From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753078AbdHOPkQ (ORCPT ); Tue, 15 Aug 2017 11:40:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56384 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752810AbdHOPkO (ORCPT ); Tue, 15 Aug 2017 11:40:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A32C278742 Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=oleg@redhat.com Date: Tue, 15 Aug 2017 17:40:11 +0200 From: Oleg Nesterov To: Andrew Morton Cc: Andy Lutomirski , Borislav Petkov , Dmitry Safonov , "H. Peter Anvin" , Ingo Molnar , "Kirill A. Shutemov" , Linus Torvalds , Thomas Gleixner , linux-kernel@vger.kernel.org, x86@kernel.org, stable@vger.kernel.org Subject: [PATCH v2 2/2] x86/elf: remove the unnecessary ADDR_NO_RANDOMIZE checks in stack_maxrandom_size() and randomize_stack_top() Message-ID: <20170815154011.GB1076@redhat.com> References: <20170815153932.GA1073@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170815153932.GA1073@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 15 Aug 2017 15:40:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org PF_RANDOMIZE is set by load_elf_binary() only if ADDR_NO_RANDOMIZE is not set, no need to re-check after that. Signed-off-by: Oleg Nesterov Reviewed-by: Dmitry Safonov --- arch/x86/mm/mmap.c | 3 +-- fs/binfmt_elf.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index c94df12..a88cfbf 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -50,8 +50,7 @@ unsigned long tasksize_64bit(void) static unsigned long stack_maxrandom_size(unsigned long task_size) { unsigned long max = 0; - if ((current->flags & PF_RANDOMIZE) && - !(current->personality & ADDR_NO_RANDOMIZE)) { + if (current->flags & PF_RANDOMIZE) { max = (-1UL) & __STACK_RND_MASK(task_size == tasksize_32bit()); max <<= PAGE_SHIFT; } diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 879ff9c..6466153 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -664,8 +664,7 @@ static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned long random_variable = 0; - if ((current->flags & PF_RANDOMIZE) && - !(current->personality & ADDR_NO_RANDOMIZE)) { + if (current->flags & PF_RANDOMIZE) { random_variable = get_random_long(); random_variable &= STACK_RND_MASK; random_variable <<= PAGE_SHIFT; -- 2.5.0