From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756253AbcAZHMV (ORCPT ); Tue, 26 Jan 2016 02:12:21 -0500 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:30312 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752280AbcAZHMT (ORCPT ); Tue, 26 Jan 2016 02:12:19 -0500 X-IronPort-AV: E=Sophos;i="5.22,349,1449529200"; d="scan'208";a="199336063" Date: Tue, 26 Jan 2016 08:12:15 +0100 (CET) From: Julia Lawall X-X-Sender: jll@localhost6.localdomain6 To: Krzysztof Kozlowski cc: Julia Lawall , Amitoj Kaur Chawla , kyungmin.park@samsung.com, s.nawrocki@samsung.com, mchehab@osg.samsung.com, kgene@kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] media: platform: exynos4-is: media-dev: Add missing of_node_put In-Reply-To: <56A7185F.7020207@samsung.com> Message-ID: References: <20160125152136.GA19484@amitoj-Inspiron-3542> <56A6BCC3.8040407@samsung.com> <56A7185F.7020207@samsung.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 26 Jan 2016, Krzysztof Kozlowski wrote: > On 26.01.2016 15:24, Julia Lawall wrote: > > > > > > On Tue, 26 Jan 2016, Krzysztof Kozlowski wrote: > > > >> On 26.01.2016 00:21, Amitoj Kaur Chawla wrote: > >>> for_each_available_child_of_node and for_each_child_of_node perform an > >>> of_node_get on each iteration, so to break out of the loop an of_node_put is > >>> required. > >>> > >>> Found using Coccinelle. The simplified version of the semantic patch > >>> that is used for this is as follows: > >>> > >>> // > >>> @@ > >>> local idexpression n; > >>> expression e,r; > >>> @@ > >>> > >>> for_each_available_child_of_node(r,n) { > >>> ... > >>> ( > >>> of_node_put(n); > >>> | > >>> e = n > >>> | > >>> + of_node_put(n); > >>> ? break; > >>> ) > >>> ... > >>> } > >>> ... when != n > >>> // > >> > >> Patch iselft looks correct but why are you pasting coccinelle script > >> into the message? > >> > >> The script is already present in Linux kernel: > >> scripts/coccinelle/iterators/device_node_continue.cocci > > > > I don't think so. The continue one takes care of the case where there is > > an extraneous of_node_put before a continue, not a missing one before a > > break. But OK to drop it if it doesn't seem useful. > > > > julia > > You are right - this is not covered by that cocci patch... but I think > is covered by scripts/coccinelle/iterators/fen.cocci, isn't it? Not quite. That is for of_node_puts after normal loop completion (not sure that this problem comes up any more, but at one point there were a number of them). There are indeed a lot of ways in which the management of reference counts can go wrong... Anyway, the rule that Amitoj used seems to be pretty reliable, so I'll try to get it into the kernel source tree some day soon. julia > > BR, > Krzysztof > > > > >> This just extends the commit message without any meaningful data so with > >> removal of coccinelle script above: > >> Reviewed-by: Krzysztof Kozlowski > >> > >> Best regards, > >> Krzysztof > >> > >>> > >>> Signed-off-by: Amitoj Kaur Chawla > >>> --- > >>> drivers/media/platform/exynos4-is/media-dev.c | 12 +++++++++--- > >>> 1 file changed, 9 insertions(+), 3 deletions(-) > >