tools/bpftool: fix bpftool build with bintutils >= 2.9

Bpftool build is broken with binutils version 2.29 and later.
The cause is commit 003ca0fd2286 ("Refactor disassembler selection")
in the binutils repo, which changed the disassembler() function
signature.

Fix this by adding a new "feature" to the tools/build/features
infrastructure and make it responsible for decision which
disassembler() function signature to use.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/Makefile

@@ -9,6 +9,35 @@ MAKE = make
 CFLAGS += -Wall -O2
 CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include
 
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+FEATURE_USER = .bpf
+FEATURE_TESTS = libbfd disassembler-four-args
+FEATURE_DISPLAY = libbfd disassembler-four-args
+
+check_feat := 1
+NON_CHECK_FEAT_TARGETS := clean bpftool_clean
+ifdef MAKECMDGOALS
+ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
+  check_feat := 0
+endif
+endif
+
+ifeq ($(check_feat),1)
+ifeq ($(FEATURES_DUMP),)
+include $(srctree)/tools/build/Makefile.feature
+else
+include $(FEATURES_DUMP)
+endif
+endif
+
+ifeq ($(feature-disassembler-four-args), 1)
+CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 %.yacc.c: %.y
 	$(YACC) -o $@ -d $<
 

tools/bpf/bpf_jit_disasm.c

@@ -72,7 +72,14 @@ static void get_asm_insns(uint8_t *image, size_t len, int opcodes)
 
 	disassemble_init_for_target(&info);
 
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
 	disassemble = disassembler(bfdf);
+#endif
 	assert(disassemble);
 
 	do {

tools/bpf/bpftool/Makefile

@@ -46,6 +46,30 @@ LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
 INSTALL ?= install
 RM ?= rm -f
 
+FEATURE_USER = .bpftool
+FEATURE_TESTS = libbfd disassembler-four-args
+FEATURE_DISPLAY = libbfd disassembler-four-args
+
+check_feat := 1
+NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
+ifdef MAKECMDGOALS
+ifeq ($(filter-out $(NON_CHECK_FEAT_TARGETS),$(MAKECMDGOALS)),)
+  check_feat := 0
+endif
+endif
+
+ifeq ($(check_feat),1)
+ifeq ($(FEATURES_DUMP),)
+include $(srctree)/tools/build/Makefile.feature
+else
+include $(FEATURES_DUMP)
+endif
+endif
+
+ifeq ($(feature-disassembler-four-args), 1)
+CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 include $(wildcard *.d)
 
 all: $(OUTPUT)bpftool

tools/bpf/bpftool/jit_disasm.c

@@ -107,7 +107,14 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
 
 	disassemble_init_for_target(&info);
 
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
 	disassemble = disassembler(bfdf);
+#endif
 	assert(disassemble);
 
 	if (json_output)

tools/build/feature/Makefile

@@ -13,6 +13,7 @@ FILES=                                          \
          test-hello.bin                         \
          test-libaudit.bin                      \
          test-libbfd.bin                        \
+         test-disassembler-four-args.bin        \
          test-liberty.bin                       \
          test-liberty-z.bin                     \
          test-cplus-demangle.bin                \
@@ -188,6 +189,9 @@ $(OUTPUT)test-libpython-version.bin:
 $(OUTPUT)test-libbfd.bin:
 	$(BUILD) -DPACKAGE='"perf"' -lbfd -lz -liberty -ldl
 
+$(OUTPUT)test-disassembler-four-args.bin:
+	$(BUILD) -lbfd -lopcodes
+
 $(OUTPUT)test-liberty.bin:
 	$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
 

tools/build/feature/test-disassembler-four-args.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <bfd.h>
+#include <dis-asm.h>
+
+int main(void)
+{
+	bfd *abfd = bfd_openr(NULL, NULL);
+
+	disassembler(bfd_get_arch(abfd),
+		     bfd_big_endian(abfd),
+		     bfd_get_mach(abfd),
+		     abfd);
+
+	return 0;
+}