test_kernel_flag.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3/*
 4 * Copyright (C) 2025 Microsoft Corporation
 5 *
 6 * Author: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
 7 */
 8
 9#include "vmlinux.h"
10#include <errno.h>
11#include <bpf/bpf_helpers.h>
12#include <bpf/bpf_tracing.h>
13
14char _license[] SEC("license") = "GPL";
15
16__u32 monitored_tid;
17
18SEC("lsm.s/bpf")
19int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size, bool kernel)
20{
21	__u32 tid;
22
23	tid = bpf_get_current_pid_tgid() & 0xFFFFFFFF;
24	if (!kernel || tid != monitored_tid)
25		return 0;
26	else
27		return -EINVAL;
28}