[tip:core/urgent] objtool: Query pkg-config for libelf location

From: tip-bot for Rolf Eike Beer
Date: Thu Mar 28 2019 - 08:37:45 EST


Commit-ID: 056d28d135bca0b1d0908990338e00e9dadaf057
Gitweb: https://git.kernel.org/tip/056d28d135bca0b1d0908990338e00e9dadaf057
Author: Rolf Eike Beer <eb@xxxxxxxxx>
AuthorDate: Tue, 26 Mar 2019 12:48:39 -0500
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 28 Mar 2019 13:32:01 +0100

objtool: Query pkg-config for libelf location

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

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

diff --git a/Makefile b/Makefile
index c0a34064c574..eef3d3f87c3b 100644
--- a/Makefile
+++ b/Makefile
@@ -950,9 +950,11 @@ 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
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index c9d038f91af6..53f8be0f4a1f 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -25,14 +25,17 @@ LIBSUBCMD = $(LIBSUBCMD_OUTPUT)libsubcmd.a
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 += -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES)
-LDFLAGS += -lelf $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
+CFLAGS += -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
+LDFLAGS += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)

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