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

commit eefb8c124fd969e9a174ff2bedff86aa305a7438 upstream.

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>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Makefile b/Makefile
index 7c001e21e28e7d12a81332d1a67cd41120ea1ac5..8c40c8e7c27432ce747eb08d42bc2b77020d9717 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 6b84afdd75382c2ee3d0aa0f514784c2fd9e87ea..98aac5b4bdb7e069d23f19c85b1a234dcf8a091d 100644 (file)
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -102,7 +102,7 @@ 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; \