diff --git a/debuggerd/Android.mk b/debuggerd/Android.mk
index 6469db4..9ce94c5 100644
--- a/debuggerd/Android.mk
+++ b/debuggerd/Android.mk
@@ -54,7 +54,7 @@
 
 
 include $(CLEAR_VARS)
-LOCAL_SRC_FILES := crasher.c
+LOCAL_SRC_FILES := crasher.cpp
 LOCAL_SRC_FILES_arm    := arm/crashglue.S
 LOCAL_SRC_FILES_arm64  := arm64/crashglue.S
 LOCAL_SRC_FILES_mips   := mips/crashglue.S
@@ -63,9 +63,9 @@
 LOCAL_SRC_FILES_x86_64 := x86_64/crashglue.S
 LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
 LOCAL_MODULE_TAGS := optional
-LOCAL_CFLAGS += -fstack-protector-all -Werror -Wno-free-nonheap-object -Wno-date-time
+LOCAL_CPPFLAGS := $(common_cppflags) -fstack-protector-all -Wno-free-nonheap-object -Wno-date-time
 #LOCAL_FORCE_STATIC_EXECUTABLE := true
-LOCAL_SHARED_LIBRARIES := libcutils liblog libc
+LOCAL_SHARED_LIBRARIES := libcutils liblog
 
 # The arm emulator has VFP but not VFPv3-D32.
 ifeq ($(ARCH_ARM_HAVE_VFP_D32),true)
diff --git a/debuggerd/crasher.c b/debuggerd/crasher.cpp
similarity index 93%
rename from debuggerd/crasher.c
rename to debuggerd/crasher.cpp
index 75f070b..bdeaf0b 100644
--- a/debuggerd/crasher.c
+++ b/debuggerd/crasher.cpp
@@ -22,8 +22,9 @@
 
 extern const char* __progname;
 
-void crash1(void);
-void crashnostack(void);
+extern "C" void crash1(void);
+extern "C" void crashnostack(void);
+
 static int do_action(const char* arg);
 
 static void maybe_abort() {
@@ -159,6 +160,10 @@
         __assert("some_file.c", 123, "false");
     } else if (!strcmp(arg, "assert2")) {
         __assert2("some_file.c", 123, "some_function", "false");
+    } else if (!strcmp(arg, "fortify")) {
+        char buf[10];
+        __read_chk(-1, buf, 32, 10);
+        while (true) pause();
     } else if (!strcmp(arg, "LOG_ALWAYS_FATAL")) {
         LOG_ALWAYS_FATAL("hello %s", "world");
     } else if (!strcmp(arg, "LOG_ALWAYS_FATAL_IF")) {
@@ -172,7 +177,7 @@
     } else if (!strcmp(arg, "heap-usage")) {
         abuse_heap();
     } else if (!strcmp(arg, "SIGSEGV-unmapped")) {
-        char* map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+        char* map = reinterpret_cast<char*>(mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0));
         munmap(map, sizeof(int));
         map[0] = '8';
     }
@@ -189,6 +194,7 @@
     fprintf(stderr, "  abort                 call abort()\n");
     fprintf(stderr, "  assert                call assert() without a function\n");
     fprintf(stderr, "  assert2               call assert() with a function\n");
+    fprintf(stderr, "  fortify               fail a _FORTIFY_SOURCE check\n");
     fprintf(stderr, "  LOG_ALWAYS_FATAL      call LOG_ALWAYS_FATAL\n");
     fprintf(stderr, "  LOG_ALWAYS_FATAL_IF   call LOG_ALWAYS_FATAL\n");
     fprintf(stderr, "  SIGFPE                cause a SIGFPE\n");
diff --git a/libnativeloader/dlext_namespaces.h b/libnativeloader/dlext_namespaces.h
new file mode 100644
index 0000000..ca9e619
--- /dev/null
+++ b/libnativeloader/dlext_namespaces.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2016 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 __ANDROID_DLEXT_NAMESPACES_H__
+#define __ANDROID_DLEXT_NAMESPACES_H__
+
+#include <android/dlext.h>
+
+__BEGIN_DECLS
+
+/*
+ * Initializes public and anonymous namespaces. The public_ns_sonames is the list of sonames
+ * to be included into public namespace separated by colon. Example: "libc.so:libm.so:libdl.so".
+ * The libraries in this list should be loaded prior to this call.
+ *
+ * The anon_ns_library_path is the search path for anonymous namespace. The anonymous namespace
+ * is used in the case when linker cannot identify the caller of dlopen/dlsym. This happens
+ * for the code not loaded by dynamic linker; for example calls from the mono-compiled code.
+ */
+extern bool android_init_namespaces(const char* public_ns_sonames,
+                                    const char* anon_ns_library_path);
+
+
+enum {
+  /* A regular namespace is the namespace with a custom search path that does
+   * not impose any restrictions on the location of native libraries.
+   */
+  ANDROID_NAMESPACE_TYPE_REGULAR = 0,
+
+  /* An isolated namespace requires all the libraries to be on the search path
+   * or under permitted_when_isolated_path. The search path is the union of
+   * ld_library_path and default_library_path.
+   */
+  ANDROID_NAMESPACE_TYPE_ISOLATED = 1,
+
+  /* The shared namespace clones the list of libraries of the caller namespace upon creation
+   * which means that they are shared between namespaces - the caller namespace and the new one
+   * will use the same copy of a library if it was loaded prior to android_create_namespace call.
+   *
+   * Note that libraries loaded after the namespace is created will not be shared.
+   *
+   * Shared namespaces can be isolated or regular. Note that they do not inherit the search path nor
+   * permitted_path from the caller's namespace.
+   */
+  ANDROID_NAMESPACE_TYPE_SHARED = 2,
+  ANDROID_NAMESPACE_TYPE_SHARED_ISOLATED = ANDROID_NAMESPACE_TYPE_SHARED |
+                                           ANDROID_NAMESPACE_TYPE_ISOLATED,
+};
+
+/*
+ * Creates new linker namespace.
+ * ld_library_path and default_library_path represent the search path
+ * for the libraries in the namespace.
+ *
+ * The libraries in the namespace are searched by folowing order:
+ * 1. ld_library_path (Think of this as namespace-local LD_LIBRARY_PATH)
+ * 2. In directories specified by DT_RUNPATH of the "needed by" binary.
+ * 3. deault_library_path (This of this as namespace-local default library path)
+ *
+ * When type is ANDROID_NAMESPACE_TYPE_ISOLATED the resulting namespace requires all of
+ * the libraries to be on the search path or under the permitted_when_isolated_path;
+ * the search_path is ld_library_path:default_library_path. Note that the
+ * permitted_when_isolated_path path is not part of the search_path and
+ * does not affect the search order. It is a way to allow loading libraries from specific
+ * locations when using absolute path.
+ * If a library or any of its dependencies are outside of the permitted_when_isolated_path
+ * and search_path, and it is not part of the public namespace dlopen will fail.
+ */
+extern struct android_namespace_t* android_create_namespace(const char* name,
+                                                            const char* ld_library_path,
+                                                            const char* default_library_path,
+                                                            uint64_t type,
+                                                            const char* permitted_when_isolated_path);
+
+__END_DECLS
+
+#endif /* __ANDROID_DLEXT_NAMESPACES_H__ */
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index 33d5b62..927cbec 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -19,7 +19,7 @@
 
