Hi all, On Tue, Sep 13, 2022 at 01:55:48PM -0700, Nathan Huckleberry wrote: > 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 > > Did this patch get lost somewhere? I do not see it picked up. It is needed to avoid a new WIP warning from clang for catching these CFI failures: drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c:89:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] .mode_valid = mdp4_lvds_connector_mode_valid, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. Cheers, Nathan
