1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <bpf/btf.h>
4
5 /*
6 * A hash map with a key-less BTF (btf_key_type_id == 0) used to be accepted
7 * and then NULL-deref in btf_type_show() when dumped through bpffs. A fixed
8 * kernel rejects it at creation; verify that rejection, with a keyed positive
9 * control so the -EINVAL is about the missing key type and not some unrelated
10 * failure.
11 */
check_keyless(int map_type,__u32 map_flags,int btf_fd,int val_id)12 static void check_keyless(int map_type, __u32 map_flags, int btf_fd, int val_id)
13 {
14 LIBBPF_OPTS(bpf_map_create_opts, opts);
15 int map_fd;
16
17 opts.map_flags = map_flags;
18 opts.btf_fd = btf_fd;
19 opts.btf_value_type_id = val_id;
20
21 /* Positive control: the same map with a real key type is accepted. */
22 opts.btf_key_type_id = val_id;
23 map_fd = bpf_map_create(map_type, "keyed_map", 4, 4, 8, &opts);
24 if (!ASSERT_GE(map_fd, 0, "keyed create is accepted"))
25 return;
26 close(map_fd);
27
28 /* A key-less BTF must be rejected. */
29 opts.btf_key_type_id = 0;
30 map_fd = bpf_map_create(map_type, "keyless_map", 4, 4, 8, &opts);
31 ASSERT_EQ(map_fd, -EINVAL, "key-less create is rejected");
32 if (map_fd >= 0)
33 close(map_fd);
34 }
35
test_btf_map_keyless(void)36 void test_btf_map_keyless(void)
37 {
38 int btf_fd, val_id;
39 struct btf *btf;
40
41 btf = btf__new_empty();
42 if (!ASSERT_OK_PTR(btf, "btf__new_empty"))
43 return;
44
45 val_id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
46 if (!ASSERT_GT(val_id, 0, "btf__add_int"))
47 goto out;
48
49 if (!ASSERT_OK(btf__load_into_kernel(btf), "btf__load_into_kernel"))
50 goto out;
51 btf_fd = btf__fd(btf);
52
53 if (test__start_subtest("hash"))
54 check_keyless(BPF_MAP_TYPE_HASH, 0, btf_fd, val_id);
55 if (test__start_subtest("rhash"))
56 check_keyless(BPF_MAP_TYPE_RHASH, BPF_F_NO_PREALLOC, btf_fd, val_id);
57 out:
58 btf__free(btf);
59 }
60