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IV35532: SEGFAULT ON OBJECT ALLOCATION IN JAVA7SR3/JAVA626SR5 WITH -XGCPO LICY:METRONOME

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APAR status

  • Closed as program error.

Error description

  • Error Message: A SIGSEGV/GPF is received when allocating (or
    right after) a large object allocation on soft realtime
    (-Xgcpolicy:metronome on the command-line but -Xrealtime is
    not).
    .
    Stack Trace: N/A
    .
    

Local fix

  • Using 64-bit jvm will likely fix the problem.
    

Problem summary

  • Recently with the change of increasing the number of size
    classes in Java7SR3/Java626SR5 has exposed a bug in our existing
    code base.
    Specifically the problem is caused when attempt to allocate a
    large objects for a large size class (<TLD> 4k-64k) near the end
    of the address space.  A check at this point fails due to
    integer overflow and we allocate the object incorrectly.
    We will seg fault either immediately at that large allocation or
    on the next subsequent allocation (depends on page size).
    

Problem conclusion

  • This defect will be fixed in:
    7.0.0 SR4
    6.0.1 SR5
    WRT-V3 SR4
    .
    Object allocation code has been corrected so that the checking
    code never overflows
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV35532

  • Reported component name

    WRT VM

  • Reported component ID

    5724R0403

  • Reported release

    300

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-01-18

  • Closed date

    2013-01-18

  • Last modified date

    2013-03-04

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

    IV35531

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

Fix information

  • Fixed component name

    WRT VM

  • Fixed component ID

    5724R0403

Applicable component levels

  • R300 PSY

       UP

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Document Information

Modified date:
04 March 2013