| From 5241ab4cf42d3a93b933b55d3d53f43049081fa1 Mon Sep 17 00:00:00 2001 |
| From: Masahiro Yamada <yamada.masahiro@socionext.com> |
| Date: Mon, 29 Jul 2019 18:15:17 +0900 |
| Subject: kbuild: initialize CLANG_FLAGS correctly in the top Makefile |
| |
| From: Masahiro Yamada <yamada.masahiro@socionext.com> |
| |
| commit 5241ab4cf42d3a93b933b55d3d53f43049081fa1 upstream. |
| |
| CLANG_FLAGS is initialized by the following line: |
| |
| CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%)) |
| |
| ..., which is run only when CROSS_COMPILE is set. |
| |
| Some build targets (bindeb-pkg etc.) recurse to the top Makefile. |
| |
| When you build the kernel with Clang but without CROSS_COMPILE, |
| the same compiler flags such as -no-integrated-as are accumulated |
| into CLANG_FLAGS. |
| |
| If you run 'make CC=clang' and then 'make CC=clang bindeb-pkg', |
| Kbuild will recompile everything needlessly due to the build command |
| change. |
| |
| Fix this by correctly initializing CLANG_FLAGS. |
| |
| Fixes: 238bcbc4e07f ("kbuild: consolidate Clang compiler flags") |
| Cc: <stable@vger.kernel.org> # v5.0+ |
| Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> |
| Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> |
| Acked-by: Nick Desaulniers <ndesaulniers@google.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| Makefile | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/Makefile |
| +++ b/Makefile |
| @@ -400,6 +400,7 @@ KBUILD_AFLAGS_MODULE := -DMODULE |
| KBUILD_CFLAGS_MODULE := -DMODULE |
| KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds |
| GCC_PLUGINS_CFLAGS := |
| +CLANG_FLAGS := |
| |
| # Read KERNELRELEASE from include/config/kernel.release (if it exists) |
| KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null) |
| @@ -506,7 +507,7 @@ endif |
| |
| ifeq ($(cc-name),clang) |
| ifneq ($(CROSS_COMPILE),) |
| -CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE:%-=%)) |
| +CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) |
| GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit)) |
| CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) |
| GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) |
