linux-kernel - Re: [PATCH] drm: Release resources with a safer function

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Message-ID: <20161005131750.GC20761@phenom.ffwll.local>
Date:   Wed, 5 Oct 2016 15:17:50 +0200
From:   Daniel Vetter <daniel@...ll.ch>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     airlied@...ux.ie, kernel-janitors@...r.kernel.org,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH] drm: Release resources with a safer function

On Sun, Oct 02, 2016 at 08:01:22AM +0200, Christophe JAILLET wrote:
> We should use 'ida_simple_remove()' instead of 'ida_remove()' when freeing
> resources allocated with 'ida_simple_get()'.
> 
> This as been spotted with the following coccinelle script which tries to
> detect missing 'ida_simple_remove()' call in error handling paths.
> 
> ///////////////
> @@
> expression x;
> identifier l;
> @@
> 
> *   x = ida_simple_get(...);
>     ...
>     if (...) {
>     ...
>     }
>     ...
>     if (...) {
>        ...
>        goto l;
>     }
>     ...
> *   l: ... when != ida_simple_remove(...);
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>

kerneldoc for ida_simple_get/remove is rather sparse, would be great to
improve that a bit. Merged this one to drm-misc now, follow-up patch for
the place Ville spotted would be great too.
-Daniel

> ---
>  drivers/gpu/drm/drm_connector.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 26bb78c76481..2e7430283043 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -250,10 +250,10 @@ int drm_connector_init(struct drm_device *dev,
>  	connector->debugfs_entry = NULL;
>  out_put_type_id:
>  	if (ret)
> -		ida_remove(connector_ida, connector->connector_type_id);
> +		ida_simple_remove(connector_ida, connector->connector_type_id);
>  out_put_id:
>  	if (ret)
> -		ida_remove(&config->connector_ida, connector->index);
> +		ida_simple_remove(&config->connector_ida, connector->index);
>  out_put:
>  	if (ret)
>  		drm_mode_object_unregister(dev, &connector->base);
> -- 
> 2.7.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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