Reject mapping an imported dma-buf since is's an invalid use-case.
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1502986891-36764-2-git-send-email-noralf@tronnes.org
 
        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;