IV89242: PROBLEMS WITH ALLOCATING HUGE OBJECTS

APAR status

• Closed as program error.

Error description

• Error Message: There are two possible symptoms:
  - A segmentation error raised by the JVM in J9ZERZ10
  - Massive amounts of memory corruption of zeros which could have
  various consequences
  .
  Stack Trace: J9ZERZ10
  J9ZeroMemory
  .
  This problem only affects z Systems.
  

Local fix

Problem summary

• When allocating a huge object, the assembly function J9ZERZ10
  which is responsible for zero initializing memory will zero far
  more memory than it is suppose to when the size of the object
  being created is >= 0x7FFFFFFC bytes (2GB - 4) for a regular
  object and 0x7FFFFFF8 bytes (2GB - 8) for an array. If an object
  larger than this is requested then when J9ZERZ10 starts writing
  excess zeros to memory, it may hit the end of the JVM's memory
  and trigger a segmentation error, or it will leave a very large
  amount of memory corrupted with zeros.
  

Problem conclusion

• The JVM has been updated to correctly handle allocation of all
  object sizes possible in the Java specification.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR3 FP20  (8.0.3.20)
     7 R1 SR4 FP20  (7.1.4.20)
  .
  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

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R270 PSY

     UP