From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753454AbbCDWO5 (ORCPT ); Wed, 4 Mar 2015 17:14:57 -0500 Received: from smtp.outflux.net ([198.145.64.163]:58727 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752174AbbCDWOx (ORCPT ); Wed, 4 Mar 2015 17:14:53 -0500 From: Kees Cook To: akpm@linux-foundation.org Cc: Kees Cook , Ingo Molnar , Michael Ellerman , Hector Marco-Gisbert , Ismael Ripoll , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, x86@kernel.org, Alexander Viro , Andy Lutomirski , Oleg Nesterov , "David A. Long" , Andrey Ryabinin , Arun Chandran , Yann Droneaud , Min-Hua Chen , Paul Burton , Alex Smith , Markos Chandras , Vineeth Vijayan , Jeff Bailey , Michael Holzheu , Ben Hutchings , Borislav Petkov , =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= , linux-kernel@vger.kernel.org, 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 v4 08/10] s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE Date: Wed, 4 Mar 2015 13:10:52 -0800 Message-Id: <1425503454-7531-9-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1425503454-7531-1-git-send-email-keescook@chromium.org> References: <1425503454-7531-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 1.9.1