Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759965AbXHKLON (ORCPT ); Sat, 11 Aug 2007 07:14:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753886AbXHKLOB (ORCPT ); Sat, 11 Aug 2007 07:14:01 -0400 Received: from py-out-1112.google.com ([64.233.166.179]:46688 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752518AbXHKLOA (ORCPT ); Sat, 11 Aug 2007 07:14:00 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=fGpfP4SoeSKXnmrUx3Woe67PKDv7CZNrK0cUk9+X7hV0xXM/uur8dvW2fsRKpyC71E973xw7mCLVqMnSW/hq2G6VtwtRSWG68jyQGX/LDgEMYdXTRFT4bfPmvt6hkYSl/yPi7Uaz8wnoXXdGtzZAVsf8Cz0aMD17pVAiPyZhy3g= Message-ID: Date: Sat, 11 Aug 2007 13:13:59 +0200 From: "Markus Rechberger" To: "Trent Piepho" Subject: Re: [v4l-dvb-maintainer] [2.6 patch] dvb_frontend_ioctl(): fix check-after-use Cc: "Manu Abraham" , v4l-dvb-maintainer@linuxtv.org, linux-kernel@vger.kernel.org, "Adrian Bunk" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070730222817.GE3972@stusta.de> <1a297b360707312052l14adb72el8ee59c74b7757605@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2049 Lines: 56 On 8/11/07, Trent Piepho wrote: > On Fri, 10 Aug 2007, Markus Rechberger wrote: > > On 8/1/07, Manu Abraham wrote: > > > On 7/31/07, Adrian Bunk wrote: > > > > The Coverity checker spotted that we have already oops'ed if "fe" was > > > NULL. > > > > > > > > --- linux-2.6.23-rc1-mm1/drivers/media/dvb/dvb-core/dvb_frontend.c.old > > > > +++ linux-2.6.23-rc1-mm1/drivers/media/dvb/dvb-core/dvb_frontend.c > > > > @@ -706,11 +706,11 @@ static int dvb_frontend_ioctl(struct ino > > > > - if (!fe || fepriv->exit) > > > > + if (fepriv->exit) > > > > return -ENODEV; > > > > This issue has been known for a while including some other problems at > > that part. > > > > > http://article.gmane.org/gmane.linux.drivers.dvb/35351/match=patch+dvb_net+hotplugging+support > > > > this includes a link where this and more got discussed in May. > > For dvb_net_close, I like the patch I already posted better. To fix the > check-after-use, it's not "use" part that's the problem, it's the "check" > part > that isn't necessary. > > I traced the dvb-net code, > http://article.gmane.org/gmane.linux.kernel/543689, > and I'm sure that dvbdev can't be NULL. > > My patch also deletes a few pieces of duplicated code by calling > dvb_generic_release(). > > The only problem is that practically no one uses dvb-net, so it's very hard > to > test these patches. > I didn't see this patch, it would be fine if it would get applied. > In all the dvb code, were is the locking for device open and release? I > don't > see it. What is preventing two threads from trying to open and/or close the > same dvb device at the same time? > Haven't looked at that yet, since I moreover work to get the em28xx driver included now. Markus - 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/