1 /* Copyright (C) 2017 The Android Open Source Project
2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3  *
4  * This file implements interfaces from the file jvmti.h. This implementation
5  * is licensed under the same terms as the file jvmti.h.  The
6  * copyright and license information for the file jvmti.h follows.
7  *
8  * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
9  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
10  *
11  * This code is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License version 2 only, as
13  * published by the Free Software Foundation.  Oracle designates this
14  * particular file as subject to the "Classpath" exception as provided
15  * by Oracle in the LICENSE file that accompanied this code.
16  *
17  * This code is distributed in the hope that it will be useful, but WITHOUT
18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
20  * version 2 for more details (a copy is included in the LICENSE file that
21  * accompanied this code).
22  *
23  * You should have received a copy of the GNU General Public License version
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25  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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30  */
31 
32 #include "ti_class_loader-inl.h"
33 
34 #include <limits>
35 
36 #include <android-base/logging.h>
37 #include <android-base/stringprintf.h>
38 
39 #include "art_field-inl.h"
40 #include "art_jvmti.h"
41 #include "dex/dex_file.h"
42 #include "dex/dex_file_types.h"
43 #include "events-inl.h"
44 #include "gc/allocation_listener.h"
45 #include "gc/heap.h"
46 #include "instrumentation.h"
47 #include "jit/jit.h"
48 #include "jit/jit_code_cache.h"
49 #include "jni/jni_env_ext-inl.h"
50 #include "jvmti_allocator.h"
51 #include "mirror/array-alloc-inl.h"
52 #include "mirror/array-inl.h"
53 #include "mirror/class.h"
54 #include "mirror/class_ext.h"
55 #include "mirror/object.h"
56 #include "nativehelper/scoped_local_ref.h"
57 #include "object_lock.h"
58 #include "runtime.h"
59 #include "transform.h"
60 
61 namespace openjdkjvmti {
62 
AddToClassLoader(art::Thread * self,art::Handle<art::mirror::ClassLoader> loader,const art::DexFile * dex_file)63 bool ClassLoaderHelper::AddToClassLoader(art::Thread* self,
64                                          art::Handle<art::mirror::ClassLoader> loader,
65                                          const art::DexFile* dex_file) {
66   art::ScopedObjectAccessUnchecked soa(self);
67   art::StackHandleScope<3> hs(self);
68   if (art::ClassLinker::IsBootClassLoader(soa, loader.Get())) {
69     art::Runtime::Current()->GetClassLinker()->AppendToBootClassPath(self, dex_file);
70     return true;
71   }
72   art::Handle<art::mirror::Object> java_dex_file_obj(
73       hs.NewHandle(FindSourceDexFileObject(self, loader)));
74   if (java_dex_file_obj.IsNull()) {
75     return false;
76   }
77   art::Handle<art::mirror::LongArray> old_cookie(hs.NewHandle(GetDexFileCookie(java_dex_file_obj)));
78   art::Handle<art::mirror::LongArray> cookie(hs.NewHandle(
79       AllocateNewDexFileCookie(self, old_cookie, dex_file)));
80   if (cookie.IsNull()) {
81     return false;
82   }
83   art::ScopedAssertNoThreadSuspension nts("Replacing cookie fields in j.l.DexFile object");
84   UpdateJavaDexFile(java_dex_file_obj.Get(), cookie.Get());
85   return true;
86 }
87 
UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,art::ObjPtr<art::mirror::LongArray> new_cookie)88 void ClassLoaderHelper::UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
89                                           art::ObjPtr<art::mirror::LongArray> new_cookie) {
90   art::ArtField* internal_cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
91       "mInternalCookie", "Ljava/lang/Object;");
92   art::ArtField* cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
93       "mCookie", "Ljava/lang/Object;");
94   CHECK(internal_cookie_field != nullptr);
95   art::ObjPtr<art::mirror::LongArray> orig_cookie(
96       cookie_field->GetObject(java_dex_file)->AsLongArray());
97   internal_cookie_field->SetObject<false>(java_dex_file, new_cookie);
98   if (!orig_cookie.IsNull()) {
99     cookie_field->SetObject<false>(java_dex_file, new_cookie);
100   }
101 }
102 
GetDexFileCookie(art::Handle<art::mirror::Object> java_dex_file_obj)103 art::ObjPtr<art::mirror::LongArray> ClassLoaderHelper::GetDexFileCookie(
104     art::Handle<art::mirror::Object> java_dex_file_obj) {
105   // mCookie is nulled out if the DexFile has been closed but mInternalCookie sticks around until
106   // the object is finalized. Since they always point to the same array if mCookie is not null we
107   // just use the mInternalCookie field. We will update one or both of these fields later.
108   art::ArtField* internal_cookie_field = java_dex_file_obj->GetClass()->FindDeclaredInstanceField(
109       "mInternalCookie", "Ljava/lang/Object;");
110   // TODO Add check that mCookie is either null or same as mInternalCookie
111   CHECK(internal_cookie_field != nullptr);
112   return internal_cookie_field->GetObject(java_dex_file_obj.Get())->AsLongArray();
113 }
114 
AllocateNewDexFileCookie(art::Thread * self,art::Handle<art::mirror::LongArray> cookie,const art::DexFile * dex_file)115 art::ObjPtr<art::mirror::LongArray> ClassLoaderHelper::AllocateNewDexFileCookie(
116     art::Thread* self,
117     art::Handle<art::mirror::LongArray> cookie,
118     const art::DexFile* dex_file) {
119   art::StackHandleScope<1> hs(self);
120   CHECK(cookie != nullptr);
121   CHECK_GE(cookie->GetLength(), 1);
122   art::Handle<art::mirror::LongArray> new_cookie(
123       hs.NewHandle(art::mirror::LongArray::Alloc(self, cookie->GetLength() + 1)));
124   if (new_cookie == nullptr) {
125     self->AssertPendingOOMException();
126     return nullptr;
127   }
128   // Copy the oat-dex field at the start.
129   new_cookie->SetWithoutChecks<false>(0, cookie->GetWithoutChecks(0));
130   // This must match the casts in runtime/native/dalvik_system_DexFile.cc:ConvertDexFilesToJavaArray
131   new_cookie->SetWithoutChecks<false>(
132       1, static_cast<int64_t>(reinterpret_cast<uintptr_t>(dex_file)));
133   new_cookie->Memcpy(2, cookie.Get(), 1, cookie->GetLength() - 1);
134   return new_cookie.Get();
135 }
136 
GetDexElementList(art::Thread * self,art::Handle<art::mirror::ClassLoader> loader)137 art::ObjPtr<art::mirror::ObjectArray<art::mirror::Object>> ClassLoaderHelper::GetDexElementList(
138     art::Thread* self,
139     art::Handle<art::mirror::ClassLoader> loader) {
140   art::StackHandleScope<4> hs(self);
141 
142   art::Handle<art::mirror::Class>
143       base_dex_loader_class(hs.NewHandle(self->DecodeJObject(
144           art::WellKnownClasses::dalvik_system_BaseDexClassLoader)->AsClass()));
145 
146   // Get all the ArtFields so we can look in the BaseDexClassLoader
147   art::ArtField* path_list_field = art::jni::DecodeArtField(
148       art::WellKnownClasses::dalvik_system_BaseDexClassLoader_pathList);
149   art::ArtField* dex_path_list_element_field =
150       art::jni::DecodeArtField(art::WellKnownClasses::dalvik_system_DexPathList_dexElements);
151 
152   // Check if loader is a BaseDexClassLoader
153   art::Handle<art::mirror::Class> loader_class(hs.NewHandle(loader->GetClass()));
154   // Currently only base_dex_loader is allowed to actually define classes but if this changes in the
155   // future we should make sure to support all class loader types.
156   if (!loader_class->IsSubClass(base_dex_loader_class.Get())) {
157     LOG(ERROR) << "The classloader " << loader_class->PrettyClass() << " is not a "
158                << base_dex_loader_class->PrettyClass() << " which is currently the only "
159                << "supported class loader type!";
160     return nullptr;
161   }
162   // Start navigating the fields of the loader (now known to be a BaseDexClassLoader derivative)
163   art::Handle<art::mirror::Object> path_list(
164       hs.NewHandle(path_list_field->GetObject(loader.Get())));
165   CHECK(path_list != nullptr);
166   art::ObjPtr<art::mirror::ObjectArray<art::mirror::Object>> dex_elements_list =
167       dex_path_list_element_field->GetObject(path_list.Get())->AsObjectArray<art::mirror::Object>();
168   return dex_elements_list;
169 }
170 
171 // TODO This should return the actual source java.lang.DexFile object for the klass being loaded.
FindSourceDexFileObject(art::Thread * self,art::Handle<art::mirror::ClassLoader> loader)172 art::ObjPtr<art::mirror::Object> ClassLoaderHelper::FindSourceDexFileObject(
173     art::Thread* self, art::Handle<art::mirror::ClassLoader> loader) {
174   art::ObjPtr<art::mirror::Object> res = nullptr;
175   VisitDexFileObjects(self,
176                       loader,
177                       [&] (art::ObjPtr<art::mirror::Object> dex_file) {
178                         res = dex_file;
179                         // Just stop at the first one.
180                         // TODO It would be cleaner to put the art::DexFile into the
181                         // dalvik.system.DexFile the class comes from but it is more annoying
182                         // because we would need to find this class. It is not necessary for proper
183                         // function since we just need to be in front of the classes old dex file in
184                         // the path.
185                         return false;
186                       });
187   return res;
188 }
189 
190 }  // namespace openjdkjvmti
191