4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nick Desaulniers <nick.desaulniers@xxxxxxxxx> commit df16aaac26e92e97ab7234d3f93c953466adc4b5 upstream. When compiling with `make CC=clang HOSTCC=clang`, I was seeing warnings that clang did not recognize -fno-delete-null-pointer-checks for HOSTCC targets. These were added in commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang"). Clang does not support -fno-delete-null-pointer-checks, so adding it to HOSTCFLAGS if HOSTCC is clang does not make sense. It's not clear why the other warnings were disabled, and just for HOSTCFLAGS, but I can remove them, add -Werror to HOSTCFLAGS and compile with clang just fine. Suggested-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> [nc: Backport to 4.9; adjust context] Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- Makefile | 5 ----- 1 file changed, 5 deletions(-) --- a/Makefile +++ b/Makefile @@ -306,11 +306,6 @@ HOSTCXX = g++ HOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer -std=gnu89 HOSTCXXFLAGS = -O2 -ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1) -HOSTCFLAGS += -Wno-unused-value -Wno-unused-parameter \ - -Wno-missing-field-initializers -fno-delete-null-pointer-checks -endif - # Decide whether to build built-in, modular, or both. # Normally, just do built-in.