tools/perf/util/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
  12 /*
  13  * Get bpf_prog_info in continuous memory
  14  *
  15  * struct bpf_prog_info has multiple arrays. The user has option to choose
  16  * arrays to fetch from kernel. The following APIs provide an uniform way to
  17  * fetch these data. All arrays in bpf_prog_info are stored in a single
  18  * continuous memory region. This makes it easy to store the info in a
  19  * file.
  20  *
  21  * Before writing perf_bpil to files, it is necessary to
  22  * translate pointers in bpf_prog_info to offsets. Helper functions
  23  * bpil_addr_to_offs() and bpil_offs_to_addr()
  24  * are introduced to switch between pointers and offsets.
  25  *
  26  * Examples:
  27  *   # To fetch map_ids and prog_tags:
  28  *   __u64 arrays = (1UL << PERF_BPIL_MAP_IDS) |
  29  *           (1UL << PERF_BPIL_PROG_TAGS);
  30  *   struct perf_bpil *info_linear =
  31  *           get_bpf_prog_info_linear(fd, arrays);
  32  *
  33  *   # To save data in file
  34  *   bpil_addr_to_offs(info_linear);
  35  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
  36  *
  37  *   # To read data from file
  38  *   read(f, info_linear, <proper_size>);
  39  *   bpil_offs_to_addr(info_linear);
  40  */
  41 enum perf_bpil_array_types {
  42         PERF_BPIL_FIRST_ARRAY = 0,
  43         PERF_BPIL_JITED_INSNS = 0,
  44         PERF_BPIL_XLATED_INSNS,
  45         PERF_BPIL_MAP_IDS,
  46         PERF_BPIL_JITED_KSYMS,
  47         PERF_BPIL_JITED_FUNC_LENS,
  48         PERF_BPIL_FUNC_INFO,
  49         PERF_BPIL_LINE_INFO,
  50         PERF_BPIL_JITED_LINE_INFO,
  51         PERF_BPIL_PROG_TAGS,
  52         PERF_BPIL_LAST_ARRAY,
  53 };
  54
  55 struct perf_bpil {
  56         /* size of struct bpf_prog_info, when the tool is compiled */
  57         __u32                   info_len;
  58         /* total bytes allocated for data, round up to 8 bytes */
  59         __u32                   data_len;
  60         /* which arrays are included in data */
  61         __u64                   arrays;
  62         struct bpf_prog_info    info;
  63         __u8                    data[];
  64 };
  65
  66 struct perf_bpil *
  67 get_bpf_prog_info_linear(int fd, __u64 arrays);
  68
  69 void
  70 bpil_addr_to_offs(struct perf_bpil *info_linear);
  71
  72 void
  73 bpil_offs_to_addr(struct perf_bpil *info_linear);
  74
  75 #endif /* HAVE_LIBBPF_SUPPORT */
  76 #endif /* __PERF_BPF_UTILS_H */