[PATCH v3 1/2] drm/gem: drm_gem_dumb_map_offset(): reject dma-buf

[Daniel Vetter]

On Thu, Aug 17, 2017 at 06:21:30PM +0200, Noralf Trønnes wrote:
> Reject mapping an imported dma-buf since is's an invalid use-case.
> 
> Cc: Philipp Zabel <p.zabel at pengutronix.de>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Sean Paul <seanpaul at chromium.org>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>

I think acks from someone using mali would be good too. amdgpu already has
such checks, so I think on the desktop side we're ok.

Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>

But I think this one here definitely needs a few more acks. I could break
uabi if we're unlucky, so let's not rush it.
-Daniel

> ---
>  drivers/gpu/drm/drm_gem.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index ad4e9cf..8da5801 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -333,6 +333,12 @@ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
>  	if (!obj)
>  		return -ENOENT;
>  
> +	/* Don't allow imported objects to be mapped */
> +	if (obj->import_attach) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
>  	ret = drm_gem_create_mmap_offset(obj);
>  	if (ret)
>  		goto out;
> -- 
> 2.7.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch