From owner-freebsd-current@FreeBSD.ORG Wed Oct 29 09:29:49 2003 Return-Path: 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 AA18316A4CF for ; Wed, 29 Oct 2003 09:29:49 -0800 (PST) Received: from mail.speakeasy.net (mail5.speakeasy.net [216.254.0.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6608343FDF for ; Wed, 29 Oct 2003 09:29:48 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 1055 invoked from network); 29 Oct 2003 17:29:47 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender )encrypted SMTP for ; 29 Oct 2003 17:29:47 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.9/8.12.9) with ESMTP id h9THTQce033358; Wed, 29 Oct 2003 12:29:27 -0500 (EST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.4 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <20031028234825.GB2284@dan.emsphone.com> Date: Wed, 29 Oct 2003 12:29:26 -0500 (EST) From: John Baldwin To: Dan Nelson X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) cc: current@freebsd.org Subject: Re: page fault in propagate_priority X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Wed, 29 Oct 2003 17:29:49 -0000 On 28-Oct-2003 Dan Nelson wrote: > In the last episode (Oct 28), John Baldwin said: >> On 28-Oct-2003 Dan Nelson wrote: >> > I've gotten the following panic twice in the last few days. I'm >> > pretty sure truss has something to do with it, since I just started >> > trussing something when it paniced. No crashdumps unfortunately, >> > and the system locks up hard so I have to reset it. >> > >> > The fault address is 0x24 so it looks like a null pointer >> > dereference of some sort. I've added asserts to propagate_priority >> > any place a pointer to a structure is dereferenced, so if it >> > happens again I should have the line number at least. >> > >> > panic1 was on an Oct 15 kernel, panic2 was on an Oct 27 kernel. >> >> It might help some if you could use gdb -k on your kernel.debug and >> do 'l *propagate_priority+0x66' to see where it is dying. > > Yes, definitely :) > > (gdb) l *propagate_priority+0x66 > 0xc0575b36 is in propagate_priority (../../../kern/kern_mutex.c:178). > 171 m = td->td_blocked; > 172 MPASS(m != NULL); > 173 > 174 /* > 175 * Check if the thread needs to be moved up on > 176 * the blocked chain > 177 */ > 178 if (td == TAILQ_FIRST(&m->mtx_blocked)) { > 179 continue; > 180 } > 181 > 182 td1 = TAILQ_PREV(td, threadqueue, td_lockq); > > So I guess m was NULL here. If I had INVARIANTS enabled, it would have > paniced at line 172. Time to re-enable those kernel debug options :) Well, mtx_blocked might be null. You don't happen to have ADAPTIVE_MUTEXES on do you? -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/