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Commit cae73f23 authored by Song Liu's avatar Song Liu Committed by Arnaldo Carvalho de Melo
Browse files

bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump() 



This patches uses bpf_program__get_prog_info_linear() to simplify the
logic in prog.c do_dump().

Committer testing:

Before:

  # bpftool prog dump xlated id 208 > /tmp/dump.xlated.before
  # bpftool prog dump jited id 208 > /tmp/dump.jited.before
  # bpftool map dump id 107 > /tmp/map.dump.before

After:

  # ~acme/git/perf/tools/bpf/bpftool/bpftool map dump id 107 > /tmp/map.dump.after
  # ~acme/git/perf/tools/bpf/bpftool/bpftool prog dump xlated id 208 > /tmp/dump.xlated.after
  # ~acme/git/perf/tools/bpf/bpftool/bpftool prog dump jited id 208 > /tmp/dump.jited.after
  # diff -u /tmp/dump.xlated.before /tmp/dump.xlated.after
  # diff -u /tmp/dump.jited.before /tmp/dump.jited.after
  # diff -u /tmp/map.dump.before /tmp/map.dump.after
  # ~acme/git/perf/tools/bpf/bpftool/bpftool prog dump xlated id 208
     0: (bf) r6 = r1
     1: (85) call bpf_get_current_pid_tgid#80800
     2: (63) *(u32 *)(r10 -328) = r0
     3: (bf) r2 = r10
     4: (07) r2 += -328
     5: (18) r1 = map[id:107]
     7: (85) call __htab_map_lookup_elem#85680
     8: (15) if r0 == 0x0 goto pc+1
     9: (07) r0 += 56
    10: (b7) r7 = 0
    11: (55) if r0 != 0x0 goto pc+52
    12: (bf) r1 = r10
    13: (07) r1 += -328
    14: (b7) r2 = 64
    15: (bf) r3 = r6
    16: (85) call bpf_probe_read#-46848
    17: (bf) r2 = r10
    18: (07) r2 += -320
    19: (18) r1 = map[id:106]
    21: (07) r1 += 208
    22: (61) r0 = *(u32 *)(r2 +0)
    23: (35) if r0 >= 0x200 goto pc+3
    24: (67) r0 <<= 3
    25: (0f) r0 += r1
    26: (05) goto pc+1
    27: (b7) r0 = 0
    28: (15) if r0 == 0x0 goto pc+35
    29: (71) r1 = *(u8 *)(r0 +0)
    30: (15) if r1 == 0x0 goto pc+33
    31: (b7) r5 = 64
    32: (79) r1 = *(u64 *)(r10 -320)
    33: (15) if r1 == 0x2 goto pc+2
    34: (15) if r1 == 0x101 goto pc+3
    35: (55) if r1 != 0x15 goto pc+19
    36: (79) r3 = *(u64 *)(r6 +16)
    37: (05) goto pc+1
    38: (79) r3 = *(u64 *)(r6 +24)
    39: (15) if r3 == 0x0 goto pc+15
    40: (b7) r1 = 0
    41: (63) *(u32 *)(r10 -260) = r1
    42: (bf) r1 = r10
    43: (07) r1 += -256
    44: (b7) r2 = 256
    45: (85) call bpf_probe_read_str#-46704
    46: (b7) r5 = 328
    47: (63) *(u32 *)(r10 -264) = r0
    48: (bf) r1 = r0
    49: (67) r1 <<= 32
    50: (77) r1 >>= 32
    51: (25) if r1 > 0xff goto pc+3
    52: (07) r0 += 72
    53: (57) r0 &= 255
    54: (bf) r5 = r0
    55: (bf) r4 = r10
    56: (07) r4 += -328
    57: (bf) r1 = r6
    58: (18) r2 = map[id:105]
    60: (18) r3 = 0xffffffff
    62: (85) call bpf_perf_event_output_tp#-45104
    63: (bf) r7 = r0
    64: (bf) r0 = r7
    65: (95) exit
  #

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Reviewed-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: kernel-team@fb.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190312053051.2690567-4-songliubraving@fb.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 34be1646

tools/bpf/bpftool/prog.c

+59 −207
Original line number Diff line number Diff line
@@ -401,41 +401,31 @@ static int do_show(int argc, char **argv) 


static int do_dump(int argc, char **argv)

{

	unsigned int finfo_rec_size, linfo_rec_size, jited_linfo_rec_size;

	void *func_info = NULL, *linfo = NULL, *jited_linfo = NULL;

	unsigned int nr_finfo, nr_linfo = 0, nr_jited_linfo = 0;

	struct bpf_prog_info_linear *info_linear;

	struct bpf_prog_linfo *prog_linfo = NULL;

	unsigned long *func_ksyms = NULL;

	struct bpf_prog_info info = {};

	unsigned int *func_lens = NULL;

	enum {DUMP_JITED, DUMP_XLATED} mode;

	const char *disasm_opt = NULL;

	unsigned int nr_func_ksyms;

	unsigned int nr_func_lens;

	struct bpf_prog_info *info;

	struct dump_data dd = {};

	__u32 len = sizeof(info);

	void *func_info = NULL;

	struct btf *btf = NULL;

	unsigned int buf_size;

	char *filepath = NULL;

	bool opcodes = false;

	bool visual = false;

	char func_sig[1024];

	unsigned char *buf;

	bool linum = false;

	__u32 *member_len;

	__u64 *member_ptr;

	__u32 member_len;

	__u64 arrays;

	ssize_t n;

	int err;

	int fd;



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

		if (disasm_init())

			return -1;



		member_len = &info.jited_prog_len;

		member_ptr = &info.jited_prog_insns;

		mode = DUMP_JITED;

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

		member_len = &info.xlated_prog_len;

		member_ptr = &info.xlated_prog_insns;

		mode = DUMP_XLATED;

	} else {

		p_err("expected 'xlated' or 'jited', got: %s", *argv);

		return -1;
@@ -474,175 +464,50 @@ static int do_dump(int argc, char **argv) 
		return -1;

	}



	err = bpf_obj_get_info_by_fd(fd, &info, &len);

	if (err) {

		p_err("can't get prog info: %s", strerror(errno));

		return -1;

	}



	if (!*member_len) {

		p_info("no instructions returned");

		close(fd);

		return 0;

	}



	buf_size = *member_len;



	buf = malloc(buf_size);

	if (!buf) {

		p_err("mem alloc failed");

		close(fd);

		return -1;

	}



	nr_func_ksyms = info.nr_jited_ksyms;

	if (nr_func_ksyms) {

		func_ksyms = malloc(nr_func_ksyms * sizeof(__u64));

		if (!func_ksyms) {

			p_err("mem alloc failed");

			close(fd);

			goto err_free;

		}

	}



	nr_func_lens = info.nr_jited_func_lens;

	if (nr_func_lens) {

		func_lens = malloc(nr_func_lens * sizeof(__u32));

		if (!func_lens) {

			p_err("mem alloc failed");

			close(fd);

			goto err_free;

		}

	}



	nr_finfo = info.nr_func_info;

	finfo_rec_size = info.func_info_rec_size;

	if (nr_finfo && finfo_rec_size) {

		func_info = malloc(nr_finfo * finfo_rec_size);

		if (!func_info) {

			p_err("mem alloc failed");

			close(fd);

			goto err_free;

		}

	}



	linfo_rec_size = info.line_info_rec_size;

	if (info.nr_line_info && linfo_rec_size && info.btf_id) {

		nr_linfo = info.nr_line_info;

		linfo = malloc(nr_linfo * linfo_rec_size);

		if (!linfo) {

			p_err("mem alloc failed");

			close(fd);

			goto err_free;

		}

	}



	jited_linfo_rec_size = info.jited_line_info_rec_size;

	if (info.nr_jited_line_info &&

	    jited_linfo_rec_size &&

	    info.nr_jited_ksyms &&

	    info.nr_jited_func_lens &&

	    info.btf_id) {

		nr_jited_linfo = info.nr_jited_line_info;

		jited_linfo = malloc(nr_jited_linfo * jited_linfo_rec_size);

		if (!jited_linfo) {

			p_err("mem alloc failed");

			close(fd);

			goto err_free;

		}

	}



	memset(&info, 0, sizeof(info));

	if (mode == DUMP_JITED)

		arrays = 1UL << BPF_PROG_INFO_JITED_INSNS;

	else

		arrays = 1UL << BPF_PROG_INFO_XLATED_INSNS;



	*member_ptr = ptr_to_u64(buf);

	*member_len = buf_size;

	info.jited_ksyms = ptr_to_u64(func_ksyms);

	info.nr_jited_ksyms = nr_func_ksyms;

	info.jited_func_lens = ptr_to_u64(func_lens);

	info.nr_jited_func_lens = nr_func_lens;

	info.nr_func_info = nr_finfo;

	info.func_info_rec_size = finfo_rec_size;

	info.func_info = ptr_to_u64(func_info);

	info.nr_line_info = nr_linfo;

	info.line_info_rec_size = linfo_rec_size;

	info.line_info = ptr_to_u64(linfo);

	info.nr_jited_line_info = nr_jited_linfo;

	info.jited_line_info_rec_size = jited_linfo_rec_size;

	info.jited_line_info = ptr_to_u64(jited_linfo);

	arrays |= 1UL << BPF_PROG_INFO_JITED_KSYMS;

	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;

	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;

	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;

	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;



	err = bpf_obj_get_info_by_fd(fd, &info, &len);

	info_linear = bpf_program__get_prog_info_linear(fd, arrays);

	close(fd);

	if (err) {

	if (IS_ERR_OR_NULL(info_linear)) {

		p_err("can't get prog info: %s", strerror(errno));

		goto err_free;

	}



	if (*member_len > buf_size) {

		p_err("too many instructions returned");

		goto err_free;

	}



	if (info.nr_jited_ksyms > nr_func_ksyms) {

		p_err("too many addresses returned");

		goto err_free;

	}



	if (info.nr_jited_func_lens > nr_func_lens) {

		p_err("too many values returned");

		goto err_free;

	}



	if (info.nr_func_info != nr_finfo) {

		p_err("incorrect nr_func_info %d vs. expected %d",

		      info.nr_func_info, nr_finfo);

		goto err_free;

	}



	if (info.func_info_rec_size != finfo_rec_size) {

		p_err("incorrect func_info_rec_size %d vs. expected %d",

		      info.func_info_rec_size, finfo_rec_size);

		goto err_free;

	}



	if (linfo && info.nr_line_info != nr_linfo) {

		p_err("incorrect nr_line_info %u vs. expected %u",

		      info.nr_line_info, nr_linfo);

		goto err_free;

	}



	if (info.line_info_rec_size != linfo_rec_size) {

		p_err("incorrect line_info_rec_size %u vs. expected %u",

		      info.line_info_rec_size, linfo_rec_size);

		goto err_free;

	}



	if (jited_linfo && info.nr_jited_line_info != nr_jited_linfo) {

		p_err("incorrect nr_jited_line_info %u vs. expected %u",

		      info.nr_jited_line_info, nr_jited_linfo);

		goto err_free;

		return -1;

	}



	if (info.jited_line_info_rec_size != jited_linfo_rec_size) {

		p_err("incorrect jited_line_info_rec_size %u vs. expected %u",

		      info.jited_line_info_rec_size, jited_linfo_rec_size);

	info = &info_linear->info;

	if (mode == DUMP_JITED) {

		if (info->jited_prog_len == 0) {

			p_info("no instructions returned");

			goto err_free;

		}



	if ((member_len == &info.jited_prog_len &&

	     info.jited_prog_insns == 0) ||

	    (member_len == &info.xlated_prog_len &&

	     info.xlated_prog_insns == 0)) {

		buf = (unsigned char *)(info->jited_prog_insns);

		member_len = info->jited_prog_len;

	} else {	/* DUMP_XLATED */

		if (info->xlated_prog_len == 0) {

			p_err("error retrieving insn dump: kernel.kptr_restrict set?");

			goto err_free;

		}

		buf = (unsigned char *)info->xlated_prog_insns;

		member_len = info->xlated_prog_len;

	}



	if (info.btf_id && btf__get_from_id(info.btf_id, &btf)) {

	if (info->btf_id && btf__get_from_id(info->btf_id, &btf)) {

		p_err("failed to get btf");

		goto err_free;

	}



	if (nr_linfo) {

		prog_linfo = bpf_prog_linfo__new(&info);

	func_info = (void *)info->func_info;



	if (info->nr_line_info) {

		prog_linfo = bpf_prog_linfo__new(info);

		if (!prog_linfo)

			p_info("error in processing bpf_line_info.  continue without it.");

	}
@@ -655,9 +520,9 @@ static int do_dump(int argc, char **argv) 
			goto err_free;

