1 /* 2 * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 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 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 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). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 // vframes are virtual stack frames representing source level activations. 26 // A single frame may hold several source level activations in the case of 27 // optimized code. The debugging stored with the optimized code enables 28 // us to unfold a frame as a stack of vframes. 29 // A cVFrame represents an activation of a non-java method. 30 31 // The vframe inheritance hierarchy: 32 // - vframe 33 // - javaVFrame 34 // - interpretedVFrame 35 // - compiledVFrame ; (used for both compiled Java methods and native stubs) 36 // - externalVFrame 37 // - entryVFrame ; special frame created when calling Java from C 38 39 // - BasicLock 40 41 class vframe: public ResourceObj { 42 protected: 43 frame _fr; // Raw frame behind the virtual frame. 44 RegisterMap _reg_map; // Register map for the raw frame (used to handle callee-saved registers). 45 JavaThread* _thread; // The thread owning the raw frame. 46 47 vframe(const frame* fr, const RegisterMap* reg_map, JavaThread* thread); 48 vframe(const frame* fr, JavaThread* thread); 49 public: 50 // Factory method for creating vframes 51 static vframe* new_vframe(const frame* f, const RegisterMap *reg_map, JavaThread* thread); 52 53 // Accessors 54 frame fr() const { return _fr; } 55 CodeBlob* cb() const { return _fr.cb(); } 56 nmethod* nm() const { 57 assert( cb() != NULL && cb()->is_nmethod(), "usage"); 58 return (nmethod*) cb(); 59 } 60 61 // ???? Does this need to be a copy? 62 frame* frame_pointer() { return &_fr; } 63 const RegisterMap* register_map() const { return &_reg_map; } 64 JavaThread* thread() const { return _thread; } 65 66 // Returns the sender vframe 67 virtual vframe* sender() const; 68 69 // Returns the next javaVFrame on the stack (skipping all other kinds of frame) 70 javaVFrame *java_sender() const; 71 72 // Answers if the this is the top vframe in the frame, i.e., if the sender vframe 73 // is in the caller frame 74 virtual bool is_top() const { return true; } 75 76 // Returns top vframe within same frame (see is_top()) 77 virtual vframe* top() const; 78 79 // Type testing operations 80 virtual bool is_entry_frame() const { return false; } 81 virtual bool is_java_frame() const { return false; } 82 virtual bool is_interpreted_frame() const { return false; } 83 virtual bool is_compiled_frame() const { return false; } 84 85 #ifndef PRODUCT 86 // printing operations 87 virtual void print_value() const; 88 virtual void print(); 89 #endif 90 }; 91 92 93 class javaVFrame: public vframe { 94 public: 95 // JVM state 96 virtual methodOop method() const = 0; 97 virtual int bci() const = 0; 98 virtual StackValueCollection* locals() const = 0; 99 virtual StackValueCollection* expressions() const = 0; 100 // the order returned by monitors() is from oldest -> youngest#4418568 101 virtual GrowableArray<MonitorInfo*>* monitors() const = 0; 102 103 // Debugging support via JVMTI. 104 // NOTE that this is not guaranteed to give correct results for compiled vframes. 105 // Deoptimize first if necessary. 106 virtual void set_locals(StackValueCollection* values) const = 0; 107 108 // Test operation 109 bool is_java_frame() const { return true; } 110 111 protected: 112 javaVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {} 113 javaVFrame(const frame* fr, JavaThread* thread) : vframe(fr, thread) {} 114 115 public: 116 // casting 117 static javaVFrame* cast(vframe* vf) { 118 assert(vf == NULL || vf->is_java_frame(), "must be java frame"); 119 return (javaVFrame*) vf; 120 } 121 122 // Return an array of monitors locked by this frame in the youngest to oldest order 123 GrowableArray<MonitorInfo*>* locked_monitors(); 124 125 // printing used during stack dumps 126 void print_lock_info_on(outputStream* st, int