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Message-ID: <acfbd345-e0e8-263c-ac7e-06d8419cdc90@intel.com>
Date:   Wed, 14 Sep 2022 15:47:16 +0200
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Subject: Re: [Intel-gfx] [PATCH] drm/i915: Fix return type of mode_valid
 function hook
Content-Language: en-US
To:     Nathan Huckleberry <nhuck@google.com>
Cc:     Lucas De Marchi <lucas.demarchi@intel.com>, llvm@lists.linux.dev,
        Dan Carpenter <error27@gmail.com>,
        David Airlie <airlied@linux.ie>, Tom Rix <trix@redhat.com>,
        intel-gfx@lists.freedesktop.org,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kernel@vger.kernel.org,
        Nathan Chancellor <nathan@kernel.org>,
        dri-devel@lists.freedesktop.org, Daniel Vetter <daniel@ffwll.ch>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>
References: <20220913205531.155046-1-nhuck@google.com>
From:   Andrzej Hajda <andrzej.hajda@intel.com>
Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298
 Gdansk - KRS 101882 - NIP 957-07-52-316
In-Reply-To: <20220913205531.155046-1-nhuck@google.com>
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Precedence: bulk

On 13.09.2022 22:55, 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@gmail.com>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1703
> Cc: llvm@lists.linux.dev
> Signed-off-by: Nathan Huckleberry <nhuck@google.com>

Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

Regards
Andrzej

> ---
>   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