Merge changes I8eae0c98,I09d32dcb

* changes:
  vdso should be available in all namespaces
  Unhardcode /system/lib
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 79330fc..96f424e 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -3822,8 +3822,14 @@
   // we can no longer rely on the fact that libdl.so is part of default namespace
   // this is why we want to add ld-android.so to all namespaces from ld.config.txt
   soinfo* ld_android_so = solist_get_head();
+
+  // we also need vdso to be available for all namespaces (if present)
+  soinfo* vdso = solist_get_vdso();
   for (auto it : namespaces) {
     it.second->add_soinfo(ld_android_so);
+    if (vdso != nullptr) {
+      it.second->add_soinfo(vdso);
+    }
     // somain and ld_preloads are added to these namespaces after LD_PRELOAD libs are linked
   }
 
diff --git a/linker/linker_main.cpp b/linker/linker_main.cpp
index dc1fa75..00c72d0 100644
--- a/linker/linker_main.cpp
+++ b/linker/linker_main.cpp
@@ -64,6 +64,7 @@
 static soinfo* solist;
 static soinfo* sonext;
 static soinfo* somain; // main process, always the one after libdl_info
+static soinfo* vdso; // vdso if present
 
 void solist_add_soinfo(soinfo* si) {
   sonext->next = si;
@@ -104,6 +105,10 @@
   return somain;
 }
 
+soinfo* solist_get_vdso() {
+  return vdso;
+}
+
 int g_ld_debug_verbosity;
 abort_msg_t* g_abort_message = nullptr; // For debuggerd.
 
@@ -158,6 +163,8 @@
   si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_NODELETE);
   si->set_linked();
   si->call_constructors();
+
+  vdso = si;
 }
 
 /* gdb expects the linker to be in the debug shared object list.
@@ -280,6 +287,8 @@
     }
   }
 
+  add_vdso(args);
+
   struct stat file_stat;
   // Stat "/proc/self/exe" instead of executable_path because
   // the executable could be unlinked by this point and it should
@@ -366,8 +375,6 @@
     }
   }
 
-  add_vdso(args);
-
   // Load ld_preloads and dependencies.
   std::vector<const char*> needed_library_name_list;
   size_t ld_preloads_count = 0;
diff --git a/linker/linker_main.h b/linker/linker_main.h
index 8d486e8..b37b947 100644
--- a/linker/linker_main.h
+++ b/linker/linker_main.h
@@ -70,3 +70,4 @@
 bool solist_remove_soinfo(soinfo* si);
 soinfo* solist_get_head();
 soinfo* solist_get_somain();
+soinfo* solist_get_vdso();
diff --git a/tests/dl_test.cpp b/tests/dl_test.cpp
index 38d7783..25341f4 100644
--- a/tests/dl_test.cpp
+++ b/tests/dl_test.cpp
@@ -168,7 +168,11 @@
 }
 
 #if defined(__BIONIC__)
+extern "C" void android_get_LD_LIBRARY_PATH(char*, size_t);
 static void create_ld_config_file(const char* config_file) {
+  char default_search_paths[PATH_MAX];
+  android_get_LD_LIBRARY_PATH(default_search_paths, sizeof(default_search_paths));
+
   std::ofstream fout(config_file, std::ios::out);
   fout << "dir.test = " << get_testlib_root() << "/ld_config_test_helper/" << std::endl
        << "[test]" << std::endl
@@ -176,7 +180,7 @@
        << "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;
+       << "namespace.ns2.search.paths = " << default_search_paths << ":" << get_testlib_root() << "/ns2" << std::endl;
   fout.close();
 }
 #endif
diff --git a/tests/libs/ld_config_test_helper.cpp b/tests/libs/ld_config_test_helper.cpp
index 592e8c0..87e512e 100644
--- a/tests/libs/ld_config_test_helper.cpp
+++ b/tests/libs/ld_config_test_helper.cpp
@@ -14,13 +14,37 @@
  * limitations under the License.
  */
 
+#include <dlfcn.h>
 #include <errno.h>
 #include <stdio.h>
+#if __has_include(<sys/auxv.h>)
+#include <sys/auxv.h>
+#endif
 #include <unistd.h>
 
 extern int get_value_from_lib();
 
 int main() {
+  bool skip_vdso_check = false;
+#if __has_include(<sys/auxv.h>)
+  if (getauxval(AT_SYSINFO_EHDR) == 0) {
+    skip_vdso_check = true;
+  }
+#endif
+
+  if (!skip_vdso_check) {
+    const char* vdso_name = "linux-vdso.so.1";
+#if defined(__i386__)
+    vdso_name = "linux-gate.so.1";
+#endif
+    void* handle = dlopen(vdso_name, RTLD_NOW);
+    if (handle == nullptr) {
+      printf("%s", dlerror());
+      return 1;
+    }
+    dlclose(handle);
+  }
+
   printf("%d", get_value_from_lib());
   return 0;
 }