Move libnative{bridge,loader} to art/

This change moves system/core/libnative{bridge,loader} under art/.

Bug: 137364733
Test: m
Change-Id: I9be7333d00fcd3f36cd80520e50a30ea840187ad

1 files changed, 663 insertions, 0 deletions

diff --git a/libnativeloader/native_loader_test.cpp b/libnativeloader/native_loader_test.cpp
new file mode 100644
index 0000000000..8bd7386eea
--- /dev/null
+++ b/libnativeloader/native_loader_test.cpp
@@ -0,0 +1,663 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <dlfcn.h>
+#include <memory>
+#include <unordered_map>
+
+#include <android-base/strings.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <jni.h>
+
+#include "native_loader_namespace.h"
+#include "nativeloader/dlext_namespaces.h"
+#include "nativeloader/native_loader.h"
+#include "public_libraries.h"
+
+using namespace ::testing;
+using namespace ::android::nativeloader::internal;
+
+namespace android {
+namespace nativeloader {
+
+// gmock interface that represents interested platform APIs on libdl and libnativebridge
+class Platform {
+ public:
+  virtual ~Platform() {}
+
+  // libdl APIs
+  virtual void* dlopen(const char* filename, int flags) = 0;
+  virtual int dlclose(void* handle) = 0;
+  virtual char* dlerror(void) = 0;
+
+  // These mock_* are the APIs semantically the same across libdl and libnativebridge.
+  // Instead of having two set of mock APIs for the two, define only one set with an additional
+  // argument 'bool bridged' to identify the context (i.e., called for libdl or libnativebridge).
+  typedef char* mock_namespace_handle;
+  virtual bool mock_init_anonymous_namespace(bool bridged, const char* sonames,
+                                             const char* search_paths) = 0;
+  virtual mock_namespace_handle mock_create_namespace(
+      bool bridged, const char* name, const char* ld_library_path, const char* default_library_path,
+      uint64_t type, const char* permitted_when_isolated_path, mock_namespace_handle parent) = 0;
+  virtual bool mock_link_namespaces(bool bridged, mock_namespace_handle from,
+                                    mock_namespace_handle to, const char* sonames) = 0;
+  virtual mock_namespace_handle mock_get_exported_namespace(bool bridged, const char* name) = 0;
+  virtual void* mock_dlopen_ext(bool bridged, const char* filename, int flags,
+                                mock_namespace_handle ns) = 0;
+
+  // libnativebridge APIs for which libdl has no corresponding APIs
+  virtual bool NativeBridgeInitialized() = 0;
+  virtual const char* NativeBridgeGetError() = 0;
+  virtual bool NativeBridgeIsPathSupported(const char*) = 0;
+  virtual bool NativeBridgeIsSupported(const char*) = 0;
+
+  // To mock "ClassLoader Object.getParent()"
+  virtual const char* JniObject_getParent(const char*) = 0;
+};
+
+// The mock does not actually create a namespace object. But simply casts the pointer to the
+// string for the namespace name as the handle to the namespace object.
