1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
4 * Common eBPF ELF object loading operations.
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.
10 #ifndef __LIBBPF_LIBBPF_H
11 #define __LIBBPF_LIBBPF_H
17 #include <sys/types.h> // for size_t
18 #include <linux/bpf.h>
25 #define LIBBPF_API __attribute__((visibility("default")))
29 __LIBBPF_ERRNO__START
= 4000,
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 */
49 LIBBPF_API
int libbpf_strerror(int err
, char *buf
, size_t size
);
51 enum libbpf_print_level
{
57 typedef int (*libbpf_print_fn_t
)(enum libbpf_print_level level
,
58 const char *, va_list ap
);
60 LIBBPF_API libbpf_print_fn_t
libbpf_set_print(libbpf_print_fn_t fn
);
62 /* Hide internal to user */
65 struct bpf_object_open_attr
{
67 enum bpf_prog_type prog_type
;
70 /* Helper macro to declare and initialize libbpf options struct
72 * This dance with uninitialized declaration, followed by memset to zero,
73 * followed by assignment using compound literal syntax is done to preserve
74 * ability to use a nice struct field initialization syntax and **hopefully**
75 * have all the padding bytes initialized to zero. It's not guaranteed though,
76 * when copying literal, that compiler won't copy garbage in literal's padding
77 * bytes, but that's the best way I've found and it seems to work in practice.
79 * Macro declares opts struct of given type and name, zero-initializes,
80 * including any extra padding, it with memset() and then assigns initial
81 * values provided by users in struct initializer-syntax as varargs.
83 #define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...) \
84 struct TYPE NAME = ({ \
85 memset(&NAME, 0, sizeof(struct TYPE)); \
87 .sz = sizeof(struct TYPE), \
92 struct bpf_object_open_opts
{
93 /* size of this struct, for forward/backward compatiblity */
95 /* object name override, if provided:
96 * - for object open from file, this will override setting object
97 * name from file path's base name;
98 * - for object open from memory buffer, this will specify an object
99 * name and will override default "<addr>-<buf-size>" name;
101 const char *object_name
;
102 /* parse map definitions non-strictly, allowing extra attributes/data */
104 /* process CO-RE relocations non-strictly, allowing them to fail */
105 bool relaxed_core_relocs
;
106 /* maps that set the 'pinning' attribute in their definition will have
107 * their pin_path attribute set to a file in this directory, and be
108 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
110 const char *pin_root_path
;
111 __u32 attach_prog_fd
;
113 #define bpf_object_open_opts__last_field attach_prog_fd
115 LIBBPF_API
struct bpf_object
*bpf_object__open(const char *path
);
116 LIBBPF_API
struct bpf_object
*
117 bpf_object__open_file(const char *path
, struct bpf_object_open_opts
*opts
);
118 LIBBPF_API
struct bpf_object
*
119 bpf_object__open_mem(const void *obj_buf
, size_t obj_buf_sz
,
120 struct bpf_object_open_opts
*opts
);
122 /* deprecated bpf_object__open variants */
123 LIBBPF_API
struct bpf_object
*
124 bpf_object__open_buffer(const void *obj_buf
, size_t obj_buf_sz
,
126 LIBBPF_API
struct bpf_object
*
127 bpf_object__open_xattr(struct bpf_object_open_attr
*attr
);
129 int bpf_object__section_size(const struct bpf_object
*obj
, const char *name
,
131 int bpf_object__variable_offset(const struct bpf_object
*obj
, const char *name
,
134 enum libbpf_pin_type
{
136 /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
140 /* pin_maps and unpin_maps can both be called with a NULL path, in which case
141 * they will use the pin_path attribute of each map (and ignore all maps that
142 * don't have a pin_path set).
144 LIBBPF_API
int bpf_object__pin_maps(struct bpf_object
*obj
, const char *path
);
145 LIBBPF_API
int bpf_object__unpin_maps(struct bpf_object
*obj
,
147 LIBBPF_API
int bpf_object__pin_programs(struct bpf_object
*obj
,
149 LIBBPF_API
int bpf_object__unpin_programs(struct bpf_object
*obj
,
151 LIBBPF_API
int bpf_object__pin(struct bpf_object
*object
, const char *path
);
152 LIBBPF_API
void bpf_object__close(struct bpf_object
*object
);
154 struct bpf_object_load_attr
{
155 struct bpf_object
*obj
;
157 const char *target_btf_path
;
160 /* Load/unload object into/from kernel */
161 LIBBPF_API
int bpf_object__load(struct bpf_object
*obj
);
162 LIBBPF_API
int bpf_object__load_xattr(struct bpf_object_load_attr
*attr
);
163 LIBBPF_API
int bpf_object__unload(struct bpf_object
*obj
);
164 LIBBPF_API
const char *bpf_object__name(const struct bpf_object
*obj
);
165 LIBBPF_API
unsigned int bpf_object__kversion(const struct bpf_object
*obj
);
168 LIBBPF_API
struct btf
*bpf_object__btf(const struct bpf_object
*obj
);
169 LIBBPF_API
int bpf_object__btf_fd(const struct bpf_object
*obj
);
171 LIBBPF_API
struct bpf_program
*
172 bpf_object__find_program_by_title(const struct bpf_object
*obj
,
175 LIBBPF_API
struct bpf_object
*bpf_object__next(struct bpf_object
*prev
);
176 #define bpf_object__for_each_safe(pos, tmp) \
177 for ((pos) = bpf_object__next(NULL), \
178 (tmp) = bpf_object__next(pos); \
180 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
182 typedef void (*bpf_object_clear_priv_t
)(struct bpf_object
*, void *);
183 LIBBPF_API
int bpf_object__set_priv(struct bpf_object
*obj
, void *priv
,
184 bpf_object_clear_priv_t clear_priv
);
185 LIBBPF_API
void *bpf_object__priv(const struct bpf_object
*prog
);
188 libbpf_prog_type_by_name(const char *name
, enum bpf_prog_type
*prog_type
,
189 enum bpf_attach_type
*expected_attach_type
);
190 LIBBPF_API
int libbpf_attach_type_by_name(const char *name
,
191 enum bpf_attach_type
*attach_type
);
192 LIBBPF_API
int libbpf_find_vmlinux_btf_id(const char *name
,
193 enum bpf_attach_type attach_type
);
195 /* Accessors of bpf_program */
197 LIBBPF_API
struct bpf_program
*bpf_program__next(struct bpf_program
*prog
,
198 const struct bpf_object
*obj
);
200 #define bpf_object__for_each_program(pos, obj) \
201 for ((pos) = bpf_program__next(NULL, (obj)); \
203 (pos) = bpf_program__next((pos), (obj)))
205 LIBBPF_API
struct bpf_program
*bpf_program__prev(struct bpf_program
*prog
,
206 const struct bpf_object
*obj
);
208 typedef void (*bpf_program_clear_priv_t
)(struct bpf_program
*, void *);
210 LIBBPF_API
int bpf_program__set_priv(struct bpf_program
*prog
, void *priv
,
211 bpf_program_clear_priv_t clear_priv
);
213 LIBBPF_API
void *bpf_program__priv(const struct bpf_program
*prog
);
214 LIBBPF_API
void bpf_program__set_ifindex(struct bpf_program
*prog
,
217 LIBBPF_API
const char *bpf_program__title(const struct bpf_program
*prog
,
220 /* returns program size in bytes */
221 LIBBPF_API
size_t bpf_program__size(const struct bpf_program
*prog
);
223 LIBBPF_API
int bpf_program__load(struct bpf_program
*prog
, char *license
,
225 LIBBPF_API
int bpf_program__fd(const struct bpf_program
*prog
);
226 LIBBPF_API
int bpf_program__pin_instance(struct bpf_program
*prog
,
229 LIBBPF_API
int bpf_program__unpin_instance(struct bpf_program
*prog
,
232 LIBBPF_API
int bpf_program__pin(struct bpf_program
*prog
, const char *path
);
233 LIBBPF_API
int bpf_program__unpin(struct bpf_program
*prog
, const char *path
);
234 LIBBPF_API
void bpf_program__unload(struct bpf_program
*prog
);
238 LIBBPF_API
int bpf_link__destroy(struct bpf_link
*link
);
240 LIBBPF_API
struct bpf_link
*
241 bpf_program__attach_perf_event(struct bpf_program
*prog
, int pfd
);
242 LIBBPF_API
struct bpf_link
*
243 bpf_program__attach_kprobe(struct bpf_program
*prog
, bool retprobe
,
244 const char *func_name
);
245 LIBBPF_API
struct bpf_link
*
246 bpf_program__attach_uprobe(struct bpf_program
*prog
, bool retprobe
,
247 pid_t pid
, const char *binary_path
,
249 LIBBPF_API
struct bpf_link
*
250 bpf_program__attach_tracepoint(struct bpf_program
*prog
,
251 const char *tp_category
,
252 const char *tp_name
);
253 LIBBPF_API
struct bpf_link
*
254 bpf_program__attach_raw_tracepoint(struct bpf_program
*prog
,
255 const char *tp_name
);
257 LIBBPF_API
struct bpf_link
*
258 bpf_program__attach_trace(struct bpf_program
*prog
);
262 * Libbpf allows callers to adjust BPF programs before being loaded
263 * into kernel. One program in an object file can be transformed into
264 * multiple variants to be attached to different hooks.
