IV79118: JVM CRASHES WHILE EXECUTING TRANSACTIONAL MEMORY

APAR status

• Closed as program error.

Error description

• Error Message: A 0C4 signal (segmentation error) is raised by
  JIT compiled code causing the JVM to crash. The crashing
  instruction is shown to be the instruction after TBEGIN.
  .
  Stack Trace: N/A
  .
  This problem can only happen on z Systems.
  

Local fix

• This issue can be avoided by disabling Transactional Lock
  Elision which uses Transactional Memory by setting the following
  JVM option, -Xjit:disableTLE
  Note that this may affect performance.
  

Problem summary

• Any software interrupt will abort a memory transaction, causing
  the hardware to roll back the context to the start of the
  transaction; the TBEGIN instruction. When this happens, the
  interrupt cannot be correctly decoded because the execution
  context has already been rolled back. Some interrupts can be
  filtered to avoid this problem, allowing execution to resume.
  Currently the JVM only filters 0C7 interrupts, preventing them
  from crashing the program, and then execution will resume in the
  non Transactional Memory path so the interrupt will be
  re-generated and appropriately handled. 0C4 interrupts were not
  being filtered, and they should be.
  

Problem conclusion

• The JIT compiler has been updated to filter 0C4 interrupts which
  cause execution of Transactional Memory to abort so that
  execution of the program can resume in the equivalent
  non-transactional-execution path.
  .
  This APAR will be fixed in the following Java Releases:
     7 R1 SR3 FP30  (7.1.3.30)
     8    SR2 FP10  (8.0.2.10)
  .
  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

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R130 PSY

     UP