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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 68D2CC2D0B1 for ; Thu, 6 Feb 2020 10:00:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 384A5218AC for ; Thu, 6 Feb 2020 10:00:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728286AbgBFKA3 (ORCPT ); Thu, 6 Feb 2020 05:00:29 -0500 Received: from foss.arm.com ([217.140.110.172]:56630 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727768AbgBFKA3 (ORCPT ); Thu, 6 Feb 2020 05:00:29 -0500 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 CF7581FB; Thu, 6 Feb 2020 02:00:28 -0800 (PST) Received: from [10.1.36.209] (e121487-lin.cambridge.arm.com [10.1.36.209]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 315B43F6CF; Thu, 6 Feb 2020 02:00:26 -0800 (PST) Subject: Re: [PATCH] arm: make kexec depend on MMU To: Stefan Agner , linux@armlinux.org.uk Cc: Michal Hocko , arnd@arndb.de, linus.walleij@linaro.org, nsekhar@ti.com, linux-kernel@vger.kernel.org, bgolaszewski@baylibre.com, benjamin.gaignard@linaro.org, mchehab+samsung@kernel.org, armlinux@m.disordat.com, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org, Vincenzo Frascino References: <5b595d37283f043df78259221f2b7d18e0cb0ce5.1580942558.git.stefan@agner.ch> From: Vladimir Murzin Message-ID: <14e4919a-0089-c2e7-567c-1e7fcfef9769@arm.com> Date: Thu, 6 Feb 2020 10:00:23 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <5b595d37283f043df78259221f2b7d18e0cb0ce5.1580942558.git.stefan@agner.ch> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/5/20 10:43 PM, Stefan Agner wrote: > From: Michal Hocko > > arm nommu config with KEXEC enabled doesn't compile > arch/arm/kernel/setup.c: In function 'reserve_crashkernel': > arch/arm/kernel/setup.c:1005:25: error: 'SECTION_SIZE' undeclared (first > use in this function) > crash_size, SECTION_SIZE); > > since 61603016e212 ("ARM: kexec: fix crashkernel= handling") which is > over one year without anybody noticing. I have only noticed beause of > my testing nommu config which somehow gained CONFIG_KEXEC without > an intention. This suggests that nobody is actually using KEXEC > on nommu ARM configs. It is even a question whether kexec works with > nommu. > > Make KEXEC depend on MMU to make this clear. If somebody wants to enable > there will be probably more things to take care. > > Signed-off-by: Michal Hocko > Reviewed-by: Stefan Agner > Signed-off-by: Stefan Agner > --- > arch/arm/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 96dab76da3b3..59ce8943151f 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1906,6 +1906,7 @@ config KEXEC > bool "Kexec system call (EXPERIMENTAL)" > depends on (!SMP || PM_SLEEP_SMP) > depends on !CPU_V7M > + depends on MMU > select KEXEC_CORE > help > kexec is a system call that implements the ability to shutdown your > Vincenzo sent similar patch [1] some time ago. I prefer his patch since CPU_V7M already imply !MMU. [1] https://lore.kernel.org/linux-arm-kernel/20200110123125.51092-1-vincenzo.frascino@arm.com/T/ Cheers Vladimir