Assign shared libraries stable package ids

When a shared library package is loaded into an AssetManager, the
shared library will be assigned a unique package id. Subsequent
AssetManaagers that load a shared library of the same package name
as the original shared library will use previously assigned package
name. Shared libraries will have stable package ids throughout the
lifetime of application.

Bug: 140790224
Bug: 128496033
Test: libandroidfw_tests
Test: third-party app no longer crashes on open
Test: atest CtsHostsideWebViewTests
Change-Id: Idc0315be21ea00b74d1a918b7083ad655104c008

8 files changed, 168 insertions, 20 deletions

diff --git a/core/jni/android_util_AssetManager.cpp b/core/jni/android_util_AssetManager.cpp
index ff596b440867..062b886f54a1 100644
--- a/core/jni/android_util_AssetManager.cpp
+++ b/core/jni/android_util_AssetManager.cpp
@@ -220,8 +220,12 @@ static jint CopyValue(JNIEnv* env, ApkAssetsCookie cookie, const Res_value& valu
 
 // ----------------------------------------------------------------------------
 
+static std::unique_ptr<DynamicLibManager> sDynamicLibManager =
+    std::make_unique<DynamicLibManager>();
+
 // Let the opaque type AAssetManager refer to a guarded AssetManager2 instance.
 struct GuardedAssetManager : public ::AAssetManager {
+  GuardedAssetManager() : guarded_assetmanager(sDynamicLibManager.get()) {}
   Guarded<AssetManager2> guarded_assetmanager;
 };
 
diff --git a/libs/androidfw/Android.bp b/libs/androidfw/Android.bp
index 87657191e901..3f2f3495ae8f 100644
--- a/libs/androidfw/Android.bp
+++ b/libs/androidfw/Android.bp
@@ -44,6 +44,7 @@ cc_library {
         "AttributeResolution.cpp",
         "ChunkIterator.cpp",
         "ConfigDescription.cpp",
+        "DynamicLibManager.cpp",
         "Idmap.cpp",
         "LoadedArsc.cpp",
         "Locale.cpp",
diff --git a/libs/androidfw/AssetManager2.cpp b/libs/androidfw/AssetManager2.cpp
index ca4143f3e215..2c6be41052e8 100644
--- a/libs/androidfw/AssetManager2.cpp
+++ b/libs/androidfw/AssetManager2.cpp
@@ -25,6 +25,7 @@
 
 #include "android-base/logging.h"
 #include "android-base/stringprintf.h"
+#include "androidfw/DynamicLibManager.h"
 #include "androidfw/ResourceUtils.h"
 #include "androidfw/Util.h"
 #include "utils/ByteOrder.h"
@@ -66,7 +67,12 @@ struct FindEntryResult {
   StringPoolRef entry_string_ref;
 };
 
-AssetManager2::AssetManager2() {
+AssetManager2::AssetManager2() : dynamic_lib_manager_(std::make_unique<DynamicLibManager>()) {
+  memset(&configuration_, 0, sizeof(configuration_));
+}
+
+AssetManager2::AssetManager2(DynamicLibManager* dynamic_lib_manager)
+    : dynamic_lib_manager_(dynamic_lib_manager) {
   memset(&configuration_, 0, sizeof(configuration_));
 }
 
@@ -85,24 +91,44 @@ void AssetManager2::BuildDynamicRefTable() {
   package_groups_.clear();
   package_ids_.fill(0xff);
 
-  // A mapping from apk assets path to the runtime package id of its first loaded package.
+  // Overlay resources are not directly referenced by an application so their resource ids
+  // can change throughout the application's lifetime. Assign overlay package ids last.
+  std::vector<const ApkAssets*> sorted_apk_assets(apk_assets_);
+  std::stable_partition(sorted_apk_assets.begin(), sorted_apk_assets.end(), [](const ApkAssets* a) {
+    return !a->IsOverlay();
+  });
+
   std::unordered_map<std::string, uint8_t> apk_assets_package_ids;
+  std::unordered_map<std::string, uint8_t> package_name_package_ids;
+
+  // Assign stable package ids to application packages.
+  uint8_t next_available_package_id = 0U;
+  for (const auto& apk_assets : sorted_apk_assets) {
+    for (const auto& package : apk_assets->GetLoadedArsc()->GetPackages()) {
+      uint8_t package_id = package->GetPackageId();
+      if (package->IsOverlay()) {
+        package_id = GetDynamicLibManager()->FindUnassignedId(next_available_package_id);
+        next_available_package_id = package_id + 1;
+      } else if (package->IsDynamic()) {
+        package_id = GetDynamicLibManager()->GetAssignedId(package->GetPackageName());
+      }
 
