kern/38098: kqueue is not thread safe

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>Number:         38098
>Category:       kern
>Synopsis:       kqueue is not thread safe
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 24 18:30:02 +0000 2008
>Originator:     Andrew Doran
>Release:        4.99.54
>Organization:
The NetBSD Project
>Environment:
n/a
>Description:
kqueue state is not shared between processes, but is shared between LWPs
within a process. The kqueue code assumes a single threaded system.
For example, in a few places it makes calls that may block, and after
resuming proceeds without re-checking the continued validity of the operation.

>How-To-Repeat:
Code inspection.
>Fix:
Modify the kqueue code to be thread+MP safe.