Load libRS_internal.so from the rs namespace

Bug: 64747884
Test: VtsHalRenderscriptV1_0TargetTest successful on the device built
with BOARD_VNDK_VERSION=current and [system] namespace config is applied
to /data/nativetest[64]/* processes.

Merged-In: I9e967c80ac2dba718cd47e1f378bcbf18abe9ad2
Change-Id: I9e967c80ac2dba718cd47e1f378bcbf18abe9ad2
(cherry picked from commit a7ef697a0a520015f961012d53d852a8cece20df)
diff --git a/renderscript/1.0/default/Device.cpp b/renderscript/1.0/default/Device.cpp
index 3aae060..4831a8b 100644
--- a/renderscript/1.0/default/Device.cpp
+++ b/renderscript/1.0/default/Device.cpp
@@ -1,6 +1,9 @@
 #include "Context.h"
 #include "Device.h"
 
+#include <android/dlext.h>
+#include <dlfcn.h>
+
 namespace android {
 namespace hardware {
 namespace renderscript {
@@ -39,7 +42,25 @@
     static_assert(sizeof(size_t) <= sizeof(uint64_t), "RenderScript HIDL Error: sizeof(size_t) > sizeof(uint64_t)");
 
     const char* filename = "libRS_internal.so";
-    void* handle = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
+    // Try to load libRS_internal.so from the "rs" namespace directly.
+    typedef struct android_namespace_t* (*GetExportedNamespaceFnPtr)(const char*);
+    GetExportedNamespaceFnPtr getExportedNamespace =
+        (GetExportedNamespaceFnPtr)dlsym(RTLD_DEFAULT, "android_get_exported_namespace");
+    void* handle = nullptr;
+    if (getExportedNamespace != nullptr) {
+        android_namespace_t* rs_namespace = getExportedNamespace("rs");
+        if (rs_namespace != nullptr) {
+            const android_dlextinfo dlextinfo = {
+                .flags = ANDROID_DLEXT_USE_NAMESPACE, .library_namespace = rs_namespace,
+            };
+            handle = android_dlopen_ext(filename, RTLD_LAZY | RTLD_LOCAL, &dlextinfo);
+        }
+    }
+    if (handle == nullptr) {
+        // if there is no "rs" namespace (in case when this HAL impl is loaded
+        // into a vendor process), then use the plain dlopen.
+        handle = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);
+    }
 
     dispatchTable dispatchHal = {
         .SetNativeLibDir = (SetNativeLibDirFnPtr) nullptr,