266 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
267 * form an API for this purpose.
269 * - bpf_program_prep_t:
270 * Defines a 'preprocessor', which is a caller defined function
271 * passed to libbpf through bpf_program__set_prep(), and will be
272 * called before program is loaded. The processor should adjust
273 * the program one time for each instance according to the instance id
276 * - bpf_program__set_prep:
277 * Attaches a preprocessor to a BPF program. The number of instances
278 * that should be created is also passed through this function.
280 * - bpf_program__nth_fd:
281 * After the program is loaded, get resulting FD of a given instance
282 * of the BPF program.
284 * If bpf_program__set_prep() is not used, the program would be loaded
285 * without adjustment during bpf_object__load(). The program has only
286 * one instance. In this case bpf_program__fd(prog) is equal to
287 * bpf_program__nth_fd(prog, 0).
290 struct bpf_prog_prep_result
{
292 * If not NULL, load new instruction array.
293 * If set to NULL, don't load this instance.
295 struct bpf_insn
*new_insn_ptr
;
298 /* If not NULL, result FD is written to it. */
303 * Parameters of bpf_program_prep_t:
304 * - prog: The bpf_program being loaded.
305 * - n: Index of instance being generated.
306 * - insns: BPF instructions array.
307 * - insns_cnt:Number of instructions in insns.
308 * - res: Output parameter, result of transformation.
311 * - Zero: pre-processing success.
312 * - Non-zero: pre-processing error, stop loading.
314 typedef int (*bpf_program_prep_t
)(struct bpf_program
*prog
, int n
,
315 struct bpf_insn
*insns
, int insns_cnt
,
316 struct bpf_prog_prep_result
*res
);
318 LIBBPF_API
int bpf_program__set_prep(struct bpf_program
*prog
, int nr_instance
,
319 bpf_program_prep_t prep
);
321 LIBBPF_API
int bpf_program__nth_fd(const struct bpf_program
*prog
, int n
);
324 * Adjust type of BPF program. Default is kprobe.
326 LIBBPF_API
int bpf_program__set_socket_filter(struct bpf_program
*prog
);
327 LIBBPF_API
int bpf_program__set_tracepoint(struct bpf_program
*prog
);
328 LIBBPF_API
int bpf_program__set_raw_tracepoint(struct bpf_program
*prog
);
329 LIBBPF_API
int bpf_program__set_kprobe(struct bpf_program
*prog
);
330 LIBBPF_API
int bpf_program__set_sched_cls(struct bpf_program
*prog
);
331 LIBBPF_API
int bpf_program__set_sched_act(struct bpf_program
*prog
);
332 LIBBPF_API
int bpf_program__set_xdp(struct bpf_program
*prog
);
333 LIBBPF_API
int bpf_program__set_perf_event(struct bpf_program
*prog
);
334 LIBBPF_API
int bpf_program__set_tracing(struct bpf_program
*prog
);
336 LIBBPF_API
enum bpf_prog_type
bpf_program__get_type(struct bpf_program
*prog
);
337 LIBBPF_API
void bpf_program__set_type(struct bpf_program
*prog
,
338 enum bpf_prog_type type
);
340 LIBBPF_API
enum bpf_attach_type
341 bpf_program__get_expected_attach_type(struct bpf_program
*prog
);
343 bpf_program__set_expected_attach_type(struct bpf_program
*prog
,
344 enum bpf_attach_type type
);
346 LIBBPF_API
bool bpf_program__is_socket_filter(const struct bpf_program
*prog
);
347 LIBBPF_API
bool bpf_program__is_tracepoint(const struct bpf_program
*prog
);
348 LIBBPF_API
bool bpf_program__is_raw_tracepoint(const struct bpf_program
*prog
);
349 LIBBPF_API
bool bpf_program__is_kprobe(const struct bpf_program
*prog
);
350 LIBBPF_API
bool bpf_program__is_sched_cls(const struct bpf_program
*prog
);
351 LIBBPF_API
bool bpf_program__is_sched_act(const struct bpf_program
*prog
);
352 LIBBPF_API
bool bpf_program__is_xdp(const struct bpf_program
*prog
);
353 LIBBPF_API
bool bpf_program__is_perf_event(const struct bpf_program
*prog
);
354 LIBBPF_API
bool bpf_program__is_tracing(const struct bpf_program
*prog
);
357 * No need for __attribute__((packed)), all members of 'bpf_map_def'
358 * are all aligned. In addition, using __attribute__((packed))
359 * would trigger a -Wpacked warning message, and lead to an error
364 unsigned int key_size
;
365 unsigned int value_size
;
366 unsigned int max_entries
;
367 unsigned int map_flags
;
371 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
372 * so no need to worry about a name clash.
375 LIBBPF_API
struct bpf_map
*
376 bpf_object__find_map_by_name(const struct bpf_object
*obj
, const char *name
);
379 bpf_object__find_map_fd_by_name(const struct bpf_object
*obj
, const char *name
);
382 * Get bpf_map through the offset of corresponding struct bpf_map_def
383 * in the BPF object file.
385 LIBBPF_API
struct bpf_map
*
386 bpf_object__find_map_by_offset(struct bpf_object
*obj
, size_t offset
);
388 LIBBPF_API
struct bpf_map
*
389 bpf_map__next(const struct bpf_map
*map
, const struct bpf_object
*obj
);
390 #define bpf_object__for_each_map(pos, obj) \
391 for ((pos) = bpf_map__next(NULL, (obj)); \
393 (pos) = bpf_map__next((pos), (obj)))
394 #define bpf_map__for_each bpf_object__for_each_map
396 LIBBPF_API
struct bpf_map
*
397 bpf_map__prev(const struct bpf_map
*map
, const struct bpf_object
*obj
);
399 LIBBPF_API
int bpf_map__fd(const struct bpf_map
*map
);
400 LIBBPF_API
const struct bpf_map_def
*bpf_map__def(const struct bpf_map
*map
);
401 LIBBPF_API
const char *bpf_map__name(const struct bpf_map
*map
);
402 LIBBPF_API __u32
bpf_map__btf_key_type_id(const struct bpf_map
*map
);
403 LIBBPF_API __u32
bpf_map__btf_value_type_id(const struct bpf_map
*map
);
405 typedef void (*bpf_map_clear_priv_t
)(struct bpf_map
*, void *);
406 LIBBPF_API
int bpf_map__set_priv(struct bpf_map
*map
, void *priv
,
407 bpf_map_clear_priv_t clear_priv
);
408 LIBBPF_API
void *bpf_map__priv(const struct bpf_map
*map
);
409 LIBBPF_API
int bpf_map__reuse_fd(struct bpf_map
*map
, int fd
);
410 LIBBPF_API
int bpf_map__resize(struct bpf_map
*map
, __u32 max_entries
);
411 LIBBPF_API
bool bpf_map__is_offload_neutral(const struct bpf_map
*map
);
412 LIBBPF_API
bool bpf_map__is_internal(const struct bpf_map
*map
);
413 LIBBPF_API
void bpf_map__set_ifindex(struct bpf_map
*map
, __u32 ifindex
);
414 LIBBPF_API
int bpf_map__set_pin_path(struct bpf_map
*map
, const char *path
);
415 LIBBPF_API
const char *bpf_map__get_pin_path(const struct bpf_map
*map
);
416 LIBBPF_API
bool bpf_map__is_pinned(const struct bpf_map
*map
);
417 LIBBPF_API
int bpf_map__pin(struct bpf_map
*map
, const char *path
);
418 LIBBPF_API
int bpf_map__unpin(struct bpf_map
*map
, const char *path
);
420 LIBBPF_API
int bpf_map__set_inner_map_fd(struct bpf_map
*map
, int fd
);
422 LIBBPF_API
long libbpf_get_error(const void *ptr
);
424 struct bpf_prog_load_attr
{
426 enum bpf_prog_type prog_type
;
427 enum bpf_attach_type expected_attach_type
;
433 LIBBPF_API
int bpf_prog_load_xattr(const struct bpf_prog_load_attr
*attr
,
434 struct bpf_object
**pobj
, int *prog_fd
);
435 LIBBPF_API
int bpf_prog_load(const char *file
, enum bpf_prog_type type
,
436 struct bpf_object
**pobj
, int *prog_fd
);
438 struct xdp_link_info
{
446 LIBBPF_API
int bpf_set_link_xdp_fd(int ifindex
, int fd
, __u32 flags
);
447 LIBBPF_API
int bpf_get_link_xdp_id(int ifindex
, __u32
*prog_id
, __u32 flags
);
448 LIBBPF_API
int bpf_get_link_xdp_info(int ifindex
, struct xdp_link_info
*info
,
449 size_t info_size
, __u32 flags
);
453 typedef void (*perf_buffer_sample_fn
)(void *ctx
, int cpu
,
454 void *data
, __u32 size
);
455 typedef void (*perf_buffer_lost_fn
)(void *ctx
, int cpu
, __u64 cnt
);
457 /* common use perf buffer options */
458 struct perf_buffer_opts
{
459 /* if specified, sample_cb is called for each sample */
460 perf_buffer_sample_fn sample_cb
;
461 /* if specified, lost_cb is called for each batch of lost samples */
462 perf_buffer_lost_fn lost_cb
;
463 /* ctx is provided to sample_cb and lost_cb */
467 LIBBPF_API
struct perf_buffer
*
468 perf_buffer__new(int map_fd
, size_t page_cnt
,
469 const struct perf_buffer_opts
*opts
);
471 enum bpf_perf_event_ret
{
472 LIBBPF_PERF_EVENT_DONE
= 0,
473 LIBBPF_PERF_EVENT_ERROR
= -1,
474 LIBBPF_PERF_EVENT_CONT
= -2,
477 struct perf_event_header
;
479 typedef enum bpf_perf_event_ret
480 (*perf_buffer_event_fn
)(void *ctx
, int cpu
, struct perf_event_header
*event
);
482 /* raw perf buffer options, giving most power and control */
483 struct perf_buffer_raw_opts
{
484 /* perf event attrs passed directly into perf_event_open() */
485 struct perf_event_attr
*attr
;
486 /* raw event callback */
487 perf_buffer_event_fn event_cb
;
488 /* ctx is provided to event_cb */
490 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
491 * max_entries of given PERF_EVENT_ARRAY map)
494 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
496 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
500 LIBBPF_API
struct perf_buffer
*
501 perf_buffer__new_raw(int map_fd
, size_t page_cnt
,
502 const struct perf_buffer_raw_opts
*opts
);
504 LIBBPF_API
void perf_buffer__free(struct perf_buffer
*pb
);
505 LIBBPF_API
int perf_buffer__poll(struct perf_buffer
*pb
, int timeout_ms
);
507 typedef enum bpf_perf_event_ret
508 (*bpf_perf_event_print_t
)(struct perf_event_header
*hdr
,
510 LIBBPF_API
enum bpf_perf_event_ret
511 bpf_perf_event_read_simple(void *mmap_mem
, size_t mmap_size
, size_t page_size
,
512 void **copy_mem
, size_t *copy_size
,
513 bpf_perf_event_print_t fn
, void *private_data
);
516 typedef int (*libbpf_dump_nlmsg_t
)(void *cookie
, void *msg
, struct nlattr
**tb
);
517 int libbpf_netlink_open(unsigned int *nl_pid
);
518 int libbpf_nl_get_link(int sock
, unsigned int nl_pid
,
519 libbpf_dump_nlmsg_t dump_link_nlmsg
, void *cookie
);
520 int libbpf_nl_get_class(int sock
, unsigned int nl_pid
, int ifindex
,
521 libbpf_dump_nlmsg_t dump_class_nlmsg
, void *cookie
);
522 int libbpf_nl_get_qdisc(int sock
, unsigned int nl_pid
, int ifindex
,
523 libbpf_dump_nlmsg_t dump_qdisc_nlmsg
, void *cookie
);
524 int libbpf_nl_get_filter(int sock
, unsigned int nl_pid
, int ifindex
, int handle
,
525 libbpf_dump_nlmsg_t dump_filter_nlmsg
, void *cookie
);
527 struct bpf_prog_linfo
;
528 struct bpf_prog_info
;
530 LIBBPF_API
void bpf_prog_linfo__free(struct bpf_prog_linfo
*prog_linfo
);
531 LIBBPF_API
struct bpf_prog_linfo
*
532 bpf_prog_linfo__new(const struct bpf_prog_info
*info
);
533 LIBBPF_API
const struct bpf_line_info
*
534 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo
*prog_linfo
,
535 __u64 addr
, __u32 func_idx
, __u32 nr_skip
);
536 LIBBPF_API
const struct bpf_line_info
*
537 bpf_prog_linfo__lfind(const struct bpf_prog_linfo
*prog_linfo
,
538 __u32 insn_off
, __u32 nr_skip
);
541 * Probe for supported system features
543 * Note that running many of these probes in a short amount of time can cause
544 * the kernel to reach the maximal size of lockable memory allowed for the
545 * user, causing subsequent probes to fail. In this case, the caller may want
546 * to adjust that limit with setrlimit().
