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1 /* Copyright (C) 2016 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 #ifndef ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_
33 #define ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_
34 
35 #include <string>
36 
37 #include <jni.h>
38 
39 #include "art_jvmti.h"
40 #include "art_method.h"
41 #include "base/array_ref.h"
42 #include "class_linker.h"
43 #include "dex_file.h"
44 #include "gc_root-inl.h"
45 #include "globals.h"
46 #include "jni_env_ext-inl.h"
47 #include "jvmti.h"
48 #include "linear_alloc.h"
49 #include "mem_map.h"
50 #include "mirror/array-inl.h"
51 #include "mirror/array.h"
52 #include "mirror/class-inl.h"
53 #include "mirror/class.h"
54 #include "mirror/class_loader-inl.h"
55 #include "mirror/string-inl.h"
56 #include "oat_file.h"
57 #include "obj_ptr.h"
58 #include "scoped_thread_state_change-inl.h"
59 #include "stack.h"
60 #include "ti_class_definition.h"
61 #include "thread_list.h"
62 #include "transform.h"
63 #include "utf.h"
64 #include "utils/dex_cache_arrays_layout-inl.h"
65 
66 namespace openjdkjvmti {
67 
68 class RedefinitionDataHolder;
69 class RedefinitionDataIter;
70 
71 // Class that can redefine a single class's methods.
72 class Redefiner {
73  public:
74   // Redefine the given classes with the given dex data. Note this function does not take ownership
75   // of the dex_data pointers. It is not used after this call however and may be freed if desired.
76   // The caller is responsible for freeing it. The runtime makes its own copy of the data. This
77   // function does not call the transformation events.
78   static jvmtiError RedefineClassesDirect(ArtJvmTiEnv* env,
79                                           art::Runtime* runtime,
80                                           art::Thread* self,
81                                           const std::vector<ArtClassDefinition>& definitions,
82                                           /*out*/std::string* error_msg);
83 
84   // Redefine the given classes with the given dex data. Note this function does not take ownership
85   // of the dex_data pointers. It is not used after this call however and may be freed if desired.
86   // The caller is responsible for freeing it. The runtime makes its own copy of the data.
87   static jvmtiError RedefineClasses(ArtJvmTiEnv* env,
88                                     EventHandler* event_handler,
89                                     art::Runtime* runtime,
90                                     art::Thread* self,
91                                     jint class_count,
92                                     const jvmtiClassDefinition* definitions,
93                                     /*out*/std::string* error_msg);
94 
95   static jvmtiError IsModifiableClass(jvmtiEnv* env, jclass klass, jboolean* is_redefinable);
96 
97   static std::unique_ptr<art::MemMap> MoveDataToMemMap(const std::string& original_location,
98                                                        art::ArrayRef<const unsigned char> data,
99                                                        std::string* error_msg);
100 
101  private:
102   class ClassRedefinition {
103    public:
104     ClassRedefinition(Redefiner* driver,
105                       jclass klass,
106                       const art::DexFile* redefined_dex_file,
107                       const char* class_sig,
108                       art::ArrayRef<const unsigned char> orig_dex_file)
109       REQUIRES_SHARED(art::Locks::mutator_lock_);
110 
111     // NO_THREAD_SAFETY_ANALYSIS so we can unlock the class in the destructor.
112     ~ClassRedefinition() NO_THREAD_SAFETY_ANALYSIS;
113 
114     // Move constructor so we can put these into a vector.
ClassRedefinition(ClassRedefinition && other)115     ClassRedefinition(ClassRedefinition&& other)
116         : driver_(other.driver_),
117           klass_(other.klass_),
118           dex_file_(std::move(other.dex_file_)),
119           class_sig_(std::move(other.class_sig_)),
120           original_dex_file_(other.original_dex_file_) {
121       other.driver_ = nullptr;
122     }
123 
124     art::mirror::Class* GetMirrorClass() REQUIRES_SHARED(art::Locks::mutator_lock_);
125     art::mirror::ClassLoader* GetClassLoader() REQUIRES_SHARED(art::Locks::mutator_lock_);
126 
GetDexFile()127     const art::DexFile& GetDexFile() {
128       return *dex_file_;
129     }
130 
131     art::mirror::DexCache* CreateNewDexCache(art::Handle<art::mirror::ClassLoader> loader)
132         REQUIRES_SHARED(art::Locks::mutator_lock_);
133 
134     // This may return nullptr with a OOME pending if allocation fails.
135     art::mirror::Object* AllocateOrGetOriginalDexFile()
136         REQUIRES_SHARED(art::Locks::mutator_lock_);
137 
RecordFailure(jvmtiError e,const std::string & err)138     void RecordFailure(jvmtiError e, const std::string& err) {
139       driver_->RecordFailure(e, class_sig_, err);
140     }
141 
142     bool FinishRemainingAllocations(/*out*/RedefinitionDataIter* cur_data)
143         REQUIRES_SHARED(art::Locks::mutator_lock_);
144 
145     bool AllocateAndRememberNewDexFileCookie(
146         art::Handle<art::mirror::ClassLoader> source_class_loader,
147         art::Handle<art::mirror::Object> dex_file_obj,
148         /*out*/RedefinitionDataIter* cur_data)
149           REQUIRES_SHARED(art::Locks::mutator_lock_);
150 
151     void FindAndAllocateObsoleteMethods(art::mirror::Class* art_klass)
152         REQUIRES(art::Locks::mutator_lock_);
153 
154     // Checks that the dex file contains only the single expected class and that the top-level class
155     // data has not been modified in an incompatible manner.
156     bool CheckClass() REQUIRES_SHARED(art::Locks::mutator_lock_);
157 
158     // Checks that the contained class can be successfully verified.
159     bool CheckVerification(const RedefinitionDataIter& holder)
160         REQUIRES_SHARED(art::Locks::mutator_lock_);
161 
162     // Preallocates all needed allocations in klass so that we can pause execution safely.
163     bool EnsureClassAllocationsFinished(/*out*/RedefinitionDataIter* data)
164         REQUIRES_SHARED(art::Locks::mutator_lock_);
165 
166     // This will check that no constraints are violated (more than 1 class in dex file, any changes
167     // in number/declaration of methods & fields, changes in access flags, etc.)
168     bool CheckRedefinitionIsValid() REQUIRES_SHARED(art::Locks::mutator_lock_);
169 
170     // Checks that the class can even be redefined.
171     bool CheckRedefinable() REQUIRES_SHARED(art::Locks::mutator_lock_);
172 
173     // Checks that the dex file does not add/remove methods, or change their modifiers or types.
174     bool CheckSameMethods() REQUIRES_SHARED(art::Locks::mutator_lock_);
175 
176     // Checks that the dex file does not modify fields types or modifiers.
177     bool CheckSameFields() REQUIRES_SHARED(art::Locks::mutator_lock_);
178 
179     void UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
180                            art::ObjPtr<art::mirror::LongArray> new_cookie)
181         REQUIRES(art::Locks::mutator_lock_);
182 
183     void UpdateFields(art::ObjPtr<art::mirror::Class> mclass)
184         REQUIRES(art::Locks::mutator_lock_);
185 
186     void UpdateMethods(art::ObjPtr<art::mirror::Class> mclass,
187                        art::ObjPtr<art::mirror::DexCache> new_dex_cache,
188                        const art::DexFile::ClassDef& class_def)
189         REQUIRES(art::Locks::mutator_lock_);
190 
191     void UpdateClass(art::ObjPtr<art::mirror::Class> mclass,
192                      art::ObjPtr<art::mirror::DexCache> new_dex_cache,
193                      art::ObjPtr<art::mirror::Object> original_dex_file)
194         REQUIRES(art::Locks::mutator_lock_);
195 
196     void RestoreObsoleteMethodMapsIfUnneeded(const RedefinitionDataIter* cur_data)
197         REQUIRES(art::Locks::mutator_lock_);
198 
199     void ReleaseDexFile() REQUIRES_SHARED(art::Locks::mutator_lock_);
200 
201     void UnregisterBreakpoints() REQUIRES_SHARED(art::Locks::mutator_lock_);
202     // This should be done with all threads suspended.
203     void UnregisterJvmtiBreakpoints() REQUIRES(art::Locks::mutator_lock_);
204 
205    private:
206     Redefiner* driver_;
207     jclass klass_;
208     std::unique_ptr<const art::DexFile> dex_file_;
209     std::string class_sig_;
210     art::ArrayRef<const unsigned char> original_dex_file_;
211   };
212 
213   ArtJvmTiEnv* env_;
214   jvmtiError result_;
215   art::Runtime* runtime_;
216   art::Thread* self_;
217   std::vector<ClassRedefinition> redefinitions_;
218   // Kept as a jclass since we have weird run-state changes that make keeping it around as a
219   // mirror::Class difficult and confusing.
220   std::string* error_msg_;
221 
Redefiner(ArtJvmTiEnv * env,art::Runtime * runtime,art::Thread * self,std::string * error_msg)222   Redefiner(ArtJvmTiEnv* env,
223             art::Runtime* runtime,
224             art::Thread* self,
225             std::string* error_msg)
226       : env_(env),
227         result_(ERR(INTERNAL)),
228         runtime_(runtime),
229         self_(self),
230         redefinitions_(),
231         error_msg_(error_msg) { }
232 
233   jvmtiError AddRedefinition(ArtJvmTiEnv* env, const ArtClassDefinition& def)
234       REQUIRES_SHARED(art::Locks::mutator_lock_);
235 
236   static jvmtiError GetClassRedefinitionError(art::Handle<art::mirror::Class> klass,
237                                               /*out*/std::string* error_msg)
238       REQUIRES_SHARED(art::Locks::mutator_lock_);
239 
240   jvmtiError Run() REQUIRES_SHARED(art::Locks::mutator_lock_);
241 
242   bool CheckAllRedefinitionAreValid() REQUIRES_SHARED(art::Locks::mutator_lock_);
243   bool CheckAllClassesAreVerified(RedefinitionDataHolder& holder)
244       REQUIRES_SHARED(art::Locks::mutator_lock_);
245   bool EnsureAllClassAllocationsFinished(RedefinitionDataHolder& holder)
246       REQUIRES_SHARED(art::Locks::mutator_lock_);
247   bool FinishAllRemainingAllocations(RedefinitionDataHolder& holder)
248       REQUIRES_SHARED(art::Locks::mutator_lock_);
249   void ReleaseAllDexFiles() REQUIRES_SHARED(art::Locks::mutator_lock_);
250   void UnregisterAllBreakpoints() REQUIRES_SHARED(art::Locks::mutator_lock_);
251   // Restores the old obsolete methods maps if it turns out they weren't needed (ie there were no
252   // new obsolete methods).
253   void RestoreObsoleteMethodMapsIfUnneeded(RedefinitionDataHolder& holder)
254       REQUIRES(art::Locks::mutator_lock_);
255 
256   void RecordFailure(jvmtiError result, const std::string& class_sig, const std::string& error_msg);
RecordFailure(jvmtiError result,const std::string & error_msg)257   void RecordFailure(jvmtiError result, const std::string& error_msg) {
258     RecordFailure(result, "NO CLASS", error_msg);
259   }
260 
261   friend struct CallbackCtx;
262   friend class RedefinitionDataHolder;
263   friend class RedefinitionDataIter;
264 };
265 
266 }  // namespace openjdkjvmti
267 
268 #endif  // ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_
269