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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 C5D93C43381 for ; Wed, 27 Mar 2019 18:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 92FE1205C9 for ; Wed, 27 Mar 2019 18:57:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553713030; bh=9nDqIEb76G8C/Cp+h8hH03laCKi49iH8DibKd4JYtOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YSnyUS8L/cb4NKsFe/2Q1BT5VYWGbvmnCJJ2OV0ValOQ3y9B+iAhqFOPZ+8E4oz2u Rg9pl4e7hDVHYN2TCTJzk4u8B51Whxa6avb/KEYhc16zygUyPGWLahPDYxm2WRu73N Jl2ZWlYDYp8mmlCnCILu3tIOyUjZHC1YJJ5gCyAo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390305AbfC0S5I (ORCPT ); Wed, 27 Mar 2019 14:57:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:60124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389716AbfC0SQO (ORCPT ); Wed, 27 Mar 2019 14:16:14 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6814120449; Wed, 27 Mar 2019 18:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553710573; bh=9nDqIEb76G8C/Cp+h8hH03laCKi49iH8DibKd4JYtOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sr6WpchQ5Zr48fuULbLFVvTh7wvXEKfV8jkHopwWfEHpM+VP3eGL2LP/fKYrPtPPE 8v5Ekv4ujroiKJEW6Tu4Rz84pPoyr+xO8tnI6tHstzFI076gs/+J81C5s3EsRtKqEz /4eSEcM1GrgbqjfFn3g0K1r9Wihe1H9HZ6+dYaKQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Rafael=20=C3=81vila=20de=20Esp=C3=ADndola?= , Nick Desaulniers , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Brijesh Singh , Cao Jin , Ingo Molnar , Joerg Roedel , Masahiro Yamada , Masami Hiramatsu , Thomas Gleixner , Tri Vo , dima@golovin.in, morbo@google.com, x86-ml , Sasha Levin Subject: [PATCH AUTOSEL 4.19 182/192] x86/build: Mark per-CPU symbols as absolute explicitly for LLD Date: Wed, 27 Mar 2019 14:10:14 -0400 Message-Id: <20190327181025.13507-182-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190327181025.13507-1-sashal@kernel.org> References: <20190327181025.13507-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael Ávila de Espíndola [ Upstream commit d071ae09a4a1414c1433d5ae9908959a7325b0ad ] Accessing per-CPU variables is done by finding the offset of the variable in the per-CPU block and adding it to the address of the respective CPU's block. Section 3.10.8 of ld.bfd's documentation states: For expressions involving numbers, relative addresses and absolute addresses, ld follows these rules to evaluate terms: Other binary operations, that is, between two relative addresses not in the same section, or between a relative address and an absolute address, first convert any non-absolute term to an absolute address before applying the operator." Note that LLVM's linker does not adhere to the GNU ld's implementation and as such requires implicitly-absolute terms to be explicitly marked as absolute in the linker script. If not, it fails currently with: ld.lld: error: ./arch/x86/kernel/vmlinux.lds:153: at least one side of the expression must be absolute ld.lld: error: ./arch/x86/kernel/vmlinux.lds:154: at least one side of the expression must be absolute Makefile:1040: recipe for target 'vmlinux' failed This is not a functional change for ld.bfd which converts the term to an absolute symbol anyways as specified above. Based on a previous submission by Tri Vo . Reported-by: Dmitry Golovin Signed-off-by: Rafael Ávila de Espíndola [ Update commit message per Boris' and Michael's suggestions. ] Signed-off-by: Nick Desaulniers [ Massage commit message more, fix typos. ] Signed-off-by: Borislav Petkov Tested-by: Dmitry Golovin Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Brijesh Singh Cc: Cao Jin Cc: Ingo Molnar Cc: Joerg Roedel Cc: Masahiro Yamada Cc: Masami Hiramatsu Cc: Thomas Gleixner Cc: Tri Vo Cc: dima@golovin.in Cc: morbo@google.com Cc: x86-ml Link: https://lkml.kernel.org/r/20181219190145.252035-1-ndesaulniers@google.com Signed-off-by: Sasha Levin --- arch/x86/kernel/vmlinux.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 5dd3317d761f..c63bab98780c 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -411,7 +411,7 @@ SECTIONS * Per-cpu symbols which need to be offset from __per_cpu_load * for the boot processor. */ -#define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load +#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load INIT_PER_CPU(gdt_page); INIT_PER_CPU(irq_stack_union); -- 2.19.1