LXR linux/samples/bpf/syscall_tp

   1// SPDX-License-Identifier: GPL-2.0-only
   2/* Copyright (c) 2017 Facebook
   3 */
   4#include <uapi/linux/bpf.h>
   5#include "bpf_helpers.h"
   6
   7struct syscalls_enter_open_args {
   8        unsigned long long unused;
   9        long syscall_nr;
  10        long filename_ptr;
  11        long flags;
  12        long mode;
  13};
  14
  15struct syscalls_exit_open_args {
  16        unsigned long long unused;
  17        long syscall_nr;
  18        long ret;
  19};
  20
  21struct bpf_map_def SEC("maps") enter_open_map = {
  22        .type = BPF_MAP_TYPE_ARRAY,
  23        .key_size = sizeof(u32),
  24        .value_size = sizeof(u32),
  25        .max_entries = 1,
  26};
  27
  28struct bpf_map_def SEC("maps") exit_open_map = {
  29        .type = BPF_MAP_TYPE_ARRAY,
  30        .key_size = sizeof(u32),
  31        .value_size = sizeof(u32),
  32        .max_entries = 1,
  33};
  34
  35static __always_inline void count(void *map)
  36{
  37        u32 key = 0;
  38        u32 *value, init_val = 1;
  39
  40        value = bpf_map_lookup_elem(map, &key);
  41        if (value)
  42                *value += 1;
  43        else
  44                bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
  45}
  46
  47SEC("tracepoint/syscalls/sys_enter_open")
  48int trace_enter_open(struct syscalls_enter_open_args *ctx)
  49{
  50        count((void *)&enter_open_map);
  51        return 0;
  52}
  53
  54SEC("tracepoint/syscalls/sys_exit_open")
  55int trace_enter_exit(struct syscalls_exit_open_args *ctx)
  56{
  57        count((void *)&exit_open_map);
  58        return 0;
  59}
  60