1 /*
2 * Copyright (C) 2014 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 "native_bridge_art_interface.h"
18
19 #include <signal.h>
20
21 #include "nativebridge/native_bridge.h"
22
23 #include "art_method-inl.h"
24 #include "base/logging.h"
25 #include "base/macros.h"
26 #include "dex_file-inl.h"
27 #include "mirror/class-inl.h"
28 #include "scoped_thread_state_change.h"
29 #include "sigchain.h"
30
31 namespace art {
32
GetMethodShorty(JNIEnv * env,jmethodID mid)33 static const char* GetMethodShorty(JNIEnv* env, jmethodID mid) {
34 ScopedObjectAccess soa(env);
35 ArtMethod* m = soa.DecodeMethod(mid);
36 return m->GetShorty();
37 }
38
GetNativeMethodCount(JNIEnv * env,jclass clazz)39 static uint32_t GetNativeMethodCount(JNIEnv* env, jclass clazz) {
40 if (clazz == nullptr) {
41 return 0;
42 }
43
44 ScopedObjectAccess soa(env);
45 mirror::Class* c = soa.Decode<mirror::Class*>(clazz);
46
47 uint32_t native_method_count = 0;
48 for (auto& m : c->GetMethods(sizeof(void*))) {
49 native_method_count += m.IsNative() ? 1u : 0u;
50 }
51 return native_method_count;
52 }
53
GetNativeMethods(JNIEnv * env,jclass clazz,JNINativeMethod * methods,uint32_t method_count)54 static uint32_t GetNativeMethods(JNIEnv* env, jclass clazz, JNINativeMethod* methods,
55 uint32_t method_count) {
56 if ((clazz == nullptr) || (methods == nullptr)) {
57 return 0;
58 }
59 ScopedObjectAccess soa(env);
60 mirror::Class* c = soa.Decode<mirror::Class*>(clazz);
61
62 uint32_t count = 0;
63 for (auto& m : c->GetMethods(sizeof(void*))) {
64 if (m.IsNative()) {
65 if (count < method_count) {
66 methods[count].name = m.GetName();
67 methods[count].signature = m.GetShorty();
68 methods[count].fnPtr = m.GetEntryPointFromJni();
69 count++;
70 } else {
71 LOG(WARNING) << "Output native method array too small. Skipping " << PrettyMethod(&m);
72 }
73 }
74 }
75 return count;
76 }
77
78 // Native bridge library runtime callbacks. They represent the runtime interface to native bridge.
79 //
80 // The interface is expected to expose the following methods:
81 // getMethodShorty(): in the case of native method calling JNI native function CallXXXXMethodY(),
82 // native bridge calls back to VM for the shorty of the method so that it can prepare based on
83 // host calling convention.
84 // getNativeMethodCount() and getNativeMethods(): in case of JNI function UnregisterNatives(),
85 // native bridge can call back to get all native methods of specified class so that all
86 // corresponding trampolines can be destroyed.
87 static android::NativeBridgeRuntimeCallbacks native_bridge_art_callbacks_ {
88 GetMethodShorty, GetNativeMethodCount, GetNativeMethods
89 };
90
LoadNativeBridge(std::string & native_bridge_library_filename)91 bool LoadNativeBridge(std::string& native_bridge_library_filename) {
92 VLOG(startup) << "Runtime::Setup native bridge library: "
93 << (native_bridge_library_filename.empty() ? "(empty)" : native_bridge_library_filename);
94 return android::LoadNativeBridge(native_bridge_library_filename.c_str(),
95 &native_bridge_art_callbacks_);
96 }
97
PreInitializeNativeBridge(std::string dir)98 void PreInitializeNativeBridge(std::string dir) {
99 VLOG(startup) << "Runtime::Pre-initialize native bridge";
100 #ifndef __APPLE__ // Mac OS does not support CLONE_NEWNS.
101 if (unshare(CLONE_NEWNS) == -1) {
102 LOG(WARNING) << "Could not create mount namespace.";
103 }
104 android::PreInitializeNativeBridge(dir.c_str(), GetInstructionSetString(kRuntimeISA));
105 #else
106 UNUSED(dir);
107 #endif
108 }
109
InitializeNativeBridge(JNIEnv * env,const char * instruction_set)110 void InitializeNativeBridge(JNIEnv* env, const char* instruction_set) {
111 if (android::InitializeNativeBridge(env, instruction_set)) {
112 if (android::NativeBridgeGetVersion() >= 2U) {
113 #ifdef _NSIG // Undefined on Apple, but we don't support running on Mac, anyways.
114 // Managed signal handling support added in version 2.
115 for (int signal = 0; signal < _NSIG; ++signal) {
116 android::NativeBridgeSignalHandlerFn fn = android::NativeBridgeGetSignalHandler(signal);
117 if (fn != nullptr) {
118 SetSpecialSignalHandlerFn(signal, fn);
119 }
120 }
121 #endif
122 }
123 }
124 }
125
UnloadNativeBridge()126 void UnloadNativeBridge() {
127 android::UnloadNativeBridge();
128 }
129
130 } // namespace art
131