Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261174AbVA0UcZ (ORCPT ); Thu, 27 Jan 2005 15:32:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261172AbVA0UcY (ORCPT ); Thu, 27 Jan 2005 15:32:24 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:35536 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261174AbVA0UcL (ORCPT ); Thu, 27 Jan 2005 15:32:11 -0500 Date: Thu, 27 Jan 2005 20:32:06 +0000 From: Christoph Hellwig To: Arjan van de Ven Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, torvalds@osdl.org Subject: Re: Patch 4/6 randomize the stack pointer Message-ID: <20050127203206.GA2180@infradead.org> Mail-Followup-To: Christoph Hellwig , Arjan van de Ven , linux-kernel@vger.kernel.org, akpm@osdl.org, torvalds@osdl.org References: <20050127101117.GA9760@infradead.org> <20050127101322.GE9760@infradead.org> <20050127202335.GA2033@infradead.org> <20050127202720.GA12390@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050127202720.GA12390@infradead.org> User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 823 Lines: 22 > The patch below replaces the existing 8Kb randomisation of the userspace > stack pointer (which is currently only done for Hyperthreaded P-IVs) with a > more general randomisation over a 64Kb range. 64Kb is not a lot, but it's a > start and once the dust settles we can increase this value to a more > agressive value. Why are we doing this for x86 only, btw? > +unsigned long arch_align_stack(unsigned long sp) > +{ > + if (randomize_va_space) > + sp -= ((get_random_int() % 4096) << 4); > + return sp & ~0xf; > +} this looks like it'd work nicely on all architectures. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/