[Linaro-mm-sig] [RFC] ARM DMA mapping TODO, v1
benh at kernel.crashing.org
Fri Apr 29 22:37:17 UTC 2011
On Fri, 2011-04-29 at 20:29 +0200, Arnd Bergmann wrote:
> If that is the case, we can probably work around this by turning the
> linear mapping (except for the kernel binary) into nonexecutable mode,
> if we don't do that already.
> This is desirable for security purposes anyway
You'd still have an "edge" problem if you use large pages for the linear
mapping, you can't obviously make part of the kernel text NX and you'd
have to make sure you 'exclude' from those GPU allocations whatever
overlaps with your last executable large page.
In a way, it's a similar problem I have with bolted memory on BookE
where I can't restrict GPU allocations to memory that isn't bolted :-)
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