On Fri, Aug 27, 2021 at 09:30:14AM -0700, Kees Cook wrote:
> With the recent fixes for flexible arrays and expanded FORTIFY_SOURCE
> coverage, it is now possible to enable -Warray-bounds. Since both
> GCC and Clang include -Warray-bounds in -Wall, we just need to stop
> disabling it.
>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Cc: linux-kbuild@xxxxxxxxxxxxxxx
> Co-developed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
> Makefile | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index e4f5895badb5..8e7e73a642e2 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -995,7 +995,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
>
> # We'll want to enable this eventually, but it's not going away for 5.7 at least
> KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
> -KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
> KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
>
This patch causes 'alpha' builds to fail when trying to build an image with
gcc 11.2.
In file included from include/linux/string.h:20,
from include/linux/bitmap.h:11,
from include/linux/cpumask.h:12,
from include/linux/smp.h:13,
from include/linux/lockdep.h:14,
from include/linux/spinlock.h:63,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:6,
from include/linux/mm.h:10,
from include/linux/pagemap.h:8,
from arch/alpha/mm/init.c:10:
In function '__memset',
inlined from '__bad_pagetable' at arch/alpha/mm/init.c:79:2:
arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
In function '__memset',
inlined from '__bad_page' at arch/alpha/mm/init.c:86:2:
arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
In function '__memset',
inlined from 'paging_init' at arch/alpha/mm/init.c:256:2:
arch/alpha/include/asm/string.h:37:32: error: '__builtin_memset' offset [0, 8191] is out of the bounds [0, 0] [-Werror=array-bounds]
37 | return __builtin_memset(s, c, n);
Seen in next-20210830.
Guenter
