Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262610AbTFXSjP (ORCPT ); Tue, 24 Jun 2003 14:39:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262687AbTFXSjP (ORCPT ); Tue, 24 Jun 2003 14:39:15 -0400 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:31246 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id S262610AbTFXSjM (ORCPT ); Tue, 24 Jun 2003 14:39:12 -0400 Date: Tue, 24 Jun 2003 11:52:42 -0700 (PDT) From: Linus Torvalds To: Pavel Machek cc: kernel list , Rusty trivial patch monkey Russell Subject: Re: Provide example copy_in_user implementation In-Reply-To: <20030624102551.GE159@elf.ucw.cz> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 532 Lines: 20 On Tue, 24 Jun 2003, Pavel Machek wrote: > > ...so it should be exactly as fast. No it shouldn't. You should do the access_ok() only _once_ (well, twice: once for source and once for dest). Also, anything that copies memory one byte at a time is just asking to be shot. Linus - 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/