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=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham 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 8A7FDC433E0 for ; Wed, 24 Jun 2020 21:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 615882072E for ; Wed, 24 Jun 2020 21:09:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ulgAO6ky" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390034AbgFXVJy (ORCPT ); Wed, 24 Jun 2020 17:09:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388453AbgFXVJx (ORCPT ); Wed, 24 Jun 2020 17:09:53 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31FBFC061573 for ; Wed, 24 Jun 2020 14:09:53 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id 207so1615403pfu.3 for ; Wed, 24 Jun 2020 14:09:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=i2jIkhYgexjs9KkwlPySDcA/4RhGGwlAKSrpoMnhGmk=; b=ulgAO6kyxk2umRKRWH6nMJnay5+JI9S+MN+66ac15rcJgmGZtAYk+H5+fPCQqHCN4n YwMVU0XBQEhTdVY5OHD749qpd8Pozz/SM+1Buf2jPE/xGsC+B8G3MYh7c8rCA848s7mL 3wpkBMp2MTJmyiCiTEBPNG6vBbmHu+xghA1mKpCcjOJyJnqEFuFwGJ/pFH0IcAb5JQC+ A2lLOE//kF+ciANNdx3Etcs1w4HXCok/pytM4pC9m2UbLu8T+ZNQiWPiX0fGAsI8+xBJ v8AHa7fV3npUoZ0xdjzOFVVo0SV0pKjAQOJojHM+9coxAbL/MqHPcTuHuRnLuuT3AK8g iPTg== 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:from:date :message-id:subject:to:cc; bh=i2jIkhYgexjs9KkwlPySDcA/4RhGGwlAKSrpoMnhGmk=; b=t/olefxXObuT7kJr4EcFYUCKpkNEqKbMj50OfrWJvq2KWQ0KCmHTNRh/3rEc2IWsP4 s2+oyS2ORPqN+H/nb5IUbgWFVif2MiBJqFo+f0DiMg4lPMFe2V18Sd0/S725n8Pid6vI i1uZF+Mu7LXRDjFM2d3RDhQiCWir+LNWkZGjAo60TnRykUHjzo0qpbud6mZ6c4nawClS UJ8d4XtKUejevN60mKla0but0bg0TuTl5AZ7DH4vp2lyemx8AIyt10vK4hIsf+M9sJT/ yeUS9YhrfszuuCd57DxP1dwtEI3g0dY6msRLaXe/k9dzecZjUr4GiUYDgWOCo/qss7pT m+ZA== X-Gm-Message-State: AOAM533nR9A4vSQU3vNVQ6x7z1hkxNgDUz/IbAHaKbdC0ytvunHiwf1S H7z0JLIYGvsuozA7XH2grTU3yqWKq8v8GYMFiH0LgQ== X-Google-Smtp-Source: ABdhPJyx7J+Crf2HbQKcuBNOiCwJq3seEefhf6EE+jeFP724rCfUEgtaO9Vi1jID9/eG3LhJZ3IQ+YfzgYs3IE2HM8s= X-Received: by 2002:a63:5644:: with SMTP id g4mr22699481pgm.381.1593032992558; Wed, 24 Jun 2020 14:09:52 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <20200624203200.78870-18-samitolvanen@google.com> In-Reply-To: From: Nick Desaulniers Date: Wed, 24 Jun 2020 14:09:40 -0700 Message-ID: Subject: Re: [PATCH 17/22] arm64: vdso: disable LTO To: Sami Tolvanen Cc: Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , Linux Kbuild mailing list , LKML , linux-pci@vger.kernel.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Andi Kleen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 24, 2020 at 1:58 PM Nick Desaulniers wrote: > > On Wed, Jun 24, 2020 at 1:33 PM Sami Tolvanen wrote: > > > > Filter out CC_FLAGS_LTO for the vDSO. > > Just curious about this patch (and the following one for x86's vdso), > do you happen to recall specifically what the issues with the vdso's > are? + Andi (tangential, I actually have a bunch of tabs open with slides from http://halobates.de/ right now) 58edae3aac9f2 67424d5a22124 $ git log -S DISABLE_LTO > > > > > Signed-off-by: Sami Tolvanen > > --- > > arch/arm64/kernel/vdso/Makefile | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile > > index 556d424c6f52..cfad4c296ca1 100644 > > --- a/arch/arm64/kernel/vdso/Makefile > > +++ b/arch/arm64/kernel/vdso/Makefile > > @@ -29,8 +29,8 @@ ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ > > ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 > > ccflags-y += -DDISABLE_BRANCH_PROFILING > > > > -CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) > > -KBUILD_CFLAGS += $(DISABLE_LTO) > > +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \ > > + $(CC_FLAGS_LTO) > > KASAN_SANITIZE := n > > UBSAN_SANITIZE := n > > OBJECT_FILES_NON_STANDARD := y > > -- -- Thanks, ~Nick Desaulniers