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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2C4BEC433E0 for ; Fri, 24 Jul 2020 09:14:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D7B3206EB for ; Fri, 24 Jul 2020 09:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727811AbgGXJOD (ORCPT ); Fri, 24 Jul 2020 05:14:03 -0400 Received: from foss.arm.com ([217.140.110.172]:58236 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726572AbgGXJOD (ORCPT ); Fri, 24 Jul 2020 05:14:03 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6FE71D6E; Fri, 24 Jul 2020 02:14:02 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.5.213]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 43EF53F66E; Fri, 24 Jul 2020 02:14:00 -0700 (PDT) Date: Fri, 24 Jul 2020 10:13:52 +0100 From: Mark Rutland To: Anshuman Khandual Cc: Kefeng Wang , Catalin Marinas , Will Deacon , Mikko Perttunen , Sumit Gupta , Viresh Kumar , Hulk Robot , "linux-kernel@vger.kernel.org List" , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH -next] arm64: Export __cpu_logical_map Message-ID: <20200724091308.GA44746@C02TD0UTHF1T.local> References: <20200724030433.22287-1-wangkefeng.wang@huawei.com> <82f750c4-d423-1ed8-a158-e75153745e07@huawei.com> <7998529f-da52-5e46-dd09-b9b11d83ec1a@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7998529f-da52-5e46-dd09-b9b11d83ec1a@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote: > > On 07/24/2020 08:38 AM, Kefeng Wang wrote: > > +maillist > > This does not seem to be a correct method of posting any patch. > > > > > On 2020/7/24 11:04, Kefeng Wang wrote: > >> ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined! > > > >> > >> ARM64 tegra194-cpufreq driver use cpu_logical_map, export > >> __cpu_logical_map to fix build issue. > > Commit 887d5fc82cb4 ("cpufreq: Add Tegra194 cpufreq driver") which adds > this particular driver is present just on linux-next. But as expected, > the driver does not use __cpu_logical_map directly but instead accesses > it via cpu_logical_map() wrapper. Wondering, how did you even trigger > the modpost error ? The wrapper in is: | /* | * Logical CPU mapping. | */ | extern u64 __cpu_logical_map[NR_CPUS]; | #define cpu_logical_map(cpu) __cpu_logical_map[cpu] ... and use of that would blow up as described. > >> > >> Reported-by: Hulk Robot > >> Signed-off-by: Kefeng Wang > >> --- > >>   arch/arm64/kernel/setup.c | 1 + > >>   1 file changed, 1 insertion(+) > >> > >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > >> index c793276ec7ad9..3aea05fbb9998 100644 > >> --- a/arch/arm64/kernel/setup.c > >> +++ b/arch/arm64/kernel/setup.c > >> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void) > >>   arch_initcall(reserve_memblock_reserved_regions); > >>     u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; > >> +EXPORT_SYMBOL(__cpu_logical_map); If modules are using cpu_logical_map(), this looks sane ot me, but I wonder if we should instead turn cpu_logical_map() into a C wrapper in smp.c, or at least mark __cpu_logical_map as __ro_after_init lest someone have the bright idea to fiddle with it. Mark.