xref: /linux/samples/bpf/tracex4_user.c (revision d8e473182ab9e85708067be81d20424045d939fa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
3  */
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <signal.h>
7 #include <unistd.h>
8 #include <stdbool.h>
9 #include <string.h>
10 #include <time.h>
11 
12 #include <bpf/bpf.h>
13 #include <bpf/libbpf.h>
14 
15 struct pair {
16 	long long val;
17 	__u64 ip;
18 };
19 
20 static __u64 time_get_ns(void)
21 {
22 	struct timespec ts;
23 
24 	clock_gettime(CLOCK_MONOTONIC, &ts);
25 	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
26 }
27 
28 static void print_old_objects(int fd)
29 {
30 	long long val = time_get_ns();
31 	__u64 key, next_key;
32 	struct pair v;
33 
34 	key = write(1, "\e[1;1H\e[2J", 11); /* clear screen */
35 
36 	key = -1;
37 	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
38 		bpf_map_lookup_elem(fd, &next_key, &v);
39 		key = next_key;
40 		if (val - v.val < 1000000000ll)
41 			/* object was allocated more then 1 sec ago */
42 			continue;
43 		printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
44 		       next_key, (val - v.val) / 1000000000ll, v.ip);
45 	}
46 }
47 
48 int main(int ac, char **argv)
49 {
50 	struct bpf_link *links[2];
51 	struct bpf_program *prog;
52 	struct bpf_object *obj;
53 	char filename[256];
54 	int map_fd, j = 0;
55 
56 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
57 	obj = bpf_object__open_file(filename, NULL);
58 	if (libbpf_get_error(obj)) {
59 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
60 		return 0;
61 	}
62 
63 	/* load BPF program */
64 	if (bpf_object__load(obj)) {
65 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
66 		goto cleanup;
67 	}
68 
69 	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
70 	if (map_fd < 0) {
71 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
72 		goto cleanup;
73 	}
74 
75 	bpf_object__for_each_program(prog, obj) {
76 		links[j] = bpf_program__attach(prog);
77 		if (libbpf_get_error(links[j])) {
78 			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
79 			links[j] = NULL;
80 			goto cleanup;
81 		}
82 		j++;
83 	}
84 
85 	while (1) {
86 		print_old_objects(map_fd);
87 		sleep(1);
88 	}
89 
90 cleanup:
91 	for (j--; j >= 0; j--)
92 		bpf_link__destroy(links[j]);
93 
94 	bpf_object__close(obj);
95 	return 0;
96 }
97