diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 927 |
1 files changed, 689 insertions, 238 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index c8fbc050fd78..4259c9f0cfe7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -207,7 +207,8 @@ static const char * const libbpf_type_to_btf_name[] = { struct bpf_map { int fd; char *name; - size_t offset; + int sec_idx; + size_t sec_offset; int map_ifindex; int inner_map_fd; struct bpf_map_def def; @@ -234,6 +235,7 @@ struct bpf_object { size_t nr_programs; struct bpf_map *maps; size_t nr_maps; + size_t maps_cap; struct bpf_secdata sections; bool loaded; @@ -260,6 +262,7 @@ struct bpf_object { } *reloc; int nr_reloc; int maps_shndx; + int btf_maps_shndx; int text_shndx; int data_shndx; int rodata_shndx; @@ -512,6 +515,7 @@ static struct bpf_object *bpf_object__new(const char *path, obj->efile.obj_buf = obj_buf; obj->efile.obj_buf_sz = obj_buf_sz; obj->efile.maps_shndx = -1; + obj->efile.btf_maps_shndx = -1; obj->efile.data_shndx = -1; obj->efile.rodata_shndx = -1; obj->efile.bss_shndx = -1; @@ -646,7 +650,9 @@ static int compare_bpf_map(const void *_a, const void *_b) const struct bpf_map *a = _a; const struct bpf_map *b = _b; - return a->offset - b->offset; + if (a->sec_idx != b->sec_idx) + return a->sec_idx - b->sec_idx; + return a->sec_offset - b->sec_offset; } static bool bpf_map_type__is_map_in_map(enum bpf_map_type type) @@ -763,24 +769,55 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, return -ENOENT; } -static bool bpf_object__has_maps(const struct bpf_object *obj) +static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) { - return obj->efile.maps_shndx >= 0 || - obj->efile.data_shndx >= 0 || - obj->efile.rodata_shndx >= 0 || - obj->efile.bss_shndx >= 0; + struct bpf_map *new_maps; + size_t new_cap; + int i; + + if (obj->nr_maps < obj->maps_cap) + return &obj->maps[obj->nr_maps++]; + + new_cap = max(4ul, obj->maps_cap * 3 / 2); + new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); + if (!new_maps) { + pr_warning("alloc maps for object failed\n"); + return ERR_PTR(-ENOMEM); + } + + obj->maps_cap = new_cap; + obj->maps = new_maps; + + /* zero out new maps */ + memset(obj->maps + obj->nr_maps, 0, + (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); + /* + * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) + * when failure (zclose won't close negative fd)). + */ + for (i = obj->nr_maps; i < obj->maps_cap; i++) { + obj->maps[i].fd = -1; + obj->maps[i].inner_map_fd = -1; + } + + return &obj->maps[obj->nr_maps++]; } static int -bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, - enum libbpf_map_type type, Elf_Data *data, - void **data_buff) +bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, + int sec_idx, Elf_Data *data, void **data_buff) { - struct bpf_map_def *def = &map->def; char map_name[BPF_OBJ_NAME_LEN]; + struct bpf_map_def *def; + struct bpf_map *map; + + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); map->libbpf_type = type; - map->offset = ~(typeof(map->offset))0; + map->sec_idx = sec_idx; + map->sec_offset = 0; snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name, libbpf_type_to_btf_name[type]); map->name = strdup(map_name); @@ -788,7 +825,10 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, pr_warning("failed to alloc map name\n"); return -ENOMEM; } + pr_debug("map '%s' (global data): at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); + def = &map->def; def->type = BPF_MAP_TYPE_ARRAY; def->key_size = sizeof(int); def->value_size = data->d_size; @@ -808,29 +848,61 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, return 0; } -static int bpf_object__init_maps(struct bpf_object *obj, int flags) +static int bpf_object__init_global_data_maps(struct bpf_object *obj) +{ + int err; + + if (!obj->caps.global_data) + return 0; + /* + * Populate obj->maps with libbpf internal maps. + */ + if (obj->efile.data_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA, + obj->efile.data_shndx, + obj->efile.data, + &obj->sections.data); + if (err) + return err; + } + if (obj->efile.rodata_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA, + obj->efile.rodata_shndx, + obj->efile.rodata, + &obj->sections.rodata); + if (err) + return err; + } + if (obj->efile.bss_shndx >= 0) { + err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS, + obj->efile.bss_shndx, + obj->efile.bss, NULL); + if (err) + return err; + } + return 0; +} + +static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) { - int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0; - bool strict = !(flags & MAPS_RELAX_COMPAT); Elf_Data *symbols = obj->efile.symbols; + int i, map_def_sz = 0, nr_maps = 0, nr_syms; Elf_Data *data = NULL; - int ret = 0; + Elf_Scn *scn; + + if (obj->efile.maps_shndx < 0) + return 0; if (!symbols) return -EINVAL; - nr_syms = symbols->d_size / sizeof(GElf_Sym); - if (obj->efile.maps_shndx >= 0) { - Elf_Scn *scn = elf_getscn(obj->efile.elf, - obj->efile.maps_shndx); - - if (scn) - data = elf_getdata(scn, NULL); - if (!scn || !data) { - pr_warning("failed to get Elf_Data from map section %d\n", - obj->efile.maps_shndx); - return -EINVAL; - } + scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d\n", + obj->efile.maps_shndx); + return -EINVAL; } /* @@ -840,16 +912,8 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * * TODO: Detect array of map and report error. */ - if (obj->caps.global_data) { - if (obj->efile.data_shndx >= 0) - nr_maps_glob++; - if (obj->efile.rodata_shndx >= 0) - nr_maps_glob++; - if (obj->efile.bss_shndx >= 0) - nr_maps_glob++; - } - - for (i = 0; data && i < nr_syms; i++) { + nr_syms = symbols->d_size / sizeof(GElf_Sym); + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; if (!gelf_getsym(symbols, i, &sym)) @@ -858,79 +922,59 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) continue; nr_maps++; } - - if (!nr_maps && !nr_maps_glob) - return 0; - /* Assume equally sized map definitions */ - if (data) { - pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, - nr_maps, data->d_size); - - map_def_sz = data->d_size / nr_maps; - if (!data->d_size || (data->d_size % nr_maps) != 0) { - pr_warning("unable to determine map definition size " - "section %s, %d maps in %zd bytes\n", - obj->path, nr_maps, data->d_size); - return -EINVAL; - } - } - - nr_maps += nr_maps_glob; - obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); - if (!obj->maps) { - pr_warning("alloc maps for object failed\n"); - return -ENOMEM; - } - obj->nr_maps = nr_maps; - - for (i = 0; i < nr_maps; i++) { - /* - * fill all fd with -1 so won't close incorrect - * fd (fd=0 is stdin) when failure (zclose won't close - * negative fd)). - */ - obj->maps[i].fd = -1; - obj->maps[i].inner_map_fd = -1; + pr_debug("maps in %s: %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + + map_def_sz = data->d_size / nr_maps; + if (!data->d_size || (data->d_size % nr_maps) != 0) { + pr_warning("unable to determine map definition size " + "section %s, %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + return -EINVAL; } - /* - * Fill obj->maps using data in "maps" section. - */ - for (i = 0, map_idx = 0; data && i < nr_syms; i++) { + /* Fill obj->maps using data in "maps" section. */ + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; const char *map_name; struct bpf_map_def *def; + struct bpf_map *map; if (!gelf_getsym(symbols, i, &sym)) continue; if (sym.st_shndx != obj->efile.maps_shndx) continue; - map_name = elf_strptr(obj->efile.elf, - obj->efile.strtabidx, + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + + map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, sym.st_name); if (!map_name) { pr_warning("failed to get map #%d name sym string for obj %s\n", - map_idx, obj->path); + i, obj->path); return -LIBBPF_ERRNO__FORMAT; } - obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC; - obj->maps[map_idx].offset = sym.st_value; + map->libbpf_type = LIBBPF_MAP_UNSPEC; + map->sec_idx = sym.st_shndx; + map->sec_offset = sym.st_value; + pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n", + map_name, map->sec_idx, map->sec_offset); if (sym.st_value + map_def_sz > data->d_size) { pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", obj->path, map_name); return -EINVAL; } - obj->maps[map_idx].name = strdup(map_name); - if (!obj->maps[map_idx].name) { + map->name = strdup(map_name); + if (!map->name) { pr_warning("failed to alloc map name\n"); return -ENOMEM; } - pr_debug("map %d is \"%s\"\n", map_idx, - obj->maps[map_idx].name); + pr_debug("map %d is \"%s\"\n", i, map->name); def = (struct bpf_map_def *)(data->d_buf + sym.st_value); /* * If the definition of the map in the object file fits in @@ -939,7 +983,7 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * calloc above. */ if (map_def_sz <= sizeof(struct bpf_map_def)) { - memcpy(&obj->maps[map_idx].def, def, map_def_sz); + memcpy(&map->def, def, map_def_sz); } else { /* * Here the map structure being read is bigger than what @@ -959,37 +1003,340 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) return -EINVAL; } } - memcpy(&obj->maps[map_idx].def, def, - sizeof(struct bpf_map_def)); + memcpy(&map->def, def, sizeof(struct bpf_map_def)); } - map_idx++; } + return 0; +} - if (!obj->caps.global_data) - goto finalize; +static const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, + __u32 id) +{ + const struct btf_type *t = btf__type_by_id(btf, id); - /* - * Populate rest of obj->maps with libbpf internal maps. - */ - if (obj->efile.data_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_DATA, - obj->efile.data, - &obj->sections.data); - if (!ret && obj->efile.rodata_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_RODATA, - obj->efile.rodata, - &obj->sections.rodata); - if (!ret && obj->efile.bss_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_BSS, - obj->efile.bss, NULL); -finalize: - if (!ret) + while (true) { + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_VOLATILE: + case BTF_KIND_CONST: + case BTF_KIND_RESTRICT: + case BTF_KIND_TYPEDEF: + t = btf__type_by_id(btf, t->type); + break; + default: + return t; + } + } +} + +static bool get_map_field_int(const char *map_name, + const struct btf *btf, + const struct btf_type *def, + const struct btf_member *m, + const void *data, __u32 *res) { + const struct btf_type *t = skip_mods_and_typedefs(btf, m->type); + const char *name = btf__name_by_offset(btf, m->name_off); + __u32 int_info = *(const __u32 *)(const void *)(t + 1); + + if (BTF_INFO_KIND(t->info) != BTF_KIND_INT) { + pr_warning("map '%s': attr '%s': expected INT, got %u.\n", + map_name, name, BTF_INFO_KIND(t->info)); + return false; + } + if (t->size != 4 || BTF_INT_BITS(int_info) != 32 || + BTF_INT_OFFSET(int_info)) { + pr_warning("map '%s': attr '%s': expected 32-bit non-bitfield integer, " + "got %u-byte (%d-bit) one with bit offset %d.\n", + map_name, name, t->size, BTF_INT_BITS(int_info), + BTF_INT_OFFSET(int_info)); + return false; + } + if (BTF_INFO_KFLAG(def->info) && BTF_MEMBER_BITFIELD_SIZE(m->offset)) { + pr_warning("map '%s': attr '%s': bitfield is not supported.\n", + map_name, name); + return false; + } + if (m->offset % 32) { + pr_warning("map '%s': attr '%s': unaligned fields are not supported.\n", + map_name, name); + return false; + } + + *res = *(const __u32 *)(data + m->offset / 8); + return true; +} + +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 struct btf_type *var, *def, *t; + const struct btf_var_secinfo *vi; + const struct btf_var *var_extra; + const struct btf_member *m; + const void *def_data; + const char *map_name; + struct bpf_map *map; + int vlen, i; + + vi = (const struct btf_var_secinfo *)(const void *)(sec + 1) + var_idx; + var = btf__type_by_id(obj->btf, vi->type); + var_extra = (const void *)(var + 1); + map_name = btf__name_by_offset(obj->btf, var->name_off); + vlen = BTF_INFO_VLEN(var->info); + + if (map_name == NULL || map_name[0] == '\0') { + pr_warning("map #%d: empty name.\n", var_idx); + return -EINVAL; + } + if ((__u64)vi->offset + vi->size > data->d_size) { + pr_warning("map '%s' BTF data is corrupted.\n", map_name); + return -EINVAL; + } + if (BTF_INFO_KIND(var->info) != BTF_KIND_VAR) { + pr_warning("map '%s': unexpected var kind %u.\n", + map_name, BTF_INFO_KIND(var->info)); + return -EINVAL; + } + if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED && + var_extra->linkage != BTF_VAR_STATIC) { + pr_warning("map '%s': unsupported var linkage %u.\n", + map_name, var_extra->linkage); + return -EOPNOTSUPP; + } + + def = skip_mods_and_typedefs(obj->btf, var->type); + if (BTF_INFO_KIND(def->info) != BTF_KIND_STRUCT) { + pr_warning("map '%s': unexpected def kind %u.\n", + map_name, BTF_INFO_KIND(var->info)); + return -EINVAL; + } + if (def->size > vi->size) { + pr_warning("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_warning("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); + + def_data = data->d_buf + vi->offset; + vlen = BTF_INFO_VLEN(def->info); + m = (const void *)(def + 1); + for (i = 0; i < vlen; i++, m++) { + const char *name = btf__name_by_offset(obj->btf, m->name_off); + + if (!name) { + pr_warning("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, def, m, + def_data, &map->def.type)) + return -EINVAL; + pr_debug("map '%s': found type = %u.\n", + map_name, map->def.type); + } else if (strcmp(name, "max_entries") == 0) { + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &map->def.max_entries)) + return -EINVAL; + pr_debug("map '%s': found max_entries = %u.\n", + map_name, map->def.max_entries); + } else if (strcmp(name, "map_flags") == 0) { + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &map->def.map_flags)) + return -EINVAL; + pr_debug("map '%s': found map_flags = %u.