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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 EFD39C64E7B for ; Mon, 30 Nov 2020 12:04:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 6E47E206D8 for ; Mon, 30 Nov 2020 12:04:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="xQ4aRWh2"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="EwVQLNws" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E47E206D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=FOx5SJ3Fkza3lg/XZ8Lx1IaERvJgKrrJJnAfiNY93QA=; b=xQ4aRWh2MAUzkj+/YzA2O8vOI ylgkldaW9aapzlD54dA7CieIaG/CzBuyEdgzJT5XiBfACEg91j/SPeLxc6mfJ3FAQcrdA7Gl6tLu2 UycVbtp2PUyFm65zdwY1oIQvqEn9MhRRMcgcKg9lWanXvWkZa0n0pqUmvi0KfLhBgwn9QhQnGg5qy vneRyU64zAbv0oh+nrHwSQoU7zQjIbQe/D4UGmm7CBhT1iC1SvnYhDZaJzwGGYjpfe0Jv66MpdKGK HkgQzhcQeFL/vfj3wdX+AXPgpP1pX8PurFFWvXJaCku3zWbCM47p657T4NFVHnMF7XKOQKzPDbndC k28jq/k2Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kjhtI-0001Ac-1J; Mon, 30 Nov 2020 12:02:49 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kjhsA-0000eh-By for linux-arm-kernel@lists.infradead.org; Mon, 30 Nov 2020 12:01:39 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 89B91206CB; Mon, 30 Nov 2020 12:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606737697; bh=A/tQpaRCdVBxIrK5CVrihAXJGL1D0YMcA4iympcoTzk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EwVQLNwsXH/bdnWP/eU1At5WBpjCSdAR6JTRNITU+0kyAYmyC7vfvCGB5aglCFG6x MgF+azWjp5V9E9RCzfCIxmq6AyuSMIhVSOBmKKJ8jGetiIbmZ9+phj0IYAntF8L2n+ Jz+cOfBAzUsJpOu6/EZ4Jj48GG8LJpvvDpy7mI9s= Date: Mon, 30 Nov 2020 12:01:31 +0000 From: Will Deacon To: Sami Tolvanen Subject: Re: [PATCH v7 00/17] Add support for Clang LTO Message-ID: <20201130120130.GF24563@willie-the-truck> References: <20201118220731.925424-1-samitolvanen@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201130_070138_609226_D6150AAD X-CRM114-Status: GOOD ( 19.48 ) 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: linux-arch@vger.kernel.org, Kees Cook , "Paul E. McKenney" , kernel-hardening@lists.openwall.com, Peter Zijlstra , Greg Kroah-Hartman , Masahiro Yamada , linux-kbuild@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, Steven Rostedt , clang-built-linux@googlegroups.com, linux-pci@vger.kernel.org, Josh Poimboeuf , 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Sami, On Wed, Nov 18, 2020 at 02:07:14PM -0800, Sami Tolvanen wrote: > This patch series adds support for building the kernel with Clang's > Link Time Optimization (LTO). In addition to performance, the primary > motivation for LTO is to allow Clang's Control-Flow Integrity (CFI) to > be used in the kernel. Google has shipped millions of Pixel devices > running three major kernel versions with LTO+CFI since 2018. > > Most of the patches are build system changes for handling LLVM bitcode, > which Clang produces with LTO instead of ELF object files, postponing > ELF processing until a later stage, and ensuring initcall ordering. > > Note that v7 brings back arm64 support as Will has now staged the > prerequisite memory ordering patches [1], and drops x86_64 while we work > on fixing the remaining objtool warnings [2]. Sounds like you're going to post a v8, but that's the plan for merging that? The arm64 parts look pretty good to me now. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel