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

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

The following reply was made to PR kern/42992; it has been noted by GNATS.

From: "Paul Koning" <Paul_Koning%Dell.com@localhost>
To: <gnats-bugs%NetBSD.org@localhost>,
        <kern-bug-people%netbsd.org@localhost>,
        <gnats-admin%netbsd.org@localhost>,
        <netbsd-bugs%netbsd.org@localhost>
Cc: 
Subject: RE: kern/42992: KGDB does not work once interrupts are enabled
Date: Wed, 17 Mar 2010 15:37:05 -0400

 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
 >=20
 > The following reply was made to PR kern/42992; it has been noted by
 > GNATS.
 >=20
 > 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
 >=20
 >  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.
 >=20
 >  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.
 >=20
 >  --
 >  David A. Holland
 >  dholland%netbsd.org@localhost
 >=20