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    SubjectRe: [take12 0/3] kevent: Generic event handling mechanism.
    On Wed, Aug 23, 2006 at 11:49:22AM +0200, Jari Sundell ( wrote:
    > >> Only void * I'm seeing belongs to the user, (udata) perhaps you are
    > >> talking of something different?
    > >
    > >Yes, exactly about it.
    > >
    > >I put union {
    > > u32 a[2];
    > > void *b;
    > >}
    > >epcially to eliminate that problem.
    > It's just random data of a known maximum size appended to the struct,
    > I'm sure you can find a clean way to handle it. If you mangle the
    > first variable name in your union, you'll end up with something that
    > should be usable instead of udata.

    If there will be usual pointer, size of the whole structure will be
    different in kernel and userspace.

    > >And I'm not that sure aboit stuff like uptr_t or how they call pointers
    > >in userspace and kernelspace.
    > Well, I can't find any use of pointers in your struct ukevent, nor in
    > any of the kqueue events in my man page. So if this is a deficit it
    > applies to both, I guess?

    No, it will change sizes of the structure in kernelspace and userspace,
    so they just can not communicate.

    > >ukevent is aligned to 8 bytes already (it's size selected to be 40 bytes),
    > >so it should not be a problem.
    > >
    > >> Eric
    > Even if it is so, wouldn't it be better to be explicit about it?

    Ok, I will add a comment about it.

    > Rakshasa

    Evgeniy Polyakov
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      Last update: 2006-08-23 12:25    [W:0.022 / U:30.680 seconds]
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