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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 87A7BC4363D for ; Sun, 4 Oct 2020 03:26:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DD2F206A2 for ; Sun, 4 Oct 2020 03:26:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726617AbgJDD0H (ORCPT ); Sat, 3 Oct 2020 23:26:07 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:35082 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726226AbgJDD0E (ORCPT ); Sat, 3 Oct 2020 23:26:04 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 602EC29B004 From: Gabriel Krisman Bertazi To: luto@kernel.org, tglx@linutronix.de Cc: hch@lst.de, hpa@zytor.com, bp@alien8.de, rric@kernel.org, peterz@infradead.org, mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org, dave.hansen@linux.intel.com, sean.j.christopherson@intel.com, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH v3 05/10] elf: Expose ELF header in compat_start_thread Date: Sat, 3 Oct 2020 23:25:31 -0400 Message-Id: <20201004032536.1229030-6-krisman@collabora.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201004032536.1229030-1-krisman@collabora.com> References: <20201004032536.1229030-1-krisman@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Like it is done for SET_PERSONALITY with x86, which requires the ELF header to select correct personality parameters, x86 requires the headers on compat_start_thread to choose starting CS for ELF32 binaries, instead of relying on the going-away TIF_IA32/X32 flags. This patch adds an indirection macro to ELF invocations of START_THREAD, that x86 can reimplement to receive the extra parameter just for ELF files. This requires no changes to other architectures who don't need the header information, they can continue to use the original start_thread for ELF and non-ELF binaries, and it prevents affecting non-ELF code paths for x86. Signed-off-by: Gabriel Krisman Bertazi --- fs/binfmt_elf.c | 2 +- fs/compat_binfmt_elf.c | 9 +++++++-- include/linux/elf.h | 5 +++++ 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 13d053982dd7..7fec77a38b8d 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1279,7 +1279,7 @@ static int load_elf_binary(struct linux_binprm *bprm) #endif finalize_exec(bprm); - start_thread(regs, elf_entry, bprm->p); + START_THREAD(elf_ex, regs, elf_entry, bprm->p); retval = 0; out: return retval; diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index 2d24c765cbd7..12b991368f0a 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -106,8 +106,13 @@ #endif #ifdef compat_start_thread -#undef start_thread -#define start_thread compat_start_thread +#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \ + compat_start_thread(regs, new_ip, new_sp) +#endif + +#ifdef COMPAT_START_THREAD +#undef START_THREAD +#define START_THREAD COMPAT_START_THREAD #endif #ifdef compat_arch_setup_additional_pages diff --git a/include/linux/elf.h b/include/linux/elf.h index 5d5b0321da0b..6dbcfe7a3fd7 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -22,6 +22,11 @@ SET_PERSONALITY(ex) #endif +#ifndef START_THREAD +#define START_THREAD(elf_ex, regs, elf_entry, start_stack) \ + start_thread(regs, elf_entry, start_stack) +#endif + #define ELF32_GNU_PROPERTY_ALIGN 4 #define ELF64_GNU_PROPERTY_ALIGN 8 -- 2.28.0