1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "classfile/vmSymbols.hpp"
27 #include "code/nmethod.hpp"
28 #include "compiler/compilationPolicy.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "interpreter/linkResolver.hpp"
32 #include "memory/universe.hpp"
33 #include "oops/method.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "prims/jniCheck.hpp"
36 #include "prims/jvmtiExport.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/interfaceSupport.inline.hpp"
39 #include "runtime/javaCalls.hpp"
40 #include "runtime/javaThread.hpp"
41 #include "runtime/jniHandles.inline.hpp"
42 #include "runtime/mutexLocker.hpp"
43 #include "runtime/os.inline.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.inline.hpp"
48 #if INCLUDE_JVMCI
49 #include "jvmci/jvmciJavaClasses.hpp"
50 #endif
51
52 // -----------------------------------------------------
53 // Implementation of JavaCallWrapper
54
55 JavaCallWrapper::JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS) {
56 JavaThread* thread = THREAD;
57
58 guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
59 assert(!thread->owns_locks(), "must release all locks when leaving VM");
60 guarantee(thread->can_call_java(), "cannot make java calls from the native compiler");
61 assert(!thread->preempting(), "");
62 _result = result;
63
64 // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,
65 // since it can potentially block.
66 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);
67
68 // clear any pending exception in thread (native calls start with no exception pending)
69 thread->clear_pending_exception();
70
71 // After this, we are official in JavaCode. This needs to be done before we change any of the thread local
72 // info, since we cannot find oops before the new information is set up completely.
73 ThreadStateTransition::transition_from_vm(thread, _thread_in_Java, true /* check_asyncs */);
74
75 // Make sure to set the oop's after the thread transition - since we can block there. No one is GC'ing
76 // the JavaCallWrapper before the entry frame is on the stack.
77 _callee_method = callee_method();
78 _receiver = receiver();
79
80 #ifdef CHECK_UNHANDLED_OOPS
81 THREAD->allow_unhandled_oop(&_receiver);
82 #endif // CHECK_UNHANDLED_OOPS
83
84 _thread = thread;
85 _handles = _thread->active_handles(); // save previous handle block & Java frame linkage
86
87 // For the profiler, the last_Java_frame information in thread must always be in
88 // legal state. We have no last Java frame if last_Java_sp == nullptr so
89 // the valid transition is to clear _last_Java_sp and then reset the rest of
90 // the (platform specific) state.
91
92 _anchor.copy(_thread->frame_anchor());
93 _thread->frame_anchor()->clear();
94
95 debug_only(_thread->inc_java_call_counter());
96 _thread->set_active_handles(new_handles); // install new handle block and reset Java frame linkage
97
98 MACOS_AARCH64_ONLY(_thread->enable_wx(WXExec));
99 }
100
101
102 JavaCallWrapper::~JavaCallWrapper() {
103 assert(_thread == JavaThread::current(), "must still be the same thread");
104
105 MACOS_AARCH64_ONLY(_thread->enable_wx(WXWrite));
106
107 // restore previous handle block & Java frame linkage
108 JNIHandleBlock *_old_handles = _thread->active_handles();
109 _thread->set_active_handles(_handles);
110
111 _thread->frame_anchor()->zap();
112
113 debug_only(_thread->dec_java_call_counter());
114
115 // Old thread-local info. has been restored. We are not back in the VM.
116 ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
117
118 // State has been restored now make the anchor frame visible for the profiler.
119 _thread->frame_anchor()->copy(&_anchor);
120
121 // Release handles after we are marked as being inside the VM again, since this
122 // operation might block
123 JNIHandleBlock::release_block(_old_handles, _thread);
124
125 if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
126 // If we get here, the Java code threw an exception that unwound a frame.
127 // It could be that the new frame anchor has not passed through the required
128 // StackWatermark barriers. Therefore, we process any such deferred unwind
129 // requests here.
130 StackWatermarkSet::after_unwind(_thread);
131 }
132 }
133
134
135 void JavaCallWrapper::oops_do(OopClosure* f) {
136 f->do_oop((oop*)&_receiver);
137 handles()->oops_do(f);
138 }
139
140
141 // Helper methods
142 static BasicType runtime_type_from(JavaValue* result) {
143 switch (result->get_type()) {
144 case T_BOOLEAN: // fall through
145 case T_CHAR : // fall through
146 case T_SHORT : // fall through
147 case T_INT : // fall through
148 #ifndef _LP64
149 case T_OBJECT : // fall through
150 case T_ARRAY : // fall through
151 #endif
152 case T_BYTE : // fall through
153 case T_VOID : return T_INT;
154 case T_LONG : return T_LONG;
155 case T_FLOAT : return T_FLOAT;
156 case T_DOUBLE : return T_DOUBLE;
157 #ifdef _LP64
158 case T_ARRAY : // fall through
159 case T_OBJECT: return T_OBJECT;
160 #endif
161 default:
162 ShouldNotReachHere();
163 return T_ILLEGAL;
164 }
165 }
166
167 // ============ Virtual calls ============
168
169 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
170 CallInfo callinfo;
171 Handle receiver = args->receiver();
172 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
173 LinkInfo link_info(spec_klass, name, signature);
174 LinkResolver::resolve_virtual_call(
175 callinfo, receiver, recvrKlass, link_info, true, CHECK);
176 methodHandle method(THREAD, callinfo.selected_method());
177 assert(method.not_null(), "should have thrown exception");
178
179 // Invoke the method
180 JavaCalls::call(result, method, args, CHECK);
181 }
182
183
184 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
185 JavaCallArguments args(receiver);
186 call_virtual(result, spec_klass, name, signature, &args, CHECK);
187 }
188
189
190 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
191 JavaCallArguments args(receiver);
192 args.push_oop(arg1);
193 call_virtual(result, spec_klass, name, signature, &args, CHECK);
194 }
195
196
197
198 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
199 JavaCallArguments args(receiver);
200 args.push_oop(arg1);
201 args.push_oop(arg2);
202 call_virtual(result, spec_klass, name, signature, &args, CHECK);
203 }
204
205
206 // ============ Special calls ============
207
208 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
209 CallInfo callinfo;
210 LinkInfo link_info(klass, name, signature);
211 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
212 methodHandle method(THREAD, callinfo.selected_method());
213 assert(method.not_null(), "should have thrown exception");
214
215 // Invoke the method
216 JavaCalls::call(result, method, args, CHECK);
217 }
218
219
220 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
221 JavaCallArguments args(receiver);
222 call_special(result, klass, name, signature, &args, CHECK);
223 }
224
225
226 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
227 JavaCallArguments args(receiver);
228 args.push_oop(arg1);
229 call_special(result, klass, name, signature, &args, CHECK);
230 }
231
232
233 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
234 JavaCallArguments args(receiver);
235 args.push_oop(arg1);
236 args.push_oop(arg2);
237 call_special(result, klass, name, signature, &args, CHECK);
238 }
239
240
241 // ============ Static calls ============
242
243 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
244 CallInfo callinfo;
245 LinkInfo link_info(klass, name, signature);
246 LinkResolver::resolve_static_call(callinfo, link_info, StaticMode::initialize_klass, CHECK);
247 methodHandle method(THREAD, callinfo.selected_method());
248 assert(method.not_null(), "should have thrown exception");
249
250 // Invoke the method
251 JavaCalls::call(result, method, args, CHECK);
252 }
253
254
255 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
256 JavaCallArguments args;
257 call_static(result, klass, name, signature, &args, CHECK);
258 }
259
260
261 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
262 JavaCallArguments args(arg1);
263 call_static(result, klass, name, signature, &args, CHECK);
264 }
265
266
267 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
268 JavaCallArguments args;
269 args.push_oop(arg1);
270 args.push_oop(arg2);
271 call_static(result, klass, name, signature, &args, CHECK);
272 }
273
274
275 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
276 JavaCallArguments args;
277 args.push_oop(arg1);
278 args.push_oop(arg2);
279 args.push_oop(arg3);
280 call_static(result, klass, name, signature, &args, CHECK);
281 }
282
283 // ============ allocate and initialize new object instance ============
284
285 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
286 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
287 Handle obj = klass->allocate_instance_handle(CHECK_NH);
288 JavaValue void_result(T_VOID);
289 args->set_receiver(obj); // inserts <obj> as the first argument.
290 JavaCalls::call_special(&void_result, klass,
291 vmSymbols::object_initializer_name(),
292 constructor_signature, args, CHECK_NH);
293 // Already returned a Null Handle if any exception is pending.
294 return obj;
295 }
296
297 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
298 JavaCallArguments args;
299 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
300 }
301
302 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS) {
303 JavaCallArguments args;
304 args.push_oop(arg1);
305 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
306 }
307
308 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
309 JavaCallArguments args;
310 args.push_oop(arg1);
311 args.push_oop(arg2);
312 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
313 }
314
315 // -------------------------------------------------
316 // Implementation of JavaCalls (low level)
317
318
319 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
320 // Check if we need to wrap a potential OS exception handler around thread.
321 // This is used for e.g. Win32 structured exception handlers.
322 // Need to wrap each and every time, since there might be native code down the
323 // stack that has installed its own exception handlers.
324 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
325 }
326
327 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
328
329 JavaThread* thread = THREAD;
330 assert(method.not_null(), "must have a method to call");
331 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
332 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
333
334 // Verify the arguments
335 if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
336 args->verify(method, result->get_type());
337 }
338 // Ignore call if method is empty
339 if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
340 assert(result->get_type() == T_VOID, "an empty method must return a void value");
341 return;
342 }
343
344 #ifdef ASSERT
345 { InstanceKlass* holder = method->method_holder();
346 // A klass might not be initialized since JavaCall's might be used during the executing of
347 // the <clinit>. For example, a Thread.start might start executing on an object that is
348 // not fully initialized! (bad Java programming style)
349 assert(holder->is_linked(), "rewriting must have taken place");
350 }
351 #endif
352
353 CompilationPolicy::compile_if_required(method, CHECK);
354
355 // Figure out if the result value is an oop or not (Note: This is a different value
356 // than result_type. result_type will be T_INT of oops. (it is about size)
357 BasicType result_type = runtime_type_from(result);
358 bool oop_result_flag = is_reference_type(result->get_type());
359
360 // Find receiver
361 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
362
363 // When we reenter Java, we need to re-enable the reserved/yellow zone which
364 // might already be disabled when we are in VM.
365 thread->stack_overflow_state()->reguard_stack_if_needed();
366
367 // Check that there are shadow pages available before changing thread state
368 // to Java. Calculate current_stack_pointer here to make sure
369 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
370 address sp = os::current_stack_pointer();
371 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
372 // Throw stack overflow exception with preinitialized exception.
373 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
374 return;
375 } else {
376 // Touch pages checked if the OS needs them to be touched to be mapped.
377 os::map_stack_shadow_pages(sp);
378 }
379
380 // do call
381 { JavaCallWrapper link(method, receiver, result, CHECK);
382 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
383
384 // NOTE: if we move the computation of the result_val_address inside
385 // the call to call_stub, the optimizer produces wrong code.
386 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
387 intptr_t* parameter_address = args->parameters();
388
389 address entry_point;
390 {
391 // The enter_interp_only_mode use handshake to set interp_only mode
392 // so no safepoint should be allowed between is_interp_only_mode() and call
393 NoSafepointVerifier nsv;
394 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
395 entry_point = method->interpreter_entry();
396 } else {
397 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
398 // so we can go compiled via a i2c.
399 entry_point = method->from_interpreted_entry();
400 #if INCLUDE_JVMCI
401 // Gets the alternative target (if any) that should be called
402 Handle alternative_target = args->alternative_target();
403 if (!alternative_target.is_null()) {
404 // Must extract verified entry point from HotSpotNmethod after VM to Java
405 // transition in JavaCallWrapper constructor so that it is safe with
406 // respect to nmethod sweeping.
407 address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
408 if (verified_entry_point != nullptr) {
409 thread->set_jvmci_alternate_call_target(verified_entry_point);
410 entry_point = method->adapter()->get_i2c_entry();
411 }
412 }
413 #endif
414 }
415 }
416 StubRoutines::call_stub()(
417 (address)&link,
418 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
419 result_val_address, // see NOTE above (compiler problem)
420 result_type,
421 method(),
422 entry_point,
423 parameter_address,
424 args->size_of_parameters(),
425 CHECK
426 );
427
428 result = link.result(); // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
429 // Preserve oop return value across possible gc points
430 if (oop_result_flag) {
431 thread->set_vm_result_oop(result->get_oop());
432 }
433 }
434 } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
435
436 // Check if a thread stop or suspend should be executed
437 // The following assert was not realistic. Thread.stop can set that bit at any moment.
438 //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
439
440 // Restore possible oop return
441 if (oop_result_flag) {
442 result->set_oop(thread->vm_result_oop());
443 thread->set_vm_result_oop(nullptr);
444 }
445 }
446
447
448 //--------------------------------------------------------------------------------------
449 // Implementation of JavaCallArguments
450
451 inline bool is_value_state_indirect_oop(uint state) {
452 assert(state != JavaCallArguments::value_state_oop,
453 "Checking for handles after removal");
454 assert(state < JavaCallArguments::value_state_limit,
455 "Invalid value state %u", state);
456 return state != JavaCallArguments::value_state_primitive;
457 }
458
459 inline oop resolve_indirect_oop(intptr_t value, uint state) {
460 switch (state) {
461 case JavaCallArguments::value_state_handle:
462 {
463 oop* ptr = reinterpret_cast<oop*>(value);
464 return Handle::raw_resolve(ptr);
465 }
466
467 case JavaCallArguments::value_state_jobject:
468 {
469 jobject obj = reinterpret_cast<jobject>(value);
470 return JNIHandles::resolve(obj);
471 }
472
473 default:
474 ShouldNotReachHere();
475 return nullptr;
476 }
477 }
478
479 intptr_t* JavaCallArguments::parameters() {
480 // First convert all handles to oops
481 for(int i = 0; i < _size; i++) {
482 uint state = _value_state[i];
483 assert(state != value_state_oop, "Multiple handle conversions");
484 if (is_value_state_indirect_oop(state)) {
485 oop obj = resolve_indirect_oop(_value[i], state);
486 _value[i] = cast_from_oop<intptr_t>(obj);
487 _value_state[i] = value_state_oop;
488 }
489 }
490 // Return argument vector
491 return _value;
492 }
493
494
495 class SignatureChekker : public SignatureIterator {
496 private:
497 int _pos;
498 BasicType _return_type;
499 u_char* _value_state;
500 intptr_t* _value;
501
502 public:
503 SignatureChekker(Symbol* signature,
504 BasicType return_type,
505 bool is_static,
506 u_char* value_state,
507 intptr_t* value) :
508 SignatureIterator(signature),
509 _pos(0),
510 _return_type(return_type),
511 _value_state(value_state),
512 _value(value)
513 {
514 if (!is_static) {
515 check_value(true); // Receiver must be an oop
516 }
517 do_parameters_on(this);
518 check_return_type(return_type);
519 }
520
521 private:
522 void check_value(bool is_reference) {
523 uint state = _value_state[_pos++];
524 if (is_reference) {
525 guarantee(is_value_state_indirect_oop(state),
526 "signature does not match pushed arguments: %u at %d",
527 state, _pos - 1);
528 } else {
529 guarantee(state == JavaCallArguments::value_state_primitive,
530 "signature does not match pushed arguments: %u at %d",
531 state, _pos - 1);
532 }
533 }
534
535 void check_return_type(BasicType t) {
536 guarantee(t == _return_type, "return type does not match");
537 }
538
539 void check_single_word() {
540 check_value(false);
541 }
542
543 void check_double_word() {
544 check_value(false);
545 check_value(false);
546 }
547
548 void check_reference() {
549 intptr_t v = _value[_pos];
550 if (v != 0) {
551 // v is a "handle" referring to an oop, cast to integral type.
552 // There shouldn't be any handles in very low memory.
553 guarantee((size_t)v >= os::vm_page_size(),
554 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
555 // Verify the pointee.
556 oop vv = resolve_indirect_oop(v, _value_state[_pos]);
557 guarantee(oopDesc::is_oop_or_null(vv, true),
558 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
559 _pos, v, p2i(vv));
560 }
561
562 check_value(true); // Verify value state.
563 }
564
565 friend class SignatureIterator; // so do_parameters_on can call do_type
566 void do_type(BasicType type) {
567 switch (type) {
568 case T_BYTE:
569 case T_BOOLEAN:
570 case T_CHAR:
571 case T_SHORT:
572 case T_INT:
573 case T_FLOAT: // this one also
574 check_single_word(); break;
575 case T_LONG:
576 case T_DOUBLE:
577 check_double_word(); break;
578 case T_ARRAY:
579 case T_OBJECT:
580 check_reference(); break;
581 default:
582 ShouldNotReachHere();
583 }
584 }
585 };
586
587
588 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
589 guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
590
591 // Treat T_OBJECT and T_ARRAY as the same
592 if (is_reference_type(return_type)) return_type = T_OBJECT;
593
594 // Check that oop information is correct
595 Symbol* signature = method->signature();
596
597 SignatureChekker sc(signature,
598 return_type,
599 method->is_static(),
600 _value_state,
601 _value);
602 }