If vm_page_grab() allocates a new page, the page is not inserted into

page queue even when the allocation is not wired.  It is
responsibility of the vm_page_grab() caller to ensure that the page
does not end on the vm_object queue but not on the pagedaemon queue,
which would effectively create unpageable unwired page.

In exec_map_first_page() and vm_imgact_hold_page(), activate the page
immediately after unbusying it, to avoid leak.

In the uiomove_object_page(), deactivate page before the object is
unlocked.  There is no leak, since the page is deactivated after
uiomove_fromphys() finished.  But allowing non-queued non-wired page
in the unlocked object queue makes it impossible to assert that leak
does not happen in other places.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 1202061..8ef0821 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -993,6 +993,7 @@ exec_map_first_page(imgp)
 	vm_page_xunbusy(ma[0]);
 	vm_page_lock(ma[0]);
 	vm_page_hold(ma[0]);
+	vm_page_activate(ma[0]);
 	vm_page_unlock(ma[0]);
 	VM_OBJECT_WUNLOCK(object);