1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2021 Facebook */
3#include <test_progs.h>
4#include "test_legacy_printk.skel.h"
5
6static int execute_one_variant(bool legacy)
7{
8	struct test_legacy_printk *skel;
9	int err, zero = 0, my_pid = getpid(), res, map_fd;
10
11	skel = test_legacy_printk__open();
12	if (!ASSERT_OK_PTR(skel, "skel_open"))
13		return -errno;
14
15	bpf_program__set_autoload(skel->progs.handle_legacy, legacy);
16	bpf_program__set_autoload(skel->progs.handle_modern, !legacy);
17
18	err = test_legacy_printk__load(skel);
19	/* no ASSERT_OK, we expect one of two variants can fail here */
20	if (err)
21		goto err_out;
22
23	if (legacy) {
24		map_fd = bpf_map__fd(skel->maps.my_pid_map);
25		err = bpf_map_update_elem(map_fd, &zero, &my_pid, BPF_ANY);
26		if (!ASSERT_OK(err, "my_pid_map_update"))
27			goto err_out;
28		err = bpf_map_lookup_elem(map_fd, &zero, &res);
29	} else {
30		skel->bss->my_pid_var = my_pid;
31	}
32
33	err = test_legacy_printk__attach(skel);
34	if (!ASSERT_OK(err, "skel_attach"))
35		goto err_out;
36
37	usleep(1); /* trigger */
38
39	if (legacy) {
40		map_fd = bpf_map__fd(skel->maps.res_map);
41		err = bpf_map_lookup_elem(map_fd, &zero, &res);
42		if (!ASSERT_OK(err, "res_map_lookup"))
43			goto err_out;
44	} else {
45		res = skel->bss->res_var;
46	}
47
48	if (!ASSERT_GT(res, 0, "res")) {
49		err = -EINVAL;
50		goto err_out;
51	}
52
53err_out:
54	test_legacy_printk__destroy(skel);
55	return err;
56}
57
58void test_legacy_printk(void)
59{
60	/* legacy variant should work everywhere */
61	ASSERT_OK(execute_one_variant(true /* legacy */), "legacy_case");
62
63	/* execute modern variant, can fail the load on old kernels */
64	execute_one_variant(false);
65}
66