[PATCH 4.14 003/185] objtool: Query pkg-config for libelf location

From: Greg Kroah-Hartman
Date: Thu Oct 03 2019 - 12:07:32 EST


From: Rolf Eike Beer <eb@xxxxxxxxx>

commit 056d28d135bca0b1d0908990338e00e9dadaf057 upstream.

If it is not in the default location, compilation fails at several points.

Signed-off-by: Rolf Eike Beer <eb@xxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/91a25e992566a7968fedc89ec80e7f4c83ad0548.1553622500.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
Makefile | 4 +++-
tools/objtool/Makefile | 7 +++++--
2 files changed, 8 insertions(+), 3 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -949,9 +949,11 @@ mod_sign_cmd = true
endif
export mod_sign_cmd

+HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
+
ifdef CONFIG_STACK_VALIDATION
has_libelf := $(call try-run,\
- echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
+ echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
ifeq ($(has_libelf),1)
objtool_target := tools/objtool FORCE
else
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -26,14 +26,17 @@ LIBSUBCMD = $(LIBSUBCMD_OUTPUT)libsubcm
OBJTOOL := $(OUTPUT)objtool
OBJTOOL_IN := $(OBJTOOL)-in.o

+LIBELF_FLAGS := $(shell pkg-config libelf --cflags 2>/dev/null)
+LIBELF_LIBS := $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
+
all: $(OBJTOOL)

INCLUDES := -I$(srctree)/tools/include \
-I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
-I$(srctree)/tools/objtool/arch/$(ARCH)/include
WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
-CFLAGS += -Wall -Werror $(WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES)
-LDFLAGS += -lelf $(LIBSUBCMD)
+CFLAGS += -Wall -Werror $(WARNINGS) -fomit-frame-pointer -O2 -g $(INCLUDES) $(LIBELF_FLAGS)
+LDFLAGS += $(LIBELF_LIBS) $(LIBSUBCMD)

# Allow old libelf to be used:
elfshdr := $(shell echo '$(pound)include <libelf.h>' | $(CC) $(CFLAGS) -x c -E - | grep elf_getshdr)