Re: gigaset: freeing an active object

From: Paul Bolle
Date: Sun Dec 06 2015 - 15:12:30 EST


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

Thanks,


Paul Bolle
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