xref: /linux/tools/perf/util/bpf-utils.h (revision ec714e371f22f716a04e6ecb2a24988c92b26911)
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  */
51 enum 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 
65 struct 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 
76 struct perf_bpil *
77 get_bpf_prog_info_linear(int fd, __u64 arrays);
78 
79 void
80 bpil_addr_to_offs(struct perf_bpil *info_linear);
81 
82 void
83 bpil_offs_to_addr(struct perf_bpil *info_linear);
84 
85 #endif /* HAVE_LIBBPF_SUPPORT */
86 #endif /* __PERF_BPF_UTILS_H */
87