IV88646: JVM CRASHES WHEN TRYING TO PRINT A STACK TRACE

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV or GPF is raised in libj9vm26.so when a
  Java program tries to print the stack trace stored in a
  Throwable object
  .
  Stack Trace: Native stack:
  getOriginalROMMethod
  iterateStackTrace
  getStackTrace
  java_lang_J9VMInternals_getStackTrace
  Java stack:
  java/lang/J9VMInternals.getStackTrace
  java/lang/Throwable.getInternalStackTrace
  java/lang/Throwable.printStackTrace
  java/lang/Throwable.printStackTrace
  .
  

Local fix

• -Xnoclassgc
  This option prevents class unloading. Note that this option may
  increase the memory footprint of the application
  

Problem summary

• When trying to print the stack trace stored in a Throwable
  object, it is possible for the class of one of the methods in
  the stack trace to get unloaded. If that method was JIT compiled
  and the unloading happens during a narrow timing window, then
  the metadata structure describing said method will get altered
  which could lead to a NULL dereference.
  

Problem conclusion

• The JVM has been updated to prevent altering of the metadata
  structure while it is still in use during the printing of a
  stack trace
  .
  This APAR will be fixed in the following Java Releases:
     6 R1 SR8 FP40  (6.1.8.40)
     7 R1 SR3 FP60  (7.1.3.60)
     7    SR10      (7.0.10.0)
     8    SR3 FP12  (8.0.3.12)
  .
  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

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R260 PSY

     UP

• R270 PSY

     UP