Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755297AbZJKQDX (ORCPT ); Sun, 11 Oct 2009 12:03:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754466AbZJKQDV (ORCPT ); Sun, 11 Oct 2009 12:03:21 -0400 Received: from casper.infradead.org ([85.118.1.10]:37763 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754353AbZJKQDU (ORCPT ); Sun, 11 Oct 2009 12:03:20 -0400 Date: Sun, 11 Oct 2009 09:03:13 -0700 From: Arjan van de Ven To: Alan Cox Cc: John Kacur , linux-kernel@vger.kernel.org, Thomas Gleixner , Frederic Weisbecker , Ingo Molnar , Christoph Hellwig , Jonathan Corbet , Andrew Morton , Vincent Sanders , linux-scsi@vger.kernel.org Subject: Re: [PATCH RFC] [PATCH] drivers/scsi/ch.c: Remove BKL in ch_open Message-ID: <20091011090313.1b8f0eb1@infradead.org> In-Reply-To: <20091011165408.51d4f413@lxorguk.ukuu.org.uk> References: <20091011153709.4438cf9c@lxorguk.ukuu.org.uk> <20091011082917.6ebbd810@infradead.org> <20091011165408.51d4f413@lxorguk.ukuu.org.uk> Organization: Intel X-Mailer: Claws Mail 3.7.2 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 989 Lines: 36 On Sun, 11 Oct 2009 16:54:08 +0100 Alan Cox wrote: > > > I'm not so sure. In fact there are some quite umm interesting > > > questions about this code, and some of them are shared with other > > > modules too. > > > > > > Consider the following sequence > > > > > > CPU1 CPU2 > > > register_chrdev > > > ok > > > open device > > > takes lock > > > > > > but open does not take the BKL, so the BKL is not protecting you at > > all against this.. > > But module load/unload does it does? looking at the code.... so far failing to find where. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/