Re: [PATCH] drm/rockchip: Fix return type of cdn_dp_connector_mode_valid

From: Nathan Chancellor
Date: Tue Sep 13 2022 - 19:20:49 EST


On Tue, Sep 13, 2022 at 01:55:55PM -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 cdn_dp_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>

Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>

> ---
> drivers/gpu/drm/rockchip/cdn-dp-core.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> index c204e9b95c1f..518ee13b1d6f 100644
> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
> @@ -283,8 +283,9 @@ static int cdn_dp_connector_get_modes(struct drm_connector *connector)
> return ret;
> }
>
> -static int cdn_dp_connector_mode_valid(struct drm_connector *connector,
> - struct drm_display_mode *mode)
> +static enum drm_mode_status
> +cdn_dp_connector_mode_valid(struct drm_connector *connector,
> + struct drm_display_mode *mode)
> {
> struct cdn_dp_device *dp = connector_to_dp(connector);
> struct drm_display_info *display_info = &dp->connector.display_info;
> --
> 2.37.2.789.g6183377224-goog
>
>