1 /* 2 * Copyright (c) 2003, 2019, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/symbolTable.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "interpreter/interpreter.hpp" 29 #include "interpreter/oopMapCache.hpp" 30 #include "jvmtifiles/jvmtiEnv.hpp" 31 #include "logging/log.hpp" 32 #include "logging/logStream.hpp" 33 #include "memory/allocation.inline.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "oops/instanceKlass.hpp" 36 #include "oops/oop.inline.hpp" 37 #include "prims/jvmtiAgentThread.hpp" 38 #include "prims/jvmtiEventController.inline.hpp" 39 #include "prims/jvmtiImpl.hpp" 40 #include "prims/jvmtiRedefineClasses.hpp" 41 #include "runtime/atomic.hpp" 42 #include "runtime/deoptimization.hpp" 43 #include "runtime/frame.inline.hpp" 44 #include "runtime/handles.inline.hpp" 45 #include "runtime/interfaceSupport.inline.hpp" 46 #include "runtime/javaCalls.hpp" 47 #include "runtime/os.hpp" 48 #include "runtime/serviceThread.hpp" 49 #include "runtime/signature.hpp" 50 #include "runtime/thread.inline.hpp" 51 #include "runtime/threadSMR.hpp" 52 #include "runtime/vframe.hpp" 53 #include "runtime/vframe_hp.hpp" 54 #include "runtime/vmOperations.hpp" 55 #include "utilities/exceptions.hpp" 56 57 // 58 // class JvmtiAgentThread 59 // 60 // JavaThread used to wrap a thread started by an agent 61 // using the JVMTI method RunAgentThread. 62 // 63 64 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg) 65 : JavaThread(start_function_wrapper) { 66 _env = env; 67 _start_fn = start_fn; 68 _start_arg = start_arg; 69 } 70 71 void 72 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) { 73 // It is expected that any Agent threads will be created as 74 // Java Threads. If this is the case, notification of the creation 75 // of the thread is given in JavaThread::thread_main(). 76 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread"); 77 assert(thread == JavaThread::current(), "sanity check"); 78 79 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread; 80 dthread->call_start_function(); 81 } 82 83 void 84 JvmtiAgentThread::call_start_function() { 85 ThreadToNativeFromVM transition(this); 86 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg); 87 } 88 89 90 // 91 // class GrowableCache - private methods 92 // 93 94 void GrowableCache::recache() { 95 int len = _elements->length(); 96 97 FREE_C_HEAP_ARRAY(address, _cache); 98 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal); 99 100 for (int i=0; i<len; i++) { 101 _cache[i] = _elements->at(i)->getCacheValue(); 102 // 103 // The cache entry has gone bad. Without a valid frame pointer 104 // value, the entry is useless so we simply delete it in product 105 // mode. The call to remove() will rebuild the cache again 106 // without the bad entry. 107 // 108 if (_cache[i] == NULL) { 109 assert(false, "cannot recache NULL elements"); 110 remove(i); 111 return; 112 } 113 } 114 _cache[len] = NULL; 115 116 _listener_fun(_this_obj,_cache); 117 } 118 119 bool GrowableCache::equals(void* v, GrowableElement *e2) { 120 GrowableElement *e1 = (GrowableElement *) v; 121 assert(e1 != NULL, "e1 != NULL"); 122 assert(e2 != NULL, "e2 != NULL"); 123 124 return e1->equals(e2); 125 } 126 127 // 128 // class GrowableCache - public methods 129 // 130 131 GrowableCache::GrowableCache() { 132 _this_obj = NULL; 133 _listener_fun = NULL; 134 _elements = NULL; 135 _cache = NULL; 136 } 137 138 GrowableCache::~GrowableCache() { 139 clear(); 140 delete _elements; 141 FREE_C_HEAP_ARRAY(address, _cache); 142 } 143 144 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) { 145 _this_obj = this_obj; 146 _listener_fun = listener_fun; 147 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true); 148 recache(); 149 } 150 151 // number of elements in the collection 152 int GrowableCache::length() { 153 return _elements->length(); 154 } 155 156 // get the value of the index element in the collection 157 GrowableElement* GrowableCache::at(int index) { 158 GrowableElement *e = (GrowableElement *) _elements->at(index); 159 assert(e != NULL, "e != NULL"); 160 return e; 161 } 162 163 int GrowableCache::find(GrowableElement* e) { 164 return _elements->find(e, GrowableCache::equals); 165 } 166 167 // append a copy of the element to the end of the collection 168 void GrowableCache::append(GrowableElement* e) { 169 GrowableElement *new_e = e->clone(); 170 _elements->append(new_e); 171 recache(); 172 } 173 174 // insert a copy of the element using lessthan() 175 void GrowableCache::insert(GrowableElement* e) { 176 GrowableElement *new_e = e->clone(); 177 _elements->append(new_e); 178 179 int n = length()-2; 180 for (int i=n; i>=0; i--) { 181 GrowableElement *e1 = _elements->at(i); 182 GrowableElement *e2 = _elements->at(i+1); 183 if (e2->lessThan(e1)) { 184 _elements->at_put(i+1, e1); 185 _elements->at_put(i, e2); 186 } 187 } 188 189 recache(); 190 } 191 192 // remove the element at index 193 void GrowableCache::remove (int index) { 194 GrowableElement *e = _elements->at(index); 195 assert(e != NULL, "e != NULL"); 196 _elements->remove(e); 197 delete e; 198 recache(); 199 } 200 201 // clear out all elements, release all heap space and 202 // let our listener know that things have changed. 203 void GrowableCache::clear() { 204 int len = _elements->length(); 205 for (int i=0; i<len; i++) { 206 delete _elements->at(i); 207 } 208 _elements->clear(); 209 recache(); 210 } 211 212 void GrowableCache::oops_do(OopClosure* f) { 213 int len = _elements->length(); 214 for (int i=0; i<len; i++) { 215 GrowableElement *e = _elements->at(i); 216 e->oops_do(f); 217 } 218 } 219 220 void GrowableCache::metadata_do(void f(Metadata*)) { 221 int len = _elements->length(); 222 for (int i=0; i<len; i++) { 223 GrowableElement *e = _elements->at(i); 224 e->metadata_do(f); 225 } 226 } 227 228 // 229 // class JvmtiBreakpoint 230 // 231 232 JvmtiBreakpoint::JvmtiBreakpoint() { 233 _method = NULL; 234 _bci = 0; 235 _class_holder = NULL; 236 } 237 238 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) { 239 _method = m_method; 240 _class_holder = _method->method_holder()->klass_holder(); 241 #ifdef CHECK_UNHANDLED_OOPS 242 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are 243 // sometimes allocated on the heap. 244 // 245 // The code handling JvmtiBreakpoints allocated on the stack can't be 246 // interrupted by a GC until _class_holder is reachable by the GC via the 247 // oops_do method. 248 Thread::current()->allow_unhandled_oop(&_class_holder); 249 #endif // CHECK_UNHANDLED_OOPS 250 assert(_method != NULL, "_method != NULL"); 251 _bci = (int) location; 252 assert(_bci >= 0, "_bci >= 0"); 253 } 254 255 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) { 256 _method = bp._method; 257 _bci = bp._bci; 258 _class_holder = bp._class_holder; 259 } 260 261 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) { 262 Unimplemented(); 263 return false; 264 } 265 266 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) { 267 return _method == bp._method 268 && _bci == bp._bci; 269 } 270 271 bool JvmtiBreakpoint::is_valid() { 272 // class loader can be NULL 273 return _method != NULL && 274 _bci >= 0; 275 } 276 277 address JvmtiBreakpoint::getBcp() const { 278 return _method->bcp_from(_bci); 279 } 280 281 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) { 282 ((Method*)_method->*meth_act)(_bci); 283 284 // add/remove breakpoint to/from versions of the method that are EMCP. 285 Thread *thread = Thread::current(); 286 InstanceKlass* ik = _method->method_holder(); 287 Symbol* m_name = _method->name(); 288 Symbol* m_signature = _method->signature(); 289 290 // search previous versions if they exist 291 for (InstanceKlass* pv_node = ik->previous_versions(); 292 pv_node != NULL; 293 pv_node = pv_node->previous_versions()) { 294 Array<Method*>* methods = pv_node->methods(); 295 296 for (int i = methods->length() - 1; i >= 0; i--) { 297 Method* method = methods->at(i); 298 // Only set breakpoints in running EMCP methods. 