diff --git a/tests/Android.bp b/tests/Android.bp
index 8f1c11f..084d393 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -298,7 +298,13 @@
                 "libLLVMSupport",
             ],
         }
-    }
+    },
+
+    product_variables: {
+        debuggable: {
+            cppflags: ["-DUSE_LD_CONFIG_FILE"],
+        },
+    },
 }
 
 // -----------------------------------------------------------------------------
@@ -592,6 +598,12 @@
     sanitize: {
         never: false,
     },
+
+    product_variables: {
+        debuggable: {
+            cppflags: ["-DUSE_LD_CONFIG_FILE"],
+        },
+    },
 }
 
 subdirs = ["libs"]
diff --git a/tests/dl_test.cpp b/tests/dl_test.cpp
index aa8bd57..857640a 100644
--- a/tests/dl_test.cpp
+++ b/tests/dl_test.cpp
@@ -23,6 +23,8 @@
 #include <stdint.h>
 
 #include <string>
+#include <iostream>
+#include <fstream>
 
 #include "gtest_globals.h"
 #include "utils.h"
@@ -109,4 +111,131 @@
 #endif
 }
 
-// TODO: Add tests for LD_PRELOADs
+
+TEST(dl, exec_without_ld_preload) {
+#if defined(__BIONIC__)
+  std::string helper = get_testlib_root() +
+      "/ld_preload_test_helper/ld_preload_test_helper";
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "12345");
+#endif
+}
+
+TEST(dl, exec_with_ld_preload) {
+#if defined(__BIONIC__)
+  std::string helper = get_testlib_root() +
+      "/ld_preload_test_helper/ld_preload_test_helper";
+  std::string env = std::string("LD_PRELOAD=") + get_testlib_root() + "/ld_preload_test_helper_lib2.so";
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.SetEnv({ env.c_str(), nullptr });
+  // ld_preload_test_helper calls get_value_from_lib() and returns the value.
+  // The symbol is defined by two libs: ld_preload_test_helper_lib.so and
+  // ld_preloaded_lib.so. The former is DT_NEEDED and the latter is LD_PRELOADED
+  // via this execution. The main executable is linked to the LD_PRELOADED lib
+  // and the value given from the lib is returned.
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "54321");
+#endif
+}
+
+
+// ld_config_test_helper must fail because it is depending on a lib which is not
+// in the search path
+//
+// Call sequence is...
+// _helper -- (get_value_from_lib()) -->
+//     _lib1.so -- (get_value_from_another_lib()) -->
+//       _lib2.so (returns 12345)
+// The two libs are in ns2/ subdir.
+TEST(dl, exec_without_ld_config_file) {
+#if defined(__BIONIC__)
+  std::string error_message = "CANNOT LINK EXECUTABLE \"" + get_testlib_root() + "/ld_config_test_helper/ld_config_test_helper\": library \"ld_config_test_helper_lib1.so\" not found\n";
+  std::string helper = get_testlib_root() +
+      "/ld_config_test_helper/ld_config_test_helper";
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, -6, error_message.c_str());
+#endif
+}
+
+#if defined(__BIONIC__)
+static void create_ld_config_file(std::string& config_file) {
+  std::ofstream fout(config_file.c_str(), std::ios::out);
+  fout << "dir.test = " << get_testlib_root() << "/ld_config_test_helper/" << std::endl
+       << "[test]" << std::endl
+       << "additional.namespaces = ns2" << std::endl
+       << "namespace.default.search.paths = " << get_testlib_root() << std::endl
+       << "namespace.default.links = ns2" << std::endl
+       << "namespace.default.link.ns2.shared_libs = libc.so:libm.so:libdl.so:ld_config_test_helper_lib1.so" << std::endl
+       << "namespace.ns2.search.paths = /system/${LIB}:" << get_testlib_root() << "/ns2" << std::endl;
+  fout.close();
+}
+#endif
+
+#ifdef USE_LD_CONFIG_FILE
+
+// _lib1.so and _lib2.so are now searchable by having another namespace 'ns2'
+// whose search paths include the 'ns2/' subdir.
+TEST(dl, exec_with_ld_config_file) {
+#if defined(__BIONIC__)
+  std::string helper = get_testlib_root() +
+      "/ld_config_test_helper/ld_config_test_helper";
+  std::string config_file = get_testlib_root() + "/ld.config.txt";
+  create_ld_config_file(config_file);
+  std::string env = std::string("LD_CONFIG_FILE=") + config_file;
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.SetEnv({ env.c_str(), nullptr });
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "12345");
+#endif
+}
+
+// _lib3.so has same symbol as lib2.so but returns 54321. _lib3.so is
+// LD_PRELOADed. This test is to ensure LD_PRELOADed libs are available to
+// additional namespaces other than the default namespace.
+TEST(dl, exec_with_ld_config_file_with_ld_preload) {
+#if defined(__BIONIC__)
+  std::string helper = get_testlib_root() +
+      "/ld_config_test_helper/ld_config_test_helper";
+  std::string config_file = get_testlib_root() + "/ld.config.txt";
+  create_ld_config_file(config_file);
+  std::string env = std::string("LD_CONFIG_FILE=") + config_file;
+  std::string env2 = std::string("LD_PRELOAD=") + get_testlib_root() + "/ld_config_test_helper_lib3.so";
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.SetEnv({ env.c_str(), env2.c_str(), nullptr });
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, 0, "54321");
+#endif
+}
+
+#endif // USE_LD_CONFIG_FILE
+
+// ensures that LD_CONFIG_FILE env var does not work for production builds.
+// The test input is the same as exec_with_ld_config_file, but it must fail in
+// this case.
+TEST(dl, disable_ld_config_file) {
+#if defined(__BIONIC__)
+  if (getuid() == 0) {
+    // when executed from the shell (e.g. not as part of CTS), skip the test.
+    // This test is only for CTS.
+    return;
+  }
+  std::string error_message = "CANNOT LINK EXECUTABLE \"" + get_testlib_root() + "/ld_config_test_helper/ld_config_test_helper\": library \"ld_config_test_helper_lib1.so\" not found\n";
+  std::string helper = get_testlib_root() +
+      "/ld_config_test_helper/ld_config_test_helper";
+  std::string config_file = get_testlib_root() + "/ld.config.txt";
+  create_ld_config_file(config_file);
+  std::string env = std::string("LD_CONFIG_FILE=") + config_file;
+  chmod(helper.c_str(), 0755);
+  ExecTestHelper eth;
+  eth.SetArgs({ helper.c_str(), nullptr });
+  eth.SetEnv({ env.c_str(), nullptr });
+  eth.Run([&]() { execve(helper.c_str(), eth.GetArgs(), eth.GetEnv()); }, -6, error_message.c_str());
+#endif
+}
diff --git a/tests/libs/Android.bp b/tests/libs/Android.bp
index 973a8d2..c1600cc 100644
--- a/tests/libs/Android.bp
+++ b/tests/libs/Android.bp
@@ -617,3 +617,59 @@
     defaults: ["bionic_testlib_defaults"],
     srcs: ["preinit_syscall_test_helper.cpp"],
 }
+
+cc_test {
+    name: "ld_preload_test_helper",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_preload_test_helper.cpp"],
+    shared_libs: ["ld_preload_test_helper_lib1"],
+    ldflags: ["-Wl,--rpath,${ORIGIN}/.."],
+}
+
+cc_test_library {
+    name: "ld_preload_test_helper_lib1",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_preload_test_helper_lib1.cpp"],
+}
+
+cc_test_library {
+    name: "ld_preload_test_helper_lib2",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_preload_test_helper_lib2.cpp"],
+}
+
+cc_test {
+    name: "ld_config_test_helper",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_config_test_helper.cpp"],
+    shared_libs: ["ld_config_test_helper_lib1"],
+    ldflags: ["-Wl,--rpath,${ORIGIN}/.."],
+}
+
+cc_test_library {
+    name: "ld_config_test_helper_lib1",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_config_test_helper_lib1.cpp"],
+    shared_libs: ["ld_config_test_helper_lib2"],
+    relative_install_path: "/ns2",
+}
+
+cc_test_library {
+    name: "ld_config_test_helper_lib2",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_config_test_helper_lib2.cpp"],
+    relative_install_path: "/ns2",
+}
+
+cc_test_library {
+    name: "ld_config_test_helper_lib3",
+    host_supported: false,
+    defaults: ["bionic_testlib_defaults"],
+    srcs: ["ld_config_test_helper_lib3.cpp"],
+}
diff --git a/tests/libs/ld_config_test_helper.cpp b/tests/libs/ld_config_test_helper.cpp
new file mode 100644
index 0000000..592e8c0
--- /dev/null
+++ b/tests/libs/ld_config_test_helper.cpp
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+extern int get_value_from_lib();
+
+int main() {
+  printf("%d", get_value_from_lib());
+  return 0;
+}
diff --git a/tests/libs/ld_config_test_helper_lib1.cpp b/tests/libs/ld_config_test_helper_lib1.cpp
new file mode 100644
index 0000000..fc5401a
--- /dev/null
+++ b/tests/libs/ld_config_test_helper_lib1.cpp
@@ -0,0 +1,4 @@
+extern int get_value_from_another_lib();
+int get_value_from_lib() {
+  return get_value_from_another_lib();
+}
diff --git a/tests/libs/ld_config_test_helper_lib2.cpp b/tests/libs/ld_config_test_helper_lib2.cpp
new file mode 100644
index 0000000..a620a6c
--- /dev/null
+++ b/tests/libs/ld_config_test_helper_lib2.cpp
@@ -0,0 +1,3 @@
+int get_value_from_another_lib() {
+  return 12345;
+}
diff --git a/tests/libs/ld_config_test_helper_lib3.cpp b/tests/libs/ld_config_test_helper_lib3.cpp
new file mode 100644
index 0000000..93d1cd8
--- /dev/null
+++ b/tests/libs/ld_config_test_helper_lib3.cpp
@@ -0,0 +1,3 @@
+int get_value_from_another_lib() {
+  return 54321;
+}
diff --git a/tests/libs/ld_preload_test_helper.cpp b/tests/libs/ld_preload_test_helper.cpp
new file mode 100644
index 0000000..592e8c0
--- /dev/null
+++ b/tests/libs/ld_preload_test_helper.cpp
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+extern int get_value_from_lib();
+
+int main() {
+  printf("%d", get_value_from_lib());
+  return 0;
+}
diff --git a/tests/libs/ld_preload_test_helper_lib1.cpp b/tests/libs/ld_preload_test_helper_lib1.cpp
new file mode 100644
index 0000000..74e89db
--- /dev/null
+++ b/tests/libs/ld_preload_test_helper_lib1.cpp
@@ -0,0 +1,3 @@
+int get_value_from_lib() {
+  return 12345;
+}
diff --git a/tests/libs/ld_preload_test_helper_lib2.cpp b/tests/libs/ld_preload_test_helper_lib2.cpp
new file mode 100644
index 0000000..9239891
--- /dev/null
+++ b/tests/libs/ld_preload_test_helper_lib2.cpp
@@ -0,0 +1,3 @@
+int get_value_from_lib() {
+  return 54321;
+}