Re: Exist operating systems that ship without blobs?

[David Young <dyoung%pobox.com@localhost>]

On Sun, Feb 21, 2016 at 09:25:52PM -0500, Thor Lancelot Simon wrote:
> On Fri, Feb 19, 2016 at 04:33:40PM -0600, David Young wrote:
> > 
> > BTW, I think a reasonable precaution to take with a lot of devices,
> > their firmware and drivers, open- or closed-source (but especially
> > closed source), is to put them under supervision of, say, an IOMMU.
> 
> It's reasonable, for sure, but it's not enough.  There are BSD derived
> operating systems out there which do this to complicate life for 
> malicious hot-plug PCIe devices.  Unfortunately, it doesn't really work,
> since you can always find some sensitive region that does have DMA enabled
> (if you get in early enough, the pages used for the disk transfers that
> bring in kernel modules, for example -- or libc) and scribble on it.

Not sure I follow.  You are talking about a malicious device that
performs bus-mastering accesses before the OS has initialized the IOMMU?

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981