Re: [PATCH] drm/i915: Fix return type of mode_valid function hook

[Nathan Chancellor]

On Tue, Sep 13, 2022 at 01:55:27PM -0700, Nathan Huckleberry wrote:
> All of the functions used for intel_dvo_dev_ops.mode_valid have a return
> type of enum drm_mode_status, but the mode_valid field in the struct
> definition has a return type of int.
> 
> The mismatched return type breaks forward edge kCFI since the underlying
> function definitions do not match the function hook definition.
> 
> The return type of the mode_valid field 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/i915/display/intel_dvo_dev.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dvo_dev.h b/drivers/gpu/drm/i915/display/intel_dvo_dev.h
> index d96c3cc46e50..50205f064d93 100644
> --- a/drivers/gpu/drm/i915/display/intel_dvo_dev.h
> +++ b/drivers/gpu/drm/i915/display/intel_dvo_dev.h
> @@ -75,8 +75,8 @@ struct intel_dvo_dev_ops {
>  	 *
>  	 * \return MODE_OK if the mode is valid, or another MODE_* otherwise.
>  	 */
> -	int (*mode_valid)(struct intel_dvo_device *dvo,
> -			  struct drm_display_mode *mode);
> +	enum drm_mode_status (*mode_valid)(struct intel_dvo_device *dvo,
> +					   struct drm_display_mode *mode);
>  
>  	/*
>  	 * Callback for preparing mode changes on an output
> -- 
> 2.37.2.789.g6183377224-goog
>