Messages in this thread | | | Date | Tue, 21 Jan 2014 11:46:25 -0800 | From | Dmitry Torokhov <> | Subject | Re: [PATCHv5 01/10] Thermal: Do kfree in _unregister functions |
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Hi Durgadoss,
On Fri, Jan 17, 2014 at 05:26:18AM +0530, Durgadoss R wrote: > Currently the thermal_release function does > kfree for all devices when they call device_unregister. > This makes code scattering i.e whenever we add new > devices (to thermal class) we need to add its > corresponding kfree in thermal_release function. > And the if-else is also growing lengthy. > > Instead, do all kfree() of devices in their own > _unregister functions. This makes the code look > clean and easy to maintain. > > Signed-off-by: Durgadoss R <durgadoss.r@intel.com> > --- > drivers/thermal/thermal_core.c | 17 +++++------------ > 1 file changed, 5 insertions(+), 12 deletions(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 338a88b..165afc6 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -1042,18 +1042,7 @@ EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device); > > static void thermal_release(struct device *dev) > { > - struct thermal_zone_device *tz; > - struct thermal_cooling_device *cdev; > - > - if (!strncmp(dev_name(dev), "thermal_zone", > - sizeof("thermal_zone") - 1)) { > - tz = to_thermal_zone(dev); > - kfree(tz); > - } else if(!strncmp(dev_name(dev), "cooling_device", > - sizeof("cooling_device") - 1)){ > - cdev = to_cooling_device(dev); > - kfree(cdev); > - } > + /* No-op since kfree(dev) is done in _unregister functions */ > } > > static struct class thermal_class = { > @@ -1146,6 +1135,7 @@ __thermal_cooling_device_register(struct device_node *np, > unregister: > release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id); > device_unregister(&cdev->device); > + kfree(cdev);
This is broken, you can not assume that you are holding the last reference. Please observe help text of DEBUG_KOBJECT_RELEASE config option, activate said option and try unregistering thermal device.
Thanks.
-- Dmitry
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