Re: [PATCH] pinctrl: protect pinctrl_list add

[Stephen Warren <swarren@wwwdotorg.org>]

On 02/03/2014 04:39 AM, Stanislaw Gruszka wrote:
> We have few fedora bug reports about list corruption on pinctrl,
> for example:
> https://bugzilla.redhat.com/show_bug.cgi?id=1051918
> 
> Most likely corruption happen due lack of protection of pinctrl_list
> when adding new nodes to it. Patch corrects that.
> 
> Fixes: 57b676f9c1b ("pinctrl: fix and simplify locking")

After that patch ...

> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c

> @@ -851,7 +851,9 @@ static struct pinctrl *create_pinctrl(struct device *dev)
>  	kref_init(&p->users);
>  
>  	/* Add the pinctrl handle to the global list */
> +	mutex_lock(&pinctrl_list_mutex);

That variable doesn't exist; it got replaced with the "global"
pinctrl_mutex. Also, since that patch, IIRC some other changes have been
made to the locking structure, so this patch might need adjustments not
to conflict with those changes?

>  	list_add_tail(&p->node, &pinctrl_list);
> +	mutex_unlock(&pinctrl_list_mutex);