IJ11368: JAVA JIT PPC: CRASH IN JIT COMPILED CODE ON PPC MACHINES

APAR status

• Closed as program error.

Error description

• Error Message: SEGSEGV in the JIT library.
  .
  Stack Trace: N/A
  .
  The problem can occur in many different ways, but it's most
  likely to cause a crash inside a compiled method or in the JIT
  library. Other symptoms are possible including bad Object
  contents.
  The problem can only occur when running on PowerPC machines
  (AIX, and Power Linux). The x86 and zSeries JIT is not effected
  by this problem.
  

Local fix

• The problem can be avoided by using the java command line
  options to exclude the compilation of the method causing the
  problem, but in many cases it will not be obvious which method
  caused the problem. There is no global option that will avoid
  the problem for all JIT compiled methods.
  -Xjit:exclude={<pkg/class.method>*}
  Where <pkg/class.method> is the method signature of the method
  that caused the problem.
  

Problem summary

• The JIT must insure that register GPR0 is not used for some
  operands of specific PPC instruction that take GPR0 to mean the
  value 0 rather then the contents of GPR0. When the JIT
  encounters such a case it will spill the register contents to
  some other register. If this happens during internal control
  flow sections of the code it's possible for the contents of a
  register to become corrupted by failing to restoring the spilled
  register contents when taking some paths within the internal
  control flow.
  

Problem conclusion

• The JIT was modified such that the use of GPR0 is not allowed
  for a particular virtual register.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5  FP27 (8.0.5.27)
     7 R1 SR4  FP60 (7.1.4.60)
     7    SR10 FP60 (7.0.10.60)
  .
  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