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