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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 727C4C5CFEB for ; Wed, 11 Jul 2018 15:41:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3926D20875 for ; Wed, 11 Jul 2018 15:41:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3926D20875 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387452AbeGKPqJ (ORCPT ); Wed, 11 Jul 2018 11:46:09 -0400 Received: from foss.arm.com ([217.140.101.70]:38958 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732452AbeGKPqJ (ORCPT ); Wed, 11 Jul 2018 11:46:09 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0D3287A9; Wed, 11 Jul 2018 08:41:15 -0700 (PDT) Received: from e107155-lin (unknown [10.1.210.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 653213F5B1; Wed, 11 Jul 2018 08:41:13 -0700 (PDT) Date: Wed, 11 Jul 2018 16:41:10 +0100 From: Sudeep Holla To: Wei Yongjun Cc: Arnd Bergmann , Greg Kroah-Hartman , Liviu Dudau , Lorenzo Pieralisi , Sudeep Holla , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH -next] misc: vexpress: Fix potential NULL dereference in vexpress_syscfg_probe() Message-ID: <20180711154110.GB10578@e107155-lin> References: <1531315058-183762-1-git-send-email-weiyongjun1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1531315058-183762-1-git-send-email-weiyongjun1@huawei.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 11, 2018 at 01:17:38PM +0000, Wei Yongjun wrote: > platform_get_resource() may fail and return NULL, so we should > better check it's return value to avoid a NULL pointer dereference > a bit later in the code. > > This is detected by Coccinelle semantic patch. > > @@ > expression pdev, res, n, t, e, e1, e2; > @@ > > res = platform_get_resource(pdev, t, n); > + if (!res) > + return -EINVAL; > ... when != res == NULL > e = devm_ioremap(e1, res->start, e2); Instead of adding unnecessary check here, I would go with replacing it with devm_ioremap_resource as it's designed to deal with that (patch inline) Regards, Sudeep -->8 >From a6de466984e657dad24dcbe87e5dde2d21cb8d35 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Wed, 11 Jul 2018 16:17:39 +0100 Subject: [PATCH] misc: vexpress/syscfg: Use devm_ioremap_resource() to map memory Instead of checking the return value of platform_get_resource(), we can use devm_ioremap_resource() which has the NULL pointer check and the memory region requesting. devm_ioremap_resource is designed to replace calls to devm_request_mem_region followed by devm_ioremap, so let's use the same. Cc: Liviu Dudau Cc: Lorenzo Pieralisi Signed-off-by: Sudeep Holla --- drivers/misc/vexpress-syscfg.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index 80a6f199077c..6c3591cdf855 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -258,13 +258,9 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) INIT_LIST_HEAD(&syscfg->funcs); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!devm_request_mem_region(&pdev->dev, res->start, - resource_size(res), pdev->name)) - return -EBUSY; - - syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); - if (!syscfg->base) - return -EFAULT; + syscfg->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(syscfg->base)) + return PTR_ERR(syscfg->base); /* Must use dev.parent (MFD), as that's where DT phandle points at... */ bridge = vexpress_config_bridge_register(pdev->dev.parent, -- 2.7.4