From fd17e272be9c50190f1185a1007d72dc1eedb903 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 3 Sep 2020 13:35:36 -0700 Subject: tools/bpftool: Replace bpf_program__title() with bpf_program__section_name() bpf_program__title() is deprecated, switch to bpf_program__section_name() and avoid compilation warnings. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200903203542.15944-9-andriin@fb.com --- tools/bpf/bpftool/prog.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools/bpf/bpftool/prog.c') diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index d393eb8263a6..f7923414a052 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1304,7 +1304,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) enum bpf_prog_type prog_type = common_prog_type; if (prog_type == BPF_PROG_TYPE_UNSPEC) { - const char *sec_name = bpf_program__title(pos, false); + const char *sec_name = bpf_program__section_name(pos); err = get_prog_type_by_name(sec_name, &prog_type, &expected_attach_type); @@ -1398,7 +1398,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) err = bpf_obj_pin(bpf_program__fd(prog), pinfile); if (err) { p_err("failed to pin program %s", - bpf_program__title(prog, false)); + bpf_program__section_name(prog)); goto err_close_obj; } } else { -- cgit From aff52e685eb39984f3a613e8a5c570d97e5d2414 Mon Sep 17 00:00:00 2001 From: YiFei Zhu Date: Tue, 15 Sep 2020 16:45:42 -0700 Subject: bpftool: Support dumping metadata Dump metadata in the 'bpftool prog' list if it's present. For some formatting some BTF code is put directly in the metadata dumping. Sanity checks on the map and the kind of the btf_type to make sure we are actually dumping what we are expecting. A helper jsonw_reset is added to json writer so we can reuse the same json writer without having extraneous commas. Sample output: $ bpftool prog 6: cgroup_skb name prog tag bcf7977d3b93787c gpl [...] btf_id 4 metadata: a = "foo" b = 1 $ bpftool prog --json --pretty [{ "id": 6, [...] "btf_id": 4, "metadata": { "a": "foo", "b": 1 } } ] Signed-off-by: YiFei Zhu Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Cc: YiFei Zhu Link: https://lore.kernel.org/bpf/20200915234543.3220146-5-sdf@google.com --- tools/bpf/bpftool/prog.c | 199 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 199 insertions(+) (limited to 'tools/bpf/bpftool/prog.c') diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index f7923414a052..d942c1e3372c 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -29,6 +29,9 @@ #include "main.h" #include "xlated_dumper.h" +#define BPF_METADATA_PREFIX "bpf_metadata_" +#define BPF_METADATA_PREFIX_LEN (sizeof(BPF_METADATA_PREFIX) - 1) + const char * const prog_type_name[] = { [BPF_PROG_TYPE_UNSPEC] = "unspec", [BPF_PROG_TYPE_SOCKET_FILTER] = "socket_filter", @@ -151,6 +154,198 @@ static void show_prog_maps(int fd, __u32 num_maps) } } +static void *find_metadata(int prog_fd, struct bpf_map_info *map_info) +{ + struct bpf_prog_info prog_info; + __u32 prog_info_len; + __u32 map_info_len; + void *value = NULL; + __u32 *map_ids; + int nr_maps; + int key = 0; + int map_fd; + int ret; + __u32 i; + + memset(&prog_info, 0, sizeof(prog_info)); + prog_info_len = sizeof(prog_info); + ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len); + if (ret) + return NULL; + + if (!prog_info.nr_map_ids) + return NULL; + + map_ids = calloc(prog_info.nr_map_ids, sizeof(__u32)); + if (!map_ids) + return NULL; + + nr_maps = prog_info.nr_map_ids; + memset(&prog_info, 0, sizeof(prog_info)); + prog_info.nr_map_ids = nr_maps; + prog_info.map_ids = ptr_to_u64(map_ids); + prog_info_len = sizeof(prog_info); + + ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len); + if (ret) + goto free_map_ids; + + for (i = 0; i < prog_info.nr_map_ids; i++) { + map_fd = bpf_map_get_fd_by_id(map_ids[i]); + if (map_fd < 0) + goto free_map_ids; + + memset(map_info, 0, sizeof(*map_info)); + map_info_len = sizeof(*map_info); + ret = bpf_obj_get_info_by_fd(map_fd, map_info, &map_info_len); + if (ret < 0) { + close(map_fd); + goto free_map_ids; + } + + if (map_info->type != BPF_MAP_TYPE_ARRAY || + map_info->key_size != sizeof(int) || + map_info->max_entries != 1 || + !map_info->btf_value_type_id || + !strstr(map_info->name, ".rodata")) { + close(map_fd); + continue; + } + + value = malloc(map_info->value_size); + if (!value) { + close(map_fd); + goto free_map_ids; + } + + if (bpf_map_lookup_elem(map_fd, &key, value)) { + close(map_fd); + free(value); + value = NULL; + goto free_map_ids; + } + + close(map_fd); + break; + } + +free_map_ids: + free(map_ids); + return value; +} + +static bool has_metadata_prefix(const char *s) +{ + return strncmp(s, BPF_METADATA_PREFIX, BPF_METADATA_PREFIX_LEN) == 0; +} + +static void show_prog_metadata(int fd, __u32 num_maps) +{ + const struct btf_type *t_datasec, *t_var; + struct bpf_map_info map_info; + struct btf_var_secinfo *vsi; + bool printed_header = false; + struct btf *btf = NULL; + unsigned int i, vlen; + void *value = NULL; + const char *name; + int err; + + if (!num_maps) + return; + + memset(&map_info, 0, sizeof(map_info)); + value = find_metadata(fd, &map_info); + if (!value) + return; + + err = btf__get_from_id(map_info.btf_id, &btf); + if (err || !btf) + goto out_free; + + t_datasec = btf__type_by_id(btf, map_info.btf_value_type_id); + if (!btf_is_datasec(t_datasec)) + goto out_free; + + vlen = btf_vlen(t_datasec); + vsi = btf_var_secinfos(t_datasec); + + /* We don't proceed to check the kinds of the elements of the DATASEC. + * The verifier enforces them to be BTF_KIND_VAR. + */ + + if (json_output) { + struct btf_dumper d = { + .btf = btf, + .jw = json_wtr, + .is_plain_text = false, + }; + + for (i = 0; i < vlen; i++, vsi++) { + t_var = btf__type_by_id(btf, vsi->type); + name = btf__name_by_offset(btf, t_var->name_off); + + if (!has_metadata_prefix(name)) + continue; + + if (!printed_header) { + jsonw_name(json_wtr, "metadata"); + jsonw_start_object(json_wtr); + printed_header = true; + } + + jsonw_name(json_wtr, name + BPF_METADATA_PREFIX_LEN); + err = btf_dumper_type(&d, t_var->type, value + vsi->offset); + if (err) { + p_err("btf dump failed: %d", err); + break; + } + } + if (printed_header) + jsonw_end_object(json_wtr); + } else { + json_writer_t *btf_wtr = jsonw_new(stdout); + struct btf_dumper d = { + .btf = btf, + .jw = btf_wtr, + .is_plain_text = true, + }; + + if (!btf_wtr) { + p_err("jsonw alloc failed"); + goto out_free; + } + + for (i = 0; i < vlen; i++, vsi++) { + t_var = btf__type_by_id(btf, vsi->type); + name = btf__name_by_offset(btf, t_var->name_off); + + if (!has_metadata_prefix(name)) + continue; + + if (!printed_header) { + printf("\tmetadata:"); + printed_header = true; + } + + printf("\n\t\t%s = ", name + BPF_METADATA_PREFIX_LEN); + + jsonw_reset(btf_wtr); + err = btf_dumper_type(&d, t_var->type, value + vsi->offset); + if (err) { + p_err("btf dump failed: %d", err); + break; + } + } + if (printed_header) + jsonw_destroy(&btf_wtr); + } + +out_free: + btf__free(btf); + free(value); +} + static void print_prog_header_json(struct bpf_prog_info *info) { jsonw_uint_field(json_wtr, "id", info->id); @@ -228,6 +423,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd) emit_obj_refs_json(&refs_table, info->id, json_wtr); + show_prog_metadata(fd, info->nr_map_ids); + jsonw_end_object(json_wtr); } @@ -297,6 +494,8 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd) emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); printf("\n"); + + show_prog_metadata(fd, info->nr_map_ids); } static int show_prog(int fd) -- cgit