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 gbs_in_range(__u64 val)18static 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") BPF_PROG(test1,int n,int ret)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