IJ07063: JAVA JIT: CRASH WHEN USING LOCK RESERVATION

APAR status

• Closed as program error.

Error description

• Error Message: Seg Fault in objectMonitorExit()
  Note that although the customer observed the crash in the above
  function, the nature of the issue means that there could be
  different symptoms.
  .
  Stack Trace: {libj9vm29.so}{objectMonitorExit}
  {libj9jit29.so}{fast_jitMethodMonitorExit@AF138_126}
  {libj9jit29.so}{jitMethodMonitorExit}
  {libj9vm29.so}{runJavaThread}
  {libj9vm29.so}{javaProtectedThreadProc}
  {libj9prt29.so}{omrsig_protect}
  {libj9vm29.so}{javaThreadProc}
  {libj9thr29.so}{thread_wrapper}
  {libpthreads.a}{_pthread_body}
  .
  Lock Reservation was turned on by default in SR5 for 'Random'
  and 'StringBuffer' objects, releases before this will not
  encounter this issue.
  This issue can only be found on PowerPC Platforms (LinuxPPC and
  AIX)
  

Local fix

• Lock Reservation can be disabled using the command line option:
  -Xjit:disableLockReservation
  This might affect performance by approximately 1% in a typical
  large server scenario.
  

Problem summary

• Register allocation during Lock Reservation fails to properly
  spill registers, this can cause values used later in the program
  to be overwritten and discarded.
  

Problem conclusion

• Fixed the Register Allocator to preserve values of registers
  properly.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP17  (8.0.5.17)
  .
  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