Allow for overlaying dynamic shared libraries

Overlays targeting shared libraries should be loaded into the
resources of every target that depends on the shared library.

Static shared libraries are currently not supported because overlays
should override all versions of static shared libraries and there is
not currently support for an overlay targeting multiple APKs.

Also created a test instrumentation and host test suite for testing
overlays and packages on the system image.

Bug: 140790224
Test: atest OverlayRemountedTest
Change-Id: I20a217b6368d6cf92b2b9f46908fd58012933f72

1 files changed, 11 insertions, 1 deletions

diff --git a/cmds/idmap2/libidmap2/ResourceMapping.cpp b/cmds/idmap2/libidmap2/ResourceMapping.cpp
index 229628c7dd8b..407478945151 100644
--- a/cmds/idmap2/libidmap2/ResourceMapping.cpp
+++ b/cmds/idmap2/libidmap2/ResourceMapping.cpp
@@ -33,6 +33,8 @@ namespace android::idmap2 {
 
 namespace {
 
+#define REWRITE_PACKAGE(resid, package_id) \
+  (((resid)&0x00ffffffU) | (((uint32_t)(package_id)) << 24U))
 #define EXTRACT_PACKAGE(resid) ((0xff000000 & (resid)) >> 24)
 
 std::string ConcatPolicies(const std::vector<std::string>& policies) {
@@ -154,6 +156,7 @@ Result<ResourceMapping> ResourceMapping::CreateResourceMapping(const AssetManage
     return Error("root element is not <overlay> tag");
   }
 
+  const uint8_t target_package_id = target_package->GetPackageId();
   const uint8_t overlay_package_id = overlay_package->GetPackageId();
   auto overlay_it_end = root_it.end();
   for (auto overlay_it = root_it.begin(); overlay_it != overlay_it_end; ++overlay_it) {
@@ -187,6 +190,9 @@ Result<ResourceMapping> ResourceMapping::CreateResourceMapping(const AssetManage
       continue;
     }
 
+    // Retrieve the compile-time resource id of the target resource.
+    target_id = REWRITE_PACKAGE(target_id, target_package_id);
+
     if (overlay_resource->dataType == Res_value::TYPE_STRING) {
       overlay_resource->data += string_pool_offset;
     }
@@ -214,6 +220,7 @@ Result<ResourceMapping> ResourceMapping::CreateResourceMappingLegacy(
     const AssetManager2* target_am, const AssetManager2* overlay_am,
     const LoadedPackage* target_package, const LoadedPackage* overlay_package) {
   ResourceMapping resource_mapping;
+  const uint8_t target_package_id = target_package->GetPackageId();
   const auto end = overlay_package->end();
   for (auto iter = overlay_package->begin(); iter != end; ++iter) {
     const ResourceId overlay_resid = *iter;
@@ -225,11 +232,14 @@ Result<ResourceMapping> ResourceMapping::CreateResourceMappingLegacy(
     // Find the resource with the same type and entry name within the target package.
     const std::string full_name =
         base::StringPrintf("%s:%s", target_package->GetPackageName().c_str(), name->c_str());
-    const ResourceId target_resource = target_am->GetResourceId(full_name);
+    ResourceId target_resource = target_am->GetResourceId(full_name);
     if (target_resource == 0U) {
       continue;
     }
 
+    // Retrieve the compile-time resource id of the target resource.
+    target_resource = REWRITE_PACKAGE(target_resource, target_package_id);
+
     resource_mapping.AddMapping(target_resource, Res_value::TYPE_REFERENCE, overlay_resid,
                                 /* rewrite_overlay_reference */ false);
   }