diff options
-rw-r--r-- | tools/lib/bpf/btf.c | 197 | ||||
-rw-r--r-- | tools/lib/bpf/btf.h | 8 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.map | 9 |
3 files changed, 169 insertions, 45 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index fa1b147c63c6..0258cf108c0a 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -78,10 +78,32 @@ struct btf { void *types_data; size_t types_data_cap; /* used size stored in hdr->type_len */ - /* type ID to `struct btf_type *` lookup index */ + /* type ID to `struct btf_type *` lookup index + * type_offs[0] corresponds to the first non-VOID type: + * - for base BTF it's type [1]; + * - for split BTF it's the first non-base BTF type. + */ __u32 *type_offs; size_t type_offs_cap; + /* number of types in this BTF instance: + * - doesn't include special [0] void type; + * - for split BTF counts number of types added on top of base BTF. + */ __u32 nr_types; + /* if not NULL, points to the base BTF on top of which the current + * split BTF is based + */ + struct btf *base_btf; + /* BTF type ID of the first type in this BTF instance: + * - for base BTF it's equal to 1; + * - for split BTF it's equal to biggest type ID of base BTF plus 1. + */ + int start_id; + /* logical string offset of this BTF instance: + * - for base BTF it's equal to 0; + * - for split BTF it's equal to total size of base BTF's string section size. + */ + int start_str_off; void *strs_data; size_t strs_data_cap; /* used size stored in hdr->str_len */ @@ -176,7 +198,7 @@ static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off) __u32 *p; p = btf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32), - btf->nr_types + 1, BTF_MAX_NR_TYPES, 1); + btf->nr_types, BTF_MAX_NR_TYPES, 1); if (!p) return -ENOMEM; @@ -252,12 +274,16 @@ static int btf_parse_str_sec(struct btf *btf) const char *start = btf->strs_data; const char *end = start + btf->hdr->str_len; - if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || - start[0] || end[-1]) { + if (btf->base_btf && hdr->str_len == 0) + return 0; + if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || end[-1]) { + pr_debug("Invalid BTF string section\n"); + return -EINVAL; + } + if (!btf->base_btf && start[0]) { pr_debug("Invalid BTF string section\n"); return -EINVAL; } - return 0; } @@ -372,19 +398,9 @@ static int btf_parse_type_sec(struct btf *btf) struct btf_header *hdr = btf->hdr; void *next_type = btf->types_data; void *end_type = next_type + hdr->type_len; - int err, i = 0, type_size; - - /* VOID (type_id == 0) is specially handled by btf__get_type_by_id(), - * so ensure we can never properly use its offset from index by - * setting it to a large value - */ - err = btf_add_type_idx_entry(btf, UINT_MAX); - if (err) - return err; + int err, type_size; while (next_type + sizeof(struct btf_type) <= end_type) { - i++; - if (btf->swapped_endian) btf_bswap_type_base(next_type); @@ -392,7 +408,7 @@ static int btf_parse_type_sec(struct btf *btf) if (type_size < 0) return type_size; if (next_type + type_size > end_type) { - pr_warn("BTF type [%d] is malformed\n", i); + pr_warn("BTF type [%d] is malformed\n", btf->start_id + btf->nr_types); return -EINVAL; } @@ -417,7 +433,7 @@ static int btf_parse_type_sec(struct btf *btf) __u32 btf__get_nr_types(const struct btf *btf) { - return btf->nr_types; + return btf->start_id + btf->nr_types - 1; } /* internal helper returning non-const pointer to a type */ @@ -425,13 +441,14 @@ 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]; + if (type_id < btf->start_id) + return btf_type_by_id(btf->base_btf, type_id); + return btf->types_data + btf->type_offs[type_id - btf->start_id]; } const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id) { - if (type_id > btf->nr_types) + if (type_id >= btf->start_id + btf->nr_types) return NULL; return btf_type_by_id((struct btf *)btf, type_id); } @@ -440,9 +457,13 @@ static int determine_ptr_size(const struct btf *btf) { const struct btf_type *t; const char *name; - int i; + int i, n; - for (i = 1; i <= btf->nr_types; i++) { + if (btf->base_btf && btf->base_btf->ptr_sz > 0) + return btf->base_btf->ptr_sz; + + n = btf__get_nr_types(btf); + for (i = 1; i <= n; i++) { t = btf__type_by_id(btf, i); if (!btf_is_int(t)) continue; @@ -725,7 +746,7 @@ void btf__free(struct btf *btf) free(btf); } -struct btf *btf__new_empty(void) +static struct btf *btf_new_empty(struct btf *base_btf) { struct btf *btf; @@ -733,12 +754,21 @@ struct btf *btf__new_empty(void) if (!btf) return ERR_PTR(-ENOMEM); + btf->nr_types = 0; + btf->start_id = 1; + btf->start_str_off = 0; btf->fd = -1; btf->ptr_sz = sizeof(void *); btf->swapped_endian = false; + if (base_btf) { + btf->base_btf = base_btf; + btf->start_id = btf__get_nr_types(base_btf) + 1; + btf->start_str_off = base_btf->hdr->str_len; + } + /* +1 for empty string at offset 0 */ - btf->raw_size = sizeof(struct btf_header) + 1; + btf->raw_size = sizeof(struct btf_header) + (base_btf ? 