IZ77969: JAVA6 JIT - CRASH IN JIT COMPILED CODE

APAR status

• Closed as program error.

Error description

• Error Message: SIGSEGV while executing in JIT compiled code.
  .
  Stack Trace: N/A
  .
  I can say that the problem is rare, but there is no special
  circumstances are required in order to hit the problem. It's
  simply the results of various code sequences manipulated by
  various JIT optimizations that lead to a particular code
  sequence where the problem can occur.
  The problem only exists in Java6. Java5 is not effect. The
  problem can happen on any IBM JVM platform (xSeries, pSeries and
  zSeries)
  

Local fix

• The problem can be avoided by using the following Java command
  line option. This option will degrade performance slightly (in
  most cases the cost will be less then 1%):
  -Xjit:disableStoreSinking
  

Problem summary

• The JIT would incorrectly reorder the code such that a store
  that was meant to execute before a value is modified is moved
  below the modification resulting in an incorrect value being
  stored.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR9
  .
  The JIT was modified so that this problem will not occur
  .
  To obtain the fix:
  Install build 20100630 or later
  

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

• R600 PSN

     UP