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 <byteswap.h> 14 #include <limits.h> 15 #include <errno.h> 16 #include <linux/err.h> 17 #include <fcntl.h> 18 #include <unistd.h> 19 #include <sys/syscall.h> 20 #include <libelf.h> 21 #include "relo_core.h" 22 23 /* Android's libc doesn't support AT_EACCESS in faccessat() implementation 24 * ([0]), and just returns -EINVAL even if file exists and is accessible. 25 * See [1] for issues caused by this. 26 * 27 * So just redefine it to 0 on Android. 28 * 29 * [0] https://android.googlesource.com/platform/bionic/+/refs/heads/android13-release/libc/bionic/faccessat.cpp#50 30 * [1] https://github.com/libbpf/libbpf-bootstrap/issues/250#issuecomment-1911324250 31 */ 32 #ifdef __ANDROID__ 33 #undef AT_EACCESS 34 #define AT_EACCESS 0 35 #endif 36 37 /* make sure libbpf doesn't use kernel-only integer typedefs */ 38 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 39 40 /* prevent accidental re-addition of reallocarray() */ 41 #pragma GCC poison reallocarray 42 43 #include "libbpf.h" 44 #include "btf.h" 45 46 #ifndef EM_BPF 47 #define EM_BPF 247 48 #endif 49 50 #ifndef R_BPF_64_64 51 #define R_BPF_64_64 1 52 #endif 53 #ifndef R_BPF_64_ABS64 54 #define R_BPF_64_ABS64 2 55 #endif 56 #ifndef R_BPF_64_ABS32 57 #define R_BPF_64_ABS32 3 58 #endif 59 #ifndef R_BPF_64_32 60 #define R_BPF_64_32 10 61 #endif 62 63 #ifndef SHT_LLVM_ADDRSIG 64 #define SHT_LLVM_ADDRSIG 0x6FFF4C03 65 #endif 66 67 /* if libelf is old and doesn't support mmap(), fall back to read() */ 68 #ifndef ELF_C_READ_MMAP 69 #define ELF_C_READ_MMAP ELF_C_READ 70 #endif 71 72 /* Older libelf all end up in this expression, for both 32 and 64 bit */ 73 #ifndef ELF64_ST_VISIBILITY 74 #define ELF64_ST_VISIBILITY(o) ((o) & 0x03) 75 #endif 76 77 #define JUMPTABLES_SEC ".jumptables" 78 79 #define BTF_INFO_ENC(kind, kind_flag, vlen) \ 80 ((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN)) 81 #define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type) 82 #define BTF_INT_ENC(encoding, bits_offset, nr_bits) \ 83 ((encoding) << 24 | (bits_offset) << 16 | (nr_bits)) 84 #define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \ 85 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \ 86 BTF_INT_ENC(encoding, bits_offset, bits) 87 #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset) 88 #define BTF_PARAM_ENC(name, type) (name), (type) 89 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size) 90 #define BTF_TYPE_FLOAT_ENC(name, sz) \ 91 BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) 92 #define BTF_TYPE_DECL_TAG_ENC(value, type, component_idx) \ 93 BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), type), (component_idx) 94 #define BTF_TYPE_TYPE_TAG_ENC(value, type) \ 95 BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TYPE_TAG, 0, 0), type) 96 97 #ifndef likely 98 #define likely(x) __builtin_expect(!!(x), 1) 99 #endif 100 #ifndef unlikely 101 #define unlikely(x) __builtin_expect(!!(x), 0) 102 #endif 103 #ifndef min 104 # define min(x, y) ((x) < (y) ? (x) : (y)) 105 #endif 106 #ifndef max 107 # define max(x, y) ((x) < (y) ? (y) : (x)) 108 #endif 109 #ifndef offsetofend 110 # define offsetofend(TYPE, FIELD) \ 111 (offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD)) 112 #endif 113 #ifndef __alias 114 #define __alias(symbol) __attribute__((alias(#symbol))) 115 #endif 116 117 /* Check whether a string `str` has prefix `pfx`, regardless if `pfx` is 118 * a string literal known at compilation time or char * pointer known only at 119 * runtime. 120 */ 121 #define str_has_pfx(str, pfx) \ 122 (strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0) 123 124 /* suffix check */ 125 static inline bool str_has_sfx(const char *str, const char *sfx) 126 { 127 size_t str_len = strlen(str); 128 size_t sfx_len = strlen(sfx); 129 130 if (sfx_len > str_len) 131 return false; 132 return strcmp(str + str_len - sfx_len, sfx) == 0; 133 } 134 135 /* Symbol versioning is different between static and shared library. 136 * Properly versioned symbols are needed for shared library, but 137 * only the symbol of the new version is needed for static library. 138 * Starting with GNU C 10, use symver attribute instead of .symver assembler 139 * directive, which works better with GCC LTO builds. 140 */ 141 #if defined(SHARED) && defined(__GNUC__) && __GNUC__ >= 10 142 143 #define DEFAULT_VERSION(internal_name, api_name, version) \ 144 __attribute__((symver(#api_name "@@" #version))) 145 #define COMPAT_VERSION(internal_name, api_name, version) \ 146 __attribute__((symver(#api_name "@" #version))) 147 148 #elif defined(SHARED) 149 150 #define COMPAT_VERSION(internal_name, api_name, version) \ 151 asm(".symver " #internal_name "," #api_name "@" #version); 152 #define DEFAULT_VERSION(internal_name, api_name, version) \ 153 asm(".symver " #internal_name "," #api_name "@@" #version); 154 155 #else /* !SHARED */ 156 157 #define COMPAT_VERSION(internal_name, api_name, version) 158 #define DEFAULT_VERSION(internal_name, api_name, version) \ 159 extern typeof(internal_name) api_name \ 160 __attribute__((alias(#internal_name))); 161 162 #endif 163 164 extern void libbpf_print(enum libbpf_print_level level, 165 const char *format, ...) 166 __attribute__((format(printf, 2, 3))); 167 168 #define __pr(level, fmt, ...) \ 169 do { \ 170 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ 171 } while (0) 172 173 #define pr_warn(fmt, ...) __pr(LIBBPF_WARN, fmt, ##__VA_ARGS__) 174 #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) 175 #define pr_debug(fmt, ...) __pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__) 176 177 /** 178 * @brief **libbpf_errstr()** returns string corresponding to numeric errno 179 * @param err negative numeric errno 180 * @return pointer to string representation of the errno, that is invalidated 181 * upon the next call. 182 */ 183 const char *libbpf_errstr(int err); 184 185 #define errstr(err) libbpf_errstr(err) 186 187 #ifndef __has_builtin 188 #define __has_builtin(x) 0 189 #endif 190 191 struct bpf_link { 192 int (*detach)(struct bpf_link *link); 193 void (*dealloc)(struct bpf_link *link); 194 char *pin_path; /* NULL, if not pinned */ 195 int fd; /* hook FD, -1 if not applicable */ 196 bool disconnected; 197 }; 198 199 /* 200 * Re-implement glibc's reallocarray() for libbpf internal-only use. 201 * reallocarray(), unfortunately, is not available in all versions of glibc, 202 * so requires extra feature detection and using reallocarray() stub from 203 * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates 204 * build of libbpf unnecessarily and is just a maintenance burden. Instead, 205 * it's trivial to implement libbpf-specific internal version and use it 206 * throughout libbpf. 