diff options
-rw-r--r-- | tools/lib/bpf/btf.c | 139 |
1 files changed, 75 insertions, 64 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index a3d259e614b0..7c9957893ef2 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -31,11 +31,12 @@ struct btf { struct btf_header *hdr; void *data; }; - struct btf_type **types; + __u32 *type_offs; + __u32 type_offs_cap; const char *strings; void *nohdr_data; + void *types_data; __u32 nr_types; - __u32 types_size; __u32 data_size; int fd; int ptr_sz; @@ -46,30 +47,30 @@ static inline __u64 ptr_to_u64(const void *ptr) return (__u64) (unsigned long) ptr; } -static int btf_add_type(struct btf *btf, struct btf_type *t) +static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off) { - if (btf->types_size - btf->nr_types < 2) { - struct btf_type **new_types; + /* nr_types is 1-based, so N types means we need N+1-sized array */ + if (btf->nr_types + 2 > btf->type_offs_cap) { + __u32 *new_offs; __u32 expand_by, new_size; - if (btf->types_size == BTF_MAX_NR_TYPES) + if (btf->type_offs_cap == BTF_MAX_NR_TYPES) return -E2BIG; - expand_by = max(btf->types_size >> 2, 16U); - new_size = min(BTF_MAX_NR_TYPES, btf->types_size + expand_by); + expand_by = max(btf->type_offs_cap / 4, 16U); + new_size = min(BTF_MAX_NR_TYPES, btf->type_offs_cap + expand_by); - new_types = libbpf_reallocarray(btf->types, new_size, sizeof(*new_types)); - if (!new_types) + new_offs = libbpf_reallocarray(btf->type_offs, new_size, sizeof(*new_offs)); + if (!new_offs) return -ENOMEM; - if (btf->nr_types == 0) - new_types[0] = &btf_void; + new_offs[0] = UINT_MAX; /* VOID is specially handled */ - btf->types = new_types; - btf->types_size = new_size; + btf->type_offs = new_offs; + btf->type_offs_cap = new_size; } - btf->types[++(btf->nr_types)] = t; + btf->type_offs[btf->nr_types + 1] = type_off; return 0; } @@ -147,7 +148,7 @@ static int btf_parse_str_sec(struct btf *btf) return 0; } -static int btf_type_size(struct btf_type *t) +static int btf_type_size(const struct btf_type *t) { int base_size = sizeof(struct btf_type); __u16 vlen = btf_vlen(t); @@ -185,22 +186,25 @@ static int btf_type_size(struct btf_type *t) static int btf_parse_type_sec(struct btf *btf) { struct btf_header *hdr = btf->hdr; - void *nohdr_data = btf->nohdr_data; - void *next_type = nohdr_data + hdr->type_off; - void *end_type = nohdr_data + hdr->str_off; + void *next_type = btf->nohdr_data + hdr->type_off; + void *end_type = next_type + hdr->type_len; + + btf->types_data = next_type; while (next_type < end_type) { - struct btf_type *t = next_type; int type_size; int err; - type_size = btf_type_size(t); + err = btf_add_type_idx_entry(btf, next_type - btf->types_data); + if (err) + return err; + + type_size = btf_type_size(next_type); if (type_size < 0) return type_size; + next_type += type_size; - err = btf_add_type(btf, t); - if (err) - return err; + btf->nr_types++; } return 0; @@ -211,12 +215,20 @@ __u32 btf__get_nr_types(const struct btf *btf) return btf->nr_types; } +/* internal helper returning non-const pointer to a type */ +static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id) +{ + if (type_id == 0) + return &btf_void; + + return btf->types_data + btf->type_offs[type_id]; +} + const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) { if (type_id > btf->nr_types) return NULL; - - return btf->types[type_id]; + return btf_type_by_id((struct btf *)btf, type_id); } static int determine_ptr_size(const struct btf *btf) @@ -414,7 +426,7 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name) return 0; for (i = 1; i <= btf->nr_types; i++) { - const struct btf_type *t = btf->types[i]; + const struct btf_type *t = btf__type_by_id(btf, i); const char *name = btf__name_by_offset(btf, t->name_off); if (name && !strcmp(type_name, name)) @@ -433,7 +445,7 @@ __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name, return 0; for (i = 1; i <= btf->nr_types; i++) { - const struct btf_type *t = btf->types[i]; + const struct btf_type *t = btf__type_by_id(btf, i); const char *name; if (btf_kind(t) != kind) @@ -455,7 +467,7 @@ void btf__free(struct btf *btf) close(btf->fd); free(btf->data); - free(btf->types); + free(btf->type_offs); free(btf); } @@ -789,7 +801,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf) __u32 i; for (i = 1; i <= btf->nr_types; i++) { - struct btf_type *t = btf->types[i]; + struct btf_type *t = btf_type_by_id(btf, i); /* Loader needs to fix up some of the things compiler * couldn't get its hands on while emitting BTF. This @@ -1655,7 +1667,7 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext, /* special BTF "void" type is made canonical immediately */ d->map[0] = 0; for (i = 1; i <= btf->nr_types; i++) { - struct btf_type *t = d->btf->types[i]; + struct btf_type *t = btf_type_by_id(d->btf, i); /* VAR and DATASEC are never deduped and are self-canonical */ if (btf_is_var(t) || btf_is_datasec(t)) @@ -1694,7 +1706,7 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx) struct btf_type *t; for (i = 1; i <= d->btf->nr_types; i++) { - t = d->btf->types[i]; + t = btf_type_by_id(d->btf, i); r = fn(&t->name_off, ctx); if (r) return r; @@ -2229,7 +2241,7 @@ static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2) */ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) { - struct btf_type *t = d->btf->types[type_id]; + struct btf_type *t = btf_type_by_id(d->btf, type_id); struct hashmap_entry *hash_entry; struct btf_type *cand; /* if we don't find equivalent type, then we are canonical */ @@ -2256,7 +2268,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_int(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_int(t, cand)) { new_id = cand_id; break; @@ -2268,7 +2280,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_enum(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_enum(t, cand)) { new_id = cand_id; break; @@ -2291,7 +2303,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_common(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_common(t, cand)) { new_id = cand_id; break; @@ -2350,13 +2362,13 @@ static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id) { __u32 orig_type_id = type_id; - if (!btf_is_fwd(d->btf->types[type_id])) + if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) return type_id; while (is_type_mapped(d, type_id) && d->map[type_id] != type_id) type_id = d->map[type_id]; - if (!btf_is_fwd(d->btf->types[type_id])) + if (!btf_is_fwd(btf__type_by_id(d->btf, type_id))) return type_id; return orig_type_id; @@ -2484,8 +2496,8 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, if (btf_dedup_hypot_map_add(d, canon_id, cand_id)) return -ENOMEM; - cand_type = d->btf->types[cand_id]; - canon_type = d->btf->types[canon_id]; + cand_type = btf_type_by_id(d->btf, cand_id); + canon_type = btf_type_by_id(d->btf, canon_id); cand_kind = btf_kind(cand_type); canon_kind = btf_kind(canon_type); @@ -2636,8 +2648,8 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d) targ_type_id = d->hypot_map[cand_type_id]; t_id = resolve_type_id(d, targ_type_id); c_id = resolve_type_id(d, cand_type_id); - t_kind = btf_kind(d->btf->types[t_id]); - c_kind = btf_kind(d->btf->types[c_id]); + t_kind = btf_kind(btf__type_by_id(d->btf, t_id)); + c_kind = btf_kind(btf__type_by_id(d->btf, c_id)); /* * Resolve FWD into STRUCT/UNION. * It's ok to resolve FWD into STRUCT/UNION that's not yet @@ -2705,7 +2717,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) if (d->map[type_id] <= BTF_MAX_NR_TYPES) return 0; - t = d->btf->types[type_id]; + t = btf_type_by_id(d->btf, type_id); kind = btf_kind(t); if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION) @@ -2726,7 +2738,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because * FWD and compatible STRUCT/UNION are considered equivalent. */ - cand_type = d->btf->types[cand_id]; + cand_type = btf_type_by_id(d->btf, cand_id); if (!btf_shallow_equal_struct(t, cand_type)) continue; @@ -2798,7 +2810,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) if (d->map[type_id] <= BTF_MAX_NR_TYPES) return resolve_type_id(d, type_id); - t = d->btf->types[type_id]; + t = btf_type_by_id(d->btf, type_id); d->map[type_id] = BTF_IN_PROGRESS_ID; switch (btf_kind(t)) { @@ -2816,7 +2828,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_common(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_common(t, cand)) { new_id = cand_id; break; @@ -2840,7 +2852,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_array(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_array(t, cand)) { new_id = cand_id; break; @@ -2872,7 +2884,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) h = btf_hash_fnproto(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; - cand = d->btf->types[cand_id]; + cand = btf_type_by_id(d->btf, cand_id); if (btf_equal_fnproto(t, cand)) { new_id = cand_id; break; @@ -2920,9 +2932,9 @@ static int btf_dedup_ref_types(struct btf_dedup *d) */ static int btf_dedup_compact_types(struct btf_dedup *d) { - struct btf_type **new_types; + __u32 *new_offs; __u32 next_type_id = 1; - char *types_start, *p; + void *p; int i, len; /* we are going to reuse hypot_map to store compaction remapping */ @@ -2930,41 +2942,40 @@ static int btf_dedup_compact_types(struct btf_dedup *d) for (i = 1; i <= d->btf->nr_types; i++) d->hypot_map[i] = BTF_UNPROCESSED_ID; - types_start = d->btf->nohdr_data + d->btf->hdr->type_off; - p = types_start; + p = d->btf->types_data; for (i = 1; i <= d->btf->nr_types; i++) { if (d->map[i] != i) continue; - len = btf_type_size(d->btf->types[i]); + len = btf_type_size(btf__type_by_id(d->btf, i)); if (len < 0) return len; - memmove(p, d->btf->types[i], len); + memmove(p, btf__type_by_id(d->btf, i), len); d->hypot_map[i] = next_type_id; - d->btf->types[next_type_id] = (struct btf_type *)p; + d->btf->type_offs[next_type_id] = p - d->btf->types_data; p += len; next_type_id++; } /* shrink struct btf's internal types index and update btf_header */ d->btf->nr_types = next_type_id - 1; - d->btf->types_size = d->btf->nr_types; - d->btf->hdr->type_len = p - types_start; - new_types = libbpf_reallocarray(d->btf->types, (1 + d->btf->nr_types), - sizeof(struct btf_type *)); - if (!new_types) + d->btf->type_offs_cap = d->btf->nr_types + 1; + d->btf->hdr->type_len = p - d->btf->types_data; + new_offs = libbpf_reallocarray(d->btf->type_offs, d->btf->type_offs_cap, + sizeof(*new_offs)); + if (!new_offs) return -ENOMEM; - d->btf->types = new_types; + d->btf->type_offs = new_offs; /* make sure string section follows type information without gaps */ - d->btf->hdr->str_off = p - (char *)d->btf->nohdr_data; + d->btf->hdr->str_off = p - d->btf->nohdr_data; memmove(p, d->btf->strings, d->btf->hdr->str_len); d->btf->strings = p; p += d->btf->hdr->str_len; - d->btf->data_size = p - (char *)d->btf->data; + d->btf->data_size = p - d->btf->data; return 0; } @@ -2997,7 +3008,7 @@ static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id) */ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id) { - struct btf_type *t = d->btf->types[type_id]; + struct btf_type *t = btf_type_by_id(d->btf, type_id); int i, r; switch (btf_kind(t)) { |