Re: [PATCH] ARM: EXYNOS: Handle of of_iomap() failure

From: Krzysztof Kozlowski
Date: Tue Feb 03 2015 - 03:09:31 EST


On wto, 2015-02-03 at 12:20 +0900, Kukjin Kim wrote:
> Krzysztof Kozlowski wrote:
> >
> > Prevent possible NULL pointer dereference if of_iomap() fails. Handle
> > the error by skipping such power domain.
> >
> > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> > ---
> > arch/arm/mach-exynos/pm_domains.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
> > index 20f267121b3e..fd7640a6b503 100644
> > --- a/arch/arm/mach-exynos/pm_domains.c
> > +++ b/arch/arm/mach-exynos/pm_domains.c
> > @@ -128,6 +128,13 @@ static __init int exynos4_pm_init_power_domain(void)
> > pd->pd.name = kstrdup(np->name, GFP_KERNEL);
> > pd->name = pd->pd.name;
> > pd->base = of_iomap(np, 0);
> > + if (!pd->base) {
> > + dev_warn(&pdev->dev, "Failed to map memory\n");
> > + kfree(pd);
> > + of_node_put(np);
> > + continue;
> > + }
> > +
> > pd->pd.power_off = exynos_pd_power_off;
> > pd->pd.power_on = exynos_pd_power_on;
> >
> > --
>
> Looks good and applied.

Thanks!

> BTW if we need more error handling like this, how about
> error handling for failing of of_find_device_by_node() something like following?

I'll take a look into this.

Best regards,
Krzysztof

>
> diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
> index 20f2671..234f967 100644
> --- a/arch/arm/mach-exynos/pm_domains.c
> +++ b/arch/arm/mach-exynos/pm_domains.c
> @@ -116,6 +116,10 @@ static __init int exynos4_pm_init_power_domain(void)
> struct device *dev;
>
> pdev = of_find_device_by_node(np);
> + if (!pdev) {
> + /* error handling */
> + }
> +
> dev = &pdev->dev;
>
> pd = kzalloc(sizeof(*pd), GFP_KERNEL);
>
> I mean I'm not sure how many error/exception handling is required...
>
> Note you can see your patch in Samsung tree tonight in my time.
>
> Thanks, Kukjin

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