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(), "Unexpected Java upcall whilst processing preemption");
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
99
100 JavaCallWrapper::~JavaCallWrapper() {
101 assert(_thread == JavaThread::current(), "must still be the same thread");
102
103 // restore previous handle block & Java frame linkage
104 JNIHandleBlock *_old_handles = _thread->active_handles();
105 _thread->set_active_handles(_handles);
106
107 _thread->frame_anchor()->zap();
108
109 DEBUG_ONLY(_thread->dec_java_call_counter());
110
111 // Old thread-local info. has been restored. We are not back in the VM.
112 ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
113
114 // State has been restored now make the anchor frame visible for the profiler.
115 _thread->frame_anchor()->copy(&_anchor);
116
117 // Release handles after we are marked as being inside the VM again, since this
118 // operation might block
119 JNIHandleBlock::release_block(_old_handles, _thread);
120
121 if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
122 // If we get here, the Java code threw an exception that unwound a frame.
123 // It could be that the new frame anchor has not passed through the required
124 // StackWatermark barriers. Therefore, we process any such deferred unwind
125 // requests here.
126 StackWatermarkSet::after_unwind(_thread);
127 }
128 }
129
130
131 void JavaCallWrapper::oops_do(OopClosure* f) {
132 f->do_oop((oop*)&_receiver);
133 handles()->oops_do(f);
134 }
135
136
137 // Helper methods
138 static BasicType runtime_type_from(JavaValue* result) {
139 switch (result->get_type()) {
140 case T_BOOLEAN: // fall through
141 case T_CHAR : // fall through
142 case T_SHORT : // fall through
143 case T_INT : // fall through
144 #ifndef _LP64
145 case T_OBJECT : // fall through
146 case T_ARRAY : // fall through
147 #endif
148 case T_BYTE : // fall through
149 case T_VOID : return T_INT;
150 case T_LONG : return T_LONG;
151 case T_FLOAT : return T_FLOAT;
152 case T_DOUBLE : return T_DOUBLE;
153 #ifdef _LP64
154 case T_ARRAY : // fall through
155 case T_OBJECT: return T_OBJECT;
156 #endif
157 default:
158 ShouldNotReachHere();
159 return T_ILLEGAL;
160 }
161 }
162
163 // ============ Virtual calls ============
164
165 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
166 CallInfo callinfo;
167 Handle receiver = args->receiver();
168 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
169 LinkInfo link_info(spec_klass, name, signature);
170 LinkResolver::resolve_virtual_call(
171 callinfo, receiver, recvrKlass, link_info, true, CHECK);
172 methodHandle method(THREAD, callinfo.selected_method());
173 assert(method.not_null(), "should have thrown exception");
174
175 // Invoke the method
176 JavaCalls::call(result, method, args, CHECK);
177 }
178
179
180 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
181 JavaCallArguments args(receiver);
182 call_virtual(result, spec_klass, name, signature, &args, CHECK);
183 }
184
185
186 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
187 JavaCallArguments args(receiver);
188 args.push_oop(arg1);
189 call_virtual(result, spec_klass, name, signature, &args, CHECK);
190 }
191
192
193
194 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
195 JavaCallArguments args(receiver);
196 args.push_oop(arg1);
197 args.push_oop(arg2);
198 call_virtual(result, spec_klass, name, signature, &args, CHECK);
199 }
200
201
202 // ============ Special calls ============
203
204 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
205 CallInfo callinfo;
206 LinkInfo link_info(klass, name, signature);
207 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
208 methodHandle method(THREAD, callinfo.selected_method());
209 assert(method.not_null(), "should have thrown exception");
210
211 // Invoke the method
212 JavaCalls::call(result, method, args, CHECK);
213 }
214
215
216 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
217 JavaCallArguments args(receiver);
218 call_special(result, klass, name, signature, &args, CHECK);
219 }
220
221
222 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
223 JavaCallArguments args(receiver);
224 args.push_oop(arg1);
225 call_special(result, klass, name, signature, &args, CHECK);
226 }
227
228
229 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
230 JavaCallArguments args(receiver);
231 args.push_oop(arg1);
232 args.push_oop(arg2);
233 call_special(result, klass, name, signature, &args, CHECK);
234 }
235
236
237 // ============ Static calls ============
238
239 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
240 CallInfo callinfo;
241 LinkInfo link_info(klass, name, signature);
242 LinkResolver::resolve_static_call(callinfo, link_info, ClassInitMode::init, CHECK);
243 methodHandle method(THREAD, callinfo.selected_method());
244 assert(method.not_null(), "should have thrown exception");
245
246 // Invoke the method
247 JavaCalls::call(result, method, args, CHECK);
248 }
249
250
251 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
252 JavaCallArguments args;
253 call_static(result, klass, name, signature, &args, CHECK);
254 }
255
256
257 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
258 JavaCallArguments args(arg1);
259 call_static(result, klass, name, signature, &args, CHECK);
260 }
261
262
263 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
264 JavaCallArguments args;
265 args.push_oop(arg1);
266 args.push_oop(arg2);
267 call_static(result, klass, name, signature, &args, CHECK);
268 }
269
270
271 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
272 JavaCallArguments args;
273 args.push_oop(arg1);
274 args.push_oop(arg2);
275 args.push_oop(arg3);
276 call_static(result, klass, name, signature, &args, CHECK);
277 }
278
279 // ============ allocate and initialize new object instance ============
280
281 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
282 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
283 Handle obj = klass->allocate_instance_handle(CHECK_NH);
284 JavaValue void_result(T_VOID);
285 args->set_receiver(obj); // inserts <obj> as the first argument.
