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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 E0892C433E0 for ; Mon, 29 Jun 2020 20:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3304206A1 for ; Mon, 29 Jun 2020 20:33:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593462827; bh=Ie/PtohFDNOi+umCC4vojT6M6OKKj7WlFys5FF3v0E8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=S3rAvf9FFO6OXyyD9Nuf2fy0EFYGymFw3Suc9BCrIoYQ8Hx4Mc8S0csQYWsQuUraY nZ12mkY6vhqz8zituv4MV3JCEZqTFwOLBg87SQqH2nmTGsdAefS5Au68sLRqQ9Uboh BNZ31LiHHObEuLXEcXxbw0Ufrx7bVqfSXmBn7eCY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388691AbgF2Udq (ORCPT ); Mon, 29 Jun 2020 16:33:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:37026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732295AbgF2TZR (ORCPT ); Mon, 29 Jun 2020 15:25:17 -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 963D3253E5; Mon, 29 Jun 2020 15:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593445320; bh=Ie/PtohFDNOi+umCC4vojT6M6OKKj7WlFys5FF3v0E8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0MfZixJu41l4cCvuNk4WPGUDqOgHVYQdmGW4rk6YxpwGMMS00erN0ReWvFBc9/g44 VCODbiCfDPcoQ3DKJTv/C9SxaH+8pc8qd6sJ1KHaX8v6+9XG0/5H8ovEp0oZzz1pAB 8geoDKLu4Ctl19LWxj5HIo2xfq+jKBxTsEZ+1He4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ard Biesheuvel , Ingo Molnar , Nathan Chancellor , Sasha Levin Subject: [PATCH 4.9 087/191] x86/boot/compressed: Relax sed symbol type regex for LLVM ld.lld Date: Mon, 29 Jun 2020 11:38:23 -0400 Message-Id: <20200629154007.2495120-88-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629154007.2495120-1-sashal@kernel.org> References: <20200629154007.2495120-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:39+00:00 X-stable: review 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: Ard Biesheuvel commit bc310baf2ba381c648983c7f4748327f17324562 upstream. The final build stage of the x86 kernel captures some symbol addresses from the decompressor binary and copies them into zoffset.h. It uses sed with a regular expression that matches the address, symbol type and symbol name, and mangles the captured addresses and the names of symbols of interest into #define directives that are added to zoffset.h The symbol type is indicated by a single letter, which we match strictly: only letters in the set 'ABCDGRSTVW' are matched, even though the actual symbol type is relevant and therefore ignored. Commit bc7c9d620 ("efi/libstub/x86: Force 'hidden' visibility for extern declarations") made a change to the way external symbol references are classified, resulting in 'startup_32' now being emitted as a hidden symbol. This prevents the use of GOT entries to refer to this symbol via its absolute address, which recent toolchains (including Clang based ones) already avoid by default, making this change a no-op in the majority of cases. However, as it turns out, the LLVM linker classifies such hidden symbols as symbols with static linkage in fully linked ELF binaries, causing tools such as NM to output a lowercase 't' rather than an upper case 'T' for the type of such symbols. Since our sed expression only matches upper case letters for the symbol type, the line describing startup_32 is disregarded, resulting in a build error like the following arch/x86/boot/header.S:568:18: error: symbol 'ZO_startup_32' can not be undefined in a subtraction expression init_size: .long (0x00000000008fd000 - ZO_startup_32 + (((0x0000000001f6361c + ((0x0000000001f6361c >> 8) + 65536) - 0x00000000008c32e5) + 4095) & ~4095)) # kernel initialization size Given that we are only interested in the value of the symbol, let's match any character in the set 'a-zA-Z' instead. Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Tested-by: Nathan Chancellor Signed-off-by: Nathan Chancellor Signed-off-by: Sasha Levin --- arch/x86/boot/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 3b16935b22bcc..d1df7d2e31b1e 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -87,7 +87,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE SETUP_OBJS = $(addprefix $(obj)/,$(setup-y)) -sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p' +sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p' quiet_cmd_zoffset = ZOFFSET $@ cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@ -- 2.25.1