1 /*
2 * Copyright (c) 1997, 2026, 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/inlineKlass.hpp"
34 #include "oops/method.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "prims/jniCheck.hpp"
37 #include "prims/jvmtiExport.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/interfaceSupport.inline.hpp"
40 #include "runtime/javaCalls.hpp"
41 #include "runtime/javaThread.hpp"
42 #include "runtime/jniHandles.inline.hpp"
43 #include "runtime/mutexLocker.hpp"
44 #include "runtime/os.inline.hpp"
45 #include "runtime/sharedRuntime.hpp"
46 #include "runtime/signature.hpp"
47 #include "runtime/stubRoutines.hpp"
48 #include "runtime/thread.inline.hpp"
49
50 // -----------------------------------------------------
51 // Implementation of JavaCallWrapper
52
53 JavaCallWrapper::JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS) {
54 JavaThread* thread = THREAD;
55
56 guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
57 assert(!thread->owns_locks(), "must release all locks when leaving VM");
58 guarantee(thread->can_call_java(), "cannot make java calls from the native compiler");
59 assert(!thread->preempting(), "Unexpected Java upcall whilst processing preemption");
60 _result = result;
61
62 // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,
63 // since it can potentially block.
64 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);
65
66 // clear any pending exception in thread (native calls start with no exception pending)
67 thread->clear_pending_exception();
68
69 // After this, we are official in JavaCode. This needs to be done before we change any of the thread local
70 // info, since we cannot find oops before the new information is set up completely.
71 ThreadStateTransition::transition_from_vm(thread, _thread_in_Java, true /* check_asyncs */);
72
73 // Make sure to set the oop's after the thread transition - since we can block there. No one is GC'ing
74 // the JavaCallWrapper before the entry frame is on the stack.
75 _callee_method = callee_method();
76 _receiver = receiver();
77
78 #ifdef CHECK_UNHANDLED_OOPS
79 THREAD->allow_unhandled_oop(&_receiver);
80 #endif // CHECK_UNHANDLED_OOPS
81
82 _thread = thread;
83 _handles = _thread->active_handles(); // save previous handle block & Java frame linkage
84
85 // For the profiler, the last_Java_frame information in thread must always be in
86 // legal state. We have no last Java frame if last_Java_sp == nullptr so
87 // the valid transition is to clear _last_Java_sp and then reset the rest of
88 // the (platform specific) state.
89
90 _anchor.copy(_thread->frame_anchor());
91 _thread->frame_anchor()->clear();
92
93 DEBUG_ONLY(_thread->inc_java_call_counter());
94 _thread->set_active_handles(new_handles); // install new handle block and reset Java frame linkage
95 }
96
97
98 JavaCallWrapper::~JavaCallWrapper() {
99 assert(_thread == JavaThread::current(), "must still be the same thread");
100
101 // restore previous handle block & Java frame linkage
102 JNIHandleBlock *_old_handles = _thread->active_handles();
103 _thread->set_active_handles(_handles);
104
105 _thread->frame_anchor()->zap();
106
107 DEBUG_ONLY(_thread->dec_java_call_counter());
108
109 // Old thread-local info. has been restored. We are not back in the VM.
110 ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
111
112 // State has been restored now make the anchor frame visible for the profiler.
113 _thread->frame_anchor()->copy(&_anchor);
114
115 // Release handles after we are marked as being inside the VM again, since this
116 // operation might block
117 JNIHandleBlock::release_block(_old_handles, _thread);
118
119 if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
120 // If we get here, the Java code threw an exception that unwound a frame.
121 // It could be that the new frame anchor has not passed through the required
122 // StackWatermark barriers. Therefore, we process any such deferred unwind
123 // requests here.
124 StackWatermarkSet::after_unwind(_thread);
125 }
126 }
127
128
129 void JavaCallWrapper::oops_do(OopClosure* f) {
130 f->do_oop((oop*)&_receiver);
131 handles()->oops_do(f);
132 }
133
134
135 // Helper methods
136 static BasicType runtime_type_from(JavaValue* result) {
137 switch (result->get_type()) {
138 case T_BOOLEAN : // fall through
139 case T_CHAR : // fall through
140 case T_SHORT : // fall through
141 case T_INT : // fall through
142 #ifndef _LP64
143 case T_OBJECT : // fall through
144 case T_ARRAY : // fall through
145 case T_FLAT_ELEMENT: // fall through
146 #endif
147 case T_BYTE : // fall through
148 case T_VOID : return T_INT;
149 case T_LONG : return T_LONG;
150 case T_FLOAT : return T_FLOAT;
151 case T_DOUBLE : return T_DOUBLE;
152 #ifdef _LP64
153 case T_ARRAY : // fall through
154 case T_OBJECT : return T_OBJECT;
155 #endif
156 default:
157 ShouldNotReachHere();
158 return T_ILLEGAL;
159 }
160 }
161
162 // ============ Virtual calls ============
163
164 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
165 CallInfo callinfo;
166 Handle receiver = args->receiver();
167 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
168 LinkInfo link_info(spec_klass, name, signature);
169 LinkResolver::resolve_virtual_call(
170 callinfo, receiver, recvrKlass, link_info, true, CHECK);
171 methodHandle method(THREAD, callinfo.selected_method());
172 assert(method.not_null(), "should have thrown exception");
173
174 // Invoke the method
175 JavaCalls::call(result, method, args, CHECK);
176 }
177
178
179 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
180 JavaCallArguments args(receiver);
181 call_virtual(result, spec_klass, name, signature, &args, CHECK);
182 }
183
184
185 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
186 JavaCallArguments args(receiver);
187 args.push_oop(arg1);
188 call_virtual(result, spec_klass, name, signature, &args, CHECK);
189 }
190
191
192
193 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
194 JavaCallArguments args(receiver);
195 args.push_oop(arg1);
196 args.push_oop(arg2);
197 call_virtual(result, spec_klass, name, signature, &args, CHECK);
198 }
199
200
201 // ============ Special calls ============
202
203 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
204 CallInfo callinfo;
205 LinkInfo link_info(klass, name, signature);
206 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
207 methodHandle method(THREAD, callinfo.selected_method());
208 assert(method.not_null(), "should have thrown exception");
209
210 // Invoke the method
211 JavaCalls::call(result, method, args, CHECK);
212 }
213
214
215 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
216 JavaCallArguments args(receiver);
217 call_special(result, klass, name, signature, &args, CHECK);
218 }
219
220
221 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
222 JavaCallArguments args(receiver);
223 args.push_oop(arg1);
224 call_special(result, klass, name, signature, &args, CHECK);
225 }
226
227
228 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
229 JavaCallArguments args(receiver);
230 args.push_oop(arg1);
231 args.push_oop(arg2);
232 call_special(result, klass, name, signature, &args, CHECK);
233 }
234
235
236 // ============ Static calls ============
237
238 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
239 CallInfo callinfo;
240 LinkInfo link_info(klass, name, signature);
241 LinkResolver::resolve_static_call(callinfo, link_info, ClassInitMode::init, CHECK);
242 methodHandle method(THREAD, callinfo.selected_method());
243 assert(method.not_null(), "should have thrown exception");
244
245 // Invoke the method
246 JavaCalls::call(result, method, args, CHECK);
247 }
248
249
250 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
251 JavaCallArguments args;
252 call_static(result, klass, name, signature, &args, CHECK);
253 }
254
255
256 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
257 JavaCallArguments args(arg1);
258 call_static(result, klass, name, signature, &args, CHECK);
259 }
260
261
262 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
263 JavaCallArguments args;
264 args.push_oop(arg1);
265 args.push_oop(arg2);
266 call_static(result, klass, name, signature, &args, CHECK);
267 }
268
269
270 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
271 JavaCallArguments args;
272 args.push_oop(arg1);
273 args.push_oop(arg2);
274 args.push_oop(arg3);
275 call_static(result, klass, name, signature, &args, CHECK);
276 }
277
278 // ============ allocate and initialize new object instance ============
279
280 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
281 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
282 Handle obj = klass->allocate_instance_handle(CHECK_NH);
283 JavaValue void_result(T_VOID);
284 args->set_receiver(obj); // inserts <obj> as the first argument.
285 JavaCalls::call_special(&void_result, klass,
286 vmSymbols::object_initializer_name(),
287 constructor_signature, args, CHECK_NH);
288 // Already returned a Null Handle if any exception is pending.
289 return obj;
290 }
291
292 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
293 JavaCallArguments args;
294 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
295 }
296
297 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS) {
298 JavaCallArguments args;
299 args.push_oop(arg1);
300 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
301 }
302
303 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
304 JavaCallArguments args;
305 args.push_oop(arg1);
306 args.push_oop(arg2);
307 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
308 }
309
310 // -------------------------------------------------
311 // Implementation of JavaCalls (low level)
312
313
314 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
315 // Check if we need to wrap a potential OS exception handler around thread.
