On Thu, 17 Mar 2005 21:53:04 -0500
Daniel Phillips <[EMAIL PROTECTED]> wrote:
> On Thursday 17 March 2005 17:49, Nicolas Boulay wrote:
> > uh ? I beleive that user space lib should talk directly to the card
> > to have the full speed.
>
> Yes.
Yes and no. Yes, it should be as direct as possible.
No, there needs to be a layer in between that keeps
user space from screwing the card or the whole machine.
IMHO there needs to be at least a check whether the
send commands can do anything harmfull. I also see
now that Timothy is right, a bit of hw support for this
kind of stuff will help.
> Furthermore, there may not be anything to split. I propose the
> following:
>
> - An unprivileged task can only submit commands via indirect DMA.
> Each indirect DMA buffer is submitted by ioctling the kernel
Can you explain this a little bit ?
> - PIO is only available to privileged tasks, normally only the kernel
> driver.
How is this differentiation going to provide security ?
If i can DMA to any memory location on the card, then i
can also overwrite the PIO registers with indirect DMA.
Or do i miss something ?
Attila Kinali
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