The issue with using `-fno-builtin-*` flags was that they were not
retained during an LTO link with LLVM. This was fixed in clang-11 by
https://reviews.llvm.org/D71193
(0508c994f0b14144041f2cfd3ba9f9a80f03de08), which is also the minimum
supported version of clang for LTO. Use `-fno-builtin-bcmp` instead.
With this applid, we can cleanly revert
commit 5f074f3e192f ("lib/string.c: implement a basic bcmp")
Reviewed-by: Kees Cook <keesc...@chromium.org>
Suggested-by: Nathan Chancellor <natechancel...@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulni...@google.com>
---
Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/Makefile b/Makefile
index e523dc8d30e0..def590b743a9 100644
--- a/Makefile
+++ b/Makefile
@@ -579,6 +579,7 @@ CLANG_FLAGS += -no-integrated-as
endif
CLANG_FLAGS += -Werror=unknown-warning-option
CLANG_FLAGS += -fno-builtin-stpcpy
+CLANG_FLAGS += -fno-builtin-bcmp
KBUILD_CFLAGS += $(CLANG_FLAGS)
KBUILD_AFLAGS += $(CLANG_FLAGS)
export CLANG_FLAGS
--
2.28.0.297.g1956fa8f8d-goog
