From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Moore Subject: Re: TUN problems (regression?) Date: Fri, 21 Dec 2012 11:27:57 -0500 Message-ID: <2090364.S7KStA6R4d@sifl> References: <4151394.nMo40zlg68@sifl> <1356046697.21834.3606.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: Jason Wang , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mx1.redhat.com ([209.132.183.28]:3491 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751091Ab2LUQ23 (ORCPT ); Fri, 21 Dec 2012 11:28:29 -0500 In-Reply-To: <1356046697.21834.3606.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thursday, December 20, 2012 03:38:17 PM Eric Dumazet wrote: > On Thu, 2012-12-20 at 18:16 -0500, Paul Moore wrote: > > [CC'ing netdev in case this is a known problem I just missed ...] > > > > Hi Jason, > > > > I started doing some more testing with the multiqueue TUN changes and I > > ran > > into a problem when running tunctl: running it once w/o arguments works as > > expected, but running it a second time results in failure and a > > kmem_cache_sanity_check() failure. The problem appears to be very > > repeatable on my test VM and happens independent of the LSM/SELinux fixup > > patches. > > > > Have you seen this before? > > Obviously code in tun_flow_init() is wrong... > > static int tun_flow_init(struct tun_struct *tun) > { > int i; > > tun->flow_cache = kmem_cache_create("tun_flow_cache", > sizeof(struct tun_flow_entry), > 0, 0, NULL); > if (!tun->flow_cache) > return -ENOMEM; > ... > } > > > I have no idea why we would need a kmem_cache per tun_struct, > and why we even need a kmem_cache. > > > I would try following patch : > > drivers/net/tun.c | 24 +++--------------------- > 1 file changed, 3 insertions(+), 21 deletions(-) Thanks, that solved my problem. Also, in case you were still curious, I was using SLUB. -- paul moore security and virtualization @ redhat