Re: gigaset: freeing an active object

From: Tilman Schmidt
Date: Mon Dec 07 2015 - 04:27:43 EST


Am 06.12.2015 um 21:12 schrieb Paul Bolle:
> On zo, 2015-12-06 at 16:29 +0100, Tilman Schmidt wrote:
>> So the solution might be as simple as moving the kfree() call from
>> gigaset_freecshw() to gigaset_device_release(). Something like this:
>>
>> --- a/drivers/isdn/gigaset/ser-gigaset.c
>> +++ b/drivers/isdn/gigaset/ser-gigaset.c
>> @@ -370,19 +370,18 @@ static void gigaset_freecshw(struct cardstate
>> *cs)
>> tasklet_kill(&cs->write_tasklet);
>> if (!cs->hw.ser)
>> return;
>> - dev_set_drvdata(&cs->hw.ser->dev.dev, NULL);
>> platform_device_unregister(&cs->hw.ser->dev);
>> - kfree(cs->hw.ser);
>> - cs->hw.ser = NULL;
>> }
>>
>> static void gigaset_device_release(struct device *dev)
>> {
>> - struct platform_device *pdev = to_platform_device(dev);
>> + struct cardstate *cs = dev_get_drvdata(dev);
>>
>> - /* adapted from platform_device_release() in drivers/base/platform.c */
>> - kfree(dev->platform_data);
>> - kfree(pdev->resource);
>> + if (!cs)
>> + return;
>> + dev_set_drvdata(dev, NULL);
>> + kfree(cs->hw.ser);
>> + cs->hw.ser = NULL;
>> }
>
> This solution assumes that the struct platform_device is moved out of
> the struct ser_cardstate, doesn't it? In other words, this is something
> to do on top of my (draft) patch.

No, that wasn't my intention. I thought of that solution as an
alternative, not an increment to your patch.

> Otherwise we'd still be freeing memory
> managed through reference counting.

Now I#m confused. I thought by following Peter's suggestion to put the
kfree() in the release method we'd avoid just that.

Regards,
Tilman

--
Tilman Schmidt E-Mail: tilman@xxxxxxx
Bonn, Germany
Nous, on a des fleurs et des bougies pour nous protÃger.

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