[PATCH 46/48] staging: etnaviv: rewrite submit interface to use copy from user

[Russell King - ARM Linux]

On Fri, Sep 25, 2015 at 01:57:58PM +0200, Lucas Stach wrote:
> This rewrites the submit interface to copy the command stream from user
> memory. This mitigates a potential attack vector of the old interface
> where userspace could submit a command buffer that would be validated by
> the kernel, but is still mapped into userspace. This could be exploited
> by changing the command stream after validation but before the actual
> GPU execution.
> 
> A nice side effect is that validation and reloc patching can now operate
> on cached memory and only the final result is copied to a writecombined
> command buffer which should make those operations a bit more efficient.
> 
> A simplification to the interface is the removal of the ability to push
> multiple command buffers per submit. As we don't use it for context
> restore buffers and the fact that userspace doesn't need to work with
> a fixed command buffer size anymore, with the potential risk to overflow
> its size in the middle of an atomic stream section, there is no need
> for this complication anymore.
> 
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>

Applied, thanks.

-- 
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.