The mode_valid field in drm_connector_helper_funcs is expected to be of type: enum drm_mode_status (* mode_valid) (struct drm_connector *connector, struct drm_display_mode *mode); The mismatched return type breaks forward edge kCFI since the underlying function definition does not match the function hook definition. The return type of mdp4_lvds_connector_mode_valid should be changed from int to enum drm_mode_status. Reported-by: Dan Carpenter <error27@xxxxxxxxx> Link: https://github.com/ClangBuiltLinux/linux/issues/1703 Cc: llvm@xxxxxxxxxxxxxxx Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx> --- drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c index 7288041dd86a..7444b75c4215 100644 --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c @@ -56,8 +56,9 @@ static int mdp4_lvds_connector_get_modes(struct drm_connector *connector) return ret; } -static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector, - struct drm_display_mode *mode) +static enum drm_mode_status +mdp4_lvds_connector_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode) { struct mdp4_lvds_connector *mdp4_lvds_connector = to_mdp4_lvds_connector(connector); -- 2.37.2.789.g6183377224-goog