xref: /linux/tools/testing/selftests/bpf/prog_tests/map_btf.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2023. Huawei Technologies Co., Ltd */
3 #include <test_progs.h>
4 
5 #include "normal_map_btf.skel.h"
6 #include "map_in_map_btf.skel.h"
7 
8 static void do_test_normal_map_btf(void)
9 {
10 	struct normal_map_btf *skel;
11 	int i, err, new_fd = -1;
12 	int map_fd_arr[64];
13 
14 	skel = normal_map_btf__open_and_load();
15 	if (!ASSERT_OK_PTR(skel, "open_load"))
16 		return;
17 
18 	err = normal_map_btf__attach(skel);
19 	if (!ASSERT_OK(err, "attach"))
20 		goto out;
21 
22 	skel->bss->pid = getpid();
23 	usleep(1);
24 	ASSERT_TRUE(skel->bss->done, "done");
25 
26 	/* Use percpu_array to slow bpf_map_free_deferred() down.
27 	 * The memory allocation may fail, so doesn't check the returned fd.
28 	 */
29 	for (i = 0; i < ARRAY_SIZE(map_fd_arr); i++)
30 		map_fd_arr[i] = bpf_map_create(BPF_MAP_TYPE_PERCPU_ARRAY, NULL, 4, 4, 256, NULL);
31 
32 	/* Close array fd later */
33 	new_fd = dup(bpf_map__fd(skel->maps.array));
34 out:
35 	normal_map_btf__destroy(skel);
36 	if (new_fd < 0)
37 		return;
38 	/* Use kern_sync_rcu() to wait for the start of the free of the bpf
39 	 * program and use an assumed delay to wait for the release of the map
40 	 * btf which is held by other maps (e.g, bss). After that, array map
41 	 * holds the last reference of map btf.
42 	 */
43 	kern_sync_rcu();
44 	usleep(4000);
45 	/* Spawn multiple kworkers to delay the invocation of
46 	 * bpf_map_free_deferred() for array map.
47 	 */
48 	for (i = 0; i < ARRAY_SIZE(map_fd_arr); i++) {
49 		if (map_fd_arr[i] < 0)
50 			continue;
51 		close(map_fd_arr[i]);
52 	}
53 	close(new_fd);
54 }
55 
56 static void do_test_map_in_map_btf(void)
57 {
58 	int err, zero = 0, new_fd = -1;
59 	struct map_in_map_btf *skel;
60 
61 	skel = map_in_map_btf__open_and_load();
62 	if (!ASSERT_OK_PTR(skel, "open_load"))
63 		return;
64 
65 	err = map_in_map_btf__attach(skel);
66 	if (!ASSERT_OK(err, "attach"))
67 		goto out;
68 
69 	skel->bss->pid = getpid();
70 	usleep(1);
71 	ASSERT_TRUE(skel->bss->done, "done");
72 
73 	/* Close inner_array fd later */
74 	new_fd = dup(bpf_map__fd(skel->maps.inner_array));
75 	/* Defer the free of inner_array */
76 	err = bpf_map__delete_elem(skel->maps.outer_array, &zero, sizeof(zero), 0);
77 	ASSERT_OK(err, "delete inner map");
78 out:
79 	map_in_map_btf__destroy(skel);
80 	if (new_fd < 0)
81 		return;
82 	/* Use kern_sync_rcu() to wait for the start of the free of the bpf
83 	 * program and use an assumed delay to wait for the free of the outer
84 	 * map and the release of map btf. After that, inner map holds the last
85 	 * reference of map btf.
86 	 */
87 	kern_sync_rcu();
88 	usleep(10000);
89 	close(new_fd);
90 }
91 
92 void test_map_btf(void)
93 {
94 	if (test__start_subtest("array_btf"))
95 		do_test_normal_map_btf();
96 	if (test__start_subtest("inner_array_btf"))
97 		do_test_map_in_map_btf();
98 }
99