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

Stephen Boyd
2015-10-21T23:13:10Z

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

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project