tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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 */