Fix symbol lookup order during relocation

Relocate symbol against DF_1_GLOBAL shared libraries
  loaded before this shared library. This includes
  main executable, ld_preloads and other libraries
  that have DF_1_GLOBAL flag set.

Bug: 2643900
Bug: 15432753
Bug: 18186310

(cherry picked from commit d225a5e652)

Change-Id: I4e889cdf2dfbf8230b0790053d311ee6b0d0ee2d

tests/libs/dl_preempt_library_1.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+// This one should be preempted by the function
+// defined in the main executable.
+extern "C" int __attribute__((weak)) main_global_default_serial() {
+  return 2716057;
+}
+
+// Even though this one is defined by the main
+// executable it should not be preempted
+// because of protected visibility
+extern "C" int __attribute__((weak, visibility("protected"))) main_global_protected_serial() {
+  return 3370318;
+}
+
+extern "C" int main_global_default_get_serial() {
+  return main_global_default_serial();
+}
+
+extern "C" int main_global_protected_get_serial() {
+  return main_global_protected_serial();
+}
+
+// Trying to preempt functions from a DT_NEEDED .so
+extern "C" int lib_global_default_serial() {
+  return 3370318;
+}
+
+extern "C" int lib_global_protected_serial() {
+  return 2716057;
+}