From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.outflux.net (smtp.outflux.net [IPv6:2001:19d0:2:6:c0de:0:736d:7470]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id E61F01A0058 for ; Fri, 27 Feb 2015 14:14:46 +1100 (AEDT) From: Kees Cook To: akpm@linux-foundation.org Subject: [PATCH 1/5] arm: factor out mmap ASLR into mmap_rnd Date: Thu, 26 Feb 2015 19:07:10 -0800 Message-Id: <1425006434-3106-2-git-send-email-keescook@chromium.org> In-Reply-To: <1425006434-3106-1-git-send-email-keescook@chromium.org> References: <1425006434-3106-1-git-send-email-keescook@chromium.org> Cc: linux-mips@linux-mips.org, Arun Chandran , Catalin Marinas , Heiko Carstens , linux-kernel@vger.kernel.org, Min-Hua Chen , Paul Mackerras , Ismael Ripoll , Yann Droneaud , linux-s390@vger.kernel.org, Russell King , Andrey Ryabinin , Behan Webster , x86@kernel.org, Hector Marco-Gisbert , "David A. Long" , Ben Hutchings , Kees Cook , Will Deacon , linux-fsdevel@vger.kernel.org, Alex Smith , Michael Holzheu , linux-arm-kernel@lists.infradead.org, Jeff Bailey , Paul Burton , Oleg Nesterov , Ralf Baechle , Andy Lutomirski , Vineeth Vijayan , Markos Chandras , =?UTF-8?q?Jan-Simon=20M=C3=B6ller?= , Martin Schwidefsky , linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org, Alexander Viro List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Move logic for mmap ASLR into separate function. Signed-off-by: Kees Cook --- arch/arm/mm/mmap.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 5e85ed371364..0f8bc158f2c6 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -169,14 +169,21 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -void arch_pick_mmap_layout(struct mm_struct *mm) +static unsigned long mmap_rnd(void) { - unsigned long random_factor = 0UL; + unsigned long rnd = 0UL; /* 8 bits of randomness in 20 address space bits */ if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) - random_factor = (get_random_int() % (1 << 8)) << PAGE_SHIFT; + rnd = (get_random_int() % (1 << 8)) << PAGE_SHIFT; + + return rnd; +} + +void arch_pick_mmap_layout(struct mm_struct *mm) +{ + unsigned long random_factor = mmap_rnd(); if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; -- 1.9.1