1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24
25 #ifndef SHARE_VM_RUNTIME_VFRAME_HPP
26 #define SHARE_VM_RUNTIME_VFRAME_HPP
27
28 #include "code/debugInfo.hpp"
29 #include "code/debugInfoRec.hpp"
30 #include "code/location.hpp"
31 #include "oops/oop.hpp"
32 #include "runtime/frame.hpp"
33 #include "runtime/frame.inline.hpp"
34 #include "runtime/stackValue.hpp"
35 #include "runtime/stackValueCollection.hpp"
36 #include "utilities/growableArray.hpp"
37
38 // vframes are virtual stack frames representing source level activations.
39 // A single frame may hold several source level activations in the case of
40 // optimized code. The debugging stored with the optimized code enables
41 // us to unfold a frame as a stack of vframes.
42 // A cVFrame represents an activation of a non-java method.
43
44 // The vframe inheritance hierarchy:
45 // - vframe
46 // - javaVFrame
47 // - interpretedVFrame
48 // - compiledVFrame ; (used for both compiled Java methods and native stubs)
49 // - externalVFrame
50 // - entryVFrame ; special frame created when calling Java from C
51
52 // - BasicLock
53
54 class vframe: public ResourceObj {
55 protected:
56 frame _fr; // Raw frame behind the virtual frame.
57 RegisterMap _reg_map; // Register map for the raw frame (used to handle callee-saved registers).
58 JavaThread* _thread; // The thread owning the raw frame.
59
60 vframe(const frame* fr, const RegisterMap* reg_map, JavaThread* thread);
61 vframe(const frame* fr, JavaThread* thread);
62 public:
63 // Factory method for creating vframes
64 static vframe* new_vframe(const frame* f, const RegisterMap *reg_map, JavaThread* thread);
65
66 // Accessors
67 frame fr() const { return _fr; }
68 CodeBlob* cb() const { return _fr.cb(); }
69 CompiledMethod* nm() const {
70 assert( cb() != NULL && cb()->is_compiled(), "usage");
71 return (CompiledMethod*) cb();
72 }
73
74 // ???? Does this need to be a copy?
75 frame* frame_pointer() { return &_fr; }
76 const RegisterMap* register_map() const { return &_reg_map; }
77 JavaThread* thread() const { return _thread; }
78
79 // Returns the sender vframe
80 virtual vframe* sender() const;
81
82 // Returns the next javaVFrame on the stack (skipping all other kinds of frame)
83 javaVFrame *java_sender() const;
84
85 // Answers if the this is the top vframe in the frame, i.e., if the sender vframe
86 // is in the caller frame
87 virtual bool is_top() const { return true; }
88
89 // Returns top vframe within same frame (see is_top())
90 virtual vframe* top() const;
91
92 // Type testing operations
93 virtual bool is_entry_frame() const { return false; }
94 virtual bool is_java_frame() const { return false; }
95 virtual bool is_interpreted_frame() const { return false; }
96 virtual bool is_compiled_frame() const { return false; }
97
98 #ifndef PRODUCT
99 // printing operations
100 virtual void print_value() const;
101 virtual void print();
102 #endif
103 };
104
105
106 class javaVFrame: public vframe {
107 public:
108 // JVM state
109 virtual Method* method() const = 0;
110 virtual int bci() const = 0;
111 virtual StackValueCollection* locals() const = 0;
112 virtual StackValueCollection* expressions() const = 0;
113 // the order returned by monitors() is from oldest -> youngest#4418568
114 virtual GrowableArray<MonitorInfo*>* monitors() const = 0;
115
116 // Debugging support via JVMTI.
117 // NOTE that this is not guaranteed to give correct results for compiled vframes.
118 // Deoptimize first if necessary.
119 virtual void set_locals(StackValueCollection* values) const = 0;
120
121 // Test operation
122 bool is_java_frame() const { return true; }
123
124 protected:
125 javaVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {}
126 javaVFrame(const frame* fr, JavaThread* thread) : vframe(fr, thread) {}
127
128 public:
129 // casting
130 static javaVFrame* cast(vframe* vf) {
131 assert(vf == NULL || vf->is_java_frame(), "must be java frame");
132 return (javaVFrame*) vf;
133 }
134
135 // Return an array of monitors locked by this frame in the youngest to oldest order
136 GrowableArray<MonitorInfo*>* locked_monitors();
137
138 // printing used during stack dumps and diagnostics
139 static void print_locked_object_class_name(outputStream* st, Handle obj, const char* lock_state);
140 void print_lock_info_on(outputStream* st, int frame_count);
141 void print_lock_info(int frame_count) { print_lock_info_on(tty, frame_count); }
142
143 #ifndef PRODUCT
144 public:
145 // printing operations
146 void print();
147 void print_value() const;
148 void print_activation(int index) const;
149
150 // verify operations
151 virtual void verify() const;
152
153 // Structural compare
154 bool structural_compare(javaVFrame* other);
155 #endif
156 friend class vframe;
157 };
158
159 class interpretedVFrame: public javaVFrame {
160 public:
161 // JVM state
162 Method* method() const;
163 int bci() const;
164 StackValueCollection* locals() const;
165 StackValueCollection* expressions() const;
166 GrowableArray<MonitorInfo*>* monitors() const;
167
168 void set_locals(StackValueCollection* values) const;
169
170 // Test operation
171 bool is_interpreted_frame() const { return true; }
172
173 protected:
174 interpretedVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : javaVFrame(fr, reg_map, thread) {};
175
176 public:
177 // Accessors for Byte Code Pointer
178 u_char* bcp() const;
179 void set_bcp(u_char* bcp);
180
181 // casting
182 static interpretedVFrame* cast(vframe* vf) {
183 assert(vf == NULL || vf->is_interpreted_frame(), "must be interpreted frame");
184 return (interpretedVFrame*) vf;
185 }
186
187 private:
188 static const int bcp_offset;
189 intptr_t* locals_addr_at(int offset) const;
190 StackValueCollection* stack_data(bool expressions) const;
191 // returns where the parameters starts relative to the frame pointer
192 int start_of_parameters() const;
193
194 #ifndef PRODUCT
195 public:
196 // verify operations
197 void verify() const;
198 #endif
199 friend class vframe;
200 };
201
202
203 class externalVFrame: public vframe {
204 protected:
205 externalVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {}
206
207 #ifndef PRODUCT
208 public:
209 // printing operations
210 void print_value() const;
211 void print();
212 #endif
213 friend class vframe;
214 };
215
216 class entryVFrame: public externalVFrame {
217 public:
218 bool is_entry_frame() const { return true; }
219
220 protected:
221 entryVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread);
222
223 public:
224 // casting
225 static entryVFrame* cast(vframe* vf) {
226 assert(vf == NULL || vf->is_entry_frame(), "must be entry frame");
227 return (entryVFrame*) vf;
228 }
229
230 #ifndef PRODUCT
231 public:
232 // printing
233 void print_value() const;
234 void print();
235 #endif
236 friend class vframe;
237 };
238
239
240 // A MonitorInfo is a ResourceObject that describes a the pair:
241 // 1) the owner of the monitor
242 // 2) the monitor lock
243 class MonitorInfo : public ResourceObj {
244 private:
245 oop _owner; // the object owning the monitor
246 BasicLock* _lock;
247 oop _owner_klass; // klass (mirror) if owner was scalar replaced
248 bool _eliminated;
249 bool _owner_is_scalar_replaced;
250 public:
251 // Constructor
252 MonitorInfo(oop owner, BasicLock* lock, bool eliminated, bool owner_is_scalar_replaced) {
253 if (!owner_is_scalar_replaced) {
254 _owner = owner;
255 _owner_klass = NULL;
256 } else {
257 assert(eliminated, "monitor should be eliminated for scalar replaced object");
258 _owner = NULL;
259 _owner_klass = owner;
260 }
261 _lock = lock;
262 _eliminated = eliminated;
263 _owner_is_scalar_replaced = owner_is_scalar_replaced;
264 }
265 // Accessors
266 oop owner() const {
267 assert(!_owner_is_scalar_replaced, "should not be called for scalar replaced object");
268 return _owner;
269 }
270 oop owner_klass() const {
271 assert(_owner_is_scalar_replaced, "should not be called for not scalar replaced object");
272 return _owner_klass;
273 }
274 BasicLock* lock() const { return _lock; }
275 bool eliminated() const { return _eliminated; }
276 bool owner_is_scalar_replaced() const { return _owner_is_scalar_replaced; }
277 };
278
279 class vframeStreamCommon : StackObj {
280 protected:
281 // common
282 frame _frame;
283 JavaThread* _thread;
284 RegisterMap _reg_map;
285 enum { interpreted_mode, compiled_mode, at_end_mode } _mode;
286
287 int _sender_decode_offset;
288
289 // Cached information
290 Method* _method;
291 int _bci;
292
293 // Should VM activations be ignored or not
294 bool _stop_at_java_call_stub;
295
296 bool fill_in_compiled_inlined_sender();
297 void fill_from_compiled_frame(int decode_offset);
298 void fill_from_compiled_native_frame();
299
300 void found_bad_method_frame();
301
302 void fill_from_interpreter_frame();
303 bool fill_from_frame();
304
305 // Helper routine for security_get_caller_frame
306 void skip_prefixed_method_and_wrappers();
307
308 public:
309 // Constructor
310 vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) {
311 _thread = thread;
312 }
313
314 // Accessors
315 Method* method() const { return _method; }
316 int bci() const { return _bci; }
317 intptr_t* frame_id() const { return _frame.id(); }
318 address frame_pc() const { return _frame.pc(); }
319
320 CodeBlob* cb() const { return _frame.cb(); }
321 CompiledMethod* nm() const {
322 assert( cb() != NULL && cb()->is_compiled(), "usage");
323 return (CompiledMethod*) cb();
324 }
325
326 // Frame type
327 bool is_interpreted_frame() const { return _frame.is_interpreted_frame(); }
328 bool is_entry_frame() const { return _frame.is_entry_frame(); }
329
330 // Iteration
331 void next() {
332 // handle frames with inlining
333 if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) return;
334
335 // handle general case
336 do {
337 _frame = _frame.sender(&_reg_map);
338 } while (!fill_from_frame());
339 }
340 void security_next();
341
342 bool at_end() const { return _mode == at_end_mode; }
343
344 // Implements security traversal. Skips depth no. of frame including
345 // special security frames and prefixed native methods
346 void security_get_caller_frame(int depth);
347
348 // Helper routine for JVM_LatestUserDefinedLoader -- needed for 1.4
349 // reflection implementation
350 void skip_reflection_related_frames();
351 };
352
353 class vframeStream : public vframeStreamCommon {
354 public:
355 // Constructors
356 vframeStream(JavaThread* thread, bool stop_at_java_call_stub = false)
357 : vframeStreamCommon(thread) {
358 _stop_at_java_call_stub = stop_at_java_call_stub;
359
360 if (!thread->has_last_Java_frame()) {
361 _mode = at_end_mode;
362 return;
363 }
364
365 _frame = _thread->last_frame();
366 while (!fill_from_frame()) {
367 _frame = _frame.sender(&_reg_map);
368 }
369 }
370
371 // top_frame may not be at safepoint, start with sender
372 vframeStream(JavaThread* thread, frame top_frame, bool stop_at_java_call_stub = false);
373 };
374
375
376 inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() {
377 if (_sender_decode_offset == DebugInformationRecorder::serialized_null) {
378 return false;
379 }
380 fill_from_compiled_frame(_sender_decode_offset);
381 return true;
382 }
383
384
385 inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {
386 _mode = compiled_mode;
387
388 // Range check to detect ridiculous offsets.
389 if (decode_offset == DebugInformationRecorder::serialized_null ||
390 decode_offset < 0 ||
391 decode_offset >= nm()->scopes_data_size()) {
392 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
393 // If we read nmethod::scopes_data at serialized_null (== 0)
394 // or if read some at other invalid offset, invalid values will be decoded.
395 // Based on these values, invalid heap locations could be referenced
396 // that could lead to crashes in product mode.
397 // Therefore, do not use the decode offset if invalid, but fill the frame
398 // as it were a native compiled frame (no Java-level assumptions).
399 #ifdef ASSERT
400 if (WizardMode) {
401 ttyLocker ttyl;
402 tty->print_cr("Error in fill_from_frame: pc_desc for "
403 INTPTR_FORMAT " not found or invalid at %d",
404 p2i(_frame.pc()), decode_offset);
405 nm()->print();
406 nm()->method()->print_codes();
407 nm()->print_code();
408 nm()->print_pcs();
409 }
410 #endif
411 // Provide a cheap fallback in product mode. (See comment above.)
412 found_bad_method_frame();
413 fill_from_compiled_native_frame();
414 return;
415 }
416
417 // Decode first part of scopeDesc
418 DebugInfoReadStream buffer(nm(), decode_offset);
419 _sender_decode_offset = buffer.read_int();
420 _method = buffer.read_method();
421 _bci = buffer.read_bci();
422
423 assert(_method->is_method(), "checking type of decoded method");
424 }
425
426 // The native frames are handled specially. We do not rely on ScopeDesc info
427 // since the pc might not be exact due to the _last_native_pc trick.
428 inline void vframeStreamCommon::fill_from_compiled_native_frame() {
429 _mode = compiled_mode;
430 _sender_decode_offset = DebugInformationRecorder::serialized_null;
431 _method = nm()->method();
432 _bci = 0;
433 }
434
435 inline bool vframeStreamCommon::fill_from_frame() {
436 // Interpreted frame
437 if (_frame.is_interpreted_frame()) {
438 fill_from_interpreter_frame();
439 return true;
440 }
441
442 // Compiled frame
443
444 if (cb() != NULL && cb()->is_compiled()) {
445 if (nm()->is_native_method()) {
446 // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick.
447 fill_from_compiled_native_frame();
448 } else {
449 PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc());
450 int decode_offset;
451 if (pc_desc == NULL) {
452 // Should not happen, but let fill_from_compiled_frame handle it.
453
454 // If we are trying to walk the stack of a thread that is not
455 // at a safepoint (like AsyncGetCallTrace would do) then this is an
456 // acceptable result. [ This is assuming that safe_for_sender
457 // is so bullet proof that we can trust the frames it produced. ]
458 //
459 // So if we see that the thread is not safepoint safe
460 // then simply produce the method and a bci of zero
461 // and skip the possibility of decoding any inlining that
462 // may be present. That is far better than simply stopping (or
463 // asserting. If however the thread is safepoint safe this
464 // is the sign of a compiler bug and we'll let
465 // fill_from_compiled_frame handle it.
466
467
468 JavaThreadState state = _thread->thread_state();
469
470 // in_Java should be good enough to test safepoint safety
471 // if state were say in_Java_trans then we'd expect that
472 // the pc would have already been slightly adjusted to
473 // one that would produce a pcDesc since the trans state
474 // would be one that might in fact anticipate a safepoint
475
476 if (state == _thread_in_Java ) {
477 // This will get a method a zero bci and no inlining.
478 // Might be nice to have a unique bci to signify this
479 // particular case but for now zero will do.
480
481 fill_from_compiled_native_frame();
482
483 // There is something to be said for setting the mode to
484 // at_end_mode to prevent trying to walk further up the
485 // stack. There is evidence that if we walk any further
486 // that we could produce a bad stack chain. However until
487 // we see evidence that allowing this causes us to find
488 // frames bad enough to cause segv's or assertion failures
489 // we don't do it as while we may get a bad call chain the
490 // probability is much higher (several magnitudes) that we
491 // get good data.
492
493 return true;
494 }
495 decode_offset = DebugInformationRecorder::serialized_null;
496 } else {
497 decode_offset = pc_desc->scope_decode_offset();
498 }
499 fill_from_compiled_frame(decode_offset);
500 }
501 return true;
502 }
503
504 // End of stack?
505 if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {
506 _mode = at_end_mode;
507 return true;
508 }
509
510 return false;
511 }
512
513
514 inline void vframeStreamCommon::fill_from_interpreter_frame() {
515 Method* method = _frame.interpreter_frame_method();
516 address bcp = _frame.interpreter_frame_bcp();
517 int bci = method->validate_bci_from_bcp(bcp);
518 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
519 // AsyncGetCallTrace interrupts the VM asynchronously. As a result
520 // it is possible to access an interpreter frame for which
521 // no Java-level information is yet available (e.g., becasue
522 // the frame was being created when the VM interrupted it).
523 // In this scenario, pretend that the interpreter is at the point
524 // of entering the method.
525 if (bci < 0) {
526 found_bad_method_frame();
527 bci = 0;
528 }
529 _mode = interpreted_mode;
530 _method = method;
531 _bci = bci;
532 }
533
534 #endif // SHARE_VM_RUNTIME_VFRAME_HPP