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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42026ECAAD1 for ; Wed, 31 Aug 2022 08:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231724AbiHaI6O (ORCPT ); Wed, 31 Aug 2022 04:58:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231819AbiHaI5c (ORCPT ); Wed, 31 Aug 2022 04:57:32 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1187CCD797; Wed, 31 Aug 2022 01:56:59 -0700 (PDT) Received: from fraeml712-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4MHdHT34dFz67yhg; Wed, 31 Aug 2022 16:53:09 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (7.191.163.240) by fraeml712-chm.china.huawei.com (10.206.15.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 31 Aug 2022 10:56:53 +0200 Received: from localhost (10.202.226.42) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 31 Aug 2022 09:56:52 +0100 Date: Wed, 31 Aug 2022 09:56:51 +0100 From: Jonathan Cameron To: Robert Richter CC: Alison Schofield , Vishal Verma , Ira Weiny , Ben Widawsky , Dan Williams , , , Bjorn Helgaas , "Rafael J. Wysocki" , Len Brown Subject: Re: [PATCH 02/15] cxl/core: Check physical address before mapping it in devm_cxl_iomap_block() Message-ID: <20220831095651.00000c73@huawei.com> In-Reply-To: <20220831081603.3415-3-rrichter@amd.com> References: <20220831081603.3415-1-rrichter@amd.com> <20220831081603.3415-3-rrichter@amd.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.42] X-ClientProxiedBy: lhrpeml100006.china.huawei.com (7.191.160.224) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 Aug 2022 10:15:50 +0200 Robert Richter wrote: > The physical base address of a CXL range can be invalid and is then > set to CXL_RESOURCE_NONE. Early check this case before mapping a > memory block in devm_cxl_iomap_block(). An example of when it is invalid would be a useful addition to this description. Feels to me like this is papering over the cracks in something we should have ruled out earlier in the flow. Jonathan > > Signed-off-by: Robert Richter > --- > drivers/cxl/core/regs.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c > index 39a129c57d40..f216c017a474 100644 > --- a/drivers/cxl/core/regs.c > +++ b/drivers/cxl/core/regs.c > @@ -165,6 +165,9 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, > void __iomem *ret_val; > struct resource *res; > > + if (addr == CXL_RESOURCE_NONE) > + return NULL; > + > res = devm_request_mem_region(dev, addr, length, dev_name(dev)); > if (!res) { > resource_size_t end = addr + length - 1;