Re: [PATCH 5.4 105/132] drm/msm: Split the a5xx preemption record

From: Greg Kroah-Hartman
Date: Tue Sep 15 2020 - 18:14:26 EST


On Tue, Sep 15, 2020 at 09:54:39AM -0600, Jordan Crouse wrote:
> On Tue, Sep 15, 2020 at 04:13:27PM +0200, Greg Kroah-Hartman wrote:
> > From: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> >
> > commit 34221545d2069dc947131f42392fd4cebabe1b39 upstream.
> >
> > The main a5xx preemption record can be marked as privileged to
> > protect it from user access but the counters storage needs to be
> > remain unprivileged. Split the buffers and mark the critical memory
> > as privileged.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
> Hi. The MSM_BO_MAP_PRIV feature was added after 5.4.
>
> Since we are pulling in 7b3f3948c8b7 ("drm/msm: Disable preemption on all
> 5xx targets)" preemption will be disabled in the 5.4 stable tree which is enough
> to cover the security concern that this patch helped address.
>
> This patch can be dropped.

Now dropped,t hanks!

greg k-h