From owner-freebsd-stable@FreeBSD.ORG Wed Apr 29 20:50:45 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7063B1065670 for ; Wed, 29 Apr 2009 20:50:45 +0000 (UTC) (envelope-from amesbury@umn.edu) Received: from mta-a3.tc.umn.edu (mta-a3.tc.umn.edu [134.84.119.232]) by mx1.freebsd.org (Postfix) with ESMTP id 1ECCD8FC12 for ; Wed, 29 Apr 2009 20:50:44 +0000 (UTC) (envelope-from amesbury@umn.edu) Received: from [160.94.247.212] (optimator.oitsec.umn.edu [160.94.247.212]) by mta-a3.tc.umn.edu (UMN smtpd) with ESMTP for ; Wed, 29 Apr 2009 15:28:09 -0500 (CDT) X-Umn-Remote-Mta: [N] optimator.oitsec.umn.edu [160.94.247.212] #+LO+TS+AU+HN X-Umn-Classification: local Message-ID: <49F8B859.7060908@umn.edu> Date: Wed, 29 Apr 2009 15:28:09 -0500 From: Alan Amesbury User-Agent: Thunderbird 2.0.0.21 (X11/20090318) MIME-Version: 1.0 To: freebsd-stable@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Garbled output from kgdb? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Apr 2009 20:50:45 -0000 One of my systems (FreeBSD 7.1-RELEASE-p3/amd64) has panicked a couple times recently without an identified cause. This most recent time I was able to obtain a crash dump from the system, but output from kgdb is garbled. -------------------- Output #1 -------------------- % pwd /usr/obj/usr/src/sys/[REDACTED] % sudo kgdb kernel.debug ~/crash/vmcore.0 GNU gdb 6.1.1 [FreeBSD] Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "amd64-marcel-freebsd"... Unread portion of the kernel message buffer: kernel trap 12 with interrupts disabled Fatal trap 12: page fault while in kernel mode cpuid = 3; apic id = 07 fault virtual addresske rn= el0 xt60r afapul t 1co2de w= isutpehrv isiorn twerritreu pdtasta d,i spaagbe lnoet dpres ent instruction pointer = 0x8:0xffffffff80424561 s tack pFoianttera l = 0x10t:0xfffrffaffpfac057af0 frame pointer = 0x10:0xffffff00010f86e0 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 processor eflags = resume, IOPL = 0 current process = 11 (idle: cpu3) trap number = 12 panic: page fault cpuid = 3 Uptime: 40d10h35m18s Physical memory: 8176 MB Dumping 691 MB: 676 660 644 628 612 596 580 564 548 532 516 500 484 468 452 436 420 404 388 372 356 340 324 308 292 276 260 244 228 212 196 180 164 148 132 116 100 84 68 52 36 20 4 Reading symbols from /boot/kernel/daemon_saver.ko...Reading symbols from /boot/kernel/daemon_saver.ko.symbols...done. done. Loaded symbols for /boot/kernel/daemon_saver.ko #0 doadump () at pcpu.h:195 195 __asm __volatile("movq %%gs:0,%0" : "=r" (td)); (kgdb) list *0x8:0xffffffff80424561 A syntax error in expression, near `:0xffffffff80424561'. ------------------ End output #1 ------------------ I've seen a thread on garbled serial console output and have seen symptoms of this on several of my systems (including this one), but that's been more of an annoyance than anything about which I'm actually worried... until now. (I've actually suspected hardware/BIOS issues relating to serial port access, which is why I've stayed out of that thread.) That the crash dump includes similar corruption suggests to me that it's not the serial device, but something a bit closer to FreeBSD itself. Any ideas what's causing the garbled output in kgdb? -- Alan Amesbury OIT Security and Assurance University of Minnesota