1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 3 /* 4 * Internal libbpf helpers. 5 * 6 * Copyright (c) 2019 Facebook 7 */ 8 9 #ifndef __LIBBPF_LIBBPF_INTERNAL_H 10 #define __LIBBPF_LIBBPF_INTERNAL_H 11 12 #include <stdlib.h> 13 #include <limits.h> 14 #include <errno.h> 15 #include <linux/err.h> 16 #include "libbpf_legacy.h" 17 #include "relo_core.h" 18 19 /* make sure libbpf doesn't use kernel-only integer typedefs */ 20 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 21 22 /* prevent accidental re-addition of reallocarray() */ 23 #pragma GCC poison reallocarray 24 25 #include "libbpf.h" 26 #include "btf.h" 27 28 #ifndef EM_BPF 29 #define EM_BPF 247 30 #endif 31 32 #ifndef R_BPF_64_64 33 #define R_BPF_64_64 1 34 #endif 35 #ifndef R_BPF_64_ABS64 36 #define R_BPF_64_ABS64 2 37 #endif 38 #ifndef R_BPF_64_ABS32 39 #define R_BPF_64_ABS32 3 40 #endif 41 #ifndef R_BPF_64_32 42 #define R_BPF_64_32 10 43 #endif 44 45 #ifndef SHT_LLVM_ADDRSIG 46 #define SHT_LLVM_ADDRSIG 0x6FFF4C03 47 #endif 48 49 /* if libelf is old and doesn't support mmap(), fall back to read() */ 50 #ifndef ELF_C_READ_MMAP 51 #define ELF_C_READ_MMAP ELF_C_READ 52 #endif 53 54 /* Older libelf all end up in this expression, for both 32 and 64 bit */ 55 #ifndef GELF_ST_VISIBILITY 56 #define GELF_ST_VISIBILITY(o) ((o) & 0x03) 57 #endif 58 59 #define BTF_INFO_ENC(kind, kind_flag, vlen) \ 60 ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) 61 #define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type) 62 #define BTF_INT_ENC(encoding, bits_offset, nr_bits) \ 63 ((encoding) << 24 | (bits_offset) << 16 | (nr_bits)) 64 #define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \ 65 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \ 66 BTF_INT_ENC(encoding, bits_offset, bits) 67 #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset) 68 #define BTF_PARAM_ENC(name, type) (name), (type) 69 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size) 70 #define BTF_TYPE_FLOAT_ENC(name, sz) \ 71 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) 72 73 #ifndef likely 74 #define likely(x) __builtin_expect(!!(x), 1) 75 #endif 76 #ifndef unlikely 77 #define unlikely(x) __builtin_expect(!!(x), 0) 78 #endif 79 #ifndef min 80 # define min(x, y) ((x) < (y) ? (x) : (y)) 81 #endif 82 #ifndef max 83 # define max(x, y) ((x) < (y) ? (y) : (x)) 84 #endif 85 #ifndef offsetofend 86 # define offsetofend(TYPE, FIELD) \ 87 (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) 88 #endif 89 90 /* Symbol versioning is different between static and shared library. 91 * Properly versioned symbols are needed for shared library, but 92 * only the symbol of the new version is needed for static library. 93 */ 94 #ifdef SHARED 95 # define COMPAT_VERSION(internal_name, api_name, version) \ 96 asm(".symver " #internal_name "," #api_name "@" #version); 97 # define DEFAULT_VERSION(internal_name, api_name, version) \ 98 asm(".symver " #internal_name "," #api_name "@@" #version); 99 #else 100 # define COMPAT_VERSION(internal_name, api_name, version) 101 # define DEFAULT_VERSION(internal_name, api_name, version) \ 102 extern typeof(internal_name) api_name \ 103 __attribute__((alias(#internal_name))); 104 #endif 105 106 extern void libbpf_print(enum libbpf_print_level level, 107 const char *format, ...) 108 __attribute__((format(printf, 2, 3))); 109 110 #define __pr(level, fmt, ...) \ 111 do { \ 112 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ 113 } while (0) 114 115 #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) 116 #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) 117 #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) 118 119 #ifndef __has_builtin 120 #define __has_builtin(x) 0 121 #endif 122 /* 123 * Re-implement glibc's reallocarray() for libbpf internal-only use. 124 * reallocarray(), unfortunately, is not available in all versions of glibc, 125 * so requires extra feature detection and using reallocarray() stub from 126 * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates 127 * build of libbpf unnecessarily and is just a maintenance burden. Instead, 128 * it's trivial to implement libbpf-specific internal version and use it 129 * throughout libbpf. 