[PATCH] drm/gem: Check for valid formats

[Maíra Canal]

On 1/5/23 12:26, Daniel Vetter wrote:
> On Tue, Jan 03, 2023 at 09:53:23AM -0300, Maíra Canal wrote:
>> Currently, drm_gem_fb_create() doesn't check if the pixel format is
>> supported, which can lead to the acceptance of invalid pixel formats
>> e.g. the acceptance of invalid modifiers. Therefore, add a check for
>> valid formats on drm_gem_fb_create().
>>
>> Moreover, note that this check is only valid for atomic drivers,
>> because, for non-atomic drivers, checking drm_any_plane_has_format() is
>> not possible since the format list for the primary plane is fake, and
>> we'd therefor reject valid formats.
>>
>> Suggested-by: Thomas Zimmermann <tzimmermann at suse.de>
>> Signed-off-by: Maíra Canal <mcanal at igalia.com>
> 
> Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> I think to really make sure we have consensus it'd be good to extend this
> to a series which removes all the callers to drm_any_plane_has_format()
> from the various drivers, and then unexports that helper. That way your
> series here will have more eyes on it :-)

I took a look at the callers to drm_any_plane_has_format() and there are only
3 callers (amdgpu, i915 and vmwgfx). They all use drm_any_plane_has_format()
before calling drm_framebuffer_init(). So, I'm not sure I could remove
drm_any_plane_has_format() from those drivers. Maybe adding this same check
to drm_gem_fb_init() and refactor the drivers to make them use drm_gem_fb_init(),
but I guess this would be part of a different series.

Best Regards,
- Maíra Canal

> -Daniel
>