Re: [PATCH 06/24] input/keyboard: fix dangling pointers

From: Wolfram Sang
Date: Tue Mar 30 2010 - 08:35:24 EST


Hi Dmitry,

> On Sat, Mar 20, 2010 at 03:12:47PM +0100, Wolfram Sang wrote:
> > Fix I2C-drivers which missed setting clientdata to NULL before freeing the
> > structure it points to. Also fix drivers which do this _after_ the structure
> > was freed already.
> >
>
> I am not sure if setting clientdata to NULL before freeing the data is
> that important; we really want to be sure that we don't leave clientdata
> dangling when we finish unbinding the driver. If there are another
> thread the change will not really help the problem of accessing
> non-existing client data.
>
> I will apply lm8323 portion of the patch but leave qt2160 as is.

We reached an agreement that a) setting the clientdata-pointer to NULL should
be done in the i2c-core [1] and b) how to do it. Based on that, I will do the
modification of the i2c-core for 2.6.34 (as it fixes the dangling pointers) and
then create one single patch removing the then superflous calls to
i2c_set_clientdata for 2.6.35 (as it is a cleanup). As you already applied the
above patch to your branch: you don't have to revert, we will fix it for you in
the next round.

Sorry for the detour!

Kind regards,

Wolfram

[1] http://thread.gmane.org/gmane.linux.drivers.i2c/5674/focus=5729

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