130 */ 131 static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) 132 { 133 size_t total; 134 135 #if __has_builtin(__builtin_mul_overflow) 136 if (unlikely(__builtin_mul_overflow(nmemb, size, &total))) 137 return NULL; 138 #else 139 if (size == 0 || nmemb > ULONG_MAX / size) 140 return NULL; 141 total = nmemb * size; 142 #endif 143 return realloc(ptr, total); 144 } 145 146 struct btf; 147 struct btf_type; 148 149 struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id); 150 const char *btf_kind_str(const struct btf_type *t); 151 const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id); 152 153 static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t) 154 { 155 return (enum btf_func_linkage)(int)btf_vlen(t); 156 } 157 158 static inline __u32 btf_type_info(int kind, int vlen, int kflag) 159 { 160 return (kflag << 31) | (kind << 24) | vlen; 161 } 162 163 enum map_def_parts { 164 MAP_DEF_MAP_TYPE = 0x001, 165 MAP_DEF_KEY_TYPE = 0x002, 166 MAP_DEF_KEY_SIZE = 0x004, 167 MAP_DEF_VALUE_TYPE = 0x008, 168 MAP_DEF_VALUE_SIZE = 0x010, 169 MAP_DEF_MAX_ENTRIES = 0x020, 170 MAP_DEF_MAP_FLAGS = 0x040, 171 MAP_DEF_NUMA_NODE = 0x080, 172 MAP_DEF_PINNING = 0x100, 173 MAP_DEF_INNER_MAP = 0x200, 174 175 MAP_DEF_ALL = 0x3ff, /* combination of all above */ 176 }; 177 178 struct btf_map_def { 179 enum map_def_parts parts; 180 __u32 map_type; 181 __u32 key_type_id; 182 __u32 key_size; 183 __u32 value_type_id; 184 __u32 value_size; 185 __u32 max_entries; 186 __u32 map_flags; 187 __u32 numa_node; 188 __u32 pinning; 189 }; 190 191 int parse_btf_map_def(const char *map_name, struct btf *btf, 192 const struct btf_type *def_t, bool strict, 193 struct btf_map_def *map_def, struct btf_map_def *inner_def); 194 195 void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 196 size_t cur_cnt, size_t max_cnt, size_t add_cnt); 197 int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); 198 199 static inline bool libbpf_is_mem_zeroed(const char *p, ssize_t len) 200 { 201 while (len > 0) { 202 if (*p) 203 return false; 204 p++; 205 len--; 206 } 207 return true; 208 } 209 210 static inline bool libbpf_validate_opts(const char *opts, 211 size_t opts_sz, size_t user_sz, 212 const char *type_name) 213 { 214 if (user_sz < sizeof(size_t)) { 215 pr_warn("%s size (%zu) is too small\n", type_name, user_sz); 216 return false; 217 } 218 if (!libbpf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { 219 pr_warn("%s has non-zero extra bytes\n", type_name); 220 return false; 221 } 222 return true; 223 } 224 225 #define OPTS_VALID(opts, type) \ 226 (!(opts) || libbpf_validate_opts((const char *)opts, \ 227 offsetofend(struct type, \ 228 type##__last_field), \ 229 (opts)->sz, #type)) 230 #define OPTS_HAS(opts, field) \ 231 ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) 232 #define OPTS_GET(opts, field, fallback_value) \ 233 (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) 234 #define OPTS_SET(opts, field, value) \ 235 do { \ 236 if (OPTS_HAS(opts, field)) \ 237 (opts)->field = value; \ 238 } while (0) 239 240 #define OPTS_ZEROED(opts, last_nonzero_field) \ 241 ({ \ 242 ssize_t __off = offsetofend(typeof(*(opts)), last_nonzero_field); \ 243 !(opts) || libbpf_is_mem_zeroed((const void *)opts + __off, \ 244 (opts)->sz - __off); \ 245 }) 246 247 248 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); 249 int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); 250 int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 251 const char *str_sec, size_t str_len); 252 253 struct bpf_prog_load_params { 254 enum bpf_prog_type prog_type; 255 enum bpf_attach_type expected_attach_type; 256 const char *name; 257 const struct bpf_insn *insns; 258 size_t insn_cnt; 259 const char *license; 260 __u32 kern_version; 261 __u32 attach_prog_fd; 262 __u32 attach_btf_obj_fd; 263 __u32 attach_btf_id; 264 __u32 prog_ifindex; 265 __u32 prog_btf_fd; 266 __u32 prog_flags; 267 268 __u32 func_info_rec_size; 269 const void *func_info; 270 __u32 func_info_cnt; 271 272 __u32 line_info_rec_size; 273 const void *line_info; 274 __u32 line_info_cnt; 275 276 __u32 log_level; 277 char *log_buf; 278 size_t log_buf_sz; 279 }; 280 281 int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr); 282 283 int bpf_object__section_size(const struct bpf_object *obj, const char *name, 284 __u32 *size); 285 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, 286 __u32 *off); 287 struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf); 288 void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, 289 const char **prefix, int *kind); 290 291 struct btf_ext_info { 292 /* 293 * info points to the individual info section (e.g. func_info and 294 * line_info) from the .BTF.ext. It does not include the __u32 rec_size. 295 */ 296 void *info; 297 __u32 rec_size; 298 __u32 len; 299 }; 300 301 #define for_each_btf_ext_sec(seg, sec) \ 302 for (sec = (seg)->info; \ 303 (void *)sec < (seg)->info + (seg)->len; \ 304 sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \ 305 (seg)->rec_size * sec->num_info) 306 307 #define for_each_btf_ext_rec(seg, sec, i, rec) \ 308 for (i = 0, rec = (void *)&(sec)->data; \ 309 i < (sec)->num_info; \ 310 i++, rec = (void *)rec + (seg)->rec_size) 311 312 /* 313 * The .BTF.ext ELF section layout defined as 314 * struct btf_ext_header 315 * func_info subsection 316 * 317 * The func_info subsection layout: 318 * record size for struct bpf_func_info in the func_info subsection 319 * struct btf_sec_func_info for section #1 320 * a list of bpf_func_info records for section #1 321 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 322 * but may not be identical 323 * struct btf_sec_func_info for section #2 324 * a list of bpf_func_info records for section #2 325 * ...... 326 * 327 * Note that the bpf_func_info record size in .BTF.ext may not 328 * be the same as the one defined in include/uapi/linux/bpf.h. 329 * The loader should ensure that record_size meets minimum 330 * requirement and pass the record as is to the kernel. The 331 * kernel will handle the func_info properly based on its contents. 332 */ 333 struct btf_ext_header { 334 __u16 magic; 335 __u8 version; 336 __u8 flags; 337 __u32 hdr_len; 338 339 /* All offsets are in bytes relative to the end of this header */ 340 __u32 func_info_off; 341 __u32 func_info_len; 342 __u32 line_info_off; 343 __u32 line_info_len; 344 345 /* optional part of .BTF.ext header */ 346 __u32 core_relo_off; 347 __u32 core_relo_len; 348 }; 349 350 struct btf_ext { 351 union { 352 struct btf_ext_header *hdr; 353 void *data; 354 }; 355 struct btf_ext_info func_info; 356 struct btf_ext_info line_info; 357 struct btf_ext_info core_relo_info; 358 __u32 data_size; 359 }; 360 361 struct btf_ext_info_sec { 362 __u32 sec_name_off; 363 __u32 num_info; 364 /* Followed by num_info * record_size number of bytes */ 365 __u8 data[]; 366 }; 367 368 /* The minimum bpf_func_info checked by the loader */ 369 struct bpf_func_info_min { 370 __u32 insn_off; 371 __u32 type_id; 372 }; 373 374 /* The minimum bpf_line_info checked by the loader */ 375 struct bpf_line_info_min { 376 __u32 insn_off; 377 __u32 file_name_off; 378 __u32 line_off; 379 __u32 line_col; 380 }; 381 382 383 typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); 384 typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); 385 int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx); 386 int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx); 387 int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); 388 int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); 389 390 extern enum libbpf_strict_mode libbpf_mode; 391 392 /* handle direct returned errors */ 393 static inline int libbpf_err(int ret) 394 { 395 if (ret < 0) 396 errno = -ret; 397 return ret; 398 } 399 400 /* handle errno-based (e.g., syscall or libc) errors according to libbpf's 401 * strict mode settings 402 */ 403 static inline int libbpf_err_errno(int ret) 404 { 405 if (libbpf_mode & LIBBPF_STRICT_DIRECT_ERRS) 406 /* errno is already assumed to be set on error */ 407 return ret < 0 ? -errno : ret; 408 409 /* legacy: on error return -1 directly and don't touch errno */ 410 return ret; 411 } 412 413 /* handle error for pointer-returning APIs, err is assumed to be < 0 always */ 414 static inline void *libbpf_err_ptr(int err) 415 { 416 /* set errno on error, this doesn't break anything */ 417 errno = -err; 418 419 if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) 420 return NULL; 421 422 /* legacy: encode err as ptr */ 423 return ERR_PTR(err); 424 } 425 426 /* handle pointer-returning APIs' error handling */ 427 static inline void *libbpf_ptr(void *ret) 428 { 429 /* set errno on error, this doesn't break anything */ 430 if (IS_ERR(ret)) 431 errno = -PTR_ERR(ret); 432 433 if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) 434 return IS_ERR(ret) ? NULL : ret; 435 436 /* legacy: pass-through original pointer */ 437 return ret; 438 } 439 440 static inline bool str_is_empty(const char *s) 441 { 442 return !s || !s[0]; 443 } 444 445 static inline bool is_ldimm64_insn(struct bpf_insn *insn) 446 { 447 return insn->code == (BPF_LD | BPF_IMM | BPF_DW); 448 } 449 450 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ 451