207 */ 208 static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size) 209 { 210 size_t total; 211 212 #if __has_builtin(__builtin_mul_overflow) 213 if (unlikely(__builtin_mul_overflow(nmemb, size, &total))) 214 return NULL; 215 #else 216 if (size == 0 || nmemb > ULONG_MAX / size) 217 return NULL; 218 total = nmemb * size; 219 #endif 220 return realloc(ptr, total); 221 } 222 223 /* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst 224 * is zero-terminated string no matter what (unless sz == 0, in which case 225 * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs 226 * in what is returned. Given this is internal helper, it's trivial to extend 227 * this, when necessary. Use this instead of strncpy inside libbpf source code. 228 */ 229 static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz) 230 { 231 size_t i; 232 233 if (sz == 0) 234 return; 235 236 sz--; 237 for (i = 0; i < sz && src[i]; i++) 238 dst[i] = src[i]; 239 dst[i] = '\0'; 240 } 241 242 __u32 get_kernel_version(void); 243 244 struct btf; 245 struct btf_type; 246 247 struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id); 248 const char *btf_kind_str(const struct btf_type *t); 249 const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id); 250 const struct btf_header *btf_header(const struct btf *btf); 251 void btf_set_base_btf(struct btf *btf, const struct btf *base_btf); 252 int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **id_map); 253 254 static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t) 255 { 256 return (enum btf_func_linkage)(int)btf_vlen(t); 257 } 258 259 static inline __u32 btf_type_info(int kind, int vlen, int kflag) 260 { 261 return (kflag << 31) | (kind << 24) | vlen; 262 } 263 264 enum map_def_parts { 265 MAP_DEF_MAP_TYPE = 0x001, 266 MAP_DEF_KEY_TYPE = 0x002, 267 MAP_DEF_KEY_SIZE = 0x004, 268 MAP_DEF_VALUE_TYPE = 0x008, 269 MAP_DEF_VALUE_SIZE = 0x010, 270 MAP_DEF_MAX_ENTRIES = 0x020, 271 MAP_DEF_MAP_FLAGS = 0x040, 272 MAP_DEF_NUMA_NODE = 0x080, 273 MAP_DEF_PINNING = 0x100, 274 MAP_DEF_INNER_MAP = 0x200, 275 MAP_DEF_MAP_EXTRA = 0x400, 276 277 MAP_DEF_ALL = 0x7ff, /* combination of all above */ 278 }; 279 280 struct btf_map_def { 281 enum map_def_parts parts; 282 __u32 map_type; 283 __u32 key_type_id; 284 __u32 key_size; 285 __u32 value_type_id; 286 __u32 value_size; 287 __u32 max_entries; 288 __u32 map_flags; 289 __u32 numa_node; 290 __u32 pinning; 291 __u64 map_extra; 292 }; 293 294 int parse_btf_map_def(const char *map_name, struct btf *btf, 295 const struct btf_type *def_t, bool strict, 296 struct btf_map_def *map_def, struct btf_map_def *inner_def); 297 298 void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz, 299 size_t cur_cnt, size_t max_cnt, size_t add_cnt); 300 int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt); 301 302 static inline bool libbpf_is_mem_zeroed(const char *p, ssize_t len) 303 { 304 while (len > 0) { 305 if (*p) 306 return false; 307 p++; 308 len--; 309 } 310 return true; 311 } 312 313 static inline bool libbpf_validate_opts(const char *opts, 314 size_t opts_sz, size_t user_sz, 315 const char *type_name) 316 { 317 if (user_sz < sizeof(size_t)) { 318 pr_warn("%s size (%zu) is too small\n", type_name, user_sz); 319 return false; 320 } 321 if (!libbpf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) { 322 pr_warn("%s has non-zero extra bytes\n", type_name); 323 return false; 324 } 325 return true; 326 } 327 328 #define OPTS_VALID(opts, type) \ 329 (!(opts) || libbpf_validate_opts((const char *)opts, \ 330 offsetofend(struct type, \ 331 type##__last_field), \ 332 (opts)->sz, #type)) 333 #define OPTS_HAS(opts, field) \ 334 ((opts) && opts->sz >= offsetofend(typeof(*(opts)), field)) 335 #define OPTS_GET(opts, field, fallback_value) \ 336 (OPTS_HAS(opts, field) ? (opts)->field : fallback_value) 337 #define OPTS_SET(opts, field, value) \ 338 do { \ 339 if (OPTS_HAS(opts, field)) \ 340 (opts)->field = value; \ 341 } while (0) 342 343 #define OPTS_ZEROED(opts, last_nonzero_field) \ 344 ({ \ 345 ssize_t __off = offsetofend(typeof(*(opts)), last_nonzero_field); \ 346 !(opts) || libbpf_is_mem_zeroed((const void *)opts + __off, \ 347 (opts)->sz - __off); \ 348 }) 349 350 enum kern_feature_id { 351 /* v4.14: kernel support for program & map names. */ 352 FEAT_PROG_NAME, 353 /* v5.2: kernel support for global data sections. */ 354 FEAT_GLOBAL_DATA, 355 /* BTF support */ 356 FEAT_BTF, 357 /* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */ 358 FEAT_BTF_FUNC, 359 /* BTF_KIND_VAR and BTF_KIND_DATASEC support */ 360 FEAT_BTF_DATASEC, 361 /* BTF_FUNC_GLOBAL is supported */ 362 FEAT_BTF_GLOBAL_FUNC, 363 /* BPF_F_MMAPABLE is supported for arrays */ 364 FEAT_ARRAY_MMAP, 365 /* kernel support for expected_attach_type in BPF_PROG_LOAD */ 366 FEAT_EXP_ATTACH_TYPE, 367 /* bpf_probe_read_{kernel,user}[_str] helpers */ 368 FEAT_PROBE_READ_KERN, 369 /* BPF_PROG_BIND_MAP is supported */ 370 FEAT_PROG_BIND_MAP, 371 /* Kernel support for module BTFs */ 372 FEAT_MODULE_BTF, 373 /* BTF_KIND_FLOAT support */ 374 FEAT_BTF_FLOAT, 375 /* BPF perf link support */ 376 FEAT_PERF_LINK, 377 /* BTF_KIND_DECL_TAG support */ 378 FEAT_BTF_DECL_TAG, 379 /* BTF_KIND_TYPE_TAG support */ 380 FEAT_BTF_TYPE_TAG, 381 /* memcg-based accounting for BPF maps and progs */ 382 FEAT_MEMCG_ACCOUNT, 383 /* BPF cookie (bpf_get_attach_cookie() BPF helper) support */ 384 FEAT_BPF_COOKIE, 385 /* BTF_KIND_ENUM64 support and BTF_KIND_ENUM kflag support */ 386 FEAT_BTF_ENUM64, 387 /* Kernel uses syscall wrapper (CONFIG_ARCH_HAS_SYSCALL_WRAPPER) */ 388 FEAT_SYSCALL_WRAPPER, 389 /* BPF multi-uprobe link support */ 390 FEAT_UPROBE_MULTI_LINK, 391 /* Kernel supports arg:ctx tag (__arg_ctx) for global subprogs natively */ 392 FEAT_ARG_CTX_TAG, 393 /* Kernel supports '?' at the front of datasec names */ 394 FEAT_BTF_QMARK_DATASEC, 395 /* Kernel supports LDIMM64 imm offsets past 512 MiB. */ 396 FEAT_LDIMM64_FULL_RANGE_OFF, 397 /* Kernel supports uprobe syscall */ 398 FEAT_UPROBE_SYSCALL, 399 /* Kernel supports BTF layout information */ 400 FEAT_BTF_LAYOUT, 401 __FEAT_CNT, 402 }; 403 404 enum kern_feature_result { 405 FEAT_UNKNOWN = 0, 406 FEAT_SUPPORTED = 1, 407 FEAT_MISSING = 2, 408 }; 409 410 struct kern_feature_cache { 411 enum kern_feature_result res[__FEAT_CNT]; 412 int token_fd; 413 }; 414 415 bool feat_supported(struct kern_feature_cache *cache, enum kern_feature_id feat_id); 416 bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id); 417 void bpf_object_set_feat_cache(struct bpf_object *obj, struct kern_feature_cache *cache); 418 419 int probe_kern_syscall_wrapper(int token_fd); 420 int probe_memcg_account(int token_fd); 421 int bump_rlimit_memlock(void); 422 423 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz); 424 int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz); 425 int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 426 const char *str_sec, size_t str_len, 427 int token_fd); 428 int libbpf__load_raw_btf_hdr(const struct btf_header *hdr, 429 const char *raw_types, const char *str_sec, 430 const char *layout_sec, int token_fd); 431 struct btf *bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *orig_btf); 432 int btf_load_into_kernel(struct btf *btf, 433 char *log_buf, size_t log_sz, __u32 log_level, 434 int token_fd); 435 struct btf *btf_load_from_kernel(__u32 id, struct btf *base_btf, int token_fd); 436 437 struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf); 438 void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, 439 const char **prefix, int *kind); 440 441 struct btf_ext_info { 442 /* 443 * info points to the individual info section (e.g. func_info and 444 * line_info) from the .BTF.ext. It does not include the __u32 rec_size. 445 */ 446 void *info; 447 __u32 rec_size; 448 __u32 len; 449 /* optional (maintained internally by libbpf) mapping between .BTF.ext 450 * section and corresponding ELF section. This is used to join 451 * information like CO-RE relocation records with corresponding BPF 452 * programs defined in ELF sections 453 */ 454 __u32 *sec_idxs; 455 int sec_cnt; 456 }; 457 458 #define for_each_btf_ext_sec(seg, sec) \ 459 for (sec = (seg)->info; \ 460 (void *)sec < (seg)->info + (seg)->len; \ 461 sec = (void *)sec + sizeof(struct btf_ext_info_sec) + \ 462 (seg)->rec_size * sec->num_info) 463 464 #define for_each_btf_ext_rec(seg, sec, i, rec) \ 465 for (i = 0, rec = (void *)&(sec)->data; \ 466 i < (sec)->num_info; \ 467 i++, rec = (void *)rec + (seg)->rec_size) 468 469 /* 470 * The .BTF.ext ELF section layout defined as 471 * struct btf_ext_header 472 * func_info subsection 473 * 474 * The func_info subsection layout: 475 * record size for struct bpf_func_info in the func_info subsection 476 * struct btf_ext_info_sec for section #1 477 * a list of bpf_func_info records for section #1 478 * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h 479 * but may not be identical 480 * struct btf_ext_info_sec for section #2 481 * a list of bpf_func_info records for section #2 482 * ...... 483 * 484 * Note that the bpf_func_info record size in .BTF.ext may not 485 * be the same as the one defined in include/uapi/linux/bpf.h. 486 * The loader should ensure that record_size meets minimum 487 * requirement and pass the record as is to the kernel. The 488 * kernel will handle the func_info properly based on its contents. 489 */ 490 struct btf_ext_header { 491 __u16 magic; 492 __u8 version; 493 __u8 flags; 494 __u32 hdr_len; 495 496 /* All offsets are in bytes relative to the end of this header */ 497 __u32 func_info_off; 498 __u32 func_info_len; 499 __u32 line_info_off; 500 __u32 line_info_len; 501 502 /* optional part of .BTF.ext header */ 503 __u32 core_relo_off; 504 __u32 core_relo_len; 505 }; 506 507 struct btf_ext { 508 union { 509 struct btf_ext_header *hdr; 510 void *data; 511 }; 512 void *data_swapped; 513 bool swapped_endian; 514 struct btf_ext_info func_info; 515 struct btf_ext_info line_info; 516 struct btf_ext_info core_relo_info; 517 __u32 data_size; 518 }; 519 520 struct btf_ext_info_sec { 521 __u32 sec_name_off; 522 __u32 num_info; 523 /* Followed by num_info * record_size number of bytes */ 524 __u8 data[]; 525 }; 526 527 /* The minimum bpf_func_info checked by the loader */ 528 struct bpf_func_info_min { 529 __u32 insn_off; 530 __u32 type_id; 531 }; 532 533 /* The minimum bpf_line_info checked by the loader */ 534 struct bpf_line_info_min { 535 __u32 insn_off; 536 __u32 file_name_off; 537 __u32 