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1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3/*
4 * Common eBPF ELF object loading operations.
5 *
6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
8 * Copyright (C) 2015 Huawei Inc.
9 */
10#ifndef __LIBBPF_LIBBPF_H
11#define __LIBBPF_LIBBPF_H
12
13#include <stdarg.h>
14#include <stdio.h>
15#include <stdint.h>
16#include <stdbool.h>
17#include <sys/types.h> // for size_t
18#include <linux/bpf.h>
19
20#ifdef __cplusplus
21extern "C" {
22#endif
23
24#ifndef LIBBPF_API
25#define LIBBPF_API __attribute__((visibility("default")))
26#endif
27
28enum libbpf_errno {
29 __LIBBPF_ERRNO__START = 4000,
30
31 /* Something wrong in libelf */
32 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
33 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
34 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
35 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
36 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
37 LIBBPF_ERRNO__RELOC, /* Relocation failed */
38 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
39 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
40 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
41 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
42 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
43 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
44 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
45 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */
46 __LIBBPF_ERRNO__END,
47};
48
49LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
50
51enum libbpf_print_level {
52 LIBBPF_WARN,
53 LIBBPF_INFO,
54 LIBBPF_DEBUG,
55};
56
57typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
58 const char *, va_list ap);
59
60LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
61
62/* Hide internal to user */
63struct bpf_object;
64
65struct bpf_object_open_attr {
66 const char *file;
67 enum bpf_prog_type prog_type;
68};
69
70LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
71LIBBPF_API struct bpf_object *
72bpf_object__open_xattr(struct bpf_object_open_attr *attr);
73struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
74 int flags);
75LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
76 size_t obj_buf_sz,
77 const char *name);
78int bpf_object__section_size(const struct bpf_object *obj, const char *name,
79 __u32 *size);
80int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
81 __u32 *off);
82LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
83LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
84 const char *path);
85LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
86 const char *path);
87LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
88 const char *path);
89LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
90LIBBPF_API void bpf_object__close(struct bpf_object *object);
91
92struct bpf_object_load_attr {
93 struct bpf_object *obj;
94 int log_level;
95 const char *target_btf_path;
96};
97
98/* Load/unload object into/from kernel */
99LIBBPF_API int bpf_object__load(struct bpf_object *obj);
100LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
101LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
102LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
103LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
104
105struct btf;
106LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
107LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
108
109LIBBPF_API struct bpf_program *
110bpf_object__find_program_by_title(const struct bpf_object *obj,
111 const char *title);
112
113LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
114#define bpf_object__for_each_safe(pos, tmp) \
115 for ((pos) = bpf_object__next(NULL), \
116 (tmp) = bpf_object__next(pos); \
117 (pos) != NULL; \
118 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
119
120typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
121LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
122 bpf_object_clear_priv_t clear_priv);
123LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);
124
125LIBBPF_API int
126libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
127 enum bpf_attach_type *expected_attach_type);
128LIBBPF_API int libbpf_attach_type_by_name(const char *name,
129 enum bpf_attach_type *attach_type);
130
131/* Accessors of bpf_program */
132struct bpf_program;
133LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
134 const struct bpf_object *obj);
135
136#define bpf_object__for_each_program(pos, obj) \
137 for ((pos) = bpf_program__next(NULL, (obj)); \
138 (pos) != NULL; \
139 (pos) = bpf_program__next((pos), (obj)))
140
141LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
142 const struct bpf_object *obj);
143
144typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
145
146LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
147 bpf_program_clear_priv_t clear_priv);
148
149LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
150LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
151 __u32 ifindex);
152
153LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
154 bool needs_copy);
155
156LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
157 __u32 kern_version);
158LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
159LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
160 const char *path,
161 int instance);
162LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
163 const char *path,
164 int instance);
165LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
166LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
167LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
168
169struct bpf_link;
170
171LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
172
173LIBBPF_API struct bpf_link *
174bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
175LIBBPF_API struct bpf_link *
176bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
177 const char *func_name);
178LIBBPF_API struct bpf_link *
179bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
180 pid_t pid, const char *binary_path,
181 size_t func_offset);
182LIBBPF_API struct bpf_link *
183bpf_program__attach_tracepoint(struct bpf_program *prog,
184 const char *tp_category,
185 const char *tp_name);
186LIBBPF_API struct bpf_link *
187bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
188 const char *tp_name);
189
190struct bpf_insn;
191
192/*
193 * Libbpf allows callers to adjust BPF programs before being loaded
194 * into kernel. One program in an object file can be transformed into
195 * multiple variants to be attached to different hooks.
196 *
197 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
198 * form an API for this purpose.
199 *
200 * - bpf_program_prep_t:
201 * Defines a 'preprocessor', which is a caller defined function
202 * passed to libbpf through bpf_program__set_prep(), and will be
203 * called before program is loaded. The processor should adjust
204 * the program one time for each instance according to the instance id
205 * passed to it.
206 *
207 * - bpf_program__set_prep:
208 * Attaches a preprocessor to a BPF program. The number of instances
209 * that should be created is also passed through this function.
210 *
211 * - bpf_program__nth_fd:
212 * After the program is loaded, get resulting FD of a given instance
213 * of the BPF program.
214 *
215 * If bpf_program__set_prep() is not used, the program would be loaded
216 * without adjustment during bpf_object__load(). The program has only
217 * one instance. In this case bpf_program__fd(prog) is equal to
218 * bpf_program__nth_fd(prog, 0).
219 */
220
221struct bpf_prog_prep_result {
222 /*
223 * If not NULL, load new instruction array.
224 * If set to NULL, don't load this instance.
225 */
226 struct bpf_insn *new_insn_ptr;
227 int new_insn_cnt;
228
229 /* If not NULL, result FD is written to it. */
230 int *pfd;
231};
232
233/*
234 * Parameters of bpf_program_prep_t:
235 * - prog: The bpf_program being loaded.
236 * - n: Index of instance being generated.
237 * - insns: BPF instructions array.
238 * - insns_cnt:Number of instructions in insns.
239 * - res: Output parameter, result of transformation.
240 *
241 * Return value:
242 * - Zero: pre-processing success.
243 * - Non-zero: pre-processing error, stop loading.
244 */
245typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
246 struct bpf_insn *insns, int insns_cnt,
247 struct bpf_prog_prep_result *res);
248
249LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
250 bpf_program_prep_t prep);
251
252LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
253
254/*
255 * Adjust type of BPF program. Default is kprobe.
256 */
257LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
258LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
259LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
260LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
261LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
262LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
263LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
264LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
265LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
266 enum bpf_prog_type type);
267LIBBPF_API void
268bpf_program__set_expected_attach_type(struct bpf_program *prog,
269 enum bpf_attach_type type);
270
271LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
272LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
273LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
274LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
275LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
276LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
277LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
278LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
279
280/*
281 * No need for __attribute__((packed)), all members of 'bpf_map_def'
282 * are all aligned. In addition, using __attribute__((packed))
283 * would trigger a -Wpacked warning message, and lead to an error
284 * if -Werror is set.
285 */
286struct bpf_map_def {
287 unsigned int type;
288 unsigned int key_size;
289 unsigned int value_size;
290 unsigned int max_entries;
291 unsigned int map_flags;
292};
293
294/*
295 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
296 * so no need to worry about a name clash.
297 */
298struct bpf_map;
299LIBBPF_API struct bpf_map *
300bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
301
302LIBBPF_API int
303bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
304
305/*
306 * Get bpf_map through the offset of corresponding struct bpf_map_def
307 * in the BPF object file.
308 */
309LIBBPF_API struct bpf_map *
310bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
311
312LIBBPF_API struct bpf_map *
313bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
314#define bpf_object__for_each_map(pos, obj) \
315 for ((pos) = bpf_map__next(NULL, (obj)); \
316 (pos) != NULL; \
317 (pos) = bpf_map__next((pos), (obj)))
318#define bpf_map__for_each bpf_object__for_each_map
319
320LIBBPF_API struct bpf_map *
321bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
322
323LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
324LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
325LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
326LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
327LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
328
329typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
330LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
331 bpf_map_clear_priv_t clear_priv);
332LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
333LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
334LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
335LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
336LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
337LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
338LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
339LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
340
341LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
342
343LIBBPF_API long libbpf_get_error(const void *ptr);
344
345struct bpf_prog_load_attr {
346 const char *file;
347 enum bpf_prog_type prog_type;
348 enum bpf_attach_type expected_attach_type;
349 int ifindex;
350 int log_level;
351 int prog_flags;
352};
353
354LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
355 struct bpf_object **pobj, int *prog_fd);
356LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
357 struct bpf_object **pobj, int *prog_fd);
358
359LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
360LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
361
362struct perf_buffer;
363
364typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
365 void *data, __u32 size);
366typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
367
368/* common use perf buffer options */
369struct perf_buffer_opts {
370 /* if specified, sample_cb is called for each sample */
371 perf_buffer_sample_fn sample_cb;
372 /* if specified, lost_cb is called for each batch of lost samples */
373 perf_buffer_lost_fn lost_cb;
374 /* ctx is provided to sample_cb and lost_cb */
375 void *ctx;
376};
377
378LIBBPF_API struct perf_buffer *
379perf_buffer__new(int map_fd, size_t page_cnt,
380 const struct perf_buffer_opts *opts);
381
382enum bpf_perf_event_ret {
383 LIBBPF_PERF_EVENT_DONE = 0,
384 LIBBPF_PERF_EVENT_ERROR = -1,
385 LIBBPF_PERF_EVENT_CONT = -2,
386};
387
388struct perf_event_header;
389
390typedef enum bpf_perf_event_ret
391(*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
392
393/* raw perf buffer options, giving most power and control */
394struct perf_buffer_raw_opts {
395 /* perf event attrs passed directly into perf_event_open() */
396 struct perf_event_attr *attr;
397 /* raw event callback */
398 perf_buffer_event_fn event_cb;
399 /* ctx is provided to event_cb */
400 void *ctx;
401 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
402 * max_entries of given PERF_EVENT_ARRAY map)
403 */
404 int cpu_cnt;
405 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
406 int *cpus;
407 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
408 int *map_keys;
409};
410
411LIBBPF_API struct perf_buffer *
412perf_buffer__new_raw(int map_fd, size_t page_cnt,
413 const struct perf_buffer_raw_opts *opts);
414
415LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
416LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
417
418typedef enum bpf_perf_event_ret
419 (*bpf_perf_event_print_t)(struct perf_event_header *hdr,
420 void *private_data);
421LIBBPF_API enum bpf_perf_event_ret
422bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
423 void **copy_mem, size_t *copy_size,
424 bpf_perf_event_print_t fn, void *private_data);
425
426struct nlattr;
427typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
428int libbpf_netlink_open(unsigned int *nl_pid);
429int libbpf_nl_get_link(int sock, unsigned int nl_pid,
430 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
431int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
432 libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
433int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
434 libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
435int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
436 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
437
438struct bpf_prog_linfo;
439struct bpf_prog_info;
440
441LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
442LIBBPF_API struct bpf_prog_linfo *
443bpf_prog_linfo__new(const struct bpf_prog_info *info);
444LIBBPF_API const struct bpf_line_info *
445bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
446 __u64 addr, __u32 func_idx, __u32 nr_skip);
447LIBBPF_API const struct bpf_line_info *
448bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
449 __u32 insn_off, __u32 nr_skip);
450
451/*
452 * Probe for supported system features
453 *
454 * Note that running many of these probes in a short amount of time can cause
455 * the kernel to reach the maximal size of lockable memory allowed for the
456 * user, causing subsequent probes to fail. In this case, the caller may want
457 * to adjust that limit with setrlimit().
458 */
459LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
460 __u32 ifindex);
461LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
462LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
463 enum bpf_prog_type prog_type, __u32 ifindex);
464
465/*
466 * Get bpf_prog_info in continuous memory
467 *
468 * struct bpf_prog_info has multiple arrays. The user has option to choose
469 * arrays to fetch from kernel. The following APIs provide an uniform way to
470 * fetch these data. All arrays in bpf_prog_info are stored in a single
471 * continuous memory region. This makes it easy to store the info in a
472 * file.
473 *
474 * Before writing bpf_prog_info_linear to files, it is necessary to
475 * translate pointers in bpf_prog_info to offsets. Helper functions
476 * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
477 * are introduced to switch between pointers and offsets.
478 *
479 * Examples:
480 * # To fetch map_ids and prog_tags:
481 * __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
482 * (1UL << BPF_PROG_INFO_PROG_TAGS);
483 * struct bpf_prog_info_linear *info_linear =
484 * bpf_program__get_prog_info_linear(fd, arrays);
485 *
486 * # To save data in file
487 * bpf_program__bpil_addr_to_offs(info_linear);
488 * write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
489 *
490 * # To read data from file
491 * read(f, info_linear, <proper_size>);
492 * bpf_program__bpil_offs_to_addr(info_linear);
493 */
494enum bpf_prog_info_array {
495 BPF_PROG_INFO_FIRST_ARRAY = 0,
496 BPF_PROG_INFO_JITED_INSNS = 0,
497 BPF_PROG_INFO_XLATED_INSNS,
498 BPF_PROG_INFO_MAP_IDS,
499 BPF_PROG_INFO_JITED_KSYMS,
500 BPF_PROG_INFO_JITED_FUNC_LENS,
501 BPF_PROG_INFO_FUNC_INFO,
502 BPF_PROG_INFO_LINE_INFO,
503 BPF_PROG_INFO_JITED_LINE_INFO,
504 BPF_PROG_INFO_PROG_TAGS,
505 BPF_PROG_INFO_LAST_ARRAY,
506};
507
508struct bpf_prog_info_linear {
509 /* size of struct bpf_prog_info, when the tool is compiled */
510 __u32 info_len;
511 /* total bytes allocated for data, round up to 8 bytes */
512 __u32 data_len;
513 /* which arrays are included in data */
514 __u64 arrays;
515 struct bpf_prog_info info;
516 __u8 data[];
517};
518
519LIBBPF_API struct bpf_prog_info_linear *
520bpf_program__get_prog_info_linear(int fd, __u64 arrays);
521
522LIBBPF_API void
523bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
524
525LIBBPF_API void
526bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
527
528/*
529 * A helper function to get the number of possible CPUs before looking up
530 * per-CPU maps. Negative errno is returned on failure.
531 *
532 * Example usage:
533 *
534 * int ncpus = libbpf_num_possible_cpus();
535 * if (ncpus < 0) {
536 * // error handling
537 * }
538 * long values[ncpus];
539 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
540 *
541 */
542LIBBPF_API int libbpf_num_possible_cpus(void);
543
544#ifdef __cplusplus
545} /* extern "C" */
546#endif
547
548#endif /* __LIBBPF_LIBBPF_H */