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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 D1163C2BA19 for ; Wed, 15 Apr 2020 20:39:19 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 97BCC206E9 for ; Wed, 15 Apr 2020 20:39:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="W60JO/QY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97BCC206E9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Subject:MIME-Version:Message-ID: In-Reply-To:Date:References:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=QIBLbjQGMQVPpCxL/r41VyliZWp+jc48J/J7Hq+N1Eg=; b=W60JO/QY6pjxvo gqmM875ifT899gX1Ok6asCkBGjsFafUtg6Ptbv99ZbPu1d68jp6phtOJjImfyLwIV8MqHODj/UhRu adm/7IYE2inNpw1yq+AjVFzA5jESSaWYXB54fyx79eiM1yIv7Ce9rnAPZhsfL5WIytyv9G5rHRLVY kFw+Uj+LqSYn1cujCisyoXHm0Mzxw1pIEuom2xs80KjQ/j8Dp4wIkSwGIpUgPnxLiVBdB+cW1D7LV iDGXcOecpCgHv/ESatKE2lEwfaUoBI9+/JUwjPp9+6XOXRunXrGM8RnEoGit4Umrz/9sYJbHiuE+O RyC+t7ggUbKv1xXP1e1w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOooW-0000tV-IB; Wed, 15 Apr 2020 20:39:16 +0000 Received: from out01.mta.xmission.com ([166.70.13.231]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOooT-0000t4-TF; Wed, 15 Apr 2020 20:39:15 +0000 Received: from in02.mta.xmission.com ([166.70.13.52]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jOooS-0004C2-N9; Wed, 15 Apr 2020 14:39:12 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jOooR-0003t4-RV; Wed, 15 Apr 2020 14:39:12 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: James Morse References: <20200326180730.4754-1-james.morse@arm.com> <20200326180730.4754-3-james.morse@arm.com> Date: Wed, 15 Apr 2020 15:36:12 -0500 In-Reply-To: <20200326180730.4754-3-james.morse@arm.com> (James Morse's message of "Thu, 26 Mar 2020 18:07:29 +0000") Message-ID: <873694h4g3.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jOooR-0003t4-RV; ; ; mid=<873694h4g3.fsf@x220.int.ebiederm.org>; ; ; hst=in02.mta.xmission.com; ; ; ip=68.227.160.95; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-XM-AID: U2FsdGVkX1+X5YLJAn2Oq4fRFsCfQJrXrCxI7w2ruHg= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH 2/3] mm/memory_hotplug: Allow arch override of non boot memory resource names X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200415_133913_945538_9EF834B3 X-CRM114-Status: UNSURE ( 9.85 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anshuman Khandual , Catalin Marinas , Bhupesh Sharma , kexec@lists.infradead.org, linux-mm@kvack.org, Andrew Morton , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org James Morse writes: > Memory added to the system by hotplug has a 'System RAM' resource created > for it. This is exposed to user-space via /proc/iomem. > > This poses problems for kexec on arm64. If kexec decides to place the > kernel in one of these newly onlined regions, the new kernel will find > itself booting from a region not described as memory in the firmware > tables. > > Arm64 doesn't have a structure like the e820 memory map that can be > re-written when memory is brought online. Instead arm64 uses the UEFI > memory map, or the memory node from the DT, sometimes both. We never > rewrite these. > > Allow an architecture to specify a different name for these hotplug > regions. Gah. No. Please find a way to pass the current memory map to the loaded kexec'd kernel. Starting a kernel with no way for it to know what the current memory map is just plain scary. Eric _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel