RE: kern/42992: KGDB does not work once interrupts are enabled

["Paul Koning" <Paul_Koning%Dell.com@localhost>]

Agreed, it's a partial fix, but a useful one.

The most natural way for KGDB to behave is that a breakpoint stops all
CPUs.  So the full fix would mean telling the other CPUs to stop.  I
don't know how that is done, or if there is a way to do that.

        paul

> -----Original Message-----
> From: David Holland [mailto:dholland-bugs%netbsd.org@localhost]
> Sent: Wednesday, March 17, 2010 3:25 PM
> To: kern-bug-people%netbsd.org@localhost; gnats-admin%netbsd.org@localhost; 
> netbsd-
> bugs%netbsd.org@localhost; Paul Koning
> Subject: Re: kern/42992: KGDB does not work once interrupts are
enabled
> 
> The following reply was made to PR kern/42992; it has been noted by
> GNATS.
> 
> From: David Holland <dholland-bugs%netbsd.org@localhost>
> To: gnats-bugs%NetBSD.org@localhost
> Cc:
> Subject: Re: kern/42992: KGDB does not work once interrupts are
enabled
> Date: Wed, 17 Mar 2010 19:22:55 +0000
> 
>  On Wed, Mar 17, 2010 at 07:20:01PM +0000, paul_koning%dell.com@localhost 
> wrote:
>   > The solution is to put a splserial() early in kgdb_trap with the
>   > matching splx() at the two exits.  This cures the problem and
makes
>   > KGDB work reliably.
> 
>  That's not going to fix it on a multiprocessor machine though, at
>  least in general. Does this matter? I don't remember if kgdb is
>  supposed to be multiprocessor-safe.
> 
>  --
>  David A. Holland
>  dholland%netbsd.org@localhost
>