LXR linux/tools/perf/include/bpf/bpf.h

   1// SPDX-License-Identifier: GPL-2.0
   2#ifndef _PERF_BPF_H
   3#define _PERF_BPF_H
   4
   5#include <uapi/linux/bpf.h>
   6
   7/*
   8 * A helper structure used by eBPF C program to describe map attributes to
   9 * elf_bpf loader, taken from tools/testing/selftests/bpf/bpf_helpers.h:
  10 */
  11struct bpf_map {
  12        unsigned int type;
  13        unsigned int key_size;
  14        unsigned int value_size;
  15        unsigned int max_entries;
  16        unsigned int map_flags;
  17        unsigned int inner_map_idx;
  18        unsigned int numa_node;
  19};
  20
  21#define bpf_map(name, _type, type_key, type_val, _max_entries)  \
  22struct bpf_map SEC("maps") name = {                             \
  23        .type        = BPF_MAP_TYPE_##_type,                    \
  24        .key_size    = sizeof(type_key),                        \
  25        .value_size  = sizeof(type_val),                        \
  26        .max_entries = _max_entries,                            \
  27};                                                              \
  28struct ____btf_map_##name {                                     \
  29        type_key key;                                           \
  30        type_val value;                                         \
  31};                                                              \
  32struct ____btf_map_##name __attribute__((section(".maps." #name), used)) \
  33        ____btf_map_##name = { }
  34
  35/*
  36 * FIXME: this should receive .max_entries as a parameter, as careful
  37 *        tuning of these limits is needed to avoid hitting limits that
  38 *        prevents other BPF constructs, such as tracepoint handlers,
  39 *        to get installed, with cryptic messages from libbpf, etc.
  40 *        For the current need, 'perf trace --filter-pids', 64 should
  41 *        be good enough, but this surely needs to be revisited.
  42 */
  43#define pid_map(name, value_type) bpf_map(name, HASH, pid_t, value_type, 64)
  44
  45static int (*bpf_map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags) = (void *)BPF_FUNC_map_update_elem;
  46static void *(*bpf_map_lookup_elem)(struct bpf_map *map, void *key) = (void *)BPF_FUNC_map_lookup_elem;
  47
  48static void (*bpf_tail_call)(void *ctx, void *map, int index) = (void *)BPF_FUNC_tail_call;
  49
  50#define SEC(NAME) __attribute__((section(NAME),  used))
  51
  52#define probe(function, vars) \
  53        SEC(#function "=" #function " " #vars) function
  54
  55#define syscall_enter(name) \
  56        SEC("syscalls:sys_enter_" #name) syscall_enter_ ## name
  57
  58#define syscall_exit(name) \
  59        SEC("syscalls:sys_exit_" #name) syscall_exit_ ## name
  60
  61#define license(name) \
  62char _license[] SEC("license") = #name; \
  63int _version SEC("version") = LINUX_VERSION_CODE;
  64
  65static int (*probe_read)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read;
  66static int (*probe_read_str)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read_str;
  67
  68static int (*perf_event_output)(void *, struct bpf_map *, int, void *, unsigned long) = (void *)BPF_FUNC_perf_event_output;
  69
  70#endif /* _PERF_BPF_H */
  71