Re: New debug kernel installation mechanism committed to HEAD

[Richard Nyberg <rnyberg@xxxxxxxx>]

At Thu, 21 Oct 2004 01:59:13 -0400,
Andrew Atrens wrote:
> 
> Btw, is there a how-to somewhere on how one would load a kernel module
> into gdb to do post-mortem on a vmcore? If one can't do this, then having
> debug info in modules would definitely be less useful.

Yes. See the FreeBSD developer handbook.
http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/
Section 11.7 in particular.

> Should this work? -
>
> gdb -k kernel.0 vmcore.0
> gdb> add-symbol-file /nvidia.ko 0xc060d000
> gdb> bt

I do this on a regular basis:
gdb -k kernel.debug vmcore.9

follow this chain to get the address of my module
*linker_files.tqh_first.link.tqe_next.link.tqe_next

objdump --headers /usr/arla/bin/nnpfs.ko | grep text
to see the relocation address.

add address and relocation address

add-symbol-file /usr/arla/bin/nnpfs.ko sum-of-addresses

bt

        -Richard