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
10 struct st_ops_args {
11 __u64 a;
12 };
13
14 static 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
49 done:
50 epilogue_tailcall__destroy(skel);
51 }
52
53 void 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 }
61
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