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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
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     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.
    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 
    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 
    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 
    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);
    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