On Wed, Feb 02, 2022 at 03:21:49PM -0800, Guenter Roeck wrote: > On 2/2/22 14:11, Kees Cook wrote: > > On Wed, Feb 02, 2022 at 08:09:03AM -0800, Guenter Roeck wrote: > > > 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); > > > > Ah! With Arnd and Nathan's help, I saw: > > https://lore.kernel.org/all/20210912160149.2227137-3-linux@xxxxxxxxxxxx/ > > Guilty as charged. Sorry, I didn't try to analyze the problem, > or I might have noticed (and saved you some work). No worries! It manifests as a completely different warning. It just happens to come from the same internal diagnostics info, I think. :) I was just delighted to see it already had a solution! -Kees -- Kees Cook
