Re: [PATCH] input: keyboard: cap11xx: Add missing of_node_put

From: Dmitry Torokhov
Date: Wed Jan 27 2016 - 18:49:08 EST


On Mon, Jan 25, 2016 at 09:01:21PM +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/input/keyboard/cap11xx.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
> index 378db10..27cd7df 100644
> --- a/drivers/input/keyboard/cap11xx.c
> +++ b/drivers/input/keyboard/cap11xx.c
> @@ -304,8 +304,10 @@ static int cap11xx_init_leds(struct device *dev,
> led->cdev.brightness = LED_OFF;
>
> error = of_property_read_u32(child, "reg", &reg);
> - if (error != 0 || reg >= num_leds)
> - return -EINVAL;
> + if (error != 0 || reg >= num_leds) {
> + error = -EINVAL;
> + goto putchild;

Instead of jumping to a label I added of_node_put here and also below
and applied, thank you.

I believe there is another input driver that returns from
for_each_child_of_node() without dropping reference.

Thanks.

--
Dmitry