From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267923AbUI1P3n (ORCPT ); Tue, 28 Sep 2004 11:29:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267974AbUI1P3m (ORCPT ); Tue, 28 Sep 2004 11:29:42 -0400 Received: from umhlanga.stratnet.net ([12.162.17.40]:51092 "EHLO umhlanga.STRATNET.NET") by vger.kernel.org with ESMTP id S267936AbUI1P3k (ORCPT ); Tue, 28 Sep 2004 11:29:40 -0400 To: Paul Jackson Cc: greg@kroah.com, linux-kernel@vger.kernel.org X-Message-Flag: Warning: May contain useful information References: <1096302710971@topspin.com> <10963027102899@topspin.com> <20040927131014.695b8212.pj@sgi.com> <52fz53e526.fsf@topspin.com> <20040927234333.7cceff47.pj@sgi.com> From: Roland Dreier Date: Tue, 28 Sep 2004 08:29:39 -0700 In-Reply-To: <20040927234333.7cceff47.pj@sgi.com> (Paul Jackson's message of "Mon, 27 Sep 2004 23:43:33 -0700") Message-ID: <52mzzacsyk.fsf@topspin.com> User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Security Through Obscurity, linux) MIME-Version: 1.0 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: roland@topspin.com Subject: Re: [PATCH][1/2] [RESEND] kobject: add HOTPLUG_ENV_VAR Content-Type: text/plain; charset=us-ascii X-SA-Exim-Version: 4.1 (built Tue, 17 Aug 2004 11:06:07 +0200) X-SA-Exim-Scanned: Yes (on eddore) X-OriginalArrivalTime: 28 Sep 2004 15:29:39.0861 (UTC) FILETIME=[F8479450:01C4A56F] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Your patch is buggy: + length += snprintf (buffer + length, max(buffer_size - length, 0), "DEVICE=/proc/bus/usb/%03d/%03d", usb_dev->bus->busnum, usb_dev->devnum); snprintf() returns the number of characters that would be written not counting the trailing NUL. So the next env var is going to be concatenated with this one. It's precisely this sort of easy-to-make off-by-one bug that convinces me the hotplug environment variable handling needs to be wrapped up in a helper macro or function. Thanks, Roland