xref: /linux/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c (revision 06bc7ff0a1e0f2b0102e1314e3527a7ec0997851)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Verify that context-sensitive SCX kfuncs (even "unlocked" ones) are
4  * restricted to only SCX struct_ops programs. Non-SCX struct_ops programs,
5  * such as TCP congestion control programs, should be rejected by the BPF
6  * verifier when attempting to call these kfuncs.
7  *
8  * Copyright (C) 2026 Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
9  * Copyright (C) 2026 Cheng-Yang Chou <yphbchou0911@gmail.com>
10  */
11 
12 #include <bpf/bpf.h>
13 #include <scx/common.h>
14 #include <unistd.h>
15 #include <errno.h>
16 #include <stdio.h>
17 #include "non_scx_kfunc_deny.bpf.skel.h"
18 #include "scx_test.h"
19 
run(void * ctx)20 static enum scx_test_status run(void *ctx)
21 {
22 	struct non_scx_kfunc_deny *skel;
23 	int err;
24 
25 	skel = non_scx_kfunc_deny__open();
26 	if (!skel) {
27 		SCX_ERR("Failed to open skel");
28 		return SCX_TEST_FAIL;
29 	}
30 
31 	err = non_scx_kfunc_deny__load(skel);
32 	non_scx_kfunc_deny__destroy(skel);
33 
34 	if (err == 0) {
35 		SCX_ERR("non-SCX BPF program loaded when it should have been rejected");
36 		return SCX_TEST_FAIL;
37 	}
38 
39 	return SCX_TEST_PASS;
40 }
41 
42 struct scx_test non_scx_kfunc_deny = {
43 	.name = "non_scx_kfunc_deny",
44 	.description = "Verify that non-SCX struct_ops programs cannot call SCX kfuncs",
45 	.run = run,
46 };
47 REGISTER_SCX_TEST(&non_scx_kfunc_deny)
48