Hi Arnd, 2018-01-18 4:40 GMT+09:00 Arnd Bergmann <arnd@xxxxxxxx>: > On Wed, Jan 17, 2018 at 5:12 PM, Masahiro Yamada > <yamada.masahiro@xxxxxxxxxxxxx> wrote: >> 2018-01-11 18:22 GMT+09:00 Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>: >>> From: Xiongfeng Wang <xiongfeng.wang@xxxxxxxxxx> >>> >>> gcc-8 reports many -Wpacked-not-aligned warnings. The below are some >>> examples. >>> >>> ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct >>> ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] >>> } __attribute__ ((packed)); >>> >>> ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct >>> ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] >>> } __attribute__ ((packed)); >>> >>> ./include/linux/ceph/msgr.h:67:1: warning: alignment 1 of 'struct >>> ceph_entity_addr' is less than 8 [-Wpacked-not-aligned] >>> } __attribute__ ((packed)); >>> >>> This patch suppress this kind of warnings for default setting. >>> >>> Signed-off-by: Xiongfeng Wang <xiongfeng.wang@xxxxxxxxxx> >>> --- >>> scripts/Makefile.extrawarn | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn >>> index c6ebf42..8d53570 100644 >>> --- a/scripts/Makefile.extrawarn >>> +++ b/scripts/Makefile.extrawarn >>> @@ -11,6 +11,8 @@ >>> # are not supported by all versions of the compiler >>> # ========================================================================== >>> >>> +KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) >>> + >> >> I moved this to else case of KBUILD_ENABLE_EXTRA_GCC_CHECKS >> >> Please let me know if you see a problem. > > It means we get the warning for any argument to W=, not just W=1, but > that's probably fine. Oops, you are right. I retrace it. > I'd like to one day clean up the clang warnings > and those that we disable unconditionally in the top-level Makefile > so that each warning gets enabled at a specific level. Yup. As a loosely related item, I see some confusion for DTC extra warning checks. I have sent a patch. > For the time > being, I'm happy with the packed-not-aligned disabled by default. > > Arnd Anyway, I picked the original patch. You may move it to the top-level Makefile when you work on it. -- Best Regards Masahiro Yamada -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
