Re: Debugging using GDB and gdbserver

[Justin Wojdacki <justin.wojdacki@analog.com>]

Daniel Jacobowitz wrote:
>
> Wait, wait.  What are you trying to do?  Originally you were talking
> about userspace debugging via gdbserver.  Now you're talking about
> kernel debugging via kgdb.  They're separate (and coexisting can cause
> problems if you are not careful with your exception handlers; I do not
> remember when my patches to make that work went into the tree, or if
> someone else did it).
> 
> gdbserver can just use TCP.
> 
> --
> Daniel Jacobowitz                           Debian GNU/Linux Developer
> MontaVista Software                         Carnegie Mellon University

Sorry for the confusion. I've been discussing userspace debugging via
gdbserver the entire time. However, I've noticed that gdbserver
doesn't seem to be fully functional because the kernel doesn't seem to
be handling the "BREAK 5" instruction correctly. You mentioned
problems with board exception handling and I looked at the ddb series
board support code. In there, I found handling for software
breakpoints, and got the impression from the code that it was a
general debugging interface, not just for kernel debugging. Again,
sorry for the confusion.

As it stands right now, when I get hit a "BREAK 5" instruction,
gdbserver never get's a chance to handle it, as the kernel keeps
scheduling the child process I'm trying to debug, and hitting the
"BREAK 5" instruction over and over again. What I can't seem to find
out is how gdbserver is supposed to get scheduled again. 

-- 
-------------------------------------------------
Justin Wojdacki        
justin.wojdacki@analog.com         (408) 350-5032
Communications Processors Group -- Analog Devices