xref: /linux/samples/bpf/spintest_user.c (revision f85f5ae45ad945270a8884261de8249431e8b5a6)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <unistd.h>
4 #include <string.h>
5 #include <assert.h>
6 #include <bpf/libbpf.h>
7 #include <bpf/bpf.h>
8 #include "trace_helpers.h"
9 
10 int main(int ac, char **argv)
11 {
12 	struct bpf_object *obj = NULL;
13 	struct bpf_link *links[20];
14 	long key, next_key, value;
15 	struct bpf_program *prog;
16 	int map_fd, i, j = 0;
17 	char filename[256];
18 	struct ksym *sym;
19 
20 	if (load_kallsyms()) {
21 		printf("failed to process /proc/kallsyms\n");
22 		return 2;
23 	}
24 
25 	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
26 	obj = bpf_object__open_file(filename, NULL);
27 	if (libbpf_get_error(obj)) {
28 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
29 		obj = NULL;
30 		goto cleanup;
31 	}
32 
33 	/* load BPF program */
34 	if (bpf_object__load(obj)) {
35 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
36 		goto cleanup;
37 	}
38 
39 	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
40 	if (map_fd < 0) {
41 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
42 		goto cleanup;
43 	}
44 
45 	bpf_object__for_each_program(prog, obj) {
46 		links[j] = bpf_program__attach(prog);
47 		if (libbpf_get_error(links[j])) {
48 			fprintf(stderr, "bpf_program__attach failed\n");
49 			links[j] = NULL;
50 			goto cleanup;
51 		}
52 		j++;
53 	}
54 
55 	for (i = 0; i < 5; i++) {
56 		key = 0;
57 		printf("kprobing funcs:");
58 		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
59 			bpf_map_lookup_elem(map_fd, &next_key, &value);
60 			assert(next_key == value);
61 			sym = ksym_search(value);
62 			key = next_key;
63 			if (!sym) {
64 				printf("ksym not found. Is kallsyms loaded?\n");
65 				continue;
66 			}
67 
68 			printf(" %s", sym->name);
69 		}
70 		if (key)
71 			printf("\n");
72 		key = 0;
73 		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
74 			bpf_map_delete_elem(map_fd, &next_key);
75 		sleep(1);
76 	}
77 
78 cleanup:
79 	for (j--; j >= 0; j--)
80 		bpf_link__destroy(links[j]);
81 
82 	bpf_object__close(obj);
83 	return 0;
84 }
85