1 /*
2 * Copyright (c) 2003, 2023, 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/javaClasses.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "code/nmethod.hpp"
29 #include "interpreter/interpreter.hpp"
30 #include "interpreter/oopMapCache.hpp"
31 #include "jvmtifiles/jvmtiEnv.hpp"
32 #include "logging/log.hpp"
33 #include "logging/logStream.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "oops/instanceKlass.hpp"
37 #include "oops/klass.inline.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "oops/oopHandle.inline.hpp"
40 #include "prims/jvmtiAgentThread.hpp"
41 #include "prims/jvmtiEventController.inline.hpp"
42 #include "prims/jvmtiImpl.hpp"
43 #include "prims/jvmtiRedefineClasses.hpp"
44 #include "runtime/continuation.hpp"
45 #include "runtime/deoptimization.hpp"
46 #include "runtime/frame.inline.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/javaCalls.hpp"
50 #include "runtime/javaThread.hpp"
51 #include "runtime/jniHandles.hpp"
52 #include "runtime/os.hpp"
53 #include "runtime/serviceThread.hpp"
54 #include "runtime/signature.hpp"
55 #include "runtime/threadSMR.hpp"
56 #include "runtime/vframe.inline.hpp"
57 #include "runtime/vframe_hp.hpp"
58 #include "runtime/vmOperations.hpp"
59 #include "utilities/exceptions.hpp"
60
61 //
62 // class JvmtiAgentThread
63 //
64 // JavaThread used to wrap a thread started by an agent
65 // using the JVMTI method RunAgentThread.
66 //
67
68 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
69 : JavaThread(start_function_wrapper) {
70 _env = env;
71 _start_fn = start_fn;
72 _start_arg = start_arg;
73 }
74
75 void
76 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
77 // It is expected that any Agent threads will be created as
78 // Java Threads. If this is the case, notification of the creation
79 // of the thread is given in JavaThread::thread_main().
80 assert(thread == JavaThread::current(), "sanity check");
81
82 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
83 dthread->call_start_function();
84 }
85
86 void
87 JvmtiAgentThread::call_start_function() {
88 ThreadToNativeFromVM transition(this);
89 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
90 }
91
92
93 //
94 // class GrowableCache - private methods
95 //
96
97 void GrowableCache::recache() {
98 int len = _elements->length();
99
100 FREE_C_HEAP_ARRAY(address, _cache);
101 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
102
103 for (int i=0; i<len; i++) {
104 _cache[i] = _elements->at(i)->getCacheValue();
105 //
106 // The cache entry has gone bad. Without a valid frame pointer
107 // value, the entry is useless so we simply delete it in product
108 // mode. The call to remove() will rebuild the cache again
109 // without the bad entry.
110 //
111 if (_cache[i] == nullptr) {
112 assert(false, "cannot recache null elements");
113 remove(i);
114 return;
115 }
116 }
117 _cache[len] = nullptr;
118
119 _listener_fun(_this_obj,_cache);
120 }
121
122 bool GrowableCache::equals(void* v, GrowableElement *e2) {
123 GrowableElement *e1 = (GrowableElement *) v;
124 assert(e1 != nullptr, "e1 != nullptr");
125 assert(e2 != nullptr, "e2 != nullptr");
126
127 return e1->equals(e2);
128 }
129
130 //
131 // class GrowableCache - public methods
132 //
133
134 GrowableCache::GrowableCache() {
135 _this_obj = nullptr;
136 _listener_fun = nullptr;
137 _elements = nullptr;
138 _cache = nullptr;
139 }
140
141 GrowableCache::~GrowableCache() {
142 clear();
143 delete _elements;
144 FREE_C_HEAP_ARRAY(address, _cache);
145 }
146
147 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
148 _this_obj = this_obj;
149 _listener_fun = listener_fun;
150 _elements = new (mtServiceability) GrowableArray<GrowableElement*>(5, mtServiceability);
151 recache();
152 }
153
154 // number of elements in the collection
155 int GrowableCache::length() {
156 return _elements->length();
157 }
158
159 // get the value of the index element in the collection
160 GrowableElement* GrowableCache::at(int index) {
161 GrowableElement *e = (GrowableElement *) _elements->at(index);
162 assert(e != nullptr, "e != nullptr");
163 return e;
164 }
165
166 int GrowableCache::find(GrowableElement* e) {
167 return _elements->find(e, GrowableCache::equals);
168 }
169
170 // append a copy of the element to the end of the collection
171 void GrowableCache::append(GrowableElement* e) {
172 GrowableElement *new_e = e->clone();
173 _elements->append(new_e);
174 recache();
175 }
176
177 // remove the element at index
178 void GrowableCache::remove (int index) {
179 GrowableElement *e = _elements->at(index);
180 assert(e != nullptr, "e != nullptr");
181 _elements->remove(e);
182 delete e;
183 recache();
184 }
185
186 // clear out all elements, release all heap space and
187 // let our listener know that things have changed.
