From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <5003E635.8080200@metafoo.de> Date: Mon, 16 Jul 2012 12:00:21 +0200 From: Lars-Peter Clausen MIME-Version: 1.0 To: Hartmut Knaack CC: linux-iio@vger.kernel.org, jic23@kernel.org Subject: Re: [PATCH 1/2] fixes for adt7410 References: <50032AC1.1030207@gmx.de> <50032F46.9040904@metafoo.de> <50033B3F.70304@gmx.de> In-Reply-To: <50033B3F.70304@gmx.de> Content-Type: text/plain; charset=ISO-8859-15 List-ID: On 07/15/2012 11:50 PM, Hartmut Knaack wrote: > Lars-Peter Clausen schrieb: >> On 07/15/2012 10:40 PM, Hartmut Knaack wrote: >>> This patch adds some checks prior to accessing device attribute lists in industrialio-event.c. >>> >>> Signed-off-by: Harmut Knaack >>> --- >>> diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c >>> index b49059d..fe68e90 100644 >>> --- a/drivers/iio/industrialio-event.c >>> +++ b/drivers/iio/industrialio-event.c >>> @@ -425,11 +425,13 @@ int iio_device_register_eventset(struct iio_dev *indio_dev) >>> *attrcount_orig); >>> attrn = attrcount_orig; >>> /* Add all elements from the list. */ >>> - list_for_each_entry(p, >>> - &indio_dev->event_interface->dev_attr_list, >>> - l) >>> - indio_dev->event_interface->group.attrs[attrn++] = >>> - &p->dev_attr.attr; >>> + if (indio_dev->event_interface->dev_attr_list.next) >> next should never be NULL. If it is this means that INIT_LIST_HEAD has not >> been called on the list and the correct fix is to make sure that it is called. > Exactly. If the channels-attributes have not been set, INIT_LIST_HEAD (called through __iio_add_event_config_attrs) is not called. So, should we just stop instantiating the device if it does not have channel information? The correct fix is to call INIT_LIST_HEAD right after the struct which contains the list has been allocated. Sascha already sent a patch which does this as well. See: http://www.spinics.net/lists/linux-iio/msg05946.html - Lars