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,HEADER_FROM_DIFFERENT_DOMAINS,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 C1655C282C5 for ; Thu, 24 Jan 2019 19:49:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9111B20663 for ; Thu, 24 Jan 2019 19:49:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548359357; bh=2ZsPHUaXym3MPjXKtlaQnhUw8BdmQ76Kiis1P+OCEnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0VDlOJ2LpkWLoGSDMN7Jt8N4t/MZ48gPgfC0gmlU0E/Tpq+2GdCN1P5a0eNb7pg2R fJq5qZkWHsvujQEM+sHuHgWPZA8SXp5h9KFYScOlQnSuVhfoT9NylZ8cu6ECfNuWED TFVNUutipJ9CA3T5NDs7eOU7Xgz332bpfzyWDkH0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732554AbfAXTtQ (ORCPT ); Thu, 24 Jan 2019 14:49:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:41598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732866AbfAXTlT (ORCPT ); Thu, 24 Jan 2019 14:41:19 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 6EE8120663; Thu, 24 Jan 2019 19:41:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358877; bh=2ZsPHUaXym3MPjXKtlaQnhUw8BdmQ76Kiis1P+OCEnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2SyJgUDcwhgBQkTE+5YvbUzdGgci6/v226v+hBz98OMmZ2kWNEZCjWeHAZ8iSoStH 2W1kazzkC/cADVX2WyuSGaR2CNt4+kEk5QZigpyv7NyT5IyYqu42xsOvIyTczy0MR4 ifXA9yaY96uQUCMRnPck7kqmWCEMBdPJcHvw+bO8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nick Desaulniers , Peter Smith , Ard Biesheuvel , Will Deacon , Sasha Levin Subject: [PATCH 4.20 058/127] arm64: relocatable: fix inconsistencies in linker script and options Date: Thu, 24 Jan 2019 20:20:04 +0100 Message-Id: <20190124190214.648699474@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124190211.984305387@linuxfoundation.org> References: <20190124190211.984305387@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 3bbd3db86470c701091fb1d67f1fab6621debf50 ] readelf complains about the section layout of vmlinux when building with CONFIG_RELOCATABLE=y (for KASLR): readelf: Warning: [21]: Link field (0) should index a symtab section. readelf: Warning: [21]: Info field (0) should index a relocatable section. Also, it seems that our use of '-pie -shared' is contradictory, and thus ambiguous. In general, the way KASLR is wired up at the moment is highly tailored to how ld.bfd happens to implement (and conflate) PIE executables and shared libraries, so given the current effort to support other toolchains, let's fix some of these issues as well. - Drop the -pie linker argument and just leave -shared. In ld.bfd, the differences between them are unclear (except for the ELF type of the produced image [0]) but lld chokes on seeing both at the same time. - Rename the .rela output section to .rela.dyn, as is customary for shared libraries and PIE executables, so that it is not misidentified by readelf as a static relocation section (producing the warnings above). - Pass the -z notext and -z norelro options to explicitly instruct the linker to permit text relocations, and to omit the RELRO program header (which requires a certain section layout that we don't adhere to in the kernel). These are the defaults for current versions of ld.bfd. - Discard .eh_frame and .gnu.hash sections to avoid them from being emitted between .head.text and .text, screwing up the section layout. These changes only affect the ELF image, and produce the same binary image. [0] b9dce7f1ba01 ("arm64: kernel: force ET_DYN ELF type for ...") Cc: Nick Desaulniers Cc: Peter Smith Tested-by: Nick Desaulniers Signed-off-by: Ard Biesheuvel Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/Makefile | 2 +- arch/arm64/kernel/vmlinux.lds.S | 9 +++++---- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 6cb9fc7e9382..8978f60779c4 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -18,7 +18,7 @@ ifeq ($(CONFIG_RELOCATABLE), y) # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour # for relative relocs, since this leads to better Image compression # with the relocation offsets always being zero. -LDFLAGS_vmlinux += -pie -shared -Bsymbolic \ +LDFLAGS_vmlinux += -shared -Bsymbolic -z notext -z norelro \ $(call ld-option, --no-apply-dynamic-relocs) endif diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 03b00007553d..7fa008374907 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -99,7 +99,8 @@ SECTIONS *(.discard) *(.discard.*) *(.interp .dynamic) - *(.dynsym .dynstr .hash) + *(.dynsym .dynstr .hash .gnu.hash) + *(.eh_frame) } . = KIMAGE_VADDR + TEXT_OFFSET; @@ -192,12 +193,12 @@ SECTIONS PERCPU_SECTION(L1_CACHE_BYTES) - .rela : ALIGN(8) { + .rela.dyn : ALIGN(8) { *(.rela .rela*) } - __rela_offset = ABSOLUTE(ADDR(.rela) - KIMAGE_VADDR); - __rela_size = SIZEOF(.rela); + __rela_offset = ABSOLUTE(ADDR(.rela.dyn) - KIMAGE_VADDR); + __rela_size = SIZEOF(.rela.dyn); . = ALIGN(SEGMENT_ALIGN); __initdata_end = .; -- 2.19.1