Linux sandbox: add basic Yama support

sandbox/linux/services/yama_unittests.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sandbox/linux/services/yama.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "base/compiler_specific.h"
+#include "sandbox/linux/tests/unit_tests.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sandbox {
+
+namespace {
+
+TEST(Yama, GetStatus) {
+  int status1 = Yama::GetStatus();
+  int status2 = Yama::GetStatus();
+
+  // In theory someone could change the status while this runs, accept
+  // this risk.
+  EXPECT_EQ(status1, status2);
+  ASSERT_LE(Yama::STATUS_DONT_KNOW, status1);
+  ASSERT_GE(Yama::STATUS_ENFORCING, status1);
+
+  // This test is not running sandboxed, there is no reason to not know the
+  // status.
+  EXPECT_NE(Yama::STATUS_DONT_KNOW, status1);
+
+  const bool yama_available = (status1 == Yama::STATUS_ENFORCING ||
+                               status1 == Yama::STATUS_NOT_ENFORCING);
+
+  // Again, this could be racy if someone touches Yama while this test runs.
+  EXPECT_EQ(yama_available, Yama::IsAvailable());
+
+  fprintf(stdout,
+          "Yama present: %s - enforcing: %s\n",
+          yama_available ? "Y" : "N",
+          Yama::STATUS_ENFORCING == status1 ? "Y" : "N");
+}
+
+}  // namespace
+
+}  // namespace sandbox