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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 98041C56201 for ; Fri, 20 Nov 2020 19:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35FA02240A for ; Fri, 20 Nov 2020 19:47:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="XzoPI1cr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729114AbgKTTrY (ORCPT ); Fri, 20 Nov 2020 14:47:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729119AbgKTTrY (ORCPT ); Fri, 20 Nov 2020 14:47:24 -0500 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ED28C061A48 for ; Fri, 20 Nov 2020 11:47:24 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id 10so8879529pfp.5 for ; Fri, 20 Nov 2020 11:47:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=elr/neHdSPND1QBbHYVTIKRGGtBg1vE7OdThIsRU5pI=; b=XzoPI1crChRR6wLQGUnQdTruNmuVNj0hkcwU6yjn8xXrOzmnTuw8bZwNjYOSUMiNjn EBV38WHid50TNovyKvDuuqOK6ny2jvmInIM/dgDYVmxiGIxn7be54rsKduzrLe/jMV3q ANWN/74SZ1EEZvtawKD5ujXQl6B2YxxD3r8JI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=elr/neHdSPND1QBbHYVTIKRGGtBg1vE7OdThIsRU5pI=; b=WtW8OJ1H4N5duCNANFoJ2G9MxYFGvXnAWQnixXb+If2UtqWOBjBMFxo4CUz2fiH5lD zQ+GCimfKenXIENfJ75+gYcbUvUg7eCNUFmWBh+w41uUKfKXTKwbJf3GBe0Ianq6DlsA SprnTPWVuJMzbJH3oUYugD+h9C8C2He9xSuL4QZ68/iodAX88mhOGsYon5ISNFJHss/L YOb6IM5nfp6oWhFX97bCF5AwseZAS0YCijmB52kUebVCm0ApdQvvJwOJKIzPkxsLyfj/ ZU0ncGWogSp81j4Fgr6k8U1LU1YOHVk9JcYLvbYN7JO2G/DNSkHUgQmGGHqbCMUWJ8dh eIRw== X-Gm-Message-State: AOAM530Pr38W7IcToPUWrGEQcdR16hBPDLDsU1zRy9uYu5dUm7G7qVU3 ZF2QfJTomVMo8rHU8IA52fr4sA== X-Google-Smtp-Source: ABdhPJwnsGzh6rI5stQsBcWRn8N0h8Ns8b+OJp9DPF9o8s3fODKrXmSZ/a2sub1vz+HM8LuYBAXNBw== X-Received: by 2002:a62:ea09:0:b029:197:bad4:1e78 with SMTP id t9-20020a62ea090000b0290197bad41e78mr8311744pfh.22.1605901643516; Fri, 20 Nov 2020 11:47:23 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id h16sm4507596pfo.185.2020.11.20.11.47.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Nov 2020 11:47:22 -0800 (PST) Date: Fri, 20 Nov 2020 11:47:21 -0800 From: Kees Cook To: Sami Tolvanen Cc: Nick Desaulniers , Masahiro Yamada , Steven Rostedt , Will Deacon , Josh Poimboeuf , Peter Zijlstra , Greg Kroah-Hartman , "Paul E. McKenney" , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , Linux Kbuild mailing list , LKML , linux-pci@vger.kernel.org Subject: Re: [PATCH v7 02/17] kbuild: add support for Clang LTO Message-ID: <202011201144.3F2BB70C@keescook> References: <20201118220731.925424-1-samitolvanen@google.com> <20201118220731.925424-3-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Fri, Nov 20, 2020 at 08:23:11AM -0800, Sami Tolvanen wrote: > Changing the ThinLTO config to a choice and moving it after the main > LTO config sounds like a good idea to me. I'll see if I can change > this in v8. Thanks! Originally, I thought this might be a bit ugly once GCC LTO is added, but this could be just a choice like we're done for the stack initialization. Something like an "LTO" choice of NONE, CLANG_FULL, CLANG_THIN, and in the future GCC, etc. -- Kees Cook