From patchwork Wed Mar 4 02:10:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 5928101 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 73C189F36A for ; Wed, 4 Mar 2015 02:15:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A6367203E6 for ; Wed, 4 Mar 2015 02:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9820203DB for ; Wed, 4 Mar 2015 02:15:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758093AbbCDCOh (ORCPT ); Tue, 3 Mar 2015 21:14:37 -0500 Received: from smtp.outflux.net ([198.145.64.163]:33280 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756437AbbCDCMq (ORCPT ); Tue, 3 Mar 2015 21:12:46 -0500 Received: from www.outflux.net (serenity.outflux.net [10.2.0.2]) by vinyl.outflux.net (8.14.4/8.14.4/Debian-4.1ubuntu1) with ESMTP id t242AbUV002306; Tue, 3 Mar 2015 18:10:37 -0800 From: Kees Cook To: akpm@linux-foundation.org Cc: Kees Cook , linux-kernel@vger.kernel.org, Hector Marco-Gisbert , Ismael Ripoll , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, x86@kernel.org, Alexander Viro , Oleg Nesterov , Andy Lutomirski , "David A. Long" , Andrey Ryabinin , Arun Chandran , Min-Hua Chen , Dan McGee , Yann Droneaud , Paul Burton , Alex Smith , Markos Chandras , Vineeth Vijayan , Jeff Bailey , Michael Holzheu , Ben Hutchings , Behan Webster , =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= , linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 08/10] s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE Date: Tue, 3 Mar 2015 18:10:23 -0800 Message-Id: <1425435025-30284-9-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1425435025-30284-1-git-send-email-keescook@chromium.org> References: <1425435025-30284-1-git-send-email-keescook@chromium.org> X-MIMEDefang-Filter: outflux$Revision: 1.316 $ X-HELO: www.outflux.net X-Scanned-By: MIMEDefang 2.73 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In preparation for moving ET_DYN randomization into the ELF loader (which requires a static ELF_ET_DYN_BASE), this redefines s390's existing ET_DYN randomization in a call to arch_mmap_rnd(). This refactoring results in the same ET_DYN randomization on s390. Signed-off-by: Kees Cook --- arch/s390/include/asm/elf.h | 8 +++++--- arch/s390/mm/mmap.c | 11 ++--------- 2 files changed, 7 insertions(+), 12 deletions(-) diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index c9df40b5c0ac..2e63de8aac7c 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -161,10 +161,12 @@ extern unsigned int vdso_enabled; /* This is the location that an ET_DYN program is loaded if exec'ed. Typical use of this is to invoke "./ld.so someprog" to test out a new version of the loader. We need to make sure that it is out of the way of the program - that it will "exec", and that there is sufficient room for the brk. */ - + that it will "exec", and that there is sufficient room for the brk. 64-bit + tasks are aligned to 4GB. */ extern unsigned long randomize_et_dyn(void); -#define ELF_ET_DYN_BASE randomize_et_dyn() +#define ELF_ET_DYN_BASE (randomize_et_dyn() + (is_32bit_task() ? \ + (STACK_TOP / 3 * 2) : \ + (STACK_TOP / 3 * 2) & ~((1UL << 32) - 1))) /* This yields a mask that user programs can use to figure out what instruction set this CPU supports. */ diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index a94504d99c47..8c11536f972d 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -179,17 +179,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, unsigned long randomize_et_dyn(void) { - unsigned long base; - - base = STACK_TOP / 3 * 2; - if (!is_32bit_task()) - /* Align to 4GB */ - base &= ~((1UL << 32) - 1); - if (current->flags & PF_RANDOMIZE) - base += arch_mmap_rnd(); + return arch_mmap_rnd(); - return base; + return 0UL; } #ifndef CONFIG_64BIT