286 JavaCalls::call_special(&void_result, klass,
287 vmSymbols::object_initializer_name(),
288 constructor_signature, args, CHECK_NH);
289 // Already returned a Null Handle if any exception is pending.
290 return obj;
291 }
292
293 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
294 JavaCallArguments args;
295 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
296 }
297
298 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS) {
299 JavaCallArguments args;
300 args.push_oop(arg1);
301 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
302 }
303
304 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
305 JavaCallArguments args;
306 args.push_oop(arg1);
307 args.push_oop(arg2);
308 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
309 }
310
311 // -------------------------------------------------
312 // Implementation of JavaCalls (low level)
313
314
315 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
316 // Check if we need to wrap a potential OS exception handler around thread.
317 // This is used for e.g. Win32 structured exception handlers.
318 // Need to wrap each and every time, since there might be native code down the
319 // stack that has installed its own exception handlers.
320 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
321 }
322
323 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
324
325 JavaThread* thread = THREAD;
326 assert(method.not_null(), "must have a method to call");
327 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
328 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
329
330 // Verify the arguments
331 if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
332 args->verify(method, result->get_type());
333 }
334 // Ignore call if method is empty
335 if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
336 assert(result->get_type() == T_VOID, "an empty method must return a void value");
337 return;
338 }
339
340 #ifdef ASSERT
341 { InstanceKlass* holder = method->method_holder();
342 // A klass might not be initialized since JavaCall's might be used during the executing of
343 // the <clinit>. For example, a Thread.start might start executing on an object that is
344 // not fully initialized! (bad Java programming style)
345 assert(holder->is_linked(), "rewriting must have taken place");
346 }
347 #endif
348
349 CompilationPolicy::compile_if_required(method, CHECK);
350
351 // Figure out if the result value is an oop or not (Note: This is a different value
352 // than result_type. result_type will be T_INT of oops. (it is about size)
353 BasicType result_type = runtime_type_from(result);
354 bool oop_result_flag = is_reference_type(result->get_type());
355
356 // Find receiver
357 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
358
359 // When we reenter Java, we need to re-enable the reserved/yellow zone which
360 // might already be disabled when we are in VM.
361 thread->stack_overflow_state()->reguard_stack_if_needed();
362
363 // Check that there are shadow pages available before changing thread state
364 // to Java. Calculate current_stack_pointer here to make sure
365 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
366 address sp = os::current_stack_pointer();
367 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
368 // Throw stack overflow exception with preinitialized exception.
369 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
370 return;
371 } else {
372 // Touch pages checked if the OS needs them to be touched to be mapped.
373 os::map_stack_shadow_pages(sp);
374 }
375
376 // do call
377 { JavaCallWrapper link(method, receiver, result, CHECK);
378 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
379
380 // NOTE: if we move the computation of the result_val_address inside
381 // the call to call_stub, the optimizer produces wrong code.
382 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
383 intptr_t* parameter_address = args->parameters();
384
385 address entry_point;
386 {
387 // The enter_interp_only_mode use handshake to set interp_only mode
388 // so no safepoint should be allowed between is_interp_only_mode() and call
389 NoSafepointVerifier nsv;
390 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
391 entry_point = method->interpreter_entry();
392 } else {
393 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
394 // so we can go compiled via a i2c.
395 entry_point = method->from_interpreted_entry();
396 #if INCLUDE_JVMCI
397 // Gets the alternative target (if any) that should be called
398 Handle alternative_target = args->alternative_target();
399 if (!alternative_target.is_null()) {
400 // Must extract verified entry point from HotSpotNmethod after VM to Java
401 // transition in JavaCallWrapper constructor so that it is safe with
402 // respect to nmethod sweeping.
403 address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
404 if (verified_entry_point != nullptr) {
405 thread->set_jvmci_alternate_call_target(verified_entry_point);
406 entry_point = method->get_i2c_entry();
407 }
408 }
409 #endif
410 }
411 }
412 {
413 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
414 StubRoutines::call_stub()(
415 (address)&link,
416 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
417 result_val_address, // see NOTE above (compiler problem)
418 result_type,
419 method(),
420 entry_point,
421 parameter_address,
422 args->size_of_parameters(),
423 CHECK
424 );
425 }
426
427 result = link.result(); // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
428 // Preserve oop return value across possible gc points
429 if (oop_result_flag) {
430 thread->set_vm_result_oop(result->get_oop());
431 }
432 }
433 } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
434
435 // Check if a thread stop or suspend should be executed
436 // The following assert was not realistic. Thread.stop can set that bit at any moment.
437 //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
438
439 // Restore possible oop return
440 if (oop_result_flag) {
441 result->set_oop(thread->vm_result_oop());
442 thread->set_vm_result_oop(nullptr);
443 }
444 }
445
446
447 //--------------------------------------------------------------------------------------
448 // Implementation of JavaCallArguments
449
450 inline bool is_value_state_indirect_oop(uint state) {
451 assert(state != JavaCallArguments::value_state_oop,
452 "Checking for handles after removal");
453 assert(state < JavaCallArguments::value_state_limit,
454 "Invalid value state %u", state);
455 return state != JavaCallArguments::value_state_primitive;
456 }
457
458 inline oop resolve_indirect_oop(intptr_t value, uint state) {
459 switch (state) {
460 case JavaCallArguments::value_state_handle:
461 {
462 oop* ptr = reinterpret_cast<oop*>(value);
463 return Handle::raw_resolve(ptr);
464 }
465
466 case JavaCallArguments::value_state_jobject:
467 {
468 jobject obj = reinterpret_cast<jobject>(value);
469 return JNIHandles::resolve(obj);
470 }
471
472 default:
473 ShouldNotReachHere();
474 return nullptr;
475 }
476 }
477
478 intptr_t* JavaCallArguments::parameters() {
479 // First convert all handles to oops
480 for(int i = 0; i < _size; i++) {
481 uint state = _value_state[i];
482 assert(state != value_state_oop, "Multiple handle conversions");
483 if (is_value_state_indirect_oop(state)) {
484 oop obj = resolve_indirect_oop(_value[i], state);
485 _value[i] = cast_from_oop<intptr_t>(obj);
486 _value_state[i] = value_state_oop;
487 }
488 }
489 // Return argument vector
490 return _value;
491 }
492
493
494 class SignatureChekker : public SignatureIterator {
495 private:
496 int _pos;
497 BasicType _return_type;
498 u_char* _value_state;
499 intptr_t* _value;
500
501 public:
502 SignatureChekker(Symbol* signature,
503 BasicType return_type,
504 bool is_static,
505 u_char* value_state,
506 intptr_t* value) :
507 SignatureIterator(signature),
508 _pos(0),
509 _return_type(return_type),
510 _value_state(value_state),
511 _value(value)
512 {
513 if (!is_static) {
514 check_value(true); // Receiver must be an oop
515 }
516 do_parameters_on(this);
517 check_return_type(return_type);
518 }
519
520 private:
521 void check_value(bool is_reference) {
522 uint state = _value_state[_pos++];
523 if (is_reference) {
524 guarantee(is_value_state_indirect_oop(state),
525 "signature does not match pushed arguments: %u at %d",
526 state, _pos - 1);
527 } else {
528 guarantee(state == JavaCallArguments::value_state_primitive,
529 "signature does not match pushed arguments: %u at %d",
530 state, _pos - 1);
531 }
532 }
533
534 void check_return_type(BasicType t) {
535 guarantee(t == _return_type, "return type does not match");
536 }
537
538 void check_single_word() {
539 check_value(false);
540 }
541
542 void check_double_word() {
543 check_value(false);
544 check_value(false);
545 }
546
547 void check_reference() {
548 intptr_t v = _value[_pos];
549 if (v != 0) {
550 // v is a "handle" referring to an oop, cast to integral type.
551 // There shouldn't be any handles in very low memory.
552 guarantee((size_t)v >= os::vm_page_size(),
553 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
554 // Verify the pointee.
555 oop vv = resolve_indirect_oop(v, _value_state[_pos]);
556 guarantee(oopDesc::is_oop_or_null(vv),
557 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
558 _pos, v, p2i(vv));
559 }
560
561 check_value(true); // Verify value state.
562 }
563
564 friend class SignatureIterator; // so do_parameters_on can call do_type
565 void do_type(BasicType type) {
566 switch (type) {
567 case T_BYTE:
568 case T_BOOLEAN:
569 case T_CHAR:
570 case T_SHORT:
571 case T_INT:
572 case T_FLOAT: // this one also
573 check_single_word(); break;
574 case T_LONG:
575 case T_DOUBLE:
576 check_double_word(); break;
577 case T_ARRAY:
578 case T_OBJECT:
579 check_reference(); break;
580 default:
581 ShouldNotReachHere();
582 }
583 }
584 };
585
586
587 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
588 guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
589
590 // Treat T_OBJECT and T_ARRAY as the same
591 if (is_reference_type(return_type)) return_type = T_OBJECT;
592
593 // Check that oop information is correct
594 Symbol* signature = method->signature();
595
596 SignatureChekker sc(signature,
597 return_type,
598 method->is_static(),
599 _value_state,
600 _value);
601 }