kern/37917: /bin/ps no longer shows zombies

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>Number:         37917
>Category:       kern
>Synopsis:       /bin/ps no longer shows zombies
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 30 09:05:00 +0000 2008
>Originator:     Andrew Doran
>Release:        4.99.51
>Organization:
The NetBSD Project
>Environment:
n/a
>Description:
Zombie processes no longer show up due to p_reflock being used by
the sysctl code to hold process structures. p_reflock excludes
all references when a process beings to exit.


>How-To-Repeat:
Code inspection.
>Fix:
Add another 'reflock' style lock only for system monitoring. Drain all
references in proc_free(). Adjust sysctl/exit code to make safe use of
process substructures as they are being torn down.