[RFC bpf-next 3/4] selftests/bpf: add tests for u[ret]probe attach by name

[Alan Maguire <alan.maguire@xxxxxxxxxx>]

add tests that verify attaching by name for a local and library
function succeed for uprobe and uretprobe using new "func_name"
option for bpf_program__attach_uprobe_opts().

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
---
 .../selftests/bpf/prog_tests/attach_probe.c        | 41 +++++++++++++++++++++-
 .../selftests/bpf/progs/test_attach_probe.c        | 16 +++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index d0bd51e..521d7bd 100644
--- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
+++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
@@ -10,12 +10,18 @@ static void method(void) {
 	return ;
 }
 
+/* attach point for byname uprobe */
+static void method2(void) {
+	return;
+}
+
 void test_attach_probe(void)
 {
 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
 	int duration = 0;
 	struct bpf_link *kprobe_link, *kretprobe_link;
 	struct bpf_link *uprobe_link, *uretprobe_link;
+	struct bpf_link *uprobe_byname_link, *uretprobe_byname_link;
 	struct test_attach_probe* skel;
 	size_t uprobe_offset;
 	ssize_t base_addr, ref_ctr_offset;
@@ -92,7 +98,30 @@ void test_attach_probe(void)
 		goto cleanup;
 	skel->links.handle_uretprobe = uretprobe_link;
 
-	/* trigger & validate kprobe && kretprobe */
+	uprobe_opts.func_name = "method2";
+	uprobe_opts.retprobe = false;
+	uprobe_opts.ref_ctr_offset = 0;
+	uprobe_byname_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uprobe_byname,
+							     0 /* this pid */,
+							     "/proc/self/exe",
+							     0, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uprobe_byname_link, "attach_uprobe_byname"))
+		goto cleanup;
+	skel->links.handle_uprobe_byname = uprobe_byname_link;
+
+	/* test attach by name for a library function */
+	uprobe_opts.func_name = "usleep";
+	uprobe_opts.retprobe = true;
+	uprobe_opts.ref_ctr_offset = 0;
+	uretprobe_byname_link = bpf_program__attach_uprobe_opts(skel->progs.handle_uretprobe_byname,
+								0 /* this pid */,
+								"/proc/self/exe",
+								0, &uprobe_opts);
+	if (!ASSERT_OK_PTR(uretprobe_byname_link, "attach_uretprobe_byname"))
+		goto cleanup;
+	skel->links.handle_uretprobe_byname = uretprobe_byname_link;
+
+	/* trigger & validate kprobe && kretprobe && uretprobe by name */
 	usleep(1);
 
 	if (CHECK(skel->bss->kprobe_res != 1, "check_kprobe_res",
@@ -105,6 +134,9 @@ void test_attach_probe(void)
 	/* trigger & validate uprobe & uretprobe */
 	method();
 
+	/* trigger & validate uprobe attached by name */
+	method2();
+
 	if (CHECK(skel->bss->uprobe_res != 3, "check_uprobe_res",
 		  "wrong uprobe res: %d\n", skel->bss->uprobe_res))
 		goto cleanup;
@@ -112,6 +144,13 @@ void test_attach_probe(void)
 		  "wrong uretprobe res: %d\n", skel->bss->uretprobe_res))
 		goto cleanup;
 
+	if (CHECK(skel->bss->uprobe_byname_res != 5, "check_uprobe_byname_res",
+		  "wrong uprobe byname res: %d\n", skel->bss->uprobe_byname_res))
+		goto cleanup;
+	if (CHECK(skel->bss->uretprobe_byname_res != 6, "check_uretprobe_byname_res",
+		  "wrong uretprobe byname res: %d\n", skel->bss->uretprobe_byname_res))
+		goto cleanup;
+
 cleanup:
 	test_attach_probe__destroy(skel);
 	ASSERT_EQ(uprobe_ref_ctr, 0, "uprobe_ref_ctr_cleanup");
diff --git a/tools/testing/selftests/bpf/progs/test_attach_probe.c b/tools/testing/selftests/bpf/progs/test_attach_probe.c
index 8056a4c..efa56bd 100644
--- a/tools/testing/selftests/bpf/progs/test_attach_probe.c
+++ b/tools/testing/selftests/bpf/progs/test_attach_probe.c
@@ -10,6 +10,8 @@
 int kretprobe_res = 0;
 int uprobe_res = 0;
 int uretprobe_res = 0;
+int uprobe_byname_res = 0;
+int uretprobe_byname_res = 0;
 
 SEC("kprobe/sys_nanosleep")
 int handle_kprobe(struct pt_regs *ctx)
@@ -39,4 +41,18 @@ int handle_uretprobe(struct pt_regs *ctx)
 	return 0;
 }
 
+SEC("uprobe/trigger_func_byname")
+int handle_uprobe_byname(struct pt_regs *ctx)
+{
+	uprobe_byname_res = 5;
+	return 0;
+}
+
+SEC("uretprobe/trigger_func_byname")
+int handle_uretprobe_byname(struct pt_regs *ctx)
+{
+	uretprobe_byname_res = 6;
+	return 0;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
1.8.3.1