IV84322: CRASH/ASSERT IN GC WITH BAD O-SLOT.

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: Stack will likely include
  doStackSlot__31MM_ParallelScavengerRootScannerFPP8J9ObjectPvPCv
  .
  the problem can only occur when object synchronization is used
  and two GC cycles execute during a single execution of a method.
  

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
  -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 leave
  stale object address in a stack slot after the GC runs.  The
  stale object address value could then cause problems for a
  second GC if the method in question keeps running across 2 GC
  cycles.
  

Problem conclusion

• The JIT'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 SR3 FP50  (7.1.3.50)
     6 R1 SR8 FP30  (6.1.8.30)
     7    SR9 FP50  (7.0.9.50)
     8    SR3 FP10  (8.0.3.10)
     6    SR16 FP40  (6.0.16.40)
  
  .
  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

• R130 PSY

     UP

• R260 PSY

     UP