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.
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30  */
31 
32 #ifndef ART_OPENJDKJVMTI_ART_JVMTI_H_
33 #define ART_OPENJDKJVMTI_ART_JVMTI_H_
34 
35 #include <memory>
36 #include <type_traits>
37 #include <unordered_map>
38 #include <unordered_set>
39 
40 #include <jni.h>
41 
42 #include <android-base/logging.h>
43 
44 #include "deopt_manager.h"
45 #include "base/casts.h"
46 #include "base/macros.h"
47 #include "base/strlcpy.h"
48 #include "base/mutex.h"
49 #include "events.h"
50 #include "jni/java_vm_ext.h"
51 #include "jni/jni_env_ext.h"
52 #include "jvmti.h"
53 #include "ti_breakpoint.h"
54 
55 namespace art {
56 class ArtField;
57 class ArtMethod;
58 class ShadowFrame;
59 }  // namespace art
60 
61 namespace openjdkjvmti {
62 
63 class ObjectTagTable;
64 
65 // A special version that we use to identify special tooling interface versions which mostly matches
66 // the jvmti spec but everything is best effort. This is used to implement the userdebug
67 // 'debug-anything' behavior.
68 //
69 // This is the value 0x70010200.
70 static constexpr jint kArtTiVersion = JVMTI_VERSION_1_2 | 0x40000000;
71 
72 // A structure that is a jvmtiEnv with additional information for the runtime.
73 struct ArtJvmTiEnv : public jvmtiEnv {
74   art::JavaVMExt* art_vm;
75   void* local_data;
76 
77   // The ti_version we are compatible with. This is only for giving the correct value for GetVersion
78   // when running on a userdebug/eng device.
79   jint ti_version;
80 
81   jvmtiCapabilities capabilities;
82 
83   EventMasks event_masks;
84   std::unique_ptr<ArtJvmtiEventCallbacks> event_callbacks;
85 
86   // Tagging is specific to the jvmtiEnv.
87   std::unique_ptr<ObjectTagTable> object_tag_table;
88 
89   // Set of watched fields is unique to each jvmtiEnv.
90   // TODO It might be good to follow the RI and only let one jvmtiEnv ever have the watch caps so
91   // we can record this on the field directly. We could do this either using free access-flag bits
92   // or by putting a list in the ClassExt of a field's DeclaringClass.
93   // TODO Maybe just have an extension to let one put a watch on every field, that would probably be
94   // good enough maybe since you probably want either a few or all/almost all of them.
95   std::unordered_set<art::ArtField*> access_watched_fields GUARDED_BY(event_info_mutex_);
96   std::unordered_set<art::ArtField*> modify_watched_fields GUARDED_BY(event_info_mutex_);
97 
98   // Set of breakpoints is unique to each jvmtiEnv.
99   std::unordered_set<Breakpoint> breakpoints GUARDED_BY(event_info_mutex_);
100   std::unordered_set<const art::ShadowFrame*> notify_frames GUARDED_BY(event_info_mutex_);
101 
102   // RW lock to protect access to all of the event data.
103   art::ReaderWriterMutex event_info_mutex_ DEFAULT_MUTEX_ACQUIRED_AFTER;
104 
105   std::string last_error_ GUARDED_BY(last_error_mutex_);
106   // Lock to touch the last-error-message.
107   art::Mutex last_error_mutex_ BOTTOM_MUTEX_ACQUIRED_AFTER;
108 
109   ArtJvmTiEnv(art::JavaVMExt* runtime, EventHandler* event_handler, jint ti_version);
110 
AsArtJvmTiEnvArtJvmTiEnv111   static ArtJvmTiEnv* AsArtJvmTiEnv(jvmtiEnv* env) {
112     return art::down_cast<ArtJvmTiEnv*>(env);
113   }
114 
115   // Top level lock. Nothing can be held when we get this except for mutator lock for full
116   // thread-suspension.
117   static art::Mutex *gEnvMutex ACQUIRED_AFTER(art::Locks::mutator_lock_);
118 };
119 
120 // Macro and constexpr to make error values less annoying to write.
121 #define ERR(e) JVMTI_ERROR_ ## e
122 static constexpr jvmtiError OK = JVMTI_ERROR_NONE;
123 
124 // Special error code for unimplemented functions in JVMTI
125 static constexpr jvmtiError ERR(NOT_IMPLEMENTED) = JVMTI_ERROR_NOT_AVAILABLE;
126 
GetJniEnv(jvmtiEnv * env)127 static inline JNIEnv* GetJniEnv(jvmtiEnv* env) {
128   JNIEnv* ret_value = nullptr;
129   jint res = reinterpret_cast<ArtJvmTiEnv*>(env)->art_vm->GetEnv(
130       reinterpret_cast<void**>(&ret_value), JNI_VERSION_1_1);
131   if (res != JNI_OK) {
132     return nullptr;
133   }
134   return ret_value;
135 }
136 
137 template <typename T>
138 class JvmtiDeleter {
139  public:
JvmtiDeleter()140   JvmtiDeleter() : env_(nullptr) {}
JvmtiDeleter(jvmtiEnv * env)141   explicit JvmtiDeleter(jvmtiEnv* env) : env_(env) {}
142 
143   JvmtiDeleter(JvmtiDeleter&) = default;
144   JvmtiDeleter(JvmtiDeleter&&) = default;
145   JvmtiDeleter& operator=(const JvmtiDeleter&) = default;
146 
operator()147   void operator()(T* ptr) const {
148     CHECK(env_ != nullptr);
149     jvmtiError ret = env_->Deallocate(reinterpret_cast<unsigned char*>(ptr));
150     CHECK(ret == ERR(NONE));
151   }
152 
153  private:
154   mutable jvmtiEnv* env_;
155 };
156 
157 template <typename T>
158 class JvmtiDeleter<T[]> {
159  public:
JvmtiDeleter()160   JvmtiDeleter() : env_(nullptr) {}
JvmtiDeleter(jvmtiEnv * env)161   explicit JvmtiDeleter(jvmtiEnv* env) : env_(env) {}
162 
163   JvmtiDeleter(JvmtiDeleter&) = default;
164   JvmtiDeleter(JvmtiDeleter&&) = default;
165   JvmtiDeleter& operator=(const JvmtiDeleter&) = default;
166 
167   template <typename U>
operator()168   void operator()(U* ptr) const {
169     CHECK(env_ != nullptr);
170     jvmtiError ret = env_->Deallocate(reinterpret_cast<unsigned char*>(ptr));
171     CHECK(ret == ERR(NONE));
172   }
173 
174  private:
175   mutable jvmtiEnv* env_;
176 };
177 
178 template <typename T>
179 using JvmtiUniquePtr = std::unique_ptr<T, JvmtiDeleter<T>>;
180 
181 template <typename T>
182 ALWAYS_INLINE
MakeJvmtiUniquePtr(jvmtiEnv * env,T * mem)183 static inline JvmtiUniquePtr<T> MakeJvmtiUniquePtr(jvmtiEnv* env, T* mem) {
184   return JvmtiUniquePtr<T>(mem, JvmtiDeleter<T>(env));
185 }
186 
187 template <typename T>
188 ALWAYS_INLINE
MakeJvmtiUniquePtr(jvmtiEnv * env,unsigned char * mem)189 static inline JvmtiUniquePtr<T> MakeJvmtiUniquePtr(jvmtiEnv* env, unsigned char* mem) {
190   return JvmtiUniquePtr<T>(reinterpret_cast<T*>(mem), JvmtiDeleter<T>(env));
191 }
192 
193 template <typename T>
194 ALWAYS_INLINE
AllocJvmtiUniquePtr(jvmtiEnv * env,jvmtiError * error)195 static inline JvmtiUniquePtr<T> AllocJvmtiUniquePtr(jvmtiEnv* env, jvmtiError* error) {
196   unsigned char* tmp;
197   *error = env->Allocate(sizeof(T), &tmp);
198   if (*error != ERR(NONE)) {
199     return JvmtiUniquePtr<T>();
200   }
201   return JvmtiUniquePtr<T>(tmp, JvmtiDeleter<T>(env));
202 }
203 
204 template <typename T>
205 ALWAYS_INLINE
AllocJvmtiUniquePtr(jvmtiEnv * env,size_t count,jvmtiError * error)206 static inline JvmtiUniquePtr<T> AllocJvmtiUniquePtr(jvmtiEnv* env,
207                                                     size_t count,
208                                                     jvmtiError* error) {
209   unsigned char* tmp;
210   *error = env->Allocate(sizeof(typename std::remove_extent<T>::type) * count, &tmp);
211   if (*error != ERR(NONE)) {
212     return JvmtiUniquePtr<T>();
213   }
214   return JvmtiUniquePtr<T>(reinterpret_cast<typename std::remove_extent<T>::type*>(tmp),
215                            JvmtiDeleter<T>(env));
216 }
217 
218 ALWAYS_INLINE
CopyDataIntoJvmtiBuffer(ArtJvmTiEnv * env,const unsigned char * source,jint len,unsigned char ** dest)219 static inline jvmtiError CopyDataIntoJvmtiBuffer(ArtJvmTiEnv* env,
220                                                  const unsigned char* source,
221                                                  jint len,
222                                                  /*out*/unsigned char** dest) {
223   jvmtiError res = env->Allocate(len, dest);
224   if (res != OK) {
225     return res;
226   }
227   memcpy(reinterpret_cast<void*>(*dest),
228          reinterpret_cast<const void*>(source),
229          len);
230   return OK;
231 }
232 
233 ALWAYS_INLINE
CopyString(jvmtiEnv * env,const char * src,jvmtiError * error)234 static inline JvmtiUniquePtr<char[]> CopyString(jvmtiEnv* env, const char* src, jvmtiError* error) {
235   if (src == nullptr) {
236     JvmtiUniquePtr<char[]> ret = AllocJvmtiUniquePtr<char[]>(env, 0, error);
237     return ret;
238   }
239   size_t len = strlen(src) + 1;
240   JvmtiUniquePtr<char[]> ret = AllocJvmtiUniquePtr<char[]>(env, len, error);
241   if (ret != nullptr) {
242     strlcpy(ret.get(), src, len);
243   }
244   return ret;
245 }
246 
247 const jvmtiCapabilities kPotentialCapabilities = {
248     .can_tag_objects                                 = 1,
249     .can_generate_field_modification_events          = 1,
250     .can_generate_field_access_events                = 1,
251     .can_get_bytecodes                               = 1,
252     .can_get_synthetic_attribute                     = 1,
253     .can_get_owned_monitor_info                      = 1,
254     .can_get_current_contended_monitor               = 1,
255     .can_get_monitor_info                            = 1,
256     .can_pop_frame                                   = 1,
257     .can_redefine_classes                            = 1,
258     .can_signal_thread                               = 1,
259     .can_get_source_file_name                        = 1,
260     .can_get_line_numbers                            = 1,
261     .can_get_source_debug_extension                  = 1,
262     .can_access_local_variables                      = 1,
263     .can_maintain_original_method_order              = 1,
264     .can_generate_single_step_events                 = 1,
265     .can_generate_exception_events                   = 1,
266     .can_generate_frame_pop_events                   = 1,
267     .can_generate_breakpoint_events                  = 1,
268     .can_suspend                                     = 1,
269     .can_redefine_any_class                          = 0,
270     .can_get_current_thread_cpu_time                 = 0,
271     .can_get_thread_cpu_time                         = 0,
272     .can_generate_method_entry_events                = 1,
273     .can_generate_method_exit_events                 = 1,
274     .can_generate_all_class_hook_events              = 0,
275     .can_generate_compiled_method_load_events        = 0,
276     .can_generate_monitor_events                     = 1,
277     .can_generate_vm_object_alloc_events             = 1,
278     .can_generate_native_method_bind_events          = 1,
279     .can_generate_garbage_collection_events          = 1,
280     .can_generate_object_free_events                 = 1,
281     .can_force_early_return                          = 0,
282     .can_get_owned_monitor_stack_depth_info          = 1,
283     .can_get_constant_pool                           = 0,
284     .can_set_native_method_prefix                    = 0,
285     .can_retransform_classes                         = 1,
286     .can_retransform_any_class                       = 0,
287     .can_generate_resource_exhaustion_heap_events    = 0,
288     .can_generate_resource_exhaustion_threads_events = 0,
289 };
290 
291 // These are capabilities that are disabled if we were loaded without being debuggable.
292 //
293 // This includes the following capabilities:
294 //   can_retransform_any_class:
295 //   can_retransform_classes:
296 //   can_redefine_any_class:
297 //   can_redefine_classes:
298 //   can_pop_frame:
299 //     We need to ensure that inlined code is either not present or can always be deoptimized. This
300 //     is not guaranteed for non-debuggable processes since we might have inlined bootclasspath code
301 //     on a threads stack.
302 const jvmtiCapabilities kNonDebuggableUnsupportedCapabilities = {
303     .can_tag_objects                                 = 0,
304     .can_generate_field_modification_events          = 0,
305     .can_generate_field_access_events                = 0,
306     .can_get_bytecodes                               = 0,
307     .can_get_synthetic_attribute                     = 0,
308     .can_get_owned_monitor_info                      = 0,
309     .can_get_current_contended_monitor               = 0,
310     .can_get_monitor_info                            = 0,
311     .can_pop_frame                                   = 1,
312     .can_redefine_classes                            = 1,
313     .can_signal_thread                               = 0,
314     .can_get_source_file_name                        = 0,
315     .can_get_line_numbers                            = 0,
316     .can_get_source_debug_extension                  = 0,
317     .can_access_local_variables                      = 0,
318     .can_maintain_original_method_order              = 0,
319     .can_generate_single_step_events                 = 0,
320     .can_generate_exception_events                   = 0,
321     .can_generate_frame_pop_events                   = 0,
322     .can_generate_breakpoint_events                  = 0,
323     .can_suspend                                     = 0,
324     .can_redefine_any_class                          = 1,
325     .can_get_current_thread_cpu_time                 = 0,
326     .can_get_thread_cpu_time                         = 0,
327     .can_generate_method_entry_events                = 0,
328     .can_generate_method_exit_events                 = 0,
329     .can_generate_all_class_hook_events              = 0,
330     .can_generate_compiled_method_load_events        = 0,
331     .can_generate_monitor_events                     = 0,
332     .can_generate_vm_object_alloc_events             = 0,
333     .can_generate_native_method_bind_events          = 0,
334     .can_generate_garbage_collection_events          = 0,
335     .can_generate_object_free_events                 = 0,
336     .can_force_early_return                          = 0,
337     .can_get_owned_monitor_stack_depth_info          = 0,
338     .can_get_constant_pool                           = 0,
339     .can_set_native_method_prefix                    = 0,
340     .can_retransform_classes                         = 1,
341     .can_retransform_any_class                       = 1,
342     .can_generate_resource_exhaustion_heap_events    = 0,
343     .can_generate_resource_exhaustion_threads_events = 0,
344 };
345 
346 }  // namespace openjdkjvmti
347 
348 #endif  // ART_OPENJDKJVMTI_ART_JVMTI_H_
349