xref: /openbmc/linux/samples/bpf/tracex4_user.c (revision 5c816641)
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 #include <sys/resource.h>
12 
13 #include <bpf/bpf.h>
14 #include <bpf/libbpf.h>
15 
16 struct pair {
17 	long long val;
18 	__u64 ip;
19 };
20 
21 static __u64 time_get_ns(void)
22 {
23 	struct timespec ts;
24 
25 	clock_gettime(CLOCK_MONOTONIC, &ts);
26 	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
27 }
28 
29 static void print_old_objects(int fd)
30 {
31 	long long val = time_get_ns();
32 	__u64 key, next_key;
33 	struct pair v;
34 
35 	key = write(1, "\e[1;1H\e[2J", 11); /* clear screen */
36 
37 	key = -1;
38 	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
39 		bpf_map_lookup_elem(fd, &next_key, &v);
40 		key = next_key;
41 		if (val - v.val < 1000000000ll)
42 			/* object was allocated more then 1 sec ago */
43 			continue;
44 		printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
45 		       next_key, (val - v.val) / 1000000000ll, v.ip);
46 	}
47 }
48 
49 int main(int ac, char **argv)
50 {
51 	struct bpf_link *links[2];
52 	struct bpf_program *prog;
53 	struct bpf_object *obj;
54 	char filename[256];
55 	int map_fd, i, j = 0;
56 
57 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
58 	obj = bpf_object__open_file(filename, NULL);
59 	if (libbpf_get_error(obj)) {
60 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
61 		return 0;
62 	}
63 
64 	/* load BPF program */
65 	if (bpf_object__load(obj)) {
66 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
67 		goto cleanup;
68 	}
69 
70 	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
71 	if (map_fd < 0) {
72 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
73 		goto cleanup;
74 	}
75 
76 	bpf_object__for_each_program(prog, obj) {
77 		links[j] = bpf_program__attach(prog);
78 		if (libbpf_get_error(links[j])) {
79 			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
80 			links[j] = NULL;
81 			goto cleanup;
82 		}
83 		j++;
84 	}
85 
86 	for (i = 0; ; i++) {
87 		print_old_objects(map_fd);
88 		sleep(1);
89 	}
90 
91 cleanup:
92 	for (j--; j >= 0; j--)
93 		bpf_link__destroy(links[j]);
94 
95 	bpf_object__close(obj);
96 	return 0;
97 }
98