188 void GrowableCache::clear() {
189 int len = _elements->length();
190 for (int i=0; i<len; i++) {
191 delete _elements->at(i);
192 }
193 _elements->clear();
194 recache();
195 }
196
197 //
198 // class JvmtiBreakpoint
199 //
200
201 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location)
202 : _method(m_method), _bci((int)location) {
203 assert(_method != nullptr, "No method for breakpoint.");
204 assert(_bci >= 0, "Negative bci for breakpoint.");
205 oop class_holder_oop = _method->method_holder()->klass_holder();
206 _class_holder = OopHandle(JvmtiExport::jvmti_oop_storage(), class_holder_oop);
207 }
208
209 JvmtiBreakpoint::~JvmtiBreakpoint() {
210 _class_holder.release(JvmtiExport::jvmti_oop_storage());
211 }
212
213 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
214 _method = bp._method;
215 _bci = bp._bci;
216 _class_holder = OopHandle(JvmtiExport::jvmti_oop_storage(), bp._class_holder.resolve());
217 }
218
219 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
220 return _method == bp._method
221 && _bci == bp._bci;
222 }
223
224 address JvmtiBreakpoint::getBcp() const {
225 return _method->bcp_from(_bci);
226 }
227
228 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
229 ((Method*)_method->*meth_act)(_bci);
230
231 // add/remove breakpoint to/from versions of the method that are EMCP.
232 Thread *thread = Thread::current();
233 InstanceKlass* ik = _method->method_holder();
234 Symbol* m_name = _method->name();
235 Symbol* m_signature = _method->signature();
236
237 // search previous versions if they exist
238 for (InstanceKlass* pv_node = ik->previous_versions();
239 pv_node != nullptr;
240 pv_node = pv_node->previous_versions()) {
241 Array<Method*>* methods = pv_node->methods();
242
243 for (int i = methods->length() - 1; i >= 0; i--) {
244 Method* method = methods->at(i);
245 // Only set breakpoints in EMCP methods.
246 // EMCP methods are old but not obsolete. Equivalent
247 // Modulo Constant Pool means the method is equivalent except
248 // the constant pool and instructions that access the constant
249 // pool might be different.
250 // If a breakpoint is set in a redefined method, its EMCP methods
251 // must have a breakpoint also.
252 // None of the methods are deleted until none are running.
253 // This code could set a breakpoint in a method that
254 // is never reached, but this won't be noticeable to the programmer.
255 if (!method->is_obsolete() &&
256 method->name() == m_name &&
257 method->signature() == m_signature) {
258 ResourceMark rm;
259 log_debug(redefine, class, breakpoint)
260 ("%sing breakpoint in %s(%s)", meth_act == &Method::set_breakpoint ? "sett" : "clear",
261 method->name()->as_C_string(), method->signature()->as_C_string());
262 (method->*meth_act)(_bci);
263 break;
264 }
265 }
266 }
267 }
268
269 void JvmtiBreakpoint::set() {
270 each_method_version_do(&Method::set_breakpoint);
271 }
272
273 void JvmtiBreakpoint::clear() {
274 each_method_version_do(&Method::clear_breakpoint);
275 }
276
277 void JvmtiBreakpoint::print_on(outputStream* out) const {
278 #ifndef PRODUCT
279 ResourceMark rm;
280 const char *class_name = (_method == nullptr) ? "null" : _method->klass_name()->as_C_string();
281 const char *method_name = (_method == nullptr) ? "null" : _method->name()->as_C_string();
282 out->print("Breakpoint(%s,%s,%d,%p)", class_name, method_name, _bci, getBcp());
283 #endif
284 }
285
286
287 //
288 // class VM_ChangeBreakpoints
289 //
290 // Modify the Breakpoints data structure at a safepoint
291 //
292
293 void VM_ChangeBreakpoints::doit() {
294 switch (_operation) {
295 case SET_BREAKPOINT:
296 _breakpoints->set_at_safepoint(*_bp);
297 break;
298 case CLEAR_BREAKPOINT:
299 _breakpoints->clear_at_safepoint(*_bp);
300 break;
301 default:
302 assert(false, "Unknown operation");
303 }
304 }
305
306 //
307 // class JvmtiBreakpoints
308 //
309 // a JVMTI internal collection of JvmtiBreakpoint
310 //
311
312 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
313 _bps.initialize(this,listener_fun);
314 }
315
316 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
317
318 void JvmtiBreakpoints::print() {
319 #ifndef PRODUCT
320 LogTarget(Trace, jvmti) log;
321 LogStream log_stream(log);
322
323 int n = _bps.length();
324 for (int i=0; i<n; i++) {
325 JvmtiBreakpoint& bp = _bps.at(i);
326 log_stream.print("%d: ", i);
327 bp.print_on(&log_stream);
328 log_stream.cr();
329 }
330 #endif
331 }
332
333
334 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
335 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
336
337 int i = _bps.find(bp);
338 if (i == -1) {
339 _bps.append(bp);
340 bp.set();
341 }
342 }
343
344 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
345 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
346
347 int i = _bps.find(bp);
348 if (i != -1) {
349 _bps.remove(i);
350 bp.clear();
351 }
352 }
353
354 int JvmtiBreakpoints::length() { return _bps.length(); }
355
356 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
357 if ( _bps.find(bp) != -1) {
358 return JVMTI_ERROR_DUPLICATE;
359 }
360 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
361 VMThread::execute(&set_breakpoint);
362 return JVMTI_ERROR_NONE;
363 }
364
365 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
366 if ( _bps.find(bp) == -1) {
367 return JVMTI_ERROR_NOT_FOUND;
368 }
369
370 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
371 VMThread::execute(&clear_breakpoint);
372 return JVMTI_ERROR_NONE;
373 }
374
375 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
376 bool changed = true;
377 // We are going to run thru the list of bkpts
378 // and delete some. This deletion probably alters
379 // the list in some implementation defined way such
380 // that when we delete entry i, the next entry might
381 // no longer be at i+1. To be safe, each time we delete
382 // an entry, we'll just start again from the beginning.
