Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932359AbWBPVuZ (ORCPT ); Thu, 16 Feb 2006 16:50:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932485AbWBPVuZ (ORCPT ); Thu, 16 Feb 2006 16:50:25 -0500 Received: from zcars04f.nortel.com ([47.129.242.57]:11224 "EHLO zcars04f.nortel.com") by vger.kernel.org with ESMTP id S932362AbWBPVuY (ORCPT ); Thu, 16 Feb 2006 16:50:24 -0500 Message-ID: <43F4F397.5000704@nortel.com> Date: Thu, 16 Feb 2006 15:50:15 -0600 From: "Christopher Friesen" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040115 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Ingo Molnar CC: Daniel Walker , linux-kernel@vger.kernel.org, Ulrich Drepper , Thomas Gleixner , Arjan van de Ven , Andrew Morton Subject: Re: [patch 0/6] lightweight robust futexes: -V3 References: <20060216094130.GA29716@elte.hu> <1140107585.21681.18.camel@localhost.localdomain> <20060216172435.GC29151@elte.hu> <1140111257.21681.26.camel@localhost.localdomain> <20060216202357.GA21415@elte.hu> <20060216212651.GB25738@elte.hu> In-Reply-To: <20060216212651.GB25738@elte.hu> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 16 Feb 2006 21:50:17.0372 (UTC) FILETIME=[F984B5C0:01C63342] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 734 Lines: 17 Ingo Molnar wrote: > basically, ->futex_offset is not blindly trusted by the kernel either: > it's simply used to calculate a "userspace pointer" value, which it then > uses in a (secure) get_user() access, to do a FUTEX_WAKEUP. [Note that > FUTEX_WAKEUP is already done at do_exit() time via the ->clear_child_tid > userspace pointer.] All in one: this is totally safe. As mentioned by Paul...how do you deal with 32/64 compatibility where your pointers are different sizes? Chris - 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/