-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@xxxxxxxxxxxxxxx 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 Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> --- v1 -> v2: https://lore.kernel.org/r/20220201232229.2992968-1-nathan@xxxxxxxxxx/ * Move to W=1 instead of W=2 so that new instances are caught (Arnd). * Add links to the ClangBuiltLinux issue tracker. scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index d53825503874..8be892887d71 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -51,6 +51,7 @@ KBUILD_CFLAGS += -Wno-sign-compare KBUILD_CFLAGS += -Wno-format-zero-length KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare +KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) endif endif base-commit: 26291c54e111ff6ba87a164d85d4a4e134b7315c -- 2.35.1