-  // 0x01 is reserved for the android package.
-  int next_package_id = 0x02;
-  const size_t apk_assets_count = apk_assets_.size();
-  for (size_t i = 0; i < apk_assets_count; i++) {
-    const ApkAssets* apk_assets = apk_assets_[i];
-    const LoadedArsc* loaded_arsc = apk_assets->GetLoadedArsc();
+      // Map the path of the apk assets to the package id of its first loaded package.
+      apk_assets_package_ids[apk_assets->GetPath()] = package_id;
 
-    for (const std::unique_ptr<const LoadedPackage>& package : loaded_arsc->GetPackages()) {
-      // Get the package ID or assign one if a shared library.
-      int package_id;
-      if (package->IsDynamic()) {
-        package_id = next_package_id++;
-      } else {
-        package_id = package->GetPackageId();
-      }
+      // Map the package name of the package to the first loaded package with that package id.
+      package_name_package_ids[package->GetPackageName()] = package_id;
+    }
+  }
+
+  const int apk_assets_count = apk_assets_.size();
+  for (int i = 0; i < apk_assets_count; i++) {
+    const auto& apk_assets = apk_assets_[i];
+    for (const auto& package : apk_assets->GetLoadedArsc()->GetPackages()) {
+      const auto package_id_entry = package_name_package_ids.find(package->GetPackageName());
+      CHECK(package_id_entry != package_name_package_ids.end())
+          << "no package id assgined to package " << package->GetPackageName();
+      const uint8_t package_id = package_id_entry->second;
 
       // Add the mapping for package ID to index if not present.
       uint8_t idx = package_ids_[package_id];
@@ -123,7 +149,7 @@ void AssetManager2::BuildDynamicRefTable() {
 
             PackageGroup& target_package_group = package_groups_[target_idx];
 
-            // Create a special dynamic reference table for the overlay to rewite references to
+            // Create a special dynamic reference table for the overlay to rewrite references to
             // overlay resources as references to the target resources they overlay.
             auto overlay_table = std::make_shared<OverlayDynamicRefTable>(
                 loaded_idmap->GetOverlayDynamicRefTable(target_package_id));
@@ -153,8 +179,6 @@ void AssetManager2::BuildDynamicRefTable() {
         package_group->dynamic_ref_table->mEntries.replaceValueFor(
             package_name, static_cast<uint8_t>(entry.package_id));
       }
-
-      apk_assets_package_ids.insert(std::make_pair(apk_assets->GetPath(), package_id));
     }
   }
 
@@ -1279,6 +1303,16 @@ uint8_t AssetManager2::GetAssignedPackageId(const LoadedPackage* package) const
   return 0;
 }
 
+DynamicLibManager* AssetManager2::GetDynamicLibManager() const {
+  auto dynamic_lib_manager =
+      std::get_if<std::unique_ptr<DynamicLibManager>>(&dynamic_lib_manager_);
+  if (dynamic_lib_manager) {
+    return (*dynamic_lib_manager).get();
+  } else {
+    return *std::get_if<DynamicLibManager*>(&dynamic_lib_manager_);
+  }
+}
+
 std::unique_ptr<Theme> AssetManager2::NewTheme() {
   return std::unique_ptr<Theme>(new Theme(this));
 }
diff --git a/libs/androidfw/DynamicLibManager.cpp b/libs/androidfw/DynamicLibManager.cpp
new file mode 100644
index 000000000000..895b7695bf26
--- /dev/null
+++ b/libs/androidfw/DynamicLibManager.cpp
@@ -0,0 +1,34 @@
+/*
+ * 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 "androidfw/DynamicLibManager.h"
+
+namespace android {
+
+uint8_t DynamicLibManager::GetAssignedId(const std::string& library_package_name) {
+  auto lib_entry = shared_lib_package_ids_.find(library_package_name);
+  if (lib_entry != shared_lib_package_ids_.end()) {
+    return lib_entry->second;
+  }
+
+  return shared_lib_package_ids_[library_package_name] = next_package_id_++;
+}
+
+uint8_t DynamicLibManager::FindUnassignedId(uint8_t start_package_id) {
+  return (start_package_id < next_package_id_) ? next_package_id_ : start_package_id;
+}
+
+} // namespace android
diff --git a/libs/androidfw/include/androidfw/AssetManager2.h b/libs/androidfw/include/androidfw/AssetManager2.h
index 00cbbcad56e6..b2cec2a42994 100644
--- a/libs/androidfw/include/androidfw/AssetManager2.h
+++ b/libs/androidfw/include/androidfw/AssetManager2.h
@@ -27,6 +27,7 @@
 #include "androidfw/ApkAssets.h"
 #include "androidfw/Asset.h"
 #include "androidfw/AssetManager.h"
+#include "androidfw/DynamicLibManager.h"
 #include "androidfw/ResourceTypes.h"
 #include "androidfw/Util.h"
 
@@ -94,6 +95,7 @@ class AssetManager2 {
   };
 
   AssetManager2();
+  explicit AssetManager2(DynamicLibManager* dynamic_lib_manager);
 
