From 2f8c3b1b9459d2d4f1d24ebc07dd5ff11e23683b Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 2 Feb 2022 16:05:16 -0700 Subject: [PATCH] Makefile.extrawarn: Move -Wunaligned-access to W=1 -Wunaligned-access is a new warning in clang that is default enabled for arm and arm64 under certain circumstances within the clang frontend (see LLVM commit below). On v5.17-rc2, an ARCH=arm allmodconfig build shows 1284 total/70 unique instances of this warning (most of the instances are in header files), which is quite noisy. To keep a normal build green through CONFIG_WERROR, only show this warning with W=1, which will allow automated build systems to catch new instances of the warning so that the total number can be driven down to zero eventually since catching unaligned accesses at compile time would be generally useful. Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/35737df4dcd28534bd3090157c224c19b501278a Link: https://github.com/ClangBuiltLinux/linux/issues/1569 Link: https://github.com/ClangBuiltLinux/linux/issues/1576 Change-Id: I964e7ce2cbbe7608743cbc545a565283232ea7aa Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Masahiro Yamada [nathan: Fix conflict due to lack of afe956c577b2d] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index aa858f2e2834..6b15c3b6c012 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -72,5 +72,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) +KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) endif endif