From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754560AbcEJAT5 (ORCPT ); Mon, 9 May 2016 20:19:57 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57383 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753977AbcEJAFj (ORCPT ); Mon, 9 May 2016 20:05:39 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Kees Cook , Ralf Baechle , Andrew Morton , Linus Torvalds , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 07/54] mips: extract logic for mmap_rnd() Date: Mon, 9 May 2016 17:04:26 -0700 Message-Id: <1462838713-31343-8-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1462838713-31343-1-git-send-email-kamal@canonical.com> References: <1462838713-31343-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt21 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Kees Cook commit 1f0569df0b0285e7ec2432d804a4921b06a61618 upstream. In preparation for splitting out ET_DYN ASLR, extract the mmap ASLR selection into a separate function. Signed-off-by: Kees Cook Reviewed-by: Ingo Molnar Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- arch/mips/mm/mmap.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index f1baadd..9a4f1f5 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -142,18 +142,26 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, addr0, len, pgoff, flags, DOWN); } +static unsigned long mmap_rnd(void) +{ + unsigned long rnd; + + rnd = (unsigned long)get_random_int(); + rnd <<= PAGE_SHIFT; + if (TASK_IS_32BIT_ADDR) + rnd &= 0xfffffful; + else + rnd &= 0xffffffful; + + return rnd; +} + void arch_pick_mmap_layout(struct mm_struct *mm) { unsigned long random_factor = 0UL; - if (current->flags & PF_RANDOMIZE) { - random_factor = get_random_int(); - random_factor = random_factor << PAGE_SHIFT; - if (TASK_IS_32BIT_ADDR) - random_factor &= 0xfffffful; - else - random_factor &= 0xffffffful; - } + if (current->flags & PF_RANDOMIZE) + random_factor = mmap_rnd(); if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; -- 2.7.4