Commit 600b7b26 authored by Andres Freund's avatar Andres Freund Committed by Arnaldo Carvalho de Melo
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tools bpftool: Fix compilation error with new binutils 

binutils changed the signature of init_disassemble_info(), which now causes
compilation to fail for tools/bpf/bpftool/jit_disasm.c, e.g. on debian
unstable.

Relevant binutils commit:

  https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07



Wire up the feature test and switch to init_disassemble_info_compat(),
which were introduced in prior commits, fixing the compilation failure.

I verified that bpftool can still disassemble bpf programs, both with an
old and new dis-asm.h API. There are no output changes for plain and json
formats. When comparing the output from old binutils (2.35)
to new bintuils with the patch (upstream snapshot) there are a few output
differences, but they are unrelated to this patch. An example hunk is:

     2f:	pop    %r14
     31:	pop    %r13
     33:	pop    %rbx
  -  34:	leaveq
  -  35:	retq
  +  34:	leave
  +  35:	ret

Signed-off-by: default avatarAndres Freund <andres@anarazel.de>
Acked-by: default avatarQuentin Monnet <quentin@isovalent.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ben Hutchings <benh@debian.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de
Link: https://lore.kernel.org/r/20220801013834.156015-8-andres@anarazel.de


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent bab211f6

tools/bpf/bpftool/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ INSTALL ?= install 
RM ?= rm -f



FEATURE_USER = .bpftool

FEATURE_TESTS = libbfd disassembler-four-args zlib libcap \

FEATURE_TESTS = libbfd disassembler-four-args disassembler-init-styled zlib libcap \

	clang-bpf-co-re

FEATURE_DISPLAY = libbfd disassembler-four-args zlib libcap \

	clang-bpf-co-re
@@ -117,6 +117,9 @@ endif 
ifeq ($(feature-disassembler-four-args), 1)

CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE

endif

ifeq ($(feature-disassembler-init-styled), 1)

    CFLAGS += -DDISASM_INIT_STYLED

endif



LIBS = $(LIBBPF) -lelf -lz

LIBS_BOOTSTRAP = $(LIBBPF_BOOTSTRAP) -lelf -lz

tools/bpf/bpftool/jit_disasm.c

+34 −8
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <sys/stat.h>

#include <limits.h>

#include <bpf/libbpf.h>

#include <tools/dis-asm-compat.h>



#include "json_writer.h"

#include "main.h"
@@ -39,15 +40,12 @@ static void get_exec_path(char *tpath, size_t size) 
}



static int oper_count;

static int fprintf_json(void *out, const char *fmt, ...)

static int printf_json(void *out, const char *fmt, va_list ap)

{

	va_list ap;

	char *s;

	int err;



	va_start(ap, fmt);

	err = vasprintf(&s, fmt, ap);

	va_end(ap);

	if (err < 0)

		return -1;
@@ -73,6 +71,32 @@ static int fprintf_json(void *out, const char *fmt, ...) 
	return 0;

}



static int fprintf_json(void *out, const char *fmt, ...)

{

	va_list ap;

	int r;



	va_start(ap, fmt);

	r = printf_json(out, fmt, ap);

	va_end(ap);



	return r;

}



static int fprintf_json_styled(void *out,

			       enum disassembler_style style __maybe_unused,

			       const char *fmt, ...)

{

	va_list ap;

	int r;



	va_start(ap, fmt);

	r = printf_json(out, fmt, ap);

	va_end(ap);



	return r;

}



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

		       const char *arch, const char *disassembler_options,

		       const struct btf *btf,
@@ -99,11 +123,13 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, 
	assert(bfd_check_format(bfdf, bfd_object));



	if (json_output)

		init_disassemble_info(&info, stdout,

				      (fprintf_ftype) fprintf_json);

		init_disassemble_info_compat(&info, stdout,

					     (fprintf_ftype) fprintf_json,

					     fprintf_json_styled);

	else

		init_disassemble_info(&info, stdout,

				      (fprintf_ftype) fprintf);

		init_disassemble_info_compat(&info, stdout,

					     (fprintf_ftype) fprintf,

					     fprintf_styled);



	/* Update architecture info for offload. */

	if (arch) {