316 // This is used for e.g. Win32 structured exception handlers.
317 // Need to wrap each and every time, since there might be native code down the
318 // stack that has installed its own exception handlers.
319 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
320 }
321
322 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
323
324 JavaThread* thread = THREAD;
325 assert(method.not_null(), "must have a method to call");
326 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
327 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
328
329 // Verify the arguments
330 if ((DEBUG_ONLY(true ||) CheckJNICalls)) {
331 args->verify(method, result->get_type());
332 }
333 // Ignore call if method is empty
334 if (method->is_empty_method()) {
335 assert(result->get_type() == T_VOID, "an empty method must return a void value");
336 return;
337 }
338
339 #ifdef ASSERT
340 { InstanceKlass* holder = method->method_holder();
341 // A klass might not be initialized since JavaCall's might be used during the executing of
342 // the <clinit>. For example, a Thread.start might start executing on an object that is
343 // not fully initialized! (bad Java programming style)
344 assert(holder->is_linked(), "rewriting must have taken place");
345 }
346 #endif
347
348 CompilationPolicy::compile_if_required(method, CHECK);
349
350 // Figure out if the result value is an oop or not (Note: This is a different value
351 // than result_type. result_type will be T_INT of oops. (it is about size)
352 BasicType result_type = runtime_type_from(result);
353 bool oop_result_flag = is_reference_type(result->get_type());
354
355 // Find receiver
356 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
357
358 // When we reenter Java, we need to re-enable the reserved/yellow zone which
359 // might already be disabled when we are in VM.
360 thread->stack_overflow_state()->reguard_stack_if_needed();
361
362 // Check that there are shadow pages available before changing thread state
363 // to Java. Calculate current_stack_pointer here to make sure
364 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
365 address sp = os::current_stack_pointer();
366 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
367 // Throw stack overflow exception with preinitialized exception.
368 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
369 return;
370 } else {
371 // Touch pages checked if the OS needs them to be touched to be mapped.
372 os::map_stack_shadow_pages(sp);
373 }
374
375 jobject value_buffer = nullptr;
376 if (InlineTypeReturnedAsFields && (result->get_type() == T_OBJECT)) {
377 // Pre allocate a buffered inline type in case the result is returned
378 // flattened by compiled code
379 InlineKlass* vk = method->returns_inline_type();
380 if (vk != nullptr && vk->can_be_returned_as_fields()) {
381 oop instance = vk->allocate_instance(CHECK);
382 value_buffer = JNIHandles::make_local(thread, instance);
383 result->set_jobject(value_buffer);
384 }
385 }
386
387 // do call
388 { JavaCallWrapper link(method, receiver, result, CHECK);
389 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
390
391 // NOTE: if we move the computation of the result_val_address inside
392 // the call to call_stub, the optimizer produces wrong code.
393 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
394 intptr_t* parameter_address = args->parameters();
395
396 address entry_point;
397 {
398 // The enter_interp_only_mode use handshake to set interp_only mode
399 // so no safepoint should be allowed between is_interp_only_mode() and call
400 NoSafepointVerifier nsv;
401 bool is_interp_only_mode = (StressCallingConvention && (os::random() % (1 << 10)) == 0) || thread->is_interp_only_mode();
402 if (JvmtiExport::can_post_interpreter_events() && is_interp_only_mode) {
403 entry_point = method->interpreter_entry();
404 } else {
405 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
406 // so we can go compiled via a i2c.
407 entry_point = method->from_interpreted_entry();
408 }
409 }
410 {
411 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
412 StubRoutines::call_stub()(
413 (address)&link,
414 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
415 result_val_address, // see NOTE above (compiler problem)
416 result_type,
417 method(),
418 entry_point,
419 parameter_address,
420 args->size_of_parameters(),
421 CHECK
422 );
423 }
424
425 result = link.result(); // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
426 // Preserve oop return value across possible gc points
427 if (oop_result_flag) {
428 thread->set_vm_result_oop(result->get_oop());
429 }
430 }
431 } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
432
433 // Check if a thread stop or suspend should be executed
434 // The following assert was not realistic. Thread.stop can set that bit at any moment.
