1 files changed, 49 insertions, 4 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
index 78e450609803..58522195081b 100644
--- a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c
@@ -41,13 +41,43 @@ static int process_sample(void *ctx, void *data, size_t len)
 void test_ringbuf_multi(void)
 {
 	struct test_ringbuf_multi *skel;
-	struct ring_buffer *ringbuf;
+	struct ring_buffer *ringbuf = NULL;
+	struct ring *ring_old;
+	struct ring *ring;
 	int err;
+	int page_size = getpagesize();
+	int proto_fd = -1;
 
-	skel = test_ringbuf_multi__open_and_load();
-	if (CHECK(!skel, "skel_open_load", "skeleton open&load failed\n"))
+	skel = test_ringbuf_multi__open();
+	if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
 		return;
 
+	/* validate ringbuf size adjustment logic */
+	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_before");
+	ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size + 1), "rb1_resize");
+	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), 2 * page_size, "rb1_size_after");
+	ASSERT_OK(bpf_map__set_max_entries(skel->maps.ringbuf1, page_size), "rb1_reset");
+	ASSERT_EQ(bpf_map__max_entries(skel->maps.ringbuf1), page_size, "rb1_size_final");
+
+	proto_fd = bpf_map_create(BPF_MAP_TYPE_RINGBUF, NULL, 0, 0, page_size, NULL);
+	if (CHECK(proto_fd < 0, "bpf_map_create", "bpf_map_create failed\n"))
+		goto cleanup;
+
+	err = bpf_map__set_inner_map_fd(skel->maps.ringbuf_hash, proto_fd);
+	if (CHECK(err != 0, "bpf_map__set_inner_map_fd", "bpf_map__set_inner_map_fd failed\n"))
+		goto cleanup;
+
+	err = test_ringbuf_multi__load(skel);
+	if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
+		goto cleanup;
+
+	close(proto_fd);
+	proto_fd = -1;
+
+	/* make sure we can't resize ringbuf after object load */
+	if (!ASSERT_ERR(bpf_map__set_max_entries(skel->maps.ringbuf1, 3 * page_size), "rb1_resize_after_load"))
+		goto cleanup;
+
 	/* only trigger BPF program for current process */
 	skel->bss->pid = getpid();
 
@@ -56,11 +86,24 @@ void test_ringbuf_multi(void)
 	if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n"))
 		goto cleanup;
 
+	/* verify ring_buffer__ring returns expected results */
+	ring = ring_buffer__ring(ringbuf, 0);
+	if (!ASSERT_OK_PTR(ring, "ring_buffer__ring_idx_0"))
+		goto cleanup;
+	ring_old = ring;
+	ring = ring_buffer__ring(ringbuf, 1);
+	ASSERT_ERR_PTR(ring, "ring_buffer__ring_idx_1");
+
 	err = ring_buffer__add(ringbuf, bpf_map__fd(skel->maps.ringbuf2),
 			      process_sample, (void *)(long)2);
 	if (CHECK(err, "ringbuf_add", "failed to add another ring\n"))
 		goto cleanup;
 
+	/* verify adding a new ring didn't invalidate our older pointer */
+	ring = ring_buffer__ring(ringbuf, 0);
+	if (!ASSERT_EQ(ring, ring_old, "ring_buffer__ring_again"))
+		goto cleanup;
+
 	err = test_ringbuf_multi__attach(skel);
 	if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err))
 		goto cleanup;
@@ -81,7 +124,7 @@ void test_ringbuf_multi(void)
 
 	/* poll for samples, should get 2 ringbufs back */
 	err = ring_buffer__poll(ringbuf, -1);
-	if (CHECK(err != 4, "poll_res", "expected 4 records, got %d\n", err))
+	if (CHECK(err != 2, "poll_res", "expected 2 records, got %d\n", err))
 		goto cleanup;
 
 	/* expect extra polling to return nothing */
@@ -97,6 +140,8 @@ void test_ringbuf_multi(void)
 	      2L, skel->bss->total);
 
 cleanup:
+	if (proto_fd >= 0)
+		close(proto_fd);
 	ring_buffer__free(ringbuf);
 	test_ringbuf_multi__destroy(skel);
 }