On Wed, Aug 18, 2021 at 01:11:17AM -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 a4aca01a4835..af22b83cede7 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1072,7 +1072,6 @@ 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 += -Wno-array-bounds
> KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
>
> # Another good warning that we'll want to enable eventually
alpha:defconfig:
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);
xtensa:allmodconfig:
--------------
Error log:
In file included from include/linux/uaccess.h:11,
from include/linux/sched/task.h:11,
from arch/xtensa/kernel/process.c:21:
arch/xtensa/kernel/process.c: In function 'copy_thread':
arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above array bounds of 'long unsigned int[16]'
