IV55957: ARRAYS.COPYOF MAY NOT CORRECTLY INITIALIZE DATA TO NULL

APAR status

• Closed as program error.

Error description

• Error Message: When Arrays.copyOf is used to create a new array
  that is larger than the original the additional locations should
  be zero initialized, but under some circumstances this may not
  happen.
  .
  Stack Trace: N/A
  .
  

Local fix

• The problem can be avoided by preventing the JIT from compiling
  the method using the following option:
  -Xjit:exclude={java/util/Arrays.copyOf(*},dontinline={java/util/
  Arrays.copyOf(*}
  

Problem summary

• The problem was caused by an over generalisation of an
  optimization to remove unnecessary zero initialization.
  

Problem conclusion

• This APAR will be fixed in the following Java Releases:
     7 R1 SR1       (7.1.1.0)
     7    SR7       (7.0.7.0)
     6 R1 SR8       (6.1.8.0)
  .
  The JIT has been modified so that the copyOf method will
  correctly apply zero initialization to the newly allocated
  array.
  

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