From patchwork Mon Mar 14 19:48:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 12780701 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 CBBDBC433F5 for ; Mon, 14 Mar 2022 19:50:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244649AbiCNTv6 (ORCPT ); Mon, 14 Mar 2022 15:51:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244628AbiCNTvx (ORCPT ); Mon, 14 Mar 2022 15:51:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D922C3EF01; Mon, 14 Mar 2022 12:50:25 -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 ams.source.kernel.org (Postfix) with ESMTPS id 0E17BB80F96; Mon, 14 Mar 2022 19:50:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AF52C340EE; Mon, 14 Mar 2022 19:50:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647287421; bh=pyw+uUsWl3RVdP8v6qowJOWyQJdm2VaPP/Bj2TK1ByM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V35xPzC0SANL4OOpntptnxwfH3nLIYI5VEaA9BrwfwAu8bvPOHyAqVUw21vYwVrAk BE5/t7c15HReRasVusQQv81fElEBG3vFWSvir6e8NJI0FHrAmInGhKkxkr64Ge2tSt 3Y5mzD6EWbBR2HGUd2PvFkmH64XSZ6Ije2djTBcdzpvhRp/Y+bGCgBRz4Q0WVx9TqW O4H6xttVahB95D7TRtPhoEdwKcjVctFHjWNYaQazpf9nZQlppkShxTpdFuo2PA2xNb FmQWRJtWbFVp4Pz8M8/ZiWhPityGzRb61SWCJO6KTXLpHDReAXGSpmLEadGt/jWb01 VkyTxadUGALpQ== From: Nathan Chancellor To: Peter Zijlstra , x86@kernel.org Cc: Andy Lutomirski , "H. Peter Anvin" , Nick Desaulniers , Masahiro Yamada , linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, llvm@lists.linux.dev, Nathan Chancellor Subject: [PATCH 2/2] x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy Date: Mon, 14 Mar 2022 12:48:42 -0700 Message-Id: <20220314194842.3452-3-nathan@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220314194842.3452-1-nathan@kernel.org> References: <20220314194842.3452-1-nathan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org There are two outstanding issues with CONFIG_X86_X32_ABI and llvm-objcopy, with similar root causes: 1. llvm-objcopy does not properly convert .note.gnu.property when going from x86_64 to x86_x32, resulting in a corrupted section when linking: https://github.com/ClangBuiltLinux/linux/issues/1141 2. llvm-objcopy produces corrupted compressed debug sections when going from x86_64 to x86_x32, also resulting in an error when linking: https://github.com/ClangBuiltLinux/linux/issues/514 After commit 41c5ef31ad71 ("x86/ibt: Base IBT bits"), the .note.gnu.property section is always generated when CONFIG_X86_KERNEL_IBT is enabled, which causes the first issue to become visible with an allmodconfig build: ld.lld: error: arch/x86/entry/vdso/vclock_gettime-x32.o:(.note.gnu.property+0x1c): program property is too short To avoid this error, do not allow CONFIG_X86_X32_ABI to be selected when using llvm-objcopy. If the two issues ever get fixed in llvm-objcopy, this can be turned into a feature check. Signed-off-by: Nathan Chancellor --- arch/x86/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b903bfcd713c..0f0672d2c816 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2864,6 +2864,11 @@ config IA32_AOUT config X86_X32_ABI bool "x32 ABI for 64-bit mode" depends on X86_64 + # llvm-objcopy does not convert x86_64 .note.gnu.property or + # compressed debug sections to x86_x32 properly: + # https://github.com/ClangBuiltLinux/linux/issues/514 + # https://github.com/ClangBuiltLinux/linux/issues/1141 + depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) help Include code to run binaries for the x32 native 32-bit ABI for 64-bit processors. An x32 process gets access to the