The DRM core setplane code should check that the plane is usable on the specified CRTC before calling into the driver.

Prior to this patch, a plane's possible_crtcs field was purely informational for userspace and was never actually verified at the kernel level (aside from the primary plane helper).

Cc: dri-devel@lists.freedesktop.org Reviewed-by: Chon Ming Lee chon.ming.lee@intel.com Signed-off-by: Matt Roper matthew.d.roper@intel.com --- drivers/gpu/drm/drm_crtc.c | 7 +++++++ drivers/gpu/drm/drm_plane_helper.c | 6 ------ 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 37a3e07..1cfd1e3 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -2153,6 +2153,13 @@ int drm_mode_setplane(struct drm_device *dev, void *data, } crtc = obj_to_crtc(obj);

+ /* Check whether this plane is usable on this CRTC */ + if (!(plane->possible_crtcs & drm_crtc_mask(crtc))) { + DRM_DEBUG_KMS("Invalid crtc for plane\n"); + ret = -EINVAL; + goto out; + } + fb = drm_framebuffer_lookup(dev, plane_req->fb_id); if (!fb) { DRM_DEBUG_KMS("Unknown framebuffer ID %d\n", diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index d966afa..b601233 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -137,12 +137,6 @@ int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc, return -EINVAL; }

- /* Primary planes are locked to their owning CRTC */ - if (plane->possible_crtcs != drm_crtc_mask(crtc)) { - DRM_DEBUG_KMS("Cannot change primary plane CRTC\n"); - return -EINVAL; - } - /* Disallow scaling */ src_w >>= 16; src_h >>= 16;