4 files changed, 30 insertions, 2 deletions

diff --git a/core/java/android/content/res/ApkAssets.java b/core/java/android/content/res/ApkAssets.java
index 143c00dd4d81..653e243f5e06 100644
--- a/core/java/android/content/res/ApkAssets.java
+++ b/core/java/android/content/res/ApkAssets.java
@@ -78,6 +78,11 @@ public final class ApkAssets {
      */
     public static final int PROPERTY_DISABLE_INCREMENTAL_HARDENING = 1 << 4;
 
+    /**
+     * The apk assets only contain the overlayable declarations information.
+     */
+    public static final int PROPERTY_ONLY_OVERLAYABLES = 1 << 5;
+
     /** Flags that change the behavior of loaded apk assets. */
     @IntDef(prefix = { "PROPERTY_" }, value = {
             PROPERTY_SYSTEM,
diff --git a/libs/androidfw/LoadedArsc.cpp b/libs/androidfw/LoadedArsc.cpp
index fbfae5e2bcbe..c9d5e074271b 100644
--- a/libs/androidfw/LoadedArsc.cpp
+++ b/libs/androidfw/LoadedArsc.cpp
@@ -494,6 +494,8 @@ std::unique_ptr<const LoadedPackage> LoadedPackage::Load(const Chunk& chunk,
   util::ReadUtf16StringFromDevice(header->name, arraysize(header->name),
                                   &loaded_package->package_name_);
 
+  const bool only_overlayable = (property_flags & PROPERTY_ONLY_OVERLAYABLES) != 0;
+
   // A map of TypeSpec builders, each associated with an type index.
   // We use these to accumulate the set of Types available for a TypeSpec, and later build a single,
   // contiguous block of memory that holds all the Types together with the TypeSpec.
@@ -502,6 +504,9 @@ std::unique_ptr<const LoadedPackage> LoadedPackage::Load(const Chunk& chunk,
   ChunkIterator iter(chunk.data_ptr(), chunk.data_size());
   while (iter.HasNext()) {
     const Chunk child_chunk = iter.Next();
+    if (only_overlayable && child_chunk.type() != RES_TABLE_OVERLAYABLE_TYPE) {
+      continue;
+    }
     switch (child_chunk.type()) {
       case RES_STRING_POOL_TYPE: {
         const auto pool_address = child_chunk.header<ResChunk_header>();
@@ -655,6 +660,9 @@ std::unique_ptr<const LoadedPackage> LoadedPackage::Load(const Chunk& chunk,
                      << name_to_actor_it->first << "'.";
           return {};
         }
+        if (only_overlayable) {
+          break;
+        }
 
         // Iterate over the overlayable policy chunks contained within the overlayable chunk data
         ChunkIterator overlayable_iter(child_chunk.data_ptr(), child_chunk.data_size());
@@ -800,14 +808,21 @@ bool LoadedArsc::LoadTable(const Chunk& chunk, const LoadedIdmap* loaded_idmap,
     global_string_pool_ = util::make_unique<OverlayStringPool>(loaded_idmap);
   }
 
+  const bool only_overlayable = (property_flags & PROPERTY_ONLY_OVERLAYABLES) != 0;
+
   const size_t package_count = dtohl(header->packageCount);
   size_t packages_seen = 0;
 
-  packages_.reserve(package_count);
+  if (!only_overlayable) {
+    packages_.reserve(package_count);
+  }
 
   ChunkIterator iter(chunk.data_ptr(), chunk.data_size());
   while (iter.HasNext()) {
     const Chunk child_chunk = iter.Next();
+    if (only_overlayable && child_chunk.type() != RES_TABLE_PACKAGE_TYPE) {
+      continue;
+    }
     switch (child_chunk.type()) {
       case RES_STRING_POOL_TYPE:
         // Only use the first string pool. Ignore others.
@@ -837,6 +852,10 @@ bool LoadedArsc::LoadTable(const Chunk& chunk, const LoadedIdmap* loaded_idmap,
           return false;
         }
         packages_.push_back(std::move(loaded_package));
+        if (only_overlayable) {
+          // Overlayable is always in the first package, no need to process anything else.
+          return true;
+        }
       } break;
 
       default:
diff --git a/libs/androidfw/include/androidfw/LoadedArsc.h b/libs/androidfw/include/androidfw/LoadedArsc.h
index 4d12885ad291..3a7287187781 100644
--- a/libs/androidfw/include/androidfw/LoadedArsc.h
+++ b/libs/androidfw/include/androidfw/LoadedArsc.h
@@ -96,6 +96,9 @@ enum : package_property_t {
   // The apk assets is owned by the application running in this process and incremental crash
   // protections for this APK must be disabled.
   PROPERTY_DISABLE_INCREMENTAL_HARDENING = 1U << 4U,
+
+  // The apk assets only contain the overlayable declarations information.
+  PROPERTY_ONLY_OVERLAYABLES = 1U << 5U,
 };
 
 struct OverlayableInfo {
diff --git a/services/core/java/com/android/server/om/OverlayManagerService.java b/services/core/java/com/android/server/om/OverlayManagerService.java
index d471c8abb1b2..e54f12c37559 100644
--- a/services/core/java/com/android/server/om/OverlayManagerService.java
+++ b/services/core/java/com/android/server/om/OverlayManagerService.java
@@ -1301,7 +1301,8 @@ public final class OverlayManagerService extends SystemService {
 
             ApkAssets apkAssets = null;
             try {
-                apkAssets = ApkAssets.loadFromPath(pkg.getSplits().get(0).getPath());
+                apkAssets = ApkAssets.loadFromPath(pkg.getSplits().get(0).getPath(),
+                        ApkAssets.PROPERTY_ONLY_OVERLAYABLES);
                 return apkAssets.getOverlayableInfo(targetOverlayableName);
             } finally {
                 if (apkAssets != null) {