IV63803: JIT-COMPILED METHOD WITH DIVISION OR MODULO RETURNS INCORRECT RE SULT

APAR status

• Closed as program error.

Error description

• Error Message: A Java method with a large number of division or
  modulo operations may return incorrect results after being
  JIT-compiled. This issue was first discovered in IBM DB2 Content
  Manager's Resource Manager application (the
  com/ibm/mm/icmrm/util/RMTokenValidator.encrypt method) but may
  be encountered in other programs too.This issue only affects
  System z platforms (z/OS and Linux).
  .
  Stack Trace: N/A
  .
  

Local fix

• This issue can be avoided by excluding the offending method from
  compilation with a JVM option,
  e.g.-Xjit:exclude={com/ibm/mm/icmrm/util/RMTokenValidator.encryp
  t*}
  

Problem summary

• The problem is caused by an incorrect placement of a register
  spill within the division instruction sequence by the JIT
  compiler.
  

Problem conclusion

• The JIT compiler has been updated to produce correct code in
  this scenario.
  .
  This APAR will be fixed in the following Java Releases:
     6    SR16 FP2  (6.0.16.2)
     7 R1 SR2       (7.1.2.0)
     5.0  SR16 FP9  (5.0.16.9)
     6 R1 SR8 FP2   (6.1.8.2)
     7    SR8       (7.0.8.0)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, Java maintenance is available
  from:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IV63802

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA 5 JIT

• Fixed component ID

  620500124

Applicable component levels

• R500 PSY

     UP