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
24 * 2 along with this work; if not, write to the Free Software Foundation,
25 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
26 *
27 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
28 * or visit www.oracle.com if you need additional information or have any
29 * questions.
30 */
31
32#include "ti_class_loader.h"
33
34#include <limits>
35
36#include "android-base/stringprintf.h"
37
38#include "art_field-inl.h"
39#include "art_jvmti.h"
40#include "base/array_slice.h"
41#include "base/logging.h"
42#include "dex_file.h"
43#include "dex_file_types.h"
44#include "events-inl.h"
45#include "gc/allocation_listener.h"
46#include "gc/heap.h"
47#include "instrumentation.h"
48#include "jit/jit.h"
49#include "jit/jit_code_cache.h"
50#include "jni_env_ext-inl.h"
51#include "jvmti_allocator.h"
52#include "mirror/class.h"
53#include "mirror/class_ext.h"
54#include "mirror/object.h"
55#include "object_lock.h"
56#include "runtime.h"
57#include "ScopedLocalRef.h"
58#include "transform.h"
59
60namespace openjdkjvmti {
61
62bool ClassLoaderHelper::AddToClassLoader(art::Thread* self,
63                                         art::Handle<art::mirror::ClassLoader> loader,
64                                         const art::DexFile* dex_file) {
65  art::ScopedObjectAccessUnchecked soa(self);
66  art::StackHandleScope<3> hs(self);
67  if (art::ClassLinker::IsBootClassLoader(soa, loader.Get())) {
68    art::Runtime::Current()->GetClassLinker()->AppendToBootClassPath(self, *dex_file);
69    return true;
70  }
71  art::Handle<art::mirror::Object> java_dex_file_obj(
72      hs.NewHandle(FindSourceDexFileObject(self, loader)));
73  if (java_dex_file_obj.IsNull()) {
74    return false;
75  }
76  art::Handle<art::mirror::LongArray> old_cookie(hs.NewHandle(GetDexFileCookie(java_dex_file_obj)));
77  art::Handle<art::mirror::LongArray> cookie(hs.NewHandle(
78      AllocateNewDexFileCookie(self, old_cookie, dex_file)));
79  if (cookie.IsNull()) {
80    return false;
81  }
82  art::ScopedAssertNoThreadSuspension nts("Replacing cookie fields in j.l.DexFile object");
83  UpdateJavaDexFile(java_dex_file_obj.Get(), cookie.Get());
84  return true;
85}
86
87void ClassLoaderHelper::UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
88                                          art::ObjPtr<art::mirror::LongArray> new_cookie) {
89  art::ArtField* internal_cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
90      "mInternalCookie", "Ljava/lang/Object;");
91  art::ArtField* cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
92      "mCookie", "Ljava/lang/Object;");
93  CHECK(internal_cookie_field != nullptr);
94  art::ObjPtr<art::mirror::LongArray> orig_internal_cookie(
95      internal_cookie_field->GetObject(java_dex_file)->AsLongArray());
96  art::ObjPtr<art::mirror::LongArray> orig_cookie(
97      cookie_field->GetObject(java_dex_file)->AsLongArray());
98  internal_cookie_field->SetObject<false>(java_dex_file, new_cookie);
99  if (!orig_cookie.IsNull()) {
100    cookie_field->SetObject<false>(java_dex_file, new_cookie);
101  }
102}
103
104art::ObjPtr<art::mirror::LongArray> ClassLoaderHelper::GetDexFileCookie(
105    art::Handle<art::mirror::Object> java_dex_file_obj) {
106  // mCookie is nulled out if the DexFile has been closed but mInternalCookie sticks around until
107  // the object is finalized. Since they always point to the same array if mCookie is not null we
108  // just use the mInternalCookie field. We will update one or both of these fields later.
109  art::ArtField* internal_cookie_field = java_dex_file_obj->GetClass()->FindDeclaredInstanceField(
110      "mInternalCookie", "Ljava/lang/Object;");
111  // TODO Add check that mCookie is either null or same as mInternalCookie
112  CHECK(internal_cookie_field != nullptr);
113  return internal_cookie_field->GetObject(java_dex_file_obj.Get())->AsLongArray();
114}
115
116art::ObjPtr<art::mirror::LongArray> ClassLoaderHelper::AllocateNewDexFileCookie(
117    art::Thread* self,
118    art::Handle<art::mirror::LongArray> cookie,
119    const art::DexFile* dex_file) {
120  art::StackHandleScope<1> hs(self);
121  CHECK(cookie != nullptr);
122  CHECK_GE(cookie->GetLength(), 1);
123  art::Handle<art::mirror::LongArray> new_cookie(
124      hs.NewHandle(art::mirror::LongArray::Alloc(self, cookie->GetLength() + 1)));
125  if (new_cookie == nullptr) {
126    self->AssertPendingOOMException();
127    return nullptr;
128  }
129  // Copy the oat-dex field at the start.
130  new_cookie->SetWithoutChecks<false>(0, cookie->GetWithoutChecks(0));
131  // This must match the casts in runtime/native/dalvik_system_DexFile.cc:ConvertDexFilesToJavaArray
132  new_cookie->SetWithoutChecks<false>(
133      1, static_cast<int64_t>(reinterpret_cast<uintptr_t>(dex_file)));
134  new_cookie->Memcpy(2, cookie.Get(), 1, cookie->GetLength() - 1);
135  return new_cookie.Get();
136}
137
138// TODO This should return the actual source java.lang.DexFile object for the klass being loaded.
139art::ObjPtr<art::mirror::Object> ClassLoaderHelper::FindSourceDexFileObject(
140    art::Thread* self, art::Handle<art::mirror::ClassLoader> loader) {
141  const char* dex_path_list_element_array_name = "[Ldalvik/system/DexPathList$Element;";
142  const char* dex_path_list_element_name = "Ldalvik/system/DexPathList$Element;";
143  const char* dex_file_name = "Ldalvik/system/DexFile;";
144  const char* dex_path_list_name = "Ldalvik/system/DexPathList;";
145  const char* dex_class_loader_name = "Ldalvik/system/BaseDexClassLoader;";
146
147  CHECK(!self->IsExceptionPending());
148  art::StackHandleScope<5> hs(self);
149  art::ClassLinker* class_linker = art::Runtime::Current()->GetClassLinker();
150
151  art::Handle<art::mirror::ClassLoader> null_loader(hs.NewHandle<art::mirror::ClassLoader>(
152      nullptr));
153  art::Handle<art::mirror::Class> base_dex_loader_class(hs.NewHandle(class_linker->FindClass(
154      self, dex_class_loader_name, null_loader)));
155
156  // Get all the ArtFields so we can look in the BaseDexClassLoader
157  art::ArtField* path_list_field = base_dex_loader_class->FindDeclaredInstanceField(
158      "pathList", dex_path_list_name);
159  CHECK(path_list_field != nullptr);
160
161  art::ArtField* dex_path_list_element_field =
162      class_linker->FindClass(self, dex_path_list_name, null_loader)
163        ->FindDeclaredInstanceField("dexElements", dex_path_list_element_array_name);
164  CHECK(dex_path_list_element_field != nullptr);
165
166  art::ArtField* element_dex_file_field =
167      class_linker->FindClass(self, dex_path_list_element_name, null_loader)
168        ->FindDeclaredInstanceField("dexFile", dex_file_name);
169  CHECK(element_dex_file_field != nullptr);
170
171  // Check if loader is a BaseDexClassLoader
172  art::Handle<art::mirror::Class> loader_class(hs.NewHandle(loader->GetClass()));
173  // Currently only base_dex_loader is allowed to actually define classes but if this changes in the
174  // future we should make sure to support all class loader types.
175  if (!loader_class->IsSubClass(base_dex_loader_class.Get())) {
176    LOG(ERROR) << "The classloader is not a BaseDexClassLoader which is currently the only "
177               << "supported class loader type!";
178    return nullptr;
179  }
180  // Start navigating the fields of the loader (now known to be a BaseDexClassLoader derivative)
181  art::Handle<art::mirror::Object> path_list(
182      hs.NewHandle(path_list_field->GetObject(loader.Get())));
183  CHECK(path_list != nullptr);
184  CHECK(!self->IsExceptionPending());
185  art::Handle<art::mirror::ObjectArray<art::mirror::Object>> dex_elements_list(hs.NewHandle(
186      dex_path_list_element_field->GetObject(path_list.Get())->
187      AsObjectArray<art::mirror::Object>()));
188  CHECK(!self->IsExceptionPending());
189  CHECK(dex_elements_list != nullptr);
190  size_t num_elements = dex_elements_list->GetLength();
191  // Iterate over the DexPathList$Element to find the right one
192  for (size_t i = 0; i < num_elements; i++) {
193    art::ObjPtr<art::mirror::Object> current_element = dex_elements_list->Get(i);
194    CHECK(!current_element.IsNull());
195    // TODO It would be cleaner to put the art::DexFile into the dalvik.system.DexFile the class
196    // comes from but it is more annoying because we would need to find this class. It is not
197    // necessary for proper function since we just need to be in front of the classes old dex file
198    // in the path.
199    art::ObjPtr<art::mirror::Object> first_dex_file(
200        element_dex_file_field->GetObject(current_element));
201    if (!first_dex_file.IsNull()) {
202      return first_dex_file;
203    }
204  }
205  return nullptr;
206}
207
208}  // namespace openjdkjvmti
209