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=-9.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 6932FC433E0 for ; Sun, 12 Jul 2020 08:59:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47EF52070B for ; Sun, 12 Jul 2020 08:59:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="et8c4srf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728461AbgGLI7d (ORCPT ); Sun, 12 Jul 2020 04:59:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725765AbgGLI7a (ORCPT ); Sun, 12 Jul 2020 04:59:30 -0400 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08E66C061794; Sun, 12 Jul 2020 01:59:30 -0700 (PDT) Received: by mail-io1-xd44.google.com with SMTP id v8so10415484iox.2; Sun, 12 Jul 2020 01:59:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=+Dl8Q1XzZiYA4GO8ZZtoY/mYTNvNLG4yL/TSgXjOVXM=; b=et8c4srf7jKz/ghq6ldgJw1wpsajAh/iicKsgGLSk5HCxGZ5CQ86IFUST3G/dAZS9R BK+JEehQthnnir07FeiPcL/qpVUZ2NGCyUjND9byzvK8PnixOnaWkF96m/M5kUymOL2C LII6vqDG01OkywVTUDEiMrt1QcYjd+y6es/0VA01BLEP3VrfKh/wxRZhab4S/+5xDWOB xe88vsXrHJ2oYLtwubG993g1CAsa5aM8/V0M7++JN1XNtMqDZiEmh7FXGrho8fAIGKiT KJW0LpTSPQuedYjKrMO8KvYmRECOyDbXavBRUCJEaU4kO1PGAriZ+FRdd/Me8DIzlfab p9uA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc:content-transfer-encoding; bh=+Dl8Q1XzZiYA4GO8ZZtoY/mYTNvNLG4yL/TSgXjOVXM=; b=CafyuPnaQWggO8PEixrRbkVAkgjZD8f+UkmoKcWcFsIIRaq3RLpP5cwWOhMKEYh4g8 7WxtNI9ca8lHQjl1ja7ble2ASNCYrAXjbMY4EDJhmkYKvfYZ+opVMil8K3MAJ4AUxtp1 ThSji8sFkAuCrCmuoI8SKYA/MUZ2lYLZJbG3fCmkC6CJnX22aAki8TujsHHuyKuqXE1c JGVxO18dDrfMHjtyX9YzEM/x6A0CS15REVPqzvxL5SpXT2NINXroaR5kuuPEZs3Ssa+8 O7GUgeZZ30hY3jNuXo92vW3anwL6vy/EqoGatulaOuTz3X2ABz27nuyd2vdbcj1sbCZT HGQg== X-Gm-Message-State: AOAM5327tf9z0the4zjHMjxdw8A4JgjbiCsSC1ieJkvlNQ9WMeswB739 cjSsXZ8h9jX9FML4QC/xNOGhWU2wnuT4JxOdrLw= X-Google-Smtp-Source: ABdhPJz6yajbht8v21aUb5AqbeseJZbW7WiEMt9+Xzj6unIHhgR9p8E/p5dg9MyRRh3U33wQNCR5IYqWyZHeGZXnsKY= X-Received: by 2002:a05:6602:1555:: with SMTP id h21mr6773338iow.163.1594544369052; Sun, 12 Jul 2020 01:59:29 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> In-Reply-To: <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Sun, 12 Jul 2020 10:59:17 +0200 Message-ID: Subject: Re: [PATCH 00/22] add support for Clang LTO To: Paul Menzel Cc: Sami Tolvanen , Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , Clang-Built-Linux ML , 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 11, 2020 at 6:32 PM Paul Menzel wrote: > > Dear Sami, > > > Am 24.06.20 um 22:31 schrieb Sami Tolvanen: > > This patch series adds support for building x86_64 and arm64 kernels > > 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's > > Pixel devices have shipped with LTO+CFI kernels 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 first objtool patch in the series is already in linux-next, > > but as it's needed with LTO, I'm including it also here to make testing > > easier. > > [=E2=80=A6] > > Thank you very much for sending