From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751209AbWGPVMo (ORCPT ); Sun, 16 Jul 2006 17:12:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751210AbWGPVMo (ORCPT ); Sun, 16 Jul 2006 17:12:44 -0400 Received: from mx1.suse.de ([195.135.220.2]:11195 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751209AbWGPVMn (ORCPT ); Sun, 16 Jul 2006 17:12:43 -0400 From: Andi Kleen To: Ingo Molnar Subject: Re: [PATCH for 2.6.18-rc2] [2/8] i386/x86-64: Don't randomize stack top when no randomization personality is set Date: Sun, 16 Jul 2006 23:14:07 +0200 User-Agent: KMail/1.9.1 Cc: torvalds@osdl.org, akpm@osdl.org, discuss@x86-64.org, linux-kernel@vger.kernel.org, Chuck Ebbert <76306.1226@compuserve.com> References: <44ba2f8d.0hsur33TTkK+bbJl%ak@suse.de> <20060716204712.GA29161@elte.hu> In-Reply-To: <20060716204712.GA29161@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200607162314.07764.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 16 July 2006 22:47, Ingo Molnar wrote: > * Andi Kleen wrote: > > unsigned long arch_align_stack(unsigned long sp) > > { > > - if (randomize_va_space) > > + if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) > > sp -= get_random_int() % 8192; > > return sp & ~0xf; > > i'm not opposing this patch at all, but didnt the performance problems > go away when the 0xf was changed to 0x7f? Yes, but i sent the patch before that other patch was available. I guess it's a separate issue anyways - this patch is just concerned about disabling randomization consistently. Performance optimization can be done in another one. -Andi