   // Sets/resets the underlying ApkAssets for this AssetManager. The ApkAssets
   // are not owned by the AssetManager, and must have a longer lifetime.
@@ -371,6 +373,8 @@ class AssetManager2 {
   // Retrieve the assigned package id of the package if loaded into this AssetManager
   uint8_t GetAssignedPackageId(const LoadedPackage* package) const;
 
+  DynamicLibManager* GetDynamicLibManager() const;
+
   // The ordered list of ApkAssets to search. These are not owned by the AssetManager, and must
   // have a longer lifetime.
   std::vector<const ApkAssets*> apk_assets_;
@@ -389,6 +393,9 @@ class AssetManager2 {
   // may need to be purged.
   ResTable_config configuration_;
 
+  // Component responsible for assigning package ids to shared libraries.
+  std::variant<std::unique_ptr<DynamicLibManager>, DynamicLibManager*> dynamic_lib_manager_;
+
   // Cached set of bags. These are cached because they can inherit keys from parent bags,
   // which involves some calculation.
   std::unordered_map<uint32_t, util::unique_cptr<ResolvedBag>> cached_bags_;
diff --git a/libs/androidfw/include/androidfw/DynamicLibManager.h b/libs/androidfw/include/androidfw/DynamicLibManager.h
new file mode 100644
index 000000000000..1ff7079573d2
--- /dev/null
+++ b/libs/androidfw/include/androidfw/DynamicLibManager.h
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROIDFW_DYNAMICLIBMANAGER_H
+#define ANDROIDFW_DYNAMICLIBMANAGER_H
+
+#include <string>
+#include <unordered_map>
+
+#include "android-base/macros.h"
+
+namespace android {
+
+// Manages assigning resource ids for dynamic resources.
+class DynamicLibManager {
+ public:
+  DynamicLibManager() = default;
+
+  // Retrieves the assigned package id for the library.
+  uint8_t GetAssignedId(const std::string& library_package_name);
+
+  // Queries in ascending order for the first available package id that is not currently assigned to
+  // a library.
+  uint8_t FindUnassignedId(uint8_t start_package_id);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DynamicLibManager);
+
+  uint8_t next_package_id_ = 0x02;
+  std::unordered_map<std::string, uint8_t> shared_lib_package_ids_;
+};
+
+} // namespace android
+
+#endif //ANDROIDFW_DYNAMICLIBMANAGER_H
diff --git a/libs/androidfw/include/androidfw/MutexGuard.h b/libs/androidfw/include/androidfw/MutexGuard.h
index 64924f433245..8891512958f0 100644
--- a/libs/androidfw/include/androidfw/MutexGuard.h
+++ b/libs/androidfw/include/androidfw/MutexGuard.h
@@ -47,7 +47,8 @@ class Guarded {
   static_assert(!std::is_pointer<T>::value, "T must not be a raw pointer");
 
  public:
-  explicit Guarded() : guarded_() {
+  template <typename ...Args>
+  explicit Guarded(Args&& ...args) : guarded_(std::forward<Args>(args)...) {
   }
 
   template <typename U = T>
diff --git a/libs/androidfw/tests/AssetManager2_test.cpp b/libs/androidfw/tests/AssetManager2_test.cpp
index b3190be8caf1..2f6f3dfcaf1c 100644
--- a/libs/androidfw/tests/AssetManager2_test.cpp
+++ b/libs/androidfw/tests/AssetManager2_test.cpp
@@ -214,6 +214,25 @@ TEST_F(AssetManager2Test, FindsResourceFromAppLoadedAsSharedLibrary) {
   EXPECT_EQ(fix_package_id(appaslib::R::array::integerArray1, 0x02), value.data);
 }
 
+TEST_F(AssetManager2Test, AssignsUnchangingPackageIdToSharedLibrary) {
+  DynamicLibManager lib_manager;
+  AssetManager2 assetmanager(&lib_manager);
+  assetmanager.SetApkAssets(
+      {lib_one_assets_.get(), lib_two_assets_.get(), libclient_assets_.get()});
+
+  AssetManager2 assetmanager2(&lib_manager);
+  assetmanager2.SetApkAssets(
+      {lib_two_assets_.get(), lib_one_assets_.get(), libclient_assets_.get()});
+
+  uint32_t res_id = assetmanager.GetResourceId("com.android.lib_one:string/foo");
+  ASSERT_NE(0U, res_id);
+
+  uint32_t res_id_2 = assetmanager2.GetResourceId("com.android.lib_one:string/foo");
+  ASSERT_NE(0U, res_id_2);
+
+  ASSERT_EQ(res_id, res_id_2);
+}
+
 TEST_F(AssetManager2Test, GetSharedLibraryResourceName) {
   AssetManager2 assetmanager;
   assetmanager.SetApkAssets({lib_one_assets_.get()});