--- a/hotspot/src/share/vm/prims/whitebox.cpp	Thu Jan 19 11:10:33 2017 +0100
+++ b/hotspot/src/share/vm/prims/whitebox.cpp	Thu Jan 19 11:49:30 2017 +0100
@@ -40,6 +40,8 @@
 #include "memory/universe.hpp"
 #include "memory/oopFactory.hpp"
 #include "oops/constantPool.hpp"
+#include "oops/objArrayKlass.hpp"
+#include "oops/objArrayOop.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/wbtestmethods/parserTests.hpp"
 #include "prims/whitebox.hpp"
@@ -1403,19 +1405,52 @@
 
 WB_ENTRY(void, WB_DefineModule(JNIEnv* env, jobject o, jobject module, jstring version, jstring location,
                                 jobjectArray packages))
-  Modules::define_module(module, version, location, packages, CHECK);
+  ResourceMark rm(THREAD);
+
+  objArrayOop packages_oop = objArrayOop(JNIHandles::resolve(packages));
+  objArrayHandle packages_h(THREAD, packages_oop);
+  int num_packages = (packages_h == NULL ? 0 : packages_h->length());
+
+  char** pkgs = NULL;
+  if (num_packages > 0) {
+    pkgs = NEW_RESOURCE_ARRAY_IN_THREAD(THREAD, char*, num_packages);
+    for (int x = 0; x < num_packages; x++) {
+      oop pkg_str = packages_h->obj_at(x);
+      if (pkg_str == NULL || !pkg_str->is_a(SystemDictionary::String_klass())) {
+        THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
+                  err_msg("Bad package name"));
+      }
+      pkgs[x] = java_lang_String::as_utf8_string(pkg_str);
+    }
+  }
+  Modules::define_module(module, version, location, (const char* const*)pkgs, num_packages, CHECK);
 WB_END
 
 WB_ENTRY(void, WB_AddModuleExports(JNIEnv* env, jobject o, jobject from_module, jstring package, jobject to_module))
-  Modules::add_module_exports_qualified(from_module, package, to_module, CHECK);
+  ResourceMark rm(THREAD);
+  char* package_name = NULL;
+  if (package != NULL) {
+      package_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(package));
+  }
+  Modules::add_module_exports_qualified(from_module, package_name, to_module, CHECK);
 WB_END
 
 WB_ENTRY(void, WB_AddModuleExportsToAllUnnamed(JNIEnv* env, jobject o, jclass module, jstring package))
-  Modules::add_module_exports_to_all_unnamed(module, package, CHECK);
+  ResourceMark rm(THREAD);
+  char* package_name = NULL;
+  if (package != NULL) {
+      package_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(package));
+  }
+  Modules::add_module_exports_to_all_unnamed(module, package_name, CHECK);
 WB_END
 
 WB_ENTRY(void, WB_AddModuleExportsToAll(JNIEnv* env, jobject o, jclass module, jstring package))
-  Modules::add_module_exports(module, package, NULL, CHECK);
+  ResourceMark rm(THREAD);
+  char* package_name = NULL;
+  if (package != NULL) {
+      package_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(package));
+  }
+  Modules::add_module_exports(module, package_name, NULL, CHECK);
 WB_END
 
 WB_ENTRY(void, WB_AddReadsModule(JNIEnv* env, jobject o, jobject from_module, jobject source_module))
@@ -1423,11 +1458,21 @@
 WB_END
 
 WB_ENTRY(void, WB_AddModulePackage(JNIEnv* env, jobject o, jclass module, jstring package))
-  Modules::add_module_package(module, package, CHECK);
+  ResourceMark rm(THREAD);
+  char* package_name = NULL;
+  if (package != NULL) {
+      package_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(package));
+  }
+  Modules::add_module_package(module, package_name, CHECK);
 WB_END
 
 WB_ENTRY(jobject, WB_GetModuleByPackageName(JNIEnv* env, jobject o, jobject loader, jstring package))
-  return Modules::get_module_by_package_name(loader, package, THREAD);
+  ResourceMark rm(THREAD);
+  char* package_name = NULL;
+  if (package != NULL) {
+      package_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(package));
+  }
+  return Modules::get_module_by_package_name(loader, package_name, THREAD);
 WB_END
 
 WB_ENTRY(jlong, WB_IncMetaspaceCapacityUntilGC(JNIEnv* env, jobject wb, jlong inc))