Re: [PATCH] crypto: drbg: fix crypto api abuse

Gilad Ben-Yossef
2022-02-28T09:09:13Z

Hi,

On Sun, Feb 27, 2022 at 12:12 PM Gilad Ben-Yossef <gilad@benyossef.com> wrote:
...

>
> I think the right thing to do right now is to verify that we indeed
> have a general issue and not something specific to one singular
> platform
> So the question becomes - do indeed the DMA api forbits aliased
> mappings and if so, under what conditions?
>
> Any ideas on how to check this?

OK, I've looked into this further and I think I was wrong.
The DMA api doesn't like overlapping writable mappings, but it seems
an overlapping read-only and writable mapping are fine.
If so I can indeed resolve this in the driver code by better
specifying DMA direction. Let me give this a go and let's drop this
patch in the meantime.

Thank you and sorry for the noise.

Gilad

--
Gilad Ben-Yossef
Chief Coffee Drinker

values of β will give rise to dom!