IV72270: CRASH CAUSED BY MEMORY CORRUPTION FROM ARRAY DATA COPIED TO THE WRONG ADDRESS

APAR status

• Closed as program error.

Error description

• Error Message: A variety of error messages are possible,
  depending on the memory corruption caused by the faulty array
  copy.
  .
  Stack Trace:
  .
  

Local fix

• -Xjit:disableIdiomRecognition prevents the error.  Any resulting
  performance impact can be mitigated by limiting this option to
  the problematic methods.
  

Problem summary

• The JIT compiler recognizes a data-copying loops and replaces
  them with faster bulk copy operations.  Occasionally, the
  compiler would do this incorrectly in cases where the
  destination array reference would change during the loop.  The
  resulting bulk copy operation moved data to the wrong location
  in memory.
  

Problem conclusion

• The compiler has been changed to leave data-copying loops
  unaltered whenever the array references can change during the
  loop.  This preserves the original correct behaviour of the
  loop.
  .
  This APAR will be fixed in the following Java Releases:
     6 R1 SR8 FP4   (6.1.8.4)
     8    SR1       (8.0.1.0)
     7 R1 SR3       (7.1.3.0)
     6    SR16 FP4  (6.0.16.4)
  .
  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

• R260 PSY

     UP

• R130 PSY

     UP

• R600 PSY

     UP