[Intel-gfx] [PATCH 1/4] drm/i915/opregion: fix leaking fw on error path

[Jani Nikula]

On Thu, 07 Nov 2019, Lucas De Marchi <lucas.demarchi at intel.com> wrote:
> Convert the code to return-early style and fix missing calls
> to release_firmware() if vbt is not valid.

I don't understand where anything would leak in the current code. Please
elaborate.

You could make a case for a change in style to avoid so much
indentation, but don't claim it fixes stuff if it doesn't.

>
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_opregion.c | 28 +++++++++++--------
>  1 file changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
> index 969ade623691..9738511147b1 100644
> --- a/drivers/gpu/drm/i915/display/intel_opregion.c
> +++ b/drivers/gpu/drm/i915/display/intel_opregion.c
> @@ -872,23 +872,29 @@ static int intel_load_vbt_firmware(struct drm_i915_private *dev_priv)
>  		return ret;
>  	}
>  
> -	if (intel_bios_is_valid_vbt(fw->data, fw->size)) {
> -		opregion->vbt_firmware = kmemdup(fw->data, fw->size, GFP_KERNEL);
> -		if (opregion->vbt_firmware) {
> -			DRM_DEBUG_KMS("Found valid VBT firmware \"%s\"\n", name);
> -			opregion->vbt = opregion->vbt_firmware;
> -			opregion->vbt_size = fw->size;
> -			ret = 0;
> -		} else {
> -			ret = -ENOMEM;
> -		}
> -	} else {
> +	if (!intel_bios_is_valid_vbt(fw->data, fw->size)) {
>  		DRM_DEBUG_KMS("Invalid VBT firmware \"%s\"\n", name);
>  		ret = -EINVAL;
> +		goto err_release_fw;
> +	}
> +
> +	opregion->vbt_firmware = kmemdup(fw->data, fw->size, GFP_KERNEL);
> +	if (!opregion->vbt_firmware) {
> +		ret = -ENOMEM;
> +		goto err_release_fw;
>  	}
>  
> +	opregion->vbt = opregion->vbt_firmware;
> +	opregion->vbt_size = fw->size;
> +
> +	DRM_DEBUG_KMS("Found valid VBT firmware \"%s\"\n", name);
> +
>  	release_firmware(fw);
>  
> +	return 0;

With ret = 0 at the beginning you could just remove the the above three
lines and let this run through the below code.

> +
> +err_release_fw:
> +	release_firmware(fw);

Usually we'd have a blank line before the ret.

BR,
Jani.

>  	return ret;
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center