IV65284: JAVA CRASH/ASSERT IN GC WITH BAD O-SLOT

APAR status

• Closed as program error.

Error description

• Error Message:
  ** ASSERTION FAILED ** at ParallelScavenger.cpp:2486: ((MM_Stack
  SlotValidator(MM_StackSlotValidator::NOT_ON_HEAP, *slotPtr, stac
  kLocation, walkState).validate(_env)))
  
  Stack Trace: The stack trace of the crash will likely include
  this routine:
  
  {libj9gc26.so}{doStackSlot__31MM_ParallelScavengerRootScannerFPP
  8J9ObjectPvPCv}
  

Local fix

• If the method associated with the bad O-slot can be determined
  from either the error log or snap trace output then the method
  can be excluded from JIT compilation using this option:
  
  -Xjit:exclude={package/classname.methodname(*}
  

Problem summary

• Under some circumstances, the JIT could incorrectly analyze a
  code path involving an exception throw and catch, and could
  consequently generate code that does not always initialize a
  local object reference before the GC runs.  The un-initialized
  value could then cause problems for GC.
  

Problem conclusion

• The JIT compiler's live monitor analysis has been fixed so that
  throw-catch paths are processed accurately.
  .
  This APAR will be fixed in the following Java Releases:
     7 R1 SR2  FP10 (7.1.2.10)
     7    SR8  FP10  (7.0.8.10)
     6 R1 SR8  FP3  (6.1.8.3)
     6    SR16 FP3  (6.0.16.3)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the 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:

  PI33621

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

     UP

• R260 PSY

     UP

• R600 PSY

     UP