IJ24781: JAVA JIT: CRASH IN RESOLVECLASSREF() DURING AOT LOAD

APAR status

• Closed as program error.

Error description

• Error Message: SIGSEGV in resolveClassRef() during the code
  relocation stage during a AOT load of JIT compiled code stored
  in the shared class cache.
  .
  Stack Trace: {libj9vm29.so}{resolveClassRef}
  {libj9vm29.so}{resolveStaticFieldRefInto}
  {libj9jit29.so}{jitCTResolveStaticFieldRefWithMethod}
  {libj9jit29.so}{TR_RelocationRecordDataAddress::findDataAddress(
  TR_RelocationRuntime*,TR_RelocationTarget*)}
  ...
  .
  The problem can only occur during a AOT load operation when
  shared classes is enabled (-Xshareclasses). The problem is
  possible with standard AOT settings but is far more likely when
  using -Xaot:forceAOT with a large AOT cache size (-Xscmx...)
  The problem could occur on any CPU platform running the J9 JVM.
  

Local fix

• The problem can avoided by disabling AOT:
  -Xnoaot
  This is likely to cause higher CPU utilization and lower
  throughput during the startup phase of the JVM. It is also
  likely to cause the startup phase to last longer. After startup,
  the performance should be as good as when AOT was enabled.
  

Problem summary

• In some cases the JIT might decide to share symbol information
  with a field from a method that we examined as a inlining
  candidate but not inlined. This results in a problem when
  generating AOT code because the relocation information can't be
  described properly.
  

Problem conclusion

• The JIT was modified so that it detects when a relocation issue
  has occurred and will abort loading the AOT method.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR6 FP15  (8.0.6.15)
  .
  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