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 __u32 btf__get_nr_types(const struct btf *btf); 76 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 77 __u32 id); 78 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 79 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 80 LIBBPF_API int btf__fd(const struct btf *btf); 81 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); 82 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 83 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 84 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 85 __u32 expected_key_size, 86 __u32 expected_value_size, 87 __u32 *key_type_id, __u32 *value_type_id); 88 89 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); 90 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 91 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, 92 __u32 *size); 93 LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf, 94 const struct btf_ext *btf_ext, 95 const char *sec_name, __u32 insns_cnt, 96 void **func_info, __u32 *cnt); 97 LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf, 98 const struct btf_ext *btf_ext, 99 const char *sec_name, __u32 insns_cnt, 100 void **line_info, __u32 *cnt); 101 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); 102 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); 103 104 struct btf_dedup_opts { 105 unsigned int dedup_table_size; 106 bool dont_resolve_fwds; 107 }; 108 109 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 110 const struct btf_dedup_opts *opts); 111 112 struct btf_dump; 113 114 struct btf_dump_opts { 115 void *ctx; 116 }; 117 118 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 119 120 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 121 const struct btf_ext *btf_ext, 122 const struct btf_dump_opts *opts, 123 btf_dump_printf_fn_t printf_fn); 124 LIBBPF_API void btf_dump__free(struct btf_dump *d); 125 126 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 127 128 /* 129 * A set of helpers for easier BTF types handling 130 */ 131 static inline __u16 btf_kind(const struct btf_type *t) 132 { 133 return BTF_INFO_KIND(t->info); 134 } 135 136 static inline __u16 btf_vlen(const struct btf_type *t) 137 { 138 return BTF_INFO_VLEN(t->info); 139 } 140 141 static inline bool btf_kflag(const struct btf_type *t) 142 { 143 return BTF_INFO_KFLAG(t->info); 144 } 145 146 static inline bool btf_is_int(const struct btf_type *t) 147 { 148 return btf_kind(t) == BTF_KIND_INT; 149 } 150 151 static inline bool btf_is_ptr(const struct btf_type *t) 152 { 153 return btf_kind(t) == BTF_KIND_PTR; 154 } 155 156 static inline bool btf_is_array(const struct btf_type *t) 157 { 158 return btf_kind(t) == BTF_KIND_ARRAY; 159 } 160 161 static inline bool btf_is_struct(const struct btf_type *t) 162 { 163 return btf_kind(t) == BTF_KIND_STRUCT; 164 } 165 166 static inline bool btf_is_union(const struct btf_type *t) 167 { 168 return btf_kind(t) == BTF_KIND_UNION; 169 } 170 171 static inline bool btf_is_composite(const struct btf_type *t) 172 { 173 __u16 kind = btf_kind(t); 174 175 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 176 } 177 178 static inline bool btf_is_enum(const struct btf_type *t) 179 { 180 return btf_kind(t) == BTF_KIND_ENUM; 181 } 182 183 static inline bool btf_is_fwd(const struct btf_type *t) 184 { 185 return btf_kind(t) == BTF_KIND_FWD; 186 } 187 188 static inline bool btf_is_typedef(const struct btf_type *t) 189 { 190 return btf_kind(t) == BTF_KIND_TYPEDEF; 191 } 192 193 static inline bool btf_is_volatile(const struct btf_type *t) 194 { 195 return btf_kind(t) == BTF_KIND_VOLATILE; 196 } 197 198 static inline bool btf_is_const(const struct btf_type *t) 199 { 200 return btf_kind(t) == BTF_KIND_CONST; 201 } 202 203 static inline bool btf_is_restrict(const struct btf_type *t) 204 { 205 return btf_kind(t) == BTF_KIND_RESTRICT; 206 } 207 208 static inline bool btf_is_mod(const struct btf_type *t) 209 { 210 __u16 kind = btf_kind(t); 211 212 return kind == BTF_KIND_VOLATILE || 213 kind == BTF_KIND_CONST || 214 kind == BTF_KIND_RESTRICT; 215 } 216 217 static inline bool btf_is_func(const struct btf_type *t) 218 { 219 return btf_kind(t) == BTF_KIND_FUNC; 220 } 221 222 static inline bool btf_is_func_proto(const struct btf_type *t) 223 { 224 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 225 } 226 227 static inline bool btf_is_var(const struct btf_type *t) 228 { 229 return btf_kind(t) == BTF_KIND_VAR; 230 } 231 232 static inline bool btf_is_datasec(const struct btf_type *t) 233 { 234 return btf_kind(t) == BTF_KIND_DATASEC; 235 } 236 237 static inline __u8 btf_int_encoding(const struct btf_type *t) 238 { 239 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 240 } 241 242 static inline __u8 btf_int_offset(const struct btf_type *t) 243 { 244 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 245 } 246 247 static inline __u8 btf_int_bits(const struct btf_type *t) 248 { 249 return BTF_INT_BITS(*(__u32 *)(t + 1)); 250 } 251 252 static inline struct btf_array *btf_array(const struct btf_type *t) 253 { 254 return (struct btf_array *)(t + 1); 255 } 256 257 static inline struct btf_enum *btf_enum(const struct btf_type *t) 258 { 259 return (struct btf_enum *)(t + 1); 260 } 261 262 static inline struct btf_member *btf_members(const struct btf_type *t) 263 { 264 return (struct btf_member *)(t + 1); 265 } 266 267 /* Get bit offset of a member with specified index. */ 268 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 269 __u32 member_idx) 270 { 271 const struct btf_member *m = btf_members(t) + member_idx; 272 bool kflag = btf_kflag(t); 273 274 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 275 } 276 /* 277 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 278 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 279 */ 280 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 281 __u32 member_idx) 282 { 283 const struct btf_member *m = btf_members(t) + member_idx; 284 bool kflag = btf_kflag(t); 285 286 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 287 } 288 289 static inline struct btf_param *btf_params(const struct btf_type *t) 290 { 291 return (struct btf_param *)(t + 1); 292 } 293 294 static inline struct btf_var *btf_var(const struct btf_type *t) 295 { 296 return (struct btf_var *)(t + 1); 297 } 298 299 static inline struct btf_var_secinfo * 300 btf_var_secinfos(const struct btf_type *t) 301 { 302 return (struct btf_var_secinfo *)(t + 1); 303 } 304 305 #ifdef __cplusplus 306 } /* extern "C" */ 307 #endif 308 309 #endif /* __LIBBPF_BTF_H */ 310