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 "oops/inlineKlass.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 #if INCLUDE_JVMCI
50 #include "jvmci/jvmciJavaClasses.hpp"
51 #endif
52
53 // -----------------------------------------------------
54 // Implementation of JavaCallWrapper
55
56 JavaCallWrapper::JavaCallWrapper(const methodHandle& callee_method, Handle receiver, JavaValue* result, TRAPS) {
57 JavaThread* thread = THREAD;
58
59 guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
60 assert(!thread->owns_locks(), "must release all locks when leaving VM");
61 guarantee(thread->can_call_java(), "cannot make java calls from the native compiler");
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 case T_FLAT_ELEMENT: // fall through
152 #endif
153 case T_BYTE : // fall through
154 case T_VOID : return T_INT;
155 case T_LONG : return T_LONG;
156 case T_FLOAT : return T_FLOAT;
157 case T_DOUBLE : return T_DOUBLE;
158 #ifdef _LP64
159 case T_ARRAY : // fall through
160 case T_OBJECT : return T_OBJECT;
161 #endif
162 default:
163 ShouldNotReachHere();
164 return T_ILLEGAL;
165 }
166 }
167
168 // ============ Virtual calls ============
169
170 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
171 CallInfo callinfo;
172 Handle receiver = args->receiver();
173 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
174 LinkInfo link_info(spec_klass, name, signature);
175 LinkResolver::resolve_virtual_call(
176 callinfo, receiver, recvrKlass, link_info, true, CHECK);
177 methodHandle method(THREAD, callinfo.selected_method());
178 assert(method.not_null(), "should have thrown exception");
179
180 // Invoke the method
181 JavaCalls::call(result, method, args, CHECK);
182 }
183
184
185 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
186 JavaCallArguments args(receiver);
187 call_virtual(result, spec_klass, name, signature, &args, CHECK);
188 }
189
190
191 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
192 JavaCallArguments args(receiver);
193 args.push_oop(arg1);
194 call_virtual(result, spec_klass, name, signature, &args, CHECK);
195 }
196
197
198
199 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
200 JavaCallArguments args(receiver);
201 args.push_oop(arg1);
202 args.push_oop(arg2);
203 call_virtual(result, spec_klass, name, signature, &args, CHECK);
204 }
205
206
207 // ============ Special calls ============
208
209 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
210 CallInfo callinfo;
211 LinkInfo link_info(klass, name, signature);
212 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
213 methodHandle method(THREAD, callinfo.selected_method());
214 assert(method.not_null(), "should have thrown exception");
215
216 // Invoke the method
217 JavaCalls::call(result, method, args, CHECK);
218 }
219
220
221 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
222 JavaCallArguments args(receiver);
223 call_special(result, klass, name, signature, &args, CHECK);
224 }
225
226
227 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
228 JavaCallArguments args(receiver);
229 args.push_oop(arg1);
230 call_special(result, klass, name, signature, &args, CHECK);
231 }
232
233
234 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
235 JavaCallArguments args(receiver);
236 args.push_oop(arg1);
237 args.push_oop(arg2);
238 call_special(result, klass, name, signature, &args, CHECK);
239 }
240
241
242 // ============ Static calls ============
243
244 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
245 CallInfo callinfo;
246 LinkInfo link_info(klass, name, signature);
247 LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);
248 methodHandle method(THREAD, callinfo.selected_method());
249 assert(method.not_null(), "should have thrown exception");
250
251 // Invoke the method
252 JavaCalls::call(result, method, args, CHECK);
253 }
254
255
256 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
257 JavaCallArguments args;
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, TRAPS) {
263 JavaCallArguments args(arg1);
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, TRAPS) {
269 JavaCallArguments args;
270 args.push_oop(arg1);
271 args.push_oop(arg2);
272 call_static(result, klass, name, signature, &args, CHECK);
273 }
274
275
276 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
277 JavaCallArguments args;
278 args.push_oop(arg1);
279 args.push_oop(arg2);
280 args.push_oop(arg3);
281 call_static(result, klass, name, signature, &args, CHECK);
282 }
283
284 // ============ allocate and initialize new object instance ============
285
286 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
287 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
288 Handle obj = klass->allocate_instance_handle(CHECK_NH);
289 JavaValue void_result(T_VOID);
290 args->set_receiver(obj); // inserts <obj> as the first argument.
291 JavaCalls::call_special(&void_result, klass,
292 vmSymbols::object_initializer_name(),
293 constructor_signature, args, CHECK_NH);
294 // Already returned a Null Handle if any exception is pending.
