From:   Kees Cook <keescook@chromium.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Kees Cook <keescook@chromium.org>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Marco Elver <elver@google.com>, Arnd Bergmann <arnd@arndb.de>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Jiri Olsa <jolsa@kernel.org>, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
Subject: [PATCH] lib/test_ubsan: Silence compile-time array bounds warnings
Date:   Fri,  3 Dec 2021 01:30:00 -0800
Message-Id: <20211203093000.3714620-1-keescook@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The UBSAN tests intentionally operate beyond array bounds, so silence
the warning visible with a -Warray-bounds build:

lib/test_ubsan.c: In function 'test_ubsan_object_size_mismatch':
lib/test_ubsan.c:109:16: error: array subscript 'long long int[0]' is partly outside array bounds of 'volatile int[1]' [-Werror=array-bounds]
  109 |         val2 = *ptr;
      |                ^~~~
lib/test_ubsan.c:104:22: note: while referencing 'val'
  104 |         volatile int val __aligned(8) = 4;
      |                      ^~~

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 lib/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Makefile b/lib/Makefile
index 08959b10bac9..2742a54a4275 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_KASAN_MODULE_TEST) += test_kasan_module.o
 CFLAGS_test_kasan_module.o += -fno-builtin
 obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
 CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla)
+CFLAGS_test_ubsan.o += $(call cc-disable-warning, array-bounds)
 UBSAN_SANITIZE_test_ubsan.o := y
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
-- 
2.30.2