From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <5494A3D6.60607@gmx.de> Date: Fri, 19 Dec 2014 23:16:54 +0100 From: Hartmut Knaack MIME-Version: 1.0 To: Daniel Baluta , jic23@kernel.org CC: lars@metafoo.de, pmeerw@pmeerw.net, gwendal@chromium.org, srinivas.pandruvada@linux.intel.com, beomho.seo@samsung.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, octavian.purdila@intel.com Subject: Re: [RFC PATCH] iio: ak8975: Make sure chipset is always initialized References: <1418923002-901-1-git-send-email-daniel.baluta@intel.com> In-Reply-To: <1418923002-901-1-git-send-email-daniel.baluta@intel.com> Content-Type: text/plain; charset=UTF-8 List-ID: Daniel Baluta schrieb am 18.12.2014 um 18:16: > When using ACPI, if acpi_match_device fails then chipset enum will be > uninitialized and &ak_def_array[chipset] will point to some bad address. > > This fixes the following compilation warning: > > drivers/iio/magnetometer/ak8975.c: In function ‘ak8975_probe’: > drivers/iio/magnetometer/ak8975.c:788:14: warning: ‘chipset’ may be used > uninitialized in this function [-Wmaybe-uninitialized] > data->def =ak_def_array[chipset]; > > Reported-by: Octavian Purdila > Signed-off-by: Daniel Baluta > --- > This is a RFC because while I'm pretty sure that chipset should be initialized > with AK_MAX_TYPE in ak8975_match_acpi_device, I am not sure if we can live with > a NULL return value of ak8975_match_acpi_device. Current implementation ignores > return value of ak8975_match_acpi_device. This seems to be the actual problem: these _match_acpi_device functions return NULL on failure, and this should be checked for. > > The same situation is for kxcjk-1013, bmc150-accel, bmg160 and possible other > drivers. > > drivers/iio/magnetometer/ak8975.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c > index 0d10a4b..cdf9e77 100644 > --- a/drivers/iio/magnetometer/ak8975.c > +++ b/drivers/iio/magnetometer/ak8975.c > @@ -716,6 +716,7 @@ static const char *ak8975_match_acpi_device(struct device *dev, > { > const struct acpi_device_id *id; > > + *chipset =K_MAX_TYPE; > id =cpi_match_device(dev->driver->acpi_match_table, dev); > if (!id) > return NULL; >