383 // We'll stop when we make a pass thru the whole list without
384 // deleting anything.
385 while (changed) {
386 int len = _bps.length();
387 changed = false;
388 for (int i = 0; i < len; i++) {
389 JvmtiBreakpoint& bp = _bps.at(i);
390 if (bp.method()->method_holder() == klass) {
391 bp.clear();
392 _bps.remove(i);
393 // This changed 'i' so we have to start over.
394 changed = true;
395 break;
396 }
397 }
398 }
399 }
400
401 //
402 // class JvmtiCurrentBreakpoints
403 //
404
405 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = nullptr;
406 address * JvmtiCurrentBreakpoints::_breakpoint_list = nullptr;
407
408
409 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
410 if (_jvmti_breakpoints != nullptr) return (*_jvmti_breakpoints);
411 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
412 assert(_jvmti_breakpoints != nullptr, "_jvmti_breakpoints != nullptr");
413 return (*_jvmti_breakpoints);
414 }
415
416 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
417 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
418 assert(this_jvmti != nullptr, "this_jvmti != nullptr");
419
420 debug_only(int n = this_jvmti->length(););
421 assert(cache[n] == nullptr, "cache must be null terminated");
422
423 set_breakpoint_list(cache);
424 }
425
426 ///////////////////////////////////////////////////////////////
427 //
428 // class VM_BaseGetOrSetLocal
429 //
430
431 const jvalue VM_BaseGetOrSetLocal::_DEFAULT_VALUE = {0L};
432 // Constructor for non-object getter
433
434 VM_BaseGetOrSetLocal::VM_BaseGetOrSetLocal(JavaThread* calling_thread, jint depth,
435 jint index, BasicType type, jvalue value, bool set, bool self)
436 : _calling_thread(calling_thread)
437 , _depth(depth)
438 , _index(index)
439 , _type(type)
440 , _value(value)
441 , _jvf(nullptr)
442 , _set(set)
443 , _self(self)
444 , _result(JVMTI_ERROR_NONE)
445 {
446 }
447
448 // Check that the klass is assignable to a type with the given signature.
449 // Another solution could be to use the function Klass::is_subtype_of(type).
450 // But the type class can be forced to load/initialize eagerly in such a case.
451 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
452 // It is better to avoid such a behavior.
453 bool VM_BaseGetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
454 assert(ty_sign != nullptr, "type signature must not be null");
455 assert(thread != nullptr, "thread must not be null");
456 assert(klass != nullptr, "klass must not be null");
457
458 int len = (int) strlen(ty_sign);
459 if ((ty_sign[0] == JVM_SIGNATURE_CLASS ||
460 ty_sign[0] == JVM_SIGNATURE_PRIMITIVE_OBJECT) &&
461 ty_sign[len-1] == JVM_SIGNATURE_ENDCLASS) { // Need pure class/interface name
462 ty_sign++;
463 len -= 2;
464 }
465 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len);
466 if (klass->name() == ty_sym) {
467 return true;
468 }
469 // Compare primary supers
470 int super_depth = klass->super_depth();
471 int idx;
472 for (idx = 0; idx < super_depth; idx++) {
473 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
474 return true;
475 }
476 }
477 // Compare secondary supers
478 const Array<Klass*>* sec_supers = klass->secondary_supers();
479 for (idx = 0; idx < sec_supers->length(); idx++) {
480 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
481 return true;
482 }
483 }
484 return false;
485 }
486
487 // Checks error conditions:
488 // JVMTI_ERROR_INVALID_SLOT
489 // JVMTI_ERROR_TYPE_MISMATCH
490 // Returns: 'true' - everything is Ok, 'false' - error code
491
492 bool VM_BaseGetOrSetLocal::check_slot_type_lvt(javaVFrame* jvf) {
493 Method* method = jvf->method();
494 if (!method->has_localvariable_table()) {
495 // Just to check index boundaries.
496 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
497 if (_index < 0 || _index + extra_slot >= method->max_locals()) {
498 _result = JVMTI_ERROR_INVALID_SLOT;
499 return false;
500 }
501 return true;
502 }
503
504 jint num_entries = method->localvariable_table_length();
505 if (num_entries == 0) {
506 _result = JVMTI_ERROR_INVALID_SLOT;
507 return false; // There are no slots
508 }
509 int signature_idx = -1;
510 int vf_bci = jvf->bci();
511 LocalVariableTableElement* table = method->localvariable_table_start();
512 for (int i = 0; i < num_entries; i++) {
513 int start_bci = table[i].start_bci;
514 int end_bci = start_bci + table[i].length;
515
516 // Here we assume that locations of LVT entries
517 // with the same slot number cannot be overlapped
518 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
519 signature_idx = (int) table[i].descriptor_cp_index;
520 break;
521 }
522 }
523 if (signature_idx == -1) {
524 _result = JVMTI_ERROR_INVALID_SLOT;
525 return false; // Incorrect slot index
526 }
527 Symbol* sign_sym = method->constants()->symbol_at(signature_idx);
528 BasicType slot_type = Signature::basic_type(sign_sym);
529
530 switch (slot_type) {
531 case T_BYTE:
532 case T_SHORT:
533 case T_CHAR:
534 case T_BOOLEAN:
535 slot_type = T_INT;
536 break;
537 case T_ARRAY:
538 case T_PRIMITIVE_OBJECT:
539 slot_type = T_OBJECT;
540 break;
541 default:
542 break;
543 };
544 if (_type != slot_type) {
545 _result = JVMTI_ERROR_TYPE_MISMATCH;
546 return false;
547 }
548
549 jobject jobj = _value.l;
550 if (_set && slot_type == T_OBJECT && jobj != nullptr) { // null reference is allowed
551 // Check that the jobject class matches the return type signature.
552 oop obj = JNIHandles::resolve_external_guard(jobj);
553 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
554 Klass* ob_k = obj->klass();
555 NULL_CHECK(ob_k, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
556
557 const char* signature = (const char *) sign_sym->as_utf8();
558 if (!is_assignable(signature, ob_k, VMThread::vm_thread())) {
559 _result = JVMTI_ERROR_TYPE_MISMATCH;
560 return false;
561 }
562 }
563 return true;
564 }
565
566 bool VM_BaseGetOrSetLocal::check_slot_type_no_lvt(javaVFrame* jvf) {
567 Method* method = jvf->method();
568 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
569
570 if (_index < 0 || _index + extra_slot >= method->max_locals()) {
571 _result = JVMTI_ERROR_INVALID_SLOT;
572 return false;
573 }
574 StackValueCollection *locals = _jvf->locals();
575 BasicType slot_type = locals->at(_index)->type();
576
577 if (slot_type == T_CONFLICT) {
578 _result = JVMTI_ERROR_INVALID_SLOT;
579 return false;
580 }
581 if (extra_slot) {
582 BasicType extra_slot_type = locals->at(_index + 1)->type();
583 if (extra_slot_type != T_INT) {
584 _result = JVMTI_ERROR_INVALID_SLOT;
585 return false;
586 }
587 }
588 if (_type != slot_type && (_type == T_OBJECT || slot_type != T_INT)) {
589 _result = JVMTI_ERROR_TYPE_MISMATCH;
590 return false;
591 }
592 return true;
593 }
594
595 static bool can_be_deoptimized(vframe* vf) {
596 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
597 }
598
599 bool VM_GetOrSetLocal::doit_prologue() {
600 if (!_eb.deoptimize_objects(_depth, _depth)) {
601 // The target frame is affected by a reallocation failure.
