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
7 char _license[] SEC("license") = "GPL";
8
9 __u64 test1_hits = 0;
10 __u64 address_low = 0;
11 __u64 address_high = 0;
12 int wasted_entries = 0;
13 long total_entries = 0;
14
15 #define ENTRY_CNT 32
16 struct perf_branch_entry entries[ENTRY_CNT] = {};
17
18 static inline bool gbs_in_range(__u64 val)
19 {
20 return (val >= address_low) && (val < address_high);
21 }
22
23 SEC("fexit/bpf_testmod_loop_test")
24 int 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
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