IV97015: SIG_BUS CRASH EXECUTING DIRECTBYTEBUFFER CODE

APAR status

• Closed as program error.

Error description

• Error Message: The JVM crashes with a SIG_BUS when executing
  code using DirectByteBuffer or any other routines that make use
  of the Unsafe API to access native memory (typically a memory
  mapped file) that has been freed/deleted/resized or is not
  accessible (i.e disk full).
  .
  Stack Trace: The stacktrace will likely start with a method that
  is accessing a DirectByteBuffer (or any other method that is
  making use of the Unsafe API to access native memory directly).
  i.e.
  {java/nio/MappedByteBuffer.load}
  .
  The problem has to do with accessing native (non-Java managed)
  memory that is no longer accessible by the system. Typically
  this is caused by memory mapped file that is not accessible
  causing the operating system to throw a SIG_BUS when it is
  unable to satisfy a memory read/write request.
  

Local fix

• The issue is likely due to an issue with the file system where a
  file was unexpectedly deleted or unaccessible due to any number
  of possible reasons (disk or network failures for example). The
  issue can be avoided by making sure that memory mapped files are
  always accessible throughout the life of the Java application
  that is accessing it. Making sure that the disk always has
  available space is a big part of this.
  

Problem summary

• A memory mapped file becoming unaccessible causing a SIG_BUS to
  be thrown when the JVM is accessing a DirectByteBuffer that is
  linked to that memory mapped file.
  

Problem conclusion

• The JVM will catch the SIG_BUS and convert it into a
  java.lang.InternalError exception.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR4 FP10  (8.0.4.10)
  .
  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