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 __s64 btf__resolve_size(const struct btf *btf, __u32 type_id); 80 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id); 81 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id); 82 LIBBPF_API int btf__fd(const struct btf *btf); 83 LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 84 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size); 85 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); 86 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf); 87 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, 88 __u32 expected_key_size, 89 __u32 expected_value_size, 90 __u32 *key_type_id, __u32 *value_type_id); 91 92 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); 93 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); 94 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, 95 __u32 *size); 96 LIBBPF_API int btf_ext__reloc_func_info(const struct btf *btf, 97 const struct btf_ext *btf_ext, 98 const char *sec_name, __u32 insns_cnt, 99 void **func_info, __u32 *cnt); 100 LIBBPF_API int btf_ext__reloc_line_info(const struct btf *btf, 101 const struct btf_ext *btf_ext, 102 const char *sec_name, __u32 insns_cnt, 103 void **line_info, __u32 *cnt); 104 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext); 105 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext); 106 107 LIBBPF_API struct btf *libbpf_find_kernel_btf(void); 108 109 struct btf_dedup_opts { 110 unsigned int dedup_table_size; 111 bool dont_resolve_fwds; 112 }; 113 114 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 115 const struct btf_dedup_opts *opts); 116 117 struct btf_dump; 118 119 struct btf_dump_opts { 120 void *ctx; 121 }; 122 123 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 124 125 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 126 const struct btf_ext *btf_ext, 127 const struct btf_dump_opts *opts, 128 btf_dump_printf_fn_t printf_fn); 129 LIBBPF_API void btf_dump__free(struct btf_dump *d); 130 131 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 132 133 struct btf_dump_emit_type_decl_opts { 134 /* size of this struct, for forward/backward compatiblity */ 135 size_t sz; 136 /* optional field name for type declaration, e.g.: 137 * - struct my_struct <FNAME> 138 * - void (*<FNAME>)(int) 139 * - char (*<FNAME>)[123] 140 */ 141 const char *field_name; 142 /* extra indentation level (in number of tabs) to emit for multi-line 143 * type declarations (e.g., anonymous struct); applies for lines 144 * starting from the second one (first line is assumed to have 145 * necessary indentation already 146 */ 147 int indent_level; 148 /* strip all the const/volatile/restrict mods */ 149 bool strip_mods; 150 }; 151 #define btf_dump_emit_type_decl_opts__last_field strip_mods 152 153 LIBBPF_API int 154 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 155 const struct btf_dump_emit_type_decl_opts *opts); 156 157 /* 158 * A set of helpers for easier BTF types handling 159 */ 160 static inline __u16 btf_kind(const struct btf_type *t) 161 { 162 return BTF_INFO_KIND(t->info); 163 } 164 165 static inline __u16 btf_vlen(const struct btf_type *t) 166 { 167 return BTF_INFO_VLEN(t->info); 168 } 169 170 static inline bool btf_kflag(const struct btf_type *t) 171 { 172 return BTF_INFO_KFLAG(t->info); 173 } 174 175 static inline bool btf_is_void(const struct btf_type *t) 176 { 177 return btf_kind(t) == BTF_KIND_UNKN; 178 } 179 180 static inline bool btf_is_int(const struct btf_type *t) 181 { 182 return btf_kind(t) == BTF_KIND_INT; 183 } 184 185 static inline bool btf_is_ptr(const struct btf_type *t) 186 { 187 return btf_kind(t) == BTF_KIND_PTR; 188 } 189 190 static inline bool btf_is_array(const struct btf_type *t) 191 { 192 return btf_kind(t) == BTF_KIND_ARRAY; 193 } 194 195 static inline bool btf_is_struct(const struct btf_type *t) 196 { 197 return btf_kind(t) == BTF_KIND_STRUCT; 198 } 199 200 static inline bool btf_is_union(const struct btf_type *t) 201 { 202 return btf_kind(t) == BTF_KIND_UNION; 203 } 204 205 static inline bool btf_is_composite(const struct btf_type *t) 206 { 207 __u16 kind = btf_kind(t); 208 209 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 210 } 211 212 static inline bool btf_is_enum(const struct btf_type *t) 213 { 214 return btf_kind(t) == BTF_KIND_ENUM; 215 } 216 217 static inline bool btf_is_fwd(const struct btf_type *t) 218 { 219 return btf_kind(t) == BTF_KIND_FWD; 220 } 221 222 static inline bool btf_is_typedef(const struct btf_type *t) 223 { 224 return btf_kind(t) == BTF_KIND_TYPEDEF; 225 } 226 227 static inline bool btf_is_volatile(const struct btf_type *t) 228 { 229 return btf_kind(t) == BTF_KIND_VOLATILE; 230 } 231 232 static inline bool btf_is_const(const struct btf_type *t) 233 { 234 return btf_kind(t) == BTF_KIND_CONST; 235 } 236 237 static inline bool btf_is_restrict(const struct btf_type *t) 238 { 239 return btf_kind(t) == BTF_KIND_RESTRICT; 240 } 241 242 static inline bool btf_is_mod(const struct btf_type *t) 243 { 244 __u16 kind = btf_kind(t); 245 246 return kind == BTF_KIND_VOLATILE || 247 kind == BTF_KIND_CONST || 248 kind == BTF_KIND_RESTRICT; 249 } 250 251 static inline bool btf_is_func(const struct btf_type *t) 252 { 253 return btf_kind(t) == BTF_KIND_FUNC; 254 } 255 256 static inline bool btf_is_func_proto(const struct btf_type *t) 257 { 258 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 259 } 260 261 static inline bool btf_is_var(const struct btf_type *t) 262 { 263 return btf_kind(t) == BTF_KIND_VAR; 264 } 265 266 static inline bool btf_is_datasec(const struct btf_type *t) 267 { 268 return btf_kind(t) == BTF_KIND_DATASEC; 269 } 270 271 static inline __u8 btf_int_encoding(const struct btf_type *t) 272 { 273 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 274 } 275 276 static inline __u8 btf_int_offset(const struct btf_type *t) 277 { 278 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 279 } 280 281 static inline __u8 btf_int_bits(const struct btf_type *t) 282 { 283 return BTF_INT_BITS(*(__u32 *)(t + 1)); 284 } 285 286 static inline struct btf_array *btf_array(const struct btf_type *t) 287 { 288 return (struct btf_array *)(t + 1); 289 } 290 291 static inline struct btf_enum *btf_enum(const struct btf_type *t) 292 { 293 return (struct btf_enum *)(t + 1); 294 } 295 296 static inline struct btf_member *btf_members(const struct btf_type *t) 297 { 298 return (struct btf_member *)(t + 1); 299 } 300 301 /* Get bit offset of a member with specified index. */ 302 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 303 __u32 member_idx) 304 { 305 const struct btf_member *m = btf_members(t) + member_idx; 306 bool kflag = btf_kflag(t); 307 308 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 309 } 310 /* 311 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 312 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 313 */ 314 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 315 __u32 member_idx) 316 { 317 const struct btf_member *m = btf_members(t) + member_idx; 318 bool kflag = btf_kflag(t); 319 320 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 321 } 322 323 static inline struct btf_param *btf_params(const struct btf_type *t) 324 { 325 return (struct btf_param *)(t + 1); 326 } 327 328 static inline struct btf_var *btf_var(const struct btf_type *t) 329 { 330 return (struct btf_var *)(t + 1); 331 } 332 333 static inline struct btf_var_secinfo * 334 btf_var_secinfos(const struct btf_type *t) 335 { 336 return (struct btf_var_secinfo *)(t + 1); 337 } 338 339 #ifdef __cplusplus 340 } /* extern "C" */ 341 #endif 342 343 #endif /* __LIBBPF_BTF_H */ 344