IV74616: SEGMENTATION ERROR ON POWER AND Z PLATFORMS OR NULL POINTER EXCE PTION ON X86 PLATFORM WITH AOT ENABLED

APAR status

• Closed as program error.

Error description

• Error Message: A Segmentation error with vmState=0x00000000 on
  POWER and z Systems is raised, or a Null Pointer Exception is
  raised on x86.
  .
  Stack Trace: N/A
  .
  This only happens when AOT mode is enabled.
  

Local fix

• -Xaot:disableLoopVersioner
  Note that this can affect performance.
  

Problem summary

• The problem happens when executing a method that was AOT
  compiled using the Loop Versioner optimization, which is capable
  of moving a load of a field out of a loop.  Since this can move
  the load to a location in the program that is manipulating an
  object that doesn't possess that field, the compiler inserts a
  type check before loading the field.  Under certain
  circumstances, AOT compilations are unable to generate the
  required type check, in which case the compiler would
  erroneously neglect to emit any type check.  When the resulting
  code runs, the invalid field load could access memory outside
  the Java heap, causing a crash.
  

Problem conclusion

• The JIT compiler has been fixed to avoid moving field loads out
  of loops during AOT compilations.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR1 FP10  (8.0.1.10)
  .
  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