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Commit 29a9c10e authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Alexei Starovoitov
Browse files

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: default avatarStanislav Fomichev <sdf@google.com>
Acked-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ae9435f6

tools/bpf/bpftool/Makefile

+11 −2
Original line number Diff line number Diff line
@@ -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

tools/bpf/bpftool/jit_disasm.c

+7 −1
Original line number Diff line number Diff line
@@ -109,7 +109,7 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, 
		if (inf) {

			bfdf->arch_info = inf;

		} else {

			p_err("No libfd support for %s", arch);

			p_err("No libbfd support for %s", arch);

			return;

		}

	}
@@ -183,3 +183,9 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, 


	bfd_close(bfdf);

}



int disasm_init(void)

{

	bfd_init();

	return 0;

}

tools/bpf/bpftool/main.c

+0 −3
Original line number Diff line number Diff line
@@ -31,7 +31,6 @@ 
 * SOFTWARE.

 */



#include <bfd.h>

#include <ctype.h>

#include <errno.h>

#include <getopt.h>
@@ -399,8 +398,6 @@ int main(int argc, char **argv) 
	if (argc < 0)

		usage();



	bfd_init();



	ret = cmd_select(cmds, argc, argv, do_help);



	if (json_output)

tools/bpf/bpftool/main.h

+14 −0
Original line number Diff line number Diff line
@@ -147,8 +147,22 @@ int prog_parse_fd(int *argc, char ***argv); 
int map_parse_fd(int *argc, char ***argv);

int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len);



#ifdef HAVE_LIBBFD_SUPPORT

void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

		       const char *arch, const char *disassembler_options);

int disasm_init(void);

#else

static inline

void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

		       const char *arch, const char *disassembler_options)

{

}

static inline int disasm_init(void)

{

	p_err("No libbfd support");

	return -1;

}

#endif

void print_data_json(uint8_t *data, size_t len);

void print_hex_data_json(uint8_t *data, size_t len);

tools/bpf/bpftool/prog.c

+3 −0
Original line number Diff line number Diff line
@@ -467,6 +467,9 @@ static int do_dump(int argc, char **argv) 
	int fd;



	if (is_prefix(*argv, "jited")) {

		if (disasm_init())

			return -1;



		member_len = &info.jited_prog_len;

		member_ptr = &info.jited_prog_insns;

	} else if (is_prefix(*argv, "xlated")) {