Allow stack to grow up to address space limit

Allow stack to grow up to address space limit

commit bd726c90b6b8ce87602208701b208a208e6d5600 upstream.

Fix expand_upwards() on architectures with an upward-growing stack (parisc,
metag and partly IA-64) to allow the stack to reliably grow exactly up to
the address space limit given by TASK_SIZE.

Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
[sw0312.kim: cherry-pick from linux-3.10.y to apply CVE]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I827de17000efa8216b6aea9ffdc510e4052b3add