these changes. > > Do you have a branch, where your current work can be pulled from? Your > branch on GitHub [1] seems 15 months old. > Agreed it's easier to git-pull. I have seen [1] - not sure if this is the latest version. Alternatively, you can check patchwork LKML by searching for $submitter. ( You can open patch 01/22 and download the whole patch-series by following the link "series", see [3]. ) - Sedat - [1] https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.= git/log/?h=3Dlto [2] https://lore.kernel.org/patchwork/project/lkml/list/?series=3D&submitte= r=3D19676 [3] https://lore.kernel.org/patchwork/series/450026/mbox/ 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=-9.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 9DBC1C433E1 for ; Sun, 12 Jul 2020 09:01:27 +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 5D4662072D for ; 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Sun, 12 Jul 2020 01:59:29 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> In-Reply-To: <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> From: Sedat Dilek Date: Sun, 12 Jul 2020 10:59:17 +0200 Message-ID: Subject: Re: [PATCH 00/22] add support for Clang LTO To: Paul Menzel X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200712_045935_138012_86666F88 X-CRM114-Status: GOOD ( 20.66 ) 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: , Reply-To: sedat.dilek@gmail.com Cc: linux-arch@vger.kernel.org, x86@kernel.org, Kees Cook , "Paul E. McKenney" , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , Masahiro Yamada , linux-kbuild@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, Clang-Built-Linux ML , Sami Tolvanen , linux-pci@vger.kernel.org, Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gU2F0LCBKdWwgMTEsIDIwMjAgYXQgNjozMiBQTSBQYXVsIE1lbnplbCA8cG1lbnplbEBtb2xn ZW4ubXBnLmRlPiB3cm90ZToKPgo+IERlYXIgU2FtaSwKPgo+Cj4gQW0gMjQuMDYuMjAgdW0gMjI6 MzEgc2NocmllYiBTYW1pIFRvbHZhbmVuOgo+ID4gVGhpcyBwYXRjaCBzZXJpZXMgYWRkcyBzdXBw b3J0IGZvciBidWlsZGluZyB4ODZfNjQgYW5kIGFybTY0IGtlcm5lbHMKPiA+IHdpdGggQ2xhbmcn cyBMaW5rIFRpbWUgT3B0aW1pemF0aW9uIChMVE8pLgo+ID4KPiA+IEluIGFkZGl0aW9uIHRvIHBl cmZvcm1hbmNlLCB0aGUgcHJpbWFyeSBtb3RpdmF0aW9uIGZvciBMVE8gaXMgdG8gYWxsb3cKPiA+ IENsYW5nJ3MgQ29udHJvbC1GbG93IEludGVncml0eSAoQ0ZJKSB0byBiZSB1c2VkIGluIHRoZSBr ZXJuZWwuIEdvb2dsZSdzCj4gPiBQaXhlbCBkZXZpY2VzIGhhdmUgc2hpcHBlZCB3aXRoIExUTytD Rkkga2VybmVscyBzaW5jZSAyMDE4Lgo+ID4KPiA+IE1vc3Qgb2YgdGhlIHBhdGNoZXMgYXJlIGJ1 aWxkIHN5c3RlbSBjaGFuZ2VzIGZvciBoYW5kbGluZyBMTFZNIGJpdGNvZGUsCj4gPiB3aGljaCBD bGFuZyBwcm9kdWNlcyB3aXRoIExUTyBpbnN0ZWFkIG9mIEVMRiBvYmplY3QgZmlsZXMsIHBvc3Rw b25pbmcKPiA+IEVMRiBwcm9jZXNzaW5nIHVudGlsIGEgbGF0ZXIgc3RhZ2UsIGFuZCBlbnN1cmlu ZyBpbml0Y2FsbCBvcmRlcmluZy4KPiA+Cj4gPiBOb3RlIHRoYXQgZmlyc3Qgb2JqdG9vbCBwYXRj aCBpbiB0aGUgc2VyaWVzIGlzIGFscmVhZHkgaW4gbGludXgtbmV4dCwKPiA+IGJ1dCBhcyBpdCdz IG5lZWRlZCB3aXRoIExUTywgSSdtIGluY2x1ZGluZyBpdCBhbHNvIGhlcmUgdG8gbWFrZSB0ZXN0 