299 if (method->is_running_emcp() && 300 method->name() == m_name && 301 method->signature() == m_signature) { 302 ResourceMark rm; 303 log_debug(redefine, class, breakpoint) 304 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear", 305 method->name()->as_C_string(), method->signature()->as_C_string()); 306 (method->*meth_act)(_bci); 307 break; 308 } 309 } 310 } 311 } 312 313 void JvmtiBreakpoint::set() { 314 each_method_version_do(&Method::set_breakpoint); 315 } 316 317 void JvmtiBreakpoint::clear() { 318 each_method_version_do(&Method::clear_breakpoint); 319 } 320 321 void JvmtiBreakpoint::print_on(outputStream* out) const { 322 #ifndef PRODUCT 323 ResourceMark rm; 324 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string(); 325 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string(); 326 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp()); 327 #endif 328 } 329 330 331 // 332 // class VM_ChangeBreakpoints 333 // 334 // Modify the Breakpoints data structure at a safepoint 335 // 336 337 void VM_ChangeBreakpoints::doit() { 338 switch (_operation) { 339 case SET_BREAKPOINT: 340 _breakpoints->set_at_safepoint(*_bp); 341 break; 342 case CLEAR_BREAKPOINT: 343 _breakpoints->clear_at_safepoint(*_bp); 344 break; 345 default: 346 assert(false, "Unknown operation"); 347 } 348 } 349 350 void VM_ChangeBreakpoints::oops_do(OopClosure* f) { 351 // The JvmtiBreakpoints in _breakpoints will be visited via 352 // JvmtiExport::oops_do. 353 if (_bp != NULL) { 354 _bp->oops_do(f); 355 } 356 } 357 358 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) { 359 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses 360 if (_bp != NULL) { 361 _bp->metadata_do(f); 362 } 363 } 364 365 // 366 // class JvmtiBreakpoints 367 // 368 // a JVMTI internal collection of JvmtiBreakpoint 369 // 370 371 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) { 372 _bps.initialize(this,listener_fun); 373 } 374 375 JvmtiBreakpoints:: ~JvmtiBreakpoints() {} 376 377 void JvmtiBreakpoints::oops_do(OopClosure* f) { 378 _bps.oops_do(f); 379 } 380 381 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) { 382 _bps.metadata_do(f); 383 } 384 385 void JvmtiBreakpoints::print() { 386 #ifndef PRODUCT 387 LogTarget(Trace, jvmti) log; 388 LogStream log_stream(log); 389 390 int n = _bps.length(); 391 for (int i=0; i<n; i++) { 392 JvmtiBreakpoint& bp = _bps.at(i); 393 log_stream.print("%d: ", i); 394 bp.print_on(&log_stream); 395 log_stream.cr(); 396 } 397 #endif 398 } 399 400 401 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) { 402 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 403 404 int i = _bps.find(bp); 405 if (i == -1) { 406 _bps.append(bp); 407 bp.set(); 408 } 409 } 410 411 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) { 412 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint"); 413 414 int i = _bps.find(bp); 415 if (i != -1) { 416 _bps.remove(i); 417 bp.clear(); 418 } 419 } 420 421 int JvmtiBreakpoints::length() { return _bps.length(); } 422 423 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) { 424 if ( _bps.find(bp) != -1) { 425 return JVMTI_ERROR_DUPLICATE; 426 } 427 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp); 428 VMThread::execute(&set_breakpoint); 429 return JVMTI_ERROR_NONE; 430 } 431 432 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) { 433 if ( _bps.find(bp) == -1) { 434 return JVMTI_ERROR_NOT_FOUND; 435 } 436 437 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp); 438 VMThread::execute(&clear_breakpoint); 439 return JVMTI_ERROR_NONE; 440 } 441 442 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) { 443 bool changed = true; 444 // We are going to run thru the list of bkpts 445 // and delete some. This deletion probably alters 446 // the list in some implementation defined way such 447 // that when we delete entry i, the next entry might 448 // no longer be at i+1. To be safe, each time we delete 449 // an entry, we'll just start again from the beginning. 