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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 6129EC433E2 for ; Fri, 17 Jul 2020 20:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40567207EA for ; Fri, 17 Jul 2020 20:26:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595017586; bh=/hYopkLccKkwFpSirohLu9rK4PERmsXifMkvfY8na74=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=XMjOcpQvDD2BS8wb2eyvancZMJRIEl/qDFOHGc5vrX3aBMuEVGwdjZMVZydto2U+s SGe1rYIwpHqQLyedeng5KNUXA+nvwm9XKZ4p82R8Xu2vjk+sFiKg2o3zT0ANsKGEr3 hpbaU2h9l2JQIN1OG9CmBY8FwX/Cqgrmq/M0XOmc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgGQU0W (ORCPT ); Fri, 17 Jul 2020 16:26:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:32944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgGQU0W (ORCPT ); Fri, 17 Jul 2020 16:26:22 -0400 Received: from localhost (mobile-166-175-191-139.mycingular.net [166.175.191.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9C36A20684; Fri, 17 Jul 2020 20:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595017582; bh=/hYopkLccKkwFpSirohLu9rK4PERmsXifMkvfY8na74=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=s3QH/t9ocNHEPH2/jvWRB8qEQKIK64CQ+GlRWp8yjZLbWaD3J5hfVQ80kDY7xshpH xeiUCkt/Irn0dwJ5rev9qj5TqMu055YbwJsqTl3kaW+lblQMHHzeP7vMEYgEstIATL o2+gGzz8bNJr4YllTtvOL6MhViMZk5u3gpLyaYYU= Date: Fri, 17 Jul 2020 15:26:20 -0500 From: Bjorn Helgaas To: Sami Tolvanen Cc: Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , 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 11/22] pci: lto: fix PREL32 relocations Message-ID: <20200717202620.GA768846@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200624203200.78870-12-samitolvanen@google.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org OK by me, but please update the subject to match convention: PCI: Fix PREL32 relocations for LTO and include a hint in the commit log about what LTO is. At least expand the initialism once. Googling for "LTO" isn't very useful. With Clang's Link Time Optimization (LTO), the compiler ... ? On Wed, Jun 24, 2020 at 01:31:49PM -0700, Sami Tolvanen wrote: > With LTO, the compiler can rename static functions to avoid global > naming collisions. As PCI fixup functions are typically static, > renaming can break references to them in inline assembly. This > change adds a global stub to DECLARE_PCI_FIXUP_SECTION to fix the > issue when PREL32 relocations are used. > > Signed-off-by: Sami Tolvanen Acked-by: Bjorn Helgaas > --- > include/linux/pci.h | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/include/linux/pci.h b/include/linux/pci.h > index c79d83304e52..1e65e16f165a 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1909,19 +1909,24 @@ enum pci_fixup_pass { > }; > > #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS > -#define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > - class_shift, hook) \ > - __ADDRESSABLE(hook) \ > +#define ___DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > + class_shift, hook, stub) \ > + void stub(struct pci_dev *dev) { hook(dev); } \ > asm(".section " #sec ", \"a\" \n" \ > ".balign 16 \n" \ > ".short " #vendor ", " #device " \n" \ > ".long " #class ", " #class_shift " \n" \ > - ".long " #hook " - . \n" \ > + ".long " #stub " - . \n" \ > ".previous \n"); > + > +#define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > + class_shift, hook, stub) \ > + ___DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > + class_shift, hook, stub) > #define DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > class_shift, hook) \ > __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ > - class_shift, hook) > + class_shift, hook, __UNIQUE_ID(hook)) > #else > /* Anonymous variables would be nice... */ > #define DECLARE_PCI_FIXUP_SECTION(section, name, vendor, device, class, \ > -- > 2.27.0.212.ge8ba1cc988-goog >