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 #define BTF_TYPE_TAG_ENC(value, type, component_idx) \ 73 BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TAG, 0, 0), type), (component_idx) 74 75 #ifndef likely 76 #define likely(x) __builtin_expect(!!(x), 1) 77 #endif 78 #ifndef unlikely 79 #define unlikely(x) __builtin_expect(!!(x), 0) 80 #endif 81 #ifndef min 82 # define min(x, y) ((x) < (y) ? (x) : (y)) 83 #endif 84 #ifndef max 85 # define max(x, y) ((x) < (y) ? (y) : (x)) 86 #endif 87 #ifndef offsetofend 88 # define offsetofend(TYPE, FIELD) \ 89 (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) 90 #endif 91 92 /* Check whether a string `str` has prefix `pfx`, regardless if `pfx` is 93 * a string literal known at compilation time or char * pointer known only at 94 * runtime. 95 */ 96 #define str_has_pfx(str, pfx) \ 97 (strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0) 98 99 /* Symbol versioning is different between static and shared library. 100 * Properly versioned symbols are needed for shared library, but 101 * only the symbol of the new version is needed for static library. 102 * Starting with GNU C 10, use symver attribute instead of .symver assembler 103 * directive, which works better with GCC LTO builds. 104 */ 105 #if defined(SHARED) && defined(__GNUC__) && __GNUC__ >= 10 106 107 #define DEFAULT_VERSION(internal_name, api_name, version) \ 108 __attribute__((symver(#api_name "@@" #version))) 109 #define COMPAT_VERSION(internal_name, api_name, version) \ 110 __attribute__((symver(#api_name "@" #version))) 111 112 #elif defined(SHARED) 113 114 #define COMPAT_VERSION(internal_name, api_name, version) \ 115 asm(".symver " #internal_name "," #api_name "@" #version); 116 #define DEFAULT_VERSION(internal_name, api_name, version) \ 117 asm(".symver " #internal_name "," #api_name "@@" #version); 118 119 #else /* !SHARED */ 120 121 #define COMPAT_VERSION(internal_name, api_name, version) 122 #define DEFAULT_VERSION(internal_name, api_name, version) \ 123 extern typeof(internal_name) api_name \ 124 __attribute__((alias(#internal_name))); 125 126 #endif 127 128 extern void libbpf_print(enum libbpf_print_level level, 129 const char *format, ...) 130 __attribute__((format(printf, 2, 3))); 131 132 #define __pr(level, fmt, ...) \ 133 do { \ 134 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ 135 } while (0) 136 137 #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) 138 #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) 139 #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) 140 141 #ifndef __has_builtin 142 #define __has_builtin(x) 0 143 #endif 144 /* 145 * Re-implement glibc's reallocarray() for libbpf internal-only use. 146 * reallocarray(), unfortunately, is not available in all versions of glibc, 147 * so requires extra feature detection and using reallocarray() stub from 148 * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates 149 * build of libbpf unnecessarily and is just a maintenance burden. Instead, 150 * it's trivial to implement libbpf-specific internal version and use it 151 * throughout libbpf. 152 */ 153 static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) 154 { 155 size_t total; 156 157 #if __has_builtin(__builtin_mul_overflow) 158 if (unlikely(__builtin_mul_overflow(nmemb, size, &total))) 159 return NULL; 160 #else 161 if (size == 0 || nmemb > ULONG_MAX / size) 162 return NULL; 163 total = nmemb * size; 164 #endif 165 return realloc(ptr, total); 166 } 167 168 struct btf; 169 struct btf_type; 170 171 struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id); 172 const char *btf_kind_str(const struct btf_type *t); 173 const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id); 174 175 static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t) 176 { 177 return (enum btf_func_linkage)(int)btf_vlen(t); 178 } 179 180 static inline __u32 btf_type_info(int kind, int vlen, int kflag) 181 { 182 return (kflag << 31) | (kind << 24) | vlen; 183 } 184 185 enum map_def_parts { 186 MAP_DEF_MAP_TYPE = 0x001, 187 MAP_DEF_KEY_TYPE = 0x002, 188 MAP_DEF_KEY_SIZE = 0x004, 189 MAP_DEF_VALUE_TYPE = 0x008, 190 MAP_DEF_VALUE_SIZE = 0x010, 191 MAP_DEF_MAX_ENTRIES = 0x020, 192 MAP_DEF_MAP_FLAGS = 0x040, 193 MAP_DEF_NUMA_NODE = 0x080, 194 MAP_DEF_PINNING = 0x100, 195 MAP_DEF_INNER_MAP = 0x200, 196 197 MAP_DEF_ALL = 0x3ff, /* combination of all above */ 198 }; 199 200 struct btf_map_def { 201 enum map_def_parts parts; 202 __u32 map_type; 203 __u32 key_type_id; 204 __u32 key_size; 205 __u32 value_type_id; 206 __u32 value_size; 207 __u32 max_entries; 208 __u32 map_flags; 209 __u32 numa_node; 210 __u32 pinning; 211 }; 212 213 int parse_btf_map_def(const char *map_name, struct btf *btf, 214 const struct btf_type *def_t, bool strict, 215 struct btf_map_def *map_def, struct btf_map_def *inner_def); 216 217 void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 218 size_t cur_cnt, size_t max_cnt, size_t add_cnt); 219 int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); 220 221 static inline bool libbpf_is_mem_zeroed(const char *p, ssize_t len) 222 { 223 while (len > 0) { 224 if (*p) 225 return false; 226 p++; 227 len--; 228 } 229 return true; 230 } 231 232 static inline bool libbpf_validate_opts(const char *opts, 233 size_t opts_sz, size_t user_sz, 234 const char *type_name) 235 { 236 if (user_sz < sizeof(size_t)) { 237 pr_warn("%s size (%zu) is too small\n", type_name, user_sz); 238 return false; 239 } 240 if (!libbpf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { 241 pr_warn("%s has non-zero extra bytes\n", type_name); 242 return false; 243 } 244 return true; 245 } 246 247 #define OPTS_VALID(opts, type) \ 248 (!(opts) || libbpf_validate_opts((const char *)opts, \ 249 offsetofend(struct type, \ 250 type##__last_field), \ 251 (opts)->sz, #type)) 252 #define OPTS_HAS(opts, field) \ 253 ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) 254 #define OPTS_GET(opts, field, fallback_value) \ 255 (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) 256 #define OPTS_SET(opts, field, value) \ 257 do { \ 258 if (OPTS_HAS(opts, field)) \ 259 (opts)->field = value; \ 260 } while (0) 261 262 #define OPTS_ZEROED(opts, last_nonzero_field) \ 263 ({ \ 264 ssize_t __off = offsetofend(typeof(*(opts)), last_nonzero_field); \ 265 !(opts) || libbpf_is_mem_zeroed((const void *)opts + __off, \ 266 (opts)->sz - __off); \ 267 }) 268 269 270 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); 271 int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); 272 int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 273 const char *str_sec, size_t str_len); 274 275 struct bpf_prog_load_params { 276 enum bpf_prog_type prog_type; 277 enum bpf_attach_type expected_attach_type; 278 const char *name; 279 const struct bpf_insn *insns; 280 size_t insn_cnt; 281 const char *license; 282 __u32 kern_version; 283 __u32 attach_prog_fd; 284 __u32 attach_btf_obj_fd; 285 __u32 attach_btf_id; 286 __u32 prog_ifindex; 287 __u32 prog_btf_fd; 288 __u32 prog_flags; 289 290 __u32 func_info_rec_size; 291 const void *func_info; 292 __u32 func_info_cnt; 293 294 __u32 line_info_rec_size; 295 const void *line_info; 296 __u32 line_info_cnt; 297 298 __u32 log_level; 299 char *log_buf; 300 size_t log_buf_sz; 301 }; 302 303 int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr); 304 305 int bpf_object__section_size(const struct bpf_object *obj, const char *name, 306 __u32 *size); 307 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, 308 __u32 *off); 309 struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf); 310 void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, 311 const char **prefix, int *kind); 312 313 struct btf_ext_info { 314 /* 315 * info points to the individual info section (e.g. func_info and 316 * line_info) from the .BTF.ext. It does not include the __u32 rec_size. 317 */ 318 void *info; 319 __u32 rec_size; 320 __u32 len; 321 }; 322 323 #define for_each_btf_ext_sec(seg, sec) \ 324 for (sec = (seg)->info; \ 325 (void *)sec < (seg)->info + (seg)->len; \ 326 sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \ 327 (seg)->rec_size * sec->num_info) 328 329 #define for_each_btf_ext_rec(seg, sec, i, rec) \ 330 for (i = 0, rec = (void *)&(sec)->data; \ 331 i < (sec)->num_info; \ 332 i++, rec = (void *)rec + (seg)->rec_size) 333 334 /* 335 * The .BTF.ext ELF section layout defined as 336 * struct btf_ext_header 337 * func_info subsection 338 * 339 * The func_info subsection layout: 340 * record size for struct bpf_func_info in the func_info subsection 341 * struct btf_sec_func_info for section #1 342 * a list of bpf_func_info records for section #1 343 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 344 * but may not be identical 345 * struct btf_sec_func_info for section #2 346 * a list of bpf_func_info records for section #2 347 * ...... 348 * 349 * Note that the bpf_func_info record size in .BTF.ext may not 350 * be the same as the one defined in include/uapi/linux/bpf.h. 351 * The loader should ensure that record_size meets minimum 352 * requirement and pass the record as is to the kernel. The 353 * kernel will handle the func_info properly based on its contents. 354 */ 355 struct btf_ext_header { 356 __u16 magic; 357 __u8 version; 358 __u8 flags; 359 __u32 hdr_len; 360 361 /* All offsets are in bytes relative to the end of this header */ 362 __u32 func_info_off; 363 __u32 func_info_len; 364 __u32 line_info_off; 365 __u32 line_info_len; 366 367 /* optional part of .BTF.ext header */ 368 __u32 core_relo_off; 369 __u32 core_relo_len; 370 }; 371 372 struct btf_ext { 373 union { 374 struct btf_ext_header *hdr; 375 void *data; 376 }; 377 struct btf_ext_info func_info; 378 struct btf_ext_info line_info; 379 struct btf_ext_info core_relo_info; 380 __u32 data_size; 381 }; 382 383 struct btf_ext_info_sec { 384 __u32 sec_name_off; 385 __u32 num_info; 386 /* Followed by num_info * record_size number of bytes */ 387 __u8 data[]; 388 }; 389 390 /* The minimum bpf_func_info checked by the loader */ 391 struct bpf_func_info_min { 392 __u32 insn_off; 393 __u32 type_id; 394 }; 395 396 /* The minimum bpf_line_info checked by the loader */ 397 struct bpf_line_info_min { 398 __u32 insn_off; 399 __u32 file_name_off; 400 __u32 line_off; 401 __u32 line_col; 402 }; 403 404 405 typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); 406 typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); 407 int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx); 408 int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx); 409 int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); 410 int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); 411 412 extern enum libbpf_strict_mode libbpf_mode; 413 414 /* handle direct returned errors */ 415 static inline int libbpf_err(int ret) 416 { 417 if (ret < 0) 418 errno = -ret; 419 return ret; 420 } 421 422 /* handle errno-based (e.g., syscall or libc) errors according to libbpf's 423 * strict mode settings 424 */ 425 static inline int libbpf_err_errno(int ret) 426 { 427 if (libbpf_mode & LIBBPF_STRICT_DIRECT_ERRS) 428 /* errno is already assumed to be set on error */ 429 return ret < 0 ? -errno : ret; 430 431 /* legacy: on error return -1 directly and don't touch errno */ 432 return ret; 433 } 434 435 /* handle error for pointer-returning APIs, err is assumed to be < 0 always */ 436 static inline void *libbpf_err_ptr(int err) 437 { 438 /* set errno on error, this doesn't break anything */ 439 errno = -err; 440 441 if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) 442 return NULL; 443 444 /* legacy: encode err as ptr */ 445 return ERR_PTR(err); 446 } 447 448 /* handle pointer-returning APIs' error handling */ 449 static inline void *libbpf_ptr(void *ret) 450 { 451 /* set errno on error, this doesn't break anything */ 452 if (IS_ERR(ret)) 453 errno = -PTR_ERR(ret); 454 455 if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) 456 return IS_ERR(ret) ? NULL : ret; 457 458 /* legacy: pass-through original pointer */ 459 return ret; 460 } 461 462 static inline bool str_is_empty(const char *s) 463 { 464 return !s || !s[0]; 465 } 466 467 static inline bool is_ldimm64_insn(struct bpf_insn *insn) 468 { 469 return insn->code == (BPF_LD | BPF_IMM | BPF_DW); 470 } 471 472 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ 473