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IV44794: INCORRECT NULLPOINTEREXCEPTION FROM FIELD

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APAR status

  • Closed as program error.

Error description

  • Error Message: A NullPointerException is thrown in a context
    where a field is being used, and that field has very recently
    been initialized by a constructor.
    .
    Stack Trace: N/A
    .
    

Local fix

  • -Xjit:disableLookahead
    

Problem summary

  • An alias computation in the JIT compiler that was intended to
    combine several sources of information could erroneously omit
    one source.  This caused the optimizer to conclude incorrectly
    that a constructor does not alter a particular field, leading it
    to assume that the field must be null, and then to transform the
    code accordingly in such a way that a NullPointerException is
    thrown.
    It is also possible that this can affect non-reference fields,
    causing them to appear incorrectly to contain zeros.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.1 SR7
    7.0.0 SR6
    .
    The alias computation was fixed so it does not omit any sources
    of alias information.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV44794

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    260

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-06-24

  • Closed date

    2013-08-14

  • Last modified date

    2013-08-14

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    PI11124

Fix information

  • Fixed component name

    JIT

  • Fixed component ID

    620700124

Applicable component levels

  • R260 PSY

       UP

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Document Information

Modified date:
14 August 2013