IV83042: UNEXPECTED SEGMENTATION FAULT IN JIT-COMPILED CODE

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  The JVM unexpectedly throws NullPointerException, or, if -Xrs
  was
          given, crashes with a segmentation fault. The current
  thread is in
          the JIT-compiled body for a method that was compiled at
  optimization
          level hot or above.
  

Local fix

• It is possible to work around the issue by passing
  -Xjit:disablePRE. This
        option may degrade performance, but it can be restricted
  to the
        problematic method to minimize the impact.
  

Problem summary

• An instanceof operation was determined by a control flow
  sensitive
        analysis to operate on non-null object references only.
  This analysis
        result was preserved after an optimization called partial
  redundancy
        elimination moved the computation out of a loop, where the
  reference was
        no longer guaranteed to be non-null. As a result, the
  compiler generated
        an instruction sequence for instanceof without a null
  test, which
        later dereferenced a null pointer.
  

Problem conclusion

• The JIT compiler has been modified so that partial redundancy
  elimination
        will invalidate this analysis result when it moves a
  computation.
  
  .
  This APAR will be fixed in the following Java Releases:
     8    SR3       (8.0.3.0)
  .
  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

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