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 _result = result;
62
63 // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,
64 // since it can potentially block.
65 JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);
66
67 // clear any pending exception in thread (native calls start with no exception pending)
68 thread->clear_pending_exception();
69
70 // After this, we are official in JavaCode. This needs to be done before we change any of the thread local
71 // info, since we cannot find oops before the new information is set up completely.
72 ThreadStateTransition::transition_from_vm(thread, _thread_in_Java, true /* check_asyncs */);
73
74 // Make sure to set the oop's after the thread transition - since we can block there. No one is GC'ing
75 // the JavaCallWrapper before the entry frame is on the stack.
76 _callee_method = callee_method();
77 _receiver = receiver();
78
79 #ifdef CHECK_UNHANDLED_OOPS
80 THREAD->allow_unhandled_oop(&_receiver);
81 #endif // CHECK_UNHANDLED_OOPS
82
83 _thread = thread;
84 _handles = _thread->active_handles(); // save previous handle block & Java frame linkage
85
86 // For the profiler, the last_Java_frame information in thread must always be in
87 // legal state. We have no last Java frame if last_Java_sp == nullptr so
88 // the valid transition is to clear _last_Java_sp and then reset the rest of
89 // the (platform specific) state.
90
91 _anchor.copy(_thread->frame_anchor());
92 _thread->frame_anchor()->clear();
93
94 debug_only(_thread->inc_java_call_counter());
95 _thread->set_active_handles(new_handles); // install new handle block and reset Java frame linkage
96
97 MACOS_AARCH64_ONLY(_thread->enable_wx(WXExec));
98 }
99
100
101 JavaCallWrapper::~JavaCallWrapper() {
102 assert(_thread == JavaThread::current(), "must still be the same thread");
103
104 MACOS_AARCH64_ONLY(_thread->enable_wx(WXWrite));
105
106 // restore previous handle block & Java frame linkage
107 JNIHandleBlock *_old_handles = _thread->active_handles();
108 _thread->set_active_handles(_handles);
109
110 _thread->frame_anchor()->zap();
111
112 debug_only(_thread->dec_java_call_counter());
113
114 // Old thread-local info. has been restored. We are not back in the VM.
115 ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
116
117 // State has been restored now make the anchor frame visible for the profiler.
118 _thread->frame_anchor()->copy(&_anchor);
119
120 // Release handles after we are marked as being inside the VM again, since this
121 // operation might block
122 JNIHandleBlock::release_block(_old_handles, _thread);
123
124 if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
125 // If we get here, the Java code threw an exception that unwound a frame.
126 // It could be that the new frame anchor has not passed through the required
127 // StackWatermark barriers. Therefore, we process any such deferred unwind
128 // requests here.
129 StackWatermarkSet::after_unwind(_thread);
130 }
131 }
132
133
134 void JavaCallWrapper::oops_do(OopClosure* f) {
135 f->do_oop((oop*)&_receiver);
136 handles()->oops_do(f);
137 }
138
139
140 // Helper methods
141 static BasicType runtime_type_from(JavaValue* result) {
142 switch (result->get_type()) {
143 case T_BOOLEAN: // fall through
144 case T_CHAR : // fall through
145 case T_SHORT : // fall through
146 case T_INT : // fall through
147 #ifndef _LP64
148 case T_OBJECT : // fall through
149 case T_ARRAY : // fall through
150 #endif
151 case T_BYTE : // fall through
152 case T_VOID : return T_INT;
153 case T_LONG : return T_LONG;
154 case T_FLOAT : return T_FLOAT;
155 case T_DOUBLE : return T_DOUBLE;
156 #ifdef _LP64
157 case T_ARRAY : // fall through
158 case T_OBJECT: return T_OBJECT;
159 #endif
160 default:
161 ShouldNotReachHere();
162 return T_ILLEGAL;
163 }
164 }
165
166 // ============ Virtual calls ============
167
168 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
169 CallInfo callinfo;
170 Handle receiver = args->receiver();
171 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
172 LinkInfo link_info(spec_klass, name, signature);
173 LinkResolver::resolve_virtual_call(
174 callinfo, receiver, recvrKlass, link_info, true, CHECK);
175 methodHandle method(THREAD, callinfo.selected_method());
176 assert(method.not_null(), "should have thrown exception");
177
178 // Invoke the method
179 JavaCalls::call(result, method, args, CHECK);
180 }
181
182
183 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
184 JavaCallArguments args(receiver);
185 call_virtual(result, spec_klass, name, signature, &args, CHECK);
186 }
187
188
189 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
190 JavaCallArguments args(receiver);
191 args.push_oop(arg1);
192 call_virtual(result, spec_klass, name, signature, &args, CHECK);
193 }
194
195
196
197 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
198 JavaCallArguments args(receiver);
199 args.push_oop(arg1);
200 args.push_oop(arg2);
201 call_virtual(result, spec_klass, name, signature, &args, CHECK);
202 }
203
204
205 // ============ Special calls ============
206
207 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
208 CallInfo callinfo;
209 LinkInfo link_info(klass, name, signature);
210 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
211 methodHandle method(THREAD, callinfo.selected_method());
212 assert(method.not_null(), "should have thrown exception");
213
214 // Invoke the method
215 JavaCalls::call(result, method, args, CHECK);
216 }
217
218
219 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
220 JavaCallArguments args(receiver);
221 call_special(result, klass, name, signature, &args, CHECK);
222 }
223
224
225 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
226 JavaCallArguments args(receiver);
227 args.push_oop(arg1);
228 call_special(result, klass, name, signature, &args, CHECK);
229 }
230
231
232 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
233 JavaCallArguments args(receiver);
234 args.push_oop(arg1);
235 args.push_oop(arg2);
236 call_special(result, klass, name, signature, &args, CHECK);
237 }
238
239
240 // ============ Static calls ============
241
242 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
243 CallInfo callinfo;
244 LinkInfo link_info(klass, name, signature);
245 LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);
246 methodHandle method(THREAD, callinfo.selected_method());
247 assert(method.not_null(), "should have thrown exception");
248
249 // Invoke the method
250 JavaCalls::call(result, method, args, CHECK);
251 }
252
253
254 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
255 JavaCallArguments args;
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, TRAPS) {
261 JavaCallArguments args(arg1);
262 call_static(result, klass, name, signature, &args, CHECK);
263 }
264
265
266 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
267 JavaCallArguments args;
268 args.push_oop(arg1);
269 args.push_oop(arg2);
270 call_static(result, klass, name, signature, &args, CHECK);
271 }
272
273
274 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
275 JavaCallArguments args;
276 args.push_oop(arg1);
277 args.push_oop(arg2);
278 args.push_oop(arg3);
279 call_static(result, klass, name, signature, &args, CHECK);
280 }
281
282 // ============ allocate and initialize new object instance ============
283
284 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
285 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
286 Handle obj = klass->allocate_instance_handle(CHECK_NH);
287 JavaValue void_result(T_VOID);
288 args->set_receiver(obj); // inserts <obj> as the first argument.
