1// SPDX-License-Identifier: GPL-2.0-only
 2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
 3
 4#include <test_progs.h>
 5#include "pro_epilogue.skel.h"
 6#include "epilogue_tailcall.skel.h"
 7#include "pro_epilogue_goto_start.skel.h"
 8#include "epilogue_exit.skel.h"
 9
10struct st_ops_args {
11	__u64 a;
12};
13
14static void test_tailcall(void)
15{
16	LIBBPF_OPTS(bpf_test_run_opts, topts);
17	struct epilogue_tailcall *skel;
18	struct st_ops_args args;
19	int err, prog_fd;
20
21	skel = epilogue_tailcall__open_and_load();
22	if (!ASSERT_OK_PTR(skel, "epilogue_tailcall__open_and_load"))
23		return;
24
25	topts.ctx_in = &args;
26	topts.ctx_size_in = sizeof(args);
27
28	skel->links.epilogue_tailcall =
29		bpf_map__attach_struct_ops(skel->maps.epilogue_tailcall);
30	if (!ASSERT_OK_PTR(skel->links.epilogue_tailcall, "attach_struct_ops"))
31		goto done;
32
33	/* Both test_epilogue_tailcall and test_epilogue_subprog are
34	 * patched with epilogue. When syscall_epilogue_tailcall()
35	 * is run, test_epilogue_tailcall() is triggered.
36	 * It executes a tail call and control is transferred to
37	 * test_epilogue_subprog(). Only test_epilogue_subprog()
38	 * does args->a += 1, thus final args.a value of 10001
39	 * guarantees that only the epilogue of the
40	 * test_epilogue_subprog is executed.
41	 */
42	memset(&args, 0, sizeof(args));
43	prog_fd = bpf_program__fd(skel->progs.syscall_epilogue_tailcall);
44	err = bpf_prog_test_run_opts(prog_fd, &topts);
45	ASSERT_OK(err, "bpf_prog_test_run_opts");
46	ASSERT_EQ(args.a, 10001, "args.a");
47	ASSERT_EQ(topts.retval, 10001 * 2, "topts.retval");
48
49done:
50	epilogue_tailcall__destroy(skel);
51}
52
53void test_pro_epilogue(void)
54{
55	RUN_TESTS(pro_epilogue);
56	RUN_TESTS(pro_epilogue_goto_start);
57	RUN_TESTS(epilogue_exit);
58	if (test__start_subtest("tailcall"))
59		test_tailcall();
60}