		}



		n = write(fd, buf, *member_len);

		n = write(fd, buf, member_len);

		close(fd);

		if (n != *member_len) {

		if (n != member_len) {

			p_err("error writing output file: %s",

			      n < 0 ? strerror(errno) : "short write");

			goto err_free;
@@ -665,19 +530,19 @@ static int do_dump(int argc, char **argv) 


		if (json_output)

			jsonw_null(json_wtr);

	} else if (member_len == &info.jited_prog_len) {

	} else if (mode == DUMP_JITED) {

		const char *name = NULL;



		if (info.ifindex) {

			name = ifindex_to_bfd_params(info.ifindex,

						     info.netns_dev,

						     info.netns_ino,

		if (info->ifindex) {

			name = ifindex_to_bfd_params(info->ifindex,

						     info->netns_dev,

						     info->netns_ino,

						     &disasm_opt);

			if (!name)

				goto err_free;

		}



		if (info.nr_jited_func_lens && info.jited_func_lens) {

		if (info->nr_jited_func_lens && info->jited_func_lens) {

			struct kernel_sym *sym = NULL;

			struct bpf_func_info *record;

			char sym_name[SYM_MAX_NAME];
@@ -685,17 +550,16 @@ static int do_dump(int argc, char **argv) 
			__u64 *ksyms = NULL;

			__u32 *lens;

			__u32 i;



			if (info.nr_jited_ksyms) {

			if (info->nr_jited_ksyms) {

				kernel_syms_load(&dd);

				ksyms = (__u64 *) info.jited_ksyms;

				ksyms = (__u64 *) info->jited_ksyms;

			}



			if (json_output)

				jsonw_start_array(json_wtr);



			lens = (__u32 *) info.jited_func_lens;

			for (i = 0; i < info.nr_jited_func_lens; i++) {

			lens = (__u32 *) info->jited_func_lens;

			for (i = 0; i < info->nr_jited_func_lens; i++) {

				if (ksyms) {

					sym = kernel_syms_search(&dd, ksyms[i]);

					if (sym)
@@ -707,7 +571,7 @@ static int do_dump(int argc, char **argv) 
				}



				if (func_info) {

					record = func_info + i * finfo_rec_size;

					record = func_info + i * info->func_info_rec_size;

					btf_dumper_type_only(btf, record->type_id,

							     func_sig,

							     sizeof(func_sig));
@@ -744,49 +608,37 @@ static int do_dump(int argc, char **argv) 
			if (json_output)

				jsonw_end_array(json_wtr);

		} else {

			disasm_print_insn(buf, *member_len, opcodes, name,

			disasm_print_insn(buf, member_len, opcodes, name,

					  disasm_opt, btf, NULL, 0, 0, false);

		}

	} else if (visual) {

		if (json_output)

			jsonw_null(json_wtr);

		else

			dump_xlated_cfg(buf, *member_len);

			dump_xlated_cfg(buf, member_len);

	} else {

		kernel_syms_load(&dd);

		dd.nr_jited_ksyms = info.nr_jited_ksyms;

		dd.jited_ksyms = (__u64 *) info.jited_ksyms;

		dd.nr_jited_ksyms = info->nr_jited_ksyms;

		dd.jited_ksyms = (__u64 *) info->jited_ksyms;

		dd.btf = btf;

		dd.func_info = func_info;

		dd.finfo_rec_size = finfo_rec_size;

		dd.finfo_rec_size = info->func_info_rec_size;

		dd.prog_linfo = prog_linfo;



		if (json_output)

			dump_xlated_json(&dd, buf, *member_len, opcodes,

			dump_xlated_json(&dd, buf, member_len, opcodes,

					 linum);

		else

			dump_xlated_plain(&dd, buf, *member_len, opcodes,

			dump_xlated_plain(&dd, buf, member_len, opcodes,

					  linum);

		kernel_syms_destroy(&dd);

	}



	free(buf);

	free(func_ksyms);

	free(func_lens);

	free(func_info);

	free(linfo);

	free(jited_linfo);

	bpf_prog_linfo__free(prog_linfo);

	free(info_linear);

	return 0;



err_free:

	free(buf);

	free(func_ksyms);

	free(func_lens);

	free(func_info);

	free(linfo);

	free(jited_linfo);

	bpf_prog_linfo__free(prog_linfo);

	free(info_linear);

	return -1;

}