From owner-freebsd-current@FreeBSD.ORG Tue Aug 9 20:42:29 2005 Return-Path: X-Original-To: current@FreeBSD.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 67EE116A41F; Tue, 9 Aug 2005 20:42:29 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from mv.twc.weather.com (mv.twc.weather.com [65.212.71.225]) by mx1.FreeBSD.org (Postfix) with ESMTP id C3FEE43D48; Tue, 9 Aug 2005 20:42:28 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: from [10.50.40.201] (Not Verified[65.202.103.25]) by mv.twc.weather.com with NetIQ MailMarshal (v6, 0, 3, 8) id ; Tue, 09 Aug 2005 16:57:13 -0400 From: John Baldwin To: "Bjoern A. Zeeb" Date: Tue, 9 Aug 2005 14:44:09 -0400 User-Agent: KMail/1.8 References: <200508091048.50086.jhb@FreeBSD.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200508091444.10415.jhb@FreeBSD.org> Cc: FreeBSD current mailing list , ume@FreeBSD.org Subject: Re: LOR + panic in scope6.c X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Aug 2005 20:42:29 -0000 On Tuesday 09 August 2005 11:28 am, Bjoern A. Zeeb wrote: > On Tue, 9 Aug 2005, John Baldwin wrote: > > On Tuesday 09 August 2005 07:40 am, Bjoern A. Zeeb wrote: > > > Hi, > > > > > > HEAD as of yesterday + rwatson mega-commit from today. > > > > > > lock order reversal > > > 1st 0xffffff0000ad6bf0 if_afdata (if_afdata) @ > > > sys/netinet6/scope6.c:415 2nd 0xffffffff8081dd30 user map (user map) @ > > > sys/vm/vm_map.c:2997 KDB: stack backtrace: > > > > > > --- trap 0xc, rip = 0xffffffff804990a0, rsp = 0xffffffff809dc3f0, rbp = > > > 0xffffffff809dc430 --- in6_setscope() at in6_setscope+0x50 > > > in6_ifdetach() at in6_ifdetach+0x24a > > > if_detach() at if_detach+0x39 > > > ether_ifdetach() at ether_ifdetach+0x35 > > > sk_attach() at sk_attach+0x51a > > > > > > Fatal trap 12: page fault while in kernel mode > > > fault virtual address = 0x18 > > > fault code = supervisor read, page not present > > > instruction pointer = 0x8:0xffffffff804990a0 > > > stack pointer = 0x10:0xffffffff809dc3f0 > > > frame pointer = 0x10:0xffffffff809dc430 > > > code segment = base 0x0, limit 0xfffff, type 0x1b > > > = DPL 0, pres 1, long 1, def32 0, gran 1 > > > processor eflags = interrupt enabled, resume, IOPL = 0 > > > current process = 0 (swapper) > > > [thread pid 0 tid 0 ] > > > Stopped at in6_setscope+0x50: movq 0x18(%rax),%r13 > > > > > > (gdb) l *0xffffffff804990a0 > > > 0xffffffff804990a0 is in in6_setscope (sys/netinet6/scope6.c:417). > > > 412 u_int32_t zoneid = 0; > > > 413 struct scope6_id *sid; > > > 414 > > > 415 IF_AFDATA_LOCK(ifp); > > > 416 > > > 417 sid = SID(ifp); > > > 418 > > > 419 #ifdef DIAGNOSTIC > > > 420 if (sid == NULL) { /* should not happen */ > > > 421 panic("in6_setscope: scope array is NULL"); > > > > Well, SID is a macro that expands this to: > > > > sid = ifp->if_afdata[AF_INET6]->scope6_id > > > > If if_afdata[AF_INET6] has already been freed that could be the problem. > > It might have never been non-null either I guess. You can try having > > in6_setscope() bail if ifp->if_afdata[AF_INET6] is NULL. > > I will. I think I found another problem with attach/detach in sk. > Might be a double free. > The above seems to happen in the "No PHY found" case (which I fixed > already locally and everything went away). Well, I've seen this when attach fails on de(4) as well, so I think it's some sort of bug where you ether_ifdetach() an interface before it's fully up or something. > I will further investigate. The LOR might as well be bogus because of > the trap. Yes, LOR's with user map or system map after a page fault are usually bogus, the real problem is a trap while holding a lock. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org