From 3150f7c7af68c78e410c328b406223d748f9c7ba Mon Sep 17 00:00:00 2001
From: dimitry <dimitry@google.com>
Date: Wed, 12 Sep 2018 01:09:19 +0200
Subject: [PATCH] Add error_msg argument to CloseNativeLibrary

error_msg is set when dlclose/NativeBridgeUnloadLibrary fails.

Bug: https://issuetracker.google.com/79126103
Test: make
Change-Id: I043580209538ff47320e8d9a304a21c00c4b149f
---
 .../include/nativebridge/native_bridge.h       |  2 +-
 .../include/nativeloader/native_loader.h       |  5 +++--
 libnativeloader/native_loader.cpp              | 18 +++++++++++++++---
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/libnativebridge/include/nativebridge/native_bridge.h b/libnativebridge/include/nativebridge/native_bridge.h
index 9bfc93523..28f192748 100644
--- a/libnativebridge/include/nativebridge/native_bridge.h
+++ b/libnativebridge/include/nativebridge/native_bridge.h
@@ -99,7 +99,7 @@ bool NativeBridgeError();
 bool NativeBridgeNameAcceptable(const char* native_bridge_library_filename);
 
 // Decrements the reference count on the dynamic library handler. If the reference count drops
-// to zero then the dynamic library is unloaded.
+// to zero then the dynamic library is unloaded. Returns 0 on success and non-zero on error.
 int NativeBridgeUnloadLibrary(void* handle);
 
 // Get last error message of native bridge when fail to load library or search symbol.
diff --git a/libnativeloader/include/nativeloader/native_loader.h b/libnativeloader/include/nativeloader/native_loader.h
index 19a17832e..c1d9d2a92 100644
--- a/libnativeloader/include/nativeloader/native_loader.h
+++ b/libnativeloader/include/nativeloader/native_loader.h
@@ -47,8 +47,9 @@ void* OpenNativeLibrary(JNIEnv* env,
                         bool* needs_native_bridge,
                         std::string* error_msg);
 
-__attribute__((visibility("default")))
-bool CloseNativeLibrary(void* handle, const bool needs_native_bridge);
+__attribute__((visibility("default"))) bool CloseNativeLibrary(void* handle,
+                                                               const bool needs_native_bridge,
+                                                               std::string* error_msg);
 
 #if defined(__ANDROID__)
 // Look up linker namespace by class_loader. Returns nullptr if
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index 67c1c103b..b3e2b97fe 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -710,9 +710,21 @@ void* OpenNativeLibrary(JNIEnv* env,
 #endif
 }
 
-bool CloseNativeLibrary(void* handle, const bool needs_native_bridge) {
-    return needs_native_bridge ? NativeBridgeUnloadLibrary(handle) :
-                                 dlclose(handle);
+bool CloseNativeLibrary(void* handle, const bool needs_native_bridge, std::string* error_msg) {
+  bool success;
+  if (needs_native_bridge) {
+    success = (NativeBridgeUnloadLibrary(handle) == 0);
+    if (!success) {
+      *error_msg = NativeBridgeGetError();
+    }
+  } else {
+    success = (dlclose(handle) == 0);
+    if (!success) {
+      *error_msg = dlerror();
+    }
+  }
+
+  return success;
 }
 
 #if defined(__ANDROID__)