K 10
svn:author
V 5
markj
K 8
svn:date
V 27
2017-04-10T21:01:42.781970Z
K 7
svn:log
V 633
Busy the map in vm_map_protect().

We are otherwise susceptible to a race with a concurrent vm_map_wire(),
which may drop the map lock to fault pages into the object chain. In
particular, vm_map_protect() will only copy newly writable wired pages
into the top-level object when MAP_ENTRY_USER_WIRED is set, but
vm_map_wire() only sets this flag after its fault loop. We may thus end
up with a writable wired entry whose top-level object does not contain the
entire range of pages.

Reported and tested by:	pho
Reviewed by:	kib
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D10349

END