diff options
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/bpf_helpers.h | 1 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 281 |
2 files changed, 259 insertions, 23 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index 60aad054eea1..da00b87aa199 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -12,6 +12,7 @@ #define __uint(name, val) int (*name)[val] #define __type(name, val) typeof(val) *name +#define __array(name, val) typeof(val) *name[] /* Helper macro to print out debug messages */ #define bpf_printk(fmt, ...) \ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9c845cf4cfcf..445ee903f9cd 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; @@ -1918,7 +1923,7 @@ static int build_map_pin_path(struct bpf_map *map, const char *path) static int parse_btf_map_def(struct bpf_object *obj, struct bpf_map *map, const struct btf_type *def, - bool strict, + bool strict, bool is_inner, const char *pin_root_path) { const struct btf_type *t; @@ -2036,10 +2041,79 @@ static int parse_btf_map_def(struct bpf_object *obj, } 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 (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", @@ -2138,10 +2212,11 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, 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, pin_root_path); + 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, @@ -2174,6 +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; } } @@ -2560,7 +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; @@ -3538,6 +3615,22 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) 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)) { @@ -3558,6 +3651,11 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) 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; } @@ -3602,6 +3700,31 @@ bpf_object__create_maps(struct bpf_object *obj) } } + 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) { @@ -4873,9 +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_type *sec, *var, *def; + const struct btf_var_secinfo *vi; + 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) { @@ -4898,21 +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; } @@ -5984,6 +6212,14 @@ static void bpf_map__destroy(struct bpf_map *map) 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; @@ -6543,9 +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; |