From 350bdad61cc6551db649fcaeb8642f4a1d6b139a Mon Sep 17 00:00:00 2001
From: Dimitry Ivanov <dimitry@google.com>
Date: Tue, 1 Mar 2016 13:11:28 -0800
Subject: [PATCH] linker: print "not accessible" error message to the log

Print properties of the namespace on "library is not accessible"
error to better diagnose problems with native library accessiblity

Bug: http://b/27406143
Change-Id: Icf3d6c604f09dfa015de863fdb1267d343930d2a
---
 linker/linker.cpp    | 21 +++++++++++++++++++--
 tests/dlext_test.cpp |  8 ++++++--
 tests/gtest_main.cpp |  7 +++++++
 tests/utils.h        |  2 ++
 4 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/linker/linker.cpp b/linker/linker.cpp
index a38a56603..0afbd40d0 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -93,6 +93,9 @@ struct android_namespace_t {
     default_library_paths_ = library_paths;
   }
 
+  const std::vector<std::string>& get_permitted_paths() const {
+    return permitted_paths_;
+  }
   void set_permitted_paths(std::vector<std::string>&& permitted_paths) {
     permitted_paths_ = permitted_paths;
   }
@@ -1814,8 +1817,22 @@ static bool load_library(android_namespace_t* ns,
       }
     } else {
       // do not load libraries if they are not accessible for the specified namespace.
-      DL_ERR("library \"%s\" is not accessible for the namespace \"%s\"",
-             name, ns->get_name());
+      const char* needed_or_dlopened_by = task->get_needed_by() == nullptr ?
+                                          "(unknown)" :
+                                          task->get_needed_by()->get_realpath();
+
+      DL_ERR("library \"%s\" needed or dlopened by \"%s\" is not accessible for the namespace \"%s\"",
+             name, needed_or_dlopened_by, ns->get_name());
+
+      PRINT("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the"
+            " namespace: [name=\"%s\", ld_library_paths=\"%s\", default_library_paths=\"%s\","
+            " permitted_paths=\"%s\"]",
+            name, realpath.c_str(),
+            needed_or_dlopened_by,
+            ns->get_name(),
+            android::base::Join(ns->get_ld_library_paths(), ':').c_str(),
+            android::base::Join(ns->get_default_library_paths(), ':').c_str(),
+            android::base::Join(ns->get_permitted_paths(), ':').c_str());
       return false;
     }
   }
diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index c64ec159f..66d885952 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -799,7 +799,9 @@ TEST(dlext, ns_isolated) {
   // Check dlopen by absolute path
   handle2 = android_dlopen_ext(lib_private_external_path.c_str(), RTLD_NOW, &extinfo);
   ASSERT_TRUE(handle2 == nullptr);
-  ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" is not accessible for the namespace \"private_isolated1\"", dlerror());
+  ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" needed"
+            " or dlopened by \"" + get_executable_name() +  "\" is not accessible"
+            " for the namespace \"private_isolated1\"", dlerror());
 
   extinfo.library_namespace = ns_isolated2;
 
@@ -899,7 +901,9 @@ TEST(dlext, ns_shared) {
   // Check dlopen by absolute path
   handle2 = android_dlopen_ext(lib_private_external_path.c_str(), RTLD_NOW, &extinfo);
   ASSERT_TRUE(handle2 == nullptr);
-  ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" is not accessible for the namespace \"private_isolated_shared\"", dlerror());
+  ASSERT_EQ("dlopen failed: library \"" + lib_private_external_path + "\" needed"
+            " or dlopened by \"" + get_executable_name() + "\" is not accessible"
+            " for the namespace \"private_isolated_shared\"", dlerror());
 
   // load libnstest_root.so to shared namespace in order to check that everything is different
   // except shared libnstest_dlopened.so
diff --git a/tests/gtest_main.cpp b/tests/gtest_main.cpp
index 7360f1239..ad23aa80c 100644
--- a/tests/gtest_main.cpp
+++ b/tests/gtest_main.cpp
@@ -46,6 +46,12 @@
 
 #endif
 
+static std::string g_executable_name;
+
+const std::string& get_executable_name() {
+  return g_executable_name;
+}
+
 namespace testing {
 namespace internal {
 
@@ -1113,6 +1119,7 @@ static bool PickOptions(std::vector<char*>& args, IsolationTestOptions& options)
 }
 
 int main(int argc, char** argv) {
+  g_executable_name = argv[0];
   std::vector<char*> arg_list;
   for (int i = 0; i < argc; ++i) {
     arg_list.push_back(argv[i]);
diff --git a/tests/utils.h b/tests/utils.h
index 828c8d052..a335c6663 100644
--- a/tests/utils.h
+++ b/tests/utils.h
@@ -119,4 +119,6 @@ static inline void AssertChildExited(int pid, int expected_exit_status) {
   ASSERT_EQ(expected_exit_status, WEXITSTATUS(status));
 }
 
+const std::string& get_executable_name();
+
 #endif
-- 
2.11.0