[PATCH 14/22] gpu: host1x: Forbid relocation address shifting in the firewall

[Erik Faye-Lund]

On Tue, May 23, 2017 at 2:14 AM, Dmitry Osipenko <digetx at gmail.com> wrote:
> Incorrectly shifted relocation address will cause a lower memory corruption
> and likely a hang on a write or a read of an arbitrary data in case of IOMMU
> absent. As of now there is no use for the address shifting (at least on
> Tegra20) and adding a proper shifting / sizes validation is much more work.
> Let's forbid it in the firewall till a proper validation is implemented.
>
> Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
> ---
>  drivers/gpu/host1x/job.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
> index 190353944d23..1a1568e64ba8 100644
> --- a/drivers/gpu/host1x/job.c
> +++ b/drivers/gpu/host1x/job.c
> @@ -332,6 +332,10 @@ static bool check_reloc(struct host1x_reloc *reloc, struct host1x_bo *cmdbuf,
>         if (reloc->cmdbuf.bo != cmdbuf || reloc->cmdbuf.offset != offset)
>                 return false;
>
> +       /* relocation shift value validation isn't implemented yet */
> +       if (reloc->shift)
> +               return false;
> +
>         return true;
>  }
>
> --
> 2.13.0
>

Good call.


Reviewed-by: Erik Faye-Lund <kusmabite at gmail.com>