linux-kernel - Re: [RFC PATCH v3 3/9] software_node: Fix failure to hold refcount in software_node_get_next

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Message-ID: <20201020133148.GB843@valkosipuli.retiisi.org.uk>
Date:   Tue, 20 Oct 2020 16:31:48 +0300
From:   Sakari Ailus <sakari.ailus@....fi>
To:     Daniel Scally <djrscally@...il.com>
Cc:     linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
        linux.walleij@...aro.org, prabhakar.mahadev-lad.rj@...renesas.com,
        heikki.krogerus@...ux.intel.com, dmitry.torokhov@...il.com,
        laurent.pinchart+renesas@...asonboard.com,
        kieran.bingham+renesas@...asonboard.com, jacopo+renesas@...ndi.org,
        robh@...nel.org, davem@...emloft.net, linux@...musvillemoes.dk,
        andriy.shevchenko@...ux.intel.com, sergey.senozhatsky@...il.com,
        rostedt@...dmis.org, pmladek@...e.com, mchehab@...nel.org,
        tian.shu.qiu@...el.com, bingbu.cao@...el.com,
        sakari.ailus@...ux.intel.com, yong.zhi@...el.com,
        rafael@...nel.org, gregkh@...uxfoundation.org, kitakar@...il.com,
        dan.carpenter@...cle.org
Subject: Re: [RFC PATCH v3 3/9] software_node: Fix failure to hold refcount
 in software_node_get_next_child

Hi Daniel,

On Mon, Oct 19, 2020 at 11:58:57PM +0100, Daniel Scally wrote:
> The software_node_get_next_child() function currently does not hold a kref
> to the child software_node; fix that.
> 
> Fixes: 59abd83672f7 ("drivers: base: Introducing software nodes to the firmware node framework")
> Signed-off-by: Daniel Scally <djrscally@...il.com>
> ---
> Changes in v3:
> 	- split out from the full software_node_graph*() patch
> 
>  drivers/base/swnode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index f01b1cc61..741149b90 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -450,7 +450,7 @@ software_node_get_next_child(const struct fwnode_handle *fwnode,
>  		c = list_next_entry(c, entry);
>  	else
>  		c = list_first_entry(&p->children, struct swnode, entry);
> -	return &c->fwnode;
> +	return software_node_get(&c->fwnode);

I believe similarly, the function should drop the reference to the previous
node, and not expect the caller to do this. The OF equivalent does the
same.

>  }
>  
>  static struct fwnode_handle *

-- 
Kind regards,

Sakari Ailus