port-i386/40702: ddb freezes when stepping over lock prefix

[ignatios%cs.uni-bonn.de@localhost]

>Number:         40702
>Category:       port-i386
>Synopsis:       ddb freezes when stepping over lock prefix
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 20 22:15:00 +0000 2009
>Originator:     ignatios%cs.uni-bonn.de@localhost
>Release:        NetBSD 5.0_RC2
>Organization:
        University of Bonn, CS Dept.
>Environment:
System: NetBSD laplace 5.0_RC2 NetBSD 5.0_RC2 (GENERIC) #3: Fri Feb 20 22:33:59 
CET 2009 
ignatios@random86:/var/itch/sources/5/oi386/sys/arch/i386/compile/GENERIC i386
Architecture: i386
Machine: i386
>Description:
        s(ingle step) through "lock cmpsomething" that's in cpu_simple_lock.
        The ddb prompt doesn't return. Nothing else happens.
>How-To-Repeat:
        try to single-step with ddb through pccbb_pci_callback.
>Fix:
        unknown.