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=-14.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY, 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 59B0DC433E7 for ; Mon, 12 Oct 2020 21:02:58 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 4CF64206DC for ; Mon, 12 Oct 2020 21:02:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="aKY2mjZq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CF64206DC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20172-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 8092 invoked by uid 550); 12 Oct 2020 21:02:51 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 8051 invoked from network); 12 Oct 2020 21:02:50 -0000 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=SnB7E0mI9F7Ie4RlS2cFfqKwCDcopSImUj3IgUSKIxI=; b=aKY2mjZqZCjoAe1tt9s9T2FsyHGWEg2r94yXrTIjifMKj+9G5PGXHdmHun7LMLnVVf Iyx0hqwAI4RdNjsS7WRjj36UFpYvhE5Z30RnvNh8wxzPTZqIDq/V6FSJyRhQlm3vqAgv czJMjy/QiJI5hFODJh0hCucbVTQNfJmHuR7Ss= 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=SnB7E0mI9F7Ie4RlS2cFfqKwCDcopSImUj3IgUSKIxI=; b=YztOpEYU21wRHYE0aayU7H5jgXxba4tK2dcApk+j6t4nf0bmqmjcgkLUErq2B1ZBo0 npe8chQHnk3zh4SnageTTNFXjQ3hl7QvapIVeIcFPJprdn6AQQ0Hv9beGpOCtUZzC77O og6SVQeu9uiTZXTh4wWZRxVfn2c6Kzmrn7oVz4GQNN7ZXRO/LBwn06Z5I2xIbZfmuHzB JnhKknPJbi8C6V2VLIEw7ciXL/5bptpV6ZYwGUZyslXW3zX7+giFmAGqBwfS2ja59v3e S3061Mqb6VeDHK1SwQvW8jm/2iWj/qEboKR0vFeCBRcIkMvqKu9mmxHgrnocpemrLHe3 zOeg== X-Gm-Message-State: AOAM5300phfBi0TZI02kVw9lsKL9SVc9wp9y+ujSTkfEI9KcVxbh0Ysu iDtjSFk0bynT1Bp4UcUX928Z7g== X-Google-Smtp-Source: ABdhPJzJnGcA0q8XKKQGw3kIUgQPIXUnpTwBiY6N5ghL0OHEl3zmbEFuNMnAsinW9yZvnNW49rm+aQ== X-Received: by 2002:a63:5a11:: with SMTP id o17mr14040343pgb.287.1602536557163; Mon, 12 Oct 2020 14:02:37 -0700 (PDT) Date: Mon, 12 Oct 2020 14:02:35 -0700 From: Kees Cook To: Will Deacon Cc: Sami Tolvanen , Masahiro Yamada , Steven Rostedt , Peter Zijlstra , Greg Kroah-Hartman , "Paul E. McKenney" , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v5 25/29] arm64: allow LTO_CLANG and THINLTO to be selected Message-ID: <202010121402.1EB5242@keescook> References: <20201009161338.657380-1-samitolvanen@google.com> <20201009161338.657380-26-samitolvanen@google.com> <20201012083116.GA785@willie-the-truck> <202010121344.53780D8CD2@keescook> <20201012205108.GA1620@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201012205108.GA1620@willie-the-truck> On Mon, Oct 12, 2020 at 09:51:09PM +0100, Will Deacon wrote: > On Mon, Oct 12, 2020 at 01:44:56PM -0700, Kees Cook wrote: > > On Mon, Oct 12, 2020 at 09:31:16AM +0100, Will Deacon wrote: > > > On Fri, Oct 09, 2020 at 09:13:34AM -0700, Sami Tolvanen wrote: > > > > Allow CONFIG_LTO_CLANG and CONFIG_THINLTO to be enabled. > > > > > > > > Signed-off-by: Sami Tolvanen > > > > Reviewed-by: Kees Cook > > > > --- > > > > arch/arm64/Kconfig | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > > > index ad522b021f35..7016d193864f 100644 > > > > --- a/arch/arm64/Kconfig > > > > +++ b/arch/arm64/Kconfig > > > > @@ -72,6 +72,8 @@ config ARM64 > > > > select ARCH_USE_SYM_ANNOTATIONS > > > > select ARCH_SUPPORTS_MEMORY_FAILURE > > > > select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK > > > > + select ARCH_SUPPORTS_LTO_CLANG > > > > + select ARCH_SUPPORTS_THINLTO > > > > > > Please don't enable this for arm64 until we have the dependency stuff sorted > > > out. I posted patches [1] for this before, but I think they should be part > > > of this series as they don't make sense on their own. > > > > Oh, hm. We've been trying to trim down this series, since it's already > > quite large. Why can't [1] land first? It would make this easier to deal > > with, IMO. > > I'm happy to handle [1] along with the LTO Kconfig change when the time > comes, if that helps. I just don't want to merge dead code! Okay, understood. Thanks! > > Will > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=rwonce/read-barrier-depends -- Kees Cook