From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752250AbbC2Jz3 (ORCPT ); Sun, 29 Mar 2015 05:55:29 -0400 Received: from mail.skyhub.de ([78.46.96.112]:39147 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbbC2Jz1 (ORCPT ); Sun, 29 Mar 2015 05:55:27 -0400 Date: Sun, 29 Mar 2015 11:53:34 +0200 From: Borislav Petkov To: Ingo Molnar Cc: Hector Marco-Gisbert , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Alexander Viro , Jan-Simon , linux-fsdevel@vger.kernel.org, kees Cook , Ismael Ripoll Subject: Re: [PATCH] mm/x86: AMD Bulldozer ASLR fix Message-ID: <20150329095334.GA4973@pd.tnic> References: <20150326190800.GF27751@pd.tnic> <1427456301-3764-1-git-send-email-hecmargi@upv.es> <20150327144438.GA3254@pd.tnic> <20150329085122.GA25177@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150329085122.GA25177@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 29, 2015 at 10:51:22AM +0200, Ingo Molnar wrote: > s/reduces the mmapped file's entropy by 3 bits > > Which does: > > - a grammar fix > > - measure it in bits, as later on we are talking about randomness in > bits as well. Fixed. > Btw., does this limitation affect both executable and non-executable > mmap()s? Only executable mappings. > Because data mmap()s don't need this I$ related workaround, right? So > we could relax it for data-mmap()s? Well, AFAIR, we wanted to keep this as less intrusive as possble. If we're going to relax this, one way to solve it would be to pass down @prot from do_mmap_pgoff() and friends to get_unmapped_area() which would need to touch other arches. I'm not sure it is worth it... -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --