From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755628AbYLJWeu (ORCPT ); Wed, 10 Dec 2008 17:34:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751448AbYLJWel (ORCPT ); Wed, 10 Dec 2008 17:34:41 -0500 Received: from kroah.org ([198.145.64.141]:41290 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751382AbYLJWek (ORCPT ); Wed, 10 Dec 2008 17:34:40 -0500 Date: Wed, 10 Dec 2008 14:28:12 -0800 From: Greg KH To: Neil Horman Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [PATCH] ibmphp: Fix module ref count underflow Message-ID: <20081210222812.GA1513@kroah.com> References: <20081210194334.GA25257@hmsreliant.think-freely.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081210194334.GA25257@hmsreliant.think-freely.org> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 10, 2008 at 02:43:34PM -0500, Neil Horman wrote: > Hey- > I happened to notice that the ibmphp hotplug driver does something > rather silly in its init routine. It purposely calls module_put so as to > underflow its module ref count to avoid being removed from the kernel. This is > bad practice, and wrong, since it provides a window for subsequent module_gets > to reset the refcount to zero, allowing an unload to race in and cause all sorts > of mysterious panics. If the module is unsafe to load, it should inform the > kernel as such with a call to __unsafe. The patch below does that. > > Regards > Neil > > Signed-off-by: Neil Horman Jesse is the PCI maintainer now, you should send this to him to verify that it goes in. Feel free to add my: Acked-by: Greg Kroah-Hartman to this, nice job. thanks, greg k-h