perf/util/bpf-utils.h

0001 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
0002
0003 #ifndef __PERF_BPF_UTILS_H
0004 #define __PERF_BPF_UTILS_H
0005
0006 #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
0007
0008 #ifdef HAVE_LIBBPF_SUPPORT
0009
0010 #include <bpf/libbpf.h>
0011
0012 /*
0013  * Get bpf_prog_info in continuous memory
0014  *
0015  * struct bpf_prog_info has multiple arrays. The user has option to choose
0016  * arrays to fetch from kernel. The following APIs provide an uniform way to
0017  * fetch these data. All arrays in bpf_prog_info are stored in a single
0018  * continuous memory region. This makes it easy to store the info in a
0019  * file.
0020  *
0021  * Before writing perf_bpil to files, it is necessary to
0022  * translate pointers in bpf_prog_info to offsets. Helper functions
0023  * bpil_addr_to_offs() and bpil_offs_to_addr()
0024  * are introduced to switch between pointers and offsets.
0025  *
0026  * Examples:
0027  *   # To fetch map_ids and prog_tags:
0028  *   __u64 arrays = (1UL << PERF_BPIL_MAP_IDS) |
0029  *           (1UL << PERF_BPIL_PROG_TAGS);
0030  *   struct perf_bpil *info_linear =
0031  *           get_bpf_prog_info_linear(fd, arrays);
0032  *
0033  *   # To save data in file
0034  *   bpil_addr_to_offs(info_linear);
0035  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
0036  *
0037  *   # To read data from file
0038  *   read(f, info_linear, <proper_size>);
0039  *   bpil_offs_to_addr(info_linear);
0040  */
0041 enum perf_bpil_array_types {
0042     PERF_BPIL_FIRST_ARRAY = 0,
0043     PERF_BPIL_JITED_INSNS = 0,
0044     PERF_BPIL_XLATED_INSNS,
0045     PERF_BPIL_MAP_IDS,
0046     PERF_BPIL_JITED_KSYMS,
0047     PERF_BPIL_JITED_FUNC_LENS,
0048     PERF_BPIL_FUNC_INFO,
0049     PERF_BPIL_LINE_INFO,
0050     PERF_BPIL_JITED_LINE_INFO,
0051     PERF_BPIL_PROG_TAGS,
0052     PERF_BPIL_LAST_ARRAY,
0053 };
0054
0055 struct perf_bpil {
0056     /* size of struct bpf_prog_info, when the tool is compiled */
0057     __u32           info_len;
0058     /* total bytes allocated for data, round up to 8 bytes */
0059     __u32           data_len;
0060     /* which arrays are included in data */
0061     __u64           arrays;
0062     struct bpf_prog_info    info;
0063     __u8            data[];
0064 };
0065
0066 struct perf_bpil *
0067 get_bpf_prog_info_linear(int fd, __u64 arrays);
0068
0069 void
0070 bpil_addr_to_offs(struct perf_bpil *info_linear);
0071
0072 void
0073 bpil_offs_to_addr(struct perf_bpil *info_linear);
0074
0075 #endif /* HAVE_LIBBPF_SUPPORT */
0076 #endif /* __PERF_BPF_UTILS_H */