+#define TO_ANDROID_NAMESPACE(str) \
+  reinterpret_cast<struct android_namespace_t*>(const_cast<char*>(str))
+
+#define TO_BRIDGED_NAMESPACE(str) \
+  reinterpret_cast<struct native_bridge_namespace_t*>(const_cast<char*>(str))
+
+#define TO_MOCK_NAMESPACE(ns) reinterpret_cast<Platform::mock_namespace_handle>(ns)
+
+// These represents built-in namespaces created by the linker according to ld.config.txt
+static std::unordered_map<std::string, Platform::mock_namespace_handle> namespaces = {
+    {"platform", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("platform"))},
+    {"default", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("default"))},
+    {"art", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("art"))},
+    {"sphal", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("sphal"))},
+    {"vndk", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("vndk"))},
+    {"neuralnetworks", TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("neuralnetworks"))},
+};
+
+// The actual gmock object
+class MockPlatform : public Platform {
+ public:
+  explicit MockPlatform(bool is_bridged) : is_bridged_(is_bridged) {
+    ON_CALL(*this, NativeBridgeIsSupported(_)).WillByDefault(Return(is_bridged_));
+    ON_CALL(*this, NativeBridgeIsPathSupported(_)).WillByDefault(Return(is_bridged_));
+    ON_CALL(*this, mock_get_exported_namespace(_, _))
+        .WillByDefault(Invoke([](bool, const char* name) -> mock_namespace_handle {
+          if (namespaces.find(name) != namespaces.end()) {
+            return namespaces[name];
+          }
+          return TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE("(namespace not found"));
+        }));
+  }
+
+  // Mocking libdl APIs
+  MOCK_METHOD2(dlopen, void*(const char*, int));
+  MOCK_METHOD1(dlclose, int(void*));
+  MOCK_METHOD0(dlerror, char*());
+
+  // Mocking the common APIs
+  MOCK_METHOD3(mock_init_anonymous_namespace, bool(bool, const char*, const char*));
+  MOCK_METHOD7(mock_create_namespace,
+               mock_namespace_handle(bool, const char*, const char*, const char*, uint64_t,
+                                     const char*, mock_namespace_handle));
+  MOCK_METHOD4(mock_link_namespaces,
+               bool(bool, mock_namespace_handle, mock_namespace_handle, const char*));
+  MOCK_METHOD2(mock_get_exported_namespace, mock_namespace_handle(bool, const char*));
+  MOCK_METHOD4(mock_dlopen_ext, void*(bool, const char*, int, mock_namespace_handle));
+
+  // Mocking libnativebridge APIs
+  MOCK_METHOD0(NativeBridgeInitialized, bool());
+  MOCK_METHOD0(NativeBridgeGetError, const char*());
+  MOCK_METHOD1(NativeBridgeIsPathSupported, bool(const char*));
+  MOCK_METHOD1(NativeBridgeIsSupported, bool(const char*));
+
+  // Mocking "ClassLoader Object.getParent()"
+  MOCK_METHOD1(JniObject_getParent, const char*(const char*));
+
+ private:
+  bool is_bridged_;
+};
+
+static std::unique_ptr<MockPlatform> mock;
+
+// Provide C wrappers for the mock object.
+extern "C" {
+void* dlopen(const char* file, int flag) {
+  return mock->dlopen(file, flag);
+}
+
+int dlclose(void* handle) {
+  return mock->dlclose(handle);
+}
+
+char* dlerror(void) {
+  return mock->dlerror();
+}
+
+bool android_init_anonymous_namespace(const char* sonames, const char* search_path) {
+  return mock->mock_init_anonymous_namespace(false, sonames, search_path);
+}
+
+struct android_namespace_t* android_create_namespace(const char* name, const char* ld_library_path,
+                                                     const char* default_library_path,
+                                                     uint64_t type,
+                                                     const char* permitted_when_isolated_path,
+                                                     struct android_namespace_t* parent) {
