Re: [PATCH 1/5] clk: add missing of_node_put

Julia Lawall
2015-10-22T05:52:29Z

On Wed, 21 Oct 2015, Stephen Boyd wrote:

> On 10/21, Julia Lawall wrote:
> > for_each_matching_node_and_match performs an of_node_get on each iteration,
> > so a break out of the loop requires an of_node_put.
> >
> > A simplified version of the semantic patch that fixes this problem is as
> > follows (http://coccinelle.lip6.fr):
> >
> > // <smpl>
> > @@
> > expression e1,e2,e;
> > local idexpression np;
> > @@
> >
> > for_each_matching_node_and_match(np, e1, e2) {
> > ... when != of_node_put(np)
> > when != e = np
> > (
> > return np;
> > |
> > + of_node_put(np);
> > ? return ...;
> > )
> > ...
> > }
> > // </smpl>
> >
> > Besides the problem identified by the semantic patch, this patch adds an
> > of_node_get in front of saving np in a field of parent, to account for the
> > fact that this value will be put on going on to the next element in the
> > iteration, and then adds of_node_puts in the two loops where the parent
> > pointer can be freed.
> >
> > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> >
> > ---
>
> Applied to clk-next, except I collapsed the of_node_get() into
> the assignment.
>
> ---8<---
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index d366bfb66c58..2eae76f21d6f 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3205,8 +3205,7 @@ void __init of_clk_init(const struct of_device_id *matches)
> }
>
> parent->clk_init_cb = match->data;
> - of_node_get(np);
> - parent->np = np;
> + parent->np = of_node_get(np);

Thanks!

julia

> list_add_tail(&parent->node, &clk_provider_list);
> }
>
>
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