(IFastSerializable obj, Boolean defered)
     at FastSerialization.Serializer..ctor(IStreamWriter writer, IFastSerializable entryObject)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.CreateFromEventPipeEventSources(TraceEventDispatcher source, IOStreamStreamWriter streamWriter, TraceLogOptions options)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.CreateFromEventPipeEventSources(TraceEventDispatcher source, String etlxFilePath, TraceLogOptions options)
     at Microsoft.Diagnostics.Tracing.Etlx.TraceLog.CreateFromEventPipeDataFile(String filePath, String etlxFilePath, TraceLogOptions options)
     at PerfView.EventPipePerfViewData.GetTraceLog(TextWriter log, Action`3 onLostEvents)
  [Error: exception while opening EventPipe data.]
  Completed: Opening with-rbp-chain-walk.nettrace   (Elapsed Time: 6.332 sec)

Possible fixes:

1. Skip symbols with EndAddress <= StartAddress (invalid range)
2. Change (int) to (long) cast for consistency with UniversalMapping
3. Add null guard on loadedModule as defense-in-depth

Expected

.nettrace file opens and shows views, possibly with an indicator that the symbols had invalid ranges

Actual

When double clicking the nettrace, no views appeared, and just the message Error: exception while opening EventPipe data. appeared.