From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755803Ab2AXMtx (ORCPT ); Tue, 24 Jan 2012 07:49:53 -0500 Received: from mail-vx0-f174.google.com ([209.85.220.174]:35823 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754671Ab2AXMtw (ORCPT ); Tue, 24 Jan 2012 07:49:52 -0500 Message-ID: <1327416561.32498.10.camel@lappy> Subject: Re: [PATCH] net: caif: Don't act on notification for non-caif devices From: Sasha Levin To: Sjur =?ISO-8859-1?Q?Br=E6ndeland?= Cc: davem@davemloft.net, davej@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 24 Jan 2012 09:49:21 -0500 In-Reply-To: References: <1327390229-30170-1-git-send-email-levinsasha928@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.2.2 Content-Transfer-Encoding: 8bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-01-24 at 11:52 +0100, Sjur Brændeland wrote: > > Nack, we have to handle other device types than just ARPHDR_CAIF after > introducing > CAIF over USB/NCM. I'd rather fix this in netns by removing the BUG_ON > and return > NULL. How about this instead: [snip] I think that doing it this way is wrong for two reasons: 1. The code in net/ assumes net_generic is a trivial dereference and doesn't check that it's not NULL. This means that if anything goes wrong there you'll have a more dangerous NULL deref instead of a BUG(). 2. You'll need to add other device to that if() statement anyway, as it currently looks like this: cfg = get_cfcnfg(dev_net(dev)); caifdevs = caif_device_list(dev_net(dev)); if (!cfg || !caifdevs) return 0; caifd = caif_get(dev); if (caifd == NULL && dev->type != ARPHRD_CAIF) return 0; What my patch did was simply move the type check to above the net_generic call, it didn't add any new checks - which according to what you said, you'll need to do anyway. -- Sasha.