Date: Mon, 23 Feb 2009 16:17:53 -0500 From: John Baldwin <jhb@freebsd.org> To: "David Christensen" <davidch@broadcom.com> Cc: "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Subject: Re: Hopefully Simple Question on Debugging Kernel Modules Message-ID: <200902231617.54340.jhb@freebsd.org> In-Reply-To: <5D267A3F22FD854F8F48B3D2B52381933950E91B04@IRVEXCHCCR01.corp.ad.broadcom.com> References: <5D267A3F22FD854F8F48B3D2B5238193394588D54D@IRVEXCHCCR01.corp.ad.broadcom.com> <200902231257.28060.jhb@freebsd.org> <5D267A3F22FD854F8F48B3D2B52381933950E91B04@IRVEXCHCCR01.corp.ad.broadcom.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Monday 23 February 2009 3:51:18 pm David Christensen wrote: > > > > Just use gdb on bce.ko (built with debug symbols): > > > > > > > > gdb /path/to/if_bce.ko > > > > (gdb) l *bce_intr+0x8df > > > > > > > > If you get a crashdump you can run kgdb on it and just walk up to > > the > > relevant > > > > stack frame and use 'l' there to get a listing. > > > > > > > > > > One thing that I've never figured out is how debugging symbols are > > > handled in module builds these days. If I go to /sys/modules/bce and > > > do 'make', it generates a .ko and explicitly strips it. I wind up > > > having to re-run the link command by hand so I get symbols. What is > > > the correct way to do this? Note that I'm not interested in answers > > > that involve "go to /usr/src and run make buildkernel" =-) > > > > make DEBUG_FLAGS=-g is what I use. The same thing works for userland > > tools > > and the kernel (usually we put 'makeoptions DEBUG_FLAGS=-g' in a kernel > > config so it is "automatic" for kernels though). > > So is the use of COPTS=-g mentioned in the Developer's Handbook > (http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-kld.html) > deprecated? I wasn't able to build with symbols until I used DEBUG_FLAGS='g. Yes. kgdb is now also smarter in that it should automatically load symbols for kld's. There's no need to use add-symbol-file to add symbols by hand anymore. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200902231617.54340.jhb>