+  return TO_ANDROID_NAMESPACE(
+      mock->mock_create_namespace(false, name, ld_library_path, default_library_path, type,
+                                  permitted_when_isolated_path, TO_MOCK_NAMESPACE(parent)));
+}
+
+bool android_link_namespaces(struct android_namespace_t* from, struct android_namespace_t* to,
+                             const char* sonames) {
+  return mock->mock_link_namespaces(false, TO_MOCK_NAMESPACE(from), TO_MOCK_NAMESPACE(to), sonames);
+}
+
+struct android_namespace_t* android_get_exported_namespace(const char* name) {
+  return TO_ANDROID_NAMESPACE(mock->mock_get_exported_namespace(false, name));
+}
+
+void* android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* info) {
+  return mock->mock_dlopen_ext(false, filename, flags, TO_MOCK_NAMESPACE(info->library_namespace));
+}
+
+// libnativebridge APIs
+bool NativeBridgeIsSupported(const char* libpath) {
+  return mock->NativeBridgeIsSupported(libpath);
+}
+
+struct native_bridge_namespace_t* NativeBridgeGetExportedNamespace(const char* name) {
+  return TO_BRIDGED_NAMESPACE(mock->mock_get_exported_namespace(true, name));
+}
+
+struct native_bridge_namespace_t* NativeBridgeCreateNamespace(
+    const char* name, const char* ld_library_path, const char* default_library_path, uint64_t type,
+    const char* permitted_when_isolated_path, struct native_bridge_namespace_t* parent) {
+  return TO_BRIDGED_NAMESPACE(
+      mock->mock_create_namespace(true, name, ld_library_path, default_library_path, type,
+                                  permitted_when_isolated_path, TO_MOCK_NAMESPACE(parent)));
+}
+
+bool NativeBridgeLinkNamespaces(struct native_bridge_namespace_t* from,
+                                struct native_bridge_namespace_t* to, const char* sonames) {
+  return mock->mock_link_namespaces(true, TO_MOCK_NAMESPACE(from), TO_MOCK_NAMESPACE(to), sonames);
+}
+
+void* NativeBridgeLoadLibraryExt(const char* libpath, int flag,
+                                 struct native_bridge_namespace_t* ns) {
+  return mock->mock_dlopen_ext(true, libpath, flag, TO_MOCK_NAMESPACE(ns));
+}
+
+bool NativeBridgeInitialized() {
+  return mock->NativeBridgeInitialized();
+}
+
+bool NativeBridgeInitAnonymousNamespace(const char* public_ns_sonames,
+                                        const char* anon_ns_library_path) {
+  return mock->mock_init_anonymous_namespace(true, public_ns_sonames, anon_ns_library_path);
+}
+
+const char* NativeBridgeGetError() {
+  return mock->NativeBridgeGetError();
+}
+
+bool NativeBridgeIsPathSupported(const char* path) {
+  return mock->NativeBridgeIsPathSupported(path);
+}
+
+}  // extern "C"
+
+// A very simple JNI mock.
+// jstring is a pointer to utf8 char array. We don't need utf16 char here.
+// jobject, jclass, and jmethodID are also a pointer to utf8 char array
+// Only a few JNI methods that are actually used in libnativeloader are mocked.
+JNINativeInterface* CreateJNINativeInterface() {
+  JNINativeInterface* inf = new JNINativeInterface();
+  memset(inf, 0, sizeof(JNINativeInterface));
+
+  inf->GetStringUTFChars = [](JNIEnv*, jstring s, jboolean*) -> const char* {
+    return reinterpret_cast<const char*>(s);
+  };
+
+  inf->ReleaseStringUTFChars = [](JNIEnv*, jstring, const char*) -> void { return; };
+
+  inf->NewStringUTF = [](JNIEnv*, const char* bytes) -> jstring {
+    return reinterpret_cast<jstring>(const_cast<char*>(bytes));
+  };
+
+  inf->FindClass = [](JNIEnv*, const char* name) -> jclass {
+    return reinterpret_cast<jclass>(const_cast<char*>(name));
+  };
+
+  inf->CallObjectMethodV = [](JNIEnv*, jobject obj, jmethodID mid, va_list) -> jobject {
+    if (strcmp("getParent", reinterpret_cast<const char*>(mid)) == 0) {
+      // JniObject_getParent can be a valid jobject or nullptr if there is
+      // no parent classloader.
+      const char* ret = mock->JniObject_getParent(reinterpret_cast<const char*>(obj));
+      return reinterpret_cast<jobject>(const_cast<char*>(ret));
+    }
+    return nullptr;
+  };
+
+  inf->GetMethodID = [](JNIEnv*, jclass, const char* name, const char*) -> jmethodID {
+    return reinterpret_cast<jmethodID>(const_cast<char*>(name));
+  };
+
+  inf->NewWeakGlobalRef = [](JNIEnv*, jobject obj) -> jobject { return obj; };
+
+  inf->IsSameObject = [](JNIEnv*, jobject a, jobject b) -> jboolean {
+    return strcmp(reinterpret_cast<const char*>(a), reinterpret_cast<const char*>(b)) == 0;
+  };
+
+  return inf;
+}
+
+static void* const any_nonnull = reinterpret_cast<void*>(0x12345678);
+
+// Custom matcher for comparing namespace handles
+MATCHER_P(NsEq, other, "") {
+  *result_listener << "comparing " << reinterpret_cast<const char*>(arg) << " and " << other;
+  return strcmp(reinterpret_cast<const char*>(arg), reinterpret_cast<const char*>(other)) == 0;
+}
+
+/////////////////////////////////////////////////////////////////
+
+// Test fixture
+class NativeLoaderTest : public ::testing::TestWithParam<bool> {
+ protected:
+  bool IsBridged() { return GetParam(); }
+
+  void SetUp() override {
+    mock = std::make_unique<NiceMock<MockPlatform>>(IsBridged());
+
+    env = std::make_unique<JNIEnv>();
+    env->functions = CreateJNINativeInterface();
+  }
+
+  void SetExpectations() {
+    std::vector<std::string> default_public_libs =
+        android::base::Split(preloadable_public_libraries(), ":");
+    for (auto l : default_public_libs) {
+      EXPECT_CALL(*mock, dlopen(StrEq(l.c_str()), RTLD_NOW | RTLD_NODELETE))
+          .WillOnce(Return(any_nonnull));
+    }
+  }
+
+  void RunTest() { InitializeNativeLoader(); }
+
+  void TearDown() override {
+    ResetNativeLoader();
+    delete env->functions;
+    mock.reset();
+  }
+
+  std::unique_ptr<JNIEnv> env;
+};
+
+/////////////////////////////////////////////////////////////////
+
+TEST_P(NativeLoaderTest, InitializeLoadsDefaultPublicLibraries) {
+  SetExpectations();
+  RunTest();
+}
+
+INSTANTIATE_TEST_SUITE_P(NativeLoaderTests, NativeLoaderTest, testing::Bool());
+
+/////////////////////////////////////////////////////////////////
+
+class NativeLoaderTest_Create : public NativeLoaderTest {
+ protected:
+  // Test inputs (initialized to the default values). Overriding these
+  // must be done before calling SetExpectations() and RunTest().
+  uint32_t target_sdk_version = 29;
+  std::string class_loader = "my_classloader";
+  bool is_shared = false;
+  std::string dex_path = "/data/app/foo/classes.dex";
+  std::string library_path = "/data/app/foo/lib/arm";
+  std::string permitted_path = "/data/app/foo/lib";
+
+  // expected output (.. for the default test inputs)
+  std::string expected_namespace_name = "classloader-namespace";
+  uint64_t expected_namespace_flags =
+      ANDROID_NAMESPACE_TYPE_ISOLATED | ANDROID_NAMESPACE_TYPE_ALSO_USED_AS_ANONYMOUS;
+  std::string expected_library_path = library_path;
+  std::string expected_permitted_path = std::string("/data:/mnt/expand:") + permitted_path;
+  std::string expected_parent_namespace = "platform";
+  bool expected_link_with_platform_ns = true;
+  bool expected_link_with_art_ns = true;
+  bool expected_link_with_sphal_ns = !vendor_public_libraries().empty();
+  bool expected_link_with_vndk_ns = false;
+  bool expected_link_with_default_ns = false;
+  bool expected_link_with_neuralnetworks_ns = true;
+  std::string expected_shared_libs_to_platform_ns = default_public_libraries();
+  std::string expected_shared_libs_to_art_ns = art_public_libraries();
+  std::string expected_shared_libs_to_sphal_ns = vendor_public_libraries();
+  std::string expected_shared_libs_to_vndk_ns = vndksp_libraries();
+  std::string expected_shared_libs_to_default_ns = default_public_libraries();