\n", + map_name, map->def.map_flags); + } else if (strcmp(name, "key_size") == 0) { + __u32 sz; + + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &sz)) + return -EINVAL; + pr_debug("map '%s': found key_size = %u.\n", + map_name, sz); + if (map->def.key_size && map->def.key_size != sz) { + pr_warning("map '%s': conflictling key size %u != %u.\n", + map_name, map->def.key_size, sz); + return -EINVAL; + } + map->def.key_size = sz; + } else if (strcmp(name, "key") == 0) { + __s64 sz; + + t = btf__type_by_id(obj->btf, m->type); + if (!t) { + pr_warning("map '%s': key type [%d] not found.\n", + map_name, m->type); + return -EINVAL; + } + if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { + pr_warning("map '%s': key spec is not PTR: %u.\n", + map_name, BTF_INFO_KIND(t->info)); + return -EINVAL; + } + sz = btf__resolve_size(obj->btf, t->type); + if (sz < 0) { + pr_warning("map '%s': can't determine key size for type [%u]: %lld.\n", + map_name, t->type, sz); + return sz; + } + pr_debug("map '%s': found key [%u], sz = %lld.\n", + map_name, t->type, sz); + if (map->def.key_size && map->def.key_size != sz) { + pr_warning("map '%s': conflictling key size %u != %lld.\n", + map_name, map->def.key_size, sz); + return -EINVAL; + } + map->def.key_size = sz; + map->btf_key_type_id = t->type; + } else if (strcmp(name, "value_size") == 0) { + __u32 sz; + + if (!get_map_field_int(map_name, obj->btf, def, m, + def_data, &sz)) + return -EINVAL; + pr_debug("map '%s': found value_size = %u.\n", + map_name, sz); + if (map->def.value_size && map->def.value_size != sz) { + pr_warning("map '%s': conflictling value size %u != %u.\n", + map_name, map->def.value_size, sz); + return -EINVAL; + } + map->def.value_size = sz; + } else if (strcmp(name, "value") == 0) { + __s64 sz; + + t = btf__type_by_id(obj->btf, m->type); + if (!t) { + pr_warning("map '%s': value type [%d] not found.\n", + map_name, m->type); + return -EINVAL; + } + if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { + pr_warning("map '%s': value spec is not PTR: %u.\n", + map_name, BTF_INFO_KIND(t->info)); + return -EINVAL; + } + sz = btf__resolve_size(obj->btf, t->type); + if (sz < 0) { + pr_warning("map '%s': can't determine value size for type [%u]: %lld.\n", + map_name, t->type, sz); + return sz; + } + pr_debug("map '%s': found value [%u], sz = %lld.\n", + map_name, t->type, sz); + if (map->def.value_size && map->def.value_size != sz) { + pr_warning("map '%s': conflictling value size %u != %lld.\n", + map_name, map->def.value_size, sz); + return -EINVAL; + } + map->def.value_size = sz; + map->btf_value_type_id = t->type; + } else { + if (strict) { + pr_warning("map '%s': unknown field '%s'.\n", + map_name, name); + return -ENOTSUP; + } + pr_debug("map '%s': ignoring unknown field '%s'.\n", + map_name, name); + } + } + + if (map->def.type == BPF_MAP_TYPE_UNSPEC) { + pr_warning("map '%s': map type isn't specified.\n", map_name); + return -EINVAL; + } + + return 0; +} + +static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict) +{ + const struct btf_type *sec = NULL; + int nr_types, i, vlen, err; + const struct btf_type *t; + const char *name; + Elf_Data *data; + Elf_Scn *scn; + + if (obj->efile.btf_maps_shndx < 0) + return 0; + + scn = elf_getscn(obj->efile.elf, obj->efile.btf_maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d (%s)\n", + obj->efile.maps_shndx, MAPS_ELF_SEC); + return -EINVAL; + } + + nr_types = btf__get_nr_types(obj->btf); + for (i = 1; i <= nr_types; i++) { + t = btf__type_by_id(obj->btf, i); + if (BTF_INFO_KIND(t->info) != BTF_KIND_DATASEC) + continue; + name = btf__name_by_offset(obj->btf, t->name_off); + if (strcmp(name, MAPS_ELF_SEC) == 0) { + sec = t; + break; + } + } + + if (!sec) { + pr_warning("DATASEC '%s' not found.\n", MAPS_ELF_SEC); + return -ENOENT; + } + + vlen = BTF_INFO_VLEN(sec->info); + for (i = 0; i < vlen; i++) { + err = bpf_object__init_user_btf_map(obj, sec, i, + obj->efile.btf_maps_shndx, + data, strict); + if (err) + return err; + } + + return 0; +} + +static int bpf_object__init_maps(struct bpf_object *obj, int flags) +{ + bool strict = !