kasan: turn on -fsanitize-address-use-after-scope
In the upcoming gcc7 release, the -fsanitize=kernel-address option at
first implied new -fsanitize-address-use-after-scope option. This would
cause link errors on older kernels because they don't have two new
functions required for use-after-scope support. Therefore, gcc7 changed
default to -fno-sanitize-address-use-after-scope.
Now the kernel has everything required for that feature since commit
828347f8f9a5 ("kasan: support use-after-scope detection"). So, to make it
work, we just have to enable use-after-scope in CFLAGS.
Link: http://lkml.kernel.org/r/1481207977-28654-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 37323b0..9576775 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -28,4 +28,6 @@
CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
endif
endif
+
+CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
endif