IV93389: PROGRAM CRASH IN JITTED METHOD BECAUSE OF INCORRECT REGISTER VALUE AROUND JAVA/LANG/CLASS.ISASSIGNABLEFROM

APAR status

• Closed as program error.

Error description

• Error Message: Typical symptoms are segmentation faults in JIT
  compiled methods around java/lang/Class.isAssignableFrom
  .
  Stack Trace: N/A
  .
  This only affects Java8 and newer releases when running on the
  x86 architecture.
  

Local fix

• The environment variable TR_disableInlineIsAssignableFrom can be
  set to disable the optimization causing the problem.
  

Problem summary

• This happens occasionally when executing the optimized version
  of Java method isAssignableFrom. The register gets wrong value
  when the program jumps from the fast path to the slow path in
  some corner cases and the value loading, which is before the
  destination label, is missed.
  

Problem conclusion

• The optimized version of isAssignableFrom is fixed to make sure
  that the value loading is after the destination label and the
  reigster gets correct value.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR4 FP2   (8.0.4.2)
  .
  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