1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2021 Facebook */
3#include "vmlinux.h"
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6
7char _license[] SEC("license") = "GPL";
8
9__u64 test1_hits = 0;
10__u64 address_low = 0;
11__u64 address_high = 0;
12int wasted_entries = 0;
13long total_entries = 0;
14
15#define ENTRY_CNT 32
16struct perf_branch_entry entries[ENTRY_CNT] = {};
17
18static inline bool gbs_in_range(__u64 val)
19{
20	return (val >= address_low) && (val < address_high);
21}
22
23SEC("fexit/bpf_testmod_loop_test")
24int BPF_PROG(test1, int n, int ret)
25{
26	long i;
27
28	total_entries = bpf_get_branch_snapshot(entries, sizeof(entries), 0);
29	total_entries /= sizeof(struct perf_branch_entry);
30
31	for (i = 0; i < ENTRY_CNT; i++) {
32		if (i >= total_entries)
33			break;
34		if (gbs_in_range(entries[i].from) && gbs_in_range(entries[i].to))
35			test1_hits++;
36		else if (!test1_hits)
37			wasted_entries++;
38	}
39	return 0;
40}
41