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 0A79CC282CB for ; Tue, 5 Feb 2019 19:12:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D78792083B for ; Tue, 5 Feb 2019 19:12:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727164AbfBETMF convert rfc822-to-8bit (ORCPT ); Tue, 5 Feb 2019 14:12:05 -0500 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:60109 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726114AbfBETMF (ORCPT ); Tue, 5 Feb 2019 14:12:05 -0500 X-Originating-IP: 91.224.148.103 Received: from xps13 (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 92560240007; Tue, 5 Feb 2019 19:11:59 +0000 (UTC) Date: Tue, 5 Feb 2019 20:11:58 +0100 From: Miquel Raynal To: Wen Yang Cc: "tudor.ambarus@microchip.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-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3] mtd: rawnand: atmel: fix possible object reference leak Message-ID: <20190205201158.3cbcc628@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, For the next version can you please post a series with the three commits which are fixing the same reference leak? No need to add a cover letter though. Wen Yang wrote on Tue, 5 Feb 2019 14:32:41 +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: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver") > Signed-off-by: Wen Yang > Suggested-by: Boris Brezillon > Reviewed-by: Boris Brezillon > Reviewed-by: Miquel Raynal > Acked-by: Miquel Raynal > Cc: Tudor Ambarus > Cc: Boris Brezillon > Cc: Miquel Raynal > Cc: Richard Weinberger > Cc: David Woodhouse > Cc: Brian Norris > Cc: Marek Vasut > Cc: Nicolas Ferre > Cc: Alexandre Belloni > Cc: Ludovic Desroches > Cc: linux-mtd@lists.infradead.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/mtd/nand/raw/atmel/pmecc.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/atmel/pmecc.c b/drivers/mtd/nand/raw/atmel/pmecc.c > index 555a74e..1477368 100644 > --- a/drivers/mtd/nand/raw/atmel/pmecc.c > +++ b/drivers/mtd/nand/raw/atmel/pmecc.c > @@ -876,16 +876,22 @@ static struct atmel_pmecc *atmel_pmecc_get_by_node(struct device *userdev, > { > struct platform_device *pdev; > struct atmel_pmecc *pmecc, **ptr; > + int ret; > > pdev = of_find_device_by_node(np); > - if (!pdev || !platform_get_drvdata(pdev)) > + if (!pdev) > return ERR_PTR(-EPROBE_DEFER); > + if (!platform_get_drvdata(pdev)) { > + ret = -EPROBE_DEFER; > + goto err_put_device; > + } > > ptr = devres_alloc(devm_atmel_pmecc_put, sizeof(*ptr), GFP_KERNEL); > - if (!ptr) > - return ERR_PTR(-ENOMEM); > + if (!ptr) { > + ret = -ENOMEM; > + goto err_put_device; > + } > > - get_device(&pdev->dev); > pmecc = platform_get_drvdata(pdev); I just realized in the three cases, a first call to platform_get_drvdata() is done to check if the returned pointer is valid, and then a second one is done to actually retrieve the pointer. Please avoid this repetition. Thanks, Miquèl