1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2017 Facebook
*/
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <linux/perf_event.h>
#include <errno.h>
#include <sys/resource.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.
* This requires kernel CONFIG_FTRACE_SYSCALLS to be set.
*/
static void usage(const char *cmd)
{
printf("USAGE: %s [-i num_progs] [-h]\n", cmd);
printf(" -i num_progs # number of progs of the test\n");
printf(" -h # help\n");
}
static void verify_map(int map_id)
{
__u32 key = 0;
__u32 val;
if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
return;
}
if (val == 0) {
fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
return;
}
val = 0;
if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
fprintf(stderr, "map_update failed: %s\n", strerror(errno));
return;
}
}
static int test(char *filename, int num_progs)
{
int map0_fds[num_progs], map1_fds[num_progs], fd, i, j = 0;
struct bpf_link *links[num_progs * 4];
struct bpf_object *objs[num_progs];
struct bpf_program *prog;
for (i = 0; i < num_progs; i++) {
objs[i] = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(objs[i])) {
fprintf(stderr, "opening BPF object file failed\n");
objs[i] = NULL;
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(objs[i])) {
fprintf(stderr, "loading BPF object file failed\n");
goto cleanup;
}
map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
"enter_open_map");
map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
"exit_open_map");
if (map0_fds[i] < 0 || map1_fds[i] < 0) {
fprintf(stderr, "finding a map in obj file failed\n");
goto cleanup;
}
bpf_object__for_each_program(prog, objs[i]) {
links[j] = bpf_program__attach(prog);
if (libbpf_get_error(links[j])) {
fprintf(stderr, "bpf_program__attach failed\n");
links[j] = NULL;
goto cleanup;
}
j++;
}
printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);
}
/* current load_bpf_file has perf_event_open default pid = -1
* and cpu = 0, which permits attached bpf execution on
* all cpus for all pid's. bpf program execution ignores
* cpu affinity.
*/
/* trigger some "open" operations */
fd = open(filename, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "open failed: %s\n", strerror(errno));
return 1;
}
close(fd);
/* verify the map */
for (i = 0; i < num_progs; i++) {
verify_map(map0_fds[i]);
verify_map(map1_fds[i]);
}
cleanup:
for (j--; j >= 0; j--)
bpf_link__destroy(links[j]);
for (i--; i >= 0; i--)
bpf_object__close(objs[i]);
return 0;
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
int opt, num_progs = 1;
char filename[256];
while ((opt = getopt(argc, argv, "i:h")) != -1) {
switch (opt) {
case 'i':
num_progs = atoi(optarg);
break;
case 'h':
default:
usage(argv[0]);
return 0;
}
}
setrlimit(RLIMIT_MEMLOCK, &r);
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
return test(filename, num_progs);
}
|
