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 #include "libbpf_common.h" 12 13 #ifdef __cplusplus 14 extern "C" { 15 #endif 16 17 #define BTF_ELF_SEC ".BTF" 18 #define BTF_EXT_ELF_SEC ".BTF.ext" 19 #define MAPS_ELF_SEC ".maps" 20 21 struct btf; 22 struct btf_ext; 23 struct btf_type; 24 25 struct bpf_object; 26 27 /* 28 * The .BTF.ext ELF section layout defined as 29 * struct btf_ext_header 30 * func_info subsection 31 * 32 * The func_info subsection layout: 33 * record size for struct bpf_func_info in the func_info subsection 34 * struct btf_sec_func_info for section #1 35 * a list of bpf_func_info records for section #1 36 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 37 * but may not be identical 38 * struct btf_sec_func_info for section #2 39 * a list of bpf_func_info records for section #2 40 * ...... 41 * 42 * Note that the bpf_func_info record size in .BTF.ext may not 43 * be the same as the one defined in include/uapi/linux/bpf.h. 44 * The loader should ensure that record_size meets minimum 45 * requirement and pass the record as is to the kernel. The 46 * kernel will handle the func_info properly based on its contents. 47 */ 48 struct btf_ext_header { 49 __u16 magic; 50 __u8 version; 51 __u8 flags; 52 __u32 hdr_len; 53 54 /* All offsets are in bytes relative to the end of this header */ 55 __u32 func_info_off; 56 __u32 func_info_len; 57 __u32 line_info_off; 58 __u32 line_info_len; 59 60 /* optional part of .BTF.ext header */ 61 __u32 field_reloc_off; 62 __u32 field_reloc_len; 63 }; 64 65 LIBBPF_API void btf__free(struct btf *btf); 66 LIBBPF_API struct btf *btf__new(const void *data, __u32 size); 67 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext); 68 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext); 69 LIBBPF_API struct btf *btf__parse_raw(const char *path); 70 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); 71 LIBBPF_API int btf__load(struct btf *btf); 72 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 73 const char *type_name); 74 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, 75 const char *type_name, __u32 kind); 76 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf); 77 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf, 78 __u32 id); 79 LIBBPF_API size_t btf__pointer_size(const struct btf *btf); 80 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz); 81 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 82 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 83 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id); 84 LIBBPF_API int btf__fd(const struct btf *btf); 85 LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 86 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); 87 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 88 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 89 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 90 __u32 expected_key_size, 91 __u32 expected_value_size, 92 __u32 *key_type_id, __u32 *value_type_id); 93 94 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); 95 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 96 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, 97 __u32 *size); 98 LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf, 99 const struct btf_ext *btf_ext, 100 const char *sec_name, __u32 insns_cnt, 101 void **func_info, __u32 *cnt); 102 LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf, 103 const struct btf_ext *btf_ext, 104 const char *sec_name, __u32 insns_cnt, 105 void **line_info, __u32 *cnt); 106 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); 107 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); 108 109 LIBBPF_API struct btf *libbpf_find_kernel_btf(void); 110 111 struct btf_dedup_opts { 112 unsigned int dedup_table_size; 113 bool dont_resolve_fwds; 114 }; 115 116 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 117 const struct btf_dedup_opts *opts); 118 119 struct btf_dump; 120 121 struct btf_dump_opts { 122 void *ctx; 123 }; 124 125 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 126 127 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 128 const struct btf_ext *btf_ext, 129 const struct btf_dump_opts *opts, 130 btf_dump_printf_fn_t printf_fn); 131 LIBBPF_API void btf_dump__free(struct btf_dump *d); 132 133 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 134 135 struct btf_dump_emit_type_decl_opts { 136 /* size of this struct, for forward/backward compatiblity */ 137 size_t sz; 138 /* optional field name for type declaration, e.g.: 139 * - struct my_struct <FNAME> 140 * - void (*<FNAME>)(int) 141 * - char (*<FNAME>)[123] 142 */ 143 const char *field_name; 144 /* extra indentation level (in number of tabs) to emit for multi-line 145 * type declarations (e.g., anonymous struct); applies for lines 146 * starting from the second one (first line is assumed to have 147 * necessary indentation already 148 */ 149 int indent_level; 150 /* strip all the const/volatile/restrict mods */ 151 bool strip_mods; 152 }; 153 #define btf_dump_emit_type_decl_opts__last_field strip_mods 154 155 LIBBPF_API int 156 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 157 const struct btf_dump_emit_type_decl_opts *opts); 158 159 /* 160 * A set of helpers for easier BTF types handling 161 */ 162 static inline __u16 btf_kind(const struct btf_type *t) 163 { 164 return BTF_INFO_KIND(t->info); 165 } 166 167 static inline __u16 btf_vlen(const struct btf_type *t) 168 { 169 return BTF_INFO_VLEN(t->info); 170 } 171 172 static inline bool btf_kflag(const struct btf_type *t) 173 { 174 return BTF_INFO_KFLAG(t->info); 175 } 176 177 static inline bool btf_is_void(const struct btf_type *t) 178 { 179 return btf_kind(t) == BTF_KIND_UNKN; 180 } 181 182 static inline bool btf_is_int(const struct btf_type *t) 183 { 184 return btf_kind(t) == BTF_KIND_INT; 185 } 186 187 static inline bool btf_is_ptr(const struct btf_type *t) 188 { 189 return btf_kind(t) == BTF_KIND_PTR; 190 } 191 192 static inline bool btf_is_array(const struct btf_type *t) 193 { 194 return btf_kind(t) == BTF_KIND_ARRAY; 195 } 196 197 static inline bool btf_is_struct(const struct btf_type *t) 198 { 199 return btf_kind(t) == BTF_KIND_STRUCT; 200 } 201 202 static inline bool btf_is_union(const struct btf_type *t) 203 { 204 return btf_kind(t) == BTF_KIND_UNION; 205 } 206 207 static inline bool btf_is_composite(const struct btf_type *t) 208 { 209 __u16 kind = btf_kind(t); 210 211 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 212 } 213 214 static inline bool btf_is_enum(const struct btf_type *t) 215 { 216 return btf_kind(t) == BTF_KIND_ENUM; 217 } 218 219 static inline bool btf_is_fwd(const struct btf_type *t) 220 { 221 return btf_kind(t) == BTF_KIND_FWD; 222 } 223 224 static inline bool btf_is_typedef(const struct btf_type *t) 225 { 226 return btf_kind(t) == BTF_KIND_TYPEDEF; 227 } 228 229 static inline bool btf_is_volatile(const struct btf_type *t) 230 { 231 return btf_kind(t) == BTF_KIND_VOLATILE; 232 } 233 234 static inline bool btf_is_const(const struct btf_type *t) 235 { 236 return btf_kind(t) == BTF_KIND_CONST; 237 } 238 239 static inline bool btf_is_restrict(const struct btf_type *t) 240 { 241 return btf_kind(t) == BTF_KIND_RESTRICT; 242 } 243 244 static inline bool btf_is_mod(const struct btf_type *t) 245 { 246 __u16 kind = btf_kind(t); 247 248 return kind == BTF_KIND_VOLATILE || 249 kind == BTF_KIND_CONST || 250 kind == BTF_KIND_RESTRICT; 251 } 252 253 static inline bool btf_is_func(const struct btf_type *t) 254 { 255 return btf_kind(t) == BTF_KIND_FUNC; 256 } 257 258 static inline bool btf_is_func_proto(const struct btf_type *t) 259 { 260 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 261 } 262 263 static inline bool btf_is_var(const struct btf_type *t) 264 { 265 return btf_kind(t) == BTF_KIND_VAR; 266 } 267 268 static inline bool btf_is_datasec(const struct btf_type *t) 269 { 270 return btf_kind(t) == BTF_KIND_DATASEC; 271 } 272 273 static inline __u8 btf_int_encoding(const struct btf_type *t) 274 { 275 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 276 } 277 278 static inline __u8 btf_int_offset(const struct btf_type *t) 279 { 280 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 281 } 282 283 static inline __u8 btf_int_bits(const struct btf_type *t) 284 { 285 return BTF_INT_BITS(*(__u32 *)(t + 1)); 286 } 287 288 static inline struct btf_array *btf_array(const struct btf_type *t) 289 { 290 return (struct btf_array *)(t + 1); 291 } 292 293 static inline struct btf_enum *btf_enum(const struct btf_type *t) 294 { 295 return (struct btf_enum *)(t + 1); 296 } 297 298 static inline struct btf_member *btf_members(const struct btf_type *t) 299 { 300 return (struct btf_member *)(t + 1); 301 } 302 303 /* Get bit offset of a member with specified index. */ 304 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 305 __u32 member_idx) 306 { 307 const struct btf_member *m = btf_members(t) + member_idx; 308 bool kflag = btf_kflag(t); 309 310 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 311 } 312 /* 313 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 314 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 315 */ 316 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 317 __u32 member_idx) 318 { 319 const struct btf_member *m = btf_members(t) + member_idx; 320 bool kflag = btf_kflag(t); 321 322 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 323 } 324 325 static inline struct btf_param *btf_params(const struct btf_type *t) 326 { 327 return (struct btf_param *)(t + 1); 328 } 329 330 static inline struct btf_var *btf_var(const struct btf_type *t) 331 { 332 return (struct btf_var *)(t + 1); 333 } 334 335 static inline struct btf_var_secinfo * 336 btf_var_secinfos(const struct btf_type *t) 337 { 338 return (struct btf_var_secinfo *)(t + 1); 339 } 340 341 #ifdef __cplusplus 342 } /* extern "C" */ 343 #endif 344 345 #endif /* __LIBBPF_BTF_H */ 346