Add test validating that libbpf adjusts (and reflects adjusted) ringbuf size early, before bpf_object is loaded. Also make sure we can't successfully resize ringbuf map after bpf_object is loaded. Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- .../testing/selftests/bpf/prog_tests/ringbuf_multi.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c index eb5f7f5aa81a..1455911d9fcb 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c @@ -50,6 +50,13 @@ void test_ringbuf_multi(void) 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; @@ -65,6 +72,10 @@ void test_ringbuf_multi(void) 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(); -- 2.30.2
