From nobody Mon Jun 15 18:33:10 2026 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 E490CC433EF for ; Mon, 25 Apr 2022 15:18:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234807AbiDYPVs (ORCPT ); Mon, 25 Apr 2022 11:21:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230471AbiDYPVq (ORCPT ); Mon, 25 Apr 2022 11:21:46 -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 AC3D6B6E4B for ; Mon, 25 Apr 2022 08:18:38 -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 5225B60E06 for ; Mon, 25 Apr 2022 15:18:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B7E6C385A7; Mon, 25 Apr 2022 15:18:35 +0000 (UTC) From: Catalin Marinas To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jonathan Corbet , Eric Biederman , Kees Cook , Luis Machado , Richard Earnshaw Subject: [PATCH] elf: Fix the arm64 MTE ELF segment name and value Date: Mon, 25 Apr 2022 16:18:33 +0100 Message-Id: <20220425151833.2603830-1-catalin.marinas@arm.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Unfortunately, the name/value choice for the MTE ELF segment type (PT_ARM_MEMTAG_MTE) was pretty poor: LOPROC+1 is already in use by PT_AARCH64_UNWIND, as defined in the AArch64 ELF ABI (https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst). Update the ELF segment type value to LOPROC+2 and also change the define to PT_AARCH64_MEMTAG_MTE to match the AArch64 ELF ABI namespace. The AArch64 ELF ABI document is updating accordingly (segment type not previously mentioned in the document). Signed-off-by: Catalin Marinas Fixes: 761b9b366cec ("elf: Introduce the ARM MTE ELF segment type") Cc: Will Deacon Cc: Jonathan Corbet Cc: Eric Biederman Cc: Kees Cook Cc: Luis Machado Cc: Richard Earnshaw Reviewed-by: Kees Cook --- Luckily, the commit being fixed here only went in for 5.18-rc1, so there is= no ABI change in a mainline release. FYI, the corresponding pull request for the AArch64 ELF ABI: https://github.com/ARM-software/abi-aa/pull/148 I don't expect any further change to the segment name/value. Documentation/arm64/memory-tagging-extension.rst | 4 ++-- arch/arm64/kernel/elfcore.c | 2 +- include/uapi/linux/elf.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/Documentation/arm64/memory-tagging-extension.rst b/Documentati= on/arm64/memory-tagging-extension.rst index dd27f78d7608..dbae47bba25e 100644 --- a/Documentation/arm64/memory-tagging-extension.rst +++ b/Documentation/arm64/memory-tagging-extension.rst @@ -228,10 +228,10 @@ Core dump support ----------------- =20 The allocation tags for user memory mapped with ``PROT_MTE`` are dumped -in the core file as additional ``PT_ARM_MEMTAG_MTE`` segments. The +in the core file as additional ``PT_AARCH64_MEMTAG_MTE`` segments. The program header for such segment is defined as: =20 -:``p_type``: ``PT_ARM_MEMTAG_MTE`` +:``p_type``: ``PT_AARCH64_MEMTAG_MTE`` :``p_flags``: 0 :``p_offset``: segment file offset :``p_vaddr``: segment virtual address, same as the corresponding diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c index 2b3f3d0544b9..98d67444a5b6 100644 --- a/arch/arm64/kernel/elfcore.c +++ b/arch/arm64/kernel/elfcore.c @@ -95,7 +95,7 @@ int elf_core_write_extra_phdrs(struct coredump_params *cp= rm, loff_t offset) for_each_mte_vma(current, vma) { struct elf_phdr phdr; =20 - phdr.p_type =3D PT_ARM_MEMTAG_MTE; + phdr.p_type =3D PT_AARCH64_MEMTAG_MTE; phdr.p_offset =3D offset; phdr.p_vaddr =3D vma->vm_start; phdr.p_paddr =3D 0; diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 787c657bfae8..7ce993e6786c 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -42,7 +42,7 @@ typedef __s64 Elf64_Sxword; =20 =20 /* ARM MTE memory tag segment type */ -#define PT_ARM_MEMTAG_MTE (PT_LOPROC + 0x1) +#define PT_AARCH64_MEMTAG_MTE (PT_LOPROC + 0x2) =20 /* * Extended Numbering