450 // We'll stop when we make a pass thru the whole list without 451 // deleting anything. 452 while (changed) { 453 int len = _bps.length(); 454 changed = false; 455 for (int i = 0; i < len; i++) { 456 JvmtiBreakpoint& bp = _bps.at(i); 457 if (bp.method()->method_holder() == klass) { 458 bp.clear(); 459 _bps.remove(i); 460 // This changed 'i' so we have to start over. 461 changed = true; 462 break; 463 } 464 } 465 } 466 } 467 468 // 469 // class JvmtiCurrentBreakpoints 470 // 471 472 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL; 473 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL; 474 475 476 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() { 477 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints); 478 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun); 479 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL"); 480 return (*_jvmti_breakpoints); 481 } 482 483 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) { 484 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj; 485 assert(this_jvmti != NULL, "this_jvmti != NULL"); 486 487 debug_only(int n = this_jvmti->length();); 488 assert(cache[n] == NULL, "cache must be NULL terminated"); 489 490 set_breakpoint_list(cache); 491 } 492 493 494 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) { 495 if (_jvmti_breakpoints != NULL) { 496 _jvmti_breakpoints->oops_do(f); 497 } 498 } 499 500 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) { 501 if (_jvmti_breakpoints != NULL) { 502 _jvmti_breakpoints->metadata_do(f); 503 } 504 } 505 506 /////////////////////////////////////////////////////////////// 507 // 508 // class VM_GetOrSetLocal 509 // 510 511 // Constructor for non-object getter 512 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type) 513 : _thread(thread) 514 , _calling_thread(NULL) 515 , _depth(depth) 516 , _index(index) 517 , _type(type) 518 , _jvf(NULL) 519 , _set(false) 520 , _result(JVMTI_ERROR_NONE) 521 { 522 } 523 524 // Constructor for object or non-object setter 525 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value) 526 : _thread(thread) 527 , _calling_thread(NULL) 528 , _depth(depth) 529 , _index(index) 530 , _type(type) 531 , _value(value) 532 , _jvf(NULL) 533 , _set(true) 534 , _result(JVMTI_ERROR_NONE) 535 { 536 } 537 538 // Constructor for object getter 539 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index) 540 : _thread(thread) 541 , _calling_thread(calling_thread) 542 , _depth(depth) 543 , _index(index) 544 , _type(T_OBJECT) 545 , _jvf(NULL) 546 , _set(false) 547 , _result(JVMTI_ERROR_NONE) 548 { 549 } 550 551 vframe *VM_GetOrSetLocal::get_vframe() { 552 if (!_thread->has_last_Java_frame()) { 553 return NULL; 554 } 555 RegisterMap reg_map(_thread); 556 vframe *vf = _thread->last_java_vframe(®_map); 557 int d = 0; 558 while ((vf != NULL) && (d < _depth)) { 559 vf = vf->java_sender(); 560 d++; 561 } 562 return vf; 563 } 564 565 javaVFrame *VM_GetOrSetLocal::get_java_vframe() { 566 vframe* vf = get_vframe(); 567 if (vf == NULL) { 568 _result = JVMTI_ERROR_NO_MORE_FRAMES; 569 return NULL; 570 } 571 javaVFrame *jvf = (javaVFrame*)vf; 572 573 if (!vf->is_java_frame()) { 574 _result = JVMTI_ERROR_OPAQUE_FRAME; 575 return NULL; 576 } 577 return jvf; 578 } 579 580 // Check that the klass is assignable to a type with the given signature. 581 // Another solution could be to use the function Klass::is_subtype_of(type). 582 // But the type class can be forced to load/initialize eagerly in such a case. 583 // This may cause unexpected consequences like CFLH or class-init JVMTI events. 584 // It is better to avoid such a behavior. 585 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) { 586 assert(ty_sign != NULL, "type signature must not be NULL"); 587 assert(thread != NULL, "thread must not be NULL"); 588 assert(klass != NULL, "klass must not be NULL"); 589 590 int len = (int) strlen(ty_sign); 591 if ((ty_sign[0] == 'L' || ty_sign[0] == 'Q') && ty_sign[len-1] == ';') { // Need pure class/interface name 592 ty_sign++; 593 len -= 2; 594 } 595 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len); 596 if (klass->name() == ty_sym) { 597 return true; 598 } 599 // Compare primary supers 600 int super_depth = klass->super_depth(); 601 int idx; 602 for (idx = 0; idx < super_depth; idx++) { 603 if (klass->primary_super_of_depth(idx)->name() == ty_sym) { 604 return true; 605 } 606 } 607 // Compare secondary supers 608 const Array<Klass*>* sec_supers = klass->secondary_supers(); 609 for (idx = 0; idx < sec_supers->length(); idx++) { 610 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) { 611 return true; 612 } 613 } 614 return false; 615 } 616 617 // Checks error conditions: 618 // JVMTI_ERROR_INVALID_SLOT 619 // JVMTI_ERROR_TYPE_MISMATCH 620 // Returns: 'true' - everything is Ok, 'false' - error code 621 622 bool VM_GetOrSetLocal::check_slot_type_lvt(javaVFrame* jvf) { 623 Method* method_oop = jvf->method(); 624 jint num_entries = method_oop->localvariable_table_length(); 625 if (num_entries == 0) { 626 _result = JVMTI_ERROR_INVALID_SLOT; 627 return false; // There are no slots 628 } 629 int signature_idx = -1; 630 int vf_bci = jvf->bci(); 631 LocalVariableTableElement* table = method_oop->localvariable_table_start(); 632 for (int i = 0; i < num_entries; i++) { 633 int start_bci = table[i].start_bci; 634 int end_bci = start_bci + table[i].length; 635 636 // Here we assume that locations of LVT entries 637 // with the same slot number cannot be overlapped 638 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) { 639 signature_idx = (int) table[i].descriptor_cp_index; 640 break; 641 } 642 } 643 if (signature_idx == -1) { 644 _result = JVMTI_ERROR_INVALID_SLOT; 645 return false; // Incorrect slot index 646 } 647 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx); 648 const char* signature = (const char *) sign_sym->as_utf8(); 649 BasicType slot_type = char2type(signature[0]); 650 651 switch (slot_type) { 652 case T_BYTE: 653 case T_SHORT: 654 case T_CHAR: 655 case T_BOOLEAN: 656 slot_type = T_INT; 657 break; 658 case T_ARRAY: 659 case T_VALUETYPE: 660 slot_type = T_OBJECT; 661 break; 662 default: 663 break; 664 }; 665 if (_type != slot_type) { 666 _result = JVMTI_ERROR_TYPE_MISMATCH; 667 return false; 668 } 669 670 jobject jobj = _value.l; 671 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed 672 // Check that the jobject class matches the return type signature. 673 JavaThread* cur_thread = JavaThread::current(); 674 HandleMark hm(cur_thread); 675 676 Handle obj(cur_thread, JNIHandles::resolve_external_guard(jobj)); 677 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 678 Klass* ob_k = obj->klass(); 679 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false)); 680 681 if (!is_assignable(signature, ob_k, cur_thread)) { 682 _result = JVMTI_ERROR_TYPE_MISMATCH; 683 return false; 684 } 685 } 686 return true; 687 } 688 689 bool VM_GetOrSetLocal::check_slot_type_no_lvt(javaVFrame* jvf) { 690 Method* method_oop = jvf->method(); 691 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0; 692 693 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) { 694 _result = JVMTI_ERROR_INVALID_SLOT; 695 return false; 696 } 697 StackValueCollection *locals = _jvf->locals(); 698 BasicType slot_type = locals->at(_index)->type(); 699 700 if (slot_type == T_CONFLICT) { 701 _result = JVMTI_ERROR_INVALID_SLOT; 702 return false; 703 } 704 if (extra_slot) { 705 BasicType extra_slot_type = locals->at(_index + 1)->type(); 706 if (extra_slot_type != T_INT) { 707 _result = JVMTI_ERROR_INVALID_SLOT; 708 return false; 709 } 710 } 711 if (_type != slot_type && (_type == T_OBJECT || slot_type != T_INT)) { 712 _result = JVMTI_ERROR_TYPE_MISMATCH; 713 return false; 714 } 715 return true; 716 } 717 718 static bool can_be_deoptimized(vframe* vf) { 719 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized()); 720 } 721 722 bool VM_GetOrSetLocal::doit_prologue() { 723 _jvf = get_java_vframe(); 724 NULL_CHECK(_jvf, false); 725 726 Method* method_oop = _jvf->method(); 727 if (method_oop->is_native()) { 728 if (getting_receiver() && !method_oop->is_static()) { 729 return true; 730 } else { 731 _result = JVMTI_ERROR_OPAQUE_FRAME; 732 return false; 733 } 734 } 735 736 if (!check_slot_type_no_lvt(_jvf)) { 737 return false; 738 } 739 if (method_oop->has_localvariable_table()) { 740 return check_slot_type_lvt(_jvf); 741 } 742 return true; 743 } 744 745 void VM_GetOrSetLocal::doit() { 746 InterpreterOopMap oop_mask; 747 _jvf->method()->mask_for(_jvf->bci(), &oop_mask); 748 if (oop_mask.is_dead(_index)) { 749 // The local can be invalid and uninitialized in the scope of current bci 750 _result = JVMTI_ERROR_INVALID_SLOT; 751 return; 752 } 753 if (_set) { 754 // Force deoptimization of frame if compiled because it's 755 // possible the compiler emitted some locals as constant values, 756 // meaning they are not mutable. 757 if (can_be_deoptimized(_jvf)) { 758 759 // Schedule deoptimization so that eventually the local 760 // update will be written to an interpreter frame. 761 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id()); 762 763 // Now store a new value for the local which will be applied 764 // once deoptimization occurs. Note however that while this 765 // write is deferred until deoptimization actually happens 766 // can vframe created after this point will have its locals 767 // reflecting this update so as far as anyone can see the 768 // write has already taken place. 769 770 // If we are updating an oop then get the oop from the handle 771 // since the handle will be long gone by the time the deopt 772 // happens. The oop stored in the deferred local will be 773 // gc'd on its own. 774 if (_type == T_OBJECT || _type == T_VALUETYPE) { 775 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l)); 776 } 777 // Re-read the vframe so we can see that it is deoptimized 778 // [ Only need because of assert in update_local() ] 779 _jvf = get_java_vframe(); 780 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value); 781 return; 782 } 783 StackValueCollection *locals = _jvf->locals(); 784 HandleMark hm; 785 786 switch (_type) { 787 case T_INT: locals->set_int_at (_index, _value.i); break; 788 case T_LONG: locals->set_long_at (_index, _value.j); break; 789 case T_FLOAT: locals->set_float_at (_index, _value.f); break; 790 case T_DOUBLE: locals->set_double_at(_index, _value.d); break; 791 case T_OBJECT: 792 case T_VALUETYPE: { 793 Handle ob_h(Thread::current(), JNIHandles::resolve_external_guard(_value.l)); 794 locals->set_obj_at (_index, ob_h); 795 break; 796 } 797 default: ShouldNotReachHere(); 798 } 799 _jvf->set_locals(locals); 800 } else { 801 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) { 802 assert(getting_receiver(), "Can only get here when getting receiver"); 803 oop receiver = _jvf->fr().get_native_receiver(); 804 _value.l = JNIHandles::make_local(_calling_thread, receiver); 805 } else { 806 StackValueCollection *locals = _jvf->locals(); 807 808 switch (_type) { 809 case T_INT: _value.i = locals->int_at (_index); break; 810 case T_LONG: _value.j = locals->long_at (_index); break; 811 case T_FLOAT: _value.f = locals->float_at (_index); break; 812 case T_DOUBLE: _value.d = locals->double_at(_index); break; 813 case T_OBJECT: 814 case T_VALUETYPE: { 815 // Wrap the oop to be returned in a local JNI handle since 816 // oops_do() no longer applies after doit() is finished. 817 oop obj = locals->obj_at(_index)(); 818 _value.l = JNIHandles::make_local(_calling_thread, obj); 819 break; 820 } 821 default: ShouldNotReachHere(); 822 } 823 } 824 } 825 } 826 827 828 bool VM_GetOrSetLocal::allow_nested_vm_operations() const { 829 return true; // May need to deoptimize 830 } 831 832 833 VM_GetReceiver::VM_GetReceiver( 834 JavaThread* thread, JavaThread* caller_thread, jint depth) 835 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {} 836 837 ///////////////////////////////////////////////////////////////////////////////////////// 838 839 // 840 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp 841 // 842 843 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) { 844 // external suspend should have caught suspending a thread twice 845 846 // Immediate suspension required for JPDA back-end so JVMTI agent threads do 847 // not deadlock due to later suspension on transitions while holding 848 // raw monitors. Passing true causes the immediate suspension. 849 // java_suspend() will catch threads in the process of exiting 850 // and will ignore them. 851 java_thread->java_suspend(); 852 853 // It would be nice to have the following assertion in all the time, 854 // but it is possible for a racing resume request to have resumed 855 // this thread right after we suspended it. Temporarily enable this 856 // assertion if you are chasing a different kind of bug. 857 // 858 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL || 859 // java_thread->is_being_ext_suspended(), "thread is not suspended"); 860 861 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) { 862 // check again because we can get delayed in java_suspend(): 863 // the thread is in process of exiting. 864 return false; 865 } 866 867 return true; 868 } 869 870 bool JvmtiSuspendControl::resume(JavaThread *java_thread) { 871 // external suspend should have caught resuming a thread twice 872 assert(java_thread->is_being_ext_suspended(), "thread should be suspended"); 873 874 // resume thread 875 { 876 // must always grab Threads_lock, see JVM_SuspendThread 877 MutexLocker ml(Threads_lock); 878 java_thread->java_resume(); 879 } 880 881 return true; 882 } 883 884 885 void JvmtiSuspendControl::print() { 886 #ifndef PRODUCT 887 ResourceMark rm; 888 LogStreamHandle(Trace, jvmti) log_stream; 889 log_stream.print("Suspended Threads: ["); 890 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) { 891 #ifdef JVMTI_TRACE 892 const char *name = JvmtiTrace::safe_get_thread_name(thread); 893 #else 894 const char *name = ""; 895 #endif /*JVMTI_TRACE */ 896 log_stream.print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_'); 897 if (!thread->has_last_Java_frame()) { 898 log_stream.print("no stack"); 899 } 900 log_stream.print(") "); 901 } 902 log_stream.print_cr("]"); 903 #endif 904 } 905 906 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( 907 nmethod* nm) { 908 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); 909 event._event_data.compiled_method_load = nm; 910 // Keep the nmethod alive until the ServiceThread can process 911 // this deferred event. 912 nmethodLocker::lock_nmethod(nm); 913 return event; 914 } 915 916 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( 917 nmethod* nm, jmethodID id, const void* code) { 918 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); 919 event._event_data.compiled_method_unload.nm = nm; 920 event._event_data.compiled_method_unload.method_id = id; 921 event._event_data.compiled_method_unload.code_begin = code; 922 // Keep the nmethod alive until the ServiceThread can process 923 // this deferred event. This will keep the memory for the 924 // generated code from being reused too early. We pass 925 // zombie_ok == true here so that our nmethod that was just 926 // made into a zombie can be locked. 927 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */); 928 return event; 929 } 930 931 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event( 932 const char* name, const void* code_begin, const void* code_end) { 933 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED); 934 // Need to make a copy of the name since we don't know how long 935 // the event poster will keep it around after we enqueue the 936 // deferred event and return. strdup() failure is handled in 937 // the post() routine below. 938 event._event_data.dynamic_code_generated.name = os::strdup(name); 939 event._event_data.dynamic_code_generated.code_begin = code_begin; 940 event._event_data.dynamic_code_generated.code_end = code_end; 941 return event; 942 } 943 944 void JvmtiDeferredEvent::post() { 945 assert(ServiceThread::is_service_thread(Thread::current()), 946 "Service thread must post enqueued events"); 947 switch(_type) { 948 case TYPE_COMPILED_METHOD_LOAD: { 949 nmethod* nm = _event_data.compiled_method_load; 950 JvmtiExport::post_compiled_method_load(nm); 951 // done with the deferred event so unlock the nmethod 952 nmethodLocker::unlock_nmethod(nm); 953 break; 954 } 955 case TYPE_COMPILED_METHOD_UNLOAD: { 956 nmethod* nm = _event_data.compiled_method_unload.nm; 957 JvmtiExport::post_compiled_method_unload( 958 _event_data.compiled_method_unload.method_id, 959 _event_data.compiled_method_unload.code_begin); 960 // done with the deferred event so unlock the nmethod 961 nmethodLocker::unlock_nmethod(nm); 962 break; 963 } 964 case TYPE_DYNAMIC_CODE_GENERATED: { 965 JvmtiExport::post_dynamic_code_generated_internal( 966 // if strdup failed give the event a default name 967 (_event_data.dynamic_code_generated.name == NULL) 968 ? "unknown_code" : _event_data.dynamic_code_generated.name, 969 _event_data.dynamic_code_generated.code_begin, 970 _event_data.dynamic_code_generated.code_end); 971 if (_event_data.dynamic_code_generated.name != NULL) { 972 // release our copy 973 os::free((void *)_event_data.dynamic_code_generated.name); 974 } 975 break; 976 } 977 default: 978 ShouldNotReachHere(); 979 } 980 } 981 982 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; 983 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; 984 985 bool JvmtiDeferredEventQueue::has_events() { 986 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 987 return _queue_head != NULL; 988 } 989 990 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { 991 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 992 993 // Events get added to the end of the queue (and are pulled off the front). 994 QueueNode* node = new QueueNode(event); 995 if (_queue_tail == NULL) { 996 _queue_tail = _queue_head = node; 997 } else { 998 assert(_queue_tail->next() == NULL, "Must be the last element in the list"); 999 _queue_tail->set_next(node); 1000 _queue_tail = node; 1001 } 1002 1003 Service_lock->notify_all(); 1004 assert((_queue_head == NULL) == (_queue_tail == NULL), 1005 "Inconsistent queue markers"); 1006 } 1007 1008 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { 1009 assert(Service_lock->owned_by_self(), "Must own Service_lock"); 1010 1011 assert(_queue_head != NULL, "Nothing to dequeue"); 1012 1013 if (_queue_head == NULL) { 1014 // Just in case this happens in product; it shouldn't but let's not crash 1015 return JvmtiDeferredEvent(); 1016 } 1017 1018 QueueNode* node = _queue_head; 1019 _queue_head = _queue_head->next(); 1020 if (_queue_head == NULL) { 1021 _queue_tail = NULL; 1022 } 1023 1024 assert((_queue_head == NULL) == (_queue_tail == NULL), 1025 "Inconsistent queue markers"); 1026 1027 JvmtiDeferredEvent event = node->event(); 1028 delete node; 1029 return event; 1030 }