1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021 Facebook */
3 
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 
8 char _license[] SEC("license") = "GPL";
9 
10 struct {
11 	__uint(type, BPF_MAP_TYPE_HASH);
12 	__uint(max_entries, 1);
13 	__type(key, int);
14 	__type(value, long);
15 } hash1 SEC(".maps");
16 
17 struct {
18 	__uint(type, BPF_MAP_TYPE_HASH);
19 	__uint(max_entries, 1);
20 	__type(key, int);
21 	__type(value, long);
22 } hash2 SEC(".maps");
23 
24 int pass1 = 0;
25 int pass2 = 0;
26 
27 SEC("fentry/__htab_map_lookup_elem")
28 int BPF_PROG(on_lookup, struct bpf_map *map)
29 {
30 	int key = 0;
31 
32 	if (map == (void *)&hash1) {
33 		pass1++;
34 		return 0;
35 	}
36 	if (map == (void *)&hash2) {
37 		pass2++;
38 		/* htab_map_gen_lookup() will inline below call
39 		 * into direct call to __htab_map_lookup_elem()
40 		 */
41 		bpf_map_lookup_elem(&hash2, &key);
42 		return 0;
43 	}
44 
45 	return 0;
46 }
47