native_loader.cpp revision 3d5a43449f414cde4b7602a20b764f28c58dd740 
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#endif
25
26#include <algorithm>
27#include <vector>
28#include <string>
29#include <mutex>
30
31#include "android-base/macros.h"
32#include "android-base/strings.h"
33
34namespace android {
35
36#ifdef __ANDROID__
37// TODO(dimitry): move this to system properties.
38static const char* kPublicNativeLibraries = "libandroid.so:"
39                                            // TODO (dimitry): This is a workaround for http://b/26436837
40                                            // will be removed before the release.
41                                            "libart.so:"
42                                            // END OF WORKAROUND
43                                            "libc.so:"
44                                            "libdl.so:"
45                                            "libEGL.so:"
46                                            "libGLESv1_CM.so:"
47                                            "libGLESv2.so:"
48                                            "libGLESv3.so:"
49                                            "libjnigraphics.so:"
50                                            "liblog.so:"
51                                            "libmediandk.so:"
52                                            "libm.so:"
53                                            "libOpenMAXAL.so:"
54                                            "libOpenSLES.so:"
55                                            "libstdc++.so:"
56                                            "libz.so";
57
58class LibraryNamespaces {
59 public:
60  LibraryNamespaces() : initialized_(false) { }
61
62  android_namespace_t* GetOrCreate(JNIEnv* env, jobject class_loader,
63                                   bool is_shared,
64                                   jstring java_library_path,
65                                   jstring java_permitted_path) {
66    ScopedUtfChars library_path(env, java_library_path);
67
68    std::string permitted_path;
69    if (java_permitted_path != nullptr) {
70      ScopedUtfChars path(env, java_permitted_path);
71      permitted_path = path.c_str();
72    }
73
74    if (!initialized_ && !InitPublicNamespace(library_path.c_str())) {
75      return nullptr;
76    }
77
78    std::lock_guard<std::mutex> guard(mutex_);
79
80    auto it = FindNamespaceByClassLoader(env, class_loader);
81
82    if (it != namespaces_.end()) {
83      return it->second;
84    }
85
86    uint64_t namespace_type = ANDROID_NAMESPACE_TYPE_ISOLATED;
87    if (is_shared) {
88      namespace_type |= ANDROID_NAMESPACE_TYPE_SHARED;
89    }
90
91    android_namespace_t* ns =
92            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    namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), ns));
101
102    return ns;
103  }
104
105 private:
106  bool InitPublicNamespace(const char* library_path) {
107    // Make sure all the public libraries are loaded
108    std::vector<std::string> sonames = android::base::Split(kPublicNativeLibraries, ":");
109    for (const auto& soname : sonames) {
110      if (dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE) == nullptr) {
111        return false;
112      }
113    }
114
115    // Some apps call dlopen from generated code unknown to linker in which
116    // case linker uses anonymous namespace. See b/25844435 for details.
117    initialized_ = android_init_namespaces(kPublicNativeLibraries, library_path);
118
119    return initialized_;
120  }
121
122  std::vector<std::pair<jweak, android_namespace_t*>>::const_iterator
123  FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
124    return std::find_if(namespaces_.begin(), namespaces_.end(),
125            [&](const std::pair<jweak, android_namespace_t*>& value) {
126              return env->IsSameObject(value.first, class_loader);
127            });
128  }
129
130  bool initialized_;
131  std::mutex mutex_;
132  std::vector<std::pair<jweak, android_namespace_t*>> namespaces_;
133
134  DISALLOW_COPY_AND_ASSIGN(LibraryNamespaces);
135};
136
137static LibraryNamespaces* g_namespaces = new LibraryNamespaces;
138#endif
139
140
141void* OpenNativeLibrary(JNIEnv* env, int32_t target_sdk_version, const char* path,
142                        jobject class_loader, bool is_shared, jstring java_library_path,
143                        jstring java_permitted_path) {
144#if defined(__ANDROID__)
145  if (target_sdk_version == 0 || class_loader == nullptr) {
146    return dlopen(path, RTLD_NOW);
147  }
148
149  android_namespace_t* ns =
150      g_namespaces->GetOrCreate(env, class_loader, is_shared,
151                                java_library_path, java_permitted_path);
152
153  if (ns == nullptr) {
154    return nullptr;
155  }
156
157  android_dlextinfo extinfo;
158  extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
159  extinfo.library_namespace = ns;
160
161  return android_dlopen_ext(path, RTLD_NOW, &extinfo);
162#else
163  UNUSED(env, target_sdk_version, class_loader, is_shared,
164         java_library_path, java_permitted_path);
165  return dlopen(path, RTLD_NOW);
166#endif
167}
168
169}; //  android namespace
170