From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753675AbdHVTTu (ORCPT ); Tue, 22 Aug 2017 15:19:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44670 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414AbdHVTOy (ORCPT ); Tue, 22 Aug 2017 15:14:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleg Nesterov , Thomas Gleixner , Dmitry Safonov , Andy Lutomirski , Andrew Morton , Borislav Petkov , Linus Torvalds , "Kirill A. Shutemov" Subject: [PATCH 4.12 31/41] x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks Date: Tue, 22 Aug 2017 12:13:59 -0700 Message-Id: <20170822190943.178983577@linuxfoundation.org> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170822190941.918296529@linuxfoundation.org> References: <20170822190941.918296529@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 01578e36163cdd0e4fd61d9976de15f13364e26d upstream. The ADDR_NO_RANDOMIZE checks in stack_maxrandom_size() and randomize_stack_top() are not required. 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 Signed-off-by: Thomas Gleixner Reviewed-by: Dmitry Safonov Cc: Andy Lutomirski Cc: Andrew Morton Cc: Borislav Petkov Cc: Linus Torvalds Cc: "Kirill A. Shutemov" Link: http://lkml.kernel.org/r/20170815154011.GB1076@redhat.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/mmap.c | 3 +-- fs/binfmt_elf.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) --- 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; } --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -666,8 +666,7 @@ static unsigned long randomize_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;