295 return obj;
296 }
297
298 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
299 JavaCallArguments args;
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, TRAPS) {
304 JavaCallArguments args;
305 args.push_oop(arg1);
306 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
307 }
308
309 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
310 JavaCallArguments args;
311 args.push_oop(arg1);
312 args.push_oop(arg2);
313 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
314 }
315
316 // -------------------------------------------------
317 // Implementation of JavaCalls (low level)
318
319
320 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
321 // Check if we need to wrap a potential OS exception handler around thread.
322 // This is used for e.g. Win32 structured exception handlers.
323 // Need to wrap each and every time, since there might be native code down the
324 // stack that has installed its own exception handlers.
325 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
326 }
327
328 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
329
330 JavaThread* thread = THREAD;
331 assert(method.not_null(), "must have a method to call");
332 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
333 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
334
335 // Verify the arguments
336 if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
337 args->verify(method, result->get_type());
338 }
339 // Ignore call if method is empty
340 if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
341 assert(result->get_type() == T_VOID, "an empty method must return a void value");
342 return;
343 }
344
345 #ifdef ASSERT
346 { InstanceKlass* holder = method->method_holder();
347 // A klass might not be initialized since JavaCall's might be used during the executing of
348 // the <clinit>. For example, a Thread.start might start executing on an object that is
349 // not fully initialized! (bad Java programming style)
350 assert(holder->is_linked(), "rewriting must have taken place");
351 }
352 #endif
353
354 CompilationPolicy::compile_if_required(method, CHECK);
355
356 // Figure out if the result value is an oop or not (Note: This is a different value
357 // than result_type. result_type will be T_INT of oops. (it is about size)
358 BasicType result_type = runtime_type_from(result);
359 bool oop_result_flag = is_reference_type(result->get_type());
360
361 // Find receiver
362 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
363
364 // When we reenter Java, we need to re-enable the reserved/yellow zone which
365 // might already be disabled when we are in VM.
366 thread->stack_overflow_state()->reguard_stack_if_needed();
367
368 // Check that there are shadow pages available before changing thread state
369 // to Java. Calculate current_stack_pointer here to make sure
370 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
371 address sp = os::current_stack_pointer();
372 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
373 // Throw stack overflow exception with preinitialized exception.
374 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
375 return;
376 } else {
377 // Touch pages checked if the OS needs them to be touched to be mapped.
378 os::map_stack_shadow_pages(sp);
379 }
380
381 jobject value_buffer = nullptr;
382 if (InlineTypeReturnedAsFields && (result->get_type() == T_OBJECT)) {
383 // Pre allocate a buffered inline type in case the result is returned
384 // flattened by compiled code
385 InlineKlass* vk = method->returns_inline_type(thread);
386 if (vk != nullptr && vk->can_be_returned_as_fields()) {
387 oop instance = vk->allocate_instance(CHECK);
388 value_buffer = JNIHandles::make_local(thread, instance);
389 result->set_jobject(value_buffer);
390 }
391 }
392
393 // do call
394 { JavaCallWrapper link(method, receiver, result, CHECK);
395 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
396
397 // NOTE: if we move the computation of the result_val_address inside
398 // the call to call_stub, the optimizer produces wrong code.
399 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
400 intptr_t* parameter_address = args->parameters();
401
402 address entry_point;
403 {
404 // The enter_interp_only_mode use handshake to set interp_only mode
405 // so no safepoint should be allowed between is_interp_only_mode() and call
406 NoSafepointVerifier nsv;
407 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
408 entry_point = method->interpreter_entry();
409 } else {
410 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
411 // so we can go compiled via a i2c.
412 entry_point = method->from_interpreted_entry();
413 #if INCLUDE_JVMCI
414 // Gets the alternative target (if any) that should be called
415 Handle alternative_target = args->alternative_target();
416 if (!alternative_target.is_null()) {
417 // Must extract verified entry point from HotSpotNmethod after VM to Java
418 // transition in JavaCallWrapper constructor so that it is safe with
419 // respect to nmethod sweeping.
420 address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
421 if (verified_entry_point != nullptr) {
422 thread->set_jvmci_alternate_call_target(verified_entry_point);
423 entry_point = method->adapter()->get_i2c_entry();
424 }
425 }
426 #endif
427 }
428 }
429 StubRoutines::call_stub()(
430 (address)&link,
431 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
432 result_val_address, // see NOTE above (compiler problem)
433 result_type,
434 method(),
435 entry_point,
436 parameter_address,
437 args->size_of_parameters(),
438 CHECK
439 );
440
441 result = link.result(); // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
442 // Preserve oop return value across possible gc points
443 if (oop_result_flag) {
444 thread->set_vm_result(result->get_oop());
445 }
446 }
447 } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
448
449 // Check if a thread stop or suspend should be executed
450 // The following assert was not realistic. Thread.stop can set that bit at any moment.
