Re: [PATCH] drm/meson: fix canvas release in bind function

[Neil Armstrong]

On 03/07/2024 17:58, Yao Zi wrote:
> Allocated canvases may not be released on the error exit path of
> meson_drv_bind_master(), leading to resource leaking. Rewrite exit path
> to release canvases on error.
>
> Fixes: 2bf6b5b0e374 ("drm/meson: exclusively use the canvas provider module")
> Signed-off-by: Yao Zi <ziyao@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/meson/meson_drv.c | 37 +++++++++++++++----------------
>   1 file changed, 18 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 17a5cca007e2..4bd0baa2a4f5 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -250,29 +250,20 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>   	if (ret)
>   		goto free_drm;
>   	ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_0);
> -	if (ret) {
> -		meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
> -		goto free_drm;
> -	}
> +	if (ret)
> +		goto free_canvas_osd1;
>   	ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_1);
> -	if (ret) {
> -		meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
> -		meson_canvas_free(priv->canvas, priv->canvas_id_vd1_0);
> -		goto free_drm;
> -	}
> +	if (ret)
> +		goto free_canvas_vd1_0;
>   	ret = meson_canvas_alloc(priv->canvas, &priv->canvas_id_vd1_2);
> -	if (ret) {
> -		meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
> -		meson_canvas_free(priv->canvas, priv->canvas_id_vd1_0);
> -		meson_canvas_free(priv->canvas, priv->canvas_id_vd1_1);
> -		goto free_drm;
> -	}
> +	if (ret)
> +		goto free_canvas_vd1_1;
>   
>   	priv->vsync_irq = platform_get_irq(pdev, 0);
>   
>   	ret = drm_vblank_init(drm, 1);
>   	if (ret)
> -		goto free_drm;
> +		goto free_canvas_vd1_2;
>   
>   	/* Assign limits per soc revision/package */
>   	for (i = 0 ; i < ARRAY_SIZE(meson_drm_soc_attrs) ; ++i) {
> @@ -288,11 +279,11 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>   	 */
>   	ret = drm_aperture_remove_framebuffers(&meson_driver);
>   	if (ret)
> -		goto free_drm;
> +		goto free_canvas_vd1_2;
>   
>   	ret = drmm_mode_config_init(drm);
>   	if (ret)
> -		goto free_drm;
> +		goto free_canvas_vd1_2;
>   	drm->mode_config.max_width = 3840;
>   	drm->mode_config.max_height = 2160;
>   	drm->mode_config.funcs = &meson_mode_config_funcs;
> @@ -307,7 +298,7 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>   	if (priv->afbcd.ops) {
>   		ret = priv->afbcd.ops->init(priv);
>   		if (ret)
> -			goto free_drm;
> +			goto free_canvas_vd1_2;
>   	}
>   
>   	/* Encoder Initialization */
> @@ -371,6 +362,14 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>   exit_afbcd:
>   	if (priv->afbcd.ops)
>   		priv->afbcd.ops->exit(priv);
> +free_canvas_vd1_2:
> +	meson_canvas_free(priv->canvas, priv->canvas_id_vd1_2);
> +free_canvas_vd1_1:
> +	meson_canvas_free(priv->canvas, priv->canvas_id_vd1_1);
> +free_canvas_vd1_0:
> +	meson_canvas_free(priv->canvas, priv->canvas_id_vd1_0);
> +free_canvas_osd1:
> +	meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
>   free_drm:
>   	drm_dev_put(drm);
>   

This would deserve a devm_meson_canvas_alloc(), but as-is:

Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>