602 _result = JVMTI_ERROR_OUT_OF_MEMORY;
603 return false;
604 }
605
606 return true;
607 }
608
609 void VM_BaseGetOrSetLocal::doit() {
610 _jvf = get_java_vframe();
611 if (_jvf == nullptr) {
612 return;
613 };
614
615 frame fr = _jvf->fr();
616 if (_set && _depth != 0 && Continuation::is_frame_in_continuation(_jvf->thread(), fr)) {
617 _result = JVMTI_ERROR_OPAQUE_FRAME; // deferred locals are not fully supported in continuations
618 return;
619 }
620
621 Method* method = _jvf->method();
622 if (getting_receiver()) {
623 if (method->is_static()) {
624 _result = JVMTI_ERROR_INVALID_SLOT;
625 return;
626 }
627 } else {
628 if (method->is_native()) {
629 _result = JVMTI_ERROR_OPAQUE_FRAME;
630 return;
631 }
632
633 if (!check_slot_type_no_lvt(_jvf)) {
634 return;
635 }
636 if (method->has_localvariable_table() &&
637 !check_slot_type_lvt(_jvf)) {
638 return;
639 }
640 }
641
642 InterpreterOopMap oop_mask;
643 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
644 if (oop_mask.is_dead(_index)) {
645 // The local can be invalid and uninitialized in the scope of current bci
646 _result = JVMTI_ERROR_INVALID_SLOT;
647 return;
648 }
649 if (_set) {
650 if (fr.is_heap_frame()) { // we want this check after the check for JVMTI_ERROR_INVALID_SLOT
651 assert(Continuation::is_frame_in_continuation(_jvf->thread(), fr), "sanity check");
652 // If the topmost frame is a heap frame, then it hasn't been thawed. This can happen
653 // if we are executing at a return barrier safepoint. The callee frame has been popped,
654 // but the caller frame has not been thawed. We can't support a JVMTI SetLocal in the callee
655 // frame at this point, because we aren't truly in the callee yet.
656 // fr.is_heap_frame() is impossible if a continuation is at a single step or breakpoint.
657 _result = JVMTI_ERROR_OPAQUE_FRAME; // deferred locals are not fully supported in continuations
658 return;
659 }
660
661 // Force deoptimization of frame if compiled because it's
662 // possible the compiler emitted some locals as constant values,
663 // meaning they are not mutable.
664 if (can_be_deoptimized(_jvf)) {
665 // Continuation can't be unmounted at this point (it was checked/reported in get_java_vframe).
666 if (Continuation::is_frame_in_continuation(_jvf->thread(), fr)) {
667 _result = JVMTI_ERROR_OPAQUE_FRAME; // can't deoptimize for top continuation frame
668 return;
669 }
670
671 // Schedule deoptimization so that eventually the local
672 // update will be written to an interpreter frame.
673 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
674
675 // Now store a new value for the local which will be applied
676 // once deoptimization occurs. Note however that while this
677 // write is deferred until deoptimization actually happens
678 // can vframe created after this point will have its locals
679 // reflecting this update so as far as anyone can see the
680 // write has already taken place.
681
682 // If we are updating an oop then get the oop from the handle
683 // since the handle will be long gone by the time the deopt
684 // happens. The oop stored in the deferred local will be
685 // gc'd on its own.
686 if (_type == T_OBJECT || _type == T_PRIMITIVE_OBJECT) {
687 _value.l = cast_from_oop<jobject>(JNIHandles::resolve_external_guard(_value.l));
688 }
689 // Re-read the vframe so we can see that it is deoptimized
690 // [ Only need because of assert in update_local() ]
691 _jvf = get_java_vframe();
692 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
693 return;
694 }
695 StackValueCollection *locals = _jvf->locals();
696 Thread* current_thread = VMThread::vm_thread();
697 HandleMark hm(current_thread);
698
699 switch (_type) {
700 case T_INT: locals->set_int_at (_index, _value.i); break;
701 case T_LONG: locals->set_long_at (_index, _value.j); break;
702 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
703 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
704 case T_OBJECT:
705 case T_PRIMITIVE_OBJECT: {
706 Handle ob_h(current_thread, JNIHandles::resolve_external_guard(_value.l));
707 locals->set_obj_at (_index, ob_h);
708 break;
709 }
710 default: ShouldNotReachHere();
711 }
712 _jvf->set_locals(locals);
713 } else {
714 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
715 assert(getting_receiver(), "Can only get here when getting receiver");
716 oop receiver = _jvf->fr().get_native_receiver();
717 _value.l = JNIHandles::make_local(_calling_thread, receiver);
718 } else {
719 StackValueCollection *locals = _jvf->locals();
720
721 switch (_type) {
722 case T_INT: _value.i = locals->int_at (_index); break;
723 case T_LONG: _value.j = locals->long_at (_index); break;
724 case T_FLOAT: _value.f = locals->float_at (_index); break;
725 case T_DOUBLE: _value.d = locals->double_at(_index); break;
726 case T_OBJECT:
727 case T_PRIMITIVE_OBJECT: {
728 // Wrap the oop to be returned in a local JNI handle since
729 // oops_do() no longer applies after doit() is finished.
730 oop obj = locals->obj_at(_index)();
731 _value.l = JNIHandles::make_local(_calling_thread, obj);
732 break;
733 }
734 default: ShouldNotReachHere();
735 }
736 }
737 }
738 }
739
740 bool VM_BaseGetOrSetLocal::allow_nested_vm_operations() const {
741 return true; // May need to deoptimize
742 }
743
744
745 ///////////////////////////////////////////////////////////////
746 //
747 // class VM_GetOrSetLocal
748 //
749
750 // Constructor for non-object getter
751 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, bool self)
752 : VM_BaseGetOrSetLocal(nullptr, depth, index, type, _DEFAULT_VALUE, false, self),
753 _thread(thread),
754 _eb(false, nullptr, nullptr)
755 {
756 }
757
758 // Constructor for object or non-object setter
759 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value, bool self)
760 : VM_BaseGetOrSetLocal(nullptr, depth, index, type, value, true, self),
761 _thread(thread),
762 _eb(type == T_OBJECT, JavaThread::current(), thread)
763 {
764 }
765
766 // Constructor for object getter
767 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index, bool self)
768 : VM_BaseGetOrSetLocal(calling_thread, depth, index, T_OBJECT, _DEFAULT_VALUE, false, self),
769 _thread(thread),
770 _eb(true, calling_thread, thread)
771 {
772 }
773
774 vframe *VM_GetOrSetLocal::get_vframe() {
775 if (!_thread->has_last_Java_frame()) {
776 return nullptr;
777 }
778 RegisterMap reg_map(_thread,
779 RegisterMap::UpdateMap::include,
780 RegisterMap::ProcessFrames::include,
781 RegisterMap::WalkContinuation::include);
782 vframe *vf = JvmtiEnvBase::get_cthread_last_java_vframe(_thread, ®_map);
783 int d = 0;
784 while ((vf != nullptr) && (d < _depth)) {
785 vf = vf->java_sender();
786 d++;
787 }
788 return vf;
789 }
790
791 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
792 vframe* vf = get_vframe();
793 if (!(_self || _thread->is_carrier_thread_suspended())) {
794 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
795 return nullptr;
796 }
797 if (vf == nullptr) {
798 _result = JVMTI_ERROR_NO_MORE_FRAMES;
799 return nullptr;
800 }
801 javaVFrame *jvf = (javaVFrame*)vf;
802
803 if (!vf->is_java_frame()) {
804 _result = JVMTI_ERROR_OPAQUE_FRAME;
805 return nullptr;
806 }
807 return jvf;
808 }
809
810 VM_GetReceiver::VM_GetReceiver(
811 JavaThread* thread, JavaThread* caller_thread, jint depth, bool self)
812 : VM_GetOrSetLocal(thread, caller_thread, depth, 0, self) {}
813
814
815 ///////////////////////////////////////////////////////////////
816 //
817 // class VM_VirtualThreadGetOrSetLocal
818 //
819
820 // Constructor for non-object getter
821 VM_VirtualThreadGetOrSetLocal::VM_VirtualThreadGetOrSetLocal(JvmtiEnv* env, Handle vthread_h, jint depth,
822 jint index, BasicType type, bool self)
823 : VM_BaseGetOrSetLocal(nullptr, depth, index, type, _DEFAULT_VALUE, false, self)
824 {
825 _env = env;
826 _vthread_h = vthread_h;
827 }
828
829 // Constructor for object or non-object setter
830 VM_VirtualThreadGetOrSetLocal::VM_VirtualThreadGetOrSetLocal(JvmtiEnv* env, Handle vthread_h, jint depth,
831 jint index, BasicType type, jvalue value, bool self)
832 : VM_BaseGetOrSetLocal(nullptr, depth, index, type, value, true, self)
833 {
834 _env = env;
835 _vthread_h = vthread_h;
836 }
837
838 // Constructor for object getter
839 VM_VirtualThreadGetOrSetLocal::VM_VirtualThreadGetOrSetLocal(JvmtiEnv* env, Handle vthread_h, JavaThread* calling_thread,
840 jint depth, int index, bool self)
841 : VM_BaseGetOrSetLocal(calling_thread, depth, index, T_OBJECT, _DEFAULT_VALUE, false, self)
842 {
843 _env = env;
844 _vthread_h = vthread_h;
845 }
846
847 javaVFrame *VM_VirtualThreadGetOrSetLocal::get_java_vframe() {
848 Thread* cur_thread = Thread::current();
849 oop cont = java_lang_VirtualThread::continuation(_vthread_h());
850 assert(cont != nullptr, "vthread contintuation must not be null");
851
852 javaVFrame* jvf = nullptr;
853 JavaThread* java_thread = JvmtiEnvBase::get_JavaThread_or_null(_vthread_h());
854 bool is_cont_mounted = (java_thread != nullptr);
855
856 if (!(_self || JvmtiVTSuspender::is_vthread_suspended(_vthread_h()))) {
857 _result = JVMTI_ERROR_THREAD_NOT_SUSPENDED;
858 return nullptr;
859 }
860
861 if (is_cont_mounted) {
862 vframeStream vfs(java_thread);
863
864 if (!vfs.at_end()) {
865 jvf = vfs.asJavaVFrame();
866 jvf = JvmtiEnvBase::check_and_skip_hidden_frames(java_thread, jvf);
867 }
868 } else {
869 vframeStream vfs(cont);
870
871 if (!vfs.at_end()) {
872 jvf = vfs.asJavaVFrame();
873 jvf = JvmtiEnvBase::check_and_skip_hidden_frames(_vthread_h(), jvf);
874 }
875 }
876 int d = 0;
877 while ((jvf != nullptr) && (d < _depth)) {
878 jvf = jvf->java_sender();
879 d++;
880 }
881
882 if (d < _depth || jvf == nullptr) {
883 _result = JVMTI_ERROR_NO_MORE_FRAMES;
884 return nullptr;
885 }
886
887 if ((_set && !is_cont_mounted) || !jvf->is_java_frame()) {
888 _result = JVMTI_ERROR_OPAQUE_FRAME;
889 return nullptr;
890 }
891 return jvf;
892 }
893
894 VM_VirtualThreadGetReceiver::VM_VirtualThreadGetReceiver(
895 JvmtiEnv* env, Handle vthread_h, JavaThread* caller_thread, jint depth, bool self)
896 : VM_VirtualThreadGetOrSetLocal(env, vthread_h, caller_thread, depth, 0, self) {}
897
898
899 /////////////////////////////////////////////////////////////////////////////////////////
900 //
901 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
902 //
903
904 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
905 return java_thread->java_suspend();
906 }
907
908 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
909 return java_thread->java_resume();
910 }
911
912 void JvmtiSuspendControl::print() {
913 #ifndef PRODUCT
914 ResourceMark rm;
915 LogStreamHandle(Trace, jvmti) log_stream;
916 log_stream.print("Suspended Threads: [");
917 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
918 #ifdef JVMTI_TRACE
919 const char *name = JvmtiTrace::safe_get_thread_name(thread);
920 #else
921 const char *name = "";
922 #endif /*JVMTI_TRACE */
923 log_stream.print("%s(%c ", name, thread->is_suspended() ? 'S' : '_');
924 if (!thread->has_last_Java_frame()) {
925 log_stream.print("no stack");
926 }
927 log_stream.print(") ");
928 }
929 log_stream.print_cr("]");
930 #endif
931 }
932
933 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
934 nmethod* nm) {
935 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
936 event._event_data.compiled_method_load = nm;
937 return event;
938 }
939
940 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
941 jmethodID id, const void* code) {
942 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
943 event._event_data.compiled_method_unload.method_id = id;
944 event._event_data.compiled_method_unload.code_begin = code;
945 return event;
946 }
947
948 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
949 const char* name, const void* code_begin, const void* code_end) {
950 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
951 // Need to make a copy of the name since we don't know how long
952 // the event poster will keep it around after we enqueue the
953 // deferred event and return. strdup() failure is handled in
954 // the post() routine below.
955 event._event_data.dynamic_code_generated.name = os::strdup(name);
956 event._event_data.dynamic_code_generated.code_begin = code_begin;
957 event._event_data.dynamic_code_generated.code_end = code_end;
958 return event;
959 }
960
961 JvmtiDeferredEvent JvmtiDeferredEvent::class_unload_event(const char* name) {
962 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_CLASS_UNLOAD);
963 // Need to make a copy of the name since we don't know how long
964 // the event poster will keep it around after we enqueue the
965 // deferred event and return. strdup() failure is handled in
966 // the post() routine below.
967 event._event_data.class_unload.name = os::strdup(name);
968 return event;
969 }
970
971 void JvmtiDeferredEvent::post() {
972 assert(Thread::current()->is_service_thread(),
973 "Service thread must post enqueued events");
974 switch(_type) {
975 case TYPE_COMPILED_METHOD_LOAD: {
976 nmethod* nm = _event_data.compiled_method_load;
977 JvmtiExport::post_compiled_method_load(nm);
978 break;
979 }
980 case TYPE_COMPILED_METHOD_UNLOAD: {
981 JvmtiExport::post_compiled_method_unload(
982 _event_data.compiled_method_unload.method_id,
983 _event_data.compiled_method_unload.code_begin);
984 break;
985 }
986 case TYPE_DYNAMIC_CODE_GENERATED: {
987 JvmtiExport::post_dynamic_code_generated_internal(
988 // if strdup failed give the event a default name
989 (_event_data.dynamic_code_generated.name == nullptr)
990 ? "unknown_code" : _event_data.dynamic_code_generated.name,
991 _event_data.dynamic_code_generated.code_begin,
992 _event_data.dynamic_code_generated.code_end);
993 if (_event_data.dynamic_code_generated.name != nullptr) {
994 // release our copy
995 os::free((void *)_event_data.dynamic_code_generated.name);
996 }
997 break;
998 }
999 case TYPE_CLASS_UNLOAD: {
1000 JvmtiExport::post_class_unload_internal(
1001 // if strdup failed give the event a default name
1002 (_event_data.class_unload.name == nullptr)
1003 ? "unknown_class" : _event_data.class_unload.name);
1004 if (_event_data.class_unload.name != nullptr) {
1005 // release our copy
1006 os::free((void *)_event_data.class_unload.name);
1007 }
1008 break;
1009 }
1010 default:
1011 ShouldNotReachHere();
1012 }
1013 }
1014
1015 void JvmtiDeferredEvent::post_compiled_method_load_event(JvmtiEnv* env) {
1016 assert(_type == TYPE_COMPILED_METHOD_LOAD, "only user of this method");
1017 nmethod* nm = _event_data.compiled_method_load;
1018 JvmtiExport::post_compiled_method_load(env, nm);
1019 }
1020
1021 void JvmtiDeferredEvent::run_nmethod_entry_barriers() {
1022 if (_type == TYPE_COMPILED_METHOD_LOAD) {
1023 _event_data.compiled_method_load->run_nmethod_entry_barrier();
1024 }
1025 }
1026
1027
1028 // Keep the nmethod for compiled_method_load from being unloaded.
1029 void JvmtiDeferredEvent::oops_do(OopClosure* f, CodeBlobClosure* cf) {
1030 if (cf != nullptr && _type == TYPE_COMPILED_METHOD_LOAD) {
1031 cf->do_code_blob(_event_data.compiled_method_load);
1032 }
1033 }
1034
1035 // The GC calls this and marks the nmethods here on the stack so that
1036 // they cannot be unloaded while in the queue.
1037 void JvmtiDeferredEvent::nmethods_do(CodeBlobClosure* cf) {
1038 if (cf != nullptr && _type == TYPE_COMPILED_METHOD_LOAD) {
1039 cf->do_code_blob(_event_data.compiled_method_load);
1040 }
1041 }
1042
1043
1044 bool JvmtiDeferredEventQueue::has_events() {
1045 // We save the queued events before the live phase and post them when it starts.
1046 // This code could skip saving the events on the queue before the live
1047 // phase and ignore them, but this would change how we do things now.
1048 // Starting the service thread earlier causes this to be called before the live phase begins.
1049 // The events on the queue should all be posted after the live phase so this is an
1050 // ok check. Before the live phase, DynamicCodeGenerated events are posted directly.
1051 // If we add other types of events to the deferred queue, this could get ugly.
1052 return JvmtiEnvBase::get_phase() == JVMTI_PHASE_LIVE && _queue_head != nullptr;
1053 }
1054
1055 void JvmtiDeferredEventQueue::enqueue(JvmtiDeferredEvent event) {
1056 // Events get added to the end of the queue (and are pulled off the front).
1057 QueueNode* node = new QueueNode(event);
1058 if (_queue_tail == nullptr) {
1059 _queue_tail = _queue_head = node;
1060 } else {
1061 assert(_queue_tail->next() == nullptr, "Must be the last element in the list");
1062 _queue_tail->set_next(node);
1063 _queue_tail = node;
1064 }
1065
1066 assert((_queue_head == nullptr) == (_queue_tail == nullptr),
1067 "Inconsistent queue markers");
1068 }
1069
1070 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1071 assert(_queue_head != nullptr, "Nothing to dequeue");
1072
1073 if (_queue_head == nullptr) {
1074 // Just in case this happens in product; it shouldn't but let's not crash
1075 return JvmtiDeferredEvent();
1076 }
1077
1078 QueueNode* node = _queue_head;
1079 _queue_head = _queue_head->next();
1080 if (_queue_head == nullptr) {
1081 _queue_tail = nullptr;
1082 }
1083
1084 assert((_queue_head == nullptr) == (_queue_tail == nullptr),
1085 "Inconsistent queue markers");
1086
1087 JvmtiDeferredEvent event = node->event();
1088 delete node;
1089 return event;
1090 }
1091
1092 void JvmtiDeferredEventQueue::post(JvmtiEnv* env) {
1093 // Post events while nmethods are still in the queue and can't be unloaded.
1094 while (_queue_head != nullptr) {
1095 _queue_head->event().post_compiled_method_load_event(env);
1096 dequeue();
1097 }
1098 }
1099
1100 void JvmtiDeferredEventQueue::run_nmethod_entry_barriers() {
1101 for(QueueNode* node = _queue_head; node != nullptr; node = node->next()) {
1102 node->event().run_nmethod_entry_barriers();
1103 }
1104 }
1105
1106
1107 void JvmtiDeferredEventQueue::oops_do(OopClosure* f, CodeBlobClosure* cf) {
1108 for(QueueNode* node = _queue_head; node != nullptr; node = node->next()) {
1109 node->event().oops_do(f, cf);
1110 }
1111 }
1112
1113 void JvmtiDeferredEventQueue::nmethods_do(CodeBlobClosure* cf) {
1114 for(QueueNode* node = _queue_head; node != nullptr; node = node->next()) {
1115 node->event().nmethods_do(cf);
1116 }
1117 }