diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 705 |
1 files changed, 485 insertions, 220 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8f480e29a6b0..977add1b73e2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -310,6 +310,7 @@ struct bpf_map { int map_ifindex; int inner_map_fd; struct bpf_map_def def; + __u32 btf_var_idx; __u32 btf_key_type_id; __u32 btf_value_type_id; __u32 btf_vmlinux_value_type_id; @@ -318,6 +319,9 @@ struct bpf_map { enum libbpf_map_type libbpf_type; void *mmaped; struct bpf_struct_ops *st_ops; + struct bpf_map *inner_map; + void **init_slots; + int init_slots_sz; char *pin_path; bool pinned; bool reused; @@ -389,6 +393,7 @@ struct bpf_object { int nr_reloc_sects; int maps_shndx; int btf_maps_shndx; + __u32 btf_maps_sec_btf_id; int text_shndx; int symbols_shndx; int data_shndx; @@ -1914,109 +1919,54 @@ 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, bool is_inner, + 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 +1976,25 @@ 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 +2002,13 @@ 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; @@ -2068,71 +2018,207 @@ 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; map->btf_value_type_id = t->type; + } + else if (strcmp(name, "values") == 0) { + int err; + + if (is_inner) { + pr_warn("map '%s': multi-level inner maps not supported.\n", + map->name); + return -ENOTSUP; + } + if (i != vlen - 1) { + pr_warn("map '%s': '%s' member should be last.\n", + map->name, name); + return -EINVAL; + } + if (!bpf_map_type__is_map_in_map(map->def.type)) { + pr_warn("map '%s': should be map-in-map.\n", + map->name); + return -ENOTSUP; + } + if (map->def.value_size && map->def.value_size != 4) { + pr_warn("map '%s': conflicting value size %u != 4.\n", + map->name, map->def.value_size); + return -EINVAL; + } + map->def.value_size = 4; + t = btf__type_by_id(obj->btf, m->type); + if (!t) { + pr_warn("map '%s': map-in-map inner type [%d] not found.\n", + map->name, m->type); + return -EINVAL; + } + if (!btf_is_array(t) || btf_array(t)->nelems) { + pr_warn("map '%s': map-in-map inner spec is not a zero-sized array.\n", + map->name); + return -EINVAL; + } + t = skip_mods_and_typedefs(obj->btf, btf_array(t)->type, + NULL); + if (!btf_is_ptr(t)) { + pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n", + map->name, btf_kind(t)); + return -EINVAL; + } + t = skip_mods_and_typedefs(obj->btf, t->type, NULL); + if (!btf_is_struct(t)) { + pr_warn("map '%s': map-in-map inner def is of unexpected kind %u.\n", + map->name, btf_kind(t)); + return -EINVAL; + } + + map->inner_map = calloc(1, sizeof(*map->inner_map)); + if (!map->inner_map) + return -ENOMEM; + map->inner_map->sec_idx = obj->efile.btf_maps_shndx; + map->inner_map->name = malloc(strlen(map->name) + + sizeof(".inner") + 1); + if (!map->inner_map->name) + return -ENOMEM; + sprintf(map->inner_map->name, "%s.inner", map->name); + + err = parse_btf_map_def(obj, map->inner_map, t, strict, + true /* is_inner */, NULL); + if (err) + return err; } else if (strcmp(name, "pinning") == 0) { __u32 val; int err; - if (!get_map_field_int(map_name, obj->btf, m, &val)) + if (is_inner) { + pr_debug("map '%s': inner def can't be pinned.