1// SPDX-License-Identifier: GPL-2.0
 2#include <stdio.h>
 3#include <linux/bpf.h>
 4#include <unistd.h>
 5#include <linux/filter.h>
 6#include <linux/seccomp.h>
 7#include <sys/prctl.h>
 8#include <bpf/bpf.h>
 9#include "bpf_load.h"
10#include <sys/resource.h>
11
12/* install fake seccomp program to enable seccomp code path inside the kernel,
13 * so that our kprobe attached to seccomp_phase1() can be triggered
14 */
15static void install_accept_all_seccomp(void)
16{
17	struct sock_filter filter[] = {
18		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
19	};
20	struct sock_fprog prog = {
21		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
22		.filter = filter,
23	};
24	if (prctl(PR_SET_SECCOMP, 2, &prog))
25		perror("prctl");
26}
27
28int main(int ac, char **argv)
29{
30	FILE *f;
31	char filename[256];
32	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
33
34	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
35	setrlimit(RLIMIT_MEMLOCK, &r);
36
37	if (load_bpf_file(filename)) {
38		printf("%s", bpf_log_buf);
39		return 1;
40	}
41
42	install_accept_all_seccomp();
43
44	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
45	(void) f;
46
47	read_trace_pipe();
48
49	return 0;
50}