Re: [PATCH] can: mpc5xxx_can: check of_iomap return before use

[Fabio Estevam]

On Mon, Jul 9, 2018 at 4:16 PM, Nicholas Mc Guire <hofrat@xxxxxxxxx> wrote:
>  of_iompa() can return NULL so that return needs to be checked and NULL

s/of_iompa/of_iomap/

> treated as failure. While at it also take care of the missing
> of_node_put() in the error path.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
> Fixes: commit afa17a500a36 ("net/can: add driver for mscan family & mpc52xx_mscan")
> ---
>
> Problem was found by an experimental coccinelle script
>
> Patch was compiletested with: mpc5200_defconfig + CONFIG_CAN=y,
> CONFIG_CAN_MSCAN=y, CONFIG_CAN_MPC5XXX=y
> (with a number of sparse warnings not related to the proposed change)
>
> Patch is against 4.18-rc3 (localversion-next is next-20180706)
>
>  drivers/net/can/mscan/mpc5xxx_can.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
> index c7427bd..2949a38 100644
> --- a/drivers/net/can/mscan/mpc5xxx_can.c
> +++ b/drivers/net/can/mscan/mpc5xxx_can.c
> @@ -86,6 +86,11 @@ static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
>                 return 0;
>         }
>         cdm = of_iomap(np_cdm, 0);
> +       if (!cdm) {
> +               of_node_put(np_cdm);
> +               dev_err(&ofdev->dev, "can't map clock node!\n");
> +               return 0;

I think you should return an error code here. -ENOMEM maybe?