Need hints debugging KGSSAPI

[Attila Bogár]

Hi,

I'd like to spend some time finding out myself what's wrong with the 
kerberized nfs server on the FreeBSD 9-STABLE.

I thought the solution is to simply force DES+RFC1964 GSSAPI, but 
unfortunately it's not that simple.
I built a patched nfs-utils package by merging the patch referenced from
https://bugzilla.redhat.com/show_bug.cgi?id=802469 - with the legacy 
option did not resolve the problem.

I have some wireshark traces which show that one EL6 box get 3 times 
auth_denied however the other succeeds for the 3rd time.  I can 
reproduce this.

My kernel is a GENERIC + some option as per Rick's page:
options         KGSSAPI
device          crypto
device          cryptodev

I know, that all interesting NFS/GSSAPI job is done within kernel space.

I suppose it's not possible to unload the KGSSAPI module:
http://svnweb.freebsd.org/base/head/sys/kgssapi/gss_impl.c?view=markup&pathrev=224084

What's the best way to debug the kernel other than inserting debug 
messages into the source tree+recompiling+rebooting?

What debugger do you recommend?
Is there an up-to-date tutorial on FreeBSD kernel debugging?

Any constructive comments appreciated.

Thanks,
   Attila