line_off; 538 __u32 line_col; 539 }; 540 541 /* Functions to byte-swap info records */ 542 543 typedef void (*info_rec_bswap_fn)(void *); 544 545 static inline void bpf_func_info_bswap(struct bpf_func_info *i) 546 { 547 i->insn_off = bswap_32(i->insn_off); 548 i->type_id = bswap_32(i->type_id); 549 } 550 551 static inline void bpf_line_info_bswap(struct bpf_line_info *i) 552 { 553 i->insn_off = bswap_32(i->insn_off); 554 i->file_name_off = bswap_32(i->file_name_off); 555 i->line_off = bswap_32(i->line_off); 556 i->line_col = bswap_32(i->line_col); 557 } 558 559 static inline void bpf_core_relo_bswap(struct bpf_core_relo *i) 560 { 561 i->insn_off = bswap_32(i->insn_off); 562 i->type_id = bswap_32(i->type_id); 563 i->access_str_off = bswap_32(i->access_str_off); 564 i->kind = bswap_32(i->kind); 565 } 566 567 enum btf_field_iter_kind { 568 BTF_FIELD_ITER_IDS, 569 BTF_FIELD_ITER_STRS, 570 }; 571 572 struct btf_field_desc { 573 /* once-per-type offsets */ 574 int t_off_cnt, t_offs[2]; 575 /* member struct size, or zero, if no members */ 576 int m_sz; 577 /* repeated per-member offsets */ 578 int m_off_cnt, m_offs[1]; 579 }; 580 581 struct btf_field_iter { 582 struct btf_field_desc desc; 583 void *p; 584 int m_idx; 585 int off_idx; 586 int vlen; 587 }; 588 589 int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t, enum btf_field_iter_kind iter_kind); 590 __u32 *btf_field_iter_next(struct btf_field_iter *it); 591 592 typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx); 593 typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx); 594 int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx); 595 int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx); 596 __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name, 597 __u32 kind); 598 599 /* handle direct returned errors */ 600 static inline int libbpf_err(int ret) 601 { 602 if (ret < 0) 603 errno = -ret; 604 return ret; 605 } 606 607 /* handle errno-based (e.g., syscall or libc) errors according to libbpf's 608 * strict mode settings 609 */ 610 static inline int libbpf_err_errno(int ret) 611 { 612 /* errno is already assumed to be set on error */ 613 return ret < 0 ? -errno : ret; 614 } 615 616 /* handle error for pointer-returning APIs, err is assumed to be < 0 always */ 617 static inline void *libbpf_err_ptr(int err) 618 { 619 /* set errno on error, this doesn't break anything */ 620 errno = -err; 621 return NULL; 622 } 623 624 /* handle pointer-returning APIs' error handling */ 625 static inline void *libbpf_ptr(void *ret) 626 { 627 /* set errno on error, this doesn't break anything */ 628 if (IS_ERR(ret)) 629 errno = -PTR_ERR(ret); 630 631 return IS_ERR(ret) ? NULL : ret; 632 } 633 634 static inline bool str_is_empty(const char *s) 635 { 636 return !s || !s[0]; 637 } 638 639 static inline bool is_ldimm64_insn(struct bpf_insn *insn) 640 { 641 return insn->code == (BPF_LD | BPF_IMM | BPF_DW); 642 } 643 644 static inline void bpf_insn_bswap(struct bpf_insn *insn) 645 { 646 __u8 tmp_reg = insn->dst_reg; 647 648 insn->dst_reg = insn->src_reg; 649 insn->src_reg = tmp_reg; 650 insn->off = bswap_16(insn->off); 651 insn->imm = bswap_32(insn->imm); 652 } 653 654 /* Unconditionally dup FD, ensuring it doesn't use [0, 2] range. 655 * Original FD is not closed or altered in any other way. 656 * Preserves original FD value, if it's invalid (negative). 657 */ 658 static inline int dup_good_fd(int fd) 659 { 660 if (fd < 0) 661 return fd; 662 return fcntl(fd, F_DUPFD_CLOEXEC, 3); 663 } 664 665 /* if fd is stdin, stdout, or stderr, dup to a fd greater than 2 666 * Takes ownership of the fd passed in, and closes it if calling 667 * fcntl(fd, F_DUPFD_CLOEXEC, 3). 668 */ 669 static inline int ensure_good_fd(int fd) 670 { 671 int old_fd = fd, saved_errno; 672 673 if (fd < 0) 674 return fd; 675 if (fd < 3) { 676 fd = dup_good_fd(fd); 677 saved_errno = errno; 678 close(old_fd); 679 errno = saved_errno; 680 if (fd < 0) { 681 pr_warn("failed to dup FD %d to FD > 2: %d\n", old_fd, -saved_errno); 682 errno = saved_errno; 683 } 684 } 685 return fd; 686 } 687 688 static inline int sys_dup3(int oldfd, int newfd, int flags) 689 { 690 return syscall(__NR_dup3, oldfd, newfd, flags); 691 } 692 693 /* Some versions of Android don't provide memfd_create() in their libc 694 * implementation, so avoid complications and just go straight to Linux 695 * syscall. 696 */ 697 static inline int sys_memfd_create(const char *name, unsigned flags) 698 { 699 return syscall(__NR_memfd_create, name, flags); 700 } 701 702 /* Point *fixed_fd* to the same file that *tmp_fd* points to. 703 * Regardless of success, *tmp_fd* is closed. 704 * Whatever *fixed_fd* pointed to is closed silently. 705 */ 706 static inline int reuse_fd(int fixed_fd, int tmp_fd) 707 { 708 int err; 709 710 err = sys_dup3(tmp_fd, fixed_fd, O_CLOEXEC); 711 err = err < 0 ? -errno : 0; 712 close(tmp_fd); /* clean up temporary FD */ 713 return err; 714 } 715 716 /* The following two functions are exposed to bpftool */ 717 int bpf_core_add_cands(struct bpf_core_cand *local_cand, 718 size_t local_essent_len, 719 const struct btf *targ_btf, 720 const char *targ_btf_name, 721 int targ_start_id, 722 struct bpf_core_cand_list *cands); 723 void bpf_core_free_cands(struct bpf_core_cand_list *cands); 724 725 struct usdt_manager *usdt_manager_new(struct bpf_object *obj); 726 void usdt_manager_free(struct usdt_manager *man); 727 struct bpf_link * usdt_manager_attach_usdt(struct usdt_manager *man, 728 const struct bpf_program *prog, 729 pid_t pid, const char *path, 730 const char *usdt_provider, const char *usdt_name, 731 __u64 usdt_cookie); 732 733 static inline bool is_pow_of_2(size_t x) 734 { 735 return x && (x & (x - 1)) == 0; 736 } 737 738 static inline __u32 ror32(__u32 v, int bits) 739 { 740 return (v >> bits) | (v << (32 - bits)); 741 } 742 743 #define PROG_LOAD_ATTEMPTS 5 744 int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts); 745 746 bool glob_match(const char *str, const char *pat); 747 748 long elf_find_func_offset(Elf *elf, const char *binary_path, const char *name); 749 long elf_find_func_offset_from_file(const char *binary_path, const char *name); 750 751 struct elf_fd { 752 Elf *elf; 753 int fd; 754 }; 755 756 int elf_open(const char *binary_path, struct elf_fd *elf_fd); 757 void elf_close(struct elf_fd *elf_fd); 758 759 int elf_resolve_syms_offsets(const char *binary_path, int cnt, 760 const char **syms, unsigned long **poffsets, 761 int st_type); 762 int elf_resolve_pattern_offsets(const char *binary_path, const char *pattern, 763 unsigned long **poffsets, size_t *pcnt); 764 765 int probe_fd(int fd); 766 767 #define SHA256_DIGEST_LENGTH 32 768 #define SHA256_DWORD_SIZE SHA256_DIGEST_LENGTH / sizeof(__u64) 769 770 void libbpf_sha256(const void *data, size_t len, __u8 out[SHA256_DIGEST_LENGTH]); 771 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ 772