xref: /third_party/libbpf/src/libbpf_internal.h (revision 7c2aad20)
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 <fcntl.h>
17#include <unistd.h>
18
19#if defined HAVE_LIBELF
20#include <libelf.h>
21#include <gelf.h>
22#endif  //
23
24#ifdef HAVE_ELFIO
25#include "elfio_c_wrapper.h"
26#include <linux/memfd.h>
27#include <sys/syscall.h>
28#include <limits.h>
29typedef struct Elf64_Ehdr Elf64_Ehdr;
30typedef struct Elf64_Shdr Elf64_Shdr;
31typedef struct Elf64_Sym Elf64_Sym;
32typedef Elf64_Sym GElf_Sym;
33typedef struct Elf64_Shdr GElf_Shdr;
34typedef struct Elf64_Rel Elf64_Rel;
35typedef Elf64_Half GElf_Versym ;
36typedef struct {
37  void *d_buf;
38  size_t d_size;
39} Elf_Data;
40
41typedef struct {
42  Elf64_Word	vda_name;		/* Version or dependency names */
43  Elf64_Word	vda_next;		/* Offset in bytes to next verdaux entry */
44} GElf_Verdaux;
45
46typedef struct {
47  Elf64_Half	vd_version;		/* Version revision */
48  Elf64_Half	vd_flags;		/* Version information */
49  Elf64_Half	vd_ndx;			/* Version Index */
50  Elf64_Half	vd_cnt;			/* Number of associated aux entries */
51  Elf64_Word	vd_hash;		/* Version name hash value */
52  Elf64_Word	vd_aux;			/* Offset in bytes to verdaux array */
53  Elf64_Word	vd_next;		/* Offset in bytes to next verdef entry */
54} GElf_Verdef;
55
56#define ELF64_ST_TYPE(val) ELF_ST_TYPE (val)
57#define ELF64_ST_BIND(val) ELF_ST_BIND (val)
58#define GELF_ST_BIND(val) ELF64_ST_BIND (val)
59#define elf_errmsg(val) "error"
60#define SHT_GNU_versym	  0x6fffffff
61#define SHT_GNU_verdef	  0x6ffffffd
62#endif
63
64#include "relo_core.h"
65
66/* make sure libbpf doesn't use kernel-only integer typedefs */
67#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
68
69/* prevent accidental re-addition of reallocarray() */
70#pragma GCC poison reallocarray
71
72#include "libbpf.h"
73#include "btf.h"
74
75#ifndef EM_BPF
76#define EM_BPF 247
77#endif
78
79#ifndef R_BPF_64_64
80#define R_BPF_64_64 1
81#endif
82#ifndef R_BPF_64_ABS64
83#define R_BPF_64_ABS64 2
84#endif
85#ifndef R_BPF_64_ABS32
86#define R_BPF_64_ABS32 3
87#endif
88#ifndef R_BPF_64_32
89#define R_BPF_64_32 10
90#endif
91
92#ifndef SHT_LLVM_ADDRSIG
93#define SHT_LLVM_ADDRSIG 0x6FFF4C03
94#endif
95
96/* if libelf is old and doesn't support mmap(), fall back to read() */
97#ifndef ELF_C_READ_MMAP
98#define ELF_C_READ_MMAP ELF_C_READ
99#endif
100
101/* Older libelf all end up in this expression, for both 32 and 64 bit */
102#ifndef ELF64_ST_VISIBILITY
103#define ELF64_ST_VISIBILITY(o) ((o) & 0x03)
104#endif
105
106#define BTF_INFO_ENC(kind, kind_flag, vlen) \
107	((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
108#define BTF_TYPE_ENC(name, info, size_or_type) (name), (info), (size_or_type)
109#define BTF_INT_ENC(encoding, bits_offset, nr_bits) \
110	((encoding) << 24 | (bits_offset) << 16 | (nr_bits))
111#define BTF_TYPE_INT_ENC(name, encoding, bits_offset, bits, sz) \
112	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_INT, 0, 0), sz), \
113	BTF_INT_ENC(encoding, bits_offset, bits)
114#define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset)
115#define BTF_PARAM_ENC(name, type) (name), (type)
116#define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
117#define BTF_TYPE_FLOAT_ENC(name, sz) \
118	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz)
119#define BTF_TYPE_DECL_TAG_ENC(value, type, component_idx) \
120	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), type), (component_idx)
121#define BTF_TYPE_TYPE_TAG_ENC(value, type) \
122	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TYPE_TAG, 0, 0), type)
123
124#ifndef likely
125#define likely(x) __builtin_expect(!!(x), 1)
126#endif
127#ifndef unlikely
128#define unlikely(x) __builtin_expect(!!(x), 0)
129#endif
130#ifndef min
131# define min(x, y) ((x) < (y) ? (x) : (y))
132#endif
133#ifndef max
134# define max(x, y) ((x) < (y) ? (y) : (x))
135#endif
136#ifndef offsetofend
137# define offsetofend(TYPE, FIELD) \
138	(offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
139#endif
140#ifndef __alias
141#define __alias(symbol) __attribute__((alias(#symbol)))
142#endif
143
144/* Check whether a string `str` has prefix `pfx`, regardless if `pfx` is
145 * a string literal known at compilation time or char * pointer known only at
146 * runtime.
147 */
148#define str_has_pfx(str, pfx) \
149	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
150
151/* suffix check */
152static inline bool str_has_sfx(const char *str, const char *sfx)
153{
154	size_t str_len = strlen(str);
155	size_t sfx_len = strlen(sfx);
156
157	if (sfx_len > str_len)
158		return false;
159	return strcmp(str + str_len - sfx_len, sfx) == 0;
160}
161
162/* Symbol versioning is different between static and shared library.
163 * Properly versioned symbols are needed for shared library, but
164 * only the symbol of the new version is needed for static library.
165 * Starting with GNU C 10, use symver attribute instead of .symver assembler
166 * directive, which works better with GCC LTO builds.
167 */
168#if defined(SHARED) && defined(__GNUC__) && __GNUC__ >= 10
169
170#define DEFAULT_VERSION(internal_name, api_name, version) \
171	__attribute__((symver(#api_name "@@" #version)))
172#define COMPAT_VERSION(internal_name, api_name, version) \
173	__attribute__((symver(#api_name "@" #version)))
174
175#elif defined(SHARED)
176
177#define COMPAT_VERSION(internal_name, api_name, version) \
178	asm(".symver " #internal_name "," #api_name "@" #version);
179#define DEFAULT_VERSION(internal_name, api_name, version) \
180	asm(".symver " #internal_name "," #api_name "@@" #version);
181
182#else /* !SHARED */
183
184#define COMPAT_VERSION(internal_name, api_name, version)
185#define DEFAULT_VERSION(internal_name, api_name, version) \
186	extern typeof(internal_name) api_name \
187	__attribute__((alias(#internal_name)));
188
189#endif
190
191extern void libbpf_print(enum libbpf_print_level level,
192			 const char *format, ...)
193	__attribute__((format(printf, 2, 3)));
194
195#define __pr(level, fmt, ...)	\
196do {				\
197	libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__);	\
198} while (0)
199
200#define pr_warn(fmt, ...)	__pr(LIBBPF_WARN, fmt, ##__VA_ARGS__)
201#define pr_info(fmt, ...)	__pr(LIBBPF_INFO, fmt, ##__VA_ARGS__)
202#define pr_debug(fmt, ...)	__pr(LIBBPF_DEBUG, fmt, ##__VA_ARGS__)
203
204#ifndef __has_builtin
205#define __has_builtin(x) 0
206#endif
207
208struct bpf_link {
209	int (*detach)(struct bpf_link *link);
210	void (*dealloc)(struct bpf_link *link);
211	char *pin_path;		/* NULL, if not pinned */
212	int fd;			/* hook FD, -1 if not applicable */
213	bool disconnected;
214};
215
216/*
217 * Re-implement glibc's reallocarray() for libbpf internal-only use.
218 * reallocarray(), unfortunately, is not available in all versions of glibc,
219 * so requires extra feature detection and using reallocarray() stub from
220 * <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates
221 * build of libbpf unnecessarily and is just a maintenance burden. Instead,
222 * it's trivial to implement libbpf-specific internal version and use it
223 * throughout libbpf.
224 */
225static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size)
226{
227	size_t total;
228
229#if __has_builtin(__builtin_mul_overflow)
230	if (unlikely(__builtin_mul_overflow(nmemb, size, &total)))
231		return NULL;
232#else
233	if (size == 0 || nmemb > ULONG_MAX / size)
234		return NULL;
235	total = nmemb * size;
236#endif
237	return realloc(ptr, total);
238}
239
240/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
241 * is zero-terminated string no matter what (unless sz == 0, in which case
242 * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
243 * in what is returned. Given this is internal helper, it's trivial to extend
244 * this, when necessary. Use this instead of strncpy inside libbpf source code.
245 */
246static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
247{
248	size_t i;
249
250	if (sz == 0)
251		return;
252
253	sz--;
254	for (i = 0; i < sz && src[i]; i++)
255		dst[i] = src[i];
256	dst[i] = '\0';
257}
258
259__u32 get_kernel_version(void);
260
261struct btf;
262struct btf_type;
263
264struct btf_type *btf_type_by_id(const struct btf *btf, __u32 type_id);
265const char *btf_kind_str(const struct btf_type *t);
266const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
267
268static inline enum btf_func_linkage btf_func_linkage(const struct btf_type *t)
269{
270	return (enum btf_func_linkage)(int)btf_vlen(t);
271}
272
273static inline __u32 btf_type_info(int kind, int vlen, int kflag)
274{
275	return (kflag << 31) | (kind << 24) | vlen;
276}
277
278enum map_def_parts {
279	MAP_DEF_MAP_TYPE	= 0x001,
280	MAP_DEF_KEY_TYPE	= 0x002,
281	MAP_DEF_KEY_SIZE	= 0x004,
282	MAP_DEF_VALUE_TYPE	= 0x008,
283	MAP_DEF_VALUE_SIZE	= 0x010,
284	MAP_DEF_MAX_ENTRIES	= 0x020,
285	MAP_DEF_MAP_FLAGS	= 0x040,
286	MAP_DEF_NUMA_NODE	= 0x080,
287	MAP_DEF_PINNING		= 0x100,
288	MAP_DEF_INNER_MAP	= 0x200,
289	MAP_DEF_MAP_EXTRA	= 0x400,
290
291	MAP_DEF_ALL		= 0x7ff, /* combination of all above */
292};
293
294struct btf_map_def {
295	enum map_def_parts parts;
296	__u32 map_type;
297	__u32 key_type_id;
298	__u32 key_size;
299	__u32 value_type_id;
300	__u32 value_size;
301	__u32 max_entries;
302	__u32 map_flags;
303	__u32 numa_node;
304	__u32 pinning;
305	__u64 map_extra;
306};
307
308int parse_btf_map_def(const char *map_name, struct btf *btf,
309		      const struct btf_type *def_t, bool strict,
310		      struct btf_map_def *map_def, struct btf_map_def *inner_def);
311
312void *libbpf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz,
313		     size_t cur_cnt, size_t max_cnt, size_t add_cnt);
314int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt);
315
316static inline bool libbpf_is_mem_zeroed(const char *p, ssize_t len)
317{
318	while (len > 0) {
319		if (*p)
320			return false;
321		p++;
322		len--;
323	}
324	return true;
325}
326
327static inline bool libbpf_validate_opts(const char *opts,
328					size_t opts_sz, size_t user_sz,
329					const char *type_name)
330{
331	if (user_sz < sizeof(size_t)) {
332		pr_warn("%s size (%zu) is too small\n", type_name, user_sz);
333		return false;
334	}
335	if (!libbpf_is_mem_zeroed(opts + opts_sz, (ssize_t)user_sz - opts_sz)) {
336		pr_warn("%s has non-zero extra bytes\n", type_name);
337		return false;
338	}
339	return true;
340}
341
342#define OPTS_VALID(opts, type)						      \
343	(!(opts) || libbpf_validate_opts((const char *)opts,		      \
344					 offsetofend(struct type,	      \
345						     type##__last_field),     \
346					 (opts)->sz, #type))
347#define OPTS_HAS(opts, field) \
348	((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))
349#define OPTS_GET(opts, field, fallback_value) \
350	(OPTS_HAS(opts, field) ? (opts)->field : fallback_value)
351#define OPTS_SET(opts, field, value)		\
352	do {					\
353		if (OPTS_HAS(opts, field))	\
354			(opts)->field = value;	\
355	} while (0)
356
357#define OPTS_ZEROED(opts, last_nonzero_field)				      \
358({									      \
359	ssize_t __off = offsetofend(typeof(*(opts)), last_nonzero_field);     \
360	!(opts) || libbpf_is_mem_zeroed((const void *)opts + __off,	      \
361					(opts)->sz - __off);		      \
362})
363
364enum kern_feature_id {
365	/* v4.14: kernel support for program & map names. */
366	FEAT_PROG_NAME,
367	/* v5.2: kernel support for global data sections. */
368	FEAT_GLOBAL_DATA,
369	/* BTF support */
370	FEAT_BTF,
371	/* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
372	FEAT_BTF_FUNC,
373	/* BTF_KIND_VAR and BTF_KIND_DATASEC support */
374	FEAT_BTF_DATASEC,
375	/* BTF_FUNC_GLOBAL is supported */
376	FEAT_BTF_GLOBAL_FUNC,
377	/* BPF_F_MMAPABLE is supported for arrays */
378	FEAT_ARRAY_MMAP,
379	/* kernel support for expected_attach_type in BPF_PROG_LOAD */
380	FEAT_EXP_ATTACH_TYPE,
381	/* bpf_probe_read_{kernel,user}[_str] helpers */
382	FEAT_PROBE_READ_KERN,
383	/* BPF_PROG_BIND_MAP is supported */
384	FEAT_PROG_BIND_MAP,
385	/* Kernel support for module BTFs */
386	FEAT_MODULE_BTF,
387	/* BTF_KIND_FLOAT support */
388	FEAT_BTF_FLOAT,
389	/* BPF perf link support */
390	FEAT_PERF_LINK,
391	/* BTF_KIND_DECL_TAG support */
392	FEAT_BTF_DECL_TAG,
393	/* BTF_KIND_TYPE_TAG support */
394	FEAT_BTF_TYPE_TAG,
395	/* memcg-based accounting for BPF maps and progs */
396	FEAT_MEMCG_ACCOUNT,
397	/* BPF cookie (bpf_get_attach_cookie() BPF helper) support */
398	FEAT_BPF_COOKIE,
399	/* BTF_KIND_ENUM64 support and BTF_KIND_ENUM kflag support */
400	FEAT_BTF_ENUM64,
401	/* Kernel uses syscall wrapper (CONFIG_ARCH_HAS_SYSCALL_WRAPPER) */
402	FEAT_SYSCALL_WRAPPER,
403	/* BPF multi-uprobe link support */
404	FEAT_UPROBE_MULTI_LINK,
405	__FEAT_CNT,
406};
407
408int probe_memcg_account(void);
409bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id);
410int bump_rlimit_memlock(void);
411
412int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz);
413int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
414int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
415			 const char *str_sec, size_t str_len);
416int btf_load_into_kernel(struct btf *btf, char *log_buf, size_t log_sz, __u32 log_level);
417
418struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf);
419void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
420				const char **prefix, int *kind);
421
422struct btf_ext_info {
423	/*
424	 * info points to the individual info section (e.g. func_info and
425	 * line_info) from the .BTF.ext. It does not include the __u32 rec_size.
426	 */
427	void *info;
428	__u32 rec_size;
429	__u32 len;
430	/* optional (maintained internally by libbpf) mapping between .BTF.ext
431	 * section and corresponding ELF section. This is used to join
432	 * information like CO-RE relocation records with corresponding BPF
433	 * programs defined in ELF sections
434	 */
435	__u32 *sec_idxs;
436	int sec_cnt;
437};
438
439#define for_each_btf_ext_sec(seg, sec)					\
440	for (sec = (seg)->info;						\
441	     (void *)sec < (seg)->info + (seg)->len;			\
442	     sec = (void *)sec + sizeof(struct btf_ext_info_sec) +	\
443		   (seg)->rec_size * sec->num_info)
444
445#define for_each_btf_ext_rec(seg, sec, i, rec)				\
446	for (i = 0, rec = (void *)&(sec)->data;				\
447	     i < (sec)->num_info;					\
448	     i++, rec = (void *)rec + (seg)->rec_size)
449
450/*
451 * The .BTF.ext ELF section layout defined as
452 *   struct btf_ext_header
453 *   func_info subsection
454 *
455 * The func_info subsection layout:
456 *   record size for struct bpf_func_info in the func_info subsection
457 *   struct btf_sec_func_info for section #1
458 *   a list of bpf_func_info records for section #1
459 *     where struct bpf_func_info mimics one in include/uapi/linux/bpf.h
460 *     but may not be identical
461 *   struct btf_sec_func_info for section #2
462 *   a list of bpf_func_info records for section #2
463 *   ......
464 *
465 * Note that the bpf_func_info record size in .BTF.ext may not
466 * be the same as the one defined in include/uapi/linux/bpf.h.
467 * The loader should ensure that record_size meets minimum
468 * requirement and pass the record as is to the kernel. The
469 * kernel will handle the func_info properly based on its contents.
470 */
471struct btf_ext_header {
472	__u16	magic;
473	__u8	version;
474	__u8	flags;
475	__u32	hdr_len;
476
477	/* All offsets are in bytes relative to the end of this header */
478	__u32	func_info_off;
479	__u32	func_info_len;
480	__u32	line_info_off;
481	__u32	line_info_len;
482
483	/* optional part of .BTF.ext header */
484	__u32	core_relo_off;
485	__u32	core_relo_len;
486};
487
488struct btf_ext {
489	union {
490		struct btf_ext_header *hdr;
491		void *data;
492	};
493	struct btf_ext_info func_info;
494	struct btf_ext_info line_info;
495	struct btf_ext_info core_relo_info;
496	__u32 data_size;
497};
498
499struct btf_ext_info_sec {
500	__u32	sec_name_off;
501	__u32	num_info;
502	/* Followed by num_info * record_size number of bytes */
503	__u8	data[];
504};
505
506/* The minimum bpf_func_info checked by the loader */
507struct bpf_func_info_min {
508	__u32   insn_off;
509	__u32   type_id;
510};
511
512/* The minimum bpf_line_info checked by the loader */
513struct bpf_line_info_min {
514	__u32	insn_off;
515	__u32	file_name_off;
516	__u32	line_off;
517	__u32	line_col;
518};
519
520struct elf_sym {
521	const char *name;
522	GElf_Sym sym;
523	GElf_Shdr sh;
524	int ver;
525	bool hidden;
526};
527
528struct elf_sym_iter {
529#ifdef  HAVE_LIBELF
530	Elf *elf;
531#elif HAVE_ELFIO
532	pelfio_t elf;
533	psection_t symsSec;
534#endif
535	Elf_Data *syms;
536	Elf_Data *versyms;
537	Elf_Data *verdefs;
538	size_t nr_syms;
539	size_t strtabidx;
540	size_t verdef_strtabidx;
541	size_t next_sym_idx;
542	struct elf_sym sym;
543	int st_type;
544};
545
546
547
548typedef int (*type_id_visit_fn)(__u32 *type_id, void *ctx);
549typedef int (*str_off_visit_fn)(__u32 *str_off, void *ctx);
550int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx);
551int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx);
552int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx);
553int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx);
554__s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name,
555				 __u32 kind);
556
