From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Fri, 7 Jul 2017 11:33:00 +0200 Subject: [PATCH] pwm: sun4i: add NULL check on of_match_device() return value In-Reply-To: References: <20170707063939.GA20510@embeddedgus> Message-ID: <20170707093300.GD15652@ulmo.fritz.box> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > 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 > > --- > > 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. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: