* VDSO is never mapped with MAP_GROWSDOWN
* The first page  of growsdown vma may be a guard page, so any attempt
  to read it is suppressed by SIGBUS.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>