557typedef int (*kallsyms_cb_t)(unsigned long long sym_addr, char sym_type,
558			     const char *sym_name, void *ctx);
559
560int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *arg);
561
562/* handle direct returned errors */
563static inline int libbpf_err(int ret)
564{
565	if (ret < 0)
566		errno = -ret;
567	return ret;
568}
569
570/* handle errno-based (e.g., syscall or libc) errors according to libbpf's
571 * strict mode settings
572 */
573static inline int libbpf_err_errno(int ret)
574{
575	/* errno is already assumed to be set on error */
576	return ret < 0 ? -errno : ret;
577}
578
579/* handle error for pointer-returning APIs, err is assumed to be < 0 always */
580static inline void *libbpf_err_ptr(int err)
581{
582	/* set errno on error, this doesn't break anything */
583	errno = -err;
584	return NULL;
585}
586
587/* handle pointer-returning APIs' error handling */
588static inline void *libbpf_ptr(void *ret)
589{
590	/* set errno on error, this doesn't break anything */
591	if (IS_ERR(ret))
592		errno = -PTR_ERR(ret);
593
594	return IS_ERR(ret) ? NULL : ret;
595}
596
597static inline bool str_is_empty(const char *s)
598{
599	return !s || !s[0];
600}
601
602static inline bool is_ldimm64_insn(struct bpf_insn *insn)
603{
604	return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
605}
606
607/* if fd is stdin, stdout, or stderr, dup to a fd greater than 2
608 * Takes ownership of the fd passed in, and closes it if calling
609 * fcntl(fd, F_DUPFD_CLOEXEC, 3).
610 */
611static inline int ensure_good_fd(int fd)
612{
613	int old_fd = fd, saved_errno;
614
615	if (fd < 0)
616		return fd;
617	if (fd < 3) {
618		fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
619		saved_errno = errno;
620		close(old_fd);
621		errno = saved_errno;
622		if (fd < 0) {
623			pr_warn("failed to dup FD %d to FD > 2: %d\n", old_fd, -saved_errno);
624			errno = saved_errno;
625		}
626	}
627	return fd;
628}
629
630/* The following two functions are exposed to bpftool */
631int bpf_core_add_cands(struct bpf_core_cand *local_cand,
632		       size_t local_essent_len,
633		       const struct btf *targ_btf,
634		       const char *targ_btf_name,
635		       int targ_start_id,
636		       struct bpf_core_cand_list *cands);
637void bpf_core_free_cands(struct bpf_core_cand_list *cands);
638
639struct usdt_manager *usdt_manager_new(struct bpf_object *obj);
640void usdt_manager_free(struct usdt_manager *man);
641struct bpf_link * usdt_manager_attach_usdt(struct usdt_manager *man,
642					   const struct bpf_program *prog,
643					   pid_t pid, const char *path,
644					   const char *usdt_provider, const char *usdt_name,
645					   __u64 usdt_cookie);
646
647static inline bool is_pow_of_2(size_t x)
648{
649	return x && (x & (x - 1)) == 0;
650}
651
652#define PROG_LOAD_ATTEMPTS 5
653int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts);
654
655bool glob_match(const char *str, const char *pat);
656
657#ifdef  HAVE_LIBELF
658long elf_find_func_offset(Elf *elf, const char *binary_path, const char *name);
659#elif HAVE_ELFIO
660long elf_find_func_offset(pelfio_t elf, const char *binary_path, const char *name);
661#endif
662long elf_find_func_offset_from_file(const char *binary_path, const char *name);
663
664struct elf_fd {
665#ifdef HAVE_LIBELF
666	Elf *elf;
667#elif HAVE_ELFIO
668	pelfio_t elf;
669#endif
670	int fd;
671};
672
673int elf_open(const char *binary_path, struct elf_fd *elf_fd);
674void elf_close(struct elf_fd *elf_fd);
675
676int elf_resolve_syms_offsets(const char *binary_path, int cnt,
677			     const char **syms, unsigned long **poffsets);
678int elf_resolve_pattern_offsets(const char *binary_path, const char *pattern,
679				 unsigned long **poffsets, size_t *pcnt);
680
681#endif /* __LIBBPF_LIBBPF_INTERNAL_H */
682