IJ06411: CRASH IN JIT IN FINDBESTFREEREGISTER ON Z

APAR status

• Closed as program error.

Error description

• Error Message: The error will be a segmentation error and is
  more likely to appear on a 31-bit JVM. It will look as follows:
  Type=Segmentation error vmState=0x0005ff06
  .
  Stack Trace: OMR::Z::Machine::findBestFreeRegister
  OMR::Z::Machine::assignBestRegisterSingle
  OMR::Z::Machine::assignBestRegister
  OMR::Z::Instruction::assignRegisterNoDependencies
  .
  This problem can only happen on z Systems.
  

Local fix

• This crash happens during compilation of a method. The name of
  that method is specified during the crash. The following command
  line option can be used when launching the application to avoid
  compiling this method, hence preventing the crash:
  -Xjit:exclude={package/Class.method(signature)}
  

Problem summary

• During register assignment, the JIT Compiler will call a routine
  to find an available register for an instruction. This routine
  may try to access an element outside the bounds of an array,
  causing undefined behaviour. This can result in a segmentation
  fault.
  

Problem conclusion

• The JIT compiler has been updated to perform correct boundary
  checking before accessing array elements inside the problematic
  routine.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP15  (8.0.5.15)
  .
  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