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    SubjectRe: UIO: missing resource mapping
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    Am Freitag, den 13.07.2012, 21:19 +0300 schrieb Michael S. Tsirkin:
    >
    > UIO has the same property, doesn't it? Multiple users can
    > access device memory through sysfs.


    Indeed, that's a similar problem. I haven't tried it (yet), but this
    particular problem can maybe circumvented by using mmap with the
    MAP_PRIVATE flag. Doing so is the responsibility of the driver
    programmer (like Hans already said). Even if that mmap trick does not
    work, it is pretty much sure that a BAR is already used by another
    program, if a related kernel driver is loaded. In that case the kernel
    has a chance to avoid such BAR race conditions by not giving the
    possibility to map them to the userspace.

    Nevertheless, I'm pretty sure that the possibility via sysfs to access
    BARs, which are already managed by a kernel driver, opens the door for
    denial of service attacks.

    On the other hand, I'm quite a newbie on this topic and maybe I don't
    see the big picture here. Therefore it is up to you guys to make the
    right decision (if needed).

    --
    Gruß
    Dominic

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