Re: [PATCH v2 3/3] pppoatm: protect against freeing of vcc

From: David Woodhouse
Date: Fri Nov 30 2012 - 13:33:35 EST


On Fri, 2012-11-30 at 18:00 +0100, Krzysztof Mazur wrote:
> On Fri, Nov 30, 2012 at 04:23:46PM +0000, David Woodhouse wrote:
> >
> > +static void br2684_release_cb(struct atm_vcc *atmvcc)
> > +{
> > + struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
> > +
> > + /*
> > + * A race with br2684_xmit_vcc() might cause a spurious wakeup just
> > + * after that function *stops* the queue, and qspace might actually
> > + * go negative before the queue stops again. We cope with that.
> > + */
>
> We cannot race with br2684_xmit_vcc() because both br2684_xmit_vcc()
> and br2684_release_cb() are called with locked sk->sk_lock.slock.

Ah, right. For some reason I thought the lock was already dropped when
->release_cb() was called. In that case I'll remove the comment. Thanks.

--
dwmw2

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