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

From: Daniel Jacobowitz
Date: Thu Feb 26 2004 - 11:16:28 EST


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
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