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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 5952DC433FE for ; Wed, 9 Dec 2020 18:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20E5D23C44 for ; Wed, 9 Dec 2020 18:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733274AbgLISrN (ORCPT ); Wed, 9 Dec 2020 13:47:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733163AbgLISrF (ORCPT ); Wed, 9 Dec 2020 13:47:05 -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 D5953C0613CF for ; Wed, 9 Dec 2020 10:46:24 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id w6so1611743pfu.1 for ; Wed, 09 Dec 2020 10:46:24 -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=SLck9T+fSmc7a2TIjVWcYDoy5sXjzN2t3Wk/7vfAiNU=; b=bhK6iE8+kmUpXazU8RtlUQWQoj/gYhhd10dZE+8+sfMSvHRbFPAuMemfMZJpCk7KLo qxI34DHiizH6q+cv+JjdskR2bDrHOJERUYjVOoU/koSNLjgctg0ASc+O/d+o5Fy0r+DH P5qzC/WyE2Q1lPKJXmbTIwcCv4Kq6A5+KZNJ8= 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=SLck9T+fSmc7a2TIjVWcYDoy5sXjzN2t3Wk/7vfAiNU=; b=pHlz/FKQ9aknl41NifVP85fWaCIa/JJcp/9UzlFSiXsQoYnfEKzIb7YviZuuiCAlGV doR9JF1+RQ4x8nZzQN8FdFcAAlj6y08kPhvNdeCwMPiqej5b7UkLkFHmr6gi61bwORpx dTVyBNIhWSzio39f/5JU6xmIUeyxTR0SK72NcOiscL8l4I9QdV0K9E9nM06snfHQxiOG ka9RCwIyxTkdTvEttSTnm2d0ugoKnLXm5oyY+S3vTFfbIl2kun6nIN7aPaTQ/VKA3f+D 9LJy56pRZCWB5DqbMIcl67XKqvsExpPRGFLLfXg2rg0J1KSSdc2i8KGW1d9cZNc8GNHY dZsQ== X-Gm-Message-State: AOAM531cjISnnxOZOeZxWjPDdTe9bb8ktIBf+DIeT5/PdHGVFOSkkM6b 9VEVzJRA104YwBSzTUyNQrtjrA== X-Google-Smtp-Source: ABdhPJxsOMJXYHgO++DFsy46q+XDaL5LbfNiKSXWrHsgDpx4L/Vpg9szW4GEOZ4o6Z++CZWZM+WnLA== X-Received: by 2002:a62:84ca:0:b029:19e:6f95:11b1 with SMTP id k193-20020a6284ca0000b029019e6f9511b1mr3534614pfd.68.1607539584427; Wed, 09 Dec 2020 10:46:24 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id w70sm3499919pfd.65.2020.12.09.10.46.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Dec 2020 10:46:23 -0800 (PST) Date: Wed, 9 Dec 2020 10:46:22 -0800 From: Kees Cook To: Arnd Bergmann Cc: Andrew Morton , Linus Torvalds , Ard Biesheuvel , Arnd Bergmann , Masahiro Yamada , Michal Marek , Nathan Chancellor , Nick Desaulniers , Marco Elver , Randy Dunlap , Dmitry Vyukov , George Popescu , Herbert Xu , Peter Oberparleiter , Andrey Ryabinin , clang-built-linux , Linux Kbuild mailing list , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 5/7] ubsan: Enable for all*config builds Message-ID: <202012091045.34E3CC3FA@keescook> References: <20201203004437.389959-1-keescook@chromium.org> <20201203004437.389959-6-keescook@chromium.org> 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-kernel@vger.kernel.org On Thu, Dec 03, 2020 at 09:51:40AM +0100, Arnd Bergmann wrote: > On Thu, Dec 3, 2020 at 1:44 AM Kees Cook wrote: > > > > With UBSAN_OBJECT_SIZE disabled for GCC, only UBSAN_ALIGNMENT remained > > a noisy UBSAN option. Disable it for COMPILE_TEST so the rest of UBSAN > > can be used for full all*config builds or other large combinations. > > > > Link: https://lore.kernel.org/lkml/CAHk-=wgXW=YLxGN0QVpp-1w5GDd2pf1W-FqY15poKzoVfik2qA@mail.gmail.com/ > > Signed-off-by: Kees Cook > > Have you checked if this has a notable impact on allmodconfig compile speed > with gcc or clang? I think I've seen significant increases in build times before > with this, but I don't remember the actual magnitude. > > Making it 20% slower would probably be ok, but making it twice as slow might > be too much. And for Clang, it's about 7m40s before and 8m30s after, so roughly 12% slower. -- Kees Cook