From owner-freebsd-net@freebsd.org Thu Jul 23 23:49:35 2020 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9A129367A00; Thu, 23 Jul 2020 23:49:35 +0000 (UTC) (envelope-from jmg@gold.funkthat.com) Received: from gold.funkthat.com (gate2.funkthat.com [208.87.223.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "gate2.funkthat.com", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BCTZl0tCsz4K5G; Thu, 23 Jul 2020 23:49:34 +0000 (UTC) (envelope-from jmg@gold.funkthat.com) Received: from gold.funkthat.com (localhost [127.0.0.1]) by gold.funkthat.com (8.15.2/8.15.2) with ESMTPS id 06NNnQoL053031 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 23 Jul 2020 16:49:26 -0700 (PDT) (envelope-from jmg@gold.funkthat.com) Received: (from jmg@localhost) by gold.funkthat.com (8.15.2/8.15.2/Submit) id 06NNnPdb053030; Thu, 23 Jul 2020 16:49:25 -0700 (PDT) (envelope-from jmg) Date: Thu, 23 Jul 2020 16:49:25 -0700 From: John-Mark Gurney To: Kristof Provost Cc: "Bjoern A. Zeeb" , freebsd-net@freebsd.org, freebsd-current@freebsd.org Subject: Re: somewhat reproducable vimage panic Message-ID: <20200723234925.GL4213@funkthat.com> Mail-Followup-To: Kristof Provost , "Bjoern A. Zeeb" , freebsd-net@freebsd.org, freebsd-current@freebsd.org References: <20200721202323.GE4213@funkthat.com> <38F5A3A6-B578-4BA4-8F69-C248163CB6E0@libassi.se> <20200722060514.GF4213@funkthat.com> <20200722193443.GG4213@funkthat.com> <6C149617-55BB-4A87-B993-195E5E133790@lists.zabbadoz.net> <20200722221509.GI4213@funkthat.com> <2FFC49F9-83DE-4FA1-A47F-1D8A7AF4B241@FreeBSD.org> <6847FB6B-0B1A-43C7-B567-15BF21AB5D56@FreeBSD.org> <8B72C0B9-9CF0-4557-81D7-77190775805C@lists.zabbadoz.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: FreeBSD 11.3-STABLE amd64 X-PGP-Fingerprint: D87A 235F FB71 1F3F 55B7 ED9B D5FF 5A51 C0AC 3D65 X-Files: The truth is out there X-URL: https://www.funkthat.com/ X-Resume: https://www.funkthat.com/~jmg/resume.html X-TipJar: bitcoin:13Qmb6AeTgQecazTWph4XasEsP7nGRbAPE X-to-the-FBI-CIA-and-NSA: HI! HOW YA DOIN? can i haz chizburger? User-Agent: Mutt/1.6.1 (2016-04-27) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (gold.funkthat.com [127.0.0.1]); Thu, 23 Jul 2020 16:49:26 -0700 (PDT) X-Rspamd-Queue-Id: 4BCTZl0tCsz4K5G X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:32354, ipnet:208.87.216.0/21, country:US] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jul 2020 23:49:35 -0000 Kristof Provost wrote this message on Thu, Jul 23, 2020 at 11:02 +0200: > On 23 Jul 2020, at 11:00, Bjoern A. Zeeb wrote: > > On 23 Jul 2020, at 8:09, Kristof Provost wrote: > > > >> On 23 Jul 2020, at 9:19, Kristof Provost wrote: > >>> On 23 Jul 2020, at 0:15, John-Mark Gurney wrote: > >>>> So, it's pretty easy to trigger, just attach a couple USB ethernet > >>>> adapters, in my case, they were ure, but likely any two spare > >>>> ethernet > >>>> interfaces will work, and wire them back to back.. > >>>> > >>> I???ve been able to trigger it using epair as well: > >>> > >>> `sudo sh testinterfaces.txt epair0a epair0b` > >>> > >>> I did have to comment out the waitcarrier() check. > >>> > >> I???ve done a little bit of digging, and I think I???m starting to > >> see how this breaks. > >> > >> This always affects the jailed vlan interfaces. They???re getting > >> deleted, but the ifp doesn???t go away just yet because it???s still > >> in use by the multicast code. > >> The multicast code does its cleanup in task queues, > > > > Wow, did I miss that back then? Did I review a change and not notice? > > Sorry if that was the case. > > > > Vnet teardown is blocking and forceful. > > Doing deferred cleanup work isn???t a good idea at all. > > I think that is the real problem here. > > > > I???d rather have us fix this than putting more bandaids into the > > code. > > > Yeah, agreed. I think hselasky has a better fix: > https://reviews.freebsd.org/D24914 > > I just saw his e-mail in a different thread. I'm testing out this patch now, and let people know how it goes.. It'll be nice to not have to worry about these panics.. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."