1 /*
2  * Copyright (C) 2008 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 "java_lang_reflect_Constructor.h"
18 
19 #include "nativehelper/jni_macros.h"
20 
21 #include "art_method-inl.h"
22 #include "base/enums.h"
23 #include "class_linker-inl.h"
24 #include "class_linker.h"
25 #include "dex/dex_file_annotations.h"
26 #include "jni_internal.h"
27 #include "mirror/class-inl.h"
28 #include "mirror/method.h"
29 #include "mirror/object-inl.h"
30 #include "native_util.h"
31 #include "reflection.h"
32 #include "scoped_fast_native_object_access-inl.h"
33 #include "well_known_classes.h"
34 
35 namespace art {
36 
Constructor_getExceptionTypes(JNIEnv * env,jobject javaMethod)37 static jobjectArray Constructor_getExceptionTypes(JNIEnv* env, jobject javaMethod) {
38   ScopedFastNativeObjectAccess soa(env);
39   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod)
40       ->GetInterfaceMethodIfProxy(kRuntimePointerSize);
41   mirror::ObjectArray<mirror::Class>* result_array =
42       annotations::GetExceptionTypesForMethod(method);
43   if (result_array == nullptr) {
44     // Return an empty array instead of a null pointer.
45     ObjPtr<mirror::Class> class_class = mirror::Class::GetJavaLangClass();
46     ObjPtr<mirror::Class> class_array_class =
47         Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
48     if (class_array_class == nullptr) {
49       return nullptr;
50     }
51     ObjPtr<mirror::ObjectArray<mirror::Class>> empty_array =
52         mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
53     return soa.AddLocalReference<jobjectArray>(empty_array);
54   } else {
55     return soa.AddLocalReference<jobjectArray>(result_array);
56   }
57 }
58 
59 /*
60  * We can also safely assume the constructor isn't associated
61  * with an interface, array, or primitive class. If this is coming from
62  * native, it is OK to avoid access checks since JNI does not enforce them.
63  */
Constructor_newInstance0(JNIEnv * env,jobject javaMethod,jobjectArray javaArgs)64 static jobject Constructor_newInstance0(JNIEnv* env, jobject javaMethod, jobjectArray javaArgs) {
65   ScopedFastNativeObjectAccess soa(env);
66   ObjPtr<mirror::Constructor> m = soa.Decode<mirror::Constructor>(javaMethod);
67   StackHandleScope<1> hs(soa.Self());
68   Handle<mirror::Class> c(hs.NewHandle(m->GetDeclaringClass()));
69   if (UNLIKELY(c->IsAbstract())) {
70     soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;", "Can't instantiate %s %s",
71                                    c->IsInterface() ? "interface" : "abstract class",
72                                    c->PrettyDescriptor().c_str());
73     return nullptr;
74   }
75   // Verify that we can access the class.
76   if (!m->IsAccessible() && !c->IsPublic()) {
77     // Go 2 frames back, this method is always called from newInstance0, which is called from
78     // Constructor.newInstance(Object... args).
79     ObjPtr<mirror::Class> caller = GetCallingClass(soa.Self(), 2);
80     // If caller is null, then we called from JNI, just avoid the check since JNI avoids most
81     // access checks anyways. TODO: Investigate if this the correct behavior.
82     if (caller != nullptr && !caller->CanAccess(c.Get())) {
83       if (c->PrettyDescriptor() == "dalvik.system.DexPathList$Element") {
84         // b/20699073.
85         LOG(WARNING) << "The dalvik.system.DexPathList$Element constructor is not accessible by "
86                         "default. This is a temporary workaround for backwards compatibility "
87                         "with class-loader hacks. Please update your application.";
88       } else {
89         soa.Self()->ThrowNewExceptionF(
90             "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
91             c->PrettyClass().c_str(),
92             caller->PrettyClass().c_str());
93         return nullptr;
94       }
95     }
96   }
97   if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(soa.Self(), c, true, true)) {
98     DCHECK(soa.Self()->IsExceptionPending());
99     return nullptr;
100   }
101   bool movable = true;
102   if (!kMovingClasses && c->IsClassClass()) {
103     movable = false;
104   }
105 
106   // String constructor is replaced by a StringFactory method in InvokeMethod.
107   if (c->IsStringClass()) {
108     return InvokeMethod(soa, javaMethod, nullptr, javaArgs, 2);
109   }
110 
111   ObjPtr<mirror::Object> receiver =
112       movable ? c->AllocObject(soa.Self()) : c->AllocNonMovableObject(soa.Self());
113   if (receiver == nullptr) {
114     return nullptr;
115   }
116   jobject javaReceiver = soa.AddLocalReference<jobject>(receiver);
117   InvokeMethod(soa, javaMethod, javaReceiver, javaArgs, 2);
118   // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
119   return javaReceiver;
120 }
121 
Constructor_newInstanceFromSerialization(JNIEnv * env,jclass unused ATTRIBUTE_UNUSED,jclass ctorClass,jclass allocClass)122 static jobject Constructor_newInstanceFromSerialization(JNIEnv* env, jclass unused ATTRIBUTE_UNUSED,
123                                                         jclass ctorClass, jclass allocClass) {
124     jmethodID ctor = env->GetMethodID(ctorClass, "<init>", "()V");
125     DCHECK(ctor != NULL);
126     return env->NewObject(allocClass, ctor);
127 }
128 
129 static JNINativeMethod gMethods[] = {
130   FAST_NATIVE_METHOD(Constructor, getExceptionTypes, "()[Ljava/lang/Class;"),
131   FAST_NATIVE_METHOD(Constructor, newInstance0, "([Ljava/lang/Object;)Ljava/lang/Object;"),
132   FAST_NATIVE_METHOD(Constructor, newInstanceFromSerialization, "(Ljava/lang/Class;Ljava/lang/Class;)Ljava/lang/Object;"),
133 };
134 
register_java_lang_reflect_Constructor(JNIEnv * env)135 void register_java_lang_reflect_Constructor(JNIEnv* env) {
136   REGISTER_NATIVE_METHODS("java/lang/reflect/Constructor");
137 }
138 
139 }  // namespace art
140