1#include <stdio.h>
2#include <linux/bpf.h>
3#include <unistd.h>
4#include <linux/filter.h>
5#include <linux/seccomp.h>
6#include <sys/prctl.h>
7#include "libbpf.h"
8#include "bpf_load.h"
9
10/* install fake seccomp program to enable seccomp code path inside the kernel,
11 * so that our kprobe attached to seccomp_phase1() can be triggered
12 */
13static void install_accept_all_seccomp(void)
14{
15	struct sock_filter filter[] = {
16		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
17	};
18	struct sock_fprog prog = {
19		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
20		.filter = filter,
21	};
22	if (prctl(PR_SET_SECCOMP, 2, &prog))
23		perror("prctl");
24}
25
26int main(int ac, char **argv)
27{
28	FILE *f;
29	char filename[256];
30
31	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
32
33	if (load_bpf_file(filename)) {
34		printf("%s", bpf_log_buf);
35		return 1;
36	}
37
38	install_accept_all_seccomp();
39
40	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
41	(void) f;
42
43	read_trace_pipe();
44
45	return 0;
46}
47