From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964838AbXBLKFJ (ORCPT ); Mon, 12 Feb 2007 05:05:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964828AbXBLKFJ (ORCPT ); Mon, 12 Feb 2007 05:05:09 -0500 Received: from dsl.static81213182239.ttnet.net.tr ([81.213.182.239]:15192 "EHLO bonsai.taydin.org" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S964838AbXBLKFI (ORCPT ); Mon, 12 Feb 2007 05:05:08 -0500 X-Greylist: delayed 1523 seconds by postgrey-1.27 at vger.kernel.org; Mon, 12 Feb 2007 05:05:08 EST From: Timur Aydin To: linux-kernel@vger.kernel.org Subject: Adjusting destination pointer with copy_to_user Date: Mon, 12 Feb 2007 11:39:44 +0200 Message-ID: <87ire7af4v.fsf@bonsai.taydin.org> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.92 (gnu/linux) 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 Hi, I am passing a packet consisting of a fixed length header and a variable length data block to a user mode application. The user mode application passes the pointer of its buffer with an ioctl call (buff_ptr). When the driver receives buff_ptr, it makes two calls to pass the packet to user mode: copy_to_user(buff_ptr, header, header_size); copy_to_user(buff_ptr + header_size, data, data_size); Is this a valid usage? Or can I only use buff_ptr here? Timur