Fix lookup logic for linked namespaces

When looking for already loaded libraries include
linked namespaces to the search, but check if
the library is accessible from the main namespace.

Bug: http://b/36008422
Bug: http://b/35417197
Bug: http://b/34052337
Bug: http://b/36660652
Bug: https://issuetracker.google.com/36636090
Test: run bionic-unit-tests --gtest_filter=dl*:Dl*
Change-Id: Ic7c1d48114da3ca5dc6512ef03f595dd17b6ed17
(cherry picked from commit d3e7d088453e089b3d625b0864ccdf3c74893f18)

1 files changed, 51 insertions, 8 deletions

diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index 808b708da..a0226a6f6 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -672,8 +672,59 @@ TEST(dlext, ns_smoke) {
   ASSERT_TRUE(handle != nullptr) << dlerror();
   dlclose(handle);
 
+  // dlopen for a public library using an absolute path should work
+  // 1. For isolated namespaces
   android_dlextinfo extinfo;
   extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
+  extinfo.library_namespace = ns2;
+  handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+  ASSERT_TRUE(handle == handle_public);
+
+  dlclose(handle);
+
+  // 1.1 even if it wasn't loaded before
+  dlclose(handle_public);
+
+  handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW | RTLD_NOLOAD);
+  ASSERT_TRUE(handle_public == nullptr);
+  ASSERT_EQ(std::string("dlopen failed: library \"") + lib_public_path +
+               "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
+
+  handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+
+  handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
+  ASSERT_TRUE(handle == handle_public);
+
+  dlclose(handle);
+
+  // 2. And for regular namespaces (make sure it does not load second copy of the library)
+  extinfo.library_namespace = ns1;
+  handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+  ASSERT_TRUE(handle == handle_public);
+
+  dlclose(handle);
+
+  // 2.1 Unless it was not loaded before - in which case it will load a duplicate.
+  // TODO(dimitry): This is broken. Maybe we need to deprecate non-isolated namespaces?
+  dlclose(handle_public);
+
+  handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW | RTLD_NOLOAD);
+  ASSERT_TRUE(handle_public == nullptr);
+  ASSERT_EQ(std::string("dlopen failed: library \"") + lib_public_path +
+               "\" wasn't loaded and RTLD_NOLOAD prevented it", dlerror());
+
+  handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+
+  handle_public = dlopen(lib_public_path.c_str(), RTLD_NOW);
+
+  ASSERT_TRUE(handle != handle_public);
+
+  dlclose(handle);
+
   extinfo.library_namespace = ns1;
 
   void* handle1 = android_dlopen_ext(root_lib, RTLD_NOW, &extinfo);
@@ -685,14 +736,6 @@ TEST(dlext, ns_smoke) {
 
   ASSERT_TRUE(handle1 != handle2);
 
-  // dlopen for a public library using an absolute path should work for isolated namespaces
-  extinfo.library_namespace = ns2;
-  handle = android_dlopen_ext(lib_public_path.c_str(), RTLD_NOW, &extinfo);
-  ASSERT_TRUE(handle != nullptr) << dlerror();
-  ASSERT_TRUE(handle == handle_public);
-
-  dlclose(handle);
-
   typedef const char* (*fn_t)();
 
   fn_t ns_get_local_string1 = reinterpret_cast<fn_t>(dlsym(handle1, "ns_get_local_string"));