Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753532AbaKJRCl (ORCPT ); Mon, 10 Nov 2014 12:02:41 -0500 Received: from mail-ie0-f172.google.com ([209.85.223.172]:39047 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbaKJRCj (ORCPT ); Mon, 10 Nov 2014 12:02:39 -0500 Message-ID: <1415638955.9613.4.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: [Xen-devel] BUG in xennet_make_frags with paged skb data From: Eric Dumazet To: David Vrabel Cc: Zoltan Kiss , netdev@vger.kernel.org, "David S. Miller" , Konrad Rzeszutek Wilk , Boris Ostrovsky , Stefan Bader , Jay Vosburgh , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Date: Mon, 10 Nov 2014 09:02:35 -0800 In-Reply-To: <5460EAF1.5020903@citrix.com> References: <20141106214940.GD44162@ubuntu-hedt> <545CA27F.4070400@citrix.com> <20141110143517.GA74005@ubuntu-hedt> <5460CEA5.3070201@citrix.com> <5460EA45.2080202@linaro.org> <5460EAF1.5020903@citrix.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 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 On Mon, 2014-11-10 at 16:42 +0000, David Vrabel wrote: > On 10/11/14 16:39, Zoltan Kiss wrote: > > > > The BUG_ON suggested by Stefan would be still reasonable: > > > > BUG_ON(((page-compound_head(page))*PAGE_SIZE)+offset+len > > > PAGE_SIZE< > Well, it wouldn't trigger but I don't think it is useful any more. Right. This BUG_ON() does not make sense (its current implementation is assuming a very precise layout anyway) If we really wanted some debugging, we would need something more generic and done in core networking stack, not in a particular driver. -- 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/