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