xref: /linux/tools/testing/selftests/bpf/prog_tests/btf_map_keyless.c (revision 2beb1b31a12b57e19cd5c82ea6d54e56520605e8)
1*6265b44fSJiayuan Chen // SPDX-License-Identifier: GPL-2.0
2*6265b44fSJiayuan Chen #include <test_progs.h>
3*6265b44fSJiayuan Chen #include <bpf/btf.h>
4*6265b44fSJiayuan Chen 
5*6265b44fSJiayuan Chen /*
6*6265b44fSJiayuan Chen  * A hash map with a key-less BTF (btf_key_type_id == 0) used to be accepted
7*6265b44fSJiayuan Chen  * and then NULL-deref in btf_type_show() when dumped through bpffs. A fixed
8*6265b44fSJiayuan Chen  * kernel rejects it at creation; verify that rejection, with a keyed positive
9*6265b44fSJiayuan Chen  * control so the -EINVAL is about the missing key type and not some unrelated
10*6265b44fSJiayuan Chen  * failure.
11*6265b44fSJiayuan Chen  */
check_keyless(int map_type,__u32 map_flags,int btf_fd,int val_id)12*6265b44fSJiayuan Chen static void check_keyless(int map_type, __u32 map_flags, int btf_fd, int val_id)
13*6265b44fSJiayuan Chen {
14*6265b44fSJiayuan Chen 	LIBBPF_OPTS(bpf_map_create_opts, opts);
15*6265b44fSJiayuan Chen 	int map_fd;
16*6265b44fSJiayuan Chen 
17*6265b44fSJiayuan Chen 	opts.map_flags = map_flags;
18*6265b44fSJiayuan Chen 	opts.btf_fd = btf_fd;
19*6265b44fSJiayuan Chen 	opts.btf_value_type_id = val_id;
20*6265b44fSJiayuan Chen 
21*6265b44fSJiayuan Chen 	/* Positive control: the same map with a real key type is accepted. */
22*6265b44fSJiayuan Chen 	opts.btf_key_type_id = val_id;
23*6265b44fSJiayuan Chen 	map_fd = bpf_map_create(map_type, "keyed_map", 4, 4, 8, &opts);
24*6265b44fSJiayuan Chen 	if (!ASSERT_GE(map_fd, 0, "keyed create is accepted"))
25*6265b44fSJiayuan Chen 		return;
26*6265b44fSJiayuan Chen 	close(map_fd);
27*6265b44fSJiayuan Chen 
28*6265b44fSJiayuan Chen 	/* A key-less BTF must be rejected. */
29*6265b44fSJiayuan Chen 	opts.btf_key_type_id = 0;
30*6265b44fSJiayuan Chen 	map_fd = bpf_map_create(map_type, "keyless_map", 4, 4, 8, &opts);
31*6265b44fSJiayuan Chen 	ASSERT_EQ(map_fd, -EINVAL, "key-less create is rejected");
32*6265b44fSJiayuan Chen 	if (map_fd >= 0)
33*6265b44fSJiayuan Chen 		close(map_fd);
34*6265b44fSJiayuan Chen }
35*6265b44fSJiayuan Chen 
test_btf_map_keyless(void)36*6265b44fSJiayuan Chen void test_btf_map_keyless(void)
37*6265b44fSJiayuan Chen {
38*6265b44fSJiayuan Chen 	int btf_fd, val_id;
39*6265b44fSJiayuan Chen 	struct btf *btf;
40*6265b44fSJiayuan Chen 
41*6265b44fSJiayuan Chen 	btf = btf__new_empty();
42*6265b44fSJiayuan Chen 	if (!ASSERT_OK_PTR(btf, "btf__new_empty"))
43*6265b44fSJiayuan Chen 		return;
44*6265b44fSJiayuan Chen 
45*6265b44fSJiayuan Chen 	val_id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
46*6265b44fSJiayuan Chen 	if (!ASSERT_GT(val_id, 0, "btf__add_int"))
47*6265b44fSJiayuan Chen 		goto out;
48*6265b44fSJiayuan Chen 
49*6265b44fSJiayuan Chen 	if (!ASSERT_OK(btf__load_into_kernel(btf), "btf__load_into_kernel"))
50*6265b44fSJiayuan Chen 		goto out;
51*6265b44fSJiayuan Chen 	btf_fd = btf__fd(btf);
52*6265b44fSJiayuan Chen 
53*6265b44fSJiayuan Chen 	if (test__start_subtest("hash"))
54*6265b44fSJiayuan Chen 		check_keyless(BPF_MAP_TYPE_HASH, 0, btf_fd, val_id);
55*6265b44fSJiayuan Chen 	if (test__start_subtest("rhash"))
56*6265b44fSJiayuan Chen 		check_keyless(BPF_MAP_TYPE_RHASH, BPF_F_NO_PREALLOC, btf_fd, val_id);
57*6265b44fSJiayuan Chen out:
58*6265b44fSJiayuan Chen 	btf__free(btf);
59*6265b44fSJiayuan Chen }
60