548 LIBBPF_API
bool bpf_probe_prog_type(enum bpf_prog_type prog_type
,
550 LIBBPF_API
bool bpf_probe_map_type(enum bpf_map_type map_type
, __u32 ifindex
);
551 LIBBPF_API
bool bpf_probe_helper(enum bpf_func_id id
,
552 enum bpf_prog_type prog_type
, __u32 ifindex
);
555 * Get bpf_prog_info in continuous memory
557 * struct bpf_prog_info has multiple arrays. The user has option to choose
558 * arrays to fetch from kernel. The following APIs provide an uniform way to
559 * fetch these data. All arrays in bpf_prog_info are stored in a single
560 * continuous memory region. This makes it easy to store the info in a
563 * Before writing bpf_prog_info_linear to files, it is necessary to
564 * translate pointers in bpf_prog_info to offsets. Helper functions
565 * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
566 * are introduced to switch between pointers and offsets.
569 * # To fetch map_ids and prog_tags:
570 * __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
571 * (1UL << BPF_PROG_INFO_PROG_TAGS);
572 * struct bpf_prog_info_linear *info_linear =
573 * bpf_program__get_prog_info_linear(fd, arrays);
575 * # To save data in file
576 * bpf_program__bpil_addr_to_offs(info_linear);
577 * write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
579 * # To read data from file
580 * read(f, info_linear, <proper_size>);
581 * bpf_program__bpil_offs_to_addr(info_linear);
583 enum bpf_prog_info_array
{
584 BPF_PROG_INFO_FIRST_ARRAY
= 0,
585 BPF_PROG_INFO_JITED_INSNS
= 0,
586 BPF_PROG_INFO_XLATED_INSNS
,
587 BPF_PROG_INFO_MAP_IDS
,
588 BPF_PROG_INFO_JITED_KSYMS
,
589 BPF_PROG_INFO_JITED_FUNC_LENS
,
590 BPF_PROG_INFO_FUNC_INFO
,
591 BPF_PROG_INFO_LINE_INFO
,
592 BPF_PROG_INFO_JITED_LINE_INFO
,
593 BPF_PROG_INFO_PROG_TAGS
,
594 BPF_PROG_INFO_LAST_ARRAY
,
597 struct bpf_prog_info_linear
{
598 /* size of struct bpf_prog_info, when the tool is compiled */
600 /* total bytes allocated for data, round up to 8 bytes */
602 /* which arrays are included in data */
604 struct bpf_prog_info info
;
608 LIBBPF_API
struct bpf_prog_info_linear
*
609 bpf_program__get_prog_info_linear(int fd
, __u64 arrays
);
612 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear
*info_linear
);
615 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear
*info_linear
);
618 * A helper function to get the number of possible CPUs before looking up
619 * per-CPU maps. Negative errno is returned on failure.
623 * int ncpus = libbpf_num_possible_cpus();
627 * long values[ncpus];
628 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
631 LIBBPF_API
int libbpf_num_possible_cpus(void);
637 #endif /* __LIBBPF_LIBBPF_H */