Re: [PATCH] of: resolver: Add missing of_node_put

From: Mark Rutland
Date: Wed Jan 27 2016 - 11:06:04 EST


On Wed, Jan 27, 2016 at 08:50:17PM +0530, Amitoj Kaur Chawla wrote:
> for_each_child_of_node performs an of_node_get on each iteration, so
> to break out of the loop an of_node_put is required.
>
> Found using Coccinelle. The semantic patch used for this is as follows:
>
> // <smpl>
> @@
> expression e;
> local idexpression n;
> @@
>
> for_each_child_of_node(..., n) {
> ... when != of_node_put(n)
> when != e = n
> (
> return n;
> |
> + of_node_put(n);
> ? return ...;
> )
> ...
> }
> // </smpl
>
> Signed-off-by: Amitoj Kaur Chawla <amitoj1606@xxxxxxxxx>
> ---
> drivers/of/resolver.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
> index 640eb4c..e2a0143 100644
> --- a/drivers/of/resolver.c
> +++ b/drivers/of/resolver.c
> @@ -40,8 +40,10 @@ static struct device_node *__of_find_node_by_full_name(struct device_node *node,
>
> for_each_child_of_node(node, child) {
> found = __of_find_node_by_full_name(child, full_name);
> - if (found != NULL)
> + if (found != NULL) {
> + of_node_put(child);
> return found;
> + }
> }
>
> return NULL;

I don't think this is quite right. When child == found, this change will
leave it decremented.

Thanks,
Mark.