Messages in this thread | | | Date | Mon, 10 Jul 2017 14:26:53 -0500 | From | "Gustavo A. R. Silva" <> | Subject | Re: [PATCH] pwm: sun4i: add NULL check on of_match_device() return value |
| |
Hi all,
Quoting Thierry Reding <thierry.reding@gmail.com>:
> On Fri, Jul 07, 2017 at 03:16:23PM +0800, Chen-Yu Tsai wrote: >> On Fri, Jul 7, 2017 at 2:39 PM, Gustavo A. R. Silva >> <garsilva@embeddedor.com> wrote: >> > Check return value from call to of_match_device() >> > in order to prevent a NULL pointer dereference. >> > >> > In case of NULL print error message and return -ENODEV >> > >> > Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> >> > --- >> > drivers/pwm/pwm-sun4i.c | 4 ++++ >> > 1 file changed, 4 insertions(+) >> > >> > diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c >> > index 1284ffa..295ca19 100644 >> > --- a/drivers/pwm/pwm-sun4i.c >> > +++ b/drivers/pwm/pwm-sun4i.c >> > @@ -321,6 +321,10 @@ static int sun4i_pwm_probe(struct >> platform_device *pdev) >> > const struct of_device_id *match; >> > >> > match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev); >> >> AFAIK this simply can not and should not fail with a device tree >> only driver with properly populated of_device_id tables. > > Technically this could happen if someone manually created the platform > device. In that case the core will try to match by name if there is no > device node to use for a match against the list of of_device_ids. > > In my opinion it's best to let things crash in this situation to make > it really obvious that people have done something wrong. >
I get it.
Thanks for clarifying. -- Gustavo A. R. Silva
| |