selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls

Add vmlinux.h generation to selftest/bpf's Makefile. Use it from newly added
test_vmlinux to trace nanosleep syscall using 5 different types of programs:
  - tracepoint;
  - raw tracepoint;
  - raw tracepoint w/ direct memory reads (tp_btf);
  - kprobe;
  - fentry.

These programs are realistic variants of real-life tracing programs,
excercising vmlinux.h's usage with tracing applications.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200313172336.1879637-5-andriin@fb.com

1 files changed, 43 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/vmlinux.c b/tools/testing/selftests/bpf/prog_tests/vmlinux.c
new file mode 100644
index 000000000000..04939eda1325
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/vmlinux.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include <test_progs.h>
+#include <time.h>
+#include "test_vmlinux.skel.h"
+
+#define MY_TV_NSEC 1337
+
+static void nsleep()
+{
+	struct timespec ts = { .tv_nsec = MY_TV_NSEC };
+
+	(void)nanosleep(&ts, NULL);
+}
+
+void test_vmlinux(void)
+{
+	int duration = 0, err;
+	struct test_vmlinux* skel;
+	struct test_vmlinux__bss *bss;
+
+	skel = test_vmlinux__open_and_load();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		return;
+	bss = skel->bss;
+
+	err = test_vmlinux__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	/* trigger everything */
+	nsleep();
+
+	CHECK(!bss->tp_called, "tp", "not called\n");
+	CHECK(!bss->raw_tp_called, "raw_tp", "not called\n");
+	CHECK(!bss->tp_btf_called, "tp_btf", "not called\n");
+	CHECK(!bss->kprobe_called, "kprobe", "not called\n");
+	CHECK(!bss->fentry_called, "fentry", "not called\n");
+
+cleanup:
+	test_vmlinux__destroy(skel);
+}