Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758066AbaFSWkM (ORCPT ); Thu, 19 Jun 2014 18:40:12 -0400 Received: from terminus.zytor.com ([198.137.202.10]:35194 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757338AbaFSWkL (ORCPT ); Thu, 19 Jun 2014 18:40:11 -0400 Message-ID: <53A366B3.8020808@zytor.com> Date: Thu, 19 Jun 2014 15:39:47 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Greg KH , Daniel Vetter CC: Rob Clark , Maarten Lankhorst , linux-arch@vger.kernel.org, Thomas Hellstrom , Linux Kernel Mailing List , "dri-devel@lists.freedesktop.org" , "linaro-mm-sig@lists.linaro.org" , Thierry Reding , Colin Cross , Sumit Semwal , "linux-media@vger.kernel.org" Subject: Re: [REPOST PATCH 1/8] fence: dma-buf cross-device synchronization (v17) References: <20140618102957.15728.43525.stgit@patser> <20140618103653.15728.4942.stgit@patser> <20140619011327.GC10921@kroah.com> <20140619170059.GA1224@kroah.com> <20140619200159.GA27883@kroah.com> In-Reply-To: <20140619200159.GA27883@kroah.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/19/2014 01:01 PM, Greg KH wrote: > On Thu, Jun 19, 2014 at 09:15:36PM +0200, Daniel Vetter wrote: >> On Thu, Jun 19, 2014 at 7:00 PM, Greg KH wrote: >>>>>> + BUG_ON(f1->context != f2->context); >>>>> >>>>> Nice, you just crashed the kernel, making it impossible to debug or >>>>> recover :( >>>> >>>> agreed, that should probably be 'if (WARN_ON(...)) return NULL;' >>>> >>>> (but at least I wouldn't expect to hit that under console_lock so you >>>> should at least see the last N lines of the backtrace on the screen >>>> ;-)) >>> >>> Lots of devices don't have console screens :) >> >> Aside: This is a pet peeve of mine and recently I've switched to >> rejecting all patch that have a BUG_ON, period. > > Please do, I have been for a few years now as well for the same reasons > you cite. > I'm actually concerned about this trend. Downgrading things to WARN_ON can allow a security bug in the kernel to continue to exist, for example, or make the error message disappear. I am wondering if the right thing here isn't to have a user (command line?) settable policy as to how to proceed on an assert violation, instead of hardcoding it at compile time. -hpa -- 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/