| // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) |
| /* Copyright (c) 2018 Facebook */ |
| |
| #include <byteswap.h> |
| #include <endian.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <sys/utsname.h> |
| #include <sys/param.h> |
| #include <sys/stat.h> |
| #include <linux/kernel.h> |
| #include <linux/err.h> |
| #include <linux/btf.h> |
| #include <gelf.h> |
| #include "btf.h" |
| #include "bpf.h" |
| #include "libbpf.h" |
| #include "libbpf_internal.h" |
| #include "hashmap.h" |
| #include "strset.h" |
| |
| #define BTF_MAX_NR_TYPES 0x7fffffffU |
| #define BTF_MAX_STR_OFFSET 0x7fffffffU |
| |
| static struct btf_type btf_void; |
| |
| struct btf { |
| /* raw BTF data in native endianness */ |
| void *raw_data; |
| /* raw BTF data in non-native endianness */ |
| void *raw_data_swapped; |
| __u32 raw_size; |
| /* whether target endianness differs from the native one */ |
| bool swapped_endian; |
| |
| /* |
| * When BTF is loaded from an ELF or raw memory it is stored |
| * in a contiguous memory block. The hdr, type_data, and, strs_data |
| * point inside that memory region to their respective parts of BTF |
| * representation: |
| * |
| * +--------------------------------+ |
| * | Header | Types | Strings | |
| * +--------------------------------+ |
| * ^ ^ ^ |
| * | | | |
| * hdr | | |
| * types_data-+ | |
| * strs_data------------+ |
| * |
| * If BTF data is later modified, e.g., due to types added or |
| * removed, BTF deduplication performed, etc, this contiguous |
| * representation is broken up into three independently allocated |
| * memory regions to be able to modify them independently. |
| * raw_data is nulled out at that point, but can be later allocated |
| * and cached again if user calls btf__raw_data(), at which point |
| * raw_data will contain a contiguous copy of header, types, and |
| * strings: |
| * |
| * +----------+ +---------+ +-----------+ |
| * | Header | | Types | | Strings | |
| * +----------+ +---------+ +-----------+ |
| * ^ ^ ^ |
| * | | | |
| * hdr | | |
| * types_data----+ | |
| * strset__data(strs_set)-----+ |
| * |
| * +----------+---------+-----------+ |
| * | Header | Types | Strings | |
| * raw_data----->+----------+---------+-----------+ |
| */ |
| struct btf_header *hdr; |
| |
| void *types_data; |
| size_t types_data_cap; /* used size stored in hdr->type_len */ |
| |
| /* 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; |
| |
| /* only one of strs_data or strs_set can be non-NULL, depending on |
| * whether BTF is in a modifiable state (strs_set is used) or not |
| * (strs_data points inside raw_data) |
| */ |
| void *strs_data; |
| /* a set of unique strings */ |
| struct strset *strs_set; |
| /* whether strings are already deduplicated */ |
| bool strs_deduped; |
| |
| /* BTF object FD, if loaded into kernel */ |
| int fd; |
| |
| /* Pointer size (in bytes) for a target architecture of this BTF */ |
| int ptr_sz; |
| }; |
| |
| static inline __u64 ptr_to_u64(const void *ptr) |
| { |
| return (__u64) (unsigned long) ptr; |
| } |
| |
| /* Ensure given dynamically allocated memory region pointed to by *data* with |
| * capacity of *cap_cnt* elements each taking *elem_sz* bytes has enough |
| * memory to accommodate *add_cnt* new elements, assuming *cur_cnt* elements |
| * are already used. At most *max_cnt* elements can be ever allocated. |
| * If necessary, memory is reallocated and all existing data is copied over, |
| * new pointer to the memory region is stored at *data, new memory region |
| * capacity (in number of elements) is stored in *cap. |
| * On success, memory pointer to the beginning of unused memory is returned. |
| * On error, NULL is returned. |
| */ |
| void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, |
| size_t cur_cnt, size_t max_cnt, size_t add_cnt) |
| { |
| size_t new_cnt; |
| void *new_data; |
| |
| if (cur_cnt + add_cnt <= *cap_cnt) |
| return *data + cur_cnt * elem_sz; |
| |
| /* requested more than the set limit */ |
| if (cur_cnt + add_cnt > max_cnt) |
| return NULL; |
| |
| new_cnt = *cap_cnt; |
| new_cnt += new_cnt / 4; /* expand by 25% */ |
| if (new_cnt < 16) /* but at least 16 elements */ |
| new_cnt = 16; |
| if (new_cnt > max_cnt) /* but not exceeding a set limit */ |
| new_cnt = max_cnt; |
| if (new_cnt < cur_cnt + add_cnt) /* also ensure we have enough memory */ |
| new_cnt = cur_cnt + add_cnt; |
| |
| new_data = libbpf_reallocarray(*data, new_cnt, elem_sz); |
| if (!new_data) |
| return NULL; |
| |
| /* zero out newly allocated portion of memory */ |
| memset(new_data + (*cap_cnt) * elem_sz, 0, (new_cnt - *cap_cnt) * elem_sz); |
| |
| *data = new_data; |
| *cap_cnt = new_cnt; |
| return new_data + cur_cnt * elem_sz; |
| } |
| |
| /* Ensure given dynamically allocated memory region has enough allocated space |
| * to accommodate *need_cnt* elements of size *elem_sz* bytes each |
| */ |
| int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt) |
| { |
| void *p; |
| |
| if (need_cnt <= *cap_cnt) |
| return 0; |
| |
| p = libbpf_add_mem(data, cap_cnt, elem_sz, *cap_cnt, SIZE_MAX, need_cnt - *cap_cnt); |
| if (!p) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static void *btf_add_type_offs_mem(struct btf *btf, size_t add_cnt) |
| { |
| return libbpf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32), |
| btf->nr_types, BTF_MAX_NR_TYPES, add_cnt); |
| } |
| |
| static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off) |
| { |
| __u32 *p; |
| |
| p = btf_add_type_offs_mem(btf, 1); |
| if (!p) |
| return -ENOMEM; |
| |
| *p = type_off; |
| return 0; |
| } |
| |
| static void btf_bswap_hdr(struct btf_header *h) |
| { |
| h->magic = bswap_16(h->magic); |
| h->hdr_len = bswap_32(h->hdr_len); |
| h->type_off = bswap_32(h->type_off); |
| h->type_len = bswap_32(h->type_len); |
| h->str_off = bswap_32(h->str_off); |
| h->str_len = bswap_32(h->str_len); |
| } |
| |
| static int btf_parse_hdr(struct btf *btf) |
| { |
| struct btf_header *hdr = btf->hdr; |
| __u32 meta_left; |
| |
| if (btf->raw_size < sizeof(struct btf_header)) { |
| pr_debug("BTF header not found\n"); |
| return -EINVAL; |
| } |
| |
| if (hdr->magic == bswap_16(BTF_MAGIC)) { |
| btf->swapped_endian = true; |
| if (bswap_32(hdr->hdr_len) != sizeof(struct btf_header)) { |
| pr_warn("Can't load BTF with non-native endianness due to unsupported header length %u\n", |
| bswap_32(hdr->hdr_len)); |
| return -ENOTSUP; |
| } |
| btf_bswap_hdr(hdr); |
| } else if (hdr->magic != BTF_MAGIC) { |
| pr_debug("Invalid BTF magic: %x\n", hdr->magic); |
| return -EINVAL; |
| } |
| |
| if (btf->raw_size < hdr->hdr_len) { |
| pr_debug("BTF header len %u larger than data size %u\n", |
| hdr->hdr_len, btf->raw_size); |
| return -EINVAL; |
| } |
| |
| meta_left = btf->raw_size - hdr->hdr_len; |
| if (meta_left < (long long)hdr->str_off + hdr->str_len) { |
| pr_debug("Invalid BTF total size: %u\n", btf->raw_size); |
| return -EINVAL; |
| } |
| |
| if ((long long)hdr->type_off + hdr->type_len > hdr->str_off) { |
| pr_debug("Invalid BTF data sections layout: type data at %u + %u, strings data at %u + %u\n", |
| hdr->type_off, hdr->type_len, hdr->str_off, hdr->str_len); |
| return -EINVAL; |
| } |
| |
| if (hdr->type_off % 4) { |
| pr_debug("BTF type section is not aligned to 4 bytes\n"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_parse_str_sec(struct btf *btf) |
| { |
| const struct btf_header *hdr = btf->hdr; |
| const char *start = btf->strs_data; |
| const char *end = start + btf->hdr->str_len; |
| |
| 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; |
| } |
| |
| static int btf_type_size(const struct btf_type *t) |
| { |
| const int base_size = sizeof(struct btf_type); |
| __u16 vlen = btf_vlen(t); |
| |
| switch (btf_kind(t)) { |
| case BTF_KIND_FWD: |
| case BTF_KIND_CONST: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_PTR: |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_FUNC: |
| case BTF_KIND_FLOAT: |
| case BTF_KIND_TYPE_TAG: |
| return base_size; |
| case BTF_KIND_INT: |
| return base_size + sizeof(__u32); |
| case BTF_KIND_ENUM: |
| return base_size + vlen * sizeof(struct btf_enum); |
| case BTF_KIND_ENUM64: |
| return base_size + vlen * sizeof(struct btf_enum64); |
| case BTF_KIND_ARRAY: |
| return base_size + sizeof(struct btf_array); |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| return base_size + vlen * sizeof(struct btf_member); |
| case BTF_KIND_FUNC_PROTO: |
| return base_size + vlen * sizeof(struct btf_param); |
| case BTF_KIND_VAR: |
| return base_size + sizeof(struct btf_var); |
| case BTF_KIND_DATASEC: |
| return base_size + vlen * sizeof(struct btf_var_secinfo); |
| case BTF_KIND_DECL_TAG: |
| return base_size + sizeof(struct btf_decl_tag); |
| default: |
| pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t)); |
| return -EINVAL; |
| } |
| } |
| |
| static void btf_bswap_type_base(struct btf_type *t) |
| { |
| t->name_off = bswap_32(t->name_off); |
| t->info = bswap_32(t->info); |
| t->type = bswap_32(t->type); |
| } |
| |
| static int btf_bswap_type_rest(struct btf_type *t) |
| { |
| struct btf_var_secinfo *v; |
| struct btf_enum64 *e64; |
| struct btf_member *m; |
| struct btf_array *a; |
| struct btf_param *p; |
| struct btf_enum *e; |
| __u16 vlen = btf_vlen(t); |
| int i; |
| |
| switch (btf_kind(t)) { |
| case BTF_KIND_FWD: |
| case BTF_KIND_CONST: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_PTR: |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_FUNC: |
| case BTF_KIND_FLOAT: |
| case BTF_KIND_TYPE_TAG: |
| return 0; |
| case BTF_KIND_INT: |
| *(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1)); |
| return 0; |
| case BTF_KIND_ENUM: |
| for (i = 0, e = btf_enum(t); i < vlen; i++, e++) { |
| e->name_off = bswap_32(e->name_off); |
| e->val = bswap_32(e->val); |
| } |
| return 0; |
| case BTF_KIND_ENUM64: |
| for (i = 0, e64 = btf_enum64(t); i < vlen; i++, e64++) { |
| e64->name_off = bswap_32(e64->name_off); |
| e64->val_lo32 = bswap_32(e64->val_lo32); |
| e64->val_hi32 = bswap_32(e64->val_hi32); |
| } |
| return 0; |
| case BTF_KIND_ARRAY: |
| a = btf_array(t); |
| a->type = bswap_32(a->type); |
| a->index_type = bswap_32(a->index_type); |
| a->nelems = bswap_32(a->nelems); |
| return 0; |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| for (i = 0, m = btf_members(t); i < vlen; i++, m++) { |
| m->name_off = bswap_32(m->name_off); |
| m->type = bswap_32(m->type); |
| m->offset = bswap_32(m->offset); |
| } |
| return 0; |
| case BTF_KIND_FUNC_PROTO: |
| for (i = 0, p = btf_params(t); i < vlen; i++, p++) { |
| p->name_off = bswap_32(p->name_off); |
| p->type = bswap_32(p->type); |
| } |
| return 0; |
| case BTF_KIND_VAR: |
| btf_var(t)->linkage = bswap_32(btf_var(t)->linkage); |
| return 0; |
| case BTF_KIND_DATASEC: |
| for (i = 0, v = btf_var_secinfos(t); i < vlen; i++, v++) { |
| v->type = bswap_32(v->type); |
| v->offset = bswap_32(v->offset); |
| v->size = bswap_32(v->size); |
| } |
| return 0; |
| case BTF_KIND_DECL_TAG: |
| btf_decl_tag(t)->component_idx = bswap_32(btf_decl_tag(t)->component_idx); |
| return 0; |
| default: |
| pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t)); |
| return -EINVAL; |
| } |
| } |
| |
| 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, type_size; |
| |
| while (next_type + sizeof(struct btf_type) <= end_type) { |
| if (btf->swapped_endian) |
| btf_bswap_type_base(next_type); |
| |
| type_size = btf_type_size(next_type); |
| if (type_size < 0) |
| return type_size; |
| if (next_type + type_size > end_type) { |
| pr_warn("BTF type [%d] is malformed\n", btf->start_id + btf->nr_types); |
| return -EINVAL; |
| } |
| |
| if (btf->swapped_endian && btf_bswap_type_rest(next_type)) |
| return -EINVAL; |
| |
| err = btf_add_type_idx_entry(btf, next_type - btf->types_data); |
| if (err) |
| return err; |
| |
| next_type += type_size; |
| btf->nr_types++; |
| } |
| |
| if (next_type != end_type) { |
| pr_warn("BTF types data is malformed\n"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_validate_str(const struct btf *btf, __u32 str_off, const char *what, __u32 type_id) |
| { |
| const char *s; |
| |
| s = btf__str_by_offset(btf, str_off); |
| if (!s) { |
| pr_warn("btf: type [%u]: invalid %s (string offset %u)\n", type_id, what, str_off); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_validate_id(const struct btf *btf, __u32 id, __u32 ctx_id) |
| { |
| const struct btf_type *t; |
| |
| t = btf__type_by_id(btf, id); |
| if (!t) { |
| pr_warn("btf: type [%u]: invalid referenced type ID %u\n", ctx_id, id); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int btf_validate_type(const struct btf *btf, const struct btf_type *t, __u32 id) |
| { |
| __u32 kind = btf_kind(t); |
| int err, i, n; |
| |
| err = btf_validate_str(btf, t->name_off, "type name", id); |
| if (err) |
| return err; |
| |
| switch (kind) { |
| case BTF_KIND_UNKN: |
| case BTF_KIND_INT: |
| case BTF_KIND_FWD: |
| case BTF_KIND_FLOAT: |
| break; |
| case BTF_KIND_PTR: |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_VAR: |
| case BTF_KIND_DECL_TAG: |
| case BTF_KIND_TYPE_TAG: |
| err = btf_validate_id(btf, t->type, id); |
| if (err) |
| return err; |
| break; |
| case BTF_KIND_ARRAY: { |
| const struct btf_array *a = btf_array(t); |
| |
| err = btf_validate_id(btf, a->type, id); |
| err = err ?: btf_validate_id(btf, a->index_type, id); |
| if (err) |
| return err; |
| break; |
| } |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: { |
| const struct btf_member *m = btf_members(t); |
| |
| n = btf_vlen(t); |
| for (i = 0; i < n; i++, m++) { |
| err = btf_validate_str(btf, m->name_off, "field name", id); |
| err = err ?: btf_validate_id(btf, m->type, id); |
| if (err) |
| return err; |
| } |
| break; |
| } |
| case BTF_KIND_ENUM: { |
| const struct btf_enum *m = btf_enum(t); |
| |
| n = btf_vlen(t); |
| for (i = 0; i < n; i++, m++) { |
| err = btf_validate_str(btf, m->name_off, "enum name", id); |
| if (err) |
| return err; |
| } |
| break; |
| } |
| case BTF_KIND_ENUM64: { |
| const struct btf_enum64 *m = btf_enum64(t); |
| |
| n = btf_vlen(t); |
| for (i = 0; i < n; i++, m++) { |
| err = btf_validate_str(btf, m->name_off, "enum name", id); |
| if (err) |
| return err; |
| } |
| break; |
| } |
| case BTF_KIND_FUNC: { |
| const struct btf_type *ft; |
| |
| err = btf_validate_id(btf, t->type, id); |
| if (err) |
| return err; |
| ft = btf__type_by_id(btf, t->type); |
| if (btf_kind(ft) != BTF_KIND_FUNC_PROTO) { |
| pr_warn("btf: type [%u]: referenced type [%u] is not FUNC_PROTO\n", id, t->type); |
| return -EINVAL; |
| } |
| break; |
| } |
| case BTF_KIND_FUNC_PROTO: { |
| const struct btf_param *m = btf_params(t); |
| |
| n = btf_vlen(t); |
| for (i = 0; i < n; i++, m++) { |
| err = btf_validate_str(btf, m->name_off, "param name", id); |
| err = err ?: btf_validate_id(btf, m->type, id); |
| if (err) |
| return err; |
| } |
| break; |
| } |
| case BTF_KIND_DATASEC: { |
| const struct btf_var_secinfo *m = btf_var_secinfos(t); |
| |
| n = btf_vlen(t); |
| for (i = 0; i < n; i++, m++) { |
| err = btf_validate_id(btf, m->type, id); |
| if (err) |
| return err; |
| } |
| break; |
| } |
| default: |
| pr_warn("btf: type [%u]: unrecognized kind %u\n", id, kind); |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| /* Validate basic sanity of BTF. It's intentionally less thorough than |
| * kernel's validation and validates only properties of BTF that libbpf relies |
| * on to be correct (e.g., valid type IDs, valid string offsets, etc) |
| */ |
| static int btf_sanity_check(const struct btf *btf) |
| { |
| const struct btf_type *t; |
| __u32 i, n = btf__type_cnt(btf); |
| int err; |
| |
| for (i = 1; i < n; i++) { |
| t = btf_type_by_id(btf, i); |
| err = btf_validate_type(btf, t, i); |
| if (err) |
| return err; |
| } |
| return 0; |
| } |
| |
| __u32 btf__type_cnt(const struct btf *btf) |
| { |
| return btf->start_id + btf->nr_types; |
| } |
| |
| const struct btf *btf__base_btf(const struct btf *btf) |
| { |
| return btf->base_btf; |
| } |
| |
| /* internal helper returning non-const pointer to a type */ |
| struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id) |
| { |
| if (type_id == 0) |
| return &btf_void; |
| 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->start_id + btf->nr_types) |
| return errno = EINVAL, NULL; |
| return btf_type_by_id((struct btf *)btf, type_id); |
| } |
| |
| static int determine_ptr_size(const struct btf *btf) |
| { |
| static const char * const long_aliases[] = { |
| "long", |
| "long int", |
| "int long", |
| "unsigned long", |
| "long unsigned", |
| "unsigned long int", |
| "unsigned int long", |
| "long unsigned int", |
| "long int unsigned", |
| "int unsigned long", |
| "int long unsigned", |
| }; |
| const struct btf_type *t; |
| const char *name; |
| int i, j, n; |
| |
| if (btf->base_btf && btf->base_btf->ptr_sz > 0) |
| return btf->base_btf->ptr_sz; |
| |
| n = btf__type_cnt(btf); |
| for (i = 1; i < n; i++) { |
| t = btf__type_by_id(btf, i); |
| if (!btf_is_int(t)) |
| continue; |
| |
| if (t->size != 4 && t->size != 8) |
| continue; |
| |
| name = btf__name_by_offset(btf, t->name_off); |
| if (!name) |
| continue; |
| |
| for (j = 0; j < ARRAY_SIZE(long_aliases); j++) { |
| if (strcmp(name, long_aliases[j]) == 0) |
| return t->size; |
| } |
| } |
| |
| return -1; |
| } |
| |
| static size_t btf_ptr_sz(const struct btf *btf) |
| { |
| if (!btf->ptr_sz) |
| ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); |
| return btf->ptr_sz < 0 ? sizeof(void *) : btf->ptr_sz; |
| } |
| |
| /* Return pointer size this BTF instance assumes. The size is heuristically |
| * determined by looking for 'long' or 'unsigned long' integer type and |
| * recording its size in bytes. If BTF type information doesn't have any such |
| * type, this function returns 0. In the latter case, native architecture's |
| * pointer size is assumed, so will be either 4 or 8, depending on |
| * architecture that libbpf was compiled for. It's possible to override |
| * guessed value by using btf__set_pointer_size() API. |
| */ |
| size_t btf__pointer_size(const struct btf *btf) |
| { |
| if (!btf->ptr_sz) |
| ((struct btf *)btf)->ptr_sz = determine_ptr_size(btf); |
| |
| if (btf->ptr_sz < 0) |
| /* not enough BTF type info to guess */ |
| return 0; |
| |
| return btf->ptr_sz; |
| } |
| |
| /* Override or set pointer size in bytes. Only values of 4 and 8 are |
| * supported. |
| */ |
| int btf__set_pointer_size(struct btf *btf, size_t ptr_sz) |
| { |
| if (ptr_sz != 4 && ptr_sz != 8) |
| return libbpf_err(-EINVAL); |
| btf->ptr_sz = ptr_sz; |
| return 0; |
| } |
| |
| static bool is_host_big_endian(void) |
| { |
| #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
| return false; |
| #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
| return true; |
| #else |
| # error "Unrecognized __BYTE_ORDER__" |
| #endif |
| } |
| |
| enum btf_endianness btf__endianness(const struct btf *btf) |
| { |
| if (is_host_big_endian()) |
| return btf->swapped_endian ? BTF_LITTLE_ENDIAN : BTF_BIG_ENDIAN; |
| else |
| return btf->swapped_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN; |
| } |
| |
| int btf__set_endianness(struct btf *btf, enum btf_endianness endian) |
| { |
| if (endian != BTF_LITTLE_ENDIAN && endian != BTF_BIG_ENDIAN) |
| return libbpf_err(-EINVAL); |
| |
| btf->swapped_endian = is_host_big_endian() != (endian == BTF_BIG_ENDIAN); |
| if (!btf->swapped_endian) { |
| free(btf->raw_data_swapped); |
| btf->raw_data_swapped = NULL; |
| } |
| return 0; |
| } |
| |
| static bool btf_type_is_void(const struct btf_type *t) |
| { |
| return t == &btf_void || btf_is_fwd(t); |
| } |
| |
| static bool btf_type_is_void_or_null(const struct btf_type *t) |
| { |
| return !t || btf_type_is_void(t); |
| } |
| |
| #define MAX_RESOLVE_DEPTH 32 |
| |
| __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) |
| { |
| const struct btf_array *array; |
| const struct btf_type *t; |
| __u32 nelems = 1; |
| __s64 size = -1; |
| int i; |
| |
| t = btf__type_by_id(btf, type_id); |
| for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t); i++) { |
| switch (btf_kind(t)) { |
| case BTF_KIND_INT: |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: |
| case BTF_KIND_ENUM: |
| case BTF_KIND_ENUM64: |
| case BTF_KIND_DATASEC: |
| case BTF_KIND_FLOAT: |
| size = t->size; |
| goto done; |
| case BTF_KIND_PTR: |
| size = btf_ptr_sz(btf); |
| goto done; |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_VAR: |
| case BTF_KIND_DECL_TAG: |
| case BTF_KIND_TYPE_TAG: |
| type_id = t->type; |
| break; |
| case BTF_KIND_ARRAY: |
| array = btf_array(t); |
| if (nelems && array->nelems > UINT32_MAX / nelems) |
| return libbpf_err(-E2BIG); |
| nelems *= array->nelems; |
| type_id = array->type; |
| break; |
| default: |
| return libbpf_err(-EINVAL); |
| } |
| |
| t = btf__type_by_id(btf, type_id); |
| } |
| |
| done: |
| if (size < 0) |
| return libbpf_err(-EINVAL); |
| if (nelems && size > UINT32_MAX / nelems) |
| return libbpf_err(-E2BIG); |
| |
| return nelems * size; |
| } |
| |
| int btf__align_of(const struct btf *btf, __u32 id) |
| { |
| const struct btf_type *t = btf__type_by_id(btf, id); |
| __u16 kind = btf_kind(t); |
| |
| switch (kind) { |
| case BTF_KIND_INT: |
| case BTF_KIND_ENUM: |
| case BTF_KIND_ENUM64: |
| case BTF_KIND_FLOAT: |
| return min(btf_ptr_sz(btf), (size_t)t->size); |
| case BTF_KIND_PTR: |
| return btf_ptr_sz(btf); |
| case BTF_KIND_TYPEDEF: |
| case BTF_KIND_VOLATILE: |
| case BTF_KIND_CONST: |
| case BTF_KIND_RESTRICT: |
| case BTF_KIND_TYPE_TAG: |
| return btf__align_of(btf, t->type); |
| case BTF_KIND_ARRAY: |
| return btf__align_of(btf, btf_array(t)->type); |
| case BTF_KIND_STRUCT: |
| case BTF_KIND_UNION: { |
| const struct btf_member *m = btf_members(t); |
| __u16 vlen = btf_vlen(t); |
| int i, max_align = 1, align; |
| |
| for (i = 0; i < vlen; i++, m++) { |
| align = btf__align_of(btf, m->type); |
| if (align <= 0) |
| return libbpf_err(align); |
| max_align = max(max_align, align); |
| |
| /* if field offset isn't aligned according to field |
| * type's alignment, then struct must be packed |
| */ |
| if (btf_member_bitfield_size(t, i) == 0 && |
| (m->offset % (8 * align)) != 0) |
| return 1; |
| } |
| |
| /* if struct/union size isn't a multiple of its alignment, |
| * then struct must be packed |
| */ |
| if ((t->size % max_align) != 0) |
| return 1; |
| |
| return max_align; |
| } |
| default: |
| pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t)); |
| return errno = EINVAL, 0; |
| } |
| } |
| |
| int btf__resolve_type(const struct btf *btf, __u32 type_id) |
| { |
| const struct btf_type *t; |
| int depth = 0; |
| |
| t = btf__type_by_id(btf, type_id); |
| while (depth < MAX_RESOLVE_DEPTH && |
| !btf_type_is_void_or_null(t) && |
| (btf_is_mod(t) || btf_is_typedef(t) || btf_is_var(t))) { |
| type_id = t->type; |
| t = btf__type_by_id(btf, type_id); |
| depth++; |
| } |
| |
| if (depth == MAX_RESOLVE_DEPTH || btf_type_is_void_or_null(t)) |
| return libbpf_err(-EINVAL); |
| |
| return type_id; |
| } |
| |
| __s32 btf__find_by_name(const struct btf *btf, const char *type_name) |
| { |
| __u32 i, nr_types = btf__type_cnt(btf); |
| |
| if (!strcmp(type_name, "void")) |
| return 0; |
| |
| for (i = 1; i < nr_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)) |
| return i; |
| } |
| |
| return libbpf_err(-ENOENT); |
| } |
| |
| static __s32 btf_find_by_name_kind(const struct btf *btf, int start_id, |
| const char *type_name, __u32 kind) |
| { |
| __u32 i, nr_types = btf__type_cnt(btf); |
| |
| if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void")) |
| return 0; |
| |
| for (i = start_id; i < nr_types; i++) { |
| const struct btf_type *t = btf__type_by_id(btf, i); |
| const char *name; |
| |
| if (btf_kind(t) != kind) |
| continue; |
| name = btf__name_by_offset(btf, t->name_off); |
| if (name && !strcmp(type_name, name)) |
| return i; |
| } |
| |
| return libbpf_err(-ENOENT); |
| } |
| |
| __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name, |
| __u32 kind) |
| { |
| return btf_find_by_name_kind(btf, btf->start_id, type_name, kind); |
| } |
| |
| __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name, |
| __u32 kind) |
| { |
| return btf_find_by_name_kind(btf, 1, type_name, kind); |
| } |
| |
| static bool btf_is_modifiable(const struct btf *btf) |
| { |
| return (void *)btf->hdr != btf->raw_data; |
| } |
| |
| void btf__free(struct btf *btf) |
| { |
| if (IS_ERR_OR_NULL(btf)) |
| return; |
| |
| if (btf->fd >= 0) |
| close(btf->fd); |
| |
| if (btf_is_modifiable(btf)) { |
| /* if BTF was modified after loading, it will have a split |
| * in-memory representation for header, types, and strings |
| * sections, so we need to free all of them individually. It |
| * might still have a cached contiguous raw data present, |
| * which will be unconditionally freed below. |
| */ |
| free(btf->hdr); |
| free(btf->types_data); |
| strset__free(btf->strs_set); |
| } |
| free(btf->raw_data); |
| free(btf->raw_data_swapped); |
| free(btf->type_offs); |
| free(btf); |
| } |
| |
| static struct btf *btf_new_empty(struct btf *base_btf) |
| { |
| struct btf *btf; |
| |
| btf = calloc(1, sizeof(*btf)); |
| 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__type_cnt(base_btf); |
| btf->start_str_off = base_btf->hdr->str_len; |
| } |
| |
| /* +1 for empty string at offset 0 */ |
| 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); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| btf->hdr = btf->raw_data; |
| btf->hdr->hdr_len = sizeof(struct btf_header); |
| btf->hdr->magic = BTF_MAGIC; |
| btf->hdr->version = BTF_VERSION; |
| |
| btf->types_data = btf->raw_data + btf->hdr->hdr_len; |
| btf->strs_data = btf->raw_data + btf->hdr->hdr_len; |
| btf->hdr->str_len = base_btf ? 0 : 1; /* empty string at offset 0 */ |
| |
| return btf; |
| } |
| |
| struct btf *btf__new_empty(void) |
| { |
| return libbpf_ptr(btf_new_empty(NULL)); |
| } |
| |
| struct btf *btf__new_empty_split(struct btf *base_btf) |
| { |
| return libbpf_ptr(btf_new_empty(base_btf)); |
| } |
| |
| static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf) |
| { |
| struct btf *btf; |
| int err; |
| |
| btf = calloc(1, sizeof(struct btf)); |
| if (!btf) |
| return ERR_PTR(-ENOMEM); |
| |
| btf->nr_types = 0; |
| btf->start_id = 1; |
| btf->start_str_off = 0; |
| btf->fd = -1; |
| |
| if (base_btf) { |
| btf->base_btf = base_btf; |
| btf->start_id = btf__type_cnt(base_btf); |
| btf->start_str_off = base_btf->hdr->str_len; |
| } |
| |
| btf->raw_data = malloc(size); |
| if (!btf->raw_data) { |
| err = -ENOMEM; |
| goto done; |
| } |
| memcpy(btf->raw_data, data, size); |
| btf->raw_size = size; |
| |
| btf->hdr = btf->raw_data; |
| err = btf_parse_hdr(btf); |
| if (err) |
| goto done; |
| |
| btf->strs_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->str_off; |
| btf->types_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->type_off; |
| |
| err = btf_parse_str_sec(btf); |
| err = err ?: btf_parse_type_sec(btf); |
| err = err ?: btf_sanity_check(btf); |
| if (err) |
| goto done; |
| |
| done: |
| if (err) { |
| btf__free(btf); |
| return ERR_PTR(err); |
| } |
| |
| return btf; |
| } |
| |
| struct btf *btf__new(const void *data, __u32 size) |
| { |
| return libbpf_ptr(btf_new(data, size, NULL)); |
| } |
| |
| struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf) |
| { |
| return libbpf_ptr(btf_new(data, size, base_btf)); |
| } |
| |
| 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; |
| struct btf *btf = NULL; |
| Elf_Scn *scn = NULL; |
| Elf *elf = NULL; |
| GElf_Ehdr ehdr; |
| size_t shstrndx; |
| |
| if (elf_version(EV_CURRENT) == EV_NONE) { |
| pr_warn("failed to init libelf for %s\n", path); |
| return ERR_PTR(-LIBBPF_ERRNO__LIBELF); |
| } |
| |
| fd = open(path, O_RDONLY | O_CLOEXEC); |
| if (fd < 0) { |
| err = -errno; |
| pr_warn("failed to open %s: %s\n", path, strerror(errno)); |
| return ERR_PTR(err); |
| } |
| |
| err = -LIBBPF_ERRNO__FORMAT; |
| |
| elf = elf_begin(fd, ELF_C_READ, NULL); |
| if (!elf) { |
| pr_warn("failed to open %s as ELF file\n", path); |
| goto done; |
| } |
| if (!gelf_getehdr(elf, &ehdr)) { |
| pr_warn("failed to get EHDR from %s\n", path); |
| goto done; |
| } |
| |
| if (elf_getshdrstrndx(elf, &shstrndx)) { |
| pr_warn("failed to get section names section index for %s\n", |
| path); |
| goto done; |
| } |
| |
| if (!elf_rawdata(elf_getscn(elf, shstrndx), NULL)) { |
| pr_warn("failed to get e_shstrndx from %s\n", path); |
| goto done; |
| } |
| |
| while ((scn = elf_nextscn(elf, scn)) != NULL) { |
| GElf_Shdr sh; |
| char *name; |
| |
| idx++; |
| if (gelf_getshdr(scn, &sh) != &sh) { |
| pr_warn("failed to get section(%d) header from %s\n", |
| idx, path); |
| goto done; |
| } |
| name = elf_strptr(elf, shstrndx, sh.sh_name); |
| if (!name) { |
| pr_warn("failed to get section(%d) name from %s\n", |
| idx, path); |
| goto done; |
| } |
| if (strcmp(name, BTF_ELF_SEC) == 0) { |
| btf_data = elf_getdata(scn, 0); |
| if (!btf_data) { |
| pr_warn("failed to get section(%d, %s) data from %s\n", |
| idx, name, path); |
| goto done; |
| } |
| continue; |
| } else if (btf_ext && strcmp(name, BTF_EXT_ELF_SEC) == 0) { |
| btf_ext_data = elf_getdata(scn, 0); |
| if (!btf_ext_data) { |
| pr_warn("failed to get section(%d, %s) data from %s\n", |
| idx, name, path); |
| goto done; |
| } |
| continue; |
| } |
| } |
| |
| if (!btf_data) { |
| pr_warn("failed to find '%s' ELF section in %s\n", BTF_ELF_SEC, path); |
| err = -ENODATA; |
| goto done; |
| } |
| btf = btf_new(btf_data->d_buf, btf_data->d_size, base_btf); |
| err = libbpf_get_error(btf); |
| if (err) |
| goto done; |
| |
| switch (gelf_getclass(elf)) { |
| case ELFCLASS32: |
| btf__set_pointer_size(btf, 4); |
| break; |
| case ELFCLASS64: |
| btf__set_pointer_size(btf, 8); |
| break; |
| default: |
| pr_warn("failed to get ELF class (bitness) for %s\n", path); |
| break; |
| } |
| |
| if (btf_ext && btf_ext_data) { |
| *btf_ext = btf_ext__new(btf_ext_data->d_buf, btf_ext_data->d_size); |
| err = libbpf_get_error(*btf_ext); |
| if (err) |
| goto done; |
| } else if (btf_ext) { |
| *btf_ext = NULL; |
| } |
| done: |
| if (elf) |
| elf_end(elf); |
| close(fd); |
| |
| if (!err) |
| return btf; |
| |
| if (btf_ext) |
| btf_ext__free(*btf_ext); |
| btf__free(btf); |
| |
| return ERR_PTR(err); |
| } |
| |
| struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext) |
| { |
| return libbpf_ptr(btf_parse_elf(path, NULL, btf_ext)); |
| } |
| |
| struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf) |
| { |
| return libbpf_ptr(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; |
| FILE *f = NULL; |
| __u16 magic; |
| int err = 0; |
| long sz; |
| |
| f = fopen(path, "rbe"); |
| if (!f) { |
| err = -errno; |
| goto err_out; |
| } |
| |
| /* check BTF magic */ |
| if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) { |
| err = -EIO; |
| goto err_out; |
| } |
| if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) { |
| /* definitely not a raw BTF */ |
| err = -EPROTO; |
| goto err_out; |
| } |
| |
| /* get file size */ |
| if (fseek(f, 0, SEEK_END)) { |
| err = -errno; |
| goto err_out; |
| } |
| sz = ftell(f); |
| if (sz < 0) { |
| err = -errno; |
| goto err_out; |
| } |
| /* rewind to the start */ |
| if (fseek(f, 0, SEEK_SET)) { |
| err = -errno; |
| goto err_out; |
| } |
| |
| /* pre-alloc memory and read all of BTF data */ |
| data = malloc(sz); |
| if (!data) { |
| err = -ENOMEM; |
| goto err_out; |
| } |
| if (fread(data, 1, sz, f) < sz) { |
| err = -EIO; |
| goto err_out; |
| } |
| |
| /* finally parse BTF data */ |
| btf = btf_new(data, sz, base_btf); |
| |
| err_out: |
| free(data); |
| if (f) |
| fclose(f); |
| return err ? ERR_PTR(err) : btf; |
| } |
| |
| struct btf *btf__parse_raw(const char *path) |
| { |
| return libbpf_ptr(btf_parse_raw(path, NULL)); |
| } |
| |
| struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf) |
| { |
| return libbpf_ptr(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; |
| int err; |
| |
| if (btf_ext) |
| *btf_ext = NULL; |
| |
| btf = btf_parse_raw(path, base_btf); |
| err = libbpf_get_error(btf); |
| if (!err) |
| return btf; |
| if (err != -EPROTO) |
| return ERR_PTR(err); |
| return btf_parse_elf(path, base_btf, btf_ext); |
| } |
| |
| struct btf *btf__parse(const char *path, struct btf_ext **btf_ext) |
| { |
| return libbpf_ptr(btf_parse(path, NULL, btf_ext)); |
| } |
| |
| struct btf *btf__parse_split(const char *path, struct btf *base_btf) |
| { |
| return libbpf_ptr(btf_parse(path, base_btf, NULL)); |
| } |
| |
| static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian); |
| |
| int btf_load_into_kernel(struct btf *btf, |
| char *log_buf, size_t log_sz, __u32 log_level, |
| int token_fd) |
| { |
| LIBBPF_OPTS(bpf_btf_load_opts, opts); |
| __u32 buf_sz = 0, raw_size; |
| char *buf = NULL, *tmp; |
| void *raw_data; |
| int err = 0; |
| |
| if (btf->fd >= 0) |
| return libbpf_err(-EEXIST); |
| if (log_sz && !log_buf) |
| return libbpf_err(-EINVAL); |
| |
| /* cache native raw data representation */ |
| raw_data = btf_get_raw_data(btf, &raw_size, false); |
| if (!raw_data) { |
| err = -ENOMEM; |
| goto done; |
| } |
| btf->raw_size = raw_size; |
| btf->raw_data = raw_data; |
| |
| retry_load: |
| /* if log_level is 0, we won't provide log_buf/log_size to the kernel, |
| * initially. Only if BTF loading fails, we bump log_level to 1 and |
| * retry, using either auto-allocated or custom log_buf. This way |
| * non-NULL custom log_buf provides a buffer just in case, but hopes |
| * for successful load and no need for log_buf. |
| */ |
| if (log_level) { |
| /* if caller didn't provide custom log_buf, we'll keep |
| * allocating our own progressively bigger buffers for BTF |
| * verification log |
| */ |
| if (!log_buf) { |
| buf_sz = max((__u32)BPF_LOG_BUF_SIZE, buf_sz * 2); |
| tmp = realloc(buf, buf_sz); |
| if (!tmp) { |
| err = -ENOMEM; |
| goto done; |
| } |
| buf = tmp; |
| buf[0] = '\0'; |
| } |
| |
| opts.log_buf = log_buf ? log_buf : buf; |
| opts.log_size = log_buf ? log_sz : buf_sz; |
| opts.log_level = log_level; |
| } |
| |
| opts.token_fd = token_fd; |
| if (token_fd) |
| opts.btf_flags |= BPF_F_TOKEN_FD; |
| |
| btf->fd = bpf_btf_load(raw_data, raw_size, &opts); |
| if (btf->fd < 0) { |
| /* time to turn on verbose mode and try again */ |
| if (log_level == 0) { |
| log_level = 1; |
| goto retry_load; |
| } |
| /* only retry if caller didn't provide custom log_buf, but |
| * make sure we can never overflow buf_sz |
| */ |
| if (!log_buf && errno == ENOSPC && buf_sz <= UINT_MAX / 2) |
| goto retry_load; |
| |
| err = -errno; |
| pr_warn("BTF loading error: %d\n", err); |
| /* don't print out contents of custom log_buf */ |
| if (!log_buf && buf[0]) |
| pr_warn("-- BEGIN BTF LOAD LOG ---\n%s\n-- END BTF LOAD LOG --\n", buf); |
| } |
| |
| done: |
| free(buf); |
| return libbpf_err(err); |
| } |
| |
| int btf__load_into_kernel(struct btf *btf) |
| { |
| return btf_load_into_kernel(btf, NULL, 0, 0, 0); |
| } |
| |
| int btf__fd(const struct btf *btf) |
| { |
| return btf->fd; |
| } |
| |
| void btf__set_fd(struct btf *btf, int fd) |
| { |
| btf->fd = fd; |
| } |
| |
| static const void *btf_strs_data(const struct btf *btf) |
| { |
| return btf->strs_data ? btf->strs_data : strset__data(btf->strs_set); |
| } |
| |
| static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian) |
| { |
| struct btf_header *hdr = btf->hdr; |
| struct btf_type *t; |
| void *data, *p; |
| __u32 data_sz; |
| int i; |
| |
| data = swap_endian ? btf->raw_data_swapped : btf->raw_data; |
| if (data) { |
| *size = btf->raw_size; |
| return data; |
| } |
| |
| data_sz = hdr->hdr_len + hdr->type_len + hdr->str_len; |
| data = calloc(1, data_sz); |
| if (!data) |
| return NULL; |
| p = data; |
| |
| memcpy(p, hdr, hdr->hdr_len); |
| if (swap_endian) |
| btf_bswap_hdr(p); |
| p += hdr->hdr_len; |
| |
| memcpy(p, btf->types_data, hdr->type_len); |
| if (swap_endian) { |
| 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 |
| */ |
| if (btf_bswap_type_rest(t)) |
| goto err_out; |
| btf_bswap_type_base(t); |
| } |
| } |
| p += hdr->type_len; |
| |
| memcpy(p, btf_strs_data(btf), hdr->str_len); |
| p += hdr->str_len; |
| |
| *size = data_sz; |
| return data; |
| err_out: |
| free(data); |
| return NULL; |
| } |
| |
| const void *btf__raw_data(const struct btf *btf_ro, __u32 *size) |
| { |
| struct btf *btf = (struct btf *)btf_ro; |
| __u32 data_sz; |
| void *data; |
| |
| data = btf_get_raw_data(btf, &data_sz, btf->swapped_endian); |
| if (!data) |
| return errno = ENOMEM, NULL; |
| |
| btf->raw_size = data_sz; |
| if (btf->swapped_endian) |
| btf->raw_data_swapped = data; |
| else |
| btf->raw_data = data; |
| *size = data_sz; |
| return data; |
| } |
| |
| __attribute__((alias("btf__raw_data"))) |
| const void *btf__get_raw_data(const struct btf *btf, __u32 *size); |
| |
| const char *btf__str_by_offset(const struct btf *btf, __u32 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(btf) + (offset - btf->start_str_off); |
| else |
| return errno = EINVAL, NULL; |
| } |
| |
| const char *btf__name_by_offset(const struct btf *btf, __u32 offset) |
| { |
| return btf__str_by_offset(btf, offset); |
| } |
| |
| struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf) |
| { |
| struct bpf_btf_info btf_info; |
| __u32 len = sizeof(btf_info); |
| __u32 last_size; |
| struct btf *btf; |
| void *ptr; |
| int err; |
| |
| /* we won't know btf_size until we call bpf_btf_get_info_by_fd(). so |
| * let's start with a sane default - 4KiB here - and resize it only if |
| * bpf_btf_get_info_by_fd() needs a bigger buffer. |
| */ |
| last_size = 4096; |
| ptr = malloc(last_size); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| memset(&btf_info, 0, sizeof(btf_info)); |
| btf_info.btf = ptr_to_u64(ptr); |
| btf_info.btf_size = last_size; |
| err = bpf_btf_get_info_by_fd(btf_fd, &btf_info, &len); |
| |
| if (!err && btf_info.btf_size > last_size) { |
| void *temp_ptr; |
| |
| last_size = btf_info.btf_size; |
| temp_ptr = realloc(ptr, last_size); |
| if (!temp_ptr) { |
| btf = ERR_PTR(-ENOMEM); |
| goto exit_free; |
| } |
| ptr = temp_ptr; |
| |
| len = sizeof(btf_info); |
| memset(&btf_info, 0, sizeof(btf_info)); |
| btf_info.btf = ptr_to_u64(ptr); |
| btf_info.btf_size = last_size; |
| |
| err = bpf_btf_get_info_by_fd(btf_fd, &btf_info, &len); |
| } |
| |
| if (err || btf_info.btf_size > last_size) { |
| btf = err ? ERR_PTR(-errno) : ERR_PTR(-E2BIG); |
| goto exit_free; |
| } |
| |
| btf = btf_new(ptr, btf_info.btf_size, base_btf); |
| |
| exit_free: |
| free(ptr); |
| return btf; |
| } |
| |
| struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf) |
| { |
| struct btf *btf; |
| int btf_fd; |
| |
| btf_fd = bpf_btf_get_fd_by_id(id); |
| if (btf_fd < 0) |
| return libbpf_err_ptr(-errno); |
| |
| btf = btf_get_from_fd(btf_fd, base_btf); |
| close(btf_fd); |
| |
| return libbpf_ptr(btf); |
| } |
| |
| struct btf *btf__load_from_kernel_by_id(__u32 id) |
| { |
| return btf__load_from_kernel_by_id_split(id, NULL); |
| } |
| |
| static void btf_invalidate_raw_data(struct btf *btf) |
| { |
| if (btf->raw_data) { |
| free(btf->raw_data); |
| btf->raw_data = NULL; |
| } |
| if (btf->raw_data_swapped) { |
| free(btf->raw_data_swapped); |
| btf->raw_data_swapped = NULL; |
| } |
| } |
| |
| /* Ensure BTF is ready to be modified (by splitting into a three memory |
| * regions for header, types, and strings). Also invalidate cached |
| * raw_data, if any. |
| */ |
| static int btf_ensure_modifiable(struct btf *btf) |
| { |
| void *hdr, *types; |
| struct strset *set = NULL; |
| int err = -ENOMEM; |
| |
| if (btf_is_modifiable(btf)) { |
| /* any BTF modification invalidates raw_data */ |
| btf_invalidate_raw_data(btf); |
| return 0; |
| } |
| |
| /* split raw data into three memory regions */ |
| hdr = malloc(btf->hdr->hdr_len); |
| types = malloc(btf->hdr->type_len); |
| if (!hdr || !types) |
| goto err_out; |
| |
| memcpy(hdr, btf->hdr, btf->hdr->hdr_len); |
| memcpy(types, btf->types_data, btf->hdr->type_len); |
| |
| /* build lookup index for all strings */ |
| set = strset__new(BTF_MAX_STR_OFFSET, btf->strs_data, btf->hdr->str_len); |
| if (IS_ERR(set)) { |
| err = PTR_ERR(set); |
| goto err_out; |
| } |
| |
| /* only when everything was successful, update internal state */ |
| btf->hdr = hdr; |
| btf->types_data = types; |
| btf->types_data_cap = btf->hdr->type_len; |
| btf->strs_data = NULL; |
| btf->strs_set = set; |
| /* if BTF was created from scratch, all strings are guaranteed to be |
| * unique and deduplicated |
| */ |
| 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); |
| |
| return 0; |
| |
| err_out: |
| strset__free(set); |
| free(hdr); |
| free(types); |
| return err; |
| } |
| |
| /* Find an offset in BTF string section that corresponds to a given string *s*. |
| * Returns: |
| * - >0 offset into string section, if string is found; |
| * - -ENOENT, if string is not in the string section; |
| * - <0, on any other error. |
| */ |
| int btf__find_str(struct btf *btf, const char *s) |
| { |
| int off; |
| |
| if (btf->base_btf) { |
| off = btf__find_str(btf->base_btf, s); |
| if (off != -ENOENT) |
| return off; |
| } |
| |
| /* BTF needs to be in a modifiable state to build string lookup index */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| off = strset__find_str(btf->strs_set, s); |
| if (off < 0) |
| return libbpf_err(off); |
| |
| return btf->start_str_off + off; |
| } |
| |
| /* Add a string s to the BTF string section. |
| * Returns: |
| * - > 0 offset into string section, on success; |
| * - < 0, on error. |
| */ |
| int btf__add_str(struct btf *btf, const char *s) |
| { |
| int off; |
| |
| if (btf->base_btf) { |
| off = btf__find_str(btf->base_btf, s); |
| if (off != -ENOENT) |
| return off; |
| } |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| off = strset__add_str(btf->strs_set, s); |
| if (off < 0) |
| return libbpf_err(off); |
| |
| btf->hdr->str_len = strset__data_size(btf->strs_set); |
| |
| return btf->start_str_off + off; |
| } |
| |
| static void *btf_add_type_mem(struct btf *btf, size_t add_sz) |
| { |
| return libbpf_add_mem(&btf->types_data, &btf->types_data_cap, 1, |
| btf->hdr->type_len, UINT_MAX, add_sz); |
| } |
| |
| static void btf_type_inc_vlen(struct btf_type *t) |
| { |
| t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, btf_kflag(t)); |
| } |
| |
| static int btf_commit_type(struct btf *btf, int data_sz) |
| { |
| int err; |
| |
| err = btf_add_type_idx_entry(btf, btf->hdr->type_len); |
| if (err) |
| return libbpf_err(err); |
| |
| btf->hdr->type_len += data_sz; |
| btf->hdr->str_off += data_sz; |
| btf->nr_types++; |
| return btf->start_id + btf->nr_types - 1; |
| } |
| |
| struct btf_pipe { |
| const struct btf *src; |
| struct btf *dst; |
| struct hashmap *str_off_map; /* map string offsets from src to dst */ |
| }; |
| |
| static int btf_rewrite_str(__u32 *str_off, void *ctx) |
| { |
| struct btf_pipe *p = ctx; |
| long mapped_off; |
| int off, err; |
| |
| if (!*str_off) /* nothing to do for empty strings */ |
| return 0; |
| |
| if (p->str_off_map && |
| hashmap__find(p->str_off_map, *str_off, &mapped_off)) { |
| *str_off = mapped_off; |
| return 0; |
| } |
| |
| off = btf__add_str(p->dst, btf__str_by_offset(p->src, *str_off)); |
| if (off < 0) |
| return off; |
| |
| /* Remember string mapping from src to dst. It avoids |
| * performing expensive string comparisons. |
| */ |
| if (p->str_off_map) { |
| err = hashmap__append(p->str_off_map, *str_off, off); |
| if (err) |
| return err; |
| } |
| |
| *str_off = off; |
| return 0; |
| } |
| |
| int btf__add_type(struct btf *btf, const struct btf *src_btf, const struct btf_type *src_type) |
| { |
| struct btf_pipe p = { .src = src_btf, .dst = btf }; |
| struct btf_type *t; |
| int sz, err; |
| |
| sz = btf_type_size(src_type); |
| if (sz < 0) |
| return libbpf_err(sz); |
| |
| /* deconstruct BTF, if necessary, and invalidate raw_data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| memcpy(t, src_type, sz); |
| |
| err = btf_type_visit_str_offs(t, btf_rewrite_str, &p); |
| if (err) |
| return libbpf_err(err); |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| static int btf_rewrite_type_ids(__u32 *type_id, void *ctx) |
| { |
| struct btf *btf = ctx; |
| |
| if (!*type_id) /* nothing to do for VOID references */ |
| return 0; |
| |
| /* we haven't updated btf's type count yet, so |
| * btf->start_id + btf->nr_types - 1 is the type ID offset we should |
| * add to all newly added BTF types |
| */ |
| *type_id += btf->start_id + btf->nr_types - 1; |
| return 0; |
| } |
| |
| static size_t btf_dedup_identity_hash_fn(long key, void *ctx); |
| static bool btf_dedup_equal_fn(long k1, long k2, void *ctx); |
| |
| int btf__add_btf(struct btf *btf, const struct btf *src_btf) |
| { |
| struct btf_pipe p = { .src = src_btf, .dst = btf }; |
| int data_sz, sz, cnt, i, err, old_strs_len; |
| __u32 *off; |
| void *t; |
| |
| /* appending split BTF isn't supported yet */ |
| if (src_btf->base_btf) |
| return libbpf_err(-ENOTSUP); |
| |
| /* deconstruct BTF, if necessary, and invalidate raw_data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| /* remember original strings section size if we have to roll back |
| * partial strings section changes |
| */ |
| old_strs_len = btf->hdr->str_len; |
| |
| data_sz = src_btf->hdr->type_len; |
| cnt = btf__type_cnt(src_btf) - 1; |
| |
| /* pre-allocate enough memory for new types */ |
| t = btf_add_type_mem(btf, data_sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| /* pre-allocate enough memory for type offset index for new types */ |
| off = btf_add_type_offs_mem(btf, cnt); |
| if (!off) |
| return libbpf_err(-ENOMEM); |
| |
| /* Map the string offsets from src_btf to the offsets from btf to improve performance */ |
| p.str_off_map = hashmap__new(btf_dedup_identity_hash_fn, btf_dedup_equal_fn, NULL); |
| if (IS_ERR(p.str_off_map)) |
| return libbpf_err(-ENOMEM); |
| |
| /* bulk copy types data for all types from src_btf */ |
| memcpy(t, src_btf->types_data, data_sz); |
| |
| for (i = 0; i < cnt; i++) { |
| sz = btf_type_size(t); |
| if (sz < 0) { |
| /* unlikely, has to be corrupted src_btf */ |
| err = sz; |
| goto err_out; |
| } |
| |
| /* fill out type ID to type offset mapping for lookups by type ID */ |
| *off = t - btf->types_data; |
| |
| /* add, dedup, and remap strings referenced by this BTF type */ |
| err = btf_type_visit_str_offs(t, btf_rewrite_str, &p); |
| if (err) |
| goto err_out; |
| |
| /* remap all type IDs referenced from this BTF type */ |
| err = btf_type_visit_type_ids(t, btf_rewrite_type_ids, btf); |
| if (err) |
| goto err_out; |
| |
| /* go to next type data and type offset index entry */ |
| t += sz; |
| off++; |
| } |
| |
| /* Up until now any of the copied type data was effectively invisible, |
| * so if we exited early before this point due to error, BTF would be |
| * effectively unmodified. There would be extra internal memory |
| * pre-allocated, but it would not be available for querying. But now |
| * that we've copied and rewritten all the data successfully, we can |
| * update type count and various internal offsets and sizes to |
| * "commit" the changes and made them visible to the outside world. |
| */ |
| btf->hdr->type_len += data_sz; |
| btf->hdr->str_off += data_sz; |
| btf->nr_types += cnt; |
| |
| hashmap__free(p.str_off_map); |
| |
| /* return type ID of the first added BTF type */ |
| return btf->start_id + btf->nr_types - cnt; |
| err_out: |
| /* zero out preallocated memory as if it was just allocated with |
| * libbpf_add_mem() |
| */ |
| memset(btf->types_data + btf->hdr->type_len, 0, data_sz); |
| memset(btf->strs_data + old_strs_len, 0, btf->hdr->str_len - old_strs_len); |
| |
| /* and now restore original strings section size; types data size |
| * wasn't modified, so doesn't need restoring, see big comment above |
| */ |
| btf->hdr->str_len = old_strs_len; |
| |
| hashmap__free(p.str_off_map); |
| |
| return libbpf_err(err); |
| } |
| |
| /* |
| * Append new BTF_KIND_INT type with: |
| * - *name* - non-empty, non-NULL type name; |
| * - *sz* - power-of-2 (1, 2, 4, ..) size of the type, in bytes; |
| * - encoding is a combination of BTF_INT_SIGNED, BTF_INT_CHAR, BTF_INT_BOOL. |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding) |
| { |
| struct btf_type *t; |
| int sz, name_off; |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| /* byte_sz must be power of 2 */ |
| if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16) |
| return libbpf_err(-EINVAL); |
| if (encoding & ~(BTF_INT_SIGNED | BTF_INT_CHAR | BTF_INT_BOOL)) |
| return libbpf_err(-EINVAL); |
| |
| /* deconstruct BTF, if necessary, and invalidate raw_data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type) + sizeof(int); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| /* if something goes wrong later, we might end up with an extra string, |
| * but that shouldn't be a problem, because BTF can't be constructed |
| * completely anyway and will most probably be just discarded |
| */ |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| t->name_off = name_off; |
| t->info = btf_type_info(BTF_KIND_INT, 0, 0); |
| t->size = byte_sz; |
| /* set INT info, we don't allow setting legacy bit offset/size */ |
| *(__u32 *)(t + 1) = (encoding << 24) | (byte_sz * 8); |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_FLOAT type with: |
| * - *name* - non-empty, non-NULL type name; |
| * - *sz* - size of the type, in bytes; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_float(struct btf *btf, const char *name, size_t byte_sz) |
| { |
| struct btf_type *t; |
| int sz, name_off; |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| |
| /* byte_sz must be one of the explicitly allowed values */ |
| if (byte_sz != 2 && byte_sz != 4 && byte_sz != 8 && byte_sz != 12 && |
| byte_sz != 16) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| t->name_off = name_off; |
| t->info = btf_type_info(BTF_KIND_FLOAT, 0, 0); |
| t->size = byte_sz; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* it's completely legal to append BTF types with type IDs pointing forward to |
| * types that haven't been appended yet, so we only make sure that id looks |
| * sane, we can't guarantee that ID will always be valid |
| */ |
| static int validate_type_id(int id) |
| { |
| if (id < 0 || id > BTF_MAX_NR_TYPES) |
| return -EINVAL; |
| return 0; |
| } |
| |
| /* generic append function for PTR, TYPEDEF, CONST/VOLATILE/RESTRICT */ |
| static int btf_add_ref_kind(struct btf *btf, int kind, const char *name, int ref_type_id) |
| { |
| struct btf_type *t; |
| int sz, name_off = 0; |
| |
| if (validate_type_id(ref_type_id)) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| if (name && name[0]) { |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| } |
| |
| t->name_off = name_off; |
| t->info = btf_type_info(kind, 0, 0); |
| t->type = ref_type_id; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_PTR type with: |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_ptr(struct btf *btf, int ref_type_id) |
| { |
| return btf_add_ref_kind(btf, BTF_KIND_PTR, NULL, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_ARRAY type with: |
| * - *index_type_id* - type ID of the type describing array index; |
| * - *elem_type_id* - type ID of the type describing array element; |
| * - *nr_elems* - the size of the array; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_array(struct btf *btf, int index_type_id, int elem_type_id, __u32 nr_elems) |
| { |
| struct btf_type *t; |
| struct btf_array *a; |
| int sz; |
| |
| if (validate_type_id(index_type_id) || validate_type_id(elem_type_id)) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type) + sizeof(struct btf_array); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| t->name_off = 0; |
| t->info = btf_type_info(BTF_KIND_ARRAY, 0, 0); |
| t->size = 0; |
| |
| a = btf_array(t); |
| a->type = elem_type_id; |
| a->index_type = index_type_id; |
| a->nelems = nr_elems; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* generic STRUCT/UNION append function */ |
| static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32 bytes_sz) |
| { |
| struct btf_type *t; |
| int sz, name_off = 0; |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| if (name && name[0]) { |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| } |
| |
| /* start out with vlen=0 and no kflag; this will be adjusted when |
| * adding each member |
| */ |
| t->name_off = name_off; |
| t->info = btf_type_info(kind, 0, 0); |
| t->size = bytes_sz; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_STRUCT type with: |
| * - *name* - name of the struct, can be NULL or empty for anonymous structs; |
| * - *byte_sz* - size of the struct, in bytes; |
| * |
| * Struct initially has no fields in it. Fields can be added by |
| * btf__add_field() right after btf__add_struct() succeeds. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_struct(struct btf *btf, const char *name, __u32 byte_sz) |
| { |
| return btf_add_composite(btf, BTF_KIND_STRUCT, name, byte_sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_UNION type with: |
| * - *name* - name of the union, can be NULL or empty for anonymous union; |
| * - *byte_sz* - size of the union, in bytes; |
| * |
| * Union initially has no fields in it. Fields can be added by |
| * btf__add_field() right after btf__add_union() succeeds. All fields |
| * should have *bit_offset* of 0. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz) |
| { |
| return btf_add_composite(btf, BTF_KIND_UNION, name, byte_sz); |
| } |
| |
| static struct btf_type *btf_last_type(struct btf *btf) |
| { |
| return btf_type_by_id(btf, btf__type_cnt(btf) - 1); |
| } |
| |
| /* |
| * Append new field for the current STRUCT/UNION type with: |
| * - *name* - name of the field, can be NULL or empty for anonymous field; |
| * - *type_id* - type ID for the type describing field type; |
| * - *bit_offset* - bit offset of the start of the field within struct/union; |
| * - *bit_size* - bit size of a bitfield, 0 for non-bitfield fields; |
| * Returns: |
| * - 0, on success; |
| * - <0, on error. |
| */ |
| int btf__add_field(struct btf *btf, const char *name, int type_id, |
| __u32 bit_offset, __u32 bit_size) |
| { |
| struct btf_type *t; |
| struct btf_member *m; |
| bool is_bitfield; |
| int sz, name_off = 0; |
| |
| /* last type should be union/struct */ |
| if (btf->nr_types == 0) |
| return libbpf_err(-EINVAL); |
| t = btf_last_type(btf); |
| if (!btf_is_composite(t)) |
| return libbpf_err(-EINVAL); |
| |
| if (validate_type_id(type_id)) |
| return libbpf_err(-EINVAL); |
| /* best-effort bit field offset/size enforcement */ |
| is_bitfield = bit_size || (bit_offset % 8 != 0); |
| if (is_bitfield && (bit_size == 0 || bit_size > 255 || bit_offset > 0xffffff)) |
| return libbpf_err(-EINVAL); |
| |
| /* only offset 0 is allowed for unions */ |
| if (btf_is_union(t) && bit_offset) |
| return libbpf_err(-EINVAL); |
| |
| /* decompose and invalidate raw data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_member); |
| m = btf_add_type_mem(btf, sz); |
| if (!m) |
| return libbpf_err(-ENOMEM); |
| |
| if (name && name[0]) { |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| } |
| |
| m->name_off = name_off; |
| m->type = type_id; |
| m->offset = bit_offset | (bit_size << 24); |
| |
| /* btf_add_type_mem can invalidate t pointer */ |
| t = btf_last_type(btf); |
| /* update parent type's vlen and kflag */ |
| t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, is_bitfield || btf_kflag(t)); |
| |
| btf->hdr->type_len += sz; |
| btf->hdr->str_off += sz; |
| return 0; |
| } |
| |
| static int btf_add_enum_common(struct btf *btf, const char *name, __u32 byte_sz, |
| bool is_signed, __u8 kind) |
| { |
| struct btf_type *t; |
| int sz, name_off = 0; |
| |
| /* byte_sz must be power of 2 */ |
| if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 8) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| if (name && name[0]) { |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| } |
| |
| /* start out with vlen=0; it will be adjusted when adding enum values */ |
| t->name_off = name_off; |
| t->info = btf_type_info(kind, 0, is_signed); |
| t->size = byte_sz; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_ENUM type with: |
| * - *name* - name of the enum, can be NULL or empty for anonymous enums; |
| * - *byte_sz* - size of the enum, in bytes. |
| * |
| * Enum initially has no enum values in it (and corresponds to enum forward |
| * declaration). Enumerator values can be added by btf__add_enum_value() |
| * immediately after btf__add_enum() succeeds. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz) |
| { |
| /* |
| * set the signedness to be unsigned, it will change to signed |
| * if any later enumerator is negative. |
| */ |
| return btf_add_enum_common(btf, name, byte_sz, false, BTF_KIND_ENUM); |
| } |
| |
| /* |
| * Append new enum value for the current ENUM type with: |
| * - *name* - name of the enumerator value, can't be NULL or empty; |
| * - *value* - integer value corresponding to enum value *name*; |
| * Returns: |
| * - 0, on success; |
| * - <0, on error. |
| */ |
| int btf__add_enum_value(struct btf *btf, const char *name, __s64 value) |
| { |
| struct btf_type *t; |
| struct btf_enum *v; |
| int sz, name_off; |
| |
| /* last type should be BTF_KIND_ENUM */ |
| if (btf->nr_types == 0) |
| return libbpf_err(-EINVAL); |
| t = btf_last_type(btf); |
| if (!btf_is_enum(t)) |
| return libbpf_err(-EINVAL); |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| if (value < INT_MIN || value > UINT_MAX) |
| return libbpf_err(-E2BIG); |
| |
| /* decompose and invalidate raw data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_enum); |
| v = btf_add_type_mem(btf, sz); |
| if (!v) |
| return libbpf_err(-ENOMEM); |
| |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| v->name_off = name_off; |
| v->val = value; |
| |
| /* update parent type's vlen */ |
| t = btf_last_type(btf); |
| btf_type_inc_vlen(t); |
| |
| /* if negative value, set signedness to signed */ |
| if (value < 0) |
| t->info = btf_type_info(btf_kind(t), btf_vlen(t), true); |
| |
| btf->hdr->type_len += sz; |
| btf->hdr->str_off += sz; |
| return 0; |
| } |
| |
| /* |
| * Append new BTF_KIND_ENUM64 type with: |
| * - *name* - name of the enum, can be NULL or empty for anonymous enums; |
| * - *byte_sz* - size of the enum, in bytes. |
| * - *is_signed* - whether the enum values are signed or not; |
| * |
| * Enum initially has no enum values in it (and corresponds to enum forward |
| * declaration). Enumerator values can be added by btf__add_enum64_value() |
| * immediately after btf__add_enum64() succeeds. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_enum64(struct btf *btf, const char *name, __u32 byte_sz, |
| bool is_signed) |
| { |
| return btf_add_enum_common(btf, name, byte_sz, is_signed, |
| BTF_KIND_ENUM64); |
| } |
| |
| /* |
| * Append new enum value for the current ENUM64 type with: |
| * - *name* - name of the enumerator value, can't be NULL or empty; |
| * - *value* - integer value corresponding to enum value *name*; |
| * Returns: |
| * - 0, on success; |
| * - <0, on error. |
| */ |
| int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value) |
| { |
| struct btf_enum64 *v; |
| struct btf_type *t; |
| int sz, name_off; |
| |
| /* last type should be BTF_KIND_ENUM64 */ |
| if (btf->nr_types == 0) |
| return libbpf_err(-EINVAL); |
| t = btf_last_type(btf); |
| if (!btf_is_enum64(t)) |
| return libbpf_err(-EINVAL); |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| |
| /* decompose and invalidate raw data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_enum64); |
| v = btf_add_type_mem(btf, sz); |
| if (!v) |
| return libbpf_err(-ENOMEM); |
| |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| v->name_off = name_off; |
| v->val_lo32 = (__u32)value; |
| v->val_hi32 = value >> 32; |
| |
| /* update parent type's vlen */ |
| t = btf_last_type(btf); |
| btf_type_inc_vlen(t); |
| |
| btf->hdr->type_len += sz; |
| btf->hdr->str_off += sz; |
| return 0; |
| } |
| |
| /* |
| * Append new BTF_KIND_FWD type with: |
| * - *name*, non-empty/non-NULL name; |
| * - *fwd_kind*, kind of forward declaration, one of BTF_FWD_STRUCT, |
| * BTF_FWD_UNION, or BTF_FWD_ENUM; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind) |
| { |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| |
| switch (fwd_kind) { |
| case BTF_FWD_STRUCT: |
| case BTF_FWD_UNION: { |
| struct btf_type *t; |
| int id; |
| |
| id = btf_add_ref_kind(btf, BTF_KIND_FWD, name, 0); |
| if (id <= 0) |
| return id; |
| t = btf_type_by_id(btf, id); |
| t->info = btf_type_info(BTF_KIND_FWD, 0, fwd_kind == BTF_FWD_UNION); |
| return id; |
| } |
| case BTF_FWD_ENUM: |
| /* enum forward in BTF currently is just an enum with no enum |
| * values; we also assume a standard 4-byte size for it |
| */ |
| return btf__add_enum(btf, name, sizeof(int)); |
| default: |
| return libbpf_err(-EINVAL); |
| } |
| } |
| |
| /* |
| * Append new BTF_KING_TYPEDEF type with: |
| * - *name*, non-empty/non-NULL name; |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id) |
| { |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| |
| return btf_add_ref_kind(btf, BTF_KIND_TYPEDEF, name, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_VOLATILE type with: |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_volatile(struct btf *btf, int ref_type_id) |
| { |
| return btf_add_ref_kind(btf, BTF_KIND_VOLATILE, NULL, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_CONST type with: |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_const(struct btf *btf, int ref_type_id) |
| { |
| return btf_add_ref_kind(btf, BTF_KIND_CONST, NULL, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_RESTRICT type with: |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_restrict(struct btf *btf, int ref_type_id) |
| { |
| return btf_add_ref_kind(btf, BTF_KIND_RESTRICT, NULL, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_TYPE_TAG type with: |
| * - *value*, non-empty/non-NULL tag value; |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id) |
| { |
| if (!value || !value[0]) |
| return libbpf_err(-EINVAL); |
| |
| return btf_add_ref_kind(btf, BTF_KIND_TYPE_TAG, value, ref_type_id); |
| } |
| |
| /* |
| * Append new BTF_KIND_FUNC type with: |
| * - *name*, non-empty/non-NULL name; |
| * - *proto_type_id* - FUNC_PROTO's type ID, it might not exist yet; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_func(struct btf *btf, const char *name, |
| enum btf_func_linkage linkage, int proto_type_id) |
| { |
| int id; |
| |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| if (linkage != BTF_FUNC_STATIC && linkage != BTF_FUNC_GLOBAL && |
| linkage != BTF_FUNC_EXTERN) |
| return libbpf_err(-EINVAL); |
| |
| id = btf_add_ref_kind(btf, BTF_KIND_FUNC, name, proto_type_id); |
| if (id > 0) { |
| struct btf_type *t = btf_type_by_id(btf, id); |
| |
| t->info = btf_type_info(BTF_KIND_FUNC, linkage, 0); |
| } |
| return libbpf_err(id); |
| } |
| |
| /* |
| * Append new BTF_KIND_FUNC_PROTO with: |
| * - *ret_type_id* - type ID for return result of a function. |
| * |
| * Function prototype initially has no arguments, but they can be added by |
| * btf__add_func_param() one by one, immediately after |
| * btf__add_func_proto() succeeded. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_func_proto(struct btf *btf, int ret_type_id) |
| { |
| struct btf_type *t; |
| int sz; |
| |
| if (validate_type_id(ret_type_id)) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| /* start out with vlen=0; this will be adjusted when adding enum |
| * values, if necessary |
| */ |
| t->name_off = 0; |
| t->info = btf_type_info(BTF_KIND_FUNC_PROTO, 0, 0); |
| t->type = ret_type_id; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new function parameter for current FUNC_PROTO type with: |
| * - *name* - parameter name, can be NULL or empty; |
| * - *type_id* - type ID describing the type of the parameter. |
| * Returns: |
| * - 0, on success; |
| * - <0, on error. |
| */ |
| int btf__add_func_param(struct btf *btf, const char *name, int type_id) |
| { |
| struct btf_type *t; |
| struct btf_param *p; |
| int sz, name_off = 0; |
| |
| if (validate_type_id(type_id)) |
| return libbpf_err(-EINVAL); |
| |
| /* last type should be BTF_KIND_FUNC_PROTO */ |
| if (btf->nr_types == 0) |
| return libbpf_err(-EINVAL); |
| t = btf_last_type(btf); |
| if (!btf_is_func_proto(t)) |
| return libbpf_err(-EINVAL); |
| |
| /* decompose and invalidate raw data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_param); |
| p = btf_add_type_mem(btf, sz); |
| if (!p) |
| return libbpf_err(-ENOMEM); |
| |
| if (name && name[0]) { |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| } |
| |
| p->name_off = name_off; |
| p->type = type_id; |
| |
| /* update parent type's vlen */ |
| t = btf_last_type(btf); |
| btf_type_inc_vlen(t); |
| |
| btf->hdr->type_len += sz; |
| btf->hdr->str_off += sz; |
| return 0; |
| } |
| |
| /* |
| * Append new BTF_KIND_VAR type with: |
| * - *name* - non-empty/non-NULL name; |
| * - *linkage* - variable linkage, one of BTF_VAR_STATIC, |
| * BTF_VAR_GLOBAL_ALLOCATED, or BTF_VAR_GLOBAL_EXTERN; |
| * - *type_id* - type ID of the type describing the type of the variable. |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id) |
| { |
| struct btf_type *t; |
| struct btf_var *v; |
| int sz, name_off; |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| if (linkage != BTF_VAR_STATIC && linkage != BTF_VAR_GLOBAL_ALLOCATED && |
| linkage != BTF_VAR_GLOBAL_EXTERN) |
| return libbpf_err(-EINVAL); |
| if (validate_type_id(type_id)) |
| return libbpf_err(-EINVAL); |
| |
| /* deconstruct BTF, if necessary, and invalidate raw_data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type) + sizeof(struct btf_var); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| t->name_off = name_off; |
| t->info = btf_type_info(BTF_KIND_VAR, 0, 0); |
| t->type = type_id; |
| |
| v = btf_var(t); |
| v->linkage = linkage; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new BTF_KIND_DATASEC type with: |
| * - *name* - non-empty/non-NULL name; |
| * - *byte_sz* - data section size, in bytes. |
| * |
| * Data section is initially empty. Variables info can be added with |
| * btf__add_datasec_var_info() calls, after btf__add_datasec() succeeds. |
| * |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz) |
| { |
| struct btf_type *t; |
| int sz, name_off; |
| |
| /* non-empty name */ |
| if (!name || !name[0]) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| name_off = btf__add_str(btf, name); |
| if (name_off < 0) |
| return name_off; |
| |
| /* start with vlen=0, which will be update as var_secinfos are added */ |
| t->name_off = name_off; |
| t->info = btf_type_info(BTF_KIND_DATASEC, 0, 0); |
| t->size = byte_sz; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| /* |
| * Append new data section variable information entry for current DATASEC type: |
| * - *var_type_id* - type ID, describing type of the variable; |
| * - *offset* - variable offset within data section, in bytes; |
| * - *byte_sz* - variable size, in bytes. |
| * |
| * Returns: |
| * - 0, on success; |
| * - <0, on error. |
| */ |
| int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __u32 byte_sz) |
| { |
| struct btf_type *t; |
| struct btf_var_secinfo *v; |
| int sz; |
| |
| /* last type should be BTF_KIND_DATASEC */ |
| if (btf->nr_types == 0) |
| return libbpf_err(-EINVAL); |
| t = btf_last_type(btf); |
| if (!btf_is_datasec(t)) |
| return libbpf_err(-EINVAL); |
| |
| if (validate_type_id(var_type_id)) |
| return libbpf_err(-EINVAL); |
| |
| /* decompose and invalidate raw data */ |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_var_secinfo); |
| v = btf_add_type_mem(btf, sz); |
| if (!v) |
| return libbpf_err(-ENOMEM); |
| |
| v->type = var_type_id; |
| v->offset = offset; |
| v->size = byte_sz; |
| |
| /* update parent type's vlen */ |
| t = btf_last_type(btf); |
| btf_type_inc_vlen(t); |
| |
| btf->hdr->type_len += sz; |
| btf->hdr->str_off += sz; |
| return 0; |
| } |
| |
| /* |
| * Append new BTF_KIND_DECL_TAG type with: |
| * - *value* - non-empty/non-NULL string; |
| * - *ref_type_id* - referenced type ID, it might not exist yet; |
| * - *component_idx* - -1 for tagging reference type, otherwise struct/union |
| * member or function argument index; |
| * Returns: |
| * - >0, type ID of newly added BTF type; |
| * - <0, on error. |
| */ |
| int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id, |
| int component_idx) |
| { |
| struct btf_type *t; |
| int sz, value_off; |
| |
| if (!value || !value[0] || component_idx < -1) |
| return libbpf_err(-EINVAL); |
| |
| if (validate_type_id(ref_type_id)) |
| return libbpf_err(-EINVAL); |
| |
| if (btf_ensure_modifiable(btf)) |
| return libbpf_err(-ENOMEM); |
| |
| sz = sizeof(struct btf_type) + sizeof(struct btf_decl_tag); |
| t = btf_add_type_mem(btf, sz); |
| if (!t) |
| return libbpf_err(-ENOMEM); |
| |
| value_off = btf__add_str(btf, value); |
| if (value_off < 0) |
| return value_off; |
| |
| t->name_off = value_off; |
| t->info = btf_type_info(BTF_KIND_DECL_TAG, 0, false); |
| t->type = ref_type_id; |
| btf_decl_tag(t)->component_idx = component_idx; |
| |
| return btf_commit_type(btf, sz); |
| } |
| |
| struct btf_ext_sec_setup_param { |
| __u32 off; |
| __u32 len; |
| __u32 min_rec_size; |
| struct btf_ext_info *ext_info; |
| const char *desc; |
| }; |
| |
| static int btf_ext_setup_info(struct btf_ext *btf_ext, |
| struct btf_ext_sec_setup_param *ext_sec) |
| { |
| const struct btf_ext_info_sec *sinfo; |
| struct btf_ext_info *ext_info; |
| __u32 info_left, record_size; |
| size_t sec_cnt = 0; |
| /* The start of the info sec (including the __u32 record_size). */ |
| void *info; |
| |
| if (ext_sec->len == 0) |
| return 0; |
| |
| if (ext_sec->off & 0x03) { |
| pr_debug(".BTF.ext %s section is not aligned to 4 bytes\n", |
| ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| info = btf_ext->data + btf_ext->hdr->hdr_len + ext_sec->off; |
| info_left = ext_sec->len; |
| |
| if (btf_ext->data + btf_ext->data_size < info + ext_sec->len) { |
| pr_debug("%s section (off:%u len:%u) is beyond the end of the ELF section .BTF.ext\n", |
| ext_sec->desc, ext_sec->off, ext_sec->len); |
| return -EINVAL; |
| } |
| |
| /* At least a record size */ |
| if (info_left < sizeof(__u32)) { |
| pr_debug(".BTF.ext %s record size not found\n", ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| /* The record size needs to meet the minimum standard */ |
| record_size = *(__u32 *)info; |
| if (record_size < ext_sec->min_rec_size || |
| record_size & 0x03) { |
| pr_debug("%s section in .BTF.ext has invalid record size %u\n", |
| ext_sec->desc, record_size); |
| return -EINVAL; |
| } |
| |
| sinfo = info + sizeof(__u32); |
| info_left -= sizeof(__u32); |
| |
| /* If no records, return failure now so .BTF.ext won't be used. */ |
| if (!info_left) { |
| pr_debug("%s section in .BTF.ext has no records", ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| while (info_left) { |
| unsigned int sec_hdrlen = sizeof(struct btf_ext_info_sec); |
| __u64 total_record_size; |
| __u32 num_records; |
| |
| if (info_left < sec_hdrlen) { |
| pr_debug("%s section header is not found in .BTF.ext\n", |
| ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| num_records = sinfo->num_info; |
| if (num_records == 0) { |
| pr_debug("%s section has incorrect num_records in .BTF.ext\n", |
| ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| total_record_size = sec_hdrlen + (__u64)num_records * record_size; |
| if (info_left < total_record_size) { |
| pr_debug("%s section has incorrect num_records in .BTF.ext\n", |
| ext_sec->desc); |
| return -EINVAL; |
| } |
| |
| info_left -= total_record_size; |
| sinfo = (void *)sinfo + total_record_size; |
| sec_cnt++; |
| } |
| |
| ext_info = ext_sec->ext_info; |
| ext_info->len = ext_sec->len - sizeof(__u32); |
| ext_info->rec_size = record_size; |
| ext_info->info = info + sizeof(__u32); |
| ext_info->sec_cnt = sec_cnt; |
| |
| return 0; |
| } |
| |
| static int btf_ext_setup_func_info(struct btf_ext *btf_ext) |
| { |
| struct btf_ext_sec_setup_param param = { |
| .off = btf_ext->hdr->func_info_off, |
| .len = btf_ext->hdr->func_info_len, |
| .min_rec_size = sizeof(struct bpf_func_info_min), |
| .ext_info = &btf_ext->func_info, |
| .desc = "func_info" |
| }; |
| |
| return btf_ext_setup_info(btf_ext, ¶m); |
| } |
| |
| static int btf_ext_setup_line_info(struct btf_ext *btf_ext) |
| { |
| struct btf_ext_sec_setup_param param = { |
| .off = btf_ext->hdr->line_info_off, |
| .len = btf_ext->hdr->line_info_len, |
| .min_rec_size = sizeof(struct bpf_line_info_min), |
| .ext_info = &btf_ext->line_info, |
| .desc = "line_info", |
| }; |
| |
| return btf_ext_setup_info(btf_ext, ¶m); |
| } |
| |
| static int btf_ext_setup_core_relos(struct btf_ext *btf_ext) |
| { |
| struct btf_ext_sec_setup_param param = { |
| .off = btf_ext->hdr->core_relo_off, |
| .len = btf_ext->hdr->core_relo_len, |
| .min_rec_size = sizeof(struct bpf_core_relo), |
| .ext_info = &btf_ext->core_relo_info, |
| .desc = "core_relo", |
| }; |
| |
| return btf_ext_setup_info(btf_ext, ¶m); |
| } |
| |
| static int btf_ext_parse_hdr(__u8 *data, __u32 data_size) |
| { |
| const struct btf_ext_header *hdr = (struct btf_ext_header *)data; |
| |
| if (data_size < offsetofend(struct btf_ext_header, hdr_len) || |
| data_size < hdr->hdr_len) { |
| pr_debug("BTF.ext header not found"); |
| return -EINVAL; |
| } |
| |
| if (hdr->magic == bswap_16(BTF_MAGIC)) { |
| pr_warn("BTF.ext in non-native endianness is not supported\n"); |
| return -ENOTSUP; |
| } else if (hdr->magic != BTF_MAGIC) { |
| pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic); |
| return -EINVAL; |
| } |
| |
| if (hdr->version != BTF_VERSION) { |
| pr_debug("Unsupported BTF.ext version:%u\n", hdr->version); |
| return -ENOTSUP; |
| } |
| |
| if (hdr->flags) { |
| pr_debug("Unsupported BTF.ext flags:%x\n", hdr->flags); |
| return -ENOTSUP; |
| } |
| |
| if (data_size == hdr->hdr_len) { |
| pr_debug("BTF.ext has no data\n"); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| void btf_ext__free(struct btf_ext *btf_ext) |
| { |
| if (IS_ERR_OR_NULL(btf_ext)) |
| return; |
| free(btf_ext->func_info.sec_idxs); |
| free(btf_ext->line_info.sec_idxs); |
| free(btf_ext->core_relo_info.sec_idxs); |
| free(btf_ext->data); |
| free(btf_ext); |
| } |
| |
| struct btf_ext *btf_ext__new(const __u8 *data, __u32 size) |
| { |
| struct btf_ext *btf_ext; |
| int err; |
| |
| btf_ext = calloc(1, sizeof(struct btf_ext)); |
| if (!btf_ext) |
| return libbpf_err_ptr(-ENOMEM); |
| |
| btf_ext->data_size = size; |
| btf_ext->data = malloc(size); |
| if (!btf_ext->data) { |
| err = -ENOMEM; |
| goto done; |
| } |
| memcpy(btf_ext->data, data, size); |
| |
| err = btf_ext_parse_hdr(btf_ext->data, size); |
| if (err) |
| goto done; |
| |
| if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, line_info_len)) { |
| err = -EINVAL; |
| goto done; |
| } |
| |
| err = btf_ext_setup_func_info(btf_ext); |
| if (err) |
| goto done; |
| |
| err = btf_ext_setup_line_info(btf_ext); |
| if (err) |
| goto done; |
| |
| if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, core_relo_len)) |
| goto done; /* skip core relos parsing */ |
| |
| err = btf_ext_setup_core_relos(btf_ext); |
| if (err) |
| goto done; |
| |
| done: |
| if (err) { |
| btf_ext__free(btf_ext); |
| return libbpf_err_ptr(err); |
| } |
| |
| return btf_ext; |
| } |
| |
| const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size) |
| { |
| *size = btf_ext->data_size; |
| return btf_ext->data; |
| } |
| |
| __attribute__((alias("btf_ext__raw_data"))) |
| const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size); |
| |
| |
| struct btf_dedup; |
| |
| static struct btf_dedup *btf_dedup_new(struct btf *btf, const struct btf_dedup_opts *opts); |
| static void btf_dedup_free(struct btf_dedup *d); |
| static int btf_dedup_prep(struct btf_dedup *d); |
| static int btf_dedup_strings(struct btf_dedup *d); |
| static int btf_dedup_prim_types(struct btf_dedup *d); |
| static int btf_dedup_struct_types(struct btf_dedup *d); |
| static int btf_dedup_ref_types(struct btf_dedup *d); |
| static int btf_dedup_resolve_fwds(struct btf_dedup *d); |
| static int btf_dedup_compact_types(struct btf_dedup *d); |
| static int btf_dedup_remap_types(struct btf_dedup *d); |
| |
| /* |
| * Deduplicate BTF types and strings. |
| * |
| * BTF dedup algorithm takes as an input `struct btf` representing `.BTF` ELF |
| * section with all BTF type descriptors and string data. It overwrites that |
| * memory in-place with deduplicated types and strings without any loss of |
| * information. If optional `struct btf_ext` representing '.BTF.ext' ELF section |
| * is provided, all the strings referenced from .BTF.ext section are honored |
| * and updated to point to the right offsets after deduplication. |
| * |
| * If function returns with error, type/string data might be garbled and should |
| * be discarded. |
| * |
| * More verbose and detailed description of both problem btf_dedup is solving, |
|