Re: [PATCH v4 1/8] [media] soc_camera: Do not decrement endpoint node refcount in the loop

From: Philipp Zabel
Date: Mon Sep 29 2014 - 05:45:40 EST


Am Montag, den 29.09.2014, 12:13 +0300 schrieb Dan Carpenter:
> On Mon, Sep 29, 2014 at 10:15:44AM +0200, Philipp Zabel wrote:
> > In preparation for a following patch, stop decrementing the endpoint node
> > refcount in the loop. This temporarily leaks a reference to the endpoint node,
> > which will be fixed by having of_graph_get_next_endpoint decrement the refcount
> > of its prev argument instead.
>
> Don't do this...
>
> My understanding (and I haven't invested much time into trying to
> understand this beyond glancing at the change) is that patch 1 and 2,
> introduce small bugs that are fixed in patch 3?
>
> Just fold all three patches into one patch. We need an Ack from Mauro
> and Greg and then send the patch through Grant's tree.

Yes. Patches 1 and 2 leak a reference on of_nodes touched by the loop.
As far as I am aware, all users of this code don't use the reference
counting (CONFIG_OF_DYNAMIC is disabled), so this bug should be
theoretical.

I'd be happy do as you suggest if Mauro and Greg agree.

regards
Philipp

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