+  std::string expected_shared_libs_to_neuralnetworks_ns = neuralnetworks_public_libraries();
+
+  void SetExpectations() {
+    NativeLoaderTest::SetExpectations();
+
+    ON_CALL(*mock, JniObject_getParent(StrEq(class_loader))).WillByDefault(Return(nullptr));
+
+    EXPECT_CALL(*mock, NativeBridgeIsPathSupported(_)).Times(AnyNumber());
+    EXPECT_CALL(*mock, NativeBridgeInitialized()).Times(AnyNumber());
+
+    EXPECT_CALL(*mock, mock_create_namespace(
+                           Eq(IsBridged()), StrEq(expected_namespace_name), nullptr,
+                           StrEq(expected_library_path), expected_namespace_flags,
+                           StrEq(expected_permitted_path), NsEq(expected_parent_namespace.c_str())))
+        .WillOnce(Return(TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE(dex_path.c_str()))));
+    if (expected_link_with_platform_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("platform"),
+                                              StrEq(expected_shared_libs_to_platform_ns)))
+          .WillOnce(Return(true));
+    }
+    if (expected_link_with_art_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("art"),
+                                              StrEq(expected_shared_libs_to_art_ns)))
+          .WillOnce(Return(true));
+    }
+    if (expected_link_with_sphal_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("sphal"),
+                                              StrEq(expected_shared_libs_to_sphal_ns)))
+          .WillOnce(Return(true));
+    }
+    if (expected_link_with_vndk_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("vndk"),
+                                              StrEq(expected_shared_libs_to_vndk_ns)))
+          .WillOnce(Return(true));
+    }
+    if (expected_link_with_default_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("default"),
+                                              StrEq(expected_shared_libs_to_default_ns)))
+          .WillOnce(Return(true));
+    }
+    if (expected_link_with_neuralnetworks_ns) {
+      EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), _, NsEq("neuralnetworks"),
+                                              StrEq(expected_shared_libs_to_neuralnetworks_ns)))
+          .WillOnce(Return(true));
+    }
+  }
+
+  void RunTest() {
+    NativeLoaderTest::RunTest();
+
+    jstring err = CreateClassLoaderNamespace(
+        env(), target_sdk_version, env()->NewStringUTF(class_loader.c_str()), is_shared,
+        env()->NewStringUTF(dex_path.c_str()), env()->NewStringUTF(library_path.c_str()),
+        env()->NewStringUTF(permitted_path.c_str()));
+
+    // no error
+    EXPECT_EQ(err, nullptr);
+
+    if (!IsBridged()) {
+      struct android_namespace_t* ns =
+          FindNamespaceByClassLoader(env(), env()->NewStringUTF(class_loader.c_str()));
+
+      // The created namespace is for this apk
+      EXPECT_EQ(dex_path.c_str(), reinterpret_cast<const char*>(ns));
+    } else {
+      struct NativeLoaderNamespace* ns =
+          FindNativeLoaderNamespaceByClassLoader(env(), env()->NewStringUTF(class_loader.c_str()));
+
+      // The created namespace is for the this apk
+      EXPECT_STREQ(dex_path.c_str(),
+                   reinterpret_cast<const char*>(ns->ToRawNativeBridgeNamespace()));
+    }
+  }
+
+  JNIEnv* env() { return NativeLoaderTest::env.get(); }
+};
+
+TEST_P(NativeLoaderTest_Create, DownloadedApp) {
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, BundledSystemApp) {
+  dex_path = "/system/app/foo/foo.apk";
+  is_shared = true;
+
+  expected_namespace_flags |= ANDROID_NAMESPACE_TYPE_SHARED;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, BundledVendorApp) {
+  dex_path = "/vendor/app/foo/foo.apk";
+  is_shared = true;
+
+  expected_namespace_flags |= ANDROID_NAMESPACE_TYPE_SHARED;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, UnbundledVendorApp) {
