From 41017e56af6cf99122c86655f60fe4e1b75ecf48 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 28 Apr 2020 17:27:37 -0700 Subject: [PATCH] libbpf: Refactor BTF-defined map definition parsing logic Factor out BTF map definition logic into stand-alone routine for easier reuse for map-in-map case. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200429002739.48006-2-andriin@fb.com --- tools/lib/bpf/libbpf.c | 195 ++++++++++++++++++++++++++----------------------- 1 file changed, 103 insertions(+), 92 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8e1dc69..7d10436d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1914,109 +1914,54 @@ static int build_map_pin_path(struct bpf_map *map, const char *path) return 0; } -static int bpf_object__init_user_btf_map(struct bpf_object *obj, - const struct btf_type *sec, - int var_idx, int sec_idx, - const Elf_Data *data, bool strict, - const char *pin_root_path) + +static int parse_btf_map_def(struct bpf_object *obj, + struct bpf_map *map, + const struct btf_type *def, + bool strict, + const char *pin_root_path) { - const struct btf_type *var, *def, *t; - const struct btf_var_secinfo *vi; - const struct btf_var *var_extra; + const struct btf_type *t; const struct btf_member *m; - const char *map_name; - struct bpf_map *map; int vlen, i; - vi = btf_var_secinfos(sec) + var_idx; - var = btf__type_by_id(obj->btf, vi->type); - var_extra = btf_var(var); - map_name = btf__name_by_offset(obj->btf, var->name_off); - vlen = btf_vlen(var); - - if (map_name == NULL || map_name[0] == '\0') { - pr_warn("map #%d: empty name.\n", var_idx); - return -EINVAL; - } - if ((__u64)vi->offset + vi->size > data->d_size) { - pr_warn("map '%s' BTF data is corrupted.\n", map_name); - return -EINVAL; - } - if (!btf_is_var(var)) { - pr_warn("map '%s': unexpected var kind %u.\n", - map_name, btf_kind(var)); - return -EINVAL; - } - if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED && - var_extra->linkage != BTF_VAR_STATIC) { - pr_warn("map '%s': unsupported var linkage %u.\n", - map_name, var_extra->linkage); - return -EOPNOTSUPP; - } - - def = skip_mods_and_typedefs(obj->btf, var->type, NULL); - if (!btf_is_struct(def)) { - pr_warn("map '%s': unexpected def kind %u.\n", - map_name, btf_kind(var)); - return -EINVAL; - } - if (def->size > vi->size) { - pr_warn("map '%s': invalid def size.\n", map_name); - return -EINVAL; - } - - map = bpf_object__add_map(obj); - if (IS_ERR(map)) - return PTR_ERR(map); - map->name = strdup(map_name); - if (!map->name) { - pr_warn("map '%s': failed to alloc map name.\n", map_name); - return -ENOMEM; - } - map->libbpf_type = LIBBPF_MAP_UNSPEC; - map->def.type = BPF_MAP_TYPE_UNSPEC; - map->sec_idx = sec_idx; - map->sec_offset = vi->offset; - pr_debug("map '%s': at sec_idx %d, offset %zu.\n", - map_name, map->sec_idx, map->sec_offset); - vlen = btf_vlen(def); m = btf_members(def); for (i = 0; i < vlen; i++, m++) { const char *name = btf__name_by_offset(obj->btf, m->name_off); if (!name) { - pr_warn("map '%s': invalid field #%d.\n", map_name, i); + pr_warn("map '%s': invalid field #%d.\n", map->name, i); return -EINVAL; } if (strcmp(name, "type") == 0) { - if (!get_map_field_int(map_name, obj->btf, m, + if (!get_map_field_int(map->name, obj->btf, m, &map->def.type)) return -EINVAL; pr_debug("map '%s': found type = %u.\n", - map_name, map->def.type); + map->name, map->def.type); } else if (strcmp(name, "max_entries") == 0) { - if (!get_map_field_int(map_name, obj->btf, m, + if (!get_map_field_int(map->name, obj->btf, m, &map->def.max_entries)) return -EINVAL; pr_debug("map '%s': found max_entries = %u.\n", - map_name, map->def.max_entries); + map->name, map->def.max_entries); } else if (strcmp(name, "map_flags") == 0) { - if (!get_map_field_int(map_name, obj->btf, m, + if (!get_map_field_int(map->name, obj->btf, m, &map->def.map_flags)) return -EINVAL; pr_debug("map '%s': found map_flags = %u.\n", - map_name, map->def.map_flags); + map->name, map->def.map_flags); } else if (strcmp(name, "key_size") == 0) { __u32 sz; - if (!get_map_field_int(map_name, obj->btf, m, &sz)) + if (!get_map_field_int(map->name, obj->btf, m, &sz)) return -EINVAL; pr_debug("map '%s': found key_size = %u.\n", - map_name, sz); + map->name, sz); if (map->def.key_size && map->def.key_size != sz) { pr_warn("map '%s': conflicting key size %u != %u.\n", - map_name, map->def.key_size, sz); + map->name, map->def.key_size, sz); return -EINVAL; } map->def.key_size = sz; @@ -2026,25 +1971,25 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, t = btf__type_by_id(obj->btf, m->type); if (!t) { pr_warn("map '%s': key type [%d] not found.\n", - map_name, m->type); + map->name, m->type); return -EINVAL; } if (!btf_is_ptr(t)) { pr_warn("map '%s': key spec is not PTR: %u.\n", - map_name, btf_kind(t)); + map->name, btf_kind(t)); return -EINVAL; } sz = btf__resolve_size(obj->btf, t->type); if (sz < 0) { pr_warn("map '%s': can't determine key size for type [%u]: %zd.