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IV48538: CRASH IN A METHOD COMPILED AT HIGH OPT LEVEL

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APAR status

  • Closed as program error.

Error description

  • Error Message: Under some circumstances the JIT compiler can
    incorrectly compile a method at high optimization level that
    includes profiling, resulting in the Java stack pointer being
    over-written with the C stack pointer.
    .
    Stack Trace: Because the problem causes corruption of the stack
    it is usually difficult to determine the call stack of the
    failing thread.
    .
    In the examples seen so far the failure occurs trying to execute
    non-executable code at the J9VMThread (failing rip == rbp).
    

Local fix

  • The problem can be avoided by disabling the use of JIT
    profiling:
    -Xjit:disableProfiling
    This option will likely result in slightly less optimal code
    being generated for those methods that reach the very highest
    optimization levels and so may reduce the maximum performance of
    the application. The extent of any performance impact will
    depend on the details of each application.
    

Problem summary

  • The problem is caused when a call to jitInstanceOf is placed
    within the control flow of a call to jitProfileValue, leading
    incorrect stack management.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.0 SR15
    6.0.1 SR7
    7.0.0 SR6
    .
    The JIT has been modified to handle this case correctly.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV48538

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-09-12

  • Closed date

    2013-09-12

  • Last modified date

    2013-09-12

  • 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 PSY

       UP

  • R260 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Just In Time (JIT) Compiler

Software version: 6.0

Reference #: IV48538

Modified date: 12 September 2013