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_elf(const char *path, 68 struct btf_ext **btf_ext); 69 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); 70 LIBBPF_API int btf__load(struct btf *btf); 71 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf, 72 const char *type_name); 73 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf, 74 const char *type_name, __u32 kind); 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__align_of(const struct btf *btf, __u32 id); 81 LIBBPF_API int btf__fd(const struct btf *btf); 82 LIBBPF_API void btf__set_fd(struct btf *btf, int fd); 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 LIBBPF_API struct btf *libbpf_find_kernel_btf(void); 107 108 struct btf_dedup_opts { 109 unsigned int dedup_table_size; 110 bool dont_resolve_fwds; 111 }; 112 113 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext, 114 const struct btf_dedup_opts *opts); 115 116 struct btf_dump; 117 118 struct btf_dump_opts { 119 void *ctx; 120 }; 121 122 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args); 123 124 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf, 125 const struct btf_ext *btf_ext, 126 const struct btf_dump_opts *opts, 127 btf_dump_printf_fn_t printf_fn); 128 LIBBPF_API void btf_dump__free(struct btf_dump *d); 129 130 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id); 131 132 struct btf_dump_emit_type_decl_opts { 133 /* size of this struct, for forward/backward compatiblity */ 134 size_t sz; 135 /* optional field name for type declaration, e.g.: 136 * - struct my_struct <FNAME> 137 * - void (*<FNAME>)(int) 138 * - char (*<FNAME>)[123] 139 */ 140 const char *field_name; 141 /* extra indentation level (in number of tabs) to emit for multi-line 142 * type declarations (e.g., anonymous struct); applies for lines 143 * starting from the second one (first line is assumed to have 144 * necessary indentation already 145 */ 146 int indent_level; 147 /* strip all the const/volatile/restrict mods */ 148 bool strip_mods; 149 }; 150 #define btf_dump_emit_type_decl_opts__last_field strip_mods 151 152 LIBBPF_API int 153 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, 154 const struct btf_dump_emit_type_decl_opts *opts); 155 156 /* 157 * A set of helpers for easier BTF types handling 158 */ 159 static inline __u16 btf_kind(const struct btf_type *t) 160 { 161 return BTF_INFO_KIND(t->info); 162 } 163 164 static inline __u16 btf_vlen(const struct btf_type *t) 165 { 166 return BTF_INFO_VLEN(t->info); 167 } 168 169 static inline bool btf_kflag(const struct btf_type *t) 170 { 171 return BTF_INFO_KFLAG(t->info); 172 } 173 174 static inline bool btf_is_void(const struct btf_type *t) 175 { 176 return btf_kind(t) == BTF_KIND_UNKN; 177 } 178 179 static inline bool btf_is_int(const struct btf_type *t) 180 { 181 return btf_kind(t) == BTF_KIND_INT; 182 } 183 184 static inline bool btf_is_ptr(const struct btf_type *t) 185 { 186 return btf_kind(t) == BTF_KIND_PTR; 187 } 188 189 static inline bool btf_is_array(const struct btf_type *t) 190 { 191 return btf_kind(t) == BTF_KIND_ARRAY; 192 } 193 194 static inline bool btf_is_struct(const struct btf_type *t) 195 { 196 return btf_kind(t) == BTF_KIND_STRUCT; 197 } 198 199 static inline bool btf_is_union(const struct btf_type *t) 200 { 201 return btf_kind(t) == BTF_KIND_UNION; 202 } 203 204 static inline bool btf_is_composite(const struct btf_type *t) 205 { 206 __u16 kind = btf_kind(t); 207 208 return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; 209 } 210 211 static inline bool btf_is_enum(const struct btf_type *t) 212 { 213 return btf_kind(t) == BTF_KIND_ENUM; 214 } 215 216 static inline bool btf_is_fwd(const struct btf_type *t) 217 { 218 return btf_kind(t) == BTF_KIND_FWD; 219 } 220 221 static inline bool btf_is_typedef(const struct btf_type *t) 222 { 223 return btf_kind(t) == BTF_KIND_TYPEDEF; 224 } 225 226 static inline bool btf_is_volatile(const struct btf_type *t) 227 { 228 return btf_kind(t) == BTF_KIND_VOLATILE; 229 } 230 231 static inline bool btf_is_const(const struct btf_type *t) 232 { 233 return btf_kind(t) == BTF_KIND_CONST; 234 } 235 236 static inline bool btf_is_restrict(const struct btf_type *t) 237 { 238 return btf_kind(t) == BTF_KIND_RESTRICT; 239 } 240 241 static inline bool btf_is_mod(const struct btf_type *t) 242 { 243 __u16 kind = btf_kind(t); 244 245 return kind == BTF_KIND_VOLATILE || 246 kind == BTF_KIND_CONST || 247 kind == BTF_KIND_RESTRICT; 248 } 249 250 static inline bool btf_is_func(const struct btf_type *t) 251 { 252 return btf_kind(t) == BTF_KIND_FUNC; 253 } 254 255 static inline bool btf_is_func_proto(const struct btf_type *t) 256 { 257 return btf_kind(t) == BTF_KIND_FUNC_PROTO; 258 } 259 260 static inline bool btf_is_var(const struct btf_type *t) 261 { 262 return btf_kind(t) == BTF_KIND_VAR; 263 } 264 265 static inline bool btf_is_datasec(const struct btf_type *t) 266 { 267 return btf_kind(t) == BTF_KIND_DATASEC; 268 } 269 270 static inline __u8 btf_int_encoding(const struct btf_type *t) 271 { 272 return BTF_INT_ENCODING(*(__u32 *)(t + 1)); 273 } 274 275 static inline __u8 btf_int_offset(const struct btf_type *t) 276 { 277 return BTF_INT_OFFSET(*(__u32 *)(t + 1)); 278 } 279 280 static inline __u8 btf_int_bits(const struct btf_type *t) 281 { 282 return BTF_INT_BITS(*(__u32 *)(t + 1)); 283 } 284 285 static inline struct btf_array *btf_array(const struct btf_type *t) 286 { 287 return (struct btf_array *)(t + 1); 288 } 289 290 static inline struct btf_enum *btf_enum(const struct btf_type *t) 291 { 292 return (struct btf_enum *)(t + 1); 293 } 294 295 static inline struct btf_member *btf_members(const struct btf_type *t) 296 { 297 return (struct btf_member *)(t + 1); 298 } 299 300 /* Get bit offset of a member with specified index. */ 301 static inline __u32 btf_member_bit_offset(const struct btf_type *t, 302 __u32 member_idx) 303 { 304 const struct btf_member *m = btf_members(t) + member_idx; 305 bool kflag = btf_kflag(t); 306 307 return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset; 308 } 309 /* 310 * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or 311 * BTF_KIND_UNION. If member is not a bitfield, zero is returned. 312 */ 313 static inline __u32 btf_member_bitfield_size(const struct btf_type *t, 314 __u32 member_idx) 315 { 316 const struct btf_member *m = btf_members(t) + member_idx; 317 bool kflag = btf_kflag(t); 318 319 return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0; 320 } 321 322 static inline struct btf_param *btf_params(const struct btf_type *t) 323 { 324 return (struct btf_param *)(t + 1); 325 } 326 327 static inline struct btf_var *btf_var(const struct btf_type *t) 328 { 329 return (struct btf_var *)(t + 1); 330 } 331 332 static inline struct btf_var_secinfo * 333 btf_var_secinfos(const struct btf_type *t) 334 { 335 return (struct btf_var_secinfo *)(t + 1); 336 } 337 338 #ifdef __cplusplus 339 } /* extern "C" */ 340 #endif 341 342 #endif /* __LIBBPF_BTF_H */ 343