How to get anything useful out of kgdb?

[Jeff Meegan]

You could try -O0, but also if you just care about txr, go up
to frame 12 where txr initialized to the context arg to 
em_handle_tx() and print it out there.

—j

> On May 9, 2015, at 11:02 AM, Sean Bruno <sbruno at ignoranthack.me> wrote:
> 
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> On 05/09/15 10:20, Sean Bruno wrote:
>> 
>> tl;dr  What are the kernel config options to get good output of
>> kgdb?
>> 
>> 
>> I'm trying to get the ability to debug and display internal
>> variables, as one does, with kgdb.  I'm *must* be doing this wrong
>> as I cannot get any useful output from accessing variables that
>> were JUST accessed in order to invoke a panic() that I have
>> inserted.  This is a GENERIC kernel without INVARIANTS and without
>> WITNESS:
>> 
>> https://people.freebsd.org/~sbruno/wtf_kgdb.txt
>> 
>> I seem to have debug enabled and am able to browse source, but I 
>> obviously haven't compiled correctly as things are optimized out.
>> 
> 
> Just to see what the arguments to make are when building, I touched
> if_em.c and did a NOCLEAN rebuild.
> 
> What I see is this:
> https://people.freebsd.org/~sbruno/wtf_make.txt
> 
> Should -02 and -g do anything useful here when compiling?  Do I need
> to drop the optimization flags?
> 
> sean
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