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=-15.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 15203C4338F for ; Fri, 30 Jul 2021 07:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA81C60FE7 for ; Fri, 30 Jul 2021 07:04:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237720AbhG3HEW (ORCPT ); Fri, 30 Jul 2021 03:04:22 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:13215 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237781AbhG3HEN (ORCPT ); Fri, 30 Jul 2021 03:04:13 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4GbdX03z0yz1CQdl; Fri, 30 Jul 2021 14:58:08 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 30 Jul 2021 15:04:06 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 30 Jul 2021 15:04:05 +0800 Subject: Re: [PATCH v2] lib: Use PFN_PHYS() in devmem_is_allowed() To: Liang Wang , , , , , , CC: , , , References: <20210730064915.56249-1-wangliang101@huawei.com> From: Kefeng Wang Message-ID: <12e37243-0cdb-6765-c3ef-c98fd291591c@huawei.com> Date: Fri, 30 Jul 2021 15:04:05 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210730064915.56249-1-wangliang101@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/7/30 14:49, Liang Wang wrote: > The physical address may exceed 32 bits on ARM(when ARM_LPAE enabled), > use PFN_PHYS() in devmem_is_allowed(), or the physical address may > overflow and be truncated. > > This bug was initially introduced from v2.6.37, and the function was moved > to lib when v5.10. > > Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem") > Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") > Cc: stable@vger.kernel.org # v2.6.37 > Signed-off-by: Liang Wang Reviewed-by: Kefeng Wang > --- > v2: update subject and changelog > lib/devmem_is_allowed.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/devmem_is_allowed.c b/lib/devmem_is_allowed.c > index c0d67c541849..60be9e24bd57 100644 > --- a/lib/devmem_is_allowed.c > +++ b/lib/devmem_is_allowed.c > @@ -19,7 +19,7 @@ > */ > int devmem_is_allowed(unsigned long pfn) > { > - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) > + if (iomem_is_exclusive(PFN_PHYS(pfn))) > return 0; > if (!page_is_ram(pfn)) > return 1;