Re: KGDB question

[Matt Mackall <mpm@selenic.com>]

On Thu, Mar 17, 2005 at 02:29:58PM -0800, Andrew Morton wrote:
> Jesse Barnes <jbarnes@engr.sgi.com> wrote:
> >
> > > kgdb patches are maintained in -mm kernels.
> > >
> > > Patches are in
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11/2.6.11
> > >-mm1/broken-out/*kgdb*
> > >
> > > And the patch application order is described in
> > >
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11/2.6.11
> > >-mm1/patch-series -
> > 
> > What's the latest status on these?  Last I heard, some cleanup was going to 
> > happen to make kgdb suitable for the mainline, did that ever happen?
> 
> It part-happened, then the effort seemed to die.
> 
> >  Also, 
> > it would be nice if I could connect to a remote kernel running the kgdb stubs 
> > w/o having to run gdb on the same ethernet segment.  Would that be difficult 
> > to fix?
> 
> <tries to remember how ethernet works>
> 
> Maybe we'd have to teach kgdboe to arp for the remote debug host.  I think
> Matt was talking about that a while back.
> 
> <tries to remember how ethernet switches work>
> 
> If switches send the destination MAC address through unchanged then maybe
> the problem is that the switch simply doesn't know the MAC address of the
> remote debug host yet?  If the switch has its own MAC address (it doesn't,
> does it), or if it's actually a router then perhaps you should specify the
> router's MAC address and not the remote debug host's.

I haven't tried this, but I believe you need to set up kgdboe's
destination MAC address as the MAC of the next IP hop. Switches should
be invisible to kgdboe.

-- 
Mathematics is the supreme nostalgia of our time.