435 //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
436
437 // Restore possible oop return
438 if (oop_result_flag) {
439 result->set_oop(thread->vm_result_oop());
440 thread->set_vm_result_oop(nullptr);
441 JNIHandles::destroy_local(value_buffer);
442 }
443 }
444
445
446 //--------------------------------------------------------------------------------------
447 // Implementation of JavaCallArguments
448
449 inline bool is_value_state_indirect_oop(uint state) {
450 assert(state != JavaCallArguments::value_state_oop,
451 "Checking for handles after removal");
452 assert(state < JavaCallArguments::value_state_limit,
453 "Invalid value state %u", state);
454 return state != JavaCallArguments::value_state_primitive;
455 }
456
457 inline oop resolve_indirect_oop(intptr_t value, uint state) {
458 switch (state) {
459 case JavaCallArguments::value_state_handle:
460 {
461 oop* ptr = reinterpret_cast<oop*>(value);
462 return Handle::raw_resolve(ptr);
463 }
464
465 case JavaCallArguments::value_state_jobject:
466 {
467 jobject obj = reinterpret_cast<jobject>(value);
468 return JNIHandles::resolve(obj);
469 }
470
471 default:
472 ShouldNotReachHere();
473 return nullptr;
474 }
475 }
476
477 intptr_t* JavaCallArguments::parameters() {
478 // First convert all handles to oops
479 for(int i = 0; i < _size; i++) {
480 uint state = _value_state[i];
481 assert(state != value_state_oop, "Multiple handle conversions");
482 if (is_value_state_indirect_oop(state)) {
483 oop obj = resolve_indirect_oop(_value[i], state);
484 _value[i] = cast_from_oop<intptr_t>(obj);
485 _value_state[i] = value_state_oop;
486 }
487 }
488 // Return argument vector
489 return _value;
490 }
491
492
493 class SignatureChekker : public SignatureIterator {
494 private:
495 int _pos;
496 BasicType _return_type;
497 u_char* _value_state;
498 intptr_t* _value;
499
500 public:
501 SignatureChekker(Symbol* signature,
502 BasicType return_type,
503 bool is_static,
504 u_char* value_state,
505 intptr_t* value) :
506 SignatureIterator(signature),
507 _pos(0),
508 _return_type(return_type),
509 _value_state(value_state),
510 _value(value)
511 {
512 if (!is_static) {
513 check_value(true); // Receiver must be an oop
514 }
515 do_parameters_on(this);
516 check_return_type(return_type);
517 }
518
519 private:
520 void check_value(bool is_reference) {
521 uint state = _value_state[_pos++];
522 if (is_reference) {
523 guarantee(is_value_state_indirect_oop(state),
524 "signature does not match pushed arguments: %u at %d",
525 state, _pos - 1);
526 } else {
527 guarantee(state == JavaCallArguments::value_state_primitive,
528 "signature does not match pushed arguments: %u at %d",
529 state, _pos - 1);
530 }
531 }
532
533 void check_return_type(BasicType t) {
534 guarantee(t == _return_type, "return type does not match");
535 }
536
537 void check_single_word() {
538 check_value(false);
539 }
540
541 void check_double_word() {
542 check_value(false);
543 check_value(false);
544 }
545
546 void check_reference() {
547 intptr_t v = _value[_pos];
548 if (v != 0) {
549 // v is a "handle" referring to an oop, cast to integral type.
550 // There shouldn't be any handles in very low memory.
551 guarantee((size_t)v >= os::vm_page_size(),
552 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
553 // Verify the pointee.
554 oop vv = resolve_indirect_oop(v, _value_state[_pos]);
555 guarantee(oopDesc::is_oop_or_null(vv),
556 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
557 _pos, v, p2i(vv));
558 }
559
560 check_value(true); // Verify value state.
561 }
562
563 friend class SignatureIterator; // so do_parameters_on can call do_type
564 void do_type(BasicType type) {
565 switch (type) {
566 case T_BYTE:
567 case T_BOOLEAN:
568 case T_CHAR:
569 case T_SHORT:
570 case T_INT:
571 case T_FLOAT: // this one also
572 check_single_word(); break;
573 case T_LONG:
574 case T_DOUBLE:
575 check_double_word(); break;
576 case T_ARRAY:
577 case T_OBJECT:
578 check_reference(); break;
579 default:
580 ShouldNotReachHere();
581 }
582 }
583 };
584
585
586 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
587 guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
588
589 // Treat T_OBJECT and T_ARRAY as the same
590 if (return_type == T_ARRAY) return_type = T_OBJECT;
591
592 // Check that oop information is correct
593 Symbol* signature = method->signature();
594
595 SignatureChekker sc(signature,
596 return_type,
597 method->is_static(),
598 _value_state,
599 _value);
600 }