From owner-freebsd-bugs@FreeBSD.ORG Wed Jul 14 21:10:24 2004 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id F303716A4CE for ; Wed, 14 Jul 2004 21:10:23 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id D8D0943D58 for ; Wed, 14 Jul 2004 21:10:23 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.12.11/8.12.11) with ESMTP id i6ELANeC029307 for ; Wed, 14 Jul 2004 21:10:23 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.11/8.12.11/Submit) id i6ELANwr029299; Wed, 14 Jul 2004 21:10:23 GMT (envelope-from gnats) Resent-Date: Wed, 14 Jul 2004 21:10:23 GMT Resent-Message-Id: <200407142110.i6ELANwr029299@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Robert Watson Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EABEE16A4CF; Wed, 14 Jul 2004 21:06:51 +0000 (GMT) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 93D1443D1D; Wed, 14 Jul 2004 21:06:51 +0000 (GMT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (localhost [127.0.0.1]) by fledge.watson.org (8.12.11/8.12.11) with ESMTP id i6EL6XDR064670; Wed, 14 Jul 2004 17:06:33 -0400 (EDT) (envelope-from robert@fledge.watson.org) Received: (from robert@localhost) by fledge.watson.org (8.12.11/8.12.11/Submit) id i6EL6XWL064669; Wed, 14 Jul 2004 17:06:33 -0400 (EDT) (envelope-from robert) Message-Id: <200407142106.i6EL6XWL064669@fledge.watson.org> Date: Wed, 14 Jul 2004 17:06:33 -0400 (EDT) From: Robert Watson To: FreeBSD-gnats-submit@FreeBSD.org X-Send-Pr-Version: 3.113 cc: phk@FreeBSD.org Subject: kern/69066: nmdm page fault when slattach on a null modem device X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jul 2004 21:10:24 -0000 >Number: 69066 >Category: kern >Synopsis: nmdm page fault when slattach on a null modem device >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Jul 14 21:10:23 GMT 2004 >Closed-Date: >Last-Modified: >Originator: Robert Watson >Release: FreeBSD 5-CURRENT i386 >Organization: - >Environment: Using CVS HEAD kernel from around 20040714. nmdm compiled into the kernel or loaded in a module. >Description: hippy# slattach /dev/nmdm0A /var/run/slattach.nmdm0A.pid hippy# hippy Fatal trap 12: page fault while in kernel mode cpuid = 1; apic id = 01 fault virtual address = 0x0 fault code = supervisor read, page not present instruction pointer = 0x8:0xc054e4a5 stack pointer = 0x10:0xdb0e9cac frame pointer = 0x10:0xdb0e9cb4 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, def32 1, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 47 (swi6:+) [thread 100026] Stopped at nmdm_task_tty+0x11: movl 0(%eax),%ebx db> trace nmdm_task_tty(c26f4c00,2,c22f8958,0,c07d310a) at nmdm_task_tty+0x11 taskqueue_run(c22f8940,db0e9d1c,c05de75c,0,0) at taskqueue_run+0x83 taskqueue_swi_giant_run(0) at taskqueue_swi_giant_run+0xe ithread_loop(c2308980,db0e9d48,c2308980,c05de628,0) at ithread_loop+0x134 fork_exit(c05de628,c2308980,db0e9d48) at fork_exit+0x98 fork_trampoline() at fork_trampoline+0x8 --- trap 0x1, eip = 0, esp = 0xdb0e9d7c, ebp = 0 --- (kgdb) l *nmdm_task_tty+0x11 0xc054e3e5 is in nmdm_task_tty (../../../dev/nmdm/nmdm.c:153). 148 struct softpart *sp; 149 int c; 150 151 tp = arg; 152 sp = tp->t_sc; 153 otp = sp->other->nm_tty; 154 KASSERT(otp != NULL, ("NULL otp in nmdmstart")); 155 KASSERT(otp != tp, ("NULL otp == tp nmdmstart")); 156 if (sp->other->nm_dcd) { 157 if (!(tp->t_state & TS_ISOPEN)) { Looks like sp->other is NULL. >How-To-Repeat: slattach on a null modem device seems to repeat this quite easily. It sounds a bit like a race in start up or tear-down. >Fix: Not included. >Release-Note: >Audit-Trail: >Unformatted: