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, 84 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_vmlinux.c b/tools/testing/selftests/bpf/progs/test_vmlinux.c
new file mode 100644
index 000000000000..5611b564d3b1
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_vmlinux.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include "vmlinux.h"
+#include <asm/unistd.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define MY_TV_NSEC 1337
+
+bool tp_called = false;
+bool raw_tp_called = false;
+bool tp_btf_called = false;
+bool kprobe_called = false;
+bool fentry_called = false;
+
+SEC("tp/syscalls/sys_enter_nanosleep")
+int handle__tp(struct trace_event_raw_sys_enter *args)
+{
+	struct __kernel_timespec *ts;
+
+	if (args->id != __NR_nanosleep)
+		return 0;
+
+	ts = (void *)args->args[0];
+	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+		return 0;
+
+	tp_called = true;
+	return 0;
+}
+
+SEC("raw_tp/sys_enter")
+int BPF_PROG(handle__raw_tp, struct pt_regs *regs, long id)
+{
+	struct __kernel_timespec *ts;
+
+	if (id != __NR_nanosleep)
+		return 0;
+
+	ts = (void *)PT_REGS_PARM1_CORE(regs);
+	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+		return 0;
+
+	raw_tp_called = true;
+	return 0;
+}
+
+SEC("tp_btf/sys_enter")
+int BPF_PROG(handle__tp_btf, struct pt_regs *regs, long id)
+{
+	struct __kernel_timespec *ts;
+
+	if (id != __NR_nanosleep)
+		return 0;
+
+	ts = (void *)PT_REGS_PARM1_CORE(regs);
+	if (BPF_CORE_READ(ts, tv_nsec) != MY_TV_NSEC)
+		return 0;
+
+	tp_btf_called = true;
+	return 0;
+}
+
+SEC("kprobe/hrtimer_nanosleep")
+int BPF_KPROBE(handle__kprobe,
+	       ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
+{
+	if (rqtp == MY_TV_NSEC)
+		kprobe_called = true;
+	return 0;
+}
+
+SEC("fentry/hrtimer_nanosleep")
+int BPF_PROG(handle__fentry,
+	     ktime_t rqtp, enum hrtimer_mode mode, clockid_t clockid)
+{
+	if (rqtp == MY_TV_NSEC)
+		fentry_called = true;
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";