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@xxxxxxx>
> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
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 :-)
-Daniel
> ---
> Documentation/gpu/todo.rst | 7 ++-----
> drivers/gpu/drm/drm_gem_framebuffer_helper.c | 9 +++++++++
> 2 files changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 1f8a5ebe188e..68bdafa0284f 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -276,11 +276,8 @@ Various hold-ups:
> - Need to switch to drm_fbdev_generic_setup(), otherwise a lot of the custom fb
> setup code can't be deleted.
>
> -- Many drivers wrap drm_gem_fb_create() only to check for valid formats. For
> - atomic drivers we could check for valid formats by calling
> - drm_plane_check_pixel_format() against all planes, and pass if any plane
> - supports the format. For non-atomic that's not possible since like the format
> - list for the primary plane is fake and we'd therefor reject valid formats.
> +- Need to switch to drm_gem_fb_create(), as now drm_gem_fb_create() checks for
> + valid formats for atomic drivers.
>
> - Many drivers subclass drm_framebuffer, we'd need a embedding compatible
> version of the varios drm_gem_fb_create functions. Maybe called
> diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> index e93533b86037..b8a615a138cd 100644
> --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
> @@ -9,6 +9,7 @@
> #include <linux/module.h>
>
> #include <drm/drm_damage_helper.h>
> +#include <drm/drm_drv.h>
> #include <drm/drm_fourcc.h>
> #include <drm/drm_framebuffer.h>
> #include <drm/drm_gem.h>
> @@ -164,6 +165,14 @@ int drm_gem_fb_init_with_funcs(struct drm_device *dev,
> return -EINVAL;
> }
>
> + if (drm_drv_uses_atomic_modeset(dev) &&
> + !drm_any_plane_has_format(dev, mode_cmd->pixel_format,
> + mode_cmd->modifier[0])) {
> + drm_dbg(dev, "Unsupported pixel format %p4cc / modifier 0x%llx\n",
> + &mode_cmd->pixel_format, mode_cmd->modifier[0]);
> + return -EINVAL;
> + }
> +
> for (i = 0; i < info->num_planes; i++) {
> unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
> unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
> --
> 2.38.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