289 JavaCalls::call_special(&void_result, klass,
290 vmSymbols::object_initializer_name(),
291 constructor_signature, args, CHECK_NH);
292 // Already returned a Null Handle if any exception is pending.
293 return obj;
294 }
295
296 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
297 JavaCallArguments args;
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, TRAPS) {
302 JavaCallArguments args;
303 args.push_oop(arg1);
304 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
305 }
306
307 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
308 JavaCallArguments args;
309 args.push_oop(arg1);
310 args.push_oop(arg2);
311 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
312 }
313
314 // -------------------------------------------------
315 // Implementation of JavaCalls (low level)
316
317
318 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
319 // Check if we need to wrap a potential OS exception handler around thread.
320 // This is used for e.g. Win32 structured exception handlers.
321 // Need to wrap each and every time, since there might be native code down the
322 // stack that has installed its own exception handlers.
323 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
324 }
325
326 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
327
328 JavaThread* thread = THREAD;
329 assert(method.not_null(), "must have a method to call");
330 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
331 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
332
333 // Verify the arguments
334 if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
335 args->verify(method, result->get_type());
336 }
337 // Ignore call if method is empty
338 if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
339 assert(result->get_type() == T_VOID, "an empty method must return a void value");
340 return;
341 }
342
343 #ifdef ASSERT
344 { InstanceKlass* holder = method->method_holder();
345 // A klass might not be initialized since JavaCall's might be used during the executing of
346 // the <clinit>. For example, a Thread.start might start executing on an object that is
347 // not fully initialized! (bad Java programming style)
348 assert(holder->is_linked(), "rewriting must have taken place");
349 }
350 #endif
351
352 CompilationPolicy::compile_if_required(method, CHECK);
353
354 // Figure out if the result value is an oop or not (Note: This is a different value
355 // than result_type. result_type will be T_INT of oops. (it is about size)
356 BasicType result_type = runtime_type_from(result);
357 bool oop_result_flag = is_reference_type(result->get_type());
358
359 // Find receiver
360 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
361
362 // When we reenter Java, we need to re-enable the reserved/yellow zone which
363 // might already be disabled when we are in VM.
364 thread->stack_overflow_state()->reguard_stack_if_needed();
365
366 // Check that there are shadow pages available before changing thread state
367 // to Java. Calculate current_stack_pointer here to make sure
368 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
369 address sp = os::current_stack_pointer();
370 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
371 // Throw stack overflow exception with preinitialized exception.
372 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
373 return;
374 } else {
375 // Touch pages checked if the OS needs them to be touched to be mapped.
376 os::map_stack_shadow_pages(sp);
377 }
378
379 // do call
380 { JavaCallWrapper link(method, receiver, result, CHECK);
381 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
382
383 // NOTE: if we move the computation of the result_val_address inside
384 // the call to call_stub, the optimizer produces wrong code.
385 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
386 intptr_t* parameter_address = args->parameters();
387
388 address entry_point;
389 {
390 // The enter_interp_only_mode use handshake to set interp_only mode
391 // so no safepoint should be allowed between is_interp_only_mode() and call
392 NoSafepointVerifier nsv;
393 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
394 entry_point = method->interpreter_entry();
395 } else {
396 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
397 // so we can go compiled via a i2c.
398 entry_point = method->from_interpreted_entry();
399 #if INCLUDE_JVMCI
400 // Gets the alternative target (if any) that should be called
401 Handle alternative_target = args->alternative_target();
402 if (!alternative_target.is_null()) {
403 // Must extract verified entry point from HotSpotNmethod after VM to Java
404 // transition in JavaCallWrapper constructor so that it is safe with
405 // respect to nmethod sweeping.
406 address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
407 if (verified_entry_point != nullptr) {
408 thread->set_jvmci_alternate_call_target(verified_entry_point);
409 entry_point = method->adapter()->get_i2c_entry();
410 }
411 }
412 #endif
413 }
414 }
415 StubRoutines::call_stub()(
416 (address)&link,
417 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
418 result_val_address, // see NOTE above (compiler problem)
419 result_type,
420 method(),
421 entry_point,
422 parameter_address,
423 args->size_of_parameters(),
424 CHECK
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, true),
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 }