+  dex_path = "/vendor/app/foo/foo.apk";
+  is_shared = false;
+
+  expected_namespace_name = "vendor-classloader-namespace";
+  expected_library_path = expected_library_path + ":/vendor/lib";
+  expected_permitted_path = expected_permitted_path + ":/vendor/lib";
+  expected_shared_libs_to_platform_ns =
+      expected_shared_libs_to_platform_ns + ":" + llndk_libraries();
+  expected_link_with_vndk_ns = true;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, BundledProductApp_pre30) {
+  dex_path = "/product/app/foo/foo.apk";
+  is_shared = true;
+
+  expected_namespace_flags |= ANDROID_NAMESPACE_TYPE_SHARED;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, BundledProductApp_post30) {
+  dex_path = "/product/app/foo/foo.apk";
+  is_shared = true;
+  target_sdk_version = 30;
+
+  expected_namespace_flags |= ANDROID_NAMESPACE_TYPE_SHARED;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, UnbundledProductApp_pre30) {
+  dex_path = "/product/app/foo/foo.apk";
+  is_shared = false;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, UnbundledProductApp_post30) {
+  dex_path = "/product/app/foo/foo.apk";
+  is_shared = false;
+  target_sdk_version = 30;
+
+  expected_namespace_name = "vendor-classloader-namespace";
+  expected_library_path = expected_library_path + ":/product/lib:/system/product/lib";
+  expected_permitted_path = expected_permitted_path + ":/product/lib:/system/product/lib";
+  expected_shared_libs_to_platform_ns =
+      expected_shared_libs_to_platform_ns + ":" + llndk_libraries();
+  expected_link_with_vndk_ns = true;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, NamespaceForSharedLibIsNotUsedAsAnonymousNamespace) {
+  if (IsBridged()) {
+    // There is no shared lib in translated arch
+    // TODO(jiyong): revisit this
+    return;
+  }
+  // compared to apks, for java shared libs, library_path is empty; java shared
+  // libs don't have their own native libs. They use platform's.
+  library_path = "";
+  expected_library_path = library_path;
+  // no ALSO_USED_AS_ANONYMOUS
+  expected_namespace_flags = ANDROID_NAMESPACE_TYPE_ISOLATED;
+  SetExpectations();
+  RunTest();
+}
+
+TEST_P(NativeLoaderTest_Create, TwoApks) {
+  SetExpectations();
+  const uint32_t second_app_target_sdk_version = 29;
+  const std::string second_app_class_loader = "second_app_classloader";
+  const bool second_app_is_shared = false;
+  const std::string second_app_dex_path = "/data/app/bar/classes.dex";
+  const std::string second_app_library_path = "/data/app/bar/lib/arm";
+  const std::string second_app_permitted_path = "/data/app/bar/lib";
+  const std::string expected_second_app_permitted_path =
+      std::string("/data:/mnt/expand:") + second_app_permitted_path;
+  const std::string expected_second_app_parent_namespace = "classloader-namespace";
+  // no ALSO_USED_AS_ANONYMOUS
+  const uint64_t expected_second_namespace_flags = ANDROID_NAMESPACE_TYPE_ISOLATED;
+
+  // The scenario is that second app is loaded by the first app.
+  // So the first app's classloader (`classloader`) is parent of the second
+  // app's classloader.
+  ON_CALL(*mock, JniObject_getParent(StrEq(second_app_class_loader)))
+      .WillByDefault(Return(class_loader.c_str()));
+
+  // namespace for the second app is created. Its parent is set to the namespace
+  // of the first app.
+  EXPECT_CALL(*mock, mock_create_namespace(
+                         Eq(IsBridged()), StrEq(expected_namespace_name), nullptr,
+                         StrEq(second_app_library_path), expected_second_namespace_flags,
+                         StrEq(expected_second_app_permitted_path), NsEq(dex_path.c_str())))
+      .WillOnce(Return(TO_MOCK_NAMESPACE(TO_ANDROID_NAMESPACE(second_app_dex_path.c_str()))));
+  EXPECT_CALL(*mock, mock_link_namespaces(Eq(IsBridged()), NsEq(second_app_dex_path.c_str()), _, _))
+      .WillRepeatedly(Return(true));
