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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 D30C0C2BA2B for ; Sat, 11 Apr 2020 09:30:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7376D20787 for ; Sat, 11 Apr 2020 09:30:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="ZcZ6R9Ga" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7376D20787 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4DB148E00A4; Sat, 11 Apr 2020 05:30:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 464408E0007; Sat, 11 Apr 2020 05:30:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 32C928E00A4; Sat, 11 Apr 2020 05:30:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 1B3D48E0007 for ; Sat, 11 Apr 2020 05:30:42 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CEBBD824556B for ; Sat, 11 Apr 2020 09:30:41 +0000 (UTC) X-FDA: 76695054282.05.sail24_403beac82ba60 X-HE-Tag: sail24_403beac82ba60 X-Filterd-Recvd-Size: 4245 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Sat, 11 Apr 2020 09:30:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=j/T50vNyIDroG6rZk+1WnkioFUih4u+rrzE6Gbv2xvA=; b=ZcZ6R9Ga79RDysvdKOeH0GJGN 0qoUyilQcy+UBNy5EeY2ry80tv9etfPNyKueZE4XSv2cOCLF5xSK5fTr2oV+7YVczKrH4IjonAWEv GoaU5X6ZpUQGcFjDA0Qai/zeQZ4sDGmKjoo2qdu1pADZzYDCk1AFYiW7V7d06BWtRvbta+ifPqWWZ ecM0NXRJP1uTPHRovhrmZf7TnkxuJRUqrP/npldeV7ZfU7EY2f+QR1c0Ub2TN6NG7klMAN9nrqu3w q+nFZt9DAjUnN29YQUHJ9WP1N5XT2f0QywbKlP9zMxqAWg1tRnri0h+rUGUferiS42pLqWVFevjQ0 fFIoK5ruQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:48586) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jNCSp-0006TI-Sk; Sat, 11 Apr 2020 10:30:12 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jNCSn-0004vU-D4; Sat, 11 Apr 2020 10:30:09 +0100 Date: Sat, 11 Apr 2020 10:30:09 +0100 From: Russell King - ARM Linux admin To: Baoquan He Cc: Andrew Morton , David Hildenbrand , Catalin Marinas , Bhupesh Sharma , Anshuman Khandual , kexec@lists.infradead.org, linux-mm@kvack.org, James Morse , Eric Biederman , Will Deacon , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 1/3] kexec: Prevent removal of memory in use by a loaded kexec image Message-ID: <20200411093009.GH25745@shell.armlinux.org.uk> References: <9cb4ea0d-34c3-de42-4b3f-ee25a59c4835@redhat.com> <72672e2c-a57a-8df9-0cff-8035cbce7740@redhat.com> <34274b02-60ba-eb78-eacd-6dc1146ed3cd@arm.com> <80e4d1d7-f493-3f66-f700-86f18002d692@redhat.com> <20200410121013.03b609fd572504c03a666f4a@linux-foundation.org> <20200411034414.GH2129@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200411034414.GH2129@MiWiFi-R3L-srv> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Apr 11, 2020 at 11:44:14AM +0800, Baoquan He wrote: > Because We tend to use kexec_file_load more and improve/enhance it in the > future, and gradually obsolete the old kexec_load interface which this > patchset is trying to fix on. That's not going to happen; 32-bit ARM kexec uses the kexec_load interface rather than the kexec_file_load version, and I see no one with any interest in changing that - and there's users of the former. I don't see how it's possible to convert 32-bit ARM kexec to the kexec_file_load interface - this assumes that all you have are the kernel, initrd, and commandline, but on 32-bit ARM kexec, we have kernel, initrd and the dtb blob which the user can specify. So, if we wanted to obsolete the kexec_load interface, _first_ there needs to be a way to provide users with the existing functionality they have already in place on 32-bit ARM - otherwise we're looking at a userspace regression. Especially as kexec_file_load takes precedence on some distro patched versions of the kexec tool, irrespective of which interface the user requests of the tool. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up