\n", - map_name, t->type, (ssize_t)sz); + map->name, t->type, (ssize_t)sz); return sz; } pr_debug("map '%s': found key [%u], sz = %zd.\n", - map_name, t->type, (ssize_t)sz); + map->name, t->type, (ssize_t)sz); if (map->def.key_size && map->def.key_size != sz) { pr_warn("map '%s': conflicting key size %u != %zd.\n", - map_name, map->def.key_size, (ssize_t)sz); + map->name, map->def.key_size, (ssize_t)sz); return -EINVAL; } map->def.key_size = sz; @@ -2052,13 +1997,13 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, } else if (strcmp(name, "value_size") == 0) { __u32 sz; - if (!get_map_field_int(map_name, obj->btf, m, &sz)) + if (!get_map_field_int(map->name, obj->btf, m, &sz)) return -EINVAL; pr_debug("map '%s': found value_size = %u.\n", - map_name, sz); + map->name, sz); if (map->def.value_size && map->def.value_size != sz) { pr_warn("map '%s': conflicting value size %u != %u.\n", - map_name, map->def.value_size, sz); + map->name, map->def.value_size, sz); return -EINVAL; } map->def.value_size = sz; @@ -2068,25 +2013,25 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, t = btf__type_by_id(obj->btf, m->type); if (!t) { pr_warn("map '%s': value type [%d] not found.\n", - map_name, m->type); + map->name, m->type); return -EINVAL; } if (!btf_is_ptr(t)) { pr_warn("map '%s': value spec is not PTR: %u.\n", - map_name, btf_kind(t)); + map->name, btf_kind(t)); return -EINVAL; } sz = btf__resolve_size(obj->btf, t->type); if (sz < 0) { pr_warn("map '%s': can't determine value size for type [%u]: %zd.\n", - map_name, t->type, (ssize_t)sz); + map->name, t->type, (ssize_t)sz); return sz; } pr_debug("map '%s': found value [%u], sz = %zd.\n", - map_name, t->type, (ssize_t)sz); + map->name, t->type, (ssize_t)sz); if (map->def.value_size && map->def.value_size != sz) { pr_warn("map '%s': conflicting value size %u != %zd.\n", - map_name, map->def.value_size, (ssize_t)sz); + map->name, map->def.value_size, (ssize_t)sz); return -EINVAL; } map->def.value_size = sz; @@ -2095,44 +2040,110 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, __u32 val; int err; - if (!get_map_field_int(map_name, obj->btf, m, &val)) + if (!get_map_field_int(map->name, obj->btf, m, &val)) return -EINVAL; pr_debug("map '%s': found pinning = %u.\n", - map_name, val); + map->name, val); if (val != LIBBPF_PIN_NONE && val != LIBBPF_PIN_BY_NAME) { pr_warn("map '%s': invalid pinning value %u.\n", - map_name, val); + map->name, val); return -EINVAL; } if (val == LIBBPF_PIN_BY_NAME) { err = build_map_pin_path(map, pin_root_path); if (err) { pr_warn("map '%s': couldn't build pin path.\n", - map_name); + map->name); return err; } } } else { if (strict) { pr_warn("map '%s': unknown field '%s'.\n", - map_name, name); + map->name, name); return -ENOTSUP; } pr_debug("map '%s': ignoring unknown field '%s'.\n", - map_name, name); + map->name, name); } } if (map->def.type == BPF_MAP_TYPE_UNSPEC) { - pr_warn("map '%s': map type isn't specified.\n", map_name); + pr_warn("map '%s': map type isn't specified.\n", map->name); return -EINVAL; } return 0; } +static int bpf_object__init_user_btf_map(struct bpf_object *obj, + const struct btf_type *sec, + int var_idx, int sec_idx, + const Elf_Data *data, bool strict, + const char *pin_root_path) +{ + const struct btf_type *var, *def; + const struct btf_var_secinfo *vi; + const struct btf_var *var_extra; + const char *map_name; + struct bpf_map *map; + + vi = btf_var_secinfos(sec) + var_idx; + var = btf__type_by_id(obj->btf, vi->type); + var_extra = btf_var(var); + map_name = btf__name_by_offset(obj->btf, var->name_off); + + if (map_name == NULL || map_name[0] == '\0') { + pr_warn("map #%d: empty name.\n", var_idx); + return -EINVAL; + } + if ((__u64)vi->offset + vi->size > data->d_size) { + pr_warn("map '%s' BTF data is corrupted.\n", map_name); + return -EINVAL; + } + if (!btf_is_var(var)) { + pr_warn("map '%s': unexpected var kind %u.\n", + map_name, btf_kind(var)); + return -EINVAL; + } + if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED && + var_extra->linkage != BTF_VAR_STATIC) { + pr_warn("map '%s': unsupported var linkage %u.\n", + map_name, var_extra->linkage); + return -EOPNOTSUPP; + } + + def = skip_mods_and_typedefs(obj->btf, var->type, NULL); + if (!btf_is_struct(def)) { + pr_warn("map '%s': unexpected def kind %u.\n", + map_name, btf_kind(var)); + return -EINVAL; + } + if (def->size > vi->size) { + pr_warn("map '%s': invalid def size.\n", map_name); + return -EINVAL; + } + + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + map->name = strdup(map_name); + if (!map->name) { + pr_warn("map '%s': failed to alloc map name.\n", map_name); + return -ENOMEM; + } + map->libbpf_type = LIBBPF_MAP_UNSPEC; + map->def.type = BPF_MAP_TYPE_UNSPEC; + map->sec_idx = sec_idx; + map->sec_offset = vi->offset; + pr_debug("map '%s': at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); + + return parse_btf_map_def(obj, map, def, strict, pin_root_path); +} + static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, const char *pin_root_path) { -- 2.7.4