LXR linux/tools/testing/selftests/bpf/get_cgroup_id

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2018 Facebook
   3
   4#include <linux/bpf.h>
   5#include "bpf_helpers.h"
   6
   7struct bpf_map_def SEC("maps") cg_ids = {
   8        .type = BPF_MAP_TYPE_ARRAY,
   9        .key_size = sizeof(__u32),
  10        .value_size = sizeof(__u64),
  11        .max_entries = 1,
  12};
  13
  14struct bpf_map_def SEC("maps") pidmap = {
  15        .type = BPF_MAP_TYPE_ARRAY,
  16        .key_size = sizeof(__u32),
  17        .value_size = sizeof(__u32),
  18        .max_entries = 1,
  19};
  20
  21SEC("tracepoint/syscalls/sys_enter_nanosleep")
  22int trace(void *ctx)
  23{
  24        __u32 pid = bpf_get_current_pid_tgid();
  25        __u32 key = 0, *expected_pid;
  26        __u64 *val;
  27
  28        expected_pid = bpf_map_lookup_elem(&pidmap, &key);
  29        if (!expected_pid || *expected_pid != pid)
  30                return 0;
  31
  32        val = bpf_map_lookup_elem(&cg_ids, &key);
  33        if (val)
  34                *val = bpf_get_current_cgroup_id();
  35
  36        return 0;
  37}
  38
  39char _license[] SEC("license") = "GPL";
  40__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */
  41