Re: [PATCH] arm/mach-at91/pm: Do not double put the device node

From: Alexandre Belloni
Date: Tue Aug 14 2018 - 09:28:39 EST


On 14/08/2018 09:54:56+0800, zhong jiang wrote:
> Device node iterators put the previous value of the index variable,
> so an explicit put causes a double put.
>

While for_each_matching_node_and_match will get and put the node
properly, there is also a call to of_find_device_by_node that will get a
reference to the node.

> I detect the issue with the help of Coccinelle.
>
> Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>
> ---
> arch/arm/mach-at91/pm.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
> index 32fae4d..a5ec35f 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -143,15 +143,12 @@ static int at91_pm_config_ws(unsigned int pm_mode, bool set)
>
> /* Check if enabled on SHDWC. */
> if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
> - goto put_node;
> + continue;
>
> mode |= wsi->pmc_fsmr_bit;
> if (wsi->set_polarity)
> polarity |= wsi->pmc_fsmr_bit;
> }
> -
> -put_node:
> - of_node_put(np);
> }
>
> if (mode) {
> --
> 1.7.12.4
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com