UPSTREAM: kasan: add tests for alloca poisoning

Link: http://lkml.kernel.org/r/20171204191735.132544-5-paullawrence@google.com


Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry-picked from 00a14294bb33af533f7ac002fb20623fdd8ea0d7)
Change-Id: I2c3b607d67b4a788000c62ce920cfd603f42fa06
Signed-off-by: Paul Lawrence <paullawrence@google.com>