From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net/802/mrp: fix lockdep splat Date: Tue, 14 May 2013 13:03:07 -0700 (PDT) Message-ID: <20130514.130307.629850895919092156.davem@davemloft.net> References: <20130514.120754.1745967383330029903.davem@davemloft.net> <1368559307.4519.21.camel@edumazet-glaptop> <1368560401.4519.25.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: denys@visp.net.lb, amwang@redhat.com, david.ward@ll.mit.edu, hayeswang@realtek.com, romieu@fr.zoreil.com, netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:45007 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755376Ab3ENUDM (ORCPT ); Tue, 14 May 2013 16:03:12 -0400 In-Reply-To: <1368560401.4519.25.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Tue, 14 May 2013 12:40:01 -0700 > On Tue, 2013-05-14 at 12:21 -0700, Eric Dumazet wrote: >> On Tue, 2013-05-14 at 12:07 -0700, David Miller wrote: >> >> > Can you double check that you really had Eric's patch applied? >> > lockdep appears to be complaining about the same thing in your >> > log dump, as if the patch was not really applied. >> > >> > It's saying that app->lock can be taken from the join timer in >> > softirq, but mrp_uninit_applicant() takes it without disabling >> > softirqs. >> > >> > Eric's patch explicitly fixes this, by making sure that spin_lock_bh() >> > is used there. >> >> I am going to test this myself, it seems quite simple. >> I'll add a Tested-by: tag once done. > > I definitely could trigger the bug easily without my patch : ... > And with the patch, there is no lockdep splat anymore. > > Tested-by: Eric Dumazet Applied, thanks Eric.