IJ18018: JAVA JIT: COMPILE TIME CRASH IN INSTANCEOFORCHECKCAST()

APAR status

• Closed as program error.

Error description

• Error Message: SIGSEGV received while JIT compiling a method.
  .
  Stack Trace: {libj9jit29.so}{instanceOfOrCheckCast}
  {libj9jit29.so}{jitCTInstanceOf}
  {libj9jit29.so}{TR_J9VM::isInstanceOf(TR_OpaqueClassBlock*,TR_Op
  aqueClassBlock*,bool,bool,bool)}
  {libj9jit29.so}{J9::ValuePropagation::constrainRecognizedMethod(
  TR::Node*)}
  {libj9jit29.so}{constrainCall(OMR::ValuePropagation*,TR::Node*)}
  {libj9jit29.so}{OMR::ValuePropagation::launchNode(TR::Node*,TR::
  Node*,int)}
  {libj9jit29.so}{constrainChildren(OMR::ValuePropagation*,TR::Nod
  e*)}
  {libj9jit29.so}{OMR::ValuePropagation::launchNode(TR::Node*,TR::
  Node*,int)}
  {libj9jit29.so}{OMR::ValuePropagation::processTrees(TR::TreeTop*
  ,TR::TreeTop*)}
  {libj9jit29.so}{TR::GlobalValuePropagation::processBlock(TR_Stru
  ctureSubGraphNode*,bool,bool)}
  {libj9jit29.so}{TR::GlobalValuePropagation::processStructure(TR_
  StructureSubGraphNode*,bool,bool)}
  {libj9jit29.so}{TR::GlobalValuePropagation::processRegionNode(TR
  _StructureSubGraphNode*,bool,bool)}
  {libj9jit29.so}{TR::GlobalValuePropagation::processRegionNode(TR
  _StructureSubGraphNode*,bool,bool)}
  .
  

Local fix

• The problem can be avoided by setting the following environment
  variable before starting the JVM.
  TR_disableVPFoldRecognizedMethod=1
  This option will cause the JIT to disable a small optimization
  where the issue exists. This option may show a minor effect on
  performance.
  

Problem summary

• In some cases an class that is still unresolved at JIT compile
  time can result in a NULL pointer to be dereferenced causing a
  SIGSEGV to occur.
  

Problem conclusion

• The JIT was modified such that it will not attempt this
  particular optimization unless the classes involved are
  resolved.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP41  (8.0.5.41)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  Service Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels