Date: Tue, 10 Aug 2004 22:15:32 +0200 From: Daniel Lang <dl@leo.org> To: Terrence Koeman <root@mediamonks.net> Cc: 'John Baldwin' <jhb@FreeBSD.org> Subject: Re: Lock order reversal in 5.2-CURRENT Message-ID: <20040810201532.GA53289@atrbg11.informatik.tu-muenchen.de> In-Reply-To: <200408102141323.SM01804@manrikigusari> References: <200408101535.11863.jhb@FreeBSD.org> <200408102141323.SM01804@manrikigusari>
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Hi Terrence, Terrence Koeman wrote on Tue, Aug 10, 2004 at 09:40:22PM +0200: [..] > > --- trap 0xc, eip = 0xc04b3ed2, esp = 0xd4dd7c90, ebp = 0xd4dd7ce0 --- > > mi_switch(1,0,c060d2be,9c,dbba0) at mi_switch+0x102 > > > > Does the original poster have a debug kernel built? > > > > Yes I have, but I have no experience with the debugger. I'll be happy to > carry out whatever's needed. [..] The process is documented in the developers handbook: http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html In short: - first make sure dumpdevice is set and savecore enabled in /etc/rc.conf - after a panic get a crash-dump, e.g. in ddb enter "call doadump()" - after reboot the dump should be saved to e.g. /var/crash/vmcore.0 - analyse the dump with kernel-gdb: gdb -k /usr/obj/usr/src/sys/<KERNCONF>/kernel.debug /var/crash/vmcore.0 (IIRC), so this is where the debug kernel is required. Please not that stock gdb is currently not able to act as kernel-debugger, you need to install the gdb6 port. - Start with a backtrace (bt) of the kernel, look out for corrupted data. Obvious things are 0x0 pointers, where valid data is expected. If spotted, try to trace the source of corruption. - Post any of your discoveries. Often just the stack-trace with function, arguments and source-lines can give valuable hints to the developers. HTH, Daniel -- IRCnet: Mr-Spock - Agartim billiard bumba m'abdul in papejim twista - rumba rock n rolla. Leik'ab mai. Spirzon Heroin se'osit gaula. - - Marijuana esit gaula. Haschisch. Opis. - Daniel Lang * dl@leo.org * +49 89 2600 8122 * http://www.leo.org/~dl/
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