x86/boot: kbuild: allow readelf executable to be specified

Introduce a new READELF variable to top-level Makefile, so the name of
readelf binary can be specified.

Before this change the name of the binary was hardcoded to
"$(CROSS_COMPILE)readelf" which might not be present for every
toolchain.

This allows to build with LLVM Object Reader by using make parameter
READELF=llvm-readelf.

Link: https://github.com/ClangBuiltLinux/linux/issues/771
Signed-off-by: Dmitry Golovin <dima@golovin.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/Makefile b/Makefile
index 73e3c280292770ccd4b5bb1be95c2fca391bfba8..01072d06b7cdc868f4dc873b7bbd2440e9b4cf2a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -414,6 +414,7 @@ STRIP               = $(CROSS_COMPILE)strip
 OBJCOPY                = $(CROSS_COMPILE)objcopy
 OBJDUMP                = $(CROSS_COMPILE)objdump
 OBJSIZE                = $(CROSS_COMPILE)size
+READELF                = $(CROSS_COMPILE)readelf
 PAHOLE         = pahole
 LEX            = flex
 YACC           = bison
@@ -472,7 +473,7 @@ GCC_PLUGINS_CFLAGS :=
 CLANG_FLAGS :=
 
 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE AS LD CC
-export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE PAHOLE LEX YACC AWK INSTALLKERNEL
+export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX YACC AWK INSTALLKERNEL
 export PERL PYTHON PYTHON2 PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index aa976adb7094ee37158a901a3372b079df13bcb8..1dac210f7d446b906b3c75969331a46a84db2249 100644 (file)
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -103,7 +103,7 @@ vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
 quiet_cmd_check_data_rel = DATAREL $@
 define cmd_check_data_rel
        for obj in $(filter %.o,$^); do \
-               ${CROSS_COMPILE}readelf -S $$obj | grep -qF .rel.local && { \
+               $(READELF) -S $$obj | grep -qF .rel.local && { \
                        echo "error: $$obj has data relocations!" >&2; \
                        exit 1; \
                } || true; \