IJ38060: JIT COMPILER CRASH WITH VMSTATE=0X0005FF04

APAR status

• Closed as program error.

Error description

• Error Message: Unhandled exception
  Type=Segmentation error vmState=0x0005ff04
  J9Generic_Signal_Number=00000018 Signal_Number=0000000b
  Error_Value=00000000 Signal_Code=00000035
  ...
  ...
  Method_being_compiled=<Signature of Java package/class.method
  that crashed during JIT compilation>
  .
  Stack Trace: TR::Region::allocate(const unsigned int,void*)
  TR_VirtualGuard::addNOPSite()
  virtualGuardHelper(TR::Node*,TR::CodeGenerator*)
  OMR::Z::TreeEvaluator::ificmpeqEvaluator(TR::Node*,TR::CodeGener
  ator*)
  OMR::Z::TreeEvaluator::ificmpneEvaluator(TR::Node*,TR::CodeGener
  ator*)
  OMR::CodeGenerator::evaluate(TR::Node*)
  J9::CodeGenerator::doInstructionSelection()
  OMR::CodeGenPhase::performInstructionSelectionPhase(TR::CodeGene
  rator*,TR::CodeGenPhase*)
  OMR::CodeGenPhase::performAll()
  OMR::CodeGenerator::generateCode()
  OMR::Compilation::compile()
  TR::CompilationInfoPerThreadBase::compile(J9VMThread*,TR::Compil
  ation*,TR_ResolvedMethod*,T...
  TR::CompilationInfoPerThreadBase::wrappedCompile(J9PortLibrary*,
  void*)
  .
  JIT Optimization that causes this failure was introduced in Java
  8 SR7.
  

Local fix

• This failure can be avoided by disabling JIT compiler
  optimization Global Value Propagation using JVM option
  -Xjit:disableGlobalVP
  

Problem summary

• The JIT Compiler may perform an optimization which would fold
  loading of Class pointer from the object of known fixed type to
  constant load. This optimization further inhibited other
  optimization where it is loading known field from the Class
  pointer and can fold it to constant. This prevents us from
  cleaning some cold code from the method body and while
  generating instruction for such code, JIT compiler crashes with
  segmentation fault as some of the expected data to generate
  instructions for such code was cleaned up.
  

Problem conclusion

• JIT compiler was updated to make sure it generates the optimal
  code to avoid hitting such scenarios.
  .
  This APAR will be fixed in the following Java Releases:
   8 SR7 FP6 (8.0.7.6)
  .
  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