[RFC/PATCH bpf-next 15/20] selftests/bpf: Add uprobe_multi link test

[Jiri Olsa <jolsa@xxxxxxxxxx>]

Adding uprobe_multi test for bpf_link_create attach function.

Testing attachment using the struct bpf_link_create_opts.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 .../bpf/prog_tests/uprobe_multi_test.c        | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index 179b78a4b711..abe620d844e7 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -110,6 +110,59 @@ static void test_attach_api_syms(void)
 	test_attach_api("/proc/self/exe", NULL, &opts);
 }
 
+void test_link_api(void)
+{
+	int prog_fd, link1_fd = -1, link2_fd = -1;
+	LIBBPF_OPTS(bpf_link_create_opts, opts);
+	struct uprobe_multi *skel = NULL;
+	unsigned long *offsets = NULL;
+	const char *syms[3] = {
+		"uprobe_multi_func_1",
+		"uprobe_multi_func_2",
+		"uprobe_multi_func_3",
+	};
+	const char *paths[3] = {
+		"/proc/self/exe",
+		"/proc/self/exe",
+		"/proc/self/exe",
+	};
+	int err;
+
+	err = elf_find_multi_func_offset(paths[0], 3, syms, (unsigned long **) &offsets);
+	if (!ASSERT_OK(err, "elf_find_multi_func_offset"))
+		return;
+
+	opts.uprobe_multi.paths = paths;
+	opts.uprobe_multi.offsets = offsets;
+	opts.uprobe_multi.cnt = ARRAY_SIZE(syms);
+
+	skel = uprobe_multi__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "uprobe_multi"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.test_uprobe);
+	link1_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
+	if (!ASSERT_GE(link1_fd, 0, "link_fd"))
+		goto cleanup;
+
+	opts.kprobe_multi.flags = BPF_F_UPROBE_MULTI_RETURN;
+	prog_fd = bpf_program__fd(skel->progs.test_uretprobe);
+	link2_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
+	if (!ASSERT_GE(link2_fd, 0, "link_fd"))
+		goto cleanup;
+
+	uprobe_multi_test_run(skel);
+
+cleanup:
+	if (link1_fd != -1)
+		close(link1_fd);
+	if (link2_fd != -1)
+		close(link2_fd);
+
+	uprobe_multi__destroy(skel);
+	free(offsets);
+}
+
 void test_uprobe_multi_test(void)
 {
 	if (test__start_subtest("skel_api"))
@@ -118,4 +171,6 @@ void test_uprobe_multi_test(void)
 		test_attach_api_pattern();
 	if (test__start_subtest("attach_api_syms"))
 		test_attach_api_syms();
+	if (test__start_subtest("link_api"))
+		test_link_api();
 }
-- 
2.40.0