native_loader.cpp revision 5f28b8460d9e53c5ccbe154ec244c9ae56b4a97c 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "nativeloader/native_loader.h"
18#include "ScopedUtfChars.h"
19
20#include <dlfcn.h>
21#ifdef __ANDROID__
22#include <android/dlext.h>
23#include "cutils/properties.h"
24#include "log/log.h"
25#endif
26
27#include <algorithm>
28#include <vector>
29#include <string>
30#include <mutex>
31
32#include "android-base/macros.h"
33#include "android-base/strings.h"
34
35namespace android {
36
37#ifdef __ANDROID__
38// TODO(dimitry): move this to system properties.
39static const char* kPublicNativeLibraries = "libandroid.so:"
40                                            "libc.so:"
41                                            "libcamera2ndk.so:"
42                                            "libdl.so:"
43                                            "libEGL.so:"
44                                            "libGLESv1_CM.so:"
45                                            "libGLESv2.so:"
46                                            "libGLESv3.so:"
47                                            "libicui18n.so:"
48                                            "libicuuc.so:"
49                                            "libjnigraphics.so:"
50                                            "liblog.so:"
51                                            "libmediandk.so:"
52                                            "libm.so:"
53                                            "libOpenMAXAL.so:"
54                                            "libOpenSLES.so:"
55                                            "libRS.so:"
56                                            "libstdc++.so:"
57                                            "libvulkan.so:"
58                                            "libwebviewchromium_plat_support.so:"
59                                            "libz.so";
60
61class LibraryNamespaces {
62 public:
63  LibraryNamespaces() : initialized_(false) { }
64
65  android_namespace_t* Create(JNIEnv* env,
66                              jobject class_loader,
67                              bool is_shared,
68                              jstring java_library_path,
69                              jstring java_permitted_path,
70                              int32_t target_sdk_version) {
71    ScopedUtfChars library_path(env, java_library_path);
72
73    std::string permitted_path;
74    if (java_permitted_path != nullptr) {
75      ScopedUtfChars path(env, java_permitted_path);
76      permitted_path = path.c_str();
77    }
78
79    if (!initialized_ && !InitPublicNamespace(library_path.c_str(), target_sdk_version)) {
80      return nullptr;
81    }
82
83    android_namespace_t* ns = FindNamespaceByClassLoader(env, class_loader);
84
85    LOG_FATAL_IF(ns != nullptr, "There is already a namespace associated with this classloader");
86
87    uint64_t namespace_type = ANDROID_NAMESPACE_TYPE_ISOLATED;
88    if (is_shared) {
89      namespace_type |= ANDROID_NAMESPACE_TYPE_SHARED;
90    }
91
92    ns = android_create_namespace("classloader-namespace",
93                                  nullptr,
94                                  library_path.c_str(),
95                                  namespace_type,
96                                  java_permitted_path != nullptr ?
97                                      permitted_path.c_str() :
98                                      nullptr);
99
100    if (ns != nullptr) {
101      namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns));
102    }
103
104    return ns;
105  }
106
107  android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
108    auto it = std::find_if(namespaces_.begin(), namespaces_.end(),
109                [&](const std::pair<jweak, android_namespace_t*>& value) {
110                  return env->IsSameObject(value.first, class_loader);
111                });
112    return it != namespaces_.end() ? it->second : nullptr;
113  }
114
115  void PreloadPublicLibraries() {
116    // android_init_namespaces() expects all the public libraries
117    // to be loaded so that they can be found by soname alone.
118    std::vector<std::string> sonames = android::base::Split(kPublicNativeLibraries, ":");
119    for (const auto& soname : sonames) {
120      dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE);
121    }
122  }
123
124 private:
125  bool InitPublicNamespace(const char* library_path, int32_t target_sdk_version) {
126    // Some apps call dlopen from generated code unknown to linker in which
127    // case linker uses anonymous namespace. See b/25844435 for details.
128    std::string publicNativeLibraries = kPublicNativeLibraries;
129
130    // TODO (dimitry): This is a workaround for http://b/26436837
131    // will be removed before the release.
132    if (target_sdk_version <= 23) {
133      // check if libart.so is loaded.
134      void* handle = dlopen("libart.so", RTLD_NOW | RTLD_NOLOAD);
135      if (handle != nullptr) {
136        publicNativeLibraries += ":libart.so";
137        dlclose(handle);
138      }
139    }
140    // END OF WORKAROUND
141
142    initialized_ = android_init_namespaces(publicNativeLibraries.c_str(), library_path);
143
144    return initialized_;
145  }
146
147  bool initialized_;
148  std::vector<std::pair<jweak, android_namespace_t*>> namespaces_;
149
150  DISALLOW_COPY_AND_ASSIGN(LibraryNamespaces);
151};
152
153static std::mutex g_namespaces_mutex;
154static LibraryNamespaces* g_namespaces = new LibraryNamespaces;
155
156static bool namespaces_enabled(uint32_t target_sdk_version) {
157  return target_sdk_version > 0;
158}
159#endif
160
161void PreloadPublicNativeLibraries() {
162#if defined(__ANDROID__)
163  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
164  g_namespaces->PreloadPublicLibraries();
165#endif
166}
167
168
169jstring CreateClassLoaderNamespace(JNIEnv* env,
170                                   int32_t target_sdk_version,
171                                   jobject class_loader,
172                                   bool is_shared,
173                                   jstring library_path,
174                                   jstring permitted_path) {
175#if defined(__ANDROID__)
176  if (!namespaces_enabled(target_sdk_version)) {
177    return nullptr;
178  }
179
180  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
181  android_namespace_t* ns = g_namespaces->Create(env,
182                                                 class_loader,
183                                                 is_shared,
184                                                 library_path,
185                                                 permitted_path,
186                                                 target_sdk_version);
187  if (ns == nullptr) {
188    return env->NewStringUTF(dlerror());
189  }
190#else
191  UNUSED(env, target_sdk_version, class_loader, is_shared,
192         library_path, permitted_path);
193#endif
194  return nullptr;
195}
196
197void* OpenNativeLibrary(JNIEnv* env,
198                        int32_t target_sdk_version,
199                        const char* path,
200                        jobject class_loader,
201                        jstring library_path) {
202#if defined(__ANDROID__)
203  if (!namespaces_enabled(target_sdk_version) || class_loader == nullptr) {
204    return dlopen(path, RTLD_NOW);
205  }
206
207  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
208  android_namespace_t* ns = g_namespaces->FindNamespaceByClassLoader(env, class_loader);
209
210  if (ns == nullptr) {
211    // This is the case where the classloader was not created by ApplicationLoaders
212    // In this case we create an isolated not-shared namespace for it.
213    ns = g_namespaces->Create(env, class_loader, false, library_path, nullptr, target_sdk_version);
214    if (ns == nullptr) {
215      return nullptr;
216    }
217  }
218
219  android_dlextinfo extinfo;
220  extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
221  extinfo.library_namespace = ns;
222
223  return android_dlopen_ext(path, RTLD_NOW, &extinfo);
224#else
225  UNUSED(env, target_sdk_version, class_loader, library_path);
226  return dlopen(path, RTLD_NOW);
227#endif
228}
229
230#if defined(__ANDROID__)
231android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
232  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
233  return g_namespaces->FindNamespaceByClassLoader(env, class_loader);
234}
235#endif
236
237}; //  android namespace
238