Date: Tue, 9 Sep 2008 13:22:00 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-doc@freebsd.org Cc: freebsd-gnats-submit@freebsd.org, Fritz Katz <frtzkatz@yahoo.com> Subject: Re: docs/127253: Error in Handbook: http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-ddd.html Message-ID: <200809091322.00250.jhb@freebsd.org> In-Reply-To: <200809091627.m89GRJYG070708@www.freebsd.org> References: <200809091627.m89GRJYG070708@www.freebsd.org>
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On Tuesday 09 September 2008 12:27:19 pm Fritz Katz wrote: > > >Number: 127253 > >Category: docs > >Synopsis: Error in Handbook: http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-ddd.html > >Confidential: no > >Severity: serious > >Priority: medium > >Responsible: freebsd-doc > >State: open > >Quarter: > >Keywords: > >Date-Required: > >Class: doc-bug > >Submitter-Id: current-users > >Arrival-Date: Tue Sep 09 16:30:02 UTC 2008 > >Closed-Date: > >Last-Modified: > >Originator: Fritz Katz > >Release: 7.0-RELEASE i386 > >Organization: > AAArt > >Environment: > # uname -rm > 7.0-RELEASE i386 > > >Description: > This page in the handbook appears to give bad advice: > http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-ddd.html > > # ddd -k /var/crash/kernel.0 /var/crash/vmcore.0 > > Is the handbook out-of-date? Has the '-k' option been removed from 'ddd'? > > I think the correct invocation for 'ddd' should be: > > # ddd --debugger kgdb kernel.debug /var/crash/vmcore.0 > > Following instructions in the handbook results in this message: > "GDB could not be started.", and the ddd console window prints: > > GNU DDD 3.3.11 (i386-portbld-freebsd7.0), > by Dorothea Lutkehaus and Andreas Zeller. > ... > gdb: unrecognized option '-k' > Use 'gdb --help' for a complete list of options. > > Which appears to be correct since, > # ddd --help > and > # gdb --help > shows there is no option '-k' > _________________ > > also, the second option, '/var/crash/kernel.0', also appears to > be incorrect. That file or executable does not exist. > > Is that the executable? If so, my 'kernel' is located in: > > # cd /usr/obj/usr/src/sys/AAART/ > # ls kernel* > kernel kernel.debug kernel.symbols > > _________________ > > Attempting: > # ddd --core=/var/crash/vmcore.0 > gives this message: > "/var/crash/vmcore.0" is not a core dump: File format not recognized > (gdb) > > However, the instructions for the command line debugger, 'kgdb', on this > page are OK: > > http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-gdb.html > > and the /var/crash/vmcore.0 is recognized. > > # cd /usr/obj/usr/src/sys/AAART/ > # kgdb kernel.debug /var/crash/vmcore.0 > >How-To-Repeat: > > Read the handbook and attempt to follow it's instructions. > >Fix: > Replace the offending line in the Handbook with: > > # ddd --debugger kgdb kernel.debug /var/crash/vmcore.0 I think your updates are correct. The old usage is from FreeBSD 4.x when one used 'gdb -k' rather than 'kgdb'. Crash dumps on 4.x also left a kernel image in /var/crash which explains the /var/crash/kernel.0 reference. -- John Baldwin
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