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,URIBL_BLOCKED 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 09656C282CB for ; Tue, 5 Feb 2019 15:55:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2BBE2075D for ; Tue, 5 Feb 2019 15:55:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728916AbfBEPzI convert rfc822-to-8bit (ORCPT ); Tue, 5 Feb 2019 10:55:08 -0500 Received: from relay12.mail.gandi.net ([217.70.178.232]:42277 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726550AbfBEPzI (ORCPT ); Tue, 5 Feb 2019 10:55:08 -0500 Received: from xps13 (aaubervilliers-681-1-80-177.w90-88.abo.wanadoo.fr [90.88.22.177]) (Authenticated sender: miquel.raynal@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 634AA200014; Tue, 5 Feb 2019 15:55:04 +0000 (UTC) Date: Tue, 5 Feb 2019 16:55:02 +0100 From: Miquel Raynal To: Wen Yang Cc: "harveyhuntnexus@gmail.com" , "bbrezillon@kernel.org" , "richard@nod.at" , "dwmw2@infradead.org" , "computersforpeace@gmail.com" , "marek.vasut@gmail.com" , "nicolas.ferre@microchip.com" , "alexandre.belloni@bootlin.com" , "ludovic.desroches@microchip.com" , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] mtd: rawnand: jz4780: fix possible object reference leak Message-ID: <20190205165502.2b8be890@xps13> In-Reply-To: References: Organization: Bootlin X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wen, Wen Yang wrote on Tue, 5 Feb 2019 15:07:21 +0000: > of_find_device_by_node() takes a reference to the struct device > when it finds a match via get_device, there is no need to call > get_device() twice. > We also should make sure to drop the reference to the device > taken by of_find_device_by_node() on driver unbind. > > Fixes: ae02ab00aa3c ("mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs") > Signed-off-by: Wen Yang > Suggested-by: Miquel Raynal > Cc: Harvey Hunt > Cc: Boris Brezillon > Cc: Miquel Raynal > Cc: Richard Weinberger > Cc: David Woodhouse > Cc: Brian Norris > Cc: Marek Vasut > Cc: linux-mtd@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > v2->v1: Since there is the only one user, let's remove the err_put_device label. > > drivers/mtd/nand/raw/jz4780_bch.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/mtd/nand/raw/jz4780_bch.c b/drivers/mtd/nand/raw/jz4780_bch.c > index 7201827..363465c 100644 > --- a/drivers/mtd/nand/raw/jz4780_bch.c > +++ b/drivers/mtd/nand/raw/jz4780_bch.c > @@ -281,10 +281,12 @@ static struct jz4780_bch *jz4780_bch_get(struct device_node *np) > struct jz4780_bch *bch; > > pdev = of_find_device_by_node(np); > - if (!pdev || !platform_get_drvdata(pdev)) > + if (!pdev) > return ERR_PTR(-EPROBE_DEFER); > - > - get_device(&pdev->dev); > + if (!platform_get_drvdata(pdev)) { > + put_device(&pdev->dev); > + return ERR_PTR(-EPROBE_DEFER); > + } > > bch = platform_get_drvdata(pdev); > clk_prepare_enable(bch->clk); Acked-by: Miquel Raynal Thanks, Miquèl