(flags & MAPS_RELAX_COMPAT); + int err; + + err = bpf_object__init_user_maps(obj, strict); + if (err) + return err; + + err = bpf_object__init_user_btf_maps(obj, strict); + if (err) + return err; + + err = bpf_object__init_global_data_maps(obj); + if (err) + return err; + + if (obj->nr_maps) { qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); - return ret; + } + return 0; } static bool section_have_execinstr(struct bpf_object *obj, int idx) @@ -1078,6 +1425,86 @@ static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) } } +static bool bpf_object__is_btf_mandatory(const struct bpf_object *obj) +{ + return obj->efile.btf_maps_shndx >= 0; +} + +static int bpf_object__init_btf(struct bpf_object *obj, + Elf_Data *btf_data, + Elf_Data *btf_ext_data) +{ + bool btf_required = bpf_object__is_btf_mandatory(obj); + int err = 0; + + if (btf_data) { + obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); + if (IS_ERR(obj->btf)) { + pr_warning("Error loading ELF section %s: %d.\n", + BTF_ELF_SEC, err); + goto out; + } + err = btf__finalize_data(obj, obj->btf); + if (err) { + pr_warning("Error finalizing %s: %d.\n", + BTF_ELF_SEC, err); + goto out; + } + } + if (btf_ext_data) { + if (!obj->btf) { + pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", + BTF_EXT_ELF_SEC, BTF_ELF_SEC); + goto out; + } + obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, + btf_ext_data->d_size); + if (IS_ERR(obj->btf_ext)) { + pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", + BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext)); + obj->btf_ext = NULL; + goto out; + } + } +out: + if (err || IS_ERR(obj->btf)) { + if (btf_required) + err = err ? : PTR_ERR(obj->btf); + else + err = 0; + if (!IS_ERR_OR_NULL(obj->btf)) + btf__free(obj->btf); + obj->btf = NULL; + } + if (btf_required && !obj->btf) { + pr_warning("BTF is required, but is missing or corrupted.\n"); + return err == 0 ? -ENOENT : err; + } + return 0; +} + +static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) +{ + int err = 0; + + if (!obj->btf) + return 0; + + bpf_object__sanitize_btf(obj); + bpf_object__sanitize_btf_ext(obj); + + err = btf__load(obj->btf); + if (err) { + pr_warning("Error loading %s into kernel: %d.\n", + BTF_ELF_SEC, err); + btf__free(obj->btf); + obj->btf = NULL; + if (bpf_object__is_btf_mandatory(obj)) + return err; + } + return 0; +} + static int bpf_object__elf_collect(struct bpf_object *obj, int flags) { Elf *elf = obj->efile.elf; @@ -1102,24 +1529,21 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (gelf_getshdr(scn, &sh) != &sh) { pr_warning("failed to get section(%d) header from %s\n", idx, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); if (!name) { pr_warning("failed to get section(%d) name from %s\n", idx, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } data = elf_getdata(scn, 0); if (!data) { pr_warning("failed to get section(%d) data from %s(%s)\n", idx, name, obj->path); - err = -LIBBPF_ERRNO__FORMAT; - goto out; + return -LIBBPF_ERRNO__FORMAT; } pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", idx, name, (unsigned long)data->d_size, @@ -1130,12 +1554,18 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) err = bpf_object__init_license(obj, data->d_buf, data->d_size); + if (err) + return err; } else if (strcmp(name, "version") == 0) { err = bpf_object__init_kversion(obj, data->d_buf, data->d_size); + if (err) + return err; } else if (strcmp(name, "maps") == 0) { obj->efile.maps_shndx = idx; + } else if (strcmp(name, MAPS_ELF_SEC) == 0) { + obj->efile.btf_maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { btf_data = data; } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { @@ -1144,11 +1574,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) if (obj->efile.symbols) { pr_warning("bpf: multiple SYMTAB in %s\n", obj->path); - err = -LIBBPF_ERRNO__FORMAT; - } else { - obj->efile.symbols = data; - obj->efile.strtabidx = sh.sh_link; + return -LIBBPF_ERRNO__FORMAT; } + obj->efile.symbols = data; + obj->efile.strtabidx = sh.sh_link; } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) { if (sh.sh_flags & SHF_EXECINSTR) { if (strcmp(name, ".text") == 0) @@ -1162,6 +1591,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_warning("failed to alloc program %s (%s): %s", name, obj->path, cp); + return err; } } else if (strcmp(name, ".data") == 0) { obj->efile.data = data; @@ -1173,8 +1603,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) pr_debug("skip section(%d) %s\n", idx, name); } } else if (sh.sh_type == SHT_REL) { + int nr_reloc = obj->efile.nr_reloc; void *reloc = obj->efile.reloc; - int nr_reloc = obj->efile.nr_reloc + 1; int sec = sh.sh_info; /* points to other section */ /* Only do relo for section with exec instructions */ @@ -1184,79 +1614,37 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) continue; } - reloc = reallocarray(reloc, nr_reloc, + reloc = reallocarray(reloc, nr_reloc + 1, sizeof(*obj->efile.reloc)); if (!reloc) { pr_warning("realloc failed\n"); - err = -ENOMEM; - } else { - int n = nr_reloc - 1; + return -ENOMEM; + } - obj->efile.reloc = reloc; - obj->efile.nr_reloc = nr_reloc; + obj->efile.reloc = reloc; + obj->efile.nr_reloc++; - obj->efile.reloc[n].shdr = sh; - obj->efile.reloc[n].data = data; - } + obj->efile.reloc[nr_reloc].shdr = sh; + obj->efile.reloc[nr_reloc].data = data; } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) { obj->efile.bss = data; obj->efile.bss_shndx = idx; } else { pr_debug("skip section(%d) %s\n", idx, name); } - if (err) - goto out; } if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { pr_warning("Corrupted ELF file: index of strtab invalid\n"); return -LIBBPF_ERRNO__FORMAT; } - if (btf_data) { - obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); - if (IS_ERR(obj->btf)) { - pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", - BTF_ELF_SEC, PTR_ERR(obj->btf)); - obj->btf = NULL; - } else { - err = btf__finalize_data(obj, obj->btf); - if (!err) { - bpf_object__sanitize_btf(obj); - err = btf__load(obj->btf); - } - if (err) { - pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n", - BTF_ELF_SEC, err); - btf__free(obj->btf); - obj->btf = NULL; - err = 0; - } - } - } - if (btf_ext_data) { - if (!obj->btf) { - pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", - BTF_EXT_ELF_SEC, BTF_ELF_SEC); - } else { - obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, - btf_ext_data->d_size); - if (IS_ERR(obj->btf_ext)) { - pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", - BTF_EXT_ELF_SEC, - PTR_ERR(obj->btf_ext)); - obj->btf_ext = NULL; - } else { - bpf_object__sanitize_btf_ext(obj); - } - } - } - if (bpf_object__has_maps(obj)) { + err = bpf_object__init_btf(obj, btf_data, btf_ext_data); + if (!err) err = bpf_object__init_maps(obj, flags); - if (err) - goto out; - } - err = bpf_object__init_prog_names(obj); -out: + if (!err) + err = bpf_object__sanitize_and_load_btf(obj); + if (!err) + err = bpf_object__init_prog_names(obj); return err; } @@ -1275,7 +1663,8 @@ bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) } struct bpf_program * -bpf_object__find_program_by_title(struct bpf_object *obj, const char *title) +bpf_object__find_program_by_title(const struct bpf_object *obj, + const char *title) { struct bpf_program *pos; @@ -1297,7 +1686,8 @@ static bool bpf_object__shndx_is_data(const struct bpf_object *obj, static bool bpf_object__shndx_is_maps(const struct bpf_object *obj, int shndx) { - return shndx == obj->efile.maps_shndx; + return shndx == obj->efile.maps_shndx || + shndx == obj->efile.btf_maps_shndx; } static bool bpf_object__relo_in_known_section(const struct bpf_object *obj, @@ -1341,14 +1731,14 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, prog->nr_reloc = nrels; for (i = 0; i < nrels; i++) { - GElf_Sym sym; - GElf_Rel rel; - unsigned int insn_idx; - unsigned int shdr_idx; struct bpf_insn *insns = prog->insns; enum libbpf_map_type type; + unsigned int insn_idx; + unsigned int shdr_idx; const char *name; size_t map_idx; + GElf_Sym sym; + GElf_Rel rel; if (!gelf_getrel(data, i, &rel)) { pr_warning("relocation: failed to get %d reloc\n", i); @@ -1416,9 +1806,13 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, if (maps[map_idx].libbpf_type != type) continue; if (type != LIBBPF_MAP_UNSPEC || - maps[map_idx].offset == sym.st_value) { - pr_debug("relocation: find map %zd (%s) for insn %u\n", - map_idx, maps[map_idx].name, insn_idx); + (maps[map_idx].sec_idx == sym.st_shndx && + maps[map_idx].sec_offset == sym.st_value)) { + pr_debug("relocation: found map %zd (%s, sec_idx %d, offset %zu) for insn %u\n", + map_idx, maps[map_idx].name, + maps[map_idx].sec_idx, + maps[map_idx].sec_offset, + insn_idx); break; } } @@ -1438,14 +1832,18 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, return 0; } -static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) +static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map) { struct bpf_map_def *def = &map->def; __u32 key_type_id = 0, value_type_id = 0; int ret; + /* if it's BTF-defined map, we don't need to search for type IDs */ + if (map->sec_idx == obj->efile.btf_maps_shndx) + return 0; + if (!bpf_map__is_internal(map)) { - ret = btf__get_map_kv_tids(btf, map->name, def->key_size, + ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size, def->value_size, &key_type_id, &value_type_id); } else { @@ -1453,7 +1851,7 @@ static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) * LLVM annotates global data differently in BTF, that is, * only as '.data', '.bss' or '.rodata'. */ - ret = btf__find_by_name(btf, + ret = btf__find_by_name(obj->btf, libbpf_type_to_btf_name[map->libbpf_type]); } if (ret < 0) @@ -1740,25 +2138,26 @@ bpf_object__create_maps(struct bpf_object *obj) create_attr.key_size = def->key_size; create_attr.value_size = def->value_size; create_attr.max_entries = def->max_entries; - create_attr.btf_fd = -1; + 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 (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) { + 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_fd >= 0) { + if (*pfd < 0 && (create_attr.btf_key_type_id || + create_attr.btf_value_type_id)) { cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", map->name, cp, errno); - create_attr.btf_fd = -1; + 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; @@ -2049,7 +2448,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.license = license; load_attr.kern_version = kern_version; load_attr.prog_ifindex = prog->prog_ifindex; - load_attr.prog_btf_fd = prog->btf_fd; + load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0; load_attr.func_info = prog->func_info; load_attr.func_info_rec_size = prog->func_info_rec_size; load_attr.func_info_cnt = prog->func_info_cnt; @@ -2195,8 +2594,8 @@ out: return err; } -static bool bpf_program__is_function_storage(struct bpf_program *prog, - struct bpf_object *obj) +static bool bpf_program__is_function_storage(const struct bpf_program *prog, + const struct bpf_object *obj) { return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls; } @@ -2902,17 +3301,17 @@ bpf_object__next(struct bpf_object *prev) return next; } -const char *bpf_object__name(struct bpf_object *obj) +const char *bpf_object__name(const struct bpf_object *obj) { return obj ? obj->path : ERR_PTR(-EINVAL); } -unsigned int bpf_object__kversion(struct bpf_object *obj) +unsigned int bpf_object__kversion(const struct bpf_object *obj) { return obj ? obj->kern_version : 0; } -struct btf *bpf_object__btf(struct bpf_object *obj) +struct btf *bpf_object__btf(const struct bpf_object *obj) { return obj ? obj->btf : NULL; } @@ -2933,13 +3332,14 @@ int bpf_object__set_priv(struct bpf_object *obj, void *priv, return 0; } -void *bpf_object__priv(struct bpf_object *obj) +void *bpf_object__priv(const struct bpf_object *obj) { return obj ? obj->priv : ERR_PTR(-EINVAL); } static struct bpf_program * -__bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward) +__bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj, + bool forward) { size_t nr_programs = obj->nr_programs; ssize_t idx; @@ -2964,7 +3364,7 @@ __bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward) } struct bpf_program * -bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) +bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj) { struct bpf_program *prog = prev; @@ -2976,7 +3376,7 @@ bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) } struct bpf_program * -bpf_program__prev(struct bpf_program *next, struct bpf_object *obj) +bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj) { struct bpf_program *prog = next; @@ -2998,7 +3398,7 @@ int bpf_program__set_priv(struct bpf_program *prog, void *priv, return 0; } -void *bpf_program__priv(struct bpf_program *prog) +void *bpf_program__priv(const struct bpf_program *prog) { return prog ? prog->priv : ERR_PTR(-EINVAL); } @@ -3008,7 +3408,7 @@ void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) prog->prog_ifindex = ifindex; } -const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) +const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) { const char *title; @@ -3024,7 +3424,7 @@ const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) return title; } -int bpf_program__fd(struct bpf_program *prog) +int bpf_program__fd(const struct bpf_program *prog) { return bpf_program__nth_fd(prog, 0); } @@ -3057,7 +3457,7 @@ int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, return 0; } -int bpf_program__nth_fd(struct bpf_program *prog, int n) +int bpf_program__nth_fd(const struct bpf_program *prog, int n) { int fd; @@ -3085,25 +3485,25 @@ void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) prog->type = type; } -static bool bpf_program__is_type(struct bpf_program *prog, +static bool bpf_program__is_type(const struct bpf_program *prog, enum bpf_prog_type type) { return prog ? (prog->type == type) : false; } -#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ -int bpf_program__set_##NAME(struct bpf_program *prog) \ -{ \ - if (!prog) \ - return -EINVAL; \ - bpf_program__set_type(prog, TYPE); \ - return 0; \ -} \ - \ -bool bpf_program__is_##NAME(struct bpf_program *prog) \ -{ \ - return bpf_program__is_type(prog, TYPE); \ -} \ +#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ +int bpf_program__set_##NAME(struct bpf_program *prog) \ +{ \ + if (!prog) \ + return -EINVAL; \ + bpf_program__set_type(prog, TYPE); \ + return 0; \ +} \ + \ +bool bpf_program__is_##NAME(const struct bpf_program *prog) \ +{ \ + return bpf_program__is_type(prog, TYPE); \ +} \ BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); @@ -3302,17 +3702,17 @@ bpf_program__identify_section(struct bpf_program *prog, expected_attach_type); } -int bpf_map__fd(struct bpf_map *map) +int bpf_map__fd(const struct bpf_map *map) { return map ? map->fd : -EINVAL; } -const struct bpf_map_def *bpf_map__def(struct bpf_map *map) +const struct bpf_map_def *bpf_map__def(const struct bpf_map *map) { return map ? &map->def : ERR_PTR(-EINVAL); } -const char *bpf_map__name(struct bpf_map *map) +const char *bpf_map__name(const struct bpf_map *map) { return map ? map->name : NULL; } @@ -3343,17 +3743,17 @@ int bpf_map__set_priv(struct bpf_map *map, void *priv, return 0; } -void *bpf_map__priv(struct bpf_map *map) +void *bpf_map__priv(const struct bpf_map *map) { return map ? map->priv : ERR_PTR(-EINVAL); } -bool bpf_map__is_offload_neutral(struct bpf_map *map) +bool bpf_map__is_offload_neutral(const struct bpf_map *map) { return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; } -bool bpf_map__is_internal(struct bpf_map *map) +bool bpf_map__is_internal(const struct bpf_map *map) { return map->libbpf_type != LIBBPF_MAP_UNSPEC; } @@ -3378,7 +3778,7 @@ int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd) } static struct bpf_map * -__bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i) +__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i) { ssize_t idx; struct bpf_map *s, *e; @@ -3402,7 +3802,7 @@ __bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i) } struct bpf_map * -bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) +bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj) { if (prev == NULL) return obj->maps; @@ -3411,7 +3811,7 @@ bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) } struct bpf_map * -bpf_map__prev(struct bpf_map *next, struct bpf_object *obj) +bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj) { if (next == NULL) { if (!obj->nr_maps) @@ -3423,7 +3823,7 @@ bpf_map__prev(struct bpf_map *next, struct bpf_object *obj) } struct bpf_map * -bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) +bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name) { struct bpf_map *pos; @@ -3435,7 +3835,7 @@ bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) } int -bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name) +bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name) { return bpf_map__fd(bpf_object__find_map_by_name(obj, name)); } @@ -3443,13 +3843,7 @@ bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name) struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) { - int i; - - for (i = 0; i < obj->nr_maps; i++) { - if (obj->maps[i].offset == offset) - return &obj->maps[i]; - } - return ERR_PTR(-ENOENT); + return ERR_PTR(-ENOTSUP); } long libbpf_get_error(const void *ptr) @@ -3835,3 +4229,60 @@ void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear) desc->array_offset, addr); } } + +int libbpf_num_possible_cpus(void) +{ + static const char *fcpu = "/sys/devices/system/cpu/possible"; + int len = 0, n = 0, il = 0, ir = 0; + unsigned int start = 0, end = 0; + static int cpus; + char buf[128]; + int error = 0; + int fd = -1; + + if (cpus > 0) + return cpus; + + fd = open(fcpu, O_RDONLY); + if (fd < 0) { + error = errno; + pr_warning("Failed to open file %s: %s\n", + fcpu, strerror(error)); + return -error; + } + len = read(fd, buf, sizeof(buf)); + close(fd); + if (len <= 0) { + error = len ? errno : EINVAL; + pr_warning("Failed to read # of possible cpus from %s: %s\n", + fcpu, strerror(error)); + return -error; + } + if (len == sizeof(buf)) { + pr_warning("File %s size overflow\n", fcpu); + return -EOVERFLOW; + } + buf[len] = '\0'; + + for (ir = 0, cpus = 0; ir <= len; ir++) { + /* Each sub string separated by ',' has format \d+-\d+ or \d+ */ + if (buf[ir] == ',' || buf[ir] == '\0') { + buf[ir] = '\0'; + n = sscanf(&buf[il], "%u-%u", &start, &end); + if (n <= 0) { + pr_warning("Failed to get # CPUs from %s\n", + &buf[il]); + return -EINVAL; + } else if (n == 1) { + end = start; + } + cpus += end - start + 1; + il = ir + 1; + } + } + if (cpus <= 0) { + pr_warning("Invalid #CPUs %d from %s\n", cpus, fcpu); + return -EINVAL; + } + return cpus; +} |