K 10
svn:author
V 3
mbr
K 8
svn:date
V 27
2006-09-29T07:41:24.000000Z
K 7
svn:log
V 351
MFC rev. 1.241, 1.242, 1.243

Add some Giant locks to protect against races between tty and sessrele(),
doenterpgrp(), leavepgrp(), pgdelete() and enterpgrp(). The tty code is
still under giant lock, but the session/pgrp release code just used
proctree_locks. P_CONTROLT isn't really fully locked too in enterpgrp().

Reviewed by:	jhb
Approved by:	re

END