From 29a9c10e4110e368443f0b606d71557edee7f2cc Mon Sep 17 00:00:00 2001
From: Stanislav Fomichev <sdf@google.com>
Date: Mon, 12 Nov 2018 13:44:10 -0800
Subject: bpftool: make libbfd optional

Make it possible to build bpftool without libbfd. libbfd and libopcodes are
typically provided in dev/dbg packages (binutils-dev in debian) which we
usually don't have installed on the fleet machines and we'd like a way to have
bpftool version that works without installing any additional packages.
This excludes support for disassembling jit-ted code and prints an error if
the user tries to use these features.

Tested by:
cat > FEATURES_DUMP.bpftool <<EOF
feature-libbfd=0
feature-disassembler-four-args=1
feature-reallocarray=0
feature-libelf=1
feature-libelf-mmap=1
feature-bpf=1
EOF
FEATURES_DUMP=$PWD/FEATURES_DUMP.bpftool make
ldd bpftool | grep libbfd

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 tools/bpf/bpftool/Makefile | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

(limited to 'tools/bpf/bpftool/Makefile')

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index dac7eff4c7e5..1bea6b979082 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -53,7 +53,7 @@ ifneq ($(EXTRA_LDFLAGS),)
 LDFLAGS += $(EXTRA_LDFLAGS)
 endif
 
-LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
+LIBS = -lelf $(LIBBPF)
 
 INSTALL ?= install
 RM ?= rm -f
@@ -90,7 +90,16 @@ include $(wildcard $(OUTPUT)*.d)
 
 all: $(OUTPUT)bpftool
 
-SRCS = $(wildcard *.c)
+BFD_SRCS = jit_disasm.c
+
+SRCS = $(filter-out $(BFD_SRCS),$(wildcard *.c))
+
+ifeq ($(feature-libbfd),1)
+CFLAGS += -DHAVE_LIBBFD_SUPPORT
+SRCS += $(BFD_SRCS)
+LIBS += -lbfd -lopcodes
+endif
+
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
 
 $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
-- 
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