[PATCH 08/10] drm: Forbid legacy MAP functions for DRIVER_MODESET

[Emil Velikov]

On 30 March 2016 at 10:45, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Like in
>
> commit 0e975980d435d58df2d430d688b8c18778b42218
> Author: Peter Antoine <peter.antoine at intel.com>
> Date:   Tue Jun 23 08:18:49 2015 +0100
>
>     drm: Turn off Legacy Context Functions
>
> we need to again make an exception for nouveau, but everyone else
> really doesn't need this.
>
> Cc: Peter Antoine <peter.antoine at intel.com>
> Cc: Ben Skeggs <bskeggs at redhat.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  drivers/gpu/drm/drm_bufs.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
> index d92db7007f62..e8a12a4fd400 100644
> --- a/drivers/gpu/drm/drm_bufs.c
> +++ b/drivers/gpu/drm/drm_bufs.c
> @@ -396,6 +396,10 @@ int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
>         if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
>                 return -EPERM;
>
> +       if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
> +           drm_core_check_feature(dev, DRIVER_MODESET))
> +               return -EINVAL;
> +
Wondering if making this the first check in the function won't be
better ? We have a handful of places which preemptively check
DRIVER_MODESET prior to calling drm_legacy functions and similarly
some (last time I've looked) drm_legacy functions check for
DRIVER_MODESET. Perhaps we can move all the checking into the
drm_legacy API alone ?

-Emil