aW5nCj4gPiBlYXNpZXIuCj4KPiBb4oCmXQo+Cj4gVGhhbmsgeW91IHZlcnkgbXVjaCBmb3Igc2Vu ZGluZyB0aGVzZSBjaGFuZ2VzLgo+Cj4gRG8geW91IGhhdmUgYSBicmFuY2gsIHdoZXJlIHlvdXIg Y3VycmVudCB3b3JrIGNhbiBiZSBwdWxsZWQgZnJvbT8gWW91cgo+IGJyYW5jaCBvbiBHaXRIdWIg WzFdIHNlZW1zIDE1IG1vbnRocyBvbGQuCj4KCkFncmVlZCBpdCdzIGVhc2llciB0byBnaXQtcHVs bC4KSSBoYXZlIHNlZW4gWzFdIC0gbm90IHN1cmUgaWYgdGhpcyBpcyB0aGUgbGF0ZXN0IHZlcnNp b24uCkFsdGVybmF0aXZlbHksIHlvdSBjYW4gY2hlY2sgcGF0Y2h3b3JrIExLTUwgYnkgc2VhcmNo aW5nIGZvciAkc3VibWl0dGVyLgooIFlvdSBjYW4gb3BlbiBwYXRjaCAwMS8yMiBhbmQgZG93bmxv YWQgdGhlIHdob2xlIHBhdGNoLXNlcmllcyBieQpmb2xsb3dpbmcgdGhlIGxpbmsgInNlcmllcyIs IHNlZSBbM10uICkKCi0gU2VkYXQgLQoKWzFdIGh0dHBzOi8vZ2l0Lmtlcm5lbC5vcmcvcHViL3Nj bS9saW51eC9rZXJuZWwvZ2l0L21hc2FoaXJveS9saW51eC1rYnVpbGQuZ2l0L2xvZy8/aD1sdG8K WzJdIGh0dHBzOi8vbG9yZS5rZXJuZWwub3JnL3BhdGNod29yay9wcm9qZWN0L2xrbWwvbGlzdC8/ c2VyaWVzPSZzdWJtaXR0ZXI9MTk2NzYKWzNdIGh0dHBzOi8vbG9yZS5rZXJuZWwub3JnL3BhdGNo d29yay9zZXJpZXMvNDUwMDI2L21ib3gvCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0t a2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFp bG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg== 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=-8.8 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 64A3FC433E0 for ; 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Sun, 12 Jul 2020 01:59:29 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> In-Reply-To: <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> From: Sedat Dilek Date: Sun, 12 Jul 2020 10:59:17 +0200 Message-ID: Subject: Re: [PATCH 00/22] add support for Clang LTO To: Paul Menzel Cc: Sami Tolvanen , Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , Clang-Built-Linux ML , 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, Jul 11, 2020 at 6:32 PM Paul Menzel wrote: > > Dear Sami, > > > Am 24.06.20 um 22:31 schrieb Sami Tolvanen: > > This patch series adds support for building x86_64 and arm64 kernels > > 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's > > Pixel devices have shipped with LTO+CFI kernels 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 first objtool patch in the series is already in linux-next, > > but as it's needed with LTO, I'm including it also here to make testing > > easier. > > [=E2=80=A6] > > Thank you very much for sending these changes. > > Do you have a branch, where your current work can be pulled from? Your > branch on GitHub [1] seems 15 months old. > Agreed it's easier to git-pull. I have seen [1] - not sure if this is the latest version. Alternatively, you can check patchwork LKML by searching for $submitter. ( You can open patch 01/22 and download the whole patch-series by following the link "series", see [3]. ) - Sedat - [1] https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.= git/log/?h=3Dlto [2] https://lore.kernel.org/patchwork/project/lkml/list/?series=3D&submitte= r=3D19676 [3] https://lore.kernel.org/patchwork/series/450026/mbox/