Fatal Assertion Failure at J9KnownObjectTable.cpp:207

[luke-li-2003]

The fatal assertion at openj9/runtime/compiler/env/J9KnownObjectTable.cpp fails when running with a JITServer (e.g. when running test jdk_vector_float128_j9_0 on s390x linux (link)).

This is caused by getPointer being called by openj9/runtime/compiler/optimizer/VectorAPIExpansion.cpp:668, which should not be called by the server since the server cannot obtain VM access.

[github-actions]

Issue Number: 20410
Status: Open
Recommended Components: comp:vm, comp:gc, comp:test
Recommended Assignees: pshipton, babsingh, jasonfengj9

[luke-li-2003]

@mpirvu

[mpirvu]

The server should never execute code that needs VM access. File openj9/runtime/compiler/optimizer/VectorAPIExpansion.cpp has two such offenders, one in getVectorSizeFromVectorSpecies() and one in getJ9ClassFromClassNode()

[mpirvu]

For getJ9ClassFromClassNode() the code is:

J9Class *
TR_VectorAPIExpansion::getJ9ClassFromClassNode(TR::Compilation *comp, TR::Node *classNode)
   {
   if (!classNode->getOpCode().hasSymbolReference())
      return NULL;

   TR::SymbolReference *symRef = classNode->getSymbolReference();
   if (symRef)
      {
      if (symRef->hasKnownObjectIndex())
         {
         TR_J9VMBase *fej9 = comp->fej9();

         TR::VMAccessCriticalSection getDataTypeFromClassNodeSection(fej9);

         uintptr_t javaLangClass = comp->getKnownObjectTable()->getPointer(symRef->getKnownObjectIndex());
         J9Class *j9class = (J9Class *)(intptr_t)fej9->getInt64Field(javaLangClass, "vmRef");

         return j9class;
         }
      }
   return NULL;
   }

Since the known object index is known, the server could send a message to the client with this value and the client could return the corresponding j9class.

[mpirvu]

For getVectorSizeFromVectorSpecies(), the server could send a message to the client with the known object index and the client reply with a (vec_sz_t)vectorBitSize.