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-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_env_ext-inl.h"
50#include "jvmti_allocator.h"
51#include "mirror/class.h"
52#include "mirror/class_ext.h"
53#include "mirror/object.h"
54#include "nativehelper/scoped_local_ref.h"
55#include "object_lock.h"
56#include "runtime.h"
57#include "transform.h"
58
59namespace openjdkjvmti {
60
61bool ClassLoaderHelper::AddToClassLoader(art::Thread* self,
62                                         art::Handle<art::mirror::ClassLoader> loader,
63                                         const art::DexFile* dex_file) {
64  art::ScopedObjectAccessUnchecked soa(self);
65  art::StackHandleScope<3> hs(self);
66  if (art::ClassLinker::IsBootClassLoader(soa, loader.Get())) {
67    art::Runtime::Current()->GetClassLinker()->AppendToBootClassPath(self, *dex_file);
68    return true;
69  }
70  art::Handle<art::mirror::Object> java_dex_file_obj(
71      hs.NewHandle(FindSourceDexFileObject(self, loader)));
72  if (java_dex_file_obj.IsNull()) {
73    return false;
74  }
75  art::Handle<art::mirror::LongArray> old_cookie(hs.NewHandle(GetDexFileCookie(java_dex_file_obj)));
76  art::Handle<art::mirror::LongArray> cookie(hs.NewHandle(
77      AllocateNewDexFileCookie(self, old_cookie, dex_file)));
78  if (cookie.IsNull()) {
79    return false;
80  }
81  art::ScopedAssertNoThreadSuspension nts("Replacing cookie fields in j.l.DexFile object");
82  UpdateJavaDexFile(java_dex_file_obj.Get(), cookie.Get());
83  return true;
84}
85
86void ClassLoaderHelper::UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
87                                          art::ObjPtr<art::mirror::LongArray> new_cookie) {
88  art::ArtField* internal_cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
89      "mInternalCookie", "Ljava/lang/Object;");
90  art::ArtField* cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField(
91      "mCookie", "Ljava/lang/Object;");
92  CHECK(internal_cookie_field != nullptr);
93  art::ObjPtr<art::mirror::LongArray> orig_internal_cookie(
94      internal_cookie_field->GetObject(java_dex_file)->AsLongArray());
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
103art::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
115art::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
137art::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.
172art::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