451 //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
452
453 // Restore possible oop return
454 if (oop_result_flag) {
455 result->set_oop(thread->vm_result());
456 thread->set_vm_result(nullptr);
457 JNIHandles::destroy_local(value_buffer);
458 }
459 }
460
461
462 //--------------------------------------------------------------------------------------
463 // Implementation of JavaCallArguments
464
465 inline bool is_value_state_indirect_oop(uint state) {
466 assert(state != JavaCallArguments::value_state_oop,
467 "Checking for handles after removal");
468 assert(state < JavaCallArguments::value_state_limit,
469 "Invalid value state %u", state);
470 return state != JavaCallArguments::value_state_primitive;
471 }
472
473 inline oop resolve_indirect_oop(intptr_t value, uint state) {
474 switch (state) {
475 case JavaCallArguments::value_state_handle:
476 {
477 oop* ptr = reinterpret_cast<oop*>(value);
478 return Handle::raw_resolve(ptr);
479 }
480
481 case JavaCallArguments::value_state_jobject:
482 {
483 jobject obj = reinterpret_cast<jobject>(value);
484 return JNIHandles::resolve(obj);
485 }
486
487 default:
488 ShouldNotReachHere();
489 return nullptr;
490 }
491 }
492
493 intptr_t* JavaCallArguments::parameters() {
494 // First convert all handles to oops
495 for(int i = 0; i < _size; i++) {
496 uint state = _value_state[i];
497 assert(state != value_state_oop, "Multiple handle conversions");
498 if (is_value_state_indirect_oop(state)) {
499 oop obj = resolve_indirect_oop(_value[i], state);
500 _value[i] = cast_from_oop<intptr_t>(obj);
501 _value_state[i] = value_state_oop;
502 }
503 }
504 // Return argument vector
505 return _value;
506 }
507
508
509 class SignatureChekker : public SignatureIterator {
510 private:
511 int _pos;
512 BasicType _return_type;
513 u_char* _value_state;
514 intptr_t* _value;
515
516 public:
517 SignatureChekker(Symbol* signature,
518 BasicType return_type,
519 bool is_static,
520 u_char* value_state,
521 intptr_t* value) :
522 SignatureIterator(signature),
523 _pos(0),
524 _return_type(return_type),
525 _value_state(value_state),
526 _value(value)
527 {
528 if (!is_static) {
529 check_value(true); // Receiver must be an oop
530 }
531 do_parameters_on(this);
532 check_return_type(return_type);
533 }
534
535 private:
536 void check_value(bool is_reference) {
537 uint state = _value_state[_pos++];
538 if (is_reference) {
539 guarantee(is_value_state_indirect_oop(state),
540 "signature does not match pushed arguments: %u at %d",
541 state, _pos - 1);
542 } else {
543 guarantee(state == JavaCallArguments::value_state_primitive,
544 "signature does not match pushed arguments: %u at %d",
545 state, _pos - 1);
546 }
547 }
548
549 void check_return_type(BasicType t) {
550 guarantee(t == _return_type, "return type does not match");
551 }
552
553 void check_single_word() {
554 check_value(false);
555 }
556
557 void check_double_word() {
558 check_value(false);
559 check_value(false);
560 }
561
562 void check_reference() {
563 intptr_t v = _value[_pos];
564 if (v != 0) {
565 // v is a "handle" referring to an oop, cast to integral type.
566 // There shouldn't be any handles in very low memory.
567 guarantee((size_t)v >= os::vm_page_size(),
568 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
569 // Verify the pointee.
570 oop vv = resolve_indirect_oop(v, _value_state[_pos]);
571 guarantee(oopDesc::is_oop_or_null(vv, true),
572 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
573 _pos, v, p2i(vv));
574 }
575
576 check_value(true); // Verify value state.
577 }
578
579 friend class SignatureIterator; // so do_parameters_on can call do_type
580 void do_type(BasicType type) {
581 switch (type) {
582 case T_BYTE:
583 case T_BOOLEAN:
584 case T_CHAR:
585 case T_SHORT:
586 case T_INT:
587 case T_FLOAT: // this one also
588 check_single_word(); break;
589 case T_LONG:
590 case T_DOUBLE:
591 check_double_word(); break;
592 case T_ARRAY:
593 case T_OBJECT:
594 check_reference(); break;
595 default:
596 ShouldNotReachHere();
597 }
598 }
599 };
600
601
602 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
603 guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
604
605 // Treat T_OBJECT and T_ARRAY as the same
606 if (return_type == T_ARRAY) return_type = T_OBJECT;
607
608 // Check that oop information is correct
609 Symbol* signature = method->signature();
610
611 SignatureChekker sc(signature,
612 return_type,
613 method->is_static(),
614 _value_state,
615 _value);
616 }