bpf-utils.h

 1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
 2
 3#ifndef __PERF_BPF_UTILS_H
 4#define __PERF_BPF_UTILS_H
 5
 6#define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
 7
 8#ifdef HAVE_LIBBPF_SUPPORT
 9
10#include <bpf/libbpf.h>
11#include <bpf/libbpf_version.h>
12
13#define LIBBPF_CURRENT_VERSION_GEQ(major, minor)                       \
14       (LIBBPF_MAJOR_VERSION > (major) ||                              \
15        (LIBBPF_MAJOR_VERSION == (major) && LIBBPF_MINOR_VERSION >= (minor)))
16
17#if LIBBPF_CURRENT_VERSION_GEQ(1, 7)
18// libbpf 1.7+ support the btf_dump_type_data_opts.emit_strings option.
19#define HAVE_LIBBPF_STRINGS_SUPPORT 1
20#endif
21
22/*
23 * Get bpf_prog_info in continuous memory
24 *
25 * struct bpf_prog_info has multiple arrays. The user has option to choose
26 * arrays to fetch from kernel. The following APIs provide an uniform way to
27 * fetch these data. All arrays in bpf_prog_info are stored in a single
28 * continuous memory region. This makes it easy to store the info in a
29 * file.
30 *
31 * Before writing perf_bpil to files, it is necessary to
32 * translate pointers in bpf_prog_info to offsets. Helper functions
33 * bpil_addr_to_offs() and bpil_offs_to_addr()
34 * are introduced to switch between pointers and offsets.
35 *
36 * Examples:
37 *   # To fetch map_ids and prog_tags:
38 *   __u64 arrays = (1UL << PERF_BPIL_MAP_IDS) |
39 *           (1UL << PERF_BPIL_PROG_TAGS);
40 *   struct perf_bpil *info_linear =
41 *           get_bpf_prog_info_linear(fd, arrays);
42 *
43 *   # To save data in file
44 *   bpil_addr_to_offs(info_linear);
45 *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
46 *
47 *   # To read data from file
48 *   read(f, info_linear, <proper_size>);
49 *   bpil_offs_to_addr(info_linear);
50 */
51enum perf_bpil_array_types {
52	PERF_BPIL_FIRST_ARRAY = 0,
53	PERF_BPIL_JITED_INSNS = 0,
54	PERF_BPIL_XLATED_INSNS,
55	PERF_BPIL_MAP_IDS,
56	PERF_BPIL_JITED_KSYMS,
57	PERF_BPIL_JITED_FUNC_LENS,
58	PERF_BPIL_FUNC_INFO,
59	PERF_BPIL_LINE_INFO,
60	PERF_BPIL_JITED_LINE_INFO,
61	PERF_BPIL_PROG_TAGS,
62	PERF_BPIL_LAST_ARRAY,
63};
64
65struct perf_bpil {
66	/* size of struct bpf_prog_info, when the tool is compiled */
67	__u32			info_len;
68	/* total bytes allocated for data, round up to 8 bytes */
69	__u32			data_len;
70	/* which arrays are included in data */
71	__u64			arrays;
72	struct bpf_prog_info	info;
73	__u8			data[];
74};
75
76struct perf_bpil *
77get_bpf_prog_info_linear(int fd, __u64 arrays);
78
79void
80bpil_addr_to_offs(struct perf_bpil *info_linear);
81
82void
83bpil_offs_to_addr(struct perf_bpil *info_linear);
84
85#endif /* HAVE_LIBBPF_SUPPORT */
86#endif /* __PERF_BPF_UTILS_H */