 #include <dlfcn.h>
 #ifdef __ANDROID__
-#include <android/dlext.h>
+#include "dlext_namespaces.h"
 #include "cutils/properties.h"
 #include "log/log.h"
 #endif
@@ -39,6 +39,11 @@
 static constexpr const char* kPublicNativeLibrariesSystemConfigPathFromRoot = "/etc/public.libraries.txt";
 static constexpr const char* kPublicNativeLibrariesVendorConfig = "/vendor/etc/public.libraries.txt";
 
+// (http://b/27588281) This is a workaround for apps using custom classloaders and calling
+// System.load() with an absolute path which is outside of the classloader library search path.
+// This list includes all directories app is allowed to access this way.
+static constexpr const char* kWhitelistedDirectories = "/data:/mnt/expand";
+
 static bool is_debuggable() {
   char debuggable[PROP_VALUE_MAX];
   property_get("ro.debuggable", debuggable, "0");
@@ -61,10 +66,19 @@
       library_path = library_path_utf_chars.c_str();
     }
 
-    std::string permitted_path;
+    // (http://b/27588281) This is a workaround for apps using custom
+    // classloaders and calling System.load() with an absolute path which
+    // is outside of the classloader library search path.
+    //
+    // This part effectively allows such a classloader to access anything
+    // under /data and /mnt/expand
+    std::string permitted_path = kWhitelistedDirectories;
+
     if (java_permitted_path != nullptr) {
       ScopedUtfChars path(env, java_permitted_path);
-      permitted_path = path.c_str();
+      if (path.c_str() != nullptr && path.size() > 0) {
+        permitted_path = permitted_path + ":" + path.c_str();
+      }
     }
 
     if (!initialized_ && !InitPublicNamespace(library_path.c_str())) {
@@ -105,6 +119,13 @@
   }
 
   void Initialize() {
+    // Once public namespace is initialized there is no
+    // point in running this code - it will have no effect
+    // on the current list of public libraries.
+    if (initialized_) {
+      return;
+    }
+
     std::vector<std::string> sonames;
     const char* android_root_env = getenv("ANDROID_ROOT");
     std::string root_dir = android_root_env != nullptr ? android_root_env : "/system";