frame_count); 127 void print_lock_info(int frame_count) { print_lock_info_on(tty, frame_count); } 128 129 #ifndef PRODUCT 130 public: 131 // printing operations 132 void print(); 133 void print_value() const; 134 void print_activation(int index) const; 135 136 // verify operations 137 virtual void verify() const; 138 139 // Structural compare 140 bool structural_compare(javaVFrame* other); 141 #endif 142 friend class vframe; 143 }; 144 145 class interpretedVFrame: public javaVFrame { 146 public: 147 // JVM state 148 methodOop method() const; 149 int bci() const; 150 StackValueCollection* locals() const; 151 StackValueCollection* expressions() const; 152 GrowableArray<MonitorInfo*>* monitors() const; 153 154 void set_locals(StackValueCollection* values) const; 155 156 // Test operation 157 bool is_interpreted_frame() const { return true; } 158 159 protected: 160 interpretedVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : javaVFrame(fr, reg_map, thread) {}; 161 162 public: 163 // Accessors for Byte Code Pointer 164 u_char* bcp() const; 165 void set_bcp(u_char* bcp); 166 167 // casting 168 static interpretedVFrame* cast(vframe* vf) { 169 assert(vf == NULL || vf->is_interpreted_frame(), "must be interpreted frame"); 170 return (interpretedVFrame*) vf; 171 } 172 173 private: 174 static const int bcp_offset; 175 intptr_t* locals_addr_at(int offset) const; 176 177 // returns where the parameters starts relative to the frame pointer 178 int start_of_parameters() const; 179 180 #ifndef PRODUCT 181 public: 182 // verify operations 183 void verify() const; 184 #endif 185 friend class vframe; 186 }; 187 188 189 class externalVFrame: public vframe { 190 protected: 191 externalVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread) : vframe(fr, reg_map, thread) {} 192 193 #ifndef PRODUCT 194 public: 195 // printing operations 196 void print_value() const; 197 void print(); 198 #endif 199 friend class vframe; 200 }; 201 202 class entryVFrame: public externalVFrame { 203 public: 204 bool is_entry_frame() const { return true; } 205 206 protected: 207 entryVFrame(const frame* fr, const RegisterMap* reg_map, JavaThread* thread); 208 209 public: 210 // casting 211 static entryVFrame* cast(vframe* vf) { 212 assert(vf == NULL || vf->is_entry_frame(), "must be entry frame"); 213 return (entryVFrame*) vf; 214 } 215 216 #ifndef PRODUCT 217 public: 218 // printing 219 void print_value() const; 220 void print(); 221 #endif 222 friend class vframe; 223 }; 224 225 226 // A MonitorInfo is a ResourceObject that describes a the pair: 227 // 1) the owner of the monitor 228 // 2) the monitor lock 229 class MonitorInfo : public ResourceObj { 230 private: 231 oop _owner; // the object owning the monitor 232 BasicLock* _lock; 233 oop _owner_klass; // klass if owner was scalar replaced 234 bool _eliminated; 235 bool _owner_is_scalar_replaced; 236 public: 237 // Constructor 238 MonitorInfo(oop owner, BasicLock* lock, bool eliminated, bool owner_is_scalar_replaced) { 239 if (!owner_is_scalar_replaced) { 240 _owner = owner; 241 _owner_klass = NULL; 242 } else { 243 assert(eliminated, "monitor should be eliminated for scalar replaced object"); 244 _owner = NULL; 245 _owner_klass = owner; 246 } 247 _lock = lock; 248 _eliminated = eliminated; 249 _owner_is_scalar_replaced = owner_is_scalar_replaced; 250 } 251 // Accessors 252 oop owner() const { 253 assert(!_owner_is_scalar_replaced, "should not be called for scalar replaced object"); 254 return _owner; 255 } 256 klassOop owner_klass() const { 257 assert(_owner_is_scalar_replaced, "should not be called for not scalar replaced object"); 258 return (klassOop)_owner_klass; 259 } 260 BasicLock* lock() const { return _lock; } 261 bool eliminated() const { return _eliminated; } 262 bool owner_is_scalar_replaced() const { return _owner_is_scalar_replaced; } 263 }; 264 265 class vframeStreamCommon : StackObj { 266 protected: 267 // common 268 frame _frame; 269 JavaThread* _thread; 270 RegisterMap _reg_map; 271 enum { interpreted_mode, compiled_mode, at_end_mode } _mode; 272 273 int _sender_decode_offset; 274 275 // Cached information 276 methodOop _method; 277 int _bci; 278 279 // Should VM activations be ignored or not 280 bool _stop_at_java_call_stub; 281 282 bool fill_in_compiled_inlined_sender(); 283 void fill_from_compiled_frame(int decode_offset); 284 void fill_from_compiled_native_frame(); 285 286 void found_bad_method_frame(); 287 288 void fill_from_interpreter_frame(); 289 bool fill_from_frame(); 290 291 // Helper routine for security_get_caller_frame 292 void skip_prefixed_method_and_wrappers(); 293 294 public: 295 // Constructor 296 vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) { 297 _thread = thread; 298 } 299 300 // Accessors 301 methodOop method() const { return _method; } 302 int bci() const { return _bci; } 303 intptr_t* frame_id() const { return _frame.id(); } 304 address frame_pc() const { return _frame.pc(); } 305 306 CodeBlob* cb() const { return _frame.cb(); } 307 nmethod* nm() const { 308 assert( cb() != NULL && cb()->is_nmethod(), "usage"); 309 return (nmethod*) cb(); 310 } 311 312 // Frame type 313 bool is_interpreted_frame() const { return _frame.is_interpreted_frame(); } 314 bool is_entry_frame() const { return _frame.is_entry_frame(); } 315 316 // Iteration 317 void next() { 318 // handle frames with inlining 319 if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) return; 320 321 // handle general case 322 do { 323 _frame = _frame.sender(&_reg_map); 324 } while (!fill_from_frame()); 325 } 326 327 bool at_end() const { return _mode == at_end_mode; } 328 329 // Implements security traversal. Skips depth no. of frame including 330 // special security frames and prefixed native methods 331 void security_get_caller_frame(int depth); 332 333 // Helper routine for JVM_LatestUserDefinedLoader -- needed for 1.4 334 // reflection implementation 335 void skip_reflection_related_frames(); 336 }; 337 338 class vframeStream : public vframeStreamCommon { 339 public: 340 // Constructors 341 vframeStream(JavaThread* thread, bool stop_at_java_call_stub = false) 342 : vframeStreamCommon(thread) { 343 _stop_at_java_call_stub = stop_at_java_call_stub; 344 345 if (!thread->has_last_Java_frame()) { 346 _mode = at_end_mode; 347 return; 348 } 349 350 _frame = _thread->last_frame(); 351 while (!fill_from_frame()) { 352 _frame = _frame.sender(&_reg_map); 353 } 354 } 355 356 // top_frame may not be at safepoint, start with sender 357 vframeStream(JavaThread* thread, frame top_frame, bool stop_at_java_call_stub = false); 358 }; 359 360 361 inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() { 362 if (_sender_decode_offset == DebugInformationRecorder::serialized_null) { 363 return false; 364 } 365 fill_from_compiled_frame(_sender_decode_offset); 366 return true; 367 } 368 369 370 inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) { 371 _mode = compiled_mode; 372 373 // Range check to detect ridiculous offsets. 374 if (decode_offset == DebugInformationRecorder::serialized_null || 375 decode_offset < 0 || 376 decode_offset >= nm()->scopes_data_size()) { 377 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. 378 // If we attempt to read nmethod::scopes_data at serialized_null (== 0), 379 // or if we read some at other crazy offset, 380 // we will decode garbage and make wild references into the heap, 381 // leading to crashes in product mode. 382 // (This isn't airtight, of course, since there are internal 383 // offsets which are also crazy.) 384 #ifdef ASSERT 385 if (WizardMode) { 386 tty->print_cr("Error in fill_from_frame: pc_desc for " 387 INTPTR_FORMAT " not found or invalid at %d", 388 _frame.pc(), decode_offset); 389 nm()->print(); 390 nm()->method()->print_codes(); 391 nm()->print_code(); 392 nm()->print_pcs(); 393 } 394 #endif 395 // Provide a cheap fallback in product mode. (See comment above.) 396 found_bad_method_frame(); 397 fill_from_compiled_native_frame(); 398 return; 399 } 400 401 // Decode first part of scopeDesc 402 DebugInfoReadStream buffer(nm(), decode_offset); 403 _sender_decode_offset = buffer.read_int(); 404 _method = methodOop(buffer.read_oop()); 405 _bci = buffer.read_bci(); 406 407 assert(_method->is_method(), "checking type of decoded method"); 408 } 409 410 // The native frames are handled specially. We do not rely on ScopeDesc info 411 // since the pc might not be exact due to the _last_native_pc trick. 412 inline void vframeStreamCommon::fill_from_compiled_native_frame() { 413 _mode = compiled_mode; 414 _sender_decode_offset = DebugInformationRecorder::serialized_null; 415 _method = nm()->method(); 416 _bci = 0; 417 } 418 419 inline bool vframeStreamCommon::fill_from_frame() { 420 // Interpreted frame 421 if (_frame.is_interpreted_frame()) { 422 fill_from_interpreter_frame(); 423 return true; 424 } 425 426 // Compiled frame 427 428 if (cb() != NULL && cb()->is_nmethod()) { 429 if (nm()->is_native_method()) { 430 // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick. 431 fill_from_compiled_native_frame(); 432 } else { 433 PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc()); 434 int decode_offset; 435 if (pc_desc == NULL) { 436 // Should not happen, but let fill_from_compiled_frame handle it. 437 438 // If we are trying to walk the stack of a thread that is not 439 // at a safepoint (like AsyncGetCallTrace would do) then this is an 440 // acceptable result. [ This is assuming that safe_for_sender 441 // is so bullet proof that we can trust the frames it produced. ] 442 // 443 // So if we see that the thread is not safepoint safe 444 // then simply produce the method and a bci of zero 445 // and skip the possibility of decoding any inlining that 446 // may be present. That is far better than simply stopping (or 447 // asserting. If however the thread is safepoint safe this 448 // is the sign of a compiler bug and we'll let 449 // fill_from_compiled_frame handle it. 450 451 452 JavaThreadState state = _thread->thread_state(); 453 454 // in_Java should be good enough to test safepoint safety 455 // if state were say in_Java_trans then we'd expect that 456 // the pc would have already been slightly adjusted to 457 // one that would produce a pcDesc since the trans state 458 // would be one that might in fact anticipate a safepoint 459 460 if (state == _thread_in_Java ) { 461 // This will get a method a zero bci and no inlining. 462 // Might be nice to have a unique bci to signify this 463 // particular case but for now zero will do. 464 465 fill_from_compiled_native_frame(); 466 467 // There is something to be said for setting the mode to 468 // at_end_mode to prevent trying to walk further up the 469 // stack. There is evidence that if we walk any further 470 // that we could produce a bad stack chain. However until 471 // we see evidence that allowing this causes us to find 472 // frames bad enough to cause segv's or assertion failures 473 // we don't do it as while we may get a bad call chain the 474 // probability is much higher (several magnitudes) that we 475 // get good data. 476 477 return true; 478 } 479 decode_offset = DebugInformationRecorder::serialized_null; 480 } else { 481 decode_offset = pc_desc->scope_decode_offset(); 482 } 483 fill_from_compiled_frame(decode_offset); 484 } 485 return true; 486 } 487 488 // End of stack? 489 if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) { 490 _mode = at_end_mode; 491 return true; 492 } 493 494 return false; 495 } 496 497 498 inline void vframeStreamCommon::fill_from_interpreter_frame() { 499 methodOop method = _frame.interpreter_frame_method(); 500 intptr_t bcx = _frame.interpreter_frame_bcx(); 501 int bci = method->validate_bci_from_bcx(bcx); 502 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. 503 if (bci < 0) { 504 found_bad_method_frame(); 505 bci = 0; // pretend it's on the point of entering 506 } 507 _mode = interpreted_mode; 508 _method = method; 509 _bci = bci; 510 }