+
+  RunTest();
+  jstring err = CreateClassLoaderNamespace(
+      env(), second_app_target_sdk_version, env()->NewStringUTF(second_app_class_loader.c_str()),
+      second_app_is_shared, env()->NewStringUTF(second_app_dex_path.c_str()),
+      env()->NewStringUTF(second_app_library_path.c_str()),
+      env()->NewStringUTF(second_app_permitted_path.c_str()));
+
+  // success
+  EXPECT_EQ(err, nullptr);
+
+  if (!IsBridged()) {
+    struct android_namespace_t* ns =
+        FindNamespaceByClassLoader(env(), env()->NewStringUTF(second_app_class_loader.c_str()));
+
+    // The created namespace is for the second apk
+    EXPECT_EQ(second_app_dex_path.c_str(), reinterpret_cast<const char*>(ns));
+  } else {
+    struct NativeLoaderNamespace* ns = FindNativeLoaderNamespaceByClassLoader(
+        env(), env()->NewStringUTF(second_app_class_loader.c_str()));
+
+    // The created namespace is for the second apk
+    EXPECT_STREQ(second_app_dex_path.c_str(),
+                 reinterpret_cast<const char*>(ns->ToRawNativeBridgeNamespace()));
+  }
+}
+
+INSTANTIATE_TEST_SUITE_P(NativeLoaderTests_Create, NativeLoaderTest_Create, testing::Bool());
+
+const std::function<Result<bool>(const struct ConfigEntry&)> always_true =
+    [](const struct ConfigEntry&) -> Result<bool> { return true; };
+
+TEST(NativeLoaderConfigParser, NamesAndComments) {
+  const char file_content[] = R"(
+######
+
+libA.so
+#libB.so
+
+
+      libC.so
+libD.so
+    #### libE.so
+)";
+  const std::vector<std::string> expected_result = {"libA.so", "libC.so", "libD.so"};
+  Result<std::vector<std::string>> result = ParseConfig(file_content, always_true);
+  ASSERT_TRUE(result) << result.error().message();
+  ASSERT_EQ(expected_result, *result);
+}
+
+TEST(NativeLoaderConfigParser, WithBitness) {
+  const char file_content[] = R"(
+libA.so 32
+libB.so 64
+libC.so
+)";
+#if defined(__LP64__)
+  const std::vector<std::string> expected_result = {"libB.so", "libC.so"};
+#else
+  const std::vector<std::string> expected_result = {"libA.so", "libC.so"};
+#endif
+  Result<std::vector<std::string>> result = ParseConfig(file_content, always_true);
+  ASSERT_TRUE(result) << result.error().message();
+  ASSERT_EQ(expected_result, *result);
+}
+
+TEST(NativeLoaderConfigParser, WithNoPreload) {
+  const char file_content[] = R"(
+libA.so nopreload
+libB.so nopreload
+libC.so
+)";
+
+  const std::vector<std::string> expected_result = {"libC.so"};
+  Result<std::vector<std::string>> result =
+      ParseConfig(file_content,
+                  [](const struct ConfigEntry& entry) -> Result<bool> { return !entry.nopreload; });
+  ASSERT_TRUE(result) << result.error().message();
+  ASSERT_EQ(expected_result, *result);
+}
+
+TEST(NativeLoaderConfigParser, WithNoPreloadAndBitness) {
+  const char file_content[] = R"(
+libA.so nopreload 32
+libB.so 64 nopreload
+libC.so 32
+libD.so 64
+libE.so nopreload
+)";
+
+#if defined(__LP64__)
+  const std::vector<std::string> expected_result = {"libD.so"};
+#else
+  const std::vector<std::string> expected_result = {"libC.so"};
+#endif
+  Result<std::vector<std::string>> result =
+      ParseConfig(file_content,
+                  [](const struct ConfigEntry& entry) -> Result<bool> { return !entry.nopreload; });
+  ASSERT_TRUE(result) << result.error().message();
+  ASSERT_EQ(expected_result, *result);
+}
+
+TEST(NativeLoaderConfigParser, RejectMalformed) {
+  ASSERT_FALSE(ParseConfig("libA.so 32 64", always_true));
+  ASSERT_FALSE(ParseConfig("libA.so 32 32", always_true));
+  ASSERT_FALSE(ParseConfig("libA.so 32 nopreload 64", always_true));
+  ASSERT_FALSE(ParseConfig("32 libA.so nopreload", always_true));
+  ASSERT_FALSE(ParseConfig("nopreload libA.so 32", always_true));
+  ASSERT_FALSE(ParseConfig("libA.so nopreload # comment", always_true));
+}
+
+}  // namespace nativeloader
+}  // namespace android