Re: [Kgdb-bugreport] [PATCH][3/3] Update CVS KGDB's wrt connect / detach

[Daniel Jacobowitz <dan@debian.org>]

On Thu, Feb 26, 2004 at 07:41:55AM -0700, Tom Rini wrote:
> On Thu, Feb 26, 2004 at 01:44:49PM +0530, Amit S. Kale wrote:
> 
> > On Thursday 26 Feb 2004 3:23 am, Tom Rini wrote:
> > > The following patch fixes a number of little issues here and there, and
> > > ends up making things more robust.
> > > - We don't need kgdb_might_be_resumed or kgdb_killed_or_detached.
> > >   GDB attaching is GDB attaching, we haven't preserved any of the
> > >   previous context anyhow.
> > 
> > If gdb is restarted, kgdb has to remove all breakpoints. Present kgdb does 
> > that in the code this patch removes:
> > 
> > -		if (remcom_in_buffer[0] == 'H' && remcom_in_buffer[1] == 'c') {
> > -			remove_all_break();
> > -			atomic_set(&kgdb_killed_or_detached, 0);
> > -			ok_packet(remcom_out_buffer);
> > 
> > If we don't remove breakpoints, they stay in kgdb without gdb not knowing it 
> > and causes consistency problems.
> 
> Er, what do you mean 'restarted' ?  If gdb somehow disconnects 'detach'
> or ^D^D, remove_all_break() gets called.  Is there another way for gdb
> to somehow disconnect that I don't know of?

Yes.  See the disconnect command in recent GDB versions.

> 
> > > - Don't try and look for a connection in put_packet, after we've tried
> > >   to put a packet.  Instead, when we receive a packet, GDB has
> > >   connected.
> > 
> > We have to check for gdb connection in putpacket or else following problem 
> > occurs.
> > 
> > 1. kgdb console messages are to be put.
> > 2. gdb dies
> 
> As in doesn't cleanly remove itself?

Seg faults, for instance.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer