1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 /* Copyright (c) 2018 Facebook */ 3 4 #ifndef __LIBBPF_BTF_H 5 #define __LIBBPF_BTF_H 6 7 #include <stdarg.h> 8 #include <linux/btf.h> 9 #include <linux/types.h> 10 11 #ifdef __cplusplus 12 extern "C" { 13 #endif 14 15 #ifndef LIBBPF_API 16 #define LIBBPF_API __attribute__((visibility("default"))) 17 #endif 18 19 #define BTF_ELF_SEC ".BTF" 20 #define BTF_EXT_ELF_SEC ".BTF.ext" 21 #define MAPS_ELF_SEC ".maps" 22 23 struct btf; 24 struct btf_ext; 25 struct btf_type; 26 27 struct bpf_object; 28 29 /* 30 * The .BTF.ext ELF section layout defined as 31 * struct btf_ext_header 32 * func_info subsection 33 * 34 * The func_info subsection layout: 35 * record size for struct bpf_func_info in the func_info subsection 36 * struct btf_sec_func_info for section #1 37 * a list of bpf_func_info records for section #1 38 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 39 * but may not be identical 40 * struct btf_sec_func_info for section #2 41 * a list of bpf_func_info records for section #2 42 * ...... 43 * 44 * Note that the bpf_func_info record size in .BTF.ext may not 45 * be the same as the one defined in include/uapi/linux/bpf.h. 46 * The loader should ensure that record_size meets minimum 47 * requirement and pass the record as is to the kernel. The 48 * kernel will handle the func_info properly based on its contents. 49 */ 50 struct btf_ext_header { 51 __u16 magic; 52 __u8 version; 53 __u8 flags; 54 __u32 hdr_len; 55 56 /* All offsets are in bytes relative to the end of this header */ 57 __u32 func_info_off; 58 __u32 func_info_len; 59 __u32 line_info_off; 60 __u32 line_info_len; 61 62 /* optional part of .BTF.ext header */ 63 __u32 field_reloc_off; 64 __u32 field_reloc_len; 65 }; 66 67 LIBBPF_API void btf__free(struct btf *btf); 68 LIBBPF_API struct btf *btf__new(__u8 *data, __u32 size); 69 LIBBPF_API struct btf *btf__parse_elf(const char *path, 70 struct btf_ext **btf_ext); 71 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); 72 LIBBPF_API int btf__load(struct btf *btf); 73 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 74 const char *type_name); 75 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, 76 const char *type_name, __u32 kind); 77 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf); 78 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 79 __u32 id); 80 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 81 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 82 LIBBPF_API int btf__fd(const struct btf *btf); 83 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); 84 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 85 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 86 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 87 __u32 expected_key_size, 88 __u32 expected_value_size, 89 __u32 *key_type_id, __u32 *value_type_id); 90 91 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); 92 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 93 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, 94 __u32 *size); 95 LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf, 96 const struct btf_ext *btf_ext, 97 const char *sec_name, __u32 insns_cnt, 98 void **func_info, __u32 *cnt); 99 LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf, 100 const struct btf_ext *btf_ext, 101 const char *sec_name, __u32 insns_cnt, 102 void **line_info, __u32 *cnt); 103 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); 104 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); 105 106 struct btf_dedup_opts { 107 unsigned int dedup_table_size; 108 bool dont_resolve_fwds; 109 }; 110 111 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 112 const struct btf_dedup_opts *opts); 113 114 struct btf_dump; 115 116 struct btf_dump_opts { 117 void *ctx; 118 }; 119 120 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 121 122 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 123 const struct btf_ext *btf_ext, 124 const struct btf_dump_opts *opts, 125 btf_dump_printf_fn_t printf_fn); 126 LIBBPF_API void btf_dump__free(struct btf_dump *d); 127 128 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 129 130 /* 131 * A set of helpers for easier BTF types handling 132 */ 133 static inline __u16 btf_kind(const struct btf_type *t) 134 { 135 return BTF_INFO_KIND(t->info); 136 } 137 138 static inline __u16 btf_vlen(const struct btf_type *t) 139 { 140 return BTF_INFO_VLEN(t->info); 141 } 142 143 static inline bool btf_kflag(const struct btf_type *t) 144 { 145 return BTF_INFO_KFLAG(t->info); 146 } 147 148 static inline bool btf_is_int(const struct btf_type *t) 149 { 150 return btf_kind(t) == BTF_KIND_INT; 151 } 152 153 static inline bool btf_is_ptr(const struct btf_type *t) 154 { 155 return btf_kind(t) == BTF_KIND_PTR; 156 } 157 158 static inline bool btf_is_array(const struct btf_type *t) 159 { 160 return btf_kind(t) == BTF_KIND_ARRAY; 161 } 162 163 static inline bool btf_is_struct(const struct btf_type *t) 164 { 165 return btf_kind(t) == BTF_KIND_STRUCT; 166 } 167 168 static inline bool btf_is_union(const struct btf_type *t) 169 { 170 return btf_kind(t) == BTF_KIND_UNION; 171 } 172 173 static inline bool btf_is_composite(const struct btf_type *t) 174 { 175 __u16 kind = btf_kind(t); 176 177 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 178 } 179 180 static inline bool btf_is_enum(const struct btf_type *t) 181 { 182 return btf_kind(t) == BTF_KIND_ENUM; 183 } 184 185 static inline bool btf_is_fwd(const struct btf_type *t) 186 { 187 return btf_kind(t) == BTF_KIND_FWD; 188 } 189 190 static inline bool btf_is_typedef(const struct btf_type *t) 191 { 192 return btf_kind(t) == BTF_KIND_TYPEDEF; 193 } 194 195 static inline bool btf_is_volatile(const struct btf_type *t) 196 { 197 return btf_kind(t) == BTF_KIND_VOLATILE; 198 } 199 200 static inline bool btf_is_const(const struct btf_type *t) 201 { 202 return btf_kind(t) == BTF_KIND_CONST; 203 } 204 205 static inline bool btf_is_restrict(const struct btf_type *t) 206 { 207 return btf_kind(t) == BTF_KIND_RESTRICT; 208 } 209 210 static inline bool btf_is_mod(const struct btf_type *t) 211 { 212 __u16 kind = btf_kind(t); 213 214 return kind == BTF_KIND_VOLATILE || 215 kind == BTF_KIND_CONST || 216 kind == BTF_KIND_RESTRICT; 217 } 218 219 static inline bool btf_is_func(const struct btf_type *t) 220 { 221 return btf_kind(t) == BTF_KIND_FUNC; 222 } 223 224 static inline bool btf_is_func_proto(const struct btf_type *t) 225 { 226 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 227 } 228 229 static inline bool btf_is_var(const struct btf_type *t) 230 { 231 return btf_kind(t) == BTF_KIND_VAR; 232 } 233 234 static inline bool btf_is_datasec(const struct btf_type *t) 235 { 236 return btf_kind(t) == BTF_KIND_DATASEC; 237 } 238 239 static inline __u8 btf_int_encoding(const struct btf_type *t) 240 { 241 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 242 } 243 244 static inline __u8 btf_int_offset(const struct btf_type *t) 245 { 246 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 247 } 248 249 static inline __u8 btf_int_bits(const struct btf_type *t) 250 { 251 return BTF_INT_BITS(*(__u32 *)(t + 1)); 252 } 253 254 static inline struct btf_array *btf_array(const struct btf_type *t) 255 { 256 return (struct btf_array *)(t + 1); 257 } 258 259 static inline struct btf_enum *btf_enum(const struct btf_type *t) 260 { 261 return (struct btf_enum *)(t + 1); 262 } 263 264 static inline struct btf_member *btf_members(const struct btf_type *t) 265 { 266 return (struct btf_member *)(t + 1); 267 } 268 269 /* Get bit offset of a member with specified index. */ 270 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 271 __u32 member_idx) 272 { 273 const struct btf_member *m = btf_members(t) + member_idx; 274 bool kflag = btf_kflag(t); 275 276 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 277 } 278 /* 279 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 280 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 281 */ 282 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 283 __u32 member_idx) 284 { 285 const struct btf_member *m = btf_members(t) + member_idx; 286 bool kflag = btf_kflag(t); 287 288 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 289 } 290 291 static inline struct btf_param *btf_params(const struct btf_type *t) 292 { 293 return (struct btf_param *)(t + 1); 294 } 295 296 static inline struct btf_var *btf_var(const struct btf_type *t) 297 { 298 return (struct btf_var *)(t + 1); 299 } 300 301 static inline struct btf_var_secinfo * 302 btf_var_secinfos(const struct btf_type *t) 303 { 304 return (struct btf_var_secinfo *)(t + 1); 305 } 306 307 #ifdef __cplusplus 308 } /* extern "C" */ 309 #endif 310 311 #endif /* __LIBBPF_BTF_H */ 312