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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BA0EC04A68 for ; Wed, 27 Jul 2022 17:25:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233942AbiG0RZJ (ORCPT ); Wed, 27 Jul 2022 13:25:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237123AbiG0RYA (ORCPT ); Wed, 27 Jul 2022 13:24:00 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2049D7B1E6; Wed, 27 Jul 2022 09:46:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DB47E60DDB; Wed, 27 Jul 2022 16:46:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E884FC433D6; Wed, 27 Jul 2022 16:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940361; bh=gvB9qFkp5oTwRe9KAeYPBcwDLw972dcraVKHBnGj8A8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UwdtsLiQoct0rlXj4k2A/OUHMDlnMeLYzm4ghbKvgwBe2DmmrMbTPsUEE1DpsF9EB ny7EB7wAGTbegE31y9rwqzQGqSinXtAkLy1UroWg6f0JaVLeni7Q9L8amKE7BaMbUU r76isaXs/4UXtc37uKE0ioGrWL7ONbVaVVKXdCBM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bernardo Meurer Costa , Nick Desaulniers , "Peter Zijlstra (Intel)" , Nathan Chancellor Subject: [PATCH 5.15 197/201] x86/extable: Prefer local labels in .set directives Date: Wed, 27 Jul 2022 18:11:41 +0200 Message-Id: <20220727161035.940264257@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nick Desaulniers commit 334865b2915c33080624e0d06f1c3e917036472c upstream. Bernardo reported an error that Nathan bisected down to (x86_64) defconfig+LTO_CLANG_FULL+X86_PMEM_LEGACY. LTO vmlinux.o ld.lld: error: :1:13: redefinition of 'found' .set found, 0 ^ :29:1: while in macro instantiation extable_type_reg reg=%eax, type=(17 | ((0) << 16)) ^ This appears to be another LTO specific issue similar to what was folded into commit 4b5305decc84 ("x86/extable: Extend extable functionality"), where the `.set found, 0` in DEFINE_EXTABLE_TYPE_REG in arch/x86/include/asm/asm.h conflicts with the symbol for the static function `found` in arch/x86/kernel/pmem.c. Assembler .set directive declare symbols with global visibility, so the assembler may not rename such symbols in the event of a conflict. LTO could rename static functions if there was a conflict in C sources, but it cannot see into symbols defined in inline asm. The symbols are also retained in the symbol table, regardless of LTO. Give the symbols .L prefixes making them locally visible, so that they may be renamed for LTO to avoid conflicts, and to drop them from the symbol table regardless of LTO. Fixes: 4b5305decc84 ("x86/extable: Extend extable functionality") Reported-by: Bernardo Meurer Costa Debugged-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Link: https://lore.kernel.org/r/20220329202148.2379697-1-ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/asm.h | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -149,24 +149,24 @@ # define DEFINE_EXTABLE_TYPE_REG \ ".macro extable_type_reg type:req reg:req\n" \ - ".set found, 0\n" \ - ".set regnr, 0\n" \ + ".set .Lfound, 0\n" \ + ".set .Lregnr, 0\n" \ ".irp rs,rax,rcx,rdx,rbx,rsp,rbp,rsi,rdi,r8,r9,r10,r11,r12,r13,r14,r15\n" \ ".ifc \\reg, %%\\rs\n" \ - ".set found, found+1\n" \ - ".long \\type + (regnr << 8)\n" \ + ".set .Lfound, .Lfound+1\n" \ + ".long \\type + (.Lregnr << 8)\n" \ ".endif\n" \ - ".set regnr, regnr+1\n" \ + ".set .Lregnr, .Lregnr+1\n" \ ".endr\n" \ - ".set regnr, 0\n" \ + ".set .Lregnr, 0\n" \ ".irp rs,eax,ecx,edx,ebx,esp,ebp,esi,edi,r8d,r9d,r10d,r11d,r12d,r13d,r14d,r15d\n" \ ".ifc \\reg, %%\\rs\n" \ - ".set found, found+1\n" \ - ".long \\type + (regnr << 8)\n" \ + ".set .Lfound, .Lfound+1\n" \ + ".long \\type + (.Lregnr << 8)\n" \ ".endif\n" \ - ".set regnr, regnr+1\n" \ + ".set .Lregnr, .Lregnr+1\n" \ ".endr\n" \ - ".if (found != 1)\n" \ + ".if (.Lfound != 1)\n" \ ".error \"extable_type_reg: bad register argument\"\n" \ ".endif\n" \ ".endm\n"