Merge branch 'libbpf_autoload_knob'

Andrii Nakryiko says:

====================
Add ability to turn off default auto-loading of each BPF program by libbpf on
BPF object load. This is the feature that allows BPF applications to have
optional functionality, which is only excercised on kernel that support
necessary features, while falling back to reduced/less performant
functionality, if kernel is outdated.
====================

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/autoload.c b/tools/testing/selftests/bpf/prog_tests/autoload.c
new file mode 100644
index 000000000000..3693f7d133eb
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/autoload.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include <test_progs.h>
+#include <time.h>
+#include "test_autoload.skel.h"
+
+void test_autoload(void)
+{
+	int duration = 0, err;
+	struct test_autoload* skel;
+
+	skel = test_autoload__open_and_load();
+	/* prog3 should be broken */
+	if (CHECK(skel, "skel_open_and_load", "unexpected success\n"))
+		goto cleanup;
+
+	skel = test_autoload__open();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		goto cleanup;
+
+	/* don't load prog3 */
+	bpf_program__set_autoload(skel->progs.prog3, false);
+
+	err = test_autoload__load(skel);
+	if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
+		goto cleanup;
+
+	err = test_autoload__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	usleep(1);
+
+	CHECK(!skel->bss->prog1_called, "prog1", "not called\n");
+	CHECK(!skel->bss->prog2_called, "prog2", "not called\n");
+	CHECK(skel->bss->prog3_called, "prog3", "called?!\n");
+
+cleanup:
+	test_autoload__destroy(skel);
+}