From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B35AC43381 for ; Tue, 19 Feb 2019 17:33:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 025452147A for ; Tue, 19 Feb 2019 17:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729069AbfBSRd1 (ORCPT ); Tue, 19 Feb 2019 12:33:27 -0500 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:20118 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726321AbfBSRd0 (ORCPT ); Tue, 19 Feb 2019 12:33:26 -0500 X-IronPort-AV: E=Sophos;i="5.58,388,1544482800"; d="scan'208";a="370069650" Received: from vaio-julia.rsr.lip6.fr ([132.227.76.33]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Feb 2019 18:33:24 +0100 Date: Tue, 19 Feb 2019 18:33:22 +0100 (CET) From: Julia Lawall X-X-Sender: jll@hadrien To: Tony Lindgren cc: Peng Hao , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tomi Valkeinen , Rob Herring , devicetree@vger.kernel.org, wen.yang99@zte.com.cn Subject: Re: [PATCH] arm/mach-omap2/display: fix possible object reference leak In-Reply-To: <20190219170516.GL15711@atomide.com> Message-ID: References: <1550071969-86286-1-git-send-email-peng.hao2@zte.com.cn> <20190219170516.GL15711@atomide.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 19 Feb 2019, Tony Lindgren wrote: > Hi, > > Adding devicetree list, Julia, Rob and Tomi to Cc. > > * Peng Hao [190212 23:11]: > > of_find_device_by_node() takes a reference to the struct device > > when it finds a match via get_device.When returning error we should > > call put_device. > > > > Signed-off-by: Peng Hao > > --- > > arch/arm/mach-omap2/display.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c > > index f86b72d..c6aa9ed 100644 > > --- a/arch/arm/mach-omap2/display.c > > +++ b/arch/arm/mach-omap2/display.c > > @@ -258,6 +258,7 @@ static int __init omapdss_init_of(void) > > r = of_platform_populate(node, NULL, NULL, &pdev->dev); > > if (r) { > > pr_err("Unable to populate DSS submodule devices\n"); > > + put_device(&pdev->dev); > > return r; > > } > > In general, if the device tree node is never used afterwards, > should this be just: > > r = of_platform_populate(node, NULL, NULL, &pdev->dev); > of_node_put(dev_node); > if (r) { > ... > } > > If so, Julia might have a Coccinelle recpipe for it? Unfortunately this is not really an ideal case for Coccinelle, because node is the result of calling a local function and Coccinelle doesn't by default do any interprocedural analysis. It is possible to write a rule that explicitly looks for one function that returns a device node and then the pattern of its usage in the caller, though. julia