\n", + map->name); + return -EINVAL; + } + 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; + map->btf_var_idx = var_idx; + 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, false, pin_root_path); +} + static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, const char *pin_root_path) { @@ -2163,6 +2249,7 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict, name = btf__name_by_offset(obj->btf, t->name_off); if (strcmp(name, MAPS_ELF_SEC) == 0) { sec = t; + obj->efile.btf_maps_sec_btf_id = i; break; } } @@ -2549,7 +2636,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) /* Only do relo for section with exec instructions */ if (!section_have_execinstr(obj, sec) && - strcmp(name, ".rel" STRUCT_OPS_SEC)) { + strcmp(name, ".rel" STRUCT_OPS_SEC) && + strcmp(name, ".rel" MAPS_ELF_SEC)) { pr_debug("skip relo %s(%d) for section(%d)\n", name, idx, sec); continue; @@ -3482,124 +3570,181 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map) return 0; } +static void bpf_map__destroy(struct bpf_map *map); + +static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) +{ + struct bpf_create_map_attr create_attr; + struct bpf_map_def *def = &map->def; + + memset(&create_attr, 0, sizeof(create_attr)); + + if (obj->caps.name) + create_attr.name = map->name; + create_attr.map_ifindex = map->map_ifindex; + create_attr.map_type = def->type; + create_attr.map_flags = def->map_flags; + create_attr.key_size = def->key_size; + create_attr.value_size = def->value_size; + + if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) { + int nr_cpus; + + nr_cpus = libbpf_num_possible_cpus(); + if (nr_cpus < 0) { + pr_warn("map '%s': failed to determine number of system CPUs: %d\n", + map->name, nr_cpus); + return nr_cpus; + } + pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus); + create_attr.max_entries = nr_cpus; + } else { + create_attr.max_entries = def->max_entries; + } + + if (bpf_map__is_struct_ops(map)) + create_attr.btf_vmlinux_value_type_id = + map->btf_vmlinux_value_type_id; + + create_attr.btf_fd = 0; + create_attr.btf_key_type_id = 0; + create_attr.btf_value_type_id = 0; + if (obj->btf && !bpf_map_find_btf_info(obj, map)) { + create_attr.btf_fd = btf__fd(obj->btf); + create_attr.btf_key_type_id = map->btf_key_type_id; + create_attr.btf_value_type_id = map->btf_value_type_id; + } + + if (bpf_map_type__is_map_in_map(def->type)) { + if (map->inner_map) { + int err; + + err = bpf_object__create_map(obj, map->inner_map); + if (err) { + pr_warn("map '%s': failed to create inner map: %d\n", + map->name, err); + return err; + } + map->inner_map_fd = bpf_map__fd(map->inner_map); + } + if (map->inner_map_fd >= 0) + create_attr.inner_map_fd = map->inner_map_fd; + } + + map->fd = bpf_create_map_xattr(&create_attr); + if (map->fd < 0 && (create_attr.btf_key_type_id || + create_attr.btf_value_type_id)) { + char *cp, errmsg[STRERR_BUFSIZE]; + int err = -errno; + + cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); + pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", + map->name, cp, err); + create_attr.btf_fd = 0; + create_attr.btf_key_type_id = 0; + create_attr.btf_value_type_id = 0; + map->btf_key_type_id = 0; + map->btf_value_type_id = 0; + map->fd = bpf_create_map_xattr(&create_attr); + } + + if (map->fd < 0) + return -errno; + + if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) { + bpf_map__destroy(map->inner_map); + zfree(&map->inner_map); + } + + return 0; +} + static int bpf_object__create_maps(struct bpf_object *obj) { - struct bpf_create_map_attr create_attr = {}; - int nr_cpus = 0; - unsigned int i; + struct bpf_map *map; + char *cp, errmsg[STRERR_BUFSIZE]; + unsigned int i, j; int err; for (i = 0; i < obj->nr_maps; i++) { - struct bpf_map *map = &obj->maps[i]; - struct bpf_map_def *def = &map->def; - char *cp, errmsg[STRERR_BUFSIZE]; - int *pfd = &map->fd; + map = &obj->maps[i]; if (map->pin_path) { err = bpf_object__reuse_map(map); if (err) { - pr_warn("error reusing pinned map %s\n", + pr_warn("map '%s': error reusing pinned map\n", map->name); - return err; + goto err_out; } } if (map->fd >= 0) { - pr_debug("skip map create (preset) %s: fd=%d\n", + pr_debug("map '%s': skipping creation (preset fd=%d)\n", map->name, map->fd); continue; } - if (obj->caps.name) - create_attr.name = map->name; - create_attr.map_ifindex = map->map_ifindex; - create_attr.map_type = def->type; - create_attr.map_flags = def->map_flags; - create_attr.key_size = def->key_size; - create_attr.value_size = def->value_size; - if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && - !def->max_entries) { - if (!nr_cpus) - nr_cpus = libbpf_num_possible_cpus(); - if (nr_cpus < 0) { - pr_warn("failed to determine number of system CPUs: %d\n", - nr_cpus); - err = nr_cpus; - goto err_out; - } - pr_debug("map '%s': setting size to %d\n", - map->name, nr_cpus); - create_attr.max_entries = nr_cpus; - } else { - create_attr.max_entries = def->max_entries; - } - create_attr.btf_fd = 0; - create_attr.btf_key_type_id = 0; - create_attr.btf_value_type_id = 0; - if (bpf_map_type__is_map_in_map(def->type) && - map->inner_map_fd >= 0) - create_attr.inner_map_fd = map->inner_map_fd; - if (bpf_map__is_struct_ops(map)) - create_attr.btf_vmlinux_value_type_id = - map->btf_vmlinux_value_type_id; - - if (obj->btf && !bpf_map_find_btf_info(obj, map)) { - create_attr.btf_fd = btf__fd(obj->btf); - create_attr.btf_key_type_id = map->btf_key_type_id; - create_attr.btf_value_type_id = map->btf_value_type_id; - } - - *pfd = bpf_create_map_xattr(&create_attr); - if (*pfd < 0 && (create_attr.btf_key_type_id || - create_attr.btf_value_type_id)) { - err = -errno; - cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); - pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", - map->name, cp, err); - create_attr.btf_fd = 0; - create_attr.btf_key_type_id = 0; - create_attr.btf_value_type_id = 0; - map->btf_key_type_id = 0; - map->btf_value_type_id = 0; - *pfd = bpf_create_map_xattr(&create_attr); - } + err = bpf_object__create_map(obj, map); + if (err) + goto err_out; - if (*pfd < 0) { - size_t j; - - err = -errno; -err_out: - cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); - pr_warn("failed to create map (name: '%s'): %s(%d)\n", - map->name, cp, err); - pr_perm_msg(err); - for (j = 0; j < i; j++) - zclose(obj->maps[j].fd); - return err; - } + pr_debug("map '%s': created successfully, fd=%d\n", map->name, + map->fd); if (bpf_map__is_internal(map)) { err = bpf_object__populate_internal_map(obj, map); if (err < 0) { - zclose(*pfd); + zclose(map->fd); goto err_out; } } + if (map->init_slots_sz) { + for (j = 0; j < map->init_slots_sz; j++) { + const struct bpf_map *targ_map; + int fd; + + if (!map->init_slots[j]) + continue; + + targ_map = map->init_slots[j]; + fd = bpf_map__fd(targ_map); + err = bpf_map_update_elem(map->fd, &j, &fd, 0); + if (err) { + err = -errno; + pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n", + map->name, j, targ_map->name, + fd, err); + goto err_out; + } + pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n", + map->name, j, targ_map->name, fd); + } + zfree(&map->init_slots); + map->init_slots_sz = 0; + } + if (map->pin_path && !map->pinned) { err = bpf_map__pin(map, NULL); if (err) { - pr_warn("failed to auto-pin map name '%s' at '%s'\n", - map->name, map->pin_path); - return err; + pr_warn("map '%s': failed to auto-pin at '%s': %d\n", + map->name, map->pin_path, err); + zclose(map->fd); + goto err_out; } } - - pr_debug("created map %s: fd=%d\n", map->name, *pfd); } return 0; + +err_out: + cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); + pr_warn("map '%s': failed to create: %s(%d)\n", map->name, cp, err); + pr_perm_msg(err); + for (j = 0; j < i; j++) + zclose(obj->maps[j].fd); + return err; } static int @@ -4851,9 +4996,118 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) return 0; } -static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj, - GElf_Shdr *shdr, - Elf_Data *data); +static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, + GElf_Shdr *shdr, Elf_Data *data); + +static int bpf_object__collect_map_relos(struct bpf_object *obj, + GElf_Shdr *shdr, Elf_Data *data) +{ + int i, j, nrels, new_sz, ptr_sz = sizeof(void *); + const struct btf_var_secinfo *vi = NULL; + const struct btf_type *sec, *var, *def; + const struct btf_member *member; + struct bpf_map *map, *targ_map; + const char *name, *mname; + Elf_Data *symbols; + unsigned int moff; + GElf_Sym sym; + GElf_Rel rel; + void *tmp; + + if (!obj->efile.btf_maps_sec_btf_id || !obj->btf) + return -EINVAL; + sec = btf__type_by_id(obj->btf, obj->efile.btf_maps_sec_btf_id); + if (!sec) + return -EINVAL; + + symbols = obj->efile.symbols; + nrels = shdr->sh_size / shdr->sh_entsize; + for (i = 0; i < nrels; i++) { + if (!gelf_getrel(data, i, &rel)) { + pr_warn(".maps relo #%d: failed to get ELF relo\n", i); + return -LIBBPF_ERRNO__FORMAT; + } + if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { + pr_warn(".maps relo #%d: symbol %zx not found\n", + i, (size_t)GELF_R_SYM(rel.r_info)); + return -LIBBPF_ERRNO__FORMAT; + } + name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, + sym.st_name) ? : "<?>"; + if (sym.st_shndx != obj->efile.btf_maps_shndx) { + pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n", + i, name); + return -LIBBPF_ERRNO__RELOC; + } + + pr_debug(".maps relo #%d: for %zd value %zd rel.r_offset %zu name %d ('%s')\n", + i, (ssize_t)(rel.r_info >> 32), (size_t)sym.st_value, + (size_t)rel.r_offset, sym.st_name, name); + + for (j = 0; j < obj->nr_maps; j++) { + map = &obj->maps[j]; + if (map->sec_idx != obj->efile.btf_maps_shndx) + continue; + + vi = btf_var_secinfos(sec) + map->btf_var_idx; + if (vi->offset <= rel.r_offset && + rel.r_offset + sizeof(void *) <= vi->offset + vi->size) + break; + } + if (j == obj->nr_maps) { + pr_warn(".maps relo #%d: cannot find map '%s' at rel.r_offset %zu\n", + i, name, (size_t)rel.r_offset); + return -EINVAL; + } + + if (!bpf_map_type__is_map_in_map(map->def.type)) + return -EINVAL; + if (map->def.type == BPF_MAP_TYPE_HASH_OF_MAPS && + map->def.key_size != sizeof(int)) { + pr_warn(".maps relo #%d: hash-of-maps '%s' should have key size %zu.\n", + i, map->name, sizeof(int)); + return -EINVAL; + } + + targ_map = bpf_object__find_map_by_name(obj, name); + if (!targ_map) + return -ESRCH; + + var = btf__type_by_id(obj->btf, vi->type); + def = skip_mods_and_typedefs(obj->btf, var->type, NULL); + if (btf_vlen(def) == 0) + return -EINVAL; + member = btf_members(def) + btf_vlen(def) - 1; + mname = btf__name_by_offset(obj->btf, member->name_off); + if (strcmp(mname, "values")) + return -EINVAL; + + moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8; + if (rel.r_offset - vi->offset < moff) + return -EINVAL; + + moff = rel.r_offset - vi->offset - moff; + if (moff % ptr_sz) + return -EINVAL; + moff /= ptr_sz; + if (moff >= map->init_slots_sz) { + new_sz = moff + 1; + tmp = realloc(map->init_slots, new_sz * ptr_sz); + if (!tmp) + return -ENOMEM; + map->init_slots = tmp; + memset(map->init_slots + map->init_slots_sz, 0, + (new_sz - map->init_slots_sz) * ptr_sz); + map->init_slots_sz = new_sz; + } + map->init_slots[moff] = targ_map; + + pr_debug(".maps relo #%d: map '%s' slot [%d] points to map '%s'\n", + i, map->name, moff, name); + } + + return 0; +} static int bpf_object__collect_reloc(struct bpf_object *obj) { @@ -4876,21 +5130,17 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) } if (idx == obj->efile.st_ops_shndx) { - err = bpf_object__collect_struct_ops_map_reloc(obj, - shdr, - data); - if (err) - return err; - continue; - } - - prog = bpf_object__find_prog_by_idx(obj, idx); - if (!prog) { - pr_warn("relocation failed: no section(%d)\n", idx); - return -LIBBPF_ERRNO__RELOC; + err = bpf_object__collect_st_ops_relos(obj, shdr, data); + } else if (idx == obj->efile.btf_maps_shndx) { + err = bpf_object__collect_map_relos(obj, shdr, data); + } else { + prog = bpf_object__find_prog_by_idx(obj, idx); + if (!prog) { + pr_warn("relocation failed: no prog in section(%d)\n", idx); + return -LIBBPF_ERRNO__RELOC; + } + err = bpf_program__collect_reloc(prog, shdr, data, obj); } - - err = bpf_program__collect_reloc(prog, shdr, data, obj); if (err) return err; } @@ -5955,6 +6205,40 @@ int bpf_object__pin(struct bpf_object *obj, const char *path) return 0; } +static void bpf_map__destroy(struct bpf_map *map) +{ + if (map->clear_priv) + map->clear_priv(map, map->priv); + map->priv = NULL; + map->clear_priv = NULL; + + if (map->inner_map) { + bpf_map__destroy(map->inner_map); + zfree(&map->inner_map); + } + + zfree(&map->init_slots); + map->init_slots_sz = 0; + + if (map->mmaped) { + munmap(map->mmaped, bpf_map_mmap_sz(map)); + map->mmaped = NULL; + } + + if (map->st_ops) { + zfree(&map->st_ops->data); + zfree(&map->st_ops->progs); + zfree(&map->st_ops->kern_func_off); + zfree(&map->st_ops); + } + + zfree(&map->name); + zfree(&map->pin_path); + + if (map->fd >= 0) + zclose(map->fd); +} + void bpf_object__close(struct bpf_object *obj) { size_t i; @@ -5970,29 +6254,8 @@ void bpf_object__close(struct bpf_object *obj) btf__free(obj->btf); btf_ext__free(obj->btf_ext); - for (i = 0; i < obj->nr_maps; i++) { - struct bpf_map *map = &obj->maps[i]; - - if (map->clear_priv) - map->clear_priv(map, map->priv); - map->priv = NULL; - map->clear_priv = NULL; - - if (map->mmaped) { - munmap(map->mmaped, bpf_map_mmap_sz(map)); - map->mmaped = NULL; - } - - if (map->st_ops) { - zfree(&map->st_ops->data); - zfree(&map->st_ops->progs); - zfree(&map->st_ops->kern_func_off); - zfree(&map->st_ops); - } - - zfree(&map->name); - zfree(&map->pin_path); - } + for (i = 0; i < obj->nr_maps; i++) + bpf_map__destroy(&obj->maps[i]); zfree(&obj->kconfig); zfree(&obj->externs); @@ -6516,9 +6779,8 @@ static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj, } /* Collect the reloc from ELF and populate the st_ops->progs[] */ -static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj, - GElf_Shdr *shdr, - Elf_Data *data) +static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, + GElf_Shdr *shdr, Elf_Data *data) { const struct btf_member *member; struct bpf_struct_ops *st_ops; @@ -6672,6 +6934,7 @@ int libbpf_find_vmlinux_btf_id(const char *name, enum bpf_attach_type attach_type) { struct btf *btf; + int err; btf = libbpf_find_kernel_btf(); if (IS_ERR(btf)) { @@ -6679,7 +6942,9 @@ int libbpf_find_vmlinux_btf_id(const char *name, return -EINVAL; } - return __find_vmlinux_btf_id(btf, name, attach_type); + err = __find_vmlinux_btf_id(btf, name, attach_type); + btf__free(btf); + return err; } static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) @@ -7006,7 +7271,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, err = bpf_object__load(obj); if (err) { bpf_object__close(obj); - return -EINVAL; + return err; } *pobj = obj; |