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[23.128.96.36]) by mx.google.com with ESMTPS id b6-20020a63d306000000b0059bdf5a4ecfsi1936025pgg.247.2023.10.18.05.27.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 05:27:53 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.36 as permitted sender) client-ip=23.128.96.36; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=gsIVjBfc; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.36 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by pete.vger.email (Postfix) with ESMTP id 941C980CF556; Wed, 18 Oct 2023 05:27:50 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at pete.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbjJRM1h (ORCPT + 99 others); Wed, 18 Oct 2023 08:27:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjJRM1h (ORCPT ); Wed, 18 Oct 2023 08:27:37 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 095BCA3 for ; Wed, 18 Oct 2023 05:27:36 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25D30C433C8; Wed, 18 Oct 2023 12:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697632055; bh=3oMHWPgTZG+wzUE1L2j7bPKf+yDdpXrGoQcpak/VDrs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gsIVjBfchCmuA+zAYWvguw/d9o+Nn5OfO435koR3kW6NsDUccc/np1OVblibxiCCP gkCD6jYmh2VnrNbFuB8qXkX+Kv/MmCIvP11/d76Px8N4CcMsG0VNS2SHpfqCRcYkoz 5l/lPhHiYbruGVg/bnlscThapy+Zv0UeJQNqw/fkYYyoq+ZijaK3E7hmJ5KQ/Anxl+ dn4gj8Q2f5ztj5HTeDkKZ6zSnvo9P3SDaTWMak4LxKcjR79KiwzbqPGwoC7hArpK32 pmLaxY0TtbLQtMNSYq/N3thH1HAEwQBc2Ys66sjwKAtULBvIBEdnO31w1Ji33KaQo0 Sdtugu2J3X6bA== Date: Wed, 18 Oct 2023 13:27:30 +0100 From: Will Deacon To: Andrea della Porta Cc: Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, nik.borisov@suse.com, arnd@arndb.de, keescook@chromium.org Subject: Re: [PATCH 0/4] arm64: Make Aarch32 compatibility enablement optional at boot Message-ID: <20231018122729.GA18556@willie-the-truck> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-1.2 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Wed, 18 Oct 2023 05:27:50 -0700 (PDT) Hi, On Wed, Oct 18, 2023 at 01:13:18PM +0200, Andrea della Porta wrote: > Aarch32 compatibility mode is enabled at compile time through > CONFIG_COMPAT Kconfig option. This patchset lets 32-bit support > (for both processes and syscalls) be enabled at boot time using > a kernel parameter. Also, it provides a mean for distributions > to set their own default without sacrificing compatibility support, > that is users can override default behaviour through the kernel > parameter. I proposed something similar in the past: https://lkml.kernel.org/linux-fsdevel/20210916131816.8841-1-will@kernel.org/ bu the conclusion there (see the reply from Kees) was that it was better to either use existing seccomp mechanisms or add something to control which binfmts can be loaded. Will