IV90105: JAVA IMPROPERLY REUSES STACK LOCATION

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  A local variable or temporary on the stack holds an incorrect
  value, including possibly a reference to an object of unexpected
  type, during execution of a method body compiled for profiling.
  

Local fix

• The problem can be avoided by using -Xjit:disableCompactLocals,
  at the cost of additional stack usage. If this option is
  restricted to the problematic method, the increase in stack
  usage should generally be small.
  

Problem summary

• The JIT compiler performs an analysis in order to share stack
  space between local variables and temporaries with
  nonoverlapping lifetimes. When compiling for profiling, further
  optimization could be performed after this analysis,
  invalidating the result. In this case, variables with
  overlapping lifetimes could be assigned the same storage
  location.
  

Problem conclusion

• The compiler has been modified to ensure that conflicting
  variables are assigned distinct stack locations when compiling
  for profiling.
  .
  This APAR will be fixed in the following Java Releases:
     7 R1 SR3 FP60  (7.1.3.60)
     8    SR3 FP20  (8.0.3.20)
     7    SR9 FP60  (7.0.9.60)
     6 R1 SR8 FP35  (6.1.8.35)
     6    SR16 FP35 (6.0.16.35)
  .
  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

• R260 PSY

     UP

• R600 PSY

     UP