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Problem Report 1259 Details

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This page provides all information on Problem Report 1259.

Report 1259 Actions

    Problem Report Number 1259
    Submitter's Classification Specification problem
    State Resolved
    Resolution Rejected (REJ)
    Problem Resolution ID REJ.X.0461
    Raised 1970-01-01 08:00
    Updated 2003-03-13 08:00
    Published null
    Product Standard Internationalised System Calls and Libraries Extended (UNIX 95)
    Certification Program The Open Brand certification program
    Test Suite VSU version 4.0.2
    Test Identification Base/mmap 0
    Problem Summary PG4U.00004 We request that the munmap() interface be changed to not require that references to unmapped memory fail.
    Problem Text
    We request that the munmap() interface be changed to not require
    that references to unmapped memory fail. In particular that
    the following language be removed from X/Open CAE Specification
    System Interfaces and Headers, Issue 4, Version 2, page 414,
    section "DESCRIPTION":

    "After a successful call to munmap() and before any
    subsequent mapping of the unmapped pages, further
    references to these pages will result in the delivery
    of a SIGBUS or SIGSEGV signal to the process."

    Dropping this behavior does, by implication, also impact those
    pages whose access permissions are modified by the mprotect()
    interface.

    We ask for this behavior to be dropped since the current line
    of parallel-vector machines produced by Cray Research do not
    provide the demand-paged virtual memory environment that the
    above behavior depends upon.

    Cray Research was active in the Spec 1170 process to get this
    issue resolved before the specification reached its final form.
    The sponsors of the Spec 1170 process developed a model which
    they felt would allow us to conform and they did resolve the
    vast majority of our objections. However, a couple of problems
    remained when the specification was complete.

    We contacted one of the members of the sponsor team and
    communicated our concerns to him and he was surprised to find
    out that we could not conform. He reiterated that it was the
    intention of the sponsor team that we be able to conform, but
    he agreed that our interpretation of the technical requirements
    was correct.

    There are two key rationales for this change:

    1. The intention of the Spec 1170 sponsors was to create
    a specification to which Cray Research systems could
    conform. However, this requirement excludes any
    possibility of our conformance.

    2. The behavior is not a positive behavior but is used to
    isolate faults in malfunctioning programs. This does
    not preclude the possibility that someone could use this
    in a positive manner, but that was not the intention of
    the definers of the specification. Thus, this is really
    a quality of application implementation issue.

    It certainly is expected that virtually all implementations
    will implement this behavior and will thus provide the
    fault-detection desired from this feature. However, if
    it is impossible for an implementation to provide this fault
    detection, that should not be an impediment to conformance.
    Test Output
    N.A.

    Review Information

    Review Type TSMA Review
    Start Date null
    Completed null
    Status Complete
    Review Recommendation No Resolution Given
    Review Response
    We recommend this request be forwarded to the base working group
    for approval.

    Review Type Expert Group Review
    Start Date null
    Completed null
    Status Complete
    Review Resolution No Resolution Given
    Review Conclusion
    The Base Working Group recommends that this request be denied. The
    Specification has been watered down as much as possible and there are
    unacceptable security problems arising from the proposed action.

    Review Type SA Review
    Start Date null
    Completed null
    Status Complete
    Review Resolution Rejected (REJ)
    Review Conclusion
    This request is refused.

    Problem Reporting System Options:

     

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