From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751950AbWCFIId (ORCPT ); Mon, 6 Mar 2006 03:08:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752038AbWCFIId (ORCPT ); Mon, 6 Mar 2006 03:08:33 -0500 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:19227 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S1751950AbWCFIId (ORCPT ); Mon, 6 Mar 2006 03:08:33 -0500 Message-Id: <440BFC1C.76F0.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0 Date: Mon, 06 Mar 2006 09:08:44 +0100 From: "Jan Beulich" To: "Andrew Morton" Cc: Subject: Re: [PATCH] adjust /dev/{kmem,mem,port} write handlers References: <44081B03.76F0.0078.0@novell.com> <20060304221550.6892c7ba.akpm@osdl.org> In-Reply-To: <20060304221550.6892c7ba.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> @@ -514,11 +510,10 @@ static ssize_t write_kmem(struct file * >> if (len) { >> written = copy_from_user(kbuf, buf, len); >> if (written) { >> - ssize_t ret; >> - >> + if (wrote + virtr) >> + break; >> free_page((unsigned long)kbuf); >> - ret = wrote + virtr + (len - written); >> - return ret ? ret : -EFAULT; >> + return -EFAULT; >> } >> } >> len = vwrite(kbuf, (char *)p, len); > > >I think write_kmem() still isn't quie right - it needs to update `p' (and >hence *ppos) to account for a partial copy_from_user(). (Please double-check) No, I disagree. The actual write happens with the call to vwrite(), independent of the reading of the user buffer. If any adjustment might be needed, then it would be to account for the potential of vwrite() (and similarly vread()) to return 0, resulting in no progress being possible to be made anymore. Jan