[PATCHv2 bpf-next 24/24] selftests/bpf: Add extra link to uprobe_multi tests

[Jiri Olsa <jolsa@kernel.org>]

Attaching extra program to same functions system wide for api
and link tests.

This way we can test the pid filter works properly when there's
extra system wide consumer on the same uprobe that will trigger
the original uprobe handler.

We expect to have the same counts as before.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 .../bpf/prog_tests/uprobe_multi_test.c        | 19 +++++++++++++++++++
 .../selftests/bpf/progs/uprobe_multi.c        |  6 ++++++
 2 files changed, 25 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 efa7b5d49940..9057a228c12d 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -153,6 +153,7 @@ __test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_mul
 	struct bpf_link *link1 = NULL, *link2 = NULL;
 	struct bpf_link *link3 = NULL, *link4 = NULL;
 	pid_t pid = child ? child->pid : -1;
+	struct bpf_link *link_extra = NULL;
 	struct uprobe_multi *skel = NULL;
 
 	skel = uprobe_multi__open_and_load();
@@ -183,9 +184,16 @@ __test_attach_api(const char *binary, const char *pattern, struct bpf_uprobe_mul
 	if (!ASSERT_OK_PTR(link2, "bpf_program__attach_uprobe_multi_opts_retprobe"))
 		goto cleanup;
 
+	opts->retprobe = false;
+	link_extra = bpf_program__attach_uprobe_multi_opts(skel->progs.test_uprobe_extra, -1,
+						      binary, pattern, opts);
+	if (!ASSERT_OK_PTR(link_extra, "bpf_program__attach_uprobe_multi_opts"))
+		goto cleanup;
+
 	uprobe_multi_test_run(skel, child);
 
 cleanup:
+	bpf_link__destroy(link_extra);
 	bpf_link__destroy(link4);
 	bpf_link__destroy(link3);
 	bpf_link__destroy(link2);
@@ -243,6 +251,7 @@ static void __test_link_api(struct child *child)
 		"uprobe_multi_func_2",
 		"uprobe_multi_func_3",
 	};
+	int link_extra_fd = -1;
 	int err;
 
 	err = elf_find_multi_func_offset(path, 3, syms, (unsigned long **) &offsets);
@@ -281,6 +290,14 @@ static void __test_link_api(struct child *child)
 	link4_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
 	if (!ASSERT_GE(link2_fd, 0, "link4_fd"))
 		goto cleanup;
+
+	opts.kprobe_multi.flags = 0;
+	opts.uprobe_multi.pid = 0;
+	prog_fd = bpf_program__fd(skel->progs.test_uprobe_extra);
+	link_extra_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_MULTI, &opts);
+	if (!ASSERT_GE(link_extra_fd, 0, "link_extra_fd"))
+		goto cleanup;
+
 	uprobe_multi_test_run(skel, child);
 
 cleanup:
@@ -292,6 +309,8 @@ static void __test_link_api(struct child *child)
 		close(link3_fd);
 	if (link4_fd >= 0)
 		close(link4_fd);
+	if (link_extra_fd >= 0)
+		close(link_extra_fd);
 
 	uprobe_multi__destroy(skel);
 	free(offsets);
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi.c b/tools/testing/selftests/bpf/progs/uprobe_multi.c
index 1086312b5d1e..8ee957670303 100644
--- a/tools/testing/selftests/bpf/progs/uprobe_multi.c
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi.c
@@ -102,3 +102,9 @@ int test_uprobe_bench(struct pt_regs *ctx)
 	count++;
 	return 0;
 }
+
+SEC("uprobe.multi//proc/self/exe:uprobe_multi_func_*")
+int test_uprobe_extra(struct pt_regs *ctx)
+{
+	return 0;
+}
-- 
2.41.0