diff options
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 187 |
1 files changed, 111 insertions, 76 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index b2e16efabde0..2e4fa3ce6b94 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -462,11 +462,14 @@ struct bpf_object { struct list_head list; struct btf *btf; + struct btf_ext *btf_ext; + /* Parse and load BTF vmlinux if any of the programs in the object need * it at load time. */ struct btf *btf_vmlinux; - struct btf_ext *btf_ext; + /* vmlinux BTF override for CO-RE relocations */ + struct btf *btf_vmlinux_override; void *priv; bpf_object_clear_priv_t clear_priv; @@ -4600,46 +4603,43 @@ static size_t bpf_core_essential_name_len(const char *name) return n; } -/* dynamically sized list of type IDs */ -struct ids_vec { - __u32 *data; +struct core_cand +{ + const struct btf *btf; + const struct btf_type *t; + const char *name; + __u32 id; +}; + +/* dynamically sized list of type IDs and its associated struct btf */ +struct core_cand_list { + struct core_cand *cands; int len; }; -static void bpf_core_free_cands(struct ids_vec *cand_ids) +static void bpf_core_free_cands(struct core_cand_list *cands) { - free(cand_ids->data); - free(cand_ids); + free(cands->cands); + free(cands); } -static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf, - __u32 local_type_id, - const struct btf *targ_btf) +static int bpf_core_add_cands(struct core_cand *local_cand, + size_t local_essent_len, + const struct btf *targ_btf, + const char *targ_btf_name, + int targ_start_id, + struct core_cand_list *cands) { - size_t local_essent_len, targ_essent_len; - const char *local_name, *targ_name; - const struct btf_type *t, *local_t; - struct ids_vec *cand_ids; - __u32 *new_ids; - int i, err, n; - - local_t = btf__type_by_id(local_btf, local_type_id); - if (!local_t) - return ERR_PTR(-EINVAL); - - local_name = btf__name_by_offset(local_btf, local_t->name_off); - if (str_is_empty(local_name)) - return ERR_PTR(-EINVAL); - local_essent_len = bpf_core_essential_name_len(local_name); - - cand_ids = calloc(1, sizeof(*cand_ids)); - if (!cand_ids) - return ERR_PTR(-ENOMEM); + struct core_cand *new_cands, *cand; + const struct btf_type *t; + const char *targ_name; + size_t targ_essent_len; + int n, i; n = btf__get_nr_types(targ_btf); - for (i = 1; i <= n; i++) { + for (i = targ_start_id; i <= n; i++) { t = btf__type_by_id(targ_btf, i); - if (btf_kind(t) != btf_kind(local_t)) + if (btf_kind(t) != btf_kind(local_cand->t)) continue; targ_name = btf__name_by_offset(targ_btf, t->name_off); @@ -4650,25 +4650,62 @@ static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf, if (targ_essent_len != local_essent_len) continue; - if (strncmp(local_name, targ_name, local_essent_len) == 0) { - pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s\n", - local_type_id, btf_kind_str(local_t), - local_name, i, btf_kind_str(t), targ_name); - new_ids = libbpf_reallocarray(cand_ids->data, - cand_ids->len + 1, - sizeof(*cand_ids->data)); - if (!new_ids) { - err = -ENOMEM; - goto err_out; - } - cand_ids->data = new_ids; - cand_ids->data[cand_ids->len++] = i; - } + if (strncmp(local_cand->name, targ_name, local_essent_len) != 0) + continue; + + pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s in [%s]\n", + local_cand->id, btf_kind_str(local_cand->t), + local_cand->name, i, btf_kind_str(t), targ_name, + targ_btf_name); + new_cands = libbpf_reallocarray(cands->cands, cands->len + 1, + sizeof(*cands->cands)); + if (!new_cands) + return -ENOMEM; + + cand = &new_cands[cands->len]; + cand->btf = targ_btf; + cand->t = t; + cand->name = targ_name; + cand->id = i; + + cands->cands = new_cands; + cands->len++; } - return cand_ids; -err_out: - bpf_core_free_cands(cand_ids); - return ERR_PTR(err); + return 0; +} + +static struct core_cand_list * +bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 local_type_id) +{ + struct core_cand local_cand = {}; + struct core_cand_list *cands; + size_t local_essent_len; + int err; + + local_cand.btf = local_btf; + local_cand.t = btf__type_by_id(local_btf, local_type_id); + if (!local_cand.t) + return ERR_PTR(-EINVAL); + + local_cand.name = btf__name_by_offset(local_btf, local_cand.t->name_off); + if (str_is_empty(local_cand.name)) + return ERR_PTR(-EINVAL); + local_essent_len = bpf_core_essential_name_len(local_cand.name); + + cands = calloc(1, sizeof(*cands)); + if (!cands) + return ERR_PTR(-ENOMEM); + + /* Attempt to find target candidates in vmlinux BTF first */ + err = bpf_core_add_cands(&local_cand, local_essent_len, + obj->btf_vmlinux_override ?: obj->btf_vmlinux, + "vmlinux", 1, cands); + if (err) { + bpf_core_free_cands(cands); + return ERR_PTR(err); + } + + return cands; } /* Check two types for compatibility for the purpose of field access @@ -5661,7 +5698,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog, const struct bpf_core_relo *relo, int relo_idx, const struct btf *local_btf, - const struct btf *targ_btf, struct hashmap *cand_cache) { struct bpf_core_spec local_spec, cand_spec, targ_spec = {}; @@ -5669,8 +5705,8 @@ static int bpf_core_apply_relo(struct bpf_program *prog, struct bpf_core_relo_res cand_res, targ_res; const struct btf_type *local_type; const char *local_name; - struct ids_vec *cand_ids; - __u32 local_id, cand_id; + struct core_cand_list *cands = NULL; + __u32 local_id; const char *spec_str; int i, j, err; @@ -5717,24 +5753,24 @@ static int bpf_core_apply_relo(struct bpf_program *prog, return -EOPNOTSUPP; } - if (!hashmap__find(cand_cache, type_key, (void **)&cand_ids)) { - cand_ids = bpf_core_find_cands(local_btf, local_id, targ_btf); - if (IS_ERR(cand_ids)) { + if (!hashmap__find(cand_cache, type_key, (void **)&cands)) { + cands = bpf_core_find_cands(prog->obj, local_btf, local_id); + if (IS_ERR(cands)) { pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld", prog->name, relo_idx, local_id, btf_kind_str(local_type), - local_name, PTR_ERR(cand_ids)); - return PTR_ERR(cand_ids); + local_name, PTR_ERR(cands)); + return PTR_ERR(cands); } - err = hashmap__set(cand_cache, type_key, cand_ids, NULL, NULL); + err = hashmap__set(cand_cache, type_key, cands, NULL, NULL); if (err) { - bpf_core_free_cands(cand_ids); + bpf_core_free_cands(cands); return err; } } - for (i = 0, j = 0; i < cand_ids->len; i++) { - cand_id = cand_ids->data[i]; - err = bpf_core_spec_match(&local_spec, targ_btf, cand_id, &cand_spec); + for (i = 0, j = 0; i < cands->len; i++) { + err = bpf_core_spec_match(&local_spec, cands->cands[i].btf, + cands->cands[i].id, &cand_spec); if (err < 0) { pr_warn("prog '%s': relo #%d: error matching candidate #%d ", prog->name, relo_idx, i); @@ -5778,7 +5814,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog, return -EINVAL; } - cand_ids->data[j++] = cand_spec.root_type_id; + cands->cands[j++] = cands->cands[i]; } /* @@ -5790,7 +5826,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog, * depending on relo's kind. */ if (j > 0) - cand_ids->len = j; + cands->len = j; /* * If no candidates were found, it might be both a programmer error, @@ -5834,20 +5870,19 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) struct hashmap_entry *entry; struct hashmap *cand_cache = NULL; struct bpf_program *prog; - struct btf *targ_btf; const char *sec_name; int i, err = 0, insn_idx, sec_idx; if (obj->btf_ext->core_relo_info.len == 0) return 0; - if (targ_btf_path) - targ_btf = btf__parse(targ_btf_path, NULL); - else - targ_btf = obj->btf_vmlinux; - if (IS_ERR_OR_NULL(targ_btf)) { - pr_warn("failed to get target BTF: %ld\n", PTR_ERR(targ_btf)); - return PTR_ERR(targ_btf); + if (targ_btf_path) { + obj->btf_vmlinux_override = btf__parse(targ_btf_path, NULL); + if (IS_ERR_OR_NULL(obj->btf_vmlinux_override)) { + err = PTR_ERR(obj->btf_vmlinux_override); + pr_warn("failed to parse target BTF: %d\n", err); + return err; + } } cand_cache = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL); @@ -5899,8 +5934,7 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) if (!prog->load) continue; - err = bpf_core_apply_relo(prog, rec, i, obj->btf, - targ_btf, cand_cache); + err = bpf_core_apply_relo(prog, rec, i, obj->btf, cand_cache); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %d\n", prog->name, i, err); @@ -5911,8 +5945,9 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) out: /* obj->btf_vmlinux is freed at the end of object load phase */ - if (targ_btf != obj->btf_vmlinux) - btf__free(targ_btf); + btf__free(obj->btf_vmlinux_override); + obj->btf_vmlinux_override = NULL; + if (!IS_ERR_OR_NULL(cand_cache)) { hashmap__for_each_entry(cand_cache, entry, i) { bpf_core_free_cands(entry->value); |