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    SubjectRe: 2.6.8.1-mm4
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    On Llu, 2004-08-23 at 19:21, Tomasz Torcz wrote:
    > >- This kernel has an x86 patch which alters the copy_*_user() functions so
    > > they will return -EFAULT on a fault rather than the number of bytes which
    > > remain to be copied. This is a bit of an experiment, because this seems to
    > > be the preferred API for those functions. It's a see-what-breaks thing.
    > >
    >
    > Things appear to broke. Sometimes kernel starts to spit page allocation
    > failures into log for few minutes, despite memory beeing available:

    The kernel relies on copy_from_user returning the number of bytes copied
    so no suprise there. In fact if it returns -EFAULT and you've not
    reworked all the drivers (including out of kernel serial drivers in
    particular) you get a security hole because you can move the buffer
    pointers backwards.

    Other code uses it to decide what object was passed for compatibility
    too.

    Alan


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