Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752265Ab3F0Jnm (ORCPT ); Thu, 27 Jun 2013 05:43:42 -0400 Received: from gate.crashing.org ([63.228.1.57]:45169 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751384Ab3F0Jnk (ORCPT ); Thu, 27 Jun 2013 05:43:40 -0400 Message-ID: <1372326166.18612.42.camel@pasglop> Subject: Re: [PATCH 3/8] vfio: add external user support From: Benjamin Herrenschmidt To: Stephen Rothwell Cc: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, Alexander Graf , kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, Alex Williamson , Paul Mackerras , "Paul E . McKenney" , David Gibson Date: Thu, 27 Jun 2013 19:42:46 +1000 In-Reply-To: <20130627165929.3828c261c957845a549ad95b@canb.auug.org.au> References: <1372309356-28320-1-git-send-email-aik@ozlabs.ru> <1372309356-28320-4-git-send-email-aik@ozlabs.ru> <20130627165929.3828c261c957845a549ad95b@canb.auug.org.au> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 931 Lines: 26 On Thu, 2013-06-27 at 16:59 +1000, Stephen Rothwell wrote: > > +/* Allows an external user (for example, KVM) to unlock an IOMMU > group */ > > +static void vfio_group_del_external_user(struct file *filep) > > +{ > > + struct vfio_group *group = filep->private_data; > > + > > + BUG_ON(filep->f_op != &vfio_group_fops); > > We usually reserve BUG_ON for situations where there is no way to > continue running or continuing will corrupt the running kernel. Maybe > WARN_ON() and return? Not even that. This is a user space provided "fd", we shouldn't oops the kernel because we passed a wrong argument, just return -EINVAL or something like that (add a return code). Ben. -- 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/