From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 22 May 2002 10:13:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 22 May 2002 10:13:05 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:62474 "EHLO atrey.karlin.mff.cuni.cz") by vger.kernel.org with ESMTP id ; Wed, 22 May 2002 10:13:04 -0400 Date: Wed, 22 May 2002 16:13:06 +0200 From: Pavel Machek To: Alan Cox Cc: Linus Torvalds , Andrew Morton , Rusty Russell , linux-kernel@vger.kernel.org Subject: Re: AUDIT: copy_from_user is a deathtrap. Message-ID: <20020522141306.GB29028@atrey.karlin.mff.cuni.cz> In-Reply-To: <20020521222139.GJ22878@atrey.karlin.mff.cuni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.27i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > I believe I seen some strange memcpy for PPro (or something that > > obscure) that done out-of-order accesses to trigger prefetch logic. I > > can't find it any more, so I can't be sure... > > Its festering quietly in the glibc source tree where all large and > dubiously justifiable hacks seem to end up In such case, linus, here is your "reasonable" example. For PPro, it is faster to copy out-of-order, and if we wanted to use that for copy_to_user, you'd have your example. Pavel -- Casualities in World Trade Center: ~3k dead inside the building, cryptography in U.S.A. and free speech in Czech Republic.