0 : 1); btf->raw_data = calloc(1, btf->raw_size); if (!btf->raw_data) { free(btf); @@ -752,12 +782,22 @@ struct btf *btf__new_empty(void) btf->types_data = btf->raw_data + btf->hdr->hdr_len; btf->strs_data = btf->raw_data + btf->hdr->hdr_len; - btf->hdr->str_len = 1; /* empty string at offset 0 */ + btf->hdr->str_len = base_btf ? 0 : 1; /* empty string at offset 0 */ return btf; } -struct btf *btf__new(const void *data, __u32 size) +struct btf *btf__new_empty(void) +{ + return btf_new_empty(NULL); +} + +struct btf *btf__new_empty_split(struct btf *base_btf) +{ + return btf_new_empty(base_btf); +} + +static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) { struct btf *btf; int err; @@ -766,6 +806,16 @@ struct btf *btf__new(const void *data, __u32 size) if (!btf) return ERR_PTR(-ENOMEM); + btf->nr_types = 0; + btf->start_id = 1; + btf->start_str_off = 0; + + if (base_btf) { + btf->base_btf = base_btf; + btf->start_id = btf__get_nr_types(base_btf) + 1; + btf->start_str_off = base_btf->hdr->str_len; + } + btf->raw_data = malloc(size); if (!btf->raw_data) { err = -ENOMEM; @@ -798,7 +848,13 @@ done: return btf; } -struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) +struct btf *btf__new(const void *data, __u32 size) +{ + return btf_new(data, size, NULL); +} + +static struct btf *btf_parse_elf(const char *path, struct btf *base_btf, + struct btf_ext **btf_ext) { Elf_Data *btf_data = NULL, *btf_ext_data = NULL; int err = 0, fd = -1, idx = 0; @@ -876,7 +932,7 @@ struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) err = -ENOENT; goto done; } - btf = btf__new(btf_data->d_buf, btf_data->d_size); + btf = btf_new(btf_data->d_buf, btf_data->d_size, base_btf); if (IS_ERR(btf)) goto done; @@ -921,7 +977,17 @@ done: return btf; } -struct btf *btf__parse_raw(const char *path) +struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) +{ + return btf_parse_elf(path, NULL, btf_ext); +} + +struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf) +{ + return btf_parse_elf(path, base_btf, NULL); +} + +static struct btf *btf_parse_raw(const char *path, struct btf *base_btf) { struct btf *btf = NULL; void *data = NULL; @@ -975,7 +1041,7 @@ struct btf *btf__parse_raw(const char *path) } /* finally parse BTF data */ - btf = btf__new(data, sz); + btf = btf_new(data, sz, base_btf); err_out: free(data); @@ -984,18 +1050,38 @@ err_out: return err ? ERR_PTR(err) : btf; } -struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) +struct btf *btf__parse_raw(const char *path) +{ + return btf_parse_raw(path, NULL); +} + +struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf) +{ + return btf_parse_raw(path, base_btf); +} + +static struct btf *btf_parse(const char *path, struct btf *base_btf, struct btf_ext **btf_ext) { struct btf *btf; if (btf_ext) *btf_ext = NULL; - btf = btf__parse_raw(path); + btf = btf_parse_raw(path, base_btf); if (!IS_ERR(btf) || PTR_ERR(btf) != -EPROTO) return btf; - return btf__parse_elf(path, btf_ext); + return btf_parse_elf(path, base_btf, btf_ext); +} + +struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) +{ + return btf_parse(path, NULL, btf_ext); +} + +struct btf *btf__parse_split(const char *path, struct btf *base_btf) +{ + return btf_parse(path, base_btf, NULL); } static int compare_vsi_off(const void *_a, const void *_b) @@ -1179,8 +1265,8 @@ static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endi memcpy(p, btf->types_data, hdr->type_len); if (swap_endian) { - for (i = 1; i <= btf->nr_types; i++) { - t = p + btf->type_offs[i]; + for (i = 0; i < btf->nr_types; i++) { + t = p + btf->type_offs[i]; /* btf_bswap_type_rest() relies on native t->info, so * we swap base type info after we swapped all the * additional information @@ -1223,8 +1309,10 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size) const char *btf__str_by_offset(const struct btf *btf, __u32 offset) { - if (offset < btf->hdr->str_len) - return btf->strs_data + offset; + if (offset < btf->start_str_off) + return btf__str_by_offset(btf->base_btf, offset); + else if (offset - btf->start_str_off < btf->hdr->str_len) + return btf->strs_data + (offset - btf->start_str_off); else return NULL; } @@ -1461,7 +1549,10 @@ static int btf_ensure_modifiable(struct btf *btf) /* if BTF was created from scratch, all strings are guaranteed to be * unique and deduplicated */ - btf->strs_deduped = btf->hdr->str_len <= 1; + if (btf->hdr->str_len == 0) + btf->strs_deduped = true; + if (!btf->base_btf && btf->hdr->str_len == 1) + btf->strs_deduped = true; /* invalidate raw_data representation */ btf_invalidate_raw_data(btf); @@ -1493,6 +1584,14 @@ int btf__find_str(struct btf *btf, const char *s) long old_off, new_off, len; void *p; + if (btf->base_btf) { + int ret; + + ret = btf__find_str(btf->base_btf, s); + if (ret != -ENOENT) + return ret; + } + /* BTF needs to be in a modifiable state to build string lookup index */ if (btf_ensure_modifiable(btf)) return -ENOMEM; @@ -1507,7 +1606,7 @@ int btf__find_str(struct btf *btf, const char *s) memcpy(p, s, len); if (hashmap__find(btf->strs_hash, (void *)new_off, (void **)&old_off)) - return old_off; + return btf->start_str_off + old_off; return -ENOENT; } @@ -1523,6 +1622,14 @@ int btf__add_str(struct btf *btf, const char *s) void *p; int err; + if (btf->base_btf) { + int ret; + + ret = btf__find_str(btf->base_btf, s); + if (ret != -ENOENT) + return ret; + } + if (btf_ensure_modifiable(btf)) return -ENOMEM; @@ -1549,12 +1656,12 @@ int btf__add_str(struct btf *btf, const char *s) err = hashmap__insert(btf->strs_hash, (void *)new_off, (void *)new_off, HASHMAP_ADD, (const void **)&old_off, NULL); if (err == -EEXIST) - return old_off; /* duplicated string, return existing offset */ + return btf->start_str_off + old_off; /* duplicated string, return existing offset */ if (err) return err; btf->hdr->str_len += len; /* new unique string, adjust data length */ - return new_off; + return btf->start_str_off + new_off; } static void *btf_add_type_mem(struct btf *btf, size_t add_sz) @@ -1584,7 +1691,7 @@ static int btf_commit_type(struct btf *btf, int data_sz) btf->hdr->type_len += data_sz; btf->hdr->str_off += data_sz; btf->nr_types++; - return btf->nr_types; + return btf->start_id + btf->nr_types - 1; } /* @@ -4167,14 +4274,14 @@ static int btf_dedup_compact_types(struct btf_dedup *d) memmove(p, btf__type_by_id(d->btf, i), len); d->hypot_map[i] = next_type_id; - d->btf->type_offs[next_type_id] = p - d->btf->types_data; + d->btf->type_offs[next_type_id - 1] = 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->type_offs_cap = d->btf->nr_types + 1; + d->btf->type_offs_cap = d->btf->nr_types; 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)); diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 57247240a20a..1093f6fe6800 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -31,11 +31,19 @@ enum btf_endianness { }; LIBBPF_API void btf__free(struct btf *btf); + LIBBPF_API struct btf *btf__new(const void *data, __u32 size); +LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf); LIBBPF_API struct btf *btf__new_empty(void); +LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf); + LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext); +LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf); LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext); +LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf); LIBBPF_API struct btf *btf__parse_raw(const char *path); +LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf); + LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); LIBBPF_API int btf__load(struct btf *btf); LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 4ebfadf45b47..29ff4807b909 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -337,3 +337,12 @@ LIBBPF_0.2.0 { perf_buffer__consume_buffer; xsk_socket__create_shared; } LIBBPF_0.1.0; + +LIBBPF_0.3.0 { + global: + btf__parse_elf_split; + btf__parse_raw_split; + btf__parse_split; + btf__new_empty_split; + btf__new_split; +} LIBBPF_0.2.0; |